高压变频技术在锦西石化4#炉风机节能改造中的应用及经济效益分析

本文通过对中国石油锦西炼油化工总厂热电公司4#炉引、送、二次风机的高压变频节能改造的介绍，详细叙述了改造的目的、技术方案、改造过程和原理特性。具体分析了改造效果，特别是经济效果。最后阐明节能改造的意义，这是企业由粗放型的管理向资源节约型管理转变的有效途径，是企业增效的新亮点。     

农网建设与改造问题及其解决措施

农网改造是智能化电网建设的组成部分，通过农网改造，我国农村电网将一改以往落后于城市电网的运行状态，与城市电网同时实现智能化改造，且改造后的农网与城市电网的电能质量基本一致。本文通过分析，确定了农网改造过程中可能遇到的一些问题，并且提出了解决措施。     

界首市广播电视中心数字化改造方案

数字化改造是很多电视台目前的主要任务，文章详细介绍界首市广播电视中心数字改造前的状况，改造设计整体方以及改造后的效果分析，诊为对于中小电台、电视台而言，进行数字化改造要充分考虑安全、经济、减少今后不必要的改动和重复投资。     

分配网改造的一点体会

现在我传输中心有线电视网络主要是单向广播式传输，随着科学技术的发展以及多功能双向传输业务带来增值效益，双向网络改造势在必行。双向网络改造涉及许多方面，首先是前端平台的搭建，其次是传输干线的光点扩容，通过合理的设计来分布每个光工作站覆盖用户的数量，尽可能提高网络的可靠性，降低故障率。从网络维修维护的角度来讲，分配网络双向改造也是一个重要的环节，其改造质量关系到网络运行的稳定性，因此应该充分重视分配网改造，其起点要高，质量要好。     

有线电视网络改造的新模式——FTTB＋1550nm

随着有线网络数字化的逐步深入，为满足业务的需求，各地又掀起了光传输网络改造的热潮。在改造的过程中，各地网络公司根据本地网络实际情况不同，采用了不同的网络改造模式，那么到底下一步光网络改造的方向是什么？改造的着眼点又在哪里？笔者根据近期在网络改造实践中遇到并解决的问题，得出了一些比较清晰的观点，现在总结出来，供同行们共同讨论。     

旧城改造，金牛的华丽转身

在城区旧城改造项目中，金牛区确定了四大片区作为重点改造范围，其中包括中铁二局片区、华西集团佰城片区、成都铁路局片区和西南交大片区。城北四大片区的改造是金牛区有史以来规模最大的一次旧城改造工程，     

广播电台直播车系统集成工程之车辆改造

广播电台直播车系统集成工程，是新建集成行进中的流动电台基站，其中最重要的一个环节就是对使用车辆的改造。这是整个系统集成的基础和关键，直接关系到将来整个系统工作的稳定性、安全性。基于此，介绍车辆改造的具体内容，包括车辆选型，车辆改造执行的规范、标准，车厢内空间分布与装饰，厢体内外结构、供电电源以及车顶平台等部位的改造。     

数字录音系统创新改造

城市轨道交通快速发展促进了地铁工程的改造建设，数字录音系统是地铁项目改造的重点内容，其必须要融合大量先进科学技术为支撑，才能为地铁运行提供可靠的语音播放功能。本次分析了地铁数字录音系统功能创新改造的趋势，结合地铁运行实况提出相应的改造意见。     

固定电话网络改造和演进的一种实践

随着电信市场竞争的日益加剧，在提供新业务方面，如市话详单、全网彩铃等，传统固网存在着许多无法克服的问题，因此，传统固网运营商必须对现有网络进行改造。但是，由于网上机型复杂，如果全部改造，耗资巨大。如何充分利用现有网络资源，节约改造成本，同时又能与NGN（下一代网络）、3G等未来网络相连，是传统固网运营商必须解决的问题。本文结合郑州固网的改造实践，对网络改造的方案提出了一些建议。     

国产高压变频器在齐鲁石化供排水厂的应用

本文着重介绍了国产高压变频器在齐鲁石化供排水厂西夏配水站给水泵中的改造方案。应用情况表明，全达到了用户对水泵变频改造的目的，改造是成功的。     

超高压气体放电光源玻壳材料退火工艺研究

通过分析石英材料粘度与温度的关系,得出了石英的退火温度范围．结合超高压气体放电光源的要求,对玻壳精密退火工艺进行研究．该工艺充分考虑了因玻壳厚度和降温造成的应力．给出了工艺参数的计算方法,增加了慢速降温阶段,减少了玻壳的剩余应力．     

嵌入式Linux下多路数字音频采集报警器的设计

介绍了嵌入式Linux系统下多路数字音频采集报警器的功能,给出了系统的结构,以模块化方式说明了ARM软件的实现过程,重点介绍了节目表的查询和转换方案,阐述了FPGA驱动程序的实现方法。说明了如何响应网络命令,将信息上传到监控系统。     

