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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.


Wu C.,CAS Shanghai Institute of Ceramics | Fan W.,Wuhan University | Chang J.,CAS Shanghai Institute of Ceramics
Journal of Materials Chemistry B | Year: 2013

Controllable drug delivery is one of the important ways for the therapy of bone cancer. Conventional mesoporous silica nano-particles may lack dual properties for combining controllable delivery of anti-cancer drugs and bone-forming bioactivity for bone cancer therapy. The aim of this study is to synthesize mesoporous bioactive glass (MBG) nanospheres with combined dual functions of bioactivity and controlled drug delivery, and to further investigate their delivery property of anti-cancer drugs as well as the functional effect on bone-cancer cells. MBG nanospheres with spherical morphology and internal mesoporous microstructures were successfully prepared by a facile hydrothermal method. The prepared MBG nanospheres possess high specific surface area and mesopore volume (443 m2 g-1, 0.57 cm3 g-1) as well as uniform mesopore size distribution (2.9 nm). The MBG nanospheres demonstrate excellent bioactivity by inducing apatite mineralization in simulated body fluids. An anti-cancer drug, doxorubicin hydrochloride (DOX), was successfully loaded in the MBG nanospheres with a distinctively high loading efficiency of around 90%. The loading amount of DOX can be effectively controlled by adjusting the initial drug-loading concentrations. MBG nanospheres can maintain a sustained release of DOX, and their release kinetics can be controlled by varying the pH microenvironment and initial drug-loading concentrations. In addition, the prepared MBG nanospheres showed obvious degradation by releasing Ca2+ and SiO4 4- ions in PBS. Furthermore, the delivery of DOX from MBG nanospheres into cell culture environment shows a significant inhibitory effect on the viability of osteosarcoma cells with the increase of interaction time. The prepared MBG nanospheres have high specific surface area and mesopore volume, excellent apatite-mineralization ability, distinct degradability, high DOX-loading efficiency and controllable DOX release as well as anti-cancer functions. These unique characteristics suggest that the obtained MBG nanospheres may be used for the therapy of bone cancer. This journal is © The Royal Society of Chemistry 2013. Source


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. Source


Liu X.,University of Cambridge | Liu X.,Texas State University | Zhang L.,CAS Wuhan Institute of Geodesy and Geophysics | Hong S.,Wuhan University
Biodiversity and Conservation | Year: 2011

We performed a bibliometric analysis of published biodiversity research for the period of 1900-2009, based on the Science Citation Index (SCI) database. Our analysis reveals the authorial, institutional, spatiotemporal, and categorical patterns in biodiversity research and provides an alternative demonstration of research advancements, which may serve as a potential guide for future research. The growth of article outputs has exploded since the 1990s, along with an increasing collaboration index, references, and citations. Ecology, environmental sciences, biodiversity conservations, and plant science were most frequently used subject categories in biodiversity studies, and Biological Conservation, Journal of Soil and Water Conservation, Conservation Biology and Biodiversity and Conservation were most active journals in this field. The United States was the largest contributor in global biodiversity research, as the U. S. produced the most single-country and collaborative articles, had the greatest number of top research institutions, and had a central position in collaboration networks. We perceived an increasing number of both internationally collaborative and inter-institutionally collaborative articles, with the latter form of collaboration being more prevalent than the former. A keyword analysis found several interesting terminology preferences, confirmed conservation's central position as a topic in biodiversity research, revealed the adoption of advanced technologies, and demonstrated keen interest in both the patterns and underlying processes of ecosystems. Our study reveals patterns in scientific outputs and academic collaborations and serves as an alternative and innovative way of revealing global research trends in biodiversity. © 2010 Springer Science+Business Media B.V. Source


Liu D.,Auburn University | Liu W.,Wuhan University
Ceramics International | Year: 2011

High quality epitaxial (La2/3Sr1/3)MnO3 (0 0 1) thin films were grown by pulsed laser deposition on SrTiO3 (0 0 1) substrate at optimized growth parameters. The films quality was confirmed by both structural and physical properties characterization. Channeling Rutherford Backscattering Spectrometry characterization showed the minimal channeling coefficient as low as 4%. The LSMO thin films growth on SrTiO3 substrate follows the island growth model. The Curie temperature of LSMO films is around 360 K, which is the one of the highest reported in literature. The resistivity of LSMO films showed the metal-insulate transition temperature coincides with the Curie temperature. This high quality LSMO is suitable for room temperature magnetic devices application. © 2011 Elsevier Ltd and Techna Group S.r.l. Source


Choi S.H.,University of Hong Kong | Wang K.,Wuhan University
Computers and Industrial Engineering | Year: 2012

Flexible flow shop scheduling problems are NP-hard and tend to become more complex when stochastic uncertainties are taken into consideration. Although some methods have been developed to address such problems, they remain inherently difficult to solve by any single approach. This paper presents a novel decomposition-based approach (DBA), which combines both the shortest processing time (SPT) and the genetic algorithm (GA), to minimizing the makespan of a flexible flow shop (FFS) with stochastic processing times. In the proposed DBA, a neighbouring K-means clustering algorithm is developed to firstly group the machines of an FFS into an appropriate number of machine clusters, based on their stochastic nature. Two optimal back propagation networks (BPN), corresponding to the scenarios of simultaneous and non-simultaneous job arrivals, are then selectively adopted to assign either SPT or GA to each machine cluster for sub-schedule generation. Finally, an overall schedule is generated by integrating the sub-schedules of machine clusters. Computation results show that the DBA outperforms SPT and GA alone for FFS scheduling with stochastic processing times. © 2012 Elsevier Ltd. All rights reserved. Source


The purpose of this study was to determine the effect and associated cell signaling mechanisms of indole-3-carbinol (I3C) on platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of cultured vascular smooth muscle cells (VSMCs) and neointima formation in a carotid injury model. Our data demonstrated that I3C inhibited PDGF-BB-induced proliferation of VSMCs in a dose-dependent manner without causing cell cytotoxicity, as assessed by 5-bromo-2'-deoxyuridine incorporation and WST-1 assays. Further studies revealed that the antiproliferative effect of I3C was caused by the arrest of cells in both the G0/G1 and S phases. Moreover, I3C treatment inhibited migration of VSMCs and partly reversed the expression of smooth-muscle-specific contractile markers. We also demonstrated that I3C-induced growth inhibition was associated with an inhibition of the expression of cyclin D1 and cyclin-dependent kinase 4/6, as well as an increase in p27(Kip1) levels in PDGF-stimulated VSMCs. These beneficial effects of I3C on VSMCs appeared to be at least partly mediated by the inhibition of Akt and the subsequent activation of glycogen synthase kinase (GSK) 3β. Furthermore, using a mouse carotid artery injury model, we found that treatment with 150 mg/kg I3C resulted in a significant reduction of the neointima/media ratio and cells positive for proliferating cell nuclear antigen. These results demonstrate that I3C can suppress the proliferation and migration of VSMCs and neointima hyperplasia after vascular injury via inhibition of the Akt/GSK3β pathway and suggest that this might be feasible as part of a therapeutic strategy for vascular proliferative diseases. Copyright © 2013 Elsevier Inc. All rights reserved. Source


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. Source


Ren K.,State University of New York at Buffalo | Wang Q.,Wuhan University
IEEE Wireless Communications | Year: 2013

Opportunistic spectrum access (OSA), which is considered as the core technology of hierarchical access model of dynamic spectrum access (DSA), has been extensively researched recently. Most of the existing OSA protocols, albeit theoretically sound with almost optimal performance, have to require the preknowledge of static known distributions under stochastic channels. These assumptions, however, make them impractical for more general application scenarios where channel statistics may not be readily available a priori and channel availabilities cannot be modeled as a stochastic process due to malicious jamming. More seriously, the existing OSA protocols are subject to malicious jamming attacks. That is, a cognitive jammer can always disrupt the legitimate network communication by leveraging the publicly-available channel statistic information to effectively jam the channels and thus lead to serious spectrum underutilization. In this article, we first present an in-depth overview of the existing spectrum sensing and access protocols under stochastic channels, achieving almost optimal performance in jamming- free scenarios. We then analyze the vulnerabilities of these protocols to malicious jamming attacks. Finally, we discuss spectrum sensing and access protocols under non-stochastic channels and show their robustness and resilience against various malicious jamming attacks. © 2002-2012 IEEE. Source


Wang X.,Wuhan University
American Journal of Physics | Year: 2014

A closed form solution is given for the trajectory of a particle sliding on an inclined plane with Coulomb-type friction. If the inclination of the plane is less than the friction angle, the particle eventually comes to rest and expressions for the location of this point and the duration of the motion are given. If the initial launch is inclined at a small angle with respect to the upward line of greatest slope, the direction of the velocity changes rapidly during the last instants of motion. © 2014 American Association of Physics Teachers. Source


Lei G.,Chongqing University | Shixiang L.,Wuhan University
Journal of Convergence Information Technology | Year: 2012

In the study,support vector regression with improved quantum-behaved particle swarm optimization(IQPSO-SVR) is applied to evaluate coal resources demand,and improved quantum-behaved particle swarm optimization(IQPSO) is used to choose the suitable parameters of support vector regression. Firstly,the dimensions of the input vector in the the training sample sets need to be determined and the training sample sets are created.Then, the different IQPSO-SVR models trained by the different training sample sets are generated. The experimental resuts indicate that the IQPSO-SVR model trained by the training sample sets with 4 dimensional input vector has the best evaluation results and the comparison results of the validation and prediction results for coal resources demand between the IQPSO-SVR model and the SVR model show that the evaluation results of the IQPSO-SVR model have better than those of the SVR model. Source


Discourses on ‘climate migration’ have played an instrumental role in initiating negotiations on loss and damage under the United Nations Framework Convention on Climate Change (UNFCCC). Yet, to date, the framing of climate migration has not been clear: it has been considered as a tool for reducing loss and damage (hence essentially a form of adaptation) or, alternatively, as a source of loss and damage for the migrants or for other concerned communities. Moreover, proposed approaches to address climate migration as a form of loss and damage have extended beyond compensation, and remain controversial among developed nations. In the highly politicized field of migration governance, however, this article submits that policy support and guidance in addressing loss and damage could prompt dangerous forms of political interference, such as the imposition of a Western objective of containing migrants to the Global South. It is thus suggested that top-down migration policies may not help vulnerable nations who face loss and damage in the context of climate migration. © Cambridge University Press 2016 Source


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. Source


Li C.,Wuhan University | Yang S.,Brunel University | Nguyen T.T.,Liverpool John Moores University
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2012

Particle swarm optimization (PSO) has been shown as an effective tool for solving global optimization problems. So far, most PSO algorithms use a single learning pattern for all particles, which means that all particles in a swarm use the same strategy. This monotonic learning pattern may cause the lack of intelligence for a particular particle, which makes it unable to deal with different complex situations. This paper presents a novel algorithm, called self-learning particle swarm optimizer (SLPSO), for global optimization problems. In SLPSO, each particle has a set of four strategies to cope with different situations in the search space. The cooperation of the four strategies is implemented by an adaptive learning framework at the individual level, which can enable a particle to choose the optimal strategy according to its own local fitness landscape. The experimental study on a set of 45 test functions and two real-world problems show that SLPSO has a superior performance in comparison with several other peer algorithms. © 2012 IEEE. Source


Luo Y.,Wuhan University
Applied Computational Electromagnetics Society Journal | Year: 2016

Traditional method using integral of the Bessel and Struve functions is not suitable for calculating the mutual inductance between two coplanar disk coils. Considering the monotonicity of modified Bessel and Struve functions, an alternative method using these monotonic functions is applied to calculate the mutual inductance, and numerical evaluations can be accelerated considerably. Series solutions using the generalized hypergeometric functions are further obtained by solving the infinite integrations, and these series are compared with the aforementioned integral methods. The numerical results show that the series solutions are much more faster than the integral ones, and with the series method, results of very high accuracy can be obtained within a small fraction of one second in most cases. Furthermore, we point out and prove the existence of the decoupling positions at which the mutual inductance will vanish. © 2016 ACES. Source


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. Source


Li B.,Wuhan University | Hoi S.C.H.,Nanyang Technological University
ACM Computing Surveys | Year: 2014

Online portfolio selection is a fundamental problem in computational finance, which has been extensively studied across several research communities, including finance, statistics, artificial intelligence, machine learning, and data mining. This article aims to provide a comprehensive survey and a structural understanding of online portfolio selection techniques published in the literature. From an onlinemachine learning perspective, we first formulate online portfolio selection as a sequential decision problem, and then we survey a variety of state-of-the-art approaches, which are grouped into several major categories, including benchmarks, Follow-the-Winner approaches, Follow-the-Loser approaches, Pattern-Matching-based approaches, and Meta-Learning Algorithms. In addition to the problem formulation and related algorithms, we also discuss the relationship of these algorithms with the capital growth theory so as to better understand the similarities and differences of their underlying trading ideas. This article aims to provide a timely and comprehensive survey for both machine learning and data mining researchers in academia and quantitative portfolio managers in the financial industry to help them understand the state of the art and facilitate their research and practical applications. We also discuss some open issues and evaluate some emerging new trends for future research. © 2014 ACM. Source


Cao Z.,Wuhan University | Wang Y.,City University of Hong Kong
Structural Safety | Year: 2014

The inherent spatial variability of soils is one of the major sources of uncertainties in soil properties, and it can be characterized explicitly using random field theory. In the context of random fields, the spatial correlation between the values of a soil property concerned at different locations is represented by its correlation structure (i.e., correlation functions). How to select a proper correlation function for a particular site has been a challenging task, particularly when only a limited number of project-specific test results are obtained during geotechnical site characterization. This paper develops a Bayesian model comparison approach for selection of the most probable correlation function among a pool of candidates (e.g., single exponential correlation function, binary noise correlation function, second-order Markov correlation function, and squared exponential correlation function) for a particular site using project-specific test results and site information available prior to the project (i.e., prior knowledge, such as engineering experience and judgments). Equations are derived for the proposed Bayesian model comparison approach, in which the inherent spatial variability is modeled explicitly using random field theory. Then, the proposed method is illustrated and validated through simulated cone penetration test (CPT) data and four sets of real CPT data obtained from the sand site of the US National Geotechnical Experimentation Sites (NGES) at Texas A&M University. In addition, sensitivity studies are performed to explore the effects of prior knowledge, the measurement resolution (i.e., sampling interval), and data quantity (i.e., sampling depth) on selection of the most probable correlation function for soil properties. It is found that the proposed approach properly selects the most probable correlation function and is applicable for general choices of prior knowledge. The performance of the method is improved as the measurement resolution improves and the data quantity increases. © 2013 Elsevier Ltd. Source


Chen Y.F.,Wuhan University
Zhonghua xin xue guan bing za zhi | Year: 2011

To investigate whether Resolvin E1 (RvE1) could protect against ox-LDL-induced injury on human vein vascular endothelial cells and reveal related molecular mechanisms. Human vein vascular endothelial cells were randomly assigned to six groups, which were treated with saline, RvE1, wortmanin, ox-LDL, ox-LDL and RvE1, ox-LDL and RvE1 and wortmanin, respectively. After 48 h, survival rates were determined by MTT, apoptosis rate of cells were determined by flow cytometry, TNF-α contents were assayed by ELISA, caspase 3 and 9 activities were measured by microplate reader, and the expression of p-AKT and LOX-1 were determined by Western blot. Compared with normal saline group, survival rate was markedly decreased and apoptosis rate, TNF-α content, caspase 3 and 9 activities, and the expression of LOX-1 were significantly increased in ox-LDL group (P < 0.01). Survival rate was significantly increased and apoptosis rate, TNF-α content, caspase 3 and 9 activities, and the expression of LOX-1 were significantly decreased in ox-LDL + RvE1 group compared to ox-LDL group (P < 0.01), these beneficial effects of RvE1 could be blocked by PI3K inhibitor wortmanin (P < 0.05). The present data showed that RvE1 could effectively protect against ox-LDL-induced endothelial cell injury, which might be mediated by PI3K-AKT signaling pathway. Source


Song X.S.,Wuhan University
Zhonghua yi xue za zhi | Year: 2011

To gain insights into the construction and content of literature on infectious keratitis in China during the past two decades. Through VIP-VMIS, SinoMed and PubMed databases for the period of 1989 to 2008, the literature regarding infectious keratitis published in domestic and foreign journals by China authors was retrieved. Numbers, types, time, journal distribution of documents published and provincial distribution of authors were recorded. Meanwhile the subject content was roughly analyzed. There were 1982 Chinese articles on infectious keratitis during the past two decades, of which 629 were pertaining to traditional Chinese medicine. In the remaining 1353 of Western medicine articles, 704 were published in kernel journals, 78 in serial journals of Chinese Medical Association and 443 as original research articles (including 160 basic research papers). Moreover, 30 articles regarding epidemiology and etiology of infectious keratitis were retrieved from VIP-VMIS. And 31 papers published in foreign journals were retrieved from PubMed database. During the past two decades, the China oculists have made great progress in research works on infectious keratitis. However more attention should be devoted to the basic researches, epidemiologic survey and etiologic analysis. Source


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. Source


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. Source


Liu S.,Wuhan University | Wang L.,Huazhong University of Science and Technology
International Journal of Project Management | Year: 2014

Successfully managing the risks of information technology projects continues to be a central problem for organizations regardless of whether the project is outsourced or not. While a plethora of studies has examined the effects of risks on performance, majority fail to distinguish the sourcing characteristics of the projects investigated. Furthermore, little is known about the joint effects of strategic importance and the risk on system performance across internal and outsourced projects. Based on data collected from 77 internal projects and 51 outsourced projects, we find that social subsystem and project management risks are negatively associated with system performance in both internal and outsourced projects. However, technical subsystem risk negatively affects performance only in internal projects. While social subsystem risk exerts greater influence on system performance in outsourced projects than in internal projects, the technical subsystem risk has greater effect on performance in internal than that in outsourced projects. Moreover, the effect of project management risk is not different in both types of projects. In addition, strategic importance moderates the relationship between risks and performance. The negative impact of risks on performance is greater in projects that are more strategic. Strategies are proposed to reduce the complexity and potential conflicts inherent to strategic projects because these characteristics may amplify a risk's impact. © 2014. Source


Ding Z.,Wuhan University
Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery | Year: 2013

