具有一般粘性和压力的可压缩Navier-Stokes方程组的真空状态

本文在压力和粘性系数是密度的一般函数的假设下, 研究了当初始密度间断地连接到真空时的一维粘性气体模型, 利用差分方法, 证明了可压缩Navier-Stokes方程组弱解的整体存在性和唯一性. 为了克服一般的粘性系数μ(ρ)代替通常的 ρ^θ给研究带来的困难, 本文得到了一些新的先验估计.     

Discreteness of the exterior transmission eigenvalues

In this paper we consider a kind of exterior transmission problem in which the refractive index n(x) is a piecewise positive constant. Through establishing an equivalent boundary integral system, we obtain that the set of exterior transmission eigenvalues is a discrete set. Furthermore, we prove that there does not exist a transmission eigenvalue under some conditions.