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CONSTRUCTION OF HIGH ORDER SYMPLECTIC PRK METHODS

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Journal of Computational Mathematics 1995年第1期13卷 40-50页

作者： Sun Geng(institute of Mathematics, Academia Sinica, beijing, china) 中科院数学所北京

In this paper three classes of high order symplectic partitioned Runge-Kutta (PRK) methods, which are based on the W-transformation of Hairer and Wanner, and a particular class of diagonally implicit symplectic PRK methods of arbitrarily high order, which are based on the composite algorithm, are constructed. In particular, the symplectically composite PRK methods of arbitrarily high order become explicit when applied to separable Hamiltonian systems.

关键词： PRK CONSTRUCTION OF HIGH ORDER SYMPLECTIC PRK METHODS Math

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B_c Meson Studies

高能物理与核物理 2002年第Z1期26卷 1-10页

作者： CHANG Chao-Hsi (institute of Theoretical Physics, Chinese Academy of Sciences, beijing 100080, china) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

Multi-scale calculation of settling speed of coarse particles by accelerated Stokesian dynamics without adjustable parameter

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Acta Mechanica Sinica 2009年第3期25卷 303-310页

作者： Long Wang Jiachun Li Jifu Zhou institute of Mechanics, CAS, 100190 beijing, china institute of Mechanics CAS 100190 Beijing China

The calculation of settling speed of coarse particles is firstly addressed, with accelerated Stokesian dynamics without adjustable parameters, in which far field force acting on the particle instead of particle velocity is chosen as dependent variables to consider inter-particle hydrodynamic interactions. The sedimentation of a simple cubic array of spherical particles is simulated and compared to the results available to verify and validate the numerical code and computational scheme. The improved method keeps the same computational cost of the order O（NlogN） as usual accelerated Stokesian dynamics does. Then, more realistic random suspension sedimentation is investigated with the help of Mont Carlo method. The computational results agree well with experimental fitting. Finally, the sedimentation of finer cohesive particle, which is often observed in estuary environment, is presented as a further application in coastal engineering.

关键词： Sedimentation Stokesian dynamics Many-body interactions Multi-scale

A review of the New Geophysics:a new understanding of pre-fracturing deformation in the crack-critical crust with implications for hydrocarbon production

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Petroleum Science 2008年第1期5卷 1-12页

作者： Stuart Crampin Yuan Gao School of GeoSciences University of Edinburgh UK Edinburgh Anisotropy Project British Geological Survey Edinburgh UK institute of earthquake Science China Earthquake Administration Beijing China

This paper reviews a new understanding of shear-wave splitting （seismic-birefringence） that is a fundamental revision of conventional fluid-rock deformation. It is a New Geophysics with implications for almost all solid-earth geosciences, including hydrocarbon exploration and production, and earthquake forecasting. Widespread observations of shear-wave splitting show that deformation in in situ rocks is controlled by stress-aligned fluid-saturated grain-boundary cracks and preferentially orientated pores and pore-throats pervasive in almost all igneous, metamorphic, and sedimentary rocks in the Earth＇s crust. These fluid-saturated microcracks are the most compliant elements of the rock-mass and control rock deformation. The degree of splitting shows that the microcracks in almost all rocks are so closely spaced that they verge on fracture-criticality and failure by fracturing, and are critical systems with the “butterfly wing＇s” sensitivity of all critical systems. As a result of this crack-criticality, evolution of fluid-saturated stress-aligned microcracked rock under changing conditions can be modelled with anisotropic poroelasticity （APE）. Consequently, low-level deformation can be： monitored with shear-wave splitting; future behaviour calculated with APE; future behaviour predicted with APE, if the change in conditions can be quantified; and in principle, future behaviour controlled by feed-back. This paper reviews our current understanding of the New Geophysics of low-level pre-fracturing deformation.

关键词： Crack anisotropy New Geophysics pre-fracturing deformation seismic birefringence,shear-wave splitting

δ-WAVE FOR 1-D AND 2-D HYPERBOLIC SYSTEMS

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Journal of Computational Mathematics 1996年第3期14卷 256-262页

作者： S.L. Yang(institute of Applied Mathematics, Chinese Academy of Sciences, beijing, china) CHINESE ACAD SCI INST APPL MATHBEIJINGPEOPLES R CHINA

Here a new kind of nonlinear wave, which is called δ-wave, is described by some high resolution difference solutions for Riemann problems of one-dimensional (1-D) and two-dimensional (2-D) nonlinear hyperbolic systems in conservation laws. Some phenomena are numerically shown for the solutions of Riemann problems for 2-D gas dynamics systems

关键词： Zhang WAVE FOR 1-D AND 2-D HYPERBOLIC SYSTEMS

Research progress in non-equilibrium grain-boundary segregation and intergranular embrittlement

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Progress in Natural Science:Materials International 2006年第2期16卷 109-119页

作者： XU Tingdong (Central Iron & Steel Research institute, beijing 100081, china) [a]Central Iron & Steel Research institute Beijing China

This paper is a summary of the research progress made by the author in the study of non- equilibrium grain-boundary segregation and intergranular embrittlement during the last 20 years. Some new concepts and new model... 详细信息

关键词： grain-boundaries vacancies segregation embrittlement.

ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

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同方期刊数据库

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Journal of Computational Mathematics 1996年第4期14卷 383-386页

作者： X.B. Chi(institute of Software, Chinese Academy of Sciences, beijing, china) 中科院软件所北京

In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of solving linear equationsby different ways is analysed. The numerical results are given on *** running our parallel program, the best speed up on 32 processors is over 25.

关键词： ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

N DIMENSIONAL FINITE WAVELET FILTERS

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Journal of Computational Mathematics 2003年第5期21卷 595-602页

作者： Si-long Peng (NADEC, institute of Automation, Chinese Academy of Sciences, beijing 100080, china) NADEC Institute of Automation Chinese Academy of Sciences 北京 100080

In this paper, a large class of n dimensional orthogonal and biorthognal wavelet filters (lowpass and highpass) are presented in explicit expression. We also characterize orthogonal filters with linear phase in this c... 详细信息

关键词： n Dimension Linear phase Wavelet filters.

Vertex solution theorem for the upper and lower bounds on the dynamic response of structures with uncertain-but-bounded parameters

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Acta Mechanica Sinica 2009年第3期25卷 367-379页

作者： Zhiping Qiu Xiaojun Wang institute of Solid Mechanics, Beihang University, 100083 beijing, china institute of Solid Mechanics Beihang University 100083 Beijing China

The aim of this paper is to evaluate the effects of uncertain-but-bounded parameters on the dynamic response of structures. By combining the interval mathematics and the finite element analysis, the mass matrix, damping matrix, stiffness matrix and the external loads are represented as interval matrices and vector. With the help of the optimization theory, we present the vertex solution theorem for determining both the exact upper bounds or maximum values and the exact lower bounds or minimum values of the dynamic response of structures, in which these parameters reach their extreme values on the boundary of the interval mass, damping, stiffness matrices and the interval extemal loads vector. Three examples are used to illustrate the computational aspects of the presented vertex solution theorem.

关键词： Dynamic response Vertex solution theorem ,Uncertain-but-bounded parameters