Wuhan, China
Wuhan, China

Wuhan University is located in Wuhan, Hubei, China, and is administered by the Ministry of Education of the People's Republic of China. It was selected by both Project 985 and Project 211 as a major receiver of state funding. The university is situated at Luojia Hill, with palatial buildings blending the Chinese and Western style. It was commonly regarded as one of the most beautiful campuses in China. Wikipedia.

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A daily electricity generation planning method of a cascade hydropower plants is disclosed, and the method is comprised of the steps as follows: step 1, regardless of the constraints for opening and closing the generator, taking the power similarity between the power plant group and the typical demand as one of optimization objectives, and performing a first optimization to obtain a daily electricity generation plan; step 2, according to the derived daily electricity generation plan, determining an opening and closing status for the generator; and step 3, considering the constraints for opening and closing the generator, taking the power similarity between the power plant group and the typical demand as the optimization objective, performing a second optimization to obtain the daily electricity generation plan.

Tang S.,Wuhan University | Liu C.,Wuhan University | Lei A.,Wuhan University | Lei A.,Peking University
Chemical Communications | Year: 2013

Through a nickel-catalysed Heck-type reaction, a direct coupling of alkenes with α-cyano alkyl bromides was achieved. This procedure provides a novel way for the synthesis of β,γ-unsaturated nitriles. © 2013 The Royal Society of Chemistry.

Xu C.,Wuhan University | Liu Y.,Wuhan University | Wen Y.,Wuhan University | Wang R.,German Research Center for Geosciences
Bulletin of the Seismological Society of America | Year: 2010

On 12 May 2008, the Mw 7.9 Wenchuan earthquake occurred at the eastern margin of the Tibetan plateau along the Longmen Shan fault. Based on previous geological and geophysical studies and offset maps from Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar ALOS/PALSAR data, a layered crustal structure and a five-segment rupture model are established to study the coseismic deformation of this event. Using the constrained least-squares method, a preferred coseismic slip model is derived from Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data. In particular, the Helmert variance component estimation (HVCE) method is used to determine the relative weight ratio between the GPS and InSAR data. In contrast to the initial weight ratio (0:752=0:246=0:002) among three-type observations (GPS horizontal, GPS vertical, and InSAR LOS displacement), the final optimal weight ratio is found to be 0:473=0:279=0:248, and the overall root mean square (rms) misfit for all three datasets decreases from 9.15 cm without HVCE to 5.46 cm with HVCE. As revealed by the preferred slip, the slip changes obviously along the strike direction from southwest to northeast and exhibits four asperities close to Hongkou town, Yuejiashan town, Beichuan County, and Nanba town, respectively. Two major asperities are located on the Hongkou and Beichuan segments with the maximum slip close to 10 m. The slips of Hongkou, Yuejiashan, and Beichuan segments are dominated by the thrust movement with a significant right-lateral strike-slip component. The Qingchuan segment experiences a dominant right-lateral strike slip with an average magnitude of 1-2 m. Most of the slip asperities are shallower than 10-km depth, except for the southwest part near the hypocenter where the slip may exceed 20 km. The seismic moment of the Wenchuan earthquake is 8:19 × 1020 N m (Mw 7.91) based on the layered crust model, which is slightly larger than that using a corresponding homo- geneous crust model (Mw 7.87).

Luhr H.,German Research Center for Geosciences | Xiong C.,German Research Center for Geosciences | Xiong C.,Wuhan University
Geophysical Research Letters | Year: 2010

We compare electron density predictions of the International Reference Ionosphere (IRI-2007) model with in-situ measurements of the satellites CHAMP and GRACE for the years 2000-2009. Orbital-averages of the electron density are considered. During the first half of the period (2000-2004) measurements and collocated model predictions track each other reasonably well at both sampling heights. From 2005 onward the overestimation of the electron density by the model is progressively increasing. Annual averages show that IRI-2007 values are too high by 50% for 2008 and by more than 60% by 2009. An inspection of the latitudinal and local time distributions reveals that the too high predictions primarily occur at low latitudes during daytime hours. From comparison with observations it becomes obvious that IRI-2007 is strongly overestimating the equatorial ion fountain effect during the last deep solar minimum. © 2010 by the American Geophysical Union.

Huang L.,Wuhan University | Zhu G.,China Institute of Technology | Du X.,Temple University
IEEE Wireless Communications | Year: 2013

Femtocells have emerged as a promising solution to provide wireless broadband access coverage in cellular dead zones and indoor environments. Compared with other techniques for indoor coverage, femtocells achieve better user experience with less capital expenditure and maintenance cost. However, co-channel deployments of closed subscriber group femtocells cause coverage holes in macrocells due to co-channel interference. To address this problem, cognitive radio technology has been integrated with femtocells. CR-enabled femtocells can actively sense their environment and exploit the network side information obtained from sensing to adaptively mitigate interference. We investigate three CRenabled interference mitigation techniques, including opportunistic interference avoidance, interference cancellation, and interference alignment. Macrocell activities can be obtained without significant overhead in femtocells. In this article, we present a joint opportunistic interference avoidance scheme with Gale-Shapley spectrum sharing (GSOIA) based on the interweave paradigm to mitigate both tier interferences in macro/femto heterogeneous networks. In this scheme, cognitive femtocells opportunistically communicate over available spectrum with minimal interference to macrocells; different femtocells are assigned orthogonal spectrum resources with a one-to-one matching policy to avoid intratier interference. Our simulations show considerable performance improvement of the GSOIA scheme and validate the potential benefits of CRenabled femtocells for in-home coverage. © 2002-2012 IEEE.

Guo L.,Wuhan University | Zhang H.-F.,Wuhan University | Harris N.,Open University Milton Keynes | Parrish R.,British Geological Survey | And 2 more authors.
Gondwana Research | Year: 2012

In the eastern Himalayan syntaxis, the southern Lhasa terrane is dominated by middle- to high-grade metamorphic rocks (Nyingchi Complex), which are intruded by felsic melts. U-Pb zircon dating and zircon Hf isotopic composition of these metamorphic and magmatic rocks provide important constraints on the tectono-thermal evolution of the Lhasa terrane during convergent process between Indian and Asian continents. U-Pb zircon data for an orthogneiss intruding the Nyingchi Complex yield a protolith magma crystallization age of 83.4±1.2Ma, with metamorphic ages of 65-46Ma. This orthogneiss is characterized by positive εHf (t) values of +8.3 and young Hf model ages of ~0.6Ga, indicating a derivation primarily from a depleted-mantle or juvenile crustal source. Zircons from a quartz diorite yield a magma crystallization age of 63.1±0.6Ma, with εHf (t) values of -8.2 to -2.7, suggesting that this magma was sourced from partial melting of older crustal materials. Zircon cores from a foliated biotite granite show ages ranging from 347 to 2690Ma, with age peaks at 347-403Ma, 461-648Ma and 1013-1183Ma; their zircon εHf (t) values range from -30.6 to +6.9. Both the U-Pb ages and Hf isotopic composition of the zircon cores are similar to those of detrital zircons from the Nyingchi Complex paragneiss, implying that the granite was derived from anatexis of the Nyingchi Complex metasediments. The zircon rims from the granite indicate crustal anatexis at 64.4±0.7Ma and subsequent metamorphism at 55.1±1.3 and 41.4±2.3Ma. Our results suggest that the late Cretaceous magmatism in the southern Lhasa terrane resulted from Neo-Tethys oceanic slab subduction and we infer that Paleocene crustal anatexis and metamorphism were related to the thermal perturbation caused by rollback of the northward subducted Neo-Tethyan oceanic slab. © 2011 International Association for Gondwana Research.

Cheng D.,Chinese Academy of Sciences | Qi H.,Chinese Academy of Sciences | Li Z.,Chinese Academy of Sciences | Liu J.B.,Wuhan University | Liu J.B.,Bradley University
International Journal of Robust and Nonlinear Control | Year: 2011

The stability of Boolean networks and the stabilization of Boolean control networks are investigated. Using semi-tensor product of matrices and the matrix expression of logic, the dynamics of a Boolean (control) network can be converted to a discrete time linear (bilinear) dynamics, called the algebraic form of the Boolean (control) network. Then the stability can be revealed by analyzing the transition matrix of the corresponding discrete time system. Main results consist of two parts: (i) Using logic coordinate transformation, the known sufficient condition based on incidence matrix has been improved. It can also be used in stabilizer design. (ii) Based on algebraic form, necessary and sufficient conditions for stability and stabilization, respectively, are obtained. Copyright © 2010 John Wiley & Sons, Ltd. Copyright © 2010 John Wiley & Sons, Ltd.

Shafaii Moghadam H.,Damghan University | Khademi M.,Damghan University | Hu Z.,Wuhan University | Stern R.J.,University of Texas at Dallas | And 2 more authors.
Gondwana Research | Year: 2015

The ChahJam-Biarjmand complex (CJBC), flanked by the Alborz Mountains in the north and the Lut-Tabas block to the south, is part of Central Iranian block, where the oldest continental crust of Iran is found. This complex contains granitic to tonalitic orthogneissic rocks (old plutons) and associated metasediments, amphibolites and paragneisses. Metamorphosed granitic and granodioritic dikes intrude orthogneisses as well as metasediments and are abundant close to the plutons (orthogneissic rocks). Based on the results of bulk rock trace and rare earth elements, the orthogneissic rocks are inferred to have crystallized from subduction-related melts. Amphibolites also have subduction-related signatures and are inferred to have formed both as metamorphosed volcanoclastic sediments and as attenuated basic dikes. The presence of para-amphibolites associated with paragneisses and metasediments (mica schists) could represent a sedimentary basin filled with magmatic arc erosional products. U-Pb zircon dating of the ChahJam-Biarjmand rocks yielded 238U/206Pb crystallization ages of ca. 550 to 530Ma (Ediacaran-early Cambrian). Sr-Nd isotope systematics on whole rocks (εNd(t)=-2.2 to -5.5) and zircon Hf isotope results indicate that CJBC Cadomian granitic rocks contain older, possible Mesoproterozoic, continental crust in their source. The ChahJam-Biarjmand granitic-tonalitic gneissic rocks are coeval with other similar-aged metagranites and gneisses within Iranian basement exposed in Central Iran, the Sanandaj-Sirjan Zone and the Alborz Mountains, as well as in the Tauride-Anatolide platform in western Anatolia and in NW Turkey. All these dispersed Cadomian basement rocks are interpreted to show fragments of Neoproterozoic-early Cambrian continental arcs bordering the northern active margin of Gondwana. © 2013 International Association for Gondwana Research.

Li D.-Q.,Wuhan University | Wu S.-B.,Nanchang Institute of Technology | Zhou C.-B.,Wuhan University | Phoon K.K.,National University of Singapore
Structural Safety | Year: 2012

It is common to construct a consistent multivariate distribution from non-normal marginals and Pearson product-moment correlations using the well known translation approach. A practical variant of this approach is to match the Spearman rank correlations of the measured data, rather than the Pearson correlations. In this paper, the performance of these translation methods is evaluated based on their abilities to match the following exact solutions from one benchmark bivariate example where the joint distribution is known: (1) high order joint moments, (2) joint probability density functions (PDFs), and (3) probabilities of failure. It is not surprising to find significant errors in the joint moments and PDFs. However, it is interesting to observe that the Pearson and Spearman methods produce very similar results and neither method is consistently more accurate or more conservative than the other in terms of probabilities of failure. In addition, the maximum error in the probability of failure may not be associated with a large correlation. It can happen at an intermediate correlation. © 2012 Elsevier Ltd.

Hu B.,Peking University | Li S.,Wuhan University | Zhang X.,Wuhan University | Zheng X.,Peking University
Nucleic Acids Research | Year: 2014

Histone H2A ubiquitination plays critical roles in transcriptional repression and deoxyribonucleic acid (DNA) damage response. More attention has been focused on ubiquitin E3 ligases of H2A, however, less is known about the negative regulators of H2A ubiquitination. Here we identified HSCARG as a new negative regulatory protein for H2A ubiquitination and found a possible link between regulator of H2A ubiquitination and cell cycle. Mechanistically, HSCARG interacts with polycomb repressive complex 1 (PRC1) and deubiquitinase USP7 and inhibits PRC1 ubiquitination in a USP7-dependent manner. As ubiquitination of PRC1 is critical for its E3 ligase activity toward H2A, HSCARG and USP7 are further shown to decrease the level of H2A ubiquitination. Moreover, we demonstrated that HSCARG is involved in DNA damage response through affecting the level of H2A ubiquitination and localization of RAP80 at lesion points. Knockout of HSCARG results in persistent activation of checkpoint signaling and leads to cell cycle arrest. This study unravels a novel mechanism for the regulation of H2A ubiquitination and elucidates how regulators of H2A ubiquitination affect cell cycle. © 2014 The Author(s) 2014. The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Li D.-Q.,Wuhan University | Qi X.-H.,Wuhan University | Phoon K.-K.,National University of Singapore | Zhang L.-M.,Hong Kong University of Science and Technology | Zhou C.-B.,Wuhan University
Structural Safety | Year: 2014

This paper studies the reliability of infinite slopes in the presence of spatially variable shear strength parameters that increase linearly with depth. The mean trend of the shear strength parameters increasing with depth is highlighted. The spatial variability in the undrained shear strength and the friction angle is modeled using random field theory. Infinite slope examples are presented to investigate the effect of spatial variability on the depth of critical slip line and the probability of failure. The results indicate that the mean trend of the shear strength parameters has a significant influence on clay slope reliability. The probability of failure will be overestimated if a linearly increasing trend underlying the shear strength parameters is ignored. The possibility of critical slip lines occurring at the bottom of the slope decreases considerably when the mean trend of undrained shear strength is considered. The linearly increasing mean trend of the friction angle has a considerable effect on the distribution of the critical failure depths of sandy slopes. The most likely critical slip line only lies at the bottom of the sandy slope under the special case of a constant mean trend. © 2013 Elsevier Ltd.

Wang H.,Nanchang Institute of Technology | Sun H.,Nanchang Institute of Technology | Li C.,Wuhan University | Rahnamayan S.,University of Ontario Institute of Technology | And 3 more authors.
Information Sciences | Year: 2013

Particle Swarm Optimization (PSO) has shown an effective performance for solving variant benchmark and real-world optimization problems. However, it suffers from premature convergence because of quick losing of diversity. In order to enhance its performance, this paper proposes a hybrid PSO algorithm, called DNSPSO, which employs a diversity enhancing mechanism and neighborhood search strategies to achieve a trade-off between exploration and exploitation abilities. A comprehensive experimental study is conducted on a set of benchmark functions, including rotated multimodal and shifted high-dimensional problems. Comparison results show that DNSPSO obtains a promising performance on the majority of the test problems. © 2012 Elsevier Inc. All rights reserved.

Varcoe J.R.,University of Surrey | Atanassov P.,University of New Mexico | Dekel D.R.,Cellera Inc. | Herring A.M.,Colorado School of Mines | And 8 more authors.
Energy and Environmental Science | Year: 2014

This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current state-of-the-art, technological and scientific limitations, and the future challenges (research priorities) related to the use of anion-exchange membranes in these energy technologies. All the references that the authors deemed relevant, and were available on the web by the manuscript submission date (30th April 2014), are included. © The Royal Society of Chemistry 2014.

Zhou C.-X.,Peking University | Chen X.-M.,Wuhan University | Li T.-J.,Peking University
American Journal of Surgical Pathology | Year: 2012

Central mucoepidermoid carcinoma (MEC) is a rare neoplasm arising intraosseously in the jaws. To clarify the clinicopathologic profile and pathogenesis of central MEC, clinicopathologic findings and follow-up data of 39 cases were collected and analyzed. There were 16 male and 23 female patients (median age, 43 y). Sixteen cases affected the maxilla, and 23 occurred in the mandible. Radiographically, most cases (32 of 39) showed a unilocular or multilocular radiolucency with bone destruction, and 7 were found with scattered calcification. The margins of the lesions were ill defined or diffused in 14 cases and relatively well defined in 25 cases. Most cases (26 of 39) were classified as low-grade MECs, whereas 13 were moderateto- high grade. Follow-up data were available for 35 patients with a median period of 36 months. All cases were found to be primary; local recurrence occurred in 8 cases, most (75.0%) of which were low-grade tumors. Four cases showed regional lymph node metastasis, and 1 developed distant metastasis. Of 11 cases with a clinical history of the jaw cyst, 8 initially showed a typical odontogenic cyst with local MEC-like proliferation. In summary, the most likely pathogenesis of central MEC is neoplastic transformation of the epithelial lining of an odontogenic cyst, diagnosis of which should be based on clinical, radiographic, and histopathologic findings. The immunohistochemical profile of keratins is helpful in differential diagnosis. Radical surgery is the treatment of choice, whereas the role of radiotherapy or chemotherapy is still controversial, and careful long-term follow-up is necessary. Copyright © 2011 by Lippincott Williams & Wilkins.

Chen J.,University of Oulu | Shan S.,CAS Institute of Computing Technology | He C.,Wuhan University | Zhao G.,University of Oulu | And 3 more authors.
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2010

Inspired by Weber's Law, this paper proposes a simple, yet very powerful and robust local descriptor, called the Weber Local Descriptor (WLD). It is based on the fact that human perception of a pattern depends not only on the change of a stimulus (such as sound, lighting) but also on the original intensity of the stimulus. Specifically, WLD consists of two components: differential excitation and orientation. The differential excitation component is a function of the ratio between two terms: One is the relative intensity differences of a current pixel against its neighbors, the other is the intensity of the current pixel. The orientation component is the gradient orientation of the current pixel. For a given image, we use the two components to construct a concatenated WLD histogram. Experimental results on the Brodatz and KTH-TIPS2-a texture databases show that WLD impressively outperforms the other widely used descriptors (e.g., Gabor and SIFT). In addition, experimental results on human face detection also show a promising performance comparable to the best known results on the MIT+CMU frontal face test set, the AR face data set, and the CMU profile test set. © 2010 IEEE.

Xie X.,Wuhan University | Xie X.,Beijing Normal University | Cui Y.,Wuhan University
Journal of Hydrology | Year: 2011

The water movement in irrigation districts, especially for paddy rice cultivation, is characterized by complicated factors. Soil and Water Assessment Tool (SWAT) is a popular tool for understanding the hydro-agronomic processes. However, it fails to simulate the hydrological processes and crop yields in paddy rice areas. In this study, we develop the SWAT model by incorporating new processes for irrigation and drainage. The evapotranspiration process in paddy fields is simulated on the basis of water storage conditions, and a controlling irrigation scheme is introduced to manage the irrigation and drainage operations. The irrigation function of local water storages, such as ponds and reservoirs, is extended for these storages in order to provide water in a timely manner to paddy fields. Moreover, an agronomic model is incorporated to estimate crop yields when available data sets are not satisfactory. The model is tested in Zhanghe Irrigation District, China. The simulated runoff matches well to the measurements and the results indicate the developed model is preferable to the original edition of SWAT. The estimate of the paddy rice yield is acceptable and the dynamics of water balance components approximately characterize the state of water movements in paddy fields. Therefore, the developed framework for SWAT is practical and capable of representing the hydrological processes in this irrigation district. Further work is still needed to more broadly test the model in areas with paddy rice cultivation. © 2010 Elsevier B.V.

Zhu W.,China National Offshore Oil Corporation | Lei C.,Wuhan University
Marine Geophysical Research | Year: 2013

The Cenozoic Yinggehai-Song Hong and Qiongdongnan Basins together form one of the largest Cenozoic sedimentary basins in SE Asia. Detail studying on the newly released regional seismic data, we observed their basin structure and stratigraphy are clearly different. The structure of the NW-SE elongation of the Yinggehai-Song Hong Basin is strongly controlled by the strike-slip faulting of steep Red River Fault. And the basement is covered by heavy sediments from the Red River. However, structures closely related with rifting are imagined on the seismic data from the Qiongdongnan Basin. This rifting and thinning on the northern continental margin of the South China Sea is necessary to be explained by the subduction of a Proto-South China Sea oceanic crust toward the NW Borneo block during the Eocene-Early Miocene. To test how the strike-slip faulting in the Yinggehai-Song Hong Basin and rifting in the Qiongdongnan Basin develop together in the northwest corner of the South China Sea, we reconstructed the tectonics of the northwest corner of the South China Sea and test the model with software of MSC MARC. The numerical model results indicate the South China Sea and its surrounding area can be divided into a collision-extrusion tectonic province and a Proto-South China Sea slab pull tectonic province as suggested in previous works. We suggested that offshore Red River Fault in the Yinggehai-Song Hong Basin is confirmed as a very important tectonic boundary between these two tectonic provinces. © 2013 Springer Science+Business Media Dordrecht.

Lu Q.,Wuhan University | Zhang J.,Wuhan University | Wei F.,Nanjing University of Posts and Telecommunications | Qi Y.,Wuhan University | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2013

New channel! A novel and attractive dioxygen activation by sulfinic acids was explored that is capable of performing efficiently without the assistance of transition metals or radical initiators. This reaction furnishes secondary and tertiary β-hydroxysulfones under mild conditions; β-hydroperoxysulfone was isolated as an important intermediate. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liu G.-Y.,Guangdong University of Technology | Hu J.-M.,Wuhan University | Wang H.-L.,Jinan University
Scientometrics | Year: 2012

The aim of this study is to map the intellectual structure of digital library (DL) field in China during the period of 2002-2011. Co-word analysis was employed to reveal the patterns of DL field in China through measuring the association strength of keywords in relevant journals. Data was collected from Chinese Journal Full-Text Database during the period of 2002-2011. And then, the co-occurrence matrix of keywords was analyzed by the methods of multivariate statistical analysis and social network analysis. The results mainly include five parts: seven clusters of keywords, a two-dimensional map, the density and centrality of clusters, a strategic diagram, and a relation network. The results show that there are some hot research topics and marginal topics in DL field in China, but the research topics are relatively decentralized compared with the international studies. © 2011 Akadémiai Kiadó, Budapest, Hungary.

Yuan B.,University of California at Riverside | Yuan B.,Wuhan University | Wang J.,University of California at Riverside | Cao H.,University of California at Riverside | And 2 more authors.
Nucleic Acids Research | Year: 2011

Human cells are constantly exposed to environmental and endogenous agents which can induce damage to DNA. Understanding the implications of these DNA modifications in the etiology of human diseases requires the examination about how these DNA lesions block DNA replication and induce mutations in cells. All previously reported shuttle vector-based methods for investigating the cytotoxic and mutagenic properties of DNA lesions in cells have low-throughput, where plasmids containing individual lesions are transfected into cells one lesion at a time and the products from the replication of individual lesions are analyzed separately. The advent of next-generation sequencing (NGS) technology has facilitated investigators to design scientific approaches that were previously not technically feasible or affordable. In this study, we developed a new method employing NGS, together with shuttle vector technology, to have a multiplexed and quantitative assessment of how DNA lesions perturb the efficiency and accuracy of DNA replication in cells. By using this method, we examined the replication of four carboxymethylated DNA lesions and two oxidatively induced bulky DNA lesions including (5′S) diastereomers of 8,5′-cyclo- 2′-deoxyguanosine (cyclo-dG) and 8,5′-cyclo-2′-deoxyadenosine (cyclo-dA) in five different strains of Escherichia coli cells. We further validated the results obtained from NGS using previously established methods. Taken together, the newly developed method provided a high-throughput and readily affordable method for assessing quantitatively how DNA lesions compromise the efficiency and fidelity of DNA replication in cells. © 2011 The Author(s).

Xu Y.,University of Texas at Dallas | Mao L.,University of Texas at Dallas | Mao L.,Wuhan University | Wu B.,Peking University | Zhang C.,University of Texas at Dallas
Physical Review Letters | Year: 2014

We show that a single dark soliton can exist in a spin-orbit-coupled Fermi gas with a high spin imbalance, where spin-orbit coupling favors uniform superfluids over nonuniform Fulde-Ferrell-Larkin-Ovchinnikov states, leading to dark soliton excitations in highly imbalanced gases. Above a critical spin imbalance, two topological Majorana fermions without interactions can coexist inside a dark soliton, paving a way for manipulating Majorana fermions through controlling solitons. At the topological transition point, the atom density contrast across the soliton suddenly vanishes, suggesting a signature for identifying topological solitons. © 2014 American Physical Society.

Jiang S.-H.,Wuhan University | Li D.-Q.,Wuhan University | Cao Z.-J.,Wuhan University | Zhou C.-B.,Wuhan University | Phoon K.-K.,National University of Singapore
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2015

Monte Carlo simulation (MCS) provides a conceptually simple and robust method to evaluate the system reliability of slope stability, particularly in spatially variable soils. However, it suffers from a lack of efficiency at small probability levels, which are of great interest in geotechnical design practice. To address this problem, this paper develops a MCS-based approach for efficient evaluation of the system failure probability Pf,s of slope stability in spatially variable soils. The proposed approach allows explicit modeling of the inherent spatial variability of soil properties in a system reliability analysis of slope stability. It facilitates the slope system reliability analysis using representative slip surfaces (i.e., dominating slope failure modes) and multiple stochastic response surfaces. Based on the stochastic response surfaces, the values of Pf,s are efficiently calculated using MCS with negligible computational effort. For illustration, the proposed MCS-based system reliability analysis is applied to two slope examples. Results show that the proposed approach estimates Pf,s properly considering the spatial variability of soils and improves the computational efficiency significantly at small probability levels. With the aid of the improved computational efficiency offered by the approach, a series of sensitivity studies are carried out to explore the effects of spatial variability in both the horizontal and vertical directions and the cross-correlation between uncertain soil parameters. It is found that both the spatial variability and cross-correlation affect Pf,s significantly. The proposed approach allows more insights into such effects from a system analysis point of view. © 2014 American Society of Civil Engineers.

Xiaohong Z.,Wuhan University | Xingxing L.,Wuhan University | Xingxing L.,German Research Center for Geosciences
GPS Solutions | Year: 2012

The network-based real-time kinematic (RTK) positioning has been widely used for high-accuracy applications. However, the precise point positioning (PPP) technique can also achieve centimeter to decimeter kinematic positioning accuracy without restriction of inter-station distances but is not as popular as network RTK for real-time engineering applications. Typically, PPP requires a long initialization time and continuous satellite signals to maintain the high accuracy. In case of phase breaks or loss of signals, re-initialization is usually required. An approach of instantaneous cycle slips fixing using undifferenced carrier phase measurements is proposed, which leads to instantaneous re-initialization for real-time PPP. In the proposed approach, various errors such as real-time orbit and clock errors, atmosphere delay and wind-up effects are first refined and isolated from integer cycle slips. The integer values of cycle slips can then be estimated and fixed with the LAMBDA technique by applying a cascade cycle slip resolution strategy. Numerical experiments with different user dynamics are carried out to allow a comprehensive evaluation of efficiency and robustness of the cycle slip fixing algorithm. The results show that the cycle slips can be fixed correctly in all cases considered and that data gaps of up to 300 s can be connected with high confidence. As a result, instantaneous re-initialization is achieved in the real-time PPP processing. © 2011 Springer-Verlag.

Tang X.-S.,Wuhan University | Li D.-Q.,Wuhan University | Rong G.,Wuhan University | Phoon K.-K.,National University of Singapore | Zhou C.-B.,Wuhan University
Computers and Geotechnics | Year: 2013

This paper aims to investigate the impact of copula selection on geotechnical reliability under incomplete probability information. The copula theory is introduced briefly. Thereafter, four copulas, namely Gaussian, Plackett, Frank, and No. 16 copulas, are selected to model the dependence structure between cohesion and friction angle. A copula-based approach is used to construct the joint probability density function of cohesion and friction angle with given marginal distributions and correlation coefficient. The reliability of an infinite slope and a retaining wall is presented to demonstrate the impact of copula selection on reliability. The results indicate that the probabilities of failure of geotechnical structures with given marginal distributions and correlation coefficient of shear strength parameters cannot be determined uniquely. The resulting probabilities of failure associated with different copulas can differ considerably. Such a difference increases with decreasing probability of failure. Significant difference in probabilities of failure could be observed for relatively small coefficients of variation of the shear strength parameters or a strong negative correlation between cohesion and friction angle. The Gaussian copula, often adopted out of expedience without proper validation, may not capture the dependence structure between cohesion and friction angle properly. Furthermore, the Gaussian copula may greatly underestimate the probability of failure for geotechnical structures. © 2012 Elsevier Ltd.

Wang H.,Wuhan University | Wu Z.,Wuhan University | Rahnamayan S.,University of Ontario Institute of Technology
Soft Computing | Year: 2011

This paper presents a novel algorithm based on generalized opposition-based learning (GOBL) to improve the performance of differential evolution (DE) to solve high-dimensional optimization problems efficiently. The proposed approach, namely GODE, employs similar schemes of opposition-based DE (ODE) for opposition-based population initialization and generation jumping with GOBL. Experiments are conducted to verify the performance of GODE on 19 high-dimensional problems with D = 50, 100, 200, 500, 1,000. The results confirm that GODE outperforms classical DE, real-coded CHC (crossgenerational elitist selection, heterogeneous recombination, and cataclysmic mutation) and G-CMA-ES (restart covariant matrix evolutionary strategy) on the majority of test problems. © 2010 Springer-Verlag.

Wang H.,Nanchang Institute of Technology | Rahnamayan S.,University of Ontario Institute of Technology | Wu Z.,Wuhan University
Journal of Parallel and Distributed Computing | Year: 2013

Solving high-dimensional global optimization problems is a time-consuming task because of the high complexity of the problems. To reduce the computational time for high-dimensional problems, this paper presents a parallel differential evolution (DE) based on Graphics Processing Units (GPUs). The proposed approach is called GOjDE, which employs self-adapting control parameters and generalized opposition-based learning (GOBL). The adapting parameters strategy is helpful to avoid manually adjusting the control parameters, and GOBL is beneficial for improving the quality of candidate solutions. Simulation experiments are conducted on a set of recently proposed high-dimensional benchmark problems with dimensions of 100, 200, 500 and 1,000. Simulation results demonstrate that GjODE is better than, or at least comparable to, six other algorithms, and employing GPU can effectively reduce computational time. The obtained maximum speedup is up to 75. © 2012 Elsevier Inc. All rights reserved.

Tang X.-S.,Wuhan University | Li D.-Q.,Wuhan University | Zhou C.-B.,Wuhan University | Zhou C.-B.,Nanchang University | Phoon K.-K.,National University of Singapore
Structural Safety | Year: 2015

Slope reliability under incomplete probability information is a challenging problem. In this study, three copula-based approaches are proposed to evaluate slope reliability under incomplete probability information. The Nataf distribution and copula models for characterizing the bivariate distribution of shear strength parameters are briefly introduced. Then, both global and local dispersion factors are defined to characterize the dispersion in probability of slope failure. Two illustrative examples are presented to demonstrate the validity of the proposed approaches. The results indicate that the probabilities of slope failure associated with different copulas differ considerably. The commonly used Nataf distribution or Gaussian copula produces only one of the various possible solutions of probability of slope failure. The probability of slope failure under incomplete probability information exhibits large dispersion. Both global and local dispersion factors increase with decreasing probability of slope failure, especially for small coefficients of variation and strongly negative correlations underlying shear strength parameters. The proposed three copula-based approaches can effectively reduce the dispersion in probability of slope failure and significantly improve the estimate of probability of slope failure. In comparison with the Nataf distribution, the copula-based approaches result in a more reasonable estimate of slope reliability. © 2014 Elsevier Ltd.

Zeng L.,Zhejiang University | Shi L.,Wuhan University | Zhang D.,Peking University | Wu L.,Zhejiang University
Advances in Water Resources | Year: 2012

In this study, an efficient Bayesian method based on the adaptive sparse grid interpolation is used to solve the contaminant source identification problem. The unknown parameters that characterize the contaminant source are treated as random variables and identified by the Bayesian approach. To alleviate the computational burden in the standard Markov Chain Monte Carlo (MCMC) method, a surrogate system with the polynomial form is constructed by the stochastic collocation method (SCM), which employs the interpolation based on the sparse grids rather than those based on the full tensor product. Furthermore, an adaptive scheme is used to take the different importance of the parameters into account. Therefore, the computational burden is significantly reduced. Once the surrogate system is determined, the likelihood can be evaluated by sampling the surrogate system directly, with very little computational cost. To improve the accuracy, we propose an auxiliary SCM based approach, where the surrogate system serves as a guidance for the fast adaption of the proposal distribution in the MCMC method. Numerical cases show that, under certain conditions, this method can greatly reduce the computational burden in the MCMC sampling and accurately identify the characteristics of the contaminant source. © 2011 Elsevier Ltd.

Li X.,Wuhan University | Li X.,German Research Center for Geosciences | Zhang X.,Wuhan University | Ge M.,German Research Center for Geosciences
Journal of Geodesy | Year: 2011

Integer ambiguity fixing can significantly shorten the initialization time and improve the accuracy of precise point positioning (PPP), but it still takes approximate 15 min of time to achieve reliable integer ambiguity solutions. In this contribution, we present a new strategy to augment PPP estimation with a regional reference network, so that instantaneous ambiguity fixing is achievable for users within the network coverage. In the proposed method, precise zero-differenced atmospheric delays are derived from the PPP fixed solution of the reference stations, which are disseminated to, and interpolated at user stations to correct for L1, L2 phase observations or their combinations. With the corrected observations, instantaneous ambiguity resolution can be carried out within the user PPP software, thus achieving the position solutions equivalent to the network real-time kinematic positioning (NRTK). The strategy is validated experimentally. The derived atmospheric delays and the interpolated corrections are investigated. The ambiguity fixing performance and the resulted position accuracy are assessed. The validation confirms that the new strategy can provide comparable service with NRTK. Therefore, with this new processing strategy, it is possible to integrate PPP and NRTK into a seamless positioning service, which can provide an accuracy of about 10 cm anywhere, and upgrade to a few centimeters within a regional network. © 2010 Springer-Verlag.

He K.H.,National University of Singapore | He K.H.,Wuhan University | Chen J.S.,National University of Singapore | Feng Y.P.,National University of Singapore
Applied Physics Letters | Year: 2011

The magnetization and magnetic anisotropy of FeCo/MgO(001) thin film under electric field were investigated by the first-principles calculations. Three different interface configurations were considered: Co/Fe/MgO, Fe/Co/MgO, and FeCo/FeCo/MgO. It was found that the perpendicular anisotropy was preferred for all the configurations and enhanced with increasing electric field, which was consistent with experimental results. Furthermore, our calculations indicated that the FeCo/FeCo/MgO was the most stable configuration and had the largest perpendicular magnetic anisotropy energy. The results also showed that the FeCo/FeCo/MgO and Fe/Co/MgO configurations had larger magnetoelectric coefficients than those of the Co/Fe/MgO configuration and previous report about the Fe/MgO interface. © 2011 American Institute of Physics.

Zhang H.,Wuhan University | Harris N.,Open University Milton Keynes | Guo L.,Wuhan University | Xu W.,Wuhan University
Contributions to Mineralogy and Petrology | Year: 2010

The major and trace-element geochemistry, Sr-Nd bulk-rock isotopes, U-Pb zircon chronology and Lu-Hf isotopic compositions are described for three granitic bodies which intrude the Nyingchi gneisses (Lhasa terrane) along the western margin of the eastern Himalayan syntaxis. The Bayi two-mica granite and Lunan granite-granodiorite were intruded at 22 ± 1 and 25.4 ± 0.3 Ma, respectively, whereas the Confluence biotite granite was emplaced at 49.1 ± 0.4 Ma. All share strong depletions in Y and HREE requiring a garnet-bearing source both during and following the Eocene collision of the Indian plate with the Lhasa terrane. The isotope geochemistry of these intrusives (εNd(t) = -3 to -5, 87Sr/86Sr(t) = 0.706-0.707) indicates a crustal source within the Lhasa terrane. Sr-Nd systematics of the garnet-bearing Nyingchi gneisses together with the U-Pb and Lu-Hf isotopic ratios of detrital zircons recovered from this unit identifies it as a potential melt source. The combined element and isotope geochemistry of the plutons indicate a mixed source; the gneisses provide the older component whereas the Gangdese batholith provides a younger, siliceous component. The involvement of garnet-bearing crustal material in melt sources from the Cretaceous (80 Ma) to the Miocene (20 Ma) is consistent with the presence of a thicker continental crust in the eastern Lhasa terrane, as is the presence of magmatic epidote in several plutons which indicates a regional deepening level of exposure eastwards. Post-collision crustal melting is synchronous with proposed slab break-off during the early Miocene, suggesting advective heating by rising asthenospheric melts. © 2009 Springer-Verlag.

Agency: Cordis | Branch: FP7 | Program: CP-TP | Phase: KBBE.2012.3.2-01 | Award Amount: 13.29M | Year: 2012

The PharmaSea project focuses on obstacles in marine biodiscovery research, development and commercialization and brings together a broad interdisciplinary team of academic and industry researchers and specialists to address and overcome these. The partners are ideally placed to demonstrate how to widen the bottlenecks and increase the flow of ideas and products derived from the marine microbiome towards a greater number of successes in a larger number of application areas. Despite the tremendous potential of marine biodiscovery, exploitation, particularly at a commercial scale, has been hampered by a number of constraints. These relate to access (physical and legal), genetics of the organisms, compound isolation, structure elucidation, early reliable validation of biological activity and best mechanisms of flow-through into exploitation. PharmaSea will solve these chronic bottlenecks by developing essential actions beyond the state of the art and linking them with best practice and appropriate pragmatic approaches. The robust pipeline structure established within PharmaSea will process a wide genetic basis including marine microbial strain collections held by partners and new strain collections from extreme environments (deep, cold and hot vent habitats) to produce new products with desirable characteristics for development by the SME partners in three accessible market sectors, health (infection, inflammation, CNS diseases), personal care and nutrition. The global aim of PharmaSea is to produce two compounds at larger scale and advance them to pre-clinical evaluation. To address relevant challenges in marine biodiscovery related to policy and legal issues, PharmaSea will bring together practitioners, legal experts, policy advisors/makers and other stakeholders, focusing on the feasibility of harmonising, aligning and complementing current legal frameworks with recommendations and ready to use solutions tailored to marine biodiscovery.

Li Z.,University of Groningen | Liang P.,Wuhan University | Avgeriou P.,University of Groningen
Information and Software Technology | Year: 2013

Context: Knowledge management technologies have been employed across software engineering activities for more than two decades. Knowledge-based approaches can be used to facilitate software architecting activities (e.g., architectural evaluation). However, there is no comprehensive understanding on how various knowledge-based approaches (e.g., knowledge reuse) are employed in software architecture. Objective: This work aims to collect studies on the application of knowledge-based approaches in software architecture and make a classification and thematic analysis on these studies, in order to identify the gaps in the existing application of knowledge-based approaches to various architecting activities, and promising research directions. Method: A systematic mapping study is conducted for identifying and analyzing the application of knowledge-based approaches in software architecture, covering the papers from major databases, journals, conferences, and workshops, published between January 2000 and March 2011. Results: Fifty-five studies were selected and classified according to the architecting activities they contribute to and the knowledge-based approaches employed. Knowledge capture and representation (e.g., using an ontology to describe architectural elements and their relationships) is the most popular approach employed in architecting activities. Knowledge recovery (e.g., documenting past architectural design decisions) is an ignored approach that is seldom used in software architecture. Knowledge-based approaches are mostly used in architectural evaluation, while receive the least attention in architecture impact analysis and architectural implementation. Conclusions: The study results show an increased interest in the application of knowledge-based approaches in software architecture in recent years. A number of knowledge-based approaches, including knowledge capture and representation, reuse, sharing, recovery, and reasoning, have been employed in a spectrum of architecting activities. Knowledge-based approaches have been applied to a wide range of application domains, among which "Embedded software" has received the most attention. © 2012 Elsevier B.V. All rights reserved.

Yan K.,Peking University | Yan K.,Stanford University | Fu L.,Peking University | Fu L.,Wuhan University | And 2 more authors.
Accounts of Chemical Research | Year: 2013

Graphene, the atomic thin carbon film with honeycomb lattice, holds great promise in a wide range of applications, due to its unique band structure and excellent electronic, optical, mechanical, and thermal properties. Scientists are researching this star material because of the development of various emerging preparation techniques, among which chemical vapor deposition (CVD) has received the fastest advances in the past few years. For the CVD growth of graphene, the ultimate goal is to achieve the highest quality in the largest scale and lowest cost with a precise control of layer thickness, stacking order, and crystallinity. To meet this goal, researchers need a comprehensive understanding and effective controlling of the growth process, especially to its elementary steps.In this Account, we focus on our recent progresses toward the controlled surface growth of graphene and its two-dimensional (2D) hybrids via rational designs of CVD elementary processes, namely, process engineering. A typical CVD process consists of four main elementary steps: (A) adsorption and catalytic decomposition of precursor gas, (B) diffusion and dissolution of decomposed carbon species into bulk metal, (C) segregation of dissolved carbon atoms onto the metal surface, and finally, (D) surface nucleation and growth of graphene. Absence or enhancement of each elementary step would lead to significant changes in the whole growth process. Metals with certain carbon solubility, such as nickel and cobalt, involve all four elementary steps in a typical CVD process, thus providing us an ideal system for process engineering. The elementary segregation process can be completely blocked if molybdenum is introduced into the system as an alloy catalyst, yielding perfect monolayer graphene almost independent of growth parameters. On the other hand, the segregation-only process of predissolved solid carbons is also capable of high-quality graphene growth. By using a synergetic Cu-Ni alloy, we are able to further enhance the control to such a segregation technique, especially for the thickness of graphene. By designing a cosegregation process of carbon atoms with other elements, such as nitrogen, doped graphene could be synthesized directly with a tunable doping profile.Copper with negligible carbon solubility provides another platform for process engineering, where both carbon dissolution and segregation steps are negligible in the CVD process. Carbon atoms decomposed from precursors diffuse on the surface and build up the thermodynamically stable honeycomb lattice. As a result, graphene growth on copper is self-limited, and formation of multilayer graphene is generally prohibited. Being able to control this process better, as well as the high quality produced, makes copper-based growth the dominating synthesis procedure in the graphene community. We designed a two-temperature zone system to spatially separate the catalytic decomposition step of carbon precursors and the surface graphitization step for breaking this self-limited growth feature, giving high-quality Bernal stacked bilayer graphene via van der Waals epitaxy. We performed the so-called wrinkle engineering by growing graphene on nanostructured copper foil together with a structure-preserved surface transfer. In such a way, we controlled the wrinkling or folding on graphene and further fabricated graphene nanoribbon arrays by self-masked plasma etching. Moreover, by designing a two-step patching growth process on copper, we succeeded in synthesizing the mosaic graphene, a patchwork of intrinsic and nitrogen-doped graphene connected by single crystalline graphene p-n junctions.By following a general concept of process engineering, our work on the designed CVD growth of graphene and its 2D hybrids provides a unique insight of this research field. It enables the precise growth control of graphene together with the in-depth understanding of CVD growth process, which would further stimulate the pace of graphene applications. © 2013 American Chemical Society.

