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Theoretical Study of 1,3-Dipolar Cycloaddition of Hydrazoic Acid to Substituted Ynamines

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Chinese Journal of Chemical Physics 2009年第2期22卷 143-148页

作者： Xiao-fang Chen Kun Yang ke-li han State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

The 1,3-dipolar cycloaddition reactions of various substituted ynamines with hydrazoic acid were theoretically investigated with the high-accuracy CBS-QB3 method. Two regioisomers, 4-amine, and 5-amine substituted adducts, were obtained, with the former as the preferred yield. This regioselectivity is rationalized by the frontier molecular orbital theory. The reactivity and synchronicity are enhanced with the increase of the electron-withdrawing character of the substitute on ynamine fragment. The calculations also show that the effect of solvent increases the activation energy, and the reaction becomes even harder in polar solvent.

关键词： 1,3-dipolar cycloaddition Hydrazoic acid Internal alkyne CBS-QB3 Solvent effect Substituent effect Frontier molecular orbital theory

Time-dependent Density Functional-based Tight-bind Method Efficiently Implemented with OpenMP Parallel and GPU Acceleration

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Chinese Journal of Chemical Physics 2013年第6期26卷 635-645,I0003页

作者： Guo-hong Fan ke-li han Guo-zhong He State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics ChineseAcademy of Sciences Dalian 116023 China

The time-dependent density functional-based tight-bind （TD-DFTB） method is implemented on the multi-core and the graphical processing unit （GPU） system for excited state calcu-lations of large system with hundreds or thousands of atoms. Sparse matrix and OpenMP multithreaded are used for building the Hamiltonian matrix. The diagonal of the eigenvalue problem in the ground state is implemented on the GPUs with double precision. The GPU- based acceleration fully preserves all the properties, and a considerable total speedup of 8.73 can be achieved. A Krylov-space-based algorithm with the OpenMP parallel and CPU acceleration is used for finding the lowest eigenvalue and eigenvector of the large TDDFT matrix, which greatly reduces the iterations taken and the time spent on the excited states eigenvalue problem. The Krylov solver with the GPU acceleration of matrix-vector product can converge quickly to obtain the final result and a notable speed-up of 206 times can be observed for system size of 812 atoms. The calculations on serials of small and large systems show that the fast TD-DFTB code can obtain reasonable result with a much cheaper computational requirement compared with the first-principle results of CIS and full TDDFT calculation.

关键词： Density-functional theory Tight-binding method Time-dependent densityfunctional theory Excited state Graphical processing unit Krylov iterative algorithm Sparse matrix OpenMP

Impact of Borate on Structure of Antifreeze Glycoproteins

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Chinese Journal of Chemical Physics 2021年第6期34卷 659-669,I0001,I0007-I0012页

作者： Feng-qin Long Tan Jin ke-li han Wei Zhuang State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

Antifreeze glycoproteins(AFGPs)facilitate the survival of various organisms in the polar region by preventing internal ice accumulation via an adsorption-inhibition *** of AFGP antifreeze activity by the borate buffers has been widely acknowledged as the direct experimental evidence supporting the hydroxyl,rather than methyl,binding *** the other hand,perturbation of borate binding on the AFGP configuration,which might have considerable influence on the binding efficiency of not only the hydroxyl but also the methyl groups,has rarely been quantitatively *** we studied,using molecular dynamics simulations,the perturbation on the configuration of a solvated AFGP8 protein induced by the binding of one single borate *** the freezing point,this binding not only makes the disaccharide groups adjacent to the borate-binding disaccharide close to each other but also affects the entire AFGP8 *** structural changes induced by the binding of borate on different disaccharide sidechains exhibit clear site-specificities and the effect of borate binding on the structural changes is significantly reduced at higher *** study is valuable for further understanding the relationship between the structure and antifreeze activity of these antifreeze glycoproteins.

关键词： Antifreeze glycoproteins Borate anions Molecular dynamics Clustering analysis

DFT Investigations About Pyrazine Molecules on Si(100)-2×1 Surface

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Chemical Research in Chinese Universities 2007年第4期23卷 444-451页

作者： YU Ang-yang QU Yong-quan han ke-li HE Guo-zhong Center for Computational Chemistry Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P. R. China

It is important to understand the interface of aromatic molecules on semiconductor surfaces because of the rich functionality of such molecules on semiconductor surfaces. The chemisorption of pyrazine molecules on the Si （100）- 2×1 surface has been investigated using the B3LYP density functional theory with Si9H12 one-dimer and Si15Hl6 two-dimer cluster models. The calculated results predict that N-dative bonded-state, C2=C5 [E4＋2] and the tight- bridgel,2,5,6 products may coexist on the Si（100）-2 × 1 surface.

