应用全新G′/（G+G′）展开方法求解广义非线性Schr?dinger方程和耦合非线性Schr?dinger方程组

研究了一种全新的G′/（G+G′）展开方法,并应用这种方法讨论了广义非线性Schr?dinger方程和一类耦合非线性Schr?dinger方程组新形式的精确解,包括双曲余切函数解、余切函数解和有理函数解.全新G′/（G+G′）展开方法不但直接而有效地求出方程的新精确解,而且扩大了解的范围,这种新方法对于研究偏微分方程具有广泛的应用意义.     

应用全新G'/(G+G')展开方法求解广义非线性Schrdinger方程和耦合非线性Schrdinger方程组

研究了一种全新的G'/(G+G')展开方法,并应用这种方法讨论了广义非线性Schrdinger方程和一类耦合非线性Schrdinger方程组新形式的精确解,包括双曲余切函数解、余切函数解和有理函数解.全新G'/(G+G')展开方法不但直接而有效地求出方程的新精确解,而且扩大了解的范围,这种新方法对于研究偏微分方程具有广泛的应用意义.     

逼近已知函数微商的广义Lanczos算法

给出逼近已知函数微商的广义Lanczos 算法, 构造了一列逼近算子$D_{h}^{n}$以提高稳定近似解的收敛速率. 当$n=2$时, 逼近精度达到$O(\delta^{6 \over 7})$, 而对一般的自然数$n$逼近精度为$O(\delta^{\frac{2n+2}{2n+3}})$, 这里$\delta$是近似函数的误差界.     

非线性耦合KdV方程组的一种新求解法

本文研究了构造非线性耦合Kd V方程组的无穷序列复合型新解的问题.利用函数变换与辅助方程相结合的方法,获得了非线性耦合Kd V方程组的自由Riemannθ函数、Jacobi椭圆函数、双曲函数和三角函数两两组合的无穷序列复合型新解.这些解包括了双弧子解、双周期解和弧子解与周期解复合的解.     

R\''enyi公式的推广

在本文,作为著名的R\''enyi公式(其刻画了标号连通单圈图的计数显式)的自然推广,我们研究了标号匀称$(k+1)$秩$(p,~q)$超单圈的计数问题,给出了如下的计数显式:$$U_{p,~q}^{(k+1)}=\begin{cases} \frac{p!}{2[(k-1)!]^q}\cdot\sum_{t=2}^q \frac{q^{q-t-1}\cdot sgn(tk-2)}{(q-t)!}, & p=qk, \\ 0,& p\neq qk, \end{cases}$$其中$k,~p,~q$均为正整数.     

一类耦合Benjamin-Bona-Mahony型方程组的新精确解

主要研究一类耦合的Benjamin-Bona-Mahony型方程组的显式行波解.应用(G′/G)-展开法,Jacobi椭圆函数展开法以及详细的计算,得到了方程组的多个精确行波解.所得结果推广了方程组的sechξ型孤立波解的存在性结果.     

在Banach空间中推广的 Roper-Suffridge算子(III)