To evaluate the feasibility and safety of total colonic exclusion plus side to side antiperistaltic ileorectal anastomosis in the treatment for elderly patients with slow transit constipation (STC). Clinical data of 13 patients with severe idiopathic STC undergoing the above novel procedure in Zhongnan Hospital of Wuhan University between May 2009 and September 2012 were retrospectively analyzed. The Wexner constipation score and gastrointestinal quality of life index (GIQLI) before and 6 months after operation were compared. There were 8 female and 5 male patients, with a mean age of 74 years (range 63-82 years). No procedure-related deaths or any serious complication occurred. The length of follow-up ranged from 6 to 29 months (median,12 months). The duration of surgery was (55±4) min. Blood loss was (30±2) ml. The postoperative hospital stay ranged 10 to 16 days (mean 11.4 days). The first bowel movement occurred in the 4th day (range 2nd-8th day) after operation. There was no intestinal occlusion and anastomotic leakage that required surgery in all the patients. No fecal incontinence or constipation recurrence was found. One patient developed blind loop syndrome 14 months after operation. Postoperative complications included incision fat liquefaction in 2 cases, anorectal bearing-down while bowel movement in 2 cases, and minor defecate difficulty needed glycerin enema in 1 case. Wexner scores was significantly improved from 22.8±3.3 before operation to 5.4±2.1 six months after operation (P<0.05). GQLI was significantly increased from 93.6±20.5 before operation to 120.8±13.0 six months after operation (P<0.05). At 6 months after operation, the outcome was excellent in 11 patients and good in 2 patients. Total colonic exclusion plus side to side antiperistaltic ileorectal anastomosis is easy, safe and effective in the treatment for selected elderly patients with STC. Source


Zhang B.,Wuhan University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Based on a recent proposal for the volume inside a black hole, we calculate the entropy associated with this volume and show that such entropy is proportional to the surface area of the black hole. Together with the consideration of black hole radiation, we find that the thermodynamics associated with the entropy is likely to be caused by the vacuum polarization near the horizon. © 2015 American Physical Society. Source


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. Source


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. Source


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. Source


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. Source


Wan L.,Wuhan Textile University | Zhou Q.,Zhaoqing University | Wang P.,Wuhan University | Li J.,Wuhan Textile University
Nonlinear Analysis: Real World Applications | Year: 2012

This paper investigates ultimate boundedness and a weak attractor for stochastic Hopfield neural networks (HNN) with time-varying delays. By employing the Lyapunov method and the matrix technique, some novel results and criteria on ultimate boundedness and an attractor for stochastic HNN with time-varying delays are derived. Finally, a numerical example is given to illustrate the correctness and effectiveness of our theoretical results. © 2011 Elsevier Ltd. All rights reserved. Source


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. Source


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. Source


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. Source


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. Source


Qin Y.,Wuhan University | Hiller J.E.,Michigan Technological University
Materials and Structures/Materiaux et Constructions | Year: 2014

This study simulates internal relative humidity (RH) distributions for in-service jointed plain concrete pavement slabs. A one-dimensional isothermal mass transport model is used to predict the concrete slab's RH distribution through its depth. At the top of the slab, a new statistical algorithm is applied to estimate the occurrences of drying and wetting cycles. During drying cycles, both local wind speed and ambient RH govern the slab surface's moisture convection. During the wetting cycle, the moisture at the surface is treated as a fixed saturated condition. The feasibility of this model is verified through laboratory observations of internal RH in concrete prisms as well as through field measurements of internal RH for an in-service concrete pavement. Using the developed model, predictions of internal RH distributions of in-service slabs are centered on their sensitivity to local weather conditions, including factors such as the ambient RH, wind speed, and rainfall, especially for slabs in arid regions. © 2013 RILEM. Source


Wang Q.,Hong Kong Polytechnic University | Atkinson P.M.,University of Southampton | Shi W.,Hong Kong Polytechnic University | Shi W.,Wuhan University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2015

Indicator cokriging (ICK) has been shown to be an effective subpixel mapping (SPM) algorithm. It is noniterative and involves few parameters. The original ICK-based SPM method, however, requires the semivariogram of land cover classes from prior information, usually in the form of fine spatial resolution training images. In reality, training images are not always available, or laborious work is needed to acquire them. This paper aims to seek spatial structure information for ICK when such prior land cover information is not obtainable. Specifically, the fine spatial resolution semivariogram of each class is estimated by the deconvolution process, taking the coarse spatial resolution semivariogram extracted fromthe class proportion image as input. The obtained fine spatial resolution semivariogram is then used to estimate class occurrence probability at each subpixel with the ICK method. Experiments demonstrated the feasibility of the proposed ICK with the deconvolution approach. It obtains comparable SPM accuracy to ICK that requires semivariogram estimated from fine spatial resolution training images. The proposed method extends ICK to cases where the prior spatial structure information is unavailable. © 2014 IEEE. Source


Chen S.,Xiamen University | Chen S.,University of Texas at Austin | Ji H.,University of Texas at Austin | Chou H.,University of Texas at Austin | And 7 more authors.
Advanced Materials | Year: 2013

Millimeter-size single-crystal monolayer graphene is synthesized on polycrystalline Cu foil by a method that involves suppressing loss by evaporation of the Cu at high temperature under low pressure. This significantly diminishes the number of graphene domains, and large single crystal domains up to ∼2 mm in size are grown. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Zhang H.,Wuhan University
IEEE Transactions on Energy Conversion | Year: 2015

This paper presents a new transfer function approach for calculating both the average temperature and hot spot temperature of an induction machine with the consideration of temperature-dependent material properties and speed-dependent heat transfer coefficient. Green's functions are introduced and taken as the new transfer functions. Online thermal monitoring models for induction machines are obtained based on Green's function method. Using the presented method, the hot spot temperature and average temperature can be calculated accurately and rapidly. The proposed method is validated via finite-element method and experimental measurement. © 2015 IEEE. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


Zhao D.,South-Central University for Nationalities | Li J.,South-Central University for Nationalities | Yang T.,South-Central University for Nationalities | He Z.,Wuhan University
Biosensors and Bioelectronics | Year: 2014

A "turn off-on" mode has been established by using the interaction between platinum anticancer drugs and DNA as input signal and the fluorescence reversible change of quantum dots (QDs) as output signal. The QDs fluorescence can be quenched by platinum anticancer drugs via photo-induced electron transfer process, rendering the system into "turn off" status, and the system can then be "turned on" when fluorescence is restored due to covalent conjugation between DNA and platinum anticancer drugs. This dual-directional fluorescence change realized the detection of cisplatin and DNA, overcoming the selectivity problem commonly existed in the traditional mono-directional fluorescence detection mode. The reversible fluorescent "turn off-on" mode has been further employed to study the interactions between DNA and different platinum anticancer drugs (cisplatin, oxaliplatin and carboplatin). Furthermore, the impacts of different types of DNAs (different in base sequence, chain length and ssDNA/dsDNA) on the mode are also explored. This simple, fast and convenient spectroscopic method owns promising applications in the study on interaction between medical molecules and DNA, and in biochemical detections. © 2013 Elsevier B.V. Source


Chen L.,Huazhong University of Science and Technology | Zhang T.,Huazhong University of Science and Technology | Li X.,McMaster University | Wang G.,Wuhan University
Optics Express | Year: 2013

Considering the propagation of surface plasmon polaritons (SPPs) supported by a graphene monolayer can be effectively controlled via electrostatic gating, we propose a graphene monolayer on a graded silicongrating substrate with dielectric spacer as an interlayer for plasmonic rainbow trapping in the infrared domain. Since the dispersive relation of SPPs is dependent on the width of dielectric spacer filling the silicon grating, the guided SPPs at different frequencies can be localized at different positions along the graphene surface, associated with the period of silicon grating. The group velocity of slow SPPs can be made to be several hundred times smaller than light velocity in vacuum. We also predict the capability of completely releasing the trapped SPPs by dynamically tuning the chemical potential of graphene by means of gate voltage. The advantages of such a structure include compact size, wide frequency tunability, and compatibility with current micro/nanofabrication, which holds great promise for applications in graphene-based optoelectronic devices. © 2013 Optical Society of America. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


Liu J.T.,Wuhan University
Zhonghua er ke za zhi. Chinese journal of pediatrics | Year: 2010

To facilitate early recognition of ominous clinical manifestations, to understand pathophysiology and assess treatment effects in patients with severe enterovirus 71 (EV71) associated hand, foot and mouth disease (HFMD). A retrospective analysis was performed based on the clinical records, laboratory data and treatment effects which were collected from twelve severe EV71 infected cases from nine hospitals in 2008, in Hubei province, China. Of the 12 severe cases, ten (83.3%) were male and two female. The median age was 1.96 yrs (8 m to 7 yrs). The mean hyperthermic duration was 6 days with the peak temperature over 38.5 degrees C, and mean rash duration was 7 days. Fever and rash emerged simultaneously in 4 of 5 cases with cardiopulmonary failure. The severe complications included encephalitis (10 cases), pulmonary edema or hemorrhage (5 cases). Eleven cases were checked with magnetic resonance imaging (MRI) and four cases showed characteristics of encephalitis or meningitis, two with images of naso sinusitis and ethmoid-mastoid inflammation. Chest X-ray examination showed with pulmonary edema on single or both sides (5 cases), bronchitis (4 cases), and normal image (3 cases). There was no specific finding in the cardiac ultrasound and electrocardiogram in any of the patients, as well as the white blood cell count, blood glucose, prothrombin time, partial thromboplastin time and D-dimer. Cerebrospinal fluid showed aseptic meningitis with the increase of cell count in 7 cases. All patients were treated with antibiotics and/or antivirals, such as cephalosporins, ribavirin etc. Eleven patients were treated with intravenous immunoglobulin (total dose 2 - 4.5 g/kg) for 2 - 5 days, and the highest blood concentration of immunoglobulin was detected increasing at 7 g/L. Seven cases were also treated with methylprednisolone 10 - 30 mg/(kg x d), four with dopamine, dobutamine, or digitalis. In addition, by using continuous positive airway pressure by nasal catheter and maintenance of circulation in the cases with cardiopulmonary failure could not relieve the symptoms of dyspnoea, and mechanical ventilation was required to maintain for a mean of 72 hrs (24 - 96 hrs). Except one case died of pulmonary edema in the early stage, others were cured without sequelae. Severe EV71 infection is more common in children younger than 3 years old, in which the profound complications include encephalitis and pulmonary edema. The mechanical ventilation should be critically urged for child with complicating cardiopulmonary failure as soon. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


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. Source


Tan Z.-J.,Wuhan University | Chen S.-J.,University of Missouri
Biophysical Journal | Year: 2010

Recent experiments pointed to the potential importance of ion correlation for multivalent ions such as Mg2+ ions in RNA folding. In this study, we develop an all-atom model to predict the ion electrostatics in RNA folding. The model can treat ion correlation effects explicitly by considering an ensemble of discrete ion distributions. In contrast to the previous coarse-grained models that can treat ion correlation, this new model is based on all-atom nucleic acid structures. Thus, unlike the previous coarse-grained models, this new model allows us to treat complex tertiary structures such as HIV-1 DIS type RNA kissing complexes. Theory-experiment comparisons for a variety of tertiary structures indicate that the model gives improved predictions over the Poisson-Boltzmann theory, which underestimates the Mg 2+ binding in the competition with Na+. Further systematic theory-experiment comparisons for a series of tertiary structures lead to a set of analytical formulas for Mg2+/Na+ ion-binding to various RNA and DNA structures over a wide range of Mg2+ and Na + concentrations. © 2010 by the Biophysical Society. Source


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. Source


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. Source


Soetandyo N.,U.S. National Institute of Diabetes and Digestive and Kidney Diseases | Wang Q.,U.S. National Institute of Diabetes and Digestive and Kidney Diseases | Ye Y.,U.S. National Institute of Diabetes and Digestive and Kidney Diseases | Li L.,Wuhan University
Journal of Cell Science | Year: 2010

Endoplasmic reticulum (ER)-associated degradation (ERAD) of unassembled T-cell receptor α-chain (TCRα) is reliant on the presence of two basic residues in the transmembrane (TM) segment of TCRα. The precise role of these residues in ER quality control is unclear. Here, we show that a TCRα mutant lacking these intramembrane charged residues has a tendency to form homooligomers through an interchain disulfide bond that involves a specific pair of cysteine residues. Covalent oligomerization of TCRα appears to stabilize it at the ER membrane. The presence of a single lysine residue at specific positions within the TCRα TM domain abolishes its oligomerization and causes its rapid degradation. Conversely, when TCRα oligomerization is induced by a bivalent compound, the degradation of TCRα is inhibited. Together, these results suggest that the intramembrane charged residues in TCRα do not function as a signal for substrate recognition in ERAD. Instead, their primary role is to reduce TCRα oligomerization, maintaining it in a retrotranslocation-competent state. Our results also suggest that the ERAD machinery is inefficient when coping with oligomerized substrates, indicating a requirement for chaperone-mediated protein disassembly in the ER lumen prior to retrotranslocation. Source


Ma W.,Wuhan University
Chemistry and Biodiversity | Year: 2014

The origin of life is a field full of controversies, not only because of our vague understanding concerning the relevant issues, but also, perhaps more often, owing to our dim conceptual framework throughout the whole field. To improve this situation, an in-depth conceptual dissection is presented here. It is elucidated that, at its core, the origin of life has three aspects. The facts involved in the process are taken as the historical aspect, which is destined to be uncertain and often irrelevant to debate regarding details. The rules involved include two distinct aspects: chemical mechanisms operated in the whole process, while evolutionary mechanisms joined in only after the emergence of the first Darwinian entities - and then accounted for the subsequent buildup of complexity (this cannot be explained solely by natural selection). Basically, we can ask about the possibility of any assumed event in the origin of life: 'Is it evolutionarily plausible, chemically feasible, and historically likely?' Clues from any of the three aspects may be quite valuable in directing our explorations on the other two. This conceptual dissection provides a clearer context for the field, which may even be more useful than any sort of specific research. © 2014 Verlag Helvetica Chimica Acta AG. Source


Shi W.,Huazhong Agricultural University | Lei A.,Wuhan University
Tetrahedron Letters | Year: 2014

Conjugated diynes have attracted more and more attention not only for their unique rod like structures and wide existence in nature product, but also the abundant properties and derivations of them. Although oxidative dimerization of alkynes or Cadiot-Chodkiewicz reactions were the main pathway and have achieved great success in the synthesis of diynes, oxidative cross coupling, FBW rearrangement as well as diyne metathesis emerged rapidly recently. Moreover, diynes could be precursors of basic heterocycles, which represented an emerging research area. This Letter will cover the recent progresses in the synthesis and further derivations of diynes. © 2014 Elsevier Ltd. All rights reserved. Source


Zhang B.,Wuhan University
Information Sciences | Year: 2016

Li recently investigated type-2 triangular norms and their residual operators. In this paper, the flaws in calculations of T-extension operations of t-(co)norms and their residual operations are presented with counterexamples. Moreover, incorrect conclusions are corrected. © 2016 Elsevier Inc. All rights reserved. Source


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. Source


Yan Q.,Wuhan University
Acta Mathematica Scientia | Year: 2016

This paper is concerned with periodic optimal control problems governed by semilinear parabolic differential equations with impulse control. Pontryagin's maximum principle is derived. The proofs rely on a unique continuation estimate at one time for a linear parabolic equation. © 2016 Wuhan Institute of Physics and Mathematics. Source


Zhang W.,Wuhan University
BMC systems biology | Year: 2012

The biochemical oscillator that controls periodic events during the Xenopus embryonic cell cycle is centered on the activity of CDKs, and the cell cycle is driven by a protein circuit that is centered on the cyclin-dependent protein kinase CDK1 and the anaphase-promoting complex (APC). Many studies have been conducted to confirm that the interactions in the cell cycle can produce oscillations and predict behaviors such as synchronization, but much less is known about how the various elaborations and collective behavior of the basic oscillators can affect the robustness of the system. Therefore, in this study, we investigate and model a multi-cell system of the Xenopus embryonic cell cycle oscillators that are coupled through a common complex protein, and then analyze their synchronization ability under four different external stimuli, including a constant input signal, a square-wave periodic signal, a sinusoidal signal and a noise signal. Through bifurcation analysis and numerical simulations, we obtain synchronization intervals of the sensitive parameters in the individual oscillator and the coupling parameters in the coupled oscillators. Then, we analyze the effects of these parameters on the synchronization period and amplitude, and find interesting phenomena, e.g., there are two synchronization intervals with activation coefficient in the Hill function of the activated CDK1 that activates the Plk1, and different synchronization intervals have distinct influences on the synchronization period and amplitude. To quantify the speediness and robustness of the synchronization, we use two quantities, the synchronization time and the robustness index, to evaluate the synchronization ability. More interestingly, we find that the coupled system has an optimal signal strength that maximizes the synchronization index under different external stimuli. Simulation results also show that the ability and robustness of the synchronization for the square-wave periodic signal of cyclin synthesis is strongest in comparison to the other three different signals. These results suggest that the reaction process in which the activated cyclin-CDK1 activates the Plk1 has a very important influence on the synchronization ability of the coupled system, and the square-wave periodic signal of cyclin synthesis is more conducive to the synchronization and robustness of the coupled cell-cycle oscillators. Our study provides insight into the internal mechanisms of the cell cycle system and helps to generate hypotheses for further research. Source


Xue J.,Wuhan University
European journal of histochemistry : EJH | Year: 2010

Quantum dots (QDs) are a new class of fluorescent probes to detect biomarker expression. The role of caveolin-1 (Cav-1) in tongue squamous cell carcinoma (TSCC) is still unknown. This study aimed to investigate the expression profile of Cav-1 in carcinogenesis and development of TSCC by QDs immunofluorescence histochemistry (QDs-IHC) and discuss the relationship between the Cav-1 expression and the clinicopathological outcomes. QDs-IHC was used to detect Cav-1 expression in tissue microarrays including normal tongue mucosa (NTM; n=10), hyperplastic tongue mucosa (HTM; n=10), tongue pre-cancer lesions (TPL; n=15) and primary tongue squamous cell carcinoma (PTSCC; n=61). Correlations between the Cav-1 expression and clinicopathologic variables were evaluated statistically. Cells positive for Cav-1 were clearly detected and bright images were obtained in a fine, granular pattern at the cell membrane and cytoplasm using QDs-IHC. The rate of Cav-1 immunoreactivity increased progressively from NTM (0%), HTM (0%), TPL (36%) to PTSCC (74%). When compared with each other, there was statistical significance among PTSCC, TPL and NTM as well as among PTSCC, TPL and HTM. Moreover, Cav-1 expression level in PTSCC was correlated positively with clinical stage and histologic grade. QDs-IHC could accurately detect protein location in tongue mucosa. An increased expression of Cav-1 in the stepwise carcinogenesis from NTM, HTM, TPL to PTSCC suggested that Cav-1 might be an oncogene in the development of tongue squamous cell carcinoma. Source


