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Changsha, China

Central South University located in Changsha, a historic and cultural city in Hunan province, central south of the People's Republic of China. CSU was established in April 2000 on the basis of the amalgamation of the three former individual universities, namely Central South University of Mining and Technology , Hunan Medical University and Changsha Railway University . Wikipedia.

Han X.,Central South University
Scientific World Journal | Year: 2014

A symmetric basis of trigonometric polynomial space is presented. Based on the basis, symmetric trigonometric polynomial approximants like Bernstein polynomials are constructed. Two kinds of nodes are given to show that the trigonometric polynomial sequence is uniformly convergent. The convergence of the derivative of the trigonometric polynomials is shown. Trigonometric quasi-interpolants of reproducing one degree of trigonometric polynomials are constructed. Some interesting properties of the trigonometric polynomials are given. © 2014 Xuli Han.

Zou J.-P.,Central South University | Wang R.-Z.,University of British Columbia
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2012

Vertically orientated TiO 2 nanotube array with diameters ranging from 60 up to 80 nm and length of 4 μm was grown on titanium by anodization. Crack initiation, propagation and saturation were studied using the substrate straining test. The results show that annealing obviously modifies the interfaces. With the increase of tensile strain, cracks in TiO 2 nanotube films propagate rapidly and reach the saturation within a narrow strain gap. Interfacial shear strengths of TiO 2 nanotube films without annealing, with 250°C annealing and with 400°C annealing can be estimated as 163.3, 370.2 and 684.5 MPa, respectively. The critical energy release rates of TiO 2 nanotube films are calculated as 49.6, 102.6 and 392.7 J/m 2, respectively. The fracture toughnesses of TiO 2 nanotube films are estimated as 0.996, 1.433 and 2.803 MPa·m 1/2, respectively. The interfacial bonding mechanism of TiO 2 nanotube film is chemical bonding. © 2012 The Nonferrous Metals Society of China.

Yang P.H.H.,Central South University
Applied Clay Science | Year: 2010

Composite conductive powders of kaolin coated with antimony-doped tin oxide nanoparticles (Sb-SnO2/kaolin, SSK) were prepared by co-precipitation. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), transmission electron microcopy (TEM), high-resolution TEM (HRTEM) and energy-dispersive X-ray spectrometry (EDS). Effects of pH value, hydrolysis temperature, kaolin content, content of doped antimony, calcination temperature and time on the resistivity of SSK were studied under the optimum experimental conditions, the resistivity was less than 10Ωcm. The rod-like kaolinite particles were coated with a layer of 35nm thickness of well-crystallized, dense and uniform antimony-doped tin oxide (Sb-SnO2). A possible mechanism for coating of Sb-SnO2 nanoparticles on the surface of kaolin rods is proposed. © 2010 Elsevier B.V.

Zhao C.,Central South University | Hobbs B.E.,University of Western Australia | Ord A.,University of Western Australia
Journal of Contaminant Hydrology | Year: 2012

The main purpose of this paper is to investigate the effects of different domain shapes in general and trapezoidal domain shape in particular on the morphological evolution of nonaqueous phase liquid (NAPL) dissolution fronts in two-dimensional fluid-saturated porous media. After the governing equations of NAPL dissolution problems are briefly described, the numerical procedure consisting of a combination of the finite element and finite difference methods is used to solve these equations. The related numerical simulation results have demonstrated that: (1) domain shapes have a significant effect on both the propagating speed and the morphological evolution pattern of a NAPL dissolution front in the fluid-saturated porous medium; (2) an increase in the divergent angle of a trapezoidal domain can lead to a decrease in the propagating speed of the NAPL dissolution front; (3) the morphological evolution pattern of the NAPL dissolution front in a rectangular domain is remarkably different from that in a trapezoidal domain of a large divergent angle; (4) for a rectangular domain, the simplified dispersion model, which is commonly used in the theoretical analysis and numerical simulation, is valid for solving NAPL dissolution instability problems in fluid-saturated porous media; and (5) compared with diverging flow (when the trapezoidal domain is inclined outward), converging flow (when the trapezoidal domain is inclined inward) can enhance the growth of NAPL fingers, indicating that pump-and-treat systems by extracting contaminated groundwater might enhance NAPL dissolution fingering and lead to less uniform dissolution fronts. © 2012 Elsevier B.V.

Wang H.,Hunan University | Li G.Y.,Hunan University | Li E.,Central South University
Computer Methods in Applied Mechanics and Engineering | Year: 2010

In automotive industry, structural optimization for crashworthiness criteria is of special importance in the early design stage. To reduce the vehicle design cycle, metamodeling techniques have become so widespread... In this study, a time-based metamodeling technique is proposed for the vehicle design. The characteristics of the proposed method are the construction of a time-based objective function and establishment of a metamodel by support vector regression (SVR). Compared with other popular metamodel-based optimization methods, the design space of the proposed method is expanded to time domain. Thus, more information and features can be extracted in the expanded time domain. To validate the performance of the time-based metamodeling technique, cylinder impacting and full vehicle frontal collision are optimized by the proposed method. The results demonstrate that the proposed method has potential capability to solve the crashworthiness vehicle design. © 2010 Elsevier B.V.

Liao E.,Central South University
Frontiers of Medicine in China | Year: 2013

Recently, fibroblast growth factor 23 (FGF23) has sparked widespread interest because of its potential role in regulating phosphate and vitamin D metabolism. In this review, we summarized the FGF superfamily, the mechanism of FGF23 on phosphate and vitamin D metabolism, and the FGF23 related bone disease. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Wang L.,Central South University
Sensors and Actuators, A: Physical | Year: 2016

Both of the coil and the object of the traditional eddy current non-contact gap sensor system are made of metal. However, the rigidness of metal makes it difficult to develop a stretchable coil with low cost, and the system cannot work if the object is non-metallic. To overcome the limitations, an eddy current non-contact gap sensor system, in which both the coil and the object are made of stretchable conductive polymer composite, is designed. The current in the composite coil causes an induced current in the composite object covered on the non-metallic surface, leading to the occurrence of the eddy current effect. The experimental data show that the impedance of the composite coil changes regularly with the lift-off. The results verify the feasibility of using the system completely made of the composite to measure the non-contact gap between the non-metallic surfaces. © 2016 Elsevier B.V. All rights reserved.

Zhou S.,Central South University | Solana J.R.,University of Cantabria
Journal of Physical Chemistry B | Year: 2013

The first three coefficients of the high temperature series expansion (HTSE) of the Helmholtz free energy for a number of simple potential models with hard-sphere cores plus continuous tails are obtained for the first time from Monte Carlo simulations. The potential models considered include Square-well, Sutherland, attractive Yukawa, and triangle-well with different potential ranges, as well as a model potential qualitatively resembling the depletion potential in colloidal dispersions. The simulation data are used to evaluate performance of a recent coupling parameter series expansion (CPSE) in calculating for these coefficients, and a traditional macroscopic compressibility approximation (MCA) for the second-order coefficient only. A comprehensive comparison based on these coefficients from the two theoretical approaches and simulations enables one to conclude that (i) unlike one common experience that the widely used MCA usually underestimates the second-order coefficient, the MCA can both overestimate and underestimate the second-order coefficient, and worsens as the range of the potential decreases; and (ii) in contrast, the CPSE not only reproduce the trends in the density dependence of the perturbation coefficients, even the third one, observed in the simulations, but also the agreement is quantitative in most cases, and this clearly highlights the potential of the CPSE in providing accurate estimations for the higher-order coefficients, thus giving rise to an accurate higher-order HTSE. © 2013 American Chemical Society.

Xu Y.,Central South University | Agrawal O.P.,Southern Illinois University Carbondale
Journal of Vibration and Acoustics, Transactions of the ASME | Year: 2014

In this paper, we use three operators called K-, A-, and B-operators to define the equation of motion of an oscillator. In contrast to fractional integral and derivative operators which use fractional power kernels or their variations in their definitions, the K-, A-, and B-operators allow the kernel to be arbitrary. In the case, when the kernel is a power kernel, these operators reduce to fractional integral and derivative operators. Thus, they are more general than the fractional integral and derivative operators. Because of the general nature of the K-, A-, and B-operators, the harmonic oscillators are called the generalized harmonic oscillators. The equations of motion of a generalized harmonic oscillator are obtained using a generalized Euler-Lagrange equation presented recently. In general, the resulting equations cannot be solved in closed form. A finite difference scheme is presented to solve these equations. To verify the effectiveness of the numerical scheme, a problem is considered for which a closed form solution could be found. Numerical solution for the problem is compared with the analytical solution, which demonstrates that the numerical scheme is convergent. Copyright © 2014 by ASME.

Xie M.,Central South University
Applied Mechanics and Materials | Year: 2013

China is the state with world's fastest development and longest line mileage operated in high speed rail (HSR) industry, which authorizes a reduction in transportation costs and can be a tool for tourism destination development. This paper gives a detail introduction to the HSR between Wuhan and Shenzhen, especially on line plan and the current operation scheme. Then it concludes the impact of HSR between Wuhan and Shenzhen to tourism market along the line. At last, we give some suggestions on how to develop tourism industry better in HSR economy. © (2013) Trans Tech Publications, Switzerland.

Xie K.,Tongji University | Wang X.,Tongji University | Huang H.,Central South University | Chen X.,Tongji University
Accident Analysis and Prevention | Year: 2013

Most traffic crashes in Chinese cities occur at signalized intersections. Research on the intersection safety problem in China is still in its early stage. The recent development of an advanced traffic information system in Shanghai enables in-depth intersection safety analyses using road design, traffic operation, and crash data. In Shanghai, the road network density is relatively high and the distance between signalized intersections is small, averaging about 200 m. Adjacent signalized intersections located along the same corridor share similar traffic flows, and signals are usually coordinated. Therefore, when studying intersection safety in Shanghai, it is essential to account for intersection correlations within corridors. In this study, data for 195 signalized intersections along 22 corridors in the urban areas of Shanghai were collected. Mean speeds and speed variances of corridors were acquired from taxis equipped with Global Positioning Systems (GPS). Bayesian hierarchical models were applied to identify crash risk factors at both the intersection and the corridor levels. Results showed that intersections along corridors with lower mean speeds were associated with fewer crashes than those with higher speeds, and those intersections along two-way roads, under elevated roads, and in close proximity to each other, tended to have higher crash frequencies. © 2012 Elsevier Ltd.

Guo L.,Central South University
Journal of Convergence Information Technology | Year: 2012

A data driven technique, bivariate kernel density estimator, is used to deduce the scatterer distribution in order to extract the true scatterer distribution in real mobile environment. Under the assumption of single reflection of signal, the TOA /AOA and TOA /AOD measurements are used to obtain the unknown position of the scatterers by means of a nonlinear optimization procedure under nonlinear constraints respectively; Simulation results show that the proposed method can better fit the real scatterer distribution models.

Wu M.,Central South University
Journal of Convergence Information Technology | Year: 2012

The task of Query-Focused Multi-Document Summarization is intended to improve agreement in content among human-generated model summaries. Query-focus also aids the automated summarizers in directing the summary at specific topics, which may result in better agreement with these model summaries. This paper explores terms weighting method for query based summarization. It considers the term weight, combines it to score important of sentences, and then it selects the summary sentences and orders them. Experimental result shows that the proposed summarization method is effective.

Zhou S.,Central South University | Zhou S.,University of South China
Journal of Chemical Physics | Year: 2010

A new free energy density functional is advanced for general nonhard sphere potentials characterized by a repulsive core with a singular point at zero separation. The present functional is characterized by several features. (i) It does not involve with dividing the potentials into hard-sphere-like contribution and tail contribution in sharp contrast with usual effective hard sphere model+mean field approximation for tail contribution. (ii) It has no recourse to the use of weighted density and is computationally modest; it also does not resort to an equation of state and/or an excess Helmholtz free energy of bulk fluid over a range of density as input. Consequently, all of input information can be obtained by numerical solution of a bulk Ornstein-Zernike integral equation theory (OZ IET). Correspondingly, despite the use of bulk second-order direct correlation function (DCF) as input, the functional is applicable to the subcritical region. (iii) There is no any adjustable parameter associated with the present functional, and an effective hard sphere diameter entering the functional can be determined self-consistently and analytically once the input information, i.e., the second-order DCF and pressure of the coexistence bulk fluid, are obtained by the OZ IET. The present functional is applied to a core-softened fluid subject to varying external fields, and the density distributions predicted by the present functional are more self-consistent with available simulation results than a previous third-order+second-order perturbation density functional theory. © 2010 American Institute of Physics.

Liu H.,Central South University | Liu Y.,Tsinghua University | Li J.,Tsinghua University
Physical Chemistry Chemical Physics | Year: 2010

Ionic liquids (IL) are widely used in electrochemistry due to their excellent properties such as good ionic conductivity, wide electrochemical potential window, high viscosity, high thermal stability, wide liquid range and tunable solvent properties. In electrochemistry, the performance of an electrochemical system is dependent on the properties of the interface at the IL/electrode. This review presents the surface electrochemistry in ILs, and the interfacial structures of IL/electrode and heterogeneous electron-transfer kinetics are detailed. Finally, the updated researches on the electrochemical applications of ILs such as electrode deposition, electrosynthesis, electrocatalysis, electrochemical biosensing, electrochemical capacitor and lithium batteries are demonstrated. © 2010 the Owner Societies.

Jiang Y.,Central South University | Liu M.,University of Tubingen
Granular Matter | Year: 2013

Proportional paths as summed up by the Goldscheider Rule (GR) - stating that given a constant strain rate, the evolution of the stress maintains the ratios of its components - is a characteristics of elasto-plastic motion in granular media. Barodesy, a constitutive relation proposed recently by Kolymbas, is a model that, with GR as input, successfully accounts for data from soil mechanical experiments. Granular solid hydrodynamics (GSH), a theory derived from general principles of physics and two assumptions about the basic behavior of granular media, is constructed to qualitatively account for a wide range of observation - from elastic waves over elasto-plastic deformation to rapid dense flow. In this paper, showing the close resemblance of results from Barodesy and GSH, we further validate GSH and provide an understanding for GR. © 2013 Springer-Verlag Berlin Heidelberg.

Wang H.,Hunan University | Li E.,Central South University | Li G.Y.,Hunan University
Computational Mechanics | Year: 2011

This paper presents a crashworthiness design optimization method based on a metamodeling technique. The crashworthiness optimization is a highly nonlinear and large scale problem, which is composed various nonlinearities, such as geometry, material and contact and needs a large number expensive evaluations. In order to obtain a robust approximation efficiently, a probability-based least square support vector regression is suggested to construct metamodels by considering structure risk minimization. Further, to save the computational cost, an intelligent sampling strategy is applied to generate sample points at the stage of design of experiment (DOE). In this paper, a cylinder, a full vehicle frontal collision is involved. The results demonstrate that the proposed metamodel-based optimization is efficient and effective in solving crashworthiness, design optimization problems. © 2010 Springer-Verlag.

Liu D.,Central South University | Cong W.L.,Kansas State University | Pei Z.J.,Kansas State University | Tang Y.,Guangdong University of Technology
International Journal of Machine Tools and Manufacture | Year: 2012

Knowing cutting force in rotary ultrasonic machining (RUM) can help optimizing input variables. RUM of brittle materials has been investigated both experimentally and theoretically. However, there are no reports on cutting force models for RUM of brittle materials. This paper presents a mechanistic model for cutting force in RUM of brittle materials. Assuming that brittle fracture is the primary mechanism of material removal in RUM of brittle materials, the cutting force model is developed step by step. On the basis of this mechanistic model, relationships between cutting force and input variables (such as spindle speed, feed rate, ultrasonic vibration amplitude, abrasive size, and abrasive concentration) are predicted. Experiments are conducted for model verification and experimental results agree well with model predictions. © 2011 Elsevier Ltd. Allrightsreserved.

Zhao C.B.,Central South University | Zhao C.B.,CSIRO
Science China Technological Sciences | Year: 2015

This paper aims to provide a brief introduction to recent advances in numerical algorithms and methods in the emerging computational geoscience filed with general simulation characteristics of modeling multiple chemical and physical processes that take place in ore-generating systems within the Earth’s crust. Due to significant differences between Earth systems and engineering systems, the existing numerical algorithms and methods, which are designed for simulating realistic problems in the engineering fields, may not be straightforwardly used to simulate ore-generating problems without significant improvements. Thus, extensive and systematic studies have been conducted, in recent years, to develop new numerical algorithms and methods for simulating different aspects of ore-generating problems. Not only can the outcomes of these studies provide new simulation tools for better understanding the controlled dynamic mechanisms that take place in ore-generating systems, but also they have enriched the research contents of computational mechanics in the broad sense. © 2015, Science China Press and Springer-Verlag Berlin Heidelberg.

Cheng Y.,Central South University
Transport | Year: 2012

To begin with, the current paper introduces the meaning of freight multimodal transport in order to select the best transport path in multimodal network. Secondly, the forming mechanism of freight multimodal transport cost has been illustrated. In addition to that the construction and the character of the freight multimodal cost have been analyzed carefully, and the mathematics model is set up so that to figure out the total cost of multimodal. Finally, a case of multimodal is given out and analyzed. The results indicate that the model and way to select the best multimodal path in the multimodal network are reasonable and effective. © 2012 Copyright Vilnius Gediminas Technical University (VGTU) Press Technika.

Jiang S.,Michigan State University | Cao D.,Michigan State University | Li Y.,University of Sichuan | Liu J.,Central South University | Peng F.Z.,Michigan State University
IEEE Transactions on Power Electronics | Year: 2012

This paper presents a novel synchronous-frame repetitive controller for three-phase UPS inverters. Distinguished from conventional repetitive control techniques, the proposed synchronous-frame approach minimizes the repetitive control time delay to one-sixth of the fundamental period such that the dynamic response is significantly improved. In order to overcome the harmonic distortions under severe load conditions (e.g., unbalanced and nonlinear), in this paper, three synchronous rotating frames are deliberately selected, in each of which the repetitive controller is incorporated. Resultantly, the (6n ± 1)th harmonics as well as the triplen harmonics are compensated. Moreover, a high-performance fourth-order linear phase infinite-impulse-response filter is applied to further enhance the accuracy of steady-state tracking. The proposed controller is programmed on the 16-bit fixed-point digital signal processor (TI TMS320LF2407) and eliminates high-resolution current sensors for cost effectiveness. Simulations and experimental tests have been carried out based on an 18-kW three-phase UPS system. Low total harmonic distortion (<2) has been achieved under heavily distorted nonlinear load and unbalanced load. Fast dynamic response has been demonstrated during step load transients. © 2006 IEEE.

Zhao C.,Central South University | Hobbs B.E.,University of Western Australia | Ord A.,University of Western Australia
International Journal for Numerical and Analytical Methods in Geomechanics | Year: 2015

This paper mainly deals with the theoretical aspects of chemical dissolution-front instability problems in two-dimensional fluid-saturated porous media under non-isothermal conditions. In the case of the mineral dissolution ratio (that is defined as the ratio of the dissolved-mineral equilibrium concentration in the pore fluid to the molar concentration of the dissolvable mineral in the solid matrix of the fluid-saturated porous medium) approaching zero, the corresponding critical condition has been mathematically derived when temperature variation effects are considered. As a complementary tool, the computational simulation method is used to simulate the morphological evolution of chemical dissolution fronts in two-dimensional fluid-saturated porous media under non-isothermal conditions. The related theoretical and numerical results have demonstrated that: (i) a temperature increase in a non-isothermal chemical dissolution system can have some influence on the propagation speed of the planar chemical dissolution front in the system. Generally, the chemical dissolution front in the non-isothermal chemical dissolution system propagates slower than that in the counterpart isothermal chemical dissolution system when the temperature of the non-isothermal chemical dissolution system is higher than that of the counterpart isothermal chemical dissolution system; (ii) a temperature increase in the non-isothermal chemical dissolution system can stabilize the chemical dissolution front propagating in the system, because it can cause a decrease in the Zhao number of the system but does not affect the critical Zhao number of the system; and (iii) the temperature gradient in the upstream direction of a chemical dissolution front is smaller than that in the downstream direction of the chemical dissolution front when the non-isothermal chemical dissolution system is supercritical. © 2014 John Wiley & Sons, Ltd.

Li M.,Central South University | Lai A.C.K.,City University of Hong Kong
Applied Energy | Year: 2015

Ground (or geothermal) heat exchangers are attracting a great deal of attention as a way of using shallow geothermal energy. This paper provides not only a critical review but also a thorough introduction to the analysis of heat transfer by borehole and foundation pile ground heat exchangers, with an emphasis on different analytical models. The literature is reviewed in a time-scale framework because of the diversity of the time and space scales involved in the thermal processes of ground heat exchangers. We summarize, discuss, and evaluate major advances in this field, including heat-source models, short-time models, models for energy piles, in situ thermal-response tests, indoor sandbox experiments, and parameter estimation as an inverse problem. Of particular note is that the unit-step temperature response (i.e., G-function) of a ground heat exchanger with one U-shaped pipe is calculated; and six analytical models are compared: an infinite cylinder-source model, two infinite line-source models, two finite line-source models, and a composite-medium line-source model. This paper closes by identifying several unsolved problems that require solutions. © 2015 Elsevier Ltd.

Kanwar Y.S.,Northwestern University | Sun L.,Northwestern University | Xie P.,Northwestern University | Liu F.-Y.,Central South University | Chen S.,Northwestern University
Annual Review of Pathology: Mechanisms of Disease | Year: 2011

Diabetic nephropathy is a well-known complication of diabetes and is a leading cause of chronic renal failure in the Western world. It is characterized by the accumulation of extracellular matrix in the glomerular and tubulointerstitial compartments and by the thickening and hyalinization of intrarenal vasculature. The various cellular events and signaling pathways activated during diabetic nephropathy may be similar in different cell types. Such cellular events include excessive channeling of glucose intermediaries into various metabolic pathways with generation of advanced glycation products, activation of protein kinase C, increased expression of transforming growth factor β? and GTP-binding proteins, and generation of reactive oxygen species. In addition to these metabolic and biochemical derangements, changes in the intraglomerular hemodynamics, modulated in part by local activation of the renin-angiotensin system, compound the hyperglycemia-induced injury. Events involving various intersecting pathways occur in most cell types of the kidney. Copyright © 2011 by Annual Reviews. All rights reserved.

Sun L.,Central South University | Kanwar Y.S.,Northwestern University
Kidney International | Year: 2015

An ancillary paradigm that has evolved recently in the pathogenesis of diabetic nephropathy includes subclinical microinflammation with influx of macrophages and consequent generation of myriad proinflammatory cytokines and ensuing kidney damage. Among various proinflammatory cytokines, tumor necrosis factor-α (TNF-α) has attracted the most attention, since it amplifies the inflammatory network of cytokines, leading to worsening of the progression of diabetic nephropathy. The article by Awad et al. examines the role of TNF-α in the pathogenesis of experimental diabetic nephropathy.

Lu X.,Central South University | Li H.-X.,City University of Hong Kong
Journal of Mechanical Design, Transactions of the ASME | Year: 2011

In real-world applications, a nominal model is often used to approximate the design of an industrial system. This approximation could make the traditional design method less effective due to the existence of model uncertainty. In this paper, a novel stability-based approach is proposed to design the system ensuring robust stability under model uncertainty. First, the design variables and their variation bounds are configured to make the system stable. Then, a robust design is developed to incorporate system eigenvalues that are less sensitive to model uncertainty. Finally, the tolerance of the design space will be maximized under given performance constraints. A simulation example is conducted to demonstrate the effectiveness of the proposed robust design method. © 2011 American Society of Mechanical Engineers.

Nie X.-W.,Central South University
Scripta Materialia | Year: 2011

Recently, Aufrecht et al. (Scripta Mater. 62 (2010) 227) published a paper investigating the previously proposed polytypic phase transformation C14 NbCr 2 to C15 NbCr 2. In their analysis, they considered that the phase transformation does not occur for high-purity alloys, and the conditions and small amounts of atmospheric contaminations induce the formation of an η-carbide-type phase. However, I point out here that previous experimental results do not agree well with their analysis. Aufrecht et al. also do not adequately acknowledge earlier work on this topic, and their experiments are not strict enough. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Fang Z.,Central South University
Thermochimica Acta | Year: 2011

Some basic matters concerning with the heat effect at electrode-electrolyte interface are briefly introduced in this paper. They include the concepts and definition about the electrochemical Peltier heat (EPH) and the Peltier coefficient for the electrode process, the absolute scale, the fundamental equations on this scale for thermoelectrochemistry, and the issues of the entropy changes on this scale and EPHs for the standard hydrogen electrode reaction as well as other standard electrode reactions. The EPH of electrode-electrolyte interface is specially emphasized to be a quantity related to reversible process; thereupon it can be measured and also be calculated by the change in the function of state, or entropy, on the absolute scale. The changes in entropy on the absolute scale, EPHs and the electrochemical Peltier coefficients for some of the most common standard electrode reactions in aqueous solution at 298.15 K are given. © 2011 Elsevier B.V. All rights reserved.

Liang X.,Central South University
Journal of Petroleum Science and Engineering | Year: 2010

This paper presents a procedure that systematically accounts for the interactions between wells in a reservoir. The reservoir is considered to be an input-output system with the injection rates as the input and production rates as the output. A simple capacitance model is developed to infer the interwell connectivity only from the injection/production data fluctuations on a reservoir. A commercial simulator on a synthetic field with five injectors and four producers is used to test the approach. The simulation results show that the simple capacitance model satisfactorily captures the long time dependent behavior between injectors and producers. © 2009.

Chen Q.,Central South University
PLoS ONE | Year: 2015

The planning of urban bus-only lane networks is an important measure to improve bus service and bus priority. To determine the effective arrangement of bus-only lanes, a bi-level programming model for urban bus lane layout is developed in this study that considers accessibility and budget constraints. The goal of the upper-level model is to minimize the total travel time, and the lower-level model is a capacity-constrained traffic assignment model that describes the passenger flow assignment on bus lines, in which the priority sequence of the transfer times is reflected in the passengers' route-choice behaviors. Using the proposed bi-level programming model, optimal bus lines are selected from a set of candidate bus lines; thus, the corresponding bus lane network on which the selected bus lines run is determined. The solution method using a genetic algorithm in the bi-level programming model is developed, and two numerical examples are investigated to demonstrate the efficacy of the proposed model. Copyright © 2015 Qun Chen.

Jin X.-F.,Beijing Institute of Pharmacology and Toxicology | Jin X.-F.,Central South University | Wu N.,Beijing Institute of Pharmacology and Toxicology | Wang L.,Beijing Institute of Pharmacology and Toxicology | Li J.,Beijing Institute of Pharmacology and Toxicology
Cellular and Molecular Neurobiology | Year: 2013

As a class of important endogenous small noncoding RNAs that regulate gene expression at the posttranscriptional level, microRNAs (miRNAs) play a critical role in many physiological and pathological processes. It is believed that miRNAs contribute to the development, differentiation, and synaptic plasticity of the neurons, and their dysregulation has been linked to a series of diseases. MiRNAs exist in the tissues and as circulating miRNAs in several body fluids, including plasma or serum, cerebrospinal fluid, urine, and saliva. There are significant differences between the circulating miRNA expression profiles of healthy individuals and those of patients. Consequently, circulating miRNAs are likely to become a novel class of noninvasive and sensitive biomarkers. Although little is known about the origin and functions of circulating miRNAs at present, their roles in the clinical diagnosis and prognosis of diseases make them attractive markers, particularly for tumors and cardiovascular diseases. Until now, however, there have been limited data regarding the roles of circulating miRNAs in central nervous system (CNS) diseases. This review focuses on the characteristics of circulating miRNAs and their values as potential biomarkers in CNS diseases, particularly in Alzheimer's disease, Huntington's disease, multiple sclerosis, schizophrenia, and bipolar disorder. © 2013 Springer Science+Business Media New York.

