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1.
“我有一个梦想:某一天三大运营商员工不摆摊了,不打架了,员工年收入差距缩小了,前端营业员待遇提高了,后端装维与资源矛盾化解了,服务质量提高了,恶性竞争消除了,重复建设停止了,不再破坏对手广告了,不互挖墙角搞策反了,不再零元购机了,不打价格战了,都能活的有尊严了”.  相似文献   

2.
    
江湖最近挺乱. 金融海啸了,经济危机了;奥巴马当选了,杨致远下课了;三聚氰胺走了又来了,"林书记"来了又走了;百度乱卖广告被央视曝光了,首富黄光裕涉嫌违法被拘查了;国家开始上万亿的花钱了,央行敢于一百零八个基点的降息了!  相似文献   

3.
Wedding……     
兄弟结婚了,朋友结婚了,朋友的朋友结婚了;男的结婚了,女的结婚了,不男不女的也结婚了;有感情的结婚了,没感情的结婚了,认识不认识的结婚已经无所谓了……  相似文献   

4.
本文提出了一种无需检测电感电流及其过零点的简单数字控制方案,实现了临界连续模式功率因数校正器的控制。取得了功率开关管的ZVZCS,消除了整流二极管和快恢复二极管的反向恢复带来的损耗,提高了变换器的效率和可靠性;另外,数字控制器克服了模拟IC控制器的开关频率限制问题,消除了输入电流的低频畸变,提高了功率因数;同时,也降低了输入电感的值,降低了成本的同时提高了功率密度。为实现中小功率数字控制功率因数校正器的产品化提供了一个良好的解决方案。  相似文献   

5.
《通信世界》2012,(26):6
"我有一个梦想:某一天三大运营商员工不摆摊了,不打架了,员工年收入差距缩小了,前端营业员待遇提高了,后端装维与资源矛盾化解了,服务质量提高了,恶性竞争消除了,重复建设  相似文献   

6.
本文研究了供水系统运行状态实时模拟模型,首先对数据进行了预处理,然后运用多元线性回归,给出了准则判断了数据优势;建立了供水系统与用水量之间的数学模型,并给出了误差分析,探讨了供水量和用水量对模型的影响。  相似文献   

7.
CMMI利用了两个或多个单一学科的模型实现了组织的集成化过程改进,提炼了公共过程域,缩减了过程域的总数量,提高了软件开发质量和生产效率,推动了软件产业的发展。对CMMI的重要内容做了相应解释,并阐述了在应用CMMI中的经验和感想。  相似文献   

8.
铝电解电容器技术的新进展   总被引:3,自引:3,他引:0  
详细讨论了电子技术的发展对铝电解电容器的性能要求,提出了其技术对策,分析了存在的技术瓶颈,找出了它的技术出路,探讨了它的技术难点,给出了当前我国铝电解电容器行业的技术现状,指出了未来发展方向。  相似文献   

9.
分析了小波压缩的相关理论知识,着重对JPEG2000系统中的ROI功能进行了研究,实现了ROI的构思和实用算法,给出了性能分析,进而分析了目前ROI算法的局限性并给出了ROI的改进算法,做出了相应的实验结果分析.  相似文献   

10.
一种基于数字电路的纳秒级脉冲产生方法   总被引:4,自引:0,他引:4  
张涛  李熹  郭德淳 《现代电子技术》2006,29(10):119-120,123
介绍了超宽带无线电的基本概念和技术特点,对几种典型的超宽带窄脉冲产生方法进行了描述和比较,提出了一种采用数字电路实现超宽带纳秒级窄脉冲的新方法,叙述了电路的基本原理和核心器件的主要性能,给出了电路结构,并对试验电路进行了测试。最后给出了测试结果并对测试结果进行了分析,得出了相关的结论。  相似文献   