OBJECTIVES: The cholinergic anti-inflammatory pathway has been elucidated as a regulator of inflammatory responses in several experimental models of diseases. This regulatory mechanism is mediated by acetylcholine, released from efferent vagus nerve, interacts with α7 nicotinic acetylcholine receptors on immune cells. Experimental evidence indicates that vagus nerve stimulation or α7 nicotinic acetylcholine receptor agonists control proinflammatory cytokine production and protect animals in diverse lethal models. The aim of the study was to investigate effect of the cholinergic anti-inflammatory pathway in acute lung injury in an experimental model of severe acute pancreatitis (SAP). METHODS: In taurocholate-induced SAP in rats, pancreatitis was preceded by pretreatment with the nicotinic receptor agonist nicotine or unilateral left cervical vagotomy. RESULTS: Pretreatment with nicotine strongly alleviated severity of SAP-associated lung injury through attenuating serum amylase, lipase, and interleukin 6 levels; pancreas and lung pathological injury; lung myeloperoxidase activity; lung tumor necrosis factor-α; and high-mobility group box 1 expression. Inversely, vagotomy pretreatment resulted in an enhanced severity of pancreatitis and lung injury. CONCLUSIONS: Our results reveal the role of the cholinergic anti-inflammatory pathway in experimental SAP-associated lung injury; nicotine pretreatment exerts a protective effect and vagotomy pretreatment exerts the opposite effect. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source


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. Source


He Y.,Wuhan University
PLoS pathogens | Year: 2010

The reports on the origin of human CD8(+) Valpha24(+) T-cell receptor (TCR) natural killer T (NKT) cells are controversial. The underlying mechanism that controls human CD4 versus CD8 NKT cell development is not well-characterized. In the present study, we have studied total 177 eligible patients and subjects including 128 healthy latent Epstein-Barr-virus(EBV)-infected subjects, 17 newly-onset acute infectious mononucleosis patients, 16 newly-diagnosed EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. We have established human-thymus/liver-SCID chimera, reaggregated thymic organ culture, and fetal thymic organ culture. We here show that the average frequency of total and CD8(+) NKT cells in PBMCs from 128 healthy latent EBV-infected subjects is significantly higher than in 17 acute EBV infectious mononucleosis patients, 16 EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. However, the frequency of total and CD8(+) NKT cells is remarkably increased in the acute EBV infectious mononucleosis patients at year 1 post-onset. EBV-challenge promotes CD8(+) NKT cell development in the thymus of human-thymus/liver-SCID chimeras. The frequency of total (3% of thymic cells) and CD8(+) NKT cells ( approximately 25% of NKT cells) is significantly increased in EBV-challenged chimeras, compared to those in the unchallenged chimeras (<0.01% of thymic cells, CD8(+) NKT cells undetectable, respectively). The EBV-induced increase in thymic NKT cells is also reflected in the periphery, where there is an increase in total and CD8(+) NKT cells in liver and peripheral blood in EBV-challenged chimeras. EBV-induced thymic CD8(+) NKT cells display an activated memory phenotype (CD69(+)CD45RO(hi)CD161(+)CD62L(lo)). After EBV-challenge, a proportion of NKT precursors diverges from DP thymocytes, develops and differentiates into mature CD8(+) NKT cells in thymus in EBV-challenged human-thymus/liver-SCID chimeras or reaggregated thymic organ cultures. Thymic antigen-presenting EBV-infected dendritic cells are required for this process. IL-7, produced mainly by thymic dendritic cells, is a major and essential factor for CD8(+) NKT cell differentiation in EBV-challenged human-thymus/liver-SCID chimeras and fetal thymic organ cultures. Additionally, these EBV-induced CD8(+) NKT cells produce remarkably more perforin than that in counterpart CD4(+) NKT cells, and predominately express CD8alphaalpha homodimer in their co-receptor. Thus, upon interaction with certain viruses, CD8 lineage-specific NKT cells are developed, differentiated and matured intrathymically, a finding with potential therapeutic importance against viral infections and tumors. Source


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. Source


Huang C.,Wuhan University
Tribology International | Year: 2010

In order to investigate evolution of polishing aggregate surfaces on an aggregate wear index (AWI) wear track specimen, experimental texture measurements and data dependent system (DDS) approach were utilized to model and analyze elevation profiles collected from unpolished and polished aggregate surfaces. It was found that the DDS approach was able to characterize the evolved macrotexture and microtexture. The polishing effect induced by the interaction between tire tread and aggregate surfaces was found to reduce the microtexture roughness significantly, but showed little influence on the macrotexture. This does not imply that the macrotexture plays little role in tire tread friction. It was also found that polishing effect presented a strong relationship with grain size existing on aggregate surfaces. © 2009 Elsevier Ltd. All rights reserved. Source


Domling A.,University of Pittsburgh | Wang W.,University of Pittsburgh | Wang W.,Wuhan University | Wang K.,University of Pittsburgh
Chemical Reviews | Year: 2012

A study was conducted to investigate chemical and biological aspects of multicomponent reactions (MCRs). The high density of atoms of MCR-based compounds played an important role in their propensity for specific target classes where traditional non-MCR compounds had lower screening hit rates. Chemical transformations toward rare scaffold types annotated with unique physicochemical properties were amenable by MCR in a straightforward and short manner. X-ray diffraction investigations revealed that the bicyclic products contain varying degrees of pyramidalization of the bridgehead nitrogen atom. It was also demonstrated that another uniquely shaped scaffold, 3-azabicyclo[4.2.0]octan-4-one derivative was synthesized by combining the Ugi multicomponent reaction with [2 + 2] enone-olefin photochemical transformations. Source


Zhou Q.,Wuhan University
Nonlinear Dynamics | Year: 2016

The nonlinear longitudinal wave equation, describing the propagation of optical solitons in magneto-electro-elastic circular rod, is investigated analytically. Two integration tools that are traveling wave hypothesis and G′/G expansion scheme are recruited to extract explicit soliton solutions. The existence conditions are derived. © 2015, Springer Science+Business Media Dordrecht. Source


Long X.,Wuhan University
The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association (CSA) | Year: 2012

Trauma is the predominant causal factor for temporomandibular joint (TMJ) ankylosis. However, the relationship between condylar fracture and TMJ ankylosis is complicated. It is believed that post-traumatic TMJ ankylosis arises from TMJ intracapsular changes, including damaged cartilage, displaced or disrupted discs, haematoma formation and subsequent fibrosis and calcification in the joint. In this review, the relationship between TMJ ankylosis and condylar fracture is discussed based on clinical characteristics and animal studies. The management of TMJ ankylosis is also reviewed and discussed. Source


Ouyang X.,Wuhan University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

Meaning extension patterns can help to construct the large-scale semantic knowledge base. After analyzing the meanings of (kan) in modern Chinese, we found a new extension pattern - sequential extension. That pattern is also reflected in the meaning extensions of some other high frequency verbs. The meanings extended with the sequential pattern are characterized by the following: (1) overall continuity, (2) activating the before and after, (3) the distance determining the degree of activation. On the view of cognition, the sequential extension pattern roots in the mode of ACTING-RESULT and metonymic mechanism. © 2013 Springer-Verlag. Source


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. Source


This work presents an analytical study of dynamic behaviors of solitons in the electrical transmission line. The nonlinear dynamical model that is the modified Zakharov–Kuznetsov equation with an external force is investigated. Via the Riccati equation mapping scheme, explicit twenty seven traveling wave solutions, which include periodic solutions, rational wave solution, soliton solutions as well as soliton-like solutions, are constructed for the first time. © 2015, Springer Science+Business Media Dordrecht. Source


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. Source


He D.,Wuhan University | Kumar N.,Thapar University | Chilamkurti N.,La Trobe University
Information Sciences | Year: 2015

Abstract With an advancement of wireless communication technology, wireless sensor network (WSN) has emerged as one of the most powerful technologies which can be used in various applications, such as military surveillance, environment monitoring, industrial control, and medical monitoring. WSNs are vulnerable to large collection of attacks than traditional networks because they transmit data using a wireless channel and are deployed in unattended environments. So, in this environment, how to ensure secure communications between different communication parties becomes a challenging issue with respect to the constraints of energy consumption, and large overhead generated during various operations performed. In this direction, the mutual authentication and key agreement (MAAKA) scheme attracts much attention in recent years. In literature, MAAKA schemes were presented in last several years. However, most of these schemes cannot satisfy security requirements in WSNs. Recently, Xue et al. proposed a temporal-credential-based MAAKA scheme for WSNs and proved that it could withstand various types of attacks. However, this paper points out that Xue et al.'s MAAKA scheme is vulnerable to the off-line password guessing attack, the user impersonation attack, the sensor node impersonation attack and the modification attack. Moreover, this paper also points out that Xue et al.'s MAAKA scheme cannot provide user anonymity. To overcome weaknesses in Xue et al.'s MAAKA scheme, this paper proposes a new temporal-credential-based MAAKA scheme for WSNs. Security analysis shows the proposed MAAKA scheme could overcome the weaknesses in Xue et al.'s MAAKA scheme. Performance analysis shows the proposed MAAKA scheme has better performance than the existing benchmarked schemes in literature. Therefore, the proposed MAAKA scheme is more suitable for providing security for various applications in WSNs. © 2015 Elsevier Inc. Source


Yang Y.,Wuhan University | Misra A.,University of Kansas
CMES - Computer Modeling in Engineering and Sciences | Year: 2010

Gradient theories have found wide applications in modeling of strain softening phenomena. This paper presents a higher order stress-strain theory to describe the damage behavior of strain softening materials. In contrast to most conventional gradient approaches for damage modeling, the present higher order theory considers strain gradients and their conjugate higher-order stress such that stable numerical solutions may be achieved. We have described the derivation of the required constitutive relationships, the governing equations and its weak form for this higher-order theory. The constitutive coefficients were obtained from a granular media approach such that the internal length scale parameter reflects the natural granularity of the underlying microstructure. The weak form was discretized using an element-free Galerkin (EFG) formulation that readily admits approximation functions of higher-order continuity. We have also discussed the implementation of essential boundary conditions and linearization of the derived discrete equations. Finally, the applicability of the derived model is demonstrated through two examples with different imperfections designed to initiate dislocation bands and shear bands, respectively. © 2010 Tech Science Press. Source


With the rapid progress of wireless mobile communications, the authenticated key agreement (AKA) protocol has attracted an increasing amount of attention. However, due to the limitations of bandwidth and storage of the mobile devices, most of the existing AKA protocols are not suitable for wireless mobile communications. Recently, Lo and others presented an efficient AKA protocol based on elliptic curve cryptography and included their protocol in 3GPP2 specifications. However, in this letter, we point out that Lo and others' protocol is vulnerable to an offline password guessing attack. To resist the attack, we also propose an efficient countermeasure. © 2012 ETRI. Source


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. Source


Control of projects is a core issue for organizations. Successful projects, such as information systems projects, enable organizations to develop a superior supply network and enhance the capability of operations management. A few studies have investigated the effects of control on project performance; however, complexity risk has not been integrated into the relationship between control and performance. Limited evidence has been provided concerning whether modes of control differ in their effectiveness in the presence of a single risk factor. Based on quantitative data obtained from 128 information systems projects, behavior, outcome, clan, and self-control are empirically determined to be positively associated with the system performance of projects. However, complexity risk generates a mixed moderating effect on the relationship between control and performance. In the presence of a high complexity risk, the effects of behavior and self-control on performance are low, whereas the effectiveness of outcome and clan control increases. This finding implies that complexity risk is a double-edged sword with regard to control. Each control mode exhibits different characteristics and effectiveness under high complexity risk. Therefore, appropriate control modes should be carefully selected, and highly effective control modes, such as outcome and clan control, should be prioritized in managing complex system projects. © 2015 Elsevier B.V. All rights reserved. Source


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. Source


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. Source


Li Z.,Huazhong University of Science and Technology | Zhong K.,Huazhong University of Science and Technology | Li Y.F.,City University of Hong Kong | Zhou X.,Wuhan University | Shi Y.,Huazhong University of Science and Technology
Optics Letters | Year: 2013

This Letter presents a multiview phase shifting (MPS) framework for full-resolution and high-speed reconstruction of arbitrary shape dynamic objects. Unlike conventional methods, this framework can directly find the corresponding points from the wrapped phase-maps. Therefore, only a minimum number of images are required for phase shifting to measure arbitrary shape objects, including discontinuous surfaces. Benefit from phase shifting MPS can achieve full spatial resolution and high, accurate 3D reconstruction. Benefit from multiview constraint MPS is also robust to discontinuities. Experimental results are presented to verify the performance of the proposed technique. © 2013 Optical Society of America. Source


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. Source


Jiarong Y.,Wuhan University
Acta Mathematica Scientia | Year: 2011

Simplify the proof on the domain of convergence of multiple power series and consider the case where some of z1,...,zn are contained only in a finite number of terms of the series. Obtain some results on holomorphic functions in Cn. © 2011 Wuhan Institute of Physics and Mathematics. Source


Maofa W.,Wuhan University
Acta Mathematica Scientia | Year: 2011

In this article, we study the boundedness of weighted composition operators between different vector-valued Dirichlet spaces. Some sufficient and necessary conditions for such operators to be bounded are obtained exactly, which are different completely from the scalar-valued case. As applications, we show that these vector-valued Dirichlet spaces are different counterparts of the classical scalar-valued Dirichlet space and characterize the boundedness of multiplication operators between these different spaces. © 2011 Wuhan Institute of Physics and Mathematics. Source


Yu S.B.,Wuhan University
Zhonghua xin xue guan bing za zhi | Year: 2011

To evaluate the current status of chronic heart failure (CHF) in Hubei province and analyze the epidemiology of CHF including the general condition, etiology and pharmacological therapy. Data of in-hospital patients with CHF were investigated between 2000 and 2010 from 12 hospitals in Hubei Province. Inclusion criteria: over 18 years of age, organic heart disease and with the symptom of HF including dyspnea and fatigue. Patients with a history of myocardial infarction in the prior 12 months, congenital heart disease, pericardial disease and the history of cancer were excluded. (1) A total of 12 450 patients were enrolled (7166 male, 57.56%). The average age was (62.0 ± 14.5) years. Patients in the scale of age ≥ 80, 70 - 79, 60 - 69, 50 - 59, 40 - 49 and < 40 was 9.53% (1187/12 450), 30.80% (3835/12 450), 23.45% (2920/12 450), 18.81% (2342/12 450), 10.73% (1336/12 450) and 6.67% (830/12 450), respectively (P < 0.01). The NYHA class I, II, III and IV was 0.60%, 23.20%, 50.31% and 26.50%, respectively. (2) The age of patients was significant reduced from 2000 - 2003, 2004 - 2006 to 2007 - 2010 [(66.4 ± 14.1) years, (64.9 ± 14.4) years and (64.2 ± 14.8) years, P < 0.01]. (3) The major causes of CHF were hypertension (31.54%), coronary heart disease (28.24%), dilated cardiomyopathy (26.57%) and rheumatic valvular heart disease (17.49%). The most frequent etiology for CHF was rheumatic valvular heart disease in patients aged less than 40 years old, dilated cardiomyopathy in patients aged 40 - 49 and 50 - 59 years and hypertension in patients aged 60-69, 70-79 and ≥ 80 years. (4) Drug use was as follows: Digitalis (47.49%), diuretics (68.75%), ACEI (50.66%), β-blocker (44.06%) and aldosterone antagonist (53.08%). Use of digitalis (Wald χ(2) = 903.41, P < 0.01;r = 0.271, P < 0.01), diuretics (Wald χ(2) = 818.05, P < 0.01; r = 0.249, P < 0.01), aldosterone antagonists (Wald χ(2) = 76.92, P < 0.01; r = 0.091, P < 0.01) increased while the β-blocker (Wald χ(2) = 160.65, P < 0.01; r = -0.117, P < 0.01) declined in proportion to NYHA class increase. The age of in-hospital patients with CHF declined in the previous 10 years. The primary etiology was hypertension for aged CHF in-hospital patients with CHF. There was big gap between guideline recommended standard therapy and current drug use for in-hospital patients with CHF in Hubei province. Source


Liu J.-L.,China University of Petroleum - East China | Xia R.,Wuhan University
Acta Mechanica Sinica/Lixue Xuebao | Year: 2013

In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube (CNT) ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thoroughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materials, and hold potential for enhancing their mechanical, chemical, optical and electronic properties. © 2012 The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg. Source


Chen Q.,Wuhan University
Zhongguo gu shang = China journal of orthopaedics and traumatology | Year: 2011

To explore the effects of debridement combined with vacuum sealing drainage (VSD) technique in treatment of high-pressure paint injection injuries of hand. From April 2005 to August 2010,14 patients with high-pressure paint injection injuries of hand were treated with debridement and VSD technique within 6 hours after injury. All the patients were male,ranging in age from 23 to 47 years with an average of 36.5 years. All injuries occurred left hand,thumb injured in 5 cases,index finger in 3 cases, middle finger in 2 cases and palm in 4 cases. Injured hands swelled obviously with poor blood circulation. When the wounds were covered with fresh granulation tissue without inflammatory effusion after operation of 3-4 times, the skingrafting (9 cases) or transfer flap (5 cases) were done on the wounds. All the patients were followed up from 8 to 16 months with an average of 12 months. All the wounds obtained good healing. Therapeutic effects were estimated according to TAM criteria, 7 cases were excellent,6 good and 1 fair. In high-pressure paint injection injuries of hands,debridement combined with VSD technique can avoid wound infection,promote the growth of granulation tissue. It is beneficial to wound healing. Source


There are potentially huge amounts of water stored in Earth’s mantle, and the water solubilities in the silicate minerals range from tens to thousands of part per minion (ppm, part per million). Exploring water in the mantle has attracted much attention from the societies of mineralogy and geophysics in recent years. In the subducting slab, serpentine breaks down at high temperature, generating a series of dense hydrous magnesium silicate (DHMS) phases, such as phase A, chondrodite, clinohumite, etc. These phases may serve as carriers of water as hydroxyl into the upper mantle and the mantle transition zone (MTZ). On the other hand, wadsleyite and ringwoodite, polymorphs of olivine, are most the abundant minerals in the MTZ, and able to absorb significant amount of water (up to about 3 wt.% H2O). Hence, the MTZ becomes a very important layer for water storage in the mantle, and hydration plays important roles in physics and chemistry of the MTZ. In this paper, we will discuss two aspects of hydrous silicate minerals: (1) crystal structures and (2) equations of state (EoSs). © 2016 Science China Press and Springer-Verlag Berlin Heidelberg Source


