4040A型喷油器垫片分选控制系统的设计

喷油器垫片分选关系到喷油器产品的品质,传统垫片分选需大量工人进行人工分选,属于劳动密集型工作,为降低工人的劳动强度,设计了4040A型喷油器垫片分选控制系统。分选机采用PLC作为主控系统,通过伺服电机控制模拟压力,在运动过程中测量喷油体组件和后顶针组件的长度,再经计算选出合适的垫片;同时介绍了垫片分选机的工作过程、实现方法等。运行结果表明,该控制系统能实现自动测量、自动选取垫片的功能,达到预期效果。     

NTC热敏电阻的温度测量技术及线性电路

文章从NTC热敏电阻的性能参数出发,对NTC热敏电阻温度测量技术、接口电路、输入标定的应用进行了分析。     

NTC热敏电阻及其应用分析

从NTC热敏电阻的基本特性出发,对NTC热敏电阻在温度控制、自动增益调整、温度补偿、温度测量等方面的应用进行了分析。     

基于STM32的螺母自动检测分选机设计

本文设计一款基于STM32的螺母自动检测和分选系统,系统使用STM32F103xzet6单片机作为核心控制器件,通过精密位移传感器应用比较测量法实现螺母厚度和中径的准确测量。系统包含完善的机械和气动结构,保证检测、分选自动化实现。经测试系统可实现测量、分选工作且测量偏差仅为0.02mm,满足测量精度要求,与其他检测系统相比,该系统结构简单、准确可靠、功能完善、成本低廉。     

一种激光测量干涉仪的研究

近年来,激光测量干涉技术的研究受到越来越多的重视,特别是随着现代工程技术的飞速发展,高精度的低频微小振动测量已经成为目前工业和科学发展中迫切需要解决的问题.在综合考虑了众多高精度测量方法的基础上,本文提出了一种用于激光测量干涉技术的改进型迈克耳逊激光干涉仪.     

一种数据采集器的温度特性实验系统

基于NI myDAQ和NI USB6009数据采集器,用LabVIEW设计和制作了能同时测量4种温度传感器温度特性的实验教学系统。该系统可实时记录并直观显示温度传感器输出参数随温度的变化过程,还可根据需求设定数据记录时长及数据量。用该系统测量了Cu50铜电阻、NTC热敏电阻、PN结电压和AD590电流型集成电路温度传感器输出电流等参数随温度的变化关系,实验结果与采用分立式传统仪器测量的结果吻合。     

高精度机床仿形头在石棉厚度监测中的应用

针对石棉生产过程中石棉厚度动态监测难的问题,采用高精度机床仿形头作为厚度监测传感器,将实际的厚度(位移)经传感器转换成电信号,并采用高精度电桥来获得微弱的厚度(位移)信号,通过高精度的仪表放大器完成信号的转换,最后用高精度数显表显示测量结果. 利用该方法制做的测量仪,分辨率为1,测量范围为0.01—5mm, 测量偏差小于0.5%.     

一种测量共模抑制比的方法

通过对常用的测量共模抑制比的方法的分析 ,提出了一种高精度的简便的测量运放的共模抑制比的方法.     

二维几何特征的机器视觉高精度自动测量(英文)

为了对零件上二维几何特征进行高精度自动测量,建立了机器视觉协同测量系统.介绍了系统的硬件组成、功能结构及工作原理,建立了特征图像坐标与测量空间坐标之间的映射关系,提出了小视场图像测量路径的规划方法.在被测目标全景图像信息的协同下,自动采集具有高物面分辨率的小视场序列图像,自动构造辅助测量特征并提取被测特征的参数.应用该系统测量100mm的孔距,结果表明:相对误差的绝对值不超过0.03%;当小视场图像的物面分辨力是大视场图像的16倍时,小视场图像的测量精度比大视场图像平均提高14倍.故该系统适用于对大尺寸零件上分布的二维复杂几何特征进行高精度自动测量.     

尖晶石系NTC热敏电阻材料导电机理的研究进展

通过对尖晶石系NTC热敏电阻材料导电机理的讨论和目前研究现状的综合分析,认为跳跃导电模型可以成功地解释NTC热敏电阻材料许多性质和现象,在将来的研究中要更加关注材料体系中晶界势垒的形成对材料导电机理和性能影响的研究.     

数字式温度检测系统的设计

介绍单片机控制的数字式温度检测电路。利用NTC实现温度采集，经过AT89C51处理后显示。可在温度精度要求不高的场合使用。     

车灯表面质量分级装置

This paper introduces an installation for quickly classifying automobile‘s metal reflectors based on their roughness.The measuring principle and the mechanical structure are presented.Schematics of circuits and experimental results are given.Elimination and reduction of the effect of background lights or different bulbs on the measuring results are also described in detail.     

Managing senior management team boundaries and school improvement: an investigation of the school leader role

The present study purpose was to investigate the unique role and activities of school principals in managing their senior management team (SMT) boundaries. The study examined how school principals’ internal and external activities mediate the relationship of principals’ personal factors from the Big Five typology, the team and contextual characteristics of functional heterogeneity and goal interdependence to SMT effectiveness and school outcomes of teachers’ absenteeism, school violence and academic emphasis. The results of the structural equation model from a sample of 92 schools indicate that internal activities fully mediate the relationship between principal extraversion and conscientiousness, SMT functional heterogeneity, intra-and inter-team goal interdependence to SMT effectiveness. The external activities were found to fully mediate the relationship between principal extraversion, SMT functional heterogeneity, intra-and inter-team goal interdependence to school outcomes. By concluding that both internal and external activities remain fundamental to overall effectiveness, this study may provide principals with boundary management techniques and practices. The findings may encourage principals to establish priorities and allocate their time, resources and attention effectively both inward and outward the SMT boundary so as to improve SMT and school outcomes.     

Science Education in Nigeria: An Examination of People’s Perceptions about Female Participation in Science, Mathematics and Technology

The paper brings to focus people’s perception about female involvement in science, mathematics and technology (SMT). Data for the study were obtained from a survey conducted in March, 2005 in two Local Government Areas of Osun state, Southwest Nigeria. The paper reveals that: (i) about 57% of household heads, 45.6% of mothers and 57.6% of the children are of the opinion that both boys and girls are given equal right to SMT education (ii) social forces play an important role in determining people’s attitude to SMT (iii) though, parents and stakeholders perceptions about girls’ participation in some professions is changing, however, socio-cultural and economic factors still determine which sex to encourage to read SMT.     

SMT中焊膏使用常见问题分析

SMT是现代电子产品追求小型化,特别是大规模、高集成电路(IC),不得不采用的一项组装技术.作为新兴技术,在实际应用中总存在一些问题,就其使用的焊锡膏在实际应用中出现的问题进行了分析,供从事SMT人员借鉴.     

热敏电阻在输液装置中的一例应用

介绍了利用NTC热敏电阻的耗散特性而做的一例输液过程监控装置。     

杨氏模量实验的改进

伸长法测定杨氏模量实验通常采用光杠杆来测量钢丝形变,存在间接测量量较多、调整仪器和测量时间较长等缺点.具体实验数据及其不确定度的分析证明,采用百分表直接测量钢丝的伸长量可以有效克服这些缺点.