关键词： Density functional theory Surface Activation energy Adsorption energy

恩格列净对射血分数保留型心力衰竭患者运动耐量的改善效果研究

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罕少疾病杂志 2024年第5期31卷 58-59,64页

作者：杨菊月宋建强韩克丽南阳师范学院校医院内科河南南阳473000 南阳市第一人民医院心血管内科河南南阳473000

目的观察恩格列净治疗射血分数保留型心力衰竭(HEpEF)的效果及对运动耐量改善的影响。方法前瞻性地选取2020年6月至2023年6月我院收治的73例HEpEF患者作为研究对象。根据数字随机表法随机分成给予沙库巴曲缬沙坦(36例,对照组)和恩格列净... 详细信息

目的观察恩格列净治疗射血分数保留型心力衰竭(HEpEF)的效果及对运动耐量改善的影响。方法前瞻性地选取2020年6月至2023年6月我院收治的73例HEpEF患者作为研究对象。根据数字随机表法随机分成给予沙库巴曲缬沙坦(36例,对照组)和恩格列净+沙库巴曲缬沙坦(37例,观察组)。对比疗效、运动耐量[代谢当量、峰值摄氧量(PeakVO_(2))、通气二氧化碳当量斜率(VE/VCO_(2)slope)]、生活质量[明尼苏达心力衰竭生活质量问卷(MLHFQ)]和安全性。结果观察组显效率56.76%(21/37),高于对照组的33.33%(12/36)(P0.05)。结论恩格列净治疗HEpEF可提高运动耐量改善效果,并提升预后效果,且安全性可靠。

关键词：心力衰竭恩格列净运动耐量心肺功能

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Transient Absorption of the Chlorophyll a in Ethanol

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Chinese Journal of Chemical Physics 2006年第1期19卷 6-10页

作者： Ying Shi Y. J. Shiu Charlene Su S.H. lin ke-li han State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 115023 Institute of Atomic and Molecular Sciences Academia Sinica.Taipei Department of Chemistry National Taiwan University Taipei

The excited state of Chlorophyll a is *** by ferntosecond transient absorption. The transient absorption spectra of Q band and By band of Chlorophyll a in ethanol have been observed. The fast kinetics of Chlorophyll a which exhibit two ultrafast components were also ineasured. The one is assigned to transient absorption of the inhomogencously broadened ground state absorption spectrum, while the other is the response of the solvent to the change of the electron configuration in the excited state due to solvation dynamics of the polar solvent molecules. To understand the anisotropy of Chlorophyll a in ethanol, the anisotropy profile was also performed by 405 nm excitation and found that the anisotropy profile is 0.143. The possible combination of θda, θdb and η at at excitation of By band has been simulated.

关键词： Femtosecond Chlorophyll a Transient absorption

Rh(Ⅱ) carbene S-H insertion into H_2S via the stepwise mechanism

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Chinese Chemical Letters 2007年第1期18卷 107-110页

作者： Zhen Feng liu Xian Fang Yue Qiang Wei ke li han State key Laboratory of Molecular Reaction Dynamics~ Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

The mechanism of Rh（Ⅱ） carbene S-H insertion into H2S in gas phase has been studied by B3LYP functional. Calculation results showed that the Rh（Ⅱ） carbene S-H insertion into H2S took only stepwise channels and n... 详细信息

关键词： Sulfonium ylides 1,2-Hydrogen shift Density functional calculations Dirhodium(Ⅱ) carbene

Insertion of O—H Bond of Rh(Ⅱ)-methylene Carbene into Alcohols: A Stepwise Mechanism More Plausible than a Concerted Mechanism

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Chemical Research in Chinese Universities 2007年第2期23卷 221-225页

作者： liU Zhen-feng WANG Yong YUE Xian-fang han ke-li State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dcdian 116023 P. R. China

The mechanisms of insertion of O-H bond of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol were studied by using B3LYP functional both in gas phase and in CH2 C12. The formation of free alcoholic oxonium ylides is found to be impossible. Alcoholic oxonium ylide are formed as the intermediates before beth the stepwise and the concerted transition states of insertion of O-H bend of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol. With re- gard to the mechanisms of insertion of O-H of Rh（ Ⅱ ） -methylene carbene into alcohols, analysis of the energy bartiers of the two mechanisms indicate that the stepwise mechanism is more plausible than the concerted mechanism.

关键词： Oxonium ylide 1,2-Hydrogen shift Density functional calculation Dirhodium( Ⅱ ) methylene carbene

Quantum Wave Packet Studies on F+HBr Reaction

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Chemical Research in Chinese Universities 2007年第1期23卷 96-100页

作者： QUAN Wei-long TANG Ping-ying TANG Bi-yu han ke-li Department of Physics Institute of Modern Physics Xiangtan University Xiangtan 411105 P. R. China School of Mathematics and Physics Lanzhou Jiaotong University Lanzhou 730070 P. R. China Center for Computational Chemistry and State key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P. R. China

Time-dependent quantum wave packet calculations were carried out for the F ＋ HBr reaction on the latest London-Erying-Polanyi-Sato potential energy surface constructed by Persky et al. The calculated reaction probabilities dramatically increase near the zero collision energy and then slightly decrease with increasing collision energy, which corresponds well to the behavior of a barrierless reaction. The effects of reagent HBr excitation were examined, it is shown that both the vibrational and the rotational excitations of reagent HBr have a negative effect on the reactivity of F ＋ HBr. The integral cross-section for the ground state of the reagent HBr decreases at a low collision energy and then becomes plat with increasing collision energy, which is reasonable for the feasibility of such an exothermal reaction. The rate constant that was obtained is slightly higher than that obtained in the quasi-classical trajectory calculation.

关键词： Barrierless reaction Reaction cross-section Rate constant Ro-vibrational excitation