印刷电路板生产废水综合治理措施

随着印刷电路板的需求量不断增多,其生产过程中出现的废水也成为人们重视的社会问题,需要借助综合性的治理措施来做好废水处理工作,减少对环境的污染。文章介绍了印刷电路板废水的现状,以及印刷电路板废水的常用处理技术,并提出印刷电路板生产废水综合治理及回收措施。     

印刷电路板故障测试的可靠性分析

印刷电路板是在电子工厂生产当中产量规模较大的一种电子产品,但是由于在生产工作当中会受到各种因素的影响而出现了一些低质量的印刷电路板,而这种印刷电路板会存在短路和断路的技术故障,投放在产品安装的应用中时会使电子产品不能够正常运转,影响了正常工作的开展,所以,技术人员需要对所生产的印刷电路板进行全面监测,找出印刷电路板的故...     

孔壁镀层空洞

孔壁镀层空洞是印刷电路板(双面、多层和盲孔板)金属化孔最常见的问题之一,也是印刷电路板报废项目之一,因此解决和控制印刷电路板孔壁镀层空洞是多数印刷电路板厂家重点控制的内容之     

浅谈电子丝网印刷中PCB的印制技术

丝网印刷在印制电路板(PCB)上具有得天独厚的优势,文中通过分析丝网印刷和电路板印制的特点,介绍电路板丝网印刷各工序的技术要点,以及电路板丝网印刷常用的几种油墨的应用方法。     

相加法制作双面印刷电路板新技术

相加法制作双面印刷电路板新技术长春光机学院张南哲苏春辉许素莲（１３００２２）一汽延边汽车厂张学哲（１３３０００）本文在单面印刷电路板制作新工艺的基础上研究了双面印刷电路板的制作新工艺。１双面印刷电路板的制作新工艺用导电糊制作双面印刷电路板的主要工艺流...     

高速数字系统印刷电路板的设计要点

讨论了调整数字系统印刷电路板中信号完整性问题的形成原因,并结合实例总结了设计此类印刷电路板的一般要点。     

新书介绍

《2013印刷电路板电子组装技术概述》;《高密度印刷电路板技术》;《2011软性电路板技术简介》     

新书介绍

《2013印刷电路板电子组装技术概述》；《高密度印刷电路板技术》；《2011软性电路板技术简介》。     

Indium公司推出WF9945波峰焊助焊剂

对建立环境友好电子产业的全球性模仿加速了在印刷电路板和印刷电路板组装材料中无卤化的进程。在很多焊料公司仅仅关注于在锡膏产品减少或不使用卤素的时候.     

轻松制作双面印刷电路板

<正> 预涂布感光敷铜板不但可以用来制作单面印刷电路板,而且用其制作双面印刷电路板也十分方便快捷,这对于科研新品开发、教学用单块及小批量业余电子制作都是非常便利的。下面介绍用“即时得”预涂布感光敷铜板制作双面印刷电路板的具体操作方法。 一、画双面印刷电路板图:用手工或电脑Potel绘制印刷电路板图的方法在许多报刊、书籍上已有详细刊载,这里只强调两点: 1.画电路板图时过孔要少,尽量用元件的引脚作电路板的过孔。     

UMTS及EPC网络QoS机制的研究

随着社会的发展,用户对业务质量的需求也日益提高,为此3GPP组织加强了对QoS的研究,在UMTS阶段引入了端到端QoS机制,并在LTE阶段对QoS机制进行了扩展和增强,目前QoS的研究是3GPP研究的一个热点。本文对3GPP移动通信网QoS演进进行了介绍,分析了UMTS和EPC网络的QoS实现机制,并对两种QoS实现机制进行了分析。     

一种红外探测器效应的实时模拟方法

文中剖析了Ogre渲染引擎的工作原理,描述了基于GPU的后处理技术,利用Ogre渲染引擎通过GPU实现了二维快速傅里叶变换,添加了探测器成像系统调制传递函数(MTF),实现了系统线性噪声和随机噪声的添加,模拟了实时三维红外场景中的探测器效应.     

