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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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Using unmodified Au nanoparticles as colorimetric probes for TNT based on their competitive reactions with melamine

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Chinese Chemical Letters 2014年第9期25卷 1271-1274页

作者： Xiao-Dong Xia Hao-Wen Huang Key Laboratory of Theoretical Chemistry and Molecular Simulation Minister of EducationSchool of Chemistry and Chemical EngineeringHunan University of Science and Technology

Gold nanoparticles （Au NPs） can serve as visualized colorimetric probes for various targets and modification-free sensing strategies are preferred. The donor-acceptor interaction between the electron-rich melamine （MA） and the electron-deficient trinitrotoluene （TNT） allows formation of a supramolecule in aqueous solution. Melamine alone makes the initially individual reddish Au NPs aggregate into gray/blue Au NP assemblies due to melamine forming multiple ligand sites toward the Au NPs. Interestingly, the preformed supramolecule of MA-TNT disenables aggregation of the Au NPs. Therefore the unmodified Au NPs provide facile colorimetric probes for TNT detection in aqueous solution. Rapid identification of TNT is established by naked eye inspection. By using spectrophotometer tools, quantification of TNT is accomplished with a linear range of 80μmol L-1 to 1.2 mmol/L-1 and a limit of detection （LOD） of 27μmol/L^-1. In contrast to previous strategy with surface-modified Au NPs, here a modification-free sensing strategy for TNT assay has been developed with greater convenience, rapidity, and cost-effectiveness.

关键词： Electron donor-acceptor interaction Gold nanoparticles Melamine Trinitrotoluene Colorirnetry

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An Improved Third-order CWENO-Z Scheme at critical points 2

An Improved Third-order CWENO-Z Scheme at critical points

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2019 2nd International Conference on Advanced Materials, Intelligent Manufacturing and Automation, AMIMA 2019

作者： Tang, Shujiang Li, Mingjun Han, Shuang School of Mathematics and Computational Science Xiangtan University Xiangtan Hunan411105 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan Hunan411105 China

In this paper, by modifying the smoothness factor of the third-order CWENO scheme, we present the two-parameter CWENO-NZ3 scheme to improve accuracy at critical points. We selected some classical examples for numerical simulation, such as one-dimensional Sod shock tube, Shock-entropy wave interaction, Riemann problem with strong discontinuity and Rayleigh-Taylor instability problem. Numerically comparing with the classical third-order CWENO schemes, it is found that the improved schemes not only improve accuracy and resolution at the extreme points, but also reduce dissipation. © Published under licence by IOP Publishing Ltd.

关键词： Shock tubes

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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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Synthesis ofOxadiazolo[4,5-a]thiazolo[2,3-b]pyrimidin-9(10H)-ones via 1,3-Dipolar Cycloaddition of Nitrile Oxide to Thiazolo[3,2-a]pyrimidin-3-one Derivatives

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中国化学(英文版) 2010年第6期28卷 977-980页

作者： Li Xiaofang Zheng Aiting Liu Bin Yu Xianyong Yi Pinggui Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education & Hunan Province College Key Laboratory of QSAR/QSPRSchool of Chemistry and Chemical EngineeringHunan University of Science and TechnologyXiangtanHunan 411201Ch

A new class of[1,2,4]oxadiazolo[4,5-a]thiazolo[2,3-b]pyrimidin-9(10H)-one was prepared in moderate yields by the reaction of nitrile oxide with 2-arylmethylidene-6,7-dihydro-5H-thiazolo[3,2-a]*** reaction site of dipolarphile is the C=N of thiazolo[3,2-a]pyrimidin-3-one rather than the expected C=C of *** structures of the products were characterized thoroughly by IR,elemental analysis,MS,and NMR analysis.

关键词： thiazolo[3,2-a]pyrimidine 1,3-dipolar cycloaddition nitrile oxide [1,2,4]oxadiazolo[4,5-a]thiazolo[2,3-b]pyrimidin-9(10H)-one

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Tuning plasmon absorption of unmodified silver nanoplates for sensitive and selective detection of copper ions by introduction of ascorbate

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Chinese Chemical Letters 2014年第10期25卷 1403-1406页

作者： Xiao-Dong Xia Tian-Lun Wang Xiao-Yuan Yuan Key Laboratory of Theoretical Chemistry and Molecular Simulation Minister of EducationSchool of Chemistry and Chemical EngineeringHunan University of Science and Technology

Silver nanoplates as novel optical sensors for Cu^2＋ detection have been *** nanoplates are synthesized via previous H_2O_2-NaBH_4 cyclic oxidation-reduction *** introduction of ascorbate as mild reductants,Cu^2＋ ions are reduced into Cu~＋ and the Cu^＋ is further reduced to Cu,which is deposited on the surface of the silver *** deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon ***,trace Cu^2＋ can be *** shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu^2＋concentration over a range of 40-340 μmol L^（-1） with a limit of detection of 9.0 μmol L^（-1）.Moreover,such silver nanoplate-based optical sensors provide good selectivity for Cu^2＋ detection,and most other metal ions do not disturb its ***,the practicality of the proposed sensor was *** Cu^2＋assay is advantageous in its simplicity,selectivity,and cost-effectiveness.

