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South China Normal University is a comprehensive university in Guangzhou, capital of Guangdong province, in the People's Republic of China. The university is featured distinctively by both teaching and research, consisting of diverse branches of learning such as philosophy, economics, law, education, literature, history, science, technology, and management. There is also an elementary school in this university. Wikipedia.

Zhang G.-M.,Liverpool John Moores University | Zhang C.-Z.,South China Normal University | Harvey D.M.,Liverpool John Moores University
Ultrasonics | Year: 2012

Many sparse signal representation (SSR) algorithms have been developed in the past decade. The advantages of SSR such as compact representations and super resolution lead to the state of the art performance of SSR for processing ultrasonic non-destructive evaluation (NDE) signals. Choosing a suitable SSR algorithm and designing an appropriate overcomplete dictionary is a key for success. After a brief review of sparse signal representation methods and the design of overcomplete dictionaries, this paper addresses the recent accomplishments of SSR for processing ultrasonic NDE signals. The advantages and limitations of SSR algorithms and various overcomplete dictionaries widely-used in ultrasonic NDE applications are explored in depth. Their performance improvement compared to conventional signal processing methods in many applications such as ultrasonic flaw detection and noise suppression, echo separation and echo estimation, and ultrasonic imaging is investigated. The challenging issues met in practical ultrasonic NDE applications for example the design of a good dictionary are discussed. Representative experimental results are presented for demonstration. © 2011 Elsevier B.V. All rights reserved.

Xiao J.,South China Normal University | Li L.,Sun Yat Sen University
Expert Systems with Applications | Year: 2011

Research on optimization in continuous domains gains much of focus in swarm computation recently. A hybrid ant colony optimization approach which combines with the continuous population-based incremental learning and the differential evolution for continuous domains is proposed in this paper. It utilizes the ant population distribution and combines the continuous population-based incremental learning to dynamically generate the Gaussian probability density functions during evolution. To alleviate the less diversity problem in traditional population-based ant colony algorithms, differential evolution is employed to calculate Gaussian mean values for the next generation in the proposed method. Experimental results on a large set of test functions show that the new approach is promising and performs better than most of the state-of-the-art ACO algorithms do in continuous domains. © 2011 Elsevier Ltd. All rights reserved.

Xing L.,University of Utah | Xing L.,South China Normal University | Vatamanu J.,University of Utah | Borodin O.,U.S. Army | And 2 more authors.
Journal of Physical Chemistry C | Year: 2012

The double layer composition and structure of the mixed-solvent electrolyte tetramethylene sulfone/dimethyl carbonate (TMS/DMC) doped with LiPF6 near the graphite surface have been investigated using molecular dynamics simulations as a function of applied potential between the electrodes ranging from 0 to 6 V. Three solvent compositions, with TMS/DMC ratios of 1:2, 1:1, and 2:1 doped with LiPF6 salt, were investigated. At uncharged electrodes, electrolyte composition at the interfaces was found to be similar to that of bulk electrolyte for TMS/DMC ratios of 1:1 and 1:2 systems but deviated from the bulk for a TMS/DMC ratio of 2:1. At negative electrodes the polar solvent TMS preferentially adsorbs at the electrode surface displacing the almost nonpolar DMC solvent. The preferential partitioning of TMS relative to DMC to the negative electrode surface is consistent with the stronger binding of the former with Li+ that partitions to the anode surface as potential becomes more negative as well as with the ability of relatively polar TMS to better respond to the electrostatic potential near a charged surface. At the positive electrode, TMS/DMC ratios were found to be similar to bulk compositions that is different to the behavior observed in ethylene carbonate (EC)/DMC/LiPF6 electrolyte where preferential partitioning of a more polar EC molecule was observed on both electrodes. Our results also show that, in TMS/DMC/LiPF6 electrolyte, DMC is located approximately 0.8 Å further way from the positive electrode than in EC/DMC/LiPF6 indicating that it might be more difficult to oxidize DMC in the TMS-based electrolytes that is consistent with experimentally reported increased oxidative stability of the latter. Finally, changes of the Li+ solvation shell and double layer capacitance were analyzed as a function of electrode potential. © 2012 American Chemical Society.

Yuan P.,South China Normal University | Ding C.,Hong Kong University of Science and Technology
Finite Fields and their Applications | Year: 2011

Using a lemma proved by Akbary, Ghioca, and Wang, we derive several theorems on permutation polynomials over finite fields. These theorems give not only a unified treatment of some earlier constructions of permutation polynomials, but also new specific permutation polynomials over Fq. A number of earlier theorems and constructions of permutation polynomials are generalized. The results presented in this paper demonstrate the power of this lemma when it is employed together with other techniques. © 2011 Elsevier Inc. All Rights Reserved.

Sun P.C.,Beijing Normal University | Wu Y.L.,Beijing Normal University | Gao J.W.,South China Normal University | Cheng G.A.,Beijing Normal University | And 2 more authors.
Advanced Materials | Year: 2013

A large contrast in the electrical and thermal conductivities via a first order phase transition in surface-functionalized carbon nanotube(CNT)/hexadecane composites is reported. Surface modification of the CNTs improves the electrical conductivity contrast and the stability of the composites. We demonstrate that, with these composites, the electrical conductivity changes above 105 times and the thermal conductivity varies up to 3 times at 18 °C. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xing L.,University of Utah | Xing L.,South China Normal University | Vatamanu J.,University of Utah | Borodin O.,U.S. Army | Bedrov D.,University of Utah
Journal of Physical Chemistry Letters | Year: 2013

The capacitance enhancement experimentally observed in electrodes with complex morphology of random subnanometer wide pores is an intriguing phenomena, yet the mechanisms for such enhancement are not completely understood. Our atomistic molecular dynamics simulations demonstrate that in subnanometer slit-geometry nanopores, a factor of 2 capacitance enhancement (compared to a flat electrode) is possible for the 1-ethyl-3-methylimidazolium (EMIM)-bis(trifluoro-methylsulfonyl)imide (TFSI) ionic liquid electrolyte. This capacitance enhancement is a result of a fast charge separation inside the nanopore due to abrupt expulsion of co-ions from the pore while maintaining an elevated counterion density due to strong screening of electrostatic repulsive interactions by the conductive pore. Importantly, we find that the capacitance enhancement can be very asymmetric. For the negatively charged 7.5 Å wide pore, the integral capacitance is 100% larger than on a flat surface; however, on the positive electrode, almost no enhancement is observed. Detailed analysis of structure and composition of electrolyte inside nanopores shows that the capacitance enhancement and the shape of differential capacitance strongly depend on the details of the ion chemical structure and a delicate balance of ion-surface and ion-ion interactions. © 2012 American Chemical Society.

Koner A.L.,University of Oxford | Krndija D.,University of Oxford | Hou Q.,South China Normal University | Sherratt D.J.,University of Oxford | Howarth M.,University of Oxford
ACS Nano | Year: 2013

Fluorescent nanoparticles have enabled many discoveries regarding how molecular machines function. Quantum dots have been the dominant class of fluorescent nanoparticles but suffer from blinking and from a substantial dark fraction - particles where the fluorescence is never seen - complicating any analysis of biological function. Nanoparticles composed of conjugated fluorescent polymers (Pdots) have recently been shown to have high brightness and no blinking. Here we develop a robust and efficient means to measure the dark fraction of Pdots, conjugating Atto dyes to the nanoparticles and testing fluorescence colocalization of dye and Pdot puncta. This established that the Pdots we generated had minimal dark fraction: ∼3%. The application of nanoparticles in biological environments is highly sensitive to surface functionalization. For Pdots we found that passivation with uncharged hydroxy-terminated polyethylene glycol caused a dramatic reduction in nonspecific cell binding and aggregation compared to a charged coating. Using carbonyl di-imidazole the hydroxy-Pdots were functionalized efficiently with streptavidin for high stability targeting, allowing specific labeling of mammalian cells. Type I insulin-like growth factor receptor (IGF1R) regulates cell survival and development, with roles in aging, heart disease, and cancer. We used hydroxy-Pdots to track the dynamics of IGF1R on a breast cancer cell-line, determining the diffusion characteristics and showing cholesterol-containing membrane nanodomains were important for receptor mobility at the plasma membrane. The near-unity bright fraction and low nonspecific binding of hydroxy-Pdots, combined with Pdot photostability and lack of blinking, provides many advantages for investigations at the single molecule level. © 2013 American Chemical Society.

Li X.,Cincinnati Childrens Hospital Medical Center | Li X.,South China Normal University | Sipple J.,Cincinnati Childrens Hospital Medical Center | Pang Q.,Cincinnati Childrens Hospital Medical Center | And 2 more authors.
Blood | Year: 2012

Salidroside is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea, which has potent antioxidant properties. Here we show that salidroside prevented the loss of hematopoietic stem cells (HSCs) in mice under oxidative stress. Quiescent HSCs were recruited into cell cycling on in vivo challenge with oxidative stress, which was blocked by salidroside. Surprisingly, salidroside does not prevent the production of reactive oxygen species but reduces hydrogen peroxide-induced DNAstrand breaks in bone marrow cells enriched for HSCs. We tested whether salidroside enhances oxidative DNAdamage repair in mice deficient for 5 DNA repair pathways known to be involved in oxidative DNA damage repair; we found that salidroside activated poly(ADPribose) polymerase-1 (PARP-1), a component of the base excision repair pathway, in mouse bone marrow HSCs as well as primary fibroblasts and human lymphoblasts. PARP-1 activation by salidroside protects quiescent HSCs from oxidative stress-induced cycling in native animals and self-renewal defect in transplanted recipients, which was abrogated by genetic ablation or pharmacologic inhibition of PARP-1. Together, these findings suggest that activation of PARP-1 by salidroside could affect the homeostasis and function of HSCs and contribute to the antioxidant effects of salidroside. © 2012 by The American Society of Hematology.

Wang Y.,Beijing Institute of Technology | Yin J.,South China Normal University
Nonlinear Analysis: Real World Applications | Year: 2011

In this paper, we investigate a class of degenerate parabolic periodic equations with nonlocal terms under Neumann boundary conditions. By using the theory of the Leray-Schauder degree, we obtain the existence of non-trivial nonnegative periodic solutions. © 2011 Elsevier Ltd. All rights reserved.

Sun H.,Guangzhou University | Lai J.-P.,South China Normal University | Fung Y.S.,University of Hong Kong
Journal of Chromatography A | Year: 2014

A novel method coupling molecular imprinting solid-phase extraction (MISPE) and micellar electrokinetic capillary chromatography (MEKC) was developed to enable the hourly determination of low level of ambient carbonyls, and study their partition between gaseous phase and particulate phase. With 2,4-dinitroaniline (DNAN) as dummy imprinting template, the unreacted 2,4-Dinitrophenylhydrazine (DNPH) in sampling solution could be removed effectively using MISPE, and an average recovery of 97. ±. 5.3% (n= 5) for the carbonyl-DNPH derivatives was achieved. Owing to the high enrichment due to sample clean-up, and the improvement of MEKC separation efficiency, many low abundant carbonyls could be detected by hourly in the field study. © 2014 Elsevier B.V.

Yu R.,Medical Research Council | Yu R.,South China Normal University | Calder A.J.,Medical Research Council | Mobbs D.,Medical Research Council | Mobbs D.,Columbia University
Human Brain Mapping | Year: 2014

Advantageous inequality (AI) aversion, or paying at a personal cost to achieve equal reward distribution, represents a unique feature of human behavior. Here, we show that individuals have strong preferences for fairness in both disadvantageous (DI) and advantageous inequality (AI) situations, such that they alter others' payoff at a personal financial cost. At the neural level, we found that both types of inequality activated the putamen, orbitofrontal cortex, and insula, regions implicated in motivation. Individual difference analyses found that those who spent more money to increase others' payoff had stronger activity in putamen when they encountered AI and less functional connectivity between putamen and both orbitofrontal cortex and anterior insula. Conversely, those who spent more money to reduce others' payoff had stronger activity in amygdala in response to DI and less functional connectivity between amygdala and ventral anterior cingulate cortex. These dissociations suggest that both types of inequality are processed by similar brain areas, yet modulated by different neural pathways. © 2013 Wiley Periodicals, Inc.

Li K.,South China Normal University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In order to promote the practical application of hybrid learning in colleges and universities in Guangdong, a study named “Hybrid learning application patterns in colleges and universities in Guangdong province” was carried out. This study, supported by education technology centers from colleges and universities in Guangdong province, adopts grounded theory analysis method of qualitative study in summing up several patterns of hybrid learning activities of teachers and students. The result of this study has a guiding significance and referential value to promote the teaching design and application of hybrid learning practice. © Springer International Publishing Switzerland 2015.

Cao Z.,South China University of Technology | Peng L.,South China Normal University
Journal of Convergence Information Technology | Year: 2010

Routing and scheduling act important roles in improving capacity and throughput in wireless mesh networks. In this paper, Cayley graph model is suggested for wireless Mesh Networks (WMN) with MIMO channels for efficient routing and fair scheduling. The model is based on the multiple interfaces, directional antennas, single channel mesh model. And the link edges or active edges can be viewed as connections between node pairs. A node can have as many links as its interface permits, but links are limited not conflicting with the interference model in wireless network. By placing edges into different channel plane virtually, the Cayley graph model allows a node to use maximum active edges under orthogonal channels. The model is helpful for WMN routing and scheduling schemes with the symmetry coding character in WMN. Consequently, layered active edge group scheduling algorithm and destination oriented routing schemes are proposed for maximum capacity and throughput. Furthermore, efficient transformations are used to take advantage of previous maximum active edge group scheduling for fairness.

You J.,South China Normal University | Lin M.-P.,National Taiwan Normal University
Journal of Consulting and Clinical Psychology | Year: 2015

Objective: This study predicted suicide attempts (SA) by time-varying frequency of nonsuicidal self-injury (NSSI) beyond the contributions of their shared risk factors and examined gender differences in this association. This study also tested for a moderating effect of NSSI in the relationship between suicide ideation (SI) and SA. Method: A large number of Chinese adolescents participated in this study (the exact number of participants varied from 3,623 to 6,911 in different analyses). They completed questionnaires assessing NSSI, SA, SI, borderline personality disorder features, depressive symptoms, and self-criticism 3 times at 6-month intervals. Generalized estimating equations were used to test the hypotheses. Results: In females, but not in males, NSSI was significantly associated with future SA after controlling for the effects of shared risk factors. With the same frequency of SI, the frequency of NSSI also enhanced the risk for future SA. Conclusions: This study established a longitudinal association between NSSI and SA, which could not be fully accounted for by their shared risk factors, in Chinese female community adolescents. Moreover, female adolescents who frequently engage in NSSI may gain the capability for attempting suicide. © 2014 American Psychological Association.

Zhang X.,South China Normal University | Zhang X.,University of Tennessee at Knoxville | Paquette M.R.,University of Memphis | Zhang S.,University of Tennessee at Knoxville
Journal of Foot and Ankle Research | Year: 2013

Background: Flip-flops and sandals are popular choices of footwear due to their convenience. However, the effects of these types of footwear on lower extremity biomechanics are still poorly understood. Therefore, the objective of this study was to investigate differences in ground reaction force (GRF), center of pressure (COP) and lower extremity joint kinematic and kinetic variables during level-walking in flip-flops, sandals and barefoot compared to running shoes. Methods: Ten healthy males performed five walking trials in the four footwear conditions at 1.3 m/s. Three-dimensional GRF and kinematic data were simultaneously collected. Results: A smaller loading rate of the 1st peak vertical GRF and peak propulsive GRF and greater peak dorsiflexion moment in early stance were found in shoes compared to barefoot, flip-flops and sandals. Barefoot walking yielded greater mediolateral COP displacement, flatter foot contact angle, increased ankle plantarflexion contact angle, and smaller knee flexion contact angle and range of motion compared to all other footwear. Conclusions: The results from this study indicate that barefoot, flip-flops and sandals produced different peak GRF variables and ankle moment compared to shoes while all footwear yield different COP and ankle and knee kinematics compared to barefoot. The findings may be helpful to researchers and clinicians in understanding lower extremity mechanics of open-toe footwear. © 2013 Zhang et al.; licensee BioMed Central Ltd.

Tu X.,Nanyang Technological University | Mario L.Y.,Nanyang Technological University | Mei T.,South China Normal University
Optics Express | Year: 2010

We theoretically investigate coupled Fano structures which combine the characteristics of both directly coupled Fabry-Perot cavities (DCFPC) and a side-coupled integrated spaced sequence of resonators (SCISSOR). Asymmetric and symmetric Fano resonances in a single and doubly-coupled Fano unit are analytically derived based on Fabry-Perot approach. It is found that doubly-coupled Fano units show a special asymmetric EIT-like lineshape. This structure shows an index changing sensitivity of 10 6 about two orders higher than that of the single Fano resonator, which is promising for index sensor application. A unique frequency detuning method of EIT like lineshape is also found in the doubly-coupled Fano units. The multiple coupled Fano unit structure demonstrates potentials for applications of tunable optical filter and slow light, whereas for the latter it shows much higher group delay than that of SCISSORS and DCFPC with the same parameters.© 2009 Optical Society of America.

Xian G.-M.,South China Normal University
Expert Systems with Applications | Year: 2010

This paper presents a combined discrete wavelet transform (DWT) and support vector machine (SVM) technique for mechanical failure classification of spherical roller bearing application in high performance hydraulic injection molding machine. The proposed technique consists of preprocessing the mechanical failure vibration signal samples using Db2 discrete wavelet transform at the fourth level of decomposition of vibration signal for mechanical failure classification. After feature extraction from vibration signal, support vector machine is used for decision of mechanical failure types of the spherical roller bearing. The classification results indicate the effectiveness of the combined DWT and SVM based technique for mechanical failure classification of hydraulic injection molding machine. © 2010 Published by Elsevier Ltd.

Liu W.,South China Normal University | Lin W.,Nanyang Technological University
IEEE Transactions on Image Processing | Year: 2013

Accurate estimation of Gaussian noise level is of fundamental interest in a wide variety of vision and image processing applications as it is critical to the processing techniques that follow. In this paper, a new effective noise level estimation method is proposed on the basis of the study of singular values of noise-corrupted images. Two novel aspects of this paper address the major challenges in noise estimation: 1) the use of the tail of singular values for noise estimation to alleviate the influence of the signal on the data basis for the noise estimation process and 2) the addition of known noise to estimate the content-dependent parameter, so that the proposed scheme is adaptive to visual signals, thereby enabling a wider application scope of the proposed scheme. The analysis and experiment results demonstrate that the proposed algorithm can reliably infer noise levels and show robust behavior over a wide range of visual content and noise conditions, and that is outperforms relevant existing methods. © 1992-2012 IEEE.

Yuan P.,South China Normal University | Ding C.,Hong Kong University of Science and Technology
Finite Fields and their Applications | Year: 2014

Permutation polynomials are an interesting subject of mathematics and have applications in other areas of mathematics and engineering. In this paper, we develop general theorems on permutation polynomials over finite fields. As a demonstration of the theorems, we present a number of classes of explicit permutation polynomials on Fq. © 2014 Elsevier Inc.

Yuan P.,South China Normal University | Ding C.,Hong Kong University of Science and Technology
Finite Fields and their Applications | Year: 2014

Let q be a power of 2, k a positive integer and let Sk=x+x q+⋯+xqk-1ε Fq[x]. In this paper, we present a number of classes of explicit permutation polynomials on Fq3 k, which are of the form L(x)+ S2k a + S2k b, where ε{1,qk,q2k}, bε{1,qk,q2k}, and L(x) are linearized polynomials. We also point out an application of these permutation polynomials in combinatorics, cryptography and sequences. © 2014 Elsevier Inc.

Chen X.,South China Normal University | Chen X.,Shanghai Normal University | Zhang H.,Shanghai Normal University | Ruan K.,Fujian Agriculture and forestry University | Shi W.,Shanghai Normal University
Journal of Alloys and Compounds | Year: 2012

We reported the annealing effect on the electrical behaviors of BiFeO 3 thin films integrated on LaNiO 3 (LNO) layers buffered Si substrates by sol-gel spin-coating technique. All the BiFeO 3 thin films exhibit the reversible bipolar resistive switching behaviors with Pt/BiFeO 3/LNO configuration. The electrical conduction mechanism of the devices was dominated by the Ohmic conduction in the low resistance state and trap-controlled space charged limited current in the high resistance state. Good diode-like rectification property was observed in device with BiFeO 3 film annealed at 500 °C, but vanished in device with BiFeO 3 film annealed at 600 °C. This was attributed to the asymmetrical contact between top and bottom interfaces as well as the distinct oxygen vacancy density verified by XPS. Furthermore, the modification of Schottky-like barrier due to the drift of oxygen vacancies was suggested to be responsible for the resistance switching behaviors of Pt/BiFeO 3/LNO devices. © 2012 Elsevier B.V. All rights reserved.

Ai B.-Q.,South China Normal University | He Y.-F.,Hebei University
Journal of Chemical Physics | Year: 2010

Transport of the Brownian particles driven by Ĺvy flights coexisting with subdiffusion in asymmetric periodic potentials is investigated in the absence of any external driving forces. Using the Langevin-type dynamics with subordination techniques, we obtain the group velocity which can measure the transport. It is found that the group velocity increases monotonically with the subdiffusive index and there exists an optimal value of the Ĺvy index at which the group velocity takes its maximal value. There is a threshold value of the subdiffusive index below which the ratchet effects will disappear. The nonthermal character of the Ĺvy flights and the asymmetry of the potential are necessary to obtain the directed transport. Some peculiar phenomena induced by the competition between Ĺvy flights and subdiffusion are also observed. The pseudonormal diffusion will appear on the level of the median. © 2010 American Institute of Physics.

Li X.,South China Normal University | Cao Y.,Sun Yat Sen University | Yang G.,Sun Yat Sen University
Physical Chemistry Chemical Physics | Year: 2010

A thermodynamic model has been proposed to address the transition from the two-dimensional to three-dimensional growth modes in the quantum dots self-assembly. It was found that the surface energy density of substrates and the mismatch between quantum dots and substrates play key roles in the transition of the growth modes. The high (low) surface energy density of substrate and the low (high) mismatch between quantum dots and substrate result in the large (small) critical thickness of the wetting layer, which further determines the growth mode of quantum dots. These findings suggested that we could control the transition of the quantum dots growth mode by substrate manipulation. The theoretical results were consistent with experimental observations, which implied that the established thermodynamic theory could be expected to be a general approach for pursuing the evolution of the growth mode in the quantum dots self-assembly. © the Owner Societies.

Wu C.,University of Washington | Hansen S.J.,Fred Hutchinson Cancer Research Center | Hou Q.,South China Normal University | Yu J.,Clemson University | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2011

Lighting up brain tumors: Highly fluorescent nanodots that consist of semiconducting polymer blends were attached to the peptide ligand chlorotoxin. The nanodot-chlorotoxin conjugates were specifically targeted to malignant brain tumors in a transgenic mouse model, thus proving their potential as in vivo probes for clinical cancer diagnostics (see picture). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shi C.,Hainan Normal University | Dai X.,Sun Yat Sen University | Liang P.,Sun Yat Sen University | Liang P.,JiShou University | Zhang H.,South China Normal University
IEEE Transactions on Wireless Communications | Year: 2012

How to improve the short-term fairness and increase the aggregated throughput simultaneously is a major problem in WLANs, yet has not been solved satisfactorily in previous work, especially in the situation that network loads vary significantly. To improve the performance in saturation state, we propose a novel access mechanism that sets an optimal Contention Window (CW) for all nodes in the network. By introducing a new parameter of CW Index (CWI), we present a linear CW adjustment rule based on the active node number and then develop an estimation algorithm of node number with three thresholds. Compared to previous algorithms, the new algorithm predicts the future node number based on the current network status, thus minimizes the fluctuating effect of idle slot intervals observed at each process. Moreover, it can identify the dense degree of idle slot intervals and track the changes of the accurate node number quickly. By selecting the optimal CWI adaptively, the maximum aggregated throughput keeps basically a constant despite the variation of the number of nodes. Meanwhile, by eliminating multiple transmission attempts of the same node, the short-term fairness is improved significantly. To evaluate the mechanism, we derive closed-form expressions for the network performance. The simulation results demonstrate the validity and good scalability of the proposed access mechanism. © 2012 IEEE.