Schwarzer R.,Free University of Berlin | Cao D.S.,Central South University | Lippke S.,Free University of Berlin
Journal of Adolescent Health | Year: 2010

Purpose: Interventions to improve physical activity (PA) might be successful when treatments are matched to the requirements of the recipients, in particular to their stage of change. This intervention study examines PA in Chinese high school students whose stage of change at the beginning of the study was identified. Methods: Two minimal interventions (1 hour) were provided: resource communication and strategic planning. We assumed that preintenders would benefit in terms of PA frequency mainly from resource communication, and intenders would benefit from planning. Adolescents were assigned to an experimental and a control group. Moreover, they were divided according to stage (preintender, intender, actor). In the experimental group, each stage group received interventions. The data were analyzed with repeated measures analyses of variance (N = 534). Stage groups and treatment (resource communication, planning, and controls) were chosen as between-subjects factors. PA frequency was the dependent variable measured at two points in time 4 weeks apart (pre-post measures). Results: Preintenders in the resource communication condition improved their activity levels, whereas intenders increased their PA not only in the planning but also in resource communication conditions. Actors maintained their activity independently of the treatment they received, which was in line with the hypotheses. Conclusions: Matching PA interventions for adolescents to at least two stages of change might be a promising approach. Those who are not motivated to exercise benefit from resource-based messages, whereas those who have behavioral intentions benefit from planning. © 2010 Society for Adolescent Health and Medicine. All rights reserved.

Edens B.M.,Northwestern University | Ajroud-Driss S.,Northwestern University | Ma L.,Central South University | Ma Y.-C.,Northwestern University
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2015

Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is characterized by the degeneration of spinal motor neurons and muscle atrophy. Although the genetic cause of SMA has been mapped to the Survival Motor Neuron1 (SMN1) gene, mechanisms underlying selective motor neuron degeneration in SMA remain largely unknown. Here we review the latest developments and our current understanding of the molecular mechanisms underlying SMA pathogenesis, focusing on the animal model systems that have been developed, as well as new diagnostic and treatment strategies that have been identified using these model systems. This article is part of a special issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis. © 2014 Elsevier B.V.

He Z.,Central South University
Nonlinear Dynamics | Year: 2015

In this paper, the complex dynamics of a predator–prey model with group defense and impulsive state feedback control is studied both theoretically and numerically. We obtain the sufficient conditions for the existence and stability of semi-trivial solution and positive periodic solutions by using the Poincaré map and the analogue of the Poincaré criterion. Moreover, the theoretical analysis reveals that the positive periodic solution bifurcates from the semi-trivial solution through a fold bifurcation. Numerical simulations are also illustrated, which agree well with our theoretical analysis, but also to exhibit the complex dynamical behaviors, such as the period-2, 3, 4, 6, 8 solutions and chaotic solution, cascade of period-doubling bifurcation and inverse period-doubling bifurcation. Moreover, the superiority of impulsive state feedback control strategy is also exhibited over the impulsive fixed-time control. © 2014, Springer Science+Business Media Dordrecht.

Yang Y.,Guangdong Ocean University | Li M.,Central South University
International Journal of Thermal Sciences | Year: 2014

A composite-medium line-source model has been recently developed for modeling short-time thermal processes of borehole ground heat exchangers. The composite-medium line-source model is attractive for applications where the short-term or high-frequency responses of borehole ground heat exchangers are important. In this paper, the short-time performance of this analytical model is examined in depth by comparing it with a two-dimensional finite volume model. The numerical model can address the heat capacity of circulating water by using a novel time-varying boundary condition on the inner walls of the U-shaped tube, in addition to the heat capacities of U-shaped tube and grouting material. Both the numerical and the analytical composite-medium models are validated using an independent sandbox experiment. Comparisons between the two models are also made for different parameters, including heating rate, the spacing of the U-tube legs, thermal properties, and borehole radius. Overall, the composite-medium line-source model gives the virtually same results as the numerical model except for the first several minutes: the analytical solution overestimates temperature responses during the first 3 min, which is caused by the line-source assumption ignoring the heat capacities of the fluid and the U-shaped pipe. © 2014 Elsevier Masson SAS. All rights reserved.

Zhang L.,University of Arizona | Cao P.,Central South University | Radha K.C.,University of Arizona
International Journal of Rock Mechanics and Mining Sciences | Year: 2010

Polyaxial strength test data of five rocks are used to examine the Mohr-Coulomb, Drucker-Prager, modified Lade, Mogi-Coulomb and three-dimensional (3D) Hoek-Brown criteria regarding their ability, with parameters determined based on the triaxial compression test data, to represent the rock behavior under polyaxial stress states. Then the five strength criteria, with parameters determined based on the triaxial compression test data, are used to analyze wellbore stability of both vertical and inclined boreholes. The results show that the Mohr-Coulomb criterion under-predicts the polyaxial strength and estimates the highest minimum mud pressure required for wellbore stability while the Drucker-Prager criterion over-predicts the polyaxial strength and estimates the lowest minimum mud pressure. The modified Lade, Mogi-Coulomb and 3D Hoek-Brown criteria, with parameters based on triaxial test data, can either over-predict or under-predict the polyaxial strength. The over-prediction of the modified Lade criterion can be very large, and thus it may be unsafe to use it to estimate the minimum mud pressure. Both the over-prediction and under-prediction are relatively small for the 3D Hoek-Brown and Mogi-Coulomb criteria. Therefore, the 3D Hoek-Brown and Mogi-Coulomb criteria are recommended for wellbore stability analysis. © 2010 Elsevier Ltd.

Liu G.,Central South University
International Journal of Electrical Power and Energy Systems | Year: 2014

In the last few years, due to soaring fuel prices and gas emissions, renewable energy technologies have been suggested as the power source for infrastructures. The interest in solar photovoltaic (PV) assisted street lighting systems stems from the fact that they are sustainable and environmentally friendly compared to conventional energy powered systems. The present paper investigates and compares the economic feasibility of two types of systems: islanded and grid-connected system, for the street lighting systems in Hunan Province, China. Based on two options of solar panel materials, a simulation model of the system is developed for economic, technical and environmental feasibility. The comprehensively sustainability feasibility of these systems is conducted taking into account the cost, energy generation, CO2 emissions and renewable fraction. Radar plot is employed to integrate all the sustainability indicators into a general indicator, which presents system's sustainability as a real number in the interval [0, 2]. Results show that for street lighting systems of all the cities, single crystal panel has a larger number of annual electricity generation, less emissions and higher environmental performance, but is more expansive than polycrystalline. It is also found that when the feed-in tariff higher than 1.27 CNY/kW h, the cost of energy (COE) of the solar powered lighting systems is less than a pure grid powered system. This will incite the use of solar PV in infrastructures. Through comparing the scores of sustainability, it is found that the Loudi system has the highest feasibility while the Yongzhou system has the lowest in the province. © 2013 Elsevier Ltd. All rights reserved.

Patil M.,Georgia Regents University | Pabla N.,Georgia Regents University | Pabla N.,St Jude Childrens Research Hospital | Dong Z.,Georgia Regents University | Dong Z.,Central South University
Cellular and Molecular Life Sciences | Year: 2013

Originally identified as a mediator of DNA damage response (DDR), checkpoint kinase 1 (Chk1) has a broader role in checkpoint activation in DDR and normal cell cycle regulation. Chk1 activation involves phosphorylation at conserved sites. However, recent work has identified a splice variant of Chk1, which may regulate Chk1 in both DDR and normal cell cycle via molecular interaction. Upon activation, Chk1 phosphorylates a variety of substrate proteins, resulting in the activation of DNA damage checkpoints, cell cycle arrest, DNA repair, and/or cell death. Chk1 and its related signaling may be an effective therapeutic target in diseases such as cancer. © 2013 Springer Basel.

Bao R.,Central South University | Yi J.,Kunming University of Science and Technology
International Journal of Refractory Metals and Hard Materials | Year: 2014

In this paper, the densification and microstructural evolution of microwave fabricated WC-8Co composites were studied. Experimental results showed that shrinkage rate increased at 1275-1325 C. The shape of most WC grains was turned into truncated trigonal prism at 1300 C for 5 min. The apparent activation energy of WC coarsening in microwave prepared alloy was 84.48 Kcal/mol, which was much lower than that in vacuum sintering. Finally, the local liquid phase sintering mechanism of microwave sintered WC-Co cemented carbide based on the hot spots formation was proposed. © 2013 Elsevier Ltd.

Liu X.,Japan International Center for Materials Nanoarchitectonics | Liu X.,Central South University | Ma R.,Japan International Center for Materials Nanoarchitectonics | Bando Y.,Japan International Center for Materials Nanoarchitectonics | Sasaki T.,Japan International Center for Materials Nanoarchitectonics
Advanced Functional Materials | Year: 2014

A low-cost oil bath synthetic route is presented to produce uniform and highly crystalline layered cobalt hydroxide nanocones (NCs) intercalated with dodecyl sulfate anions (C12H25OSO3-, DS-). A new exfoliating procedure, by gradually unravelling/ unzipping these NCs through heat treatment in formamide-water binary solution, is developed to prepare unilamellar nanosheets. Moreover, the NCs can be readily modified with various inorganic or organic anions via a conventional anion-exchange process at ambient temperature. The exchanged product, for example, NO3--intercalated NCs, can be more easily and rapidly transformed into cobalt oxides (e.g., Co3O4 and CoO) than the original DS--intercalated form while retaining a conical feature. Both the cobalt hydroxide NCs and exfoliated nanosheets are electrochemically redoxable, exhibiting a Faradaic pseudocapacitive behavior. The magnetic measurements further reveal both antiferromagnetic behaviors for transformed Co3O4 and CoO NCs. Their Néel temperature values are lower than those of bulk oxides due to finite size and geometric confinement effect. The peculiar conical feature of NCs with a hollow interior and tunable layer spacing, as well as exfoliated unilamellar nanosheets with all surface area exposed, may show promise for potential applications in electrochemical energy storage and magnetic devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liu Z.,City University of Hong Kong | Liu Z.,Central South University | Li H.-X.,City University of Hong Kong
IEEE Transactions on Industrial Informatics | Year: 2014

Effective thermal management is crucial to the optimal operation and health management of lithium-ion batteries. The online estimation of the temperature distribution in vehicle battery systems is not easy, as there are only a few sensors available on site. Furthermore, the thermal behaviors of batteries are difficult to predict, as their dynamics are strongly time-varying. In this paper, a hybrid model is developed for spatiotemporal estimation of temperature distribution in lithium-ion batteries. A simple but effective nominal model is first developed for real-time thermal management using a time/space separation method. Subsequently, a data-based neural model is proposed to compensate the model-plant mismatch caused by the spatial nonlinearity and other model uncertainties. The developed algorithm is simple and can be readily integrated into existing battery management systems. Simulation studies demonstrate the effectiveness of the proposed method. © 2005-2012 IEEE.

Zhou Y.,CAS Dalian Institute of Chemical Physics | Zhou Y.,Central South University | Li X.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Bao X.,CAS Dalian Institute of Chemical Physics
Journal of Materials Chemistry | Year: 2012

Carbon has been widely used as a catalyst support and adsorbent in industry. However, it suffers from poor stability due to its limited mechanical strength, particularly under high pressures and temperatures. We report here a carbide derived carbon (CDC) layer on a porous SiC surface, which has the properties of high mechanical strength and is easy to shape. The CDC exhibits an amorphous structure and contains mainly mesopores with a BET surface area of 125 m 2 g -1. The CDC-SiC composite yields a comparable performance to coconut activated carbon (AC) as a catalyst support in the probe reaction hydrogenation of 4-carboxybenzaldehyde. The further introduction of TiO 2 nanoparticles enhances the activity and stability significantly because of the improved dispersion of Pd particles on CDC-SiC. The activity is 4 times higher than the Pd/AC catalyst. Pd-TiO 2/CDC-SiC shows great promise as an alternative to the current AC supported Pd catalyst for the crude terephthalic acid hydropurification industry. © 2012 The Royal Society of Chemistry.

The changes in the capacitance and the dielectric constant of multi-wall carbon nanotube filled silicone rubber composite during the compressive creep are studied. At the moment of the sudden compression, the capacitance and the dielectric constant decrease instantaneously, and the absolute values of the instantaneous decrements increase with the increase of the sudden compressive pressure. When the compressive pressure holds constant, the capacitance and the dielectric constant increase gradually and tend to be stable over time. Based on the viscoelastic theory, the mathematical model for the variations in the dielectric constant during the compressive creep is established. With the increase of the sudden compressive pressure, the dielectric constant retardation times hold constant and the stable normalized dielectric constant increases. With the increase of the carbon nanotube volume percent, the dielectric constant retardation times and the stable normalized dielectric constant decreases. © 2016 Elsevier Ltd.

Liu J.,Central South University | Jiang S.,Michigan State University | Cao D.,Michigan State University | Peng F.Z.,Michigan State University
IEEE Transactions on Industrial Informatics | Year: 2013

This paper presents a fixed frequency operating sliding mode (SM) current control method with fast response and improved stability. Different from the conventional SM control with variable switching frequency, the fixed-frequency SM controller is proposed to control the modulation index and shoot-through duty ratio of the voltage-fed quasi-Z-source inverter (qZSI), which will not increase the passive components and filter design difficulty. A large-signal dynamic model of the system has been established, which can be used for the system stability control in a wide operating range. By using linear approximation, the system small-signal model is also obtained to analyze the control system stability and transient response. Compared with the conventional current mode controller, the proposed SM controller can achieve faster response, lower current ripple and better stability for qZSI when the supply and load variation is large. Experimental results are presented to demonstrate the validity of the theoretical design and the effectiveness of the proposed controller. © 2012 IEEE.

Tan C.,Central South University
Expert Systems with Applications | Year: 2011

An extension of TOPSIS, a multi-criteria interval-valued intuitionistic fuzzy decision making technique, to a group decision environment is investigated, where inter-dependent or interactive characteristics among criteria and preference of decision makers are taken into account. To get a broad view of the techniques used, first, some operational laws on interval-valued intuitionistic fuzzy values are introduced. Based on these operational laws, a generalized interval-valued intuitionistic fuzzy geometric aggregation operator is proposed which is used to aggregate decision makers' opinions in group decision making process. In addition, some of its properties are discussed. Then Choquet integral-based Hamming distance between interval-valued intuitionistic fuzzy values is defined. Combining the interval-valued intuitionistic fuzzy geometric aggregation operator with Choquet integral-based Hamming distance, an extension of TOPSIS method is developed to deal with a multi-criteria interval-valued intuitionistic fuzzy group decision making problems. Finally, an illustrative example is used to illustrate the developed procedures. © 2010 Elsevier Ltd. All rights reserved.

Yang D.-R.,Hunan University | Zhu H.-Z.,Hunan University | Zhu H.-Z.,Central South University
World Journal of Gastroenterology | Year: 2015

Hepatitis C virus (HCV) is a major human pathogen of chronic hepatitis and related liver diseases. Innate immunity is the first line of defense against invading foreign pathogens, and its activation is dependent on the recognition of these pathogens by several key sensors. The interferon (IFN) system plays an essential role in the restriction of HCV infection via the induction of hundreds of IFN-stimulated genes (ISGs) that inhibit viral replication and spread. However, numerous factors that trigger immune dysregulation, including viral factors and host genetic factors, can help HCV to escape host immune response, facilitating viral persistence. In this review, we aim to summarize recent advances in understanding the innate immune response to HCV infection and the mechanisms of ISGs to suppress viral survival, as well as the immune evasion strategies for chronic HCV infection. © 2015 Baishideng Publishing Group Inc. All rights reserved.

Wu F.,Georgia Institute of Technology | Wu F.,Central South University | Magasinski A.,Georgia Institute of Technology | Yushin G.,Georgia Institute of Technology
Journal of Materials Chemistry A | Year: 2014

In order to achieve high capacity utilization and high rate performance of lithium sulfide (Li2S) cathode materials, it is critical to identify scalable methods for low-cost preparation of nanostructured Li2S or Li2S-carbon composites. Here, we report on the preparation and characterization of nanoporous Li2S and multiwalled (MW) carbon nanotube (CNT)-linked Li2S powders, prepared for the first time via a versatile solution-based method. The addition of MWCNTs enhances electrical conductivity and structural stability of the Li2S-based cathodes and reduces polarization of cells operating at high current densities. The nanostructured Li2S-based cathodes containing 20 wt% MWCNT showed promising discharge capacities of up to ∼1050 mA h g-1 S at a slow rate of C/20 and ∼800 mA h g-1 S at a C/2 rate. Quite remarkably, without any electrolyte additives (such as polysulfides or lithium nitrate) MWCNT-linked Li2S cathodes demonstrated up to ∼90% capacity retention after 100 cycles in half cells (vs. Li foil) at a C/5 and C/10 rates. This journal is © the Partner Organisations 2014.

Huang Y.,Central South University | Min C.,Shenzhen University | Dastmalchi P.,Louisiana State University | Veronis G.,Louisiana State University
Optics Express | Year: 2015

We introduce slow-light enhanced subwavelength scale refractive index sensors which consist of a plasmonic metal-dielectric-metal (MDM) waveguide based slow-light system sandwiched between two conventional MDM waveguides. We first consider a MDM waveguide with small width structrue for comparison, and then consider two MDM waveguide based slow light systems: a MDM waveguide side-coupled to arrays of stub resonators system and a MDM waveguide side-coupled to arrays of double-stub resonators system. We find that, as the group velocity decreases, the sensitivity of the effective index of the waveguide mode to variations of the refractive index of the fluid filling the sensors as well as the sensitivities of the reflection and transmission coefficients of the waveguide mode increase. The sensing characteristics of the slow-light waveguide based sensor structures are systematically analyzed. We show that the slowlight enhanced sensors lead to not only 3.9 and 3.5 times enhancements in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, but also to 2 and 3 times reductions in the required sensing length, respectively, compared to a sensor using a MDM waveguide with small width structure. © 2015 Optical Society of America.

Qurashi A.,Emory University | Liu H.,Emory University | Ray L.,Emory University | Nelson D.L.,Baylor College of Medicine | And 2 more authors.
Human Molecular Genetics | Year: 2012

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a progressive neurodegenerative disorder recognized in fragile X premutation carriers. Using Drosophila, we previously identified elongated non-coding CGG repeats in FMR1 allele as the pathogenic cause of FXTAS. Here, we use this same FXTAS Drosophila model to conduct a chemical screen that reveals small molecules that can ameliorate the toxic effects of fragile X premutation ribo-CGG (rCGG) repeats, among them several known phospholipase A 2 (PLA 2) inhibitors. We show that specific inhibition of PLA 2 activity could mitigate the neuronal deficits caused by fragile X premutation rCGG repeats, including lethality and locomotion deficits. Furthermore, through a genetic screen, we identified a PLA 2 Drosophila ortholog that specifically modulates rCGG repeat-mediated neuronal toxicity. Our results demonstrate the utility of Drosophila models for unbiased small molecule screens and point to PLA 2 as a possible therapeutic target to treat FXTAS. © The Author 2012. Published by Oxford University Press. All rights reserved.

Lin H.,Central South University | Sun S.,China University of Mining and Technology
Disaster Advances | Year: 2012

Layered rock mass slopes widely existed in the practice of geotechnical engineering. Therefore, the study of their deformation and mechanical properties is essential for the safe design of slopes. This study uses FLAC3D numerical calculation software to simulate interactions between layered rock mass slope and pile. In the process of numerical simulation, a three-spring pile unit is employed to simulate piles placed in six positions of the slope. By changing the length of the pile, this article performs a research on the reinforcement effect of pile from different influencing factors, such as overall displacement of slope, monitoring point displacement and shear stress of slope rock mass. The analysis reveals that, when pile positions are set at the middle and lower parts to ensure that piles pass through the most dangerous slip surface, the best deformation effect of rock mass results. Piles at the slope toe helps change the stress condition of the corresponding rock mass and decrease the stress concentration phenomenon. As the pile length increases, the displacement saltation in the slope occurs on a gradually decreasing basis and presents a well-distributed changing trend. A critical pile length exists and controlling displacement by proceeding with increasing pile length renders no obvious effect when the length goes beyond critical pile length.

Guo K.,Central South University
Journal of Computational Information Systems | Year: 2011

A novel approach is introduced to match 3D incomplete object. Firstly, Point-pair Set is constructed by filtrating points with similar curvature; then similar Triangle-pair Set is established through searching similar triangle skeleton in Point-pair Set; finally, optimal transformation is selected from the Triangle-pair Set using scoring function to determine the optimal matching. Experiments indicate an encouraging matching efficiency and running time complexity to irregular surfaces. © 2011 Binary Information Press.

Wang S.,Georgia Regents University | Dong Z.,Georgia Regents University | Dong Z.,Central South University
American Journal of Physiology - Renal Physiology | Year: 2013

Cilia, membraneenclosed organelles protruding from the apical side of cells, can be divided into two classes: motile and primary cilia. During the past decades, motile cilia have been intensively studied. However, it was not until the 1990s that people began to realize the importance of primary cilia as cellular-specific sensors, particularly in kidney tubular epithelial cells. Furthermore, accumulating evidence indicates that primary cilia may be involved in the regulation of cell proliferation, differentiation, apoptosis, and planar cell polarity. Many signaling pathways, such as Wnt, Notch, Hedgehog, and mammalian target of rapamycin, have been located to the primary cilia. Thus primary cilia have been regarded as a hub that integrates signals from the extracellular environment. More importantly, dysfunction of this organelle may contribute to the pathogenesis of a large spectrum of human genetic diseases, named ciliopathies. The significance of primary cilia in acquired human diseases such as hypertension and diabetes has gradually drawn attention. Interestingly, recent reports disclosed that cilia length varies during kidney injury, and shortening of cilia enhances the sensitivity of epithelial cells to injury cues. This review briefly summarizes the current status of cilia research and explores the potential mechanisms of cilia-length changes during kidney injury as well as provides some thoughts to allure more insightful ideas and promotes the further study of primary cilia in the context of kidney injury. © 2013 by the American Physiological Society.

Selmi C.,University of California at Davis | Selmi C.,Humanitas Clinical and Research Center | Lu Q.,Central South University | Humble M.C.,National Health Research Institute
Journal of Autoimmunity | Year: 2012

The higher concordant occurrence of autoimmune diseases in monozygotic twins compared to dizygotic or sibling pairs supports the role for genetic susceptibility. For most conditions, however, concordance rates are considerably below 100% and lead to the estimate of the weight of genetics coined "heritability" In the group of autoimmune diseases heritability ranges between 0.008 and 1 with median values of approximately 0.60. A complementary term coined "environmentability" represents the environmental influence on individual phenotype, and can include dietary habits, chemicals, or hygienic conditions. Genome-wide association data in complex diseases confirmed a role for the environment in disease etiology as significantly associated polymorphisms were found only in subgroups of patients and controls. Environmental links to autoimmunity range from anecdotal associations or case series to largely investigated experimental and epidemiological studies. A bibliographic analysis reveals that the number of publications dedicated to environmental factors in autoimmunity has grown on average by 7% every year since 1997. The National Institute of Environmental Health Sciences (NIEHS) convened an expert panel workshop to review the body of literature examining the role of the environment in the development of autoimmune disease and to identify conclusions, confidences, and critical knowledge gaps in this area. The results of the workshop discussion are summarized in the articles found in this issue of the Journal of Autoimmunity. © 2012 Elsevier Ltd.

Objective To compare death rates from road traffic injuries in China in 2002-2007 when derived from police-reported data versus death registration data. Methods In China, police-recorded data are obtained from police records by means of a standardized, closed-ended data collection form; these data are published in the China statistical yearbook of communication and transportation. Official death registration data, on the other hand, are obtained from death certificates completed by physicians and are published in the China health statistics yearbook. We searched both sources for data on road traffic deaths in 2002-2007, used the χ2 test to compare the mortality rates obtained, and performed linear regression to look for statistically significant trends in road traffic mortality over the period. Findings For 2002-2007, the rate of death from road traffic injuries based on death registration data was about twice as high as the rate reported by the police. Linear regression showed a significant decrease of 27% (95% confidence interval, CI: 35-19) in the death rate over the period according to police sources but no significant change according to death registration data. Conclusion The widely-cited recent drop in road traffic mortality in China, based on police-reported data, may not reflect a genuine decrease. The quality of the data obtained from police reports, which drives decision-making by the Government of China and international organizations, needs to be investigated, monitored and improved.

Siddiqui C.,University of Central Florida | Abdel-Aty M.,University of Central Florida | Huang H.,Central South University
Accident Analysis and Prevention | Year: 2012

Exploring the significant variables related to specific types of crashes is vitally important in the planning stage of a transportation network. This paper aims to identify and examine important variables associated with total crashes and severe crashes per traffic analysis zone (TAZ) in four counties of the state of Florida by applying nonparametric statistical techniques such as data mining and random forest. The intention of investigating these factors in such aggregate level analysis is to incorporate proactive safety measures in transportation planning. Total and severe crashes per TAZ were modeled to provide predictive decision trees. The variables which carried higher weight of importance for total crashes per TAZ were - total number of intersections per TAZ, airport trip productions, light truck productions, and total roadway segment length with 35 mph posted speed limit. The other significant variables identified for total crashes were total roadway length with 15 mph posted speed limit, total roadway length with 65 mph posted speed limit, and non-home based work productions. For severe crashes, total number of intersections per TAZ, light truck productions, total roadway length with 35 mph posted speed limit, and total roadway length with 65 mph posted speed limit were among the significant variables. These variables were further verified and supported by the random forest results. © 2011 Elsevier Ltd. All rights reserved.

The question of what determines genetic diversity has long remained unsolved by the modern evolutionary theory (MET). However, it has not deterred researchers from producing interpretations of genetic diversity by using MET. We examine the two observations of genetic diversity made in the 1960s that contributed to the development of MET. The interpretations of these observations by MET are widely known to be inadequate. We review the recent progress of an alternative framework, the maximum genetic diversity (MGD) hypothesis, that uses axioms and natural selection to explain the vast majority of genetic diversity as being at equilibrium that is largely determined by organismal complexity. The MGD hypothesis absorbs the proven virtues of MET and considers its assumptions relevant only to a much more limited scope. This new synthesis has accounted for the overlooked phenomenon of progression towards higher complexity, and more importantly, been instrumental in directing productive research. © 2016 Elsevier Inc.