News Article | December 22, 2016
Site: www.eurekalert.org

CINCINNATI--Cancer researchers at the University of Cincinnati (UC) College of Medicine have found an obesity-associated protein's role in leukemia development and drug response which could lead to more effective therapies for the illness. The study, which will be published in the Dec. 22 online edition of Cancer Cell and led by Jianjun Chen, PhD, associate professor in the Department of Cancer Biology, provided evidence that FTO--the protein associated with fat mass and obesity--plays a critical cancer-promoting role by regulating expression of a set of genes through a mechanism involving ribonucleic acid (RNA) modification and thereby increasing the reproduction of leukemia cells and prohibiting drug response. "N6-methyladenosine (m6A) RNA methylation, the most prevalent internal modification in messenger RNAs (mRNAs, which translate DNA) in genes, was first identified in 1970s. In 2011, Dr. Chuan He, professor of chemistry at the University of Chicago, a co-senior author of this paper, discovered for the first time that FTO actually functions as an eraser of m6A methylation. This means that it can remove the modification from RNA transcripts, or RNA copies, thereby showing that m6A modification is a reversible process and is highly likely it is of biological importance. In 2012, two groups independently reported the development of novel sequencing technologies to profile all m6A modification areas in the entire genome and showed that roughly one-third of mRNAs in individual mammal cells are targets of m6A modification, highlighting the prevalence and potential functional importance of m6A modification. "Recent studies have shown that m6A modification in mRNAs or non-coding RNAs plays critical roles in virtually all major normal biological processes such as tissue development and stem cell self-renewal and differentiation. However, little is known about the biological importance of m6A modification in the regulation of cancer-causing genes and/or tumor-suppressing genes in the development of tumors." Researchers in the study analyzed a microarray dataset of 100 human acute myeloid leukemia (AML) samples from patients and nine normal control samples as well as other large-scale microarray datasets of AML samples. They found that FTO was highly expressed in various subtypes of leukemia samples such as those that contained chromosome crossover (genetic exchange between chromosomes) or mutations in certain genes. The high level of FTO expression contributed to cancer cells multiplying and surviving and also promoted the development of leukemia in animal models and the non-response of cancer cells to therapeutic agents. Additionally, researchers found that genes like ASB2 and RARA, which were reported to inhibit leukemia cell growth and/or mediate the response of leukemia cells to therapeutic agents, were suppressed in the AML samples with higher FTO expression. The suppression of these genes was attributed to FTO-controlled decreased stability of their mRNA and was connected to FTO's m6A demethylase activity. "Our study shows, for the first time, the functional importance of the m6A modification machinery in leukemia," says Chen. "In addition, given the functional importance of FTO in the formation of leukemia and drug response, targeting FTO signaling may present a new therapeutic strategy to treat leukemia. As FTO may also play a cancer-promoting role in various types of solid tumors, besides leukemia, our discoveries may have a broad impact in cancer biology and cancer therapy. Further studies are needed to advance our understanding of the critical role of FTO in various types of cancers and to develop more effective novel therapeutic strategies based on such understanding to treat cancers." In addition to researchers from the University of Cincinnati, scientists from Howard Hughes Medical Institute and the University of Chicago; Baylor College of Medicine; and the First Affiliated Hospital Zhejiang University, Wuhan University and Sun Yat-Sen University Cancer Center, all in China, were involved in the study. This study was funded by the National Institutes of Health (CA178454, CA182528,CA214965 and GM071440), the Leukemia & Lymphoma Society, the American Cancer Society, Howard Hughes Medical Institute, the Damon Runyon Cancer Research Foundation, the China Scholarship Council and the Foundation of Innovation Team for Basic and Clinical Research of Zhejiang Province. The authors cite no conflict of interest.

News Article | December 16, 2015
Site: www.nature.com

During the past two decades, Chinese science has undergone profound growth. China's investment in research and development surpassed that of the European Union in 2013, and it is predicted to overtake that of the United States by the end of the decade (see Nature http://doi.org/w5r; 2014).The proportion of published scientific papers that include Chinese co-authors has jumped from 2.4% in 1997 to 19% in 2014 — second only to the US contribution last year of 25%. Those statistics are impressive. But if China is to become a true scientific superpower, it must be able to produce great scientists who are not just knowledgeable but also creative and skilled in innovation. And great scientists need great mentors to lead the way. In recognition of the vision, dedication and hard work of those charged with nurturing the next generation of Chinese researchers, this year's Nature Awards for Mentoring in Science honour five researchers in China. The winners, feted in an 8 December ceremony, were chosen by panels composed of Chinese scientists and Springer Nature editorial representatives (see go.nature.com/hdi5k7). Submissions included statements from five people who had been mentored by the nominee and statements from the nominees reflecting their own thoughts on mentoring. Owing to China's size, submissions were divided into 'north' and 'south', with awards for lifetime and mid-career achievement in each. The 50,000-yuan (US$7,815) lifetime-achievement award for northern China was shared between immunologist Xuetao Cao, who is president of the Chinese Academy of Medical Sciences, and plant scientist Xingwang Deng, dean of the School of Advanced Agricultural Sciences at Peking University. The winner for southern China is Hongyuan Chen, an electroanalytical chemist and director of the Institute of Chemical Biology at Nanjing University. In the mid-career category, the 50,000-yuan awards for northern and southern China went, respectively, to Yigong Shi, a structural biologist and dean of life sciences at Tsinghua University in Beijing, and Hongbing Shu, an immunologist at Wuhan University. Like many Asian nations, China is often seen as a place of rigid hierarchies rooted in deference to power. One trait shared by all the winners, and indeed by all those nominated, is an understanding that the only authority in science is evidence — and that conventional wisdom must always be open to question. Shi, who was named a chair professor of molecular biology at Princeton University in New Jersey before he returned to China in 2008, thinks that most Chinese students are too wary of contradicting senior researchers and accepted scientific ideas. “I encourage my students to think critically and to challenge the authorities, including myself, so that they can learn that established rules can be broken, and with that, new fields of research can be built,” he says. Cao agrees. “We should inspire students to have confidence to challenge the dogma in the textbook and address fundamental questions in science,” he says. The lesson is not lost on the winners' protégés. “The scientific literature is a baffling mass of conflicting ideas and results, accepted wisdom and false assumptions,” notes Weilin Chen, a cancer immunologist at Zhejiang University and one of Cao's former PhD students at the Second Military Medical University in Shanghai. “Professor Cao often said that creativity comes from different directions with different views,” she says. “And he treats everyone, regardless of whether they are a PhD student or a visiting scholar, with the same high regard.” In the past, most Chinese labs were indeed quite rigid, with a single senior professor directing junior professors, postdocs and students along strictly hierarchical lines. With the rapid expansion of research institutes, however — fuelled by a large influx of researchers returning from overseas — the structure of many labs has begun to follow a less-hierarchical model, with many independent principal investigators all pursuing their own agendas and research directions. The mentors honoured by Nature have recognized the importance of instilling young researchers with the self-confidence that they need to establish their own intellectual identity and to make their own way in the world. “In my opinion, simply imparting knowledge is not enough,” says Hongyuan Chen. “A mentor should teach students the way of thinking. In the area of science, I guide my students to think in a scientific way, and give them the opportunity to solve problems independently.” He thinks that a good mentor must have a keen sense of when a student requires guidance and when he or she needs freedom. “For students who are just starting out, we need to give them more-detailed instructions to let them get used to research gradually,” he says. “And for those who have a solid knowledge base, strong independence and creativity, I let them think and practise in their own ways.” Jingjuan Xu, a former PhD student of Hongyuan Chen's and now an analytical chemist at Nanjing University, says that Chen provided an open environment that fostered imagination and creativity. “He encouraged us to read philosophy and literature, and think from different aspects,” recalls the chemist. “He said that every student is an independent, thinking being; a good mentor should nurture them to become 'horses' rather than 'sheep'.” Good mentors also recognize that it is not enough to produce successful scientists — it is just as important to teach others how to be effective, inspiring leaders themselves. Lei Li, a postdoc of Deng's at Yale University in New Haven, Connecticut, and now a professor in the School of Life Sciences at Peking University, recounts her own training in Deng's lab. “As I became more senior in the lab, Professor Deng started to ask me to help others in their lab techniques and in reading their manuscripts, which I soon realized was part of a system,” she says. “When he discovered performance issues, he never just criticized; he took time to find the root of the problem. And in several instances, he delegated me to do the pep talk.” The testimonials for the award winners all strongly reflect the scientists' unwavering dedication to the success of their protégés. But one story in particular stands out. In 2005, immunologist Bo Zhong, now at Wuhan University, applied to do a PhD in Hongbing Shu's lab after graduating with a major in English. “I was determined to study biology after graduation because I was interested in nature,” says Zhong. At Wuhan, “Dr Shu had recently been appointed as dean of life sciences, and his group [at the National Jewish Medical and Research Center in Denver, Colorado] had just published a milestone discovery in Molecular Cell. Every student with ambition wanted to join his lab — and so did I”. Zhong knew that it wouldn't be easy. “I had to admit that my background was much weaker than those who majored in biology,” he says. “I downloaded all his publications but found that I could hardly understand them. I knocked on the door to his office, and asked many naive questions. He patiently explained the details, recommended more publications to me and encouraged me to ask him if I had any difficulty in understanding the studies. Following his instructions, I read more papers, and wrote a five-page summary about pattern recognition and signalling, and asked whether I could join his lab. To my surprise, he agreed.” Shu admits that he was unsure about Zhong's potential at first, but after seeing his determination, Shu felt that Zhong deserved a chance to show what he could do. He doesn't regret the decision. “After I was convinced of his ambition and drive for a scientific career, I took him without hesitation. He has so far proved himself as one of the most successful students trained in my lab.” After taking him on, Shu asked Zhong to turn the summary that he had written into a full review paper, which became the first publication to come out of the newly formed lab. Shu thinks that patience and perseverance are among the most important traits of good mentorship, something he learnt from one of his own mentors: his PhD supervisor, Harish Joshi, a cell biologist at Emory University in Atlanta, Georgia. “I have always remembered what he told me when I was in his lab. 'Do not fire them; fire them up!',” Shu recalls. “In my 17- years' mentoring life, I have never given up on any one of my students.” A well-known Chinese saying goes, “If someone is your teacher for just one day, you should regard that person as your parent for the rest of your life.” The influence that great mentors have does indeed live long — and not just in their students, but in their students' students. “When I started my own lab in 2012, I often asked myself what Yigong would do,” says Liang Feng, a structural biologist at Stanford University in California and a former PhD student of Shi's. “I kept all e-mail communications Yigong sent to me or to the lab, and often went back to read them. They are like a 'how-to' guide for running a lab. For me and many others, Yigong was not only a great mentor and a role model, but also a relentless supporter and a lifelong friend.” The word used to describe the most revered teachers, shifu — a portmanteau of the words for teacher, laoshi, and father, fuqin — echoes the deep connection that forms between exceptional mentors and their protégés. None of the scientists who nominated their mentors for an award takes this filial bond for granted. In the words of Hongyuan Chen's protégé Jing-juan Xu, “I think that 'father' is really too high a standard to expect from a teacher. But we are the lucky children, because Professor Chen treated us like his own kids.”

News Article | December 5, 2016
Site: www.materialstoday.com

The recipient of the 2017 Acta Biomaterialia Gold Medal is Professor Allan S. Hoffman,             Emeritus Professor of Bioengineering at the University of Washington in Seattle. The Award will be presented at the 2017 Meeting of the Society for Biomaterials to be held in Minneapolis in April 2017. Professor Hoffman studied at M.I.T., where he received his B.S., M.S., and Sc.D. degrees in Chemical Engineering between 1953 and 1957. He taught on the faculty of the Chemical Engineering Department at M.I.T. for a total of ten years. He then spent 46 years as Professor of Bioengineering and Chemical Engineering at the University of Washington in Seattle, Washington. Prof. Hoffman’s major research interests are in drug delivery; diagnostic assays; “smart”, stimuli-responsive polymers; hydrogels; and chemical and biological modification of biomaterial surfaces. He has published over 400 peer-reviewed articles and is co-inventor on over 35 issued patents.  He is co-Editor (along with Buddy D. Ratner, Fred J. Schoen and Jack E. Lemons) of “Biomaterials Science”, Elsevier Publishers, now in its 3rd Edition. His early work in 1984 on the use of “smart” polymers in a temperature-driven phase separation immunoassay sparked a huge worldwide interest in such stimuli-responsive polymers as biomaterials.  Biomedical applications of “smart” polymers continue to grow rapidly around the world at the present time. He has been an Honorary Professor at: Sichuan University, Chengdu, China; South China University of Technology, Guangzhou, China; Wuhan University, Wuhan, China; Shanghai University, Shanghai, China; and Aarhus University, Aarhus, Denmark. In 2013 he completed a four-year appointment (2009-2013) as WCU (“World Class University”) Distinguished Professor at the Kyungpook National University Medical School in Daegu, South Korea. Professor Hoffman was elected to the US National Academy of Engineering in 2005.  His other recognitions and awards include Presidency of the US Society for Biomaterials (1983); the “Biomaterials Science Prize” of the Japanese Society for Biomaterials (1990); the Founders’ Award of the US Society for Biomaterials (in 2000); the Chandra Sharma Award of the Society for Biomaterials and Artificial Organs of India (2003); the “International Polymer Research Award” of the Japanese Society of Polymer Science (2006), and the Founder’s Award of the US Controlled Release Society (2007); Special symposia have been organized in Maui, Hawaii by his colleagues to celebrate his 60th, 70th and 80th birthdays. Former students, along with many academic colleagues, have also organized symposia which they have called “Hoffman Family Symposia” (HFS) and since 2010 there have been four, the first two were in Tokyo, Japan in 2012 and 2014, the third was in Gwangju, Korea in 2015, and a fourth was in Taipei, Taiwan September, 2016.  A fifth HFS will be held in Shanghai, China this coming October, 2017.

Chen X.,Shanghai JiaoTong University | Fang T.,Shanghai JiaoTong University | Huo H.,Shanghai JiaoTong University | Li D.,Wuhan University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011

Linearly nonseparability and class imbalance of very high resolution (VHR) imagery make feature selection for object-oriented classification quite challenging, while such characteristics, especially class imbalance, have usually been ignored in open literature. To cope with the challenges, this paper proposes a new graph-based feature selection method named locally weighted discriminating projection (LWDP). First, the popular graph-based criteria of feature selection are reformulated to present linear or nonlinear mapping in feature space. Second, weight matrices of graphs characterize dissimilarity rather than similarity between pairwise neighbors, to well-preserved local structure when the difference of distance between a sample and its neighbors is large. Finally, LWDP provides a new perspective to alleviate class imbalance at both global and local levels, by restricting the pairwise relationships in the weight matrices. Specifically, neighborhood unions are introduced to employ the local class distribution and class size to constrain pairwise relationships in the weight matrices when classifying unbalanced sample sets. To evaluate the performances of LWDP in low dimensions, a holistic scoring scheme is proposed to stress the performances under low dimensions. In addition, overall accuracy curves and Kappa Index of Agreement (KIA) curves, which exhibit KIA in dimensions, are also used. The experimental results show that LWDP and its kernel extension outperform the other classic or latest methods in processing unbalanced sample set of VHR airborne imagery. © 2006 IEEE.

Wei H.,CAS Institute of Physics | Xu H.,CAS Institute of Physics | Xu H.,Wuhan University
Materials Today | Year: 2014

Plasmonics is a rapidly developing research field with many potential applications in fields ranging from bioscience, information processing and communication to quantum optics. It is based on the generation, manipulation and transfer of surface plasmons (SPs) that have the ability to manipulate light at the nanoscale. Realizing plasmonic applications requires understanding how the SP-based properties depend on the nanostructures and how these properties can be controlled. For that purpose composite nanostructures are particularly interesting because many novel and extraordinary properties unattainable in single nanostructures can be obtained by designing composite nanostructures with various materials. Here, we review recent advances in the studies of three classes of composite nanostructure that are important for plasmonics: metal-metal, metal-dielectric, and metal-semiconductor composite nanostructures. © 2014 Elsevier Ltd.

Zhou C.-H.,Wuhan University | Zhao J.-Y.,Wuhan University | Pang D.-W.,Wuhan University | Zhang Z.-L.,Wuhan University | Zhang Z.-L.,Wuhan Institute of Biotech
Analytical Chemistry | Year: 2014

A novel colorimetric assay method based on enzyme-induced metallization has been proposed for detection of alkaline phosphatase (ALP), and it was further applied to highly sensitive detection of avian influenza virus particles coupled with immunomagnetic separation. The enzyme-induced metallization-based color change strategy combined the amplification of the enzymatic reaction with the unique optical properties of metal nanoparticles (NPs), which could lead to a great enhancement in optical signal. The detection limit for ALP detection was 0.6 amol/50 μL which was 4-6 orders of magnitude more sensitive than other metal NP-based colorimetric methods. Moreover, this technique was successfully employed to a colorimetric viral immunosensor, which could be applied to complex samples without complicated sample pretreatment and sophisticated instruments, and a detection limit as low as 17.5 pg mL-1 was achieved. This work not only provides a simple and sensitive sensing approach for ALP and virus detection but also offers an effective signal enhancement strategy for development of a highly sensitive nonaggregation metal NP-based colorimetric assay method. © 2014 American Chemical Society.

Li Q.,CAS Institute of Physics | Wei H.,CAS Institute of Physics | Xu H.,CAS Institute of Physics | Xu H.,Wuhan University
Nano Letters | Year: 2014

Surface plasmons, the collective oscillations of electrons at metal surface, provide the ability to enhance the weak interaction between individual quantum emitters and photons for quantum information applications. The generation of single plasmons by coupling silver nanowire with single quantum emitters opens the prospects of using quantum optical techniques to control single surface plasmons and designing novel quantum plasmonic devices. However, the real applications will deal with multiple plasmons generated from multiple quantum emitters. Here we report the first experimental demonstration of resolving single plasmons generated by a pair of quantum dots (QDs) on a silver nanowire waveguide. The accurate positions of the two QDs with separation ranging from micrometers to 200 nm within the diffraction limit are determined by using super-resolution imaging method. The efficiency of plasmon generation due to the exciton-plasmon coupling is obtained for each QD. Our research takes a crucial step toward the experimental study of coupled systems of multiple quantum emitters and plasmonic waveguides and would shed new light on the study of light-matter interactions for potential quantum optics and quantum information applications. © 2014 American Chemical Society.

Xiao L.,Pacific Northwest National Laboratory | Xiao L.,Central China Normal University | Cao Y.,Pacific Northwest National Laboratory | Cao Y.,Wuhan University | And 7 more authors.
Advanced Materials | Year: 2012

A novel vulcanized polyaniline nanotube/sulfur composite was prepared successfully via an in situ vulcanization process by heating a mixture of polyaniline nanotube and sulfur at 280 °C. The electrode could retain a discharge capacity of 837 mAh g -1 after 100 cycles at a 0.1 C rate and manifested 76% capacity retention up to 500 cycles at a 1 C rate. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wang B.,Institute of Materials Research and Engineering of Singapore | Zhang X.,Wuhan University | Garcia-Vidal F.J.,Autonomous University of Madrid | Yuan X.,Nankai University | Teng J.,Institute of Materials Research and Engineering of Singapore
Physical Review Letters | Year: 2012

Here we investigate theoretically and numerically the coupling between surface plasmon polaritons (SPPs) in monolayer graphene sheet arrays that have a period much smaller than the wavelength. We show that when the collective SPP is excited with an out-of-phase illumination, the beam tends to propagate toward the opposite direction of the Bloch momentum, reflecting a negative coupling between the constituent SPPs. In contrast, for in-phase illumination, the incident beam is split into two collective SPPs that are highly collimated and display low propagation loss. Moreover, the coupling between the individual SPPs results in a reduction of the modal wavelength of the SPP in comparison with that of a single graphene sheet. © 2012 American Physical Society.

Pan D.,CAS Institute of Physics | Wei H.,CAS Institute of Physics | Xu H.,CAS Institute of Physics | Xu H.,Wuhan University | Xu H.,Lund University
Optics Express | Year: 2013

Optical interferometric logic gates in metal slot waveguide network are designed and investigated by electromagnetic simulations. The designed logic gates can realize all fundamental logic operations. A single Y-shaped junction can work as logic gate for four logic functions: AND, NOT, OR and XOR. By cascading two Y-shaped junctions, NAND, NOR and XNOR can be realized. The working principle is analyzed in detail. In the simulations, these gates show large intensity contrast for the Boolean logic states of the output. These results can be useful for future integrated optical computing. © 2013 Optical Society of America.

Liang F.,Wuhan University | Liang F.,Arizona State University | Chen B.,University of California at San Francisco
Current Medicinal Chemistry | Year: 2010

Single-walled carbon nanotubes (SWNTs), a member of the carbon family, are the one-dimensional analogues of zero-dimensional fullerene molecules with unique structural and electronic properties. Since the discovery of SWNTs, they have been extensively studied for biomedical applications. In biological media SWNTs have unique near-infrared intrinsic fluorescence, inherent Raman spectroscopy and photoacoustic signal associated with the graphene in SWNTs which makes them ideal for noninvasive and high sensitivity detection. SWNTs have been broadly investigated as imaging agents for the evaluation of tumor targeting and localization of SWNTs in vitro and in vivo. Rational functionalization can also endow SWNTs with desired properties for biomedical applications. Functionalized SWNTs with significantly reduced toxicity have been employed as carriers to deliver various anticancer drugs, proteins and nucleic acids to the diseased tissues specifically and maximize the bioavailability of the drugs by improving solubility and increasing circulation time. This manuscript will highlight the recent employment of SWNTs in the field of nanomedicine and bioimaging, and also outline the challenges and future opportunities for biomedical applications of SWNTs. © 2010 Bentham Science Publishers Ltd.

Song Z.,Pennsylvania State University | Song Z.,Wuhan University | Xu T.,Pennsylvania State University | Gordin M.L.,Pennsylvania State University | And 6 more authors.
Nano Letters | Year: 2012

Electroactive polymers are a new generation of "green" cathode materials for rechargeable lithium batteries. We have developed nanocomposites combining graphene with two promising polymer cathode materials, poly(anthraquinonyl sulfide) and polyimide, to improve their high-rate performance. The polymer-graphene nanocomposites were synthesized through a simple in situ polymerization in the presence of graphene sheets. The highly dispersed graphene sheets in the nanocomposite drastically enhanced the electronic conductivity and allowed the electrochemical activity of the polymer cathode to be efficiently utilized. This allows for ultrafast charging and discharging; the composite can deliver more than 100 mAh/g within just a few seconds. © 2012 American Chemical Society.

Zhang Y.,Nanjing University of Information Science and Technology | Seidel D.J.,College Park | Zhang S.,Wuhan University
Journal of Climate | Year: 2013

Estimates of trends in planetary boundary layer height over Europe are presented, based on daily radiosonde observations at 25 stations during 1973-2010 and using a bulk Richardson number approach to determine heights. Most stations show statistically significant increases in daytime heights in all four seasons, but fewer show statistically significant trends in nighttime heights. Daytime height variations show an expected strong negative correlation with surface relative humidity and strong positive correlation with surface temperature at most stations studied, on both year-to-year and day-to-day time scales. Similar relations hold for long-term trends: increasing daytime boundary layer height is associated with decreasing surface relative humidity and increasing surface temperature atmost stations. The extent towhich these changes are regionally representative or local reflections of environmental changes near the observing stations is difficult to ascertain. © 2013 American Meteorological Society.

Zhu H.,Hong Kong University of Science and Technology | Zhang L.M.,Hong Kong University of Science and Technology | Zhang L.L.,Shanghai JiaoTong University | Zhou C.B.,Wuhan University
Computers and Geotechnics | Year: 2013

The permeability function for a soil may change spatially due to uncertainties in soil fabric. The main objective of this paper is to investigate how the spatial variability of permeability function propagates to the variability of the pore-water pressures and groundwater table in a slope as well as the stability of the slope. A random field analysis method is explored by assigning discrete random values to a 2D space and controlling the density of random field grid to improve the calculation accuracy. Sequences of random numbers are generated using fast Fourier transform. In a given heterogeneous slope subject to steady-state rainfall infiltration, a parametric study shows that the matric suctions are 0.5-1.25 times those in a homogeneous slope when the correlation length of log-permeability varies from 0.4 to 50 times the slope height. The groundwater table is no longer unique with a spatially variable permeability function. There exists a critical correlation length approximately five times the slope height at which the change in the groundwater table is maximal and the mean factor of safety is minimal. The mean factor of safety of the heterogeneous slopes is smaller than that of a homogenous slope with mean input parameters. The spatial variability of soil influences the range of the calculated factor of safety significantly but does not influence the mean factor of safety substantially. © 2012 Elsevier Ltd.

Massachusetts Institute of Technology, Wuhan University and Shanghai JiaoTong University | Date: 2014-03-13

This invention relates to methods, compositions, and kits for enzymatic phosphorothioation of the sugar-phosphate backbone of nucleic acids. The invention allows for phosphorothioation of pre-existing nucleic acids.

Cao Y.,Pacific Northwest National Laboratory | Cao Y.,Wuhan University | Xiao L.,Pacific Northwest National Laboratory | Wang W.,Pacific Northwest National Laboratory | And 6 more authors.
Advanced Materials | Year: 2011

Single crystalline Na 4Mn 9O 18 nanowires are prepared with a polymer-pyrolysis method. This material shows a high, reversible sodium ion insertion/extraction capacity, excellent cycling ability, and promising rate capability for sodium-ion battery applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

JUPITER, FL - November 21, 2016 - While there have been advances in the treatment of hormone-driven breast cancer, resistance to these therapies remains a significant problem. Side effects, including an increased risk of uterine cancer among postmenopausal women, also severely curtail their use for prevention. However, a new study by scientists from the Florida campus of The Scripps Research Institute (TSRI) offers a novel structure-based drug design strategy aimed at altering the basic landscape of this type of breast cancer treatment. The findings show that the current approach is not the only, or even the best way, to block the estrogen receptor. "We have created a different approach that gives us a mechanism to produce new types of therapeutic molecules," said TSRI Associate Professor Kendall Nettles. "There are a lot of ways to avoid resistance and other cancer risks, and this gives us a tool box full of alternative approaches that could limit or eliminate those effects." "With the standard method, no one understands the structural basis," he continued. "With our approach we know exactly how we did it. If you can see the shape of the receptor protein and see how the drug works on it, that makes the development process that much faster." The findings were published November 21, 2016, by the journal Nature Chemical Biology. The current method of creating this class of drugs, which includes tamoxifen, involves attaching a bulky cluster of atoms with a chainlike structure (called, appropriately, a side chain) to molecules that disrupt the estrogen receptor binding site. The team's strategy taps a technique called x-ray crystallography to visualize the drug candidate as it binds to the receptor. This image is used to guide the production of estrogen receptor degraders that also lack the side chain, helping to reduce the risk of resistance and the development of other cancers. "Our structure-trapping approach to X-ray crystallography provides a molecular snapshot of how subtle changes to a compound series generate a range of graded activity profiles," said Research Associate Jerome C. Nwachukwu, who was co-first author with Research Associate Sathish Srinivasan. "This structurally distinct mechanism, acting indirectly rather than involvement of the typical side chain, provides a new way to design biologically distinct molecules for breast cancer prevention and treatment." The new method also makes it possible to identify structural rules for how the molecules interact. "This is the first example of a structure-based design strategy targeting the estrogen receptor where there is a clear correlation between the chemistry, crystal structure and activity, which is another big advance that will be of broad interest to the cancer community," Srinivasan said. "We show that indirect antagonism can result in inhibition of proliferation in a predictive fashion." In addition to Nettles, Srinivasan and Nwachukwu, other authors of the study, "Full Antagonism of the Estrogen Receptor without a Prototypical Ligand Side Chain," include Nelson E. Bruno, Venkatasubramanian Dharmarajan, Devrishi Goswami, Scott Novick, Jason Nowak and Patrick R Griffin of TSRI; Irida Kastrati, Nittaya Boonmuen, Yuechao Zhao, Benita S. Katzenellenbogen and John A. Katzenellenbogen, Jian Min and Jonna Frasor of the University of Illinois; Hai-Bing Zhou of Wuhan University (China). The study was supported by the National Institutes of Health (grants PHS 5R37DK015556, 5R33CA132022, 5R01DK077085, 1U01GM102148 and 5R01CA130932); the Breast Cancer Research Foundation, BallenIsles Men's Golf Association, Frenchman's Creek Women for Cancer Research, Susan G. Komen for the Cure® (grant PDF12229484), the National Natural Science Foundation of China (grants 81172935, 81373255 and 81573279) and Hubei Province's Outstanding Medical Academic Leader Program. The Scripps Research Institute (TSRI) is one of the world's largest independent, not-for-profit organizations focusing on research in the biomedical sciences. TSRI is internationally recognized for its contributions to science and health, including its role in laying the foundation for new treatments for cancer, rheumatoid arthritis, hemophilia, and other diseases. An institution that evolved from the Scripps Metabolic Clinic founded by philanthropist Ellen Browning Scripps in 1924, the institute now employs more than 2,500 people on its campuses in La Jolla, CA, and Jupiter, FL, where its renowned scientists--including two Nobel laureates and 20 members of the National Academy of Science, Engineering or Medicine--work toward their next discoveries. The institute's graduate program, which awards PhD degrees in biology and chemistry, ranks among the top ten of its kind in the nation. For more information, see http://www. .

News Article | October 26, 2016
Site: www.eurekalert.org

(Boston)--Researchers have determined that two Phase 1 drugs (CX-4945 and JQ1) can work together to efficiently kill T-cell acute lymphoblastic leukemia cells while having minimal impact on normal blood cells. Although both drugs were previously tested as single agents in clinical trials to treat cancers, the success of the combined actions on cancer cells was previously unknown until now. The findings appear in the journal Haematologica. Acute lymphoblastic leukemia, also known as acute lymphocytic leukemia or acute lymphoid leukemia, is a form of cancer of the white blood cells, characterized by the overproduction and accumulation of cancerous, immature white blood cells, known as lymphoblasts. Despite treatment improvement, T-cell leukemia remains fatal in 20 percent of pediatric and 50 percent of adult patients. Both CX-4945 and JQ1 are in clinical trials now as single agents to treat solid and hematological cancers. "Previous studies provided us a rationale to test the combination of CX-4945 and JQ1 on refractory/relapsed T-cell leukemia," said corresponding author Hui Feng, MD, PhD, assistant professor of pharmacology & experimental therapeutics at Boston University School of Medicine (BUSM). "Our findings suggest that the combination treatment of CX-4945 and JQ1 could be an effective strategy to target refractory/relapsed T-cell leukemia," she added. According to the researchers the efficacy of using a combination of JQ1 and CX-4945 in treating other cancers should also be investigated. This research was led by Haiwei Lian, a co-trained PhD candidate in Feng's laboratory and Dr. Hui Fu's laboratory at Wuhan University (China), through a close collaboration with the late Dr. David Seldin and Dr. Esther Landesman at BUSM. Funding for this study was provided by Boston University, the National Institutes of Health, the Leukemia Research Foundation, the St. Baldrick Foundation, the Rally Foundation and the Alex Lemonade Stand Foundation.

Yin H.,Hong Kong University of Science and Technology | Yin H.,Wuhan University | He Y.,ENSTA ParisTech | Sun Q.,Hong Kong University of Science and Technology
Journal of the Mechanics and Physics of Solids | Year: 2014

Distinctive temperature and stress oscillations can be observed in superelastic shape memory alloys (SMAs) when they subject to displacement-controlled cyclic phase transition. In this paper, we examine the effect of the deformation frequency on the thermal and mechanical responses of the polycrystalline superelastic NiTi rods under stress-induced cyclic phase transition. By synchronized measurement of the evolutions in overall temperature and stress-strain curve over the frequency range of 0.0004-1 Hz (corresponding average strain rate range of 4.8×10-5/s-1.2×10 -1/s) in stagnant air, it was found that both the temperature evolution and the stress-strain curve vary significantly with the frequency and the number of cycles. For each frequency, steady-state cyclic thermal and mechanical responses of the specimen were reached after a transient stage, exhibiting stabilization. In the steady-state, the average temperature oscillated around a mean temperature plateau which increased monotonically with the frequency and rose rapidly in the high frequency range due to the rapid accumulation of hysteresis heat. The oscillation was mainly caused by the release and absorption of latent heat and increased with the frequency, eventually reaching a saturation value. The variations in the stress responses followed similar frequency dependence as the temperature. The steady-state stress-strain hysteresis loop area, as a measure of the materials damping capacity, first increased then decreased with the frequency in a non-monotonic manner. The experimental data were analyzed and discussed based on the simplified lumped heat transfer analysis and the Clausius-Clapeyron relationship, incorporating the inherent thermomechanical coupling in the materials response. We found that, for given material's properties and specimen geometries, all such frequency-dependent variations in temperature, stress and damping capacity were essentially determined by the competition between the time scale of the heat release (i.e. the phase transition frequency) and the time scale of the heat transfer to the ambient. The results emphasize that, the two time scales of loading and heat transfer must be clearly specified when characterizing and modeling the cyclic behavior of SMA materials. © 2014 Elsevier Ltd.

Jia B.,Wuhan University | Mei Y.,Nanjing Southeast University | Cheng L.,Wuhan University | Zhou J.,Wuhan University | Zhang L.,Wuhan University
ACS Applied Materials and Interfaces | Year: 2012

Regenerated cellulose (RC) films coated with copper (Cu) nanoparticles were prepared from cellulose-cuprammonium solution through coagulation in aq. NaOH and subsequent reduction in aq. NaBH 4. Structure and morphology of the nanocomposite films were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The results established the migration of Cu 2+ from the inner to the surface of the RC films during the coagulation of cellulose-cuprammonium solution and the reduction from Cu 2+ to Cu 0. Cu nanoparticles were found to be firmly embedded on the surface of the RC films. The RC films coated with Cu nanoparticles showed efficient antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The dramatic reduction of viable bacteria could be observed within 0.5 h of exposure, and all of the bacteria were killed within 1 h. © 2012 American Chemical Society.

Ma Z.M.,Wuhan University | Ma Z.M.,Linyi Normal University | Hu B.Q.,Wuhan University
Information Sciences | Year: 2013

This paper builds the topological and lattice structures of L-fuzzy rough sets by introducing lower and upper sets. In particular, it is shown that when the L-relation is reflexive, the upper (resp. lower) set is equivalent to the lower (resp. upper) L-fuzzy approximation set. Then by the upper (resp. lower) set, it is indicated that an L-preorder is the equivalence condition under which the set of all the lower (resp. upper) L-fuzzy approximation sets and the Alexandrov L-topology are identical. However, associating with an L-preorder, the equivalence condition that L-interior (resp. closure) operator accords with the lower (resp. upper) L-fuzzy approximation operator is investigated. At last, it is proven that the set of all the lower (resp. upper) L-fuzzy approximation sets forms a complete lattice when the L-relation is reflexive. © 2012 Published by Elsevier Inc. All rights reserved.

Liu X.,Hong Kong University of Science and Technology | Long Y.-Z.,Hong Kong University of Science and Technology | Long Y.-Z.,Qingdao University | Liao L.,Wuhan University | And 2 more authors.
ACS Nano | Year: 2012

High-performance flexible electronics has attracted much attention in recent years due to potential applications in flexible displays, artificial skin, radio frequency identification, sensor tapes, etc. Various materials such as organic and inorganic semiconductor nanowires, carbon nanotubes, graphene, etc. have been explored as the active semiconductor components for flexible devices. Among them, inorganic semiconductor nanowires are considered as highly promising materials due to their relatively high carrier mobility, reliable control on geometry and electronic properties, and cost-effective synthesis processes. In this review, recent progress on the assembly of high-performance inorganic semiconductor nanowires and their applications for large-scale flexible electronics will be summarized. In particular, nanowire-based integrated circuitry and high-frequency electronics will be highlighted. © 2012 American Chemical Society.

Yan P.,Hong Kong University of Science and Technology | Wang X.S.,Hong Kong University of Science and Technology | Wang X.R.,Hong Kong University of Science and Technology | Wang X.R.,Wuhan University
Physical Review Letters | Year: 2011

The spin-wave transportation through a transverse magnetic domain wall (DW) in a magnetic nanowire is studied. It is found that the spin wave passes through a DW without reflection. A magnon, the quantum of the spin wave, carries opposite spins on the two sides of the DW. As a result, there is a spin angular momentum transfer from the propagating magnons to the DW. This magnonic spin-transfer torque can efficiently drive a DW to propagate in the opposite direction to that of the spin wave. © 2011 American Physical Society.

Ahadi A.,Hong Kong University of Science and Technology | Ahadi A.,Wuhan University | Sun Q.,Hong Kong University of Science and Technology
Acta Materialia | Year: 2014

We investigated the effects of grain size on the rate-dependent thermomechanical responses of polycrystalline superelastic NiTi (with an average grain size from 10 to 90 nm) under both monotonic and cyclic tensile loading-unloading. Measurements of stress-strain curves, hysteresis loop area, and temperature fields are synchronized using in situ infrared thermography in the strain rate range from ε̇ = 4 × 10-5 s -1 to ε̇ = 1 × 10-1 s-1. It is found that with the grain size reduction to the nanoscale, the rate dependence of the transformation stress and the hysteresis loop area gradually weakens and finally tends to vanish for a grain size of 10 nm. Under cyclic loading, the non-isothermal cyclic stability of the polycrystal is significantly improved as manifested by 64% reduction in heat accumulation and 91% reduction in stress variations when the grain size is reduced from 90 to 27 nm. It is shown that such significant improvements in the cyclic stability and decrease of the rate sensitivity (while preserving large (≈5%) recoverable strain) originate from the rapid decrease of internal heat sources (the latent heat and the hysteresis heat) and the rapid decrease of the temperature dependence of the transformation stress with the grain size. This work strongly implies that the heat accumulation in cyclic loading of superelastic NiTi SMAs, as one of the sources of poor fatigue response, can be reduced by extreme grain refinement. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Wu P.,Anhui University | Shen H.,Wuhan University | Zhang L.,Wuhan University | Gottsche F.-M.,Karlsruhe Institute of Technology
Remote Sensing of Environment | Year: 2015

Land surface temperature (LST) and its diurnal variation are important when evaluating climate change, the land-atmosphere energy budget, and the global hydrological cycle. However, the available satellite LST products have either a coarse spatial resolution or a low temporal resolution, which constrains their potential applications. This paper proposes a spatio-temporal integrated temperature fusion model (STITFM) for the retrieval of high temporal and spatial resolution LST from multi-scale polar-orbiting and geostationary satellite observations. Compared with the traditional fusion methods for LST with two different sensors, the proposed method is able to fuse the LST from arbitrary sensors in a unified framework. The model was tested using LST with fine, moderate, and coarse-resolutions. Data from the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM. +) sensors, the Moderate Resolution Imaging Spectroradiometer (MODIS), the Geostationary Operational Environmental Satellite (GOES) Imager, and the Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) were used. The fused LST values were evaluated with in situ LST obtained from the Surface Radiation Budget Network (SURFRAD) and the Land Surface Analysis Satellite Application Facility (LSA SAF) project. The final validation results indicate that the STITFM is accurate to within about 2.5. K. © 2014 Elsevier Inc.

Wan L.,Wuhan University | Liu H.,Wuhan University | Skala D.,University of Belgrade
Applied Catalysis B: Environmental | Year: 2014

The MnCO3/ZnO catalyst with different Mn/Zn molar ratio were prepared using co-precipitation method and used for biodiesel synthesis in subcritical methanol. Prepared catalyst samples were characterized by basic strength, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The triglyceride (TG) conversion and fatty acid methyl ester (FAME) yield were determined using high performance liquid chromatography (HPLC). The effects of Mn/Zn molar ratio, calcination temperature and time, catalyst amount, molar ratio of methanol to oil, and transesterification reaction temperature and time, in regards to the catalyst activity were investigated. Results showed that a maximum TG conversion of 99.25% and FAME yield of 94.20% were obtained using MnCO3/ZnO catalyst (Mn/Zn molar ratio of 1:1) calcined at 573K for 0.5h under such reaction conditions for biodiesel synthesis as 4wt% of catalyst, methanol/oil molar ratio of 18:1, reaction temperature of 448K, and reaction time of 1h. The catalyst kept TG conversion above 91.54% and FAME yield above 86.26% after 17-cycle reuse in batch reaction without regeneration processes. Further reuse of catalyst is followed by deactivation mainly caused by the transformation of small particle ZnO to lamellate zinc glycerolate. © 2014 Elsevier B.V.

Jiang S.-H.,Wuhan University | Li D.-Q.,Wuhan University | Zhang L.-M.,Hong Kong University of Science and Technology | Zhou C.-B.,Wuhan University
Engineering Geology | Year: 2014

This paper proposes a non-intrusive stochastic finite element method for slope reliability analysis considering spatially variable shear strength parameters. The two-dimensional spatial variation in the shear strength parameters is modeled by cross-correlated non-Gaussian random fields, which are discretized by the Karhunen-Loève expansion. The procedure for a non-intrusive stochastic finite element method is presented. Two illustrative examples are investigated to demonstrate the capacity and validity of the proposed method. The proposed non-intrusive stochastic finite element method does not require the user to modify existing deterministic finite element codes, which provides a practical tool for analyzing slope reliability problems that require complex finite element analysis. It can also produce satisfactory results for low failure risk corresponding to most practical cases. The non-intrusive stochastic finite element method can efficiently evaluate the slope reliability considering spatially variable shear strength parameters, which is much more efficient than the Latin hypercube sampling (LHS) method. Ignoring spatial variability of shear strength parameters will result in unconservative estimates of the probability of slope failure if the coefficients of variation of the shear strength parameters exceed a critical value or the factor of slope safety is relatively low. The critical coefficient of variation of shear strength parameters increases with the factor of slope safety. © 2013 Elsevier B.V.

Shanxi Jincheng Power Supply Company, State Grid Corporation of China, Wuhan University and Taiyuan Zhongtianxing Electrical Power Technology Co. | Date: 2013-09-09

An RTV anti-pollution flashover coating, and preparation method, includes components of the following weight parts: polydimethylsiloxane 100 parts, a reinforcing filler 4 to 10 parts, a catalyst 0.1 to 1 part, a crosslinking agent 1 to 5 parts, a hydrophobic agent 3 to 6 parts, a pigment 1 to 2 parts, decabromodiphenyl ether 1 to 2 parts, and toluene 30 to 40 parts. The hydrophobic agent is a mixture of a substance having a structure represented by Formula I and any one or more of a low-molecular weight silicone oil, dihydroxydiphenyl silane, fluorine-containing silicone oil and white oil. In Formula I, R is any one of acetoxy CH_(3)COO, methoxy CH_(3)O, ketoximo MeEtCNO, an amide group AcMeN, amino C_(6)H_(11)NH and acetonyl H_(2)CCMeO; R^(1)Si is a polysiloxane group or a fluorine-containing siloxane group, and has a structural formula represented by Formula II, where n=1 to 4, and R_(2 )is CH_(3) or CF_(3).

Adoko A.C.,CAS Wuhan Institute of Rock and Soil Mechanics | Gokceoglu C.,Hacettepe University | Wu L.,Wuhan University | Zuo Q.J.,Wuhan University
International Journal of Rock Mechanics and Mining Sciences | Year: 2013

Since rockburst is a violent expulsion of rock in high geostress condition, this causes considerable damages to underground structures, equipments and most importantly presents serious menaces to workers' safety. Rockburst has been associated with thousands of accidents and casualties recently in China. Due to this importance, this research was intended to predict rockburst intensity based on fuzzy inference system (FIS) and adaptive neuro-fuzzy inference systems (ANFIS), and field measurements data. A total of 174 rockburst events were compiled from various published research works. Five different models were investigated. The maximum tangential stress, the uniaxial compressive strength, the uniaxial tensile strength of the surrounding rock and the elastic strain energy index were considered as the inputs while the actual rockburst intensity was the output. In some models, the inputs were extended to the stress coefficient and the rock brittleness coefficient. The results obtained from the study conclude that the knowledge-based FIS model shows lowest performance with 45.8%, 13.2%, 16.5% and 66.52% of the variance account for (VAF), root-mean square error (RMSE), mean absolute percentage error (MAPE) and the percentage of the successful prediction (PSP) indices, while the ANFIS model indicates the best performance with 92%, 1.71%, 0.94% and 95.6% of VAR, RMSE, MAPE and PSP indices, respectively. These results suggest that the developed models in the present study can be used for the rockburst prediction, and this may help to reduce the casualties sourced from the rockbursts. © 2013 Elsevier Ltd.

