拟线性双曲抛物耦合组的激波解及高维等温辐射激波解的线性稳定性

本文讨论双曲抛物耦合守恒律组的激波解的一致稳定性,证明了伴随线性化问题的能量估计及存在性,由此并可得非线性问题解的存在性.对等温辐射激波,稳定性等价于Lax的等温音速激波不等式.     

THE GENERAL INITIAL-BOUNDARY VALUE PROBLEMS FOR LINEAR HYPERBOLIC-PARABOLIC COUPLED SYSTEM

In this paper, the author considers the general initial boundary value problem of hyperbolic-parabolic coupled system and gives the normal form of boundary conditions, sufficient and necessary for the BVP and the conjugate BVP to be weLl-posed. Furthermore, the author proves the existence of differentiable solution in Sobolev spaces of high order.     

正对称组在角状区域内的合格边值问题

本文考虑角状区域内正对称组的稳定合格边值问题,在“恰当定号”的假设下,对于非特征边界,得到了非齐次边值问题当资料为H~1时的H~1强解存在性及相应的能量不等式(定理2);对于一侧为特征的边界,用逼近法证明了其L~2适定性(定理3)。以上结果用于讨论对称双曲组,得劈状区域中的H~1及L~2适定性(定理4、5)。     

变秩特征边界正对称组的齐次合格边值问题

本文考虑在变秩特征边界附近为双曲型的正对称组的齐次合格边值问题的L~2适定性。设,在Ω中是正对称组合格边值问题。Ω为x<0,Γ=Γ1Γ2={y≤0}{y≥0}。 若B正定,π关于B恰当定号,π_1(?)π_2在Γ_1∩Γ_2上,则边值问题存在唯一强解u∈L~2(Ω)。又若共轭问题也满足同样条件,则L~2强弱解一致。     

THE L~2-BOUNDEDNESS OF PSEUDODIFFERENTIAL OPERATORS WITH NONSMOOTH COEFFICIENT SYMBOLS

§1. Introduction In application of nonlinear boundary value problems, it is sometimes important to know that L~2-boundedness of a class of pseudo-differential operators with symbols whioh have nonsmooth coefficients. In [2], Coifman and Meyer proved that the operator σ(x, D) is bounded in L~2(R~n) if its symbold (x, ξ) satisfies: