GLOBAL SHOCK SOLUTIONS TO A CLASS OF PISTON PROBLEMS FOR THE SYSTEM OF ONE DIMENSIONAL ISENTROPIC FLOW

The autors apply the result obtained in [1] to consider a class of discontinuous piston problems for the system of one dimensional isentropic flow and prove that this problem admits a unique global classical discontinuous solution only containing one shock.     

一类积分微分方程初值问题的正解

本文讨论了初值问题ｘ’＝ｇ（ｔ，ｘ，Ｔｘ），ｘ（０）＝ｘ０的正解的存在性。     

一类非线性发展方程初边值问题解的Blow—up

本文利用Fourier变换方法,研究了一类非线性拟双曲方程的初边值问题的解的bolw-up问题,并给出了其解在有限时间内bolw-up的条件。     

ON THE INITIAL BOUNDARY VALUE PROBLEMS FOR QUASILINEAR SYMMETRIC HYPERBOILC SYSTEM AND THEIR APPLICATIONS

In this paper we discuss the initial-boundary value problems for qnasilinear gymmetrio hyperbolic system and their applications. It is proved that Theorem 1, Suppose \(\Omega \) is a bomded domain, its boundary \(\partial \Omega \) is sufficient smooth. We consider the quasilinear symmetric hyperbolic system \[\sum\limits_{i = 0}^n {{a^i}(x,u)\frac{{\partial u}}{{\partial {x_i}}}} = f(x,u)\] in the domain \([0,h] \times \Omega \). The initial-boimda/ry conditions \[\begin{array}{l} {\left. u \right|_{{x_0} = 0}} = 0\{\left. {Mu} \right|_{\partial \Omega }} = 0 \end{array}\] are given. If \({a^0}\) is positive definite，\(\partial \Omega \) is noncharaGieristic, \(Mu = 0\) is stable admissible and all coefficients are smooth enough, some of derivatives of \(f(x,0)\) at \({{x_0} = 0}\) vanish., then the smooth solution of (1), (2) uniquely exists, if h is sufficiently small. Theorem 2. We consider the semi-Unear symmetric hyperbolic system \[\sum\limits_{i = 0}^n {{a^i}(x,u)\frac{{\partial u}}{{\partial {x_i}}}} = f(x,u)\] The initial-boundary conditions are still \[\begin{array}{l} {\left. u \right|_{{x_0} = 0}} = 0\{\left. {Mu} \right|_{\partial \Omega }} = 0 \end{array}\] If the bowndary \(\partial \Omega \) is a regular characteristic, \(Mu = 0\) is normally admissible and other conditions is the same as that in the theorem 1., then the smooth solution of (3), (4) still wriiquely exists if hM sufficiently small.     

关于Hirota-Satsuma系统初值问题的局部和整体适定性

本文利用ＫＤＶ方程所对应的线性方程解所具有的光滑效应及压缩映像原理,得到了Ｈｉｒｏｔａ－Ｓａｔｓｕｍａ系统初值问题的局部和整体适定性结果．     

一类非线性三阶三点边值问题的解和正解

考察了一类含有一阶和二阶导数的非线性三阶三点边值问题的解和正解.通过构造适当的Banach空间并且利用相应的积分方程建立了两个存在定理.主要结论表明,只要非线性项在其定义域的某个子集上的"高度"是适当的,该问题存在一个解或者正解.     

一类奇异二阶边值问题正解存在的充分必要条件

本文研究了一类奇异二阶边值问题u′′+a(t)f(u)+b(t)g(u)=0,u(0)-u′(0)=0,u(1)+u′(1)=0的C     

THE GLOBAL EXISTENCE OF BV SOLUTIONS OF THE ISENTROPIC p-SYSTEM WITH LARGE INITIAL DATA

In this paper,we study the global existence of BV solutions of the initial value problem for the isentropic p-system,where the state equation of the gas is given by P=Av^-γ.For γ> 1,the general existence result for large initial data has not been obtained.By using the Glimm scheme,Nishida,Smoller and Diperna successively obtained the global existence results for(γ-1)TV(v₀(x),u₀(x)) being small.In the present paper,by adopting a rescaling technique,we improve th...     