Yu R.,MRC Cognition and Brain science Unit | Yu R.,South China Normal University | Mobbs D.,MRC Cognition and Brain science Unit | Mobbs D.,Columbia University | And 5 more authors.
Cortex | Year: 2014

Mammalian studies show that frustration is experienced when goal-directed activity is blocked. Despite frustration's strongly negative role in health, aggression and social relationships, the neural mechanisms are not well understood. To address this we developed a task in which participants were blocked from obtaining a reward, an established method of producing frustration. Levels of experienced frustration were parametrically varied by manipulating the participants' motivation to obtain the reward prior to blocking. This was achieved by varying the participants' proximity to a reward and the amount of effort expended in attempting to acquire it. In experiment 1, we confirmed that proximity and expended effort independently enhanced participants' self-reported desire to obtain the reward, and their self-reported frustration and response vigor (key-press force) following blocking. In experiment 2, we used functional magnetic resonance imaging (fMRI) to show that both proximity and expended effort modulated brain responses to blocked reward in regions implicated in animal models of reactive aggression, including the amygdala, midbrain periaqueductal grey (PAG), insula and prefrontal cortex. Our findings suggest that frustration may serve an energizing function, translating unfulfilled motivation into aggressive-like surges via a cortical, amygdala and PAG network. © 2014 Elsevier Ltd.

Chen X.,South China Normal University | Hu W.,Sun Yat Sen University | Wu S.,Sun Yat Sen University | Bao D.,Sun Yat Sen University
Applied Physics Letters | Year: 2014

In this work, amorphous MgZnO/ZnO heterostructure films were deposited on Pt/TiO2/SiO2/Si at room temperature. By programming the proper compliance current, bipolar resistive switching performances of TiN/MgZnO/ZnO/Pt devices were stabilized; the dispersion of switching voltages and resistance states of devices were suppressed simultaneously. In view of filamentary model, the elimination of secondary and multiple nanofilaments in higher compliance current was suggested to be responsible for the observed improvement. Furthermore, the good endurance and retention behaviors of the optimized TiN/MgZnO/ZnO/Pt devices were confirmed, ensuring its potential application for resistive random access memory. This simple optimizing method by programming proper compliance current is promising for resistive switching devices required avoiding damage. © 2014 AIP Publishing LLC.

Shan X.-Z.,South China Normal University
Habitat International | Year: 2014

The motives of people for visiting urban green spaces (UGS) mirror their needs and expectations on UGS, which help to ascertain why people patronize UGS in the way they do. Such knowledge can promote effective decision making in satisfying the public needs and anticipations for UGS. However, the efforts to address the motives for visiting UGS are limited, whereby less attention is given to the related socio-demographic variations. This study concentrated on the motives for visiting UGS and the relevant differences across social groups in Guangzhou, China. Data were obtained from the responses of 595 visitors by using stratified random sampling, and in-person questionnaire survey at 24 UGS across the city. The results indicated that the nature- and exercise-dominated multiple motives call for multi-purpose management and multifunctional planning and design of the UGS. The significant variations in the motives for visiting were associated with the socio-demographic factors. Decision-makers should seriously consider the particular needs and expectations of the diverse groups, and consider these factors in the decision-making process concerning UGS. Further work could investigate non-users and associations of age and characteristics of UGS with motives for visiting. With complexities of cities, more attention needs to be given to the use of consistent methodologies in future research to obtain comparable findings and further generalizations. © 2013 Elsevier Ltd.

Li M.,CAS South China Botanical Garden | Li Y.,CAS South China Botanical Garden | Li Y.,Xinjiang University | Li H.,South China Normal University | Wu G.,CAS South China Botanical Garden
Tree Physiology | Year: 2011

Paper mulberry (Broussonetia papyrifera L. Vent) is well known for its bark fibers, which are used for making paper, cloth, rope, etc. It was found that, in addition to its well-documented role in the enhancement of plant salt tolerance, overexpression of the Na+/H+ antiporter (AtNHX5) gene in paper mulberry plants showed high drought tolerance. After exposure to water deficiency and salt stress, the wild-type (WT) plants all died, while the AtNHX5-overexpressing plants remained alive under high salt stress, and had a higher survival rate (>66) under drought stress. Measurements of ion levels indicated that Na+ and K+ contents were all higher in AtNHX5-overexpressing leaves than in WT leaves in high saline conditions. The AtNHX5 plants had higher leaf water content and leaf chlorophyll contents, accumulated more proline and soluble sugars, and had less membrane damage than the WT plants under water deficiency and high saline conditions. Taken together, the results indicate that the AtNHX5 gene could enhance the tolerance of paper mulberry plants to multiple environmental stresses by promoting the accumulation of more effective osmolytes (ions, soluble sugars, proline) to counter the osmotic stress caused by abiotic factors. © The Author 2011. Published by Oxford University Press. All rights reserved.

Yuan P.,South China Normal University | Zeng X.,Sun Yat Sen University
Finite Fields and their Applications | Year: 2011

Kai Zhou (2008) [8] gave an explicit representation of the class of linear permutation polynomials and computed the number of them. In this paper, we give a simple proof of the above results. © 2011 Elsevier Inc. All rights reserved.

Zhu Q.,Ningbo University | Yang X.,Honghe University | Wang H.,South China Normal University
Journal of the Franklin Institute | Year: 2010

In this paper we study stochastic stability of delayed recurrent neural networks with both Markovian jump parameters and nonlinear disturbances. Based on the Lyapunov stability theory, the properties of a Brownian motion, the generalized It's formula and linear matrix inequalities technique, some new delay-dependent conditions are derived to guarantee the stochastically asymptotic stability of the trivial solution or zero solution. In particular, the activation functions in this paper depend on Markovian jump parameters and they are more general than those usual Lipschitz conditions. Also, time delays proposed in this paper comprise both constant delays and time-varying delays. Moreover, the derivative of time delays is allowed to take any value. Therefore, the results obtained in this paper are less conservatism and generalize those given in the previous literature. Finally, two numerical examples and their simulations are used to show the effectiveness of the obtained results. © 2010 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Xue Z.-Y.,South China Normal University
International Journal of Theoretical Physics | Year: 2010

We propose, in analogy with trapped ions, scalable quantum computation schemes with superconducting charge qubits couple to a micro-wave cavity mode. Single-qubit addressing can be achieved and selective qubit-cavity coupling can be effectively controlled by the external magnetic flux, thus gate operations can be selectively performed. During the implementation of a certain (virtual) excitation operation all the qubits and cavity parameters can be chosen to be fixed, the only parameter needs to be tunable is the external magnetic flux. This is a more efficient way of controlling the system dynamics as it is much easier for experimental realization. © Springer Science+Business Media, LLC 2010.

Zhang D.D.,University of Hong Kong | Lee H.F.,University of Hong Kong | Wang C.,Jinan University | Li B.,South China Normal University | And 3 more authors.
Global Ecology and Biogeography | Year: 2011

Aim It has long been assumed that deteriorating climate (cooling and warming above the norm) could shrink the carrying capacity of agrarian lands, depriving the human population of sufficient food. Population collapses (i.e. negative population growth) follow. However, this human-ecological relationship has rarely been verified scientifically, and evidence of warming-caused disaster has never been found. This research sought to explore quantitatively the temporal pattern, spatial pattern and triggers of population collapses in relation to climate change at the global scale over 1100 years. Location Various countries/regions in the Northern Hemisphere (NH) during the pre-industrial era. Methods We performed time-series analysis to examine the association between temperature change and country-wide/region-wide population collapses in different climatic zones. All of the known population collapse incidents in the NH in the period ce 800-1900 were included in our data analysis. Results Nearly 90% of population collapses in various NH countries/regions occurred during periods of climate deterioration characterized by shrinking carrying capacity of the land. In addition, we found that cooling dampened the human ecosystem and brought about 80% of the collapses in warmer humid, cooler humid and dry zones, while warming adversely affected the ecosystems in dry and tropical humid zones. All of the population collapses and growth declines in periods of warm climate occurred in dry and tropical humid zones. Malthusian checks (famines, wars and epidemics) were the dominant triggers of population collapses, which peaked dramatically when climate deteriorated. Main conclusions Global demographic catastrophes and most population collapse incidents occurred in periods with great climate change, owing to overpopulation caused by diminished carrying capacity of the land and the resultant outbreak of Malthusian checks. Impacts of cooling or warming on land carrying capacity varied geographically, as a result of the diversified ecosystems in different parts of the Earth. The observed climate-population synchrony challenges Malthusian theory and demonstrates that it is not population growth alone but climate-induced subsistence shortage and population growth working synergistically, that cause large-scale human population collapses on the long-term scale. © 2010 Blackwell Publishing Ltd.

Li Q.,Chinese Academy of Sciences | Li D.,South China Normal University
Operations Research Letters | Year: 2011

In this paper we propose a projected semismooth Newton method to solve the problem of calibrating least squares covariance matrix with equality and inequality constraints. The method is globally and quadratically convergent with proper assumptions. The numerical results show that the proposed method is efficient and comparable with existing methods. © 2011 Elsevier B.V. All rights reserved.

Daochun S.,South China Normal University
Acta Mathematica Scientia | Year: 2010

By using the definition of Hausdorff distance, we prove some normality criteria for families of meromorphic algebroid functions. Some examples are given to complement the theory in this article. © 2010 Wuhan Institute of Physics and Mathematics.

Daochun S.,South China Normal University | Zongsheng G.,Beihang University
Acta Mathematica Scientia | Year: 2010

In this article, we first investigate the operational properties of algebroid functions. Then we prove two uniqueness theorems for algebroid functions. © 2010 Wuhan Institute of Physics and Mathematics.

Yan Y.,Ocean University of China | Xu Y.,Ocean University of China | Yi Z.,South China Normal University | Warren A.,Natural History Museum in London
International Journal of Systematic and Evolutionary Microbiology | Year: 2013

Three trachelocercid ciliates, Kovalevaia sulcata (Kovaleva, 1966) Foissner, 1997, Trachelocerca sagitta (Müller, 1786) Ehrenberg, 1840 and Trachelocerca ditis (Wright, 1982) Foissner, 1996, isolated from two coastal habitats at Qingdao, China, were investigated using live observation and silver impregnation methods. Data on their infraciliatüre and morphology are supplied. The small subunit rRNA (SSU rRNA) genes of K. sulcata and Trachelocerca sagitta were sequenced for the first time. Phylogenetic analyses based on SSU rRNA gene sequence data indicate that both organisms, and the previously sequenced Trachelocerca ditis, are located within the trachelocercid assemblage and that K. sulcata is sister to an unidentified taxon forming a clade that is basal to the core trachelocercids. © 2013 IUMS.

Ye J.,South China Normal University | Kaattari I.M.,Virginia Institute of Marine Science | Ma C.,Chinese Academy of Fishery Sciences | Kaattari S.,Virginia Institute of Marine Science
Fish and Shellfish Immunology | Year: 2013

Over the past 10 years our knowledge of cellular and molecular dynamics of teleost humoral immunity has increased enormously to now include: the existence of multiple isotypes, affinity-driven modulation of antibody structure and function, the unique trafficking patterns of each stage of B cell differentiation (including the plasmablast, short-lived and long-lived plasma cell, and the memory cell). Unfortunately the work which has generated the bulk of this information has generally employed defined antigens rather than vaccines. Thus, the focus of this review is to relate these aspects of immunity that are requisite for a mechanistic understanding of the generation of prophylactic immunity to the necessary analysis of responses to vaccines and vaccine candidates. © 2013 Elsevier Ltd.

Li X.,South China Normal University
Journal of Applied Physics | Year: 2012

We present a thermodynamic approach to elucidate the effects of the size and shape of nanoparticles (NPs) on endocytosis. It is found that endocytosis needs to surmount a thermodynamic energy barrier and has a minimum radius of NPs for endocytosis. Through referring to the concept of diffusion length of receptors, we obtain a simple and analytical expression for the optimal size of NPs. Furthermore, a phase diagram has been constructed, which can clarify the interrelated effects of the radius and the aspect ratio of NPs. We can identify from the phase the relation between the geometry of NP and its endocytosis rate. The theoretical results are in good agreement with the experimental observations and reveal physical mechanisms involved in the effects of the size and shape of NPs on endocytosis, which implies that these studies may provide useful guidance to the conscious design of NPs for diagnostic agents and drug delivery applications. © 2012 American Institute of Physics.

Xing L.,University of Utah | Xing L.,South China Normal University | Borodin O.,U.S. Army
Physical Chemistry Chemical Physics | Year: 2012

The oxidation induced reactions of the common lithium battery electrolyte solvent ethylene carbonate (EC) have been investigated for EC 2 using density functional theory and for selected reaction paths using Moller-Plesset perturbation theory (MP4). The importance of explicitly treating at least one solvent molecule interacting with EC during oxidation (removal of an electron) on the EC oxidation potential and decomposition reactions was shown by comparing oxidation of EC and EC 2. Accuracy of DFT results was evaluated by comparing with MP4 and G4 values for oxidation of EC. The polarized continuum model (PCM) was used to implicitly include the rest of the surrounding solvent. The oxidation potentials of EC 2 and EC 4 were found to be significantly lower than the intrinsic oxidation potential of an isolated EC and also lower than the oxidation potential of EC-BF 4 -. The exothermic proton abstraction from the ethylene group of EC by the carbonyl group of another EC was responsible for the decreased oxidative stability of EC 2 and EC 4 compared to EC. The most exothermic path with the smallest barrier for EC 2 oxidation yielded CO 2 and an ethanol radical cation. The reaction paths with the higher barrier yielded oligo(ethylene carbonate) suggesting a pathway for the experimentally observed poly(ethylene carbonate) formation of EC-based electrolytes at cathode surfaces. © 2012 the Owner Societies.

Luo Q.,South China Normal University | Luo Q.,Beijing Institute of Technology
Physical Chemistry Chemical Physics | Year: 2012

The neutral carbon aluminium cluster Al 3C and its anion Al 3C - have been investigated at the B3LYP/6-311+G(d) and BP86/6-311+G(d) levels of theory. It is suggested that the C 2v neutral cluster Al 3C could be considered as a pseudohalogen superatom with a smaller electron affinity than the iodine atom. The DFT calculation results confirm that, similar to the halogen atoms, the pseudohalogen superatom Al 3C cluster could form the compounds corresponding to the dimer, salts, interhalogen compounds, oxides, acid radicals, and coordination complexes as well as superatom compounds of halogen, showing that Al 3C has similar chemical properties to halogens and maintains its integrity in the related reactions. Based on the maintenance of integrity in the chemical assemblies [(Al 3C)(KCAl 3) n] - (n = 1-5), it could be anticipated that the neutral cluster Al 3C holds great potential as a building block for the development of future nanostructured materials. Further, corresponding experimental verifications are invited. This journal is © 2012 the Owner Societies.

Xue Z.-Y.,South China Normal University
European Physical Journal D | Year: 2013

We propose a scheme to implement controlled not gate for topological qubits in a quantum-dot and Majorana fermion hybrid system. Quantum information is encoded on pairs of Majorana fermions, which live on the the interface between topologically trivial and nontrivial sections of a quantum nanowire deposited on an s-wave superconductor. A measurement based two-qubit controlled not gate is produced with the help of parity measurements assisted by the quantum-dot and followed by prescribed single-qubit gates. The parity measurement, on the quantum-dot and a topological qubit, is achieved by the Aharonov-Casher effect. © 2013 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

Jiang L.,South China Normal University
Plant signaling & behavior | Year: 2012

Daylight UV-B (UV-B) radiation (280-315 nm) is, because of its photochemical effects and potential destructive impact, an important environmental factor for plants. After decades of fruitless attempts, a receptor molecule, UVR8, for sensing of ambient UV-B radiation by plants has been characterized, and the initial steps in signal transduction have been identified. There are, however, other signaling pathways, and there are apparent contradictions in the literature. There is still much to find out about the complex signaling network in plants for processing of information about the daylight surrounding them.

Chen Y.,South China Normal University | Lu Z.,Chongqing Three Gorges University
Finite Elements in Analysis and Design | Year: 2010

In this paper we study the fully discrete mixed finite element methods for quadratic convex optimal control problem governed by parabolic equations. The space discretization of the state variable is done using usual mixed finite elements, whereas the time discretization is based on difference methods. The state and the co-state are approximated by the lowest order RaviartThomas mixed finite element spaces and the control is approximated by piecewise constant functions. By applying some error estimates techniques of standard mixed finite element methods, we derive a priori error estimates both for the coupled state and the control approximation. Finally, we present some numerical examples which confirm our theoretical results. © 2010 Elsevier B.V. All rights reserved.

Zhang Y.,Nanyang Technological University | Mei T.,South China Normal University | Zhang D.H.,Nanyang Technological University
Applied Optics | Year: 2012

The temporal coupled-mode theory (TCMT) for a ring-bus-ring Mach-Zehnder interferometer device is developed by taking energy conservation into account. The intercavity interaction in the device is facilitated via a tricoupler, which makes the decay of modes quantitatively different from that in other existing resonator schemes. The TCMT is related to the transfer matrix formalism with energy conservation and the Q factor, and it predicts results in good agreement with the experimental results. The mode analysis from the TCMT is quite illustrative because it can mimic the transparency as an electromagnetically induced transparency expression. The analysis of the tricoupler is applicable for analyzing the transparent resonance in two other similar configurations. © 2012 Optical Society of America.

Chen Y.,South China Normal University | Lu Z.,Xiangtan University
Computer Methods in Applied Mechanics and Engineering | Year: 2010

In this paper we study the fully discrete mixed finite element methods for quadratic convex optimal control problem governed by semilinear parabolic equations. The space discretization of the state variable is done using usual mixed finite elements, whereas the time discretization is based on difference methods. The state and the co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise constant elements. By applying some error estimates techniques of mixed finite element methods, we derive a priori error estimates both for the coupled state and the control approximation. Finally, we present a numerical example which confirms our theoretical results. © 2009.

Li G.-B.,Sun Yat Sen University | Liu J.-M.,Sun Yat Sen University | Cai Y.-P.,South China Normal University | Su C.-Y.,Sun Yat Sen University
Crystal Growth and Design | Year: 2011

A series of Mn(II), Cd(II), and Co(II) metal-organic frameworks, namely, {[Mn(L1)(NCS)2(CH3OH)2] ·2(CH3OH)}n (1), {[Mn(L2) 2(NCS)2(CH3OH)2]}n (2), {[Mn(L3)2(NCS)2] ·0.5(CH3OH) ·4.5H2O}n (3), {[Cd(L1)(I)2] ·3(H2O)}n (4), {[Cd(L2)(I) 2]}n (5), {[Cd(L3)(NCS)2] ·2.5(H2O)}n (6), {[Co(L1) 2(NCS)2] ·4(H2O)}n (7), {[Co(L2)2(NCS)2] · (HCCl3) }n (8), and {[Co(L3)2(NCS)2] ·3(H2O)}n (9) (where L1 = N,N′-bis(4-pyridylmethyl)-pyromellitic diimide, L2 = N,N′-bis(3-pyridylmethyl)-pyromellitic diimide, L3 = N,N′-bis(4-pyridylmethyl)-naphthalene diimide), were synthesized and structurally characterized by elemental analyses, thermogravimetric (TG) analyses, powder X-ray diffraction, IR spectroscopy, and single-crystal X-ray diffraction. In Mn(II) complexes 1-3, L1 connects the adjacent metal centers to form an infinite one-dimensional (1D) zigzag coordination polymeric chain, L2 acts as a monodentate ligand to give mononuclear coordination motifs, while L3 bridges two metal ions to generate two-dimensional (2D) networks of the (4, 4) net topology containing rhombic grids. In Cd(II) complexes 4-6, L1, L2, and L3 act as bidentate ligands and coordinate with two metal ions to form three different coordination polymers that display diversified structures, that is, infinite 1D zigzag chain in 4, single-stranded double helical chain in 5, and 2D networks of the (4, 4) net in 6. For three Co(II) complexes, 7 is a three-dimensional (3D) framework with 3-fold interpenetrating dia topology, while 8 and 9 have similar two-dimensional (2D) networks of the (4, 4) net topology. The results show that the conformation and coordination mode of organic ligands and the coordination geometry of metal centers play important roles in determining the structure and topology of the complexes. Furthermore, the gas sorption properties were measured, and complex 7 shows a highly selective sorption behavior toward CO2, which can be a promising candidate as adsorbents for CO2/N2 separation. In addition, the luminescence properties of 5-6 were studied in the solid state at room temperature. © 2011 American Chemical Society.

Fu W.,South China Normal University
Annals of Regional Science | Year: 2016

Taking the entrepreneurial activities as a local phenomenon, this paper aims to investigate the way that individual’s active embeddedness in cluster environment influences on the entrepreneurial intentions and locational preference of the nascent entrepreneurs. Drawing on the employee survey data in the Tianhe Software Park in Guangzhou, China, the empirical results have distinguished between impacts of cluster on nurturing and anchoring nascent entrepreneurs. Firstly, it has been shown that the awareness of role model entrepreneurs in the cluster enhances the entrepreneurial intentions of the employees. Secondly, the embeddedness in personal relations with suppliers and customers has proven to exert significant impact in the locational preferences toward the cluster of origin. Overall, the findings of the paper have shed light on how cluster environment poses its impact on nascent entrepreneurs through different mechanisms in the different decision-making processes. The implications of the findings for entrepreneurial policy are discussed in the concluding section. © 2016, Springer-Verlag Berlin Heidelberg.

Xu Y.,Australian National University | Xu Y.,South China Normal University | Miroshnichenko A.E.,Australian National University | Desyatnikov A.S.,Australian National University
Optics Letters | Year: 2012

We study the transmission properties of a one-dimensional array with intersite side-coupled defect and demonstrate that, as the system undergoes sharp Fano resonance, it exhibits geometry-induced vorticity of the energy flux. The optical vortex inverts its handedness at the Fano resonance, revealing a strong link between two phenomena, both being of interference origin. Our approach is quite general and can be applied to a variety of systems; as an example we demonstrate a similar effect in photonic crystal structure. © 2012 Optical Society of America.

Huang R.,South China Normal University
World Transactions on Engineering and Technology Education | Year: 2015

Smart education is an advanced application in the development of information systems for education. As an important part of life-long education, adult education also is increasingly influenced by smart education. By analysing the nature and characteristics of smart education, the work presented in this article probed the application of new information technology to adult education. These include cloud computing, the internet of things, big data and the mobile Internet. The work has considered the characteristics of adult learning to construct an adult smart education system and explored the smart adult education environment. © 2015 WIETE.

Deng J.,South University of Science and Technology of China | Wang K.,South University of Science and Technology of China | Wu D.,Nanyang Technological University | Lv X.,South China Normal University | And 4 more authors.
Optics Express | Year: 2015

Focus on the phase reconstruction from three phase-shifting interferograms with unknown phase shifts, an advanced principal component analysis method is proposed. First, use a simple subtraction operation among interferograms, two intensity difference images are obtained easily. Second, set the center region of the data of intensity difference images to zero, and then construct a covariance matrix to obtain a transformation matrix. Third, two principal components of interferograms can be determined by the Hotelling transform and then phase can be calculated from the two normalized principal components by an arctangent function. By means of the simulation calculation and the experimental research, it is proved that the phase with high precision can be obtained rapidly by the proposed algorithm. © 2015 Optical Society of America.

Liu L.,South China Normal University
Optics Express | Year: 2015

A densely packed waveguide array (DPWA) structure for mode division multiplexing on a silicon chip is proposed. The DPWA consists of several narrow waveguides with different widths, which are densely packed with gaps of 100nm. The lateral dimension of the DPWA is comparable to the conventional multimode waveguide used for mode division multiplexing on silicon. An efficient and parallel (de)multiplexing structure is proposed. For a three-mode DPWA with a 15μm-long (de)multiplexing structure, insertion losses of -0.05dB and cross-talks of -20dB are achievable for all the modes in a wide wavelength range. The present DPWA favors a compact direct bending. In a 45μm-radius 90° bend, insertion losses of -0.1dB and cross-talks of -20dB are obtained. The proposed DPWA structure also shows a large fabrication tolerance. © 2015 Optical Society of America.

Lin J.,South China University of Technology | Ding S.,South China Normal University
Mathematical Methods in the Applied Sciences | Year: 2012

In recent paper, we prove the well-posedness for the heat flow of harmonic maps with initial data u 0 ∈ W 1,n(R n,N) and for the hydrodynamic flow of nematic liquid crystals with initial data (v0,d0)∈L n(Rn)× W 1,n(R n,S 2). © 2011 John Wiley & Sons, Ltd.

