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Pairwise entanglement and local polarization of Heisenberg model

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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 physics, xi’an institute of Post and Telecommunications, xi’an 710061, china 2 Beijing National Laboratory for Condensed Matter physics, institute of physics, Chinese Academy of Sciences, Beijing 100080, china 3 institute of modern physics, northwest university, xi’an 710069, china 4 Department of physics, Ningbo university, Ningbo 315211, 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 physics 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

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煤自燃初期的反应机理研究

燃料化学学报 2004年第6期32卷 652-657页

作者：石婷邓军王小芳文振翼西北大学化学系陕西西安710069 西安科技大学陕西西安710054

从实验得到的可能引起煤自燃的8个活性基团入手,提出了一系列简单煤分子模型,利用密度泛函DFT 6 31G对其完成了几何优化,计算了包括反应焓变、吉布斯自由能和活化能等,从热力学和动力学角度分析了计算结果。基于理论计算获得了煤活性基... 详细信息

从实验得到的可能引起煤自燃的8个活性基团入手,提出了一系列简单煤分子模型,利用密度泛函DFT 6 31G对其完成了几何优化,计算了包括反应焓变、吉布斯自由能和活化能等,从热力学和动力学角度分析了计算结果。基于理论计算获得了煤活性基团的活泼性次序,得出了煤自燃初期的反应机理主要是氧分子先进攻煤分子中的活性基团,产生活泼性很高的中间体,然后中间体进一步反应得到水或二氧化碳及其他反应产物,计算结果与实验基本符合。

关键词：煤活性基团活化能反应饥理

Potential energy surfaces for low-lying electronic states of SO_2

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Science china Chemistry 2006年第4期49卷 289-295页

作者： LI Anyang1, SUO Bing2, WEN Zhenyi2 & WANG Yubin2 1. Shanxi Key Laboratory of Physico-inorganic Chemistry, Department of Chemistry, northwest university, xi’an 710069, china 2. institute of modern physics, northwest university, xi’an 710069, china Shanxi Key Laboratory of Physico-inorganic Chemistry Department of Chemistry Northwest University Xi’an China institute of modern physics Northwest University Xi’an China

The potential energy surfaces for the nine low-lying electronic states of SO2 have been constructed by using the multi-reference second order perturbation theory (MRPT2) with the basis set cc-pVTZ. The optimized geometries and the adiabatic excitation energies of these states are in good agreement with experiments and previous calculations. The crossings and avoided crossings dis- played in the potential energy surfaces are expounded.

关键词： cross of PES, MRPT2, SO2 (sulfur dioxide).

Classification and Functional Separable Solutions to Extended Nonlinear Wave Equations

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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 physics, 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 institute of modern physics 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

Thermal decomposition of Pr[（C5H8NS2）3(C12H8N2)]

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Science china Chemistry 2005年第S1期48卷 83-87页

作者： GUO Pengjiang,JIAO Baojuan,CHEN Sanping,HU Rongzu,GAO Shengli & SHI Qizhen Department of Chemistry,northwest university Shaanxi Key Laboratory of Physico-lnorganic Chemistry,xi'an 710069,china Department of Mathematics,northwest university,xi'an 710069,china xi'an modern Chemistry Research institute,xi'an 710065,china Shaanxi Key Laboratory of Physico-inorganic Chemistry Department of Chemistry Northwest University Xi'an 710069 China Department of Mathematics Northwest University Xi'an 710069 China xi'an modern Chemistry Research institute Xi'an 710065 China

The thermal behavior of the complex Pr[(C5H8NS2)3(C12H8N2)] in a dry nitrogen flow was examined by TG-DTG analysis. The TG-DTG investigations indicated that Pr[(C5H8NS2)3-(C12H8N2)] was decomposed into Pr2S3 and deposited carbon in one step where Pr2S3 predominated in the final products. The results of non-isothermal kinetic calculations showed that the decomposition stage was the random nucleation and subsequent growth mechanism (n = 2/3), the corresponding apparent activation energy ?was 115.89 kJ·mol-1 and the pre-expo-nential constant ln[A/s] was 7.8697. The empirical kinetics model equation was proposed as/(α) =3/2(1-α)[-ln(1-α)]1/*** X-ray powder diffraction patterns of the thermal decomposition products at 800℃under N2 atmosphere show that the product can be indexed to the cubic Pr2S3 phase. The transmission electron microscopy (TEM) of the final product reveals the particle appearance of a diameter within 40 nm. The experimental results show that the praseodymium sulfide nanocrystal can be prepared from thermal decomposition of Pr[(C5H8NS2)3(C12H8N2)].

关键词： Pr[(C5H8NS2)3(C12H8N2)] thermal analysis kinetics noncrystal characteristics

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

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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 modern physics, 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

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

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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 physics institute and, Key Laboratory of physics 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/ 3-21G *(based on semi-empirical method UAM1 and ab initio method UHF/3-21G*). The com- putation results with UB3LYP/3-21G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-21G * The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (298, 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/3-21G

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

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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 modern 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

THE BETHE-SALPETER EQUATION OF SUPERSTRINGS

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Science china Mathematics 1989年第3期32卷 305-315页

作者：卫华阮图南 university of Science and Technology of china Hefei Present address: Institute of Modern Physics Northwest University 710069 Xi'an Shaanxi. university of Science and Technology of china Hefei

The concept of bound states for superstrings is analyzed, and using Schwinger’s func-tional method, the equation of the 4-string Green functionals for superstring fields, theequation of corresponding wave functionals... 详细信息

关键词： superstring field theory Schwinger’s functional method Dyson’s equations Bethe-Salpeter equation.