Chen C.,Xiangtan University | Zhang J.,Central South University
International Journal of Geomechanics | Year: 2013

Developing reliable and versatile constitutive models for geomaterials has been a challenging task for nonlinear finite-element analysis of geotechnical engineering systems.This paper is mainly concerned with the elastoplastic constitutive relationship of unbound granular materials under various stress paths. The fuzzy set plasticity theory has been developed to account for the nonlinear soil stress-strain behavior. The theory in many ways resembles the bounding surface plasticity, where the plastic modulus is a function of the distance between the current and image stress states in the stress space. Based on the concept of fuzzy set theory in mathematics, a membership function whose value ranges from 1 and 0 is introduced to specify the plastic modulus at a given stress state. Hollow cylinder and cubical test results on Hostun sand from the CASE database were selected to assess the fuzzy set plasticity model. The numerical results showed that the fuzzy set model is capable of mimicking and simulating the nonlinear behavior of loose sands under various loading paths. © 2012 American Society of Civil Engineers.

Tan Y.,Shanxi Medical University | Zhang H.,Shanxi Medical University | Xiao E.-H.,Central South University
Clinical Radiology | Year: 2013

Aim: To evaluate the dynamic computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological characteristics of perivascular epithelioid cell tumours (PEComas), thus improving the diagnosis of the tumour. Materials and methods: A retrospective analysis was undertaken of the dynamic CT, MRI, and clinicopathological characteristics of 32 PEComas diagnosed at histopathology during the period 1 January 2005 to 1 March 2012 at two hospitals. Results: The age of the patients ranged from 14-80 years (mean 43.3 years). There were more women in this group (19/32). Solitary tumours were identified in kidney (n = 16), liver (n = 7), gynaecological organs (n = 2), retroperitoneal soft tissue (n = 2), lung (n = 2), palate (n = 1), left groin (n = 1). One patient had multiple tumours in the liver, kidney, and retroperitoneal soft tissue. Dynamic CT (32 cases) and MRI (15 cases) demonstrated tumours that were of low density or hypointense on T1-weighted imaging (WI) and hyperintense on T2WI; some were isodense with fat (CT: 10/32; MRI: 6/15). The tumours usually had well-defined borders and were of a regular shape (CT: 26/32; MRI: 12/15). Tumour diameters ranged from 1.5-18 cm (mean 5.1 cm). Most tumours (CT: 21/32, MRI: 10/15) enhanced heterogeneously and significantly on arterial and venous phases. Tumours appeared slightly hypodense on delayed CT imaging, although some (6/32) had delayed enhancement. The expression rate of HMB-45 (human melanoma black monoclonal antibody) was 100% (32/32). Histological classification in 22 cases (22/32) was epithelioid angiomyolipoma (AML), three (3/32) were clear cell "sugar" tumours (CCSTs), two (2/32) were lymphangioleiomyomatosis (LAM), and two (2/32) were clear cell myomelanocytic tumours of the falciform ligament/ligamentum teres (CCMMT). Three tumours did not have a specific classification. Conclusion: Knowledge of dynamic CT, MRI, and clinicopathological characteristics could help improve the diagnosis of PEComa. © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Zheng K.,Central South University
Cement and Concrete Composites | Year: 2016

It is well recognized that finely ground soda-lime glass exhibits high pozzolanic reactivity. Fine glass grains will not undergo an Alkali-silica reaction (ASR) in the presence of alkali, and can even mitigate the ASR between alkali and reactive aggregates. Influences of the pozzolanic reaction of glass powder on solid phases, pore solution in cement paste, and the ASR mitigating effect are investigated in the study. The pozzolanic reaction of glass not only consumes portlandite to form in-situ C-S-H, which appears as reaction rim around glass grains, and precipitated C-S-H, but also reduces monosulfate level. The impacts of the pozzolanic reaction on species in pore solution are characterized by increased aluminum, sulfate, sodium, and silicon concentrations and decreased calcium concentration. The increase in aluminum and sulfate concentrations results from the decrease in solid monosulfate. Glass powder controls ASR by increasing aluminum concentration in pore solution to reduce the dissolution of amorphous silica from reactive aggregates. © 2016 Elsevier Ltd. All rights reserved.

He J.-S.,Central South University
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2010

The closed addition rules in three-element (-1, 0, 1) set and the 2n sequence pseudo-random signal coding principles were established, from which the pseudo-random signals with any number of main frequencies were generated and characterized by similar amplitude and equal distance distribution in log coordinate for these main frequencies. The results show that the 2n sequence pseudo-random signal is an ideal one for geophysical prospecting, equipment testing and frequency domain radar.

Cao Y.,Central South University
Expert Systems with Applications | Year: 2012

Financial distress prediction methods based on combination classifier become a rising trend in this field. This paper applies Choquet integral to ensemble single classifiers and proposes a Choquet integral-based combination classifier for financial distress early warning. Also, as the conditions between training and pattern recognition cannot be completely consistent, so this paper proposes an adaptive fuzzy measure by using the dynamic information in the single classifier pattern recognition results which is more reasonable than the static prior fuzzy density. Finally, a comparative analysis based on Chinese listed companies' real data is conducted to verify prediction accuracy and stability of the combination classifier. The experiment results indicate that financial distress prediction using Choquet integral-based combination classifier has higher average accuracy and stability than single classifiers. © 2011 Elsevier Ltd. All rights reserved.

Zeng L.,Central South University | Zeng L.,CSIRO | Cheng C.Y.,CSIRO
Hydrometallurgy | Year: 2010

A commercially available extractant, LIX®63 was used to investigate the extraction of molybdenum(VI) and vanadium(V) from a synthetic sulphuric acid leach solution of spent hydrodesulphurisation catalysts. The molybdenum(VI) and vanadium(V) were extracted and separated completely from other metals at pH 1.5. The loaded organic solution was easily stripped by NaOH solution with excellent phase separation. After the precipitation of most of the vanadium(V) as ammonium vanadate from the loaded strip liquor, a pure molybdate solution could be obtained by further removing the small amount of vanadium(V) remaining in the filtrate using Aliquat 336 at pH 8.5. Therefore, both pure molybdenum(VI) and vanadium(V) products can be obtained. The separation of nickel(II) and cobalt(II) from iron(III) and aluminium(III) in the raffinate after the recovery of molybdenum(VI) and vanadium(V) could be achieved by ion exchange with Dowex M4195 resin. A process flowsheet has been developed to recover the valuable metals from leach solutions of spent hydrodesulphurisation catalysts. Crown Copyright © 2009.

Lu Z.-H.,Central South University | Zhao Y.-G.,Kanagawa University
Journal of Constructional Steel Research | Year: 2010

In this paper, a total of 250 experimental tests of axially loaded circular concrete-filled steel tube (CFT) stub columns, published in the literature was summarized. The applicability of the current design codes such as ACI, Australian Standards, AISC, AIJ, Eurocode 4, DL/T and some available empirical models proposed by various researchers for calculating the axial capacity of circular CFT stub columns was examined using these experimental data. Based on the investigations, four new empirical models for predicting the axial capacity of circular CFT stub columns are proposed. The comparisons between the experimental results and the predictions of these models show that the proposed empirical models provide a direct, compact, and efficient representation of the ultimate strength of circular CFT stub columns made with not only normal strength but also high strength steel tubes and concrete. Finally, the limiting values of the maximum effective length, the compressive strength of concrete, the yield strength of steel tubes and the diameter-to-thickness for circular CFT stub columns with respect to the present empirical models are suggested. It is expected that engineers can easily use the present empirical models to estimate the axial capacities of circular CFT stub columns for engineering designs. © 2010 Elsevier Ltd. All rights reserved.

Li S.,Central South University | Sun F.,South China University of Technology | Li H.,South China University of Technology
Acta Materialia | Year: 2010

The texture evolution in commercial-purity aluminum (AA1070) processed by accumulative roll-bonding (ARB) is investigated with the aid of X-ray diffraction and crystal plasticity modeling. The experimental results indicate strong texture gradients through the sheet thickness, from rolling-type textures with orthorhombic symmetry at the center to shear-type textures with monoclinic symmetry near the surface. The experimental textures are reproduced well by polycrystal plasticity modeling carried out with deformation histories from finite element simulations. The observations of a relatively strong {4 4 11}〈11 11 8〉 component at the center and a {0 0 1}〈1 1 0〉 component at the surface are attributed to their higher orientation stability than the other rolling- and shear-type orientations. Examination of the average through-thickness textures suggests that the ARB technique may not be an effective means to develop apparent {1 1 1}〈u v w〉 components and thus to enhance the normal anisotropy of plasticity of the bulk sheet materials. © 2009 Acta Materialia Inc.

Tamas I.,University of Calgary | Smirnova A.V.,University of Calgary | He Z.,University of Calgary | He Z.,Central South University | Dunfield P.F.,University of Calgary
ISME Journal | Year: 2014

The alphaproteobacterial family Beijerinckiaceae contains generalists that grow on a wide range of substrates, and specialists that grow only on methane and methanol. We investigated the evolution of this family by comparing the genomes of the generalist organotroph Beijerinckia indica, the facultative methanotroph Methylocella silvestris and the obligate methanotroph Methylocapsa acidiphila. Highly resolved phylogenetic construction based on universally conserved genes demonstrated that the Beijerinckiaceae forms a monophyletic cluster with the Methylocystaceae, the only other family of alphaproteobacterial methanotrophs. Phylogenetic analyses also demonstrated a vertical inheritance pattern of methanotrophy and methylotrophy genes within these families. Conversely, many lateral gene transfer (LGT) events were detected for genes encoding carbohydrate transport and metabolism, energy production and conversion, and transcriptional regulation in the genome of B. indica, suggesting that it has recently acquired these genes. A key difference between the generalist B. indica and its specialist methanotrophic relatives was an abundance of transporter elements, particularly periplasmic-binding proteins and major facilitator transporters. The most parsimonious scenario for the evolution of methanotrophy in the Alphaproteobacteria is that it occurred only once, when a methylotroph acquired methane monooxygenases (MMOs) via LGT. This was supported by a compositional analysis suggesting that all MMOs in Alphaproteobacteria methanotrophs are foreign in origin. Some members of the Beijerinckiaceae subsequently lost methanotrophic functions and regained the ability to grow on multicarbon energy substrates. We conclude that B. indica is a recidivist multitroph, the only known example of a bacterium having completely abandoned an evolved lifestyle of specialized methanotrophy.

Hu D.,Central South University
Journal of Information Science | Year: 2012

We identified and analysed the 147 journals offering open access (OA) among the 2960 scholarly journals indexed by the Chinese National Knowledge Information (CNKI) database in the humanities and social sciences. Data were analysed concerning each journal's organizer, discipline, publishing cycle, areas, regions or provinces covered, and first date that content was offered free of charge, together with the journal's website construction, the way full text was accessed, and the time delay in publication. On the basis of the survey results, we identify key challenges and problems associated with OA journals in the humanities and social sciences in China, and we outline development strategies to address these issues, including actively promoting the transition of scholarly journals from print form to OA, speeding up network construction of OA journals, and enhancing the functionality of the OA journals' websites. © 2011 Chartered Institute of Library and Information Professionals.

Miura H.,University of Electro - Communications | Maruoka T.,University of Electro - Communications | Yang X.,Central South University | Jonas J.J.,McGill University
Scripta Materialia | Year: 2012

A Mg-Al-Zn alloy was multi-directionally forged at room temperature to cumulative strains of ΣΔ = 2.0. The coarse initial grains were gradually subdivided into ultrafine ones by mechanical twins. A small pass strain of Δ = 0.1 was employed and generations of twins effectively suppressed the development of sharp textures, enabling severe plastic deformation at ambient temperature. Tensile testing revealed an excellent balance of mechanical properties: 480 MPa yield stress, 525 MPa ultimate tensile strength and 5% plastic strain to fracture. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Wu M.,Central South University
International Journal of Digital Content Technology and its Applications | Year: 2011

K-means clustering is a method of cluster analysis which aims to partition n observations into k clusters in which each observation belongs to the cluster with the nearest mean. This paper compares and analyzes the word vector space model of K-means, and expands it using links information. Then it mines several links involved in social tagging network. Experimental result shows that the proposed social web clustering algorithm is effective.

Liu X.,Japan International Center for Materials Nanoarchitectonics | Liu X.,Central South University | Ma R.,Japan International Center for Materials Nanoarchitectonics | Bando Y.,Japan International Center for Materials Nanoarchitectonics | Sasaki T.,Japan International Center for Materials Nanoarchitectonics
Angewandte Chemie - International Edition | Year: 2010

Layered cobalt hydroxide nanocones intercalated with dodecyl sulfate (DS) ions (see scheme; OH- blue, Co green dots, DS ions red) could be synthesized by the microwave-assisted rolling of lamellar structures. The cones could be exfoliated into cobalt hydroxide nanosheets and converted into CoOOH and Co3O4 nanocones. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li X.,Central South University | Atkinson M.A.,University of Florida
Pediatric Diabetes | Year: 2015

Increasing evidence, both functional and morphological, supports the concept of increased intestinal permeability as an intrinsic characteristic of type 1 diabetes (T1D) in both humans and animal models of the disease. Often referred to as a 'leaky gut', its mechanistic impact on the pathogenesis of T1D remains unclear. Hypotheses that this defect influences immune responses against antigens (both self and non-self) predominate, yet others argue hyperglycemia and insulitis may contribute to increased gut permeability in T1D. To address these complicated issues, we herein review the many conceptual role(s) for a leaky gut in the pathogenesis of T1D and suggest ways that if true, therapeutic interventions aimed at the gut-pancreas axis may prove promising for future therapeutic interventions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cao Y.,Central South University
Expert Systems with Applications | Year: 2012

Financial distress prediction (FDP) has always been an important issue in the business and financial management. This research proposed a novel multiple classifier ensemble model based on firm life cycle and Choquet integral for FDP, named MCELCCh-FDP, as a new approach to tackle with financial distress. Empirical study based on Chinese listed companies' real data is conducted, and the results show that the proposed MCELCCh-FDP model has higher prediction accuracy than single classifiers. In order to verify the prediction capability of firm life cycle and Choquet integral in FDP model, comparative analysis is conducted. The experiment results indicate that the introduction of firm life cycle and Choquet integral in FDP can greatly enhance prediction accuracy. © 2011 Elsevier Ltd. All rights reserved.

Change of an electrostatic potential of mean force (EPMF) between two cylindrical rod surfaces with salt composition, ion valence, and ion size at a constant ionic strength of 0.3 M is studied by a classical density functional theory (CDFT) in a primitive model electrolyte solution. Several novel observations are made: (i) strength of a so-called like charge attraction (LCA) reduces in an invariable manner with the salt solution changing from single 2:1 electrolyte to mixture of 2:1 and 1:1 type electrolytes of varying concentration ratios; the change is even over entire range of the composition variation under low surface charge strength, and tends to be insensitive to the composition variation in the presence of the divalent counter-ion, and more and more drastic at a critical point the divalent counter-ion disappears, respectively, as the surface charge strength becomes big enough. (ii) Both monovalent counter-ion and co-ion diameters have only a marginal effect on both the LCA strength and equilibrium distance, and the former "abnormally" affects less than the latter. (iii) Depending on the surface charge strength considered, the divalent counter-ion diameter influences the LCA strength in solution comprised of 2:1 type and 1:1 type electrolytes, monotonously or non-monotonously. All of these findings provide forceful support for a recently proposed hydrogen-bonding style mechanism explaining the LCA. © 2015 Elsevier Ltd.

Liao P.,Central South University
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2010

This paper established a math model of complex surface profile errors, proposed subdivision approach algorithm for calculating the minimum distance between point and NURBS surface, and established the method for calculating complex surface profile errors based on particle swarm optimization algorithm and subdivision approach algorithm. This method can obtain precise results to calculate complex surface profile errors, can be realized easily using computer and applied to three coordinate measuring machines.

Zhang Z.,Hunan Normal University | Lin J.,Central South University
Asian Journal of Animal and Veterinary Advances | Year: 2012

The main purpose of this study was to examine the effects of Achyranthes bidentata Polysaccharides (ABP) on physical fatigue. One hundred and forty four mice were randomly divided into 4 groups: one control group and three ABP treatment groups. The control group was given isotonic sodium chloride solution and the treatment groups were given different doses of ABP (50, 100, 200 mg kg-1) by giving once a day for 28 days. After 28 days, the forced swimming test was performed and the biochemical parameters related to fatigue were examined. The results suggested that ABP had clear anti-physical fatigue effects which could extend the exhaustive swimming time of the mice, as well as increases the liver glycogen and muscle glycogen contents and decreases the blood lactic acid and blood urea nitrogen contents. © 2012 Academic Journals Inc.

Hydrophilic poly(vinyl butyral) (PVB) microporous hollow fiber membranes were prepared via thermally induced phase separation (TIPS), polyethylene glycol with molecular weight 200(PEG200) was used as diluent. The phase diagram of PVB/PEG200 system indicated L-L phase separation. The effects of preparation condition such as take-up speed, bore liquid flow rate, air-gap, and water bath temperature on the properties of the membrane were investigated. The results showed that PVB hollow fiber membrane prepared at air-gap 5 mm had a little greater tensile strength, breaking strength and elongation than those prepared at air-gap zero, and the former had a little greater rejection but smaller water permeate. The increase of the take-up speed led to the decrease of inner diameters and thickness, the increase of the bore liquid flow rate led to the increase of inner diameter and outer diameter, but the decrease of thickness. Crown Copyright © 2010.

Yang X.-L.,Central South University | Yin J.-H.,Hong Kong Polytechnic University
Rock Mechanics and Rock Engineering | Year: 2010

The upper bound theorem of limit analysis is employed to calculate the equivalent MC cohesion coefficient and friction angle to meet the demands of software written in terms of the Mohr-Coulomb (MC) failure criterion when the rock mass failure follows the modified HB failure criterion for slopes in limit state. A MC failure criterion, which is tangent to the actual modified HB failure criterion, is used to calculate the rate of external work and internal energy dissipation. The equivalent MC friction angle is obtained when the objective function is minimized. The equivalent MC friction angles and cohesion depend not only on the nonlinear HB failure criterion but also on the rock slope angles.

Zhou S.,Central South University
Journal of Chemical Physics | Year: 2013

By appealing to the coupling parameter series expansion to calculate the first seven perturbation coefficients of the high temperature series expansion (HTSE) of the free energy, analysis of convergence and low temperature adaptability of the HTSE in calculating fluid thermodynamic properties is performed for the first time; the fluid thermodynamic properties considered include critical parameters, vapor-liquid coexistence curve, thermodynamic characteristic functions, chemical potential, pressure, and constant volume excess heat capacity. To proceed with the analysis, a well known square well model is used as sample; the well widths considered range over a wide interval, and the relevant temperatures amenable to simulation calculations (used as "exact" results to analyze the HTSE) can be both very high and very low. The main discoveries reached are summarized as follows: (1) The HTSE usually converges at the 4th-order truncation, but with decrease of the temperature considered, the lowest truncation order, which makes the HTSE to converge, tends to rise. As a conservative estimate, it is considered that the HTSE always converges for reduced temperature T* higher than 0.25, whereas for T* < 0.25 there appear signs indicating that the HTSE may diverge from the 7th-order truncation. (2) Within the temperature interval with T* ≥ 0.5, the HTSE converges approximately to the correct solution, and the HTSE can be reliably used to calculate the fluid thermodynamic properties, and within this temperature interval, the 4th-order truncation is enough; whereas for T* < 0.5, such as within the temperature interval with 0.275 ≤ T * ≤ 0.355, although the HTSE does converge, it does not converge to the correct solution, and the deviations between the HTSE calculations and MC simulations become an ever-prominent issue with the rising of the density, and the slopes of the thermodynamic properties over density are not satisfactorily represented. As a result, the HTSE is not suited for calculations for temperature interval T* < 0.5. © 2013 AIP Publishing LLC.

Meng F.,Qingdao Technological University | Tan C.,Central South University | Zhang Q.,Beijing Institute of Technology
Knowledge-Based Systems | Year: 2013

The Shapley function is a very effective tool to measure the importance of elements, which can reflect the interactive characteristics among them. In this study we use the Shapley function to propose an induced generalized interval-valued intuitionistic fuzzy hybrid Shapley averaging (IG-IVIFHSA) operator. This operator does not only globally consider the importance of elements and their ordered positions, but also overall reflect the interaction among them and among their ordered positions. It is worth pointing out that most of the existing hybrid aggregation operators are special cases of our operator. Meantime, some important cases are considered, and some desirable properties are studied. Furthermore, the models for the optimal fuzzy measures on attribute set and ordered set are established, respectively. Moreover, an approach to multi-attribute decision making under interval-valued intuitionistic fuzzy environment is developed. Finally, two numerical examples are given to verify the developed method and demonstrate its practicality and feasibility. © 2013 Elsevier B.V. All rights reserved.

Li K.,Central South University
Journal of Railway Engineering Society | Year: 2016

Research purposes: Based on the impact of the surrounding urban architecture and environment on the road construction and the requirements of the height, safety and reliability of retaining structure, this paper proposed a new structure of "frame pile-slab retaining wall in deep cutting" includes multiple anchor piles and transverse bracings, by which the structure are fixedly connected. Drawing on the experience of calculation on the retaining of sheet-pile wall, this paper uses analytic method and finite element software in 2D and 3D view separately to study the overall stability of frame pile-slab retaining wall, and then the results calculated by different methods are compared and analyzed to ensure the reliability. Research conclusions: (1)By using the pile-slab retaining wall of type H the transverse bracings connected by the cast-in-place concrete with piles are set in the lower part of subgrade to increase the integrity and safety of the structure. (2)Using the transverse bracing reduces the burden of pile and limits the horizontal deformation which is from pile-slab structure to cut dues to bearing a part of bending moment, shear force and axial force. The combination of transverse bracing and "embedded pile-slab structure in foundation treatment" also effectively controls the settlement of subgrade and improves the bearing capacity of foundation. (3)Ultra-high retaining under the soil condition is realized by geotechnical engineering application of new structure, which also ensures the engineering stability, and has obvious social and economic benefit. © 2016, Editorial Department of Journal of Railway Engineering Society. All right reserved.

Zheng P.,University of Michigan | Chang X.,La Jolla Institute for Allergy and Immunology | Lu Q.,Central South University | Liu Y.,Center for Cancer and Immunology Research
Journal of Autoimmunity | Year: 2013

A long-standing but poorly understood defect in autoimmune diseases is dysfunction of the hematopoietic cells. Leukopenia is often associated with systemic lupus erythematous (SLE) and other autoimmune diseases. In addition, homeostatic proliferation of T cells, which is a host response to T-cell lymphopenia, has been implicated as potential cause of rheumatoid arthritis (RA) in human and experimental models of autoimmune diabetes in the NOD mice and the BB rats. Conversely, successful treatments of aplastic anemia by immune suppression suggest that the hematologic abnormality may have a root in autoimmune diseases. Traditionally, the link between autoimmune diseases and defects in hematopoietic cells has been viewed from the prism of antibody-mediated hemolytic cytopenia. While autoimmune destruction may well be part of pathogenesis of defects in hematopoietic system, it is worth considering the hypothesis that either leukopenia or pancytopenia may also result directly from defective hematopoietic stem cells (HSC). We have recently tested this hypothesis in the autoimmune Scurfy mice which has mutation Foxp3, the master regulator of regulatory T cells. Our data demonstrated that due to hyperactivation of mTOR, the HSC in the Scurfy mice are extremely poor in hematopoiesis. Moreover, rapamycin, an mTOR inhibitor rescued HSC defects and prolonged survival of the Scurfy mice. Our data raised the intriguing possibility that targeting mTOR dysregulation in the HSC may help to break the vicious cycle between cytopenia and autoimmune diseases. © 2013 Elsevier Ltd.

Zhu C.-X.,Central South University
International Journal of Modern Physics C | Year: 2010

This paper investigates adaptive generalized projective synchronization (GPS) between two novel hyperchaotic systems with different structure and fully uncertain parameters. Based on the Lyapunov stability theorem and the adaptive control theory, GPS between the two hyperchaotic systems is achieved by proposing a new adaptive controller and a novel parameters estimation update law. Strict theoretical proof is put forward. Numerical simulations are presented to demonstrate the effectiveness of the proposed GPS scheme and verify the theoretical results. © 2010 World Scientific Publishing Company.

Peng S.,Yale University | Peng S.,Central South University | Maihle N.J.,Yale University | Huang Y.,Yale University
Oncogene | Year: 2010

Lin28 and Oct4 are highly expressed in human embryonic stem (ES) cells and, along with two other stem cell marker proteins (Nanog and Sox2), together can convert human somatic cells to pluripotency. As an RNA-binding protein, Lin28 acts to stimulate the translation of a specific subset of mRNAs, and to inhibit the biogenesis of a group of microRNAs. Oct4 is a transcription factor essential for the maintenance of pluripotency and survival of ES cells. In this study, we report that a sub-population of epithelial ovarian cancer (EOC) cells co-expresses Lin28 and Oct4 as demonstrated in the analyses of both cell lines and patient tumor samples. We also observe that the combined expression of these proteins in tumor samples is correlated with advanced tumor grade. Intriguingly, when the expression of these two proteins is repressed in the same cells using RNA interference, there is significant reduction in cell growth and survival. We thus propose that Lin28 and Oct4 may have important roles in the initiation and/or progression of EOC, and consequently may serve as important molecular diagnostics and/or therapeutic targets for the development of novel treatment strategies in EOC patients. © 2010 Macmillan Publishers Limited.

Huang Y.,Guangxi Normal University | Huang Y.,Central South University | Zhao S.,Guangxi Normal University | Chen Z.-F.,Guangxi Normal University | And 2 more authors.
Chemical Communications | Year: 2012

We have developed an amplified fluorescence polarization aptasensor that relies on aptamer structure-switching-triggered nanoparticles (NPs) enhancement for biomolecules detection. This new type of assay exhibits higher detection sensitivity over traditional homogeneous aptasensors by two orders of magnitude and high specificity for target molecules. © 2012 The Royal Society of Chemistry.

Guo K.,Central South University
International Journal of Digital Content Technology and its Applications | Year: 2011

A novel recognition approach for deformed isometric surfaces is presented in this paper. Firstly, the Signature Matrix(SM) is constructed by computing the geodesic distance of every point pair using Fast Marching Method on Triangulate Domains (FMTD). Secondly, a normalization procedure is utilized to eliminate the difference of the Signature Matrices for the same object. Finally, a new series of moment invariants is proposed based on the Normalized Signature Matrix (NSM). In comparison with the recent methods, experiments indicate a lower computation complexity to the recognition for deformed isometric surfaces without reducing the recognition rate. In addition, extensions of this approach are introduced to the recognition for occluded and arbitrarily topologically deformed surfaces.