扬声器单元TS参数偏差对系统频率响应曲线的影响

在闭箱、开口箱、被动辐射体箱和带通箱系统的设计中,人们已认识到单元的TS参数和箱体的声学参数有紧密的配合关系。一旦箱体的结构设计有所确定,安装在箱体上的扬声器单元的TS参数也必须确定,这样,系统的低音频特性就因此而定。但是在批量投产时,TS参数的偏差将对系统的低音频特性产生变化。以开口箱的系统频率响应曲线为分析目标,要观察TS参数的偏差所产生的变化。为此,采用LEAP5扬声器设计软件作相应的模拟,证明只要TS参数的偏差在一定的范围内,频率响应曲线的变化也可以维持在一个偏差带内。这样,可根据系统的技术指标来确定TS参数的偏差。     

e-Health in Australia: A synthesis of thirty years of e-Health initiatives

This paper provides an overview of the history of e-Health initiatives in Australia. It highlights the importance of contextual factors in their evolution and the way in which certain initiatives have been managed. The first section outlines the development of e-Health systems in Australia from their inception to the present day. Then, Australia’s e-Health system is evaluated in relation to comparable countries using social mechanism theory. This provides a process-based approach for understanding the relationship between process, context and outcomes in the evaluation of e-Health initiatives in Australia and in comparable countries.     

Improved LUT Technique for HPA Nonlinear Pre-Distortion in OFDM Systems

In this paper, we focus on the Look-up Table (LUT) technique for the compensation of HPA nonlinear distortion. An improved LUT method is proposed with better performance compared with conventional LUT technique in terms of convergence speeds, BER and total degradation (TD). It can get over 8 dB gain in out-of-band spectrum re-growth suppression and about 0.3 dB BER performance gain than conventional LUT technique with the same iteration times. Also, we propose an actual application of HPA with pre-distorter in OFDM transmitter. Ai Bo was born in Shannxi Province in China on February 7, 1974. He received a BSc. Degree from Engineering Institute of Armed Police Force in 1997, a Master and Dr. degree from Xidian University in 2002 and 2004 in China respectively, and now working as a post dr. in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) of China. He is an editorial committee member of journal of “Computer Simulations”, “Information and Electronic Engineering”, an IEEE member and a senior member of Electronics Institute of China (CIE). He has published over 60 scientific papers in his research area till now. His current interests are the research and applications of OFDM techniques with emphasis on synchronization and HPA linearization techniques. Yang Zhi-Xing graduated from Tsinghua University, P.R. China in 1970. He is now a Professor and Deputy Director of State Key Lab. on Microwave and Digital Communication at the Department of Electronic Engineering and the Director of the DTV R&D Center in Tsinghua University. As a DTV technical expert for the Chinese government, Professor Yang has also been a member of the DTV standardization Committee of China and a leader of the DTV Standardization Harmonizing Group in Ministry of Information Industry of China. His major research interests include broadband information transmission technologies and DTV broadcasting systems. Pan Chang-Yong received the B.S. and M.S. degrees from the Department of Electronic Engineering in Tsinghua University, P.R. China, in 1996 and 1999, respectively. He is now an associate professor in the Department of Electronic Engineering and a member of the DTV R&D Center in Tsinghua University. His research interests are in the areas of broadband wireless transmission systems and satellite communications. Zhang Tao-Tao was born in Shandong Province in China in 1982, he received BSc. degree from Tsinghua University in 2004 and now pursing his Master degree in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. His research interests is the power amplifier linearization techniques. Wang Yong was born in Shannxi Province in China in 1976. He received a BSc., a Master and a Dr. Degree from Xidian University in China in 1997, 2002 and 2005, respectively, and now is an associate professor in Xidian University. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) in China and is an IEEE Member. His interests are broadband multimedia communications. Ge Jian-Hua was born in September, 1961 in JiangSu Province in China. He received the B.Sc., Master and Ph.D. degree from Xidian University in 1982, 1985 and 1989, respectively. He is now the professor in both Xidian University in Xi’an and Shanghai Jiaotong University in Shanghai. He is the senior member of Chinese Electronics Institute. He has won lots of scientific and technical prizes in China and published many papers. His interests are transmission communications and web security.     