关键词： Silver nanoplate Plasmon absorption Wavelength shift Optical sensor Copper ions Ascorbate

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引用

Current Bioinformatics 2014年第3期9卷 218-227页

作者： Chen, Xiao-Su Yu, Zu-Guo Zheng, Juan Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University Hunan411105 China School of Mathematical Sciences Queensland University of Technology GPO Box 2434 BrisbaneQ 4001 Australia School of Information and Engineering Xiangtan University Hunan411105 China

Whole genome sequences are generally accepted as excellent tools for studying evolutionary relationships. Due to the problems caused by the uncertainty in alignment, existing tools for phylogenetic analysis based on multiple alignments could not be directly applied to the whole-genome comparison and phylogenomic studies. There has been a growing interest in alignment-free methods for phylogenetic analysis using complete genome data. The "distances" used in these alignment-free methods are not proper distance metrics in the strict mathematical sense. In this study, we first review them in a more general frame — dissimilarity. Then we propose some new dissimilarities for phylogenetic analysis. Last three genome datasets are employed to evaluate these dissimilarities from a biological point of view. © 2014 Bentham science Publishers.

关键词： Alignment

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Gradient Recovery-Type a Posteriori Error Estimates for Steady-State Poisson-Nernst-Planck Equations

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Advances in Applied Mathematics and Mechanics 2020年第6期12卷 1353-1383页

作者： Ruigang Shen Shi Shu Ying Yang Mingjuan Fang School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtanHunan 411105China School of Mathematics and Computational Science Guangxi Colleges and Universities Key Laboratory of Data Analysis and ComputationGuilin University of Electronic TechnologyGuilinGuangxi 541004China School of Mathematics and Computational Science Guilin University of Electronic TechnologyGuilinGuangxi 541004China

In this article,we derive the a posteriori error estimators for a class of steadystate Poisson-Nernst-Planck *** the gradient recovery operator,the upper and lower bounds of the a posteriori error estimators are established both for the electrostatic potential and *** is shown by theory and numerical experiments that the error estimators are reliable and the associated adaptive computation is efficient for the steady-state PNP systems.

关键词： Poisson-Nernst-Planck equations gradient recovery a posteriori error estimate

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Mathematical simulation of Cloaking Metamaterial Structures

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Advances in Applied Mathematics and Mechanics 2012年第1期4卷 93-101页

作者： Jichun Li Yunqing Huang Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtan 411105China Department of Mathematical Sciences University of Nevada Las VegasLas VegasNevada 89154-4020USA

In this paper we present a rigorous derivation of the material parameters for both the cylinder and rectangle cloaking *** results using these material parameters are presented to demonstrate the cloaking effect.

关键词： Maxwell’s equations metamaterial finite element method cloaking structures

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Some applications of nonlinear science methods and support vector machine methods to protein problems

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Mini-Reviews in Organic Chemistry 2015年第6期12卷 493-505页

作者： Hana, Guo Sheng Yu, Zu-Guo Zhao, Zhi-Qin Hunan Key Laboratory for Computation and Simulation in Science and Engineering and Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education Xiangtan University XiangtanHunan411105 China School of Mathematical Sciences Queensland University of Technology GPO Box 2434 BrisbaneQ4001 Australia

Protein folding, prediction of protein structure and functions are most important problems in bioinformatics. The protein fold process mainly reflects in the kinetic order of folding. Predicting the structural classes of low-homology protein is a difficult problem in the prediction of protein structure. In order to understanding the mechanism of programmed cell death, it is very necessary to obtain the information about subcellular locations and functions of apoptosis proteins. Predicting protein subnuclear localizations is a challenging problem which is harder than predicting protein subcellular locations. Predicting membrane protein types is related to the structure and function of proteins. In this review, we introduce some applications of nonlinear science methods and support vector machine methods to the above protein problems. The nonlinear science methods including the horizontal visibility network, kernel method, recurrence quantification analysis, global descriptor, Lempel-Ziv complexity, and Hilbert-Huang transform are used to extract features in these approaches. © 2015 Bentham science Publishers.

关键词： Support vector machines

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