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Theoretical Study of Structure, Energetic, Hydrogen Bonds Strength and Intramolecular Proton Transfer of 2-（2-R （R=OH, NH2, SH） Phenyl （or Pyridyl）） Benzoxazoles （or Benzothiazoles）

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Chinese Journal of Chemistry 2011年第4期29卷 650-654页

作者：易平贵彭洪亮汪朝旭于贤勇李筱芳梁永宏 Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan Province College Key Laboratory of QSAR/QSPR School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan Hunan 411201 China

The ground- and excited-state intramolecular proton transfer processes of 2-（2-R （R=OH, NH2, SH） phenyl （or pyridyl）） benzoxazoles （or benzothiazoles） are investigated by the DFT methods. The calculated results indicate that in the ground state there is a high correlation （R=0.9950） between the proton transfer barrier and the intramolecular hydrogen bonds （IMHB） strength. The increase of the strength of IMHB in the proton transfer processes leads to a larger barrier contributions. Intramolecular proton transfer process pathway is along with the minimal difference of change value in the IMHB angle. In the excited-state, there is a similar relationship between the IMHB and the bartier.

关键词： density functional calculations intramolecular proton transfer hydrogen bonds benzoxazole benzothiazole

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Novel nanoporous palladium catalyst for electroreduction of hydrogen peroxide

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Rare Metals 2011年第4期30卷 332-336页

作者： YI Qingfeng NIU Fengjuan School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan 411201 China Key Laboratory of Theoretical Chemistry and Molecular Simulation （Ministry of Education of China） Hunan University of Science and Technology Xiangtan 411201 China

Titanium-supported nanoporous palladium catalyst （Pd/Ti） was prepared by a hydrothermal method using PdC12 as a precursor, ethylenediamine tetraacetic acid （EDTA） as a ligand, and formaldehyde as a reduction agent. Complex Pd-EDTA^2- is favorable for the formation of Pd particles with nanoscale sizes. The electroactivity of the Pd/Ti catalyst towards the electroreduction of hydrogen peroxide in 1 mol/L NaOH solution was evaluated by voltammetric techniques. Both linear scan voltammetric and chronoamperometric data present significantly large steady-state reduction current density of the hydrogen peroxide electroreduction on the prepared Pd/Ti catalyst. The results show that the prepared Pd/Ti catalyst is an effective electrocatalyst for the electroreduction of hydrogen peroxide in alkaline media.

关键词： electrocatalysis nanoporous materials palladium hydrogen peroxide fuel cells

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Dependence Analysis of the Solutions on the Parameters of Fractional Delay Differential Equations

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Advances in Applied Mathematics and Mechanics 2011年第5期3卷 586-597页

作者： Shuiping Yang Aiguo Xiao Xinyuan Pan School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityHunan 411105China Department of Mathematics Huizhou UniversityGuangdong 516007China

In this paper,we investigate the dependence of the solutions on the parameters(order,initial function,right-hand function)of fractional delay differential equations(FDDEs)with the Caputo fractional *** results includi... 详细信息

关键词： Fractional delay differential equation Caputo fractional derivative dependence

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A Priori and a Posteriori Error Analysis of the Discontinuous Galerkin Methods for Reissner-Mindlin Plates

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Advances in Applied Mathematics and Mechanics 2011年第6期3卷 649-662页

作者： Jun Hu Yunqing Huang LMAM and School of Mathematical Sciences Peking UniversityBeijing 100871China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtan 411105HunanChina

In this paper,we apply an a posteriori error control theory that we develop in a very recent paper to three families of the discontinuous Galerkin methods for the Reissner-Mindlin plate *** derive robust a posteriori ... 详细信息

关键词： A posteriori error analysis Reissner-Mindlin plate finite element reduction integration

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A lowest order divergence-free finite element on rectangular grids

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中国数学前沿 2011年第2期6卷 253-270页

作者： Yunqing HUANG Shangyou ZHANG Department of Mathematical Sciences University of Delaware Newark DE 19716 USA Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan 411105 China

It is shown that the conforming Q2,1;1,2-Q'1 mixed element is stable, and provides optimal order of approximation for the Stokes equations on rectangular grids. Here, Q2,1;1,2 = Q2,1 × Q1,2, and Q2,1 denotes the space of continuous piecewise-polynomials of degree 2 or less in the x direction but of degree 1 in the y direction. Q'1 is the space of discontinuous bilinear polynomials, with spurious modes filtered. To be precise, Q'1 is the divergence of the discrete velocity space Q2,1;1,2. Therefore, the resulting finite element solution for the velocity is divergence-free pointwise, when solving the Stokes equations. This element is the lowest order one in a family of divergence-free element, similar to the families of the Bernardi-Raugel element and the RaviartThomas element.

