电子束辐照下铜超微粒子氧化与还原过程的高分辨电子显微镜观察

利用电子显微镜中的电子束对铜超微粒子进行了连续地照射和跟踪观察，结果表明电子束使Ｃｕ与镜筒中的低氧压气氛发生了反应，电子束的辐照使纳米量级的Ｃｕ粒子发生了氧化并被消耗，首先生成一种类非晶膜，然后生成Ｃｕ的晶态氧化物，新生成的Ｃｕ的晶态氧化物，在电子束的进一步照射下，又发生了还原反应，不断地还原为铜     

一种新型激光干涉球径仪原理与分析

本文根据自参考剪切干涉技术，采用球面补偿自准直原理，提出了一种新型激光干涉球径义。详细介绍了该球径仪的测量原理，结构及误差分析，并给出了实验测试结果。     

激光法测量湍流流场时散射粒子的选择

激光技术测速时需要有合适的粒子。本文研究了用三维粒子动态分析仪(PDA)测量湍流流场时选择合适的散射粒子的问题。试验结果和理论分析表明:(1)散射粒子的特性参数是影响测速精度的重要因素;(2)在湍流度较高的流场中测量时应尽可能选择直径小、密度低、折射率大的粒子作为散射粒子,而且粒子散播的浓度要合适。     

Monodisperse ellipsoidal polystyrene latex particles: Preparation and characterisation

An improved version of a novel method first employed by Nagy & Keller for the preparation of monodisperse ellipsoidal polystyrene latex particles is described. The method involves embedding monodisperse spherical polystyrene latex particles as starting material in a deformable polymer matrix such as poly(vinyl alcohol) and deforming these mechanically to various predetermined macroscopic draw ratios to give ellipsoids of various axial ratios. Ellipsoids with lengths ranging from about 350 to 12250nm were prepared. Stable aqueous dispersions of these were recovered and characterised with respect to particle size and axial ratio distributions and surface morphology using electron microscopy. Axial ratios ranging from 2.0 to 5.65 were obtained for the resulting ellipsoids. Various factors influencing the monodispersity of the resulting ellipsoids in the preparation method are discussed.     

四边固支扁球壳的解析解法

以弯矩理论的单级数形式解析解为基础，应用迭加原理和将无穷级数展成无穷线性方程组的方法，得出均布荷载作用下四边固支扁球壳的闭合解。此解数学、力学模型简单、明确，使计算简化且能控制误差。     

快速凝固高温铝合金纳米相的粗化

用XRD、TEM和EDX分析确认：快凝Al－8．47Fe－1．26V－1．67Si合金在高温时效后，显微组织由．ffcα－Al和bccα－Al13（F3，V）3Si弥散纳米粒子组成．后者的粗化动力学规律符合体扩散控制的LSW机制．在427和482℃高温状态下的界面能分别为0．185和0．245J·m-2，即α粒子与基体间存在非共格关系     

具有球形胞体结构的泡沫塑料弹性常数的确定

通过微分法导出了泡沫塑料剪切模量和体积模量所满足的微分方程组，并利用泡沫塑料各向同性弹性常数间满足的关系求解；得到了泡沫塑料剪切模量与体积模量的关系，确定了剪切模量与材料孔隙比的关系；并且将本文结果同其他已有模型了对比。     

Passive Target Tracking in Non-cooperative Radar System Based on Particle Filtering

We propose a target tracking method based on particle filtering（PF） to solve the nonlinear non-Gaussian targettracking problem in the bistatic radar systems using external radiation sources. Traditional nonlinear state estimation method is extended Kalman filtering （EKF）, which is to do the first level Taylor series extension. It will cause an inaccuracy or even a scatter estimation result on condition that there is either a highly nonlinear target or a large noise square-error. Besides, Kalman filtering is the optimal resolution under a Gaussian noise assumption, and is not suitable to the nonGaussian condition. PF is a sort of statistic filtering based on Monte Carlo simulation that is using some random samples （particles） to simulate the posterior probability density of system random variables. This method can be used in any nonlinear random system. It can be concluded through simulation that PF can achieve higher accuracy than the traditional EKF.     

超微细颗粒体系微观结构的研究进展

简述了近年来国内外超微细颗粒结构特征及其聚团机理的研究进展,这些特征包括:径向分布函数、分形维数、配位数等系统静态结构性质和在流体媒介中外力场作用下超微细颗粒的聚团机理等动态性质,探讨了超微细颗粒的微观结构研究的发展方向。