THE DETECTION OF SAW FIELD IN PULSE COMPRESSOR BY LASER SCANNING PROBE

The theory of acousto-optic interaction for the SAW field with metal strip reflective arrays(MSRA)onthe piezoelectric substrate is presented.The original optical probe system is improved to detect and displaythe SAW distribution in the pulse compressor with MSRA deposited on the surface of YZ-LiNbO_3,and theresults are analysed and discussed briefly.     

Determining the input dimension of a neural network for nonlinear time series prediction

Determining the input dimension of a feed-forward neural network for nonlinear time series prediction plays an important role in the modelling.The paper first summarizes the current methods for determining the input dimension of the neural network.Then inspired by the fact that the correlation dimension of a nonlinear dynamic system is the most important feature of it ,the paper pressents a new idea that the input dimension of the neural network for nonlinear time series prediction can be taken as an integer just greater than or equal to the correlation dimension.Fimally,some validation examples and results are given.     

扫描光声显微镜

本文简单叙述了扫描光声显微镜的原理、应用、发展以及我们现阶段的研制成果,光声信号可以用振幅或相位接收的方式成象,分辨率达到4.5μm,从已获得叉指换能器,集成电路以及材料亚表面结构等样品的光声象可以说明这种显微镜技术在固体物理、材料科学,甚至医学上均具有重要的应用前景。 关键词：     

隧道声显微镜的几种模式及理论研究

讨论了隧道声显微镜(TAM)的三种工作模式,即相互作用力-隧道间距模式、改进的STM测量模式和AFM测量模式,研究了它们的工作机理。建立了一个探针-样品相互作用的模型,理论分析了相互作用力与隧道间距的关系,计算结果与实验结果一致,该结果对于研制TAM实验系统和探针制备等具有指导意义.     

扫描激光探针检测声脉压线声场

本文讨论了晶体表面存在金属线条时的声光相互作用理论,改进了原来的激光探针测量系统,新的系统能够对弱表面波声场进行成像,实验上,还对制作在YZ-LiNbO₃晶体上的声表面波脉压线声场进行了测试,并对结果进行分析和讨论。