Existence of Surface Waves and Band Gaps in Periodic Heterogeneous Half-spaces

We find a sufficient condition for the existence of surface (Rayleigh) waves based on the Rayleigh-Ritz variational method. When specialized to a homogeneous half-space, the sufficient condition recovers the known criterion for the existence of subsonic surface waves. A simple existence criterion in terms of material properties is obtained for periodic half-spaces of general anisotropic materials. Further, we numerically compute the dispersion relation of the surface waves for a half-space of periodic laminates of two materials and demonstrate the existence of surface wave band gaps.     

A comparison of master equation and Fokker-Planck equation in the thermodynamic limit

The master equation and the Fokker-Planck equation are compared thoroughly in both of the stationary and the time-dependent cases for a one-dimensional system. The comparison includes the master equation without detailed balance.     

小型13C NMR谱图数据库

本文着重介绍用当前微机系统上流行的DBASEⅡ建立谱图数据库以及用BASIC语言进行结构检索的方法。检索系统能方便地提供用户收集、修正、查询、显示和打印谱图数据和分子结构图的功能。这种系统对建立专用的小型谱图数据库有实用价值。     

予条件共轭梯度法的收敛性

本文对某些予条件共轭梯度法的收敛性进行了一些分析,如ICCG法,ILUCK(K)法、ILUCG(P)法及所谓的"TCG法",其中用了许多分裂作为对所要解的线性代数方程组的系数矩阵A进行予条件的工具,这里设A为对角优势矩阵,文中还给出了若干数值算例来说明我们分析的结果。     

二维核磁共振数据的噪声剔除与数据压缩

讨论了对二维核磁共振数据进行噪声剔除与数据压缩的一般原理与方法,介绍在Sun图形工作站上的实现情况,并给出实验结果与分析。     

Ⅱ-Ⅵ族化合物半导体超微粒子光谱性质的研究:Ⅰ硫化物

本文报道了锌、镉、汞、铅硫化物半导体极超微粒子的制备以及它们的光谱性质,比较了它们的粗、细粒子的吸收光谱和荧光光谱的差异,用量子化粒径效应解释了当超微粒子的粒径减小时出现的能级分裂.同时讨论了上述物质的极超微粒子在老化过程中的行为及其原因.