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1.
用微分形式的吴方法讨论了广义KdV—Burgers方程不同系数情况下的势对称,并且利用这些对称求得了相应的不变解,这些解对进一步研究广义KdV—Burgers方程所描述的物理现象具有重要意义.  相似文献   

2.
雷锦志  晏平 《应用数学》2003,16(3):75-81
本文使用微分代数的技巧,研究了发展方程的守恒率与对应的行波所满足方程的首次积分之间的关系.通过文本给出的结果,我们研究了Burgers方程和Burgers—KdV方程的可积性,证明了这两类方程都只有一个守恒率.利用本文给出的方法,可以通过常微分方程的研究方法来研究某些非线性发展方程.  相似文献   

3.
在本文中我们构造了解第二类Volterra方程的一般Runge—Kutta方法,并且研究了第二类Voherra方程数值解法的自适应步长控制。  相似文献   

4.
三维复Ginzburg-Landau方程的整体解的存在惟一性   总被引:2,自引:0,他引:2  
在三维空间中研究带2σ次非线性项的复值Ginzburg—Landau方程(CGL) ut=ρu (1 iγ)△u-(1 iμ)|u|^2σu,通过先验估计的方法,在适当的σ的假设下,获得该方程周期边值问题整体解的存在性和惟一性.  相似文献   

5.
研究高阶Camassa-Holm方程的行波解,采用一种新的方法求解行波方程,获得了高阶Camassa-Holm方程的一类行波解.  相似文献   

6.
王海玲  林群 《数学研究》2010,43(2):135-140
通过构造李亚普诺夫函数的方法,研究了广义的Lotka—Volterra时滞模型方程,而且给出了正平衡点的全局渐近稳定性的充分必要条件,同时对前人的结果进行了改进和推广.  相似文献   

7.
RLW—Burgers方程的精确解   总被引:6,自引:0,他引:6  
王明亮 《应用数学》1995,8(1):51-55
借助未知函数的变换,RLW-Burgers方程和KdV-Burgers方程化为易于求解的齐次形式的方程,从而得到RLW-Burgers方程和KdV-Burgers方程的精确解。  相似文献   

8.
给出了对流—扩散方程的交替分组格式,并得到该方法的无条件稳定性及具有并行本性兼顾的结果.能够适合在并行计算系统上使用.文中还进行了并行计算的数值实验.  相似文献   

9.
n维B—BBM方程和B—KdV方程的一类准确行波解   总被引:1,自引:0,他引:1  
本文求出了n维BBM方程u_i+udivu-δ△u_i=0和n维B-BBM方程u_i+udivu-μ△u-δ△u_i=0的一类指数函数的有理分式形式的准确行波解.对n维B-BBM方程的这类行波解可分解为n维Burgers方程的某行波解与n维BBM方程的某行波解的线性组合.文中还对n维KdV方程u_i+udivu+δ=0和n维B-KdV方程u_i+udivu-μ△u+δ=0给出了类似的结论.  相似文献   

10.
Whitham—Broer—Kaup浅水波方程的Backlund变换和精确解   总被引:5,自引:2,他引:3  
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·  相似文献   

11.
利用(G'/G)法求解了Dodd-Bullough-Mikhailov的精确解,得到了Dodd-Bullough-Mikhailov方程的用双曲函数,三角函数和有理函数表示的三类精确行波解.由于方法中的G为某个二阶常系数线性ODE的通解,故方法具有直接、简洁的优点;更重要的是,方法可用于求得其它许多非线性演化方程的行波解.如果对其中双曲函数表示的行波解中的参数取特殊值,那么可得已有的孤波解.  相似文献   

12.
长水波近似方程组的新精确解   总被引:3,自引:0,他引:3  
依据齐次平衡法的思想 ,首先提出了求非线性发展方程精确解的新思路 ,这种方法通过改变待定函数的次序 ,优势是使求解的复杂计算得到简化 .应用本文的思路 ,可得到某些非线性偏微分方程的新解 .其次我们给出了长水波近似方程组的一些新精确解 ,其中包括椭圆周期解 ,我们推广了有关长波近似方程的已有结果 .  相似文献   

