超双曲型方程的解的性质与 Dirichlet 问题

本文主要通过基本解、基本公式讨论了超双曲型方程的解的性质;提出超双曲型方程具非解析的广义势解;并得到超双曲型方程 Dirichlet 问题的解的表达式.特别指出:通过基本解研究超双曲型方程是自然的途径.     

两类方程Cauchy问题经典解的等价性

对于给出的一类二阶线性双曲型方程,通过未知变量替换,将其化为一阶对称双曲型方程组.可以证明这个一阶对称双曲型方程组与原来的二阶线性双曲型方程的Cauchy问题的经典解在某种意义下是等价的.     

一类变系数超双曲型方程的中量定理及其应用

对超双曲型方程的正确提法还知之不多，著名的Asgeirsson中量定理使得一些定解问题得以解决，而且它可以用来证明超双曲型方程解的拓展性。因此对Asgeirsson中量定理的推广就有重要意义。目前对变数超双曲型方程解的中量性质的研究未取得明确结论。本文针对一类变系数超双曲型方程引入了一种广义中量，利用Green公式，导出了广义中量满足一种广义E-P-D方程，证明了该广义E-P-D方程解的存在性和所具有的正则性，从而对于一类变系数的超双曲型方程，得到了解的中量定理。利用该中量定理，得到了（模）超双曲型方程Cauchy问题的解和超双曲型方程解拓展性及其应用。     

一般式双曲型方程及其应用

另一方面,当A_1B_2-A_2B_1≠0时,方程(2)必定为双曲型方程,当且仅当k=0时,退化为两相交直线。 方程(2)称为双曲型方程的一般式。 利用一般式双曲型方程来研究双曲线或其特例的性质,其优越性是十分明显的。     

非欧空间中双基本图形的度量方程及其应用

本文提出了n维球面型空间和双曲空间中双基本图形的概念,建立了球面型空间与双曲空间中双基图形的度量方程,并给出度量方程的一些应用.     

非线性带强迫项双曲型时滞微分方程解的振动性质

本文研究一类带强迫项时滞双曲型方程解的振动性质．所得应用便利的判别振动的充分条件从理论上揭示了这类方程与普通双曲型方程的差异．     

一类拟线性方程组Galerkin方法解的存在性和误差估计

§1.引言对于抛物型方程和双曲型方程的Galerkin方法,已有不少人作了讨论。如[2][3][4]是研究抛物型的,[5][6][7]是研究双曲型的。本文研究以热弹性问题为背景的下列抛物——双曲耦合初边值问题:     

一类非线性双曲型方程有限元方法的稳定性和收敛性

本文研究一类非线性双曲型方程混合问题的有限元方法的稳定性和收敛性理论.关于线性双曲型方程有限元方法的收敛性研究,已有T.Dupont,J.T.Oden等人的工作.     

关于非线性双曲型方程全离散有限元方法的稳定性和收敛性估计

本文研究非线性双曲型方程混合问题的有限元方法.这类问题的研究,对于非线性振动、渗流力学等实际问题,在理论和实用方面均有价值.关于线性、半线性双曲方程全离散有限元方法及非线性双曲方程半离散有限元方法的收敛性研究,已有[1]—[4].     

一类双曲型方程的Huygens原理

通过双曲型方程的Hadamard基本解理论,将Huygens算子识别问题转化为双曲型方程的系数满足的关系,找出了更多的Huygens算子,从而推广了Stellmacher的结果,并解析了Veselov和Berest给出的一类Huygens算子与Stellmacher算子的关系．     

Hyperbolic–parabolic singular perturbation for quasilinear equations of Kirchhoff type with weak dissipation

We consider a hyperbolic–parabolic singular perturbation problem for a quasilinear hyperbolic equation of Kirchhoff type with dissipation weak in time. The purpose of this paper is to give time‐decay convergence estimates of the difference between the solutions of the hyperbolic equation above and those of the corresponding parabolic equation, together with the unique existence of the global solutions of the hyperbolic equation above. Copyright © 2009 John Wiley & Sons, Ltd.     

几种广义非线性发展方程的新解

本文研究了构造了广义Kd V方程和广义KP-Burgers方程等几种广义非线性发展方程的新解的问题.利用三种辅助方程及其新解,获得了广义Kd V方程和广义KP-Burgers方程等几种广义非线性发展方程的新解.这些解由双曲余割函数、双曲正切函数、双曲正割函数、双曲余切函数和余割函数组成.     