逐点插入法在三维地质建模中的运用

随着科学计算可视化技术和地质信息技术的发展,三维地质建模逐渐成为石油勘探、岩土工程、GIS和科学计算可视化等领域研究与应用的热点。本文主要介绍了在三维地质建模中常用的三角剖分算法中的逐点插入法,在实际运用中进行了改进,对三维空间中的原始数据点进行三角网化并构造地质体。     

低功率半导体激光照射对神经功能恢复的影响

目的探讨低功率半导体激光对家兔神经功能恢复的影响。方法用 36只体重 2 .5kg左右的家兔随机分为 3,6 ,9和 12周 4个观察期组 ,每个观察期组随机分为半导体激光照射组 (各用家兔 5只 )和对照组 (各用家兔 4只 )。麻醉后 ,均切断左侧腓总神经 ,用 9/0尼龙单丝对端吻合神经外膜。各照射组在术后 1d开始照射家兔L5 ,6脊髓节段 ,照射激光输出功率为2mW ,每天照射 5min ,连续照射 7d。对照组不照射 ,均按期观察。结果术后 3周 ,可在照射组看到细小而稀少的再生轴突 ,对照组直到术后 6周才看到 (P <0 .0 1)。照射组的腓总神经潜伏速率均优于对照组 (P <0 .0 1) ,动作电位波幅照射组也优于对照组。展趾功能到术后 12周 ,照射组与侧健相同 ,对照组才恢复到照射组 6周的水平。结论低功率的半导体激光促进脊髓运动神经细胞功能 ,加速轴突再生     

低功率磁作用半导体激光照射对神经功能恢复的影响

目的 :探讨低功率磁作用半导体激光对家兔神经功能恢复的影响。方法 :用 5 6只体重 2 .5kg左右的家兔随机分为 3 ,6,9和 12周 4个观察期组 ,每个观察期组随机分为半导体激光照组 (各用家兔 5只 )、磁作用半导体激光照组 (各用家兔 5只 )和对照组 (各用家兔 4只 )。麻醉后 ,均切断左侧腓总神经 ,用 9 0尼龙单丝对端吻合神经外膜。各照射组在术后 1d开始照射家兔L5 ,6脊髓节段 ,照射激光输出功率为 2mW ,磁作用半导体激光照射采用在激光输出端安置强度为 5mT的恒磁场作用在激光上 ,每天照射 5min ,连续照射 7d。对照组不照射 ,均按期观察。结果 :术后 3周 ,各照射组看到细小而稀少的再生轴突 ,对照组直到术后 9周才看到 (P <0 .0 1) ,磁作用激光照射组优于激光照射组 (P <0 .0 5 ) ;各照射组的腓总神经潜伏速率和动作电位波幅均优于对照组 (P <0 .0 1) ,磁作用激光照射组优于激光照射组 (P <0 .0 5 )。展趾功能到术后 12周 ,磁作用激光照射组与侧健相同 ,激光照射组恢复到磁作用照射组 9周水平 ,对照组才恢复到磁作用半导体照射组近 6周的水平。结论 :低功率的磁半导体激光促进了脊髓运动神经细胞功能 ,加速了轴突再生。     

高校固定资产管理中云计算技术的应用探讨

随着时代的发展,国家对人才的需求量不断增加,并且对人才培养的要求越来越高。高校作为人才输出的重要基地,人们对高等教育的重视程度不断加深,尤其是近年来高校在发展的过程中其规模也在不断的扩展,导致固定资产管理中的一些问题逐渐凸显出来。本文就固定资产管理中存在的问题进行分析,进一步探讨云计算技术在高校固定资产管理中的应用。     

异向回旋媒质平板波导的模式特性分析

研究了异向回旋媒质平板波导中电磁波的模式特性,给出了电磁波在异向回旋媒质中的导行条件。根据媒质介电常数张量分量取不同的符号,分4类情况分析不同媒质参数条件下传播模式的特性,并讨论了不同情况下虚横波数模式的存在性。结果表明这种媒质中的电磁波模式与一般媒质有很大不同。