Han P.,South China Normal University
Journal of vision | Year: 2013

Gaze-contingent display paradigms play an important role in vision research. The time delay due to data transmission from eye tracker to monitor may lead to a misalignment between the gaze direction and image manipulation during eye movements, and therefore compromise the contingency. We present a method to reduce this misalignment by using a compressed exponential function to model the trajectories of saccadic eye movements. Our algorithm was evaluated using experimental data from 1,212 saccades ranging from 3° to 30°, which were collected with an EyeLink 1000 and a Dual-Purkinje Image (DPI) eye tracker. The model fits eye displacement with a high agreement (R2 > 0.96). When assuming a 10-millisecond time delay, prediction of 2D saccade trajectories using our model could reduce the misalignment by 30% to 60% with the EyeLink tracker and 20% to 40% with the DPI tracker for saccades larger than 8°. Because a certain number of samples are required for model fitting, the prediction did not offer improvement for most small saccades and the early stages of large saccades. Evaluation was also performed for a simulated 100-Hz gaze-contingent display using the prerecorded saccade data. With prediction, the percentage of misalignment larger than 2° dropped from 45% to 20% for EyeLink and 42% to 26% for DPI data. These results suggest that the saccade-prediction algorithm may help create more accurate gaze-contingent displays.

Yu R.,South China Normal University
Behavioral and Brain Sciences | Year: 2013

McCullough et al. argue that revenge has a future-oriented function, that is, to deter future harms by changing other individuals' incentives toward the self. Recent research has shown that people seek revenge even when harms are unintentional. This commentary reports these results and proposes that revenge may also serve to reduce the immediate psychological pain resulting from unfair treatment. © 2013 Cambridge University Press.

Li X.,South China Normal University | Wu J.,University of Electronic Science and Technology of China | Wang Z.M.,University of Electronic Science and Technology of China | Wang Z.M.,University of Arkansas | And 4 more authors.
Nanoscale | Year: 2014

Creating and manipulating materials at the nanoscale with controllable size, shape and nucleation site is an important task to meet the urgent demands for quantum structures with designed properties. In the last ten years, droplet epitaxy has been emerging as a versatile fabrication method for various complex nanostructures, such as quantum dots, quantum rings, double-rings, and so on. However, there is a lack of understanding of the deep nanohole formation based on droplet epitaxy at a high substrate temperature. Here we fabricate self-organized GaAs nanoholes by Ga droplet etching at high temperature based on droplet epitaxy, and they present good optoelectronic properties and have promising applications in fabrication of nanodevices due to their unique topology. A theoretical model is correspondingly proposed to explain the basic mechanism and simulate the time evolution of the nanohole structures. Our analysis shows that the morphology of the nanohole nanostructures can be well controlled through regulating experimental conditions. © 2014 The Royal Society of Chemistry.

Ouyang S.-G.,South China Normal University
Wuli Xuebao/Acta Physica Sinica | Year: 2013

The propagation and interaction properties of optical vortex solitons in a self-defocusing Kerr-type nonlocal medium are investigated by the numerical simulation method. It is indicated that the singly charged vortices are stable and the multicharged vortices are topologically unstable in both the nonlocal and local cases. And in the nonlocal and local cases the point vortices model is applicable for describing the interactions of vortices provided that the interval distances between vortices are much larger than the size of the core of the vortices. However, vortices interact differently in short distance, depending on the nonlocality, and the larger the characteristic nonlocal respond length, the larger the rotating period of two singly charged vortices. © Chinese Physical Society.

Lu D.-Q.,South China Normal University
Wuli Xuebao/Acta Physica Sinica | Year: 2013

The analytical solution for the shape-variant astigmatic elliptical breathers in strongly nonlocal nonlinear medium is obtained, and the propagation properties of this type of breather is investigated according to the solution. During propagation, the beam in x- and y-direction keeps Gaussian, the beam width and the curvature of the cophasal line vary periodically but asynchronously. For the two-dimensional off-waist input case, the initial convergence (divergence) makes the width narrowed (broaden) first near the entrance plane, no matter what the input power is; then varies periodically but asynchronously in x- and y-direction. For the one-dimensional on-waist input case, the beam might breathe only in one direction. The breather of the beam width induces the periodical variation of the curvature for the elliptically cophasal surface and the ellipticity of the pattern. If the location of the waist in x-direction and that in y-direction are identical with each other, the product of the maximum and the minimum of the ellipticity keeps equal to unify. In this case, the position of the entrance plane does not affects the maxima and the minima of the ellipticity, but affects the uniformity for the variation velocity of the ellipticity in a period. © 2013 Chinese Physical Society.

He M.,South China Normal University | Zhang S.-J.,Northeast Normal University
Journal of Pragmatics | Year: 2011

The present study adopts a new approach to face-analysis, originally proposed by Spencer-Oatey (2007:639-656) in light of identity theories, to analyze and re-conceptualize the Chinese concept of face based on data collected from a modern Chinese TV drama. The results reveal that miànzi in Chinese culture is inherently associated with the respectable identity and/or status that an individual establishes, and many Chinese miànzi phenomena can be explained and understood in terms of people's attributes or characteristics from a miànzi-sensitive perspective on identity theory. Its findings also indicate that Chinese people tend to be miànzi-sensitive about those attributes or characteristics foregrounded in social interactions of their own, as well as those of their family members, close friends, colleagues, and social groups. Based on these categories of miànzi-sensitive factors, this paper concludes that the Chinese concept of face, as a holistic term, can be categorized as individual, relational, and group miànzi. © 2011 Elsevier B.V.

Huang T.,University of Kentucky | Wang C.,University of Kentucky | Wen H.,South China Normal University
Archive for Rational Mechanics and Analysis | Year: 2012

In this paper, we consider the short time strong solution to a simplified hydrodynamic flow modeling compressible, nematic liquid crystal materials in dimension three. We establish a criterion for possible breakdown of such solutions at a finite time in terms of the temporal integral of both the maximum norm of the deformation tensor of the velocity gradient and the square of the maximum norm of the gradient of a liquid crystal director field. © 2011 Springer-Verlag.

Pan H.,South China Normal University | Xing R.,Sun Yat Sen University
Nonlinear Analysis: Real World Applications | Year: 2012

In this paper, we consider a one-dimensional prescribed mean curvature problem related to MEMS models. We obtain all exact multiplicity for classical solutions and non-classical solutions when the length L of the interval and the parameter λ change. As a by-product, it also provides a complete analytic proof for an interesting new phenomenon, which is first noticed by Brubaker and Pelesko. Our methods are based on a detailed analysis of time maps. © 2012 Elsevier Ltd. All rights reserved.

Shu Y.,South China Normal University | Lam Nina S.N. N.S.N.,Louisiana State University
Atmospheric Environment | Year: 2011

Detailed estimates of carbon dioxide emissions at fine spatial scales are critical to both modelers and decision makers dealing with global warming and climate change. Globally, traffic-related emissions of carbon dioxide are growing rapidly. This paper presents a new method based on a multiple linear regression model to disaggregate traffic-related CO 2 emission estimates from the parish-level scale to a 1×1km grid scale. Considering the allocation factors (population density, urban area, income, road density) together, we used a correlation and regression analysis to determine the relationship between these factors and traffic-related CO 2 emissions, and developed the best-fit model. The method was applied to downscale the traffic-related CO 2 emission values by parish (i.e. county) for the State of Louisiana into 1-km 2 grid cells. In the four highest parishes in traffic-related CO 2 emissions, the biggest area that has above average CO 2 emissions is found in East Baton Rouge, and the smallest area with no CO 2 emissions is also in East Baton Rouge, but Orleans has the most CO 2 emissions per unit area. The result reveals that high CO 2 emissions are concentrated in dense road network of urban areas with high population density and low CO 2 emissions are distributed in rural areas with low population density, sparse road network. The proposed method can be used to identify the emission " hot spots" at fine scale and is considered more accurate and less time-consuming than the previous methods. © 2010 Elsevier Ltd.

Li X.,South China Normal University
Journal of Applied Physics | Year: 2012

Considering the influence of atomic interactions in out-of-plane on surface energy between the layers of nanostructures underneath surface, we establish a thermodynamic model to elucidate its applications in various nanostructures, e.g., nanocrystals with positive curvature, nanocavities with negative curvature, etc. It has been found that the size and surface morphology of nanostructures play the key role in the surface energy, which results in the surface energy that decreases with decreasing size of nanoparticles, nanowires, and nanofilms, but increases with decreasing size of the nanopipes and nanocavities. The theoretical predictions are well consistent with other existing theoretical models, implying that the model could be expected to be a general approach to understand surface energy in nanomaterials. © 2012 American Institute of Physics.

Liu G.,Hebei University of Science and Technology | Hao N.,CAS Institute of Physics | Hao N.,Purdue University | Zhu S.-L.,South China Normal University | And 2 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We propose a scenario to create a topological superfluid in a periodically driven two-dimensional square optical lattice. We study the phase diagram of a spin-orbit coupled s-wave pairing superfluid in a periodically driven two-dimensional square optical lattice. We find that a phase transition from a trivial superfluid to a topological superfluid occurs when the potentials of the optical lattices are periodically changed. The topological phase is called the Floquet topological superfluid and can host Majorana fermions. © 2012 American Physical Society.

Luo W.,South China Normal University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Spectral unmixing in hyperspectral remote sensing image has been widely researched in the last two decades. N-FINDR algorithm is one of the most classical and commonly-used endmember extraction algorithms. Nevertheless, it is a timeconsuming task that cannot meet the time requirement of many applications. In order to make N-FINDR computationally feasible, we consider parallel implementation of N-FINDR algorithm on hybrid multiple-core CPU and GPU parallel platform. First, a multi-core CPU-based parallel N-FINDR algorithm is considered based on a modified N-FINDR with two improvements. And by using the increasing programmability and parallelism of commodity GPU, a GPU-based parallel N-FINDR is presented. Finally, by taking advantages of the capability of the aforementioned algorithms, a hybrid multiple-core CPU and GPU parallel N-FINDR is proposed by using a virtual thread technique and an adaptive algorithm in which the computational load can be adaptively adjusted according to the capability of CPU and GPU. In experiment, our proposed parallel N-FINDR algorithms improved the accuracy of the original N-FINDR algorithm, and most importantly, they greatly improved the performance of N-FINDR algorithm. © 2011 SPIE.

Wei Y.,Sun Yat Sen University | Chen Y.,South China Normal University
Advances in Applied Mathematics and Mechanics | Year: 2012

The theory of a class of spectral methods is extended to Volterra integro- differential equations which contain a weakly singular kernel (t - s) -μ with 0 < μ < 1. In this work, we consider the case when the underlying solutions of weakly singular Volterra integro-differential equations are sufficiently smooth. We provide a rigorous error analysis for the spectral methods, which shows that both the errors of approximate solutions and the errors of approximate derivatives of the solutions decay exponentially in L ∞-norm and weighted L 2-norm. The numerical examples are given to illustrate the theoretical results. © 2012 Global Science Press.

Liu L.,South China Normal University | Liu L.,Technical University of Denmark | Ding Y.,Technical University of Denmark | Ding Y.,Huazhong University of Science and Technology | And 2 more authors.
Optics Express | Year: 2011

A compact and efficient polarization splitting and rotating device built on the silicon-on-insulator platform is introduced, which can be readily used for the interface section of a polarization diversity circuit. The device is compact, with a total length of a few tens of microns. It is also simple, consisting of only two parallel silicon-on-insulator wire waveguides with different widths, and thus requiring no additional and nonstandard fabrication steps. A total insertion loss of - 0.6dB and an extinction ratio of 12dB have been obtained experimentally in the whole C-band. © 2011 Optical Society of America.

Peng J.,Beijing Normal University | Qu C.,South China Normal University | Gu R.,CAS Institute of Psychology | Luo Y.,Chengdu Medical College
Frontiers in Human Neuroscience | Year: 2012

Previous emotion-regulation research has shown that the late positive potential (LPP) is sensitive to the down-regulation of emotion; however, whether LPP is also sensitive to the up-regulation of emotion remains unclear. The present study examined the description-based reappraisal effects on the up-regulation of positive emotions induced by erotic and neutral images in a Chinese population. Self-reported ratings and event-related potential (ERP) were recorded when subjects viewed pleasant and neutral images, which were shown after either a neutral or positive description. Self-reported results showed that images following positive descriptions were rated as more pleasant compared to images following neutral descriptions. ERP results revealed that the P2, P3, and slow wave (SW) components were larger for erotic pictures than for neutral pictures, while the positive description condition yielded attenuated erotic image-induced P2, P3 and SW and increased SW induced by neutral images. The results demonstrated that description-based reappraisal, as a method of reappraisal, significantly modulates the emotional experience and ERP responses to erotic and neutral images. © 2012 Peng, Qu, Gu and Luo.

Li F.,Hong Kong Polytechnic University | Li Q.,Peking University | Yuan J.,Hong Kong Polytechnic University | Yuan J.,South China Normal University | And 2 more authors.
Optics Express | Year: 2014

The low coherence of the supercontinuum (SC) generated using picosecond pump pulses is a major drawback of such SC generation scheme. In this paper, we propose to first self-similarly compress a high power picosecond pump pulse by injecting it into a nonlinearity increasing fiber. The compressed pulse is then injected into a non-zero dispersionshifted fiber (NZ-DSF) for SC generation. The nonlinearity increasing fiber can be obtained by tapering a large mode area photonic crystal fiber. The fiber nonlinearity is varied by varying the pitch sizes of the air holes. By using the generalized nonlinear Schrödinger equation, we show that a 1 ps pump pulse with random noise can be compressed self-similarly down to a pulse width of 53.6 fs with negligible pedestal. The noise level of the compressed pulse is reduced at the same time. The 53.6 fs pulse can then be used to generate highly coherent SC in an NZ-DSF. By using the proposed scheme, the tolerance of noise level for highly coherent SC generation with picosecond pump pulses can be improved by 5 order of magnitude. ©2014 Optical Society of America

Li Y.,Beijing Normal University | Ding G.,Beijing Normal University | Booth J.R.,Northwestern University | Huang R.,South China Normal University | And 4 more authors.
Human Brain Mapping | Year: 2012

Previous studies have shown that white matter in the deaf brain changes due to hearing loss. However, how white-matter development is influenced by early hearing experience of deaf people is still unknown. Using diffusion tensor imaging and tract-based spatial statistics, we compared white-matter structures among three groups of subjects including 60 congenitally deaf individuals, 36 acquired deaf (AD) individuals, and 38 sex- and age-matched hearing controls (HC). The result showed that the deaf individuals had significantly reduced fractional anisotropy (FA) values in bilateral superior temporal cortex and the splenium of corpus callosum compared to HC. The reduction of FA values in acquired deafness correlated with onset age of deafness, but not the duration of deafness. To explore the underlying mechanism of FA changes in the deaf groups, we further analyzed radial and axial diffusivities and found that (1) the reduced FA values in deaf individuals compared to HC is primarily driven by higher radial diffusivity values and (2) in the AD, higher radial diffusivity was correlated with earlier onset age of deafness, but not the duration of deafness. These findings imply that early sensory experience is critical for the growth of fiber myelination, and anatomical reorganization following auditory deprivation is sensitive to early plasticity in the brain. © 2010 Wiley Periodicals, Inc.

Wang Y.,Jinan University | Smith Jr. W.O.,Virginia Institute of Marine Science | Wang X.,Ocean University of China | Li S.,South China Normal University
Geophysical Research Letters | Year: 2010

Recent investigations into the role of carbon dioxide on phytoplankton growth and composition have clearly shown differential effects among species and assemblages, suggesting that increases in oceanic CO2 may play a critical role in structuring lower trophic levels of marine systems in the future. Furthermore, alarming increases in the occurrence of harmful algal blooms (HABs) in coastal waters have been observed, and while not uniform among systems, appear in some manner to be linked to human impacts (eutrophication) on coastal systems. Models of HABs are in their infancy and do not at present include sophisticated biological effects or their environmental controls. Here we show that subtle biological responses occur in the HAB species Phaeocystis globosa Scherffel as a result of CO2 enrichment induced by gentle bubbling. The alga, which has a polymorphic life history involving the formation of both colonies and solitary cells, exhibited altered growth rates of colonial and solitary forms at [CO2] of 750 ppm, as well as increased colony formation. In addition, substantial modifications of elemental and photosynthetic constituents of the cells (C cell-1, N cell -1, potential quantum yield, chl a cell-1) occurred under elevated CO2 concentrations compared to those found at present CO2 levels. In contrast, other individual and population variables (e.g., colony diameter, total chlorophyll concentration, carbon/nitrogen ratio) were unaffected by increased CO2. Our results suggest that predictions of the future impacts of Phaeocystis blooms on coastal ecosystems and local biogeochemistry need to carefully examine the subtle biological responses of this alga in addition to community and ecosystem effects. Copyright © 2010 by the American Geophysical Union.

Huang Y.,CAS Guangzhou Institute of Geochemistry | Huang Y.,University of Chinese Academy of Sciences | Luo J.,South China Normal University | Xia B.,CAS Guangzhou Institute of Geochemistry
Journal of Cleaner Production | Year: 2013

As the largest output and export province of ceramic tiles in China, Guangdong has been faced with the contradictory problem that the ceramic tile industry brings both huge economic benefits and adverse environmental impacts. To promote energy conservation and emission reduction in the ceramic tile industry, the activity of "Cleaner Production Auditing for a Thousand Voluntary Industrial Enterprises" has been held since 2010 in Guangdong. This study presents a comprehensive application of cleaner production in a typical medium-scale ceramic tile plant, which has initially taken part in the cleaner production activity. On the basis of pre-auditing conducted in the selected plant, key auditing procedures and main objectives were determined. After the analysis of material balance and energy efficiency in key auditing procedures, 31 different measures, including facility replacement, technology improvement, process control, raw material and waste reutilization, plant management, and worker training, have been proposed and implemented in a feasible way. Through the cleaner production application, the plant achieved the expected objectives and obtained obvious progress in energy conservation and emission reduction. For each unit product, the consumption of energy and water were cut down by 4.3% and 22.33%, respectively. The SO2 emission per unit product was also reduced by 8% after the cleaner production. Although the cleaner production is a continuous process in this case, it provides a theoretical and practical basis for the sustainable development of other ceramic tile production enterprises. © 2012 Elsevier Ltd. All rights reserved.

Qiu H.,South China Agricultural University | Du Y.,South China Normal University | Yao Z.,Sun Yat Sen University
Mathematical Methods in the Applied Sciences | Year: 2013

In this paper, we consider the three-dimensional generalized Boussinesq equations, a system of equations resulting from replacing the Laplacian - Δ in the usual Boussinesq equations by a fractional Laplacian (- Δ)α. We prove the local existence in time and obtain a regularity criterion of solution for the generalized Boussinesq equations by means of the Littlewood-Paley theory and Bony's paradifferential calculus. The results in this paper can be regarded as an extension to the Serrin-type criteria for Navier-Stokes equations and magnetohydrodynamics equations, respectively. Copyright © 2012 John Wiley & Sons, Ltd.

Li J.,South China Normal University | Montagnes D.J.S.,University of Liverpool
Protist | Year: 2015

Incorporating protozoa into population models (from simple predator-prey explorations to complex food web simulations) is of conceptual, ecological, and economic importance. From theoretical and empirical perspectives, we expose unappreciated complexity in the traditional predator-prey model structure and provide a parsimonious solution, especially for protistologists. We focus on how prey abundance alters two key components of models: predator conversion efficiency (e, the proportion of prey converted to predator, before mortality loss) and predator mortality (δ, the portion of the population lost though death). Using a well-established model system (Paramecium and Didinium), we collect data to parameterize a range of existing and novel population models that differ in the functional forms of e and δ. We then compare model simulations to an empirically obtained time-series of predator-prey population dynamics. The analysis indicates that prey-dependent e and δ should be considered when structuring population models and that both prey and predator biomass also vary with prey abundance. Both of these impact the ability of the model to predict population dynamics and, therefore, should be included in theoretical model evaluations and assessment of ecosystem dynamics associated with biomass flux. © 2015 Elsevier GmbH.

Lu Y.-Y.,South China Normal University | Chen T.-S.,Sun Yat Sen University | Wang X.-P.,Jinan University | Li L.,Sun Yat Sen University
Journal of Biomedical Optics | Year: 2010

Dihydroartemisinin (DHA), a front-line antimalarial herbal compound, has been shown to possess promising anticancer activity with low toxicity. We have previously reported that DHA induced caspase-3-dependent apoptosis in human lung adenocarcinoma cells. However, the cellular target and molecular mechanism of DHAinduced apoptosis is still poorly defined. We use confocal fluorescence microscopy imaging, fluorescence resonance energy transfer, and fluorescence recovery after photobleaching techniques to explore the roles of DHA-elicited reactive oxygen species (ROS) in the DHAinduced Bcl-2 family proteins activation, mitochondrial dysfunction, caspase cascade, and cell death. Cell Counting Kit-8 assay and flow cytometry analysis showed that DHA induced ROS-mediated apoptosis. Confocal imaging analysis in a single living cell and Western blot assay showed that DHA triggered ROS-dependent Bax translocation, mitochondrial membrane depolarization, alteration of mitochondrial morphology, cytochrome c release, caspase-9, caspase-8, and caspase-3 activation, indicating the coexistence of ROS-mediated mitochondrial and death receptor pathway. Collectively, our findings demonstrate for the first time that DHA induces cell apoptosis by triggering ROS-mediated caspase-8/Bid activation and the mitochondrial pathway, which provides some novel insights into the application of DHA as a potential anticancer drug and a new therapeutic strategy by targeting ROS signaling in lung adenocarcinoma therapy in the future. © 2010 Society of Photo Optical Instrumentation Engineers.

Luo W.,South China Normal University
Proceedings - 2010 3rd International Congress on Image and Signal Processing, CISP 2010 | Year: 2010

Hyperspectral remote sensing is a new and fast growing remote sensing technology that is currently being investigated by researchers and scientists. One of the most important hyperspectral image analysis is to decompose a mixed pixel into a collection of endmembers and their corresponding abundance fractions, namely spectral unmixing. However, there is an unprecedented explosion of the hyperspectral remote sensing data. The capability of spectral unmixing with time-critical constraints from a mass hyperspectral remote sensing data has soon been an urgent requirement in many missions. Based on the original Vertex Component Analysis (VCA) endmember extraction algorithm, this paper makes full use of the advantages of Symmetrical Multiprocessing (SMP) cluster parallel environment and proposes a parallel VCA algorithm with two-level data partitioning strategy to overcome the time consuming problem. In experiment, this algorithm demonstrates high performance in hyperspectral remote sensing data exploration. ©2010 IEEE.

Wang Y.,Beijing Institute of Technology | Yin J.,South China Normal University | Ke Y.,Renmin University of China
Nonlinear Analysis: Real World Applications | Year: 2013

This paper is concerned with a spatially heterogeneous Lotka-Volterra competition model with nonlinear diffusion and nonlocal terms, under the Dirichlet boundary condition. Based on the theory of Leray-Schauder's degree, we give sufficient conditions to assure the existence of coexistence periodic solutions, which extends some results of G. Fragnelli et al. © 2012 Elsevier Ltd. All rights reserved.

Chen Y.,South China Normal University
Optics Express | Year: 2010

The properties of the phase shift of wave reflected from onedimensional photonic crystals consisting of periodic layers of singlenegative (permittivity- or permeability-negative) materials are demonstrated. As the incident angle increases, the reflection phase shift of TE wave decreases, while that of TM wave increases. The phase shifts of both polarized waves vary smoothly as the frequency changes across the photonic crystal stop band. Consequently, the difference between the phase shift of TE and that of TM wave could remain constant in a rather wide frequency range inside the stop band. These properties are useful to design wave plate or retarder which can be used in wide spectral band. In addition, a broadband photonic crystal quarter-wave plate is proposed. © 2010 Optical Society of America.