Zhou S.,Central South University
Journal of Chemical Physics | Year: 2014

In the present work, we study effects of relative arrangement of discrete surface charges on electrostatic potential of mean force (EPMF) between two surfaces immersed in a primitive model electrolyte solution. To help in exploring and ascertaining the relevant mechanism, different combinations of values for electrostatic parameters (such as ion concentration, diameter, and valence, solution temperature and relative permittivity) are investigated by solving classical density functional theory in three dimensional space, in combination with different discrete surface charge configurations and surface charge homogeneity configuration as the effects may alter along with change of the surface charge arrangement. Our findings include: (i) if counter-ion is univalent, the EPMF of charge homogeneity surface is always more repulsive than those of charge heterogeneity surfaces whether the discrete surface charges are distributed on the two face-face surfaces commensurately or non-commensurately; (ii) in presence of high valence counter-ion well depth of like charge attraction between two charge homogeneity surfaces approximately takes an averaged value of those for various charge heterogeneity surfaces whether the discrete surface charges are distributed on the two face-face surfaces commensurately or non-commensurately; (iii) the EPMF becomes ever more attractive or less repulsive with a centralization of the discrete surface charges whether the counter-ion valence is univalent, divalent or trivalent; and (iv) the EPMF in the case of charge heterogeneity surfaces is influenced by bulk electrolyte concentration, salt ion diameter and valence, solution temperature, and relative permittivity in the same manner as in the case of charge homogeneity surfaces. All of these findings can be explained self-consistently by a recently proposed hydrogen-bonding style mechanism (for dealing with the EPMF between two charge homogeneity surfaces) reinforced by two new concepts: counter-ion effective adsorption spaces belonging to different localized surface charges and hydrogen bond directivity. © 2014 AIP Publishing LLC.

Cai C.,Central South University | Gao Y.,LIAONING Technical University | Gao Y.,University of Calgary
GPS Solutions | Year: 2013

A combination of GPS and GLONASS observations can offer improved reliability, availability and accuracy for precise point positioning (PPP). We present and analyze a combined GPS/GLONASS PPP model, including both functional and stochastic components. Numerical comparison and analysis are conducted with respect to PPP based on only GPS or GLONASS observations to demonstrate the benefits of the combined GPS/GLONASS PPP. The observation residuals are analyzed for more appropriate stochastic modeling for observations from different navigation systems. An analysis is also made using different precise orbit and clock products. The performance of the combined GPS/GLONASS PPP is assessed using both static and kinematic data. The results indicate that the convergence time can be significantly reduced with the addition of GLONASS data. The positioning accuracy, however, is not significantly improved by adding GLONASS data if there is a sufficient number of GPS satellites with good geometry. © 2012 Springer-Verlag.

Zhou J.,Nanjing Medical University | Wang S.,Nanjing Medical University | Xia X.,Central South University
Current Eye Research | Year: 2012

Objective: Inflammatory reaction has been shown to involve the progress of type 2 (non-insulin-dependent) diabetes. We, therefore, examined the effects of inflammatory cytokines and angiogenic factors in the pathogenesis of proliferative diabetic retinopathy (PDR) in type 2 diabetes. Patients and methods: Vitreous fluid samples were obtained by vitrectomy from 62 eyes of PDR patients with type 2 diabetes and from 20 eyes of age-matched non-diabetic patients. The concentrations of interleukin 1 beta (IL1B), IL6, IL8, IL10, chemokine (C-C motif) ligand 2 (CCL2), endothelin 1 (EDN1), vascular endothelial growth factor (VEGF), and tumor necrosis factor (TNF) in the vitreous samples were measured by enzyme-linked immunosorbent assay (ELISA). Results: The concentrations of LI1B, IL6, IL8, CCL2, EDN1, VEGF, and TNF in the vitreous samples were considerably higher in PDR patients in comparison with the controls. However, the level of IL10 in PDR patients was similar to that obtained in the controls. Analysis of the correlations of the studied factors revealed the correlation of VEGF and IL6, VEGF and EDN1, IL8 and CCL2, and EDN1 and TNF in PDR patients. In addition, a significant positive correlation was observed between vitreous TNF as well as EDN1 and serum HbA1c levels in PDR patients. Conclusions: The inflammatory cytokines and angiogenic factors IL1B, IL6, IL8, CCL2, EDN1, VEGF, and TNF are increased in the vitreous of PDR patients without an increase in IL-10. These results add support to the role of inflammatory cytokines and angiogenic factors in the genesis of PDR. Understanding the implication of these cytokines may provide diagnostic tools and therapeutic targets for treatment and prevention of PDR. © 2012 Informa Healthcare USA, Inc.

Wei Q.,Georgia Regents University | Dong G.,Georgia Regents University | Chen J.-K.,Georgia Regents University | Ramesh G.,Georgia Regents University | And 3 more authors.
Kidney International | Year: 2013

Bax and Bak, two pro-apoptotic Bcl-2 family proteins, have been implicated in acute kidney injury following renal ischemia/reperfusion; however, definitive evidence for a role of these genes in the disease process is lacking. Here we first examined two Bax-deficient mouse models and found that only conditional Bax deletion specifically from proximal tubules could ameliorate ischemic acute kidney injury. Global (whole mouse) knockout of Bax enhanced neutrophil infiltration without significant effect on kidney injury. In contrast, global knockout of Bak protected mice from ischemic acute kidney injury with improved renal function. Interestingly, in these models, Bax or Bak knockout attenuated renal tubular cell apoptosis without significantly affecting necrotic tubular damage. Cytochrome c release in ischemic acute kidney injury was also suppressed in conditional Bax- or global Bak-knockout mice. In addition, Bak deficiency prevented mitochondrial fragmentation in ischemic acute kidney injury. Thus, our gene-knockout studies support a critical role of Bax and Bak in tubular cell apoptosis in ischemic acute kidney. Furthermore, necrosis and apoptosis have distinguishable regulatory functions. © 2013 International Society of Nephrology.

A statistical analysis of the directionality of slip traces in face-centered cubic crystals processed by a single pass of equal-channel angular extrusion was conducted based on crystal plasticity simulations. The slip traces are found to orient along various directions on each of the inspection planes, indicating a strong grain-orientation dependency. The slip traces depict preferred alignment directions that coincide with those of banded structures found in the literature and can be traced to the macroscopic deformation mode. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Qi W.H.,City University of Hong Kong | Qi W.H.,Central South University | Lee S.T.,City University of Hong Kong
Journal of Physical Chemistry C | Year: 2010

The molecular dynamic method has been used to simulate the phase stability, melting, and alloy formation of bimetallic Au-Ag nanoparticles (NPs) with cuboctahedral, decahedral, icosahedral, and spherical shapes. The alloy NPs have more negative formation energy than the core/shell NPs, indicating the former is more stable than the latter. During melting, both core/shell and alloy NPs start to melt from the surface and then the core. The melting temperature of cuboctaheral, icosahedral, and decahedral NPs is similar, indicating the small influence of shape on melting temperature. During the alloying process, the alloy formation ability follows cuboctaheral > icosahedral > decahedral NPs, revealing the significant effect of particle shape on alloying formation. Only the surface was found to become alloy whereas the core remains pure components after annealing. It is shown that the UV-vis method alone is not enough to characterize the alloy formation in the entire NP, but only in the surface shell. © 2010 American Chemical Society.

Wu M.,Central South University
Journal of Convergence Information Technology | Year: 2011

This paper proposes improved intelligent optimization algorithm for the application of feedback design. It improved Particle Swarm Optimization and Support Vector Machine model, then it combined the algorithms to improve precise of regressing, and reduce the error. It optimized the parameters in feedback design. Experimental result shows that the proposed improved intelligent optimization algorithm is effective.

Zhang Q.C.,Howard Hughes Medical Institute | Petrey D.,Howard Hughes Medical Institute | Garzon J.I.,Howard Hughes Medical Institute | Deng L.,Howard Hughes Medical Institute | And 2 more authors.
Nucleic Acids Research | Year: 2013

PrePPI (http://bhapp.c2b2.columbia.edu/PrePPI) is a database that combines predicted and experimentally determined protein-protein interactions (PPIs) using a Bayesian framework. Predicted interactions are assigned probabilities of being correct, which are derived from calculated likelihood ratios (LRs) by combining structural, functional, evolutionary and expression information, with the most important contribution coming from structure. Experimentally determined interactions are compiled from a set of public databases that manually collect PPIs from the literature and are also assigned LRs. A final probability is then assigned to every interaction by combining the LRs for both predicted and experimentally determined interactions. The current version of PrePPI contains ∼2 million PPIs that have a probability more than 0.1 of which ∼60000 PPIs for yeast and ∼370000 PPIs for human are considered high confidence (probability > 0.5). The PrePPI database constitutes an integrated resource that enables users to examine aggregate information on PPIs, including both known and potentially novel interactions, and that provides structural models for many of the PPIs. © The Author(s) 2012.

Mannoor K.,University of Maryland, Baltimore | Xu Y.,Central South University | Chen C.,University of Maryland, Baltimore
Autoimmunity | Year: 2013

A substantial proportion of circulating antibodies in healthy individuals exhibit self-reactivity. These antibodies, referred to as natural autoantibodies, are thought to arise naturally without actual antigen stimulation as they are present in human cord blood and in mice housed in germfree conditions and fed an antigen-free diet. Natural autoantibodies are mainly of the IgM class, unmutated, and typically polyreactive. They provide critical early protection against pathogens, and play important roles in maintenance of homeostasis and modulation of innate and adaptive immune responses, thereby conferring protection from rampant autoimmune and inflammatory injuries. In this review, we summarize current information regarding the properties of natural autoantibodies and the B cells that produce them, their roles in immunity and autoimmunity, their mechanisms of action, and their therapeutic potential. © Informa UK, Ltd.

Yang T.,Hunan University | Li Q.,Hunan University | Zhou B.,Central South University
Information Sciences | Year: 2013

In terms of attribute reduction of covering based rough sets, the discernibility matrix is used as a conventional method to compute all attribute reducts. However, it is inapplicable to attribute reduction in certain circumstances. In this article, a new method, referred to as the related family, is introduced to compute all attribute reducts and relative attribute reducts for covering rough sets. Its core idea is to remove superfluous attributes while keeping the approximation space of covering information system unchanged. The related family method is more powerful than the discernibility matrix method, since the former can handle complicated cases that could not be handled by the latter. In addition, a simplified version of the related family and its corresponding heuristic algorithm are also presented. © 2012 Elsevier Inc. All rights reserved.

Li M.,Central South University | Lai A.C.K.,City University of Hong Kong
Applied Energy | Year: 2013

Short-time responses of borehole ground heat exchangers (GHEs) are difficult to predict because they involve heat capacity effect and various arrangements of U-shaped tubes within boreholes. To meet this engineering challenge, this paper builds a composite-medium line-source model. The central idea of the new model is that the downward and upward channels of U-shaped tubes (not the borehole) are approximated as line sources or sinks of heat placed in a composite medium. This approach can account for not only the influence of the heat capacity of grouting material but also the difference between properties of soil and grout, whilst it is flexible enough to model various U-pipe configurations. The new composite-medium model is validated by using a reported laboratory experiment; it can yield predictions matching the experimental response profiles with acceptable accuracy for times as short as 5. min. Several uncertainties which may contribute to discrepancies between the model prediction and the laboratory data are analyzed, including heat input rate, thermal conductivities and heat capacities of the composite medium. The potential errors caused by these uncertainties are comparable to the observed discrepancies. © 2012 Elsevier Ltd.

For the first time, the classical density functional theory (DFT) is numerically solved in three- and two-dimensional spaces for a two sphere model of electrostatic interactions between two spherical nanoscale colloids immersed in a primitive model electrolyte solution. Two scientific anomalies are found that (i) contrary to what is often asserted that presence of multivalent counter ion is necessary to induce a like-charge attraction (LCA), univalent counter ion also induces the LCA only if bulk electrolyte concentration and colloid surface charge are high enough, and (ii) although the LCA in general becomes stronger with the bulk electrolyte concentration, adverse effects unexpectedly occur if the colloid surface charge quantity rises sufficiently. In addition, effects of counter ion and co-ion diameters in eliciting the LCA are first investigated and several novel phenomena such as monotonic and non-monotonic dependence of the LCA well depth on the counter ion diameter in different colloid surface charge zones are confirmed. Based these findings, a hydrogen bonding style mechanism is suggested and surprisingly, by appealing to fairly common-sense concepts such as bond energy, bond length, number of hydrogen bonds formed, and counter ion single-layer saturation adsorption capacity, self-consistently explains origin of the LCA between two spherical nanoscale particles, and all phenomena previously reported and observed in this study. © 2013 Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.

Gong H.R.,Central South University
Materials Chemistry and Physics | Year: 2011

First principles calculation reveals that ideal mechanical strengths of L12 Ir3Nb are higher than those of L12 Ir 3Hf, and that Hf and Nb atoms have different effects on the brittle behavior of Ir, i.e., the Ir3Hf bulk seems less brittle than f c c Ir, while Ir3Nb becomes more brittle. Densities of states suggest that the chemical bonding formed in Ir3Nb should be stronger and more directional than that in Ir3Hf. Calculation also shows that compared with pure Ir bulk, the bond strengths of (1 0 0)-I and (1 1 0) Ir/Ir 3X (X = Hf, Nb) interfaces have increased, while the bond strengths of (1 0 0)-II and (1 1 1) Ir/Ir3X interfaces have decreased, due to the formation of the interface. In addition, it is found out that the (1 0 0)-I interfaces are energetically favorable with negative interface energies, which is good agreement with similar experimental observations in the literature. © 2010 Elsevier B.V. All rights reserved.

Classical shear beam theory does not consider the rotation of cross sections. This paper studies the free vibration of axially loaded shear beams carrying lumped masses at elastically supported ends where rotational motion of the cross section is taken into account. By using asymptotic analysis of the Timoshenko beam theory, a unified analytical approach for dealing with free-vibration problems of nonclassical shear beams subjected to axial compressive or tensile force according to Engesser's model is presented. A simple characteristic equation is derived for axially loaded shear beams with translational and rotational springs and with attached lumped end masses. The resulting frequency equation is compared with the classical one. A condition causing the nonclassical shear beams to collapse to the classical ones is found. Natural frequencies are evaluated and mode shapes are given explicitly. The influences of the spring coefficients, axial loads, and rotational inertia on the natural frequencies are expounded. The frequency equations of shear beams with typical ends such as free-free and free-pinned ends can be recovered from the present study as special cases. © 2013 American Society of Civil Engineers.

Kong F.,Central South University | Zhang Q.,Beijing University of Civil Engineering and Architecture
Energy and Buildings | Year: 2013

In cold severe area, the exterior layers of building envelope usually experience seasonal freezing/thawing in winter. However, it would lead to severe problems especially in the newly completed building. In order to analyze the drying of envelope on building initial use, the heat and moisture coupled transfer of building envelope in severe cold area Harbin, China was simulated. The modeled result was analyzed. It is concluded that the drying rate of the newly completed building envelope is significantly high in the first year, especially in the first few months. Insulation performance of the wall in the first winter is most serious due to the high initial moisture and freezing ice content in insulation layer. For the simulated envelope, the freezing of the moisture content especially that in insulation layer had notable effect on heat transfer coefficient (thermal resistance), and the maximum of modeled envelope heat transfer coefficient in the first year winter is about 7% higher than that in the tenth year, which is taken as final hygral state. Some parameters as apparent density, specific heat, average thermal diffusivity, heat storage coefficient and thermal inertia index, which were always considered as constants for a fixed building envelope are also changed with the heat and mass transfer of building envelope. © 2013 Elsevier B.V. All rights reserved.

Li H.,Central South University | Wu B.,Hong Kong Polytechnic University
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2013

Geo-information (GI) service automated composition according to user demands is a crucial task in spatial data infrastructures. State-of-the-art GI service composition approaches face serious limitations in terms of effectiveness and stability as the general GI processing service chain (GIPSC) must be generated from individual user specifications from scratch. This paper presents a novel approach called an adaptive geo-information service evolution (AgiSE) method which overcomes these limitations by adaptively reusing and modifying previously generated GIPSC. In this method, an influence domain minimisation (IDM) criterion is employed to modify the existing GIPSC to fit the new (changed) user demands through minimum revisions. The correction of local modification is ensured by process and integrity constraints. An innovative algorithm called influence domain pursuit is developed to find the optimised solution through a heuristic backward search based on the defined IDM. Experimental analysis shows the significant improvements of using AgiSE in GI services compared with existing traditional methods. The benefits of AgiSE are the improved efficiency of GI service composition and the improved executing stability of GIPSC which were achieved by reducing the service provider load. The AgiSE presented in this paper is crucial in reusing a general unified framework for GI service composition. © 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

Liu X.,Central South University | Wu S.,Wuhan University of Technology
Construction and Building Materials | Year: 2011

The mechanical and electrical properties of graphite and carbon fiber modified asphalt concrete were measured in this paper through the indirect tensile test. The experimental results indicate that the mechanical properties of asphalt mixture are influenced by the addition of conductive component like graphite and carbon fiber, When the graphite content increased from 0 to 22 vol.%, Marshall stability decreased from 12.8 kN to 9.43 kN and residual stability from 91.1% to 87.2%. Rutting dynamic stability decreased from 3318 times/mm to 2619 times/mm. After adding the carbon fiber, when the carbon fiber content increased from 0 to 2 vol.%, their Marshall stability and residual stability increased from 12.8 kN to 13.5 kN and residual stability from 91.1% to 92.7%. Rutting dynamic stability increased from 3318 times/mm to 3403 times/mm. When modified through combination effect of graphite and carbon fiber mixed fillers, the mechanical performance and electrical property were improved greatly, their Marshall stability and residual stability has increased from 9.43 kN to 12.1 kN and residual stability from 87.2% to 89.2%. Rutting dynamic stability increased from 2619 times/mm to 3292 times/mm. Furthermore, the resilient modulus is influenced by the addition of graphite, the value of resilient modulus is as much as that of the original, it is 90% when graphite is 30 vol.% and is 70% when graphite is 45 vol.%. The electrical resistance increases reversibly with increasing tensile strain either under dynamic indirect tensile testing or static indirect tensile testing, graphite and carbon fiber modified asphalt concretes are effective for the self-monitoring of strain. It is foreseen that the strain-stress self monitoring is valuable for weighing, traffic monitoring, border monitoring and structural vibration control. © 2010 Elsevier Ltd. All rights reserved.

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

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

Wu Y.,Central South University | Pan X.,National University of Defense Technology
IEEE Transactions on Aerospace and Electronic Systems | Year: 2013

The in-flight alignment is a critical stage for airborne inertial navigation system/Global Positioning System (INS/GPS) applications. The alignment task is usually carried out by the Kalman filtering technique that necessitates a good initial attitude to obtain a satisfying performance. Due to the airborne dynamics, the in-flight alignment is much more difficult than the alignment on the ground. An optimization-based coarse alignment approach that uses GPS position/velocity as input, founded on the newly-derived velocity/position integration formulae is proposed. Simulation and flight test results show that, with the GPS lever arm well handled, it is potentially able to yield the initial heading up to 1 deg accuracy in 10 s. It can serve as a nice coarse in-flight alignment without any prior attitude information for the subsequent fine Kalman alignment. The approach can also be applied to other applications that require aligning the INS on the run. © 1965-2011 IEEE.

Wu Y.,Central South University | Pan X.,National University of Defense Technology
IEEE Transactions on Aerospace and Electronic Systems | Year: 2013

Inertial navigation applications are usually referenced to a rotating frame. Consideration of the navigation reference frame rotation in the inertial navigation algorithm design is an important but so far less seriously treated issue, especially for super high-speed flying vehicles or the future ultraprecision navigation system of several meters per hour. A rigorous approach is proposed to tackle the issue of navigation frame rotation in velocity/position computation by use of the newly-devised velocity/position integration formulae in the Part I companion paper. The two integration formulae set a well-founded cornerstone for the velocity/position algorithms' design that makes the comprehension of the inertial navigation computation principle more accessible to practitioners, and different approximations to the integrals involved give birth to various velocity/position update algorithms. Two-sample velocity and position algorithms are derived to exemplify the design process. In the context of level-flight airplane examples, the derived algorithm is analytically and numerically compared with the typical algorithms that exist in the literature. The results throw light on the problems in existing algorithms and the potential benefits of the derived algorithm. © 1965-2011 IEEE.

Mao X.-Q.,Central South University
Journal of Medical Case Reports | Year: 2014

Introduction. In general, enamel pearls are found in maxillary molars as a small globule of enamel. However, this case report describes an enamel pearl with a prolate spheroid shape which is 1.8mm wide and 8mm long. The different type of enamel pearl found in my clinic has significantly improved our understanding of enamel pearl etiology and pathophysiology. Case presentation. A 42-year-old Han Chinese woman with severe toothache received treatment in my Department of Endodontics. She had no significant past medical history. A dental examination revealed extensive distal decay in her left mandibular first molar, tenderness to percussion and palpation of the periradicular zone, and found a deep periodontal pocket on the buccal lateral. Vitality testing was negative. Periapical radiographic images revealed radiolucency around the mesial apex. Cone beam computed tomography detected an opaque enamel pearl in the furcation area with a prolate spheroid shape of 1.8mm wide and 8mm long. Conclusion: The enamel pearl described in this case report is like a very long dental root. Cone beam computed tomography may be used for evaluating enamel pearls. © 2014 Mao; licensee BioMed Central Ltd.

Zhao C.,Central South University | Hobbs B.E.,University of Western Australia | Ord A.,University of Western Australia
International Journal for Numerical and Analytical Methods in Geomechanics | Year: 2013

SUMMARY: This paper presents an instability theory that can be used to understand the fundamental behavior of an acidization dissolution front when it propagates in fluid-saturated carbonate rocks. The proposed theory includes two fundamental concepts, namely the intrinsic time and length of an acidization dissolution system, and a theoretical criterion that involves the comparison of the Zhao number and its critical value of the acidization dissolution system. The intrinsic time is used to determine the time scale at which the acidization dissolution front is formed, while the intrinsic length is used to determine the length scale at which the instability of the acidization dissolution front can be initiated. Under the assumption that the acidization dissolution reaction is a fast process, the critical Zhao number, which is used to assess the instability likelihood of an acidization dissolution front propagating in fluid-saturated carbonate rocks, has been derived in a strictly mathematical manner. Based on the proposed instability theory of a propagating acidization dissolution front, it has been theoretically recognized that: (i) the increase of the mineral dissolution ratio can stabilize the acidization dissolution front in fluid-saturated carbonate rocks; (ii) the increase of the final porosity of the carbonate rock can destabilize the acidization dissolution front, while the increase of the initial porosity can stabilize the acidization dissolution front in fluid-saturated carbonate rocks; (iii) the increase of the mineral dissolution ratio can cause an increase in the dimensionless propagation speed of the acidization dissolution front; (iv) the increase of the initial porosity can enable the acidization dissolution front to propagate faster, while the increase of the final porosity can enable the acidization dissolution front to propagate slower in the acidization dissolution system. © 2012 John Wiley & Sons, Ltd.

Wang G.,Central South University | Wu J.,Temple University
Future Generation Computer Systems | Year: 2011

Trust management is an extensively investigated topic. A lot of trust models and systems have been proposed in the literature. However, a universally agreed trust model is rarely seen due to the fact that trust is essentially subjective and different people may have different views on it. We focus on the personalization of trust in order to catch this subjective nature of trust. We propose a multi-dimensional evidence-based trust management system with multi-trusted paths (MeTrust for short) to conduct trust computation on any arbitrarily complex trusted graph. The trust computation in MeTrust is conducted at three tiers, namely, the node tier, the path tier, and the graph tier. At the node tier, we consider multi-dimensional trust. Users can define a primary dimension and alternative dimensions on their own and users can make their own privileged strategies and setup weights for different dimensions for trust computation. At the path tier, we propose to use the Frank t-norm for users to control the decay rate for trust combination, which can be tuned in between the minimum trust combination (there is no decay in terms of the path length) and the product trust combination (the decay is too fast when the path length is relatively large). At the graph tier, we propose GraphReduce, GraphAdjust, and WeightedAverage algorithms to simplify any arbitrarily complex trusted graph. We employ trust truncation and trust equivalence to guarantee that every link in the graph will be used exactly once for trust computation. We evaluated trust truncation ratio and trust success ratio through extensive experiments, which can serve as a guide for users to select from a wide spectrum of trust parameters for trust computation. © 2010 Elsevier B.V. All rights reserved.

Li Z.G.,Central South University
Materials Letters | Year: 2014

The zinc-aluminum ZA27 alloy matrix composite reinforced with TiB 2 particulates has been in situ produced via direct melt reaction technology from the Al-K2TiF6-KBF4 system. The X-ray diffraction patterns revealed the presence of TiB2 peaks while the complete absence of brittle Al3Ti and AlB2 particles, indicating the completion of reaction. The SEM micrographs revealed that the composite exhibited finer primary α-Al dendritic structure with TiB 2 particles addition. The in situ formed TiB2 particles are distributed in the interdendritic regions between the primary α-Al dendrites in ZA27 alloy matrix composite. The formation of TiB2 particles significantly enhanced the microhardness and ultimate tensile strength (UTS) of ZA27 alloy. © 2014 Elsevier B.V.

Hou M.,University of South China | Hou M.,Central South University | Han X.,University of South China
IEEE Transactions on Neural Networks | Year: 2010

It is well known that single hidden layer feedforward networks with radial basis function (RBF) kernels are universal approximators when all the parameters of the networks are obtained through all kinds of algorithms. However, as observed in most neural network implementations, tuning all the parameters of the network may cause learning complicated, poor generalization, overtraining and unstable. Unlike conventional neural network theories, this brief gives a constructive proof for the fact that a decay RBF neural network with n+1 hidden neurons can interpolate n+1 multivariate samples with zero error. Then we prove that the given decay RBFs can uniformly approximate any continuous multivariate functions with arbitrary precision without training. The faster convergence and better generalization performance than conventional RBF algorithm, BP algorithm, extreme learning machine and support vector machines are shown by means of two numerical experiments. © 2006 IEEE.

Gao J.,Beihang University | Yang Z.,Central South University | Li X.,Beihang University
Journal of Computational Physics | Year: 2012

In the implementation of spectral difference (SD) method, the conserved variables at the flux points are calculated from the solution points using extrapolation or interpolation schemes. The errors incurred in using extrapolation and interpolation would result in instability. On the other hand, the difference between the left and right conserved variables at the edge interface will introduce dissipation to the SD method when applying a Riemann solver to compute the flux at the element interface. In this paper, an optimization of the extrapolation and interpolation schemes for the fourth order SD method on quadrilateral element is carried out in the wavenumber space through minimizing their dispersion error over a selected band of wavenumbers. The optimized coefficients of the extrapolation and interpolation are presented. And the dispersion error of the original and optimized schemes is plotted and compared. An improvement of the dispersion error over the resolvable wavenumber range of SD method is obtained. The stability of the optimized fourth order SD scheme is analyzed. It is found that the stability of the 4th order scheme with Chebyshev-Gauss-Lobatto flux points, which is originally weakly unstable, has been improved through the optimization. The weak instability is eliminated completely if an additional second order filter is applied on selected flux points. One and two dimensional linear wave propagation analyses are carried out for the optimized scheme. It is found that in the resolvable wavenumber range the new SD scheme is less dispersive and less dissipative than the original scheme, and the new scheme is less anisotropic for 2D wave propagation. The optimized SD solver is validated with four computational aeroacoustics (CAA) workshop benchmark problems. The numerical results with optimized schemes agree much better with the analytical data than those with the original schemes. © 2012 Elsevier Inc.

Wang H.-B.,Central South University
Mini-Reviews in Organic Chemistry | Year: 2013

Complementary hydrogen-bonding arrays are very important for the genetic information storage and transmission. Inspired by natural complementary hydrogen-bonding arrays, researchers have been developing many artificial examples, which have been used in the construction of functional materials. The aim of this review is to highlight the complementary hydrogen-bonding arrays for supramolecular polymerizations. © 2013 Bentham Science Publishers.

