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Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2.molecule

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2. SUN Weiguo1, HOU Shilin3 & FENG Hao4 1. institute of physics, College of Chemical Engineering, Sichuan {2., Chengdu 610065, china 2. institute of theoretical physics, xihua Normal {2., nanchong 63.002. china 3. Department of physics, china Oceanography {2., Qingdao 2.6003, china 4. College of physics, Sichuan {2., Chengdu 610065, china 1. institute of physics College of Chemical Engineering Sichuan University 610065 Chengdu China 2. institute of theoretical physics Xihua Normal University 637002 Nanchong China 3. Department of physics China Oceanography University 266003 Qingdao China 4. College of physics Sichuan University 610065 Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2.molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

DFT study of the conductance of molecular wire:The effect of coupling geometry and intermolecular interaction on the transport properties

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Science china Chemistry 2006年第6期49卷 492-498页

作者： QI Yuanhua1,2. GUAN Daren1 & LIU Chengbu1 1. institute of theoretical Chemistry, Shandong {2., Jinan 2.0100, china 2. School of physics and Microelectronics, Shandong {2., Jinan 2.0061, china 1. institute of theoretical Chemistry Shandong University Jinan 250100 China 2. School of physics and Microelectronics Shandong University Jinan 250061 China

The density functional theory (DFT) combining with the non-equilibrium Green functions (NEGF) method is applied to the study of the electronic transport properties for a Di-thiol-benzene (DTB) molecule coupled to two Au(111) surfaces. The dependence of the transport properties on the bias, the coupling geometry of the molecule-electrode interface, and the intermolecular interaction are examined in detail. The results show that the existence of the hydrogen atom at the end of the DTB molecule would significantly decrease the transmission coefficients, and then the differential conductance (dI/dV). By changing the position of the DTB molecule located between two electrodes a maximum value of calculated current is observed. It is also found that the intermolecular interaction will strongly influence the transport properties of the system studied.

关键词： non-equilibrium Green functions method, transmission spectrum, the molecular projected selfconsistent Hamiltonian, projected density of state.

The lepton flavor violating signal of the extra gauge boson Z′in photon-photon collision at the ILC

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1992-1997页

作者： LIU GuoLi 1,2.1 physics Department,Zhengzhou university,Zhengzhou 450001,{2. 2.Kavli institute for theoretical physics {2.,Chinese Academy of Sciences,Beijing 100190,{2. 1. physics Department Zhengzhou University Zhengzhou 450001 China2. Kavli Institute for Theoretical Physics China Chinese Academy of Sciences Beijing 100190 China

The hitherto unconstrained lepton flavor mixings,induced by the new gauge boson Z ,which are the prediction of many new physics models,such as topcolor-assisted technicolor (TC2. models and flavor-universal TC2.models,may lead to the lepton flavor violating productions of τμˉ,τeˉ and μeˉ in photon-photon collision at the proposed International Linear Collider (ILC).Through a comparative analysis of these processes,we find that the better channel to probe the new physics models is the production of τμˉ or τeˉ which occurs at a much higher rate than μeˉ production due to the large mixing angle and the large flavor changing coupling,and may reach the detectable level of the ILC for a large part of the parameter *** the rates predicted by the Standard Model are far below the detectable level,these processes may serve as a sensitive probe for such new physics models.

关键词： new gauge boson Z lepton flavor violating processes photon-photon

Adjoint method for the optimum planning of industrial pollutant sources

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Science china Earth Sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2. HU Fei2.& ZHU Jiang2.1. College of Environmental Sciences, Peking university, Beijing 100871, china 2. LAPC, {2. of Atmospheric physics, Chinese Academy of Sciences, Beijing 10002., china 1. College of Environmental Sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1949-1952页

作者： YANG JinMin 1,2.1 Department of physics,Henan Normal university,Xinxiang 453007,{2. 2.institute of theoretical physics,Chinese Academy of Sciences,Beijing 100190,{2. 1. Department of physics Henan Normal University Xinxiang 453007 China2. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw *** work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the ***,supersymmetry can be probed via these decays at GigaZ.