假定 $X$ 是具有范数$\|\cdot\|$的复 Banach 空间, $n$ 是一个满足 $\dim X\geq n\geq2$的正整数. 本文考虑由下式定义的推广的Roper-Suffridge算子 $\Phi_{n,\beta_2, \gamma_2, \ldots , \beta_{n+1}, \gamma_{n+1}}(f)$: \begin{equation} \begin{array}{lll} \Phi _{n, \beta_2, \gamma_2, \ldots, \beta_{n+1},\gamma_{n+1}}(f)(x) &;\hspace{-3mm}=&;\hspace{-3mm}\dl\he{j=1}{n}\bigg(\frac{f(x^*_1(x))}{x^*_1(x)})\bigg)^{\beta_j}(f''(x^*_1(x))^{\gamma_j}x^*_j(x) x_j\\ &;&;+\bigg(\dl\frac{f(x^*_1(x))}{x^*_1(x)}\bigg)^{\beta_{n+1}}(f''(x^*_1(x)))^{\gamma_{n+1}}\bigg(x-\dl\he{j=1}{n}x^*_j(x) x_j\bigg),\nonumber \end{array} \end{equation} 其中 $x\in\Omega_{p_1, p_2, \ldots, p_{n+1}}$, $\beta_1=1, \gamma_1=0$ 和 \begin{equation} \begin{array}{lll} \Omega_{p_1, p_2, \ldots, p_{n+1}}=\bigg\{x\in X: \dl\he{j=1}{n}| x^*_j(x)|^{p_j}+\bigg\|x-\dl\he{j=1}{n}x^*_j(x)x_j\bigg\|^{p_{n+1}}<1\bigg\},\nonumber \end{array} \end{equation} 这里 $p_j>1 \,( j=1, 2,\ldots, n+1$), 线性无关族 $\{x_1, x_2, \ldots, x_n \}\subset X $ 与 $\{x^*_1, x^*_2, \ldots, x^*_n \}\subset X^* $ 满足 $x^*_j(x_j)=\|x_j\|=1 (j=1, 2, \ldots, n)$ 和 $x^*_j(x_k)=0 \, (j\neq k)$, 我们选取幂函数的单值分支满足 $(\frac{f(\xi)}{\xi})^{\beta_j}|_{\xi=0}= 1$ 和 $(f''(\xi))^{\gamma_j}|_{\xi=0}=1, \, j=2, \ldots , n+1$. 本文将证明: 对某些合适的常数$\beta_j, \gamma_j$, 算子$\Phi_{n,\beta_2, \gamma_2, \ldots, \beta_{n+1}, \gamma_{n+1}}(f)$ 在$\Omega_{p_1, p_2, \ldots , p_{n+1}}$上保持$\alpha$阶的殆$\beta$型螺形映照和 $\alpha$阶的$\beta$型螺形映照.     

变系数耦合KdV方程组的复合型新解

通过函数变换与第二种椭圆方程相结合的方法,构造变系数耦合KdV方程组的复合型新解.步骤一、给出第二种椭圆方程的几种新解.步骤二、利用函数变换与第二种椭圆方程相结合的方法,在符号计算系统Mathematica的帮助下,构造变系数耦合KdV方程组的由Riemannθ函数、Jacobi椭圆函数、双曲函数、三角函数和有理函数组合的复合型新解,这里包括了孤子解与周期解复合的解、双孤子解和双周期解.     

长水波近似方程组的新精确解

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 .     

A Note on the Approximate Solution of the Cauchy Problem by Number-Theoretic Nets

рябенький, в. с.曾提出用数论网络构造的常微分方程组的解来构造偏微分方程 $\frac{\partial u}{\partial t}=Q(\frac{\partial}{\partial x_1},\cdots,\frac{\partial}{\partial x_s})u,0 \leq t \leq T,-\infty相似文献   

Exact travelling wave solutions for nonlinear Schr\"{o}dinger equation with variable coefficients

In this paper, two nonlinear Schr\"{o}dinger equations with variable coefficients in nonlinear optics are investigated. Based on travelling wave transformation and the extended $(\frac{G''}{G})$-expansion method, exact travelling wave solutions to nonlinear Schr\"{o}dinger equation with time-dependent coefficients are derived successfully, which include bright and dark soliton solutions, triangular function periodic solutions, hyperbolic function solutions and rational function solutions.     

The Riccati Equation Method Combined with the Generalized Extended $(G''/G)$-Expansion Method for Solving the Nonlinear KPP Equation

An analytic study of the nonlinear Kolmogorov-Petrovskii-Piskunov (KPP) equation is presented in this paper. The Riccati equation method combined with the generalized extended $(G''/G)$-expansion method is an interesting approach to find more general exact solutions of the nonlinear evolution equations in mathematical physics. We obtain the traveling wave solutions involving parameters, which are expressed by the hyperbolic and trigonometric function solutions. When the parameters are taken as special values, the solitary and periodic wave solutions are given. Comparison of our new results in this paper with the well-known results are given.     

The ( \frac{G'}{G}) -expansion method and its applications to some nonlinear evolution equations in the mathematical physics

In the present paper, we construct the traveling wave solutions involving parameters for some nonlinear evolution equations in the mathematical physics via the (2+1)-dimensional Painlevé integrable Burgers equations, the (2+1)-dimensional Nizhnik-Novikov-Vesselov equations, the (2+1)-dimensional Boiti-Leon-Pempinelli equations and the (2+1)-dimensional dispersive long wave equations by using a new approach, namely the ( $\frac{G'}{G})$ -expansion method, where G=G(ξ) satisfies a second order linear ordinary differential equation. When the parameters are taken special values, the solitary waves are derived from the traveling waves. The traveling wave solutions are expressed by hyperbolic, trigonometric and rational functions.     