11.
胆小管超微细胞酶学研究   总被引:1,自引:0,他引:1  
以电镜细胞化学的方法,观察了小鼠胆小管酶的分布。观察的12种酶中,NDPase和G6Pase三种酶分布于胆小管微绒毛;AlPase、Na~+-K~+ATPase、Mg~(++)-ATPase、Ca~(++)-ATPase、CMPase、ACase和5'-Nase等7种酶分布于胆小管微绒毛,也分布于肝细胞邻接面细胞膜和Disse间隙微绒毛;ACPase、细胞色素氧化酶以及线粒体ATPase不分布胆小管微绒毛,也不分布Disse间隙微绒毛和肝细胞膜。据信,胆小管微绒毛上的酶参与胆汁成份的转运,提供转运所需能量以及还可能与某些代谢过程有关。本实验中磷酸水解酶类使用的铈基法及亚铁氰化钾半还原的锇酸后固定法,效果优于铅法。  相似文献   

12.
This paper presents a systematic review of models and methodologies that integrate information and communication technologies (ICT) and education. The systematic review was based on the methodology of Kitchenham. The steps used and developed correspond to the steps proposed in the methodology. The starting point of the review are the research questions, then keywords, selection of the databases, definition of the inclusion and exclusion criteria, the definition of the search chains, search process and selection of papers, the analyzes of the paper and the results of the systematic review to answer the questions posed. In the systematic review, 919 papers were found in 6 academic databases and 129 relevant papers were selected. The work developed intends to know the different models and methodologies that integrate the ICT and the education. Develop an analysis and characterize to find common elements among models and methodologies. The idea is to find limitations, disadvantages and spaces that allow to propose a new model. This systematic review is the first step in the development of a doctoral research in which the development of a U-Learning model based on Connective Learning and Experience Learning is proposed.  相似文献   

13.
米酵菌酸对小鼠肝和心肌细胞毒性作用的超微结构研究   总被引:4,自引:0,他引:4  
目的:观察米酵菌酸对小鼠肝、心肌细胞毒性作用的超微结构改变,探讨米酵菌酸中毒的机理,方法:小鼠腹腔注射不同剂量的米酵菌酸,2h后取其肝和心肌组织,通过电镜观察其细胞超微结构的改变,结果:电镜下可见肝细胞和心肌细胞的线粒肿胀,内嵴断裂,模糊或消失,基质局部或全部空亮,呈囊泡样变,偶见其中含髓样小体,上述线粒体内嵴和膜结构的病变随米酵菌酸剂量的增加而加重,结论:米酵菌酸对小鼠肝、心肌细胞毒性作用以线粒体的损伤较为突出,因此我们认为,线粒体内膜的破坏造成线粒体的功能障碍,影响细胞呼吸,使细胞缺氧导致小鼠中毒死亡。  相似文献   

