一类非线性双重退缩抛物方程的Cauchy问题

本文研究了一类非线性双重退缩抛物方程Ｃａｕｏｎｙ问题解的存在唯一性以及解的长时间性质．     

一类高阶非线性双曲型方程Cauchy问题解的爆破

本文研究一类高阶非线性双曲型方程utt-uxx+μuxxx-αuxxtt+βuxxxxtt=f(ux)x的Cauchy问题,证明问题解的存在性与唯一性,并给出解在有限时刻爆破的充分条件.     

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Laplace双曲型方程广义Cauchy问题的反问题

本文讨论了确定Ｌａｐｌｉｔｃｅ双曲型方程u_xy(x,y)+a(x,y)u_x(x,y)+b(x,y)+u_y(x,y)+q(x)u(x,y)=f(x,y)的广义Ｃａｕｃｈｙ问题中系数ｑ（ｘ）的反问题。文中利用特征法线及不动点理论，导出了与反问题等价的非线性积分方程组，证明了反问题局部解的存在唯一性，最后给出了反问题整体用的唯一性定理。     

一类广义Boussinesq型方程的Cauchy问题

证明了一类广义Boussinesq型方程Cauchy问题整体解的存在性与唯一性,并给出解在有限时刻爆破的充分条件.     

一类N维非线性波动方程的Cauchy问题

证明下列非线性波动方程的Cauchy问题v_(tt)-α△v_(tt)-Δv=g(v)-αΔg(v),x∈R~N,t>0,(1)v(x,0)=v_0(x),v_t(x,0)=v_1(x),x∈R~N(2)在空间C~2([0,∞);H~s(R~N))(s>N/2)中存在唯一整体广义解v和在空间C~2([0,∞);H~s(R~N))(s>2+N/2N)中存在唯一整体古典解v,即u∈C~2([0,∞);C_B~2(R~N)).还证明Cauchy问题(1),(2)在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m≥0,1≤p≤∞)中有唯一整体广义解v和在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m>2+N/P)中有唯一整体古典解v,即v∈C~3([0,∞);C~2(R~N)∩L~∞(R~N)).     

非线性扩散方程Cauchy问题解的唯一性和稳定性

研究方程au/at=△A(u)+Σ^N_i=1 abⁱ(u) / ax^#em/em#+c(u)Cauchy问题解的唯一性。证明了如果u∈BV_x且A(u)严格递增,则解是唯一的。     

一类拟线性退化抛物方程的Cauchy问题

对方程α（xx）u＋uαyu-αtu=f（·,u）,（x,y,t）∈R^2×（0,T）的Cauchy问题,给出了一个整体BV-弱解的定义,证明了该弱解的连续性.     

一类双色散波方程的Cauchy问题

This paper concerns with the Cauchy problem for the nonlinear double dispersive wave equation.By the priori estimates and the method in [9],It proves that the Cauchy problem admits a unique global classical solution.And by the concave method,we give sufficient conditions on the blowup of the global solution for the Cauchy problem.     

以局部有限测度为初值的拟线性退化双曲方程BV解的存在唯一性

本文讨论了下列拟线性退化双曲方程ut (?)(u)x=0,以σ-有限的Borel测度为初值条件的Cauchy问题解的存在唯一性,其中在R上是连续的非减的函数.     

The Cauchy Problem of the Porous Medium Equation with Absorption

In this paper we study the existence of solution for the following Cauchy problem {u_t = Δu^m - u^p u(x,0) = u_0(x) We show how the growth condition of initial trace is determined by the absorption.     

Lipschitz Continuous Solutions to the Cauchy Problem for Quasi-linear Hyperbolic Systems

Lipschitz continuous solutions to the Cauchy problem for 1-D first order quasilinear hyperbolic systems are considered. Based on the methods of approximation and integral equations,the author gives two...     

Propagation of singularities in the Cauchy problem for a class of degenerate hyperbolic operators

We consider second order degenerate hyperbolic Cauchy problems, the degeneracy coming either from low regularity (less than Lipschitz continuity) of the coefficients with respect to time, or from weak hyperbolicity. In the weakly hyperbolic case, we assume an intermediate condition between effective hyperbolicity and the Levi condition. We construct the fundamental solution and study the propagation of singularities using an unified approach to these different kinds of degeneracy.     

On the Cauchy Problem for a Class of Semilinear Hyperbolic Equations with Discontinuous Coefficients and Data

ln this paper we establish the existence of local solution to the Cauchy problem for a class of semilinear second order hyperbolic equations including degenerated type equations with discontinuous coefficients and data.     

耗散Schrodinger-Poisson方程组的Cauchy问题

考虑耗散Schrodinger-Poisson方程组的Cauchy问题,对于吸引力场情形,证明了该问题整体强解的存在唯一性.      

Uniqueness and stability of solution for Cauchy problem of degenerate quasilinear parabolic equations

The uniqueness and existence of BV-solutions for Cauchy problem of the form are proved.     

The method of boundary integral equations for a mixed scattering problem

In this paper we consider the scattering of an electromagnetic time-harmonic plane wave by an infinite cylinder having an open arc and a bounded domain in R² as cross section. To this end, we solve a scattering problem for the Helmholtz equation in R² where the scattering object is a combination of a crack Γ and a bounded obstacle D, and we have Dirichlet-impedance type boundary condition on Γ and Dirichlet boundary condition on ∂D (∂D∈C²). Applying potential theory, the problem can be reformulated as a boundary integral system. We establish the existence and uniqueness of a solution to the system by using the Fredholm theory.     

Existence and uniqueness results for the bending elastic beam equations

This paper deals with the solvability of the fourth-order boundary value problem $\left\{\begin{array}{c}{u}^{\left(4\right)}=f(x,u,u^{\prime \prime }),0\le x\le 1,\hfill \\ u\left(0\right)=u\left(1\right)=u^{\prime \prime }\left(0\right)=u^{\prime \prime }\left(1\right)=0,\hfill \end{array}\right.$ which models a statically bending elastic beam whose two ends are simply supported, where $f:[0,1]\times {\mathbb{R}}^2\to \mathbb{R}$ is continuous. Inequality conditions on $f$ guaranteeing the existence and uniqueness of solution are presented. The inequality conditions allow that $f(x,u,v)$ may be superlinear growth on $u$ and $v$ as $\left|(u,v)\right|\to \infty$.