Deng Z.,Huazhong University of Science and Technology | Mo X.,Huazhong University of Science and Technology | Liu S.,Wuhan University
International Journal of Medical Informatics | Year: 2014

Objective: Given the increasing number of older people, China has become an aging society. A mobile health service is a type of health informatics that provides personalized healthcare advice to those who require it, especially the older people and the middle-aged. However, few studies consider the adoption of mobile health services with regard to older and middle-aged users. This paper explored a research model based on the value attitude behavior model, theory of planned behavior, and four aging characteristic constructs to investigate how older and middle-aged citizens adopted mobile health services. Method: The hypothesized model was empirically tested using data collected from a survey of 424 residents older than 40 years in China. Structural equation modeling was used to estimate the significance of the path coefficients. Results: The findings revealed that (1) perceived value, attitude, perceived behavior control, and resistance to change can be used to predict intention to use mobile health services for the middle-aged group; (2) perceived value, attitude, perceived behavior control, technology anxiety, and self-actualization need positively affected the behavior intention of older users; and (3) subjective norm and perceived physical condition showed no significant effects on the behavior intention to use mobile health services for the two groups. The theoretical and practical implications and contributions of this study are then discussed. © 2014 Elsevier Ireland Ltd. Source


Hydrous minerals are important water carriers in the crust and the mantle, especially in the subduction zone. With the recent development of the experimental technique, studies of the electrical conductivity of hydrous silicate minerals under controlled temperature, pressure and oxygen fugacity, have helped to constrain the water distribution in the Earth’s interior. This paper introduces high pressure and temperature experimental study of electrical conductivity measurement of hydrous minerals such as serpentine, talc, brucite, phase A, super hydrous phase B and phase D, and assesses the data quality of the above minerals. The dehydration effect and the pressure effect on the bulk conductivity of the hydrous minerals are specifically emphasized. The conduction mechanism of hydrous minerals and the electrical structure of the subduction zone are discussed based on the available conductivity data. Finally, the potential research fields of the electrical conductivity of hydrous minerals is presented. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg. Source


Peng Y.-Z.,Wuhan University
Communications in Theoretical Physics | Year: 2010

A new (2+1)-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bäcklund transformation in terms of the singular manifold is obtained. And localized structures are also investigated. © Chinese Physical Society and IOP Publishing Ltd. Source


Gao X.-Y.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Chen Y.-X.,Hefei University of Technology | Hu Z.,Wuhan University
Journal of Metamorphic Geology | Year: 2013

The ultrahigh-pressure (UHP) eclogite in the Dabie orogen preserves petrological evidence for the existence of hydrous silicate melts that formed during continental subduction-zone metamorphism. This is indicated by occurrence of multiphase solid (MS) inclusions in garnet that primarily consist of K-feldspar + quartz ± epidote/allanite. All the MS inclusions are euhedral to subhedral in morphology and surrounded with radial cracks in the host garnet. Their trace element compositions were analysed by two different approaches of laser sampling. The mass budget method was used to estimate the trace element abundances of MS inclusions from their mixtures with the host garnet. The results are compared with the direct sampling of MS inclusions, providing a first-order approximation to the trace element composition of MS inclusions. The MS inclusions exhibit consistent enrichment of LILE, Sr and Pb, but depletion of HFSE in the primitive mantle-normalized spidergram. Such arc-like patterns of trace element distribution are common for continental crustal rocks. The melts have variably high K, Rb and Sr abundances, suggesting that breakdown of phengite is a basic cause for partial melting of the UHP eclogite. These MS inclusions also exhibit consistently low HFSE and Y contents, suggesting partial melting of the eclogite in the stability fields of rutile and garnet. Consequently, the trace element composition of MS inclusions provides a proxy for that of hydrous silicate melts derived from dehydration melting of the UHP eclogite during continental collision. © 2012 Blackwell Publishing Ltd. Source


Yee S.,Wuhan University
Ocean Development and International Law | Year: 2013

Conciliation is an age-old peaceful means of dispute settlement. The UN Convention on the Law of the Sea provides for both voluntary and compulsory conciliation. The importance of conciliation under UNCLOS is obvious, yet it has received little focused attention. © Taylor & Francis Group, LLC. Source


Wu X.-T.,Wuhan University
Yantu Lixue/Rock and Soil Mechanics | Year: 2013

The consolidation coefficient is not a constant in the process of soft-soil consolidation. The variation regularity of consolidation coefficient is related to engineering properties of soil, preconsolidation pressure and effective consolidation stress. When the consolidation stress is less than the preconsolidation pressure (P<σp), the consolidation coefficient decreases with the increasing of consolidation stress. When the consolidation stress equals to the preconsolidation pressure (P=σp), the consolidation coefficient takes the minimum value. When the consolidation stress is greater than the preconsolidation pressure (P>σp), the consolidation coefficient of silt increases with the increasing of consolidation stress. There is an apparent double logarithmic linear correlation between consolidation coefficient and consolidation stress (ln(Cv or Ch)-ln(P)) of Wenzhou silt. The fitting formula is a piecewise function according to the preconsolidation pressure (σp). The variation regularity of consolidation coefficient during soil consolidation gotten by improved Kadota method further illustrates and verifies the expression presented. The consolidation coefficient of silt during the entire loading procedure could be calculated by the double logarithmic fitting formula accurately, which provides the important parameter for the consolidation settlement calculation. Source


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. Source


Chen W.T.,University of Hong Kong | Zhou M.-F.,University of Hong Kong | Zhao X.-F.,University of Hong Kong | Zhao X.-F.,Wuhan University
Precambrian Research | Year: 2013

The Paleoproterozoic Hekou Group in the western Yangtze Block is a volcano-sedimentary succession that is intruded by gabbroic plutons. Sedimentary rocks in the group include slates, marble and meta-siltstones interlayered with felsic metavolcanic rocks, metabasalts and metatuffs. Both the volcanic rocks of the Hekou Group and gabbros have undergone upper greenschist to lower amphibolite facies metamorphism. Metatuff samples from different layers have average zircon U-Pb ages of ~1697Ma, slightly older than the intruding gabbroic plutons with zircon U-Pb ages of ~1684Ma. Both metabasalts and metagabbros have similar elemental and isotopic compositions, indicative of a co-magmatic origin. They are rich in TiO2 (mostly >2.5wt.%), Zr (94.5-347ppm), Ta (0.48-3.00ppm) and Th (1.05-7.61ppm) with high Nb/Y ratios (mostly >0.6) and LREE-enriched chondrite-normalized REE patterns, resembling within-plate mafic rocks. Their positive whole-rock εNd(t) (0.2 to +3.4) and zircon εHf(t) values (-3.3 to +8.4) suggest contributions from a depleted mantle source. The large range of εNd(t) and εHf(t) values, and variable degrees of Nb-Ta anomalies (Ta/LaPN=0.17-1.75) are indicative of crust contamination during magma ascending. Both the metabasalts and metagabbros are considered to have formed in a continental rift setting.Detrital zircon grains from meta-siltstones in the Hekou Group have U-Pb age populations mainly at 2070-1880. Ma, 2330-2250. Ma and 2900-2700. Ma. These age populations are comparable to those of the North Australian and North China Cratons in the Columbia supercontinent. However, in terms of geochemical features, the ~1.7. Ga within-plate mafic rocks at Hekou are similar to those from the ~1.7. Ga Leichhardt and Calvert Superbasins of the North Australian Craton, but different from those from the 1.7-1.2. Ga Zhaertai-Bayan Obo rift zone of the North China Craton. It is thus suggested that the Yangtze Block was more likely linked with the North Australian Craton in Columbia during the Late Paleoproterozoic. These rifting basins and mafic rocks may record the initial break-up of the Columbia supercontinent. © 2013 Elsevier B.V. Source


Zhao J.-H.,Wuhan University | Zhou M.-F.,University of Hong Kong
Precambrian Research | Year: 2013

The southeastern Yangtze Block, South China, contains voluminous late Neoproterozoic felsic plutonic rocks and minor mafic-ultramafic volcanic rocks. Some ca. 830Ma lavas hosted in the Neoproterozoic strata have pillow structures and micro-spinifex textures and thus previously were considered as komatiitic basalts derived from a mantle plume. These rocks have high MgO (10.1-16.3wt%), variable CaO (6.57-11.2wt%), restricted Al2O3 (11.2-13.4wt%), and low TiO2 (0.50-0.61wt%), P2O5 (0.03-0.04wt%) and incompatible trace elements. They also have negative εNd (-5.4 to -2.9), and high 207Pb/204Pb (15.71-15.76) and initial 187Os/188Os ratios (0.1100-0.1931), indicating crustal contamination. The most primitive samples show arc-like trace elemental features which are characterized by enrichment of LREE and LILE relative to HFSE in the primitive-mantle-normalized trace-element diagrams, suggesting derivation from enriched mantle sources. PRIMELT2 modeling shows that their primary magmas were produced by about 30% partial melting of a fertile peridotite source having a mantle potential temperature of 1440-1500°C. Such a potential temperature is in agreement with the estimates for ambient mantle during the Neoproterozoic. These evidence suggest that the high-Mg basalts are similar to boninites and probably be part of an ophiolite assemblage. They were generated by melting of a hot ambient mantle source in relation to slab subduction during the amalgamation of the Yangtze and Cathaysia Blocks. © 2013 Elsevier B.V. Source


Cawood P.A.,University of St. Andrews | Cawood P.A.,University of Western Australia | Wang Y.,CAS Guangzhou Institute of Geochemistry | Xu Y.,Wuhan University | Zhao G.,University of Hong Kong
Geology | Year: 2013

From the formation of Rodinia at the end of the Mesoproterozoic to the commencement of Pangea breakup at the end of the Paleozoic, the South China craton first formed and then occupied a position adjacent to Western Australia and northern India. Early Neoproterozoic suprasubduction zone magmatic arc-backarc assemblages in the craton range in age from ca. 1000 Ma to 820 Ma and display a sequential northwest decrease in age. These relations suggest formation and closure of arc systems through southeast-directed subduction, resulting in progressive northwestward accretion onto the periphery of an already assembled Rodinia. Siliciclastic units within an early Paleozoic succession that transgresses across the craton were derived from the southeast and include detritus from beyond the current limits of the craton. Detrital zircon age spectra require an East Gondwana source and are very similar to the Tethyan Himalaya and younger Paleozoic successions from Western Australia, suggesting derivation from a common source and by inference accumulation in linked basins along the northern margin of Gondwana, a situation that continued until rifting and breakup of the craton in the late Paleozoic. © 2013 Geological Society of America. Source


Studying the physical and chemical properties of rocks is significant for understanding geological and mineralization processes in mineral resource exploration. The ITRAX core scanner is a fast and non-destructive instrument to identify and determine both the physical and chemical characteristics of rocks. In this study, the ITRAX is used to study mineralized rock samples composed of marble and diorite associated with mineralization from the Baiyinnuoer skarn-type Zn-Pb deposit, which is the largest Zn-Pb deposit in northern China. Four datasets, consisting of an optical image, an X-radiographic image, magnetic susceptibility (MS) measurements, and relative elemental variations, were obtained from ITRAX examinations. The results show that the diorite associated with mineralization is characterized by a high MS value, which can be regarded as a geophysical indicator to explore for the skarn-type Zn-Pb deposits. Moreover, the ITRAX geochemical results reveal that the diorite associated with mineralization consisting of sphalerite, galena, and pyrite contains large proportions of Si, Fe, Mn, Pb, and Zn, but small amounts of Ca and Al. This suggests that the metal composition assemblages of Pb, Zn, Fe, and Mn can be regarded as a geochemical indicator to explore for the skarn-type Zn-Pb deposits. This case study demonstrates that (1) the ITRAX core scanner is a potential tool to distinguish different rock types and to identify mineralization in mineral resource exploration, and (2) the logratio transformed geochemical results reveal the Zn-Pb mineralization, and the singularity index reveals the uneven Zn-Pb mineralization or other geochemical processes. © 2013 Elsevier B.V. Source


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. Source


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.. Source


Crasquin S.,University of Paris Descartes | Forel M.-B.,Wuhan University
Earth-Science Reviews | Year: 2013

Through geological times, the main turnover of marine ostracod group occurred at the Permian-Triassic boundary (PTB) when the Palaeozoic world gave way to Meso-Cenozoic world. As quite all the groups, ostracods intensively suffered of the end Palaeozoic events but they have the particularity to pass the PTB and to be present in quite all marine environments. We have studied the ostracod assemblages from the best preserved marine Permian-Triassic sections through the world. These sections are, for most of them, located along the Palaeo-Tethys margins: South China Block and Tibet (R.P. China), Bu¨kk Mountains (Hungary), Dolomites (Italy), Taurus Mountains (Turkey) and Elbourz Mountains (Iran). These areas present different environmental settings from very shallow water to deep shelf. The biostratigraphy is well constrained by the presence of conodont index. In deep environment from external shelf to slope, all the Permian ostracods disappear slightly before the PTB and are absent from the Early Triassic. The last representatives of palaeopsychrospheric forms occur in the early Anisian.On the platforms, during the Late Permian, the ostracods are abundant and highly diversified everywhere along Peri-Tethyan margins. The typical Palaeozoic forms are mixed with the very first Meso-Cenozoic representatives. The specific extinction rates, in the latest Permian, vary from 74% to 100%. During the earliest Triassic, two different settings have to be considered: with or without microbialitic deposits. The development of microbialites gives favorable ecological conditions to ostracods. During the Griesbachian, the fauna is composed of both new comers and surviving Palaeozoic forms. The reduction of size is frequently observed. This interval is called "survival stage". During the Dienerian and the Smithian the fauna are very scarce and poor. These two substages represent the maximum of poverty for the ostracod fauna, may be due to the development of anoxia on the platforms. During the Spathian, occurs the beginning of the true recovery. The very last Palaeozoic representatives are found in the earliest Anisian which is the radiation stage of ostracod fauna with typical new comers. The interval of Palaeozoic-Meso-Cenozoic ostracod turnover is quite long (about 15. My). © 2013 Elsevier B.V. Source


Hu T.,Wuhan University | Fan J.,City University of Hong Kong | Wu Q.,Middle Tennessee State University | Zhou D.-X.,City University of Hong Kong
Journal of Machine Learning Research | Year: 2013

We consider the minimum error entropy (MEE) criterion and an empirical risk minimization learning algorithm when an approximation of Rényi's entropy (of order 2) by Parzen windowing is minimized. This learning algorithm involves a Parzen windowing scaling parameter. We present a learning theory approach for this MEE algorithm in a regression setting when the scaling parameter is large. Consistency and explicit convergence rates are provided in terms of the approximation ability and capacity of the involved hypothesis space. Novel analysis is carried out for the generalization error associated with Rényi's entropy and a Parzen windowing function, to overcome technical difficulties arising from the essential differences between the classical least squares problems and the MEE setting. An involved symmetrized least squares error is introduced and analyzed, which is related to some ranking algorithms. © 2013 Ting Hu, Jun Fan, Qiang Wu and Ding-Xuan Zhou. Source


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. Source


Yu K.,Wuhan University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2015

This paper focuses on the estimation of tsunami-wave parameters (propagation direction, propagation speed, and wavelength) using the Global Navigation Satellite System (GNSS) reflectometry (GNSS-R)-based sea surface height (SSH) measurements. By exploiting multiple surface specular reflection tracks of GNSS signals as well as the geometry of wave propagation direction and the multiple tracks, concise mathematical expressions are derived to determine the propagation direction and speed and wavelength of a tsunami wave. Real tsunami-wave data measured by buoy sensors are employed to model GNSS-R-based SSH measurements by adding Gaussian measurement noise. The simulation results demonstrate that the proposed method can achieve a propagation direction estimation accuracy of about 4.4 ^{\circ} and 5.9 ^{\circ} when the SSH error standard deviations are 10 and 20 cm, respectively. The propagation speed estimation accuracies are about 12.7 and 17.7 m/s, respectively, under the same conditions when the speed ground truth is 200 m/s. The results also show that the wavelength estimation error can be as large as 100 km when the wavelength ground truth is about 400 km. Better filtering methods are needed to improve the wavelength estimation accuracy by mitigating the effect of the SSH estimation error particularly on the wave trailing edge of small negative magnitudes. © 1980-2012 IEEE. Source


Wu Y.-B.,Wuhan University | Zheng Y.-F.,Hefei University of Technology
Gondwana Research | Year: 2013

The formation of collisional orogens is a prominent feature in convergent plate margins. It is generally a complex process involving multistage tectonism of compression and extension due to continental subduction and collision. The Paleozoic convergence between the South China Block (SCB) and the North China Block (NCB) is associated with a series of tectonic processes such as oceanic subduction, terrane accretion and continental collision, resulting in the Qinling-Tongbai-Hong'an-Dabie-Sulu orogenic belt. While the arc-continent collision orogeny is significant during the Paleozoic in the Qinling-Tongbai-Hong'an orogens of central China, the continent-continent collision orogeny is prominent during the early Mesozoic in the Dabie-Sulu orogens of east-central China. This article presents an overview of regional geology, geochronology and geochemistry for the composite orogenic belt. The Qinling-Tongbai-Hong'an orogens exhibit the early Paleozoic HP-UHP metamorphism, the Carboniferous HP metamorphism and the Paleozoic arc-type magmatism, but the three tectonothermal events are absent in the Dabie-Sulu orogens. The Triassic UHP metamorphism is prominent in the Dabie-Sulu orogens, but it is absent in the Qinling-Tongbai orogens. The Hong'an orogen records both the HP and UHP metamorphism of Triassic age, and collided continental margins contain both the juvenile and ancient crustal rocks. So do in the Qinling and Tongbai orogens. In contrast, only ancient crustal rocks were involved in the UHP metamorphism in the Dabie-Sulu orogenic belt, without involvement of the juvenile arc crust. On the other hand, the deformed and low-grade metamorphosed accretionary wedge was developed on the passive continental margin during subduction in the late Permian to early Triassic along the northern margin of the Dabie-Sulu orogenic belt, and it was developed on the passive oceanic margin during subduction in the early Paleozoic along the northern margin of the Qinling orogen. Three episodes of arc-continent collision are suggested to occur during the Paleozoic continental convergence between the SCB and NCB. The first episode of arc-continent collision is caused by northward subduction of the North Qinling unit beneath the Erlangping unit, resulting in UHP metamorphism at ca. 480-490. Ma and the accretion of the North Qinling unit to the NCB. The second episode of arc-continent collision is caused by northward subduction of the Prototethyan oceanic crust beneath an Andes-type continental arc, leading to granulite-facies metamorphism at ca. 420-430. Ma and the accretion of the Shangdan arc terrane to the NCB and reworking of the North Qinling, Erlangping and Kuanping units. The third episode of arc-continent collision is caused by northward subduction of the Paleotethyan oceanic crust, resulting in the HP eclogite-facies metamorphism at ca. 310. Ma in the Hong'an orogen and low-P metamorphism in the Qinling-Tongbai orogens as well as crustal accretion to the NCB. The closure of backarc basins is also associated with the arc-continent collision processes, with the possible cause for granulite-facies metamorphism. The massive continental subduction of the SCB beneath the NCB took place in the Triassic with the final continent-continent collision and UHP metamorphism at ca. 225-240. Ma. Therefore, the Qinling-Tongbai-Hong'an-Dabie-Sulu orogenic belt records the development of plate tectonics from oceanic subduction and arc-type magmatism to arc-continent and continent-continent collision. © 2012 International Association for Gondwana Research. Source