Zhang H.,Central South University | Ma Z.,Samsung
IEEE Transactions on Circuits and Systems for Video Technology | Year: 2014

The latest High Efficiency Video Coding (HEVC) standard only requires 50% bit-rate of the H.264/AVC at the same perceptual quality, but with a significant encoder complexity increase. Hence, it is necessary and inevitable to develop fast HEVC encoding algorithms for its potential market adoption. In this paper, we propose a fast intra mode decision for the HEVC encoder. The overall fast intra mode decision algorithm consists of both micro- and macro-level schemes. At the micro-level, we propose the Hadamard cost-based progressive rough mode search (pRMS) to selectively check the potential modes instead of traversing all candidates (i.e., up to 35 in HEVC). Fewer effective candidates will be chosen by the pRMS for the subsequent rate-distortion optimized quantization (RDOQ) to derive the rate-distortion (R-D) optimal mode. An early RDOQ skip method is also introduced to further the complexity reduction. At the macro-level, we introduce the early coding unit (CU) split termination if the estimated R-D cost [through aggregated R-D costs of (partial) sub-CUs] is already larger than the R-D cost of the current CU. On average, the proposed fast intra mode decision provides about 2.5×speedup (without any platform or source code level optimization) with just a 1.0% Bjontegaard delta rate (BD-rate) increase using the HEVC common test condition. Moreover, our proposed solution also demonstrates the state-of-the-art performance in comparison with other works. © 2013 IEEE.

A systematic theoretical investigation is performed for electrostatic potential of mean force (EPMF) between two similarly charged rods (modeling DNA) immersed in a primitive model electrolyte solution. Two scientific anomalies are disclosed: (i) although a like-charge attraction (LCA) generally becomes stronger with bulk electrolyte concentration, the opposite effect unexpectedly occurs if the two rod surfaces involved are sufficiently charged and (2) contrary to what is often asserted, that the presence of multivalent counterion is necessary to induce the LCA, it is found that the univalent counterion induces the LCA solely only if bulk electrolyte concentration rises sufficiently and the rod surface charge quantities are high. On the basis of the system energetics calculated first by a classical density functional theory in three-dimensional space, a hydrogen-bonding style mechanism is advanced to reveal the origin of the LCA, and by appealing to fairly common-sense concepts such as bond energy, bond length, number of hydrogen bonds formed, and counterion single-layer saturation adsorption capacity, the present mechanism successfully explains the scientific anomalies and effects of counterion and co-ion diameters in eliciting the LCA first investigated in this work. To add weight to the hydrogen-bonding style mechanism, a theoretical investigation is further performed regarding the effects of the rod surface charge density, co-ion valence, relative permittivity of the medium, temperature, nonelectrostatic interion interactions, and rod diameter in modifying the EPMF, and several novel phenomena are first confirmed, which is self-consistently explained by the present hydrogen-bonding style mechanism. © 2013 American Chemical Society.

Wang L.,Central South University
IEEE/ASME Transactions on Mechatronics | Year: 2016

To realize the differential structure in the piezoresistive sensor for the application where there is no condition to achieve the opposite subexcitations, an electrode-configuration-based differential structure with the subunits made of identical ingredients is designed. The subunits include 'negative coefficient unit (NCU)' and 'positive coefficient unit (PCU).' The electrodes and the piezoresistive material in NCU/PCU are located in three layers/one layer, and the connection line of the centers of the electrodes is parallel/perpendicular to the compressive pressure. The material thickness in NCU/PCU decreases/holds constant and the cross-sectional area holds constant/decreases with the increase of the pressure, contributing to the decreasing/increasing tendency of the resistance in NCU/PCU. An electrode-configuration-based differential piezoresistive sensor made of conductive polymer composite is developed as an example to verify the aforementioned idea. The results show that the differential structure with the subunits made of identical ingredients can be realized by designing the electrode configurations and the 'sensitivity'/'nonlinear error' can be improved/decreased. © 1996-2012 IEEE.

Zhu C.,Central South University
Optics Communications | Year: 2012

This paper proposes a novel image encryption scheme based on the improved hyperchaotic sequences. Firstly, the hyperchaotic sequences are modified to generate chaotic key stream that is more suitable for image encryption. Secondly, the final encryption key stream is generated by correlating the chaotic key stream and plaintext which result in both key sensitivity and plaintext sensitivity. The scheme can achieve high key sensitivity and high plaintext sensitivity through only two rounds diffusion operation. The performance test and security analysis has been performed using the histograms, correlation coefficients, information entropy, peak signal-to-noise ratio, key sensitivity analysis, differential analysis, key space analysis, decryption quality and speed analysis. Results suggest that the proposed image encryption scheme is secure and reliable, with high potential to be adopted for the secure image communication applications. © 2011 Elsevier B.V. All rights reserved.

Wan P.,Shanghai JiaoTong University | Yu X.,Central South University | Xia Q.,Shanghai JiaoTong University
Liver Transplantation | Year: 2014

Living donor liver transplantation (LDLT) has emerged as an alternative to deceased donor liver transplantation (DDLT) because of the increasing number of patients waiting for liver transplantation (LT). However, whether it can achieve operative outcomes similar to those achieved with DDLT for adult patients remains controversial. We conducted this meta-analysis to compare the operative outcomes of LDLT and DDLT recipients. A literature search was performed to identify clinical controlled studies comparing LDLT and DDLT that were published before October 2013. Four perioperative outcomes [duration of the recipient operation (DRO), red blood cell (RBC) transfusion requirement, length of the hospital stay, and cold ischemia time (CIT)] and 5 postoperative complication outcomes (biliary complications, vascular complications, intra-abdominal bleeding, perioperative death, and retransplantation) were the main outcomes assessed. Nineteen studies with a total of 5450 patients were included in the meta-analysis. In comparison with DDLT, LDLT was associated with a significantly longer DRO and a shorter CIT. We found that biliary complications [odds ratio (OR)=3.08, 95% confidence interval (CI)=1.97-4.81, P<0.001], vascular complications (OR=2.16, 95% CI=1.32-3.54, P=0.002), and retransplantation (OR=1.76, 95% CI=1.09-2.83, P=0.02) occurred more frequently for LDLT recipients, and the subgroup analysis indicated that the biliary complication rate decreased dramatically with greater LDLT experience. No significant difference was observed in RBC transfusion requirements, the lengths of hospital stays, intra-abdominal bleeding rates, or perioperative mortality between LDLT and DDLT recipients. In conclusion, LDLT is associated with a higher rate of surgical complications after transplantation. A reduction of postoperative complication rates can be achieved as centers gain greater experience with LDLT. However, LDLT is still an excellent alternative to DDLT because it facilitates access to LT. © 2014 American Association for the Study of Liver Diseases.

Zhou H.,Central South University | Ying H.,Wayne State University
IEEE Transactions on Fuzzy Systems | Year: 2013

Type-2 (T2) fuzzy controllers are emerging as the related T2 fuzzy logic, and algorithms have recently been advancing rapidly. At present, a T2 fuzzy controller is viewed and used as a black-box function generator that produces a desired nonlinear mapping between the input and output of the controller (we call the mapping analytical structure). The mathematical expression of the analytical structure, however, is not explicitly known to the controller designer. This is in sharp contrast with the analytical structure of a conventional controller, which is not only always explicitly known, but serves as a starting point for system analysis and design. Obviously, the knowledge of a T2 fuzzy controller's analytical structure can have significant benefits. They include 1) understanding more precisely how the controller works in the same sense as we understand how a conventional controller (e.g., the PID controller) functions; 2) making T2 fuzzy control more acceptable to safety-critical fields such as biomedicine; 3) taking advantage of the well-developed nonlinear control theory to develop better analysis and design methods for T2 control systems (e.g., less conservative system stability criteria); and 4) permitting rigorous comparative exploration on differences between the T2 and type-1 (T1) fuzzy controllers and their relative merits and pitfalls (e.g., performance and structural complexity). In this paper, we develop an innovative technique which is capable of deriving the analytical structure for a wide class of interval T2 Mamdani fuzzy controllers. The configuration of the controllers is typical and is substantially more general than the related efforts in the literature. It uses any number and types of interval T2 input fuzzy sets, any number and types of general or interval T2 output fuzzy sets, arbitrary fuzzy rules, Zadeh and operator, Karnik-Mendel center-of-sets type reducer, and the centroid defuzzifier. We show in detail how the derivation method works in a general setting and provide the analytical structure of an example T2 controller as well. In addition, we utilize the method to prove that a subset of the T2 fuzzy controllers are the sum of two nonlinear PI (or PD) controllers, each of which has a variable proportional gain and a variable integral gain (or derivative gain) plus a variable offset if and only if the input fuzzy sets are piecewise linear (e.g., triangular and/or trapezoidal). The sum of the two nonlinear PI (or PD) controllers is a new discovery relative to the current literature. © 1993-2012 IEEE.

Zhang S.-L.,Linzi District Peoples Hospital | Liu L.,Central South University
Experimental and Therapeutic Medicine | Year: 2015

microRNA (miR)-148a has been shown to act as an important suppressor in numerous human malignancies and is markedly downregulated in hepatocellular carcinoma; however, the role of miR-148a in the regulation of hepatocellular carcinoma cell invasion, as well as the underlying mechanism, has never been studied. In the present study, the expression level of miR-148a was found to be significantly decreased in hepatocellular carcinoma tissues and HepG2 cells when compared with that in the normal adjacent tissues. Furthermore, a novel target of miR-148a was found, sphingosine-1-phosphate receptor 1 (S1PR1), whose expression was negatively regulated by miR-148a at a post-transcriptional level in hepatocellular carcinoma HepG2 cells. Upregulation of miR-148a by transfection with miR-148a mimics notably suppressed HepG2 cell invasion, similar to the effect of the SIPR1 downregulation induced by SIPR1-specific small interfering RNA, while the restoration of S1PR1 expression reversed the inhibitory effect of miR-148a upregulation on HepG2 cell invasion. Accordingly, the current study suggests that miR-148a plays an inhibitory role in the regulation of hepatocellular carcinoma cell invasion by directly targeting S1PR1. © 2014, Spandidos Publications. All rights reserved.

Liu G.P.,University of South Wales | Liu G.P.,Central South University
IEEE Transactions on Circuits and Systems II: Express Briefs | Year: 2010

This brief studies the predictive controller design of networked systems with communication delay and data loss. A networked predictive control scheme is employed to compensate for communication delay and data loss actively rather than passively. Based on analysis of the closed-loop networked predictive control systems, a design strategy of the predictive controller is proposed. The designed predictive controller can achieve the desired control performance and also guarantee the system stability. A numerical example demonstrates the compensation for communication delay and data loss in networked systems using the proposed predictive controller design strategy. © 2010 IEEE.

Peng H.,Central South University | Xie H.,University of Texas at Austin | Goodenough J.B.,University of Texas at Austin
Journal of Power Sources | Year: 2012

Substitution of B for Ti in Li1+xTi2-xB x(PO4)3 introduces x mobile Li+ ions per formula unit in the solid-station range 0 < x ≤ 0.2. The B 2O3 is also an aid to sintering dense ceramics with more uniform particle size. With x = 0.2, the room-temperature Li+-ion conductivity is σLi = 2.0 × 10-4 S cm -1 with a motional activation energy of 0.48 eV. For x > 0.2, an intergranular B2O3-rich second phase impedes intergranular Li+-ion transport. © 2011 Elsevier B.V. All rights reserved.

Guo S.,City University of Hong Kong | Liu Y.,Central South University
Journal of Non-Crystalline Solids | Year: 2012

The critical cooling rate for marginal glass formers, like Al-based alloys, is difficult to measure experimentally. In this work, we acquired the critical cooling rate for formation of amorphous alloys by estimating the cooling rates of the specimens with critical dimensions. Analytical solutions were given to estimate the cooling rates for the gas-atomized powders and melt-spun ribbons, and as an example the critical cooling rate to form an amorphous Al 82Ni 10Y 8 alloy was estimated to be ~ 1.0 × 10 6 K s - 1. The effect of melt temperature on the cooling rate was quantitatively evaluated and its effect on the glass forming ability was also discussed. © 2012 Elsevier B.V.

Huang H.,Guilin University of Technology | Huang K.,Central South University
Powder Technology | Year: 2012

The La-Mg-Ni based composites Mm 0.80Mg 0.20Ni 2.56Co 0.50Mn 0.14Al 0.12- xwt.% AB 5 (x=0, 10, 20, 30) alloys were successfully synthesized by ball milling method. The structure and electrochemical characteristics of composites have been investigated systematically. The XRD spectroscopy shows that all these composites are mainly composed of La 2Ni 7 phase and LaNi 5 phase. The electrochemical studies suggest that the maximum discharge capacity (C max) of alloy electrodes decreases slightly from 361.8 mAh/g (x=0) to 337.9 mAh/g (x=10), 353.9 mAh/g (x=20) and 352.8 mAh/g (x=30), while the cycle durability of the composite electrodes is significantly improved. Moreover, the electrochemical kinetic measurements indicate that the x=20 composite alloy electrode presents the best overall electrochemical properties. © 2012 Elsevier B.V.

Zhang Y.,Indiana University | Zhang Y.,Central South University | Liao J.-M.,Indiana University | Zeng S.X.,Indiana University | Lu H.,Indiana University
EMBO Reports | Year: 2011

Several microRNAs mediate the functions of p53 family members. Here we characterize miR-1246 as a new target of this family. In response to DNA damage, p53 induces the expression of miR-1246 which, in turn, reduces the level of DYRK1A, a Down syndrome-associated protein kinase. Knockdown of p53 has the opposite effect. Overexpression of miR-1246 reduces DYRK1A levels and leads to the nuclear retention of NFATc1, a protein substrate of DYRK1A, and the induction of apoptosis, whereas a miR-1246-specific inhibitor prevented the nuclear import of NFATc1. Together, these results indicate that p53 inhibits DYRK1A expression through the induction of miR-1246. © 2011 European Molecular Biology Organization.

Hu G.,Central South University | Baker S.P.,Center for Injury Research and Policy
Injury Prevention | Year: 2010

Objective To identify recent increases in mortality and morbidity rates from injuries among Americans aged 65 years and over. Design A longitudinal analysis of mortality and morbidity data on injuries in the elderly, examining variations in recent trends by cause, sex, race/ethnicity and age group. Setting USA, mortality rate (2000-6) and morbidity rate (2001-7). Data sources Centers for Disease Control and Prevention's web-based injury statistics query and reporting system online database. Main outcome measures Linear regression was used to examine the statistical significance of trends in mortality and morbidity rates in the study period. The percentage change in rates was used to measure the linear trend. Race/ethnicity was classified into Hispanic (all races except black), non-Hispanic white ('white') and black. Results Injury mortality for people aged 65 years and over increased by 3% during 2000-6; morbidity increased by 7% during 2001-7. Falls mortality increased by 42% but emergency department visits for falls did not increase. Significant increases in death rates occurred in motorcycle crashes (145%), machinery (46%), poisoning (34%) and drowning (19%); morbidity rates increased in poisoning (143%), motorcycle crashes (86%), machinery (48%), bicycles (24%), struck by/against (13%) and overexertion (11%). Motor vehicle occupant injuries decreased. Conclusions The reported rate of fatal falls for people aged 65 years and over increased by 42% during 2000-6 but non-fatal falls did not increase. Research is needed to explain the inconsistent changes between fatal and non-fatal falls, and to identify risk factors contributing to the significant increases in both fatal and non-fatal injuries from machinery, motorcycle crashes and unintentional poisoning.

He R.,Mayo Medical School | Chen D.,Mayo Medical School | He S.,Central South University
Thrombosis Research | Year: 2012

Coagulation factor FXI (FXI), a plasma serine protease zymogen, has important roles in both intrinsic and extrinsic coagulation pathways and bridges the initiation and amplification phases of plasmatic hemostasis. Recent studies have provided new insight into the molecular structure and functional features of FXI and have demonstrated distinct structural and biological differences between activated factor XII (FXIIa)-mediated FXI activation and tissue factor/thrombin-mediated FXI activation. The former is important in thrombosis; the latter is more essential in hemostasis. Activated partial thromboplastin tine (aPTT) artificially reflects FXIIa-initiated intrinsic coagulation pathway in vitro. Conversely, FXIIa-inhibited diluted thromboplastin time assay may reflect tissue factor/thrombin-mediated FXI activation in vivo. Further explication of the genetic mutations of FXI deficiency has improved the understanding of the structure-function relationship of FXI. Besides its procoagulant activity, the antifibrinolytic activity of FXI was well documented in a wealth of literature. Finally, the new emerging concept of inhibiting FXI as a novel antithrombotic approach with an improved benefit-risk ratio has been supported through observations from human FXI deficiency and various animal models. Large- and small-molecule FXI inhibitors have shown promising antithrombotic effects. The present review summarizes the recent advancements in the molecular physiology of FXI and the molecular pathogenesis of FXI deficiency and discusses the evidence and progress of FXI-targeting antithrombotics development. © 2012 Elsevier Ltd. All rights reserved.

Yan M.,University of Queensland | Liu Y.,Central South University | Schaffer G.B.,University of Queensland | Qian M.,University of Queensland
Scripta Materialia | Year: 2013

In situ synchrotron radiation revealed how the scavenging of oxygen by yttrium hydride (YH 2) occurred in powder metallurgy commercially pure Ti (CP-Ti) and Ti-6Al-4V. YH 2 decomposes at >900 °C in CP-Ti and at >1100 °C in Ti-6Al-4V. Elemental Y coexists with Y 2O 3 in both CP-Ti and Ti-6Al-4V up to 1300 °C. Ex situ analytical means further confirmed that the scavenging product is Y 2O 3. Together with available diffusion data, mechanisms are proposed to understand the decomposition of YH 2 and the scavenging of oxygen in CP-Ti and Ti-6Al-4V. © 2012 Published by Elsevier Ltd.

Mao X.,Central South University | Tay G.H.,Orthopaedic Research Unit | Godbolt D.B.,Northside Pathology | Crawford R.W.,Orthopaedic Research Unit | Crawford R.W.,Queensland University of Technology
Journal of Arthroplasty | Year: 2012

The incidence of pseudotumor formation has been reported to be 1% in patients with metal-on-metal resurfacing arthroplasties. This complication is not exclusive to these patients. We report a case of pseudotumor formation secondary to femoral head-neck corrosion after a metal-on-polyethylene uncemented total hip arthroplasty. © 2012 Elsevier Inc.

Zhang X.,Central South University
Cell Biochemistry and Biophysics | Year: 2015

Among the multiple branches of nanotechnology applications in the area of medicine and biology, Nanoparticle technology is the fastest growing and shows significant future promise. Nanoscale structures, with size similar to many biological molecules, show different physical and chemical properties compared to either small molecules or bulk materials, find many applications in the fields of biomedical imaging and therapy. Gold nanoparticles (AuNPs) are relatively inert in biological environment, and have a number of physical properties that are suitable for several biomedical applications. For example, AuNPs have been successfully employed in inducing localized hyperthermia for the destruction of tumors or radiotherapy for cancer, photodynamic therapy, computed tomography imaging, as drug carriers to tumors, bio-labeling through single particle detection by electron microscopy and in photothermal microscopy. Recent advances in synthetic chemistry makes it possible to make gold nanoparticles with precise control over physicochemical and optical properties that are desired for specific clinical or biological applications. Because of the availability of several methods for easy modification of the surface of gold nanoparticles for attaching a ligand, drug or other targeting molecules, AuNPs are useful in a wide variety of applications. Even though gold is biologically inert and thus shows much less toxicity, the relatively low rate of clearance from circulation and tissues can lead to health problems and therefore, specific targeting of diseased cells and tissues must be achieved before AuNPs find their application for routine human use. © 2015, Springer Science+Business Media New York.

Hydroquinone modified hyper-cross-linked resin (HJ-Y15) was prepared from macroporous crosslinked chloromethylated polystyrene and the adsorption behaviors of HJ-Y15 for salicylic acid were studied from aqueous solution. The results indicated that the surface of HJ-Y15 was modified by formaldehyde carbonyl, quinone carbonyl, and phenolic hydroxyl groups. Freundlich model was suitable for characterizing the isotherms and the adsorption was shown to be an exothermic, spontaneous, and more ordered process. The pseudosecond-order rate equation was appropriate for describing the kinetic curves and the intraparticle diffusion was the rate-controlling step. Hydrogen bonding between formaldehyde carbonyl groups of HJ-Y15 and carboxyl groups of salicylic acid was one of the primary driving forces for the adsorption. © 2011 Wiley Periodicals, Inc.

Bao J.,Central South University | Yuan C.,University of Swansea
Infinite Dimensional Analysis, Quantum Probability and Related Topics | Year: 2014

In this note, we discuss strong convergence of exponential integrator scheme based on spatial and time discretization for a class of neutral stochastic partial differential equations driven by α-stable processes. © 2014 World Scientific Publishing Company.

Tang X.H.,Central South University
Advanced Nonlinear Studies | Year: 2014

Consider the semilinear Schrödinger equation -Δu + V(x)u = f (x, u), x ∈ ℝN, u ∈ H1(ℝN), where f is a superlinear, subcritical nonlinearity. We mainly study the case where both V and f are periodic in x and 0 belongs to a spectral gap of -Δ + V. Based on the work of Szulkin and Weth [J Funct Anal 257: 3802-3822, 2009], we develop a new technique to show the boundedness of Cerami sequences and derive a new super-quadratic condition that there exists a θ0 ∈ (0, 1) such that 1 - θ2/2 t f (x, t) ≥ ∫ θt t f (x, s)ds, ∀ θ ∈ [0, θ0] for the existence a "ground state solution" which minimizes the corresponding energy among all nontrivial solutions. Our result unifies and improves some known ones and the recent ones of Szulkin and Weth [J Funct Anal 257: 3802-3822, 2009] and Liu [Calc. Var. 45: 1-9, 2012].

O'neill K.L.,University of Nebraska Medical Center | Huang K.,University of Nebraska Medical Center | Zhang J.,University of Nebraska Medical Center | Zhang J.,Central South University | And 2 more authors.
Genes and Development | Year: 2016

The mechanism of Bax/Bak activation remains a central question in mitochondria-dependent apoptotic signaling. While it is established that all proapoptotic Bcl-2 homology 3 (BH3)-only proteins bind and neutralize the anti-apoptotic Bcl-2 family proteins, how this neutralization leads to Bax/Bak activation has been actively debated. Here, genome editing was used to generate cells deficient for all eight proapoptotic BH3-only proteins (OctaKO) and those that lack the entire Bcl-2 family (Bcl-2 allKO). Although the OctaKO cells were resistant to most apoptotic stimuli tested, they underwent Bax/Bak-dependent and p53/Rb-independent apoptosis efficiently when both Bcl-xL and Mcl-1, two anti-apoptotic Bcl-2 proteins, were inactivated or eliminated. Strikingly, when expressed in the Bcl-2 allKO cells, both Bax and Bak spontaneously associated with the outer mitochondrial membrane (OMM) through their respective helix 9, and this association triggered their homo-oligomerization/activation. Together, these results strongly suggest that the OMM, not BH3-only proteins or p53/Rb, is the long-sought-after direct activator of Bax/Bak following BH3-only-mediated neutralization of anti-apoptotic Bcl-2 proteins. © 2016 O’Neill et al.

He Y.,Yunnan Nationalities University | Shen R.,Central South University
Journal of the American Chemical Society | Year: 2013

In this paper we present a new paradigm for designing hydrogelators that exhibit sharp phase transitions in response to a series of disparate stimuli, including oxidation-reduction reactions (redox), guest-host interactions, and pH changes. We have serendipitously discovered that ferrocenoyl phenylalanine (Fc-F) monomers aggregate in water via a rapid self-assembly mechanism to form stable, multistimuli hydrogels. In comparison to other known mono- and multiresponsive gelators, Fc-F is unique because of its small size, economy of gel-forming components, and exceptionally simple molecular structure. Density functional theory (DFT) ab initio calculations suggest gel formation initially involves an antiparallel, noncovalent dimerization step wherein the ferrocenoyl moiety of one axe-like monomer conjoins with the phenyl group of the second monomer via a π-π stacking interaction to form brick-like dimers. This stacking creates a cavity in which the carboxylic acid groups of each monomer mutually interact via hydrogen bond formation, which affords additional stability to the dimer. On the basis of structural analysis via optical and electrical measurements and additional DFT calculations, we propose a possible stepwise hierachical assembly mechanism for fibril formation. Insights into the self-assembly pathway of Fc-F should prove useful for understanding gelation processes of more complex systems. We expect that Fc-F will serve as a helpful archetypical template for others to use when designing new, stimuli specific hydrogelation agents. © 2013 American Chemical Society.

Liu Y.,Central South University
Operations Research Letters | Year: 2010

Let P be a positive recurrent infinite transition matrix with invariant distribution π and (n) over(P, ̃) be a truncated and arbitrarily augmented stochastic matrix with invariant distribution (n) π. We investigate the convergence {norm of matrix} (n) π - π {norm of matrix} → 0, as n → ∞, and derive a widely applicable sufficient criterion. Moreover, computable bounds on the error {norm of matrix} (n) π - π {norm of matrix} are obtained for polynomially and geometrically ergodic chains. The bounds become rather explicit when the chains are stochastically monotone. © 2009 Elsevier B.V. All rights reserved.

Zhao Z.,Hunan University | Fan H.,Hunan University | Zhou G.,Central South University | Bai H.,Hunan University | And 4 more authors.
Journal of the American Chemical Society | Year: 2014

A novel dual-activatable fluorescence/MRI bimodal platform is designed for tumor cell imaging by using a redoxable manganese dioxide (MnO2) nanosheet-aptamer nanoprobe. The redoxable MnO2 nanosheet acts as a DNA nanocarrier, fluorescence quencher, and intracellular glutathione (GSH)-activated MRI contrast agent. In the absence of target cells, neither fluorescence signaling nor MRI contrast of the nanoprobe is activated. In the presence of target cells, the binding of aptamers to their targets weakens the adsorption of aptamers on the MnO2 nanosheets, causing partial fluorescence recovery, illuminating the target cells, and also facilitating the endocytosis of nanoprobes into target cells. After endocytosis, the reduction of MnO2 nanosheets by GSH further activates the fluorescence signals and generates large amounts of Mn2+ ions suitable for MRI. This platform should facilitate the development of various dual-activatable fluorescence/MRI bimodalities for use in cells or in vivo. © 2014 American Chemical Society.

Huang Y.-S.,Changsha University of Science and Technology | Huang Y.-S.,Central South University
International Journal of Robust and Nonlinear Control | Year: 2012

In this paper, a novel decentralized robust adaptive fuzzy control scheme is proposed for a class of large-scale multiple-input multiple-output uncertain nonlinear systems. By virtue of fuzzy logic systems and the regularized inverse matrix, the decentralized robust indirect adaptive fuzzy controller is developed such that the controller singularity problem is addressed under a united design framework; no a priori knowledge of the bounds on lumped uncertainties are being required. The closed-loop large-scale system is proved to be asymptotically stable. Simulation results confirmed the validity of the approach presented. Copyright © 2011 John Wiley & Sons, Ltd.

