多功能电子防丢器的设计与实现

随着现代生活节奏的加快,人们遗失东西的现象经常发生,防遗失产品也就应运而生．文中设计并实现了一款多功能电子防丢器,它由母机和子机两部分组成,子机置于防丢物品上,母机由主人随身携带,具有防丢和寻找功能．子机留有的外接插孔可与其他传感器设备相连,构成相应的防盗报警系统．电路主要采用集成芯片制作,所以具有电路简单,工作性能稳定,功耗及成本低等优点．     

从刻蚀电路板废液中制取硫酸铜的工艺研究

研究了以刻蚀电路板废液为原料制取硫酸铜的工艺条件。探讨了Fe3 的干扰,不同的pH以及不同浓度的NaOH和H2SO4对产品质量的影响。结果表明:采用15%~20%NaOH与20%H2SO4可使产品的回收率达92%,产品纯度可达98%。     

浅析基本数学概念在电路理论教学中的运用

不论是在电路理论的教科书中或大多数教师的教学中,普遍比较重视物理概念的学习,但运用基本数学概念解释电路原理方面却做的不足。本文以若干电路概念为例,说明数学概念对解释电路基本概念与基本理论的意义,希望起到抛砖引玉的作用。     

Alterations in Strength and Maximal Oxygen Uptake Consequent to Nautilus Circuit Weight Training

Abstract

The purpose of this study was to determine the effects of a Nautilus circuit weight training program on muscular strength and maximal oxygen uptake ([Vdot]O ₂ max) by comparing these effects to those produced by adhering to either a free weight (FW) strength training program or a running (R) program. Male college students who voluntarily enrolled in either a FW training class (n = 11), a Nautilus (N) circuit weight training class (n= 12), or a R conditioning class (n= 13) were subjects for this investigation. All groups participated in their respective programs 3 days per week for 10 weeks. Strength was assessed using a Cybex II isokinetic dynamometer set at an angular velocity of 60° · s ^?1 and a damping of 2. The FW group served as the control group for the assessment of [Vdot]O ₂ max changes, while the R group served as controls for the assessment of strength differences. ANCOVA revealed that the N and R groups experienced significant (p < .01) increases in [Vdot]O ₂ max expressed in L · min ^?1 (10.9 and 11.4%), ml · kg ^?1 · min ^?1 (10.8 and 11.7%), and ml · kgLBW ^?1 · min ^?1 (7.1 and 7.5%) when compared to the FW group. There were no significant differences between the N and R groups. There were no significant differences among groups in final peak torque values (after covariance), and torque at the beginning and end of the range of motion for the knee extensors, knee flexors, elbow extensors, and elbow flexors. In general, isokinetic strength values elicited by the N group compared favorably to those generated by the FW group. It was concluded that for a training period of short duration, Nautilus circuit weight training appears to be an equally effective alternative to standard free weight (strength) and aerobic (endurance) training programs for untrained individuals.     

利用MATLAB GUI仿真电路周期信号的分解与合成

信号的分解与合成是电子（电气）类专业的基础知识之一.基于MATLAB GUI,以周期锯齿波和方波信号为例,仿真电路周期信号的分解与合成.结果表明,利用MATLAB GUI仿真电路周期信号分解与合成,设计步骤简单、程序简洁易读、图像形象逼真.MATLAB GUI是辅助电路教学的有效工具.     

微波电子线路课程教学设计

微波电子线路课程是一门电子专业的专业基础课。对微波电子线路课程的教学进行研究和探讨,教学实践证明其有效性。     

丰田卡罗拉电动后视镜电路分析及故障诊断

后视镜主要是让驾驶员观察汽车左右两侧的行人、车辆以及其他障碍物的情况,确保行车或倒车安全。手动车外调节式后视镜,必须在停车后通过手直接调整镜框或镜面的位置,该方式不仅费事费力,而且较难一次性完成。而电动式调节后视镜,可为驾驶人在行驶过程中通过操作调节按钮来调整镜片的位置,提供更便捷、更舒适操作条件。文章先介绍电动后视镜概况,进而对卡罗拉后视镜进行电路分析,最后对其进行故障诊断。     

改进日光灯电路提高电网的功率因数

日光灯应用非常广泛,但是由于日光灯电路中的镇流器是感性负载,和电源进行能量交换,作无功运行,占用电源的容量.因此,需要改进日光灯电路,提高电源容量的利用率和电网的功率因数.     

PLC在电梯中的应用

本阐述了电梯在PLC控制下的硬件及软件的设计过程，列出了具体的主要硬件电路和电梯的控制形图，分析了主要输入点的作用，以及梯形图中主要继电器的作用。     

电机绕组绝缘与匝间短路分析

阐述了电机绝缘系统的绝缘诊断试验，以此评估电机的绝缘状态；并分析了电机绝缘的常见故障匝间短路，说明了匝间短路的内在机理。