一类高阶常微分方程边值问题的解的存在惟一性

利用Wirtinger不等式和Leray-Schauder度理论,研究一类2n阶及2n 1阶非线性常微分方程的两点边值问题的解的存在惟一性。     

GLOBAL EXISTENCE OF WEAKLY DISCONTIN UOUS SOLUTIONS TO THE CAUCHY PROBLEM WITH A KIND OF NON-SMOOTH INITIAL DATA FOR QUASILINEAR HYPERBOLIC SYSTEMS

The authors consider the Cauchy problem with a kind of non-smooth initial datafor quasilinear hyperbolic systems and obtain a necessary and sufficient condition toguarantee the existence and uniqueness of global weakly discontinuous solution.     

TWO POSITIVE SOLUTIONS FOR A CLASS OF SINGULAR BOUNDARY VALUE PROBLEMS

An existence theorem of two positive solutions of the singular BVP1/(p(t))(p(t)y′(t))′+λα(t)f(y(t))=0,t∈(0,1),αy(0)-βp(t)y′(t)=0=γy(1)+δp(t)y′(t)was established by using topological degree theory.     

GLOBAL ENTROPY SOLUTIONS TO AN INHOMOGENEOUS ISENTROPIC COMPRESSIBLE EULER SYSTEM

In this article, we develop a new technique to prove the global existene of entropy solutions to an inhomogeneous isentropic compressible Euler equations through the compensated compactness and vanishing viscosity method. In particular, the entropy solutions are uniformly bounded independent of time.     

一类非线性p-Laplace边值问题的正解

应用锥理论和不动点指数方法,在与相应齐次增算子的第一特征值相关的条件下,得到了下述非线性p-Laplace边值问题{(|u″|p-1u″)"=f(t,u),t∈(0,1),u(0)=u(1)=u″(0)=u″(1)=0的正解,改进了相关文献中的结论     

THE REGULARITY AND UNIQUENESS OF A GLOBAL SOLUTION TO THE ISENTROPIC NAVIER-STOKES EQUATION WITH ROUGH INITIAL DATA

A global weak solution to the isentropic Navier-Stokes equation with initial data around a constant state in the L¹∩ BV class was constructed in [1].In the current paper,we will continue to study the uniqueness and regularity of the constructed solution.The key ingredients are the Holder continuity estimates of the heat kernel in both spatial and time variables.With these finer estimates,we obtain higher order regularity of the constructed solution to Navier-Stokes equation,so that al...     

一维非齐次BBM方程初边值问题的整体吸引子

研究了一维非齐次BBM方程ut-uxxt-(x^2n 1)x=f(u) γuxx g(x),ux(0,t)=0,u(1,5)=0,u(x,0)=u0(x).的初值边界问题，利用Sobolev插值不等式，对解做关于时间t的一致性先验估计，证明了该问题的整体吸引子的存在性．     

GLOBAL BEHAVIOR OF POSITIVE SOLUTIONS TO A KIND OF THREE-POINT BOUNDARY VALUE PROBLEMS

In this paper, using the fixed-point index theorems and the cone theory we study the structure of the positive solutions to a kind of second-order three-point boundary value problems. We obtain the result which guarantee that the positive solution set of the three-point boundary value problem has a continuum, which means that there exists a nonempty, closed and connected subset.     

GLOBAL CLASSICAL SOLUTIONS TO THE 3-D ISENTROPIC COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH GENERAL INITIAL ENERGY

We establish the global existence and uniqueness of classical solutions to the Cauchy problem for the 3-D compressible Navier-Stokes equations under the assumption that the initial density ρ0 L∞ is appropriate small and 1 < γ < 65.Here the initial density could have vacuum and we do not require that the initial energy is small.     

A TWO-STEP EXPLICIT METHOD FOR A CLASS OF LINEAR PERIODIC INITIAL VALUE PROBLEMS

This paper presents a two-step explicit method of order four for solving a class of linear periodic initial value problems. At each computational step, only two right function evaluations and one derivative evaluation are employed. Basing on a special vector operation, the method can be extended to the vector-applicable in multidimensional space.