检索结果-南通市图书馆

A modified multi-reference second order perturbation theory

在线全文

学校读者我要写书评

暂无评论

中国科学：化学英文版 2010年第4期53卷 933-939页

作者： LI AnYang1, HAN Huixian2. SUO BingBing3, WANG YuBin3 & WEN ZhenYi3 1institute of Computational Chemistry, Chongqing {2. of Post and Telecommunications, Chongqing 400065, China 2.epartment of {2., northwest university, xi’ an 710069, China 3institute of modern {2., northwest university, xi’ an 710069, China institute of Computational Chemistry Chongqing University of Post and Telecommunications Chongqing China Department of physics Northwest University Xi’ an China institute of modern{2. Northwest University Xi’ an China

A new scheme with extended model space is proposed to improve the calculation of multi-reference second order perturbation theory (MRPT2.. The new scheme preserves the concise code structure of the original program, and avoids intruder states in constructions of the potential energy surface, which is confirmed by a series of comparable calculations. The new MRPT2.program is an available tool for the research of molecular excited states and electronic spectrum.

关键词： perturbation theory multi-reference intruder state

Pairwise entanglement and local polarization of Heisenberg model

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2008年第10期51卷 1515-1522页

作者： xi xiaoQiang1,2. ZHANG Tao3, YUE RuiHong3,4 & LIU WuMing2.1 Department of Applied Mathematics and {2., xi’an institute of Post and Telecommunications, xi’an 710061, China 2.Beijing National Laboratory for Condensed Matter {2., institute of {2., Chinese Academy of Sciences, Beijing 100080, China 3 institute of modern physics, northwest university, xi’an 710069, China 4 Department of {2., Ningbo university, Ningbo 3152.1, China Department of Applied Mathematics and physics Xi’an Institute of Post and Telecommunications Xi’an China Beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China institute of modern{2. Northwest University Xi’an China Department of physics Ningbo University Ningbo China

The characteristics of pairwise entanglement and local polarization (LP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2.for odd qubit); LP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the LP, the smaller the probability, and the same LP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3412.(for odd-qubit chain) or 0.3491 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

Doubly contracted CI method and applications

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2004年第4期47卷 276-282页

作者： WANG Yubin1, HAN Huixian1, ZHAI Gaohong2.,SUO Bin1 & WEN Zheny1,2.1. institute of {2. {2., northwest university, xian 710069, China 2. Laboratory of Physico-Inorganic Chemistry, Department of Chemistry, northwest university, xian 710069,China Correspondence should be addressed to Wen Zhenyi institute of modern{2. Northwest University Xian China Laboratory of Physico-Inorganic Chemistry Department of Chemistry Northwest University Xi’an China

Based on the hole-particle correspondence an approximate so-called doubly contracted CI scheme is proposed. Examples calculated based on the doubly contracted CI (DCCI) scheme show that the number of configurations after contraction is reduced by three orders of magnitude, and the computation time is reduced by an order of magnitude. The examples also show that compared with experiments the DCCI and uncontracted CI have similar and reasonable accuracy to some spectroscopic parameters.

关键词： doubly contracted CI hole-particle symmetry approximate MRCI

AN AB INITIO SORBIE-MURREL POTENTIAL ENERGY SURFACE OF CARBON DISULFIDE

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1995年第5期6卷 411-414页

作者： Yu Bin WANG xin Ji HONG Zhen Yi WEN(institute of {2. {2., northwest university, xian 710069) NW Univ xian Inst Modern Phys Xian 710069 Peoples R China

In this letter ab initio electronic structure calculations are performed for extensive geometries Of CS2. A newly written program is used to fit the computed energies into the Sorbie-Murrel function, whose contour plo... 详细信息

关键词： AB AN AB INITIO SORBIE-MURREL POTENTIAL ENERGY SURFACE OF CARBON DISULFIDE

Vermiform trace fossils from the Precambrian Ruyang Group, western Henan

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第3期42卷 251-254页

作者： HU Jianmin, MENG Qingren and LI Wenhou1 xi’ an College of Geology, xi’an 710054, China 2. {2. of Geophysics, Chinese Academy of Sciences, Beijing 100101, China 3 Department of Geology, northwest university, xi’an 710069, China xi’an College of Geology Xi’an China institute of Geophysics Chinese Academy of Sciences Beijing China Department of Geology Northwest University Xi’an China

THE origin and evolution of Precambrian lives has been a long-standing controversial problem. It is now generally accepted by most paleontologists that the origin of metazoa can be traced back to more than 1000 Ma, because the Ediacara and latest pre-Ediacara fauna, such as the Huainan fauna, are featured by their diversification of forms, complicated structures

关键词： Precambrian trace fossil Ruyang Group.

