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Structural and microstructural transformations in Bi_2.r_2.a_(1-x)Y_xCu_2._(8+y) system

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Chinese Science Bulletin 1997年第3期42卷 192-196页

作者： SONG Chengyu, WEN Shulin and CHE Guangcan1. Shanghai institute of Ceramics, Chinese Academy of Sciences, Shanghai 2.0050, china 2. State Key Laboratory of Supercon-ductivity, institute of physics, Chinese Academy of Sciences, beijing 100080, china Shanghai institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2.u3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity o... 详细信息

SINCE the discovery of high-Tc superconductors, experiments have revealed that the phase diagrams of La2.xSrxCuO4 and YBa2./sub>Cu3O6+x resemble each other. The antiferromagnetic phase is commonly situated in the vicinity of the superconductive phase. In Bi-2.12.sys-

关键词： Bi2.r2.a1-xYxCu2.y substitution structural transformation.

Direct CP violation in hadronic B decays

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Science china(physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2.& Lü Caidian3 1. Department of physics, Lishui University, Lishui 32.000,china 2. Department of physics, Shanghai Jiaotong University, Shanghai 2.0030, china 3. institute of High Energy physics, beijing 100049,china su.edu Department of physics Lishui University Lishui 323000 China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

Mathematical stencil and its application in finite difference approximation to the Poisson equation

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Science china Mathematics 2005年第10期48卷 1421-1429页

作者： FENG Hui~1 ZHANG Baolin~(1,2. & LIU Yang~1 1. Department of Mathematics,Wuhan University,Wuhan 430072.china 2. Laboratory of Computational physics,{2. of Applied physics and Computational Mathematics,beijing 100088. china Department of Mathematics Wuhan University Wuhan China Laboratory of Computational physics Institute of Applied Physics and Computational Mathematics Beijing China

The concept of mathematical stencil and the strategy of stencil elimination for solving the finite difference equation is presented, and then a new type of the iteration algorithm is established for the Poisson equation. The new algorithm has not only the obvious property of parallelism, but also faster convergence rate than that of the classical Jacobi iteration. Numerical experiments show that the time for the new algorithm is less than that of Jacobi and Gauss-Seidel methods to obtain the same precision, and the computational velocity increases obviously when the new iterative method, instead of Jacobi method, is applied to polish operation in multi-grid method, furthermore, the polynomial acceleration method is still applicable to the new iterative method.

关键词： mathematical stencil, stencil elimination, Poisson equation, finite difference, iterative algorithm,parallelism.

Two-dimensional simulation of Poiseuille-Rayleigh-Bénard flows in binary fluids with Soret effect

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Progress in Natural Science:Materials International 2007年第12期17卷 1389-1396页

作者： Hu Jun1 and Yin Xieyuan2.1. institute of Applied physics and Computational Mathematics, {2. 100088, china 2. Department of Modern Mechanics, University of Science and Technology of china, Hefei 2.002., china) institute of Applied physics and Computational Mathematics Beijing 100088 China Department of Modern Mechanics University of Science and Technology of China Hefei 230027 China

Poiseuille-Rayleigh-Bénard flows in binary fluids with Soret effect are directly simulated by a mixed finite element method. A temperature perturbation is used as an initial disturbed source for the basic parallel flows. The whole spatio-temporal evolution of the binary fluid flows is exhibited: initially only the disturbed mode with the wavenumber k=π is amplified while others are damped, and continuously the amplified mode grows further and the nonlinear effect becomes important; after a nonlinear evolution transition the flow system evolves finally into a periodic right traveling wave.

关键词： Poiseuille-Rayleigh-Bénard flow Soret effect through-flow.

Conductance and dielectric properties of pure C_(60) single crystal

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Chinese Science Bulletin 1997年第1期42卷 40-43页

作者： YANG Guoquan, WANG Gang, WEN Weijia, ZHOU Weiya, LU Kunquan and XIE Sisheng1. Central University for Nationalities, beijing 100081, china {2., Chinese Academy of Sciences, beijing 100080, china Central University for Nationalities Beijing China institute of physics Chinese Academy of Sciences Beijing China

THE C60 is the third stable allotrope of carbon. Much attention has been focused on C60 since it has unique properties. Much work has been carried out on it, such as the preparation of large quantities of C60, the structure studies of C60, the superconducting alkali-metal-C60 compounds, the growth of pure C60 single crystal. There is still a lot of work to do in detail, but because the size of the single ctystal is not large enough, there is some difficulty in research, for example, the electric and optical properties of the C60 single crystal.