Kempa K.,South China Normal University | Kempa K.,Boston College
Physica Status Solidi - Rapid Research Letters | Year: 2010

The proposed checkerboard Babinet series consists of pairs of Babinet complementary metamaterial structures, with the checkerboard pattern being the self-complementary structure. In this work, formulas are derived for the effective dielectric function and transmittance of all structures in the series, and it is shown that the evolution of the structures from holes to islands is a topological analog of the percolation problem, and that the highly singular checkerboard pattern represents the percolation threshold. The results are in agreement with the percolation theory of Bergman and Imry. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li C.,South China Normal University
Applied Mechanics and Materials | Year: 2014

Cultivating and developing strategic emerging industries is very important for promoting the rapid transformation of economic development mode, and adjusting and optimizing the economic structure. Financial support plays the role of guidance and support in the development process of strategic emerging industries. Based on the measurement results for financial support of strategic emerging industries in Guangdong, the paper constructs Tobit model analyzing factors which influence efficiency. The empirical results indicate that the reason why the average value of comprehensive efficiency of financial support for strategic emerging industries in Guangdong is lower scale efficiency. Financial subsidy, tax preference and government procurement is good for improving the efficiency of financial support, and financial subsidy has the most evident effect. Therefore, we should use the means of marketization operation to improve the availability efficiency of financial fund, realize recycle of financial funds, and takes different financial support measures in different development stages of strategic emerging industries. © (2014) Trans Tech Publications, Switzerland.

Tang B.,Guangdong University of Technology | Yu G.,Guangdong University of Technology | Fang J.,South China Normal University | Shi T.,Sun Yat Sen University
Journal of Hazardous Materials | Year: 2010

An emulsion liquid membrane (ELM)-crystallization process, using hypophosphorous acid as a reducing agent in the internal aqueous phase, has been developed for the purpose of recovering high-purity silver directly from dilute industrial effluents (waste rinse water). After pretreatment with HNO 3, silver in waste rinse water can be reliably recovered with high efficiency through the established process. The main parameters in the process of ELM-crystallization include the concentration of carrier in the membrane phase, the concentration of reducing agent in the internal aqueous phase, and the treatment ratio, which influence the recovery efficiency to various extents and must be controlled carefully. The results indicated that more than 99.5% (wt.) of the silver ions in the external aqueous phase were extracted by the ELM-crystallization process, with an average efficiency of recovery of 99.24% (wt.) and a purity of 99.92% (wt.). The membrane phase can be used repeatedly without loss of the efficiency of recovery. © 2009 Elsevier B.V.

Ji Y.,South China Normal University | He Y.,Tsinghua University | Liu L.,Tsinghua University | Zhong X.,Tsinghua University
FEBS Letters | Year: 2010

Here we report that miR-26b is involved in COX-2 overexpression in desferrioxamine (DFOM)-treated carcinoma of nasopharyngeal epithelial (CNE) cells. The level of miR-26b in DFOM-treated CNE cells is inversely proportional to the expression level of the COX-2 protein. Overexpression of miR-26b in DFOM-treated CNE cells inhibits cell proliferation. A luciferase reporter gene experiment suggests that the 3′ untranslated region of COX-2 carries a binding site for miR-26b. Overexpression of miR-26b marginally reduces the levels of COX-2 protein in DFOM-treated CNE cells. Moreover, knockdown of COX-2 expression had a similar effect to overexpression of miR-26b. Taken together, these results suggest that miR-26b regulates COX-2 expression in DFOM-treated cells. © 2010 Federation of European Biochemical Societies.

Xu Q.,South China Normal University
Mathematical Problems in Engineering | Year: 2013

Machine learning is the most commonly used technique to address larger and more complex tasks by analyzing the most relevant information already present in databases. In order to better predict the future trend of the index, this paper proposes a two-dimensional numerical model for machine learning to simulate major U.S. stock market index and uses a nonlinear implicit finite-difference method to find numerical solutions of the two-dimensional simulation model. The proposed machine learning method uses partial differential equations to predict the stock market and can be extensively used to accelerate large-scale data processing on the history database. The experimental results show that the proposed algorithm reduces the prediction error and improves forecasting precision. © 2013 Qingzhen Xu.

Fu P.,Indiana State University | Weng Q.,South China Normal University | Weng Q.,Indiana State University
Remote Sensing of Environment | Year: 2016

Land surface temperature (LST), derived from satellite thermal infrared (TIR) sensors, is a key variable for characterization of urban heat island, modeling of surface energy balance, estimation of evapotranspiration and soil moisture, and retrieval of air temperature. Among the satellite TIR sensors in operation, Landsat TIR sensor provides the only feasibility for long-term reconstruction of a LST dataset for environmental applications. However, a holistic technique is not currently available to generate spatially and temporally continuous LSTs from Landsat due to its 16-day revisit frequency, impact of atmospheric conditions and the SLC (Scan Line Corrector) -off gap. Previous algorithms had been developed to overcome these limitations, it is still not possible to generate LSTs at any desired date with consistent accuracy and corrections. Therefore, this study aimed to devise an algorithm to reconstruct consistent, daily LSTs at Landsat spatial resolution based solely on Landsat imagery. By selecting Beijing, China, as the study area, a total of 512 images from 1984 to 2011 were downloaded from the USGS online portal and were consistently calibrated to surface reflectance and brightness temperature. The cloud-, cloud shadow-, and snow-contaminated pixels were excluded according to quality flags; and a further screening procedure based on temporal information of Landsat spectral bands 2, 4, and 5 was conducted. Brightness temperatures were converted to LSTs through the single channel algorithm with input of water vapor from the NCEP Reanalysis dataset. Field LSTs were collected from 11 weather stations in Beijing in the year of 2008, 2009, and 2010. The proposed algorithm included four modules: Data filtEr, temporaL segmentation, periodic and trend modeling, and GAussian process (DELTA). Accuracy assessment showed that, compared with the in situ LSTs from weather stations, satellite-derived LSTs inverted through the single channel algorithm had an average accuracy of 2.3 K. Further comparison between LSTs reconstructed from the DELTA algorithm and those collected from weather stations in the year 2008 yielded a mean error of 3.5 K. Twelve LST maps reconstructed from the DELTA in 2000 showed that LSTs of different land covers exhibited similar seasonal patterns and reached their maximal values in June/July. Using LST of every August 15th as an example, the SUHI (surface urban heat island) intensity of Beijing was computed, which ranged from 3.3 K to 5.3 K from 1984 to 2011, with an increase pattern of LST in both rural and urban areas. © 2016 Elsevier Inc.

Liu S.-Z.,South China Normal University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

The title polymeric compound, [Zn(C8H5Cl 2O3)2] n , was prepared by reaction of zinc(II) chloride with 2,4-dichloro-phenoxy-acetic acid and sodium hydroxide under hydro-thermal conditions. The ZnII atom is coordinated in a distorted tetra-hedral environment by four O atoms from four 2,4-dichloro-phenoxy-acetate ligands. Each ligand bridges two ZnII atoms, forming a polymeric chain along the a axis. Adjacent chains are connected via C - H⋯Cl hydrogen bonds.

Feng S.,South China Normal University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

In the title two-dimensional coordination polymer, [Yb2(C 8H4O4)3(H2O) 6]n , the unique YbIII ion is eight-coordinated in a distorted dodeca-hedral coordination geometry by three water O atoms and five O atoms from carboxyl-ate groups belonging to four different terephthalate ligands. One of the terephthalate ligands is located around an inversion center. The coordination polymers are parallel to (121) and are connected by O-H⋯O hydrogen bonds into a three-dimensional framework.

Liu S.-Z.,South China Normal University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

The title compound, {[Cu2(C8H5Cl 2O3)(C10H8N2) 2]NO3} n was prepared by reacting copper(II) nitrate with 4,4'-bipyridine (4,4'-bipy) and (2,4-dichloro-phen-oxy)acetic acid under solvothermal conditions. Each of two copper(I) atoms in the asymmetric unit is three-coordinated by two N atoms from two 4,4'-bipy ligands and one O atom from the (2,4-dichloro-phen-oxy)acetate ligand. As both ligands act as bridging ligands, a double-stranded chain structure is observed.

Sun F.,South China Normal University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

The asymmetric unit of the title compound, {[CoEr2(C 5H2N2O4)2(SO 4)2(H2O)4]·H 2O}n , contains a CoII ion, two Er III ions, two imidazole-4,5-dicarboxyl-ate (imdc) ligands, two SO4 2- anions, four coordinated water molecules and one uncoordinated water molecule. The CoII ion is six-coordinated by two O atoms from two coordinated water molecules and two O atoms and two N atoms from two imdc ligands in a slightly distorted octa-hedral geometry. Both Er III ions are eight-coordinated in a bicapped trigonal-prismatic coordination geometry. One ErIII ion is coordinated by four O atoms from two imidazole-4,5-dicarboxyl-ate ligands, three O atoms from three SO 4 2- anions and one water O atom; the other Er III ion is bonded to five O atoms from three imdc ligands, two O atoms from two SO4 2- anions as well as one coordinated water molecule. The coordinated metal units are connected by bridging imdc ligands and sulfate ions, generating a two-dimensional heterometallic layer. The two-dimensional layers are stacked along the b axis via N - H⋯O, O - H⋯O and C - H⋯O hydrogen-bonding inter-actions between water molecules, SO4 2- anions, and imdc ligands, generating a three-dimensional framework.

Feng T.,South China Normal University | Ruifeng Z.,Hefei University of Technology
Acta Mathematica Scientia | Year: 2011

In the present paper, we define sensitive pairs via Furstenberg families and discuss the relation of three definitions: sensitivity, ℱ-sensitivity and ℱ-sensitive pairs, see Theorem 1. For transitive systems, we give some sufficient conditions to ensure the existence of ℱ-sensitive pairs. In particular, each non-minimal E system (M system, P system) has positive lower density (ℱ s, ℱ r resp.)-sensitive pairs almost everywhere. Moreover, each non-minimal M system is ℱ ts-sensitive. Finally, by some examples we show that: (1) ℱ-sensitivity can not imply the existence of ℱ-sensitive pairs. That means there exists an ℱ-sensitive system, which has no ℱ-sensitive pairs. (2) There is no immediate relation between the existence of sensitive pairs and Li-Yorke chaos, i.e., there exists a system (X,f) without Li-Yorke scrambled pairs, which has κℬ-sensitive pairs almost everywhere. (3) If the system (G,f) is sensitive, where G is a finite graph, then it has κℬ-sensitive pairs almost everywhere. © 2011 Wuhan Institute of Physics and Mathematics.

Liu L.-Y.,CAS Guangzhou Institute of Geochemistry | Liu L.-Y.,University of Chinese Academy of Sciences | Wang J.-Z.,CAS Guangzhou Institute of Geochemistry | Wei G.-L.,CAS Guangzhou Institute of Geochemistry | And 3 more authors.
Environmental Pollution | Year: 2012

Sediments collected from the continental shelf of China, embracing Yellow Sea, inner shelf of the East China Sea (ECS), and the South China Sea (SCS), were analyzed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of anthropogenic PAHs (Σ 18PAH) were 27-224 ng/g dry weight, with an average of 82 ng/g. Sedimentary PAHs in the continental shelf off China were mainly derived from mixed residues of biomass, coal, and petroleum combustion. Fluvial transport and atmospheric deposition mainly accounted for sediment PAHs in the ECS inner shelf and Yellow Sea (and the SCS), respectively. Furthermore, statistically higher levels of Σ 18PAH (28-224 ng/g; mean 110 ng/g) in the Yellow Sea sediment than in the SCS sediment (28-109 ng/g; mean 58 ng/g) were probably resulted from higher PAH emissions from coke industry and domestic coal combustion in North China than in South China. © 2012 Elsevier Ltd. All rights reserved.

Hu L.-Y.,Jiangxi Normal University | Hu L.-Y.,Beijing Computational Science Research Center | Zhang Z.-M.,South China Normal University
Journal of the Optical Society of America B: Optical Physics | Year: 2013

We investigate the statistical properties and inseparability of the field states generated by any order nonlocal coherent photon addition (CPA) to the two-mode squeezed vacuum (TMSV). It is shown that the normalization factor of the CPA-TMSV is a Legendre polynomial, a compact expression. The statistical properties are discussed according to the analytical expressions of cross-correlation function, antibunching effect, and the negativity of its Wigner function. The inseparability is presented by using Shchukin-Vogel criteria and the Einstein-Podolsky- Rosen correlation. It is found that the symmetrical CPA-TMSV may possess stronger correlation than the singlemode photon-addition case. The lower bound of entanglement of the CPA-TMSV is considered, which indicates the logarithmic negativity is invalid for verifying the entanglement when the squeezing parameter is less than a threshold value, a period function of π/2. In addition, quantum teleportation is examined, which shows that asymmetric photon-added TMSV may be more useful for teleportation than the symmetric case. © 2013 Optical Society of America.

Zhu J.,South China Normal University | Hassan S.-U.,University of Punjab | Mirza H.T.,COMSATS Institute of Information Technology | Xie Q.,KAUST
Scientometrics | Year: 2014

This paper focuses on measuring the academic research performance of Chinese universities by using Scopus database from 2007 to 2010. We have provided meaningful indicators to measure the research performance of Chinese universities as compared to world class universities of the US and the European region. Using these indicators, we first measure the quantity and quality of the research outcomes of the universities and then examine the internationalization of research by using international collaborations, international citations and international impact metrics. Using all of this data, we finally present an overall score called research performance point to measure the comprehensive research strength of the universities for the selected subject categories. The comparison identifies the gap between Chinese universities and top-tier universities from selected regions across various subject areas. We find that Chinese universities are doing well in terms of publication volume but receive less citations from their published work. We also find that the Chinese universities have relative low percentage of publications at high impact venues, which may be the reason that they are not receiving more citations. Therefore, a careful selection of publication venues may help the Chinese universities to compete with world class universities and increase their research internationalization. © 2014, Akadémiai Kiadó, Budapest, Hungary.

Li X.,South China Normal University
Physical Chemistry Chemical Physics | Year: 2016

The quest to design and fabricate new antibacterial surfaces is an important task to meet the urgent demands of biomedical applications. Recently, a mechanical mechanism for killing adherent bacteria was discovered on nanopatterned surfaces, but there is a lack of understanding of the bactericidal mechanism. Here we present a quantitative thermodynamic model to study the bactericidal mechanism of nanopatterned surfaces through analyzing the total free energy change of bacterial cells. By comparing the bacterial cells on a flat surface and nanopatterned surface, our theoretical results reveal that cicada wing-like nanopatterned surfaces have more effective bactericidal properties than flat surfaces because a patterned surface leads to a drastic increase of the contact adhesion area. Our model also reveals some details of the influence mechanism, and gives some important information about how to improve the bactericidal properties through designing the morphology of the patterned surface. © the Owner Societies 2016.

Liu G.,CAS Institute of Physics | Zhu S.-L.,South China Normal University | Jiang S.,CAS Institute of Physics | Sun F.,CAS Institute of Physics | Liu W.M.,CAS Institute of Physics
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We propose a model which includes a nearest-neighbor intrinsic spin-orbit coupling and a trimerized Hamiltonian in the kagome lattice and promises to host the transition from the quantum spin Hall insulator to the normal insulator. In addition, we design an experimental scheme to simulate and detect this transition in the ultracold atom system. The lattice intrinsic spin-orbit coupling is generated via the laser-induced-gauge-field method. Furthermore, we establish the connection between the spin Chern number and the spin-atomic density which enables us to detect the quantum spin Hall insulator directly by the standard density-profile technique used in atomic systems. © 2010 The American Physical Society.

Huang L.,Chinese University of Hong Kong | Mo L.,South China Normal University | Li Y.,Zhengzhou University
Journal of Experimental Psychology: Human Perception and Performance | Year: 2012

A large part of the empirical research in the field of visual attention has focused on various concrete paradigms. However, as yet, there has been no clear demonstration of whether or not these paradigms are indeed measuring the same underlying construct. We collected a very large data set (nearly 1.3 million trials) to address this question. We tested 257 participants on nine paradigms: conjunction search, configuration search, counting, tracking, feature access, spatial pattern, response selection, visual short-term memory, and change blindness. A fairly general attention factor was identified. Some of the participants were also tested on eight other paradigms. This general attention factor was found to be correlated with intelligence, visual marking, task switching, mental rotation, and Stroop task. On the other hand, a few paradigms that are very important in the attention literature (attentional capture, consonance-driven orienting, and inhibition of return) were found to be dissociated from this general attention factor. © 2012 American Psychological Association.

Huang M.,Hanshan Normal University | Feng W.,South China Normal University
Computers and Mathematics with Applications | Year: 2010

This paper is devoted to the study of the oscillations for forced second order delay differential equations with impulses. The results gained here are based on the information of the forcing term on a sequence of subintervals of [t0, ∞), which develops some well-known results for the equations without impulses and the equations without delay. © 2009 Elsevier Ltd. All rights reserved.

Wang X.,South China Normal University | Wang X.,University of Hong Kong | Li X.-Y.,University of Hong Kong
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2014

A layered CdS/ZnS catalyst film was synthesized on glass using the stepped chemical bath deposition method. The film catalyst was shown as visible light-driven photocatalyst capable of producing H2 under visible light. The ZnS outer layer helped suppress the recombination of photo-generated electron-hole pairs on the CdS base layer, leading to faster H2 generation. The use of the ZnS layer also greatly improved the stability of the catalyst film and prevented the leaching of Cd2+ from the CdS layer. Deposition of Ru on the catalyst film further increased its photoreactivity for H2 production. The photocatalyst was effective in H2 production together with the degradation of model organic substances, such as formic acid, methanol, and ethanol. The greatest H2 production rates were achieved using the CdS/ZnS/Ru film in the formic acid solution at 123 μmol/m2-h under visible light and 135 mmol/m2-h under the simulated solar light. The corresponding theoretical reduction rates of chemical oxygen demand (COD) were 1.9 and 2.1 g/m2-h, respectively. As the multilayer CdS/ZnS/Ru film catalyst can be easily separated from water, it has a great potential for simultaneous photocatalytic hydrogen generation and organic wastewater treatment using solar energy. © 2013 Elsevier B.V.

Chen X.S.,South China Normal University
BIT Numerical Mathematics | Year: 2010

This paper is devoted to the perturbation analysis for periodic regular matrix pairs. We present perturbation bounds for the periodic Schur decomposition of periodic regular matrix pairs with distinct eigenvalues, which extend the main result of Sun (SIAM J. Matrix Anal. Appl. 16:1328-1340, 1995). The results are illustrated by a numerical example. © Springer Science + Business Media B.V. 2009.

Guo S.,Hunan Normal University | Kendrick K.M.,University of Electronic Science and Technology of China | Yu R.,South China Normal University | Wang H.-L.S.,National Taiwan University | And 2 more authors.
Human Brain Mapping | Year: 2014

There is still no clear consensus as to which of the many functional and structural changes in the brain in schizophrenia are of most importance, although the main focus to date has been on those in the frontal and cingulate cortices. In the present study, we have used a novel holistic approach to identify brain-wide functional connectivity changes in medicated schizophrenia patients, and functional connectivity changes were analyzed using resting-state fMRI data from 69 medicated schizophrenia patients and 62 healthy controls. As far as we are aware, this is the largest population reported in the literature for a resting-state study. Voxel-based morphometry was also used to investigate gray and white matter volume changes. Changes were correlated with illness duration/symptom severity and a support vector machine analysis assessed predictive validity. A network involving the inferior parietal lobule, superior parietal gyrus, precuneus, superior marginal, and angular gyri was by far the most affected (68% predictive validity compared with 82% using all connections) and different components correlated with illness duration and positive and negative symptom severity. Smaller changes occurred in emotional memory and sensory and motor processing networks along with weakened interhemispheric connections. Our findings identify the key functional circuitry altered in schizophrenia involving the default network midline cortical system and the cortical mirror neuron system, both playing important roles in sensory and cognitive processing and particularly self-processing, all of which are affected in this disorder. Interestingly, the functional connectivity changes with the strongest links to schizophrenia involved parietal rather than frontal regions. Hum Brain Mapp 35:123-139, 2014. © 2012 Wiley Periodicals, Inc.

Ilic A.,University of Nis | Zhou B.,South China Normal University
Match | Year: 2010

Let G be a simple graph with n vertices and let μ1 ≥ μ2 ≥... ≥ μn-1 ≥ = 0 be the eigenvalues of its Laplacian matrix. The Laplacian Estrada index of a graph G is defined as LEE(G) = (equation). Using the recent connection between Estrada index of a line graph and Laplacian Estrada index, we prove that the path P" has minimal, while the star Sn has maximal LEE among trees on η vertices. In addition, we find the unique tree with the second maximal Laplacian Estrada index.

Sun Z.,Hunan University | Zeng J.,Dongguan University of Technology | Li D.,South China Normal University
BIT Numerical Mathematics | Year: 2010

Semismooth Newton method is an effective method for solving a nonsmooth equation, which arises from a reformulation of the complementarity problem. Under appropriate conditions, we verify the monotone convergence of the method. We also present semismooth Newton Schwarz iterative methods for the nonsmooth equation. Under suitable conditions, the methods exhibit monotone and superlinear convergence properties. © 2010 Springer Science + Business Media B.V.

Luo L.,Guangzhou University | Yu H.,South China Normal University
Journal of Statistical Physics | Year: 2016

In this work we prove the complete spectrum structure of the linearized relativistic Landau equation in (Formula presented.) by using the semigroup theory and the linear operator perturbation theory. Our results include the physical interesting Coulombic interaction. © 2016, Springer Science+Business Media New York.

Gutman I.,University of Kragujevac | Zhou B.,South China Normal University | Furtula B.,University of Kragujevac
Match | Year: 2010

Short time ago Liu and Liu [MATCH Commun. Math. Comput. Chem. 59 (2008) 355-372] put forward a so-called Laplacian-energy like invariant (LEL), defined as the sum of the square roots of the Laplacian eigenvalues. From its name, one could get the impression that the properties of LEL are similar to those of the Laplacian energy LE. However, already the inventors of LEL realized that LEL resembles much more the ordinary graph energy (E) than LE. We now provide further arguments supporting this conclusion. In particular, numerous earlier obtained bounds and approximations for E can be simply "translated" into bounds and approximations for LEL.

Yuan P.,South China Normal University | Zeng X.,Sun Yat Sen University
European Journal of Combinatorics | Year: 2010

Let A ⊂ {1, ..., n - 1} and let (x1, ..., xt) ∈ Zt be a sequence of integers with a maximal length such that for all (a1, ..., at) ∈ At, ∑1 ≤ i ≤ t ai xi ≢ 0 (mod n). The authors show that for any sequence of integers (x1, ..., xn + t) ∈ Zn + t, there are b1, ..., bn ∈ A and 1 ≤ k1 < k2 < ⋯ < kn ≤ n + t such that under(∑, 1 ≤ i ≤ n) bi xki ≡ 0 (mod n) . © 2009 Elsevier Ltd. All rights reserved.

You J.,South China Normal University | Lin M.-P.,National Taiwan Normal University | Leung F.,Chinese University of Hong Kong
Journal of Adolescence | Year: 2013

This study examined functions of nonsuicidal self-injury (NSSI) among a large sample of Chinese high school students over a six-month period. Among Chinese adolescents, we identified three factors of NSSI functions, namely, Affect Regulation, Social Influence, and Social Avoidance. Affect Regulation was the most frequently endorsed function of NSSI, followed by Social Influence and Social Avoidance. Adolescent male self-injurers were more likely to endorse the Social Influence function than their female counterparts. Moderate/Severe Self-injurers did not differ from Minor Self-injurers on the endorsement of various NSSI functions. All functions of NSSI exhibited small to moderate stability over the six-month assessment period. Findings suggest that Chinese adolescents engaged in NSSI for multiple reasons. These reasons also varied considerably over time within individuals. Assessment of NSSI should thus regularly assess functions of the behavior. © 2013 The Foundation for Professionals in Services for Adolescents.

Chen Y.,South China Normal University | Liu L.,Xiangtan University | Lu Z.,Chongqing Three Gorges University
Numerical Functional Analysis and Optimization | Year: 2010

In this article, we shall give a brief review on the fully discrete mixed finite element method for general optimal control problems governed by parabolic equations. The state and the co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise constant elements. Furthermore, we derive a posteriori error estimates for the finite element approximation solutions of optimal control problems. Some numerical examples are given to demonstrate our theoretical results. Copyright © Taylor & Francis Group, LLC.

Zhou B.,South China Normal University
Match | Year: 2010

The incidence energy of a graph is defined as the sum of the singular values of the incidence matrix. We obtain upper bounds for the incidence energy using the first Zagreb index.

Zhou B.,South China Normal University
Match | Year: 2010

A lot of properties especially bounds for the energy and the Laplacian energy of a graph have been known. We now establish further upper bounds for the energy and upper and lower bounds for the Laplacian energy. An upper bound for the energy of bipartite graphs is given in terms of the Laplacian eigenvalues.

