A Generalized Hirota Ansatz to Obtain Soliton-Like Solutions for a (3+l)-Dimensional Nonlinear Evolution Equation

Instead of the usual Hirota ansatz,i.e.,the functions in bilinear equations being chosen as exponentialtypes,a generalized Hirota ansatz is proposed for a (3+1)-dimensional nonlinear evolution equation.Based on theresulting generalized Hirota ansatz,a family of new explicit solutions for the equation are derived.

A more general form of lump solution,lumpoff,and instanton/rogue wave solutions of a reduced (3+1)-dimensional nonlinear evolution equation

In this manuscript,a reduced(3+1)-dimensional nonlinear evolution equation is studied.We first construct the bilinear formalism of the equation by using the binary Bell polynomials theory,then explore a lump solution to the special case for z=x.Furthermore,a more general form of lump solution of the equation is found which possesses seven arbitrary parameters and four constraint conditions.By cutting the lump by the induced soliton(s),lumpoff and instanton/rogue wave solutions are also constructed by the more general form of lump solution.

New exact solitary wave solutions to generalized mKdV equation and generalized Zakharov-Kuzentsov equation

In this paper, based on hyperbolic tanh-function method and homogeneous balance method, and auxiliary equation method, some new exact solitary solutions to the generalized mKdV equation and generalized Zakharov-Kuzentsov equation are constructed by the method of auxiliary equation with function transformation with aid of symbolic computation system Mathematica. The method is of important significance in seeking new exact solutions to the evolution equation with arbitrary nonlinear term.

Extension of Variable Separable Solutions for Nonlinear Evolution Equations

We give the generalized definitions of variable separable solutions to nonlinear evolution equations, and characterize the relation between the functional separable solution and the derivative-dependent functional separable solution. The new definitions can unify various kinds of variable separable solutions appearing in references. As application, we classify the generalized nonlinear diffusion equations that admit special functional separable solutions and obtain some exact solutions to the resulting equations.

Approximate Generalized Conditional Symmetries for Perturbed Evolution Equations

The concept of approximate generalized conditional symmetry （AGCS） for the perturbed evolution equations is introduced, and how to derive approximate conditional invariant solutions to the perturbed equations via their A GCSs is illustrated with examples.

Variable Separation for(1+1)-Dimensional Nonlinear Evolution Equations with Mixed Partial Derivatives

We present basic theory of variable separation for (1 + 1)-dimensional nonlinear evolution equations withmixed partial derivatives.As an application,we classify equations u_(xt)=A(u,u_x)u_(xxx)+B(u,u_x) that admits derivative-dependent functional separable solutions (DDFSSs) and illustrate how to construct those DDFSSs with some examples.

Solitary wave solutions for the generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony nonlinear evolution equation

In this paper,we utilize the exp(−ϕ(ξ))-expansion method to find exact and solitary wave solutions of the generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony nonlinear evolution equation.The generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony nonlinear evolution equation describes the model for the propagation of long waves that mingle with nonlinear and dissipative impact.This model is used in the analysis of the surface waves of long wavelength in hydro magnetic waves in cold plasma,liquids,acoustic waves in harmonic crystals and acoustic-gravity waves in compressible fluids.By using this method,seven different kinds of traveling wave solutions are successfully obtained for this model.The considered method and transformation techniques are efficient and consistent for solving nonlinear evolution equations and obtain exact solutions that are applied to the science and engineering fields.

含多维随机变量的广义概率密度演化方程解析解:以Euler-Bernoulli梁为例

广义概率密度演化方程的解析解,不仅具有重要理论价值,而且具有校验数值解、进而标定数值算法误差的作用.以Euler-Bernoulli简支梁为例,推导给出了梁受迫振动时跨中位移响应所对应的广义概率密度演化方程解析解.包括非平稳非高斯随机载荷作用下的解(包含2维随机变量)以及同时考虑载荷随机性和结构参数随机性时的解(分别包含2维、4维和5维随机变量).分析结果表明,真实的概率密度演化是一个十分复杂的过程,远不能用简单的概率分布函数加以描述.这一进展,可为概率密度演化理论的进一步深入研究提供一个方面的基础.

(3+1)维广义非线性发展方程的双线性Backlund变换与精确解

基于Hirota双线性方法和试探函数法,研究一个(3+1)维广义非线性发展方程的双线性Backlund变换和精确解问题。用Hirota双线性法,构造(3+1)维广义非线性发展方程的双线性形式和双线性Backlund变换。基于双线性形式和双线性Backlund变换,利用试探函数法与符号计算系统Mathematica,获得(3+1)维广义非线性发展方程的多种精确解,包括呼吸波解、复合型解、Lump周期解和孤子解,并分析解的相互作用情况。

Lump and new interaction solutions to the (3+1)-dimensional nonlinear evolution equation

In this paper,a new(3+1)-dimensional nonlinear evolution equation is introduced,through the generalized bilinear operators based on prime number p=3.By Maple symbolic calculation,one-,two-lump,and breather-type periodic soliton solutions are obtained,where the condition of positiveness and analyticity of the lump solution are considered.The interaction solutions between the lump and multi-kink soliton,and the interaction between the lump and breather-type periodic soliton are derived,by combining multi-exponential function or trigonometric sine and cosine functions with a quadratic one.In addition,new interaction solutions between a lump,periodic-solitary waves,and one-,two-or even three-kink solitons are constructed by using the ansatz technique.Finally,the characteristics of these various solutions are exhibited and illustrated graphically.

