一类Riccati矩阵方程广义自反解的双迭代算法

本文研究了一类Riccati矩阵方程广义自反解的数值计算问题.利用牛顿算法将Riccati矩阵方程的广义自反解问题转化为线性矩阵方程的广义自反解或者广义自反最小二乘解问题,再利用修正共轭梯度法计算后一问题,获得了求Riccati矩阵方程的广义自反解的双迭代算法.拓宽了求解非线性矩阵方程的迭代算法.数值算例表明双迭代算法是有效的.     

非线性反应扩散方程的广义条件对称及其精确解

利用广义条件对称,考虑非线性反应扩散方程的精确解,对应于不同的参数讨论,得到相应的方程及其允许的广义条件对称,进而得到方程的精确解.     

一般非线性扩散方程Cauchy问题广义解的渐近性质

本文研究了比较一般的非线性扩散方程的Cauchy问题广义解的渐近性质.利用试验函数与积分估计的方法,获得了广义解当t→∞时的渐近性质以及其广义整体解u(x,t),推广了该类方程Cauchy问题广义解的性质.     

分数阶广义扰动热波方程的与泛函映射解

研究了一类分数阶广义非线性扰动热波方程.首先在典型分数阶热波方程情形下得到解,接着用泛函分析映射方法,求出了分数阶广义非线性扰动热波方程初始边值问题的任意次近似解析解.最后简述了它的物理意义.求得的近似解析解,弥补了单纯用数值方法得到的模拟解的不足.     

一类广义非线性反应扩散方程奇摄动问题激波解（英文）

本文研究一类广义非线性反应扩散方程奇摄动初始边值问题.首先,构造非线性问题的外部解.其次,利用局部坐标系和伸长变量得到激波层和边界层校正项.最后,利用不动点理论研究了非线性反应扩散方程初始边值问题广义解的渐近性态.     

双参数非线性非局部奇摄动抛物型初始-边值问题的广义解

研究了一类广义抛物型方程奇摄动问题.首先在一定的条件下, 提出了一类具有两参数的非线性非局部广义抛物型方程初始 边值问题.其次证明了相应问题解的存在性.然后, 通过Fredholm积分方程得到了初始 边值问题的外部解.再利用泛函分析理论和伸长变量及多重尺度法, 分别构造了初始 边值问题广义解的边界层、初始层项,从而得到了问题的形式渐近展开式.最后利用不动点理论证明了对应的非线性非局部广义抛物型方程的奇异摄动初始 边值问题的广义解的渐近展开式的一致有效性.     

非线性记忆项下广义Tricomi方程解的爆破

研究了一类非线性记忆项的广义Tricomi方程柯西问题解的爆破现象.运用迭代技巧和修正贝塞尔方程推出了在次临界情况下非线性记忆项对广义Tricomi方程解的非局部影响.此外,还得到了其解的全局非存在性和生命跨度上界估计.     

非线性双曲型Schr(o)dinger方程L2整体解的存在性

本文讨论含L2次临界指数非线性项的广义Schrodinger方程柯西问题,用Strichartz不等式和压缩映射原理证明了在L2初值条件下方程有整体解,即u(t)∈C(R,L2(Rn)),而且证明了含L2临界指数非线性项的广义Schrodinger方程有小初值L2整体解.     

非线性双曲型Schrdinger方程L~2整体解的存在性

本文讨论含L2次临界指数非线性项的广义Schrodinger方程柯西问题,用Strichartz不等式和压缩映射原理证明了在L2初值条件下方程有整体解,即u(t)∈C(R,L2(Rn)),而且证明了含L2临界指数非线性项的广义Schrodinger方程有小初值L2整体解.     

一类广义Boussinesq方程的Wronskian行列式解

为了构造非线性孤子方程的Wronskian行列式新解,进一步研究了Wronskian技巧.本文首先给出非线性广义Boussinesq方程的双线性形式,利用Wronskian技巧构造出该非线性方程所满足的一个线性偏微分条件方程组,然后求解该微分条件方程组,得到了广义Boussinesq方程的各种Wronskian行列式解.     

