Reliability testing and reliability analysis of the over-load protective relay

The over-load protective relay is widely used for motor protection. The reliability of the over-load protective relay directly affects the safe running of a motor. The reliability testing and reliability analysis of the over-load protective relay is an important way to improve the reliability of products. In this paper, the reliability test method of the over-load protective relay is studied, and the reliability tests of the typical products are carried out on a reliability tester developed by authors. In terms of the testing results, the reliability analysis is finished. The failure reasons are found and the measures are put forward to improve the reliability of the products.     

万能电子拉伸试验机简易改造及其应用

通过万能电子拉力机与电阻测试仪的结合,获得能测试材料在外力作用下的形变、电性能变化的压力-电阻测试系统。扩展了万能电子拉力试验机的应用范围,提高了材料压力-电阻关系测试精度和科学性。     

车用喷油器驱动波形分析

本文介绍了车用喷油器驱动波形的分类、测试过程以及测试过程中注意的事项，并通过波形分析其常见故障，为车用喷油器的故障诊断和排除提供了科学的理论依据和技术支持。     

Classifying children: a historical perspective on testing and measurement*

ABSTRACT

At the end of the 19th century, children were increasingly seen as measurable and classifiable objects of study on which a scientific approach to education could be based. Two factors fed into the development of this approach: confidence in scientific methods and the expansion of national education systems. Thus, there emerged a confluence of power and science that led to the measurement and classification of children in the name of an efficiently organized social system. This merging of reason, science and efficiency in the goal of classifying children came at a time when the old unitary school system was being declared outdated and coherent teaching units through which scientific methods of learning could be applied were being developed.     

关于设备布局的最短路径算法模型

生产车间的设备布局设计是一个组合优化的问题。具有NP完全(Nondeterministic Polynomial Complete)、非线性等特性,常规方法较难以求解。本文提出实际路线运算法结合基因算法来求解最优设备布局结果,利用遗传算法探索生产车间设备布局问题时适值函数的确定方法。     

一种基于虚拟仪器的舵机测试系统研制

该文探讨了一种基于虚拟仪器组成舵机测试系统的设计思想,在软件开发中比较好的给出了舵机各个参数的测试方法和测试流程设计等,列举了几个单台参数测试的实例。利用本系统全面测试舵机的各参数性能,对开发新产品具有实用价值和理论指导意义。     

效度在语言测试中的重要性

讨论了效度在四种测试中的重要作用，以及各种效度之间的关系，说明要想达到测试的目的，设计试卷一定要把握好效度这个标准。     

巧用向量证题

相等问题、线性关系、正交分解关系、坐标、数量积、向量积求面积、混合积求体积和证三元分式不等式等问题利用向量来证题，能达到简洁、迅速之效。     

Indoor Particle Contamination in Airlaid Papermaking Workshop

An onsite testing based on eight-site air sampling was carried out in an airlaid papermak-ing workshop in Tianjin, China. By theoretical calculation, super absorbent polymer (SAP) size and its existent state in indoor static airflow were obtained. SAP content in the sampled air was tested through chemical analysis method and found to be 3.0-7.2 times that of the human health limit in production areas. The concentrations of total suspending particles (TSP) and respirable particles were achieved by weighing. Particles of the most concern differ for varied function areas. Particles smaller than 10μm are mostly produced in the main production process, and 73%-90% particles generated in packing areas are larger than 10μm. SAP raw material particles can easily changed to suspending form by inevitable extrusion and frication. Correlation between respirable particles and TSP agrees well with that in atmospheric environment.     

浅析输出假设的实证研究

目前输出假设已引起人们关注,然而其实证研究相对较少,这使得输出在外语教学中的积极作用未得到充分肯定。本文通过对典型实证研究的分析,激发人们对输出作用的进一步思考,并进行更为广泛的实证研究。