两种群非自治Lotka-Volterra竞争扩散系统的概周期解

本文讨论两种群概周期竞争扩散系统，利用微分不等式，证明了系统概周期解的存在、唯一性及其在壳扰动下的稳定性．     

求解径向Schrodinger方程解析解的一种方法以及由此延伸的讨论--叠加势基态能级与势参数关系

采用转化法.可得到一系列具有球对称势函数的径向Schrodinger方程的解析解和能级方程.这种方法是用一个恰当的尝试波函数代入Schrodinger方程后,将微分方程变成简单的可解的代数方程组,由此大大简化了运算.本文给出了库仑势、库仑势与谐振子势的叠加势以及离子与原子相互作用势的径向Schrodinger方程解析解,并得到能级方程.由于此方法中涉及一个势参数制约关系,为此以叠加势V(r)=-A1r-1-A2r-3+A3r-4为例,讨论其基态能级.得出重要结论:在库仑势上叠加上两项逆幂指数势作用后基态能量将增大,但是并不是单调增大,而是与各项势参数有关.     

非齐次Toda晶格的对称,精确解和可积性

研究非齐次Toda晶格，即一类非齐次非线性微分差分方程的对称与可积性。给出了这一类方程的Lie点对称，条件对称和精确解。给出这类方程与Toda晶格之间的可逆点变换，从而表明这一类方程是可积的。     

一类多偏差变元的二阶微分方程周期解

本文利用重合度理论研究了一类二阶多偏差变元的微分方程 x＂（t）＋f（t,x（t）,x（t-τ0（t））,x＇（t））＋∑nj=1g（x（t-τj（t）））=p（t） 的周期解问题，得到了存在周期解的新的结果．     

具奇系数发展型p-Laplace不等方程整体解的不存在性

考虑两类带奇性系数发展型p-Laplace不等方程整体非负解的不存在性,也即要证明某些拟线性抛物型方程的非线性Liouville定理.通过先验估计,证明了整体解在某个带参数的函数空间中的不存在性.当只考虑连续整体解时,可选取不带参数的函数空间并证明整体解在其中的不存在性.     

A New Modified Extended Tanh-Function Method and Its Application

In this paper, a new modified extended tanh-function method is presented for constructing soliton-like,periodic form solutions of nonlinear evolution equation (NEEs). This method is more powerful than the extended tanhfunction method [Phys. Lett. A277 (2000) 212] and the modified extended tanh-function method [Phys. Left. A285 (2001) 355]. Abundant new solutions of two physically important NEEs are obtained by using this method and symbolic computation system Maple.     

Transportation Characteristics for a Class of Generalized N-Diffusion Equation with Convection

A suitable similarity transformation group is used to reduce the power law parabolic partial equation to a classof singular nonlinear boundary value problems. Analytical solutions and numerical solutions both are presented for the specific power law index N, conductivity and convective functions, and the associated transportation characteristics are discussed in detail.     

The Fundamental Solutions of the Space, Space-Time Riesz Fractional Partial Differential Equations with Periodic Conditions

In this paper, the space-time Riesz fractional partial differential equations with periodic conditions are considered. The equations are obtained from the integral partial differential equation by replacing the time derivative with a Caputo fractional derivative and the space derivative with Riesz potential. The fundamental solutions of the space Riesz fractional partial differential equation (SRFPDE) and the space-time Riesz fractional partial differential equation (STRFPDE) are discussed, respectively. Using methods of Fourier series expansion and Laplace transform, we derive the explicit expressions of the fundamental solutions for the SRFPDE and the STRFPDE, respectively.