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Unexpected 1,3-Dipolar Cycloaddition Reaction of Thiazolo[3,2-a]pyrimidine Derivatives and Nitrilimine

Chinese Journal of Chemistry 2011年第4期29卷 741-744页

作者：李筱芳刘浩冲刘彬郑爱庭李国斌于贤勇易平贵 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 1,3-dipolar cycloaddition reactions of nitrilimine with thiazolo[3,2-a]pyrimidine derivatives was investigated. Bis-cycloadducts were obtained through a domino 1,3-dipolar cycloaddition/ring-opening/ring-opening/ 1,3-dipolar cycloaddition processes. The structures of the products were characterized thoroughly by NMR, IR, MS, elemental analysis together with X-ray crystallographic analysis.

关键词： 1,3-dipolar cycloaddition thiazolo[3,2-a]pyrimidine nitrilimine reaction mechanism synthesis

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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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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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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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Synthesis of N-confused Porphyrin Derivatives with Substituted 3-C Position

Synthesis of N-confused Porphyrin Derivatives with Substitut...

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中国化学会第八届全国无机化学学术会议

作者： Bin Liu Xiaofang Li 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 411201China 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

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Improved stability criteria for time-varying delayed T–S fuzzy systems via delay partitioning approach

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Fuzzy Sets and Systems 2011年第1期185卷 83-94页

作者： Jiyao An Guilin Wen The Key Laboratory of Advanced Design and Simulation Techniques for Special Equipment (Ministry of Education) the State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha 410082 PR China College of Information Science and Engineering Hunan University Changsha 410082 PR China

This paper focuses on the stability analysis for uncertain Takagi–Sugeno (T–S) fuzzy systems with interval time-varying delay. The uncertainties of system parameter matrices are assumed to be time-varying and norm-bounded. Some new Lyapunov–Krasovskii functionals (LKFs) are constructed by nonuniformly dividing the whole delay interval into multiple segments and choosing different Lyapunov functionals to different segments in the LKFs. By employing these LKFs, some new delay-derivative-dependent stability criteria are established for the nominal and uncertain T–S fuzzy systems in a convex way. These stability criteria are derived that depend on both the upper and lower bounds of the time derivative of the delay. By employing the new delay partitioning approach, the obtained stability criteria are stated in terms of linear matrix inequality (LMI). They are equivalent or less conservative while involving less decision variables than the existing results. Finally, numerical examples are given to illustrate the effectiveness and reduced conservatism of the proposed results.

关键词： Uncertain system T–S fuzzy system Delay-derivative-dependent stability Interval time-varying delay Linear matrix inequality (LMI)

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Determination of Trace Iron in Chinese Herbal Medicine Using CdS Quantum Dots as Fluorescence Probes

Determination of Trace Iron in Chinese Herbal Medicine Using...

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2011 SSITE International Conference on Future Material Research and Industry Application(FMRIA 2011)

作者： Yunlong Zeng Xiafei Li Chunran Tang Haowen Huang Yajing Wang Zhonghua Su Huan Zhao Yamei Hu Jin Li Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China School of Chemistry and Chemical Engineering Hunan University of Science and Technology State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University

A simple A green protocol for synthesis of high quality, water-soluble and biocompatible Cd S QDs have been developed in aqueous solution with amylum as stabilizing agentThe QDs were characterized by AMF and spectral methodsA fluorescence quenching method was developed for determination of iron(ΙΙΙ) with water soluble Cd S quantum dots(QDs) as fluorescence probeIn p H 8.5 boric acid–borax buffer solution, the QDs show a high selective to ferric ionThe common cations, such as Ca2+, Mg2+, Zn2+, Fe2+ et al, have no effect on interference but copper ionThe fluorescence intensity of the QDs decreased linearly with the iron(QDs) concentration in the range of 200 μM to 60 n M with a detection limit of 20 n MIt has been applied to determinate of iron in Angelica, Astragalus, Shouwu, ligusticum wallichii and radix rehmanniae recen.

关键词： Trace iron chinese herbal medicine quantum dots fluorescence probe amylum modified cds quantum dots

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