无铬钝化技术研究的进展

评述了文献报道和各种不同的无铬钝化工艺的特点及其发展现状。目前还没有一种无铬钝化工艺能够完全代替铬酸盐钝化工艺，某些无铬钝化工艺在某些方面已经与铬酸盐钝化相当，但其市场前景、应用范围及用户环保效果还需要进一步研究。     

Micromechanical modelling of ductile crack growth in the binder phase of WC–Co

This study focuses on numerical simulation of ductile failure in the Co binder phase of WC–Co hardmetal. The growth of edge cracks under mode I loading is considered. A computational micromechanics approach is taken where the Co binder ligaments are explicitly represented in finite element models. An embedding technique is employed. Crystal plasticity theory is used to represent plastic deformation in the Co ligaments. Crack propagation in the binder is simulated using an element removal technique based on a modified Rice and Tracey model for ductile void growth, and fracture resistance curves are generated. Parameter studies are performed for variations in microstructrual parameters such as numbers of Co ligaments ahead of the crack tip and local Co volume fraction. The importance of thermal residual stresses and finite element mesh density are also investigated.     

First Harmonic (2f) Characterisation of Resonant Frequency and Q-Factor of Micromechanical Transducers

In this paper, the response to the first harmonic component (2f) of the electrostatic force in single terminal driven electrostatic comb-drive and parallel-plate drive was used as a signal to extract device parameters, namely, the Q-factor and resonant frequency instead of the fundamental (1f) resonance response. It is shown that the difficulty in motional measurement due to electrical cross-talk (parasitics) using 1f measurement can be overcome with a higher signal-to-noise ratio of the 2f signal. Both atmospheric (low-Q) and reduced pressure environment were investigated using off-chip electronics and lock-in amplifier. The measurements were done on the electrostatic comb-drive and capacitive parallel plate sensing plates that form the two core modules of a yaw rate sensor (dual-axis resonator). The effects of AC and DC bias voltages on the measured response have been investigated. Experimental amplitude and phase response data have been analysed using the Lorentzian curve-fit, Resonance Curve Area (RCA) method, the half-power bandwidth method (3 dB) and the Nyquist plot for data fitting and determination of the Q-factor and resonance frequency.     

云南东川泥石流沟与非泥石流沟~(137)Cs示踪法物源研究

运用1 37Cs示踪法调查云南东川小江流域 6条泥石流沟、6条非泥石流沟和主河的泥沙来源。泥沙主要来源于冲沟侵蚀和滑坡崩塌堆积、坡耕地和草地。坡耕地和草地表层土壤1 37Cs平均含量分别为 0 9Bq m2 和1 98Bq m2 ,冲沟沟壁和滑坡崩塌堆积土体1 37Cs。作者通过 3种源地土体1 37Cs含量的比较 ,分析了细粒泥沙(<0 0 1mm)的来源。 6条泥石流沟冲沟侵蚀和重力侵蚀 (滑坡崩塌 )的相对产沙量变化于 90 2 %～ 1 0 0 % ,平均值为 95 1 % ,6条非泥石流沟的相对产沙量变化于 74 5 %～ 83 3% ,平均值为 78 9%。小江主河为 81 4 %。     

计算机技术在电子装备测试系统中的应用研究

在现代测试技术快速发展的今天，计算机已成为武器装备自动测试系统中不可缺少的重要组成部分。高性能的计算机软件技术更是构建智能型、集成化自动测试系统的关键所在。分析了先进的软件技术在自动测试系统中的应用状况；并以导弹地面测量雷达系统为例，具体介绍了利用系统仿真方法进行装备自动检测的技术实现。     

微区电阻测试方法及新测试仪研制

文章对国内外开展微区薄层电阻测试的方法进行了综述，特别对改进范德堡四探针技术方法的测试原理、测试过程与测试结果进行了论述与分析，对微区电阻测试方法的进一步发展提出了一种可操作的方法，并研制出新型四探针测试样机。     

超声处理对RTM成型复合材料界面性能的影响

在RTM成型过程中采用超声技术。探讨了超声处理的最佳工艺参数,着重研究超声处理对RTM成型复合材料界面性能的影响。结果表明,在RTM成型过程中采用超声技术增加了树脂对纤维增强体的浸润性,使树脂中的空气和成型过程中产生的气泡易于排出,从而减少了复合材料的孔隙率,进而改善复合材料的界面性能。     

LDA抽运Nd:YLF再生放大器的实验研究

研制了一台激光二极管列阵(LDA)抽运的Nd:YLF再生放大器。再生放大器工作波长1053 nm，重复频率1 Hz，输出4 ns宽基横模TEM00激光脉冲的能量为2 mJ。总放大倍数达到了1×10 7，输出能量稳定性优于±4.7%(峰值)。给出了再生放大器的实验装置和有关实验结果。     

岩金矿山采空区处理现状及对策

岩金矿山以浅眼留矿法为代表的空场采矿法为主要开采手段，约占50％，每年形成数百万m^3采空区，并绝大多数未进行专门处理。本文介绍数例岩金矿山采空区处理方法及效果与对策，供有关企业参考。     

三峡工程建设中若干重大技术问题的突破

三峡工程规模巨大，技术复杂。文章介绍了三峡工程建设在大江截流和混凝土防渗墙施工技术、大坝混凝土快速施工新技术、船闸高边坡施工技术、电站大型钢衬钢筋混凝土压力管道和蜗壳保温保压技术、沥青混凝土心墙、船闸金属结构、水轮发电机组等重大技术问题上的突破。