News Article | February 15, 2017
Site: www.marketwired.com

LOS ANGELES, CA--(Marketwired - February 15, 2017) - Sheppard, Mullin, Richter & Hampton LLP is pleased to announce that the firm has elevated fifteen of its attorneys to partner. The new partners are Frank A. Bacelli (Washington, D.C.), Dylan I. Ballard (San Francisco), Paul Berkowitz (Century City), Rachelle A. Costa (San Diego (Del Mar)), David D'Amour (Orange County), Anna T. Dorros (San Diego), Lisa M. Harris (Century City and New York), Jeff Kern (New York), Nam H. Kim (San Diego (Del Mar)), Jennifer Lee (Los Angeles), Marisa B. Miller (San Diego (Del Mar)), Lynsey Mitchel (Century City), Alex Y. Nie (Palo Alto), James F. Ritter (Washington, D.C.) and Karin Dougan Vogel (San Diego). Frank Bacelli is a member of the Corporate practice group in the firm's Washington, D.C. office. Bacelli focuses his practice on private equity, mergers and acquisitions, and venture capital matters. His practice involves a full range of corporate transactions, including leveraged buyouts and recapitalizations, mergers and acquisitions, venture and growth equity financings, and joint ventures. Bacelli has extensive experience as lead counsel representing portfolio companies of sponsor funds in add-on acquisitions, dispositions, corporate governance, and day-to-day legal and commercial matters. Bacelli received a J.D., magna cum laude, from Catholic University of America Columbus School of Law in 1999 and a B.A., cum laude, from University at Buffalo in 1995. Dylan Ballard is a member of the Antitrust and Competition practice group in the firm's San Francisco office. Ballard specializes in complex business litigation and white collar criminal matters, with an emphasis on antitrust and unfair competition issues. He has significant experience defending U.S. and multinational businesses in all phases of class action litigation, as well as in civil and criminal proceedings involving federal, state, and foreign enforcement agencies. Ballard received a J.D. from University of California, Hastings in 2007 and a B.A., with highest honors, from University of California, Santa Barbara in 2003. Paul Berkowitz is a member of the Labor & Employment practice group in the firm's Century City office. Berkowitz's practice involves representing employers in all aspects of labor and employment litigation in defense of wage and hour class actions and single-plaintiff harassment, discrimination, retaliation, and wrongful termination cases. He has won summary judgment and successfully defeated class certification in state and federal court. In addition to his litigation practice, Berkowitz provides clients with practical advice on a wide range of day-to-day employment law issues, including establishing effective human-resource policies and complying with federal and state laws, such as those relating to wage and hour issues, family/medical leave laws, and the discipline and termination processes. Berkowitz received a J.D., Order of the Coif, from University of California, Los Angeles in 2007 and a B.A., cum laude, from University of Arizona in 2004. Rachelle Costa is a member of the Real Estate, Land Use and Environmental practice group in the firm's San Diego (Del Mar) office. Costa represents residential and commercial real estate developers in connection with the creation of master planned communities, condominium, planned developments, custom lot subdivisions, high-rise developments, and commercial centers. She has expertise in processing residential subdivisions with the California Bureau of Real Estate and creating sales, marketing and governance documents for use by residential developers on a national basis. Costa's practice also encompasses general real estate transactions including land use, entitlement, and purchase and sale. Costa received a J.D. from University of California, Davis in 2001 and a B.A. in 1997. David D'Amour is a member of the Finance and Bankruptcy practice group in the firm's Orange County office. D'Amour represents clients in a broad range of financing transactions, including secured and unsecured credit facilities, real property secured transactions and asset-based facilities. He is also an active member of Sheppard Mullin's hospitality team, and has experience negotiating hotel management agreements, SNDAs, license agreements and related commercial agreements. D'Amour received a J.D., with high honors, from Chicago-Kent College of Law, Illinois Institute of Technology in 2007 and a B.S., cum laude, from Boston University School of Management in 2004. Anna Dorros is a member of the Real Estate, Land Use and Environmental practice group in the firm's San Diego office. Dorros has worked extensively with residential and commercial developers in connection with the developing and processing of residential, mixed-use, commercial and master planned developments. She has specialized expertise in California Bureau of Real Estate regulatory compliance matters. Dorros received a J.D. from University of California, Los Angeles in 2002 and a B.A. from Georgetown University in 1997. Lisa Harris is a member of the Labor and Employment practice group in the firm's Century City and New York offices. Harris counsels and represents management in both employment and traditional labor matters. She regularly counsels management in all aspects of employment law, including employee hiring and discipline procedures, restrictive covenants, worker classification issues, leaves of absence, wage and hour compliance, and employee severance and termination procedures. She represents employers in single and multi-plaintiff harassment and discrimination claims. Harrris also assists employers in resisting unwelcome labor union organizing drives. Harris received a J.D. from St. John's University in 2007 and a B.A. from University of California, Berkeley in 2003. Jeff Kern is a member of the Government Contracts, Investigations, and International Trade practice group in the firm's New York office. Kern's practice encompasses securities and insurance regulation, compliance, and litigation as well as internal investigations and white collar defense. He represents broker-dealers and associated individuals who are the focus of SEC, FINRA and other regulatory investigations and provides guidance in the FINRA membership application and business expansion process. Before joining Sheppard Mullin, Kern served as Senior Regional Counsel in FINRA's Department of Enforcement and Senior Trial Counsel in the New York Stock Exchange Enforcement Division. Kern received a J.D. from Duke University School of Law in 1987 and a B.A., magna cum laude, from Boston College in 1984. Nam Kim is a member in the Intellectual Property practice group in the firm's San Diego (Del Mar) office. Kim's practice focuses on patent litigation, patent preparation and prosecution, ex parte reexamination, AIA post-grant review proceedings, and IP counseling. He is involved in patent litigation matters to defend clients' IP rights against infringers and defend clients against alleged infringements. He also has extensive experience in preparing and prosecuting patent applications and provides strategic IP counseling. Mr. Kim also represents clients in reexamination and inter partes review proceedings. Kim received a J.D., cum laude, from University of Illinois College of Law in 2007, a M.S. in Physics from Cornell University in 1990 and a B.S., with honors, in Physics from Stanford University in 1985. Jennifer Lee is a member of the Corporate practice group in the firm's Los Angeles office. Lee enjoys a global practice representing public and private companies, particularly in the United States and Korea. Lee's practice covers a variety of industries, including entertainment and media, technology, manufacturing and financial services. She has represented companies in a variety of corporate transactions, including mergers and acquisitions, public and private equity and debt offerings, venture capital investments, strategic alliances and other general corporate matters. In addition, Lee has advised entrepreneurs and start-up ventures in connection with formation and general corporate matters. She has also counseled public and private companies in all aspects of corporate governance. Lee received from University of California, Los Angeles a J.D. in 2007 and a B.A., summa cum laude, Phi Beta Kappa, in 2004. Marisa Miller is a member of the Business Trial practice group in the firm's San Diego (Del Mar) office. Miller specializes in complex business litigation with a focus on energy, environmental and construction matters. She has experience handling matters in all stages of litigation, from pre-lawsuit strategy and advice to post-trial motions and appeals. Her practice also includes international and domestic arbitration, as well as regulatory matters. Miller's practice often involves high stakes business disputes and complex damages claims. Miller received a J.D. from Northwestern University School of Law in 2006 and a B.A. from University of Pennsylvania in 2002. Lynsey Mitchel is a member of the Corporate practice group in the firm's Century City office. Mitchel represents hospitals, managed care organizations, medical groups, pharmacies, home health providers, medical device retailers and other healthcare entities and providers. She has deep expertise in HMO regulatory matters and has assisted numerous clients to obtain HMO licensure as healthcare service plans under California's Knox-Keene Health Care Service Plan Act. Mitchel has represented approximately half of all currently licensed restricted Knox-Keene HMO license holders in California in their licensure process. Mitchel received a J.D., cum laude, from Pepperdine University in 2004, a M.P.H., from University of California, Los Angeles in 2001 and a B.A., magna cum laude, Texas Tech University in 1999. Alex Nie is a member of the Intellectual Property practice group in the firm's Palo Alto office. Nie's practice focuses on global intellectual property (IP) protection strategy and technology transfer issues, including patent procurement and enforcement, IP valuation and monetization, licensing, and technology transfer. His multidisciplinary technical background enables him to advise a broad spectrum of technology companies on patent issues. Nie received a J.D. from Rutgers School of Law in 2008, a Ph.D. from Rutgers University in 2001, a M.S. from Rutgers University in 2001, a M.S. from University of Science and Technology of China in 1996 and a B.S. from Wuhan University in 1993. Jim Ritter is a member of the Corporate practice group in the firm's Washington, D.C. office. Ritter has extensive experience in negotiating a wide variety of financing arrangements, including senior secured loans (both asset-based and cash flow loans) and mezzanine and other subordinated debt, secured high yield securities, acquisition financings, working capital financings, equipment leasing and other vendor finance transactions, letters of credit, derivatives contracts, and venture capital and other equity investments. Ritter received a J.D., Order of the Coif, from University of Virginia School of Law in 1986 and a B.A., cum laude, from Dartmouth College in 1981. Karin Dougan Vogel is the firm's Appellate practice leader and a member of the Business Trial practice group in the firm's San Diego office. Vogel is a Certified Specialist in Appellate Law. She has extensive experience in appeals and writs on matters involving a broad range of complex business litigation, including business related torts and contract actions, land use disputes, partnership disputes, labor law matters, bankruptcy matters, financial institutions related actions, environmental issues, arbitration issues, class action issues, federal statutory and constitutional issues, and other complex commercial disputes. Vogel practices both in state and federal appellate courts, in all aspects of the appellate process. Vogel received a J.D., cum laude, from Georgetown University in 1986 and a B.A., Union College, highest honors, in 1981. Sheppard Mullin is a full service Global 100 firm with 780 attorneys in 15 offices located in the United States, Europe and Asia. Since 1927, companies have turned to Sheppard Mullin to handle corporate and technology matters, high stakes litigation and complex financial transactions. In the U.S., the firm's clients include more than half of the Fortune 100. For more information, please visit www.sheppardmullin.com.

Yu J.,Wuhan University of Technology | Yu J.,King Abdulaziz University | Wang K.,Wuhan University of Technology | Xiao W.,Wuhan University | Cheng B.,Wuhan University of Technology
Physical Chemistry Chemical Physics | Year: 2014

Photocatalytic reduction of CO2 into renewable hydrocarbon fuels is an alternative way to develop reproducible energy, which is also a promising way to solve the problem of the greenhouse effect. In this work, graphitic carbon nitride (g-C3N4) was synthesized by directly heating thiourea at 550 °C and then a certain amount of Pt was deposited on it to form g-C3N4-Pt nanocomposites used as catalysts for photocatalytic reduction of CO2 under simulated solar irradiation. The main products of photocatalysis were CH4, CH3OH and HCHO. The deposited Pt acted as an effective cocatalyst, which not only influenced the selectivity of the product generation, but also affected the activity of the reaction. The yield of CH4 first increased upon increasing the amount of Pt deposited on the g-C3N4 from 0 to 1 wt%, then decreased at 2 wt% Pt loading. The production rates of CH 3OH and HCHO also increased with the content of Pt increasing from 0 to 0.75 wt% and the maximum yield was observed at 0.75 wt%. The Pt nanoparticles (NPs) could facilitate the transfer and enrichment of photogenerated electrons from g-C3N4 to its surface for photocatalytic reduction of CO2. At the same time, Pt was also used a catalyst to promote the oxidation of products. The transient photocurrent response further confirmed the proposed photocatalytic reduction mechanism of CO2. This work indicates that the deposition of Pt is a good strategy to improve the photoactivity and selectivity of g-C3N4 for CO2 reduction. © 2014 the Partner Organisations.

Yuan Z.,Florida State University | Liang F.,Wuhan University of Science and Technology | Liang F.,Wuhan University
Current Organic Chemistry | Year: 2014

The recent advances in the development and application of amphiphilic photomicroreactors with “soft” cavities in terms of supramolecular chemistry are reviewed. In this article, we describe how these microreactors alter the photochemical behavior of guests inside their “soft” confined and restrict microenvironment. The main aim is to show the different types of amphiphilic microreactors, the photoreactions occurring within them and the great promise of these microreactors. Finally a comparison between the “soft” cavities and “hard” cavities (such as zeolite, cage molecules, etc.) as well as the current challenges and further directions of these microreactors are also discussed at the end of this review. © 2014 Bentham Science Publishers.

Hu W.,Wuhan University | Liu G.-P.,Harbin Institute of Technology | Zhou H.,University of South Wales
IEEE Transactions on Industrial Electronics | Year: 2013

The design and implementation of Networked Control System Laboratory (NCSLab) 3-D which is a web-based 3-D control laboratory for remote real-time experimentation are introduced in this paper. NCSLab 3-D is built based on the NCSLab framework which supports the structure that the test rigs are located diversely in different parts of the world. In NCSLab 3-D, the test rigs are cataloged into several sublaboratories according to their functionalities. The laboratory building, sublaboratories, and test rigs are modeled in 3-D and reconstructed in a web-based interface using Flash 3-D engines. Users can 'walk into' these laboratories and pick up the test rigs in a virtual reality environment similar to what they do in hands-on laboratories. During the remote experiments, the 3-D models are synchronized with the real test rigs through the network data links. Users are able to zoom in, zoom out, and rotate the 3-D models freely. Therefore, the real-time experiments can be watched from any angles. NCSLab 3-D has been applied to the control engineering education in Wuhan University, China. The results of the teaching practice show that NCSLab 3-D are able to bring great convenience to both users and maintenance personnel and improve the efficiency of the laboratory equipment significantly. © 1982-2012 IEEE.

Chen Z.-Q.,University of Western Australia | Tong J.,Wuhan University | Liao Z.-T.,CAS Nanjing Institute of Geology and Palaeontology | Chen J.,Wuhan University
Global and Planetary Change | Year: 2010

The Permian/Triassic (P/Tr) transition is ecologically assessed based on examining 23 shelly communities from five shallow platform, ramp and shelf basin facies Permian-Triassic boundary (PTB) sections in South China. The shelly communities have undergone two major collapses coinciding with the two episodes of the end-Permian mass extinction. The first P/Tr extinction event devastated shelly communities in all types of settings to some extent. The basin communities have been more severely impacted than both platform and ramp communities. The survival faunas have rebounded more rapidly in shallow niches than in relatively deep habitats. The second P/Tr crisis destroyed the survival communities in shallow setting and had little impact on the basin communities in terms of community structures. The early Griesbachian communities are overall low-diversity and high-dominance. The governorship switch from brachiopods to bivalves in marine communities has been facilitated by two pulses of the end-Permian mass extinction and the whole takeover process took about 200. ka across the P/Tr boundary. Bivalve ecologic takeover initially occurred immediately after the first P/Tr extinction in shallow water habitats and was eventually completed in all niches after the second P/Tr event. Some post-extinction communities have the irregular rarefaction curves due to the unusual community structures rather than sampling intensities. © 2010.

Liao L.,University of California at Los Angeles | Liao L.,Wuhan University | Duan X.,University of California at Los Angeles
Materials Today | Year: 2012

Graphene is emerging as an attractive electronic material for future electronics. With the highest carrier mobility, high saturation velocity, high critical current densities, and single atomic thickness, graphene has great potential for ultra-high speed transistors, with the highest projected cut-off frequency exceeding 1 THz. However, the fabrication of high speed graphene transistors is of significant challenge, since conventional electronic fabrication processes often introduce undesirable defects into graphene lattices. Significant efforts have made to mitigate these challenges. Here we review the opportunities, challenges, as well as the recent advances in the development of high speed graphene transistors and circuits. © 2012 Elsevier Ltd.

Wu X.,Wuhan University | Wang X.,Jilin University | Zhang Y.,Wuhan University | Zhang Y.,Jilin University
ACS Applied Materials and Interfaces | Year: 2013

Nanoworm-like Li2FeSiO4-C composites are synthesized using triblock copolymer Pluronic P123 (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), EO20PO70EO20) as the structure directing agent (SDA) and under the effects of ethanol. As a polar nonaqueous cosolvent, ethanol has effects on the self-organization behavior of Pluronic P123 in water, which determines the final morphologies of the Li2FeSiO4-C composites synthesized. Li 2FeSiO4-C composite nanoparticles are obtained if no ethanol is added into the system during the synthesis process. When tested as lithium-ion battery cathodes, the Li2FeSiO4-C nanoworms show superior electrochemical performances. At the rate of 1 C (1 C = 166 mA g-1) the discharge capacity of the Li2FeSiO4-C nanoworms can reach 166 mAh g-1 in the voltage window of 1.5-4.8 V at room temperature. At the rates of 5, 10, and 20 C, the discharge capacities of the Li2FeSiO4-C nanoworms can stabilize at 120, 110, and 90 mAh g-1, respectively, and do not show obvious declines after hundreds of cycles. This performance of the Li2FeSiO4-C nanoworms at high rates is better than that of the Li2FeSiO 4-C nanoparticles synthesized and many other Li2FeSiO 4/C composites reported in the literature. The excellent electrochemical performances of the Li2FeSiO4-C nanoworms are believed to be related to the small sizes of the Li2FeSiO 4 nanocrystals inside the nanoworms and the carbon that coats and embeds the nanocrystals. © 2013 American Chemical Society.

Zong X.,Wuhan University of Science and Technology | Xiong S.,Wuhan University of Technology | Fang Z.,Wuhan University
Computers and Operations Research | Year: 2014

A simulation model based on temporal-spatial conflict and congestion for pedestrian-vehicle mixed evacuation has been investigated. Assuming certain spatial behaviors of individuals during emergency evacuation, a discrete particle swarm optimization with neighborhood learning factor algorithm has been proposed to solve this problem. The proposed algorithm introduces a neighborhood learning factor to simulate the sub-group phenomenon among evacuees and to accelerate the evacuation process. The approach proposed here is compared with methods from the literatures, and simulation results indicate that the proposed algorithm achieves better evacuation efficiency while maintaining lower pedestrian-vehicle conflict levels. © 2013 Elsevier Ltd.

Wang Y.,Wuhan University of Technology | Yu J.,Wuhan University of Technology | Xiao W.,Wuhan University | Li Q.,Wuhan University of Technology
Journal of Materials Chemistry A | Year: 2014

The construction and application of visible-light-driven photocatalysts falls in the central focus for the efficient utilization of renewable solar energy, which provides unprecedented opportunities for addressing the increasing concerns on energy and environmental sustainability. Herein, graphene based Au-TiO2 photocatalysts were fabricated by a simple, one-step microwave-assisted hydrothermal method, using Degussa P25 TiO2 powder (P25), graphene oxide and HAuCl4 aqueous solution as the raw materials. The effects of graphene introduction and gold loading on the photocatalytic hydrogen production rates of the as-prepared samples in a methanolic aqueous solution were investigated. The results indicated that Au-TiO2-graphene composite had a significantly increased visible light absorption and enhanced photocatalytic H2-production activity compared to the Au-TiO2 composite. In comparison, the pure TiO 2, graphene-TiO2 and graphene-Au had no appreciable visible-light-driven H2 production. The enhanced photocatalytic H2-production activity of the Au-TiO2-graphene composite is ascribed to (1) the load of the Au nanoparticles which broadens the visible light response of TiO2 due to the surface plasmon resonance (SPR) effect, and (2) the introduction of graphene, which functions as rapid electron transfer units, facilitating the space separation of photoelectron and hole pairs. The proposed H2-production activity enhancement mechanism was further confirmed by the transient photocurrent response and electrochemical impedance spectroscopy (EIS) experiments. © 2014 The Royal Society of Chemistry.

Xu J.,Wuhan University | Ben-Avraham Z.,Tel Aviv University | Kelty T.,California State University, Long Beach | Yu H.-S.,National Taiwan University
Earth-Science Reviews | Year: 2014

Geometry of basins can indicate their tectonic origin whether they are small or large. The basins of Bohai Gulf, South China Sea, East China Sea, Japan Sea, Andaman Sea, Okhotsk Sea and Bering Sea have typical geometry of dextral pull-apart. The Java, Makassar, Celebes and Sulu Seas basins together with grabens in Borneo also comprise a local dextral, transform-margin type basin system similar to the central and southern parts of the Shanxi Basin in geometry. The overall configuration of the Philippine Sea resembles a typical sinistral transpressional "pop-up" structure. These marginal basins except the Philippine Sea basin generally have similar (or compatible) rift history in the Cenozoic, but there do be some differences in the rifting history between major basins or their sub-basins due to local differences in tectonic settings. Rifting kinematics of each of these marginal basins can be explained by dextral pull-apart or transtension. These marginal basins except the Philippine Sea basin constitute a gigantic linked, dextral pull-apart basin system.Formation of the gigantic linked dextral pull-apart basin system in the NW Pacific is due to NNE- to ENE-ward motion of east Eurasia. This mainly was a response to the Indo-Asia collision which started about 50. Ma ago. The displacement of east Eurasia can be estimated using three aspects: (1) the magnitude of pull-apart of the dextral pull-apart basin system, (2) paleomagnetic data from eastern Eurasia and the region around the Arctic, and (3) the shortening deficits in the Large Tibetan Plateau. All the three aspects indicate that there was a large amount (1000 to 1200. km) of northward motion of the South China block and compatible movements of other blocks in eastern Eurasia during the rifting period of the basin system. Such a large amount of motion of the eastern Eurasia region contradicts any traditional rigid plate tectonic reconstruction, but agrees with the more recent concepts of non-rigidity of both continental and oceanic lithosphere over geological times. Based on these three estimates, the method developed for restoration of diffuse deformation of the Eurasian plate and the region around the Arctic, and the related kinematics of the marginal basins, we present plate tectonic reconstructions of these marginal basins in global plate tectonic settings at the four key times: 50, 35, 15 and 5. Ma. The plate tectonic reconstructions show that the first-order rift stage and post-rift stage of the marginal basins are correlated with the first-order slow uplift stage and the rapid uplift stage of the Tibetan Plateau, respectively. The proto-Philippine Sea basin was trapped as a sinistral transpressional pop-up structure at a position that was 20° south of its present position at about 50. Ma ago (or earlier). While the Japan arc migrated eastward during the rifting period of the Japan Sea basin, the Shikoku Basin opened and the Parece Vela Basin widened. © 2013 Elsevier B.V.

Chen R.,Wuhan University of Technology | Yu J.,Wuhan University of Technology | Xiao W.,Wuhan University
Journal of Materials Chemistry A | Year: 2013

Hierarchically porous manganese dioxide (MnO2) microspheres were fabricated by a facile hydrothermal method using potassium permanganate as the precursor at different hydrothermal temperatures. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms and Fourier transform infrared (FTIR) spectroscopy. Adsorption of methyl blue (MB) onto the as-prepared samples from aqueous solutions was investigated and discussed. It was found that MnO 2 microspheres were composed of two levels of hierarchical porous organization, viz., mesopores (2-50 nm) and macropores (>50 nm). The equilibrium adsorption data of MB on the as-prepared samples was well fitted with the Freundlich isotherm model. The sample obtained at 80 °C displayed the highest adsorption capacity with 259.2 mg g-1. In addition, adsorption data were fitted using the pseudo-second-order kinetics equation, suggesting that pseudo-second-order kinetics could well represent the adsorption kinetics. The adsorption between MB and MnO2 was mainly attributed to the strong electrostatic attraction force. The as-prepared hierarchically porous MnO2 microspheres turned out to be an effective adsorbent for the removal of MB from effluent because of their unique hierarchical porous microstructure and high specific surface areas. © 2013 The Royal Society of Chemistry.

Mao X.,Wuhan University | Jiang R.,Wuhan University | Xiao W.,Wuhan University | Yu J.,Wuhan University of Technology
Journal of Hazardous Materials | Year: 2015

Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation. © 2014 Elsevier B.V.

Yu J.,Wuhan University of Technology | Wang Y.,Wuhan University of Technology | Xiao W.,Wuhan University
Journal of Materials Chemistry A | Year: 2013

Ordered rutile TiO2 nanorods grown on transparent electro-conductive F-doped SnO2-coated (FTO) glass substrates were prepared by a simple hydrothermal method using tetrabutyl titanate as the precursor and then calcined at various temperatures. The prepared SnO 2/TiO2 composite film samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photoelectrocatalytic (PEC) activity was evaluated by PEC degradation of methylene blue (MB) aqueous solutions under UV-LED light irradiation. The results showed that rutile TiO2 nanorods with diameters of ca. 300-700 nm and lengths of ca. 5 μm vertically grew on the FTO substrate. The resulting rutile TiO2 arrays exhibited excellent stability upon annealing in a temperature range of 300-500 °C. The sample calcined at 400 °C exhibited the highest PEC activity due to the combined effects of several factors including its one-dimensional morphology, high crystallinity, close contact between the TiO2 nanorods and SnO2 layers, SnO2/TiO2 n-n heterojunction and the applied external electrostatic field. The proposed enhanced PEC mechanism was further confirmed by the transient photocurrent response and electrochemical impedance spectroscopy (EIS) experiments. © 2013 The Royal Society of Chemistry.

Li2SrGeO4:RE3+ (RE = Tb/Dy/Ce) phosphors were prepared by the conventional solid-state reaction. X-ray diffraction (XRD), photoluminescence (PL) spectra, and lifetimes were utilized to characterize samples. Under the excitation of ultraviolet (231 nm for Tb3+ and 351 nm for Dy3+), the Li2SrGeO4:Tb3+ and Li2SrGeO4:Dy3+ phosphors show their respective characteristic emissions of Tb3+ (5D 3,4 → 7FJ′, J′ = 3, 4, 5, 6) and Dy3+ (4F9/2 → 6H15/2 and 4F9/2 → 6H13/2), respectively. Ce3+ activated Li 2SrGeO4 phosphors exhibit broad band blue emission due to the 5d-4f transition of Ce3+. Co-doping Ce3+ into the LSG: Ce3+/Dy3+ samples enhances the luminescence intensity of Tb3+ and Dy3+ significantly under the excitation wavelength at 340 nm through energy transfer from Ce3+ to Tb 3+/Dy3+. In addition, the energy transfer mechanism between Ce3+ and Tb3+/Dy3+ has been demonstrated to be a resonant type via a dipole-quadrupole interaction. © 2014 Elsevier B.V. All rights reserved.

Oturan N.,University Paris Est Creteil | Wu J.,Wuhan University | Zhang H.,Wuhan University | Sharma V.K.,Florida Institute of Technology | Oturan M.A.,University Paris Est Creteil
Applied Catalysis B: Environmental | Year: 2013

This paper presents the removal of the antibiotic tetracycline (TeC) from water using electrochemical advanced oxidation processes (EAOPs); namely electrochemical oxidation (EO) and electro-Fenton (EF). The effect of different cathode materials (carbon-felt and stainless steel) on the direct/indirect electro-oxidation of tetracycline, and that of different anode materials (Ti/RuO2-IrO2, Pt and BDD) on both processes was systematically investigated for the first time. The EO process was found to be more efficient in using the carbon-felt cathode than the stainless steel cathode. The EO and the EF processes using BDD anode demonstrated superior oxidation/mineralization power. Almost total mineralization (TOC removal up to 98%) of 100mgL-1 TeC solutions was achieved after 6h treatment either by EO and/or EF treatment with BDD anode. The oxidative degradation of TeC followed pseudo-first-order-reaction kinetics in using all tested electrodes and anode/cathode configurations. Apparent rate constants of different anode/cathode configurations increased in the following sequence: Ti/RuO2-IrO2/stainless steel

Liu X.,Chinese Academy of Geological Sciences | Jahn B.-M.,National Taiwan University | Li S.,Ocean University of China | Liu Y.,Wuhan University
Tectonophysics | Year: 2013

The Tongbai orogen is located in a key tectonic position linking the Qinling orogen to the west and the Dabie-Sulu orogen to the east. This orogen comprises a Paleozoic accretionary orogenic system in the north and a Permo-Triassic collisional orogenic system in the south; hence it may serve as an ideal place to unravel the tectonic evolution from the initial oceanic subduction/accretion to the final continental collision between the Sino-Korean and Yangtze cratons. U. Pb zircon geochronology of metasedimentary and metaigneous rocks and geochemical characterization of metabasalts indicate a close genetic relationship between the individual tectonic units of the Paleozoic accretionary orogenic system: (1) the Kuanping Group as a Neoproterozoic-Ordovician subduction-accretion complex which received sediments from the Qinling microcontinent, (2) the Erlangping Group and Huanggang diorite-granodiorite complex as an Ordovician-Silurian island arc evolving from backarc basin, (3) the Qinling Group as a Precambrian microcontinent converted into continental arc during the Ordovician, (4) the Guishan Complex as a mixture of the Qinling continental arc and Devonian forearc sediments, and (5) the Nanwan Flysch as a Devonian forearc sequence deposited on the newly accreted active margin of the Sino-Korean craton. Consequently, the northern and southern boundaries of the Paleozoic accretionary orogenic system represent two sutures of the Qinling microcontinent with the Sino-Korean and Yangtze cratons. The new and previously published data reveal that the tectonic evolution of the Tongbai orogen involved a series of events from Ordovician-Early Silurian (ca 490-440 Ma) oceanic subduction and arc magmatism, Silurian-Early Devonian (ca. 440-400. Ma) arc-continent collision, Carboniferous (ca 340-310 Ma) oceanic subduction and accretion, Late Permian-Triassic (ca 260-200 Ma) continental subduction and collision, to Cretaceous (ca. 140-90. Ma) extension and lateral eastward extrusion. The entire accretionary orogenic processes until the final collision between the Sino-Korean and Yangtze cratons may have lasted more than 200. Ma. © 2013.

Lan Z.-W.,CAS Institute of Geology and Geophysics | Chen Z.-Q.,Wuhan University
Precambrian Research | Year: 2013

A total of 20 morphological types of microbially induced sedimentary structures (MISS) are recognized from the late Neoproterozoic tillite-bearing successions of the Kimberley, northwestern Australia which include alpha-petees, triradiate cracks, multidirectional linear ridges, millimeter ripples, erosional remnants and pockets and so on. Of these, triradiate cracks, multidirectional linear ridges, and millimeter ripples are reported for the first time from the Neoproterozoic worldwide. Most Kimberley MISS are morphologically comparable with their ancient and present-day counterparts whose biogenicity have been well demonstrated.In the Kimberley, during the interglacial period MISS have colonization preference to relatively coarse sandy substrates (Ranford Formation) and their abundance decreased towards the younger strata (Throssell Shale). In contrast, MISS abundance increased from the older strata (Yurabi Formation) towards the younger strata (Flat Rock Formation) during the postglacial period. However, overall, both MISS abundance and bedding plane coverage percentage increased from the Marinoan-younger Marinoan/Gaskiers interglacial successions to younger Marinoan/Gaskiers postglacial successions, indicating a proliferation of microbial mats after the younger Marinoan/Gaskiers glaciation. The increase of microbial mats could have ameliorated marine biogeochemical conditions and ecosystems, and thus laid the foundation for the rise of Ediacaran biota in Australian basins. © 2012 Elsevier B.V.

Xu H.,Wuhan University | Ma C.,Wuhan University | Zhang J.,Wuhan University | Ye K.,CAS Institute of Geology and Geophysics
Gondwana Research | Year: 2013

It is generally accepted that the low-Mg adakitic rocks were derived from the partial melting of metabasalts/eclogites. In this study, we demonstrate that the early Cretaceous low-Mg adakitic granites in the North Dabie Complex (NDC) were generated by the partial melting of the NDC orthogneisses. Here we present in-situ U-Pb and Lu-Hf isotopes in zircon with whole-rock geochemical and Sr-Nd isotopic compositions were carried out for the Tiantangzhai porphyritic monzogranites from the Dabie orogen, eastern China. The monzogranites are characterized by high Sr (576-988ppm), low Y (7.3-19.0ppm), and depletion in HREE (Yb: 0.50-1.78ppm) (thus resulting in high Sr/Y (34.3-135.2) and (La/Yb) N (17.0-105.2) ratios) without a negative Eu anomaly. They also exhibit high SiO 2 (66.5-73.5wt.%) and K 2O (2.7-4.7wt.%), and low MgO (0.4-1.6wt.%) or Mg # (28.2-45.3, mostly<40) values. Whole-rock geochemical compositions suggest that the monzogranites represent low-Mg adakitic rock with high-Si and rich-K features equilibrated with residues rich in garnet. Sr-Nd isotopic compositions (ε Nd (t)=-16.2 to -20.3, ( 87Sr/ 86Sr) i=0.707798-0.708804, t DM2(Nd)=2.3-2.6Ga) of the monzogranites are distinct from that of the eclogites and amphibolites in the Dabie orogen, but similar to that of the Neoproterozoic (700-800Ma) gneisses in the NDC. U-Pb dating of zircons gives a consistent age of 130.0±3.4Ma with discordia upper intercept age of 716±34Ma for inherited cores identified by CL imaging. Correspondingly, in-situ Lu-Hf analyses of early Cretaceous young age-spots from zircons yield initial 176Hf/ 177Hf ratios from 0.281898 to 0.282361, εHf(t) values from -28.1 to -17.6 and two-stage "crust" Hf model ages (t DM2) from 2293±89 to 2949±108Ma, which are generally in agreement with values of 0.281891 to 0.282218, -28.2 to -11.7 and 1927±87 to 2963±92Ma for the pre-Mesozoic inherited cores, respectively. As for individual core-rim pairs in zircon, Th/U ratios increase from the inherited cores to the young growth rims possibly due to variable degrees of partial melting, whereas 176Lu/ 177Hf ratios greatly decrease because of the garnet effect in residues. Thus, we suggest that the early Cretaceous low-Mg adakitic granites were derived from the partial melting of the NDC Neoproterozoic (700-800Ma) gneisses, and the foundering of the garnet-bearing residues could have caused the destruction of the over-thickened lower continental crust. © 2011 International Association for Gondwana Research.

Li J.,CAS Institute of Geology and Geophysics | Wang X.,CAS Institute of Geology and Geophysics | Yuen D.A.,University of Minnesota | Yuen D.A.,Wuhan University
Earth and Planetary Science Letters | Year: 2013

Using high-dense regional body waves for three deep earthquakes that occurred around Russia-China border, we investigate both S and P wave velocity structures in the mantle transition zone beneath Northeast China and northern part of North China Craton, where the northwestern Pacific plate is imaged to subhorizontally lie above the 660-km discontinuity. We observe an increasing trend of S-P travel time residuals along the epicentral distance within a distance range of 11-16.5°, indicating a velocity anomaly in MTZ. We seek the simplest model that explains the observed broadband waveforms and relative travel times of triplication for a confined azimuth sector. Both SH and P data suggest a ~140±20km high velocity layer lying above a slightly depressed and broad 660-km discontinuity. Shear velocity reduction of ~2.5%zone is required to compensate for the significantly large relative time between AB and CD triplicate branches and the increased trending of S-P travel time residuals as well. The MTZ, as a whole, is featured by low shear velocity and high Vp/Vs ratio. A water-rich mantle transition zone with 0.2-0.4wt% of H2O may account for the discrepancy between the observed Vp and Vs velocity structures. Our result supports the scenario of a viscosity-dominated stagnant slab with an increased thickness of ~140km, which was caused by the large viscosity contrast between the lower and upper mantles. The addition of water and eastward trench retreat might facilitate stagnation of the subducting Pacific slab beneath Northeast China. © 2013 Elsevier B.V..

Xiao C.,Wuhan University | Yongwei N.,Wuhan University | Feng T.,Interaction Labs
IEEE Transactions on Visualization and Computer Graphics | Year: 2011

This paper presents a novel unified hierarchical structure for scalable edit propagation. Our method is based on the key observation that in edit propagation, appearance varies very smoothly in those regions where the appearance is different from the user-specified pixels. Uniformly sampling in these regions leads to redundant computation. We propose to use a quadtree-based adaptive subdivision method such that more samples are selected in similar regions and less in those that are different from the user-specified regions. As a result, both the computation and the memory requirement are significantly reduced. In edit propagation, an edge-preserving propagation function is first built, and the full solution for all the pixels can be computed by interpolating from the solution obtained from the adaptively subdivided domain. Furthermore, our approach can be easily extended to accelerate video edit propagation using an adaptive octree structure. In order to improve user interaction, we introduce several new Gaussian Mixture Model (GMM) brushes to find pixels that are similar to the user-specified regions. Compared with previous methods, our approach requires significantly less time and memory, while achieving visually same results. Experimental results demonstrate the efficiency and effectiveness of our approach on high-resolution photographs and videos. © 2011 IEEE.

Liu W.,Wuhan University of Technology | Tan X.,Wuhan University | Yin K.,Wuhan University of Technology | Liu H.,Wuhan University | And 4 more authors.
Physical Review Letters | Year: 2012

Mg 2Si and Mg 2Sn are indirect band gap semiconductors with two low-lying conduction bands (the lower mass and higher mass bands) that have their respective band edges reversed in the two compounds. Consequently, for some composition x, Mg 2Si 1-xSn x solid solutions must display a convergence in energy of the two conduction bands. Since Mg 2Si 1-xSn x solid solutions are among the most prospective of the novel thermoelectric materials, we aim on exploring the influence of such a band convergence (valley degeneracy) on the Seebeck coefficient and thermoelectric properties in a series of Mg 2Si 1-xSn x solid solutions uniformly doped with Sb. Transport measurements carried out from 4 to 800 K reveal a progressively increasing Seebeck coefficient that peaks at x=0.7. At this concentration the thermoelectric figure of merit ZT reaches exceptionally large values of 1.3 near 700K. Our first principles calculations confirm that at the Sn content x 0.7 the two conduction bands coincide in energy. We explain the high Seebeck coefficient and ZT values as originating from an enhanced density-of-states effective mass brought about by the increased valley degeneracy as the two conduction bands cross over. We corroborate the increase in the density-of-states effective mass by measurements of the low temperature specific heat. The research suggests that striving to achieve band degeneracy by means of compositional variations is an effective strategy for enhancing the thermoelectric properties of these materials. © 2012 American Physical Society.

Zeng H.-B.,Hunan University of Technology | He Y.,Wuhan University | Wu M.,Wuhan University | She J.,Central South University | She J.,Tokyo University of Technology
IEEE Transactions on Automatic Control | Year: 2015

The free-weighting matrix and integral-inequality methods are widely used to derive delay-dependent criteria for the stability analysis of time-varying-delay systems because they avoid both the use of a model transformation and the technique of bounding cross terms. This technical note presents a new integral inequality, called a free-matrix-based integral inequality, that further reduces the conservativeness in those methods. It includes well-known integral inequalities as special cases. Using it to investigate the stability of systems with time-varying delays yields less conservative delay-dependent stability criteria, which are given in terms of linear matrix inequalities. Two numerical examples demonstrate the effectiveness and superiority of the method. © 1963-2012 IEEE.

Xia R.,Wuhan University | Feng X.-Q.,Tsinghua University | Wang G.-F.,Xi'an Jiaotong University
Acta Materialia | Year: 2011

We investigate the effective elastic properties of nanoporous materials with hierarchical structures, which exhibit a distinct dependence on the characteristic sizes of their microstructure. A core-shell model is first used to account for the effects of both surface tension and surface elasticity. We derive the effective Young's modulus of porous materials with one level of nanosized open or closed cells with surface effects. Then hierarchically structured nanoporous materials consisting of nanosized cells nested in another level of microsized lattice structure are considered to correlate their effective properties with the hierarchical structure. Particular attention is paid to nanoporous gold with multimodal ligament size distributions. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Han X.,Wuhan University of Technology | Qing G.,Wuhan University of Technology | Sun J.,Wuhan University | Sun T.,Wuhan University of Technology
Angewandte Chemie - International Edition | Year: 2012

Getting a charge out of lithium: The naphthalene derivative NTCDA is used to demonstrate a novel lithium ion insertion model in which each ring carbon atom can reversibly accept a lithium ion, giving discharge capacities of up to nearly 2000 mAhg -1. This method provides a new strategy for the design of high-performance organic electrodes. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yu J.,Wuhan University of Technology | Wang S.,Wuhan University of Technology | Low J.,Wuhan University of Technology | Xiao W.,Wuhan University
Physical Chemistry Chemical Physics | Year: 2013

Formaldehyde (HCHO) is a major indoor pollutant and long-term exposure to HCHO may cause health problems such as nasal tumors and skin irritation. Photocatalytic oxidation is considered as the most promising strategy for the decomposition of HCHO. Herein, for the first time, a direct g-C 3N4-TiO2 Z-scheme photocatalyst without an electron mediator was prepared by a facile calcination route utilizing affordable P25 and urea as the feedstocks. Photocatalytic activities of the as-prepared samples were evaluated by the photocatalytic oxidation decomposition of HCHO in air. It was shown that the photocatalytic activity of the prepared Z-scheme photocatalysts was highly dependent on the g-C3N4 content. At the optimal g-C3N4 content (sample U100 in this study), the apparent reaction rate constant was 7.36 × 10 -2 min-1 for HCHO decomposition, which exceeded that of pure P25 (3.53 × 10-2 min-1) by a factor of 2.1. The enhanced photocatalytic activity could be ascribed to the formation of a g-C3N4-TiO2 Z-scheme photocatalyst, which results in the efficient space separation of photo-induced charge carriers. Considering the ease of the preparation method, this work will provide new insights into the design of high-performance Z-scheme photocatalysts for indoor air purification. © 2013 The Owner Societies.

Wang C.,Wuhan University | Cheng R.,University of California at Los Angeles | Liao L.,Wuhan University | Duan X.,University of California at Los Angeles
Nano Today | Year: 2013

Thin film transistors (TFTs) represent the central device building block for large area electronics. The integration of TFTs on flexible substrates is of considerable interest for diverse applications including electronic displays and radio frequency identification, and can enable a new generation of flexible, wearable and disposable electronics. The current approach to TFTs is largely based on amorphous Si or polysilicon on glass technology, which is limited by a number of intrinsic factors, including relatively poor electronic performance or indispensable high temperature deposition processes preventing the use of flexible plastic substrate. The organic semiconductors can be processed in solution and applied onto plastic substrate at room temperature, but are typically limited by rather poor electronic performance. To this end, inorganic nanostructures have emerged as an interesting alternative material system for thin film electronics that could promise the high electronic performance of crystalline inorganic materials, and at the same time offer a low temperature processibility of organic materials. These unique attributes have opened up completely new possibilities for future thin film electronics. Here we focus on the recent advancements in the fabrication of high-performance TFTs based inorganic nanostructures, specifically involving thin films of (1) carbon nanotubes, (2) semiconductor nanowires, (3) two-dimensional layered materials, (4) quantum dots, and (5) metal oxide/nanostructure composites. We will discuss the state-of-the-art, key merits and limitations of each of these material systems. © 2013 Elsevier Ltd. All rights reserved.

Zhou P.,Wuhan University of Technology | Zhu X.,Wuhan University of Technology | Yu J.,Wuhan University of Technology | Xiao W.,Wuhan University
ACS Applied Materials and Interfaces | Year: 2013

Formaldehyde (HCHO), as the main indoor air pollutant, is highly needed to be removed by adsorption or catalytic oxidation from the indoor air. Herein, the F-, OH-, and Cl--modified anatase TiO 2 nanosheets (TNS) with exposed {001} facets were prepared by a simple hydrothermal and post-treatment method, and their HCHO adsorption performance and mechanism were investigated by the experimental analysis and theoretical simulations. Our results indicated that the adsorbed F-, OH-, and Cl- ions all could weaken the interaction between the HCHO and TNS surface, leading to the serious reduction of HCHO adsorption performance of TNS. However, different from F- and Cl- ions, OH- ion could induce the dissociative adsorption of HCHO by capturing one H atom from HCHO, resulting in the formation of one formyl group and one H2O-like group. This greatly reduced the total energy of the HCHO adsorption system. Thus, the adsorbed OH- ions could provide the additional active centers for HCHO adsorption. As a result, the NaOH-treated TNS showed the best HCHO adsorption performance mainly because its surface F- was replaced by OH-. This study will provide new insight into the design and fabrication of high performance adsorbents for removing indoor HCHO and, also, will enhance the understanding of the HCHO adsorption mechanism. © 2013 American Chemical Society.