14.
This paper describes the design and implementation of a hybrid intelligent surveillance system that consists of an embedded system and a personal computer (PC)-based system. The embedded system performs some of the image processing tasks and sends the processed data to the PC. The PC tracks persons and recognizes two-person interactions by using a grayscale side view image sequence captured by a stationary camera. Based on our previous research, we explored the optimum division of tasks between the embedded system and the PC, simulated the embedded system using dataflow models in Ptolemy, and prototyped the embedded system in real-time hardware and software using a 16-bit CISC microprocessor. This embedded system processes one 320 × 240 frame in 89 ms, which yields one-third of the rate of 30 Hz video system. In addition, the real-time embedded system prototype uses 5.7 K bytes of program memory, 854 K bytes of internal data memory and 2 M bytes external DRAM. Koichi Sato is a Ph.D. student in the Department of Electrical and Computer Engineering at The University of Texas at Austin. He earned his B.S. in University of Tokyo, Japan in 1993. He worked for Automotive Development Center in Mitsubishi Electric Corporation where he was involved in lane and automobile recognition in vehicle video processing products such as automatic cruise control and drowsiness detection systems. He enrolled in the current University at 1998 and received an M.S in 2000. In his Master's thesis he worked on human tracking and human interaction recognition. His current work includes velocity extraction using the TSV transform, object tracking, and 3D object reconstruction. Brian L. Evans is a tenured Associate Professor in the Department of Electrical and Computer Engineering at The University of Texas at Austin. His research and teaching efforts are in embedded real-time signal and image processing systems. In signal processing, his research group is focused on the design and real-time software implementation of ADSL and VDSL transceivers, for high-speed Internet access. In image processing, his group is focused on the design and real-time software implementation of high-quality halftoning for desktop printers, smart image acquisition for digital still cameras, and 3-D sonar imaging systems. In signal and image processing, Dr. Evans has published over 100 refereed conference and journal papers. Dr. Evans is the primary architect of the Signals and Systems Pack for Mathematica, which has been on the market since October 1995. He was a key contributor to UC Berkeley's Ptolemy Classic electronic design automation environment for embedded systems, which has been successfully commercialized by Agilent and Cadence. His BSEECS (1987) degree is from the Rose-Hulman Institute of Technology, and his MSEE (1988) and PhDEE (1993) degrees are from the Georgia Institute of Technology. From 1993 to 1996, he was a post-doctoral researcher in the Ptolemy project at UC Berkeley. He is a member of the Design and Implementation of Signal Processing Systems Technical Committee of the IEEE Signal Processing Society, and a Senior Member of the IEEE. He is the recipient of a 1997 National Science Foundation CAREER Award. J.K. Aggarwal has served on the faculty of The University of Texas at Austin College of Engineering since 1964 and is currently Cullen Professor of Electrical and Computer Engineering and Director of the Computer and Vision Research Center. His research interests include computer vision and pattern recognition focusing on human motion. A Fellow of IEEE since 1976 and IAPR since 1998, he received the Senior Research Award of the American Society of Engineering Education in 1992, the 1996 Technical Achievement Award of the IEEE Computer Society and the graduate teaching award at The University of Texas at Austin in 1992. He has served as Chairman of the IEEE Computer Society Technical Committee on Pattern Analysis and Machine Intelligence (1987--1989); Director of the NATO Advanced Research Workshop on Multisensor Fusion for Computer Vision, Grenoble, France (1989); Chairman of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition (1993), and President of the International Association for Pattern Recognition (1992--1994). He is a Life Fellow of IEEE and Golden Core member of IEEE Computer Society. He has authored and edited a number of books, chapters, proceedings of conferences, and papers.  相似文献   

15.
小信号多腔速调管主要性能指标简化分析   总被引:1,自引:0,他引:1  
宁曰民 《微波学报》2005,21(3):43-47
介绍了速调管在我国的发展现状和小信号条件下速调管的各种主要性能指标的简化分析方法。在这种简化分析方法中,首先不考虑非线性和相对论效应等带来的影响,并把多腔速调管看作是几个双腔速调管的级联,得出了增益、效率、带宽和输出功率等重要参数的计算公式。然后通过给出部分参数的修正系数说明了这种简化分析方法的实用价值及理论指导意义。  相似文献   

16.
电子学的崛起、发展和广泛应用是20世纪最伟大的科学技术领域之一.在电磁波理论和自由电子发展的基础上,1904年出现了第一只真空二极电子管,一般认为这标志着电子学的诞生.电磁波频谱资源的开发和利用是电子学发展的基础和动力.从电磁频谱统一的观点看,光已经象微波一样进入到电子学的领域,成为无线电电子学中不可分割的组成部分.电子学的基本任务是:研究带电粒子流与电磁场相互作用的物理概念和物理过程,以及利用相互作用的不同物理机制实现粒子与场之间能量有效转化的方法和条件.从电子器件的观点看,电子学可分为真空电子学与固态电子学;而从电子运动规律的观点看,现代电子学将处理自由电子,准自由电子和束缚电子的运动规律及其与电磁场的相互作用.1958年,电子学领域出现三个重要发现和发明:集成电路、激光和相对论自由电子的回旋辐射.相应的,半导体电子学(微电子学)、激光电子学和相对论电子学等现代电子学领域则发端于此.电子器件小型化、微型化、功能集成化将电磁频谱的开拓和占领推向光波和红外毫米波.  相似文献   

17.
王鹏周政 《微波学报》2012,28(S2):361-363
GPS 卫星定位技术已广泛应用于航空航天系统。本文通过阐述GPS 接收机的工作原理及GPS 信号的特点,分 析了接收机交调互调传导敏感度测量原理,扩展了GPS 接收机交调互调传导敏感度的试验方法。该测试方法快捷、易 于掌握,便于得到接收机互调交调抑制比参数。  相似文献   

18.
时岩 《电子技术》2012,(3):12-13
在深入理解ARM和TMSC320C5000在参与基于OMAP5910的3G无线终端的多媒体应用平台硬件系统设计基本原则的基础上,文章画出一个硬件系统原理图和印刷电路板图;各种功能模块进行测试和调试;完成与CPLD相关的硬件语言设计和调试,在QuartusII软件下用VerilogHDL编写;在掌握Linux操作系统及嵌入式操作系统的移植和开发及Linux下的驱动程序开发的基础上,完成DSP、Camera、触摸屏等底层驱动程序的开发;完成Microwindow下顶层用户界面和JPEG等应用程序的开发,和Linux驱动程序开发。  相似文献   

19.
A study of the enhancement of the mechanical sensitivity of an area-changed capacitive accelerometer by optimization of the device geometry is presented. The movable mass of the accelerometer was designed with many fingers connected in parallel and suspended over the stationary electrodes composed of differential comb fingers by means of mechanical beams anchored onto the substrate. The maximum displacement possible based on the chosen design structure was determined. From this displacement value the spring constant was calculated, and based on this spring constant value various combinations of the beam length and width were selected. The lengths and the widths were then varied and simulated using the Coventorware 2001.3 software. This was done as theoretical analysis showed that the mechanical beam dimensions are significantly more dominant in the overall device sensitivity. The displacement and spring constant variations with the beam dimensions at an applied acceleration was observed and analyzed. The same process was done for the number of fingers, length and thickness of each finger. Each of these was done in isolation based on the optimum geometry of the mechanical beams and tested to ensure that alterations of these aspects do not have a significant effect on the overall sensitivity. The modal and harmonic analysis were also simulated and observed to ensure the linearity and the stability of the dominant mode of the operation of the device. Optimum results of the device geometry are presented and discussed, along with suggested next steps.Badariah Bais received the B.S. and M.S. degrees from the Worcester Polytechnic Institute, Worcester, MA, in 1990 and 1992, respectively. Since 1997, she has been serving at the Department of Electrical, Electronics and Systems Engineering at Universiti Kebangsaan Malaysia as a teaching staff. She is currently pursuing her Ph.D. in Microelectronics at the Institute of Microengineering and Nanoelectronics (IMEN) at Universiti Kebangsaan Malaysia. Her research interests include MEMS sensors and microfabrication. She is a member of the Institute of Electrical and Electronics Engineer (IEEE).Burhanuddin Yeop Majlis received his Ph.D. in Microelectronics from University of Durham, UK in 1988, MSc. in Microelectronics from University of Wales, UK in 1980 and BSc. (Hons.) in Physics from Universiti Kebangsaan Malaysia in 1979. Now he is the director of Institute of Microengineering and Nanoelectronics (IMEN). He is a senior member of the Institute of Electrical and Electronics Engineer (IEEE) and the Chairman of IEEE Electron Devices Malaysia Chapter since 1994. He is also a member of Malaysian Solid State Science and Technology (MSSS). He has published three text books in electronics and one book on Integrated Circuits Fabrication Technology for undergraduate courses and more than 110 academic research papers. His current interest are MEMS sensor for automotive and RF applications.  相似文献   

20.
利用软硬件结合方式,设计一种针对舰艇雷达及电子对抗装备主要性能的测试及评估系统,实现非接触测试,无须上舰,在距离舰艇100~200 m的码头,采用"定量比对法"对雷达及对抗装备的关键参数进行测试和评估。  相似文献   

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