Sheng Y.-M.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Li S.-N.,Hefei University of Technology | Hu Z.,Wuhan University
Journal of Metamorphic Geology | Year: 2013

Metamorphic dehydration and partial melting are two important processes during continental collision. They have significant bearing on element transport at the slab interface under subduction-zone P-T conditions. Petrological and geochemical insights into the two processes are provided by a comprehensive study of leucocratic veins in ultrahigh-pressure (UHP) metamorphic rocks. This is exemplified by this study of a polymineralic vein within phengite-bearing UHP eclogite in the Dabie orogen. The vein is primarily composed of quartz, kyanite, epidote and phengite, with minor accessory minerals such as garnet, rutile and zircon. Primary multiphase solid inclusions occur in garnet and epidote from the both vein and host eclogite. They are composed of quartz±K-feldspar±plagioclase±K-bearing glass and exhibit irregular to negative crystal shapes that are surrounded by weak radial cracks. This suggests their precipitation from solute-rich metamorphic fluid/melt that involved the reaction of phengite breakdown. Zircon U-Pb dating for the vein gave two groups of concordant ages at 217±2 and 210±2Ma, indicating two episodes of zircon growth in the Late Triassic. The same minerals from the two rocks give consistent δ18O and δD values, suggesting that the vein-forming fluid was directly derived from the host UHP eclogite. The vein is much richer in phengite and epidote than the host eclogite, suggesting that the fluid is associated with remarkable concentration of such water-soluble elements as LILE and LREE migration. Garnet and rutile in the vein exhibit much higher contents of HREE (2.2-5.7 times) and Nb-Ta (1.8-2.0 times) than those in the eclogite, indicating that these normally water-insoluble elements became mobile and then were sunken in the vein minerals. Thus, the vein-forming agent would be primarily composed of the UHP aqueous fluid with minor amounts of the hydrous melt, which may even become a supercritical fluid to have a capacity to transport not only LILE and LREE but also HREE and HFSE at subduction-zone metamorphic conditions. Taken together, significant amounts of trace elements were transported by the vein-forming fluid due to the phengite breakdown inside the UHP eclogite during exhumation of the deeply subducted continental crust. © 2012 Blackwell Publishing Ltd. Source


Chen Y.-X.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Hu Z.,Wuhan University
Journal of Metamorphic Geology | Year: 2013

Petrological evidence is provided for anatexis of ultrahigh-pressure (UHP) metamorphic quartzite in the Sulu orogen. Some feldspar grains exhibit elongated, highly cuspate shapes or occur as interstitial, cuspate phases constituting interconnected networks along grain boundaries. Elongated veinlets composed of plagioclase + quartz ± K-feldspar also occur in grain boundaries. These features provide compelling evidence for anatexis of the UHP quartzite. Zircon grains from impure quartzite are all metamorphic growth with highly irregular shape. They contain inclusions of coesite, jadeite, rutile and lower pressure minerals, including multiphase solid inclusions that are composed of two or more phases of muscovite, quartz, K-feldspar and plagioclase. All zircon grains exhibit steep REE patterns, similar U-Pb ages and Hf isotope compositions with a weighted mean of 218 ± 2 Ma. Most grains have similar δ18O values of -0.6 to 0.1‰, but a few fall in the range -5.2 to -4.3‰. Thus, these grains would have grown from anatectic melts at various pressures. Zircon O isotope differences indicate that anatectic melts were derived from different sources with contrasting O isotopes, but similar Hf isotopes, that is, one from the quartzite itself and the other probably from the country-rock granitic gneiss. Zircon grains from pure quartzite contain relict magmatic cores and significant metamorphic overgrowths. Domains that contain eclogite facies minerals exhibit flat HREE patterns, no Eu anomalies and concordant U-Pb ages of c. 220 Ma. Similar U-Pb ages are also obtained for domains that contain lower pressure minerals and exhibit steep REE patterns and marked negative Eu anomalies. These observations indicate that zircon records subsolidus overgrowth at eclogite facies conditions but suprasolidus growth at lower pressures. Zircon enclosed by garnet gave consistent U-Pb ages of c. 214 Ma. Such garnet is interpreted as a peritectic product of the anatectic reaction that involves felsic minerals and possibly amphibole and titanite. The REE patterns of epidote and titanite also record multistage growth and metasomatism by anatectic melts. Therefore, the anatexis of UHP metamorphic rocks is evident during continental collision in the Triassic. © 2012 Blackwell Publishing Ltd. Source


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. Source


Bai J.,Wuhan University | Hu S.,Hubei Cancer Hospital
International Journal of Molecular Medicine | Year: 2012

Squamous lung cancer is a common type of lung cancer; however, its mechanism of oncogenesis is still unknown. The aim of this study was to screen candidate genes of squamous lung cancer using a bioinformatics strategy and elucidate the mechanism of squamous lung cancer. Published microarray data of the GSE3268 series was obtained from Gene Expression Omnibus (GEO). Significance analysis of microarrays was performed using the software R, and differentially expressed genes by R analysis were harvested. The relationship between transcription factors and target genes in cancer were collected from the Transcriptional regulatory element database. A transcriptome network analysis method was used to construct gene regulation networks and select the candidate genes for squamous lung cancer. SPI1, FLI1, FOS, ETS2, EGR1 and PPARG were defined as candidate genes for squamous lung cancer by the transcriptome network analysis method. Among them, 5 genes had been reported to be involved in lung cancer, except SPI1 and FLI1. Effective recall on previous knowledge conferred strong confidence in these methods. It is demonstrated that transcriptome network analysis is useful in the identification of candidate genes in disease. Source


Lucklum R.,Otto Von Guericke University of Magdeburg | Ke M.,Otto Von Guericke University of Magdeburg | Ke M.,Wuhan University | Zubtsov M.,Otto Von Guericke University of Magdeburg
Sensors and Actuators, B: Chemical | Year: 2012

Phononic crystals offer an innovative platform for acoustic liquid sensors. Based on a longitudinal cavity mode, we introduce an acoustic sensor system using a two dimensional phononic crystal with in-plane wave incidence. The phononic crystal is made up of a steel plate having two regular arrays of holes and a cavity in-between. The holes and the cavity are filled with the liquid of interest. We both theoretically and experimentally demonstrate that the transmission peak caused by the cavity mode can be used for sensor purpose. Theoretical simulation and experimental measurement show good consistency in the response of the transmission peak frequency. This frequency is primarily sensitive to the speed of sound thereby sensitive to the composition of the liquid mixture. © 2012 Elsevier B.V. All rights reserved. Source


Yi F.,Wuhan University
Ceramics International | Year: 2014

Composite ceramics of CoFe2O4/Fe3O 4 with different weight ratios were synthesized by Spark Plasma Sintering (SPS) at a sintering temperature of 500 °C. The X-ray diffraction patterns demonstrate that all samples are composed of CoFe2O 4 and Fe3O4 phases. The magnetization curves for all the composite ceramic are single-step loops indicating the existence of exchange spring effect. Due to the competition between the exchange interaction and the dipolar interaction, magnetic properties like coercivity (Hc) and remanence (Mr) are sensitive to the weight ratio of the soft phase. © 2014 Elsevier Ltd and Techna Group S.r.l. Source


Tan Z.-J.,Wuhan University | Chen S.-J.,University of Missouri
Biophysical Journal | Year: 2012

RNAs are negatively charged molecules that reside in cellular environments with macromolecular crowding. Macromolecular confinement can influence the ion effects in RNA folding. In this work, using the recently developed tightly bound ion model for ion fluctuation and correlation, we investigate the effect of confinement on ion-mediated RNA structural collapse for a simple model system. We find that for both Na+ and Mg2+, the ion efficiencies in mediating structural collapse/folding are significantly enhanced by the structural confinement. This enhancement of ion efficiency is attributed to the decreased electrostatic free-energy difference between the compact conformation ensemble and the (restricted) extended conformation ensemble due to the spatial restriction. © 2012 Biophysical Society. Source


Zhang F.,Wuhan University
International Journal of Advancements in Computing Technology | Year: 2011

Collaborative filtering makes recommendations for target users based on the items previously rated by other similar users. Due to the sparsity of the rating data, precision of recommendations has always been a big concern in the recommender system research community. Researchers have invented many methods to deal with such a problem. In this paper, we focus on the music recommender systems. We adopt collaborative filtering as the core, and utilize the music content, timbre and genre, to alleviate the sparsity problem for improving the recommendation precision. Such a method is usually called hybrid recommendation, which is built on a combination of collaborative filtering techniques and content-based filtering techniques. We show how to extract timbre and genre from music, and how to combine them with collaborative filtering fairly to generate recommendations. Experimental results suggest that the method has a better performance compared with the pure collaborative filtering one. Source


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. Source


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. Source


Wang Y.Q.,Wuhan University
Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences | Year: 2013

To explore the efficiency of using aromatase inhibitors during luteal phase in in vitro fertilization IVF stimulated cycles for patients at high risk for ovarian hyperstimulation syndrome (OHSS). A total of 139 infertile women undergoing assisted reproductive technique with high risk for OHSS were enrolled in this clinical trial. In the treatment group 43 patients received five consecutive doses of aromatase inhibitors (letrozole) and support therapy combined with embryo cryopreservation. In the control group 96 patients received support therapy alone. All the patients were evaluated clinically, echographically, hematologically and tested for their steroid hormone. There was significantly lower estrogen level in the treatment group 2, 5 and 8 days after oocyte retrieval compared with the control group (P<0.001), There was no significant difference in luteinizing hormone and progesterone levels 2, 5 and 8 days after oocyte retrieval in the treatment group and control group (P>0.05). There were 7 cases of severe OHSS in the treatment group and 18 cases of severe OHSS in the control group. The rate of severe OHSS was not significantly different in the treatment group and control group (P=0.12). No side effect was reported in either group. Treatment with letrzolein luteal phase decreases serum estrogen levels of patients after oocyte retrieval,but it couldn't reduce the risk of severe OHSS. Source


Zeng Z.,Wuhan University
Journal of Convergence Information Technology | Year: 2011

A personalized product recommendation is an effective mechanism to overcome information overload occurred when customers conduct Internet shopping. The paper presents a personalized recommender system, which integrates semantic similarity computation and TOPSIS method. First, semantic similarity is computed by constructing semantic vector-space, in order to realize the semantic content-based filtering between the product contents and customer profiles. Besides, TOPSIS method is also utilized to construct the comparison mechanism of products by calculating the utility value of each candidate product. Finally, the experiment is conducted to evaluate its recommender quality and the results show the system can give sensible recommendations and is capable of helping customers save enormous time for Internet shopping. Source


Ren W.,Wuhan University
International Journal of Network Management | Year: 2011

The Internet of Things (IOT) is envisioned as a natural evolution of the Internet, promising to enable ubiquitous connections for pervasive objects. The evolutionary merging of heterogeneous wireless networks is inevitable for smooth migration to IOT; for example, in a typical application of IOT-smart homes-there exist sensor-radio frequency identification (RFID) hybrid networks. The communication security between sensor (or RFID tags) and home control center is critical, whereas an appropriate key management scheme is a prerequisite for communication security. In this paper, we propose a compromise resilient key management scheme including key agreement schemes and key evolution policies to tackle existing remarkable asymmetry with respect to computation resources of hybrid networks. In particular, a forward and backward secure key evolution policy with formal proof is proposed. We also propose a quality of service (QoS)-aware enhancement method by measuring several metrics such as data assurance priority, attacking risk, and remaining power percentage. Security parameter negotiation and a tuning method are proposed, based on reactive measurement in real time. Our proposed scheme is built on abstract cryptographic primitives such as trapdoor permutation, pseudorandom function, pseudorandom number generator, one-way function and hash function so as to retain flexibility for concrete options. Security and performance for proposed key agreement schemes and key evolution policies are compared in detail. Three QoS-aware security strategies are proposed: performance first, security second (PFSS); security first, performance second (SFPS); and performance security made balanced (PSMB). Measurement-based negotiation of security parameters is also proposed in terms of algorithm prototype. © 2011 John Wiley & Sons, Ltd. Source


It has been suggested that the mitochondrial chimeric gene orfH79 is the cause for abortion of microspores in Honglian cytoplasmic male sterile rice, yet little is known regarding its mechanism of action. In this study, we used a mass spectrometry-based quantitative proteomics strategy to compare the mitochondrial proteome between the sterile line Yuetai A and its fertile near-isogenic line Yuetai B. We discovered a reduced quantity of specific proteins in mitochondrial complexes in Yuetai A compared with Yuetai B, indicating a defect in mitochondrial complex assembly in the sterile line. Western blotting showed that ORFH79 protein and ATP1 protein, an F(1) sector component of complex V, are both associated with large protein complexes of similar size. Respiratory complex activity assays and transmission electron microscopy revealed functional and morphological defects in the mitochondria of Yuetai A when compared with Yuetai B. In addition, we identified one sex determination TASSELSEED2-like protein increased in Yuetai A, leading to the discovery of an aberrant variation of the jasmonic acid pathway during the development of microspores. Source


Non-small-cell lung cancer (NSCLC) represents the most common deadly disease. Emerging evidences suggest that abnormal epigenetic modulation via mRNAs and microRNAs (miRNAs) might be involved in the tumorigenesis. To explore novel therapeutic target of NSCLC, a more detailed mRNAs and miRNA expression profiling study is needed. High-quality total RNA including miRNA was isolated from NSCLC tissue and para-carcinoma tissue and used for RNA and small RNA sequencing. Results were analyzed bioinformatically and validated using quantitative real-time (qRT)-PCR. A total of 3530 genes (1977 up-regulated and 1553 down-regulated) and 211 miRNAs (171 up-regulated and 30 down-regulated) were differentially expressed (DE) in NSCLC tissue versus adjacent normal tissues. Furthermore, 157 novel miRNAs were predicted in our samples. Of these, 918 significant miRNA–mRNA pairs were identified, consisting of 100 miRNAs and 443 mRNAs. Gene ontology analysis revealed that most of the target genes were enriched in the terms of plasma membrane, binding, and multiple biological-molecular signaling processes. Pathway analysis of these miRNA signatures highlights their critical roles in calcium signaling pathway. Using qRT-PCR, the expression of several DE genes (KRAS and RBM5) and miRNAs (miR-1-5p, let-7b-5p, miR-21-5p, miR-1290, miR-149-5p, chr8_28846, chrX_31594, and chr9_29897) were confirmed. The integrative analysis based on mRNA and miRNA profiling may provide more potential molecular for the tumorigenesis and development of NSCLC.Cancer Gene Therapy advance online publication, 11 March 2016; doi:10.1038/cgt.2016.5. © 2016 Nature America, Inc. Source


Chan K.Y.,Curtin University Australia | Kwong C.K.,Hong Kong Polytechnic University | Hu B.Q.,Wuhan University
Applied Soft Computing Journal | Year: 2012

In product design, various methodologies have been proposed for market segmentation, which group consumers with similar customer requirements into clusters. Central points on market segments are always used as ideal points of customer requirements for product design, which reflects particular competitive strategies to effectively reach all consumers' interests. However, existing methodologies ignore the fuzziness on consumers' customer requirements. In this paper, a new methodology is proposed to perform market segmentation based on consumers' customer requirements, which exist fuzziness. The methodology is an integration of a fuzzy compression technique for multi-dimension reduction and a fuzzy clustering technique. It first compresses the fuzzy data regarding customer requirements from high dimensions into two dimensions. After the fuzzy data is clustered into marketing segments, the centre points of market segments are used as ideal points for new product development. The effectiveness of the proposed methodology in market segmentation and identification of the ideal points for new product design is demonstrated using a case study of new digital camera design. © 2011 Elsevier B.V. All rights reserved. Source


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. Source


Yang X.,Wuhan University
Plant physiology and biochemistry : PPB / Société française de physiologie végétale | Year: 2012

Plants have been used to restore vegetation in desert region in Shapotou, where naturally biological soil crusts (BSCs) have formed after planting for several years. However, few works have been done on the allelopathic effects between the plants and soil microalgae in BSCs currently. In this study, we investigated the chemical compositions of volatile oil of Artemisia ordosica and its allelopathic effects on photosynthetic system II (PSII) and antioxidant system of Palmellococcus miniatus, a green algae isolated from BSCs. 37 components, consisted of 17 terpenoids, 14 alcohols, 2 esters, 2 ketones and other 2 components were identified in the volatile oil from A. ordosica by GC-MS analysis. High concentration of volatile oil could significantly inhibit the growth and photosynthetic activity (Fv/Fm), and decreased the photosynthetic parameters by affecting photon absorption, electron transport and the reaction center of PSII of P. miniatus, and also cause the significant increase of superoxide dismutase (SOD; EC 1.15.1.) activity, peroxidase (POD; EC 1.11.1.7) activity, reactive oxygen evolution (ROS) and malondialdehyde (MDA) contents of P. miniatus through the combined effects of components in volatile oil. The results indicated that the emission of volatile oil of A. ordosica could inhibit the growth, photosynthesis of P. miniatus through the oxidative damage, and thus might negatively affect the development of BSCs. Copyright © 2011 Elsevier Masson SAS. All rights reserved. Source