Zhou B.,South China Normal University | Ilic A.,University of Nis
Match | Year: 2010

For a connected graph, the distance spectral radius is the largest eigenvalue of its distance matrix, and the distance energy is defined as the sum of the absolute values of the eigenvalues of its distance matrix. We establish lower and upper bounds for the distance spectral radius of graphs and bipartite graphs, lower bounds for the distance energy of graphs, and characterize the extremal graphs. We also discuss upper bounds for the distance energy.

Liu W.,South China Normal University
Proceedings - 4th International Congress on Image and Signal Processing, CISP 2011 | Year: 2011

Multiwavelets extend traditional scalar wavelets to vector space, which include all the advantages of the traditional wavelets, while overcoming the shortcomings of scalar wavelets. Multiwavelets show the perfect union of symmetry, orthogonally, finitely support and smoothness. As a result, the applications of multiwavelets in image processing have shown great potential. In this paper, an image coding method based on EBCOT algorithm and multiwavelet transform was proposed. During our research, a variety of commonly-used multiwavelets were used to combine with EBCOT algorithm. The experimental results show that the proposed method is a valuable attempt of image compression. © 2011 IEEE.

Xia H.,Chinese University of Hong Kong | Liu D.,Chinese University of Hong Kong | Song K.,South China Normal University | Miao Q.,Chinese University of Hong Kong
Chemical Science | Year: 2011

This study explores a bifunctional hydrocarbon, which has two non-planar dibenzocycloheptatriene moieties linked by three cumulative C-C double bonds. This flexible conjugated molecule can adopt two conformations, namely, syn and anti, in its crystals. Of particular interest is that the molecule's solids not only function as p-type semiconductors with field effect mobility of 0.02 cm2 V-1 S-1 but also exhibit vapochromic behavior with high selectivity. Upon selectively trapping specific volatile molecules, such as toluene and m-xylene, in the crystal lattice, the guest-free crystals of the syn conformer change to the clathrate crystals of the anti conformer accompanied by a change of color from red to orange. The unique combination of the two useful functions of this molecule can be attributed to its cycloheptatriene and cumulene moieties, both of which have rarely been used in building blocks for organic functional materials. This journal is © The Royal Society of Chemistry 2011.

Ye Y.,South China Normal University
Plant signaling & behavior | Year: 2012

As a vital cell-signaling molecule, nitric oxide (NO) has been reported to regulate toxic metal responses in plants. Our recent report has suggested that caspase-3-like protease activation was detected in Arabidopsis (Arabidopsis thaliana) after Cd2+ treatment. NO contributed caspase-3-like protease activation in Cd2+ induced Arabidopsis thaliana programmed cell death (PCD), which was mediated by MPK6. It was first shown that NO promotes Cd2+-induced Arabidopsis PCD by promoting MPK6-mediated caspase-3-like activation. Our study contributed to the understanding of NO signaling pathway in Cd2+-induced Arabidopsis thaliana PCD. Although several studies have revealed that NO regulates plant PCD, compared with the study of signaling pathways involved in animal cell apoptosis, the mechanism of NO function still remains elusive and the molecular mechanisms of MAPK are far from clear in Cd2+-induced PCD. By using the fluorescence techniques and the Arabidopsis seedlings as the reference model, the subsequent researches have been performed to obtain comprehensive understanding of Cd2+-induced plant PCD.

Yue H.,South China Normal University
Plant signaling & behavior | Year: 2012

Previous studies have reported that methyl jasmonate (MeJA) can promote plant senescence. Arabidopsis thaliana BI1 (AtBI1) participates in leaf senescence and JA signal pathway. Our recent report has suggested that AtBI1 plays a crucial role in MeJA-induced leaf senescence. Concomitantly, cytosolic calcium ([Ca2+]cyt) and MPK6, a mitogen-activated protein kinase (MAPK), participate in the process of MeJA-induced leaf senescence. And AtBI1 might play its roles in delaying MeJA-induced leaf senescence by suppressing the [Ca2+]cyt-dependent activation of MPK6. Our study contributes to the understanding of the function and mechanism of AtBI1 in plant senescence. Though some of signaling molecules have been elucidated in this type of plant senescence, the mechanism of AtBI-1 functions in reducing the [Ca2+]cyt during MeJA-induced leaf senescence needs further improvement, and the source and location of Ca2+ are still not clear enough. By using the Arabidopsis and MeJA as the research model, the subsequent researches have been performed to investigate the upstream regulation and downstream function of Ca2+ in this type of plant senescence.

Wang W.,Minzu University of China | Long D.,Minzu University of China | Liang Y.,University of Electronic Science and Technology of China | Zhang G.,Minzu University of China | And 2 more authors.
Langmuir | Year: 2011

We describe a novel route for the conversion of hexagonal Sb 2Te3 nanoplates into nanorings driven by growth temperature in a simple solvothermal process. The transmission electron microscopy was employed to investigate systemically the morphology, size, crystallinity, and microstructure of the as-prepared products. The experiments indicated that the growth temperature had a great effect on the morphology of antimony telluride nanostructures. When the experiments were conducted at 200 °C, the hexagonal antimony telluride nanoplates were obtained. However, if the experiments were carried out at higher temperature of 230 °C, the hexagonal antimony telluride nanorings were achieved by dissolution of the inner part with a higher density of defects of the hexagonal nanoplates for the first time. A possible formation mechanism was proposed on the basis of experimental results and analysis. This work may open a new rational route for the synthesis of the hexagonal antimony telluride nanorings, which may have scientific and technological applications in various functional devices. © 2010 American Chemical Society.

Peng W.-C.,University of Hong Kong | Wang X.,University of Hong Kong | Wang X.,South China Normal University | Li X.-Y.,University of Hong Kong
Nanoscale | Year: 2014

The photo-degradation of organic pollutants using solar light is an attractive chemical process for water pollution control. In this study, we synthesized a new composite material consisting of silver phosphate (Ag 3PO4) sub-microcrystals grown on a layered molybdenum disulfide (MoS2) and graphene (GR) hybrid as a high-performance photocatalyst for the degradation of toxic organic pollutants. This composite photocatalyst was prepared via a simple two-step hydrothermal process that used sodium molybdate, thiourea and graphene oxide as precursors for the MoS 2/GR hybrid and silver nitrate for the Ag3PO4 sub-microcrystals. The composite Ag3PO4-0.02(MoS 2/0.005GR) was found to be the most effective catalyst for the photo-decomposition of 2,4-dichlorophenol under simulated solar light and visible light (λ ≥ 420 nm). The photocatalyst was also highly active for the degradation of nitrophenol and chlorophenol. The ultra photocatalytic activity of the novel catalyst arose from the synergetic effects of MoS 2 and GR as cocatalysts in the composite. MoS2/GR nanosheets served as electron collectors for the interfacial electron transfer from Ag3PO4 to electron acceptors in the aqueous solution and thus enhanced the separation of the photo-generated electron-hole pairs and made the holes more available for organic oxidation. In addition, the presence of MoS2 and GR provided more active adsorption sites and allowed for the activation of dissolved O2 for organic degradation in water. © 2014 the Partner Organisations.

Huang J.-H.,South China Normal University | Mai Z.-F.,Beijing Normal University
European Physical Journal C | Year: 2016

The superradiant stability is investigated for non-extremal Reissner–Nordström black holes. We use an algebraic method to demonstrate that all non-extremal Reissner–Nordström black holes are superradiantly stable against a charged massive scalar perturbation. This improves the results obtained before for non-extremal Reissner–Nordström black holes. © 2016, The Author(s).

Lin W.-W.,South China University of Technology | Liu B.,South China Normal University
Huanan Ligong Daxue Xuebao/Journal of South China University of Technology (Natural Science) | Year: 2012

Data load balancing greatly affects the performance of the Hadoop distributed file system (HDFS). In order to overcome the inefficiency and inflexibility of the default data load balancing method in HDFS, this paper devises a novel dynamic load balancing method, which dynamically allocates network bandwidth to achieve the data load balancing by controlling variables. Then, the corresponding mathematical model is constructed based on the controlled variables. Experimental results show that the devised method can not only guarantee the performance of the HDFS data access system but also improve the data load balancing efficiency in the presence of a new cluster node.

Chen X.S.,South China Normal University
BIT Numerical Mathematics | Year: 2016

The sensitivity of solutions to the periodic Sylvester equation (Formula presented.)(Formula presented.) is primarily dependent on the quantity [InlineEquation not available: see fulltext.] introduced by Granat and Kågström (SIAM J Matrix Anal Appl 28:285–300, 2006) in connection with the resolution to periodic invariant subspaces of a product of matrices. In this paper, we give some lower and upper bounds of [InlineEquation not available: see fulltext.] based on periodic Schur decompositions, which are generalizations of those of the separation between two matrices. Numerical examples are presented to illustrate the theoretical results. © 2016 Springer Science+Business Media Dordrecht

Shao Z.-G.,South China Normal University
Applied Physics Letters | Year: 2010

We construct the complex networks of human heartbeat dynamics and investigate their statistical properties, using the visibility algorithm proposed by Lacasa and co-workers [Proc. Natl. Acad. Sci. U.S.A. 105, 4972 (2008)]. Our results show that the associated networks for the time series of heartbeat interval are always scale-free, high clustering, hierarchy, and assortative mixing. In particular, the assortative coefficient of associated networks could distinguish between healthy subjects and patients with congestive heart failure. © 2010 American Institute of Physics.

Yan H.,South China Normal University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

A robust type of three-dimensional magnetic trap lattice on an atom chip combining optically induced fictitious magnetic field with microcurrent-carrying wires is proposed. Compared to the regular optical lattice, the individual trap in this three-dimensional magnetic trap lattice can be easily addressed and manipulated. © 2010 The American Physical Society.

Luo Y.,South China University of Technology | Shen S.,South China University of Technology | Luo J.,South China Normal University | Wang X.,South China University of Technology | Sun R.,South China University of Technology
Nanoscale | Year: 2015

This work reported a facile and green method to prepare highly stable and uniformly distributed Ag nanoparticles (AgNPs), in which a biopolymer xylan was used as the stabilizing and reducing agent via the Tollens reaction under microwave irradiation. Different variables were evaluated to optimize the reaction conditions. Complete characterization was performed using UV-Vis, XRD, TEM, size distribution analysis and XPS. The results revealed that AgNPs were well dispersed with diameters of 20-35 nm due to the packing of xylan. The optimal conditions were as follows: microwave irradiation temperature was 60-70 °C, microwave power was 800 W, microwave time was 30 min, the ratio of xylan to AgNO3 was 50 mg: 0.13 mmol, and ammonia concentration was 2%. In addition, the AgNPs were collected via high-speed centrifugal separation, and the supernatant was tested by HPAEC, GPC, FT-IR, and NMR. By comparing the structure of xylan before and after the reaction, the reaction mechanism was discussed. It was noted that the xylan-AgNPs composites showed high selectivity and sensitivity for Hg2+ detection. The other 15 metal ions used had no obvious effect on the detection of Hg2+, and the limit of detection (LOD) was 4.6 nM, which is lower than the allowed maximum level of 30 nM for drinking water by WHO. In addition, the xylan-AgNPs composites can be applied for Hg2+ detection in real water samples. This study provides a novel way for the high-value utilization of a rich biomass resource, and a green method for the synthesis of AgNPs for the selective and sensitive detection of harmful heavy metals. This journal is © The Royal Society of Chemistry.

Wen J.,Sun Yat Sen University | Li S.,Sun Yat Sen University | Lin Z.,Guangdong Polytechnic Normal University | Hu Y.,Sun Yat Sen University | Huang C.,South China Normal University
Information and Software Technology | Year: 2012

Context: Software development effort estimation (SDEE) is the process of predicting the effort required to develop a software system. In order to improve estimation accuracy, many researchers have proposed machine learning (ML) based SDEE models (ML models) since 1990s. However, there has been no attempt to analyze the empirical evidence on ML models in a systematic way. Objective: This research aims to systematically analyze ML models from four aspects: type of ML technique, estimation accuracy, model comparison, and estimation context. Method: We performed a systematic literature review of empirical studies on ML model published in the last two decades (1991-2010). Results: We have identified 84 primary studies relevant to the objective of this research. After investigating these studies, we found that eight types of ML techniques have been employed in SDEE models. Overall speaking, the estimation accuracy of these ML models is close to the acceptable level and is better than that of non-ML models. Furthermore, different ML models have different strengths and weaknesses and thus favor different estimation contexts. Conclusion: ML models are promising in the field of SDEE. However, the application of ML models in industry is still limited, so that more effort and incentives are needed to facilitate the application of ML models. To this end, based on the findings of this review, we provide recommendations for researchers as well as guidelines for practitioners. © 2011 Elsevier B.V. All rights reserved.

Liu Q.,South China Normal University
Current Bioinformatics | Year: 2014

A major objective for constructing gene regulatory networks is to use them as models for designing optimal therapeutic intervention policies within the context of synchronous or asynchronous probabilistic Boolean networks (PBNs). However, most of the previous works focused on the former and only few studied the latter. This paper deals with an optimal control problem in a generalized asynchronous PBN by applying the theory of controlled semi-Markov processes. Specifically, we first describe a control model for a generalized asynchronous PBN as a controlled semi- Markov process model and then solve the corresponding optimal control problem such that the probability that the network reaches a prescribed reward level during a first passage time to some target set is maximal. Numerical examples are then given to demonstrate the effectiveness of the proposed methods. © 2014 Bentham Science Publishers.

Wu S.,Hong Kong Polytechnic University | Wu S.,South China Normal University | Li J.,Hong Kong Polytechnic University | Lo S.-C.,Hong Kong Polytechnic University | And 2 more authors.
Organic Electronics: physics, materials, applications | Year: 2012

To improve the performance of the hybrid solar cells based on electrospun zinc oxide nanofibers/poly(3-hexylthiophene) (ZnO/P3HT), we modified the ZnO nanofibers with nanocrystalline cadmium sulfide (CdS) by solution process and successfully obtained CdS/ZnO core-shell nanofibers. The CdS modification at the optimum condition can dramatically improve all photovoltaic parameters and increase the power conversion efficiency of the hybrid solar cells for over 100%. In addition, the lifetimes of carriers in the hybrid solar cells characterized by impedance analyzer become much longer after the modification of CdS. The effect of CdS modification on the devices can be mainly attributed to the cascaded energy band structure of the heterojunction that favors charge transport process and thus increases the efficiencies of the devices. © 2012 Elsevier B.V. All rights reserved.

Wei G.,South China Normal University | Zeng L.,Jiangxi Normal University
Advanced Nonlinear Studies | Year: 2016

In this paper, we study the eigenvalues of the poly-Laplacian with arbitrary order on a bounded domain in an n-dimensional Euclidean space and we obtain a lower bound which generalizes the results due to Cheng and Wei [5] and gives an improvement of the results due to Cheng, Qi and Wei [3]. © 2016 by De Gruyter.

Du L.,Nanyang Technological University | Zhang X.,Nanyang Technological University | Mei T.,South China Normal University | Mei T.,Nanyang Technological University | Yuan X.,Nankai University
Optics Express | Year: 2010

A substrate with ease for fabrication is proposed for surface enhanced Raman spectroscopy (SERS). A two-dimensional dielectric grating covered by a thin silver film enables the excitation of both localized surface plasmons (LSPs) and surface plasmon polaritons (SPPs). The finitedifference time-domain simulation results show that the coupling between LSPs and SPPs is able to highly improve the Raman enhancement (2 × 109 as obtained by simulation). In addition, the near-field distribution at the top of cubic bumps along the transverse plane presents a highly regular hotspots pattern, which is required for an ideal SERS substrate. © 2009 Optical Society of America.

Talhelm T.,University of Virginia | Zhang X.,Beijing Normal University | Oishi S.,University of Virginia | Shimin C.,South China Normal University | And 3 more authors.
Science | Year: 2014

Cross-cultural psychologists have mostly contrasted East Asia with the West. However, this study shows that there are major psychological differences within China. We propose that a history of farming rice makes cultures more interdependent, whereas farming wheat makes cultures more independent, and these agricultural legacies continue to affect people in the modern world. We tested 1162 Han Chinese participants in six sites and found that rice-growing southern China is more interdependent and holistic-thinking than the wheat-growing north. To control for confounds like climate, we tested people from neighboring counties along the rice-wheat border and found differences that were just as large. We also find that modernization and pathogen prevalence theories do not fit the data.

Li X.,South China Normal University
EPL | Year: 2012

A quantitative thermodynamic model has been presented to investigate the effects of the size of carbon nanotubes and graphene on endocytosis, which provides a simple method to evaluate the optimal size with the fast endocytosis speed. It is found that the optimal radius of a close-ended nanotube increases from 12nm to 25nm by reducing its length to zero. However, an open-ended carbon nanotube has a larger optimal size than that of a close-ended nanotube. Furthermore, theoretical results show that a disk-shaped graphene has an optimal radius of about 25-100nm when its thickness decreases from 20nm to 5nm. The agreement between theoretical results and experimental observations implies that the developed model could be applicable to understand the basic physical mechanism of endocytosis of carbon nanotubes and graphene. © Copyright EPLA, 2012.

Qian J.,South China Normal University
Urban Studies | Year: 2015

This article investigates the state regulation of motorcycle taxis in Guangzhou, China. Motorcycle taxis play an important role in sustaining the livelihood of a subgroup of urban migrants. However, this urban informality has become the object of strict state regulation after the use of motorcycle was outlawed by the Guangzhou Municipal Government. This article examines how dominant representations and discourses of motorcycle mobility are implicated in the right to urban streets. On the one hand it argues that both motorcycle mobility and the motorcycle taxi are socially-produced categories made visible and intelligible through the state-led programmes to ground them in a terrain of constructed knowledge. On the other hand, it is contended that the production of ideologically charged representations and knowledge catalyzes and constitutes the spatialisation of state regulatory power. In particular, this article examines the street-level regulatory practices and how these practices restructure both social relations and state power. It indicates that the local police’s regulation of motorcycle taxis cannot be sufficiently explained merely in terms of state domination and oppression. Instead, it is anchored in the highly moralised imperative of defending the ‘good’, the ‘ordered’ and the ‘respectable’. © 2014, © Urban Studies Journal Limited 2014.

Deng D.,South China Normal University
Applied Physics B: Lasers and Optics | Year: 2012

Based on the fact that a hard-edged aperture function can be expanded into a finite sum of complex Gaussian functions, we obtain the analytical formula for the propagation of the Airy beams in free space and through the fractional Fourier transformation (FrFT) system. According to the derived formulas, the propagation properties of the Airy beams in free space and through the FrFT plane with a hard-edged aperture are illustrated numerically. © 2012 Springer-Verlag.

Zhang Y.,Nanyang Technological University | Zhang X.,Nanyang Technological University | Mei T.,South China Normal University | Mei T.,Nanyang Technological University | Fiddy M.,University of North Carolina at Charlotte
Optics Express | Year: 2010

Surface plasmon modes in structures of metal-insulator-metal (MIM), insulator-insulator-metal (HM) and insulator-metal-insulator (IMI) are studied theoretically for both lossless and lossy cases. Causality dictates which solutions of Maxwell's equations we accept for these structures. We find that for both lossless and lossy cases, the negative index modes and positive index modes are independent and should be treated separately. For the lossless case, our results differ from some published papers. By studying in detail the lossy case, we demonstrate how the curves should look like. © 2010 Optical Society of America.

Zhang Y.,Sun Yat Sen University | Lu Y.-X.,Sun Yat Sen University | Liu J.,Hefei University of Technology | Yang C.,Sun Yat Sen University | And 2 more authors.
PLoS Genetics | Year: 2013

Insect fat body is the organ for intermediary metabolism, comparable to vertebrate liver and adipose tissue. Larval fat body is disintegrated to individual fat body cells and then adult fat body is remodeled at the pupal stage. However, little is known about the dissociation mechanism. We find that the moth Helicoverpa armigera cathepsin L (Har-CL) is expressed heavily in the fat body and is released from fat body cells into the extracellular matrix. The inhibitor and RNAi experiments demonstrate that Har-CL functions in the fat body dissociation in H. armigera. Further, a nuclear protein is identified to be transcription factor Har-Relish, which was found in insect immune response and specifically binds to the promoter of Har-CL gene to regulate its activity. Har-Relish also responds to the steroid hormone ecdysone. Thus, the dissociation of the larval fat body is involved in the hormone (ecdysone)-transcription factor (Relish)-target gene (cathepsin L) regulatory pathway. © 2013 Zhang et al.

Gong Z.,South China Normal University | Nikova S.,University of Twente | Nikova S.,Catholic University of Leuven | Law Y.W.,University of Melbourne
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Resource-efficient cryptographic primitives are essential for realizing both security and efficiency in embedded systems like RFID tags and sensor nodes. Among those primitives, lightweight block cipher plays a major role as a building block for security protocols. In this paper, we describe a new family of lightweight block ciphers named KLEIN, which is designed for resource-constrained devices such as wireless sensors and RFID tags. Compared to related proposals, KLEIN has advantage in the software performance on legacy sensor platforms, while its hardware implementation can be compact as well. © 2012 Springer-Verlag.

Luo L.,Soochow University of China | Zhang L.,Soochow University of China | Dong Y.,Fudan University | Liu T.C.-Y.,South China Normal University
Lasers in Medical Science | Year: 2013

The aim of the present study was to determine the effects of low-level laser therapy (LLLT) on the homeostasis of reactive oxygen species (ROS) and expression of IGF-1 and TGF-β1 in the gastrocnemius muscles of rats following contusion. Muscle regeneration involves cell proliferation, migration, and differentiation and is regulated by growth factors. A growing body of evidence suggests that LLLT promotes skeletal muscle regeneration and accelerates tissue repair. Adult male Sprague-Dawley rats (n = 96) were randomly divided into three groups: control group (no lesion, untreated, n = 6), contusion group (n = 48), and contusion-plus-LLLT group (n = 42). Gallium aluminum arsenide (GaAlAs) laser irradiation (635 nm; beam spot, 0.4 cm 2; output power, 7 mW; power density, 17.5 mW/cm2; 20 min) was administered to the gastrocnemius contusion for 20 min daily for 10 days. Muscle remodeling was evaluated at 0 h and 1, 2, 3, 7, 14, 21, and 28 days after injury. Hematoxylin and eosin and Van Gieson staining were used to evaluate regeneration and fibrosis; muscle superoxide dismutase (SOD) and malondialdehyde (MDA) were detected via biochemical methods; expression of transforming growth factor beta-1 (TGF-β1) and insulin-like growth factor-1 (IGF-1) were investigated via immunohistochemistry. The results showed that LLLT markedly promoted the regeneration of muscle and reduced scar formation. LLLT also significantly enhanced muscle SOD activity and significantly decreased muscle MDA levels 1, 2, and 3 days after injury. LLLT increased the expression of IGF-1 2, 3, and 7 days after injury and decreased the expression of IGF-1 21 and 28 days after injury. LLLT decreased the expression of TGF-β1 3 and 28 days after injury but increased expression at 7 and 14 days after injury. Our study showed that LLLT could modulate the homeostasis of ROS and of the growth factors IGF-1 and TGF-β1, which are known to play important roles in the repair process. This may constitute a new preventive approach to muscular fibrosis. © 2012 Springer-Verlag London Ltd.

Zhu S.-L.,South China Normal University | Shao L.-B.,University of Hong Kong | Wang Z.D.,University of Hong Kong | Duan L.-M.,University of Michigan
Physical Review Letters | Year: 2011

We propose an experiment to directly probe the non-Abelian statistics of Majorana fermions by braiding them in an s-wave superfluid of ultracold atoms. We show that different orders of braiding operations give orthogonal output states that can be distinguished through Raman spectroscopy. Realization of Majorana states in an s-wave superfluid requires strong spin-orbital coupling and a controllable Zeeman field in the perpendicular direction. We present a simple laser configuration to generate the artificial spin-orbital coupling and the required Zeeman field in the dark-state subspace. © 2011 American Physical Society.

