“医疗电子影像诊断仪”实训平台的设计与实现

本文以＂医疗电子影像诊断仪＂实训平台的研制为主题,描述了该实训平台的整体构成,剖析了主要电路模块的功能,重点阐述了实训平台中各测试点及模拟故障点设置的基本理念,介绍了该平台能实现的实训项目。该平台可为医疗电子类人才的培养提供一种实用、有效的实训教学手段。     

Event-triggered non-fragile H∞ fault detection for discrete time-delayed nonlinear systems with channel fadings

In this paper, the event-triggered non-fragile H_∞ fault detection filter is designed for a class of discrete-time nonlinear systems subject to time-varying delays and channel fadings. The Lth Rice fading model is utilized to reflect the actual received measurement signals, and its channel coefficients own arbitrary probability density functions on interval [0,1]. The event-based filter is constructed to reduce unnecessary data transmissions in the communication channel, which only updates the measurement signal to the filter when the prespecified “event” is triggered. Multiplicative gain variations are utilized to describe the phenomenon of parameter variations in actual implementation of the filter. Based on Lyapunov stability theory, stochastic analysis technology along with linear matrix inequalities (LMIs) skills, sufficient conditions for the existence of the non-fragile fault detection filter are obtained which make the filtering error system stochastically stable and satisfy the H_∞ constraint. The gains of the filter can be calculated out by solving the feasible solution to a certain LMI. A simulation example is given to show the effectiveness of the proposed method.     

A cognitive TV white space-broadband power line MIMO system for indoor communication networks

Broadband power line communication (BPLC) is a promising solution to satisfy the growing data rate demands for broadband indoor communication networks. However, the BPLC transmission power spectral density (PSD) is restricted in the very high frequency (VHF) band to avoid harmful interference to the existing wireless services. In this paper, a new hybrid system is proposed utilizing BPLC and cognitive radio over TV white space (TVWS) to enhance the system capacity over BPLC in VHF, forming a VHF TVWS BPLC multiple-input multiple-output (MIMO) system. An iterative precoding algorithm is proposed to satisfy the interference limit at the TV primary user (PU) receiver (Rx) and enhance the ergodic capacity. Moreover, a power allocation algorithm is developed for the MIMO system to achieve the maximum ergodic capacity subject to the average total power constraint and limit of interference to TV PU. Simulation results demonstrate the significant enhancement in the achieved capacity by our proposed system in the VHF band compared to both previous cognitive and hybrid BPLC systems.     

安全型继电器电气特性自动测试系统架构设计

针对目前安全型继电器生产中人工测试效率低下且易出错的现状,以先进的硬件为支撑,设计了一种稳定高效的安全型继电器电气特性自动测试系统,实现了安全型继电器全部型号（包括交流型和直流型）的自动测试,大幅提升了该产品的生产效率。     

高职电类专业课程设置与教学内容体系原则的探讨

本文在对工业自动化技术和应用电子技术专业毕业生进行专业能力调查的基础上，仅就如何面向职业岗位来设置电类课程与教学内容体系原则加以探讨，试图解决高职的短学制和理论实践并举要求之间的矛盾。     

ZnO瓷粉／Ag复合材料的电学特性

通过传统的陶瓷工艺在较低的温度（〈1000℃）下制备了以ZnO陶瓷为基体的ZnO陶瓷／Ag复合材料．主要考察和讨论了其电学性能及相关问题．     

论逻辑连接词在英语议论文写作中的应用

大学英语写作作为四项基本技能之一备受关注。尤其在近几年，人们更多关注英语中的各种考试试题并对其进行了大量的研究且取得了令人瞩目的成就。但不可否认，在学生的写作中语篇连贯仍是一个突出的问题。而逻辑连接词的正确恰当的使用是达到语篇连贯的手段之一。为此，本文将着重介绍逻辑连接词在议论文中对句子的连贯作用，并分析了学生们在使用过程中所存在的问题。     

Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.     

Preliminary Study ＂A Training Coursebook on on the Compilation of Electrician＇ s Electronic Skills＂

教材是教师传授知识的载体,是学生学习知识的依据。高质量教材是培养高素质技能型人才的基本保证。《电工电子操作技能项目化实训教程》采用工作过程导向的项目化教材编写思路,在企业调研、工作任务分析、典型工作任务归纳的基础上,选择企业真实工作任务作为教材编写项目,同时融入＂电工操作证考试＂和＂初级电子仪器仪表装配工技能考核＂职业技能鉴定标准,使教材内容与职业资格证书制度有效衔接。     

大直径沉管取土灌注桩快速接头模块的设计

大直径振动取土灌注桩外套管的快速连接构造决定了大桩型的适用范围和成桩效率。文章以大直径沉管取土灌注桩快速接头模块为研究对象,设计一种新的快速接头模块的连接方式。包括连接方式的设计、凸台的设计。经CAE技术校核和加载实验,表明该研究设计能够满足使用要求。实现大直径沉管取土灌注桩快速、高效、节能的连接,并较大幅度减轻工人劳动强度。