A study on the compatibility of the generalized Kudryashov method to determine wave solutions

In this article,we establish solitary wave solutions to the Estevez-MansfieldClarkson(EMC)equation and the coupled sine-Gordon equations which are model equations to analyze the formation of shapes in liquid drops,surfaces of negative constant curvature,etc.through contriving the generalized Kudryashov method.The extracted results introduce several types’solitary waves,such as the kink soliton,bell-shape soliton,compacton,singular soliton,peakon and other sort of soliton for distinct valuation of the unknown parameters.The achieved analytic solutions are interpreted in details and their 2D and 3D graphs are sketched.The obtained solutions and the physical structures explain the soliton phenomenon and reproduce the dynamic properties of the front of the travelling wave deformation generated in the dispersive media.It shows that the generalized Kudryashov method is powerful,compatible and might be used in further works to found novel solutions for other types of nonlinear evolution equations ascending in physical science and engineering.

广义Pochhammer-Chree方程的显式精确孤波解

首先对广义Ｐｏｃｈｈａｍｍｅｒ＿Ｃｈｒｅ方程（ＰＣ方程）ｕｔ－ｕｔｘｘ＋ｒｕｘｘｔ－（ａ１ｕ＋ａ２ｕ２＋ａ３ｕ３）ｘｘ＝０（ｒ≠０）（Ⅰ）的孤波解ｕ（ξ）建立了公式∫＋∞－∞［ｕ′（ξ）］２ｄξ＝１１２ｒｖ（Ｃ＋－Ｃ－）３［３ａ３（Ｃ＋＋Ｃ－）＋２ａ２］·由此推知：广义ＰＣ方程（Ⅰ）不可能有钟状孤波解，只可能有扭状孤波解；而广义ＰＣ方程ｕｔ－ｕｔｘｘ－（ａ１ｕ＋ａ２ｕ２＋ａ３ｕ３）ｘｘ＝０（Ⅱ）可能既有钟状孤波解又有渐近值满足３ａ３（Ｃ＋＋Ｃ－）＋２ａ２＝０的扭状孤波解·进一步求出了广义ＰＣ方程（Ⅰ）的扭状孤波解。

利用(G＇/G)展开法求解广义变系数Burgers方程

近年来,变系数非线性发展方程受到越来越多的关注。2008年王明亮等提出了一种新的方法,即(G′/G)展开法。将(G′/G)展开法首次尝试应用到变系数非线性发展方程中,并以广义变系数Burgers方程为例,成功得到了在系数满足一定条件时新的精确解;又尝试将该展开法进行新的扩展,再一次对广义变系数Burgers方程求解,又成功得到了一些新解。实践证明,该展开法不仅易于求解常系数非线性发展方程,而且对变系数非线性发展方程仍很高效、简洁、实用,并且具有广泛的应用前景。

广义Hirota-Satsuma耦合KdV方程的精确解

利用(G'/G)-展开法结合数学软件Maple求得了广义Hirota-Satsuma耦合KdV方程的新精确解,包括孤波解、三角函数周期解和有理解.为了更直观地理解这些解,给出了它们的数值模拟图.

一类五阶非线性演化方程的广义孤立波解和周期解

应用指数函数法,借助计算机代数系统获得了包括五阶KdV方程、Sawada-Kotera方程和Kaup-Kupershmit方程在内的一类五阶非线性演化方程的广义孤立波解和周期解.结果表明,指数函数法结合符号计算已成为解决数学物理中非线性演化方程的强有力工具.

广义密度演化方程的δ函数序列解法

随机动力系统响应或状态向量的概率密度函数一般遵循概率密度演化方程,如Liouville方程、FPK方程和Dostupov-Pugachev方程,但是上述方程均属于高维偏微分方程,求解相当困难.基于概率守恒原理的随机事件描述导出的广义密度演化方程,其维数与系统自由度无关,为随机动力系统分析提供了可能的途径.从广义密度演化方程的形式解出发,引入δ函数的渐近序列,获得了广义密度演化方程的一种新的数值解法——广义密度演化方程的δ序列解法.将建议方法与非参数密度估计进行了对比,指出非参数密度估计是该方法的一个特例.最后,分别采用重构实例和演化实例验证了该方法在一维和多维情形下的有效性.

四阶非线性发展方程的精确解和广义条件对称

讨论了允许二阶广义条件对称的四阶非线性发展方程.通过广义条件对称方法得到了其对称约化和精确解.

广义变系数Burgers方程的显示精确解

将Riccati方程法扩展并应用到构造变系数非线性发展方程的显示精确解,发展了Riccati方程法,并用该方法获得了广义变系数Burgers方程在一定条件下的显示精确解.

变形Boussinesq方程组Ⅱ的推广解

为适应包括变系数方程在内的非线性发展方程求解的需要,试图探求辅助方程的多样化和解的形式的更为一般化,对王明亮提出的(G'/G)-展开法进行了更有意义的推广。为验证此推广的有效性,将它应用到常系数变形Boussinesq方程组Ⅱ中,取得了多组精确行波解。实践证明此推广具有很好的适用性。

一些非线性发展方程的显式行波解

该文给出了一种构造非线性发展方程显式行波解的方法 ,并用该方法得到了 Hirota-Satsuma方程组 ,一类非线性常微分方程以及广义耦合标量场方程组的显式行波解 .