关键词： C60 single crystal vapor phase growth conductance dielectric properties.

The kink-soliton and antikink-soliton in quasi-one-dimensional nonlinear monoatomic lattice

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Science china(physics,Mechanics & Astronomy) 2005年第2期48卷 150-157页

作者： XU Quan1 & TIAN Qiang2.1. Scientific and Technological Office, Daqing Teacher College, Daqing 163712. china 2. Department of physics , {2. Normal University, {2. 100875, china Scientific and Technological Office Daqing Teacher College Daqing China Department of physics Beijing Normal University Beijing China

The quasi-one-dimensional nonlinear monoatomic lattice is analyzed. The kink-soliton and antikink-soliton are presented. When the interaction of the lattice is strong in the x-direction and weak in the y-direction, the two-dimensional (2.) lattice changes to a quasi-one-dimensional lattice. Taking nearest-neighbor interaction into account, the vibration equation can be transformed into the KPI, KPII and MKP equation. Considering the cubic nonlinear potential of the vibration in the lattice, the kink-soliton solution is presented. Considering the quartic nonlinear potential and the cubic interaction potential, the kink-soliton and antikink-soliton solutions are presented.

关键词： two-dimensional nonlinear lattice, quasi-one-dimensional nonlinear lattice, kink-soliton, antikink-soliton.

Numerical study on scanning radiation acoustic field in formations generated from a borehole

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Science china(physics,Mechanics & Astronomy) 2005年第2期48卷 247-256页

作者： CHE Xiaohua1, ZHANG Hailan1, QIAO Wenxiao2.& JU Xiaodong2.1. institute of Acoustics, Chinese Academy of Sciences, beijing 100080,{2. 2. Faculty of Natural Resources & Information Technology, University of Petroleum, beijing 102.49,{2. institute of Acoustics Chinese Academy of Sciences Beijing China Faculty of Natural Resources & Information Technology University of Petroleum Beijing China

Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the element number and the delay time between the neighboring array elements of linear phased array transmitter. The steered angle of longitudinal waves generated in the formation satisfies the Snell’s law for plane waves when the incident angle on the borehole wall is less than the first critical angle. When the lobe width of the acoustic beams is narrow and the steered angle is less than the first critical angle, the acoustic field in the formation can be approximately calculated given that the linear phased array is put in the formation without borehole. The technique of scanning radiation acoustic field can be applied to enhancing investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging.

关键词： formation, linear phased array transmitter, steered angle, RAI, scanning radiation.

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science china Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2. WANG Jin3, WU Yishi1, YUAN Gu3, AI Xicheng1, WANG Li4 & ZHANG Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, institute of Chemistry, Chinese Academy of Sciences, beijing 100080,{2. 2. School of Life Science and Technology, beijing institute of Technology, beijing 100081,{2. 3. College of Chemistry and Molecular Engineering, Peking University, beijing 100080,{2. 4. Center for Condensed Matter physics, institute of physics, Chinese Academy of Sciences, beijing 100080,{2. Correspondence should be addressed to Ai Xicheng and Zhang Jianping State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China School of Life Science and Technology Beijing Institute of Technology Beijing China College of Chemistry and Molecular Engineering Peking University Beijing China Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32.ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

Experimental study of composite medium with simultaneously negative permeability and permittivity

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Science china(physics,Mechanics & Astronomy) 2004年第1期47卷 64-78页

作者： SUI Qiang1, 2.& LI Fang1 1. institute of Electronics, Chinese Academy of Sciences, beijing 100080,{2. 2. School of Information, beijing Broadcasting institute, beijing 10002.,{2. Correspondence should be addressed to Sui Qiang (email: suiqiang@***) Received July 2., 2.03 institute of Electronics Chinese Academy of Sciences Beijing 100080 China

This paper focuses on a composite medium structure that exhibits simultan- eously negative values of effective permeability and permittivity, and our experimental study in an anechoic chamber. The experiment results show that the artificial medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous metallic wires, can have a simultaneously negative effective permeability and permittivity within a frequency region in the microwave regime under certain linearly polarized waves.

关键词： permittivity, permeability, negative index of refraction, split ring resonator, LHM, RHM.