Dey R.,University of Southern California | Chen L.,University of Southern California | Chen L.,Central South University
Journal of Biomolecular Structure and Dynamics | Year: 2011

Nicotinic acetylcholine receptors (nAChR) are pentameric ligand gated ion channels whose activity can be modulated by endogenous neurotransmitters as well as by synthetic ligands that bind the same or distinct sites from the natural ligand. The subtype of α7 nAChR has been considered as a potenial therapeutic target for Alzheimer's disease, schizophrenia and other neurological and psychiatric disorders. Here we have developed a homology model of α7 nAChR based on two high resolution crystal structures with Brookhaven Protein Data Bank (PDB) codes 2QC1 and 2WN9 for threading on one monomer and then for building a pentamer, respectively. A number of small molecule binding sites are identified using Pocket Finder (J. An, M. Tortov, and R. Abagyan, Molecular & Cellular Proteomics, 4.6, 752-761 (2005)) of Internal Coordinate Mechanics (ICM). Remarkably, these computer-identified sites match perfectly with ordered solvent densities found in the high-resolution crystal structure of α1-nAChR, suggesting that the surface cavities in the α7 nAChR model are likely binding sites of small molecules. A high throughput virtual screening by flexible ligand docking of 5008 small molecule compounds was performed at three potential allosteric modulator (AM) binding sites of α7 nAChR using Molsoft ICM software (R. Abagyan, M. Tortov and D. Kuznetsov, J Comput Chem 15, 488-506, (1994)). Some experimentally verified allosteric modulators of α7 like CCMI comp-6, LY 7082101, 5-HI, TQS, PNU-120596, genistein, and NS-1738 ranked among top 100 compounds, while the rest of the compounds in the list could guide further search for new allosteric modulators. ©Adenine Press (2011).

Wang G.,Central South University | Wu J.,Temple University
Frontiers of Computer Science in China | Year: 2011

Web-based social networking is increasingly gaining popularity due to the rapid development of computer networking technologies. However, social networking applications still cannot obtain a wider acceptance by many users due to some unresolved issues, such as trust, security, and privacy. In social networks, trust is mainly studied whether a remote user behaves as expected by an interested user via other users, who are respectively named trustee, trustor, and recommenders. A trust graph consists of a trustor, a trustee, some recommenders, and the trust relationships between them. In this paper, we propose a novel FlowTrust approach to model a trust graph with network flows, and evaluate the maximum amount of trust that can flow through a trust graph using network flow theory. FlowTrust supports multi-dimensional trust. We use trust value and confidence level as two trust factors. We deduce four trust metrics from these two trust factors, which are maximum flow of trust value, maximum flow of confidence level, minimum cost of uncertainty with maximum flow of trust, and minimum cost of mistrust with maximum flow of confidence. We also propose three FlowTrust algorithms to normalize these four trust metrics. We compare our proposed FlowTrust approach with the existing RelTrust and CircuitTrust approaches. We show that all three approaches are comparable in terms of the inferred trust values. Therefore, FlowTrust is the best of the three since it also supports multi-dimensional trust. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Liao P.,Central South University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2010

The evaluation of complex surface profile error is usually difficult to perform in the field of ultra-precise manufacture and measurement. On the basis of analysis of study status of complex surface profile error, the key problem is proposed, the definition of complex surface profile error is description, and its math model is established. On the basis of analysis of NURBS surface, the subdivision approach algorithm for calculating the minimum distance between point and surface is proposed. The contradiction among calculation accuracy, encoding length and computation complexity of standard genetic algorithm is analyzed, the improved genetic algorithm is proposed, its crossover operator and mutation operator are offered. The detailed steps are established for calculating complex surface profile error based on subdivision approach algorithm and genetic algorithm. It can obtain precision result to calculate complex surface profile error by use of genetic algorithm with canonicity real number encoding and subdivision approach algorithm. This method can be realized easily on computer and is very suitable for three coordinate measuring machine.

Sun Z.,Central South University
Metrology and Measurement Systems | Year: 2011

The converging-diverging structure is introduced to extend the lower limit of measurement of vortex flowmeters. As a compact device, the converging-diverging vortex flowmeter is proposed and designed, and its performance is studied experimentally. It is found that, first of all, an up to 51% extension of the lower measurement limit can be realized through the converging-diverging structure, compared with conventional vortex flowmeters; second, the converging-diverging vortex flowmeter with a trapezoidal bluff body has a larger Strouhal number and smaller pressure loss. The results suggest that the converging-diverging vortex flowmeter provides an alternative device especially suitable for the measurement of low-velocity fluids. © 2011 Polish Academy of Sciences.

Jiang L.,Central South University
Chemistry of Natural Compounds | Year: 2013

Three tetranortriterpenoids, walsuranins A-C (1-3), as well as three known tetranortriterpenoids, anthothecol, 11β-hydroxydihydrocedrelone, and 11β-acetoxydihydrocedrelone, were isolated from the twigs and leaves of Walsura yunnanensis C. Y. Wu. Their structures were established on the basis of spectroscopic methods. Walsuranins B-C (2, 3) from this plant featured the typical rearranged A-ring structure of this compound class. © 2013 Springer Science+Business Media New York.

Lu Q.,Central South University
Journal of Autoimmunity | Year: 2013

Autoimmune diseases are characterized by aberrant immune responses against healthy cells and tissues, in which a given individual's genetic susceptibilities play a central role; however, the exact mechanisms underlying the development of these conditions remain for the most part unknown. In recent years, accumulating evidence has demonstrated that, in addition to genetics, other complementary mechanisms are involved in the pathogenesis of autoimmunity, in particular, epigenetics. Epigenetics is defined as stable and heritable patterns of gene expression that do not entail any alterations to the original DNA sequence. Epigenetic mechanisms primarily consist of DNA methylation, histone modifications and small non-coding RNA transcripts. Epigenetic marks can be affected by age and other environmental triggers, providing a plausible link between environmental factors and the onset and development of various human diseases. Because of their primary function in regulating timely gene expression, epigenetic mechanisms offer potential advantages in terms of interpreting the molecular basis of complicated diseases and providing new promising therapeutic avenues for their treatment. The present review focuses on recent progress made in elucidating the relationship between epigenetics and the pathogenesis of autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, primary Sjögren's syndrome, primary biliary cirrhosis, psoriasis and type 1 diabetes. © 2013 Elsevier Ltd.

Huang S.,Central South University
Science China Life Sciences | Year: 2012

Unbiased readings of fossils are well known to contradict some of the popular molecular groupings among primates, particularly with regard to great apes and tarsiers. The molecular methodologies today are however flawed as they are based on a mistaken theoretical interpretation of the genetic equidistance phenomenon that originally started the field. An improved molecular method the 'slow clock' was here developed based on the Maximum Genetic Diversity hypothesis, a more complete account of the unified changes in genotypes and phenotypes. The method makes use of only slow evolving sequences and requires no uncertain assumptions or mathematical corrections and hence is able to give definitive results. The findings indicate that humans are genetically more distant to orangutans than African apes are and separated from the pongid clade ~17. 6 million years ago. Also, tarsiers are genetically closer to lorises than simian primates are. Finally, the fossil times for the radiation of mammals at the K/T boundary and for the Eutheria-Metatheria split in the Early Cretaceous were independently confirmed from molecular dating calibrated using the fossil split times of gorilla-orangutan, mouse-rat, and opossum-kangaroo. Therefore, the re-established primate phylogeny indicates a remarkable unity between molecules and fossils. © 2012 The Author(s).

Zeng X.,Central South University
Journal of Physics A: Mathematical and Theoretical | Year: 2014

In this paper we will first study the spectrum of certain large Euclidean random matrices. The entries of these matrices are functions of n random points lp-norm uniformly sampled in N dimensional lp ball or lp sphere. Under the setting n/N → 0, as N and n tend to ∞, it is shown that the empirical distributions of eigenvalues of normalized Euclidean random matrices generated from the above two manifolds both converge weakly to semicircle law. We also investigate certain 'sample-covariance' type matrices whose entries are determined by n random positions from an N dimensional lp ellipsoid or its surface. When N → ∞ and n → ∞ with N/n → 0, we prove that their empirical spectral distribution converge to the same fixed distribution. © 2014 IOP Publishing Ltd.

Wu H.-N.,Beihang University | Wang J.-W.,Beihang University | Li H.-X.,City University of Hong Kong | Li H.-X.,Central South University
Automatica | Year: 2012

This paper investigates the problem of designing a distributed H∞ fuzzy controller with constraint for a class of nonlinear spatially distributed processes modeled by first-order hyperbolic partial differential equations (PDEs). The purpose of this paper is to design a distributed fuzzy state feedback controller such that the closed-loop PDE system is exponentially stable with a prescribed H∞ performance of disturbance attenuation, while the control constraint is respected. Initially, a TakagiSugeno (TS) hyperbolic PDE model is proposed to accurately represent the nonlinear PDE system. Then, based on the TS fuzzy PDE model, a distributed H∞ fuzzy controller design with constraint is developed in terms of a set of coupled differential/algebraic linear matrix inequalities (D/ALMIs) in space. Furthermore, a suboptimal distributed H∞ fuzzy controller with constraint is proposed to minimize the level of attenuation. The finite difference method in space and the existing linear matrix inequality (LMI) optimization techniques are employed to approximately solve the suboptimal fuzzy control design problem. Finally, the proposed design method is applied to the distributed control of a nonlinear system described by two coupled first-order hyperbolic PDEs to illustrate its effectiveness. © 2012 Elsevier Ltd. All rights reserved.

Jiang Y.,University of California at Santa Barbara | Liu R.,Central South University
Scripta Materialia | Year: 2010

Sulphur segregation to grain boundaries, surfaces or interfaces seriously degrades the performance of many metallic systems. The addition of appropriate dopants may reduce the sulphur effect. Here we present a first-principles study to provide physical insights into Hf and Pt interactions with S in Ni. The pair affinities are assessed through total energetics, electron localization function and differential charge density analyses. Calculations show that Hf can effectively getter S and hence inhibit S segregation even at high temperatures, while Pt cannot. © 2010 Acta Materialia Inc.

Liu G.,University of Birmingham | Zhang D.,Central South University | Meggs C.,University of Birmingham | Button T.W.,University of Birmingham
Scripta Materialia | Year: 2010

Porous Al2O3-ZrO2 composites with homogeneous and long-range ordered channels were produced by an ice template method. An increase of the initial solids loading from 40 to 70 wt.% caused the final porosity to decrease from 74% to 35%, while the compressive strength increased from 15 to 81 MPa. The sample obtained from the 80 wt.% suspension was not porous, and a critical velocity model is employed to explain this phenomenon. © 2009 Acta Materialia Inc.

Liu Y.,Montana State University | Zhang L.,Central South University
Scripta Materialia | Year: 2010

In order to predict the phase boundary dimension between two phase regions, Palatnik and Landau put forward the contact rule. Later, Zhao proposed phase boundary rules for T - xi multicomponent phase diagrams. In this study, the contact rule and phase boundary rules for T - xi multicomponent phase diagrams are derived from a geometric point of view, which contributes to a comprehensive understanding of the topological relations. The proposed formulas in this work differ slightly from those of Zhao, but can account for more geometric relations.

Li E.,Central South University
International Journal of Material Forming | Year: 2013

This paper deals with the variable blank holder force in sheet metal forming in order to reduce springback effects after forming. A structural risk minimization principle-based metamodeling technique, least square support vector regression (LSSVR) method is applied to optimization. In order to improve the efficiency, an intelligent sampling strategy proposed by Wang et al. (Mater Des 30:1468-1479, 2009a) is integrated with the LSSVR. Therefore, the proposed strategies establish an adaptive metamodeling optimization system. The optimization procedure can be carried out automatically. To valid the flexibility of this system, the presented method is used to optimize the variable blank force parameters of the models from NUMISHEET'96 and torsion rail model. Compared with other popular metamodel-based optimization methods, the test results demonstrate the potential capability for nonlinear engineering problems. © 2011 Springer-Verlag France.

Xia M.,Central South University
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2015

A thermo-mechanical coupled particle model for simulation of thermally-induced rock damage based on the particle simulation method was proposed. The simulation results of three verification examples, for which the analytical solutions are available, demonstrate the correctness and usefulness of the thermo-mechanical coupled particle model. This model is applied to simulating an application example with two cases: one is temperature-independent elastic modulus and strength, while the other is temperature-dependent elastic modulus and strength. The related simulation results demonstrate that microscopic crack initiation and propagation process with consideration of temperature-independent and temperature-dependent elastic modulus and strength are different and therefore, the corresponding macroscopic failure patterns of rock are also different. On the contrary, considering the temperature-dependent elastic modulus and strength has no or little effect on the heating conduction behavior. Numerical results, which are obtained by using the proposed model with temperature-dependent elastic modulus and strength, agree well with the experimental results. This also reveals that the rock subjected to heating experiences much more cracking than the rock subjected to cooling. © 2015 The Nonferrous Metals Society of China.

de la Cruz I.P.,Howard Hughes Medical Institute | Ma L.,Central South University | Horvitz H.R.,Howard Hughes Medical Institute
PLoS Genetics | Year: 2014

Loss-of-function mutations in the Caenorhabditis elegans gene sup-18 suppress the defects in muscle contraction conferred by a gain-of-function mutation in SUP-10, a presumptive regulatory subunit of the SUP-9 two-pore domain K+ channel associated with muscle membranes. We cloned sup-18 and found that it encodes the C. elegans ortholog of mammalian iodotyrosine deiodinase (IYD), an NADH oxidase/flavin reductase that functions in iodine recycling and is important for the biosynthesis of thyroid hormones that regulate metabolism. The FMN-binding site of mammalian IYD is conserved in SUP-18, which appears to require catalytic activity to function. Genetic analyses suggest that SUP-10 can function with SUP-18 to activate SUP-9 through a pathway that is independent of the presumptive SUP-9 regulatory subunit UNC-93. We identified a novel evolutionarily conserved serine-cysteine-rich region in the C-terminal cytoplasmic domain of SUP-9 required for its specific activation by SUP-10 and SUP-18 but not by UNC-93. Since two-pore domain K+ channels regulate the resting membrane potentials of numerous cell types, we suggest that the SUP-18 IYD regulates the activity of the SUP-9 channel using NADH as a coenzyme and thus couples the metabolic state of muscle cells to muscle membrane excitability. © 2014 de la Cruz et al.

Li Q.,University of Maryland, Baltimore | Li Q.,Central South University | Shu Y.,University of Maryland, Baltimore
Pharmaceutical Research | Year: 2014

Purpose: Previous research has led to the recognition of a cGMP signaling pathway governing drug transport. This study is to investigate whether inhibitors of phosphodiesterase type 5 (PDE5), which increase intracellular cGMP levels, modulate the cytotoxicity and uptake of anti-cancer drugs in cancer cells. Methods: The experiments were conducted with and without PDE5 inhibitors: dipyridamole, vardenafil, and/or sildenafil. The cytotoxicity of doxorubicin, cisplatin and oxaliplatin was determined in multiple cancer cell lines derived from different tissues. The cellular uptake of structurally diverse compounds was further examined in lung cancer cells with and without various endocytotic inhibitors. The tumor accumulation and the anti-tumor effect of trastuzumab were examined in a lung cancer xenograft mouse model. Results: Dipyridamole could modulate the cytotoxicity of doxorubicin, cisplatin, and oxaliplatin in cancer cells. Particularly, PDE5 inhibitors increased cellular uptake of structurally diverse compounds into lung cancer cells both in vitro and in vivo. The effect of vardenafil on drug uptake could be blocked by endocytotic inhibitors. The growth of lung cancer xenograft in nude mice was significantly suppressed by addition of vardenafil to trastuzumab treatment. Conclusion: PDE5 inhibitors may increase the efficacy of anti-cancer drugs by increasing endocytosis-mediated cellular drug uptake, and thus serve as adjuvant therapy for certain cancers such as lung cancer. © 2013 Springer Science+Business Media New York.

Cao S.,Yancheng Institute of Technology | Jiang X.,Central South University | Chen J.,Yancheng Institute of Technology
Journal of Inorganic Biochemistry | Year: 2010

The impact of Zn2+ ion on interactions of flavonols galangin (Gal), kaempferol (Kae), quercetin (Que) and myricetin (Myr) with bovine serum albumin (BSA) in aqueous solution were studied by fluorescence quenching technique. The results exhibited that Zn2+ ion affected significantly the interactions and the effect was distinct for the flavonol bearing different number of B-ring hydroxyl. Each flavonol can quench the fluorescence of BSA, displaying a quenching extent of Myr > Que > Kae > Gal, which is in good agreement with the number variation of the B-ring hydroxyl. The presence of Zn2+ ion promoted the quenching for the flavonols, exhibiting an extent of Que > Myr > Kae > Gal. The values of Ka for Kae, Que and Myr decreased whereas KSV and kq for Gal, Kae and Que increased with the number of B-ring hydroxyl. The type of BSA fluorescence quenching for Gal, Kae and Que hardly changed but the preference of static quenching increased. The values of KSV and kq for Myr remarkably decreased and the fluorescence quenching of BSA alternatively occurred via both static and dynamic type instead of only one (static or dynamic). The results suggest the key role of the B-ring hydroxyl and the distinct effect of its number in the interactions. Each flavonol may capture the BSA-bound ZnII in the solution, forming ZnII-flavonol complex that is possibly responsible for BSA fluorescence quenching. The B-ring hydroxyl could establish hydrogen bonds with BSA in the absence of Zn2+ and act as donors for chelating in the presence of Zn2+. The formation of dinuclear ZnII-Myr complex together with the hydrogen bonds between the free B-ring hydroxyl and BSA may contribute to the exceptional behavior of Myr. © 2009 Elsevier Inc. All rights reserved.

Luo Y.-B.,University of Western Australia | Luo Y.-B.,Central South University | Mastaglia F.L.,University of Western Australia | Mastaglia F.L.,Murdoch University
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2015

Dermatomyositis, polymyositis and immune-mediated necrotising myopathy are major forms of idiopathic inflammatory myopathy. We review here recent developments in understanding the pathology and pathogenesis of these diseases, and characterisation of autoantibody biomarkers. Dermatomyositis is traditionally considered to be due to a complement-mediated microangiopathy but the factors responsible for complement activation remain uncertain. Recent studies have emphasised the importance of the type I interferon pathway in the pathogenesis of the disease and have identified autoantibodies with specificities for different clinical subgroups of patients. Polymyositis is characterised by a cytotoxic T cell response targeting as yet unidentified muscle antigens presented by MHC Class I molecules, and can occur in isolation but is more often part of a multi-systemic overlap syndrome. The immune-mediated necrotising myopathies are heterogeneous and are distinguished from polymyositis by the sparseness of inflammatory infiltrates and recognition of an association with specific autoantibodies such as anti-SRP and anti-HMGCR in many cases. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis. © 2014 Elsevier B.V.

Wu Y.,Central South University
IEEE Transactions on Aerospace and Electronic Systems | Year: 2015

This note improves upon our recent work [1] by effectively depressing the adverse effect of the lever arm on attitude estimation. © 1965-2011 IEEE.

Xu X.,Central South University
Advanced Materials Research | Year: 2013

Traditional iris recognition systems transfer iris images to polar coordinates, normalize the images and achieve rotation invariance by rotating the feature vector. In order to decrease the complexity of the typical iris recognition method, we propose a new method of iris recognition based on global and local model that are extracted from preprocessed iris image without normalizing. Firstly, we applied a bank of no-tensor product wavelet filters to extract the global features of the iris. Secondly, we used a SIFT method to extract the local features points of the selected regions. Finally, we tested the similarity distances of local and global features with different weights. Experimental results show that the proposed method in this paper has the recognition accuracy of 99.5% when the equal error rate is 0.94%. Without normalizing the iris images, the proposed approach can obtain very good recognition performance. © (2013) Trans Tech Publications, Switzerland.

Zhang L.,Shandong University of Technology | Li T.,Shandong University of Technology | Xu X.,Central South University
Knowledge-Based Systems | Year: 2014

Group decision making with consensus requirement is the process of reaching group consensus, ranking the feasible alternatives and selecting the best one. In this paper, we develop a methodology for fuzzy group decision making with group consensus. Firstly, each expert makes his/her judgement on each alternative with respect to multiple criteria by the intuitionistic fuzzy sets, the group preference vectors for each alternative are calculated by the formula. Secondly, the similarity measure between two intuitionistic fuzzy sets is defined to compute each expert's decision deviation, a threshold value is used to determine the decision deviation whether be acceptable. Then, based on the expert's group consensus decision information, the group matrix is obtained by weighted similarity measure. Using the ordered weight operator, the order of the alternatives is got and the best one can be easily selected. Finally, we apply our method to facility location selection problem and the other group consensus example in [3] to verify our methodology's feasibility and effectiveness. © 2013 Elsevier B.V. All rights reserved.

Liu L.,Anyang University, China | Li S.,Anyang University, China | Deng D.,Anyang University, China | Xia N.,Central South University
Analyst | Year: 2012

In this paper, we report a simple, sensitive and selective colorimetric visualization of dopamine (DA) using dithiobis(succinimidylpropionate) (DSP)-modified gold nanoparticles (AuNPs) as probes and ferric ions as cross-linkers. Via the standard amine coupling reaction between the amino groups of DA and activated carboxyl groups of DSP, DA molecules can be assembled onto the surface of DSP-AuNPs. Accordingly, Fe3+ ions induce a change of DSP-AuNPs in color and UV-vis absorbance by coordinating to the catechol groups of the anchored DA. The pH dependence and mechanism of this method are discussed. A detection limit of 2 nM was obtained, which is lower than those achievable with currently used chromatographic and electrochemical techniques. The feasibility for the detection of DA in artificial cerebrospinal fluid has been demonstrated. © 2012 The Royal Society of Chemistry.

Xu H.-Z.,The University of Oklahoma Health Sciences Center | Xu H.-Z.,Central South University | Le Y.-Z.,The University of Oklahoma Health Sciences Center | Le Y.-Z.,Dean A Mcgee Eye Institute
Investigative Ophthalmology and Visual Science | Year: 2011

PURPOSE. The outer blood-retina barrier (BRB) separates the neural retina from the choroidal vasculature, which is responsible for approximately 80% of blood supplies in the eye. To determine the significance of outer BRB breakdown in diabetic retinopathy, the outer BRB-specific leakage of macromolecules in diabetic and ischemic rodents was investigated. METHODS. Diabetes and ischemia were induced in rodents by streptozotocin and oxygen-induced retinopathy, respectively. Diabetic and ischemic rodents were injected intravenously with fluorescein isothiocyanate (FITC)-dextran. The outer BRB-specific leakage in diabetic and ischemic rodents was visualized by fluorescent microscopy. RESULTS. A microscopic imaging assay was developed to examine outer BRB breakdown. The outer BRB-specific leakage of fluorescent macromolecules was visualized in diabetic and ischemic rodents. Substantial leakages of macromolecules through the outer BRB in diabetic and ischemic rodents were detected with this assay. The number of severe outer BRB leakage sites is inversely proportional to the size of macromolecules. Significant depletion of occludin in the RPE of ischemic and diabetic rodents was also observed. CONCLUSIONS. For the first time, a microscopic imaging assay for directly visualizing macromolecules leaked through the outer BRB in rodents was developed. Using this assay, the authors demonstrated the significance of outer BRB breakdown in diabetes and ischemia, which will have implications to the understanding, diagnosis, and treatment of diabetic macular edema and other ocular diseases with outer BRB defects. The microscopic imaging assay established in this study will likely be very useful to the development of drugs for macular edema. © 2011 The Association for Research in Vision and Ophthalmology, Inc.

Jiang M.,Hong Kong Polytechnic University | Ding X.,Hong Kong Polytechnic University | Li Z.,Central South University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2014

The coherence of radar echoes is a fundamental observable in interferometric synthetic aperture radar (InSAR) measurements. It provides a quantitative measure of the scattering properties of imaged surfaces and therefore is widely applied to study the physical processes of the Earth. However, unfortunately, the estimated coherence values are often biased due to various reasons such as radar signal nonstationarity and the bias in the estimators used. In this paper, we focus on multitemporal InSAR coherence estimation and present a hybrid approach that mitigates effectively the errors in the estimation. The proposed approach is almost completely self-adaptive and workable for both Gaussian and non-Gaussian SAR scenes. Moreover, the bias of the sample coherence can be mitigated with even only several samples included for a given pixel. Therefore, it is a more pragmatic method for accurate coherence estimation and can be applied actually. Different data sets are used to test the proposed method and demonstrate its advantages. © 1980-2012 IEEE.

This paper presents a novel procedure for estimating mass diffusivity and initial concentration for VOCs in building materials. In contrast to methods that fit data to an organic emission model, this new method determines these two parameters by two observations from a chamber test in a nonfitting and sequential way, which defines a well-posed problem and requires no iterative procedure as well as is robust to initial guess and random uncertainties. The most outstanding feature of this method is that multiple estimates of the parameters can be obtained when more than two experimental data are available; thus, these estimates constitute a sample of population of parameter estimates involving experimental errors. The averages of the sample can be regarded the best estimates of the parameters, and, more importantly, variances (standard deviations) and confidence intervals can be readily and naturally estimated making no assumption about the distribution of experimental errors. Two easy and direct ways are suggested for determining confidence limits: one is percentile method, and the other is the normal approximation. This feature highlights the major difference between the new method and common curve-fitting procedures that generally assume random errors being Gaussian distribution. © 2013 American Chemical Society.

Peng Z.,Central South University | Peng Z.,Michigan Technological University | Hwang J.-Y.,Michigan Technological University
International Materials Reviews | Year: 2015

Microwave heating has been extensively explored in various fields of materials processing. This technology exhibits unique characteristics including volumetric and selective heating, which eventually lead to many exceptional advantages over conventional processing methods including both energy and cost savings, improved product quality, faster processing and greater ecofriendliness, making microwave heating appropriate for applications in metallurgy. This paper presents a critical review on the use of microwave energy in metallurgy, with emphasis on both fundamentals of microwave heating and recent experimental efforts on extractive metallurgy via pyrometallurgical and/or hydrometallurgical routes. Applications to metallurgical processes for extraction of various metals, including heavy metals (Fe, Ni, Co, Cu, Pb and Zn), light metals (Al and Mg), rare metals (Ti, Mo, W and Re) and precious metals (Au, Ag and Pt), are reviewed and discussed. © 2015 Institute of Materials, Minerals and Mining and ASM International.

Shen B.,Scripps Research Institute | Shen B.,Central South University
Cell | Year: 2015

The 2015 Nobel Prize in Physiology or Medicine has been awarded to William C. Campbell, Satoshi Omura, and Youyou Tu for the discovery of avermectins and artemisinin, respectively, therapies that revolutionized the treatment of devastating parasite diseases. With the recent technological advances, a New Golden Age of natural products drug discovery is dawning. © 2015 Elsevier Inc.