Zhang M.,Wuhan University of Technology | Qing G.,Wuhan University of Technology | Xiong C.,Wuhan University | Cui R.,Wuhan University | And 2 more authors.
Advanced Materials | Year: 2013

A dispersion-dominated colorimetric approach for the recognition of carbohydrates based on biomolecule-responsive AuNPs is presented. Taking advantage of the unique dual-responsiveness of smart copolymers, the aggregation and dispersion of AuNPs can be modulated by both temperature and different kinds of carbohydrates, giving rise to a novel chromogenic mechanism for the recognition and testing of carbohydrates in aqueous media. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yu J.,Wuhan University of Technology | Yu Y.,Wuhan University of Technology | Zhou P.,Wuhan University of Technology | Xiao W.,Wuhan University | Cheng B.,Wuhan University of Technology
Applied Catalysis B: Environmental | Year: 2014

Various morphologies of CdS photocatalysts, including nanoparticles, nanorods, urchin-like shape and nanowires were prepared via a solvothermal process by tailoring the solvent. Based on both experimental and theoretical simulation investigation, the microstructure evolution mechanism was specified. Visible-light-driven photocatalytic activities for hydrogen production over the different CdS products were compared and rationalized. CdS nanowires prepared with the utilization of tetraethylenepentamine (TEPA) as solvent and l-cysteine as sulfur precursor displayed excellent photocatalytic H2-production activity of 803μmolh-1 with quantum efficiency (QE) of 37.7% at 420nm. The enhanced photocatalytic activity was ascribed to the high purity, good crystallinity, and unique microstructure and band structure, which was favorable for transfer of photogenerated carriers and thus reduced the recombination of electron-hole pairs. This work showed that the nature of solvent had significant influence on the photocatalytic H2-production activity of CdS, which adds knowledge on designing photocatalysts for visible-light-driven photocatalytic hydrogen evolution. © 2014 Elsevier B.V.

Cai J.,Wuhan University | Cai J.,University of Tennessee at Knoxville | Perfect E.,University of Tennessee at Knoxville | Cheng C.-L.,University of Tennessee at Knoxville | Hu X.,Wuhan University
Langmuir | Year: 2014

Spontaneous imbibition of wetting liquids in porous media is a ubiquitous natural phenomenon which has received much attention in a wide variety of fields over several decades. Many traditional and recently presented capillary-driven flow models are derived based on Hagen-Poiseuille (H-P) flow in cylindrical capillaries. However, some limitations of these models have motivated modifications by taking into account different geometrical factors. In this work, a more generalized spontaneous imbibition model is developed by considering the different sizes and shapes of pores, the tortuosity of imbibition streamlines in random porous media, and the initial wetting-phase saturation. The interrelationships of accumulated imbibition weight, imbibition rate and gas recovery and the properties of the porous media, wetting liquids, and their interactions are derived analytically. A theoretical analysis and comparison denote that the presented equations can generalize several traditional and newly developed models from the literature. The proposed model was evaluated using previously published data for spontaneous imbibition measured in various natural and engineered materials including different rock types, fibrous materials, and silica glass. The test results show that the generalized model can be used to characterize the spontaneous imbibition behavior of many different porous media and that pore shape cannot always be assumed to be cylindrical. © 2014 American Chemical Society.

Li F.,University of Kentucky | Mao G.,University of Kentucky | Tong D.,Wuhan University | Tong D.,Tsinghua University | And 5 more authors.
Cell | Year: 2013

DNA mismatch repair (MMR) ensures replication fidelity by correcting mismatches generated during DNA replication. Although human MMR has been reconstituted in vitro, how MMR occurs in vivo is unknown. Here, we show that an epigenetic histone mark, H3K36me3, is required in vivo to recruit the mismatch recognition protein hMutSα (hMSH2-hMSH6) onto chromatin through direct interactions with the hMSH6 PWWP domain. The abundance of H3K36me3 in G1 and early S phases ensures that hMutSα is enriched on chromatin before mispairs are introduced during DNA replication. Cells lacking the H3K36 trimethyltransferase SETD2 display microsatellite instability (MSI) and an elevated spontaneous mutation frequency, characteristic of MMR-deficient cells. This work reveals that a histone mark regulates MMR in human cells and explains the long-standing puzzle of MSI-positive cancer cells that lack detectable mutations in known MMR genes. © 2013 Elsevier Inc.

Li Q.,Wuhan University of Technology | Meng H.,Wuhan University of Technology | Yu J.,Wuhan University of Technology | Xiao W.,Wuhan University | And 2 more authors.
Chemistry - A European Journal | Year: 2014

In response to the increasing concerns over energy and environmental sustainability, photocatalytic water-splitting technology has attracted broad attention for its application in directly converting solar energy to valuable hydrogen (H2) energy. In this study, high-efficiency visible-light-driven photocatalytic H2 production without the assistance of precious-metal cocatalysts was achieved on graphene-Zn xCd1-xS composites with controlled compositions. The graphene-ZnxCd1-xS composites were for the first time fabricated by a one-step hydrothermal method with thiourea as an organic S source. It was found that thiourea facilitates heterogeneous nucleation of ZnxCd1-xS and in situ growth of ZnxCd 1-xS nanoparticles on graphene nanosheets. Such a scenario results in abundant and intimate interfacial contact between graphene and Zn xCd1-xS nanoparticles, efficient transfer of the photogenerated charge carriers, and enhanced photocatalytic activity for H 2 production. The highest H2-production rate of 1.06 mmol h-1 g-1 was achieved on a graphene-Zn0.5Cd 0.5S composite photocatalyst with a graphene content of 0.5 wt %, and the apparent quantum efficiency was 19.8 % at 420 nm. In comparison, the graphene-ZnxCd1-xS composite photocatalyst prepared by using an inorganic S source such as Na2S exhibited much lower activity for photocatalytic H2 production. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shu Z.,Wuhan University | Qian Y.,Clemson University | Ci S.,Shandong University of Technology
IEEE Network | Year: 2013

In this article we explore the security issues on physical layer for cognitive radio networks. First we give an overview on several existing security attacks to the physical layer in cognitive radio networks. We then discuss the related countermeasures on how to defend against these attacks. We further investigate one of the most important physical layer security parameters, the secrecy capacity of a cognitive radio network, and study the outage probability of secrecy capacity of a primary user from a theoretical point of view. Furthermore, we present performance results for secrecy capacity and outage probability between a node and its neighbors. Our work summarizes the current advances of the physical layer security and brings insights on physical layer security analysis in cognitive radio networks. © 1986-2012 IEEE.

Chen Y.,Wuhan University of Technology | Zou X.,Wuhan University
Information Sciences | Year: 2014

Previous theoretical analyses of evolutionary multi-objective optimization (EMO) mostly focus on obtaining ε-approximations of Pareto fronts. However, in practical applications, an appropriate value of ε is critical but sometimes, for a multi-objective optimization problem (MOP) with unknown attributes, difficult to determine. In this paper, we propose a new definition for the finite representation of the Pareto front - the adaptive Pareto front, which can automatically accommodate the Pareto front. Accordingly, it is more practical to take the adaptive Pareto front, or its ε-approximation (termed the ε-adaptive Pareto front) as the goal of an EMO algorithm. We then perform a runtime analysis of a (μ+1) multi-objective evolutionary algorithm ((μ+1) MOEA) for three MOPs, including a discrete MOP with a polynomial Pareto front (denoted as a polynomial DMOP), a discrete MOP with an exponential Pareto front (denoted as an exponential DMOP) and a simple continuous two-objective optimization problem (SCTOP). By employing an estimator-based update strategy in the (μ+1) MOEA, we show that (1) for the polynomial DMOP, the whole Pareto front can be obtained in the expected polynomial runtime by setting the population size μ equal to the number of Pareto vectors; (2) for the exponential DMOP, the expected polynomial runtime can be obtained by keeping μ increasing in the same order as that of the problem size n; and (3) the diversity mechanism guarantees that in the expected polynomial runtime the MOEA can obtain an ε-adaptive Pareto front of SCTOP for any given precision ε. Theoretical studies and numerical comparisons with NSGA-II demonstrate the efficiency of the proposed MOEA and should be viewed as an important step toward understanding the mechanisms of MOEAs. © 2013 Elsevier Inc. All rights reserved.

In this paper, it is shown that recently developed nonlinear singularity theory and methods can be used to recognize weak but complex geo-anomalies for the prediction of the presence of mineral deposits in areas covered by deserts, regolith or vegetation. The theory and models of singularity and generalized self-similarity developed in the context of multifractals are proposed for analyzing weak anomalies caused by buried mineralization. These anomalies can be extracted from geochemical stream sediment data and can be used for the prediction of the Fe and Sn mineral deposits of skarn and hydrothermal types in Gejiu, Yunnan and Eastern Tianshan, Xinjiang, China. Significant portions of these areas are covered by vegetation, desert or regolith. The concepts and models of local singularity and generalized self-similarity are utilized to demonstrate that the singularity index, which is the exponent of the power-law associating density with scale (area or volume) of geochemical anomaly, determines an essential dimensional property of geochemical anomaly that is independent of its geometrical scale. Singularity values calculated by means of the local singularity analysis method are capable of enhancing weak geochemical anomalies caused by deeply buried sources. The principles and methodologies proposed in this paper are demonstrated by a case study of predicting the presence of Fe mineral deposits in Eastern Tianshan, China. The singularity analysis methods, in conjunction with combined low-pass and high-pass filtering methods, were successfully applied to process regional stream sediment geochemical maps, gravity map and aeromagnetic map with the aim of extracting weak anomalies revealing locations of mafic volcanic rocks, felsic to intermediate intrusions, skarn and hydrothermal alterations in the study areas. These geological features are genetically associated with skarn and other hydrothermal iron deposits in the area. A modified fuzzy weights-of-evidence method with a correction for conditional independence of evidence was applied to integrate the evidence and to create a posterior probability map. The results show that weak geochemical anomalies caused by buried mineral deposits in the considered areas are significantly enhanced and extracted from variable backgrounds. Approximately 30% of significant target areas delineated by the integrated geo-anomalies in the study areas had been previously ignored. © 2012 Elsevier B.V.

Wang K.,Wuhan University | Zhang R.,Sun Yat Sen University
Journal of Hydrology | Year: 2011

The objectives of this study were to examine applicability of the iodine-starch method to visualize heterogenous soil water flow and to investigate relationships between soil water heterogeneity and macropore structure vs. measurement scale as well as hydraulic boundaries. The food-grade dye pigment Brilliant Blue FCF dye and iodine-starch staining patterns were used to visualize soil macropore and soil water flow patterns, respectively. Totally 10 infiltration experiments were performed in the field, among which three were used to examine the iodine-starch method and seven were for various boundary conditions (i.e., the different initial ponding depths on the soil surface) and measurement scales (i.e., the soil surface areas covered initially by the tracer solutions). The cluster analysis method was used to distinguish preferential flow regions, while information measures were applied to quantify heterogeneity information content and complexity of macropores and flow systems. Results showed that the iodine-starch method was applicable to visualize soil water flow. Heterogeneous soil water flow contained more heterogeneity information than soil macropores. With a low infiltration amount, flow patterns were similar to the macropore patterns and controlled mainly by the macropores. As the infiltration amount increased, flow patterns were influenced by both macropores and boundary conditions. As the measurement scales increased, the preferential regions were more developed. © 2010 Elsevier B.V.

Chen Y.,Wuhan University of Technology | Xie W.,Wuhan University | Zou X.,Wuhan University
Swarm and Evolutionary Computation | Year: 2013

Surrogate-assisted evolutionary algorithms have been widely utilized in science and engineering fields, while rare theoretical results were reported on how surrogates influence the performances of evolutionary algorithms (EAs). This paper focuses on theoretical analysis of a (1+1) surrogate-assisted evolutionary algorithm ((1+1)SAEA), which consists of one individual and pre-evaluates a newly generated candidate using a first-order polynomial model (FOPM) before it is precisely evaluated at each generation. By performing comparisons between a unimodal problem and a multi-modal problem, we rigorously estimate the variation of exploitation ability and exploration ability introduced via the FOPM. Theoretical results show that the FOPM employed to pre-evaluate the candidates sometimes accelerate the convergence of evolutionary algorithms, while sometimes prevents the individuals from converging to the global optimal solution. Thus, appropriate adaptive strategies of candidate generation and surrogate control are needed to accelerate the convergence of the (1+1)EA. Then, the accelerating effect of FOPM decreases monotonically with p, the probability of performing precise function evaluation when a candidate is pre-evaluated worse than the present individual. © 2013 Elsevier B.V. All rights reserved.

Chen C.-H.,National Taiwan University | Hsieh P.-S.,Industrial Technology Research Institute of Taiwan | Lee C.-Y.,National Taiwan University | Zhou H.-W.,Wuhan University
Gondwana Research | Year: 2011

The Darongshan granitic suite (~10,000km2) consists of five major units (Taima, Nadong and Jiuzhou plutons, and Pubei and Darongshan batholiths) typical of peraluminous S-type granitoids containing abundant granulite inclusions in the Cathaysia block, South China. Six samples from these plutons and batholiths have been investigated using both LA-ICPMS U-Pb age dating on zircon cores and EMP U-Th-Pb chemical age dating on monazite cores and rims. LA-ICPMS zircon results give similar major age populations ranging between 260±3 and 250±3Ma for all units, with apparent older age peaks concentrated at 1020, 800, 430 and 330Ma. On the other hand, EMP monazite results yield younger ages of 231-229Ma for Nadong, Taima, Pubei and Darongshan and 224Ma for Jiuzhou samples, with older age groups of 264Ma for Taima and 256-250Ma for Pubei units. Since the older monazite ages are similar to the majority of zircon ages, the latter are considered as inherited ages. Further because such zircon ages are similar with the emplacement time of the Emeishan large igneous province in western South China, they likely reflect the timing of metamorphism for the included fragments of granulitic crusts that had been formed by invasion of the Emeishan plume. The younger monazite ages, as present for all plutons and batholiths in the entire Darongshan area, are taken as the formation age of the host granites. Combining U-Pb zircon and EMP monazite ages known for Permo-Triassic high temperature and high pressure metamorphic rocks and granites in the Indochina block (e.g., the Kannack Complex of the Kontum massif), it is suggested that the Indosinian thermal activity had set records over both the Indochina (plus Simao) and South China blocks in two main episodes, one is 260-250Ma and the other is 231-229Ma. One plausible explanation is that these two blocks were one united continent before the Emeishan plume activity and an opening was triggered by this plume at ~260Ma. Due to forces of the approaching Sibumasu block, both the South China and Indochina blocks were amalgamated again at ~230Ma. We, therefore, advocate that double subduction of the plume-triggered oceanic crusts in opposite directions is responsible for the generation of the Darongshan granitic suite in the South China block and its counterpart in the Indochina block. © 2010 International Association for Gondwana Research.

Chang K.-C.,Wuhan University | Chen D.-Z.,National Taiwan University | Huang M.-H.,National Taiwan University
Journal of Informetrics | Year: 2012

This study utilizes panel regression model to explore the relationships between corporate performance and the patent performance measured from patent H index, current impact index (CII), and essential patent index (EPI) in the pharmaceutical company. The results demonstrate that patent H index and EPI have positive influences upon corporate performance. Furthermore, this study developed a classification for the pharmaceutical companies to divide them into four types, and provided some suggestions to them. © 2011 Elsevier Ltd.

Xu Z.,Wuhan University of Technology | Xu Z.,Huanggang Normal University | Yu J.,Wuhan University of Technology | Xiao W.,Wuhan University
Chemistry - A European Journal | Year: 2013

Mesoporous ferrihydrite/SiO2 composites were synthesized according to a water-in-oil microemulsion method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry, nitrogen-adsorption/ desorption, and by X-ray photoelectron spectroscopy. The as-prepared porous ferrihydrite/SiO2 composites showed an excellent adsorption performance for formaldehyde (HCHO) removal from indoor air at ambient temperature. It was found that the aging time during the synthesis had a sig Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kong M.,Wuhan University of Technology | Li Y.,Wuhan University of Technology | Chen X.,Wuhan University of Technology | Tian T.,Wuhan University of Technology | And 3 more authors.
Journal of the American Chemical Society | Year: 2011

TiO2 nanocrystals with tunable bulk/surface defects were synthesized and characterized with TEM, XRD, BET, positron annihilation, and photocurrent measurements. The effect of defects on photocatalytic activity was studied. It was found for the first time that decreasing the relative concentration ratio of bulk defects to surface defects in TiO2 nanocrystals could significantly improve the separation efficiency of photogenerated electrons and holes, thus significantly enhancing the photocatalytic efficiency. © 2011 American Chemical Society.

Wang M.,Wuhan University | Yang Y.,Xiamen University | Zhang Y.,Wuhan University
Nanoscale | Year: 2011

Efforts were made to synthesize LiFePO4/C composites showing both high rate capability and high tap density. First, monoclinic phase FePO4·2H2O with micro-nano hierarchical structures are synthesized using a hydrothermal method, which are then lithiated to LiFePO4/C also with hierarchical structures by a simple rheological phase method. The primary structures of FePO4·2H2O are nanoplates with ∼30 nm thickness, and the secondary structures of the materials are intertwisted micro-scale rings. The LiFePO4/C materials lithiated from these specially structured precursors also have hierarchical structures, showing discharge capacities of more than 120, 110, and 90 mAh g-1 at rates of 5 C, 10 C and 20 C, respectively, and high tap density of 1.4 g cm-3 as cathode materials for lithium ion batteries. Since tap density is an important factor that needs to be considered in fabricating real batteries in industry, these hierarchical structured LiFePO4/C moves closer to real and large-scale applications. © 2011 The Royal Society of Chemistry.

Wu X.,Wuhan University | Jiang X.,Wuhan University | Huo Q.,Jilin University | Zhang Y.,Wuhan University
Electrochimica Acta | Year: 2012

Phase-pure, monoclinic, and nanostructured Li 2FeSiO 4/C composite has been synthesized with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymer P123. The structure of the composite has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The Li 2FeSiO 4/C composite exhibits superior electrochemical properties as the cathode materials for lithium ion batteries. The discharge specific capacities can reach 230 mAh g -1 at current density of 0.1 C (1 C = 166 mA g -1) at room temperature when cycled between 1.5 and 4.8 V (vs. Li +/Li). Discharge capacities of 185, 150, and 120 mAh g -1 are obtained at high rates of 1 C, 5 C, and 10 C, respectively. The high capacities are believed to be related to both Fe 2+/Fe 3+ and Fe 3+/Fe 4+ redox couples, as suggested by the Mössbauer spectra for the electrode materials. The Li 2FeSiO 4/C composite also shows excellent rate capability and cyclability. All these results suggest that Li 2FeSiO 4/C composite is a very promising candidate as a cheap and sustainable cathode material for the next generation of rechargeable lithium ion batteries. © 2012 Elsevier Ltd.

Fan X.,CAS Beijing National Laboratory for Molecular | Cui C.,CAS Beijing National Laboratory for Molecular | Fang G.,Wuhan University | Wang J.,Hubei University | And 4 more authors.
Advanced Functional Materials | Year: 2012

Polymer solar cells (PSCs) with poly(3-hexylthiophene) (P3HT) as a donor, an indene-C 70 bisadduct (IC 70BA) as an acceptor, a layer of indium tin oxide modified by MoO 3 as a positive electrode, and Ca/Al as a negative electrode are presented. The photovoltaic performance of the PSCs was optimized by controlling spin-coating time (solvent annealing time) and thermal annealing, and the effect of the spin-coating times on absorption spectra, X-ray diffraction patterns, and transmission electron microscopy images of P3HT/IC 70BA blend films were systematically investigated. Optimized PSCs were obtained from P3HT/IC 70BA (1:1, w/w), which exhibited a high power conversion efficiency of 6.68%. The excellent performance of the PSCs is attributed to the higher crystallinity of P3HT and better a donor-acceptor interpenetrating network of the active layer prepared under the optimized conditions. In addition, PSCs with a poly(3,4-ethylenedioxy-thiophene) :poly(styrenesulfonate) (PEDOT:PSS) buffer layer under the same optimized conditions showed a PCE of 6.20%. The results indicate that the MoO 3 buffer layer in the PSCs based on P3HT/IC 70BA is superior to that of the PEDOT:PSS buffer layer, not only showing a higher device stability but also resulting in a better photovoltaic performance of the PSCs. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

I 'Top 10' scelti sono: IoT Charging Station (Chinese Academy of Sciences, Guangzhou), MEGA Drone (Harwar International Aviation), HIAR GLASSES V2 (HiScene), All-in-One VR G1/G1s (Qualcomm and CooCaa), PMS168 Motor (Dongming Electric Motor), Smart Lunch Box (Nami), Panox One Sports DV (D-Light Tech), the “am:10” Ecological Purifier (Techand Residential Environment), Smart Charging Pile (Wuhan University) e SINGULATO (Zhiche Auto).

News Article | December 2, 2016
Site: en.prnasia.com

WUHAN, China, Dec. 2, 2016 /PRNewswire/ -- In recent years, cross-border e-commerce has developed rapidly amid global trade slump. The whole world is witnessing the unprecedented opportunity of cross-border e-commerce. How to develop cross-border e-commerce in the new era, situation and market? How to seize the opportunity of the era? How to gain the initiative? On November 28, 2016, the Second Optics Valley Global Cross-border E-commerce Forum (CBEC 2016) was held at Hilton Wuhan, Huashan, Optics Valley, Wuhan, China. The forum was supported by the Wuhan Municipal People's Government and the Department of Commerce of Hubei Province, directed by the East Lake High-tech Development Zone Administrative Committee and the Wuhan Municipal Bureau of Commerce, and organized by Winliner Global Information Technology Co., Ltd. and Transn iLangNet Network Technology Co., Ltd. CBEC 2016 is one of the most globally representative cross-border e-commerce forums in China. Apart from Long Yongtu, the former Chief Negotiator and the former Vice Minister of Ministry of Foreign Trade and Economic Cooperation of China; Rolf Visser, Chairman of the Cross-border E-commerce Community and other authorities, CBEC 2016 brought together municipal leaders of over 100 Chinese cities, leaders of Chile's second-largest city Valparaiso, as well as representatives from nearly 40 overseas platforms, including Chile's renowned B2B platform Yeatrade, India's renowned e-commerce platform TradeIndia, Brazil's leading B2B platform B2Brazil, Russia's renowned B2B platform Fis, world-renowned B2B platform TradeKey, the largest US toy platform ToyDirectory, African B2B platform Esaja, Germany's renowned e-commerce platform sundheit.de, Indian B2B platform IndiaMart, South America's renowned B2C platform and South America's largest B2C platform MercadoLibre. Also, executives of renowned domestic and overseas industrial associations as well as representatives of hundreds of Chinese foreign trade enterprises were present to discuss how to open up a new era of cross-border e-commerce in the new times and trend. At the forum, the attendees looked into the future of global cross-border e-commerce. Long's speech entitled "Road of Cross-border E-commerce in the New Global Context" and Visser's speech entitled "Current Situation and Development Trend of Global Cross-border E-commerce" provided insights into the global trend of cross-border e-commerce. The attendees discussed the realistic problems of cross-border e-commerce with focus on issues such as "Promoting the Development of Cross-border E-commerce through City Cooperation" and "Building the 'Air Silk Road', Perfecting Cross-border E-commerce Industry Chain". The attendees offered impressive opinions on some perspective issues. With focus on the issue of "New Era of Cross-border E-commerce: Rise and Reform of Cross-border B2B", five world-renowned e-commerce platforms discussed how to reform cross-border e-commerce to meet the need of economic transformation in the context that B2B has gradually become a key mode of cross-border e-commerce. Artificial intelligence (AI) has gradually become an industrial hotspot. The attendees offered impressive opinions on "New Kinetics of Cross-border E-commerce: AI and Frontier Technology". In a dialogue chaired by Henry He, Chairman and CEO of Transn iLangNet, the guests portrayed an exciting future for the integration of AI with cross-border e-commerce. At last, with focus on the issue of "How Does Chile Greet Chinese Buyers and Sellers", the attendees discussed the cooperation between China and Chile. In the context of the recent successful visit of General Secretary and Chairman Xi to Chile, the Commercial Counselor of Chile in Shanghai and the executives of relevant Chilean national associations made suggestions on how Chile cements its relations with China. Apart from issue discussions, the signing ceremony of the agreement on the establishment of sister cities relationship between China's Yucheng and Chile's second-largest city Valparaiso, and the launch ceremony of the tripartite cross-border cooperation among Valparaiso, Chinese city and Winliner were held during the forum, to promote the establishment of good cooperative relations between foreign cities and Chinese cities. Winliner established the "Cross-border E-commerce Financial Engineering Research Base" in association with Wuhan University China Financial Engineering and Risk Management Research Center, to promote the transformation and upgrading of the urban economy and Chinese enterprises from the dimension of cross-border finance. On the second day of the forum, the "County Cross-border E-commerce Forum" and the "Cross-border E-commerce Fair" were held, to release service information and market demands in various cross-border sectors, support the development of China's urban economy and the cooperation among various enterprises, and promote win-win cooperation through cross-border e-commerce. In the address of Zheng Yuhong, CEO of Winliner, the County Cross-border E-commerce Forum opened. Under the framework of the "county economy", the forum will bring its role of resource integration into full play and pool the strength of all walks of life to serve the urban economy. To enrich the brainpower for the forum and intensify the intellectual support to the urban economy, numerous domestic and overseas experts, scholars and industrial executives, such as Wang Jian, a professor at the University of International Business and Economics and Chairman of the Expert Committee of the APEC E-commerce Business Alliance; and James Brierley, founder and CEO of Chile's renowned B2B platform Yeatrade were invited as think tank experts. The forum continued the keynote of the main forum. With the guest of honor-Chile as the center, the forum invited Cesar Suarez, Commercial Counselor of Chile in Shanghai and Roberto Fantuzzi H., Chairman of the Import and Export Manufacturers' Association of Chile to discuss issues such as "Sharing of Opportunities from the Chilean Market" and "Chile's Import and Export Situation and Demand for Chinese Products". The forum also looked into special issues such as "Building of Cross-border E-commerce Enterprise Credit System", "Cross-border E-commerce Risk Prevention", "Sharing of Experience in Cross-border E-commerce Industrial Park Operation" and "Sharing of Experience in Transformation and Upgrading of Cross-border E-commerce County Economy". Apart from issue discussions, the signing ceremony of the agreement on cross-border e-commerce project cooperation was held during the forum. At the ceremony, Winliner signed cross-border e-commerce cooperation project agreements with some Chinese counties and cities, and an agreement with Speedymanna on a cross-border e-commerce industrial project. The "Cross-border E-commerce Fair" was held concurrently with the "County Cross-border E-commerce Forum". Purchasers from countries such as Chile, Russia, Vietnam, Brazil and Germany discussed cooperation with Chinese manufacturers. They purchased over 1,000 types of commodities, including nearly 100 types of building materials, home products and clothing materials. In the session of keynote speeches, the speech of Chase Vance, Global Business Development Director, TopTenWholesale (the largest wholesale platform in North America) received a warm response from the suppliers present. Russian tea purchaser Omap Tea also drew great attention. There is huge potential for the tea business cooperation between China and Russia. Though the fair only lasted a half day, the scene was warm, both the buyers and the sellers signed many intent of purchase agreements. CBEC is one of the most representative global cross-border e-commerce forums in China. Aiming at the fact that global cross-border e-commerce has entered a key stage, CBEC aims to explore new trends and challenges of global cross-border e-commerce in the context of continuous deepening of the Belt & Road Initiative, discuss the new way and concept of urban economic cooperation, build an exchange and matchmaking platform, and share the development results of global e-commerce. To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/the-2016-second-optical-valley-cross-border-e-commerce-forum-held-in-wuhan-300372076.html

Gao C.,State University of New York at Stony Brook | Shi Y.,Virginia Polytechnic Institute and State University | Hou Y.T.,Virginia Polytechnic Institute and State University | Sherali H.D.,Virginia Polytechnic Institute and State University | Zhou H.,Wuhan University
IEEE Journal on Selected Areas in Communications | Year: 2011

We study a multicast communication problem in a multi-hop ad hoc network where each node is equipped with a cognitive radio (CR). The goal is to minimize the required network-wide resource to support a set of multicast sessions, with a given bit rate requirement for each multicast session. The unique characteristics and complexity associated with CR distinguish this problem from existing multicast problems for ad hoc networks. In this paper, we formulate this problem via a cross-layer approach by taking consideration of scheduling and routing jointly. Although the problem formulation is in the form of a mixed-integer linear program, we develop a polynomial-time algorithm that offers highly competitive solutions. By comparing the solution values with a lower bound, we show that the proposed algorithm can provide a solution that is close to the optimum. © 2006 IEEE.

Yuan S.,Wuhan University | Yuan S.,Northeastern University | Chen M.,Lawrence Livermore National Laboratory | Mao X.,Northeastern University | Alshawabkeh A.N.,Northeastern University
Water Research | Year: 2013

A hybrid electrolysis and Pd-catalytic oxidation process is evaluated for degradation of trichloroethylene (TCE) in groundwater. A three-electrode, one anode and two cathodes, column is employed to automatically develop a low pH condition in the Pd vicinity and a neutral effluent. Simulated groundwater containing up to 5 mM bicarbonate can be acidified to below pH 4 in the Pd vicinity using a total of 60 mA with 20 mA passing through the third electrode. By packing 2 g of Pd/Al2O3 pellets in the developed acidic region, the column efficiency for TCE oxidation in simulated groundwater (5.3 mg/L TCE) increases from 44 to 59 and 68% with increasing Fe(II) concentration from 0 to 5 and 10 mg/L, respectively. Different from Pd-catalytic hydrodechlorination under reducing conditions, this hybrid electrolysis and Pd-catalytic oxidation process is advantageous in controlling the fouling caused by reduced sulfur compounds (RSCs) because the in situ generated reactive oxidizing species, i.e., O2, H2O2 and OH, can oxidize RSCs to some extent. In particular, sulfite at concentrations less than 1 mM even greatly increases TCE oxidation by the production of SO4 •-, a strong oxidizing radical, and more OH. © 2012 Elsevier Ltd.

Novak P.,University of West Bohemia | Tenzer R.,Wuhan University
Surveys in Geophysics | Year: 2013

Due to the ESA's satellite mission GOCE launched in March 2009, gravitational gradients sampled along the orbital trajectory approximately 250 km above the Earth's surface have become available. Since 2010, gravitational gradients have routinely been applied in geodesy for the derivation of global Earth's gravitational models provided in terms of fully normalized coefficients in a spherical harmonic series representation of the Earth's gravitational potential. However, in geophysics, gravitational gradients observed by spaceborne instruments have still been applied relatively seldom. This contribution describes their possible geophysical applications in structural studies where gravitational gradients observed at satellite altitudes are compared with those derived by a spectral forward modeling technique using available global models of selected Earth's mass components as input data. In particular, GOCE gravitational gradients are interpreted in terms of a superposition principle of gravitation as combined gravitational effects generated by a homogeneous reference ellipsoid of revolution, mean topographic and ice mass density distributions, depth-dependent mass density contrasts within bathymetry and lateral mass density anomalies with sediments and crustal layers. Respective gravitational effects are one by one removed from gravitational gradients observed at approximately 250 km elevation above ground. Removing respective gravitational gradients from observed gravitational gradients gradually reveals problematic geographic areas with model deficiencies. For the full interpretation of observed gravitational gradients, deficiencies of CRUST2.0 must be corrected and effects of deeper laying mass anomalies not included in the study considered. These findings are confirmed by parameters describing spectral properties of the gravitational gradients. The methodology can be applied for validating Earth's gravitational models and for constraining crustal models in the development phase. © 2013 Springer Science+Business Media Dordrecht.

Hou T.,China University of Geosciences | Zhang Z.,China University of Geosciences | Kusky T.,Wuhan University
Ore Geology Reviews | Year: 2011

The Gushan deposit is one of the typical magnetite-apatite deposits associated with dioritic porphyries in the Lower Yangtze River Valley belt of the eastern Yangtze craton. The origin of this deposit is still uncertain and remains a controversial issue. Divergent opinions are centered on whether the iron deposits are magmatic or hydrothermal in origin. However, our field observations and mineralogical studies, combined with previous published petrological and geochemical features strongly suggest that the main ore bodies in the Gushan magnetite-apatite deposit are magmatic. Specific evidence includes the existence of gas bubbles, tubes, and miarolitic and amygdaloidal structures, melt flow banding structure and the presence of "ore breccia". New electron microprobe analyses of the pyroxene phenocrysts of the dioritic porphyry genetically associated with the Gushan magnetite-apatite deposit show that the Fe contents in the evolving magma dramatically decrease, and then gradually increase. Because there is no evidence of mafic magma recharge, this scenario (decreasing Fe) could be plausibly interpreted by Fe-rich melts separated from Fe-poor silicate melts, i.e., liquid immiscibility was triggered by minor addition of phosphorus by crustal contamination. The occurrence of massive iron ore bodies can be satisfactorily explained by the immiscible Fe-rich melt with enormous volatile contents was driven to the top of the magma chamber due to the low density. The hot and volatile-rich iron ore magma was injected along fractures and spaces between the dioritic intrusions and wall-rocks, and led to an explosion near the surface, resulting in the immediate fragmentation of the roof of the intrusion and wall-rocks, forming brecciated ores. Moreover, other types of ores can be considered as a result of post-magmatic hydrothermal activities. Our proposed metallogenic model involving the Kiruna-type mineralization is consistent with the observed phenomenon in the Gushan deposit. © 2011 Elsevier B.V.

Wang B.-Q.,University of Hong Kong | Zhou M.-F.,University of Hong Kong | Li J.-W.,Wuhan University | Yan D.-P.,China University of Geosciences
Lithos | Year: 2011

Early Mesozoic porphyritic intrusions in the Shangri-La region, southern Yidun terrane, SW China, are spatially associated with andesites and dacites. These intrusions are composed of diorite and quartz diorite, and are closely related to copper mineralization. LA-ICP-MS zircon U-Pb ages of the intrusions range from 230 to 215Ma. The associated andesites and dacites are interlayered with slates and sandstones and have ages of around 220Ma. All of the intrusive and extrusive rocks have similar, highly fractionated REE patterns and high La/Yb (13-49) ratios with no prominent Eu anomalies. They display pronounced negative Nb-Ta and Ti anomalies on primitive mantle-normalized spidergrams. Their SiO2 contents range from 56.6 to 67.1wt.%, Al2O3 from 14.2 to 17.4wt.% and MgO from 1.9 to 4.2wt.%. All the rocks have high Sr (258-1980ppm), and low Y (13-21ppm) with high Sr/Y ratios (29-102). These features suggest that both the volcanic rocks and porphyritic intrusions were derived from adakitic magmas. They have similar initial 87Sr/86Sr ratios (0.7058 to 0.7077) and εNd (-1.88 to -4.93) values, but belong to high silica (HSA) and low silica adakitic rocks (LSA). The HSA represent an early stage of magmatism (230 to 215Ma) and were derived from oceanic slab melts with limited interaction with the overlying mantle wedge during ascent. At 215Ma, more extensive interaction produced the LSA. We propose that the early adakitic magmas (HSA) formed by flat subduction leading to melting of oceanic slab, whereas subsequent slab break-off caused the significant interaction between slab melts and the mantle wedge and thus the generation of the later adakitic magmas (LSA). © 2011 Elsevier B.V.

Li J.,Wuhan University | Zhang H.,Wuhan University | Huang Y.,Xi'an University of Science and Technology | Zhang L.,Wuhan University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2014

Sparse representation has been widely used in image classification. Sparsity-based algorithms are, however, known to be time consuming. Meanwhile, recent work has shown that it is the collaborative representation (CR) rather than the sparsity constraint that determines the performance of the algorithm. We therefore propose a nonlocal joint CR classification method with a locally adaptive dictionary (NJCRC-LAD) for hyperspectral image (HSI) classification. This paper focuses on the working mechanism of CR and builds the joint collaboration model (JCM). The joint-signal matrix is constructed with the nonlocal pixels of the test pixel. A subdictionary is utilized, which is adaptive to the nonlocal signal matrix instead of the entire dictionary. The proposed NJCRC-LAD method is tested on three HSIs, and the experimental results suggest that the proposed algorithm outperforms the corresponding sparsity-based algorithms and the classical support vector machine hyperspectral classifier. © 2013 IEEE.

Liu S.,Jiangnan University | Tao D.,Jiangnan University | Zhang L.,Wuhan University
Powder Technology | Year: 2012

Utilization of environmentally benign solvents, nontoxic chemicals, and renewable materials are some of the key issues that merit important consideration in a green synthetic strategy. In this work, monodispersed magnetic Fe 2O 3 nanoparticles have been synthesized by using regenerated cellulose films as sacrificial templates. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) images indicated that the particle size of the nanoparticles was less than 50 nm. The nanoparticles had novel magnetic responsibility at room temperature and could be dispersed in water and kept at stable state for about 3 months. The nanoparticles were prepared directly without a size-selection process, and the synthetic procedure was reproducible. Furthermore, this method was facile and the process was completely green, which made this process amenable to the further development of green nanoparticle synthesis on a large-scale. © 2011 Elsevier B.V.

Han K.-J.,National Jewish Medical and Research Center | Yang Y.,Wuhan University | Xu L.-G.,National Jewish Medical and Research Center | Shu H.-B.,Wuhan University
Journal of Biological Chemistry | Year: 2010

Recognition of viral RNA by Toll-like receptor 3 (TLR3) triggers activation of the transcription factors NF-κB and IRF3 and induction of type I interferons. TRIF is a Toll-interleukin 1 receptor (TIR) domain-containing adapter protein critically involved in TLR3-mediated signaling. It has been shown that TRIF interacts with TLR3 through their respective TIR domains. In this study, we identified a splice variant of TRIF lacking the TIR domain, which is designated as TRIS. Overexpression of TRIS activates NF-κB, interferon-stimulated response element (ISRE), and the interferon-β promoter, whereas knockdown of TRIS inhibited TLR3-mediated signaling, suggesting that TRIS is involved in TLR3-mediated signaling. Furthermore, we identified an N-terminal TBK1-binding motif of TRIS or TRIF that was important for its interaction with TBK1 and ability to activate ISRE. Activation of ISRE by TRIS also needs its dimerization or oligomerization mediated by its C-terminal RIP homotypic interaction motif. Finally, we demonstrated that TRIS was associated with TRIF upon TLR3 activation by poly(I-C). These findings reveal an unexpected mechanism of TLR3-mediated signaling. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

Hang B.,Xiangtan University | Hang B.,Wuhan University
CCTAE 2010 - 2010 International Conference on Computer and Communication Technologies in Agriculture Engineering | Year: 2010

The traditional biding system does not meet the social development now. Along with the quick development of the Internet, the online biding system should be developed. This thesis focuses on analyzing how to design a secure online biding system. This system is designed for users who can release biding information, upload or download mark book and query medium mark information. © 2010 IEEE.

Wang W.,University of Hong Kong | Zhou M.-F.,University of Hong Kong | Yan D.-P.,China University of Geosciences | Li J.-W.,Wuhan University
Precambrian Research | Year: 2012

The Sibao Group on the southeastern margin of the Yangtze Block of South China is composed mainly of flysch turbidites up to ca. 4000m thick. Sandstones from the Sibao Group have intermediate to high SiO 2 (58.6-80.0wt%, average 68.2wt%) and Al 2O 3 wt% (7.4-20.6wt%, average 15wt%), typical of immature lithic varieties. Both sandstones and mudstones contain high K 2O (1.41-6.28wt%) but extremely low Na 2O (0.03-1.49wt%). Positive correlations between Al 2O 3 and Fe 2O 3 (T), TiO 2, MgO and K 2O, significant depletion of Ca, Na and Sr relative to upper continental crust and high PIA and pre-metasomatism CIA values suggest that intensive chemical weathering of the source area. Variable Cr/Th (3.9-37.0) and Co/Th (0.2-3.2) ratios indicate a source with predominant felsic and minor mafic components. Discrimination diagrams involving Ti, Al, Fe, La, Th, Sc, Hf and Co reveal the source with multiple lithologies consisting mainly of TTG-like, granitic, andesitic and felsic volcanic rocks.Predominant detrital zircons have Neoproterozoic ages from 822 to 980Ma, whereas the remaining zircons define two age groups at 1.35-2.22Ga and 2.32-2.86Ga. Twenty-six of the youngest grains have a weighted mean age of 835.3±3.6Ma, tentatively interpreted as the maximum depositional age of the Sibao Group. Neoproterozoic zircon grains have variable 177Hf/ 176Hf ratios (0.281194 to 0.282564) and e{open} Hf(t) values (-35.9 to 9.8), indicative of the involvement of juvenile and ancient recycled components. The 1.4 and 1.8Ga zircon grains have variable 177Hf/ 176Hf ratios (0.280947-0.281874), probably reflecting the growth of the supercontinent Columbia and suggesting that the Yangtze Block was separated from Columbia as an independent terrane at around 1.4Ga. The complicated provenance involving felsic to intermediate rocks and Neoproterozoic juvenile to Neoarchean mature materials suggests that the Neoproterozoic Sibao Group was deposited in a back-arc foreland basin related to the northward (present coordinate) subduction of an oceanic lithosphere beneath the southeastern Yangtze Block. © 2011 Elsevier B.V.

Yuan Y.,Wuhan University | Gotoh M.,Fukushima Medical University
Surgery Today | Year: 2010

With the increasing use of living donor liver transplantation (LDLT), the morbidity and mortality of the donors have thus become inevitable problems associated with this procedure. The most common postoperative complications among donors for LDLT involve the biliary tract. The incidence of biliary complications in donors tends to be about 5% based on recent publications. Anatomical variations in the biliary tract, higher predonation alkaline phosphatase levels, and intraoperative blood transfusions are also risk factors for biliary complications in the donors after donation. Donors with biliary complications often show unspecifi c symptoms and most of the biliary complications can be normally treated by nonsurgical methods. Interventional procedures such as percutaneous placement of a peritoneal drain, percutaneous/endoscopic biliary drainage, and combinations of balloon dilatation and/or stenting are effective in the treatment of bile leakage and biliary stricture. A clear understanding of the biliary anatomy of each donor and refi ned surgical techniques will help to minimize risk of biliary complications for living liver donors. © Springer 2010.

Zhang H.,Wuhan University | Li J.,Wuhan University | Huang Y.,Xi'an University of Science and Technology | Zhang L.,Wuhan University
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2014

As a powerful and promising statistical signal modeling technique, sparse representation has been widely used in various image processing and analysis fields. For hyperspectral image classification, previous studies have shown the effectiveness of the sparsity-based classification methods. In this paper, we propose a nonlocal weighted joint sparse representation classification (NLW-JSRC) method to improve the hyperspectral image classification result. In the joint sparsity model (JSM), different weights are utilized for different neighboring pixels around the central test pixel. The weight of one specific neighboring pixel is determined by the structural similarity between the neighboring pixel and the central test pixel, which is referred to as a nonlocal weighting scheme. In this paper, the simultaneous orthogonal matching pursuit technique is used to solve the nonlocal weighted joint sparsity model (NLW-JSM). The proposed classification algorithm was tested on three hyperspectral images. The experimental results suggest that the proposed algorithm performs better than the other sparsity-based algorithms and the classical support vector machine hyperspectral classifier. © 2013 IEEE.