13.
In this paper, a variable-coefficient Jacobi elliptic function expansion method is proposed to seek more general exact solutions of nonlinear partial differential equations. Being concise and straightforward, this method is applied to the (2+1)-dimensional Nizhnik-Novikov-Vesselov equations. As a result, many new and more general exact non-travelling wave and coefficient function solutions are obtained including Jacobi elliptic function solutions, soliton-like solutions and trigonometric function solutions. To give more physical insights to the obtained solutions, we present graphically their representative structures by setting the arbitrary functions in the solutions as specific functions.  相似文献   

14.
Based on the simplest equation method, we propose exact and traveling-wave solutions for a nonlinear convection-diffusion-reaction equation with power law nonlinearity. Such equation can be considered as a generalization of the Fisher equation and other well-known convection-diffusion-reaction equations. Two important cases are considered. The case of density-independent diffusion and the case of density-dependent diffusion. When the parameters of the equation are constant, the Bernoulli equation is used as the simplest equation. This leads to new traveling-wave solutions. Moreover, some wavefront solutions can be derived from the traveling-wave ones. The case of time-dependent velocity in the convection term is studied also. We derive exact solutions of the equations by using the Riccati equation as simplest equation. The exact and traveling-wave solutions presented in this paper can be used to explain many biological and physical phenomena.  相似文献   

15.
In this article, an enhanced (G′/G)-expansion method is suggested to find the traveling wave solutions for the modified Korteweg de-Vries (mKDV) equation. Abundant traveling wave solutions are derived, which are expressed by the hyperbolic and trigonometric functions involving several parameters. The efficiency of this method for finding these exact solutions has been demonstrated. It is shown that the proposed method is effective and can be used for many other nonlinear evolution equations (NLEEs) in mathematical physics.  相似文献   

16.
The hyperbolic function method for nonlinear wave equations is presented. In support of a computer algebra system, many exact solitary wave solutions of a class of nonlinear wave equations are obtained via the method. The method is based on the fact that the solitary wave solutions are essentially of a localized nature. Writing the solitary wave solutions of a nonlinear wave equation as the polynomials of hyperbolic functions, the nonlinear wave equation can be changed into a nonlinear system of algebraic equations. The system can be solved via Wu Elimination or Gr?bner base method. The exact solitary wave solutions of the nonlinear wave equation are obtained including many new exact solitary wave solutions.  相似文献   

17.
Based on a Riccati equation and one of its new generalized solitary solutions constructed by the Exp‐function method, new analytic solutions with free parameters and arbitrary functions of a (2 + 1)‐dimensional variable‐coefficient Broer–Kaup system are obtained. These free parameters and arbitrary functions reveal that the (2 + 1)‐dimensional variable‐coefficient Broer–Kaup system has rich spatial structures. As an illustrative example, two new spatial structures are shown by setting the arbitrary functions as different Jacobi elliptic functions. Compared with tanh‐function method and its extensions, the method proposed in this paper is more powerful and it can be applied to other nonlinear evolution equations. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

18.
An extended mapping method with a computerized symbolic computation is used for constructing a new exact travelling wave solutions for nonlinear evolution equations arising in physics, namely, generalized Zakharov Kuznetsov equation with variable coefficients. As a result, many exact travelling wave solutions are obtained which include new periodic wave solution, trigonometric function solutions and rational solutions. The method is straightforward and concise, and it can also be applied to other nonlinear evolution equations with variable coefficients arising in mathematical physics. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010  相似文献   

19.
建立了一类二变量的积分不等式,该不等式包含了一个一重积分和两个二重积分.利用分析技巧,给出了积分不等式中未知函数的估计.这一结果可以作为研究积分-微分方程解的定性性质的工具.  相似文献   

20.
The modified simple equation method is employed to find the exact solutions of the nonlinear Kolmogorov-Petrovskii-Piskunov (KPP) equation. When certain parameters of the equations are chosen to be special values, the solitary wave solutions are derived from the exact solutions. It is shown that the modified simple equation method provides an effective and powerful mathematical tool for solving nonlinear evolution equations in mathematical physics.  相似文献   

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