Yin C.,South China Normal University | Mihalache D.,Horia Hulubei National Institute of Physics and Nuclear Engineering | He Y.,Guangdong Polytechnic Normal University
Journal of the Optical Society of America B: Optical Physics | Year: 2011

We numerically study the dynamics of two-dimensional spatial solitons on the top of an external umbrella-shaped potential in the cubic-quintic complex Ginzburg-Landau model. Unique scenarios of the dynamics of dissipative spatial solitons interacting with this potential are put forward, such as generation of straight-lined arrays (or "jets"), emission of either one necklace-shaped soliton array or several such soliton arrays, soliton evolution into an oscillatory mode, and soliton spreading. In addition, by changing the number of lateral planes of the external potential, keeping fixed the other parameters of the potential, the various scenarios of soliton dynamics can transform into each other. These results suggest possible applications to signal routing in all-optical information processing devices. © 2011 Optical Society of America.

Zhang Y.,Nanyang Technological University | Darmawan S.,Nanyang Technological University | Tobing L.Y.M.,Nanyang Technological University | Mei T.,South China Normal University | Zhang D.H.,Nanyang Technological University
Journal of the Optical Society of America B: Optical Physics | Year: 2011

This paper presents theoretical studies on the ring-bus-ring (RBR) resonator system, which consist of two resonators indirectly coupled through a center waveguide between them. By controlling the intercavity interaction and engineering the phase response through incorporation of RBR with Mach-Zehnder interferometer, we show that it is possible to generate a spectrum resembling electromagnetically induced transparency (EIT), which is qualitatively different compared to other existing EIT schemes. The transparency becomes sharper as the coupling strength between resonators is increased, with the background spectrum significantly reduced as a result of additional phase shift from indirect coupling. In addition, the EIT-like spectrum is generated out of low-finesse resonators, in contrast with existing EIT schemes where the resonator's finesse is required to be high. Comparisons with finite-differencetime- domain simulation show fairly a good agreement with analytical formulations. © 2010 Optical Society of America.

Yi Z.,Ocean University of China | Yi Z.,South China Normal University | Song W.,Ocean University of China
PLoS ONE | Year: 2011

Previous systematic arrangement on the ciliate order Urostylida was mainly based on morphological data and only about 20% taxa were analyzed using molecular phylogenetic analyses. In the present investigation, 22 newly sequenced species for which alpha-tubulin, SSU rRNA genes or ITS1-5.8S-ITS2 region were sampled, refer to all families within the order. Following conclusions could be drawn: (1) the order Urostylida is not monophyletic, but a core group is always present; (2) among the family Urostylidae, six of 10 sequenced genera are rejected belonging to this family; (3) the genus Epiclintes is confirmed belonging to its own taxon; (4) the family Pseudokeronopsidae undoubtedly belongs to the core portion of urostylids; however, some or most of its members should be transferred to the family Urostylidae; (5) Bergeriellidae is confirmed to be a valid family; (6) the distinction of the taxon Acaudalia is not supported; (7) the morphology-based genus Anteholosticha is extremely polyphyletic; (8) ITS2 secondary structures of Pseudoamphisiella and Psammomitra are rather different from other urostylids; (9) partition addition bootstrap alteration (PABA) result shows that bootstrap values usually tend to increase as more gene partitions are included. © 2011 Yi, Song.

Li X.-Q.,Guangzhou Sport University | Xu Y.,South China Normal University
Optics Communications | Year: 2013

We demonstrate that Photonic Crystal (PhC) based Mach-Zehnder interferometers (MZIs) can be used to realize optical biosensor by using the Fano resonance of the MZIs. Small analyte presented in the MZIs would, however, excite higher-Q Fano resonance of the system than the big one. The scattering object in the arm would create a resonant path (discrete state) for the MZIs, which interacts with the input broadband continuum spectrum and thus results in the Fano resonance of the system. We can therefore detect the location, size and refractive index of biological analyte (down to approximately 100 nm in size) in the MZIs via the output transmission spectrum. An analytical model, which outlines the sensing mechanism, is presented together with the finite difference time domain computer simulations. Both of them validate the proposed sensing capacity. © 2013 Elsevier B.V.

Chen Y.,South China Normal University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

Broadband wave plates working in subwavelength scale are realized by one-dimensional photonic crystals containing negative-index materials. It is demonstrated that the phase shift of reflected wave as a function of frequency changes smoothly within the stop band of the photonic crystal, while it changes sharply within the pass band. In the stop band, the difference between the phase of TE and that of TM reflected wave could remain constant in a rather wide frequency range. These properties are useful for designing compact wave plates or phase retarders which can be used in broad spectral bandwidth. © 2011 Elsevier B.V. All rights reserved.

Studying the properties of nanomaterials can help us to understand the nature of the particular behavior of small-scale materials and forecast new advanced functionalized materials. The cohesive energy, as one of the most important fundamental properties, is strongly connected to the unique properties of nanostructures. In this work, we establish a theoretical model to investigate the effects of size and shape on the cohesive energies of free and embedded nanoparticles based on thermodynamic concepts. It is found that the cohesive energy of free nanoparticles usually decreases as its size decreases. However, there are two distinct variations of embedded nanoparticles in heterogeneous systems. One is that the cohesive energy decreases with the decreasing size, and the other is that the cohesive energy increases as size decreases. The present modeling results and predictions are very consistent with experiments and other existing theoretical models, implying that the model could be expected to be a general approach to understand the cohesive energy of nanomaterials. © 2014 IOP Publishing Ltd.

Zha Z.,Luoyang Normal University | Zha Z.,University of Chinese Academy of Sciences | Wang X.,South China Normal University
IEEE Transactions on Information Theory | Year: 2011

In this paper, two new families of functions in odd characteristic are constructed, and they are proved to be almost perfect nonlinear (APN) functions. Some of the open cases which were introduced by Helleseth are answered by these new APN functions. © 2011 IEEE.

Liu L.,Technical University of Denmark | Liu L.,South China Normal University | Ding Y.,Technical University of Denmark | Ding Y.,Huazhong University of Science and Technology | And 2 more authors.
Optics Letters | Year: 2011

An efficient TE-TM polarization converter built on a silicon-on-insulator nanophotonic platform is demonstrated. The strong cross-polarization coupling effect in air-cladded photonic-wire waveguides is employed to realize the conversion. A peak TE-TM coupling efficiency of 87% (-0.6 dB insertion loss) is measured experimentally. A polarization conversion efficiency of >92% with an overall insertion loss of < - 1.6 dB is obtained in a wavelength range of 40nm. The proposed device is compact, with a total length of 44 μm and can be fabricated with one lithography and etching step. © 2011 Optical Society of America.

Wen P.X.,South China Normal University | Dong L.,Software Testing Center
Proceedings - 4th International Conference on Emerging Intelligent Data and Web Technologies, EIDWT 2013 | Year: 2013

Software-as-a-Service (SaaS) is a new service delivery model which allows customers to use the provider's applications running on a cloud infrastructure, SaaS is commonly utilized and it provides benefits to service providers and customers. As more and more SaaS service emerges, how to select qualified provider is a key problem to customers. Current quality model do not consider key features of SaaS such as security and quality of service (QoS). In this paper, a new quality model is proposed which measure the security, quality of service, and software quality of the SaaS service, from the perspective of platform, provider and customer separately. Base the quality model we proposed an evaluating model which classify the SaaS service into four level, including basic level, standard level, optimized level and integrated level. By using the quality model and evaluating model, customer can evaluate the provider and the provider can use it for quality management. © 2013 IEEE.

Li X.,South China Normal University
Journal of Crystal Growth | Year: 2013

During droplet epitaxy, the shape of final crystalline quantum structures is determined by the growth temperature and As flux density. Here we develop a theoretical model with which we elucidate that the diffusion of III-column element atoms away from the droplet and the trapping of As atoms critically govern the shape of final quantum structures, yielding a shape phase diagram in the space of growth temperature and As flux density. Theoretical investigation suggests that we not only control the basic shape of quantum structures but also design the heights of ring-shaped quantum structures through regulating growth temperature and As flux intensity. © 2013 Elsevier B.V.

Alzheimer's disease irreversibly and progressively damages the brain, but the treatments in clinical trials are too slow. So, we hypothesized that the presence of erythrocyte variants with AD could be used as a noninvasive means to predict or trigger for administration of the preventive therapeutics, and the aim of this study is to develop a method using Raman spectroscopy in a rat model of Aβ25-35-induced neurotoxicity, and then evaluate the protective effect of bajijiasu by this method. Results showed that the Raman spectra fingerprints of the erythrocyte of model group were obvious different from those of the normal control, as peaks around the region 650 cm(-1) belonged to the s-s makers, 1605 cm(-1) corresponded to the high spin (deoxygenated-Hb) marker, 1374 cm(-1) arises from ν4 as a sign of concentration of O2, and 1123 and 1033 cm(-1) are associated with the trans stretching vibrations of CAC skeleton. Results also showed that bajijiasu can make these changes recover. Our study also suggested that erythrocyte variants detected using Raman spectroscopy should be tested in a specific longitudinal study for the association with AD diagnosis, and if positive, can be used as a prognostic marker.

Deng D.,South China Normal University
Optics Communications | Year: 2012

I introduce a class of rotating parabolic cylindrical beams in nonlocal nonlinear media. The rotating speed keeps fixed in the case of strong nonlocality and increases with the nonlocality being weak. For the strong nonlocal case, the analytical solutions of the modified Snyder Mitchell model agree well with the numerical simulations of the nonlocal nonlinear Schrödinger equation. By simulating the propagation of the rotating parabolic cylindrical beams in liquid crystal and nonlinear thermal media numerically, I demonstrate that there exists the rotating parabolic cylindrical cosine Gaussian quasi-soliton state. © 2012 Elsevier B.V. All rights reserved.

Xiao X.,South China University of Technology | Xiao X.,South China Normal University | Zhang W.-D.,South China University of Technology
Journal of Materials Chemistry | Year: 2010

Self-assembled three-dimensional BiOI microspheres composed of nanoplatelets were synthesized at low temperature using ethanol-water mixed solvent as reaction media and NH3·H2O as pH adjustment. The as-prepared BiOI was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, and nitrogen sorption. The possible formation mechanism for the architectures was discussed. It was found that mixed solvent and alkali play key roles in the formation of BiOI microspheres. The photocatalytic activity of the as-prepared sample was evaluated by degradation of phenol in aqueous solution under visible light irradiation. The BiOI microspheres show much higher photocatalytic activity than the random BiOI platelets. The total organic carbon measurement after the degradation process indicated that phenol was effectively mineralized over the BiOI microspheres. In addition, the BiOI microspheres are stable during the reaction and can be used repeatedly. The high catalytic performance of the BiOI microspheres comes from their narrow band gap, high surface area and high surface-to-volume ratio. © The Royal Society of Chemistry 2010.

Shu Y.,South China Normal University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Climate change is an issue that is currently under heated discussion. People believe that carbon emissions are closely related to global warming. Therefore, all nations should take responsibility for solving this problem. According to the Global Carbon Dioxide Emissions Report, released by the Netherlands Environmental Assessment Agency in 2008, China topped the list of CO2 emitting countries, accounting for about a quarter of global CO2 emissions. Anthropogenic CO2 emissions are mainly due to the use of fossil fuels. The amount of CO2 from fossil fuel combustion is an important indicator used to evaluate a country/ region's total CO2 emissions. In China, 76. 6% of CO2 emissions were from fossil fuel combustion, according to China's National Climate Change Programme. Because of global concerns about carbon reduction, high carbon emissions have put great pressure on China's economic development, environmental and ecological protection, and even its international image. Therefore, reducing carbon emissions is not only crucial to China's sustainable development; it is also an urgent international concern. It is important to know how carbon emissions have changed in China to effectively control and reduce carbon emissions from energy consumption. Based on the sectoral approach of the Intergovernmental Panel on Climate Change (IPCC) and eight fuel categories, this paper makes a bottom-up estimate of provincial-level carbon emissions, using data from China from 1990 to 2009. It finds that the values estimated in this paper are higher than in the emission inventory of the International Energy Agency and China's National Climate Change Programme. This paper also analyzes the spatial disparities and temporal changes in carbon emissions, carbon intensity, carbon per capita, and carbon density at the provincial scale. The results show that: 1) An increase in carbon emissions in the past twenty years is a serious problem in China. The spatial pattern of carbon emissions in China has undergone tremendous change over the past two decades. In 2009, there were nine provincial regions in which carbon emissions were extremely heavy; 2) With the steep growth in GDP, carbon intensity decreased year by year. The reduction in emissions was significant in Shanghai and Beijing, with both municipalities exhibiting less than half of the average carbon intensity of China. Furthermore, these cities individually ranked as the antepenultimate and last, respectively, in the annual average growth rate of carbon intensity in 2009; 3) China's low-carbon economy pattern was established in 2009 because of National Development and Reform Commission NDRC's low-carbon pilot projects and low- carbon development plan. Carbon emissions per capita could not be used to evaluate people's living standard and people's occupation of emissions space; 4) Carbon density reflects the difference in carbon emissions per unit area among all of the provincial regions. In 2009, Shanghai's carbon density was highest and Qinghai's was lowest. This paper proposes that the Chinese government should focus on those provincial regions with extra-heavy emissions, and enact policies that improve industrial structure to reduce carbon intensity, use clean energy to lessen carbon emissions per capita, and in the future, to build carbon absorption areas in accordance with carbon density. This analysis on the spatiotemporal characteristics of carbon emissions from energy consumption in China can help policy-makers and energy analysts find an effective way to control and reduce emissions.

Xiao Z.,Sun Yat Sen University | Huang H.,Sun Yat Sen University | Shao C.,Sun Yat Sen University | Xia X.,Sun Yat Sen University | And 6 more authors.
Organic Letters | Year: 2013

Asperterpenol A (1) and asperterpenol B (2), two novel sesterterpenoids with an unusual 5/8/6/6 tetracyclic ring skeleton, were isolated from a mangrove endophytic fungus Aspergillus sp. 085242. The structures were elucidated on the basis of spectroscopic methods and the absolute configurations determined by single-crystal X-ray diffraction analysis. Compounds 1 and 2 inhibit acetylcholinesterase with IC50 values of 2.3 and 3.0 μM, respectively. © 2013 American Chemical Society.

Cen Y.,South China Normal University
Guangxue Jishu/Optical Technique | Year: 2012

In digital holography, holograms are digitally recorded of by a CCD array and the reconstruction of the wave fields are performed numerically on the computer. From the perspective of the Fourier transform, the process is equivalent to spectral analysis of the digital holograms. The impulse response function of a coherent optical imaging system is determined. And complex wave filed of the real image, virtual image and dc terms are examined, under plane reference wave and spherical reference wave illumination. The results show that the real and virtual image can be interpreted as a shifted Fraunhofer diffraction, while the dc terms represent a Fresnel diffraction of the CCD array, which has nothing to do with the reference wave.

Li X.L.,South China Normal University
Journal of Physical Chemistry C | Year: 2010

A quantitative thermodynamic theory has been established to investigate the self-assembly of quantum dots (QDs) on strained substrates. It was found that the driving force of QD formation on strained substrates is different from that on common substrates without extra surface strain. The different driving force results in a smaller critical thickness of wetting layer and a lower barrier energy of QD formation on strained substrates than that on common substrates. The theoretical results not only are in good agreement with the experimental observations but also reveal physical mechanisms involved in the QD self-assembly on strained substrates, which implies that the established thermodynamic theory could be expected to be applicable to address the self-assembly of quantum dots on strained substrates. Copyright © 2010 American Chemical Society.

Pan H.,South China Normal University | Xing R.,Sun Yat Sen University
Nonlinear Analysis: Real World Applications | Year: 2016

Consider the following problem arising in Micro-Electro-Mechanical Systems (MEMS) [equation presented] where δ>0, p>1 and Ω is a bounded smooth domain in RN(N≥1). We prove that infinite time quenching is impossible for any λ>0 in this problem. It provides a remarkable contrast to the case of δ=0, in which infinite time quenching must happen for some λ when Ω is a ball in RN(N≥8). This means that the presence of the fringing field δ|∇u|2 dramatically changes the quenching behavior of the solution. We also obtain some new results about global convergence and quenching in finite time. © 2016 Elsevier Ltd. All rights reserved.

Jie W.,Hong Kong Polytechnic University | Chen X.,University of Hong Kong | Li D.,University of Hong Kong | Li D.,South China Normal University | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2015

Gallium selenide, an important second-order nonlinear semiconductor, has received much scientific interest. However, the nonlinear properties in its two-dimensional (2D) form are still unknown. A strong second harmonic generation (SHG) in bilayer and multilayer GaSe sheets is reported. This is also the first observation of SHG on 2D GaSe thin layers. The SHG of multilayer GaSe above five layers shows a quadratic dependence on the thickness; while that of a sheet thinner than five layers shows a cubic dependence. The discrepancy between the two SHG responses is attributed to the weakened stability of non-centrosymmetric GaSe in the atomically thin flakes where a layer-layer stacking order tends to favor centrosymmetric modification. Importantly, two-photon excited fluorescence has also been observed in the GaSe sheets. Our free-energy calculations based on first-principles methods support the observed nonlinear optical phenomena of the atomically thin layers. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.

Zeng J.,CAS Institute of Chemistry | Jing L.,CAS Institute of Chemistry | Hou Y.,CAS Institute of Chemistry | Jiao M.,CAS Institute of Chemistry | And 6 more authors.
Advanced Materials | Year: 2014

The effect of the anchoring group of surface ligands on the magnetic properties, especially relaxometric properties, of PEGylated Fe 3O4 nanoparticles is investigated. Systematic experimental results together with in-depth theoretical analysis reveal that the ligand binding affinity can largely vary the saturation magnetization, whereas conjugated anchoring groups can remarkably enhance the transverse relaxivity, which highlights a novel approach for achieving high-performance MRI contrast agents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xiao Y.,South China Normal University
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2012

To overcome the difficulty of complex dynamic system modeling, conventional dynamic latent variable method is deeply explored to improve the statistical monitoring performance. Firstly, we point out that dynamic latent variables contain more dynamic information than conventional latent variables, but they still have some autocorrelation. Thus, we suggest adopting non-parametric methods to modify the control charts. For monitoring the residual space, corresponding non-parameter methods are also recommended. In the second aspect, taking the process knowledge and empirical in-control ARL(average run length, ARL) verification into account, a method for choosing the lagged variables and the time-lagged length is proposed. The third feature in our research is to propose a new strategy for identifying fault variable, which is based on the cumulative sum of each variable residual and a RFE (recursive feature elimination, RFE) algorithm. The properties of the foresaid methods are verified through monitoring a double-effect evaporator process.

You J.,South China Normal University | Lin M.P.,National Taiwan Normal University | Fu K.,Chinese University of Hong Kong | Leung F.,Chinese University of Hong Kong
Journal of Abnormal Child Psychology | Year: 2013

This study examined associations of peer socialization and selection, over time, with nonsuicidal self-injury (NSSI) among 5,787 (54.2 % females) Chinese community adolescents. Both effects were tested using two aspects of adolescents' friendship networks: the best friend and the friendship group. Participants completed questionnaires assessing NSSI, depressive symptoms and maladaptive impulsive behaviors at two waves of time over a 6-month period. Results showed that even after controlling for the effects of depressive symptoms and maladaptive impulsive behaviors, the best friends' engagement in NSSI still significantly predicted adolescents' own engagement in NSSI. Adolescents' friendship groups' NSSI status also significantly predicted their own NSSI status and frequency. Additionally, adolescents with NSSI tended to join peer groups with other members also engaging in NSSI. © 2013 Springer Science+Business Media New York.

Li S.,CAS Lanzhou Institute of Chemical Physics | Li S.,University of Chinese Academy of Sciences | Jia C.,CAS Lanzhou Institute of Chemical Physics | Jia C.,University of Chinese Academy of Sciences | And 7 more authors.
Angewandte Chemie - International Edition | Year: 2011

A word in urea: A strategy of mimicking the scaffold and metal coordination behavior of oligo-2,2′-bipyridine ligands was used to obtain a triple anion helicate from a bis(biurea) receptor and phosphate ions. The successful assembly of the triple helical structure provides guidelines for the design of new anion ligands by taking advantage of the similarities of metal and anion coordination. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gao X.,Max Planck Institute of Microstructure Physics | Gao X.,South China Normal University | Rodriguez B.J.,Max Planck Institute of Microstructure Physics | Liu L.,Max Planck Institute of Microstructure Physics | And 5 more authors.
ACS Nano | Year: 2010

A nanofabrication technique combining pulsed laser deposition and a nanoporous anodic aluminum oxide membrane mask is being proposed to prepare various types of multiferroic nanocomposites, viz. periodically ordered CoFe2O4 dots covered by a continuous Pb(Zr,Ti)O 3 layer, Pb(Zr,Ti)O3 dots covered with CoFe 2O4, and Pb(Zr,Ti)O3/CoFe2O 4 bilayer heterostructure dots. By properly tuning the processing parameters, epitaxial nanodot-matrix composites can be obtained. For the composite consisting of CoFe2O4 nanostructures covered by a Pb(Zr,Ti)O3 film, an unexpected out-of-plane magnetic easy axis induced by the top Pb(Zr,Ti)O3 layer and a uniform microdomain structure can be observed. The nanocomposites tested by piezoresponse force microscopy (PFM) exhibit strong piezoelectric signals, and they also display magnetoelectric coupling revealed by magneticfield dependent capacitance measurement. © 2010 American Chemical Society.

Lei J.F.,Henan University of Science and Technology | Li L.B.,Henan University of Science and Technology | Shen X.H.,Tarim University | Du K.,Henan University of Science and Technology | And 3 more authors.
Langmuir | Year: 2013

Two kinds of ordered ZnO/TiO2 heterostructures were fabricated via a facile approach. The architecture of the TiO2 substrate could be controlled by alternating the filling forms of the template, and the morphology of the secondary ZnO nanostructure could be further tuned by adjusting the parameters of the hydrothermal reaction. Then two different morphologies of ZnO/TiO2 heteroarchitectures with ZnO nanorods and nanoplates growing on TiO2 shells and bowls were successfully achieved, respectively. © 2013 American Chemical Society.

Chen W.-S.,South China Normal University
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the title compound, [Co(C4H3N2O 2)2(H2O)2], the CoII ion is located on a twofold rotation axis and shows a distorted octahedral coordination configuration, defined by two N,O-bidentate 1H-imidazole-4- carboxylate ligands in the equatorial plane and two water molecules in the axial positions. In the crystal, O-H···O and N-H···O hydrogen bonds link the molecules into a three-dimensional supramolecular network. π-π stacking interactions between the imidazole rings [centroid-centroid distances = 3.4914 (15) and 3.6167 (15) Å] further stabilize the crystal structure.

Hong W.-Y.,South China Normal University
Wuli Xuebao/Acta Physica Sinica | Year: 2015

Nonlocal nonlinearity is one of the hottest topics in the nonlinear optics and even the nonlinear science. In this paper, the frequency chirp induced by the self-phase modulation (SPM) in a high noninstantaneous medium is investigated. It is found that the temporal distribution of the SPM-induced chirp can be approximated by the "inverted image" of the pulse intensity in the highly noninstantaneous limit. Moreover, this property does not depend on the envelope of the pulse. By using these properties, the temporal characteristics of the pulse propagation in a highly noninstantaneous medium is analyzed. © 2015 Chinese Physical Society.

Xu J.,South China Normal University
Communications in Theoretical Physics | Year: 2014

Recently a new type of experiment, i.e., Bloch oscillations of ultracold atoms in honeycomb optical potential, realized Landau - Zener transition in the vicinity of Dirac point in 2D optical lattice. We show that the slope of Dirac cone is related to the transition probability of Landau-Zener transition. Therefore, it provides a new tool to directly detect the energy spectrum in the vicinity of Dirac point. Moreover, we numerically demonstrate that our scheme is feasible and effective in a large range of the parameter of anisotropy. © 2014 Chinese Physical Society and IOP Publishing Ltd.

Tao J.,Nanyang Technological University | Wang Q.J.,Nanyang Technological University | Huang X.G.,South China Normal University
Plasmonics | Year: 2011

All-optical plasmonic switches based on a novel coupled nano-disk cavity configuration containing nonlinear material are proposed and numerically investigated. The finite difference time domain simulation results reveal that the single-disk plasmonic structure can operate as an "on-off" switch with the presence/absence of pumping light. We also demonstrate that the proposed T-shaped plasmonic structure with two disk cavities can switch signal light from one port to another under an optical pumping light, functioning as a bidirectional switch. The proposed nano-disk cavity plasmonic switches have many advantages such as compact size, requirement of low pumping light intensity, and ultra-fast switching time at a femto-second scale, which are promising for future integrated plasmonic devices for applications such as communications, signal processing, and sensing. © 2011 Springer Science+Business Media, LLC.

