非接触式指纹采集与识别的研究

为了构建一个结构紧凑、实时、高效、小型的指纹采集识别系统,提出了非接触式光学采集方法.即采用激光或非相干光源,利用激光透射、扫描和非相干光照射,通过超半球浸没透镜和双胶合透镜等组合的光学系统,运用光学非接触式方法实现完整、清晰的指纹图像的采集,这种方法有效地避免了接触式所造成的指纹的旋转、扭曲和变形,提高了采集图像的质量.从而为利用空间光调制器实现指纹的实时傅里叶相关识别提供了有效的保证.     

一种新结构的硅基无源环形波导式谐振腔

提出了一种新结构的光学环形谐振腔。该谐振腔由四根直波导和四个拐弯角处集成的全反射镜围成一个方形环构成，这种结构免去了以前的波导式环形谐振腔中必需包含的弯曲波导。设计了谐振腔的输入和输出结构，并通过计算机辅助设计软件对该设计进行了优化。     

Short-Period GaMnAs/GaAs Superlattices: Optical and Magnetic Characterization

Superlattices with magnetic layers containing from 8 to 16 GaMnAs monolayers corresponding to the mixed crystal composition between 5 and 6% of Mn and from 4 to 10 GaAs monolayers were grown by the low temperature MBE technique and characterized by Raman scattering. Folded acoustic phonons were observed for all superlattices in the Raman scattering spectra. The interlayer exchange coupling, found previously by the wide-angle neutron diffraction in selected superlattices was investigated by the spin-polarized neutron reflectometry. It was always of ferromagnetic type, no trace of antiferromagnetic coupling was found.     

砂砾岩储集层的地震反演方法

T719井区位于东营凹陷宁海断裂构造带的T94断层和胜北断层文汇区下降盘，沙四段-沙三段沉积期的古地貌沟梁相间，发育了夹于烃源岩内的规模较大的深水浊积扇体，主要储集岩为含砾砂岩和砾岩，其厚度差异较大，横向变化非常快。为研究储集层的变化细节并精细预测其分布，采用经高分辨率处理的纯波带地震数据、以测井资料为约束条件，用神经网络技术建立精细波阻抗初始模型，再利用拟线性方法细微调整，在最终反演出的具有较宽频带的绝对波阻抗剖面上，砂砾岩扇体与波阻抗的对应关系良好，其分布范围与实际钻探结果吻合。图3参5     

用线阵CCD精确测量判读镜具观察孔直径

判读镜具观察孔的直径直接影响航空照片中各种目标的观察效果。基于圆孔夫琅和费衍射测量微孔直径的原理和线阵CCD信号串行输出的特点，给出了照片判读镜具中观察孔直径测量的硬件和软件实施方案。最后对实验进行了分析。表明该方法具有科学性与实用性。     

YBa2Cu3O7?X 500–600 K Isostructural Phase Transition and Its Influence on Critical-Current Value

YBa₂Cu₃O_7–X ceramic samples voltage–current characteristics at 77 K and acoustic emission activity during thermocycling 500–600 K region have been studied. Partial oxygen sorption by these samples through heating has been established by critical-current value and acoustic emission activity at 540–550 K. During thermocycling an acoustic emission maximums have been observed on 3rd and 6th thermocycles, and these maximums correlate with some decrease of the critical-current value. It is shown that observed acoustic emission maximums are because of a phase-work hardening during thermocycling of these samples. A mechanism of this phase-work hardening influencing the critical-current value in YBa₂Cu₃O_7–X ceramic samples is discussed.     

The theoretical modelling of aerodynamic noise

This paper is a review of the present state of understanding of aerodynamically generated noise. Based on an invited lecture given at the Sixth Canadian Congress of Applied Mechanics, Vancouver, May–June 1977, and at the Indian Academy of Science, Bangalore, July 1977     

ASML公司光学光刻技术最新进展

荷兰ASML公司作为全球三大光刻机集成生产商之一，通过不断的技术创新，在全球光刻机市场上居于领先地位。在简单介绍光刻机基本工作原理和主要技术指标的基础上，详细分析了ASML公司在光学光刻技术方面的最新技术进展。     

基于声信号的轴承故障诊断方法

机械设备在运行过程中的声音包含了大量的机构运行状态信号，本文采用相关分析，小波变换原理，从应用的角度出发，对滚动轴承故障声信号进行时频分析。通过对声信号的多尺度分解和重构，分离出由故障造成的声信号突变。试验表明，该方法具有较好的可靠性和有效性。     

球罐活性缺陷的模糊评定方法

根据国内外有关标准和文献,利用模糊数学中的模糊描述和隶属度等概念,首次采用多级模糊综合评定理论,分层次地把活性缺陷的主要监测信息(即声发射源信息)和专家们的经验考虑在内,建立在用球形贮罐声发射源严重度多级模糊综合评定模型和方法,并编制计算机数据分析和处理程序,使评定结果趋于更合理和可靠.并给出在用球形贮罐声发射源严重度多级模糊综合评定算例,结果表明,该评定方法可以达到定量化的程度,与局部无损复验结果有良好的一致性.