基于ARM芯片S3C2410的PDA人机接口电路设计

随着电子技术的迅猛发展,具有耗电少、亮度高、体积小等特点的LCD（液晶显示器）被广泛应用于嵌入式系统中。S3C2410是三星公司开发的一款以ARM920T为核心的16／32位嵌入式处理器。它主要面向手持设备以及高性价比、低功耗的应用。文中介绍了三星公司设计的ARM920T嵌入式处理器$3C2410在PDA（个人数字助理）硬件设计电路中的应用。详细提供了PDA的LCD、触摸屏及键盘等人机接口模块的设计电路。该设计技术先进,结构合理,功能较完备,整体性、可扩充性强。     

A simple model for fatigue life

A simple model to handle fatigue-life length problems is discussed. The characteristic property of the model is that it combines the Palmgren-Miner rule with time invariance. The model is applied to situations with both random strength and random load. The randomness in the life is generated by the random strength and not by the random load. The only property of the random load that affects the life is its damage intensity, which is independent of the particular realization in the ergodic-load case. The damage intensity is even independent of the distribution of the random function, provided its level-crossing intensity is known. Particular attention is given to simple random strength models. In general, the exhaustion density is a random function, but in the simple models the only randomness that appears in the strength is either randomness in the time scale or randomness in the amplitude scale. The model is well-suited for comparative calculations under different load conditions, since it connects fatigue life for random loads to fatigue life for periodically oscillating loads, which is usually measured in experiments     

Excitation of a Coaxial Line Through a Transverse Slot

A rocket with removed access plate is simulated by a section of coaxial transmission line with a transverse elliptical slot cut in its sheath. The internal circuit consists of two arbitrary impedances in series with the inner conductor at its ends. The object is to find the currents in these impedances when the cylinder is illuminated from the outside by an electromagneticfield that enters the aperture and excites the internal circuit. The problem is solved by application of the reciprocal theorem. The current in a dipole antenna is determined when this is inthe far field maintained by the slotted coaxial line when driven by a generator in series with one of the load impedances. The field in the aperture is replaced by equivalent electric and magnetic dipoles. The reciprocal theorem gives the current in the load impedance when the distantdipole is driven. A numerical example is given.     

Cloud Dynamic Scheduling for Multimedia Data Encryption Using Tabu Search Algorithm

The cloud computing is interlinked with recent and out-dated technology. The cloud data storage industry is earning billion and millions of money through this technology. The cloud remote server storage is on-demand technology. The cloud users are expecting higher quality in minimal cost. The quality of service is playing a vital role in any latest technology. The cloud user always depends on thirty party service providers. This service provider is facing higher competition. The customer is choosing a service based on two parameters one is security and another one is cost. The reason behind this is all our personal data is stored on some third party server. The customer is expecting higher security level. The service provider is choosing many techniques for data security, best one is encryption mechanism. This encryption method is having many algorithms. Then again one problem is raised, that is which algorithm is best for encryption. The prediction of algorithm is one of major task. Each and every algorithm is having unique advantage. The algorithm performance is varying depends on file type. The proposed method of this article is to solve this encryption algorithm selection problem by using tabu search concept. The proposed method is to ensure best encryption method to reducing the average encode and decode time in multimedia data. The local search scheduling concept is to schedule the encryption algorithm and store that data in local memory table. The quality of service is improved by using proposed scheduling technique.

     

数字集群通信中GMSK信号解调算法的研究

详细介绍了国内某数字集群系统中使用的解调算法,推导了GMSK信号的Laurent分解过程,重点分析简化最优接收机到单脉冲匹配滤波接收机的转换过程,比较了在不同频偏环境下解调算法的性能差异并给出相关仿真结果。     

Temperature control for food in pots on cooking hobs

A control system for the temperature of food in a cooking pot is introduced. The cooking pot is heated on a consumer cooking hob. The temperature of the pot side is used as input for the controller. It is measured by an infrared detector. The infrared detector is a thermopile. The sensor signal is evaluated by a rule-based control algorithm. The system is simple, reliable, and very user friendly. An exact temperature settlement in a consumer hob is available for the first time. The system is used for automatic cooking     

便携式智能油气检测仪设计

为了防备油气浓度超标造成的安全事故,研制了便携式智能油气检测仪。采用接触燃烧式气敏传感器进行油气检测,并增加补偿元件。用电桥电路作为测量电路,用双端输入方式连接电桥与运算放大器,对所采集的信号作放大、补偿处理。采用集成电路A/D芯片进行信号A/D转换,并在LCD数字显示屏上显示油气浓度值。设计报警电路,用C＋＋语言设计软件,采用单片机进行系统控制。气敏元件的误差补偿和数字化浓度检测有创新。该检测仪适用于石油、天燃汽等储运和使用场所。     

A survey of electric and magnetic fields among VDT operators inoffices

The ambient electric and magnetic fields as well as the electromagnetic fields associated with video display terminals (VDTs) at 150 offices are measured. The aim of the study is to determine the general level of the various electromagnetic parameters in offices and establish a technical base for a case referent study of skin symptoms among VDT workers. The median value of the 50-Hz background field in the 150 offices is 0.07 μT. Seven of the offices have background levels higher than 0.5 μT, which is high enough to cause distortion of the picture on the screen. The dominant source for electric fields in the ELF range is electric equipment in the office, not the VDTs. The equivalent surface potential is less than 0.5 kV for 63% of the measured VDTs. The computer monitor is a major source of magnetic fields in the offices. The median value of the magnetic field in the ELF range in front of the VDT is 0.21 μT, and in the VLF range it is 0.03 μT