Jacobi椭圆函数展开法及其在求解非线性波动方程中的应用

给出了Jacobi椭圆函数展开法,且应用该方法获得了几种非线性波方程的准确周期解.该方法包含了双曲函数展开法,应用该方法得到的周期解包含了冲击波解和孤波解. 关键词： Jacobi椭圆函数 非线性方程 周期解 孤波解     

Manakov型非线性Schrdinger方程的Jacobi椭圆函数包络解

简化了扩展的Jacobi椭圆函数展开法 ,亦即对修正的Jacobi椭圆函数展开法进行了扩展 .把这种方法应用于Manakov型非线性Schr dinger方程 ,得到了Jacobi椭圆函数包络解 .在一定条件下 ,这些解退化成相应的包络冲击波解和包络孤立波解 .     

Manakov型非线性Schr

简化了扩展的Jacobi椭圆函数展开法,亦即对修正的Jacobi椭圆函数展开法进行了扩展.把这种方法应用于Manak0v型非线性Schrodinger方程,得到了Jacobi椭圆函数包络解.在一定条件下,这些解退化成相应的包络冲击波解和包络孤立波解.     

耦合Klein-Gordon-Schrdinger方程新的精确解

用函数变换法将耦合Klein Gordon Schr dinger方程化成可求解的不定积分形式 ,进而求出其精确解 ,包括有理函数型解、三角函数型解、双曲函数型解 ,以及椭圆函数型解 .所得结果包含了文献中用齐次平衡法所得的解为特例 .     

耦合Klein-Gordon-Schr(o)dinger方程新的精确解

用函数变换法将耦合Klein-Gordon-Schr(o)dinger方程化成可求解的不定积分形式,进而求出其精确解,包括有理函数型解、三角函数型解、双曲函数型解,以及椭圆函数型解.所得结果包含了文献中用齐次平衡法所得的解为特例.     

耦合Klein-Gordon-Schrödinger方程新的精确解

用函数变换法将耦合Klein-Gordon-Schr(o)dinger方程化成可求解的不定积分形式,进而求出其精确解,包括有理函数型解、三角函数型解、双曲函数型解,以及椭圆函数型解.所得结果包含了文献中用齐次平衡法所得的解为特例.     

修正的F展开法和推广的KdV方程新的孤波解和精确解

对F展开法进行了修正,附加含任意常数的负指数项,解决了精确解的奇点问题.用此方法讨论推广的KdV方程的周期波解.在特别情形下,获得了新的Jacobi椭圆函数精确解、孤波解和三角函数解. 关键词： 齐次平衡原则 F展开法 推广的KdV方程 孤波解     

组合KdV方程的显式精确解

借助计算机代数系统Mathematica，利用双曲函数法找到了组合KdV方程(Combined KdV Equation)的精确孤立波解，包括钟型孤立波解和扭结型孤立波解.在此基础上又对双曲函数法的思想进行了推广，从而获得了其更多的显式精确解，包括间断型激波解和指数函数型解.这种方法也适用于求解其他非线性发展方程(组). 关键词： 组合KdV方程 双曲函数法 孤立波解 精确解     

变系数Whitham-Broer-Kaup方程组的对称、约化及精确解

利用修正的Clarkson-Kruskal直接法对变系数Whitham-Broer-Kaup(VCWBK)方程组进行等价转化,建立了VCWBK方程组与常系数WBK方程组解之间的关系,并得到了常系数WBK方程组的一些对称和相似约化.借助辅助函数法得到了VCWBK方程组的一些新精确解,包括有理函数解、双曲函数的解、三角函数解和Jacobi椭圆函数解.     

三Riccati 方程的新展开法及其在非线性数学物理方程中的应用

通过对tanh函数法和射影Riccati方程法的探讨, 提出一种新的算法来求解非线性发展方程. 并且通过求解高阶 schrodinger 方程和 mKdV 方程来说明该算法.得到了这些方程的新形式解,包括新的孤立波解, 周期解等, 并图示一些新形式解.     