Exact travelling wave solutions to the space-time fractional Calogero-Degasperis equation using different methods

In this paper, we employed the ansatz method, the exp-function method and the $\left( \frac{G^{\prime }}{G}\right) $-expansion method for the first time to obtain the exact and traveling wave solutions of the space time fractional Calogero Degasperis equation. As a result, we obtained some soliton and traveling wave solutions for this equation by means of proposed three analytical methods and the aid of commercial software Maple. The results show that these methods are effective and powerful mathematical tool for solving nonlinear FDEs arising in mathematical physics.     

A Generalized （G＇/G）-Expansion Method to Find the Traveling Wave Solutions of Nonlinear Evolution Equations

In this article, we construct the exact traveling wave solutions for nonlinear evolution equations in the mathematical physics via the modified Kawahara equation, the nonlinear coupled KdV equations and the classical Boussinesq equations, by using a generalized （G＇/G）-expansion method, where G satisfies the Jacobi elliptic equation. Many exact solutions in terms of Jacobi elliptic functions are obtained.     

Solitons and Other Solutions for the Generalized KdV–mKdV Equation with Higher-order Nonlinear Terms

The generalized sub-ODEmethod, the rational (G' ⁄ G)-expansionmethod, the exp-function method and the sine-cosine method are applied for constructing many traveling wave solutions of nonlinear partial differential equations (PDEs). Some illustrative equations are investigated by these methods and many hyperbolic, trigonometric and rational function solutions are found. We apply these methods to obtain the exact solutions for the generalized KdV-mKdV (GKdV-mKdV) equation with higher-order nonlinear terms. The obtained results confirm that the proposed methods are efficient techniques for analytic treatment of a wide variety of nonlinear partial differential equations in mathematical physics. We compare between the results yielding from these methods. Also, a comparison between our new results in this paper and the well-known results are given.     

具有局部时间分数阶导数的非线性Zoomeron方程的精确解

In this paper, we are concerned with the nonlinear Zoomeron equation with local conformable time-fractional derivative. The concept of local conformable fractional derivative was newly proposed by R. Khalil et al. The bifurcation and phase portrait analysis of traveling wave solutions of the nonlinear Zoomeron equation are investigated. Moreover, by utilizing the exp(-?(ε))-expansion method and the first integral method, we obtained various exact analytical traveling wave solutions to the Zoomeron equation such as solitary wave, breaking wave and periodic wave.     

Applications of fractional complex transform and $\left( \frac{G^{\prime }}{G}\right) $-expansion method for time-fractional differential equations

In this paper, the fractional complex transform and the $\left( \frac{G^{\prime }}{G}\right) $-expansion method are employed to solve the time-fractional modfied Korteweg-de Vries equation (fmKdV),Sharma-Tasso-Olver, Fitzhugh-Nagumo equations, where $G$ satisfies a second order linear ordinary differential equation. Exact solutions are expressed in terms of hyperbolic, trigonometric and rational functions. These solutions may be useful and desirable to explain some nonlinear physical phenomena in genuinely nonlinear fractional calculus.     

A new auxiliary function method for solving the generalized coupled Hirota–Satsuma KdV system

In this letter, a new auxiliary function method is presented for constructing exact travelling wave solutions of nonlinear partial differential equations. The main idea of this method is to take full advantage of the solutions of the elliptic equation to construct exact travelling wave solutions of nonlinear partial differential equations. More new exact travelling wave solutions are obtained for the generalized coupled Hirota–Satsuma KdV system.     

Exact Traveling Wave Solutions for Higher Order Nonlinear Schrödinger Equations in Optics by Using the (G'/G, 1/G)-expansion Method

The propagation of the optical solitons is usually governed by the nonlinear Schrödinger equations. In this article, the two variable (G'/G, 1/G)-expansion method is employed to construct exact traveling wave solutions with parameters of two higher order nonlinear Schrödinger equations describing the propagation of femtosecond pulses in nonlinear optical fibers. When the parameters are replaced by special values, the well-known solitary wave solutions of these equations rediscovered from the traveling waves. Thismethod can be thought of as the generalization of well-known original (G'/G)-expansion method proposed by M. Wang et al. It is shown that the two variable (G'/G, 1/G)-expansion method provides a more powerful mathematical tool for solving many other nonlinear PDEs in mathematical physics.