关键词： Z-decay GigaZ supersymmetry

Maximal possible accretion rates for slim disks

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Science china(physics,Mechanics & Astronomy) 2009年第12期52卷 2054-2058页

作者： LIN YiQing1 & JIAO ChengLiang2.1 Department of Mathematics and physics,Xiamen university of Technology,Xiamen 36102.,{2. 2.Department of physics and institute of theoretical physics and Astrophysics,Xiamen university,Xiamen 361005,{2. 1. Department of Mathematics and physics Xiamen University of Technology Xiamen 361024 China 2. Department of physics and institute of {2. physics and Astrophysics Xiamen University Xiamen 361005 China

It was proved in the previous work that there must be a maximal possible accretion rate $ \dot M_{max} $ for a slim disk. Here we discuss how the value of $ \dot M_{max} $ depends on the two fundamental parameters of the disk, namely the mass of the central black hole M and the viscosity parameter α. It is shown that $ \dot M_{max} $ increases with decreasing α, but is almost independent of M if $ \dot M_{max} $ is measured by the Eddington accretion rate $ \dot M_{Edd} $ , which is in turn proportional to M.

关键词： accretion disks black hole physics hydrodynamics

Isospin-dependent relativistic microscopic optical potential in the Dirac Brueckner-Hartree-Fock method

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Science china(physics,Mechanics & Astronomy) 2004年第2期47卷 189-198页

作者： RONG Jian1 & MA Zhongyu1,2.3 1. china institute of Atomic Energy, Beijing 102.13, china 2. Center of Nuclear theoretical physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lan-zhou 730000, china 3. institute of theoretical physics, Chinese Academy of Sciences, Beijing 100080, china Correspondence should be addressed to Rong Jian (email: jrong@***) 1. china institute of Atomic Energy 102413 Beijing China 2. Center of Nuclear theoretical physics National Laboratory of Heavy Ion Accelerator of Lanzhou 730000 Lanzhou China 3. institute of theoretical {2. Chinese Academy of Sciences 100080 Beijing China

The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-energy in nuclear matter is adopted. The self-energy of a nucleon with E > 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-energy. The energy and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the energy dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.

关键词： Dirac Brueckner Hartree-Fock, relativistic microscopic optical potential, asymmetric nuclear matter, isospin-dependence.

Light A physics in the lepton-specific two-Higgs doublet model

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1981-1987页

作者： CAO JunJie 1,HENG ZhaoXia 2.3 & WAN PeiHua 1 1 College of physics & Information Engineering,Henan Normal university,Xinxiang 453007,{2. 2.Key Laboratory of Frontiers in theoretical physics,institute of theoretical physics,Chinese Academy of Sciences,Beijing 100190,{2. 3 Kavli institute for theoretical physics {2.,Chinese Academy of Sciences,Beijing 100190,{2. 1. College of physics & Information Engineering Henan Normal University Xinxiang 453007 China2. Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China3. Kavli Institute for Theoretical Physics China Chinese Academy of Sciences Beijing 100190 China

We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and discuss its phenomenology at colliders in the allowed parameter *** constraints we consider come from the precision electroweak data,the direct search for Higgs boson,the muon anomalous magnetic moment,as well as some theoretical consistency *** find that in the allowed parameter space the CP-odd Higgs boson A is rather light (m A < 30 GeV with 95% possibility),which is composed dominantly by the leptonic Higgs and decays dominantly into τ + τ;while the SM-like Higgs boson h (responsible largely for electroweak symmetry breaking) decays dominantly in the mode h → AA → 4τ with a large decay width,which will make the Higgs discovery more difficult at the ***,this scenario predicts rare Z decays Z → AAA and Z →τ + τA with their branching ratios ranging from 10-8 to 10-and 10-5 to 10-4 respectively,which may be accessible at the GigaZ option of the ILC.

关键词： Lepton-specific two-Higgs doublt model light Higgs boson A Z decays

The dynamical properties of Rydberg hydrogen atom near a metal surface

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Science china(physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2. DU Mengli3 & LIN Shenglu1 1. College of physics and Electronics, Shandong Normal university, Jinan 2.0014, {2. 2. Department of Mathematics and physics, Shandong institute of Architecture and Engineering, Jinan 2.0014, {2. 3. institute of theoretical physics, Chinese Academy of Sciences, Beijing 100080, {2. 1. College of physics and Electronics Shandong Normal University 250014 Jinan China 2. Department of Mathematics and physics Shandong Institute of Architecture and Engineering 250014 Jinan China 3. institute of theoretical {2. Chinese Academy of Sciences 100080 Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 2.. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.