非线性KdV-mKdV方程的新的复合函数解

利用孤立子方程KdV-mKdV的朗斯基解的形式和结构,我们提出了朗斯基形式展开法,运用这一方法获得了KdV-mKdV方程的丰富的新的复合函数解,并且朗斯基行列式中的元素不满足任何线性偏微分方程组.所得到的复合函数解是使用其它的方法得不到的.     

A second Wronskian formulation of the Boussinesq equation

A Wronskian formulation leading to rational solutions is presented for the Boussinesq equation. It involves third-order linear partial differential equations, whose representative systems are systematically solved. The resulting solutions formulas provide a direct but powerful approach for constructing rational solutions, positon solutions and complexiton solutions to the Boussinesq equation. Various examples of exact solutions of those three kinds are computed. The newly presented Wronskian formulation is different from the one previously presented by Li et al., which does not yield rational solutions.     

Triple Wronskian solutions of the coupled derivative nonlinear Schrödinger equations in optical fibers

A type of the coupled derivative nonlinear Schrödinger (CDNLS) equations are studied by means of symbolic computation, which can describe the wave propagation in birefringent optical fibers. Soliton solutions in the triple Wronskian form of the CDNLS equations are obtained. Elastic and inelastic collisions are both presented under some parametric conditions. In addition, generalized triple Wronskian solutions of a set of the coupled general derivative nonlinear Schrödinger (CGDNLS) equations are derived. Triple Wronskian identities are given to prove such solutions, which may also be used for other coupled nonlinear equations. Rational solutions of the CGDNLS equations are also obtained.     

The generalized Wronskian solutions of a inverse KdV hierarchy

A hierarchy of the inverse KdV equation is discussed. Through the bilinear form of Lax pairs, we prove a generalized Darboux-Crum theorem of the hierarchy. The Bäcklund transformation and the generalized Wronskian solutions are presented. The soliton solutions, explicit rational solutions are obtained then.     

New double Wronskian solutions of the AKNS equation

Soliton solutions, rational solutions, Matveev solutions, complexitons and interaction solutions of the AKNS equation are derived through a matrix method for constructing double Wronskian entries. The latter three solutions are novel. Moreover, rational solutions of the nonlinear Schrodinger equation are obtained by reduction.     

On intermediate solutions and the Wronskian for half-linear differential equations

The asymptotic behavior of nonoscillatory solutions of the half-linear differential equation is studied. In particular, two Wronskian-type functions, which have some interesting properties, similar to the one of the Wronskian in the linear case, are given. Using these properties and suitable integral inequalities, the existence of the so-called intermediate solutions is examined and an open problem is solved.     

Wronskian determinant solutions of the (3 + 1)-dimensional Jimbo-Miwa equation

A set of sufficient conditions consisting of systems of linear partial differential equations is obtained which guarantees that the Wronskian determinant solves the (3 + 1)-dimensional Jimbo-Miwa equation in the bilinear form. Upon solving the linear conditions, the resulting Wronskian formulations bring solution formulas, which can yield rational solutions, solitons, negatons, positons and interaction solutions.     

Generalized double Wronskian solutions of the third-order isospectral AKNS equation

The generalized double Wronskian solutions of the third-order isospectral AKNS equation are obtained. Thus we found rational solutions, Matveev solutions, complexitons and interaction solutions. Moreover, rational solutions of the mKdV equation and KdV equation in double Wronskian form are constructed by reduction.     

Novel composite function solutions of the modified KdV equation

A Wronskian form expansion method is proposed to construct novel composite function solutions to the modified Korteweg-de Vries (mKdV) equation. The method takes advantage of the forms and structures of Wronskian solutions to the mKdV equation, and Wronskian entries do not satisfy linear partial differential equations. The method can be automatically carried out in computer algebra (for example, Maple).     

带色散项的高阶非线性Schrdinger方程的精确解

对一类带色散项的高阶非线性Schrdinger方程的精确解进行研究.通过行波约化,将一类带色散项的高阶非线性Schrdinger方程化为一个高阶非线性常微分方程.再借助于计算机代数系统Mathematica通过构造非线性常微分方程的精确解,成功获得了一系列含有多个参数的包络型精确解,当精确解中参数取特殊值时可以得到两种新型的复合孤子解.并讨论了这两种孤子解存在的参数条件.