一类非线性方程激波解的Sinc-Galerkin方法

研究了一类非线性奇摄动方程的激波问题.利用Sinc-Galerkin方法,构造出边值问题的激波解,并由Newton法得到其近似解. 关键词： 非线性方程 激波 Sinc-Galerkin方法 Newton法     

Asymptopic solution for a class of semilinear singularly perturbed fractional differential equation

This paper considers a class of boundary value problems for the semilinear singularly perturbed fractional differential equation.Under the suitable conditions,first,the outer solution of the original problem is obtained;secondly,using the stretched variable and the composing expansion method the boundary layer is constructed;finally,using the theory of differential inequalities the asymptotic behaviour of solution for the problem is studied and the uniformly valid asymptotic estimation is discussed.     

一类奇摄动薄板弯曲问题的匹配渐近解

研究了一类薄板弯曲问题. 对四阶奇摄动边值问题, 引入伸长变量, 构造边界附近的内层解, 然后与外部解匹配. 最后用合成展开式理论, 得到了原问题的的渐近解. 关键词： 薄板弯曲 挠度 渐近解     

Existence and Asymptotic Stability of Periodic Solutions of the Reaction–Diffusion Equations in the Case of a Rapid Reaction

A singularly perturbed periodic in time problem for a parabolic reaction-diffusion equation in a two-dimensional domain is studied. The case of existence of an internal transition layer under the conditions of balanced and unbalanced rapid reaction is considered. An asymptotic expansion of a solution is constructed. To justify the asymptotic expansion thus constructed, the asymptotic method of differential inequalities is used. The Lyapunov asymptotic stability of a periodic solution is investigated.     

A Method for Studying the Cauchy Problem for a Singularly Perturbed Weakly Nonlinear First-Order Differential Equation

A sequence converging to the solution of the Cauchy problem for a singularly perturbed weakly nonlinear first-order differential equation is constructed. This sequence is asymptotic in the sense that the distance (with respect to the norm of the space of continuous functions) between its nth element and the solution to the problem is proportional to the (n + 1)th power of the perturbation parameter. Such a sequence can be used to justify asymptotics obtained by the boundary function method.     

Asymptotic procedure for solving boundary value problems for singularly perturbed linear impulsive systems

A justification is given of an asymptotic method for solving a boundary value problem for a linear singularly perturbed impulsive system of differential equations with fast and slow variables.     

一类奇摄动非线性方程Robin问题激波的位置

利用匹配法构造了一类奇摄动非线性方程Robin问题激波解的渐近表示式.得出了激波在边界附近出现的条件.     

A singularly perturbed reaction diffusion problem forthe nonlinear boundary condition with two parameters

A class of singularly perturbed initial boundary value problems of reaction diffusion equations for the nonlinear boundary condition with two parameters is considered. Under suitable conditions, by using the theory of differential inequalities, the existence and the asymptotic behaviour of the solution for the initial boundary value problem are studied. The obtained solution indicates that there are initial and boundary layers and the thickness of the boundary layer is less than the thickness of the initial layer.     

Solution of the Equations of Electrodiffusion by the Method of Successive Approximations

The solution of a singularly perturbed differential equation is considered that describes the passage of a steady current in a system consisting of a mixture of charged particles. A correction to the solution is obtained by splicing two asymptotic solutions. Proceeding from the magnitude of this correction, the region of applicability of this method is determined.     

Error Analysis for a Non-Monotone FEM for a Singularly Perturbed Problem with Two Small Parameters

In this paper, we consider a singularly perturbed convection-diffusion problem. The problem involves two small parameters that gives rise to two boundary layers at two endpoints of the domain. For this problem, a non-monotone finite element methods is used. A priori error bound in the maximum norm is obtained. Based on the a priori error bound, we show that there exists Bakhvalov-type mesh that gives optimal error bound of$\mathcal{O}(N^{−2})$ which is robust with respect to the two perturbation parameters. Numerical results are given that confirm the theoretical result.