Nitta N.,Georgia Institute of Technology | Wu F.,Georgia Institute of Technology | Wu F.,Central South University | Lee J.T.,Georgia Institute of Technology | Yushin G.,Georgia Institute of Technology
Materials Today | Year: 2015

This review covers key technological developments and scientific challenges for a broad range of Li-ion battery electrodes. Periodic table and potential/capacity plots are used to compare many families of suitable materials. Performance characteristics, current limitations, and recent breakthroughs in the development of commercial intercalation materials such as lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), lithium titanium oxide (LTO) and others are contrasted with that of conversion materials, such as alloying anodes (Si, Ge, Sn, etc.), chalcogenides (S, Se, Te), and metal halides (F, Cl, Br, I). New polyanion cathode materials are also discussed. The cost, abundance, safety, Li and electron transport, volumetric expansion, material dissolution, and surface reactions for each type of electrode materials are described. Both general and specific strategies to overcome the current challenges are covered and categorized. © 2014 The Authors. Published by Elsevier Ltd.

Yang X.,Central South University | Miura H.,University of Electro - Communications | Sakai T.,University of Electro - Communications
Materials and Design | Year: 2013

The microstructural development in a AZ31 magnesium alloy during cold multi-directional forging followed by annealing is investigated in a wide range of cumulative strains up to 5. The kinetics of recrystallization is accelerated accompanying with increase in the Johnson-Mehl-Avrami-Kolmogorov slope from 2.6 to 4.7 as well as an appearance of a linear Johnson-Mehl-Avrami-Kolmogorov relationship. The grain size evolved after annealing decreases with repeated multi-directional forging and approaches around 1 lm in high strain. A strong initial texture is broken gradually with repeated multi-directional forging and almost disappears at severe high strain of 5. These can be because various variants of deformation twins and their intersections introduced by multi-directional forging are homogeneously developed in high density by repeated changing of the loading directions during multi-directional forging. The annealing process and the mechanisms occurring after cold multi-directional forging are discussed comparing with those after hot multi-directional forging. © 2012 Elsevier Ltd.

Liu F.,Central South University | Chen D.-D.,Shanghai Institute of Diabetes | Sun X.,Shanghai University | Xie H.-H.,Shanghai Institute of Diabetes | And 3 more authors.
Diabetes | Year: 2014

Impaired angiogenesis and its induced refractory wound lesions are common complications of diabetes. Hydrogen sulfide (H2S) has been reported to have proangiogenic effects. We hypothesize that H2S improves diabetic wound healing by restoring endothelial progenitor cell (EPC) function in type 2 diabetes. db/db Mice were treated with sodium hydrosulfide (NaHS), 4-hydroxythiobenzamide group (HTB), or saline for 18 days. db/+ Mice were treated with DL-propargylglycine (PAG) or saline for 18 days. Plasma H 2S levels were significantly decreased in db/db mice and restored in the NaHS and HTB mice compared with the diabetic control group. Wound-closure rates were significantly faster in the NaHS and HTB groups than in the db/db group, in which the PAG group had slower wound-closure rates. Wound skin capillary densities were enhanced in the NaHS and HTB groups. EPC functions were significantly preserved in the NaHS and HTB groups but were decreased in the PAG group. Meanwhile, EPC functions of the db/+ mice were significantly reduced after in vitro PAG treatment or cystathionine-γ-lyase (CSE) silencing; EPC functions of db/db mice were significantly improved after in vitro NaHS treatment. The expressions of Ang-1 in wound skin tissue and in EPCs were upregulated in the NaHS and HTB groups compared with db/db controls, but were downregulated by in vivo PAG and in vitro siCSE treatment compared with normal controls. Diabetic EPC tube formation capacity was significantly inhibited by Ang-1 small interfering RNA before NaHS treatment compared with db/db EPCs treated with NaHS only. Taken together, these results show that H2S improves wound healing by restoration of EPC functions and activation of Ang-1 in type 2 diabetic mice. © 2014 by the American Diabetes Association.

Wu F.,Georgia Institute of Technology | Wu F.,Central South University | Lee J.T.,Georgia Institute of Technology | Nitta N.,Georgia Institute of Technology | And 4 more authors.
Advanced Materials | Year: 2015

(Graph Presented). Lithium Iodide (LiI) is reported as a promising electrolyte additive for lithium-sulfur batteries. It induces formation of Li-ion-permeable protective coatings on both positive and negative electrodes, which prevent the dissolution of polysulfides on the cathode and reduction of polysulfides on the anode. In addition to enhancing the cell cycle stability, LiI addition also decreases the cell overpotential and voltage hysteresis. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.

Xu Q.,Central South University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2011

A finite element model of rail-slab track-bridge vertical vibration was put forward, with the vibration equations formulated by using the principle of total potential energy conservation in elastic system dynamics and the "set-in-right-position" rule for matrix formulations. Using high-speed train passing slab track on bridge as an example, the influence of short-wave random irregularity on the vertical vibration responses of train-slab track-bridge system were studied with comparison between short-wave random irregularity and other types of irregularities. The calculation results show that: short-wave random irregularity has little effects on the vertical acceleration of vehicles, vertical displacements of rail, slab and bridge, while the influences on the vertical accelerations of rail and slab, vertical pressures on fastener and CA mortar are significant. In order to reduce the unfavorable effects of short-wave random irregularity, it is important to grind the rail in time.

Zhou S.,Central South University
Microfluidics and Nanofluidics | Year: 2013

In this paper, we present a systematic statistical mechanical study of a solvent-mediated interaction potential (SMIP) between two substrate surfaces patterned with nanoscale corrugations. The investigation reveals that various parameters of periodic corrugations as of period, amplitude, and phase difference provide us with a simple means of tuning the SMIP between two corrugated substrates standing face to face and immersed in solvent, and the changes of the SMIP are in the order of the thermal energy. We explain the corrugation effects by modified density distribution of the solvent particles between the corrugated substrates, and discuss the implications of our findings for the problem of self-assembly of nanoparticles by suggesting a route to help experimentalists better fabricate intercolloidal interactions necessary for expected assembled structures at the nanometer scale. © 2012 Springer-Verlag Berlin Heidelberg.

She S.,CAS Wuhan Institute of Rock and Soil Mechanics | Dong L.,Central South University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

This paper presents the statistics and analysis of academic papers published by Chinese authors in recent 30 years in rock mechanics and geotechnical engineering journals published in Chinese and English. The statistics and analysis also include academic papers citations in the key databases such as EI and SCI. The paper tries to summarize and analyze the situation and development of rock mechanics and geotechnical engineering in China in the last 30 years, especially in the last 10 years. The developments are mainly focused on rock strength and deformation theories, rock fracture and damage mechanics, rock dynamics and constitutive relationships, rock nonlinearity and rock multifield coupling, rock reinforcement and stability analysis. Finally, ten challenging issues are proposed in the field of rock mechanics and rock engineering.

Wu Y.,Central South University | Wang J.,University of New South Wales | Hu D.,National University of Defense Technology
IEEE Transactions on Signal Processing | Year: 2014

Integration of inertial navigation system (INS) and global navigation satellite system (GNSS) is usually implemented in engineering applications by way of Kalman-like filtering. This form of INS/GNSS integration is prone to attitude initialization failure, especially when the host vehicle is moving freely. This paper proposes an online constrained-optimization method to simultaneously estimate the attitude and other related parameters including GNSS antenna's lever arm and inertial sensor biases. This new technique benefits from self-initialization in which no prior attitude or sensor measurement noise information is required. Numerical results are reported to validate its effectiveness and prospect in high accurate INS/GNSS applications. © 2014 IEEE.

Wang H.-Q.,Guangxi Normal University | Li Z.-S.,Guangxi Normal University | Huang Y.-G.,Guangxi Normal University | Li Q.-Y.,Guangxi Normal University | Wang X.-Y.,Central South University
Journal of Materials Chemistry | Year: 2010

A novel non-aqueous hybrid supercapacitor was fabricated from two spherical materials - an activated mesocarbon microbead (AMCMB) and MnO2 nanowire-sphere, as the negative and positive electrodes, respectively. The preliminary results for this energy-storage device, which operates over a wide voltage range (0.0-3.0 V) using 1 M Et4NBF4 in acetonitrile (AN) as electrolytes, are presented. On the basis of a single electrode, the AMCMBMnO2 supercapacitor displays a high specific capacitance of 228 F g-1 at a scan rate of 10 mV s-1, corresponding to specific energy of 128 W h kg-1 based on based on the total mass of active materials, while maintaining desirable cycling stability and rate capability. The combination of the spherical AMCMB and MnO2 in a non-aqueous electrolyte is proved to be suitable for high-performance hybrid supercapacitor applications. © 2010 The Royal Society of Chemistry.

Chen X.,Hong Kong Polytechnic University | Xiang S.,Central South University
Mathematical Programming | Year: 2011

Using the least element solution of the P0 and Z matrix linear complementarity problem (LCP), we define an implicit solution function for linear complementarity constraints (LCC). We show that the sequence of solution functions defined by the unique solution of the regularized LCP is monotonically increasing and converges to the implicit solution function as the regularization parameter goes down to zero. Moreover, each component of the implicit solution function is convex. We find that the solution set of the irreducible P0 and Z matrix LCP can be represented by the least element solution and a Perron-Frobenius eigenvector. These results are applied to convex reformulation of mathematical programs with P0 and Z matrix LCC. Preliminary numerical results show the effectiveness and the efficiency of the reformulation. © 2009 Springer and Mathematical Programming Society.

In general, for multi-criteria group decision making problem, there exist inter-dependent or interactive phenomena among criteria or preference of experts, so that it is not suitable for us to aggregate them by conventional aggregation operators based on additive measures. In this paper, based on fuzzy measures a generalized intuitionistic fuzzy geometric aggregation operator is investigated for multiple criteria group decision making. First, some operational laws on intuitionistic fuzzy values are introduced. Then, a generalized intuitionistic fuzzy ordered geometric averaging (GIFOGA) operator is proposed. Moreover, some of its properties are given in detail. It is shown that GIFOGA operator can be represented by special t-norms and t-conorms and is a generalization of intuitionistic fuzzy ordered weighted geometric averaging operator. Further, an approach to multiple criteria group decision making with intuitionistic fuzzy information is developed where what criteria and preference of experts often have inter-dependent or interactive phenomena among criteria or preference of experts is taken into account. Finally, a practical example is provided to illustrate the developed approaches. © 2010 Springer-Verlag.

Yu-Liang L.,Central South University
Disaster Advances | Year: 2013

Residual deformation caused by earthquake is main reason that results in seismic damage of embankments. In order to study deformation behaviors of different patterns of reinforced embankment slopes under seismic excitation, shaking table tests on three embankment slope models were carried out including unreinforced embankment slope, 2-layer reinforced embankment slope and 4-layer reinforced embankment slope. By performing Wenchuan excitations of different intensities, dynamic deformation responses of embankment slopes were investigated. Both lateral residual deformation and subsidence deformation behaviors were studied. And then, the deformation modes of embankment slopes were discussed. Results show that the baseline of dynamic deformation response fluctuates obviously and embankment slope shows large seismic residual deformation when the input peak acceleration is greater than 0.4 g. Seismic residual deformation increases significantly with the increasing of input peak acceleration, especially when the input peak acceleration is greater than 0.4 g. Reinforced embankment slope shows less seismic residual deformation than unreinforced embankment slope. The reinforcing effect is more obvious under strong seismic excitation. The deformation modes of different patterns of reinforced embankment slopes are all in seismic subsidence modes.

Lin Y.-L.,Central South University
Disaster Advances | Year: 2013

Based on the prototype of single-line unballasted track railway embankment, embankment slope model with the scale of 1:8 was designed. The recorded Wenchuan excitations with different peak accelerations were performed in XZ-bi direction. Acceleration responses of embankment slope were analyzed both in time domain and frequency domain. The acceleration response spectrum of a singledegree- of-freedom (SDOF) system was also calculated. Results show that the intensity of acceleration response in slope surface is greater than that in midsection. Accelerationmagnification increases nonlinearly along the height of embankment slope and presents a decreasing trend with the increase of input peak acceleration. Exponential function and logarithmic function are recommended to describe such decreasing trend. Seismic energy with highfrequency is absorbed by embankment slope and seismic energy with frequency close to the natural frequency of embankment slope is enhanced when the seismic wave transmits upwards. The natural frequency of embankment slope is determined as 4.5 Hz with a suggestion that the construction of structure with the natural period close to 0.22 s on embankment slope should be avoided.

Zhang Q.,City University of Hong Kong | Xu D.,City University of Hong Kong | Zhou X.,City University of Hong Kong | Wu X.,Central South University | Zhang K.,City University of Hong Kong
Small | Year: 2014

A strategy is presented for the in situ synthesis of single crystalline CuO nanorods and 3D CuO nanostructures, ultra-long Cu nanowires and Cu nanoparticles at relatively low temperature onto various substrates (Si, SiO2, ITO, FTO, porous nickel, carbon cotton, etc.) by one-step thermal heating of copper foam in static air and inert gas, respectively. The density, particle sizes and morphologies of the synthesized nanostructures can be effectively controlled by simply tailoring the experimental parameters. A compressive stress based and subsequent structural rearrangements mechanism is proposed to explain the formation of the nanostructures. The as-prepared CuO nanostructures demonstrate promising electrochemical properties as the anode materials in lithium-ion batteries and also reversible wettability. Moreover, this strategy can be used to conveniently integrate these nanostructures with other nanostructures (ZnO nanorods, Co3O4 nanowires and nanowalls, TiO2 nanotubes, and Si nanowires) to achieve various hybrid hierarchical (CuO-ZnO, CuO-Co3O4, CuO-TiO 2, CuO-Si) nanocomposites with promising properties. This strategy has the potential to provide the nano society with a general way to achieve a variety of nanostructures. © 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.

Yang X.,Hunan Normal University | Zhang H.,Central South University | Xu D.,Hunan Normal University
Journal of Computational Physics | Year: 2014

The aim of this paper is to develop a novel numerical techniques for the solution of the two-dimensional fractional sub-diffusion equation. The proposed technique is based on orthogonal spline collocation (OSC) method in space and a finite difference method (FDM) in time. Stability and convergence of the proposed method are rigorously discussed and theoretically proven. We present the results of numerical experiments in one and two space variables, which confirm the predicted convergence rates and exhibit optimal accuracy in various norms. © 2013 Elsevier Inc.

Xu Q.,Central South University | Xu Q.,Brown University | Hesthaven J.S.,Brown University
Journal of Computational Physics | Year: 2013

We propose stable multi-domain spectral penalty methods suitable for solving fractional partial differential equations with fractional derivatives of any order. First, a high order discretization is proposed to approximate fractional derivatives of any order on any given grids based on orthogonal polynomials. The approximation order is analyzed and verified through numerical examples. Based on the discrete fractional derivative, we introduce stable multi-domain spectral penalty methods for solving fractional advection and diffusion equations. The equations are discretized in each sub-domain separately and the global schemes are obtained by weakly imposed boundary and interface conditions through a penalty term. Stability of the schemes are analyzed and numerical examples based on both uniform and nonuniform grids are considered to highlight the flexibility and high accuracy of the proposed schemes. © 2013 Elsevier Inc.

Hou Z.,Central South University | Wang B.,CAS Academy of Mathematics and Systems Science
International Journal of Innovative Computing, Information and Control | Year: 2011

A class of partial differential-integral equation systems is derived in operations research including queueing theory, inventory and reliability. The existence and uniqueness for solutions of the class of equation systems have not been investigated yet. In this paper, we present a solution to the class of partial differential-integral equation system via the Markov skeleton process theory and then obtain the existence of the solutions to such equation systems. Furthermore, we prove that the solution is the minimal nonnegative solution of a linear equation system. © 2011 ICIC International.

Xiang S.,Central South University | Brunner H.,Memorial University of Newfoundland | Brunner H.,Hong Kong Baptist University
BIT Numerical Mathematics | Year: 2013

In this paper, we introduce efficient methods for the approximation of solutions to weakly singular Volterra integral equations of the second kind with highly oscillatory Bessel kernels. Based on the asymptotic analysis of the solution, we derive corresponding convergence rates in terms of the frequency for the Filon method, and for piecewise constant and linear collocation methods. We also present asymptotic schemes for large values of the frequency. These schemes possess the property that the numerical solutions become more accurate as the frequency increases. © 2013 Springer Science+Business Media Dordrecht.

Yu G.,Shandong Institute of Business and Technology | Feng L.,Central South University
Match | Year: 2013

The connective eccentricity index of a graph G is defined as ξce(G) = ∑ /v ε V (G) d(ν)/ ε(v), where ε(v) and d(ν) denote the eccentricity and the degree of the vertex ν, respectively. In this paper we derive upper or lower bounds for the connective eccentricity index in terms of some graph invariants such as the radius, independence number, vertex connectivity, minimum degree, maximum degree etc. Moreover, we investigate the maximal and the minimal values of connective eccentricity index among all n-vertex graphs with fixed number of pendent vertices and characterize the extremal graphs. In addition, we study the cactus on n vertices with k cycles having the maximal connective eccentricity index.

Chen X.,Hong Kong Polytechnic University | Xiang S.,Central South University
Mathematical Programming | Year: 2013

We propose a generalized Newton method for solving the system of nonlinear equations with linear complementarity constraints in the implicit or semi-implicit time-stepping scheme for differential linear complementarity systems (DLCS). We choose a specific solution from the solution set of the linear complementarity constraints to define a locally Lipschitz continuous right-hand-side function in the differential equation. Moreover, we present a simple formula to compute an element in the Clarke generalized Jacobian of the solution function. We show that the implicit or semi-implicit time-stepping scheme using the generalized Newton method can be applied to a class of DLCS including the nondegenerate matrix DLCS and hidden Z-matrix DLCS, and has a superlinear convergence rate. To illustrate our approach, we show that choosing the least-element solution from the solution set of the Z-matrix linear complementarity constraints can define a Lipschitz continuous right-hand-side function with a computable Lipschitz constant. The Lipschitz constant helps us to choose the step size of the time-stepping scheme and guarantee the convergence. © 2012 Springer and Mathematical Optimization Society.

Peng S.,Zhaoqing University | Wang G.,Central South University | Yu S.,Deakin University
Journal of Computer and System Sciences | Year: 2013

Smartphones combine the communication capabilities of cellphones and the functions of PDA (personal digital assistant), which enable us to access a large variety of ubiquitous services, such as surfing the web, sending/receiving emails, MMS, and online shopping. However, the availability of these services provided by smartphones increases the vulnerability to worm attacks. In addition, modeling on worm propagation in smartphones is particularly challenging because it is difficult to piece together dynamics from pair-wise device interactions. To characterize the propagation dynamics of worms in smartphones, we propose an efficient worm propagation modeling scheme using a two-dimensional cellular automata based on the epidemic theory. A set of suitable local transition rules is designed for the two-dimensional cellular automata in this scheme. Moreover, this scheme integrates an infection factor to evaluate the spread degree of infected nodes, and a resistance factor to evaluate the degree that susceptible nodes resist. Five classes of epidemic states are considered: susceptible, exposed, infected, diagnosed, and recovered. We explore a strategy for simulating the dynamics of worm propagation process from a single node to the entire network. The effectiveness and rationality of the proposed model have been validated through extensive simulations. © 2012 Elsevier Inc.

Zhao Y.,Hunan University of Technology | Chen H.,Central South University | Huang L.,Hunan University of Technology
Computers and Mathematics with Applications | Year: 2012

In this paper, the existence of positive solutions for the nonlinear Caputo fractional functional differential equation in the form D0+qy(t)+r(t)f( yt)=0,∀t∈(0,1),q∈(n-1,n],y( i)(0)=0, 0≤i≤n-3,αy( n-2)(t)-βy( n-1)(t)=η(t), t∈[-τ,0],γy( n-2)(t)+δy( n-1)(t)= ξ(t),t∈[1,1+a] is studied. By constructing a special cone and using Krasnosel'skii's fixed point theorem, various results on the existence of at least one or two positive solutions to the fractional functional differential equation are established. The main results improve and generalize the existing results. © 2011 Elsevier Ltd. All rights reserved.

Zhou S.,Central South University
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2015

In this paper, we investigate effects of counterion connectivity (i.e., association of the counterions into a chain molecule) on the electrostatic potential of mean force (EPMF) between two similarly charged cylinder rods in a primitive model electrolyte solution by solving a classical density functional theory. The main findings include the following: (i) The counterion connectivity helps in inducing a like-charge-attractionlike (LCA-like) phenomenology even in a monovalent counterion solution wherein the LCA-like observation generally does not occur without the counterion connectivity. (ii) For divalent counterion solutions, the counterion connectivity can reinforce or weaken the LCA-like observation depending on the chain length N, and simply increases the equilibrium nearest surface separation of the rods corresponding to the minimum EPMF to nearly three times the counterion site diameter, whether N is large or small. (iii) If N is large enough, the LCA-like strength tends to be negatively correlated with the electrolyte concentration c over the entire range of the rod surface charge magnitude |σ∗| considered; whereas if N drops, the correlation tends to become positive with decrease of the |σ∗| value, and particularly for modest |σ∗| values, the correlation relationship exhibits an extreme value phenomenon. (iv) In the case of a 1:1 electrolyte, the EPMF effects of the diameters of counterion and coion sites are similar in both situations with and without the counterion connectivity. All of these findings can be explained self-consistently by a recently proposed hydrogen-bonding style mechanism reinforced by one additional concept: flexibility of the counterion chain and the factors affecting it, like N and counterion site valence. © 2015 American Physical Society.

Li M.,Central South University
International Journal of Heat and Mass Transfer | Year: 2013

This paper indicates that diffusion-controlled organic emissions can be identified as processes of three stages, i.e., short-, mid-, and long-term emissions. Based on two generalized mass-diffusion models, exact series and short-time solutions are derived and validated by using two reported environmental-chamber tests. Long-term emissions can be predicted by a new exponential-decay model, a simplified version of a series solution. Short-term emissions can be modeled efficiently by small-time solutions. Besides having simple forms, small-time solutions require no roots of transcendental equations and converge very fast for short times. They serve necessary complements to the exact series solutions. Especially interesting is the mid-stage emission between the very early and the late emission stages, which indicates that there is a straight-line relation between air-phase concentrations and 1/t (t is time). This simplest mathematical relation is the most desirable for engineering applications. Since all derivation has a solid mathematical-physics basis, the models presented in this paper may contribute to casting new light on the underlying mechanisms of diffusion-limited organic emissions. © 2013 Elsevier Ltd. All rights reserved.

Zhang H.,Central South University | Ma Z.,Samsung
Proceedings - IEEE International Symposium on Circuits and Systems | Year: 2013

The emerging High-Efficiency Video Coding video coding standard has shown the significant coding performance improvement compared to the H.264/AVC with the cost of huge complexity increase. Hence, HEVC fast encoding algorithms are highly demanded for real-time applications. In this paper, we propose several early termination schemes for fast intra prediction in HEVC. More specifically, variation of coding mode costs are used to terminate current coding unit (CU) mode decision as well as TU size selection, where the CU costs are derived at the rough mode decision phase using Hadamard transform. Neighboring modes' costs are also used to skip full rate-distortion optimized quantization (RDOQ). For all available test sequences provided by the JCT-VC, it demonstrates about 32% encoding time reduction for All Intra configuration with BD-RATE increase about 1.1%. Our proposal is complementary to some of other fast intra prediction methods such as fast rough mode decision. We expect more encoder speedup by integrating our method with other published works. © 2013 IEEE.

Yang X.-L.,Central South University
Archive of Applied Mechanics | Year: 2011

Conventional seismic passive pressures of earth structures are based on a linear failure criterion in earthquake zones. However, experimental evidence shows that the strength envelopes are nonlinear over a wide range of normal stresses. In this paper, the analytical expressions of seismic passive pressures acting on inclined rigid walls are derived with nonlinear failure criterion. Quasi-static representation of earthquake effects using a seismic coefficient is adopted for seismic estimations. Instead of using the nonlinear criterion, a linear failure criterion, which is tangential to the nonlinear criterion, is used to formulate the seismic passive pressure problems as nonlinear programming problems. Analytical results are presented and compared with the previously published solutions using numerical technique. The influences of the parameters in the nonlinear failure criterion on seismic pressures and failure mechanisms are discussed. © Springer-Verlag 2010.

Zhan L.,Central South University | Lin J.,Imperial College London | Dean T.A.,University of Birmingham
International Journal of Machine Tools and Manufacture | Year: 2011

About twenty years ago, the process of Creep Age Forming (CAF) was invented, and since then has been developed for the manufacture of heat treatable aluminium alloy panel components particularly, it has been successfully used for aircraft wing panels. Significant research work has been carried out in recent years and process applications have been expanded. This paper contains a review of recent research and development of this novel forming process. It covers process applications in the aircraft industry and scientific research, including the development of forming tools, experimental studies, materials and process modelling and springback prediction. Some potential future applications and challenges for deeper understanding of this novel process are also discussed. © 2010 Elsevier Ltd. All rights reserved.

Wei B.,Central South University
Structural Engineering International: Journal of the International Association for Bridge and Structural Engineering (IABSE) | Year: 2011

The influence of higher modes and their consideration in the pushover analysis of three irregular continuous bridges is discussed. Modal pushover analysis (MPA) is addressed and compared with inelastic time-history analysis (ITHA). In the operation process of MPA, each important mode is used to determine the distribution of forces for the pushover analysis separately, and the displacements of different parts of bridge are monitored to construct pushover curves for each important mode. When the analyses for all important modes of one bridge are completed, the results are combined and compared with the results of ITHA. The investigation shows, for each important mode, adopting different displacement-monitored points obtains different pushover curves. If reasonable pushover curves are selected as capacity spectra, MPA can give the results comparable with ITHA, or else MPA does not work well. Finally, how to choose reasonable displacement-monitored point to construct capacity spectrum of MPA is identified.

Li X.-F.,Central South University
Philosophical Magazine Letters | Year: 2011

Dynamic problems of quasicrystals are analysed within the framework of continuum mechanics. Phonon excitations yield wave propagation while phason excitations yield atomic diffusion. Phonon fields obey the equations of motion and phason fields obey the diffusion equations. Governing equations of elasto-hydrodynamics of decagonal quasicrystals combine characteristics of the equations of motion and diffusion. A general solution is derived in terms of two introduced auxiliary functions. It provides an easy-to-use approach to solve initial-boundary value problems encountered in elasticity problems for quasicrystals. Explicit expressions for displacements and stresses in the phonon and phason fields can be directly obtained. A derived general solution is also applicable to some planar quasicrystals such as pentagonal quasicrystals with fivefold symmetry. © 2011 Taylor & Francis.

Liu T.,Tsinghua University | Zhao C.,Central South University
Soil Dynamics and Earthquake Engineering | Year: 2013

Since the generalized transfer matrix method overcomes the intrinsic instability of the Thomson-Haskell transfer matrix method for both high frequencies and/or thick layers, it can produce stable and accurate solutions for the dynamic analysis of viscoelastic media as well as anisotropic media. This paper extends the generalized transfer matrix method to the dynamic analysis of multilayered poroelastic media. Main improvements include the presentation of the concisely explicit general solutions for the dynamic analysis of multilayered poroelastic media and the derivation of an analytical inversion of 8×8 order layer matrix corresponding to the general solutions. The explicit solutions are valid for the dynamic analysis of one-dimensional, two-dimensional and three-dimensional poroelastic medium problems. In addition, an efficient recursive scheme is proposed for accurate determination of the equivalent interface sources for multilayered poroelastic media due to excitation by a source at an arbitrary depth. For the dynamic analysis of multilayered poroelastic media, the generalized transfer matrix method recursively transfers both the interface stiffness matrix and equivalent source starting from the bottom half space to the top layer, without resort to the numerical solution of the assembled global equations as the exact stiffness matrix method does. While keeping the simplicity of the Thomson-Haskell transfer matrix method, the generalized transfer matrix method is both accurate and stable. The related numerical examples have demonstrated that the generalized transfer matrix method is an alternative approach to conducting the dynamic analysis of multilayered poroelastic media. © 2012 Elsevier Ltd.