High Performance Hydrophobic Interaction Chromatography-A New Approach to Separate Intermediates of Protein Folding──Ⅰ.Separation of Intermediates of Urea-unfolded α-Amylase

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第1期8卷 67-70页

作者： Quan BAI Yin Mao WEI Ming Hui GENG xin Du GENG(institute of {2. Separation Science northwest university xi’an, 710069) Inst. of modern Separation Science Northwest University Xi'an 710069 China Department of Chemistry Purdue University West Lafayette IN 47907 United States

Based on the different hydrophobicities of the intermediates of proteins the various conformational intermediates of the refolding of a-amylase originally denatured with 8.0 mol/L urea solution were separated with high performance hydrophobic interaction chromatography(HPHIC). Compared to the separation of the same intermediates with weak anion exchange chromatography and size-exclusion chromatography the result obtained with HPHIC is the best It would be expected that HPHIC may be a strongly potential tool to separate intermediates of some proteins which cannot be, or cannot completely be refolded by HPHIC.

关键词： Separation of Intermediates of Urea-unfolded OC High Performance Hydrophobic Interaction Chromatography-A New Approach to Separate Intermediates of Protein Folding Amylase

Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(39)Ar age dating of Dur'ngoi ophiolite

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第14期46卷 1203-1205页

作者： CHEN Liang, SUN Yong, PEI xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & CHEN Wen1. Laboratory of Continental Dynamics, northwest university,{2., China 2. Department of Geology, northwest university, xi’an, 710069, China 3. institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China Laboratory of Continental Dynamics Northwest University Xi’an China Department of Geology Northwest University Xi’an China institute of Geology Chinese Academy of Geological Sciences Beijing China

Whole rock 40Ar/39Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (345.3±7.9 Ma) with an isochorn age (336.6±7.1 Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.

关键词： Dur’ngoi ophlolite 40Ar -39Ar age Paleo-tethys.

DFT Thermodynamic Research of the Pyrolysis Mechanism of the Carbon Matrix PrecursorTol uene for Carbon Material

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2001年第2期17卷 219-225页

作者： WANG Hui, YANG Hai-feng, RAN xin-quan WEN Zheng-yi and SHI Qi-zhen (Chemistry Department, modern {2. {2. and, Key Laboratory of {2. Inorganic Chemistry of Shan-xi Province, northwest university, xi’an 710069, P. R. China) 西北大学陕西西安 710069

Based on the experiments, the standard enthalpy△H■of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-2.G *(based on semi-empirical method UAM1 and ab initio method UHF/3-2.G*). The com- putation results with UB3LYP/3-2.G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-2.G * The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (2.8, 773, 843, 963 and 1 073 K) were calculated. The thermodynamic computation result shows that when the pyrolysis temperature of toluene is lower than 963 K, the reaction path supported by thermody- namics is that the C-H bond of the methyl on the benzene ring breaks and bitoluene form, while the temperature increases (about 1 073 K), the thermodynamic calculation result turns to support the reaction path producing phenyl radicals and methyl radicals. This mechanism is in accord with the experiments.

关键词： Carbon/carbon composites Toluene Pyrolysis mechanism UB3LYP/3-2.G

Classification and Functional Separable Solutions to Extended Nonlinear Wave Equations

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2005年第10期44卷 589-596页

作者： ZHANG Shun--Li LOU Sen--Yue QU Chang--Zheng YUE Rui--Hong institute of modern{2., northwest university, xi'an 710069, China Department of Mathematics, northwest university, xi'an 710069, China Center of Nonlinear Science, Ningbo university, Ningbo 3152.1, China Department of{2., Shanghai Jiao Tong university, Shanghai 2.0030, China institute of modern{2. Northwest University Xi'an 710069 China Department of Mathematics Northwest University Xi'an 710069 China Center of Nonlinear Science Ningbo University Ningbo 315211 China Department of physics Shanghai Jiao Tong University Shanghai 200030 China

The generalized conditional Symmetry approach is applied to study the variable separation of the extendedwave equations. Complete classification of those equations admitting functional separable solutions is obtained ... 详细信息

关键词： nonlinear wave equations functional separable solutions generalized conditional symmetry