Xia R.,Wuhan University | Feng X.-Q.,Tsinghua University | Wang G.-F.,Xian 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. Source


Synchronization is an important frontier in contemporary nonlinear science. It has been developed and applied widely in the late 20th century. However, it has limited applications in geological science, especially in the study of mineralization. The ore formation of fluids is a problem of propagation of chemical waves and the generation of their spatiotemporal structures. Geological processes and spatiotemporal structures are the essence and core of all geological phenomena. Taking these ideas as guides, giving a new definition for "phase" in geochemical dynamics, and selecting the concentration data of 10 elements from stream-sediment samples on a 1: 50 000 scale, this article applies the synchronization theory to the study of the distribution of tungsten-polymetallic mineralization in the Qianlishan (Chinese Source)-Qitianling (Chinese Source) area in southern Hunan (Chinese Source) which is one of the most important metallogenetic districts in the Nanling (Chinese Source) region. The results show that there are large ore deposits in Shizhuyuan (Chinese Source), Huangshaping (Chinese Source), Xianghualing (Chinese Source), Qitianling, and other areas, which verifies the present distribution of mineral resources in southern Hunan. Moreover, this article holds that the spatiotemporal synchronization of chemical waves plays an important role in the science of metallogenesis: it leads to the regional ore zoning centered at Qitianling, confirms that the Yanshan epoch is the chief ore-forming epoch in southern Hunan, and predicts other prospective areas of specific ores. © 2011 China University of Geosciences and Springer-Verlag Berlin Heidelberg. Source


Chen Y.-X.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Hu Z.,Wuhan University
Lithos | Year: 2013

Petrological evidence is provided for partial melting of ultrahigh-pressure (UHP) metamorphic granitic gneiss in the Sulu orogen. Petrographic observations show the occurrence of elongated, highly cuspate feldspars in grain boundaries, interstitial cuspate feldspars in triple junctions, felsic veinlets mainly consisting of K-feldspar. +. quartz, and feldspar crystal faces against quartz. These features indicate that the feldspar and quartz would have grown from anatectic melts in the granitic gneiss. Zircon domains grown from these melts were identified based on CL images, mineral inclusions and REE patterns. Some large zircon grains (>. 100μm) contain small relict domains of magmatic origin, suggesting nearly complete dissolution of the protolith zircon during the anatexis. All newly grown zircon domains are categorized into two groups based on the presence or absence of coesite inclusions. One group of domains contain no coesite inclusion and exhibit high U contents but low Th/U ratios (<. 0.1), steep REE patterns with strong negative Eu anomalies, and U. Pb ages of 217. ±. 2 to 224. ±. 2. Ma. The other group of domains contain coesite inclusions and exhibit low U contents and very low Th/U ratios (<. 0.01), steep REE patterns with strong negative Eu anomalies, and U. Pb ages of 221. ±. 5 to 226. ±. 3. Ma. The two groups of zircon domains are thus interpreted as growing from the anatectic melts at different pressures because they exhibit marked negative Eu anomalies that are absent for metamorphic zircons grown from aqueous fluids. The zircon U. Pb ages of 217. ±. 2 to 226. ±. 3. Ma are close to, but slightly younger than, known ages for major UHP metamorphism in the Sulu orogen. Therefore, the UHP gneiss experienced incipient melting during the initial exhumation subsequent to the peak UHP metamorphism and extensive anatexis later at lower pressures. Muscovite relicts coexist with cuspate feldspars, suggesting that the anatectic melts originate from dehydration melting due to decompression breakdown of phengitic muscovite in the UHP granitic gneiss. As the degree of partial melting increases with temperature, significant fractions of the anatectic melts would be produced in the regional gneiss provided that the UHP rocks experienced "hot" exhumation. Such melts can be gathered together, being eventually emplaced as synexhumation granitic intrusions. © 2012 Elsevier B.V. Source


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. Source


Chen Y.-X.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Hu Z.,Wuhan University
Lithos | Year: 2013

An integrated study of petrology, geochronology and geochemistry was performed for ultrahigh-pressure metamorphic gneisses in the Sulu orogen. The results are used to elucidate the polyphase growth of such metamorphic minerals as zircon, titanite and garnet in response to pressure-temperature changes and fluid/melt action during continental collision. This provides insights into the property of metamorphic fluid/melt and their effects on trace element mobility. A combined result from REE patterns, mineral inclusions and Ti-in-zircon temperatures indicates three stages of zircon growth. Prograde growth occurred at ~. 237. Ma primarily at eclogite-facies, retrograde growth at ~. 222. Ma mostly at eclogite-facies, and the last growth at ~. 205. Ma at granulite-facies. The three stages of zircon growth are deciphered by distinct REE patterns and trace element compositions, reflecting the differences in the property of metamorphic fluid/melt. The episodic growth of metamorphic zircon is primarily dictated by the episodic concentration of Zr and Si in metamorphic fluid/melt. Relict domains of magmatic titanite are distinguished from metamorphosed and metamorphic domains by their distinctive REE patterns and trace element compositions. The metamorphic titanite exhibit variably elevated Nb contents and Nb/Ta ratios, suggesting Nb/Ta fractionation due to breakdown of amphibole and/or biotite during metamorphism. Polyphase growth of garnet is suggested by an integrated analysis of mineral inclusions, and major and trace elements in large garnet grains. Trace element abundances vary in different zones of garnet, which is ascribed to changes in the paragenesis and composition of matrix minerals involved in garnet-forming reactions at different P-T conditions. Therefore, the metamorphic growth of zircon, titanite and garnet would have occurred not only during prograde subduction but also during retrograde exhumation in the continental collision zones. Both metamorphic dehydration and partial melting would have taken place episodically during the collisional orogeny. The breakdown of hydrous minerals at high- to ultrahigh-pressure conditions is a key to fluid liberation and element supply for the growth of these accessory minerals. © 2013 Elsevier B.V. Source


Tang J.,Wuhan University
Chinese journal of traumatology = Zhonghua chuang shang za zhi / Chinese Medical Association | Year: 2013

To observe the therapeutic effect of absorbable screw in medial malleolus fracture and discuss its clinical application in orthopedics. A total of 129 patients with simple medial malleolus fracture were studied. Among them, 64 patients were treated with poly-D, L-lactic acid (PDLLA) absorbable screws, while the others were treated with metal screws. All the patients were followed up for 12-20 months (averaged 18.4 months) and the therapeutic effect was evaluated according to the American Orthopaedic Foot and Ankle Society clinical rating systems. In absorbable screw group, we obtained excellent and good results in 62 cases (96.88%); in steel screw group, 61 cases (93.85%) achieved excellent and good results. There was no significant difference between the two groups. In the treatment of malleolus fracture, absorbable screw can achieve the same result compared with metal screw fixation. Absorbable screw is preferred due to its advantages of safety, cleanliness and avoiding the removal procedure associated with metallic implants. Source


Liu S.,Wuhan Institute of Technology | Xu L.,Wuhan University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2013

The shear tests were conducted on 18 different groups of deep beams with steel fiber and polypropylene fiber and 2 groups of HPC deep beams without fiber according to the orthogonal experimental design method. The influences of steel fiber and polypropylene fiber on the process and mode of shear failure of HPC deep beams were analyzed and the shear strengthening mechanism of hybrid fiber was investigated. 6 factors, including the characteristic parameters of steel fiber (types, volume fraction, aspect ratio), the volume fraction of polypropylene fiber, the ratio of web horizontal reinforcement and the ratio of web vertical reinforcement, were compared by direct-viewing analysis of the orthogonal experiment. The results show that the hybrid fiber can greatly increase the diagonal crack-resistance strength and shear strength of HPC deep beams. The diagonal crack-resistance is increased by 83.8% while the shear strength is increased by 35.2%. The aspect ratio of steel fiber plays the most important role in diagonal crack-resistance of HPC deep beams whereas ratio of web vertical reinforcement has the minimum effect. Meanwhile the ratio of web horizontal reinforcement contributes most to the shear strength of HPC deep beams whereas the volume fraction of polypropylene fiber has the minimum effect. Based on current codes, a shear capacity calculation formula for hybrid fiber reinforced HPC deep beams is proposed, which can provide reference for engineering design. Source


This work studies the solitons and conserved quantities to Biswas–Milovic equation that models the propagation of waves in physical sciences and engineering. Two types of nonlinearity that are Kerr law and parabolic law are taken into consideration. Via the Jacobian elliptic equations expansion approach and (Formula presented.) model expansion scheme, analytical soliton and soliton-like solutions are derived. © 2015 Springer Science+Business Media Dordrecht Source


Jiang Z.,Wuhan University
Journal of Computational Information Systems | Year: 2013

Erecting shield wires is one of the effective measures to improve power frequency electric field environment around high voltage transmission line, which can reduce the impact of power frequency electric field to surroundings and human activity. There is an unknown multidimensional non-linear relationship among the quantity of shield wires, the suspended positions and shielding effectiveness. Therefore, finite element method combined with particle swarm optimization is proposed to solve this problem in the research. Shielding effectiveness is as optimization objective, the quantity, the diameter and the suspension positions of shield wires are optimization variables. Moreover, an optimization example is demonstrated, and the optimization results are satisfied. The proposed method is not only applicable to optimize shield wires, but also suitable for employing in other aspects of electromagnetic field inverse problems. © 2013 Binary Information Press. Source


Wang Q.,University of Manitoba | Wang Q.,Wuhan University
Carbon | Year: 2011

The instability of a carbon nanotube containing a polyethylene molecule subjected to compression is investigated using molecular dynamics. A decrease up to 35% in the buckling strain of the (6,6) and (10,10) carbon nanotube/polymer structures due to the attractive van der Waals interaction between the tube wall and the polymer molecule is reported. In particular, the decrease in the buckling strain of the (6,6) carbon nanotube/polymer structure is attributed to the initiation of two flattenings on the tube wall. Simulations show that the buckling strain of the structure is insensitive to the number of units of the polymer molecule. © 2010 Elsevier Ltd. All rights reserved. Source


Xu X.,Wuhan University
Proceedings - 2013 International Conference on Computational and Information Sciences, ICCIS 2013 | Year: 2013

The IOT is a huge and widely distributed the Internet that things connect things.It connects all the articles to the internet through information sensing devices. It is the second information wave after Computer, Internet and mobile communication network. With the rapid development of the Internet of Things, its security problems have become more concentrated. This paper addresses the security issues and key technologies in IOT. It elaborated the basic concepts and the principle of the IOT and combined the relevant characteristics of the IOT as well as the International main research results to analysis the security issues and key technologies of the IOT which in order to plays a positive role in the construction and the development of the IOT through the research. © 2013 IEEE. Source


The mutual inductance for the coils mentioned in the title is given in this paper, which is the generalization for the calculation method of the mutual inductance of the circular coils in the free space. Starting with the Bessel integral representation of the vector potential of a circular ring, the integral expressions of mutual inductance of the shielded circular rings with parallel axes are given by the calculation of the mutual magnetic energy, and the results are further continued analytically to the complex plane by introducing the Hankel function of the first kind, and then solved via the residue theorem. Additionally, the mutual inductance of the shielded thick coils is found based on the obtained results of the circular rings. Finally, the numerical results of the presented method are compared with those of the Finite Element Method simulations, and our method is confirmed by the good agreement between them in the numerical computations. © 2014 Taylor & Francis. Source


Liu Q.,Wuhan University | Liu Q.,Kansas State University | Clem R.J.,Kansas State University
Apoptosis | Year: 2011

To date, our knowledge of apoptosis regulation in insects comes almost exclusively from the model organism Drosophila melanogaster. In contrast, despite the identification of numerous genes that are presumed to regulate apoptosis in other insects based on sequence homology, little has been done to examine the molecular pathways that regulate apoptosis in other insects, including medically important disease vectors. In D. melanogaster, the core apoptosis pathway consists of the caspase negative regulator DIAP1, IAP antagonists, the initiator caspase Dronc and its activating protein Ark, and the effector caspase DrICE. Here we have studied the functions of several genes from the mosquito disease vector Aedes aegypti that share homology with the core apoptosis genes in D. melanogaster. Silencing of the iap1 gene in the A. aegypti cell line Aag2 caused spontaneous apoptosis, indicating that IAP1 plays a role in cell survival similar to that of DIAP1. Silencing A. aegypti ark or dronc completely inhibited apoptosis triggered by several different apoptotic stimuli. However, individual silencing of the effector caspases CASPS7 or CASPS8, which are the closest relatives to DrICE, only partially inhibited apoptosis, and silencing both CASPS7 and CASPS8 together did not have a significant additional effect. Our results suggest that the core pathway that regulates apoptosis in A. aegypti is similar to that of D. melanogaster, but that more than one effector caspase is involved in apoptosis in A. aegypti. This is interesting in light of the fact that the caspase family has expanded in mosquitoes compared to D. melanogaster. © 2010 Springer Science+Business Media, LLC. Source


Zhang B.,Wuhan University
Annals of Physics | Year: 2016

An exotic Bañados-Teitelboim-Zanelli (BTZ) black hole has an angular momentum larger than its mass in three dimension (3D), which suggests the possibility that cosmic censorship could be violated if angular momentum is extracted by the Penrose process. In this paper, we propose a mass formula for the exotic BTZ black hole and show no violation of weak cosmic censorship in the gedanken process above by understanding properly its mass formula. Unlike the other black holes, the total energy of the exotic BTZ black hole is represented by the angular momentum instead of the mass, which supports a basic point of view that the same geometry should be determined by the same energy in 3D general relativity whose equation of motion can be given either by normal 3D Einstein gravity or by exotic 3D Einstein gravity. However, only the mass of the exotic black hole is related to the thermodynamics and other forms of energy are "dumb", which is consistent with the earlier thermodynamic analysis about exotic black holes. © 2016 Elsevier Inc. Source


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. Source


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. Source


Wu X.,Wuhan University | Theodoratos D.,New Jersey Institute of Technology
VLDB Journal | Year: 2013

XML is currently the most popular format for exchanging and representing data on the web. It is used in various applications and for different types of data including structured, semistructured, and unstructured heterogeneous data types. During the period, XML was establishing itself, data streaming applications have gained increased attention and importance. Because of these developments, the querying and efficient processing of XML streams has became a central issue. In this study, we survey the state of the art in XML streaming evaluation techniques. We focus on both the streaming evaluation of XPath expressions and of XQuery queries. We classify the XPath streaming evaluation approaches according to the main data structure used for the evaluation into three categories: automaton-based approach, array-based approach, and stack-based approach. We review, analyze, and compare the major techniques proposed for each approach. We also review multiple query streaming evaluation techniques. For the XQuery streaming evaluation problem, we identify and discuss four processing paradigms adopted by the existing XQuery stream query engines: the transducer-based paradigm, the algebra-based paradigm, the automata-algebra paradigm, and the pull-based paradigm. In addition, we review optimization techniques for XQuery streaming evaluation. We address the problem of optimizing XQuery streaming evaluation as a buffer optimization problem. For all techniques discussed, we describe the research issues and the proposed algorithms and we compare them with other relevant suggested techniques. © 2012 Springer-Verlag. Source


Lu J.,University of Arkansas for Medical Sciences | Lu J.,Wuhan University | Mitra S.,University of Arkansas for Medical Sciences | Wang X.,University of Arkansas for Medical Sciences | And 2 more authors.
Antioxidants and Redox Signaling | Year: 2011

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been identified as a major receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, monocytes, platelets, cardiomyocytes, and vascular smooth muscle cells. Its expression is minimal under physiological conditions but can be induced under pathological conditions. The upregulation of LOX-1 by ox-LDL appears to be important for physiologic processes, such as endothelial cell proliferation, apoptosis, and endothelium remodeling. Pathophysiologic effects of ox-LDL in atherogenesis have also been firmly established, including endothelial cell dysfunction, smooth muscle cell growth and migration, monocyte transformation into macrophages, and finally platelet aggregation-seen in atherogenesis. Recent studies show a positive correlation between increased serum ox-LDL levels and an increased risk of colon, breast, and ovarian cancer. As in atherosclerosis, ox-LDL and its receptor LOX-1 activate the inflammatory pathway through nuclear factor-kappa B, leading to cell transformation. LOX-1 is important for maintaining the transformed state in developmentally diverse cancer cell lines and for tumor growth, suggesting a molecular connection between atherogenesis and tumorigenesis. © 2011 Mary Ann Liebert, Inc. Source


Zhao Z.-G.,Lanzhou University | Huang S.-Q.,Wuhan University
International Journal of Plant Sciences | Year: 2013

Premise of research. In flowers that are specialized, floral traits often differentiate in association with pollinator shifts. However, in species of generalized pollination, the role of pollinators in local population differentiation of floral traits is difficult to test. A crucial line of evidence is to contrast the direction and strength of pollinator selection among populations. Methodology. Variation in floral traits and pollinator assemblages was investigated in two populations of a generalist-pollinated herb, Trollius ranunculoides (Ranunculaceae), to detect the potential role of pollinators in floral differentiation. Pivotal results. The alpine population was visited more by flies, and the subalpine population was visited more by bees. Flower manipulations suggested that large flowers were more attractive to both bees and flies, while more petals were favored only by nectar-feeding flies. Compared to the subalpine population, plants in the alpine population had more petals per flower but smaller flowers where flies were predominant pollinators. Flower differences appeared to be genetically maintained in a common garden. Phenotypic selection analysis indicated stronger selection on petal number in the alpine population and oppositely more intense selection on flower diameter in the subalpine population, in accordance with the preferences of local pollinator assemblages. Conclusions. Heritability in floral traits, differences in local pollinator assemblages, and corresponding differences in phenotypic selection are together consistent with the view of pollinator-mediated selection on floral differentiation in T. ranunculoides. © 2013 by The University of Chicago. All rights reserved. Source


Wong H.,Hong Kong Polytechnic University | Hu B.Q.,Wuhan University
Journal of Hydrology | Year: 2013

The extension evaluation method (EEM) has been applied to evaluate water quality. However, in real-life applications, sample data may be given as intervals because of errors produced in measurement, poor data brought by poor information, and imprecise data induced by human errors. To deal with data set in the form of a number of intervals, the interval extension evaluation method (IEEM) has been previously introduced. However, the correlative degrees that are obtained from IEEM may yield negative numbers. In evaluating water quality one generally assigns ranks or grades that are non-negative. Then it is expected that correlative degrees must be non-negative. This paper provides a novel method, i.e., the interval clustering approach (ICA), which is based on the grey clustering approach (GCA) and interval-valued fuzzy sets, to overcome this negativity issue. The method also introduces the notion of weightings in the form of intervals, by which interval samples can be analyzed with a view to delineating the important attributes via the interval weights. To demonstrate our proposed approach, the ICA 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. Our proposed method is a useful tool for the analysis of poorly measured data, poorly collected data and imprecise hydrological data which are very commonly encountered in water research. In brief, our method is novel for analyzing interval data. The GCA is a special case of the ICA, as these intervals are degenerated single values. © 2013 Elsevier B.V. Source