关键词： Mixed finite element Stokes divergence-free element quadrilateral element rectangular grid

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A Posteriori Error Estimates of Mixed Methods for Quadratic Optimal Control Problems Governed by Parabolic Equations

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Numerical Mathematics(Theory,Methods and Applications) 2011年第4期4卷 439-458页

作者： Tianliang Hou Yanping Chen Yunqing Huang Hunan Key Laboratory for Computation and Simulation in Science and Engineering Department of MathematicsXiangtan UniversityXiangtan 411105HunanChina School of Mathematical Sciences South China Normal UniversityGuangzhou 510631GuangdongChina

In this paper,we discuss the a posteriori error estimates of the mixed finite element method for quadratic optimal control problems governed by linear parabolic *** state and the co-state are discretized by the high order Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise constant *** derive a posteriori error estimates for both the state and the control *** estimates,which are apparently not available in the literature,are an important step towards developing reliable adaptive mixed finite element approximation schemes for the control problem.

关键词： A posteriori error estimates quadratic optimal control problems parabolic equations mixed finite element methods

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Effects of substituent and solvent on the UV absorption energy of 4,4'-disubstituted stilbenes

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science China Chemistry 2011年第2期54卷 1735-1744页

作者： CAO ChenZhong CHEN GuanFan WU YaXin Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education Hunan Provincial University Key Laboratory of QSAR/QSPRSchool of Chemistry and Chemical EngineeringHunan University of Science and TechnologyXiangtan 411201China

Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter o-~c and polar substituent constant crp. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quantifying the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (ET(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.

关键词： 4,4'-disubstituted stilbene UV absorption energy excited-state substituent parameter solvent effect

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A LEGENDRE GALERKIN SPECTRAL METHOD FOR OPTIMAL CONTROL PROBLEMS

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Journal of Systems science & Complexity 2011年第4期24卷 663-671页

作者： Yanping CHEN Nianshi XIA Nianyu YI School of Mathematical Sciences South China Normal University Guangzhou 510631 China. The Faculty of Mathematics Chengyi College Jimei University Xiamen 361021 China. Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematicsand Computational Science Xiangtan University Xiangtan 411105 China.

This paper considers the Legendre Galerkin spectral approximation for the unconstralnea optimal control problems. The authors derive a posteriori error estimate for the spectral approximation scheme of optimal control problem. By choosing the appropriate basis functions, the stiff matrix of the discretization equations is sparse. And the authors use the Fast Legendre Transform to improve the efficiency of this method. Two numerical experiments demonstrating our theoretical results are presented.

关键词： Legendre-Galerkin optimal control spectral method.

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Mathematical simulation of Metamaterial Solar Cells

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Advances in Applied Mathematics and Mechanics 2011年第6期3卷 702-715页

作者： Jichun Li Yitung Chen Yang Liu Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityHunan 411105China Department of Mathematical Sciences University of Nevada Las VegasLas VegasNevada 89154-4020USA Department of Mechanical Engineering University of Nevada Las VegasLas VegasNevada 89154-4027USA

In this paper,we propose several solar cell designs based on *** numerical simulations of various designs with different materials are carried *** tests show that metamaterial solar cells are quite efficient,and over ... 详细信息

关键词： Maxwell’s equations metamaterial solar cell finite element method

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Convergent Adaptive Finite Element Method Based on Centroidal Voronoi Tessellations and Superconvergence

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Communications in Computational Physics 2011年第7期10卷 339-370页

作者： Yunqing Huang Hengfeng Qin Desheng Wang Qiang Du Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityHunan 411105China Department of Mechanical and Electronic Engineering School of Mechanical EngineeringXiangtan UniversityHunan 411105China Division of Mathematical Sciences School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Department of Mathematics Pennsylvania State UniversityUniversity ParkPA 16802USA

We present a novel adaptive finite element method(AFEM)for elliptic equations which is based upon the Centroidal Voronoi Tessellation(CVT)and superconvergent gradient *** constructions of CVT and its dual Centroidal Voronoi Delaunay Triangulation(CVDT)are facilitated by a localized Lloyd iteration to produce almost equilateral two dimensional *** with finite element solutions on such high quality triangulations,superconvergent recovery methods become particularly effective so that asymptotically exact a posteriori error estimations can be *** a seamless integration of these techniques,a convergent adaptive procedure is *** demonstrated by the numerical examples,the new AFEM is capable of solving a variety of model problems and has great potential in practical applications.

关键词： Finite element methods superconvergent gradient recovery Centroidal Voronoi Tessellation adaptive methods.

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