Zhao J.-H.,Wuhan University | Zhou M.-F.,University of Hong Kong | Yan D.-P.,China University of Geosciences | Zheng J.-P.,Wuhan University | Li J.-W.,Wuhan University
Geology | Year: 2011

The Jiangnan fold belt separates the Yangtze and Cathaysia blocks in South China and has long been considered Grenvillian in age in order to place South China in central Rodinia. It consists of deformed Early Neoproterozoic strata that are unconformably overlain by undeformed Late Neoproterozoic strata and intruded by undeformed and unmetamorphosed granitic plutons. Zircons from the Early Neoproterozoic strata yield U-Pb ages as young as 830 Ma, and one granitic pluton has a zircon U-Pb age of ca. 827 Ma. The ≥830 Ma mafic rocks along the southeastern margin of the Yangtze block have arc-affinity geochemical characters, whereas mafic rocks younger than 830 Ma have typical ocean island basalt (OIB)-like compositions. Thus, we suggest that the Early Neoproterozoic strata were deposited on an active continental margin prior to amalgamation of the Yangtze and Cathaysia blocks at ca. 830 Ma. The overlying Late Neoproterozoic strata were deposited in the intracontinental rifted Nanhua Basin at 820-730 Ma and probably reflect backarc spreading above the longlived (950-735 Ma) oceanic subduction zone along the northern and western margin of the Yangtze block. This model is consistent with the secular tectonic evolution of South China during the Neoproterozoic. The Jiangnan fold belt is therefore not a Grenvillian feature as previously suggested, and there is no evidence to place South China in central Rodinia. Instead, we believe that South China was located in a marginal position relative to this supercontinent. © 2011 Geological Society of America.

Huang Z.-H.,Wuhan University | Liu H.-L.,Wuhan University | Huang S.-Q.,Central China Normal University
Journal of Plant Ecology | Year: 2015

Aims: When sympatric flowering plant species in a natural community share pollinators, study of plant-plant interactions via interspecific pollen transfer (IPT) is essential for understanding species coexistence. However, little is known about the extent of IPT between interactive species and its causes. Methods: To explore how sympatric flowering plants sharing pollinators minimize deleterious effects of IPT, we investigated the pollination ecology of two endemic species, Salvia przewalskii and Delphinium yuanum, in an alpine meadow in the Hengduan Mountains, southwest China. We quantified conspecific and interspecific visits by shared bumblebee pollinators, amounts of pollen placed on different body sites of the pollinators and stigmatic pollen loads on open-pollinated flowers. To examine whether IPT affects female fitness, we measured pollen germination and seed production in the two species in an artificial pollination experiment. Important Findings: One bumblebee species, Bombus trifasciatus, was found to be the sole effective pollinator for the two coflowering species. Pollination experiments indicated that deposition of heterospecific pollen could significantly decrease seed set in both species. Experiments showed that S. przewalskii pollen could germinate well on stigmas of D. yuanum, inhibiting conspecific pollen germination in D. yuanum. However, seed set was not lower under open pollination than under cross-pollination within species, suggesting that no female fitness loss was caused by IPT. In foraging bouts with pollinator switches, switches from S. przewalskii to D. yuanum were relatively more frequent (8.27%) than the converse (1.72%). However, IPT from S. przewalskii to D. yuanum accounted for only 1.82% of total stigmatic pollen loads while the reverse IPT to S. przewalskii was 8.70%, indicating that more switches of bumblebees to D. yuanum did not result in higher IPT. By contrast, selection for reduced IPT to S. przewalskii would limit pollinator switches from D. yuanum. We found that a bumblebee generally carried pollen grains from both species but the two species differed in the position of pollen placement on the bumblebee's body; S. przewalskii' s pollen was concentrated on the dorsal thorax while D. yuanum' s pollen was concentrated ventrally on the head. This differential pollen placement along with pollinator fidelity largely reduced IPT between the two species with a shared pollinator. © 2015 © The Author 2015. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China. All rights reserved.

Hu X.-Y.,Wuhan University | Hu X.-Y.,University of Florida
Pedosphere | Year: 2013

Overabundance of phosphorus (P) in soils and water is of great concern and has received much attention in Florida, USA. Therefore, it is essential to analyze and predict the distribution of P in soils across large areas. This study was undertaken to model the variation of soil total phosphorus (TP) in Florida. A total of 448 soil samples were collected from different soil types. Soil samples were analyzed by chemical reference method and scanned in the visible/near-infrared (VNIR) region of 350-2500 nm. Partial least squares regression (PLSR) calibration model was developed between chemical reference values and VNIR values. The coefficient of determination (R) and the root mean squares error (RMSE) of calibration and validation sets, and the residual prediction deviation (RPD) were used to evaluate the models. The R in calibration and validation for log-transformed TP (log TP) were 0.69 and 0.65, respectively, indicating that VNIR calibration obtained in this study accounted for at least 65% of the variance in log TP using only VNIR spectra, and the high RPD of 2.82 obtained suggested that the spectral model derived in this study was suitable and robust to predict TP in a wide range of soil types, being representative of Florida soil conditions. © 2013 Soil Science Society of China.

Zheng G.,University of Birmingham | Zheng G.,Wuhan University | Muhlenbernd H.,University of Paderborn | Kenney M.,University of Birmingham | And 3 more authors.
Nature Nanotechnology | Year: 2015

Surfaces covered by ultrathin plasmonic structures - so-called metasurfaces - have recently been shown to be capable of completely controlling the phase of light, representing a new paradigm for the design of innovative optical elements such as ultrathin flat lenses, directional couplers for surface plasmon polaritons and wave plate vortex beam generation. Among the various types of metasurfaces, geometric metasurfaces, which consist of an array of plasmonic nanorods with spatially varying orientations, have shown superior phase control due to the geometric nature of their phase profile. Metasurfaces have recently been used to make computer-generated holograms, but the hologram efficiency remained too low at visible wavelengths for practical purposes. Here, we report the design and realization of a geometric metasurface hologram reaching diffraction efficiencies of 80% at 825 nm and a broad bandwidth between 630 nm and 1,050 nm. The 16-level-phase computer-generated hologram demonstrated here combines the advantages of a geometric metasurface for the superior control of the phase profile and of reflectarrays for achieving high polarization conversion efficiency. Specifically, the design of the hologram integrates a ground metal plane with a geometric metasurface that enhances the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. Because of these advantages, our strategy could be viable for various practical holographic applications. © 2015 Macmillan Publishers Limited. All rights reserved.

News Article | December 2, 2016
Site: en.prnasia.com

BEIJING, Dec. 2, 2016 /PRNewswire/ -- Persons with disabilities in China are often faced with challenging realities when seeking judicial protection to realize their basic rights, illuminated in a new report by the United Nations Development Programme (UNDP) in China, ahead of the 2016 International Day of Persons with Disabilities, celebrated annually on 3 December. "2016 is not only the one year anniversary of the 17 Sustainable Development Goals; it is also the 10 year anniversary of the adoption of the Convention on the Rights of Persons with Disabilities. It's timely to assess China's progress in providing an inclusive and accessible society for its 85 million Persons with Disabilities," said Nicholas Rosellini, UN Resident Coordinator and UNDP Resident Representative, China. Against the background of judicial progress shown in the Chinese government's recent White Paper 'New Progress in the Judicial Protection of Human Rights in China', UNDP's report 'Equal Access to Justice for Persons with Disabilities in China' explores the extent to which persons with disabilities in China can effectively navigate the judicial system. The study focuses on the barriers faced by persons with disabilities in accessing justice. It examines both the supply of legal services and the legal demand of persons with disabilities. Importantly, the study spoke to the subjective experiences of persons with disabilities in all aspects of judicial justice, from access to legal information, awareness of legal aid, to the use of legal services, taking legal action and the ability to resolve legal disputes. One of the main challenges faced by persons with disabilities is the unaffordability of available legal services, and the general lack of knowledge about free legal aid services. In the study, 78% of respondents indicated that they would not choose paid legal services mostly because they cannot afford it. At the same time, over half of the respondents did not know that the national legal aid scheme covers people living with defined "economic difficulties". The lack of accessible information about laws and legal services has contributed to such a gap. Moreover, continuous social discrimination and prejudice that all persons with disabilities face critically restricts their ability to navigate the judicial system effectively and also undermines their confidence. The study found that most respondents attributed their challenges in accessing justice to "low level of education among persons with disabilities", blaming themselves rather than external factors for the disadvantages they live with. The limited knowledge and awareness about disability and equality among service providers have also hindered effective service provision for persons with disabilities, as manifested by a lawyer's reaction to a client with visual impairment who fell off the subway platform - "You are blind, why did you even go out?" It is therefore crucial to remove the social stigma and enhance legal empowerment for persons with disabilities. The report was launched at a special event, "Achieving 17 Goals for the Future We Want", commemorating 2016 International Day of Persons with Disabilities. The event was organized by the UN Disability Subgroup, with special support of the UN Partnership to Promote the Rights of Persons with Disabilities (UNPRPD) Taskforce in China (ILO, UNDP, UNESCO, UNICEF, and UNRCO). UNDP partnered with Wuhan University Public Interest and Development Law Institute and Wuhan East-Lake Institute for Social Advancement to produce the report. The report and today's special event serves as a call for joint efforts towards the goal of an inclusive, accessible, and discrimination-free society for persons with disabilities. To download the report please click: UNDP partners with people at all levels of society to help build nations that can withstand crisis, and drive and sustain the kind of growth that improves the quality of life for everyone. On the ground in around 170 countries and territories, we offer global perspective and local insight to help empower lives and build resilient nations. www.undp.org Get in touch: UNDP on Weibo | Media Contacts | WeChat ID: undpchina

Zhang S.,Wuhan University | Xia X.,University of Pretoria
Applied Energy | Year: 2010

The improvement of the energy efficiency of belt conveyor systems can be achieved at equipment or operation levels. Switching control and variable speed control are proposed in literature to improve energy efficiency of belt conveyors. The current implementations mostly focus on lower level control loops or an individual belt conveyor without operational considerations at the system level. In this paper, an optimal switching control and a variable speed drive (VSD) based optimal control are proposed to improve the energy efficiency of belt conveyor systems at the operational level, where time-of-use (TOU) tariff, ramp rate of belt speed and other system constraints are considered. A coal conveying system in a coal-fired power plant is taken as a case study, where great saving of energy cost is achieved by the two optimal control strategies. Moreover, considerable energy saving resulting from VSD based optimal control is also proved by the case study. © 2010 Elsevier Ltd. All rights reserved.

Zhang S.,Wuhan University | Xia X.,University of Pretoria
Applied Energy | Year: 2011

The improvement of the energy efficiency of belt conveyor systems can be achieved at equipment and operation levels. Specifically, variable speed control, an equipment level intervention, is recommended to improve operation efficiency of belt conveyors. However, the current implementations mostly focus on lower level control loops without operational considerations at the system level. This paper intends to take a model based optimization approach to improve the efficiency of belt conveyors at the operational level. An analytical energy model, originating from ISO 5048, is firstly proposed, which lumps all the parameters into four coefficients. Subsequently, both an off-line and an on-line parameter estimation schemes are applied to identify the new energy model, respectively. Simulation results are presented for the estimates of the four coefficients. Finally, optimization is done to achieve the best operation efficiency of belt conveyors under various constraints. Six optimization problems of a typical belt conveyor system are formulated, respectively, with solutions in simulation for a case study. © 2011 Elsevier Ltd.

Zhao P.,George Mason University | Foerster T.,University of Munster | Yue P.,Wuhan University
Computers and Geosciences | Year: 2012

As Web services technology has matured in recent years, an increasing amount of geospatial resources and processing functions are available in the form of online Web services. Consequently, effective and efficient data processing methods for geospatial information extraction and knowledge discovery over the Web are a major challenge for research and industry. The Geoprocessing Web, which consists of light-weight protocols, crowd-sourcing capability, and the capability to process real-time geospatial data sources provided by sensors, enables distributed, interoperable and collaborative processing of geospatial data for information and knowledge discovery. This paper provides a comprehensive overview about the state-of-the-art architecture and technologies, and the most recent developments in the Geoprocessing Web. © 2012 Elsevier Ltd.

Wei Z.,Wuhan University | Wang R.,Hebei North University | Liu A.,Wuhan University
Mathematics and Computers in Simulation | Year: 2014

The paper presents a new four-dimensional hyperchaotic system developed by extension of the generalized diffusionless Lorenz equations. The model is shown to not be equivalent to any hyperchaotic system that the authors know of. In particular, the model does not display any equilibria, but can exhibit two-scroll hyperchaos as well as chaotic, quasiperiodic and periodic dynamics. For certain parameter values, coexisting attractors can be observed, e.g. hyperchaotic and periodic attractors. Investigation of the proposed system is performed through a combination of numerical simulation and mathematical analysis in order to obtain time plots, phase portraits, Lyapunov exponents, and Poincaré sections. © 2014 IMACS.

Zhuan X.,Wuhan University | Xia X.,University of Pretoria
Applied Energy | Year: 2013

The optimal operation scheduling of a pumping station with multiple pumps is formulated as a dynamic programming problem. Based on the characteristics of the problem, an extended reduced dynamic programming algorithm (RDPA) is proposed to solve the problem. Both the energy cost and the maintenance cost are considered in the performance function of the optimization problem. The extended RDPA can significantly reduce the computational time when it is compared to conventional DP algorithms. Simulation shows the feasibility of the reduction of the operation cost. © 2012 Elsevier Ltd.

Yang B.,Wuhan University | Fang L.,Wuhan University | Li J.,University of Waterloo
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2013

Accurate 3D road information is important for applications such as road maintenance and virtual 3D modeling. Mobile laser scanning (MLS) is an efficient technique for capturing dense point clouds that can be used to construct detailed road models for large areas. This paper presents a method for extracting and delineating roads from large-scale MLS point clouds. The proposed method partitions MLS point clouds into a set of consecutive " scanning lines" , which each consists of a road cross section. A moving window operator is used to filter out non-ground points line by line, and curb points are detected based on curb patterns. The detected curb points are tracked and refined so that they are both globally consistent and locally similar. To evaluate the validity of the proposed method, experiments were conducted using two types of street-scene point clouds captured by Optech's Lynx Mobile Mapper System. The completeness, correctness, and quality of the extracted roads are over 94.42%, 91.13%, and 91.3%, respectively, which proves the proposed method is a promising solution for extracting 3D roads from MLS point clouds. © 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

Wei Z.,Wuhan University | Wang Z.,Xijing University
Kybernetika | Year: 2013

By introducing a feedback control to a proposed Sprott E system, an extremely complex chaotic attractor with only one stable equilibrium is derived. The system evolves into periodic and chaotic behaviors by detailed numerical as well as theoretical analysis. Analysis results show that chaos also can be generated via a period-doubling bifurcation when the system has one and only one stable equilibrium. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to achieve modified function projective synchronized between the extended Sprott E system and original Sprott E system. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers.

Jiang Y.,Nanchang University | Jiang D.,Wuhan University
International Journal of Digital Content Technology and its Applications | Year: 2011

In this paper, we investigate the multiple attribute decision making (MADM) problems for for evaluating the security of wireless sensor network (WSN) with interval grey linguistic variables. We utilize the interval grey linguistic weighted geometric (IGLWG) operator to aggregate the interval grey linguistic variables corresponding to each alternative and get the overall value of the alternatives, then rank the alternatives and select the most desirable one(s). Finally, an illustrative example is given.

Zhuan X.,Wuhan University | Xia X.,University of Pretoria
IEEE Transactions on Control Systems Technology | Year: 2013

Considering time-of-use electricity pricing, the optimal scheduling problem of a pumping station is reformulated into a control sequence (CS) optimal scheduling problem, for which a reduced dynamic programming algorithm (RDPA) is proposed to obtain the solution. It is shown that the RDPA allows a reduction of the operational cost by about 60% compared to a basic conventional control strategy, in the example investigated. The fast computation feature of the RDPA facilitates the implementation of a model predictive control (MPC) strategy. In the simulations, RDPA within the MPC structure is found to provide robust control and a marginally increased operational cost, given a pm10% inflow rate uncertainty and a modest stochastic rainfall variability (up to 20%). © 1993-2012 IEEE.

Hu H.,Wuhan University | Damil N.,Hassan II University | Potier-Ferry M.,CNRS Study of Microstructures, Mechanics and Material Sciences lab
Journal of Computational Physics | Year: 2011

In this paper, we present a new numerical technique that permits to analyse the effect of boundary conditions on the appearance of instability patterns. Envelope equations of Landau-Ginzburg type are classically used to predict pattern formation, but it is not easy to associate boundary conditions for these macroscopic models. Indeed, envelope equations ignore boundary layers that can be important, for instance in cases where the instability starts first near the boundary. In this work, the full model is considered close to the boundary, an envelope equation in the core and they are bridged by the Arlequin method [1]. Simulation results are presented for the problem of buckling of long beams lying on a non-linear elastic foundation. © 2011 Elsevier Inc.

Sun Y.,Wuhan University | Fang Y.,City University of Hong Kong | Lim K.H.,City University of Hong Kong | Straub D.,Georgia State University
Information Systems Research | Year: 2012

Existing research has long considered service quality as a primary determinant of user satisfaction with information technology (IT) service delivery. In response to the knowledge-intensive and collaborative nature of IT service delivery in the contemporary business context, we advance the theoretical understanding of user satisfaction by re-conceptualizing IT service delivery as a bilateral, relational process between the IT staff and users. Based on this reconceptualization, we draw on social capital theory to examine the antecedents of user satisfaction with IT service delivery. Specifically, we posit that two major dimensions of social capital, i.e., cognitive capital and relational capital, not only positively affect user satisfaction but also strengthen the established relationship between service quality and user satisfaction. Furthermore, we propose that the effect of the other dimension of social capital-structural capital-on user satisfaction is fully mediated through cognitive capital and relational capital. A field study of 159 users in four financial companies provides general empirical support for our hypotheses. Theoretical and practical implications of these findings are discussed. © 2012 INFORMS.

Chao B.F.,Academia Sinica, Taiwan | Ding H.,Academia Sinica, Taiwan | Ding H.,Wuhan University
Geophysical Research Letters | Year: 2014

We extend the spherical harmonic stacking (SHS) method of Buland et al. (1979) for the radial (vertical) component in the seismogram to the transverse (horizontal) components of the displacement field. Taking advantage of the orthogonality of the spherical harmonic functions (scalar and vectorial), SHS isolates and accentuates the signals of individual singlets of the Earth's normal modes of free oscillation. We apply the SHS on the broadband Incorporated Research Institutions for Seismology (IRIS) seismograms from up to 97 IRIS seismic stations for the 2004 Sumatra-Andaman earthquake, in experiments targeted to spheroidal as well as toroidal modes - 2S1, 0S3, 2S2, 3S1, 1S3, 0T2, and 0T 3. We report the complete resolution of the singlet frequencies of these multiplets, some for the first time, and estimate the singlets' complex frequencies using the frequency domain autoregressive method of Chao and Gilbert (1980). The latter contain useful information to be used in inversions for the 3-D structure of the Earth's interior. Key Points A new spherical harmonic stacking method to resolve normal mode singlets We demonstrate the successful application of SHS in real experiments Complete resolution of singlets of interest and new findings are reported © 2014. American Geophysical Union. All Rights Reserved.

Zhou Q.,Hong Kong Baptist University | Zhou Q.,Wuhan University | Chen Y.,Wuhan University
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2011

This paper reports an investigation into the generalization of a grid-based digital elevation model (DEM) for the purpose of terrain analysis. The focus is on the method of restructuring the grid-based surface elevation data to form a triangulated irregular network (TIN) that is optimized to keep the important terrain features and slope morphology with the minimum number of sample points. The critical points of the terrain surface are extracted from the DEM based on their significance, measured not only by their local relief, but also by their importance in identifying inherent geomorphological and drainage features in the DEM. A compound method is proposed by integrating the traditional point-additive and feature-point methods to construct a drainage-constrained TIN. The outcome is then compared with those derived from other selected methods including filtering, point-additive or feature-point algorithms. The results show that the compound approach is capable of taking advantage of both point-additive and feature-point algorithms to maximally keep the terrain features and to maintain RMSE at an acceptable level, while reducing the elevation data points by over 99%. The analytical result also shows that the proposed method outperforms the compared methods with better control in retaining drainage features at the same level of RMSE. © 2010 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

Shen X.-L.,Wuhan University | Cheung C.M.K.,Hong Kong Baptist University | Lee M.K.O.,City University of Hong Kong
International Journal of Information Management | Year: 2013

The increasing popularity of Web 2.0 has dramatically changed the way in which people communicate with others in their daily life or work. However, the use of social media is fundamentally different from that of traditional information technologies. Specifically, it requires collective efforts and interdependence between two or more people, and thus the usage behavior is no longer an individual's own decision or plan. Built on critical mass theory and social influence processes, this study tries to make an attempt to understand the determinants of collective intention (we-intention), which represents one's perception of a group of people acting as a unit. Instant messaging, one of the most popular social media platforms, has been chosen for investigation, and findings from a survey showed that perceived critical mass influenced we-intention both directly and indirectly through group norm and social identity. Recognizing the importance and relevance of collective intention will advance current understanding beyond individual intention-based models which are widely adopted in prior IS research. This study may be limited by having not included other alternative social technologies, but we leave this work for future research. © 2013 Elsevier Ltd. All rights reserved.

Li X.,Wuhan University | Chen F.,Henan University | Chen X.,Wuhan University | Chen X.,Nanchang University
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2013

The objective of this research is to investigate the potential of nighttime light images, acquired with Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS), in evaluating global armed conflicts. To achieve this purpose, we assessed the relationship between armed conflicts and the satellite-observed nighttime light variation over 159 countries through annual composites of the nighttime light images. Firstly, a light ratio index was developed to reduce the data inconsistency of annual nighttime light images during 1992-2010. Then 12 countries were selected as examples for a primary investigation, and we found the outbreak of a war can reduce the light and the ceasefire can increase the light from the remote sensing images, which indicates armed conflict events always have significant impact on the nighttime light. Based on this assertion, a nighttime light variation index (NLVI) was developed to quantify the variation of the time series nighttime light. Then using conditional probability analysis, the probability of a country suffering from armed conflicts increases with increase of NLVI. Particularly, when the NLVI value is in a very high level as defined, 80% of the countries have experienced armed conflicts. Furthermore, using correlation analysis, the number of global armed conflicts is highly correlated with the global NLVI in temporal dimension, with a correlation coefficient larger than 0.77. In summary, the potential of nighttime light images in armed conflict evaluation is extended from a regional scale to a global scale by this study. © 2008-2012 IEEE.

Yang B.,Wuhan University | Wei Z.,Wuhan University | Li Q.,Wuhan University | Li J.,University of Waterloo
IEEE Geoscience and Remote Sensing Letters | Year: 2013

This letter presents a novel method for automated footprint extraction of building facades from mobile LiDAR point clouds. The proposed method first generates the georeferenced feature image of a mobile LiDAR point cloud and then uses image segmentation to extract contour areas which contain facade points of buildings, points of trees, and points of other objects in the georeferenced feature image. After all the points in each contour area are extracted, a classification based on principal component analysis (PCA) method is adopted to identify building objects from point clouds extracted in contour areas. Then, all the points in a building object are segmented into different planes using the random sample consensus algorithm. For each building, points in facade planes are chosen to calculate the direction, the start point, and the end point of the facade footprints using PCA. Finally, footprints of different facades of building are refined, harmonized, and joined. Two data sets of downtown areas and one data set of a residential area captured by Optech's LYNX mobile mapping system were tested to verify the validities of the proposed method. Experimental results show that the proposed method provides a promising and valid solution for automatically extracting building facade footprints from mobile LiDAR point clouds. © 2012 IEEE.

News Article | February 7, 2016
Site: www.techtimes.com

Camouflage clothing isn't as camouflage as it could be; however, researchers in China are working on a body armor that could almost completely hide whoever is wearing it. To show off their new technology, the researchers from the Wuhan University, built a robotic chameleon and concealed it in plasmonic displays, which are able detect background colors with light sensors, then change the color of the displays to blend in with that background. The displays themselves, which were described in ACS Nano, are made out of thin glass sheets. The sheets have a grid holes that measure a miniscule 50-nanometer wide. The researchers then covered those sheets of glass in gold, creating small domes in the holes, after which they covered the sheet again, this time in a layer of electrolyte gel with silver ions. Plasmons, or groups of electrons, are then produced when light hits the gold domes, which is able to then determine the color to reflect. The displays can produce different colors when they are connected to an electric field, which essentially changes how many of the silver ions stick to the layer of gold. According to the scientists behind the project, the robot can currently only match and produce the primary colors; however, they suggest that soon they will be able to develop a way for the robot to produce other colors too. Eventually, they hope to turn the technology into a camouflage armor that can be used on military vehicles, or even worn by people. Check out the video of the Chameleon robot in action below.

Wang Y.,Wuhan University | Tian H.,Wuhan University | Zhang L.,Wuhan University
Carbohydrate Polymers | Year: 2010

Starch nanocrystals (SN) and cellulose whiskers (CW) were fabricated successfully from the sulfuric acid hydrolysis of waxy maize starch granules and cotton linter pulp, respectively, and were characterized by transmission electron microscopy, atomic force microscopy and wide-angle X-ray diffraction. The nanocrystals and whiskers were embedded in waterborne polyurethane (WPU) matrix using a casting/evaporation technique. A synergistic reinforcing role of SN and CW in WPU was observed for the first time. With incorporation of 1 wt.% SN and 0.4 wt.% CW, the tensile strength, Young's modulus and tensile energy at break of the WPU based nanocomposites were significantly enhanced by 135%, 252% and 136%, respectively, and the elongation at break remained basically compared to pure WPU. WPU/1% SN/0.4% CW system also exhibited a much better reinforcing effect than all of WPU/SN and WPU/CW systems. Furthermore, the WPU based nanocomposites possessed greater thermal resistance. The results clearly revealed that the different polysaccharide nanocrystals and whiskers combined together to form strong hydrogen bonding networks, leading to the synergistic reinforcement of WPU. This work provides a new eco-friendly pathway to prepare polymer nanocomposites with high performance by using natural nanocrystals and whiskers together. © 2010.

Liu P.,Wuhan University | Wang Z.,Wuhan University | Lin J.,Wuhan University | Hu X.,Wuhan University
European Journal of Organic Chemistry | Year: 2012

A simple method has been developed for functionalizing glycine derivatives by iron-catalysed cross-dehydrogenative coupling (CDC) reactions. In particular, N-arylglycine derivatives reacted with alkynes by oxidative C-H/C-H coupling reactions to provide a series of substituted quinolines starting from commercially inexpensive materials. Moreover, N-arylglycine esters can be oxidatively coupled to ketones by using FeCl 3 in the presence of DDQ. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhou J.,Wuhan University | Qi X.,Huazhong Agricultural University
Letters in Applied Microbiology | Year: 2011

Aims: To develop a new nano-composite of multi-walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity.Methods and Results: A novel antimicrobial nanocomposite [MWNT-epilson-polylysine (MEPs)] was synthesized via covalent attachment of epilson-polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV-visible spectra and Fourier transform infrared spectra (FT-IR) investigations indicate that MEPs is stable, with epilson-polylysine leaching effectively eliminated. When compared to MWNTs, the new nano-composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l-1 suspensions, significant increases of 72.1, 64.5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs also shows improved antibacterial activities and excellent antiadhensive efficacies against Ps. aeruginosa and Staph. aureus.Conclusions: Epilson-polylysine functionalization of MWNTs with HDI as the bridge was found to be useful for improving the biocidal activity of MWNTs.Significance and Impact of the Study: The new nano-composite MEPs with improved antimicrobial activity will substantially facilitate the application of MWNTs as the antimicrobial material such as medical device, food, pharmaceutical process and package. © 2010 The Authors. Letters in Applied Microbiology © 2010 The Society for Applied Microbiology.

Luo P.,Wuhan University
Mathematical Methods in the Applied Sciences | Year: 2015

By the means of a differential inequality technique, we obtain a lower bound for blow-up time if p and the initial value satisfy some conditions. Also, we establish a blow-up criterion and an upper bound for blow-up time under some conditions as well as a nonblow-up and exponential decay under some other conditions. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Ye L.,Wuhan University | Tian L.,Wuhan University | Peng T.,Wuhan University | Zan L.,Wuhan University
Journal of Materials Chemistry | Year: 2011

Highly symmetrical BiOI single-crystal nanosheets (BiOI SCNs) with dominant exposed {001} facets (up to 95%) have been synthesized by annealing BiI 3 and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, fast-Fourier transform pattern, UV-vis diffuse reflectance and photoluminescence. The thickness and the {001} facets percentage of BiOI SCNs can be tuned by changing the annealing temperature. The thermal decomposition process of BiI3 and the formation mechanism of BiOI SCNs were investigated. BiOI SCNs exhibit higher photoactivity (about 7 times) than irregular BiOI for degradation of Rhodamine B (RhB) dye under visible light irradiation. The {001} facets are the reactive facets of BiOI. The origin of {001} facets-dependent photoactivity is due to an improvement of the separation efficiency of photo-induced electrons and holes. © 2011 The Royal Society of Chemistry.

Chai B.,Wuhan University | Peng T.,Wuhan University | Zeng P.,Wuhan University | Mao J.,Wuhan University
Journal of Materials Chemistry | Year: 2011

The In2S3/(Pt-TiO2) nanocomposite photocatalyst consisting of floriated In2S3 decorated with TiO2 nanoparticles was synthesized by a multi-step method, which was used for the hydrogen production under visible-light (λ ≥ 420 nm) irradiation. The obtained In2S3/(Pt-TiO2) nanocomposite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance absorption spectra (DRS), and photoluminescence spectra (PL). It is found that the Pt-TiO 2 nanoparticles embedded in the interstices of the floriated In 2S3 formed intimate contacts between the In 2S3 and Pt-TiO2, which is a benefit to significantly enhance the charge separation and then the photocatalytic activity. The effects of the mass ratio in the In2S 3/(Pt-TiO2) nanocomposites and Pt-loaded amount on the photoactivity for the hydrogen production were investigated comparatively. The results show that the In2S3/(Pt-TiO2) nanocomposite with a mass ratio of 3:2 has the maximum photocatalytic hydrogen production rate of 135 μmol h-1 under visible-light irradiation, and the possible mechanism of the obtained In2S3/(Pt- TiO2) nanocomposite as a photocatalyst for hydrogen production was proposed. This journal is © The Royal Society of Chemistry.

Liu T.,Wuhan University | Liu X.,Wuhan University | Li W.,Wuhan University
Oncotarget | Year: 2016

Cancer is a disease caused by the abnormal proliferation and differentiation of cells governed by tumorigenic factors. Chemotherapy is one of the major cancer treatment strategies, and it functions by targeting the physiological capabilities of cancer cells, including sustained proliferation and angiogenesis, the evasion of programmed cell death, tissue invasion and metastasis. Remarkably, natural products have garnered increased attention in the chemotherapy drug discovery field because they are biologically friendly and have high therapeutic effects. Tetrandrine, isolated from the root of Stephania tetrandra S Moore, is a traditional Chinese clinical agent for silicosis, autoimmune disorders, inflammatory pulmonary diseases, cardiovascular diseases and hypertension. Recently, the novel anti-tumor effects of tetrandrine have been widely investigated. More impressive is that tetrandrine affects multiple biological activities of cancer cells, including the inhibition of proliferation, angiogenesis, migration, and invasion; the induction of apoptosis and autophagy; the reversal of multidrug resistance (MDR); and the enhancement of radiation sensitization. This review focuses on introducing the latest information about the anti-tumor effects of tetrandrine on various cancers and its underlying mechanism. Moreover, we discuss the nanoparticle delivery system being developed for tetrandrine and the anti-tumor effects of other bisbenzylisoquinoline alkaloid derivatives on cancer cells. All current evidence demonstrates that tetrandrine is a promising candidate as a cancer chemotherapeutic.

Fan Z.,Wuhan University | Jie Q.-L.,Wuhan University
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

We use cluster mean-field theory, multiple block-product state, and nested cluster methods to study the ground state of a frustrated spin-Heisenberg antiferromagnetically stacked square lattice at zero temperature. By analyzing the magnetic order parameter and the geometric measure of entanglement, we find that the stacked model produces a new ordered magnetic phase because of the competition between the interlayer coupling, Jc, and the frustrated interaction, J2. The interlayer coupling, Jc, strengthens the long-range Néel phase, the new phase, and the collinear phase and destroys the disordered quantum paramagnetic (QP) phase. Increasing Jc results in the new phase gradually replacing the QP phase. The QP phase disappears at the critical point J2* = 0.5 and Jc* = 0.12. © 2014 American Physical Society.

Li G.,CAS Changchun Institute of Applied Chemistry | Li G.,Wuhan University | Lin J.,CAS Changchun Institute of Applied Chemistry
Chemical Society Reviews | Year: 2014

Nowadays there are several technologies used for flat panel displays (FPDs) and the development of FPDs with enhanced energy efficiency and improved display quality is strongly required. Field emission displays (FEDs) have been considered as one of the most promising next generation flat panel display technologies due to their excellent display performance and low energy consumption. For the development of FEDs, phosphors are irreplaceable components. In the past decade, the study of highly efficient low-voltage cathodoluminescent materials, namely FED phosphors, has become the focus of enhancing energy efficiency and realizing high-quality displays. This review summaries the recent progress in the chemical synthesis and improvement of novel, rare-earth and transition metal ions activated inorganic cathodoluminescent materials in powder and thin film forms. The discussion is focused on the modification of morphology, size, surface, composition and conductivity of phosphors and the corresponding effects on their cathodoluminescent properties. Special emphases are given to the selection of host and luminescent centers, the adjustment of emission colors through doping concentration optimization, energy transfer and mono- or co-doping activator ions, the improvement of chromaticity, color stability and color gamut as well as the saturation behavior and the degradation behavior of phosphors under the excitation of a low-voltage electron beam. Finally, the research prospects and future directions of FED phosphors are discussed with recommendations to facilitate the further study of new and highly efficient low-voltage cathodoluminescent materials. This journal is © the Partner Organisations 2014.

Wu C.,CAS Shanghai Institute of Ceramics | Chang J.,CAS Shanghai Institute of Ceramics | Fan W.,Wuhan University
Journal of Materials Chemistry | Year: 2012

Bioactive materials are playing an important role in sealing apical root canals of teeth, inducing bone/cementum tissue regeneration and inhibiting bacterial viability. Conventional Ca(OH) 2 materials have limitations for filling apical root canals of teeth due to their low mineralization ability and potential cytotoxicity. The aim of this study is to prepare bioactive mesoporous calcium-silicate (MCS) nanoparticles for the potential application of filling an apical root canal of a tooth. The mesoporous structure, specific surface area, pore volume and morphology of MCS particles were characterized. The apatite-mineralization ability, in vitro osteogenesis, drug delivery and antibacterial properties were further investigated. The results showed that MCS nanoparticles (around 100 nm) with high specific surface area and pore volume were successfully prepared by a facile template method. The prepared MCS could be easily injected to fill the apical root canal of a tooth. MCS nanoparticles induced apatite-mineralization in DMEM solution, did not show cytotoxicity, and their ionic products could stimulate the proliferation of periodontal ligament cells (PDLCs). In contrast, conventional Ca(OH) 2 materials did not induce mineralization and showed significant cytotoxic effects on PDLCs. Furthermore, MCS extracts at low concentrations (12.5 and 25 mg mL -1) induced higher ALP activity of PDLCs than those at high concentrations (50 and 100 mg mL -1). In addition, MCS extracts significantly stimulated osteogenic gene expression (OPN, ALP and OCN) of PDLCs compared to a blank control, indicating the excellent osteostimulation property of MCS. MCS nanoparticles could be used for loading the antibiotic ampicillin due to their mesoporous microstructures, and the loaded ampicillin in MCS nanoparticles could be released with a slow and sustained release profile. Moreover, it was found that pure MCS nanoparticles revealed antibacterial effects, while the delivery of ampicillin from MCS nanoparticles further inhibited bacterial viability. Therefore, the results suggest that MCS nanoparticles are an advanced biomaterial with multiple functions for filling the apical root canal of a tooth due to their unique nanostructure, injectability, apatite-mineralization, osteostimulation, drug-delivery and antibacterial properties. © The Royal Society of Chemistry 2012.

Xie S.C.,Wuhan University | Yin H.F.,Wuhan University
Science China Earth Sciences | Year: 2014

Geobiology is a new discipline on the crossing interface between earth science and life science, and aims to understand the interaction and co-evolution between organisms and environments. On the basis of the latest international achievements, the new data presented in the Beijing geobiology forum sponsored by Chinese Academy of Sciences in 2013, and the papers in this special issue, here we present an overview of the progress and perspectives on three important frontiers, including geobiology of the critical periods in Earth history, geomicrobes and their responses and feedbacks to global environmental changes, and geobiology in extreme environments. Knowledge is greatly improved about the close relationship of some significant biotic events such as origin, radiation, extinction, and recovery of organisms with the deep Earth processes and the resultant environmental processes among oceans, land, and atmosphere in the critical periods, although the specific dynamics of the co-evolution between ancient life and paleoenvironments is still largely unknown. A variety of geomicrobial functional groups were found to respond sensitively to paleoenvironmental changes, which enable the establishment of proxies for paleoenvironmental reconstruction, and to play active roles on the Earth environmental changes via elemental biogeochemical cycles and mineral bio-transformations, but to be deciphered are the mechanisms of these functional groups that change paleoenvironmental conditions. Microbes of potential geobiology significance were found and isolated from some extreme environments with their biological properties partly understood, but little is known about their geobiological functions to change Earth environments. The biotic processes to alter or modify the environments are thus proposed to be the very issue geobiology aims to decipher in the future. Geobiology will greatly extend the temporal and spatial scope of biotic research on Earth and beyond. It has great potential of application in the domains of resource exploration and global change. To achieve these aims needs coordinative multidisciplinary studies concerning geomicrobiology and related themes, database and modeling of biogeochemical cycles, typical geological environments, and coupling of biological, physical, and chemical processes. © 2013 Science China Press and Springer-Verlag Berlin Heidelberg.

Yang Z.,Wuhan University | Wang X.,Wuhan University | Liu T.,Wuhan University
Urology | Year: 2013

Objective: To compare the clinical outcomes between thulium laser transurethral enucleation of the prostate (ThuLEP) and plasmakinetic bipolar resection of the prostate (PKRP) for treating benign prostatic hyperplasia (BPH) in a prospective randomized trial with 18 months of follow-up. Methods: The study randomized 158 consecutive patients with BPH to ThuLEP (n = 79) or PKRP (n = 79). All patients were evaluated preoperatively and at 1, 3, 6, 12, and 18 months after surgery by International Prostate Symptom Score (IPSS), quality of life score (QOLS), maximum flow rate (Qmax), and postvoid residual urine volume (PVR). Results: The 79 patients in each study arm each showed no significant difference in preoperative parameters. Compared with PKRP, ThuLEP required a longer operation time (65.4 vs 47.4 minutes, P =.022) but resulted in less hemoglobin decrease (0.15 vs 0.30 g/dL, P =.045). ThuLEP also needed less catheterization time (2.1 vs 3.5 days, P =.031), irrigation volume (12.4 vs 27.2 L, P =.022), and hospital stay (2.5 vs 4.6 days, P =.026). During the 1, 3, 6, 12, and 18 months of follow-up, the procedures did not demonstrate a significant difference in Qmax, IPSS, PVR, and QOLS. Conclusion: ThuLEP and PKRP both relieve lower urinary tract symptoms equally, with high efficacy and safety. ThuLEP was statistically superior to PKRP in blood loss, catheterization time, irrigation volume, and hospital stay but inferior to PKRP in operation time. However, procedures did not differ significantly in Qmax, IPSS, PVR, and QOLS through the 18 months of follow-up. © 2013 Elsevier Inc.

Wu J.,Wuhan University | Ding X.-H.,Huazhong University of Science and Technology
Scientometrics | Year: 2013

Scientists generally do scientific collaborations with one another and sometimes change their affiliations, which leads to scientific mobility. This paper proposes a recursive reinforced name disambiguation method that integrates both coauthorship and affiliation information, especially in cases of scientific collaboration and mobility. The proposed method is evaluated using the dataset from the Thomson Reuters Scientific "Web of Science". The probability of recall and precision of the algorithm are then analyzed. To understand the effect of the name ambiguation on the h-index and g-index before and after the name disambiguation, calculations of their distribution are also presented. Evaluation experiments show that using only the affiliation information in the name disambiguation achieves better performance than that using only the coauthorship information; however, our proposed method that integrates both the coauthorship and affiliation information can control the bias in the name ambiguation to a higher extent. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Wu J.,Wuhan University
Scientometrics | Year: 2013

This paper proposes a citation rank based on spatial diversity (SDCR) in terms of cities and countries, focusing on the measurement of the "spatial" aspect in citation networks. Our main goal is to solve the citation bias caused by different geographical locations of citations. We empirically investigate spatial properties of citing distances, citation patterns and spatial diversity to understand geographical knowledge diffusion, based on the data from "Transportation Science and Technology" subject category in the Web of Science (1966-2009). We also compare the proposed ranking method with other bibliometric measures, and conduct a case study to figure out the recent ranks of the well-established authors in Transportation research. It is found that the SDCR of a focal author is highly correlated with the sum of spatial diversity weights ("strength") of all his in-links, and it is better to set the damping factors smaller than 0. 75 when ranking authors with various initial academic years by SDCR. The cases show that Hong Kong is becoming a cluster in Transportation research. © 2012 Akadémiai Kiadó, Budapest, Hungary.

Zhang C.,Wuhan University | Zhang C.,Leibniz University of Hanover | Ma C.,Wuhan University | Holtz F.,Wuhan University
Lithos | Year: 2010

Field observation, petrography and geochemistry of mafic enclaves/dikes and their host felsic rocks from the Meichuan pluton are used to propose a geodynamic model for the southern Dabie orogen, central China. The similar Sr-Nd isotopic ratios [εNd(t)=-15, (87Sr/86Sr)i=0.70550-0.70597] and zircon Hf isotopic ratios [εHf(t)=-25 to -16] indicate that the two types of magmatic rocks were formed by coeval felsic and mafic magmas during the Early Cretaceous (132±2Ma, zircon U-Pb age). The adakitic signatures of both the felsic and mafic rocks, such as very high Sr (770-1400ppm), high Sr/Y ratios (40-130), low Y (3.5-21ppm) and HREE concentrations are supposed to be features of the primary magmas, indicating that both of them were generated by partial melting of basaltic protoliths at great depths (>15kbar). The distinctive major element compositions of the felsic and mafic primary magmas could be attributable to different melting temperatures and melting degrees. The mafic enclaves/dike have distinctively high concentrations of MgO (4.4-5.8wt.%), Cr (229-374ppm) and Ni (75-163ppm), indicating a melt-mantle interaction in which olivine is partly consumed while orthopyroxene and/or pyrope are formed under high-pressure. Modeling suggests that 14% of peridotite relative to melt could have been consumed to elevate the Mg# of melt to the observed values (55-60), and that transformation from orthopyroxene to pyrope in mantle peridotite could have decreased the Al2O3 content from 18-19wt.% in the initial melts to ~15wt.% in the resultant mafic melts. Moderate negative zircon εHf(t) and bulk εNd(t) values also suggest contributions from both enriched lithospheric mantle and ancient lower crust. The results can best be explained by assuming that a block of amphibolite-composition lower continental crust was delaminated into the lithospheric mantle, leading to the formation of mafic magmas. This delamination is attributed to lithospheric extension and asthenospheric upwelling along the Yangtze River fault zone in the late Mesozoic which could have heated up the lithospheric mantle underneath the neighboring southern Dabie orogen. The strong input of heat triggered the delamination of the overlying thickened lower crust into lithospheric mantle by weakening the uppermost mantle and resulted in melting reactions in the delaminated crustal block to produce hot (~1100°C) intermediate adakitic magmas (SiO2=55-60wt.%). The ascent of these hot magmas and their underplating below the lower crust induced the generation of high-silica melts (SiO2=~70wt.%) at lower temperature (~925°C or less). Hybridization processes between the two magma types occurred during further ascent and emplacement in the crust, which could have led to the high concentrations of MgO (2.2-3.5wt.%), Cr (56-226ppm) and Ni (33-99ppm) in the host felsic rocks. © 2010 Elsevier B.V.

