Two new integrable differential-difference equations are proposed. By using Hirota's method, 3-soliton solutions of the Kaup-Kupershmidt equation type are obtained with the assistance of Mathematica. Besides, Lax ...
详细信息
Two new integrable differential-difference equations are proposed. By using Hirota's method, 3-soliton solutions of the Kaup-Kupershmidt equation type are obtained with the assistance of Mathematica. Besides, Lax pairs of these two lattices are also presented. (C) 2000 Published by Elsevier Science B.V.
We present an implementation of parallel prestack depth migration for 2-D Marmousi data. Our implementation is based on the three prestack depth migration methods: finite-difference method, split-step Fourier method a...
详细信息
ISBN:
(纸本)0769505892
We present an implementation of parallel prestack depth migration for 2-D Marmousi data. Our implementation is based on the three prestack depth migration methods: finite-difference method, split-step Fourier method and Fourier finite-difference method. In this article, a brief description of the three methods is given, and the performance of parallel implementation with Message Passing Interface (MPI) and the migration profiles of Marmousi data are presented. It is shown that the Fourier finite-difference migration produced more accurate images in the areas of large lateral velocity variations.
Two general local Cm triangular interpolation schemes by rational functions from Cm data are proposed for any nonnegative integer m. The schemes can have either 2m+1 order algebraic precision if the required data are ...
详细信息
Two general local Cm triangular interpolation schemes by rational functions from Cm data are proposed for any nonnegative integer m. The schemes can have either 2m+1 order algebraic precision if the required data are given on vertices and edges, or m+E[m/2]+1 or m+1 order algebraic precision if the data are given only at vertices. The orders of the interpolation error are estimated. Examples that show the correctness and effectiveness of the scheme are presented.
This paper aims at a comprehensive understanding of the novel elastic property of double-stranded DNA (dsDNA) discovered very recently through single-molecule manipulation techniques. A general elastic model for doubl...
详细信息
This paper aims at a comprehensive understanding of the novel elastic property of double-stranded DNA (dsDNA) discovered very recently through single-molecule manipulation techniques. A general elastic model for double-stranded biopolymers is proposed, and a structural parameter called the folding angle φ is introduced to characterize their deformations. The mechanical property of long dsDNA molecules is then studied based on this model, where the base-stacking interactions between DNA adjacent nucleotide base pairs, the steric effects of base pairs, and the electrostatic interactions along DNA backbones are taken into account. Quantitative results are obtained by using a path integral method, and excellent agreement between theory and the observations reported by five major experimental groups are attained. The strong intensity of the base stacking interactions ensures the structural stability of DNA, while the short-ranged nature of such interactions makes externally stimulated large structural fluctuations possible. The entropic elasticity, highly extensibility, and supercoiling property of DNA are all closely related to this account. The present work also suggests the possibility that negative torque can induce structural transitions in highly extended DNA from the right-handed B form to left-handed configurations similar to the Z-form configuration. Some formulas concerned with the application of path integral methods to polymeric systems are listed in the Appendixes.
作者：
白中治State Key Laboratory of Scientific
Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Chinese Academy of Sciences Beijing P R China
This paper proposes a class of parallel interval matrix multisplitting AOR methods far solving systems of interval linear equations and discusses their convergence properties under the conditions that the coefficient ...
详细信息
This paper proposes a class of parallel interval matrix multisplitting AOR methods far solving systems of interval linear equations and discusses their convergence properties under the conditions that the coefficient matrices are interval H-matrices.
The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergenc...
详细信息
The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergence of the Fletcher-Reeves method using generalized Wolfe line searches or generalized Arjimo line searches, whereas an example is constructed showing that the conditions cannot be relaxed in certain senses.
A framework for parallel algebraic multilevel preconditioning methods presented for solving large sparse systems of linear equstions with symmetric positive definite coefficient matrices,which arise in suitable finite...
详细信息
A framework for parallel algebraic multilevel preconditioning methods presented for solving large sparse systems of linear equstions with symmetric positive definite coefficient matrices,which arise in suitable finite element discretizations of many second-order self-adjoint elliptic boundary value problems. This framework not only covers all known parallel algebraic multilevel preconditioning methods, but also yields new ones. It is shown that all preconditioners within this framework have optimal orders of complexities for problems in two-dimensional(2-D) and three-dimensional (3-D) problem domains, and their relative condition numbers are bounded uniformly with respect to the numbers of both levels and nodes.
An elastic model for double-stranded polymers is constructed to study the recently observed DNA entropic elasticity, cooperative extensibility, and supercoiling property. With the introduction of a new structural para...
详细信息
An elastic model for double-stranded polymers is constructed to study the recently observed DNA entropic elasticity, cooperative extensibility, and supercoiling property. With the introduction of a new structural parameter (the folding angle ϕ), bending deformations of sugar-phosphate backbones, steric effects of nucleotide base pairs, and base-stacking interactions are considered. The comprehensive agreements between theory and experiments both on torsionally relaxed DNA and on negatively supercoiled DNA strongly indicate that base-stacking interactions, although short-ranged in nature, dominate the elasticity of DNA and, hence, are of vital biological significance.
暂无评论