MAXIMAL EMITTED POWER OF HYPERRADIANCE FROM PERTURBED JOSEPHSON SYSTEMS

Consider two magnetically coupled and perturbed long Josephson junctions which operate in synchronized modes. Under first order approximation, the soliton solution of the system is derived by using a new perturbation technique. It is shown that the perturbing parameters limit the emitted power from the system, and the physically relevant coupling parameter leads to the increase of power. The formula of maximal emitted power is given for a particular power input. The results solve some important problems left over by previous analysis.     

A MODIFIED METHOD OF DETERMINING FRACTAL DIMENSIONS OF POLYMERS AND BIOPOLYMERS

A modified method of calculating the end-to-end distance of segments with a given number of units in a single polymer chain is presented and numerical studies of some fractals by using Havlin and Ben-Avraham's and our methods are given. The results show that our method can remove the fluctuations in the end-to-end distances of the segments arising in Havlin and Ben-Avraham's method.     

A NONMONOTONE TRUST REGION METHOD FOR NONLINEAR LEAST SQUARES PROBLEMS

In this paper we present a nonmonotone trust region method for nonlinear least squares problems with zero-residual and prove its convergence properties. The extensive numerical results are reported which show that the nonmonotone trust region method is generally superior to the usual trust region method.     

能量在蛋白质α-螺旋链中传输模型的稳定性分析

引入了一个新的模型来描述α-螺旋蛋白质分子中3条单肽链的振动能量的贮存和传输，在该模型中考虑了链间的相互作用能量，并对该模型进行了稳定性分析，发现该模型存在非线性局域模，数值模拟的结果表明，该模型存在静止和运动的局域模型。     

Nonlinear Dynamics Approach to the Correlation Analysis of Protein Sequences

To clarify the randomness of protein sequences,we make a detailed analysis of a set of typical protein sequences representing each fold by using the nonlinear prediction method developed in nonlinear dynamics theory.No deterministic structures are found in these protein sequences and this implies that they behave as random chains.We also explain the controversial results obtained in previous investigations.     

Nonlinear Correlations of Protein Sequences and Symmetries of Their Structures

We investigate the nonlinear correlations of protein sequences by using the nonlinear prediction method developed in nonlinear dynamical theory. It is found that a lot of protein sequences show strong nonlinear correlations and have deterministic structures. Further investigations show that the strong nonlinear correlations of these protein sequences are due to the symmetries of their tertiary structures. Furthermore, the correlation lengths of the sequences are related to the degrees of the symmetries. These results support the duplication mechanism of protein evolution and also reveal one aspect how amino acid sequences encode their spatial structures.     

DNA与分形

生命体中脱氧核糖核酸（ＤＮＡ）分子的碱基序列记载着它生长发育的全部指令，是一部人类至今还没有读懂的“天书”．它是一种表面上看起来不规则但实际上隐含着有序结构的符号序列．对物理学来说，这是一个典型的复杂系统。最近的研究发现，ＤＮＡ碱基序列也具有自相似性，存在高度的长程关联。介绍近年来在利用分形理论对ＤＮＡ碱基序列的研究中，发展起来的二种定量分析符号序列的方法，即度量空间的ＤＮＡ行走和Ｖｏｓｓ的分解子序列方法。     

微扰Burgers-KdV方程的孤子解

对于一个其耗散项可看作微扰的Burgers-KdV(B-KdV)方程u_t+uu_x+βu_xxx=εu_xx,|ε|?1,考虑一级近似和行波情形,建立一套求通解的直接扰动方法,利用零级方程的单孤子解,获得一级方程的孤子型通解,它包含任意多个不同的孤子解,每个孤子解分别描述一个位于半无限空间的孤子阵列,分析表明,耗散使得“亮孤子”变矮变窄,“暗孤子”变浅变窄. 关键词：     

多个相异性矩阵的数据分析

本文给出了分析多个相异性矩阵的三种方法.首先找到了一种图表示,使我们对所有相异性矩阵有一个总体的了解;其次定义了一个新的相异性矩阵,它可以看作是对所有原始相异性矩阵的一个折衷处理;最后提出了一种MIMU方法.在文中我们还对由上述方法得到的坐标图进行了比较.