Liu X.,Wuhan University | Ma F.,Wuhan University
Scientometrics | Year: 2013

In order to explore the rule of knowledge creation activities at both temporal and spatial scales, this paper makes statistical analysis of the time interval and spatial displacement of consecutive knowledge creation activities of high-yield, low-yield, and ASFP (all the scientists published at least four papers), respectively. The research shows that, for high-yield scientists, the time interval of knowledge creation activities obeys heavy-tailed distribution and embodies bursting features, with both long-time silence and intensive burst of creation activities. The time interval distribution of low-yield scientists is approximate to exponential distribution, and is often randomly and occasionally distributed. For ASFP, the spatial distribution of creation activities also embodies heavy-tailed features, where their activities are intensively confined to a certain knowledge field, and where long-distance exploration across the knowledge fields has also been made in knowledge creation activities. © 2012 Akadémiai Kiadó, Budapest, Hungary.

Jiang T.,Wuhan University
Journal of Documentation | Year: 2013

Purpose: Social library systems are Web 2.0 sites where users discover interesting books, movies, and music, etc., collect these resources to their personal libraries, and share their collections with others. The purpose of this study is to identify the information seeking modes adopted by users in this context as well as to reveal the characteristics of the users who are dominated by each mode. Design/methodology/approach: An online survey was conducted to capture the background and behavior data of regular users from Douban, the most influential Chinese-language social library system. The "friend-of-a-friend" recruitment technique resulted in a total of 129 responses, 112 of which were valid and analyzed to generate both descriptive and inferential statistics. Findings: Searching, browsing, encountering, and monitoring are the four major information seeking modes adopted by social library system users. The majority of the users tend to combine two or more modes, but each user has a dominating one that helps define him/her as a searcher, browser, encounterer, or monitor. While searching is the most widely adopted mode, browsers are the most prevalent type of information seekers. Different information seekers do not demonstrate significantly different characteristics by and large, however with some exceptions. Originality/value: This study is one of the first to investigate how users look for resources in social library systems, a problem neglected by previous studies mostly focusing on how users organize and tag resources. The research findings enrich our understanding of social library systems as diverse and dynamic information seeking environments. This in turn will provide useful implications for their interface design to more effectively address the needs and expectations of special types of information seekers. © Emerald Group Publishing Limited.

Shen Z.,Wuhan University | Tong Q.,Northeastern University China
ICSPS 2010 - Proceedings of the 2010 2nd International Conference on Signal Processing Systems | Year: 2010

Cloud computing provides people the way to share distributed resources and services that belong to different organizations or sites. Since cloud computing share distributed resources via the network in the open environment, thus it makes security problems important for us to develop the cloud computing application. In this paper, we pay attention to the security requirements in cloud computing environment. We proposed a method to build a trusted computing environment for cloud computing system by integrating the trusted computing platform into cloud computing system. We propose a model system in which cloud computing system is combined with trusted computing platform with trusted platform module. In this model, some important security services, including authentication, confidentiality and integrity, are provided in cloud computing system. © 2010 IEEE.

Chang C.,Wuhan University | Duan B.,Wuhan University | Cai J.,Wuhan University | Zhang L.,Wuhan University
European Polymer Journal | Year: 2010

Novel superabsorbent hydrogels were prepared successfully from carboxymethylcellulose sodium (CMC) and cellulose in the NaOH/urea aqueous system by using epichlorohydrin (ECH) as cross-linker. The structure and morphology of the hydrogels were characterized by FT-IR spectroscope, thermogravimetric analysis and scanning electron microscope. The results revealed that the CMC contributed to the enhanced size of pore, whereas cellulose as a strong backbone in the hydrogel to support it for keeping its appearance. Their equilibrium swelling ratio in distilled water and different physiological fluids were evaluated, indicating the maximum swelling ratio in water reached an exciting level of 1000 as the hydrogels still keeping a steady appearance. Moreover, the hydrogels exhibited smart swelling and shrinking in NaCl or CaCl 2 aqueous solution, as well as the release behavior of bovine serum albumin (BSA) that could be controlled by changing CMC content. The cellulose-based hydrogels are promising for the applications in the biomaterials area. © 2009 Elsevier Ltd. All rights reserved.

Wang Y.,Wuhan University | Yang Y.,Wuhan University | Shao H.,Wuhan University
Solid State Communications | Year: 2010

The LiMnPO4/C composite material with ordered olivine structure was synthesized in 1:1(v/v) enthanol-water mixed solvent in the presence of cetyltrimethylammonium bromide (CTAB) at 240{ring operator}C. Rod-like particle morphology of the resulting LiMnPO4/C powder with a uniform particle dimension of 150 × 600 nm was observed by using scanning electron microscope and the amount of carbon coated on the particle surface was evaluated as 2.2wt% by thermogravimetric analysis, which is reported for the first time to date for LiMnPO4/C composite. The measurement of the electrochemical performance of the material used in rechargeable lithium ion battery shows that the LiMnPO4/C sample delivers an initial discharge capacity of 126.5 mA h g-1 at a constant current of 0.01 C, which is 74% of the theoretical value of 170 mA h g-1. The electrode shows good rated discharge capability and high electrochemical reversibility when compared with the reported results, which is verified further by the evaluation of the Li ion diffusion coefficient of 5.056×10-14 cm2/s in LiMnPO4/C. © 2009 Elsevier Ltd. All rights reserved.

Liu C.,Wuhan University | Liu D.,Wuhan University | Lei A.,Wuhan University | Lei A.,Jiangxi Normal University
Accounts of Chemical Research | Year: 2014

Oxidative cross-coupling reactions between two nucleophiles are a powerful synthetic strategy to synthesize various kinds of functional molecules. Along with the development of transition-metal-catalyzed oxidative cross-coupling reactions, chemists are applying more and more first-row transition metal salts (Fe, Co, etc.) as catalysts. Since first-row transition metals often can go through multiple chemical valence changes, those oxidative cross-couplings can involve single electron transfer processes. In the meantime, chemists have developed diverse mechanistic hypotheses of these types of reactions. However, none of these hypotheses have led to conclusive reaction pathways until now. From studying both our own work and that of others in this field, we believe that radical oxidative cross-coupling reactions can be classified into four models based on the final bond formations. In this Account, we categorize and summarize these models. In model I, one of the starting nucleophiles initially loses one electron to generate its corresponding radical under oxidative conditions. Then, bond formations between this radical and another nucleophile create a new radical, [Nu1-Nu2]•, followed by a further radical oxidation step to generate the cross-coupling product. The radical oxidative alkenylation with olefin, radical oxidative arylative-annulation, and radical oxidative amidation are examples of this model. In model II, one of the starting nucleophiles loses its two electrons via two steps of single-electron-transfer to generate an electrophilic intermediate, followed by a direct bond formation with the other nucleophile. For example, the oxidative C-O coupling of benzylic sp3 C-H bonds with carboxylic acids and oxidative C-N coupling of aldehydes with amides are members of this model group. For model III, both nucleophiles are oxidized to their corresponding radicals. Then, the radicals combine to form the final coupling product. The dioxygen-involved radical oxidative cross-couplings between sulfinic acids and olefins or alkynes belong to this bond formation model. Lastly, in model IV, one nucleophile loses two electrons to generate an electrophilic intermediate, while the other nucleophile loses one electron to generate a radical. Then, a bond forms between the cation and the radical to generate a cationic radical, followed by a one-electron reduction to afford the final coupling product. The oxidative coupling between arylboronic acids and simple ethers was classified in this model. At the current stage, there are only a few examples presented for models III and IV, but they represent two types of potentially important transformations. More and more examples of these two models will be developed in the future. (Chemical Equation Presented). © 2014 American Chemical Society.

Zeng T.,Wuhan University | Liu J.,Wuhan University
Artificial Intelligence in Medicine | Year: 2010

Objective: Accurate cancer prognosis prediction is critical to cancer treatment. There have been many prognosis models based on clinical markers, but few of them are satisfied in clinical applications. And with the development of microarray technologies, cancer researchers have discovered many genes as new markers from the gene expression data and have further developed powerful prognosis models based on these so-called genetic biomarkers. However, the application of such biomarkers still suffers from some problems. The first one is there are a great number of genes and a few samples in the gene expression data so that it is difficult to select a unified gene set to establish a stable classifier for prognosis. The second one is that, due to the experimental and technical reasons, there are existing noises and redundancies in gene expression data, which may lead to building a prognosis predictor with poor performance. The last but not the least one is the microarray experiments are so expensive currently that it is hard to obtain abundant samples. Therefore, it is practical to develop prognosis methods mainly based on conventional clinical markers in real cancer treatment applications. This paper aims to establish an accurate classification model for cancer prognosis, in order to make full use of the invaluable information in clinical data, especially which is usually ignored by most of the existing methods when they aim for high prediction accuracies. Methods: First, this paper gives the formal description of general classification problem, and presents a novel mixture classification model to make full use of the invaluable information in clinical data, which is similar to the traditional ensemble classification models except for putting strict constraints on the construction of mapping functions to avoid voting process. Then, a two-layer instance of the proposed model, named as MRS (Mixture of Rough set and Support vector machine), is constructed by integrating rough set and support vector machine (SVM) classification methods, in which, the rough set classifier acts as the first layer to identify some singular samples in data, and the SVM classifier acts as the second layer to classify the remaining samples. Finally, MRS is used to make prognosis prediction on two open breast cancer datasets. One dataset, denoted as BRC-1 hereafter, is a high quality, publicly available dataset of 97 breast cancer tumors of node-negative patients. The other, denoted as BRC-2 hereafter, uses baseline human primary breast tumor data from LBL breast cancer cell collection containing 174 samples. Results: We have done two experiments on BRC-1 and BRC-2, respectively. In the first experiment, the BRC-1 dataset is divided into train set with 78 patients (34 ones belonging to poor prognosis group and 44 ones belonging to good prognosis group) and test set with 19 patients (12 ones belonging to poor prognosis group and 7 ones belonging to good prognosis). After trained on the train set, the MRS can correctly classify all the 12 patients with poor prognosis, and 6 of 7 patients with good prognosis in the test set. The results are better than previous researches, even better than the 70-gene based biomarkers. And in the second experiment, we construct the classifiers using BRC-2 dataset, and compare MRS with other representative methods in Weka software by 5-fold cross-validation, and comparison results show that MRS has higher prediction accuracy than those methods. Conclusions: The proposed mixture classification model can easily integrate methods with different characteristics. It can overcome the shortcomings of traditional voting-based ensemble models and thus can make full use of the information in clinical data. The experimental results illustrate that our implemented MRS classifier can predict the breast cancer prognosis more accurately than previous prognostic methods. © 2009 Elsevier B.V.

Lue A.,Wuhan University | Zhang L.,Wuhan University
Polymer | Year: 2010

Multi-walled carbon nanotubes (MWNTs) were dispersed, for the first time, in cellulose solution in 9.5. wt% NaOH/4.5. wt% thiourea aqueous system pre-cooled to -5°C. Dynamic light scattering and transmission electron microscopy results revealed a relatively strong interaction existed between MWNTs and the cellulose macromolecules, leading to a good dispersion of MWNTs in the cellulose solution. Their rheological behaviors, especially the sol-gel transition were investigated by using the advanced rheological expanded system on the basis of Winter and Chambon theory. The gel point and gel concentration of the cellulose/MWNTs solution system were determined, indicating a regularly rheological behavior. The data of loss tangent and relaxation exponent (n) indicated an enhancement in the viscoelasticity of the MWNTs/cellulose system. The results from scaling law before and beyond the sol-gel transition in the MWNTs/cellulose system confirmed that the cluster formation and alteration of the gelation structure occurred at the gel point. Interestingly, the n values calculated by both the Winter and Chambon theory and scaling law were coincident only at relatively low temperature. The predicted gel strength values of the MWNTs/cellulose system were significantly larger than the pure cellulose solution, suggesting a relatively high strength, supported by the mechanical strength of the cellulose/MWNTs material. © 2010 Elsevier Ltd.

Yuan Q.,Wuhan University | Zhang L.,Wuhan University | Shen H.,Wuhan University | Li P.,Wuhan University
IEEE Transactions on Image Processing | Year: 2010

Image super-resolution (SR) reconstruction has been a hot research topic in recent years. This technique allows the recovery of a high-resolution (HR) image from several low-resolution (LR) images that are noisy, blurred and down-sampled. Among the available reconstruction frameworks, the maximum a posteriori (MAP) model is widely used. In this model, the regularization parameter plays an important role. If the parameter is too small, the noise will not be effectively restrained; conversely, the reconstruction result will become blurry. Therefore, how to adaptively select the optimal regularization parameter has been widely discussed. In this paper, we propose an adaptive MAP reconstruction method based upon a U-curve. To determine the regularization parameter, a U-curve function is first constructed using the data fidelity term and prior term, and then the left maximum curvature point of the curve is regarded as the optimal parameter. The proposed algorithm is tested on both simulated and actual data. Experimental results show the effectiveness and robustness of this method, both in its visual effects and in quantitative terms. © 2010 IEEE.

Xiao D.,Wuhan University | Jia H.-Z.,Wuhan University | Zhang J.,Wuhan University | Liu C.-W.,Wuhan University | And 2 more authors.
Small | Year: 2014

A novel pH- and redox- dual-responsive tumor-triggered targeting mesoporous silica nanoparticle (TTTMSN) is designed as a drug carrier. The peptide RGDFFFFC is anchored on the surface of mesoporous silica nanoparticles via disulfide bonds, which are redox-responsive, as a gatekeeper as well as a tumor-targeting ligand. PEGylated technology is employed to protect the anchored peptide ligands. The peptide and monomethoxypolyethylene glycol (MPEG) with benzoic-imine bond, which is pH-sensitive, are then connected via "click" chemistry to obtain TTTMSN. In vitro cell research demonstrates that the targeting property of TTTMSN is switched off in normal tissues with neutral pH condition, and switched on in tumor tissues with acidic pH condition after removing the MPEG segment by hydrolysis of benzoic-imine bond under acidic conditions. After deshielding of the MPEG segment, the drug-loaded nanoparticles are easily taken up by tumor cells due to the exposed peptide targeting ligand, and subsequently the redox signal glutathione in tumor cells induces rapid drug release intracellularly after the cleavage of disulfide bond. This novel intelligent TTTMSN drug delivery system has great potential for cancer therapy. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang K.,Wuhan University | Li H.,Wuhan University | Song Z.,Wuhan University
EMBO Reports | Year: 2014

Mitochondrial inner membrane fusion depends on the dynamin-related GTPase OPA1 and the function of OPA1 is regulated by proteolytic cleavage. The mitochondrial proteases Yme1L and OMA1 cleave OPA1 at S2 and S1 sites, respectively. Here, we show that OMA1 is cleaved to a short form (S-OMA1) by itself upon mitochondrial membrane depolarization; S-OMA1 is degraded quickly but could be stabilized by CCCP treatment or Prohibitin knockdown in cells. In addition, OMA1 processing is positively correlated with OPA1 cleavage at the S1 site and the regulation of mitochondrial morphology. Thus, our results reveal the molecular mechanism for OMA1 activation toward OPA1 processing. Synopsis The dynamin-related GTPase OPA1 regulates mitochondrial inner membrane fusion and is activated by Yme1L- and OMA1-mediated proteolytic cleavage. This study reveals that OMA1 undergoes self-cleavage upon mitochondrial membrane depolarization under cellular stress conditions. The processing of OMA1 is positively correlated with its activity toward OPA1 cleavage. OMA1, the protease that processes OPA1, undergoes self-cleavage upon mitochondrial membrane depolarization The processing of OMA1 is positively correlated with its activity toward OPA1 cleavage. The dynamin-related GTPase OPA1 regulates mitochondrial inner membrane fusion and is activated by Yme1L- and OMA1-mediated proteolytic cleavage. This study reveals that OMA1 undergoes self-cleavage upon mitochondrial membrane depolarization under cellular stress conditions. The processing of OMA1 is positively correlated with its activity toward OPA1 cleavage. © 2014 The Authors.

Muto K.,Nagoya University | Yamaguchi J.,Nagoya University | Lei A.,Wuhan University | Itami K.,Nagoya University
Journal of the American Chemical Society | Year: 2013

We describe mechanistic studies of a C-H/C-O biaryl coupling of 1,3-azoles and aryl pivalates catalyzed by Ni(cod)2/dcype. This study not only supports a catalytic cycle consisting of C-O oxidative addition, C-H nickelation, and reductive elimination but also provides insight into the dramatic ligand effect in C-H/C-O coupling. We have achieved the first synthesis, isolation and structure elucidation of an arylnickel(II) pivalate, which is an intermediate in the catalytic cycle after oxidative addition of a C-O bond. Furthermore, kinetic studies and kinetic isotope effect investigations reveal that the C-H nickelation is the turnover-limiting step in the catalytic cycle. © 2013 American Chemical Society.

Kunisch K.,University of Graz | Wang L.,Wuhan University
ESAIM - Control, Optimisation and Calculus of Variations | Year: 2013

Time optimal control problems for an internally controlled heat equation with pointwise control constraints are studied. By Pontryagin's maximum principle and properties of nontrivial solutions of the heat equation, we derive a bang-bang property for time optimal control. Using the bang-bang property and establishing certain connections between time and norm optimal control problems for the heat equation, necessary and sufficient conditions for the optimal time and the optimal control are obtained. © 2012 EDP Sciences, SMAI.

Meng L.,Wuhan University | Wu K.,Wuhan University | Liu C.,Wuhan University | Lei A.,Wuhan University | Lei A.,Peking University Shenzhen Graduate School
Chemical Communications | Year: 2013

The first palladium-catalysed aerobic oxidative intramolecular alkenylation of Csp3-H bonds was described. The reaction conditions were mild and molecular oxygen was used as the terminal oxidant. Kinetic studies showed that the Csp3-H metallation step was a slow step. © 2013 The Royal Society of Chemistry.

Li Q.-H.,Wuhan University | Wei L.,Wuhan University | Chen X.,Wuhan University | Wang C.-J.,Wuhan University | Wang C.-J.,CAS Shanghai Institute of Organic Chemistry
Chemical Communications | Year: 2013

Expedient access to optically active fluorinated 2,4-trans-imidazolidines was successfully developed via Cu(i)-catalyzed exo′-selective 1,3-DC of azomethine ylides with fluorinated imines. © 2013 The Royal Society of Chemistry.

Chen H.,Wuhan University | Li W.-X.,Wuhan University | Wang L.-J.,Wuhan University of Science and Technology
Journal of Nonlinear Science | Year: 2013

We prove real analyticity of all the streamlines, including the free surface, of a gravity- or capillary-gravity-driven steady flow of water over a flat bed, with a Hölder continuous vorticity function, provided that the propagating speed of the wave on the free surface exceeds the horizontal fluid velocity throughout the flow. Furthermore, if the vorticity possesses some Gevrey regularity of index s, then the stream function of class C 2,μ admits the same Gevrey regularity throughout the fluid domain; in particular if the Gevrey index s equals 1, then we obtain analyticity of the stream function. The regularity results hold not only for periodic or solitary-water waves, but also for any solution to the hydrodynamic equations of class C 2,μ . © 2013 Springer Science+Business Media New York.

Liu P.,Wuhan University | Wang Z.,Wuhan University | Hu X.,Wuhan University
European Journal of Organic Chemistry | Year: 2012

A simple and efficient method for the synthesis of 1,3-disubstituted ureas and carbamates from amides by using iodosylbenzene as the oxidant is described. Symmetric and asymmetric ureas and carbamates can be prepared by this procedure in up to 98 % yield. Ureidopeptides can also be prepared in good yield by this method. A simple and efficient method for the synthesis of 1,3-disubstituted ureas and carbamates from amides by using iodosylbenzene as the oxidant is described. By using this method, heterocyclic products can be easily obtained in excellent yield. Ureidopeptides can also be prepared in good yield by this procedure. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang S.,Wuhan University | Yang X.,Guangzhou University | Fan M.,Wuhan University
International Endodontic Journal | Year: 2013

Aim: To investigate the cytotoxicity of BioAggregate and iRoot BP Plus root canal sealer (iRoot BP Plus) to human dental pulp cells (hDPCs) and their effect on proliferation and mineralization of hDPCs and to compare their performance with that of mineral trioxide aggregate (MTA). Methodology: Human dental pulp cells were seeded onto the prepared BioAggregate, iRoot BP Plus and MTA, respectively. Cell proliferation was assessed by CCK-8 cell proliferation kit on days 1, 3, 5 and 7. ALP activity was measured to evaluate the cell differentiation potential on days 1, 3, 5 and 7. The expression of odontoblastic differentiation-related genes (dentine phosphoprotein, dentine matrix protein-1 and osteocalcin) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Statistical tests used were one-way anova and post hoc Tukey's test. Results: The proliferation of hDPCs in the MTA group was suppressed throughout the culture period, whereas the BioAggregate group and the iRoot BP Plus group first significantly increased cell numbers on day 1 (P < 0.01) and then decreased on day 3 to day 7. ALP activity was enhanced in all the three groups from day 3, whilst iRoot BP Plus showed significantly higher ALP activity than MTA (P < 0.01). qRT-PCR indicated that both BioAggregate and iRoot BP Plus groups were associated with a higher upregulation of mineralization and odontoblastic differentiation-associated gene expressions as compared to MTA group (P < 0.05). Conclusions: BioAggregate and iRoot BP Plus were nontoxic and able to induce mineralization and odontoblastic differentiation-associated gene expression in hDPCs. © 2013 International Endodontic Journal.

Zhang X.,Wuhan University | Li X.,Wuhan University | Deng N.,Wuhan University
Industrial and Engineering Chemistry Research | Year: 2012

The photocatalytic performance of cyclodextrin modified TiO 2 (TiO 2/β-CD) on the degradation of rhodamine B and bisphenol A (BPA) was studied in this work. The interactions between β-CD and TiO 2 varied as the synthesis method changes. When applying TiO 2/β-CD synthesized from photoinduced self-assembly method as photocatalyst, the initial visible light (λ ≥ 420 nm) degradation rates R 0 of rhodamine B and BPA increased by 4.6 and 3.2 times respectively. The TiO 2/β-CD hybrid material synthesized from adsorption method only showed enhancement in dye pollutants degradation. The reactivity of TiO 2/β-CD under visible light was correlated with the specific surface area of unmodified semiconductor. The mechanism for the enhanced and selective degradation of pollutants over TiO 2/β-CD was also proposed in this work. © 2011 American Chemical Society.

Hou L.,Wuhan University | Zhang H.,Wuhan University | Xue X.,Wuhan University
Separation and Purification Technology | Year: 2012

The removal of tetracycline by magnetite (Fe 3O 4) activated peroxydisulfate (Na 2S 2O 8) in the presence of ultrasound irradiation has been performed in this study. The effects of Na 2S 2O 8 concentration, Fe 3O 4 addition, ultrasonic power, initial concentration and initial pH on the degradation of tetracycline were investigated. The results showed that tetracycline removal rate increased with the increase of Fe 3O 4 dosage, but decreased with the increase of initial pH and initial tetracycline concentration. With the optimum values of Na 2S 2O 8 concentration and ultrasound power, the highest degradation rate can be achieved. The scavenging effect was examined by using ethanol, tert-butyl alcohol and 1,4-benzoquinone to evaluate the roles of sulfate radicals, hydroxyl radicals and superoxide radicals. The results indicated that sulfate radicals and the hydroxyl radicals played important roles in the degradation of tetracycline by Fe 3O 4/Na 2S 2O 8/US process. © 2011 Published by Elsevier B.V.

Chen B.,University of Saskatchewan | Fan W.,University of Saskatchewan | Liu J.,Wuhan University | Wu F.-X.,University of Saskatchewan
Briefings in Bioinformatics | Year: 2014

Cellular processes are typically carried out by protein complexes and functional modules. Identifying them plays an important role for our attempt to reveal principles of cellular organizations and functions. In this article, we review computational algorithms for identifying protein complexes and/or functional modules from protein-protein interaction (PPI) networks. We first describe issues and pitfalls when interpreting PPI networks. Then based on types of data used and main ideas involved, we briefly describe protein complex and/or functional module identification algorithms in four categories: (i) those based on topological structures of unweighted PPI networks; (ii) those based on characters of weighted PPI networks; (iii) those based on multiple data integrations; and (iv) those based on dynamic PPI networks. The PPI networks are modelled increasingly precise when integrating more types of data, and the study of protein complexes would benefit by shifting from static to dynamic PPI networks. © The Author 2013. Published by Oxford University Press.

Parameter identification of PEM (proton exchange membrane) fuel cell model is a very active area of research. Generally, it can be treated as a numerical optimization problem with complex nonlinear and multi-variable features. DE (differential evolution), which has been successfully used in various fields, is a simple yet efficient evolutionary algorithm for global numerical optimization. In this paper, with the objective of accelerating the process of parameter identification of PEM fuel cell models and reducing the necessary computational efforts, we firstly present a generic and simple ranking-based mutation operator for the DE algorithm. Then, the ranking-based mutation operator is incorporated into five highly-competitive DE variants to solve the PEM fuel cell model parameter identification problems. The main contributions of this work are the proposed ranking-based DE variants and their application to the parameter identification problems of PEM fuel cell models. Experiments have been conducted by using both the simulated voltage-current data and the data obtained from the literature to validate the performance of our approach. The results indicate that the ranking-based DE methods provide better results with respect to the solution quality, the convergence rate, and the success rate compared with their corresponding original DE methods. In addition, the voltage-current characteristics obtained by our approach are in good agreement with the original voltage-current curves in all cases. © 2013 Elsevier Ltd.

Zhang X.,Wuhan University | Zhong Z.,Wuhan University | Zhuo R.,Wuhan University
Macromolecules | Year: 2011

Polycarbonates with pendant azido groups that could be feasibly functionalized by the click reaction was reported. The composition and molecular weight of the polycarbonates were characterized by NMR and GPC. The degree of polymerization (DP) of each monomer unit was calculated by comparing the integration of signals at 3.50-3.45 and 1.12-0.95 with the signals of initiator residue at 1.75-1.61. The result suggests that the two azido compounds are less sensitive to impact in comparison with other common explosives such as trinitrotoluene and nitroglycerine whose BAM impact sensitivity is 15 and 0.2 J. Transforming the bromo groups of the polycarbonate into azido groups is performed by the reaction with sodium azide in DMF at various combinations of temperature and reaction time. The obtained PDTC-g-PEG with polycarbonates as the main chains and PEG as the side chains are found to be amphiphilic copolymers.time. The obtained PDTC-g-PEG with polycarbonates as the main chains and PEG as the side chains are found to be amphiphilic copolymers.

Wang Z.,Nanyang Technological University | Liu W.,Wuhan University | Xiao W.,Wuhan University | Lou X.W.,Nanyang Technological University
Energy and Environmental Science | Year: 2013

Amorphous CoSnO3@C nanoboxes have been synthesized by thermal annealing of CoSn(OH)6 nanoboxes, followed by carbon nanocoating. Benifiting from the unique structure, they exhibit exceptional long-term cycling stability over 400 cycles for highly reversible lithium storage. © The Royal Society of Chemistry 2013.

Chang C.,Wuhan University | He M.,Wuhan University | Zhou J.,Wuhan University | Zhang L.,Wuhan University
Macromolecules | Year: 2011

Ampholytic hydrogels with pH and salt responsive properties have been synthesized by cross-linking quaternized cellulose (QC) and carboxymethyl cellulose (CMC) with epichlorohydrin (ECH) in NaOH aqueous solution. The swelling behaviors of the QC/CMC hydrogels were studied as a function of the polymer composition, pH, and salt concentration. The equilibrium swelling ratio of the hydrogel in ultrapure water strongly depended on the composition, and increased dramatically from 8.6 to 498 g/g with the change of the weight ratio of QC to CMC from 3:1 to 1:3 (w/w). The hydrogel (Gel32) consisted of QC and CMC in the ratio of 3:2 (w/w) had the minimum swelling ratio, and it was electrically neutral. The results from Χ-potential experiments were in good agreement with the theoretically calculated stoichiometry for balanced charge, confirming that the weight ratio of QC and CMC was 1.5, corresponding to Gel32. Furthermore, all hydrogels exhibited excellent pH sensitivity in the range of pH from 1 to 13 and shrunk significantly at pH 12 on the whole. The hydrogels displayed smart swelling behaviors in NaCl, CaCl2, and FeCl 3 aqueous solutions. The results revealed that CMC mainly contributed to increasing the swelling as a result of strong water adsorption, whereas QC played a role in the controlling of the charges in the QC/CMC system, leading to the pH sensitivity. © 2011 American Chemical Society.

Li J.,Wuhan University
Cehui Xuebao/Acta Geodaetica et Cartographica Sinica | Year: 2012

The status and development background on the research of the local geoid of the world in the recent 20 years is reviewed in this paper. An updated 2'×2' digital quasi-geoid model (CNGG2011) for the National Height Datum 1985 of China is computed by using Stokes-Helmert method. More than one million land gravity measurements, 7.5″×7.5″ digital elevation data from SRTM, and 649 order B GPS/leveling data are used in the computation of CNGG2011. The average accuracy of CNGG2011 is ±0.13 m in China, and ±0.07 m and ±0.14 m in eastern and western China, respectively. The average accuracy in each province is ±0.06 m, and they are ±0.05 m and ±0.11 m in the East and the West of China respectively, and it is ±0.22 m in the Tibet area. The relationship between the gravimetric geoid and the GPS/leveling is also discussed and some strategies for geoid refinement in the future are also proposed for National Height Datum in China.

Ma H.-C.,Wuhan University
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2011

This paper reviews the applications of laser mapping technology in the fields of global glacier analysis and monitoring, local and large scale faults extraction, landslide mapping and susceptibility assessment, shoreline detection and coastal erosion monitoring. As a new type of air-or-space borne remote sensing sensor, the application of laser mapping technology (including spaceborne, airborne, vehicle-based and terrestrial) has been extended from conventional surveying and precision surveying to such various fields as cultural heritage protection. The four application fields reviewed in the paper are four major research topics that are mostly related to human-environmental interaction. The review conclusion shows that the laser mapping technology should be or is becoming an indispensable tool for above mentioned issues.

Zhai X.,Wuhan University | Xia J.,Wuhan University | Zhang Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Science of the Total Environment | Year: 2014

Water quality deterioration is a prominent issue threatening water security throughout the world. Huai River Basin, as the sixth largest basin in China, is facing the most severe water pollution and high disturbance. Statistical detection of water quality trends and identification of human interferences are significant for sustainable water quality management. Three key water quality elements (ammonium nitrogen: NH3-N, permanganate index: CODMn and dissolved oxygen: DO) at 18 monitoring stations were selected to analyze their spatio-temporal variations in the highly disturbed Huai River Basin using seasonal Mann-Kendall test and Moran's I method. Relationship between surrounding water environment and anthropogenic activities (point source emission, land use) was investigated by regression analysis. The results indicated that water environment was significantly improved on the whole from 1994 to 2005. CODMn and NH3-N concentrations decreased at half of the stations, and DO concentration increased significantly at 39% (7/18) stations. The high pollution cluster centers for both NH3-N and CODMn were in the middle stream of Shaying River and Guo River in the 2000s. Water quality of Huai River Basin was mainly influenced by point source pollution emission, flows regulated by dams, water temperature and land use variations and so on. This study was expected to provide insights into water quality evolution and foundations for water quality management in Huai River Basin, and scientific references for the implementation of water pollution prevention in China. © 2014 Elsevier B.V.

Xiao L.,Wuhan University | Liao L.,Wuhan University | Liu L.,Wuhan University
Chemical Physics Letters | Year: 2013

The structure of graphene oxide (GO) enables it to act as the olefin in cyclopropanation reaction with ethyl diazoacetate (EDA) under microwave irradiation. This versatile synthetic method offers a powerful method for the rapid chemical modification of GO. The attachment of carbethoxycarbene (CEC) to GO was confirmed by the results of FTIR, XPS, Raman, and UV-vis analysis. © 2012 Elsevier B.V. All rights reserved.

Li D.,Wuhan University | Chen Y.,Wuhan University | Lu W.,Wuhan University | Zhou C.,Wuhan University
Computers and Geotechnics | Year: 2011

This paper proposes a stochastic response surface method for reliability analysis involving correlated non-normal random variables, in which the Nataf transformation is adopted to effectively transform the correlated non-normal variables into independent standard normal variables. Transformations of random variables that are often used in reliability analyses in terms of standard normal variables are summarized. The closed-form expressions for fourth to sixth order Hermite polynomial chaos expansions involving any number of random variables are formulated. The proposed method will substantially extend the application of stochastic response surface method for reliability problems. An example of reliability analysis of rock slope stability with plane failure is presented to demonstrate the validity and capability of the proposed stochastic response surface method. The results indicate that the proposed stochastic response surface method can evaluate the reliability of rock slope stability involving correlated non-normal variables accurately and efficiently. Its accuracy is shown to be higher than that for the first-order reliability method, and it is much more efficient than direct Monte-Carlo simulation. The results also show that the number of collocation points selected should ensure that the Hermite polynomial matrix has a full rank so that different order SRSMs can produce a robust estimation of probability of failure for a specified performance function. Generally, the accuracy of SRSM increases as the order of SRSM increases. © 2010 Elsevier Ltd.

Zuo R.,Wuhan University
Applied Geochemistry | Year: 2011

Decomposing mixed geochemical patterns is a challenge in geochemical exploration and environmental assessment. In this paper, the spectrum-area technique (S-A) is used to decompose a mixed pattern of arsenic in Gangdese belt based on stream sediment data. S-A is a multifractal model based on power-law relationships between area of the set consisting of wave numbers with spectral energy density above S[. A(>S)] on the 2D frequency domain. The original spatial distribution map of arsenic obtained by inverse distance weighted (IDW) shows a mixed pattern due to superposition of different geological processes or events and is converted into the frequency domain by means of Fourier transformation. Two components, including power spectrum density and phases, are obtained. The spectrum energy density (S) and the area (A) enclosed by the above-threshold spectrum energy density is plotted on a log-log scale. Two cutoff values determined by three straight lines define three filters which decompose the original map of arsenic into background, anomalous, and high frequency (noise) components. The areas with high anomaly of arsenic mainly are located surrounding known Cu deposits, indicating that arsenic anomalies may be related to Cu mineralization. © 2011 Elsevier Ltd.

Shu N.,Wuhan University
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2011

The Intelligent system for remote sensing image processing is very necessary to be established for many applications. I discuss some problems about this kind of system, such as the segmentations of multi-scale, the semantic networks based on the distributions of ground object in a specified region, data base, algorithm base and knowledge base.

Zhang Y.,Wuhan University | Li C.,Wuhan University | Pan C.,Wuhan University
Journal of the American Ceramic Society | Year: 2012

This study introduces a facile and novel route to synthesize the N + Ni codoped anatase TiO 2 nanocrystals with exposed {001} facets through two-step hydrothermal reaction. The microstructures, chemical compositions, and photocatalytic properties of the codoped TiO 2 were characterized using X-ray diffractometer, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectrometry, and photoluminescence emission spectra. The experimental results revealed that (i) the elements N and Ni have been successfully codoped into the anatase TiO 2 with exposed {001} facets; (ii) the size of the TiO 2 reached to a narrow range of 5-15 nm; (iii) the codoped TiO 2 exhibited an additional visible light absorption band from 400 to 500 nm, which greatly improved the photocatalytic activity. The theoretical calculations for band structure and total energy also provided a good explanation for the experimental results. © 2012 The American Ceramic Society.

Wong H.,Hong Kong Polytechnic University | Hu B.Q.,Wuhan University
Journal of Hydrology | Year: 2014

The extension evaluation method (EEM) has been developed and applied to evaluate water quality. There are, however, negative values in the correlative degree (water quality grades from EEM) after the calculation. This is not natural as the correlative degree is essentially an index based on grades (rankings) of water quality by different methods, which are positive. To overcome this negativity issue, the interval clustering approach (ICA) was introduced, which is based on the grey clustering approach (GCA) and interval-valued fuzzy sets. However, the computing process and formulas of ICA are rather complex. This paper provides a novel method, i.e., improved extension evaluation method, so as to avoid negative values in the correlative degree. To demonstrate our proposed approach, the improved EEM is applied to evaluate the water quality of three different cross-sections of the Fen River, the second major branch river of the Yellow River in China and the Han Jiang River, one of the major branch rivers of the Yangtse River in China. The results of the improved evaluation method are basically the same as the official water quality. The proposed method possesses also the same merit as the EEM and ICA method, which can be applied to assess water quality when the levels of attributes are defined in terms of intervals in the water quality criteria. Existing methods are mostly applicable to data in the form of single numeric values. © 2013 Elsevier B.V.

A titania hollow fiber membrane was successfully synthesized in a macro range via a template method coupled with a sol-gel process. Thermal gravimetric and differential thermal analysis (TG-DTA) was employed to study the effect of heat treatment on the synthesized hollow fiber, and the crystal forms of the titania hollow fiber membranes at different temperatures were studied by X-ray diffraction (XRD). The pore structure of the prepared titania hollow fiber was characterized by scanning electron micrograph (SEM) and nitrogen adsorption/desorption measurements. The prepared titania hollow fiber membrane was explored as a new adsorption material for trace metals for the first time and a new method of titania hollow fiber membrane solid phase microextraction (MSPME) online coupled to inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace amount of Cd, Co, V and Ni in human serum samples. In order to validate the developed method, two certified reference materials of NIES.No.10-b rice flour and BCR No.184 bovine muscle were analyzed and the determined values were in good agreement with the certified values. © The Royal Society of Chemistry 2011.

Animals that exhibit indeterminate growth obey such a functional relationship: adult body size = f (initial size + growth rate × age). Using this framework, we investigated how and why body sizes of a toad species (Bufo andrewsi) covaried across six altitudes (760-2,100 m) in western China. Towards high altitudes, toads tended to produce large eggs, attain large sizes at metamorphism and have great average age, but grow slowly. This indicated that the former three variables contributed more to the observed altitudinal increase in body size than did the last one. The altitudinal variation in these life-history traits should be adaptive to increased climate harshness and decreased predation risks at higher altitudes. We suggest that the relative significance of responses of these size-related parameters to local environments may provide critical cues to explaining considerable variability in geographic size pattern among ectothermic vertebrates. © 2011 Springer Science+Business Media B.V.

Size-related asexual reproduction of submersed macrophytes is still poorly understood. Here, we investigate how size-related auto-fragmentation in Myriophyllum spicatum L. responds to sediment nutrients and plant density. An experiment was carried out with sediments containing two different nutrient levels and with two levels of plant density. The results show that sediment nutrients and plant density brought about a strong dependency of auto-fragment production and the amount of total non-structural carbohydrate (TNC) storage in auto-fragments on individual plant size (total plant biomass). However, these two factors acted differently on size dependency. Sediment nutrients positively affected auto-fragment production and the amount of TNC in auto-fragments of M. spicatum. High concentrations of sediment nutrients significantly increased these two traits in absolute value and the value relative to plant size. Although the auto-fragment biomass and the amount of TNC in auto-fragments did not differ between density treatments when plant size was considered, the absolute values of these two traits were much larger in the low plant density treatment than in the high plant density treatment, which suggested an indirect negative effect of plant density on the auto-fragmentation of M. spicatum. In addition, higher percentages of large auto-fragments (>100 mg) were produced by plants that grew in nutrient poor sediment and low plant density environment than plants in nutrient rich sediment and high plant density environment. These results do not solely highlight a size-dependent effect, but also a size-independent effect of auto-fragment production and the amount of TNC in auto-fragments of M. spicatum. Furthermore, such size-independent effects can be explained by the significant biomass partitioning differences and the similar TNC-concentrations in auto-fragments under different environmental conditions. © Springer Science+Business Media B.V. 2010.

A novel alumina hollow fiber was synthesized by sol-gel template method and was characterized by scanning electron microscopy, N2 adsorption technique and X-ray diffraction. With the use of prepared alumina hollow fiber as extraction membrane, a new method of flow injection (FI)-membrane solid phase microextraction (MSPME) on-line coupled to inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed for simultaneous determination of trace metals (Cu, Mn and Ni) in environmental water samples. The adsorption capacities of the alumina hollow fiber for Cu, Mn and Ni were found to be 6.6, 8.7 and 13.3mgg-1, respectively. With a preconcentration factor of 10, the limits of detection (LODs) for Cu, Mn and Ni were found to be 0.88, 0.61 and 0.38ngmL-1, respectively, and the relative standard deviations (RSDs) were ranging from 6.2 to 7.9% (n=7, c=10ngmL-1). To validate the accuracy, the proposed method was applied to the analysis of certified reference material GSBZ50009-88 environmental water and the determined values are in good agreement with the certified values. The developed method was also employed for the analysis of Yangtze River water and East Lake water, and the recoveries for the spiked samples were in the range of 87.4-110.2%. © 2011 Elsevier B.V.

We compared the growth responses of the floating-leaved species Nymphoides peltata to gradual and rapid rising water levels under two nutrient concentrations (1. g and 12. g of slow released fertilizer (N-P-K: 16-8-12) per container filled with 8. kg washed sand), and predicted the population expansion after these floods. The results showed that the capacity for petiole elongation was dependent on leaf age, and only leaves that were no more than five days old had the capability to reach the water surface when the water level increased rapidly from 50. cm to 300. cm. Plants subjected to a gradual rising water level tracked the increase in water depth whose petioles elongated at 3.96 ± 1.70. cm per day and 4.80 ± 0.16. cm per day under low and high nutrient concentrations respectively throughout the experiment period. When water levels were rapidly raised, leaf petioles elongated rapidly at 25.48 ± 1.51. cm per day and 26.64 ± 2.24. cm per day under low and high nutrient concentrations respectively during the first ten days. Plants under a constant water level maintained highest mean leaf recruitment (mean 3.0 ± 0.33 leaves and 24.4 ± 5.87 leaves every ten days under low and high nutrient concentrations, respectively). Therefore, more young leaves existed in the canopy ensuring that when the water level increases, young leaves can rapidly emerge after submergence. Gradual water level rise did not significantly affect biomass and ramet production (4.75 ± 1.41. g and 5.50 ± 1.22 ramets in low nutrient; 48.49 ± 21.45. g and 35.67 ± 11.78 ramets in high nutrient), but rapid water level rise negatively affected ramet production in both nutrient concentrations (3.00 ± 1.26 ramets and 11.25 ± 4.19 ramets in low and high nutrients, respectively). The results indicated that continual leaf recruitment and rapid petiole elongation were both important ways in which N. peltata adapted to increasing water levels. Extreme flooding may be a disturbance factor that affects plant growth and the population expansion of N. peltata, while small gradual water level rise should not harm this species. © 2010 Elsevier B.V.

Liao W.B.,China West Normal University | Lu X.,Wuhan University
Ethology Ecology and Evolution | Year: 2012

The mating pattern in animals is regarded as a consequence of sexual selection of phenotypic characters, and variations in sexual selection strength will result in different mating patterns. In view of this, we studied variation in mating patterns in the Andrew's toad Bufo andrewsi across five elevation populations (range = 1000-2100 m) in southwestern China. The results showed that there was a high male-biased operational sex ratio in all populations. Mean adult male SVL differed significantly among localities and amplexus conditions, showing a significant among-locality difference in large male advantage. Mean age of adult males differed among localities and mating status, suggesting an old-male mating advantage for all populations. A significant age-assortative mating pattern was only observed in the 2100-m site. There were significant among-locality differences in large or old-male advantage and size or old-assortative patterns. Among the sites, the operational sex ratios were positively correlated with size ratios of males (amplectant SVL/non-amplectant SVL), but not age ratios of males (amplectant age/non-amplectant age). The strength of size-assortative mating did not increase with increasing operational sex ratios. © 2012 Copyright 2012 Dipartimento di Biologia Evoluzionistica dell'Universit, Firenze, Italia.