Hyperbolic Khler-Ricci flow

In this paper, the author has considered the hyperbolic Khler-Ricci flow introduced by Kong and Liu, that is, the hyperbolic version of the famous Khler-Ricci flow. The author has explained the derivation of the equation and calculated the evolutions of various quantities associated with the equation including the curvatures. Particularly on Calabi-Yau manifolds, the equation can be simplifled to a scalar hyperbolic Monge-Ampère equation which is the hyperbolic version of the corresponding one in Khler-Ricci flow.     

On the multiple hyperbolic systems modelling phase transformation kinetics

We discuss Cahn’s time cone method modelling phase transformation kinetics. The model equation by the time cone method is an integral equation in the space-time region. First, we reduce it to a system of hyperbolic equations, and in the case of odd spatial dimensions, the reduced system is a multiple hyperbolic equation. Next, we propose a numerical method for such a hyperbolic system. By means of alternating direction implicit methods, numerical simulations for practical forward problems are implemented with satisfactory accuracy and efficiency. In particular, in the three dimensional case, our numerical method on the basis of reduced multiple hyperbolic equation is fast.     

时滞抛物型与双曲型微分方程解的振动性的讨论

对一类线性以及非线性抛物型时滞微分方程的解在第一或第二边值条件下解振动的充分必要条件进行了讨论,给出了解振动的一些结论.并且对一类线性以及带强迫项的非线性双曲型时滞微分方程的解在第一或第二边值条件下解振动的充分必要条件进行了讨论,也给出了一些结论.     

The Exact Solutions for the Benjamin-Bona-Mahony Equation

The Benjamin-Bona-Mahony (BBM) equation represents the unidirectional propagation of nonlinear dispersive long waves, which has a clear physical background, and is a more suitable mathematical and physical equation than the KdV equation. Therefore, the research on the BBM equation is very important. In this article, we put forward an effective algorithm, the modified hyperbolic function expanding method, to build the solutions of the BBM equation. We, by utilizing the modified hyperbolic function expanding method, obtain the traveling wave solutions of the BBM equation. When the parameters are taken as special values, the solitary waves are also derived from the traveling waves. The traveling wave solutions are expressed by the hyperbolic functions, the trigonometric functions and the rational functions. The modified hyperbolic function expanding method is direct, concise, elementary and effective, and can be used for many other nonlinear partial differential equations.     

双曲空间中Laplace-Beltrami方程的一个带位移的边值问题

讨论了双曲空间中Laplace-Beltrami方程的一个带位移的边值问题.首先将双曲空间中的Laplace-Beltrami方程的解转化为Clifford分析中的超正则函数.然后给出了超正则函数的Plemelj公式并讨论了相关奇异积分算子的性质,最后利用积分方程的方法和压缩不动点原理证明了Laplace-Beltrami方程的一个带位移的边值问题的解的存在性和唯一性.     

Symmetry Reduction and Exact Solutions of a Hyperbolic Monge-Amp`ere Equation

By means of the classical symmetry method,a hyperbolic Monge-Ampère equation is investigated.The symmetry group is studied and its corresponding group invariant solutions are constructed.Based on the associated vector of the obtained symmetry,the authors construct the group-invariant optimal system of the hyperbolic Monge-Ampère equation,from which two interesting classes of solutions to the hyperbolic Monge-Ampère equation are obtained successfully.     

High order implicit collocation method for the solution of two‐dimensional linear hyperbolic equation

In this article, we introduce a high‐order accurate method for solving the two dimensional linear hyperbolic equation. We apply a compact finite difference approximation of fourth order for discretizing spatial derivatives of linear hyperbolic equation and collocation method for the time component. The resulted method is unconditionally stable and solves the two‐dimensional linear hyperbolic equation with high accuracy. In this technique, the solution is approximated by a polynomial at each grid point that its coefficients are determined by solving a linear system of equations. Numerical results show that the compact finite difference approximation of fourth order and collocation method give a very efficient approach for solving the two dimensional linear hyperbolic equation. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009     

带有线性外力场的双曲平均曲率流Cauchy问题经典解的生命跨度

本文提出并研究带有线性外力场的双曲平均曲率流,通过凸曲线的支撑函数,导出一个双曲型Monge-Ampère 方程并将其转化成Riemann 不变量满足的拟线性双曲方程组。利用拟线性双曲方程组Cauchy 问题的局部解理论,讨论带有线性外力场的双曲平均曲率流Cauchy 问题经典解的生命跨度（即局部解存在的最大时间区间）。