New explicit exact solutions for a generalized Hirota—Satsuma coupled KdV system and a coupled MKdV equation

In this paper, we make use of a new generalized ansatz in the homogeneous balance method, the well-known Riccati equation and the symbolic computation to study a generalized Hirota--Satsuma coupled KdV system and a coupled MKdV equation, respectively. As a result, numerous explicit exact solutions, comprising new solitary wave solutions, periodic wave solutions and the combined formal solitary wave solutions and periodic wave solutions, are obtained.     

分数外微分在三维空间中的应用

首先介绍了分数微积分和分数微分形式。讨论了在原点处对曲线坐标的分数外微分变换,并且获得了从三维卡氏坐标到球面坐标和柱面坐标的两个分数微分变换。特别地,当v=m=1时,这两个分数微分变换约化的结果与通过外微积分获得的结果是一致的。     

New families of non-travelling wave solutions to the （2＋1）-dimensional modified dispersive water-wave system

In this paper, we introduce a further generalized projective Riccati equation method and apply it to solve the (2 1)-dimensional modified dispersive water-wave system. Many new types of non-travelling wave solutions are obtained for this system.     

NONLOCAL SYMMETRIES AND NONLOCAL RECURSION OPERATORS

1 IntroductionTl1ere is a well developed theory for local symnwtries with partial differential equations(ref[1-2]). However this theory does not apply to many systems of integrable equations, such asthe iuterlllediate wave equation whicl1 involves integrals in their definition and so are essentiallynonlocal. Oll the otl1er hand, wlien investigating differelltial equations, we often use OPeratorssuch as integrthdtherential recursion operators, which, in general, are in sonle inverse to differ-…     

获得非线性微分方程显式解析解的两种新算法

基于AC=BD的思想来求解非线性微分方程(组)。设Au=0为给定的待求解的方程,Dv=0是容易求解的方程。如果可以获得变换u=Cv使得v满足Dv=0,则能够得到Au=0的解。为了说明该种途径,本文举例给出几种变换C的表达式。     

微分方程递归算子的一种推广

微分方程的多数重要的递归算子都是积微分算子。在试图获得整个对称族时人们常常遇到困难。有时甚至由于缺乏精确性而导致伪对称。本文给出递归算子一种推广,其在某种程度上消除了这些问题。文中还给出了若干重要例子说明这种推广及其重要性。     

NEW B$\ddot{A}$CKLUND TRANSFORMATION AND EXACT SOLUTIONS FOR VARIABLE COEFFICIENT KdV EQUATION

In this paper, with the aid of Lax pairs, a new B?cklund transformation for the variable coefficient KdV equation is found, Based on the B?cklund transformation, only if integration is needed, a series of exact solutions can be obtained. This method is important for finding more new and physical-signficant solutions.     

Backlund transformation and exact solutions for whitham-broer-kaup equations in shallow water

I.IntroductionTodescribethepropagationofshallowwaterwave,manywell-knowncompletelyintegrablemodelsareintroduced,suchasKdVequatioll,Boussinesqequation,K-Pequation,WBKequation,etc.UnderBoussinesqapproximation,Whitham,BroerandKaupl"2'3]obtainednon-lilleurWBKequationwhereu=u(x,l)isthefieldofhorizontalvelocity;v=v(x,t)istheheightthatdeviatefromequilibriumpositionofliquid;a,gareconstantsthatrepresentdift'erentdispersivepower.TheEqs.(1.I),(l.2)areverygoodmodelstodescl.ibedispersivewave.Ifa=0,P…     

Whitham-Broer-Kaup浅水波方程的Backlund变换和精确解

用一种新的方法并借助Mathematica,求出了Whitham-Broer-Kaup(简记WBK)方程的一种Backlund变换,并建立了WBK方程与热传导方程及Burgers方程的联系.利用这种关系得到了WBK方程的三组精确解,其中一组为孤波解.     

获得非线性演化方程Backlund变换的一种新的途径

本文给出一种求非线性演化方程Backlund变换的方法,应用于非线性演化方程时,得到了与WTC方法一致的Backlund变换,避开了WTC方法涉及到的递推关系和截尾的讨论.