Min J.,Texas A&M University | Liu H.,Wuhan University | Chai J.,Texas A&M University
Proceedings of I3D 2010: The 2010 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games | Year: 2010

This paper presents a generative human motion model for synthesis, retargeting, and editing of personalized human motion styles. We first record a human motion database from multiple actors performing a wide variety of motion styles for particular actions. We then apply multilinear analysis techniques to construct a generative motion model of the form x = g(a, e) for particular human actions, where the parameters a and e control "identity" and "style" variations of the motion x respectively. The new modular representation naturally supports motion generalization to new actors and/or styles. We demonstrate the power and flexibility of the multilinear motion models by synthesizing personalized stylistic human motion and transferring the stylistic motions from one actor to another. We also show the effectiveness of our model by editing stylistic motion in style and/or identity space. Copyright © 2010 by the Association for Computing Machinery, Inc.

Liu D.,Auburn University | Liu W.,Wuhan University
Ceramics International | Year: 2012

Nanostructure (La 2/3Sr 1/3)MnO 3 thin films were epitaxial grown on SrTiO 3 (0 0 1) single crystal substrate by pulsed laser deposition. Both high Curie temperature (T c = 360 K) and high magnetoresistance (MR = -38% at 500 Oe magnetic fields and 320 K) were simultaneously achieved. The high Curie temperature was attributed to the high quality epitaxial LSMO films. The high low field magnetoresistance (LFMR) was attributed to the regular square nanostructure of the deposited LSMO films, where the boundaries serve as the barrier for spin-polarized tunneling and/or spin-dependent scattering. The high T c and large MR made the LSMO film very useful in room temperature magnetic devices. © 2011 Elsevier Ltd and Techna Group S.r.l.

This is a response to Alexander Zahar's article in the previous issue of Climate Law. Zahar argued that 'the principle of prevention is neither applicable nor of relevance to the problem of climate change.'1 Firstly, I discuss Zahar's scepticism toward state responsibility in the context of climate change. Secondly, I engage critically with Zahar's claim that the preventive principle only applies to the type of environmental damage that occurs in a short timeframe and in a confined space. I show that some sources of international law do recognize the applicability of the preventive principle to damage to the global environment. Lastly, I dissent with Zahar's qualification of the climate regime as a derogation to the principle of prevention. I argue that the principle of prevention is a necessary corollary of the rights of states to territorial integrity, although the modalities of application of the principle need to be refined. © koninklijke brill nv, leiden, 2015.

Gao W.,Wuhan University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

The rock burst is a kind of large disaster in deep underground engineering, thus, it is very important to predict the rock burst. The influence factors of rock burst are numerous and their relationship is very complicated. It can not be solved by use of simple methods, Generally, based on engineering analogy and geological analysis, the clustering methods have been widely used. For the complicated environment of rock burst, this clustering problem is a very complicated fuzzy and random optimization problem, and can not be solved by use of the traditional methods very well. A new bionics clustering optimization method, ant colony clustering algorithm which is recently proposed, is introduced into the prediction of rock burst for the first time. On such a basis, a new method for the prediction of rock burst is proposed. According to analysis of the data of rock burst samples and from the engineering analogy thinking by the ant colony clustering algorithm, the rock burst can be predicted. Two examples are used to verify the new algorithm. The engineering application has proved that this new algorithm can automatically sort the rock burst samples, that the validity is very high, and that the computing velocity is rapid, so it is a very practical method.

Tai Q.,Jianghan University | Zhao X.-Z.,Wuhan University
Journal of Materials Chemistry A | Year: 2014

Bifacial dye-sensitized solar cells (DSCs) that are able to utilize the incidental light from both their front- and rear-side have received increasing attention in recent years. Compared to conventional DSCs that can only be operated under front-side illumination, bifacial design will allow DSCs to generate up to 50% more electrical power. Besides, bifacial DSCs can be easily made transparent and may find broad applications in building integrated photovoltaics (BIPV) as power-generating windows and roof panels. Transparent counter electrodes (CEs) are key to the fabrication of bifacial DSCs. However, despite the fact that conventional Pt CE can be made transparent, its high cost and scarce source may hinder the large-scale application of DSCs. Therefore, many efforts have been made to develop low-cost alternative CEs based on carbon materials, conducting polymers, inorganic compounds and their composites. In this feature article, we intend to pay special attention to the recent advances in the development of Pt-free transparent CEs and highlight their applications in bifacial DSCs. This journal is © the Partner Organisations 2014.

He D.,Wuhan University | He D.,CAS Institute of Software | Chen Y.,Wuhan University | Chen J.,Wuhan University
Nonlinear Dynamics | Year: 2012

Very recently, Lee et al. (C. Lee, C. Chen, C. Wu, S. Huang, An extended chaotic maps-based key agreement protocol with user anonymity, Nonlinear Dynamics, doi:10.1007/s11071-011-0247-4) proposed a chaotic maps-based key agreement protocol with user anonymity and claimed their protocol could resist various attacks. In this paper, we will point out that Lee et al.'s protocol suffers from three weaknesses: (1) inability of resisting the privileged insider attack; (2) inability of resisting the denial-of-service attack; and (3) inability of providing anonymity. To overcome the weaknesses, we also proposed an improved protocol. The analysis shows our protocol is more suitable for practical applications. © Springer Science+Business Media B.V. 2011.

Zhang X.-X.,Wuhan University | Cheng Y.-G.,Wuhan University
Journal of Hydrodynamics | Year: 2012

Although the hydraulic transients in pipe systems are usually simulated by using a one-dimensional (1-D) approach, local three-dimensional (3-D) simulations are necessary because of obvious 3-D flow features in some local regions of the hydropower systems. This paper combines the 1-D method with a 3-D fluid flow model to simulate the Multi-Dimensional (MD) hydraulic transients in hydropower systems and proposes two methods for modeling the compressible water with the correct wave speed, and two strategies for efficiently coupling the 1-D and 3-D computational domains. The methods are validated by simulating the water hammer waves and the oscillations of the water level in a surge tank, and comparing the results with the 1-D solution data. An MD study is conducted for the transient flows in a realistic water conveying system that consists of a draft tube, a tailrace surge tank and a tailrace tunnel. It is shown that the 1-D-3-D coupling approach is an efficient and promising way to simulate the hydraulic transients in the hydropower systems in which the interactions between 1-D hydraulic fluctuations of the pipeline systems and the local 3-D flow patterns should be considered. © 2012 Publishing House for Journal of Hydrodynamics.

Li D.,Wuhan University
Cehui Xuebao/Acta Geodaetica et Cartographica Sinica | Year: 2012

On January 9th, 2012, China launched its first civilian three-line-array stereo mapping satellite-ZY-3. ZY-3 is equipped with 2 front and back view TDI CCD cameras having the resolution better than 3.5 m and the width better than 50 km, 1 TDI CCD camera with the resolution better than 2.1 m and the width better than 50 km and 1 multispectral camera with the resolution better than 5.8 m. In order to ensure accuracy and reliability, ZY-3 adopts a large platform which is equipped with double-frequency GPS and more gyroes. ZY-3 obtains its geolocation accuracy better than 15 m without GCPs, geolocation accuracy better than 3 m and plane geolocation accuracy better than 4 m with GCPs which completely satisfies 1:50000 mapping precision.

Zhou F.,Wuhan University | Zhou F.,University of New South Wales
Journal of Petroleum Science and Engineering | Year: 2012

This paper presents a numerical simulation study that demonstrates history matching and production prediction for an actual horizontal coalbed methane (CBM) well located in Australia. A brief analysis of limited core analysis and well log data is presented. Numerical reservoir simulation is used to carry out a manual history matching to the field data of gas and water production rates and well bottomhole pressure. The matching parameters are porosity, relative permeability and skin factor. The reported field data show that there are sharp changes in the well bottomhole pressure and water and gas rates. This response of the reservoir is matched with a numerical model that has a varying skin factor along the horizontal well. This is deemed reasonable given that the drilling fluid has longer contact with the formation at the heel of the well, causing more formation damage. But the field data indicates that the formation damage is mitigated quickly with production. This is explained by the fact that the invaded mud is forced back during water and gas production and coal shrinkage. The production predictions show that skin factor and coal shrinkage have important effects on the CBM production of a horizontal well. However, the coal formation damage controls the gas rate more than the shrinkage for the examined case study with the assumed coal shrinkage parameters. © 2012 Elsevier B.V.

Zheng Z.,Wuhan University
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2011

This paper puts forward a new application for image segmentation with the concept of biogeography-based optimigation(BBO). It divides one original image into three binary images to be the initial segmented images by the fractal dimension, energy and gray of each pix in original image(residence), and then reaches the image segmentation optimigation by the emigration and immigration of the pixels in the three initial segmented images .With the application of opposition-based learning(OBL) technology during the optimigation can also better the performance of image segmentation. The result of image segmentation experiment based on three aerial images(100 pixel × 100 pixel) shows that the BBOIS algorithm can be proved to be advantage and potential.

Zhang Y.,Wuhan University | Luo C.,Wuhan University | Li W.,Wuhan University | Pan C.,Wuhan University
Nanoscale | Year: 2013

Monolayer graphene sheets were deposited on a transparent and flexible polydimethylsiloxane (PDMS) substrate, and a tensile strain was loaded by stretching the substrate in one direction. It was found that an electric potential difference between stretched and static monolayer graphene sheets reached 8 mV when the strain was 5%. Theoretical calculations for the band structure and total energy revealed an alternative way to experimentally tune the band gap of monolayer graphene, and induce the generation of electricity. © The Royal Society of Chemistry 2013.

Zuo R.,Wuhan University | Carranza E.J.M.,University of Twente
Computers and Geosciences | Year: 2011

In this contribution, we describe an application of support vector machine (SVM), a supervised learning algorithm, to mineral prospectivity mapping. The free R package e1071 is used to construct a SVM with sigmoid kernel function to map prospectivity for Au deposits in western Meguma Terrain of Nova Scotia (Canada). The SVM classification accuracies of 'deposit' are 100%, and the SVM classification accuracies of the 'non-deposit' are greater than 85%. The SVM classifications of mineral prospectivity have 5-9% lower total errors, 13-14% higher false-positive errors and 25-30% lower false-negative errors compared to those of the WofE prediction. The prospective target areas predicted by both SVM and WofE reflect, nonetheless, controls of Au deposit occurrence in the study area by NE-SW trending anticlines and contact zones between Goldenville and Halifax Formations. The results of the study indicate the usefulness of SVM as a tool for predictive mapping of mineral prospectivity. © 2010 Elsevier Ltd.

Montag M.,Weizmann Institute of Science | Zhang J.,Weizmann Institute of Science | Zhang J.,Wuhan University | Milstein D.,Weizmann Institute of Science
Journal of the American Chemical Society | Year: 2012

Primary alcohol dehydrogenation by a PNP-Ru(II) catalyst was probed by low-temperature NMR experiments. Facile dehydrogenation occurred at -30 °C, but the resulting aldehydes were not found in solution, as they were trapped by the catalyst through a new mode of metal-ligand cooperation involving Ru-O coordination and an unusual, highly reversible C-C coupling with the PNP pincer ligand. © 2012 American Chemical Society.

Gao Y.,Wuhan University | Xu H.,Wuhan University | Shen Y.,Wuhan University | Wang J.,Wuhan University
Plant Molecular Biology | Year: 2013

The endosperm plays an important role in seed formation and germination, especially in rice (Oryza sativa). We used a high-throughput sequencing technique (RNA-Seq) to reveal the molecular mechanisms involved in rice endosperm development. Three cDNA libraries were taken from rice endosperm at 3, 6 and 10 days after pollination (DAP), which resulted in the detection of 21,596, 20,910 and 19,459 expressed gens, respectively. By ERANGE, we identified 10,371 differentially expressed genes (log2Ratio ≥1, FDR ≤0.001). The results were compared against three public databases (Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and MapMan) in order to annotate the gene descriptions, associate them with gene ontology terms and to assign each to pathways. A large number of genes related to ribosomes, the spliceosome and oxidative phosphorylation were found to be expressed in the early and middle stages. Plant hormone, galactose metabolism and carbon fixation related genes showed a significant increase in expression at the middle stage, whereas genes for defense against disease or response to stress as well as genes for starch/sucrose metabolism were strongly expressed during the later stages of endosperm development. Interestingly, most metabolic pathways were down-regulated between 3 and 10 DAP except for those involved in the accumulation of material, such as starch/sucrose and protein metabolism. We also identified the expression of 1,118 putative transcription factor genes in endosperm development. The RNA-Seq results provide further systematic understanding of rice endosperm development at a fine scale and a foundation for future studies. © 2013 Springer Science+Business Media Dordrecht.

Teng H.-L.,Wuhan University | Yao L.,Wuhan University | Wang C.-J.,Wuhan University | Wang C.-J.,Nankai University
Journal of the American Chemical Society | Year: 2014

An unprecedented Cu(I)-catalyzed asymmetric [6 + 3] cycloaddition of tropone with azomethine ylides was reported, which performs well over a broad scope of substrates and offers a unique and facile access to the synthetically useful bridged azabicyclo[4.3.1]decadiene derivatives in good yields with high levels of diastereoselectivities and enantioselectivities under mild conditions. © 2014 American Chemical Society.

Li S.,Wuhan University | Zhang Y.,Wuhan University | Xu X.,Wuhan University | Zhang L.,Wuhan University
Biomacromolecules | Year: 2011

Silver nanoparticles were constructed by using triple helical polysaccharide (lentinan) dissolved in water as matrix for the first time. The structure, morphology, and size of the nanocomposites in the polysaccharide aqueous solutions were investigated with UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and dynamic laser light scattering (DLS). The results revealed that the silver nanoparticles were attached to the polysaccharide chains through the strong noncovalent interactions, leading to the good dispersion of silver nanoparticles with mean radius of 6 nm in water. The silver nanoparticles were stable in the lentinan aqueous solution for 9 months. However, with an addition of NaOH, the polysaccharide with the imperfect helical structure broken partially by NaOH could aggregate in the alkali aqueous solution. The aggregation of the lentinan-bonded silver nanoparticles increased with an increase in the NaOH concentration, whereas the size of the silver nanoparticles barely changed, further confirming that the Ag nanoparticles were stable in this system. The aggregation was related to the conformation transition of the polysaccharide from the triple helix to random coil in the solution. A new method to detect the aggregates and aggregation rate was established according to the intensity of the maximum absorption peaks of the polysaccharide labeled by Ag nanoparticles in the UV spectrum. © 2011 American Chemical Society.

Jie M.,Wuhan University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

With the constant improvement of technologies for virtual interaction, it has gradually become a fashion to have virtual interactions about sports. For virtual interaction, unity 3D isn’t only effective for presenting a 3A-rated vivid virtual environment, but may also perfectly interact with Motion Sensing equipment. As brand new and cutting-edge technologies in current field of 3D digital interactive multimedia, virtual interaction and Motion Sensing technologies have broad prospects for development and great space for applied research, so they may contribute to more research and applications in terms of sports. Based on literature consultation, interview, experiment and mathematical analysis, sports forms and environment are simulated by virtual reality technologies, to create a lifelike virtual 3D environment for sports. Virtual interaction is made possible for swimming to create a brand new sports pattern. Different movement orbits of human actions are acquired from virtual environment with Kinect Motion Sensing equipment, in order that 3D human body models could move in virtual swimming scenes. Suggestions are made to further improve the creation of virtual reality environment and add virtual equipment, so that virtual realities may be more vivid. With the use of Motion Sensing technologies, the application of more sports in virtual Motion Sensing interaction will be promoted. © Springer International Publishing Switzerland 2016.

Li H.,Wuhan University | Zhang L.,Wuhan University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011

Anomaly endmembers play an important role in the application of remote sensing, such as in unmixing classification and target detection. Inspired by the iterative error analysis (IEA), a hybrid endmember extraction algorithm (HEEA) based on a local window is proposed in this paper, which focuses on improving the accuracy of endmember extraction. HEEA uses the spectral-information-divergence-spectral-angle-distance metric to measure the similarity and the orthogonal subspace projection (OSP) method to search for the endmembers, which can decrease the correlation between extracted endmember spectra. Moreover, it is based on a local window which integrates both spatial and spectral aspects to extract endmembers. A synthetic image and Airborne Visible/Infrared Imaging Spectrometer data were tested with the HEEA method, classical IEA, OSP, simplex growing algorithm, sequential maximum angle convex cone, and spectral spatial endmember extraction automatic endmember extraction method. Experimental results indicated that HEEA manifested a slightly better improvement in the rmse and spectrum information than the other methods. The effect was investigated with various SNRs and different window sizes. The robustness of HEEA is better than the classical IEA, even with lower SNR. © 2006 IEEE.

Li N.,Wuhan University | Tan Y.,Wuhan University | Deng Y.,Wuhan University | Chen L.,Wuhan University
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2014

Purpose: To compare the outcomes between posterior cruciate-retaining and posterior stabilized total knee arthroplasty (TKA) in order to evaluate which approach is superior. Methods: Randomized controlled trials (RCTs) comparing posterior cruciate-retaining with posterior stabilized TKA were reviewed which were published up to August 2011. Methodological quality of each included RCT was assessed using the Physiotherapy Evidence Database (PEDro) scale. The relevant data were analysed using Review Manager 5.1. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to determine the quality of the evidence. Results: Eight RCTs involving 888 patients with 963 knee joints met predetermined inclusion criteria. The postoperative range of motion (ROM) and flexion angle were 11.07° and 2.88° higher for patients with a posterior stabilized TKA than those with a posterior cruciate-retaining TKA, respectively [weighted mean difference (WMD), -11.07; 95 % confidence interval (CI), -18.06 to -4.08; p < 0.01 and WMD, -2.88; 95 % CI, -5.63 to -0.12; p = 0.04]. No statistical differences were observed between the two designs for knee society pain score, extension angle, 2- and 5-year knee society score, 2- and 5-year knee society function score and complications after primary TKA. Conclusion: Posterior cruciate-retaining and posterior stabilized TKA have similar clinical outcomes with regard to knee function, postoperative knee pain and the other complications. Prosthesis survivorship for both posterior cruciate-retaining and posterior stabilized TKA is satisfactory, and there are no differences between them at short- and middle-term follow-up. Level of evidence: II. © 2012 Springer-Verlag Berlin Heidelberg.

Zhou Y.,Wuhan University | Zhu Y.,Wuhan University
Viruses | Year: 2015

The pro-inflammatory cytokine interleukin (IL)-32 has gained much attention recently because of its important role in the inflammatory network. Since the discovery of IL-32 in 2005, our appreciation for its diverse roles continues to grow. Recent studies have discovered the antiviral effects induced by IL-32 and its associated regulatory mechanisms. The interactions between IL-32 and various cytokines including cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), interferon (IFN)-λ1, interleukin (IL)-6, and soluble IL-6 receptor have been described. This review aims to integrate these new findings into explicit concepts and raises the intriguing possibility of IL-32 as a therapeutic target. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Zhou Q.,Wuhan University | Zhu Q.,Wuhan University
Journal of Modern Optics | Year: 2014

Dark solitons, in a medium with competing nonlocal nonlinearities and local quintic nonlinearity, have been studied analytically in this paper. The phenomenological rectangular profile model for nonlocal response function is considered. The exact conditions for the existence of analytical dark soliton solutions are presented using variational principle. The influence of strengths and degrees of competing nonlocality as well as the strength of quintic locality, on the properties of dark solitons, are discussed. © 2014 Taylor & Francis.

The perturbed nonlinear Schrödinger equation, describing an ultra-short optical pulse propagate along the parabolic law nonlinear fibers with Raman effect and self-steepening, has been investigated using the sub-equation expansion method. The dark and singular optical solitons are obtained. Furthermore, the modulational instability (MI) is analyzed based on the standard linear-stability analysis. The MI gain is got. These results have important application features in the area of telecommunications. © 2014 Taylor & Francis.

Liu L.S.,Wuhan University
Applied Mechanics and Materials | Year: 2014

This document explains a type of Smart Tunnel Inspection Robot (STIR) for the detection of pipe culverts, including its system composition, the working principle, modules of hardware circuit, program flows and the interface of PC software. With devices of wireless video transmission, wireless data communication and the embedded technology of measurement and control, the STIR can replace human to detect and monitor various types of small diameter pipe culverts. © (2014) Trans Tech Publications, Switzerland.

Shao Z.,Wuhan University | Liu J.,Wuhan University | Cheng Q.,Huazhong University of Science and Technology
Applied Optics | Year: 2012

Aiming at the differences of physical characteristics between infrared sensors and visible ones, we introduce the focus measure operators into the curvelet domain in order to propose a novel image fusion method. First, the fast discrete curvelet transform is performed on the original images to obtain the coefficient subbands in different scales and various directions, and the focus measure values are calculated in each coefficient subband. Then, the local variance weighted strategy is employed to the lowfrequency coefficient subbands for the purpose of maintaining the low-frequency information of the infrared image and adding the low-frequency features of the visible image to the fused image; meanwhile, the fourth-order correlation coefficient match strategy is performed to the high-frequency coefficient subbands to select the suitable high-frequency information. Finally, the fused image can be obtained through the inverse curvelet transform. The practical experiments indicate that the presented method can integrate more useful information from the original images, and the fusion performance is proved to be much better than the traditional methods based on the wavelet, curvelet, and pyramids. © 2012 Optical Society of America.

Xiong C.,Helmholtz Center Potsdam | Xiong C.,Wuhan University | Luhr H.,Helmholtz Center Potsdam
Journal of Geophysical Research: Space Physics | Year: 2014

This paper presents a description of the Midlatitude Summer Night Anomaly (MSNA) in terms of solar tidal signatures, based on in situ observations from CHAMP (CHAllenging Minisatellite Payload) and GRACE (Gravity Recovery and Climate Experiment) during the solar minimum years 2008 and 2009. Our analysis is focusing on 40° to 60° magnetic latitude ranges in both hemispheres, where the reversed diurnal variations of the electron density are strongest. The results revealed that in the Southern Hemisphere the longitudinally symmetric tide D0 is particularly strong during December solstice. The well-known Weddell Sea Anomaly is caused by a simultaneous constructive interference of three components D0, DW2, and SPW1. During June solstice the eastward propagating tide DE1 is the strongest in the Northern Hemisphere, which causes a wave-2 longitudinal pattern. The two crests of the wave-2 pattern at nighttime correspond well with the MSNA feature in the Northern Hemisphere. The MSNA feature over the USA continent is particularly strong, which can be explained by the combined contributions of the components DE1, D0, and DW2. The diurnally varying difference in electron density between the USA East and West Coast can also be explained by the phase propagation of the DE1. A similar effect has also been observed in the Asian region. The peak electron densities of the tidal component D0 appear around 0700 LT and 2000 LT in the Southern and Northern Hemispheres, respectively. The time shift suggests that the two hemispheres move in antiphase up and down. The planetary wave SPW1 exhibits an electron density crest near longitude sectors where the dip equator reaches far into the summer hemisphere. ©2014. American Geophysical Union. All Rights Reserved.

Huang C.,Wuhan University | Hesselbo S.P.,University of Oxford
Gondwana Research | Year: 2014

The Early Toarcian Oceanic Anoxic Event (OAE) in the Early Jurassic Period is associated with a major negative carbon isotope excursion (CIE), mass extinction, marine transgression and global warming. The Toarcian OAE is thought to have been caused by flood basalt magmatism, and may have been a trigger for mass extinction. However, these proposed causes of the Toarcian OAE and associated biotic crisis are not adequately resolved by a precise chronology. The duration of the Toarcian OAE has been estimated to be anywhere from ~. 0.12 to ~. 0.9. Myr, most recently 0.74 to 3.26. Myr from U-Pb dating. The CIE associated with the Toarcian OAE has a similar pattern at numerous localities, and there is evidence that the marine carbon isotope variations recorded astronomical forcing signals. Here we estimate a duration of ~. 620. kyr for the main negative CIE, ~. 860. kyr for the polymorphum zone and >. 1.58. Myr for the levisoni zone based on 405-kyr astronomical eccentricity tuning of the marine section at Peniche (Portugal). This 405-kyr tuned series provides a ~. 2.5. Myr continuous high-resolution chronology through the Early Toarcian. There are 6, or possibly 7 short eccentricity cycles in the main CIE interval at Peniche. To confirm this astronomically based estimate, we analyzed three other sections at Yorkshire (UK), Dotternhausen (Germany), and Valdorbia (Italy) from marine carbon isotopic series. These four stratigraphic sections from Early Jurassic western Tethys record the Toarcian OAE with ~. 6 prominent carbon isotope cycles in the CIE that span a 600. ±. 100. kyr duration. The Peniche 405-kyr tuned series indicates that the pre- and post-CIE intervals experienced strong precession-eccentricity-forced climate change, whereas the CIE interval is marked by dominant obliquity forcing. These dramatic and abrupt changes in astronomical response in the carbon isotopes point to fundamental shifting in the Early Toarcian paleoclimate system that was directly linked to the global carbon cycle. © 2013 International Association for Gondwana Research.

Luo M.,University of Western Australia | Chen Z.-Q.,Wuhan University
Geological Journal | Year: 2014

Abundant scratching traces are described from the Early Triassic Kockatea Shale Formation in the Northampton area of the northern Perth Basin, Western Australia. Except for the Radichnus trace that represents grazing of a possible decapod mecochirids, Scalpoichnus minchinensis igen. and isp. nov. is established to accommodate other scratching sculptures, which might have been produced by arthropods that share similar feeding behaviours to those of decapods. These arthropod traces occurred on a mat-bound substratum defined by wrinkle structures. Microbial mats may have served as food resources for trace-makers feeding on the substratum. Furthermore, microbial envelopes functioning as a sole veneer in early diagenesis acted as a crucial role for the preservation of those shallow-tiered engraving traces. Abundant arthropod traces indicate frequent grazing activities probably by decapods or organisms having similar feeding habits upon microbial mat-bound substratum, implying that the deposit-feeders or omnivores survived on the matgrounds in the aftermath of the end-Permian mass extinction in Gondwanaland. © 2013 John Wiley & Sons, Ltd.

Mao F.,Wuhan University | Gong W.,Wuhan University | Ma Y.,Wuhan University
Optics Letters | Year: 2012

The aerosol lidar ratio is a key parameter for the retrieval of aerosol optical properties from elastic lidar, which changes largely for aerosols with different chemical and physical properties. We proposed a method for retrieving the aerosol lidar ratio profile by combining simultaneous ground- and space-based elastic lidars. The method was tested by a simulated case and a real case at 532 nm wavelength. The results demonstrated that our method is robust and can obtain accurate lidar ratio and extinction coefficient profiles. Our method can be useful for determining the local and global lidar ratio and validating space-based lidar datasets. © 2012 Optical Society of America.

Zhang L.,Wuhan University | Tao D.,Intelligent Systems Technology, Inc. | Huang X.,Wuhan University
IEEE Geoscience and Remote Sensing Letters | Year: 2011

In remote-sensing image target recognition, the target or background object is usually transformed to a feature vector, such as a spectral feature vector. However, this kind of vector represents only one pixel of a remote-sensing image that considers the spectral information but ignores the spatial relationship of neighboring pixels (i.e., the local texture and structure). In this letter, we propose a new way to represent an image object as a multifeature tensor that encodes both the spectral and textural information (Gabor function) and then apply the support tensor machine for target recognition. A range of experiments demonstrates that the effectiveness of the proposed method can deliver a high and correct recognition rate with a small number of training samples. © 2006 IEEE.

Zhang J.,Weizmann Institute of Science | Zhang J.,Wuhan University | Balaraman E.,Weizmann Institute of Science | Leitus G.,Weizmann Institute of Science | Milstein D.,Weizmann Institute of Science
Organometallics | Year: 2011

Electron-rich PNP-and PNN-type ruthenium(II) hydrido borohydride pincer complexes, [RuH(BH4)(tBu-PNP)] (tBu-PNP = (2,6-bis(di-tert-butylphosphinomethyl)pyridine) (5) and [RuH(BH 4)(tBu-PNN)] (tBu-PNN = 2-di-tert- butylphosphinomethyl-6-diethylaminomethylpyridine) (6), were prepared from their corresponding N2-bridged dinuclear Ru(II) complexes [(tBu-PNP) RuCl2]2(μ-N2) (3) and [(tBu-PNN) RuCl2]2(μ-N2) (4), respectively. The X-ray structure of 5 reveals a BH4 -anion η2 coordinated to ruthenium through two bridging hydrides. A variable-temperature 1H NMR study of 6 exhibits interesting fluxional behavior of the BH4 -ligand. Similarly, the Ru(II) hydrido borohydride complex 9, in which the BH4 -moiety is coordinated in a η1 bonding mode, was obtained by reaction of [RuCl 2(PPh3)(iPr-PNP)] (iPr-PNP = 2,6-bis(diisopropylphosphinomethyl)pyridine) (8) with two equivalents of NaBH4 at room temperature. The hydrido borohydride pincer complexes 5, 6, and 9 catalyze the acceptorless dehydrogenative coupling of primary alcohols to esters and the dehydrogenation of secondary alcohols to the corresponding ketones, accompanied by evolution of hydrogen gas. The reactivity follows the order 6 > 9 > 5. With the hydrido borohydride complex 6 as catalyst, high yields (up to 98%) and high turnover numbers (TON∼1000) were obtained in the dehydrogenation of primary alcohols under mild and neutral conditions. In addition, 6 effectively catalyzes the hydrogenation of nonactivated aromatic and aliphatic esters to the corresponding alcohols with TON ∼200 under a relatively mild pressure of dihydrogen and neutral and homogeneous conditions. Thus, an efficient homogeneous catalytic system for the dehydrogenation- hydrogenation reactions of alcohols is developed, which is relevant to the current interest in hydrogen storage. © 2011 American Chemical Society.

Dai D.,Wuhan University | Yang W.,Wuhan University
IEEE Geoscience and Remote Sensing Letters | Year: 2011

This letter presents a method for satellite image classification aiming at the following two objectives: 1) involving visual attention into the satellite image classification; biologically inspired saliency information is exploited in the phase of the image representation, making our method more concentrated on the interesting objects and structures, and 2) handling the satellite image classification without the learning phase. A two-layer sparse coding (TSC) model is designed to discover the true neighbors of the images and bypass the intensive learning phase of the satellite image classification. The underlying philosophy of the TSC is that an image can be more sparsely reconstructed via the images (sparse I) belonging to the same category (sparse II). The images are classified according to a newly defined image-to-category similarity based on the coding coefficients. Requiring no training phase, our method achieves very promising results. The experimental comparisons are shown on a real satellite image database. © 2010 IEEE.

Zhao L.,Wuhan University | Zhao F.,Wuhan University | Zeng B.,Wuhan University
Electrochimica Acta | Year: 2014

A novel water-compatible molecularly imprinted ionic liquid polymer - ionic liquid functionalized graphene composite film coated glassy carbon electrode (MIP - rGO-IL/GCE) is presented. It is fabricated by coating a GCE with amine-terminated ionic liquid functionalized graphene (rGO-IL) and then with water-compatible MIP suspension. The water-compatible MIP is prepared by free radical polymerization in methanol-water system using sunset yellow (SY) as template and ionic liquid 1-(α-methyl acrylate)-3-allylimidazolium bromide (1-MA-3AI-Br) as functional monomer, which can interact with SY through π-π, hydrogen-bonding and electrostatic interaction. The resulting MIP - rGO-IL/GCE shows good performance when it is used for the differential pulse voltammetric determination of SY. Under the optimized conditions (i.e. pH 7.5, 0.1 M phosphate buffer, preconcentration under open-circuit for 570 s), the peak current is linear to SY concentration in the ranges of 0.010 μM - 1.4 μM and 1.4 μM - 16 μM with sensitivities of 5.0 μA/μM mm2 and 1.4 μA/μM mm2 respectively; the detection limit is 4 nM (S/N = 3). The electrode has been successfully applied to the determination of SY in some soft drinks, and the recoveries for the standards added are 95% - 107%.© 2013 Elsevier Ltd. All rights reserved.

Zeng X.,Wuhan University | Sun Y.-X.,Wuhan University | Qu W.,Wuhan University | Zhang X.-Z.,Wuhan University | Zhuo R.-X.,Wuhan University
Biomaterials | Year: 2010

As mutation and dysfunction of p53 gene could induce most of human cancers, the p53 tumor suppressor gene was used to replace them and recover their normal functions in cancer cells. In this paper, biotinylated transferrin/avidin/biotinylated disulfide containing PEI bioconjugates (TABP-SS) mediated p53 gene delivery system was formed attributed to the 'avidin-biotin bridge'. Characteristics of the obtained TABP-SS and its p53 complexes were evaluated in terms of acid-base titration, agarose gel electrophoresis, SEM, particle size and ζ-potential measurements. The acid-base titration results showed that TABP-SS had good buffer capability. The results of gel electrophoresis indicated that TABP-SS could fully condensed DNA and would be degraded by reducing agent inside cells. In vitro cell viability and transfection of TABP-SS were investigated in COS7, HepG2, and HeLa cells. Among the three different cell lines, TABP-SS exhibited much lower cytotoxicity and higher transfection efficacy in HepG2 and HeLa cells due to the specific interactions between transferrin ligands and their receptors on tumor cells. Apoptotic morphology was observed using confocal microscopy, and the expression of p53 protein in transfected cells was evaluated by western blotting. All the results indicated that TABP-SS/p53 complex could be considered as a low toxic and high efficient tumor targeted gene delivery system, which has great potential for further clinical application. © 2010 Elsevier Ltd.

Chen S.,Wuhan University | Cheng S.-X.,Wuhan University | Zhuo R.-X.,Wuhan University
Macromolecular Bioscience | Year: 2011

Nanoparticulate drug-delivery systems have attained much importance because of their injectable property, the possibility to achieve passive targeting and active targeting, and unique advantages to realize stimuli tailored delivery. Molecular self-assembly is a powerful method for fabricating polymer-based nanoparticles, which involves various driving forces, such as hydrophobic interactions, electrostatic interactions, stereocomplexation, host/guest interactions and hydrogen bonding. By fine tuning one or many types of these interactions, self-assemblies with a wide range of structures and functions could be fabricated. In this article, recent developments in different self-assembly strategies for the preparation of polymer-based nanoparticulate delivery systems are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Guo Y.,Wuhan University | Zhou J.,Wuhan University | Zhang L.,Wuhan University
Biomacromolecules | Year: 2011

Dynamic viscoelastic properties of cellulose carbamate (CC) dissolved in NaOH aqueous solution were systematically studied for the first time. CC was microwave-assisted synthesized from the mixture of cellulose and urea and then dissolved in 7 wt % NaOH aqueous solution precooled to ?7°C. The obtained CC solution is transparent and has good liquidity. To clarify the rheological behavior of the solution, the CC solutions were investigated by dynamic viscoelastic measurements. The shear storage modulus (G′) and loss modulus (G′′) as a function of the angular frequency (ω), concentration (c), nitrogen content (N %), viscosity-average molecular weight (M?), temperature (T), and time (t) were analyzed and discussed in detail. The sol-gel transition temperature of CC (M? = 7.78 - 10 4) solution decreased from 36.5 to 31.3°C with an increase of the concentration from 3.0 to 4.3 wt % and decreased from 35.7 to 27.5°C with an increase of the nitrogen content from 1.718 to 5.878%. The gelation temperature of a 3.8 wt % CC solution dropped from 38.2 to 34.4°C with the M? of CC increased from 6.35 - 104 to 9.56 - 10 4. The gelation time of the CC solution was relatively short at 30°C, but the solution was stable for a long time at about 15°C. Moreover, the gels already formed at elevated temperature were irreversible; that is, after cooling to a lower temperature including the dissolution temperature (?7°C), they could not be dissolved to become liquid. © 2011 American Chemical Society.

Chen S.,Wuhan University | Liu Y.,Wuhan University | Chen J.,Wuhan University
Chemical Society Reviews | Year: 2014

Heterogeneous electron-transfer (ET) processes at solid electrodes play key roles in molecular electronics and electrochemical energy conversion and sensing. Electrode nanosization and/or nanostructurization are among the major current strategies for performance promotion in these fields. Besides, nano-sized/structured electrodes offer great opportunities to characterize electrochemical structures and processes with high spatial and temporal resolution. This review presents recent insights into the nanoscopic size and structure effects of electrodes and electrode materials on heterogeneous ET kinetics, by emphasizing the importance of the electric double-layer (EDL) at the electrode/electrolyte interface and the electronic structure of electrode materials. It is shown, by general conceptual analysis and recent example demonstrations of representative electrode systems including electrodes of nanometer sizes and gaps and of nanomaterials such as sp2 hybridized nanocarbons and semiconductor quantum dots, how the heterogeneous ET kinetics, the electronic structures of electrodes, the EDL structures at the electrode/electrolyte interface and the nanoscopic electrode sizes and structures may be related. This journal is © the Partner Organisations 2014.

Yang J.,Wuhan University | He L.,Wuhan University | Fu S.,University of Rhode Island
Applied Energy | Year: 2014

Driven by the desire to reduce environmental impacts and achieve energy independence, electric vehicles (EVs) are poised to receive mass acceptance from the general public. However, simultaneously connecting to electric distribution grid and charging with large number of EVs bring the necessity of optimizing the charging and discharging behaviors of EVs, due to the security and economy issue of the grid operation. To address this issue, we propose a novel EV charging model in this paper. The model concerns with following aspects, including optimal power flow (OPF), statistic characteristics of EVs, EV owners' degree of satisfaction (DoS), and the power grid cost. An improved particle swarm optimization (PSO) algorithm is proposed for the model optimization. To evaluate our proposed optimal EV charging strategy, a 10-bus power distribution system simulation is performed for performance investigation. Simulation results show that the proposed strategy can reduce the operational cost of the power grid considerately, while meeting the EV owner's driving requirement. Also, better performance on the global search capability and optimal result of the improved particle swarm optimization algorithm is verified. © 2014 Elsevier Ltd.

Xiao W.,Wuhan University | Wang D.,Wuhan University
Chemical Society Reviews | Year: 2014

Solid electrode processes fall in the central focus of electrochemistry due to their broad-based applications in electrochemical energy storage/conversion devices, sensors and electrochemical preparation. The electrolytic production of metals, alloys, semiconductors and oxides via the electrochemical reduction of solid compounds (especially solid oxides) in high temperature molten salts has been well demonstrated to be an effective and environmentally friendly process for refractory metal extraction, functional materials preparation as well as spent fuel reprocessing. The (electro)chemical reduction of solid compounds under cathodic polarizations generally accompanies a variety of changes at the cathode/melt electrochemical interface which result in diverse electrolytic products with different compositions, morphologies and microstructures. This report summarizes various (electro)chemical reactions taking place at the compound cathode/melt interface during the electrochemical reduction of solid compounds in molten salts, which mainly include: (1) the direct electro-deoxidation of solid oxides; (2) the deposition of the active metal together with the electrochemical reduction of solid oxides; (3) the electro-inclusion of cations from molten salts; (4) the dissolution- electrodeposition process, and (5) the electron hopping process and carbon deposition with the utilization of carbon-based anodes. The implications of the forenamed cathodic reactions on the energy efficiency, chemical compositions and microstructures of the electrolytic products are also discussed. We hope that a comprehensive understanding of the cathodic processes during the electrochemical reduction of solid compounds in molten salts could form a basis for developing a clean, energy efficient and affordable production process for advanced/engineering materials. © 2014 the Partner Organisations.

Fan K.,Wuhan University | Chen J.,Wuhan University | Yang F.,Wuhan University | Peng T.,Wuhan University
Journal of Materials Chemistry | Year: 2012

One dimensional structures of TiO 2 (nanowires and nanotubes) are promising for dye-sensitized solar cells due to reduced electron recombination; however, the small surface area is the main hurdle in the application of one dimensional anatase structures to dye-sensitized solar cells because of insufficient dye adsorption. Here, we address this problem with the preparation of a TiO 2 nanotube film with a high specific surface area. This film was self-assembled by ultra-fine TiO 2 nanotubes with diameter <10 nm via a simple hydrothermal method, and was applied to dye-sensitized solar cells on flexible Ti metal using a transplanting technique. Due to the higher surface area and one-dimensional structure, 6.23% efficiency was obtained with this ultra-fine TiO 2 nanotube film, which was superior to that of conventional TiO 2 nanoparticles. © 2012 The Royal Society of Chemistry.

Li Z.,Wuhan University | He M.,Wuhan University | Xu D.,Wuhan University | Liu Z.,Wuhan University
Journal of Photochemistry and Photobiology C: Photochemistry Reviews | Year: 2013

Graphene materials have recently attracted considerable attention because of its extraordinary mechanical, electronic, thermal and optical properties, leading to the wide application of graphene such as in biology and energy areas. In recent years, energy-transfer based optical biosensors using graphene materials as the energy acceptors have become the focus of researches, which take the advantages of the high surface area and ultrahigh luminescence quenching efficiency of graphene materials. These sensors have extensively covered the detection of DNA, protein, enzyme activity, metal ions and other small molecules. In this review article, we aim to provide a comprehensive discussion on the development of the graphene materials-based energy acceptor systems and sensors, sorting the sensors according to the probes with which the energy acceptors are assembled to or conjugated with the luminescent energy donors. At the end we also present an overview of future perspective and possible challenges in this rapidly developing area. © 2013 Elsevier B.V.

Li C.,Wuhan University
Investigative ophthalmology & visual science | Year: 2012

Endoplasmic reticulum (ER) stress has been demonstrated to contribute to neurodegeneration in multiple ocular diseases. However, whether ER stress can induce vascular degeneration in the retina remains unknown. We investigated the possible role of ER stress in retinal vascular degeneration in vivo, and the effects of resveratrol on tunicamycin and ischemia and reperfusion (I/R)-induced retinal vascular degeneration. Different dosages of tunicamycin, an ER stress inducer, were injected into the vitreous of mouse eyes. Retinal I/R injury was induced by elevating the intraocular pressure for 60 minutes followed by reperfusion in mice. Two dosages of resveratrol (5 and 25 mg/kg body weight per day) were administrated 2 days before retinal I/R injury, while 100 μM resveratrol were injected into the vitreous together with tunicamycin. Formation of acellular capillaries was assessed 7 days after I/R injury and tunicamycin injection, while cell bodies in ganglion cell layer and brain-specific homeobox/POU domain protein 3A (Brn3a) staining on retinal flat-mounts were analyzed 4 days after I/R injury. ER stress markers, including eukaryotic initiation factor 2α (eIF2α), CCAAT enhancer-binding protein homologous protein (CHOP), immunoglobulin binding protein (Bip), inositol requiring enzyme 1α (IRE1α), C-jun N-terminal kinase (JNK)1/2 and Xbp1 splicing, were examined by RT-PCR, or Western blots or immunostaining from retinas 1 or 2 days after tunicamycin injection and I/R injury. Tunicamycin caused ER stress and capillary degeneration in vivo, both of which were inhibited by resveratrol. Pretreatment of high dosage of resveratrol also significantly inhibited retinal I/R injury-induced capillary degeneration; however, neither of the dosages prevented the injury-induced neurodegeneration. Levels of CHOP, phosphorylated eIF2α, IRE1α, phosphorylated JNK1/2, Xbp1 splicing and Bip were elevated after I/R injury. High dosage of resveratrol pretreatment inhibited the injury-induced up-regulation of eIF2α-CHOP and IRE1α-XBP1 pathways. ER stress is an important contributor to vascular degeneration in retina. Resveratrol suppresses I/R injury and tunicamycin-induced vascular degeneration by inhibiting ER stress.