Ren W.-X.,Central South University | Chen H.-B.,National Engineering Laboratory for High Speed Railway Construction
Engineering Structures | Year: 2010

Fast-running response surface models that approximate multivariate input/output relationships of time-consuming physical-based computer models enable effective finite element (FE) model updating analyses. In this paper, a response surface-based FE model updating procedure for civil engineering structures in structural dynamics is presented. The key issues to implement such a model updating are discussed such as sampling with design of experiments, selecting the significant updating parameters and constructing a quadratic polynomial response surface. The objective function is formed by the residuals between analytical and measured natural frequencies. Single-objective optimization with equal weights of natural frequency residual of each mode is used for optimization computation. The proposed procedure is illustrated by a simulated simply supported beam and a full-size precast continuous box girder bridge tested under operational vibration conditions. The results have been compared with those obtained from the traditional sensitivity-based FE model updating method. The real application to a full-size bridge has demonstrated that the FE model updating process is efficient and converges fast with the response surface to replace the original FE model. With the response surface at hand, an optimization problem is formulated explicitly. Hence, no FE calculation is required in each optimization iteration. The response surface-based FE model updating can be easily implemented in practice with available commercial FE analysis packages. © 2010 Elsevier Ltd.

Li D.,Nanyang Technological University | Li D.,Central South University | Wong L.N.Y.,Nanyang Technological University
Rock Mechanics and Rock Engineering | Year: 2013

The point load test has been considered as a cheap and useful testing method to estimate the strengths of rocks due to its ease of testing, simplicity of specimen preparation, and possible field application. An underground oil storage rock cavern is under construction in Singapore. The strength of surrounding rock mass is very high, which favors the stability of the excavation. The tested specimens have a nominal diameter of 50 mm, except the nine specimens cored from rock block R2, of which the nominal diameter is 45 mm. The length of the specimens ranges from approximately 80 to 100 mm for diametral tests and about 40 to 50 mm for axial tests. Calcite in-filling is observed along the joint planes in some meta-sandstone specimens, in which calcite veins and scattered pyrite grains are also observed.

Kong F.,Central South University | Wang H.,Changsha Huaneng Automatic Control Group
Energy and Buildings | Year: 2011

Newly completed building envelope is always characterized by high initial moisture content, and so the liquid moisture permeability is the main feature of mass transferring on its initial use. The high initial moisture content has strong impact on indoor condition and energy consumption especially in severe cold area where the moisture freezing in building envelope would occur in winter. Therefore, accurately predicting the hygrothermal states of building envelope to obtain useful envelope parameters is very important. In order to analyze the moisture transferring performance of enclosure on building initial use in severe cold area, the paper studied the coupling transfer of heat and moisture in building envelope. The permeability and freezing of the liquid water in porous building material were considered. The moisture content gradient was used as mass transfer driving force, and the temperature gradient was used as heat transfer driving forces. Heat and moisture coupled transfer conservation equations on different transferring conditions were built. An experimental set-up was built to verify the model, and good agreements were obtained, which suggests that the model can be used to simulate the heat and moisture coupled transfer in newly completed building envelope of severe cold area. © 2011 Elsevier B.V. All rights reserved.

Zhang H.,Central South University | Ma Z.,Samsung
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Emerging High Efficiency Video Coding (HEVC) video coding standard promises the significant compression performance improvement compared to the H.264/AVC. However it comes with the tremendous encoding complexity increase. Thus, it is very useful and necessary to develop fast algorithms for HEVC, so as to reduce the encoder complexity. In this paper, we propose a fast intra prediction scheme for HEVC to reduce the prediction mode search for each prediction unit. For all available test sequences provided by the JCT-VC, it demonstrates 38% encoding time reduction for all intra case with BD-RATE increase about 2.9%. Several sub-algorithms are developed and integrated for complexity reduction. First, we applied the Hadamard transform on 2:1 downsampled prediction residual to derive the sum of absolute Hadamard transformed difference (SATD) for rough mode decision, where a progressive search process is then used to reduce effective mode candidates for fully rate-distortion optimized quantization (RDOQ). Finally, an early termination based on SATD cost and mode distances is also included in RDOQ process to further complexity reduction. Extensive simulation results demonstrate that our proposed method is quite efficient for intra mode prediction speed-up. Our proposal is complementary to other separated works on fast coding unit, prediction unit, and transform unit decision. We expect more encoder complexity reduction by combing our solution and other fast algorithms. © 2012 Springer-Verlag.

Hu Z.-Y.,CAS Shanghai Institute of Materia Medica | Yu Q.,Shanghai JiaoTong University | Pei Q.,Central South University | Guo C.,Shanghai JiaoTong University
Clinical Cancer Research | Year: 2010

Purpose: A previous meta-analysis showed that the association between the UGT1A1*28 genotype and irinotecan-induced neutropenia was influenced by irinotecan dose and that the risk of neutropenia was similar at low doses for patients with all genotypes. However, the sample sizes for the low- and high-dose groups were small. Because additional studies have now been reported, an updated and refined metaanalysis is needed. Experimental Design: Meta-analyses were done to assess the relationship between UGT1A1*28 and neutropenia. The association between UGT1A1*28 and the relative extent of glucuronidation (REG) of SN-38 was also examined. The studies included were stratified into different dose groups. Results: A total of 1,998 patients were included for the analysis of neutropenia and 581 patients were included for REG. The risk of neutropenia at low doses was significantly higher among patients with a UGT1A1*28/*28 genotype than among those carrying the UGT1A1*1 allele(s) [relative risk (RR), 2.43; 95% confidence interval, 1.34-4.39; P = 0.003]. In addition, the RR of neutropenia at low doses was comparable with that at medium doses (2.43 versus 2.00). The RR of neutropenia at high doses was significantly higher than that at low and medium doses (7.22 versus 2.04). We found the weighted mean difference of REG (UGT1A1*1/ *1 or UGT1A1*1/*28 versus UGT1A1*28/*28) increased with increasing dose of irinotecan. Conclusions: In conclusion, the UGT1A1*28/*28 genotype was associated with an increased risk of neutropenia not only at medium or high doses of irinotecan but also at low doses. The dose-dependent manner of SN-38 glucuronidation explained why the association between UGT1A1*28 and neutropenia was dose dependent. ©2010 AACR.

Wu H.B.,Nanyang Technological University | Pan A.,Nanyang Technological University | Pan A.,Central South University | Hng H.H.,Nanyang Technological University | Lou X.W.,Nanyang Technological University
Advanced Functional Materials | Year: 2013

In this work, rattle-type ball-in-ball V2O5 hollow microspheres are controllably synthesized with the assistance of carbon colloidal spheres as hard templates. Carbon spheres@vanadium-precursor (CS@V) core-shell composite microspheres are first prepared through a one-step solvothermal method. The composition of solvent for the solvothermal synthesis has great influence on the morphology and structure of the vanadium-precursor shells. V2O5 hollow microspheres with various shell architectures can be obtained after removing the carbon microspheres by calcination in air. Moreover, the interior hollow shell can be tailored by varying the temperature ramping rate and calcination temperature. The rattle-type V2O5 hollow microspheres are evaluated as a cathode material for lithium-ion batteries, which manifest high specific discharge capacity, good cycling stability and rate capability. Rattle-type V2O5 ball-in-ball hollow microspheres are controllably synthesized using carbon spheres as hard templates. Carbon spheres@vanadium- precursor (CS@V) core-shell composite microspheres with controllable morphology and structure are first prepared through a one-step solvothermal method. Rattle-type V2O5 hollow microspheres with various structures can be obtained after removing the carbon microspheres by calcination in air. When evaluated as a cathode material for lithium-ion batteries, the rattle-type V2O5 hollow microspheres manifest high specific capacity, good cycling stability and rate capability. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li M.,Central South University | Lai A.C.K.,City University of Hong Kong
International Journal of Heat and Mass Transfer | Year: 2013

This paper presents a set of classical analytical solutions to heat conduction in a two-layer composite hollow cylindrical medium, which are derived by the method of Laplace transform. The subjected boundary conditions are general and included various combinations of constant temperature, constant flux, zero flux, or convection boundary condition at either surface. The new solution can reduce to Jaeger's solution to the problems subject to constant-temperature boundary conditions, verifying that our solution is an extension version of his solution. Moreover, the solutions subject to a constant flux and a constant temperature are used to evaluate short-time accuracy of a composite-medium line-source solution. Comparison of these two solutions indicates that the temperature response is always delayed as a result of the line-source assumption. An expression for estimating the minimum threshold, beyond which the line-source solution is acceptable, is suggested for engineering applications. © 2013 Elsevier Ltd. All rights reserved.

Li D.,Central South University
International Journal of Advancements in Computing Technology | Year: 2012

P2P networks potentially offer an efficient routing architecture that is self-organizing, massively scalable, and robust in the wide-area, combining fault tolerance, load balancing, and explicit notion of locality. However, because of the high degree of autonomy, there are a number of critical challenges and problems including trust, security and non-cooperation which currently prevent the great potential of P2P technology from being revealed. Current approaches on incentive mechanisms regard peers as rational nodes. If given appropriate incentive these nodes will act positively. But the nodes join and leave the P2P system randomly and independently so that peers may be not rational. In this paper, a layered and self-supervising unstructured P2P overlay is presented for preventing cheating and securing cooperation even though peers are not rational. By our overlay, the uniqueness and succession of peers' identities are guaranteed without the need of global knowledge. The paper solves three key problems: (1) how to maintain the overlay stable in front of the dynamic topologies; (2) how information can be located and routed at a low cost; (3) how to make the overlay robust. The theoretical analysis and the experimental simulation show that our overlay improves the efficiency of routing with less processing and bandwidth cost compared with other P2P systems, and it's more fault-tolerant.

Ala-Korpela M.,Central South University | Ala-Korpela M.,University of Oulu | Kangas A.J.,University of Oulu | Inouye M.,Walter and Eliza Hall Institute of Medical Research | Inouye M.,University of Melbourne
Trends in Genetics | Year: 2011

Following the widespread use of genome-wide association studies to elucidate the genetic architectures of complex phenotypes, there has been a push to augment existing observational studies with additional layers of molecular information. The resulting high-dimensional data have led the emergence of research in integrative systems biology. Here, we examine recent progress in characterizing biological networks as well as the corresponding conceptual and analytical challenges. Using examples from metabolomics, we contend that integrative systems biology should prompt a re-examination of conventional phenotypic measures where heterogeneous or correlated phenotypes can be fine-mapped. Although still in its infancy, it is apparent that the large-scale characterization of molecular systems will transform our understanding of phenotype, biology and pathogenesis. © 2011 Elsevier Ltd.

Wang L.,Huazhong University of Science and Technology | Dun C.-X.,Huazhong University of Science and Technology | Bi W.-J.,Central South University | Zeng Y.-R.,Hubei University of Economics
Knowledge-Based Systems | Year: 2012

As an important managerial problem, the practical joint replenishment and delivery (JRD) model under stochastic demand can be regarded as the combination of a joint replenishment problem and traveling salesman problem, either one is an NP-hard problem. However, due to the JRD's difficult mathematical properties, high quality solutions for the problem have eluded researchers. This paper firstly proposes an effective and efficient hybrid differential evolution algorithm (HDE) based on the differential evolution algorithm (DE) and genetic algorithm (GA) that can solve this NP-hard problem in a robust and precise way. After determining the appropriate parameters of the HDE by parameters tuning test, the effectiveness and efficiency of the HDE are verified by benchmark functions and numerical examples. We compare the HDE with the available best approach and find that the HDE can always obtain the slightly lower total costs under some situations. Compared with another popular evolutionary algorithm, results of numerical examples also show HDE is faster than GA and the convergence rate of HDE is higher than GA. HDE is a strong candidate for the JRD under stochastic demand. © 2012 Elsevier B.V. All rights reserved.

Li D.,Central South University
International Journal of Advancements in Computing Technology | Year: 2012

Most of the P2P systems work on the assumption of truthful cooperation among peers. However, in the open environment of the Internet, some participating hosts may not cooperate as desired. As nodes are inherently selfish regarding the resources they contribute or consume, the efficient performance cannot be achieved unless they are given the correct incentives. Those incentives include incentive mechanisms, reputation mechanisms, monetary mechanisms, game theory and so on. Most mechanisms need each peer's behavior history and have to store some necessary information such as reputations or utility matrix in other nodes. However, it is difficult to continuously keep and track other peers' behavior history in such highly dynamic environments as P2P systems. The paper presents a Hotelling model which is one of the game theories for cooperation guarantee. Each node only need keep its own information, and all decisions are given based on equilibrium situations maintained by each node itself. The theoretical analysis and the experimental simulation show that the Hotelling model is good at guaranteeing cooperation.

Xie C.-Y.,Central South University
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2011

The purpose of this study is to present a weighting method, integrating of subjective weights with objective weights, for landslide susceptibility mapping based on GIS. Firstly, landslide inventory, aspect, proximity to drainage line, topography, elevation, lithology, proximity to structural line and annual precipitation, were taken as independent causal factors. Secondly, trapezoidal fuzzy number weighting (TFNW) approach was used to assess the effect of each subclass of each causal factor. Thirdly, entropy-based weighting method was used to calculate objective weights of causal factors according to the landslide density for each parameter class. Finally, the landslide susceptibility map of Guizhou Province in China, as an example, was created using weighted linear combination (WLC) model based on geographical information system (GIS). According to the susceptibility index, the study area was classified into four categories of landslide susceptibility: low, moderate, high and very high. The results of the analysis were verified using the landslide inventory map. The validation results show satisfactory agreement between the landslide susceptibility map and the existing data on landslide locations, demonstrating that the TFNW and entropy methods are efficient tools for weighting landslide causal factors.

Wan N.,University of Nebraska Medical Center | Zou B.,Central South University | Sternberg T.,University of Oxford
International Journal of Geographical Information Science | Year: 2012

Gravity-based spatial access models have been widely used to estimate spatial access to healthcare services in an attempt to capture the interaction of various factors. However, these models are inadequate in informing health resource allocation work due to their inappropriate assumption of healthcare demand. For the purpose of effective healthcare resource planning, this article proposes a three-step floating catchment area (3SFCA) method to minimize the healthcare-demand overestimation problem. Specifically, a spatial impedance-based competition scheme is incorporated into the enhanced two-step floating catchment area (E2SFCA) method to account for a reasonable model of healthcare supply and demand. A case study of spatial access to primary care physicians along the Austin-San Antonio corridor area in central Texas showed that the proposed method effectively minimizes the overestimation of healthcare demand and reflects a more balanced geographic pattern of spatial access than E2SFCA. In addition, by using an adjusted spatial access index, the 3SFCA method indicates strong potential for identifying health professional shortage areas. The study concludes that 3SFCA is a promising method to provide health professionals and decision makers with useful healthcare accessibility information. © 2012 Taylor & Francis.

Guo Y.,Central South University
Science China Information Sciences | Year: 2016

This paper investigates the controllability of Boolean control networks (BCNs) with state-dependent constraints. A kind of input transformation is proposed to transfer a BCN with state-dependent input constraints into a BCN with free control input. Based on the proposed technique, a necessary and sufficient condition for controllability is obtained. It is shown that state-dependent constraints for the state can be equivalently expressed as input constraints. When a BCN has both input and state constraints, there is a possibility that the sets of admissible controls for some states are the empty set. To treat this kind of BCN, a variation of the input transformation is proposed and the problem of controllability is solved. An illustrative example is provided to explain the proposed method and results. © 2016 Science China Press and Springer-Verlag Berlin Heidelberg

Jiang C.,Central South University | Lin Z.,Los Alamos National Laboratory | Zhao Y.,Los Alamos National Laboratory
Scripta Materialia | Year: 2010

The possible crystal structures of transition metal nitrides M2N3 (M = V or Nb) were investigated using first principles calculations. We predict that the ground state structures of V2N3 and Nb2N3 are trigonal and orthorhombic, respectively, over a wide pressure range. Examinations of the thermodynamic stabilities of trigonal V2N3 and orthorhombic Nb2N3 with respect to phase decomposition suggest that they can be prepared under moderate pressure conditions. Elastic constant calculations indicated that both nitrides were mechanically stable and are potential candidates for hard materials. © 2010 Acta Materialia Inc.

Large-scale centimetres-long single-crystal β-SiC nanowires have been prepared using CH4 as the carbon source and SiO or the mixture of Si and SiO2 as the silicon source by a simple catalyst-free CVD route under superatmospheric pressure conditions. The nanowries grown on ceramic boat or corundum substrates, with lengths of several centimetres and the average diameters of around 40 nm, were composed of single-crystal β-SiC core along the [111] direction and amorphous SiO2 shell of about 1-30 nm thick depending on the growth position along the flowing direction of the carrier gas. The total gas pressure is an important factor for the synthesis of the large-scale centimetres-long β-SiC nanowires, which can easily adjust the pressure of the vapors to supersaturation condition. The growth of the nanowires was governed by the Vapor-Solid mechanism. The β-SiC nanowires showed an intense blue light emission at room temperature. © 2011 The Royal Society of Chemistry.

Zhao C.,Central South University
Finite Elements in Analysis and Design | Year: 2011

The main purpose of this paper is to simulate computationally the kinematical motion of the frictional drill-bit of an automatic mining machine in the underground consisting of cemented granular materials. Although the finite element method has become a powerful tool for the design and analysis of many kinds of engineering products, it cannot be used, both effectively and efficiently, for dealing with the frictional drill-bit design problem that involves discrete-mechanics characteristics in nature. Thus, the particle simulation method is employed for mimicking the kinematical motion of a frictional drill-bit, which is fundamental to the design of an automatic mining machine in cemented granular materials. In order to simulate the driving force mechanism of a frictional drill-bit, both the designed velocity and the actual velocity concepts of the frictional drill-bit are proposed. This enables the particle simulation method to be used as a potential tool for the design of an automatic mining machine, which can be used as a new mining technology in some particular mining environments. To illustrate the usefulness and applicability of the proposed driving mechanism associated with the particle simulation method, it has been used for mimicking the frictional drill-bit movement of an automatic mining machine in cemented granular materials under several working conditions. The related computational simulation results have demonstrated that (1) the particle simulation method, together with the proposed driving mechanism of a frictional drill-bit, can provide a useful tool for the design of an automatic mining machine and (2) the vibrating frequency of a frictional drill-bit may have considerable effects on the motion of the frictional drill-bit in the underground consisting of cemented granular materials. © 2011 Elsevier B.V. All rights reserved.

Baker S.P.,Johns Hopkins University | Hu G.,Central South University | Wilcox H.C.,Johns Hopkins University | Baker T.D.,Johns Hopkins University
American Journal of Preventive Medicine | Year: 2013

Background: Recently, suicide exceeded motor vehicle crashes as the leading cause of injury death in the U.S. However, details of this change in suicide methods and the relationship to individual demographics, such as age and societal influences, have not been reported. Purpose: To determine the characteristics of the changes in suicide rates between 2000 and 2010. Methods: Data came from CDC's Web-Based Injury Statistics Query and Reporting System (WISQARS™). Line charts were plotted to reveal changes in suicide rates by firearm, poisoning, and hanging/suffocation (ICD-10 codes: X72-X74, X60-X69, and X70). The measure of change used is the percentage change in suicide rate between 2000 and 2010. Results: The overall suicide rate increased from 10.4 to 12.1 per 100,000 population between 2000 and 2010, a 16% increase. The majority of the increase was attributable to suicide by hanging/suffocation (52%) and by poisoning (19%). Subgroup analysis showed: (1) suicide by hanging/suffocation increased by 104% among those aged 45-59 years and rose steadily in all age groups except those aged ≥70 years; (2) the largest increase in suicide by poisoning (85%) occurred among those aged 60-69 years; and (3) suicide by firearm decreased by 24% among those aged 15-24 years but increased by 22% among those aged 45-59 years. The case fatality rates for suicide by hanging/suffocation during 2000-2010 ranged from 69% to 84%, close to those for suicide by firearm. Analyses were conducted in 2012. Conclusions: Substantial increases in suicide by hanging/suffocation and poisoning merit attention from policymakers and call for innovations and changes in suicide prevention approaches. © 2013 American Journal of Preventive Medicine.

Alt-Epping P.,University of Bern | Zhao C.,Central South University
Journal of Geochemical Exploration | Year: 2010

For a three-dimensional vertically-oriented fault zone, we consider the coupled effects of fluid flow, heat transfer and reactive mass transport, to investigate the patterns of fluid flow, temperature distribution, mineral alteration and chemically induced porosity changes. We show, analytically and numerically, that finger-like convection patterns can arise in a vertically-oriented fault zone. The onset and patterns of convective fluid flow are controlled by the Rayleigh number which is a function of the thermal properties of the fluid and the rock, the vertical temperature gradient, and the height and the permeability of the fault zone. Vigorous fluid flow causes low temperature gradients over a large region of the fault zone. In such a case, flow across lithological interfaces becomes the most important mechanism for the formation of sharp chemical reaction fronts. The degree of rock buffering, the extent and intensity of alteration, the alteration mineralogy and in some cases the formation of ore deposits are controlled by the magnitude of the flow velocity across these compositional interfaces in the rock. This indicates that alteration patterns along compositional boundaries in the rock may provide some insights into the convection pattern. The advective mass and heat exchanges between the fault zone and the wallrock depend on the permeability contrast between the fault zone and the wallrock. A high permeability contrast promotes focussed convective flow within the fault zone and diffusive exchange of heat and chemical reactants between the fault zone and the wallrock. However, a more gradual permeability change may lead to a regional-scale convective flow system where the flow pattern in the fault affects large-scale fluid flow, mass transport and chemical alteration in the wallrocks. © 2009 Elsevier B.V.

Lu Y.,Shanghai JiaoTong University | Hu X.-B.,Central South University
Oncology Reports | Year: 2014

Complement system activation contributes to various immune and inflammatory diseases, as well as cancers. However, the role of complement activation in the proliferation of cancer cells is not clear. In the present study, we investigated the consequences of complement activation on the proliferation of breast cancer cells and its possible mechanisms. We focused our study on the potential roles of the anaphylatoxins C3a and C5a in the proliferation of human breast cancer, as two important immune mediators generated after complement activation. Our study revealed that C5a stimulation, but not C3a, enhanced the proliferation of human breast cancer cells in vitro. Moreover, the expression of response gene to complement 32 (RGC-32) was pronounced in breast cancer cells in response to C5a stimulation. Notably, blockade of the C5a receptor markedly reduced the expression of RGC-32 and the proliferation of breast cancer cells stimulated by C5a. Meanwhile, silencing of RGC-32 expression reduced the proliferation of breast cancer cells induced by C5a treatment. Further investigation revealed that Akt activation was involved in C5a-induced RGC-32 expression and breast cancer cell proliferation. In conclusion, the present study indicates that C5a may promote the proliferation of breast cancer cells through Akt1 activation of the RGC-32 gene.

Mamady K.,Central South University
Journal of Environmental and Public Health | Year: 2016

Waste indiscriminate disposal is recognized as an important cause of environmental pollution and is associated with health problems. Safe management and disposal of household waste are an important problem to the capital city of Guinea (Conakry). The objective of this study was to identify socioeconomic and demographic factors associated with practice, knowledge, and safety behavior of family members regarding household waste management and to produce a remedial action plan. I found that no education background, income, and female individuals were independently associated with indiscriminate waste disposal. Unplanned residential area was an additional factor associated with indiscriminate waste disposal. I also found that the community residents had poor knowledge and unsafe behavior in relation to waste management. The promotion of environmental information and public education and implementation of community action programs on disease prevention and health promotion will enhance environmental friendliness and safety of the community. © 2016 Keita Mamady.

Lu A.,Central South University
Comments on Inorganic Chemistry | Year: 2011

Crystal and transparent ceramics have been considered to be a new generation of materials with a very important role in secure and economic sustainable development. In this paper, the advantages and disadvantages among highly crystalline transparent glass ceramics, crystals, and ceramics have been compared, including their chemical composition, preparation technology, and the equipment requirement of the materials. Based on the author's knowledge and understanding, the possibility of highly crystalline transparent glass ceramics substituting for crystals or ceramics has been discussed. The present situation and newest progress in the research of highly crystalline transparent glass ceramics have been introduced. The attractive opportunities and difficult challenges in this research direction are shown in this article. In particular, this paper focuses on some ideas from the author, rather than a simple introduction to the existing situation and research progress of transparent materials. © 2011 Copyright Taylor and Francis Group, LLC.

Ye H.,Central South University
IEEE Transactions on Automatic Control | Year: 2014

The saturated delayed feedback is presented to globally stabilize a class of feedforward nonlinear systems whose nominal dynamics is the cascade of multiple oscillators and multiple integrators. Key strategies are stated as follows. 1) To compensate the arbitrarily large input delay and to carry out the recursive analysis, we transform the concerned system into a normal form. 2) In the convergence analysis for multiple oscillators that are relatively difficult to treat, we combine the saturated delayed terms, define the composite Lyapunov functions and use the Cauchy formula. 3) For ease of the analysis on nonlinear terms, we employ saturation levels to restrict them. As applications, the usual feedforward nonlinear systems (with multiple integrators as the nominal dynamics) and the null-controllable linear systems are dealt with in some new manners; and a saturated delayed controller is presented for the well-known TORA system. © 1963-2012 IEEE.

Yang M.-G.,Central South University | Li C.-Y.,T.Y. Lin. International Engineering Consulting China CO. | Chen Z.-Q.,Hunan University
Engineering Structures | Year: 2013

Non-linear hysteresis is a complicated mechanical characteristic for magneto-rheological (MR) damper. In this paper, a new simple non-linear hysteretic model for MR damper is proposed to represent the hysteretic behavior. First, the force-displacement and force-velocity loops under a range of currents, amplitudes and frequencies are obtained by mechanical behavior test of a RD1097 type MR damper. Then the model's parameters are identified by the non-linear least square method from test data and fitted by the polynomials as functions of the supplied current. Finally, the accuracy and the effectiveness of the model are demonstrated by the RMS errors comparison between the reconstructed hysteretic curves and the experimental ones, and further are verified by seismic response reduction experiment under three excitations including the sinusoidal wave, the Pingsheng Bridge earthquake wave and the El-Centro wave. The results show that the proposed model has higher accuracy than some of existing models with explicit functions and is easier to be identified than those models with non-linear differential equations. Therefore, the proposed model can be effectively applied to simulation analysis in engineering control subjected to frequency-fixed or random excitations. © 2013 Elsevier Ltd.

Tong J.,Thomas Jefferson University | Tong J.,Central South University | Huang C.,Thomas Jefferson University | Bi F.,Thomas Jefferson University