Hao F.,Wuhan University | Hao F.,China University of Petroleum - Beijing | Zou H.,China University of Petroleum - Beijing
Marine and Petroleum Geology | Year: 2013

This article reviews the abnormal characteristics of shale gases (natural gases produced from organic-rich shales) and discusses the cause of the anomalies and mechanisms for gas enrichment and depletion in high-maturity organic-rich shales. The reported shale gas geochemical anomalies include rollover of iso-alkane/normal alkane ratios, rollover of ethane and propane isotopic compositions, abnormally light ethane and propane δ13C values as well as isotope reversals among methane, ethane and propane. These anomalies reflect the complex histories of gas generation and associated isotopic fractionation as well as in-situ "mixing and accumulation" of gases generated from different precursors at different thermal maturities. A model was proposed to explain the observed geochemical anomalies. Gas generation from kerogen cracking at relatively low thermal maturity accounted for the increase of iso-alkane/normal alkane ratios and ethane and propane δ13C values (normal trend). Simultaneous cracking of kerogen, retained oil and wet gas and associated isotopic fractionation at higher maturity caused decreasing iso-alkane/normal alkane ratios, lighter ethane and propane δ13C and corresponding conversion of carbon isotopic distribution patterns from normal through partial reversal to complete reversal. Relatively low oil expulsion efficiency at peak oil generation, low expulsion efficiency at peak gas generation and little gas loss during post-generation evolution are necessary for organic-rich shales to display the observed geochemical anomalies. High organic matter richness, high thermal maturity (high degrees of kerogen-gas and oil-gas conversions) and late-stage (the stage of peak gas generation and post-generation evolution) closed system accounted for gas enrichment in shales. Loss of free gases during post-generation evolution may result in gas depletion or even undersaturation (total gas content lower than the gas sorption capacity) in high-maturity organic-rich shales. •Geochemical anomalies of shale gases were characterized in detail.•A model was proposed to explain the observed geochemical anomalies of shale gases.•High TOC contents, high thermal maturity and late-stage closed system account for gas enrichment in shales.•Loss of free gases during post-generation evolution may result in gas depletion or even undersaturation in high-maturity organic-rich shales. © 2013 Elsevier Ltd. Source


Jiang Y.,Chinese Academy of Sciences | Hsu W.,Wuhan University
Meteoritics and Planetary Science | Year: 2012

Abstract-: Grove Mountains (GRV) 020090 is a "lherzolitic" shergottite found in the Grove Mountains, Antarctica. It exhibits two distinct textures: poikilitic and nonpoikilitic. In poikilitic areas, large pyroxene oikocrysts enclose subhedral olivine and chromite chadacrysts. Pyroxene oikocrysts are zoned from pigeonite cores to augite rims. In nonpoikilitic areas, olivine, pyroxene, and interstitial maskelynite occur as major phases, and minor phases include chromite and merrillite. Compared with typical "lherzolitic" shergottites, GRV 020090 contains a distinctly higher abundance of maskelynite (19 vol%). Olivine and pyroxene are more ferroan (Fa 28-40, En 57-72Fs 24-31Wo 4-14 and En 46-53Fs 17-21Wo 26-35), and maskelynite is more alkali-rich (Ab 43-65Or 2-7). The major phases, whole-rock (estimated) and fusion crust of GRV 020090, are relatively enriched in light rare earth elements (LREE), similar to those of the geochemically enriched basaltic shergottites, but distinct from those of LREE-depleted "lherzolitic" shergottites. Combined with a high oxygen fugacity of log fO 2=QFM-1.41±0.04 (relative to the quartz-fayalite-magnetite buffer), it is clear that GRV 020090 sampled from an oxidized and enriched mantle reservoir similar to those of other enriched shergottites. The calculated REE abundances and patterns of the melts in equilibrium with the cores of major phases are parallel to but higher than that of the whole rock, suggesting that GRV 020090 originated from a single parent magma and experienced progressive fractional crystallization in a closed system. The crystallization age recorded by baddeleyite is 192±10 (2σ) Ma, consistent with the young internal isochron ages of enriched shergottites. Baddeleyite dating results further demonstrated that the young ages, rather than ancient ages (>4Ga), appear to represent the crystallization of Martian surface lava flow. GRV 020090 shares many similarities with Roberts Massif (RBT) 04261/2, the first enriched "lherzolitic" shergottite. Detailed comparisons suggest that these two rocks are petrologically and geochemically closely related, and probably launch paired. © The Meteoritical Society, 2012. Source


A Beresella-dominated algal mound and its internal construction from Paojianggou, southwestern Tarim BasNW China are studied for the first time. This algal mound was constructed during the early-middle late Moscovian and its age is constrained by fusulinids of the Fusulina kamensis and F. quasicylindrica zones of middle Pennsylvanian age. The mound substrate beds are composed of crinoid and brachiopod grainstones. Crinoid bank and brachiopod-dominated skeletal shoals indicate a high-energy environment and produced a local topographic high on which the mound grew. Komia bafflestone of the foremound facies further increased the relief of the crinoid bank on the seafloor. The lower part of the mound framework is dominated by Shamovella-Archaeolithoporella boundstone, while the main (upper) mound framework consists predominantly of Beresella boundstone. Grainstone-packstone characterizes the windward mound flank facies. The mound capping facies include a lower skeletal packstone-wackestone and an upper lagoon facies marlstone and black shale. Various algal colonies performed different roles in the formation of the mound. Komia colonies were the mound constructors that baffled higher energy currents and entrapped fine sediment. Archaeolithoporella, Shamovella and possibly microbes (cyanobacteria) acted as the binders to stabilize mud and fine-grained sediment. Beresella colonies were the major framework constructors whose network entrapped the mud to build the mound. The growth of the Paojianggou mound in the Tarim Basin has undergone three major algal colonization stages: Komia baffling, laminar Archaeolithoporella and Shamovella encrusting and binding, and Beresella binding and stabilizing. The Paojianggou mound developed in a protected lagoonal position behind the shoals and grew during a short rise in sea level followed by a long-period sea-level fall. Its demise was caused by terrigenous siliciclastic input due to regional tectonic uplifting in the Tarim Basin during the latest Moscovian time. © 2012 John Wiley & Sons, Ltd. Source


Zhou Z.,Wuhan University
IEEE Transactions on Image Processing | Year: 2012

Uncertainties are the major inherent feature of impulse noise. This fact makes image denoising a difficult task. Understanding the uncertainties can improve the performance of image denoising. This paper presents a novel adaptive detail-preserving filter based on the cloud model (CM) to remove impulse noise. It is called the CM filter. First, an uncertainty-based detector identifies the pixels corrupted by impulse noise. Then, a weighted fuzzy mean filter is applied to remove the noise candidates. The experimental results show that, compared with the traditional switching filters, the CM filter makes a great improvement in image denoising. Even at a noise level as high as 95%, the CM filter still can restore the image with good detail preservation. © 2012 IEEE. Source


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. Source


Karkas M.D.,University of Stockholm | Akermark T.,University of Stockholm | Chen H.,University of Stockholm | Chen H.,Wuhan University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

No CO-operation: Two single-site ruthenium complexes, based on a tetradentate ligand, despite structural similarities, display a remarkable difference in their catalytic and chemical behavior (see picture). The fact that the CO-containing complex is formed in the catalytic oxidation of water suggests a novel pathway for the deactivation of ruthenium-based catalysts. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Wang J.,Hubei University | Liu C.,Hubei University | Yuan J.,Hubei University | Lei A.,Hubei University | Lei A.,Wuhan University
Angewandte Chemie - International Edition | Year: 2013

Let's get radical: The first copper-catalyzed oxidative coupling of alkenes and aldehydes was developed. Various aldehydes were utilized as substrates to construct α,β-unsaturated ketones. A preliminary mechanistic study indicated that this reaction is likely to proceed through a single-electron transfer. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Khan M.K.,King Saud University | He D.,Wuhan University
Security and Communication Networks | Year: 2012

With the popularity of Internet and wireless networks, more and more network architectures are used in multi-server environment, in which users remotely access servers through open networks. For the reliability of accessing these remote services, user must pass a verification procedure to obtain the authorization for legal resource acquisition and data exchange. Recently, several dynamic identity-based authentication protocols for multi-server environment have been proposed, but all of these protocols have been cryptanalyzed by other scholars. In this paper, we propose a new dynamic identity-based authentication protocol for multi-server environment using elliptic curve cryptography. The analysis shows that our protocol could overcome security weaknesses in the previously published protocols. Hence, our protocol is more suitable for practical applications. Copyright © 2012 John Wiley & Sons, Ltd. We propose a new dynamic identity-based authentication protocol for multi-server environment using elliptic curve cryptography. Security analysis shows that our scheme could resist various attacks. Performance analysis shows our scheme is more suitable for practical applications. © 2012 John Wiley & Sons, Ltd.. Source


Lu X.,Nanjing University | Wang H.,Wuhan University
Elements | Year: 2012

Mining activities have created great wealth, but they have also produced colossal quantities of tailings. An important source of heavy metal contamination, sulfide tailings are usually disposed of in open-air impoundments and thus are exposed to microbial oxidation. Microbial activities greatly enhance sulfide oxidation and result in the release of heavy metals and the precipitation of iron (oxy)hydroxides and sulfates. These secondary minerals in turn influence the mobility of dissolved metals and play important roles in the natural attenuation of heavy metals. Elucidating the microbe-mineral interactions in tailings will help us mitigate the environmental impacts of mining activities. Source


Zuo R.,Wuhan University
Journal of Geochemical Exploration | Year: 2012

One ore-forming element (Cu) and one rock-forming element (SiO 2) from stream sediment dataset in Tibet (China) are selected to explore the effects of cell size in geochemical mapping using fractal and multifractal models. Five raster maps for Cu and SiO 2 are obtained by the IDW method with the cell sizes of 300m, 500m, 700m, 900m, and 1100m. The results show that (1) whereas raster maps interpolated at different cell sizes have average and standard deviation values similar to those of the original data, their maximum values are lower and their minimum values are higher, indicating that the cell size slightly affects the concentration frequency distribution of geochemical patterns, and that the IDW method smoothens the original data to some extent; (2) the mean absolute error increases as the cell size increases, indicating that the cell size affects the accuracy of prediction; (3) the spatial patterns obtained with different cell sizes have different textures as indicated by different values of multifractal parameters, implying that the cell size affects the spatial texture of geochemical patterns; and (4) different Cu thresholds obtained by C-A fractal model indicates that the cell size slightly affects the delineation of geochemical anomalies. © 2011 Elsevier B.V. Source


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. Source


Ran Y.,CAS Wuhan Institute of Virology | Shu H.-B.,Wuhan University | Wang Y.-Y.,CAS Wuhan Institute of Virology
Cytokine and Growth Factor Reviews | Year: 2014

The recognition of nucleic acids is a general strategy used by the host to detect invading pathogens. Many studies have established that MITA/STING is a central component in the innate immune response to cytosolic DNA and RNA derived from pathogens. MITA can act both as a direct sensor of cyclic dinucleotides (CDNs) and as an adaptor for the recruitment of downstream signaling components. In both roles, MITA is part of signaling cascades that orchestrate innate immune defenses against various pathogens, including viruses, bacteria and parasites. Here, we highlight recent studies that have uncovered the molecular mechanisms of MITA-mediated signal transduction and regulation, and discuss some notable issues that remain elusive. © 2014 Elsevier Ltd. Source


Sun G.,Wuhan University | Fu L.,U.S. National Institutes of Health | Shi Y.-B.,U.S. National Institutes of Health
Cell and Bioscience | Year: 2014

Epigenetic modifications of histones are emerging as key factors in gene regulation by diverse transcription factors. Their roles during vertebrate development and pathogenesis are less clear. The causative effect of thyroid hormone (T3) on amphibian metamorphosis and the ability to manipulate this process for molecular and genetic studies have led to the demonstration that T3 receptor (TR) is necessary and sufficient for Xenopus metamorphosis, a process that resembles the postembryonic development (around birth) in mammals. Importantly, analyses during metamorphosis have provided some of the first in vivo evidence for the involvement of histone modifications in gene regulation by TR during vertebrate development. Furthermore, expression and functional studies suggest that various histone modifying epigenetic enzymes likely participate in multiple steps during the formation of adult intestinal stem cells during metamorphosis. The similarity between intestinal remodeling and the maturation of the mammalian intestine around birth when T3 levels are high suggests conserved roles for the epigenetic enzymes in mammalian adult intestinal stem cell development and/or proliferation. © 2014 Sun et al.; licensee BioMed Central Ltd. Source


Assessment of Ventricular Electrophysiological Characteristics. The aim of this study was to investigate the characteristics of ventricular electrophysiology following stellate ganglion block (SGB) at periinfarct zone in rabbits with myocardial infarction (MI). Sixty-four rabbits were randomly assigned to 2 groups: MI (n = 32), ligation of the anterior descending coronary and sham operation (SO) (n = 32), without coronary ligation. Both MI and SO groups were divided into 4 subgroups according to right or left SGB and corresponding control (n = 8, each). After 8 weeks, 90% of monophasic action potential duration (MAPD90) of epicardium, midmyocardium and endocardium, transmural dispersion of repolarization (TDR), effective refractory period (ERP), and ventricular fibrillation threshold (VFT) were measured at the infarct border zone (MI group) and corresponding zone (SO group) following SGB. For SGB, 0.5 mL of 0.25% bupivacaine was used. Compared with the corresponding control group, in both the MI and SO groups, left SGB (LSGB) prolonged the MAPD90 of the 3 layers, reduced TDR, and increased ERP and VFT (P < 0.05). However, right SGB (RSGB) shortened MAPD90, increased TDR, and reduced ERP and VFT (P < 0.05). The results of this study demonstrate that LSGB can increase the electrophysiological stability of ventricular myocardium. © 2012 Wiley Periodicals, Inc. Source


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. Source


Chen M.,Wuhan University
Advances in Information Sciences and Service Sciences | Year: 2012

The radio-map for indoor location is not constantly effective due to time-variant interferences in indoor environment. And this phenomenon can degrade the system performance of indoor location. In this paper, to resolve this problem, we proposed a novel real-time radio-map updating algorithm. We use the history data to real-time update the radio-map by using a kernel based method. Because of the nonlinear indoor interference, this nonlinear method can improve the system accuracy more than those linear methods. Our experiments verified the effectiveness of our proposed method. Source


Eshagh M.,University College West | Tenzer R.,Wuhan University
Computational Geosciences | Year: 2015

The sub-crustal stress induced by mantle convection has been traditionally computed using the Runcorn formulae of solving the Navier-Stokes problem. The main disadvantage of this method is a limited spectral resolution (up to degree 25 of spherical harmonics) due to a divergence of the spherical harmonic expression. To improve the spectral resolution, we propose a new method of computing the horizontal components of the sub-crustal stress based on utilising the stress function with a numerical differentiation. According to the proposed method, the stress function is functionally related to the gravity and crust structure models expressed in terms of spherical harmonics, instead of directly relating the stress components with partial derivatives of these spherical harmonics. The stress components are then computed from the stress function by applying a numerical differentiation. This modification increases the degree-dependent convergence domain of the asymptotically convergent series and consequently allows computing the stress components to a higher spectral resolution, which is compatible with currently available global crustal models. We further utilise the solution to the Vening Meinesz-Moritz inverse problem of isostasy in definition of the stress function. This definition facilitates a variable crustal thickness instead of assuming only a constant value adopted in the Runcorn formulae. The crustal thickness and sub-crustal stress are then determined directly from gravity data and a crustal structure model. We apply this numerical approach to compute the sub-crustal stress globally. Regional results are also presented and discussed over study areas of oceanic subduction zones, convergent continent-to-continent collision zones and hotspots. We demonstrate that the largest (in magnitude) sub-crustal stress occurs mainly along seismically active convergent tectonic plate boundaries. © 2014, Springer International Publishing Switzerland. Source


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. Source


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. Source


Qu Y.,CAS Institute of Zoology | Lei F.,CAS Institute of Zoology | Zhang R.,CAS Institute of Zoology | Lu X.,Wuhan University
Molecular Ecology | Year: 2010

Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species. In contrast to Europe and North America where the effects of recent glacial cycles on genetic diversity have been well studied, the genetic legacy of the Pleistocene for the Qinghai-Tibetan (Tibetan) plateau, a region where glaciation was not synchronous with the North Hemisphere ice sheet maxima, remains poorly understood. Here, we compared the phylogeographical patterns of five avian species on the Qinghai-Tibetan plateau by three mitochondrial DNA fragments: the Tibetan snow finch (Montifringilla adamsi), the Blanford's snow finch (Pyrgilauda blanfordi), the horned lark (Eremophila alpestris), the twite (Carduelis flavirostris) and the black redstart (Phoenicurus ochruros). Our results revealed the three species mostly distributed on the platform region of the plateau that experienced population expansion following the retreat of the extensive glaciation period (0.5-0.175 Ma). These results are at odds with the results from avian species of Europe and North America, where population expansions occurred after Last Glacial Maximum (LGM, 0.023-0.018 Ma). A single refugium was identified in a restricted semi-continuous area around the eastern margin of the plateau, instead of multiple independent refugia for European and North American species. For the other two species distributed on the edges of the plateau (the twite and black redstart), populations were maintained at stable levels. Edge areas are located on the eastern margin, which might have had little or no ice cover during the glaciation period. Thus, milder climate may have mitigated demographic stresses for edge species relative to the extremes experienced by platform counterparts, the present-day ranges of which were heavily ice covered during the glaciation period. Finally, various behavioural and ecological characteristics, including dispersal capacities, habitat preference and altitude specificity along with evolutionary history might have helped to shape different phylogeographical structures appearing in these five species. © 2009 Blackwell Publishing Ltd. Source


Sun Y.,Wuhan University | Fang Y.,City University of Hong Kong | Lim K.H.,City University of Hong Kong
Decision Support Systems | Year: 2012