Liu J.,Wuhan University | Li Y.,Wuhan University
Biochemical and Biophysical Research Communications | Year: 2015

MicroRNAs (miRs) are small non-coding RNAs aberrantly expressed in human tumors. Increasing evidence suggests that miRNAs are functionally important in cancers. We demonstrated miR-204 exerts its function by targeting gene involved in tumor growth and chemotherapy drugs reactivity. Here, we show that Trichostatin A (TSA) could increase ERα expression in MCF-7 and MDA-MB-231 cells by reducing miR204. Analysis of tumors growth inhibition shows that TSA promotes ERα expression, which could be reversed by miR-204 mimic transfection. When miR-204 is down regulated, the inhibition of TAM on breast cancer cells is enhanced. Caspase 3 activity is also increased. TSA and TAM combination inhibits Mcl-1 expression by decreasing phosphorylation of AKT induced by ERα increase in vivo and in vitro. © 2015 Elsevier Inc. All rights reserved.

Duan B.,Wuhan University | Gao H.,Wuhan University | He M.,Wuhan University | Zhang L.,Wuhan University
ACS Applied Materials and Interfaces | Year: 2014

A highly hydrophobic and oleophilic chitin sponge was synthesized, for the first time, via a freeze-dried method and then by using a thermal chemical vapor deposition of methyltrichlorosilane (MTCS) at different relative humidity. Fourier-transform infrared, energy-dispersive X-ray spectra, and scanning electron microscopy confirmed that the silanization occurred on the pore wall surface of the chitin sponge. The MTCS-coated chitin sponge had interconnected open-cell structures with the average pore size from 20 to 50 μm, and the MTCS nanofilaments immobilized on the chitin matrix, leading to the high hydrophobicity, as a result of the existence of a solid/air composite rough surface. Cyclic compression test indicated that the hydrophobic chitin sponges exhibited excellent elasticity and high mechanical durability. The sponges could efficiently collect organics both on the surface and bottom from the water with the highest 58 times of their own weight absorption capacities through the combination of the particular wettability and great porosity. Furthermore, the biodegradation kinetics of the chitin sponge forecasted that the chitin could be completely biodegraded within 32 days by the microorganisms in the soil. This work provided a new pathway to prepare the chitin-based materials for highly effective removal of oil from water, showing potential application in the pollutant remediation field. (Chemical Equation Presented). © 2014 American Chemical Society.

Xu M.,Wuhan University
Journal of Systems Science and Systems Engineering | Year: 2010

In this paper, we consider a newsvendor model in which a risk-averse manager faces a stochastic price-dependent demand in either an additive or a multiplicative form. An emergency purchase option is allowed after the realization of demand to satisfy the units that are short. By adopting conditional value-at-risk (CVaR) as the decision criterion, we aim to investigate the optimal pricing and ordering decisions, and the effects of parameter changes in such a setting. We provide sufficient conditions for the uniqueness of the optimal policy for both demand models. We perform comparative statics analysis to show how the optimal pricing and ordering decision behaves when changing parameters. We also compare our results with those of the newsvendor with a general utility function and with CVaR criterion under lost sales assumption. Our key results include: (i) For both demand models, the optimal selling price is decreasing in risk aversion. Hence, the optimal price of a risk-averse newsvendor is not greater than the optimal price of a risk-neutral newsvendor. (ii) In contrary to the lost sales case, for the multiplicative demand model, the optimal order quantity may not be monotonic in risk aversion. Consequently, the optimal risk-averse order quantity may be lower or higher than the optimal risk-neutral counterpart. (iii) For the additive model, the optimal order quantity is strictly increasing in the emergency purchase price, while for the multiplicative model the optimal order quantity has no such a monotonic property. Some numerical examples are conducted to verify our claims and gain more insights about the risk-averse decision-making behaviors. © Systems Engineering Society of China and Springer-Verlag Berlin Heidelberg 2010.

Xu J.,Wuhan University | Ye G.,Wuhan University | Zeng M.,Wuhan University
Journal of Alloys and Compounds | Year: 2014

Powders and ceramics of Bi1-xDy xFeO3 (x = 0, 0.05, 0.10, 0.15, 0.20, 0.25) have been successfully synthesized by a modified solid state method. X-ray diffraction and Rietveld refine of the ceramics illustrate a rhombohedral-to-orthorhombic phase transition at x = 0.10. Two types of structural phases were found to coexist with increasing the Dy content from x = 0.10 to x = 0.25. The magnetic study confirmed that the A-site Dy-doping would induce a weak ferromagnetic behavior, and the ferroelectric properties also showed its correlation with structural evolution. © 2013 Elsevier B.V. All rights reserved.

Luo Y.,Wuhan University
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2016

A method for calculating the mutual inductance of circular coils with parallel axes is presented by using the modified Bessel and modified Struve functions, which is obtained by the expansion expressions of the reciprocal distance in the cylindrical coordinates. The obtained expressions are further coped with the asymptotic expansions to facilitate the numerical calculations. The monotonicity of the modified Bessel and Struve functions is beneficial to the numerical evaluations of the improper integral, especially in the case of short thick coils or disk coils with large radial distance and small axial distance. The proposed method is several tens to hundreds times faster than the existing method using the oscillatory Bessel and Struve functions, with the same accuracy. Additionally, a closed-form solution of the mutual inductance for coplanar circular loops is given using the Gauss hypergeometric functions, and it is verified by numerical calculations. © 2016, The editorial office of Transaction of China Electrotechnical Society. All right reserved.

Cheng H.,Wuhan University | Wang S.,Wuhan University
Journal of Materials Chemistry A | Year: 2014

Currently, studies with sulphur electrode materials are focused primarily on carbon/sulphur and polymer/sulphur composites. Despite carbon/sulphur composites being a more popular research interest than polymer/sulphur composites, improving the cycle performance of sulphur by using polymers is also a major research focus. Therefore, we review the latest developments for polymer/sulphur composites in Li-S batteries. The various polymer/sulphur composites and their impacts on the electrochemical performance are discussed. Meanwhile, the synthesis approaches toward the various polymer/sulphur composites are also summarised. Finally, the future research directions involving polymer/sulphur composites are addressed. This journal is © the Partner Organisations 2014.

Chai B.,Wuhan University | Chai B.,Wuhan Polytechnic University | Peng T.,Wuhan University | Mao J.,Wuhan University | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2012

Porous graphitic carbon nitride (g-C 3N 4) was prepared by a simple pyrolysis of urea, and then a g-C 3N 4-Pt- TiO 2 nanocomposite was fabricated via a facile chemical adsorption followed by a calcination process. The obtained products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance absorption spectra, and electron microscopy. It is found that the visible-light-induced photocatalytic hydrogen evolution rate can be remarkably enhanced by coupling TiO 2 with the above g-C 3N 4, and the g-C 3N 4-Pt-TiO 2 composite with a mass ratio of 70:30 has the maximum photoactivity and excellent photostability for hydrogen production under visible-light irradiation, and the stable photocurrent of g-C 3N 4-TiO 2 is about 1.5 times higher than that of the bare g-C 3N 4. The above experimental results show that the photogenerated electrons of g-C 3N 4 can directionally migrate to Pt-TiO 2 due to the close interfacial connections and the synergistic effect existing between Pt-TiO 2 and g-C 3N 4 where photogenerated electrons and holes are efficiently separated in space, which is beneficial for retarding the charge recombination and improving the photoactivity. © 2012 the Owner Societies.

Cheng X.,Wuhan University | Zhu L.,Wuhan University | He G.,Wuhan University
Molecular Plant | Year: 2013

The brown planthopper (BPH) is the most notorious pest of rice (Oryza sativa). Studies of rice-BPH interaction have contributed to development of new rice varieties, offering an effective means for long-lasting control of BPH. Here, we review the status of knowledge of the molecular basis of rice-BPH interaction, from the perspective of immunity. The BPH has complicated feeding behaviors on rice, which are mainly related to host resistance. Now, 24 resistance genes have been detected in rice, indicating gene-for-gene relationships with biotypes of the BPH. However, only one BPH resistance gene (Bph14) was identified and characterized using map-based cloning. Bph14 encodes an immune receptor of NB-LRR family, providing a means for studying the molecular mechanisms of rice resistance to BPH. Plant hormones (e.g. salicylic acid and jasmonate/ethylene), Ca2+, mitogen-activated protein kinases (MAPKs), and OsRac1 play important roles in the immune response of rice to BPH. Signal transduction leads to modifying expression of defense-related genes and defense mechanisms against BPH, including sieve tube sealing, production of secondary metabolites, and induction of proteinase inhibitor. A model for the molecular interactions between rice and the BPH is proposed, although many details remain to be investigated that are valuable for molecular design of BPH-resistant rice varieties.© 2012 The Author.

Huizinga J.D.,McMaster University | Chen J.-H.,Wuhan University
Current Gastroenterology Reports | Year: 2014

The basic science and clinical interest in the networks of interstitial cells of Cajal (ICC) keep growing, and here, research from 2010 to mid-2013 is highlighted. Highresolution gastrointestinal manometry and spatiotemporal mapping are bringing exciting new insights into motor patterns, their function and their myogenic and neurogenic origins, as well as the role of ICC. Critically important knowledge is emerging on the partaking of PDGFRa+ cells in ICC pacemaker networks. Evidence is emerging that ICC and PDGFRa+ cells have unique direct roles in muscle innervation. Chronic constipation is associated with loss and injury to ICC, which is stimulating extensive research into maintenance and repair of ICC after injury. In gastroparesis, high-resolution electrical and mechanical studies are beginning to elucidate the pathophysiological role of ICC and the pacemaker system in this condition. Receptors and ion channels that play a role in ICC function are being discovered and characterized, which paves the way for pharmacological interventions in gut motility disorders through ICC. © Springer Science+Business Media New York 2014.

Ye L.,Wuhan University | Deng K.,South-Central University for Nationalities | Xu F.,Lanzhou University | Tian L.,Wuhan University | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2012

Black BiOCl with oxygen vacancies was prepared by UV light irradiation with Ar blowing. The as-prepared black BiOCl sample showed 20 times higher visible light photocatalytic activity than white BiOCl for RhB degradation. The trapping experiment showed that the superoxide radical () and holes (h+) were the main active species in aqueous solution under visible light irradiation.

Li T.,Wuhan University | Ai X.P.,Wuhan University | Yang H.X.,Wuhan University
Journal of Physical Chemistry C | Year: 2011

Novel Li2O/CuO nanocomposites were prepared by ball-milling the CuO and Li2O nanoparticles with rigid TiN nanopowders, where TiN nanopowders act as a conductive substrate to immobilize the electroactive nanolayer of a biphasic Li2O/CuO mixture. The as-prepared samples demonstrate a superior electrochemical capacity of 560 mAh g-1 at a moderate charge-discharge rate of 50 mA g-1 and also exhibit a quite high reversible capacity of 438 mAh g-1 even at a very high rate of 500 mA g-1 at room temperature. CV and XRD analyses revealed that the Li2O/CuO nanocomposite can realize nearly a three-electron transfer through electrochemical conversion of Cu2O/Cu to LiCuO2 and vice versa, involving lithium intercalation and deintercalation. This conversion reaction can proceed reversibly and rapidly as long as the different phases of the cathode-active particles are well-dispersed and closely contacted to create electrochemically favorable nanodomains in the electrode. The experimental results demonstrated in this study suggest the possibility to use inexpensive multivalent metal oxides as high-capacity cathode materials for construction of future-generation lithium-ion batteries through an electrochemical conversion mechanism. © 2011 American Chemical Society.

Ying C.,Wuhan University
Cellular and molecular neurobiology | Year: 2012

It is reported that adipose-derived stem cells (ADSCs) had multilineage differentiation potential, and could differentiate into neuron-like cells induced by special induction media, which may provide a new idea for restoration of erectile dysfunction (ED) after cavernous nerve injury. The aim of this research was to explore the neuronal differentiation potential of ADSCs in vitro. ADSCs isolated from inguinal adipose tissue of rat were characterized by flow cytometry, and results showed that ADSCs were positive for mesenchymal stem cell markers CD90 and CD44, but negative for hematopoietic stem cell markers. ADSCs maintained self-renewing capacity and could differentiate into adipocytes and neurocytes under special culture condition. In this research, two methods were used to induce ADSCs. In method 1, ADSCs were treated with the preinduction medium including epithelium growth factor, basic fibroblast growth factor, and brain derived neurotrophic factor (BDNF) for 3 days, then with the neurogenic induction medium containing isobutylmethylxanthine, indomethacin, and insulin. While in method 2, BDNF was not used to treat ADSCs. After induction, neuronal differentiation of ADSCs was evaluated. Neuronal markers, glial fibrillary acidic protein (GFAP), and β-tubulin III (Tuj-1) were detected by immunofluorescence and Western Blot analyses. The expressions of GFAP and Tuj-1 in method 1 were obviously higher then those in method 2. In addition, the positive rate of the neuron-like cells was higher in method 1. It suggested that ADSCs are able to differentiate into neural-like cells in vitro, and the administration of BDNF in the preinduction medium may provide a new way to modify the culture method for getting more neuron-like cells in vitro.

Cai J.-C.,Wuhan University
Chinese Physics B | Year: 2014

In this paper, the mechanism for fluid flow at low velocity in a porous medium is analyzed based on plastic flow of oil in a reservoir and the fractal approach. The analytical expressions for flow rate and velocity of non-Newtonian fluid flow in the low permeability porous medium are derived, and the threshold pressure gradient (TPG) is also obtained. It is notable that the TPG (J) and permeability (K) of the porous medium analytically exhibit the scaling behavior J ∼ K-DT/(1=DT), where DT is the fractal dimension for tortuous capillaries. The fractal characteristics of tortuosity for capillaries should be considered in analysis of non-Darcy flow in a low permeability porous medium. The model predictions of TPG show good agreement with those obtained by the available expression and experimental data. The proposed model may be conducible to a better understanding of the mechanism for nonlinear flow in the low permeability porous medium. © 2014 Chinese Physical Society and IOP Publishing Ltd.

Lin W.,Wuhan University | Chen L.,Wuhan University
Journal of the Optical Society of America B: Optical Physics | Year: 2010

We study the propagation of surface plasmon polaritons (SPPs) in nanoscale metal heterowaveguide superlattices and metal waveguide arrays (MWGAs), both realized by gradually increasing the width of guiding regions. Theoretical analysis of the transmission properties of SPPs passing through the metal heterowaveguide superlattices by the transfer matrix method reveals that the SPPs minibands and minigaps in the frequency domain exhibit a spatial tilting, implying the appearance of plasmonic Wannier-Stark ladders and the existence of time-resolved plasmonic Bloch oscillations (BOs) in the superlattices. The analytic results of the coupled wave theory show that SPPs periodically oscillate transversely in the MWGAs under conditions of multiple waveguide excitation as the behavior of spatial BOs. Numerical simulations of the dynamic evolution of SPPs in the superlattices and MWGAs by the finite-difference time-domain method demonstrate the analytical predications well. © 2009 Optical Society of America.

Li R.,Wuhan University | Zhang L.,Wuhan University | Xu M.,East China Normal University
Carbohydrate Polymers | Year: 2012

Regenerated films were successfully prepared from cellulose/NaOH/urea solution by coagulating with water at temperature from 25 to 45 °C. The results of solid 13C NMR, wide angle X-ray diffraction, scanning electron microscopy (SEM) and tensile testing revealed that the cellulose films possessed homogeneous structure and cellulose II crystalline, similar to that prepared previously by coagulating with 5 wt% H2SO4. By changing the coagulation temperature from 25 to 45 °C, tensile strength of the films was in the range of 85-139 MPa. Interestingly, the RC35 film coagulated at 35 °C exhibited the highest tensile strength (σb = 139 MPa). The inclusion complex associated with cellulose, NaOH and urea hydrates in the cellulose solution were broken by adding water (non-solvent), leading to the self-association of cellulose to regenerate through rearrangement of the hydrogen bonds. This work provided low-cost and "green" pathway to prepare cellulose films, which is important in industry. © 2011 Published by Elsevier Ltd. All rights reserved.

Cui X.,Scripps Research Institute | Gao G.,Wuhan University | Qiu Y.,East China University of Science and Technology
Biotechnology Letters | Year: 2013

Muscle-powered, biological, microelectro-mechanical system is promising for actuator and biosensor applications. Functional conjugation between the cells, tissues, and biomolecules to the microdevice is crucial for this application. Bioprinting as an enabling technology possesses the advantages of high throughput, digital control, and highly accurate delivery of various biological factors to the desired locations for numerous applications such as 3D tissue fabrication. We have now evaluated the feasibility of the precise placement of mouse myoblasts onto micro-sized cantilevers. The evenly aligned printed cells fused with each other and formed mature myotubes after only 4 days. In contrast, it took more than 14 days for randomly deposited cells to do so. The printed myotubes were functional and responded to the electrical stimulation synchronously. Furthermore, the integrated Bio-MEMS device responded to the chemical stimulation spontaneously which demonstrated the potential as a functional biosensor. The contractility of the system was recovered quickly after the removal of the chemical stimulation, which indicated the flexibility of this system and the recycling potential. © 2012 Springer Science+Business Media Dordrecht.

The effect of a strain rate and temperature on the crack tip stress and microstructure evolution ahead of a growing crack in monocrystalline nickel are studied by molecular dynamics simulations. The correlation between the microstructure evolution and stress field near the crack tip is also explored. The results indicate that the crack tip stress distribution characteristics and crack propagation dynamics are closely related to the microstructure evolution caused by the change of the strain rate and temperature. At a lower strain rate and temperature, the crack propagates by the brittle mechanism without inducing the change in atomic configuration near the crack tip. The stress concentration occurs at the crack tip of a growing crack. The crack propagation exhibits a gradual brittle-to-ductile transition with an increase in temperature and a strain rate. The peak stress is accompanied by the microstructure evolution ahead of the crack tip. © 2014 Springer Science+Business Media New York.

Epithelial–mesenchymal transition (EMT) is regarded as a crucial contributing factor to cancer progression. Diverse factors have been identified as potent EMT inducers in ovarian cancer. However, molecular mechanism sustaining EMT of ovarian cancer cells remains elusive. Here we show that the presence of SOS1/EPS8/ABI1 complex is critical for sustained EMT traits of ovarian cancer cells. Consistent with the role of SOS1/EPS8/ABI1 complex as a Rac1-specific guanine nucleotide exchange factor, depleting Rac1 results in the loss of most of mesenchymal traits in mesenchymal-like ovarian cancer cells, whereas expressing constitutively active Rac1 leads to EMT in epithelial-like ovarian cancer cells. With the aid of clinically tested inhibitors targeting various EMT-associated signaling pathways, we show that only combined treatment of mitogen-activated extracellular signal-regulated kinase 1/2 (MEK1/2) and Src inhibitors can abolish constitutively active Rac1-led EMT and mesenchymal traits displayed by mesenchymal-like ovarian cancer cells. Further experiments also reveal that EMT can be induced in epithelial-like ovarian cancer cells by co-expressing constitutively active MEK1 and Src rather than either alone. As the activities of Erk and Src are higher in ovarian cancer cells with constitutively active Rac1, we conclude that Rac1 sustains ovarian cancer cell EMT through simultaneous activation of MEK1/2 and Src signaling pathways. Importantly, we demonstrate that combined use of MEK1/2 and Src inhibitors effectively suppresses development of intraperitoneal xenografts and prolongs the survival of ovarian cancer-bearing mice. This study suggests that cocktail of MEK1/2 and Src inhibitors represents an effective therapeutic strategy against ovarian cancer progression.Oncogene advance online publication, 12 September 2016; doi:10.1038/onc.2016.323. © 2016 Macmillan Publishers Limited, part of Springer Nature.

Zhou J.,Wuhan University
Advanced Materials Research | Year: 2014

At present, planning and layout of fire station locations in our nation is mainly based on drawing method and grid method with little consideration of spatial distribution characteristics of fire risk in urban areas. Based on this background, this paper combines fire risk assessment with GIS technology and presents an approach to optimizing layout of urban fire station based on fire risk assessment. According to the result of urban fire risk assessment, the approach sets areas with higher potential fire risk as key points of urban fire safety, makes a gradual optimization of potential fire stations with 2-min respond time from fire station to fire scene and the shortest distance from fire station to various fire scenes as the major limiting factor, and finally determines the spatial layout of fire stations. This paper takes Fuzhou in Fujian Province as the study area and conducts an empirical research. © (2014) Trans Tech Publications, Switzerland.

To retrospectively compare the functional performances of rotating platform and fixed-bearing total knee arthroplasties with or without patellar resurfacing. One hundred and ninety-seven patients (205 knees) of mean age 66.4 years were randomly assigned to receive different prostheses. One hundred ninety-five patients, including 97 fixed-bearing prostheses with 37 patellae resurfaced and 106 rotating platform prostheses with 76 patellae resurfaced, were followed up for a mean duration of 32 months. Outcomes in the rotating platform with patellar resurfacing and fixed-bearing with patellar resurfacing groups did not differ significantly according to Hospital for Special Surgery (HSS) scores and flexion and extension angles. For total knee arthroplasties without patellar resurfacing, there were no significant differences in HSS score and flexion angle between the rotating platform and fixed-bearing subgroups. Although the extension angle of rotating platform prostheses was slightly better than that of the fixed-bearing in the patellar non-resurfacing group, this difference was not clinically significant. Rotating platform and fixed-bearing prostheses have similar overall postoperative outcomes with regard to postoperative HSS scores and extension and flexion angles. Rotating platform prostheses are not superior to fixed bearing prostheses. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Zhang H.,Wuhan University | Voss K.J.,University of Miami
Icarus | Year: 2011

In a recent paper Hapke et al. (Hapke, B., Shepard, M., Nelson, R., Smythe, W., Piatek, J. [2009]. Icarus 199, 210-218) performed bi-directional reflectance measurements on closely-packed particulate surfaces of micrometer-sized particles and compared these with both the Hapke IMSA photometric model, and a numerical radiative transfer algorithm, the MDYZ (Mishchenko, M., Dlugach, J., Yanovitskij, E., Zakharova, N. [1999a]. J. Quant. Spectrosc. Radiat. Trans. 63, 409-432). To account for the effects of close packing, Hapke et al. applied a diffraction truncation scheme to remove the diffraction spike and supplied the renormalized single scattering phase function to the IMSA. They found that the IMSA prediction is a better match with measurement than that of MDYZ. In this work we demonstrate that the diffraction truncation procedure outlined by Hapke et al. contains an error. By following Hapke et al.'s intended truncation scheme, we have found that the IMSA model is not sufficiently anisotropic to describe the reflectance pattern. of measurements on surface reflectance of closely packed large spherical particles. © 2011 Elsevier Inc.

Liu Y.,Wuhan University | Zhan H.,Wuhan University | Zhou Y.,Wuhan University
Electrochimica Acta | Year: 2012

Solvent exchange method is proposed for the synthesis of sulfur and S/C composite with uniform morphology. SEM, TEM and BET measurements reveal that through this approach, sulfur can subside together with carbon and then form the S/C composite in which sulfur particle is enclosed within the carbon shell even enter into the pores of Printex XE2 carbon. Comparing with sublimed sulfur, the sulfur or S/C composite deriving from the solvent exchange method all shows greatly improved electrochemical performance. Additionally, the influence of solvent on the electrochemical property of the S/C composite is investigated in terms of cycling tests, cyclic voltammetry and impedance measurements. The results show that the S/C composite sample derived from the ultrasonic solvent exchange method in o-xylene solvent has better electrochemical properties than that prepared in CS 2. It delivers a capacity of 1173.9 mAh g -1 in the initial cycle and preserves at 712.5 mAh g -1 after 50 cycles at 200 mA g -1. Furthermore, even at a high current density of 1500 mA g -1, its discharge capacity is well maintained at 529 mAh g -1 after 50 cycles, which is much higher than the capacity of 293.6 mAh g -1 for sublimed sulfur electrode. © 2012 Elsevier Ltd. All rights reserved.

Zeng J.,Wuhan University | Liu S.,Wuhan University | Cai J.,Wuhan University | Zhang L.,Wuhan University
Journal of Physical Chemistry C | Year: 2010

TiO2/cellulose composite films have been prepared via a sol-gel method from the hydrolysis of a precursor TiO2 sol solution in the regenerated cellulose films prepared on the basis of cellulose dissolution at low temperature. The structure and properties of the composite films were characterized by using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, FT-IR, UV-visible spectroscopy, and photocatalytic degradation tests. The micronanoporous structure and hydroxyl groups in the regenerated cellulose films at the wet state provided cavities and affinity for the creation and the immobilization of TiO2 nanoparticles in the cellulose matrix through electrostatic and hydrogen bonding interactions. The TiO2/cellulose composite films exhibited a good photocatalytic activity for photodegradation of phenol under weak UV light irradiation, leading to an important application in photodegradation of organic pollutant. This was a portable photocatalyst, which can be removed out easily from pollutant solution after used, leading to a "green" process. © 2010 American Chemical Society.

Liu S.-D.,Taiyuan University of Technology | Liu S.-D.,Wuhan University | Yang Z.,Taiyuan University of Technology | Liu R.-P.,Taiyuan University of Technology | Li X.-Y.,Taiyuan University of Technology
ACS Nano | Year: 2012

Fano resonances in plasmonic nanostructures are important for plasmon line shaping. Compared to a single Fano resonance, multiple Fano resonances can modify plasmon lines at several spectral positions simultaneously, but they often suffer from weak modulation depths. In this paper, plasmonic heptamer clusters comprising split nanorings are designed to form multiple Fano resonances. Three prominent Fano resonances are observed in the spectra due to the formation of multiple narrow subradiant resonances, and the multiple Fano resonances can be switched on and off by adjusting the polarization direction. Particularly, by modifying the geometry parameters, there is a large tunability of the modulation depth of each Fano resonance. Heptamer clusters comprising split nanorings are highly suitable for plasmon line shaping, and it is expected that they are useful for multiwavelength biosensing and surface-enhanced Raman scattering. © 2012 American Chemical Society.

Li D.,Wuhan University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In this lecture, I will introduce the concept of smart city and summarize its development process. Then, I will describe the key technologies of smart cities and the proposed smart city infrastructure. Smart city is based on digital city, Internet of Things (IOT), and cloud computing, which will integrate the real world with the digital world. In order to achieve a comprehensive awareness and control of people and things, with intelligent service followed, smart city with mass sensors will continue to collect vast amounts of data, called big data. Typical types of big data such as geospatial image, graph and video data, are analyzed in my talk. The big data of smart city are not only a frontier, but also the driving force to promote the development of smart city, which will bring new opportunities and challenges. I will also propose a strategy for dealing with big data and will define the basic framework for a smart city big data operation center, which will eventually lead to a bright future for smart cities. © Springer International Publishing Switzerland 2015.

Xia J.,Wuhan University | Chen L.,Wuhan University | Yanagida S.,Osaka University
Journal of Materials Chemistry | Year: 2011

Conductive polymers have been widely applied as counter electrodes in dye-sensitized solar cells. However, as one of many materials in the conductive polymer family, polypyrrole attracts little attention in this field. In this paper, polypyrrole (PPy) was synthesized by vapour phase polymerization (VPP) and electropolymerization (EP) and these PPys were employed as counter electrodes in dye-sensitized solar cells. Comparing this to the regularly used Pt counter electrode, both of them show good catalytic behaviour in dye-sensitized solar cells though the PPy electrodes have a slightly lower fill factor. Such investigation will broaden the application of conductive polymers in DSCs. Our study indicates that polypyrrole is a good candidate to replace the Pt counter electrode in DSCs. Taking into consideration the regular solvent used in DSCs, it is recommended that an insoluble conductive polymer is a good choice for the counter electrode in DSCs. © 2011 The Royal Society of Chemistry.

Guo S.,Wuhan University | Liu D.,Wuhan University
Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC | Year: 2011

Dynamic voltage restorer (DVR) has been demonstrated to be a very effective mechanism to deal with key voltage-quality disturbances. DVR is series connected in the power lines, and the LC filter is also series connected between the converter and grid. Appropriate design of LC output filter system not only could reduce the switching frequency harmonics, but also could maintain fast dynamic for low frequency, stability for control system, and high efficiency. This paper discusses the design issues of the output LC filter in DVR system and carries out the design in following aspects: 1) the parameter design of LC filter, which considering fundamental issue and cut-through frequency of LC filter; 2) the realization of virtual resistor, which uses damping method to solve the resonance problem; 3) the implementation of bypass switch, which consider the energy loss and efficiency. The design procedure is detailed presented in this paper and the validity is also demonstrated by the simulation. © 2011 IEEE.

Wei G.,Wuhan University
Procedia Engineering | Year: 2011

To solve the very complicated combination optimization problem of the optimization of mine ventilation system, the bionics algorithm-Ant colony algorithm proposed recently is used. Considering the essence of optimization of mine ventilation system, the ant colony algorithm is introduced here to solve the problem of mine ventilation system optimization. The detailed process of ant colony algorithm to optimization of mine ventilation system is described in this paper. At last, a mining engineering example is used to verify the effect of this new method. The results show that, ant colony algorithm is a very good method to solve complicated combination optimization problem. It not only can solve optimization of ventilation system, but also can solve the similar problem of scheme optimization. © 2011 Published by Elsevier Ltd.

Wang S.-T.,Wuhan University | Wang M.-Y.,Wuhan University | Su X.,Wuhan University | Yuan B.-F.,Wuhan University | Feng Y.-Q.,Wuhan University
Analytical Chemistry | Year: 2012

A novel SiO 2/TiO 2 composite monolithic capillary column was prepared by sol-gel technology and successfully applied to enrich phosphopeptides as a metal oxide affinity chromatography (MOAC) material. For the monolith preparation, tetramethoxysilane (TMOS) and tetrabutoxytitanium (TBOT) were used as silica and titania source, respectively, and glycerol was introduced to attenuate the activity of titanium precursor, which provided a mild synthetic condition. The prepared monolith was characterized by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results revealed an approximate 1/2 molar ratio of titanium to silica as well as an atom-scale homogeneity in the framework. The scanning electron microscopy (SEM) results demonstrated an excellent anchorage between the column and the inner capillary wall, and nitrogen adsorption-desorption experiments showed a bimodal porosity with a narrow mesopore distribution around 3.6 nm. The prepared monolith was then applied for selective enrichment of phosphopeptides from the digestion mixture of phosphoproteins and bovine serum albumin (BSA) as well as human blood serum, nonfat milk, and egg white using an in-tube solid phase microextraction (SPME) system. Our results showed that SiO 2/TiO 2 composite monolithic capillary column could efficiently enrich the phosphopeptides from complex matrixes. To the best of our knowledge, this is the first attempt for preparing the silica-metal composite monolithic capillary column, which offers the promising application of the monolith on phosphoproteomics study. © 2012 American Chemical Society.

He D.,Wuhan University | Zeadally S.,University of Kentucky
IEEE Communications Magazine | Year: 2015

Recent advances in healthcare technologies along with improved medical care have led to a steady increase in life expectancy over the past few decades. As a result, we have been witnessing a significant growth in the number of elderly people around the world. Ensuring a comfortable living environment for elderly people has gained much attention in recent years. By leveraging information and communication technologies, the AAL system shows great promise in satisfying many requirements of elderly people and enables them to live safely, securely, healthily, and independently. Over the last few years various AAL systems, mostly based on Wireless Body Area Network technologies, have been proposed to improve the quality of life of elderly people. Since the information transmitted in AAL systems is very personal, the security and privacy of such data are becoming important issues that must be dealt with. We first discuss the overall system architecture of a typical AAL system and its associated security requirements. Next we propose an efficient authentication protocol for the AAL system and describe how it meets various security requirements. Finally we compare the performance of the proposed authentication protocol with two other recent authentication protocols and demonstrate its superior efficiency. © 2015 IEEE.

Huang Q.,Wuhan University | Huang Q.,Huazhong Agricultural University | Zhang L.,Wuhan University
Carbohydrate Polymers | Year: 2011

A water-insoluble (1 → 3)-α-d-glucan from Poria cocos mycelia was fractionated, followed by phosphorylation with H3PO4 in LiCl/Me2SO containing urea to synthesize water-soluble phosphated derivatives. Their structures and chain conformations were investigated by FTIR, 31P NMR, SEC-LLS and viscometry. The Mark-Houwink equation for the phosphated derivative in 0.15 M aqueous NaCl at 30 °C was established to be η=2.87×10-3Mw0.860.02. On the basis of conformational parameters calculated from wormlike cylinder model, the phosphated derivative existed as a semi-stiff chain in aqueous solution. Compared with unphosphated glucan, water-solubility and chain stiffness of the phosphated derivative increased, as a result of the introduction of phosphate group on main chain. All the phosphated derivatives exhibited significantly stronger anti-tumor activities than that of the unphosphated one, suggesting the effects of solubility and expanded chain conformation on improvement of the anti-tumor activity could not be negligible. © 2010 Elsevier Ltd. All rights reserved.

Chen Y.-Z.,Wuhan University | Huang S.-Q.,Wuhan University
Oikos | Year: 2013

In many plants, leaves that are young and/or old (senescent) are not green. One adaptive hypothesis proposed that leaf color change could be a warning signal reducing insect attack. If leaf coloration involves less herbivory, it remains unclear why leaves in many species are constantly green. To examine whether green leaves reduce herbivory by physical defense as an alternative to the supposed warning signal of red leaves, we conducted comparative analyses of leaf color and protective tissues of 76 woody species in spring. The protective features (trichomes, enhanced cuticle and multiple epidermis) and the distribution of red pigments within leaves were examined in both young and mature leaves. We observed that redness was more frequent in young leaves than in senescent leaves. Compared to 36 species with red young leaves, 40 species with green young leaves showed a significantly higher incidence of enhanced cuticle and trichomes in both phylogenetic and non-phylogenetic analyses. The phylogenetic analysis indicated that the multiple origins of mechanical protection were generally associated with loss of red coloration. Our finding of relatively poor mechanical protection in red young leaves provides additional evidence for the adaptive explanation of leaf color change. © 2012 The Authors. Oikos © 2012 Nordic Society Oikos.

Qin S.-Y.,Wuhan University | Xu S.-S.,Wuhan University | Zhuo R.-X.,Wuhan University | Zhang X.-Z.,Wuhan University
Langmuir | Year: 2012

Three flexible peptides (P1: (C 17H 35CO-NH-GRGDG) 2KG; P2: (Fmoc-GRGDG) 2KG; P3: (CH 3CO-NH-GRGDG) 2KG) self-assembled to form a variety of morphologically distinct assemblies at different pHs. P1 formed nanofibers at pH 3, then self-assembled into nanospheres with pH up to 6 and further changed to lamellar structures when the pH value was further increased to 10. P2 aggregated into an entwined network structure at pH 3, and then self-assembled into well-defined nanospheres, lamellar structures, and vesicles via adjusting the pH value. However, P3 did not self-assemble into well-ordered nanostructures, presumably due to the absence of a large hydrophobic group. The varying self-assembly behaviors of the peptides at different pHs are attributed to molecular conformational changes. These self-assembled supramolecular materials might contribute to the development of new peptide-based biomaterials. © 2011 American Chemical Society.

Zhang Y.,Wuhan University | Pan C.,Wuhan University
Journal of Materials Science | Year: 2011

In this study, the P25 TiO2 nanoparticles and graphene sheets (GSs) composite were prepared from a facile thermal reaction of graphene oxide. Its microstructures and photocatalytic properties were characterized and measured using X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) specific area analysis, X-ray photoelectron spectroscopy (XPS), FT-IR spectra, and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy. Compared with pure P25 nanoparticles, the results reveal that (1) there is a red shift about 20 nm in the absorption edge of the P25/graphene composite; (2) the photocurrent of the composite is about 15 times higher than that of pure P25; (3) the visible light photocatalytic activity of the composite is enhanced greatly on decomposition of methylene blue (MB). The photocatalytic mechanism of the P25/graphene composite is also discussed. © 2010 Springer Science+Business Media, LLC.

Deng W.,Wuhan University
Journal of molecular histology | Year: 2013

Cardiac remodelling is a major determinant of heart failure (HF) and is characterised by cardiac hypertrophy, fibrosis, oxidative stress and myocytes apoptosis. Hesperetin, which belongs to the flavonoid subgroup of citrus flavonoids, is the main flavonoid in oranges and possesses multiple pharmacological properties. However, its role in cardiac remodelling remains unknown. We determined the effect of hesperetin on cardiac hypertrophy, fibrosis and heart function using an aortic banding (AB) mouse. Male, 8-10-week-old, wild-type C57 mice with or without oral hesperetin administration were subjected to AB or a sham operation. Our data demonstrated that hesperetin protected against cardiac hypertrophy, fibrosis and dysfunction induced by AB, as assessed by heart weigh/body weight, lung weight/body weight, heart weight/tibia length, echocardiographic and haemodynamic parameters, histological analysis, and gene expression of hypertrophic and fibrotic markers. Also, hesperetin attenuated oxidative stress and myocytes apoptosis induced by AB. The inhibitory effect of hesperetin on cardiac remodelling was mediated by blocking PKCα/βII-AKT, JNK and TGFβ1-Smad signalling pathways. In conclusion, we found that the orange flavonoid hesperetin protected against cardiac remodelling induced by pressure overload via inhibiting cardiac hypertrophy, fibrosis, oxidative stress and myocytes apoptosis. These findings suggest a potential therapeutic drug for cardiac remodelling and HF.

A traditional view of diverse floral traits is that they reflect differences in foraging preferences of pollinators. The role of pollinators in the evolution of floral traits has been questioned recently by broad community surveys, especially studies concerning variation in pollinator assemblages and visitation frequency, which suggest a diminished role of pollinators in floral evolution. Here, we investigate the relationships between six categories of floral traits of 29 species and 10 pollinator functional groups in an alpine meadow in the Hengduan Mountains of China, over three consecutive years. Simpson's diversity index was used to estimate the level of pollinator generalization of each plant species by considering both pollinator groups and their relative visitation frequencies. Multivariate analyses indicated that eight of the ten pollinator groups showed constant preferences for at least two floral traits, leading to a relatively stable level of ecological generalization for most floral traits (two out of three categories), despite the fact that the level of generalization of the entire community varied across years. Shape preferences of butterflies, honeybees and beeflies varied such that open flowers exhibited a lower level of ecological generalization in 2007 than closed flowers, in contrast with the other 2 years. These results suggest that temporally stabilized preferences of diverse pollinators may contribute to the evolution of specialized versus generalized floral traits; however, their role may be moderated by variation in community structure, including both the composition and abundance of plants and pollinators. © 2011 Springer-Verlag.

Wu Q.,Wuhan University | Wu Q.,University of Arizona | Kulatilake P.H.S.W.,University of Arizona
Computers and Geotechnics | Year: 2012

Fracture data available for one of the rock masses (limestone) in the dam site of Yujian River Reservoir were used to build and validate a stochastic 3-D fracture network model, and to perform a REV and equivalent continuum study in 3-D. A number of relations are developed in the paper between the rock mass mechanical parameters and fracture tensor components in 3-D. Based on the mechanical parameter values obtained in every 45° direction in 3-D, the principal parameter values, principal directions and tensors are developed for rock mass mechanical parameters to represent the REV block size properties. An incrementally linear elastic, orthotropic constitutive model is suggested to represent the equivalent continuum pre-failure mechanical behavior of the jointed rock mass by incorporating the effect of joint geometry network by the fracture tensor components. © 2012 Elsevier Ltd.

Hu B.Q.,Wuhan University | Wang C.Y.,Wuhan University
Fuzzy Sets and Systems | Year: 2014

This paper introduces new operations on the algebra of fuzzy truth values, extended supremum and extended infimum, which are generalizations of the extended operations of maximum and minimum between fuzzy truth values for type-2 fuzzy sets, respectively. Using these new operations, the properties of type-2 fuzzy relations are discussed, especially the compositions of type-2 fuzzy relations. On this basis, this paper introduces interval-valued type-2 fuzzy sets and interval-valued type-2 fuzzy relations, and discusses their properties. © 2013 Elsevier B.V.

Wu K.,Wuhan University | Wang G.P.,Wuhan University
Optics Express | Year: 2013

We introduce a Fourier analysis method to design temporal cloaks for hiding events in time domain. The cloaks are constructed with two linear time-invariant filters with different transfer functions, which can create a temporal gap and then closed it orderly, making any events occurring during the gap not detectable outside. We further reveal that even a no-gap temporal cloak can also hide events. All the analytical results are verified by fast Fourier transformation simulations. ©2013 Optical Society of America.

Fang X.,Wuhan University | Li Q.-H.,Wuhan University | Tao H.-Y.,Wuhan University | Wang C.-J.,Wuhan University | Wang C.-J.,Nankai University
Advanced Synthesis and Catalysis | Year: 2013

The first organocatalytic asymmetric addition of thiols to trifluoromethylaldimine for the construction of chiral trifluoromethylated N,S-acetals has been achieved in high yields (up to 99%) and excellent enantioselectivities (up to 95% ee) with 1 mol% of a bifunctional organocatalyst. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wang K.,Wuhan University | Choi S.H.,University of Hong Kong
Computers and Operations Research | Year: 2014

Flexible flow shop scheduling problems are NP-hard and tend to become more complex when stochastic uncertainties are taken into consideration. This paper presents a novel decomposition-based holonic approach (DBHA) for minimising the makespan of a flexible flow shop (FFS) with stochastic processing times. The proposed DBHA employs autonomous and cooperative holons to construct solutions. When jobs are released to an FFS, the machines of the FFS are firstly grouped by a neighbouring K-means clustering algorithm into an appropriate number of cluster holons, based on their stochastic nature. A scheduling policy, determined by the back propagation networks (BPNs), is then assigned to each cluster holon for schedule generation. For cluster holons of a low stochastic nature, the Genetic Algorithm Control (GAC) is adopted to generate local schedules in a centralised manner; on the other hand, for cluster holons of a high stochastic nature, the Shortest Processing Time Based Contract Net Protocol (SPT-CNP) is applied to conduct negotiations for scheduling in a decentralised manner. The combination of these two scheduling policies enables the DBHA to achieve globally good solutions, with considerable adaptability in dynamic environments. Computation results indicate that the DBHA outperforms either GAC or SPT-CNP alone for FFS scheduling with stochastic processing times. © 2013 Elsevier Ltd.

Wu K.,Wuhan University | Wang G.P.,Wuhan University
Optics Letters | Year: 2013

One-dimensional Fibonacci gratings are used to transform evanescent waves into propagating waves for far-field super-resolution imaging. By detecting far-field intensity distributions of light through objects in front of the Fibonacci grating in free space, we can observe the objects with nearly a;/9 spatial resolution. Analytical results are verified by numerical simulations. We also discuss the effect of sampling error on imaging resolution of the system. © 2013 Optical Society of America.

Chen M.-L.,Wuhan University | Wei S.-S.,Wuhan University | Yuan B.-F.,Wuhan University | Feng Y.-Q.,Wuhan University
Journal of Chromatography A | Year: 2012

A novel poly(N-acryloyltris(hydroxymethyl)aminomethane-co-pentaerythritol triacrylate) (NAHAM. -co-PETA) monolith was prepared in the 100 μm i.d. capillary and investigated for capillary liquid chromatography (cLC). The polymer monolith was synthesized by in situ polymerization of NAHAM and PETA in the presence of polyethylene glycol (PEG) in dimethyl sulfoxide (DMSO) as the porogen. The porous structure of monolith was optimized by changing the ratio of NAHAM to PETA, the molecular weight and amount of PEG. To evaluate the separation performance of the resultant polymer monolith, several groups of model compounds (including nucleosides, benzoic acids and anilines) were selected to perform cLC separation. Our results showed that these model compounds can be baseline separated on the resultant poly(NAHAM-co-PETA) monolithic column with the optimized mobile phases. The column efficiency was estimated to be 87,000 plates/m for acrylamide. In addition, this monolithic column was coupled with on-line solid-phase microextraction (SPME) for the analysis of four nucleosides (uridine, adenosine, cytidine, guanosine) in urine. The limit of detection of the proposed method was in the range from 40 to 52. ng/mL. The method reproducibility was obtained by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 8.3% and 10.2%, respectively. Recoveries of the target analytes from spiked urine samples were ranged from 86.5% to 106.8%. © 2011 Elsevier B.V.

Zhu L.,Huazhong Agricultural University | Zhu F.,Wuhan University