Yu R.,South China Normal University | Yu R.,Peking University | Zhou W.,University of Mississippi Medical Center | Zhou X.,Peking University
PLoS ONE | Year: 2011

Reward probability and uncertainty are two fundamental parameters of decision making. Whereas reward probability indicates the prospect of winning, reward uncertainty, measured as the variance of probability, indicates the degree of risk. Several lines of evidence have suggested that the anterior cingulate cortex (ACC) plays an important role in reward processing. What is lacking is a quantitative analysis of the encoding of reward probability and uncertainty in the human ACC. In this study, we addressed this issue by analyzing the feedback-related negativity (FRN), an event-related potential (ERP) component that reflects the ACC activity, in a simple gambling task in which reward probability and uncertainty were parametrically manipulated through predicting cues. Results showed that at the outcome evaluation phase, while both win and loss-related FRN amplitudes increased as the probability of win or loss decreased, only the win-related FRN was modulated by reward uncertainty. This study demonstrates the rapid encoding of reward probability and uncertainty in the human ACC and offers new insights into the functions of the ACC. © 2011 Yu et al.

Li N.-X.,South China Normal University | Jin L.-W.,South China University of Technology
International Journal on Document Analysis and Recognition | Year: 2013

This paper presents a new Bayesian-based method of unconstrained handwritten offline Chinese text line recognition. In this method, a sample of a real character or non-character in realistic handwritten text lines is jointly recognized by a traditional isolated character recognizer and a character verifier, which requires just a moderate number of handwritten text lines for training. To improve its ability to distinguish between real characters and non-characters, the isolated character recognizer is negatively trained using a linear discriminant analysis (LDA)-based strategy, which employs the outputs of a traditional MQDF classifier and the LDA transform to re-compute the posterior probability of isolated character recognition. In tests with 383 text lines in HIT-MW database, the proposed method achieved the character-level recognition rates of 71. 37% without any language model, and 80.15% with a bi-gram language model, respectively. These promising results have shown the effectiveness of the proposed method for unconstrained handwritten offline Chinese text line recognition. © 2011 Springer-Verlag.

Li G.-Y.,South China Agricultural University | Liu M.-G.,South China Normal University
ICACTE 2010 - 2010 3rd International Conference on Advanced Computer Theory and Engineering, Proceedings | Year: 2010

Differential evolution algorithm as a global optimization method in engineering field has broad applicability. In order to facilitate researchers studying differential evolution algorithm, this paper expounds, comparatives and analyses the differential evolution algorithm and its improved measures based on researching materials of differential evolution algorithm at home and abroad. It shows that differential evolution algorithm is simple, easy to use, various improvements have improved differential evolution algorithm's optimization capability in varying degrees. The future should strengthen the basic theory and collaborative optimization ways research of differential evolution algorithm. © 2010 IEEE.

Hu X.,South China Normal University | Hu X.,Anhui University of Science and Technology | Liu S.,Anhui University of Science and Technology
Dalton Transactions | Year: 2015

Responsive polymeric assemblies and hybrid superstructures fabricated from stimuli-sensitive polymers and inorganic nanoparticles (NPs) have been the subject of extensive investigations during the past few decades due to their distinct advantages such as an improved water solubility, stimuli-responsiveness, excellent biocompatibility, and facile introduction of functional units. In addition, the chemical compositions of polymeric assemblies and corresponding hybrid superstructures can be modulated via the initial synthetic design to target desired functions, fabricate smart nanostructures, and explore morphology-dependent functional optimization. Promising applications in the field of imaging, sensing, drug/gene delivery, diagnostics, and nanoreactors are being extensively investigated. This perspective article focuses on recent developments, microstructural control, and biomedical applications of stimuli-responsive polymeric assemblies as well as responsive hybrid superstructures fabricated from responsive polymers and inorganic NP building blocks (gold NPs and magnetic iron oxide NPs), and highlights their current status and future developments with selected literature reports. © 2015 The Royal Society of Chemistry.

Hong X.,South China Normal University | Luo Z.,Texas A&M University | Batteas J.D.,Texas A&M University
Journal of Solid State Chemistry | Year: 2011

In order to prepare visible-light responsive iodine-doped TiO2, a new facile synthetic approach was proposed, which started with the cost-efficient and environmentally friendly precursor of undoped anatase TiO2 to form nanotube structures as templates that collapsed and recrystallized into I-TiO2 nanopowders in HIO3 solution, followed by annealing at different temperatures. The modification of TiO 2 to incorporate iodine and form titanium dioxide with significantly enhanced absorption in the visible range of the spectrum was investigated. The extent of iodine dopant incorporation was determined by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDX) and was found to be homogenously distributed on each nanostructure as determined by electron energy-loss spectroscopy (EELS) elemental mapping and EDX spectroscopy. The modified TiO2 exhibits a dramatically extended absorption edge beyond 800 nm as compared to the original and unmodified TiO2. © 2011 Elsevier Inc. All rights reserved.

Hu X.,Anhui University of Science and Technology | Hu X.,South China Normal University | Liu G.,Anhui University of Science and Technology | Li Y.,Anhui University of Science and Technology | And 2 more authors.
Journal of the American Chemical Society | Year: 2015

The rational design of theranostic nanoparticles exhibiting synergistic turn-on of therapeutic potency and enhanced diagnostic imaging in response to tumor milieu is critical for efficient personalized cancer chemotherapy. We herein fabricate self-reporting theranostic drug nanocarriers based on hyperbranched polyprodrug amphiphiles (hPAs) consisting of hyperbranched cores conjugated with reduction-activatable camptothecin prodrugs and magnetic resonance (MR) imaging contrast agent (Gd complex), and hydrophilic coronas functionalized with guanidine residues. Upon cellular internalization, reductive milieu-actuated release of anticancer drug in the active form, activation of therapeutic efficacy (>70-fold enhancement in cytotoxicity), and turn-on of MR imaging (∼9.6-fold increase in T1 relaxivity) were simultaneously achieved in the simulated cytosol milieu. In addition, guanidine-decorated hPAs exhibited extended blood circulation with a half-life up to ∼9.8 h and excellent tumor cell penetration potency. The hyperbranched chain topology thus provides a novel theranostic polyprodrug platform for synergistic imaging/chemotherapy and enhanced tumor uptake. © 2014 American Chemical Society.

Wang Z.-P.,Guangdong Pharmaceutical University | Chen T.-S.,South China Normal University
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2013

Hepatocarcinoma, a malignant cancer, threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistence of the advanced hepatocarcinoma to chemotherapy. In this report, we assessed the antitumor activity of a prunellae spica aqueous extract (PSE) in vitro and in vivo. PSE was quantified by HPLC and UV. MTT assay showed that PSE did not effectively inhibit the growth of H22 cells. The in vivo anti-tumor activity was assessed by using the mice bearing H22 tumor. In vivo studies showed the higher antitumor efficacy of PSE without significant side effect assessed by the reduced tumor weight, and the extended survival time of the mice bearing H22 solid and ascites tumor. Collectively, PSE is a promising Chinese medicinal herb for treating hepatocarcinoma. © Copyright SPIE.

Tu X.,Nanyang Technological University | Ang S.S.N.,Institute of Materials Research and Engineering of Singapore | Chew A.B.,Institute of Materials Research and Engineering of Singapore | Teng J.,Institute of Materials Research and Engineering of Singapore | Mei T.,South China Normal University
IEEE Photonics Technology Letters | Year: 2010

We experimentally realize a cross-slot waveguide based on GaAsAlGaAsGaAs substrate carrying both of transverse-electric slot mode and transverse-magnetic slot mode. A low refractive index AlOx layer is formed between two high index GaAs layers by thermal oxidation method. A polarization splitter is obtained through a 25- μm-long ultracompact directional coupler based on the waveguide. The measured result fits well with calculation using the beam-propagation method. © 2010 IEEE.

Zheng R.,Massachusetts Institute of Technology | Zheng R.,Beijing Normal University | Gao J.,Massachusetts Institute of Technology | Gao J.,South China Normal University | And 6 more authors.
Nano Letters | Year: 2012

Different from the electrical conductivity of conductive composites, the thermal conductivity usually does not have distinctive percolation characteristics. Here we report that graphite suspensions show distinct behavior in the thermal conductivity at the electrical percolation threshold, including a sharp kink at the percolation threshold, below which thermal conductivity increases rapidly while above which the rate of increase is smaller, contrary to the electrical percolation behavior. Based on microstructural and alternating current impedance spectroscopy studies, we interpret this behavior as a result of the change of interaction forces between graphite flakes when isolated clusters of graphite flakes form percolated structures. Our results shed light on the thermal conductivity enhancement mechanisms in nanofluids and have potential applications in energy systems. © 2011 American Chemical Society.

Wang X.,South China Normal University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2010

Poly-N-isopropylacrylamide (PNIPAAm) is a new kind of intelligent material. It shows favorable thermo sensitivity because of the structure of hydrophilic acrylamino and hydrophobic isopropyl. PNIPAAm also shows good biocompatibility and non-toxicity. All the characters as above make it an ideal extra cellular matrix material for tissue engineering. This paper reviews its application in tissue engineering.

Zhang D.-W.,South China Normal University | Cao S.,South China Agricultural University
Laser Physics Letters | Year: 2016

We propose a realistic scheme to directly probe the Chern number of topological Weyl semimetals in optical lattices. The Weyl semimetal states can be realized with ultracold fermionic atoms trapped in three-dimensional optical lattices, and are topologically characterized by kz-dependent Chern number, where kz is the out-of-plane quasimomentum. We demonstrate with numerical simulations that this characteristic topological invariant can be extracted from the shift of the hybrid Wannier center in the optical lattice, based on the particle pumping approach. Through in situ measurement of atomic density, the topological properties of the Weyl semimetal states are then directly revealed. © 2016 Astro Ltd.

Jia X.,Henan Polytechnic University | Wang S.,Beijing Normal University | Qin M.,South China Normal University
New Journal of Physics | Year: 2016

Based on atomic first principles, we predict enhanced thermal spin transfer (TST) effects and small switching temperature gradient in Fe |MgO|Fe |MgO|Fe double-barrier magnetic tunnel junctions (MTJs). At room temperature, temperature gradient δ10 K with ∇T ∼10Knm?1 across barriers would be sufficient to switch the magnetic configurations circularly in a junction with 3MgOatomic layers (L), which is about one order smaller than that in Fe |MgO(3L) |Fe MTJs. This temperature gradient is under the current experimental capability. The resonant quantum-well states in companion with resonant interfacial states are responsible for the enhancement. Moreover, a thermal induced 'off' state is found in a double-barrier MTJ. © 2016 IOP Publishing Ltd.

Wu N.-Y.,Shangqiu Normal University | Gao W.,Chenguang Biotech | He X.-L.,South China Normal University | Chang Z.,Shangqiu Normal University | Xu M.-T.,Shangqiu Normal University
Biosensors and Bioelectronics | Year: 2013

A direct electrochemical DNA biosensor based on zero current potentiometry was fabricated by immobilization of ssDNA onto gold nanoparticles (AuNPs) coated pencil graphite electrode (PGE). One ssDNA/AuNPs/PGE was connected in series between clips of working and counter electrodes of a potentiostat, and then immersed into the solution together with a reference electrode, establishing a novel DNA biosensor for specific DNA detection. The variation of zero current potential difference (ΔEzcp) before and after hybridization of the self-assembled probe DNA with the target DNA was used as a signal to characterize and quantify the target DNA sequence. The whole DNA biosensor fabrication process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy with the use of ferricyanide as an electrochemical redox indicator. Under the optimized conditions, ΔEzcp was linear with the concentrations of the complementary target DNA in the range from 10nM to 1μM, with a detection limit of 6.9nM. The DNA biosensor showed a good reproducibility and selectivity. Prepared DNA biosensor is facile and sensitive, and it eliminates the need of using exogenous reagents to monitor the oligonucleotides hybridization. © 2012 Elsevier B.V..

Yan X.,South China Normal University
Advances in Information Sciences and Service Sciences | Year: 2012

Improving customer value is important process for modern organization to satisfy customer's needs and obtain competitive advantage. However, the process of identifying and choosing customer values is dynamic and full of subjective knowledge because individual worldviews and values are very different. The subjective characters of customer value bring organization managers an uncer tainproblem situation which the traditional methodology of positivism can not solve. To solve this problematic situation, this paper employs social paradigm of functionalism and interpretivism to analyze the social action of customer value. It indicates that soft system methodology which derived from interpretive paradigm can integrate subjective and objective analysis to deal with identifying and choosing customers values.

Yin X.,Shandong University | Han Y.,Qingdao University | Ge H.,Shandong University | Xu W.,Qingdao University | And 6 more authors.
Human Brain Mapping | Year: 2013

White matter (WM) asymmetries of the human brain have been well documented using diffusion tensor imaging (DTI). However, the relationship between WM asymmetry pattern and cognitive performance is poorly understood. By means of tract-based spatial statistics (TBSS) and voxel-based analyses of whole brain, this study examined the WM asymmetries and the correlations between WM integrity/asymmetries and three distinct components of attention, namely alerting, orienting, and executive control (EC), which were assessed by attention network test (ANT). We revealed a number of WM anisotropy asymmetries, including leftward asymmetry of cingulum, corticospinal tract and cerebral peduncle, rightward asymmetry of internal capsule, superior longitudinal fasciculus and posterior corona radiata, as well as heterogeneous asymmetries in anterior corpus callosum and anterior corona radiata (ACR). Moreover, specific correlation was found between asymmetric pattern of inferior frontal ACR and EC performance. Additionally, this study also proposed that there were no significant relationships of WM anisotropy asymmetries to alerting and orienting functions. Further clusters of interest analyses and probabilistic fiber tracking validated our findings. In conclusion, there are a number of differences in WM integrity between human brain hemispheres. Specially, the anisotropy asymmetry in inferior frontal ACR plays a crucial role in EC function. Our finding is supportive of the functional studies of inferior frontal regions and in keeping with the theory of the brain lateralization on human ventral attention system. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc..

Zhenzhou C.,South China Normal University
Advances in Information Sciences and Service Sciences | Year: 2012

Support Vector Machine (SVM) is an important supervised learning method used for classification, especially for 2-class problem. However, it tends to give undesired results if samples in some class form several separate clusters, i.e., multimodal. This paper presents a clustering algorithm that can be used to preprocess standard training data and show how SVM can be simply extended to deal with clustered data. The proposed method is called local SVM (LSVM) with clustering for multimodal data. First new subclasses are formed by clustering data according to each class, and then the multisubclass data is classified by a multi-class SVM. LSVM is applied to digits and images recognition problems, and the experimental results show that the performance of present method is superior to the original method.

Lu D.-Q.,South China Normal University
Guangzi Xuebao/Acta Photonica Sinica | Year: 2013

Based on the propagation equation which governs the propagation of ultra-short pulsed beams, and by utilizing the Fourier transform technique as well as the commutation relation between two mathematical operators, the analytical solution for ultra-short pulsed radially polarized beams is obtained. This solution is applicable to radially polarized beams driven by any pulse. On the basis of the solution, the propagation properties of the ultra-short pulsed radially polarized beams are discussed. It shows that the pulse at the beam periphery is delayed compares to that around the beam center. This effect results in the the varying of transverse intensity distribution of the ultra-short pulsed radially polarized beam at different temporal positions during propagation, and the asymmetric intensity distribution of the vertical profle at the head and the trail of the pulse. The method used in this paper is applicable in obtaining the analytical solution and the propagation properties for the ultra-short pulsed azimuthally polarized beams.

Lai H.-J.,Sun Yat Sen University | Pan Y.,Sun Yat Sen University | Tang Y.,South China Normal University | Yu R.,Guangdong University of Technology
IEEE Transactions on Neural Networks and Learning Systems | Year: 2013

In recent years, there has been growing interest in learning to rank. The introduction of feature selection into different learning problems has been proven effective. These facts motivate us to investigate the problem of feature selection for learning to rank. We propose a joint convex optimization formulation which minimizes ranking errors while simultaneously conducting feature selection. This optimization formulation provides a flexible framework in which we can easily incorporate various importance measures and similarity measures of the features. To solve this optimization problem, we use the Nesterov's approach to derive an accelerated gradient algorithm with a fast convergence rate O(1/T2). We further develop a generalization bound for the proposed optimization problem using the Rademacher complexities. Extensive experimental evaluations are conducted on the public LETOR benchmark datasets. The results demonstrate that the proposed method shows: 1) significant ranking performance gain compared to several feature selection baselines for ranking, and 2) very competitive performance compared to several state-of-the-art learning-to-rank algorithms. © 2012 IEEE.

Zhang T.,Hong Kong Baptist University | Zhang T.,South China Normal University | Chan C.-F.,Hong Kong Baptist University | Lan R.,Hong Kong Baptist University | And 2 more authors.
Chemistry - A European Journal | Year: 2014

A new lanthanide probe based on the fluorescence resonance energy transfer (FRET) process with the combination of ytterbium porphyrinate complex and a rhodamine B derivative unit was synthesized to detect the Hg2+ ion with responsive emission in the visible and near-IR region with a detection limit of 10 μM Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mei L.,Lund University | Svanberg S.,Lund University | Svanberg S.,South China Normal University
Applied Optics | Year: 2015

This work presents a detailed study of the theoretical aspects of the Fourier analysis method, which has been utilized for gas absorption harmonic detection in wavelength modulation spectroscopy (WMS). The lock-in detection of the harmonic signal is accomplished by studying the phase term of the inverse Fourier transform of the Fourier spectrum that corresponds to the harmonic signal. The mathematics and the corresponding simulation results are given for each procedure when applying the Fourier analysis method. The present work provides a detailed view of the WMS technique when applying the Fourier analysis method. © 2015 Optical Society of America.

Ai B.-Q.,South China Normal University | He Y.-F.,Hebei University | Zhong W.-R.,Jinan University
Soft Matter | Year: 2015

Dynamics and separation of mixed chiral microswimmers are numerically investigated in a channel with regular arrays of rigid half-circle obstacles. For zero shear flow, transport behaviors are the same for different chiral particles: the average velocity decreases with increase of the rotational diffusion coefficient, the direction of the transport can be reversed by tuning the angular velocity, and there exists an optimal value of the packing fraction at which the average velocity takes its maximal value. However, when the shear flow is considered, different chiral particles show different behaviors. By suitably tailoring parameters, particles with different chiralities can move in different directions and can be separated. In addition, we also proposed a space separation method by introducing a constant load, where counterclockwise and clockwise particles stay in different regions of the channel. © The Royal Society of Chemistry 2015.

Qiu Y.,Hong Kong University of Science and Technology | Yan K.,Hong Kong University of Science and Technology | Deng H.,Hong Kong University of Science and Technology | Deng H.,South China Normal University | Yang S.,Hong Kong University of Science and Technology
Nano Letters | Year: 2012

A photoanode based on ZnO nanotetrapods, which feature good vectorial electron transport and network forming ability, has been developed for efficient photoelectrochemical water splitting. Two strategies have been validated in significantly enhancing light harvesting. The first was demonstrated through a newly developed branch-growth method to achieve secondary and even higher generation branching of the nanotetrapods. Nitrogen-doping represents the second strategy. The pristine ZnO nanotetrapod anode yielded a photocurrent density higher than those of the corresponding nanowire devices reported so far. This photocurrent density was significantly increased for the new photoanode architecture based on the secondary branched ZnO nanotetrapods. After N-doping, the photocurrent density enjoyed an even more dramatic enhancement to 0.99 mA/cm 2 at +0.31 V vs Ag/AgCl. The photocurrent enhancement is attributed to the greatly increased roughness factor for boosting light harvesting associated with the ZnO nanotetrapod branching, and the increased visible light absorption due to the N-doping induced band gap narrowing of ZnO. © 2011 American Chemical Society.

Wang Y.,South China Normal University | Sun T.,Boston College | Paudel T.,Boston College | Zhang Y.,Boston College | And 2 more authors.
Nano Letters | Year: 2012

We show that a planar structure, consisting of an ultrathin semiconducting layer topped with a solid nanoscopically perforated metallic film and then a dielectric interference film, can highly absorb (superabsorb) electromagnetic radiation in the entire visible range, and thus can become a platform for high-efficiency solar cells. The perforated metallic film and the ultrathin absorber in this broadband superabsorber form a metamaterial effective film, which negatively refracts light in this broad frequency range. Our quantitative simulations confirm that the superabsorption bandwidth is maximized at the checkerboard pattern of the perforations. These simulations show also that the energy conversion efficiency of a single-junction amorphous silicon solar cell based on our optimized structure can exceed 12%. © 2011 American Chemical Society.

Le Thi Ngoc L.,MESA Institute for Nanotechnology | Jin M.,MESA Institute for Nanotechnology | Jin M.,South China Normal University | Wiedemair J.,MESA Institute for Nanotechnology | And 2 more authors.
ACS Nano | Year: 2013

We report a new top-down nanofabrication technology to realize large area metal nanowire (m-NW) arrays with tunable sub-20 nm separation nanogaps without the use of chemical etching or milling of the metal layer. The m-NW array nanofabrication technology is based on a self-regulating metal deposition process that is facilitated by closely spaced and isolated heterogeneous template surfaces that confine the metal deposition into two dimensions, and therefore, electrically isolated parallel arrays of m-NW can be realized with uniform and controllable nanogaps. Au-NW and Ag-NW arrays are presented with high-density ∼105 NWs cm-1, variable NW diameters down to ∼50 nm, variable nanogaps down to ∼5 nm, and very large nanogap length density ∼1 km cm-2. The m-NW arrays are designed and implemented as interdigitated nanoelectrodes for electrochemical applications and as plasmonic substrates where the coupled-mode localized surface plasmon resonance (LSPR) wavelength in the nanogaps between adjacent m-NW dimers can be precisely tuned to match any excitation source in the range from 500 to 1000 nm, thus providing optimal local electromagnetic field enhancement. A spatially averaged (n = 2500) surface-enhanced Raman scattering (SERS) analytical enhancement factor of (1.2 ± 0.1) × 107 is demonstrated from a benzenethiol monolayer chemisorbed on a Au-NW array substrate with LSPR wavelength matched to a He-Ne laser source. © 2013 American Chemical Society.

Feng C.,Nanyang Technological University | Mei T.,South China Normal University | Hu X.,Nanyang Technological University
Organic Electronics: physics, materials, applications | Year: 2011

Wet-chemical treatment on the gate dielectric, i.e. tuning the chemical properties via the choice of the buffer dielectric, has been widely employed to study the morphology and growth mode of organic semiconductors (OSCs). Through these studies, further understanding of charge transport mechanisms is obtained, and the electrical performances of organic field-effect transistors (OFETs), e.g. charge carrier mobility, on/off current ratio and subthreshold swing, thus have been greatly improved. In order to achieve a useful device, its stability becomes extremely important. In this article, the study on the charge trapping at the dielectric-dielectric interface by using the combination of poly(methyl methacrylate) (PMMA) and silicon dioxide (SiO2) dual-dielectric was carried out under dark and illuminated conditions. Our results showed that the thickness of the PMMA layer, determining the film uniformity and the magnitude of charge injection barrier, plays a decisive role in the charge trapping process. With the thickness optimized, the device stability is greatly enhanced. Our findings bring about a low-cost, easy-to-realize fabrication method to produce high-performance and stable/reliable OFETs. © 2011 Elsevier B.V. All rights reserved.

Zhang T.,Hong Kong Baptist University | Zhang T.,South China Normal University | Lan R.,Hong Kong Baptist University | Chan C.-F.,Hong Kong Baptist University | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

In this work, we demonstrate a modality of photodynamic therapy (PDT) through the design of our truly dual-functional - PDT and imaging - gadolinium complex (Gd-N), which can target cancer cells specifically. In the light of our design, the PDT drug can specifically localize on the anionic cell membrane of cancer cells in which its laser-excited photoemission signal can be monitored without triggering the phototoxic generation of reactive oxygen species - singlet oxygen - before due excitation. Comprehensive in vitro and in vivo studies had been conducted for the substantiation of the effectiveness of Gd-N as such a tumor-selective PDT photosensitizer. This treatment modality does initiate a new direction in the development of "precision medicine" in line with stem cell and gene therapies as tools in cancer therapy. © 2014, National Academy of Sciences. All rights reserved.