This study aims to address two research gaps in prior studies on knowledge sharing in virtual communities (VCs). First, prior studies have focused on knowledge sharing VCs with no explicit reward system, but VCs sharing knowledge based on a competition-based reward system (e.g., transactional VCs) have not been explored. Second, prior related studies have concentrated on the determinants of initial participation in sharing knowledge rather than sustained participation despite there being important distinctions between these two stages of participation behavior. In this study, we focus on understanding sustained participation in knowledge sharing in transactional VCs by drawing on expectancy-value theory and a social learning process. Considering that a social learning process is involved in maintaining sustained participation, we propose that task complexity and self-efficacy - two social learning factors - moderate the relationship between motivation and sustained participation. A field survey with 205 subjects in a transactional virtual community was conducted to test the research model. According to the findings, extrinsic and intrinsic motivations significantly influence sustained participation intention. A negative interaction effect between extrinsic motivation and task complexity, as well as positive interaction effect between intrinsic motivation and self-efficacy, was also observed. A non-linear interaction effect between intrinsic motivation and task complexity was also found. Study implications and future research directions are also discussed. © 2012 Elsevier B.V. All rights reserved. Source


Wei Z.,Beijing University of Technology | Zhang W.,Wuhan University
International Journal of Bifurcation and Chaos | Year: 2014

This paper reports the finding of a four-dimensional (4D) non-Sil'nikov autonomous system with three quadratic nonlinearities, which exhibits some behavior previously unobserved: hidden hyperchaotic attractors with only one stable equilibrium. The algebraical form of the non-Sil'nikov chaotic attractor is very similar to the hyperchaotic Lorenz-Stenflo system but they are different and, in fact, nonequivalent in topological structures. Of particular interest is the fact this system has only one stable equilibrium, but can exhibit hidden hyperchaos, chaos, periodic orbit. Moreover, the coexistence of attracting sets can be obtained in the system for some parameter values and different initial conditions, such as hyperchaotic attractor and point, hyper-chaotic attractor and period orbit. To further analyze the new system, the ultimate bound and positively invariant set for the modified hyperchaotic Lorenz-Stenflo system are also obtained. Moreover, the complete mathematical characterizations for 4D Hopf bifurcation are rigorously derived and studied. © World Scientific Publishing Company. Source


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). Source


He D.-B.,Wuhan University
Ruan Jian Xue Bao/Journal of Software | Year: 2013

To avoid complicated pairing operation and improve performance, Liu, et al. proposed a pairing-free certificateless signcryption scheme, and claims that their scheme is provably secure in a strengthened security model. Unfortunately, by giving concrete attacks, the sutdy indicates that Liu's et al. certificateless signcryption scheme is not secure in this strengthened security model. To solve the problem, an efficient countermeasure is also proposed. © Copyright 2013, Institute of Software, the Chinese Academy of Sciences. All rights reserved. Source


The age and body size of Amolops mantzorum between two populations distributed in western China were estimated using skeletochronology. The age at sexual mature of individuals was be estimated 2 yrs old in males for both populations while females reached sexual maturity at 2 yrs old at the low-altitude site and 3 yrs old at the high-altitude site. The oldest males and females from the high-altitude site were 7 yrs and 10 yrs old while longevity of males reached 6 yrs and 7 yrs in females at the low-altitude site. Average age between males and females differed significantly at the high-altitude site, but it did no differ significantly at the low-altitude site. For both sexes, average age did not differ significantly between the populations. On average, adult females had significantly larger body sizes than adult males for both populations. Sexual size dimorphism from the low-altitude site and the high-altitude site was 0.280 and 0.282, respectively. Body size between the populations differed significantly within each sex. Positive correlations were found between age and body size for both sexes within each site. The growth coefficient did not differ significantly within a population both sexes or in a sex between the populations. Our findings suggest that inter-population difference in body size of the frogs seems to be related to longevity of individuals, ambient temperature and construction of dams for electricity. © 2010 Koninklijke Brill NV, Leiden. Source


Sun H.L.,Wuhan University
The International journal of oral & maxillofacial implants | Year: 2011

The aim of this study was to evaluate the long-term failure rates of short dental implants (≤ 10 mm) and to analyze the influence of various factors on implant failure. The PubMed and Cochrane Library databases were consulted for follow-up studies published between the years 1980 and 2009. For those studies that met the inclusion and exclusion criteria, data concerning the number of implants (≤ 10 mm) placed and lost and any related risk factors were gathered in tables and subjected to analysis. Univariate and multivariate analyses were performed. The heterogeneity and low quality of the included studies made meta-analysis impossible. A total of 35 human studies fulfilled the criteria. The studies included 14,722 implants, of which 659 failed. The total failure rate was 4.5%. The failure rates of implants with lengths of 6, 7, 7.5, 8, 8.5, 9, and 10 mm were 4.1%, 5.9%, 0%, 2.5%, 3.2%, 0.6%, and 6.5%, respectively. A majority (57.9%) of failures occurred before prosthesis connection. There was no statistically significant difference between the failure rates of short dental implants and standard implants or between those placed in a single stage and those placed in two stages (multivariate analysis). There was a tendency toward higher failure rates for the maxilla and for dental implants with a machined surface compared with the mandible and dental implants with a rough surface, respectively. Among the risk factors examined, most failures of short implants can be attributed to poor bone quality in the maxilla and a machined surface. Although short implants in atrophied jaws can achieve similar long-term prognoses as standard dental implants with a reasonable prosthetic design according to this review, stronger evidence is essential to confirm this finding. Source


High porosity porous silver powder with about 100μm average size and 5μm pore size was fabricated by spray drying and calcining technology. Effects of calcining temperature and process of spray-dried powder on the phases, grain size, particle morphology and pore microstructure of silver powder were investigated. The results showed that porous silver with approximately spherical shape and via hole structure was obtained using 0.25mol Ag2CO3 solution of ammonia water, which was spray-dried at 200°C and calcined at 400°C for 30min with heat treatment technology curve of gradient temperature in air. And there were not Ag2CO3, Ag2O and AgO phases existing in the porous silver. However, using 0.25mol Ag2CO3 solution of ammonia water, the porous silver powder could not be fabricated by spray pyrolysis technology with a solution feed rate of 300mL/h, flux of carrier gas of 0.30MPa, and 640°C furnace set temperature. © 2010 Elsevier B.V. Source


Luo Y.,Wuhan University
Journal of Electromagnetic Waves and Applications | Year: 2014

For the circular coils of parallel axes eccentrically placed inside a cylinder of finite length and high permeability, the magnetic field and inductance are discussed and the analytic solutions are given by introducing a proper ansatz of the magnetic scalar potential (MSP), which is easy to satisfy the boundary conditions on the surface of the cylinder. By the separation of the total axial field into the source and secondary parts, the axial factor of the ansatz can be obtained, and the coefficients of the ansatz can be further found out by using the spring characteristics of the MSP. The results are further developed to find the self- and mutual inductance of the shielded circular rings and coils with rectangular cross section by calculating the corresponding magnetic flux. In addition, for the general case of the coils with parallel axes, the numerical results of the proposed method are compared with those of the finite element method simulations. For the special case of the rings coaxial with the cylinder, the results of our method are compared with those of the literature. Finally, the validity of our method is confirmed by the good agreement between them in the numerical calculations in all cases. © 2014 Taylor & Francis. Source


Hutsler J.J.,University of Nevada, Reno | Zhang H.,Wuhan University
Brain Research | Year: 2010

Multiple types of indirect evidence have been used to support theories of altered cortical connectivity in autism spectrum disorders (ASD). In other developmental disorders reduced spine expression is commonly found, while conditions such as fragile X syndrome show increased spine densities. Despite its relevance to theories of altered cortical connectivity, synaptic spine expression has not been systematically explored in ASD. Here we examine dendritic spines on Golgi-impregnated cortical pyramidal cells in the cortex of ASD subjects and age-matched control cases. Pyramidal cells were studied within both the superficial and deep cortical layers of frontal, temporal, and parietal lobe regions. Relative to controls, spine densities were greater in ASD subjects. In analyses restricted to the apical dendrites of pyramidal cells, greater spine densities were found predominantly within layer II of each cortical location and within layer V of the temporal lobe. High spine densities were associated with decreased brain weights and were most commonly found in ASD subjects with lower levels of cognitive functioning. Greater spine densities in ASD subjects provide structural support for recent suggestions of connectional changes within the cerebral cortex that may result in altered cortical computations. © 2009 Elsevier B.V. All rights reserved. Source


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. Source


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. Source


Guo Q.-T.,Fujian Electric Power Test and Research Institute | Wu T.,Wuhan University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

Neutral point ineffectively grounded power system is widely used in 3~66 kV power distribution system in China. In this power system, the single-phase-to-earth fault occurs frequently in distribution, thus how to detect the fault line with great accuracy and high efficiency is an important subject in protective relaying of power system. Reviewing the history of the methods to select the fault line in neutral point ineffectively grounded power system, this paper summarizes the existing theories of fault line selection and gives the conclusions. Source


Rostami V.,McGill University | Shao Y.,McGill University | Boyd A.J.,McGill University | He Z.,Wuhan University
Cement and Concrete Research | Year: 2012

Microstructure of Ordinary Portland Cement paste subjected to early age carbonation curing was studied to examine the effect of early carbonation on performance of paste at different ages. The study was intended to understand the mechanism of concrete carbonation at early age through the microstructure development of its cement paste. Early carbonation was carried out after 18-hour initial controlled air curing. The microstructure characterized by XRD, TGA, 29Si NMR and SEM was correlated to strength gain, CO2 uptake and pH change. It was found that early carbonation could accelerate early strength while allowing subsequent hydration. The short term carbonation created a microstructure with more strength-contributing solids than conventional hydration. Calcium hydroxide was converted to calcium carbonates, and calcium-silicate-hydrate became intermingled with carbonates, generating an amorphous calcium-silicate-hydrocarbonate binding phase. Carbonation modified C-S-H retained its original gel structure. The re-hydration procedure applied after carbonation was essential in increasing late strength and durability. © 2011 Elsevier Ltd. All rights reserved. Source


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. Source


Lei Y.,Wuhan University
Acta Mathematica Scientia | Year: 2014

This paper is concerned with the non-cutoff Boltzmann equation for full-range interactions with potential force in the whole space. We establish the global existence and optimal temporal convergence rates of classical solutions to the Cauchy problem when initial data is a small perturbation of the stationary solution. The analysis is based on the time-weighted energy method building also upon the recent studies of the non-cutoff Boltzmann equation in [1-3, 15] and the non-cutoff Vlasov-Poisson-Boltzmann system [6]. © 2014 Wuhan Institute of Physics and Mathematics. Source


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. Source


Gao X.-Y.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Chen Y.-X.,Hefei University of Technology | Guo J.,Wuhan University
Lithos | Year: 2012

Relict magmatic titanite was identified in the core of a few titanite grains with the overgrown rim of metamorphic titanite in UHP metagranite in the Dabie orogen. LA-ICPMS U-Pb dating gave Neoproterozoic ages for the magmatic titanite but Triassic ages for the metamorphic titanite. The magmatic and metamorphic titanites are clearly distinct by differences in petrological and geochemical compositions. The magmatic titanite occurs as residual cores that show bright BSE, the presence of allanite and quartz inclusions, low contents of CaO, Al 2O 3 and TiO 2 but high contents of Fe 2O 3 and MgO. In trace elements, the magmatic titanite exhibits high REE and HFSE contents, distinctly negative Eu anomalies with flat MREE-HREE patterns, and high Th/U ratios. In contrast, the metamorphic titanite occurs as rims and grains of homogeneously dark BSE that contain inclusions of epidote, quartz, K-feldspar, rutile, biotite and phengite, and have relatively high contents of CaO, Al 2O 3 and TiO 2, but low contents of Fe 2O 3 and MgO, and relatively low REE and HFSE contents, slightly negative Eu anomalies with HREE depletion relative to MREE, and low Th/U ratios. The Zr-in-titanite thermometry yields 727 to 877°C at 0.5 to 1.0GPa for the magmatic titanite, and 729 to 870°C at 1.5 to 2.0GPa for the metamorphic titanite. The Neoproterozoic U-Pb chronometric system of magmatic titanite survived the Triassic continental subduction-zone HP-UHP metamorphism. This suggests a relatively high closure temperature of >800°C for the titanite U-Pb system. The metamorphic titanite is principally a product of retrograde metamorphism during decompression exhumation at the transition from HP eclogite-facies to amphibolite-facies. Therefore, titanite holds a great potential to geochronological and petrogenetic studies of continental subduction-zone metamorphic rocks. © 2011 Elsevier B.V. Source


Yao M.,Wuhan University
Journal of Applied Optics | Year: 2016

Considering the requirement of measurement for video probe, a method for measuring points, lines and surfaces of object by using line-structured laser was presented. The line-structured light imaging model was built, where the linear laser was used as an auxiliary light source irradiating on the surface of the object. Compared to the object image, the proportional coefficient was calibrated with multiplying factor in different distances and laser line positions. The geometry parameters were calculated based on the measurement platform. The experimental results show that the measuring error is less than 10%, which indicates the method can satify the requirements of the video probe. © 2016, Editorial Board, Journal of Applied Optics. All right reserved. Source


To study the efficacy and safety of Gonadotropin-releasing hormone agonists (GnRH-a) combined with laparoscope conservative surgery in treatment of moderate or severe endometriosis. From Jan. 2007 to Jan. 2010, 68 patients with moderate or severe undergoing treatment in Renmin Hospital of Wuhan University were enrolled in this retrospective study. Three groups were classified, which were 25 patients in GnRH-a group, subcutaneous injection Leuprorelin on the second day of menstruation, every 4 weeks for 3 months. Twenty-three patients in Marvelon group, orally one marvelon tablet on the second day of menstruation, continuous 21 days for one period of treatment for 3 courses. Twenty patients in surgery group, without any medicine used preoperatively. All patients were followed by 12 months and compare their surgery time, blood loss, recovery, visual analog scale (VAS), and recurrence and so on. The operating time were (68 ± 18) min in GnRH-a group, (80 ± 21) min in Marvelon group and (90 ± 24) min in surgery group. The amount of bleeding were (118 ± 15) ml in GnRh-a group, (161 ± 18) ml in Marvelon group and (193 ± 13) ml in surgery group. There was significant lower in the operating time and amount of bleeding in GnRH-a group than those in other two groups (P < 0.05). The activity time and the anus exhaust time were shorter in patients in GnRh-a group than those in the other two groups significantly (P < 0.05). When followed up in 12 months after treatment, visual analogue scale had dropped from 3.8 (1.9 - 6.8) to 1.9 (1.1 - 2.8) in GnRh-a group, from 2.7 (1.3 - 5.5) to 1.8 (1.2 - 3.2) in Marvelon group and from 1.9 (1.0 - 4.9) to 1.6 (1.0 - 3.6) in surgery group. It was showed the most remarkable decreased VAS in GnRHa group when compared with the other two groups (P < 0.05). The recurrence rates were 12% (3/25) in GnRH-a group, 22% (5/23)in Marvelon group and 25% (5/25) in surgery group. It was found that the most significant lower recurrence was in GnRH-a group when compared with the other two groups (P < 0.05). It was safe and efficacy that GnRH-a combined with laparoscopic conservative surgery were used in treatment of endometriosis. It could bring shorter operation time, less intraoperative blood loss, quick postoperative recover, the lower recurrence rate. Source


Chen S.,Huazhong University of Science and Technology | Tian Z.,Wuhan University
International Journal of Heat and Fluid Flow | Year: 2010

We discuss the implementation of the recently developed Langmuir slip model, which possesses a clearer physical picture than the popularly used Maxwell slip model, for the lattice Boltzmann (LB) method to capture velocity slip and temperature jump in microfluidics. The implementation of this scheme is straightforward even when boundary walls do not run coincidentally along the lattice grids. Some previous LB boundary schemes for macroscopic thermal flows can be naturally recovered from the present scheme when the Knudsen number Kn → 0. The feasibility and the capability of the present scheme for thermal micro-flow simulations are explored by numerical experiments. © 2009 Elsevier Inc. All rights reserved. Source


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. Source


Chen R.-X.,Hefei University of Technology | Zheng Y.-F.,Hefei University of Technology | Hu Z.,Wuhan University
Lithos | Year: 2012

A combined study of mineral compositions and zircon U-Pb ages was carried out for a zoisite-quartz vein and its host retrograded eclogite in the Dabie orogen. The results reveal two episodes of fluid action during exhumation of the deeply subducted continental crust. The vein has a mineral paragenesis of quartz + zoisite + epidote + white mica + garnet + rutile + zircon + apatite, which is almost the same as that of the host retrograded eclogite characterized by symplectites after omphacite and/or garnet in the eclogite. Residues of magmatic zircon in the vein are similar to those in the eclogite, suggesting local sources of the metamorphic fluid for veining and physical transport of the tiny accessory mineral from the host rock to veins. There are significant differences in major and trace elements between vein-forming minerals, which are attributed to two episodes of fluid action for veining. Metamorphic zircon from the vein yields concordant U-Pb ages of 215 ± 4 to 218 ± 4. Ma. Trace element analysis indicates its precipitation from aqueous fluid during two distinct episodes under eclogite-facies and amphibolite-facies conditions, respectively. Ti-in-zircon and Zr-in-rutile thermometries yield variable temperatures from 537 to 683 °C. Thus the veining postdates the UHP metamorphic event at 225-240. Ma and took place during transition from HP eclogite-facies recrystallization to amphibolite-facies retrogression during the exhumation. The host eclogite was also retrograded in this stage to form metabasites such as amphibole eclogite to garnet amphibolite. The abundant occurrence of zoisite, epidote and phengite in the vein suggests that the metamorphic fluid is rich in Si, Al, Ca and K. The fluid composition is estimated in terms of zoisite composition and zoisite/fluid partition coefficients. The results suggest strong enrichment of LREE, Th, U, Pb, Sr, Rb and Ba, moderate enrichment of HREE, but significant depletion of HFSE. In this regard, the occurrence of metamorphic zircon and rutile in the vein suggests very local saturation of Zr and Ti in the Zo-Qtz vein-forming fluid. Therefore, the two episodes of fluid action would occur at the transition from eclogite to amphibolite facies during the exhumation and proceed with different fluid compositions and different flow behaviors. One was channelized under the eclogite-facies conditions, whereas the other is pervasive under the amphibolite-facies conditions. This provides robust constraints on the time, origin and property of metamorphic fluid during the exhumation of deeply subducted continental crust. © 2012 Elsevier B.V. Source


Shen X.-L.,Wuhan University | Cheung C.M.K.,Hong Kong Baptist University | Lee M.K.O.,City University of Hong Kong