Effect of type of processing on the microstructural features and mechanical properties of Al-Cu/SiC metal matrix composites

In this study, an aluminum based metallic matrix (Al-2wt.% Cu) was reinforced with SiC particulates using a conventional casting technique and a new disintegrated melt deposition technique. Microstructural characterization studies conducted on the samples taken from disintegrated melt deposition technique revealed a more uniform distribution of SiC particulates and good interfacial integrity between SiC particulates and metallic matrix when compared to the conventionally cast composite samples. Results of ambient temperature mechanical tests demonstrate an increase in 0.2% YS and ultimate tensile strength of samples taken from disintegrated melt deposition technique when compared with the unreinforced and conventionally cast composite samples. The results of microstructural characterization and mechanical testing were finally rationalized in terms of the nature of processing technique employed to reinforce Al-2wt.% Cu metallic matrix with SiC particulates.     

gHRV: Heart rate variability analysis made easy

In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results.     

MATLAB图像处理在水产养殖中的应用

介绍了一种通过MATLAB图像处理的方法,对水产养殖中鱼的病变情况进行监控的系统。根据中值滤波的原理,对灰度图像进行滤波,抑制噪声;根据二值化原理,将灰度图像进行二值化处理;根据收缩与扩张的原理,编写程序,对二值图像进行数次收缩与扩张,以达到去除杂质点的目的。最后采用区域矩特征的概念,找出判断鱼类出现病变的判断依据,即零阶矩,也就是白色像素的面积,只要统计出白色像素的数目,与统计数据相比较,即可判断出是否出现鱼类病变等异常情况。     

一个地下水流及溶质迁移模拟的图形化方案

本文介绍在地下水饱和系统中，对地下水流和溶质迁移模拟进行计算机图形化处理的方案。     

Annealing process of fine grained co-stabilised (Y,Mg)-PSZ/MgAl2O4 ceramics

Abstract

Co-stabilised (Y,Mg) partially stabilised zirconia (PSZ) ceramics with MgAl₂O₄ spinel additions were produced, with industrial zirconia as the main starting material. Powders were prepared using a mechanical milling–mixing process. The effect of the annealing process on the mechanical properties, phase compositions, and microstructure of fine grained PSZ ceramics was investigated.     

Flexible electronics: Prediction of substrate deformation during different steps of the lithography process

A numerical model was developed to simulate the micro-deformations of a polymeric substrate due to lithographic processing of different layers of a transistor-like structure. The results of the model were validated with the results from experiments. The model, a mechanical-thermal-hygroscopic model, takes into account the dimensional effects of temperature, moisture and stresses. It also includes the temperature dependent visco-elastic behaviour of the polymer substrate. The model can be used to predict overlay accuracies between different functional layers introduced by the lithographic process. It can also be used to understand the underlying processes such that it provides a tool to improve the overlay accuracy during actual processing.     

Critical Time Intervals for Taking in Flight Information in a Ball-Catching Task

A ball-catching task in which the ball was caused to enter on a parabolic flight path by means of a mechanical apparatus was administered to 36 male students between the ages of 18 and 40 years. An electronic device enabled the ball to be illuminated for predetermined temporal intervals during its flight. Results indicated that in this relatively unpredictable task opportunity to watch the ball for longer periods of time resulted in increased catching success. Results are discussed in relation to previous experimental work in which the ball was on a more predictable trajectory (since output information was available) and are related to the perceptual moment hypothesis.     

基于声波处理的变压器故障诊断与状态发展趋势预测

提出了一种声波检测法.该方法可以进行变压器故障诊断与趋势预测.     

虚拟仪器在振动测量系统中的应用

介绍以LabVIEW为软件平台构建的振动测试虚拟仪器系统的硬件组成及软件的设计思想,其中软件是虚拟仪器的核心。通过虚拟面板的演示表明该软件系统能够完成对信号的时域、频域的显示和分析。     

谐波参数测试方法探讨

提出了一种采用测量接收机测试射频信号源谐波参数的方法,并对该方法的特点、应用范围进行了分析,进而实现了该方法的自动化测试,解决了在没有频谱分析仪的情况下测试射频信号源谐波参数的问题。