Zheng R.,Massachusetts Institute of Technology | Zheng R.,Beijing Normal University | Gao J.,Massachusetts Institute of Technology | Gao J.,South China Normal University | And 2 more authors.
Nature Communications | Year: 2011

Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions. © 2011 Macmillan Publishers Limited. All rights reserved.

Liu C.,Dongguk University | Xu Y.,Dongguk University | Ghibaudo G.,Stendhal University | Lu X.,South China Normal University | And 2 more authors.
Applied Physics Letters | Year: 2014

Contact resistance (RC), which dominates the performance of organic field-effect transistors (OFETs), relates multiple factors such as charge injection, transport, and device architecture. Here, we focus on physical meaning of the convergence point in conventional transfer-length method, and clarify the correlation between charge injection and geometrical parameters of OFETs by simulations. We also defined the effect of band-like/hopping transport in semiconductor on the charge injection process, where less hopping transport results in lower and less gate-voltage dependent RC. These results were confirmed by experiments on pentacene OFETs and reveal the values of convergence point in OFET research. © 2014 AIP Publishing LLC.

Li J.,South China Normal University
Proceedings. Biological sciences / The Royal Society | Year: 2013

We propose that delayed predator-prey models may provide superficially acceptable predictions for spurious reasons. Through experimentation and modelling, we offer a new approach: using a model experimental predator-prey system (the ciliates Didinium and Paramecium), we determine the influence of past-prey abundance at a fixed delay (approx. one generation) on both functional and numerical responses (i.e. the influence of present : past-prey abundance on ingestion and growth, respectively). We reveal a nonlinear influence of past-prey abundance on both responses, with the two responding differently. Including these responses in a model indicated that delay in the numerical response drives population oscillations, supporting the accepted (but untested) notion that reproduction, not feeding, is highly dependent on the past. We next indicate how delays impact short- and long-term population dynamics. Critically, we show that although superficially the standard (parsimonious) approach to modelling can reasonably fit independently obtained time-series data, it does so by relying on biologically unrealistic parameter values. By contrast, including our fully parametrized delayed density dependence provides a better fit, offering insights into underlying mechanisms. We therefore present a new approach to explore time-series data and a revised framework for further theoretical studies.

Zhang B.,Chinese Academy of Sciences | Luo W.,South China Normal University | Jia X.,Australian Defence Force Academy
IEEE Transactions on Geoscience and Remote Sensing | Year: 2012

Endmember extraction (EE) is the first step in hyperspectral data unmixing. N-FINDR is one of the most commonly used EE algorithms. Nevertheless, its computational complexity is high, particularly, for a large data set. Following a parallel version of N-FINDR, i.e., P-FINDR, further improvements are presented in this paper. First, generic endmember re-extraction operation (GERO) and multiple search paths are introduced such that multiple endmembers are extracted in parallel. Second, by making full use of the advantages of the proposed algorithms, two extended schemes, i.e., extended mapping rule and multiple-stage GERO are presented, which can reduce synchronous cost and provide steady parallel performance. In experiments, the proposed algorithms have been quantitatively evaluated. The results demonstrate that they can outperform the conventional parallel computing and do not degrade the quality of EE. © 1980-2012 IEEE.

Jiao X.,South China University of Technology | Jiao X.,South China Normal University | Ding K.,South China University of Technology | He G.,South China University of Technology
Measurement: Journal of the International Measurement Confederation | Year: 2014

On the basis of analyzing the cause of coefficients distortion inhered in the existing wavelet packet transform algorithms, a new method is presented to rectify the distortion and improve the accuracy. Its principle is to implement compensation calculation by using the complementary characteristic of wavelet filters. The simulation result of a typical signal shows the method is effective in improving the accuracy of wavelet packet coefficients. The influences of the compensation calculation times and vanishing moments of the wavelet are analyzed. Theoretically, the maximum error could be reduced to 25% with one time compensation calculation. The results show that with two and four times compensation calculations, the error is reduced to 10% and 2% respectively. The experiment result of the vibration signal of a roller bearing with outer ring fault shows that the proposed method can effectively magnify the amplitude of the fault frequencies in practice. © 2013 Elsevier Ltd. All rights reserved.

Chen Z.,South China Normal University
Acta Mathematica Scientia | Year: 2014

In this article, for a transcendental entire function f(z) of finite order which has a finite Borel exceptional value α, we utilize properties of complex difference equations to prove the difference counterpart of Brück's conjecture, that is, if δ f(z)= f(z+η)-f(z) and f(z) share one value a(≠α) CM, where η ∈ ℂ is a constant such that f(z+η)≡ f(z), then δf(z)-af(z)-a=aa-α. © 2014 Wuhan Institute of Physics and Mathematics.

Yang Y.,Xiangtan University | Chen Y.,South China Normal University | Huang Y.,Xiangtan University
Acta Mathematica Scientia | Year: 2014

We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method, which shows that the errors of the approximate solution decay exponentially in L∞ norm and weighted L2-norm. The numerical examples are given to illustrate the theoretical results. © 2014 Wuhan Institute of Physics and Mathematics.

Deng C.,South China Normal University
Acta Mathematica Scientia | Year: 2014

This note is to present some results on the group invertibility of linear combinations of idempotents when the difference of two idempotents is group invertible. © 2014 Wuhan Institute of Physics and Mathematics.

McKenzie R.L.,NIWA - National Institute of Water and Atmospheric Research | Aucamp P.J.,Ptersa Environmental Management Consultants | Bais A.F.,Aristotle University of Thessaloniki | Bjorn L.O.,South China Normal University | And 3 more authors.
Photochemical and Photobiological Sciences | Year: 2011

The Montreal Protocol is working, but it will take several decades for ozone to return to 1980 levels. The atmospheric concentrations of ozone depleting substances are decreasing, and ozone column amounts are no longer decreasing. Mid-latitude ozone is expected to return to 1980 levels before mid-century, slightly earlier than predicted previously. However, the recovery rate will be slower at high latitudes. Springtime ozone depletion is expected to continue to occur at polar latitudes, especially in Antarctica, in the next few decades. Because of the success of the Protocol, increases in UV-B radiation have been small outside regions affected by the Antarctic ozone hole, and have been difficult to detect. There is a large variability in UV-B radiation due to factors other than ozone, such as clouds and aerosols. There are few long-term measurements available to confirm the increases that would have occurred as a result of ozone depletion. At mid-latitudes UV-B irradiances are currently only slightly greater than in 1980 (increases less than ∼5%), but increases have been substantial at high and polar latitudes where ozone depletion has been larger. Without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes. This would have had serious consequences for the environment and for human health. There are strong interactions between ozone depletion and changes in climate induced by increasing greenhouse gases (GHGs). Ozone depletion affects climate, and climate change affects ozone. The successful implementation of the Montreal Protocol has had a marked effect on climate change. The calculated reduction in radiative forcing due to the phase-out of chlorofluorocarbons (CFCs) far exceeds that from the measures taken under the Kyoto protocol for the reduction of GHGs. Thus the phase-out of CFCs is currently tending to counteract the increases in surface temperature due to increased GHGs. The amount of stratospheric ozone can also be affected by the increases in the concentration of GHGs, which lead to decreased temperatures in the stratosphere and accelerated circulation patterns. These changes tend to decrease total ozone in the tropics and increase total ozone at mid and high latitudes. Changes in circulation induced by changes in ozone can also affect patterns of surface wind and rainfall. The projected changes in ozone and clouds may lead to large decreases in UV at high latitudes, where UV is already low; and to small increases at low latitudes, where it is already high. This could have important implications for health and ecosystems. Compared to 1980, UV-B irradiance towards the end of the 21st century is projected to be lower at mid to high latitudes by between 5 and 20% respectively, and higher by 2-3% in the low latitudes. However, these projections must be treated with caution because they also depend strongly on changes in cloud cover, air pollutants, and aerosols, all of which are influenced by climate change, and their future is uncertain. Strong interactions between ozone depletion and climate change and uncertainties in the measurements and models limit our confidence in predicting the future UV radiation. It is therefore important to improve our understanding of the processes involved, and to continue monitoring ozone and surface UV spectral irradiances both from the surface and from satellites so we can respond to unexpected changes in the future. © 2011 The Royal Society of Chemistry and Owner Societies.

Hu S.,Guangdong University of Petrochemical Technology | Hu W.,South China Normal University
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2012

Optical solitons in the parity-time (PT)-symmetric Bessel complex potential are studied, including the linear case, and self-focusing and self-defocusing nonlinear cases. For the linear case, the PT-symmetric breaking points, eigenvalues and the eigenfunction for different modulated depths of the PT-symmetric Bessel complex potential are obtained numerically. The PT-symmetric breaking points increase linearly with increasing the real part of the modulated depths of the PT potential. Below the PT-symmetric breaking points, the eigenfunctions of linear modes are symmetrical; however, the symmetries of the eigenfunction break above the PT-symmetric breaking points. For nonlinear cases, the existence and stability of fundamental and multipole solitons are studied in self-focusing and self-defocusing media. The eigenvalue for the linear case is equal to the critical propagation constant b c of the existing soliton. Fundamental solitons are stable in the whole region and multipole solitons are stable with the propagation constants being close to b c both for self-focusing and self-defocusing nonlinearities. The range of solitons stability decreases with an increase of the number of the intensity peaks of the solitons. © 2012 IOP Publishing Ltd.

Hu S.M.,Guangdong University of Petrochemical Technology | Hu W.,South China Normal University
European Physical Journal D | Year: 2012

The existence and stability of defect solitons in optical lattices with parity-time (PT) symmetric defect are reported. For positive or zero defects, in-phase solitons and out of phase solitons can exist stably in the semi-infinite gap and the first gap, respectively. For negative defects, in-phase solitons can be stable in both the semi-infinite gap and the first gap, whereas out of phase solitons are unstable in the first gap. For in-phase solitons with positive defect in the semi-infinite gap and negative defect in the first gap, there exists a cutoff point of the propagation constant below which the defect solitons vanish. The imaginary parts of the PT-symmetric defect potentials deeply affect the stability of solitons. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2012.

Liu B.,South China University of Technology | Shen S.,South China University of Technology | Luo J.,South China Normal University | Wang X.,South China University of Technology | And 2 more authors.
RSC Advances | Year: 2013

A rapid and green method is reported to synthesize silver nanoparticles (Ag NPs) and simultaneously achieve exfoliated chitosan/clay nanocomposite under microwave irradiation, in which quaternized chitosan (QCS), montmorillonite (MMT) and Gemini surfactant were used as reducing and stabilizing agents, other chemical reductants were not involved. XRD, FT-IR, NMR, TEM and AAS were performed to characterize Ag NP-loaded QCS/clay nanocomposites. The results indicated that the formation of spherical Ag NPs (about 26 nm) were mainly associated with reduction effect of QCS, surfactant and clay hardly participate in the synthesis of Ag NP, but benefited its formation. During the formation of Ag NPs, the layers of clay were peeled, the exfoliated Ag NP-loaded QCS/clay nanocomposites were obtained. Moreover, Ag NP-loaded QCS/clay nanocomposites showed excellent antimicrobial activity. The lowest minimum inhibition concentration against microorganisms was 0.00001 wt%. At last, the antimicrobial mechanism was evaluated by TEM and SEM micrographs. © 2013 The Royal Society of Chemistry.

Tan L.,U.S. Center for Disease Control and Prevention | Huang C.,U.S. Center for Disease Control and Prevention | Peng R.,U.S. Center for Disease Control and Prevention | Tang Y.,South China Normal University | Li W.,South China University of Technology
Biosensors and Bioelectronics | Year: 2014

Applying molecular imprinting techniques to the surface of functionalized quantum dots (QDs) allows the preparation of molecularly imprinted polymers (MIPs) with accessible, surface exposed binding sites and excellent optical properties. This paper demonstrates a new strategy for producing such hybrid organic-inorganic imprinted Mn-doped ZnS QDs for specific recognition of bovine hemoglobin. The technique provides surface grafting imprinting in aqueous solutions using amino modified Mn-doped ZnS QDs as supports, acrylamide and methacrylic acid as functional monomers, γ-methacryloxypropyl trimethoxy silane as the grafting agent, and bovine hemoglobin as a template. The amino propyl functional monomer layer directs the selective occurrence of imprinting polymerization at the QDs surface through copolymerization of grafting agents with functional monomers, but also acts as an assistive monomer to drive the template into the formed polymer shells to create effective recognition sites. Using MIP-QDs composites as a fluorescence sensing material, trace amounts of bovine hemoglobin are signaled with high selectivity by emission intensity changes of Mn-doped ZnS QDs, which is embedded into the imprinted polymers. © 2014 Elsevier B.V.

Qin R.,Tianjin Normal University | Qin R.,South China Normal University | Jiang W.,Tianjin Normal University | Liu D.,Tianjin Normal University
Chemosphere | Year: 2013

A 50. μM aluminum (Al) could induce nucleolar materials containing the argyrophilic proteins scattered in the nuclei and extruded from the nuclei into the cytoplasm in the root tip cells of Allium cepa. Unfortunately, what kinds of nucleolar proteins are affected has not been reported till now. In order to go deeper into the understanding of the cytological effects of Al on nucleolus and nucleolar proteins, alterations in the cellular localization and expression of three major nucleolar proteins: nucleophosmin, nucleolin, and fibrillarin were further examined under the treatment with Al in the root tip cells of A. cepa in the present study. Cytological effects of Al on nucleolus were observed by silver-staining method and three major nucleolar proteins: nucleophosmin, nucleolin, and fibrillarin were examined by western blotting. The results indicated that in the presence of 50. μM Al for 48. h the nucleolar proteins were translocated from nucleolus to nucleoplasm and cytoplasm. Western blotting data demonstrated the relatively higher expression of the three major nucleolar proteins when compared with control. Evidence from the present investigation indicated that Al had toxic effects on Ag-NOR proteins, nucleophosmin and nucleolin, and other kinds of nucleolar proteins, fibrillarin. © 2012 Elsevier Ltd.

Chai S.,South China Normal University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

Meaning making is the central to collaborative learning in CSCL and from socio-cultural perspective this process is a social and dialogical process. This paper proposes to use socio-cultural discourse analysis to study the process of meaning making. Based on a case study, the paper analyzes the group discourse on the group forum in Moodle system. The study shows that when group members participate in collaborative activities, they are engaged in different types of discourse and through these discourses, they share information, interpret ideas, explore the problem and negotiate meaning and finally reach the shared understanding. The group product emerged from their collaborative efforts.. The study proved that this method is effective in exploring the process of meaning making in CSCL environment. © Springer-Verlag 2013.

Zhou F.,South China Normal University
Biomaterials | Year: 2012

An immunologically modified nanotube system was developed using an immunoadjuvant, glycated chitosan (GC), as surfactant of single-walled carbon nanotube (SWNTs). This SWNT-GC system not only retained both optical properties of SWNTs and immunological functions of GC, but also could enter cells due to the carrier properties of SWNTs. Cellular SWNTs induced thermal destruction of tumor cells when irradiated by a near-infrared laser and, at the same time, cellular GC could serve both as damage associated molecular pattern molecules (DAMPs) and pathogen associated molecular pattern molecules (PAMPs) to enhance the tumor immunogenicity and enhance the uptake and presentation of tumor antigens, leading to special antitumor response. Using this system and a 980 nm laser, we treated tumors, both in vitro and in vivo, and investigated the induced thermal and immunological effects. Laser + SWNT-GC afford a remarkable efficacy in suppressing tumor growth in animal cancer models, in many cases resulting in complete tumor regression and long-term survival. Mice successfully treated by Laser + SWNT-GC could establish resistance to tumor rechallenge. This system forms a multifunctional temporal-spatial continuum, which can synergize photothermal and immunological effects. The Laser + SWNT-GC could represent a promising treatment modality to induce systemic antitumor response through a local intervention, while minimizing the adverse side effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

Shu Y.,South China Normal University | Shu Y.,Louisiana State University | Lam N.S.N.,Louisiana State University | Reams M.,Louisiana State University
Environmental Research Letters | Year: 2010

Detailed estimates of carbon dioxide (CO2) emissions at fine spatial scales are useful to both modelers and decision makers who are faced with the problem of global warming and climate change. Globally, transport related emissions of carbon dioxide are growing. This letter presents a new method based on the volume-preserving principle in the areal interpolation literature to disaggregate transportation-related CO2 emission estimates from the county-level scale to a 1 km2 grid scale. The proposed volume-preserving interpolation (VPI) method, together with the distance-decay principle, were used to derive emission weights for each grid based on its proximity to highways, roads, railroads, waterways, and airports. The total CO2 emission value summed from the grids within a county is made to be equal to the original county-level estimate, thus enforcing the volume-preserving property. The method was applied to downscale the transportation-related CO2 emission values by county (i.e. parish) for the state of Louisiana into 1 km2 grids. The results reveal a more realistic spatial pattern of CO2 emission from transportation, which can be used to identify the emission 'hot spots'. Of the four highest transportation-related CO2 emission hotspots in Louisiana, high-emission grids literally covered the entire East Baton Rouge Parish and Orleans Parish, whereas CO2 emission in Jefferson Parish (New Orleans suburb) and Caddo Parish (city of Shreveport) were more unevenly distributed. We argue that the new method is sound in principle, flexible in practice, and the resultant estimates are more accurate than previous gridding approaches. © 2010 IOP Publishing Ltd.

The efficient third-harmonic generation related to intersubband transitions in GaAs/AlGaAs core/shell spherical quantum dots is studied in detail. An analytic formula for the third-harmonic-generation susceptibility under the condition of the triple resonance is derived by the compact density matrix approach and the iterative procedure. The numerical results show that a very large third-harmonic generation susceptibility of the order of magnitude of 10-12 (m/V)2 can be obtained by choosing properly the radius of the spherical quantum dot and the angular frequency of incident light to satisfy the triple resonance condition. In addition, the influence of the relaxation time on the third-harmonic generation susceptibility is clarified. These properties make spherical core/shell quantum dots be potential candidates for extensive applications in optical information storage and nanophotonic devices. © 2015 Published by Elsevier B.V.

Chen W.-D.,South China Normal University | Xiao W.-J.,South China University of Technology
Jisuanji Xuebao/Chinese Journal of Computers | Year: 2010

Recent Niswapped Networks (BSNs) are a class of two-level structure interconnection networks taking any graph as modules and connecting them in a complete bipartite manner. A simple rule for connectivity in BSNs, similar to but more uniform than the one in well-known OTIS networks or swapped networks, leads to better performances in BSNs. In this paper, the node symmetry and the fault tolerance of BSNs are investigated. It is showen that if a factor network is node transitive then so is the resulting BSN, which gives a justification for simplicities in analyses and algorithms in BSNs. Moreover, by giving a simple general construction of a maximal number of node-disjoint paths between nodes in a BSN built of a connected graph, it is proven the BSN possesses uniformly maximal fault tolerance property regardless of whether the factor network is maximally fault tolerant or not. In contrast with OTIS networks and Cartesian product networks, these results further confirm that the connectivity rule in BSNs provides a systematic competitive construction scheme for large, scalable, modular, and robust parallel architectures, while maintaining favorable properties of their factor networks.

Wang H.,South China Normal University | Hu X.,Huazhong Agricultural University
BMC Bioinformatics | Year: 2015

Background: Nuclear receptors (NRs) form a large family of ligand-inducible transcription factors that regulate gene expressions involved in numerous physiological phenomena, such as embryogenesis, homeostasis, cell growth and death. These nuclear receptors-related pathways are important targets of marketed drugs. Therefore, the design of a reliable computational model for predicting NRs from amino acid sequence has now been a significant biomedical problem. Results: Conjoint triad feature (CTF) mainly considers neighbor relationships in protein sequences by encoding each protein sequence using the triad (continuous three amino acids) frequency distribution extracted from a 7-letter reduced alphabet. In addition, chaos game representation (CGR) can investigate the patterns hidden in protein sequences and visually reveal previously unknown structure. In this paper, three methods, CTF, CGR, amino acid composition (AAC), are applied to formulate the protein samples. By considering different combinations of three methods, we study seven groups of features, and each group is evaluated by the 10-fold cross-validation test. Meanwhile, a new non-redundant dataset containing 474 NR sequences and 500 non-NR sequences is built based on the latest NucleaRDB database. Comparing the results of numerical experiments, the group of combined features with CTF and AAC gets the best result with the accuracy of 96.30% for identifying NRs from non-NRs. Moreover, if it is classified as a NR, it will be further put into the second level, which will classify a NR into one of the eight main subfamilies. At the second level, the group of combined features with CTF and AAC also gets the best accuracy of 94.73%. Subsequently, the proposed predictor is compared with two existing methods, and the comparisons show that the accuracies of two levels significantly increase to 98.79% (NR-2L: 92.56%; iNR-PhysChem: 98.18%; the first level) and 93.71% (NR-2L: 88.68%; iNR-PhysChem: 92.45%; the second level) with the introduction of our CTF-based method. Finally, each component of CTF features is analyzed via the statistical significant test, and a simplified model only with the resulting top-50 significant features achieves accuracy of 95.28%. Conclusions: The experimental results demonstrate that our CTF-based method is an effective way for predicting nuclear receptor proteins. Furthermore, the top-50 significant features obtained from the statistical significant test are considered as the "intrinsic features" in predicting NRs based on the analysis of relative importance. © 2015 Wang and Hu.

Xing L.,University of Utah | Xing L.,South China Normal University | Vatamanu J.,University of Utah | Smith G.D.,Wasatch Molecular Inc. | Bedrov D.,University of Utah
Journal of Physical Chemistry Letters | Year: 2012

Electrostatic double-layer capacitors (EDLCs) with room-temperature ionic liquids (RTILs) as electrolytes are among the most promising energy storage technologies. Utilizing atomistic molecular dynamics simulations, we demonstrate that the capacitance and energy density stored within the electric double layers (EDLs) formed at the electrode-RTIL electrolyte interface can be significantly improved by tuning the nanopatterning of the electrode surface. Significantly increased values and complex dependence of differential capacitance on applied potential were observed for surface patterns having dimensions similar to the ions' dimensions. Electrode surfaces patterned with rough edges promote ion separation in the EDL at lower potentials and therefore result in increased capacitance. The observed trends, which are not accounted for by the current basic EDL theories, provide a potentially new route for optimizing electrode structure for specific electrolytes. © 2012 American Chemical Society.

Zhang Y.-Y.,Hong Kong University of Science and Technology | Zhu X.-L.,Hong Kong University of Science and Technology | Yin Y.-A.,South China Normal University | Ma J.,Hong Kong University of Science and Technology
IEEE Electron Device Letters | Year: 2012

In this study, the characteristics of the nitride-based near-UV light-emitting diode (LED) with an InAlN/GaN superlattice (SL) electron-blocking layer (EBL) are analyzed numerically and experimentally. The emission spectra, carrier concentrations in the quantum wells, energy-band diagrams, electrostatic fields, and internal quantum efficiency are investigated. The results indicate that the LED with an InAlN/GaN SL EBL has a better hole-injection efficiency and lower electron leakage over the LED with a conventional rectangular AlGaN EBL or with an AlGaN/GaN SL EBL. The results also show that the efficiency droop is markedly improved when the InAlN/GaN SL EBL is used. © 2012 IEEE.

Xiao X.,South China University of Technology | Xiao X.,South China Normal University | Zhang W.-D.,South China University of Technology
RSC Advances | Year: 2011

Bi 7O 9I 3, a fresh member of the bismuth oxyhalide family, with hierarchical micro/nano-architecture is successfully synthesized by a one-step, template and surfactant-free solution method. The as-prepared product was characterized by various techniques. X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis confirm that the composition of the as-fabricated sample is Bi 7O 9I 3. Scanning and transmission electron microscopy observations reveal that the as-synthesized sample exhibits a microsized plate-like structure with dense nanosheets standing on their surfaces. The time-dependent morphology of the Bi 7O 9I 3 sample was investigated, and a possible formation mechanism of the hierarchical structure is proposed. More importantly, the Bi 7O 9I 3 exhibits an excellent photocatalytic activity in the degradation of phenol under visible light irradiation. The high catalytic performance of the Bi 7O 9I 3 hierarchical structure comes from its electronic band structure, high surface area and high surface-to-volume ratio. In addition, the Bi 7O 9I 3 hierarchical architecture is stable during the reaction and can be used repeatedly. The present work not only gives insight into understanding the hierarchical growth behaviour of complex bismuth oxide iodide structures in a solution-phase synthetic system, but also provides a new way to improve the photocatalytic performance by designing desirable structures and morphologies. This journal is © The Royal Society of Chemistry 2011.