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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.
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   

3.
非晶硅太阳能电池的新进展   总被引:1,自引:0,他引:1  
对非晶硅材料的物理性能及工艺优势进行了阐述,其中介绍了一种新型的刻划成图工艺,即等离子CVM,简单回顾了非晶硅太阳池的历史发展,分析了非晶硅太阳电池当前所存在的问题,提出了其发展的方向,其中,主要论述了叠层非晶硅太阳电池,并介绍了几种新型的非晶硅电池,最后,概括了非晶硅太阳电池的应用现状及前景。  相似文献   

4.
针对雷达天线现状,提出了用微带天线作为阵元的思想,分析了微带天线的优点和局限性。提出了关键技术,给出了相应的解决方案,结合实际,进行了预研构思,提出了多波束天线,单片集成天线,微带单脉冲相控阵天线等思想。  相似文献   

5.
    
《印制电路资讯》2007,(4):79-79
马,本来自由自在的在山间撒野,渴了喝点山泉,累了就睡在地上晒太阳,无忧无虑。可是自从有了伯乐,马的命运就改变了,给它的头戴上笼辔,在它的背上置放鞍具,栓着它,马的死亡率已经是十之二三了,然后再逼着它运输东西,强迫它日行千里,在它的脚上钉上铁掌,马的死亡率就过半了。  相似文献   

6.
随着科技的发展,信息技术已经应用于生活的各个方面,提高了各行业的工作效率,降低了人工成本,减轻了人的工作压力,为人们的生活提供了便捷。而随着医院看病人数的增加,现代化医院的建立,医院的管理逐渐复杂化,而医院服务器虚拟化技术的应用,保障了医院工作的连续进行,医院管理的简单化,提高了医院的工作效率。但是,医院服务器虚拟技术也存在一些漏洞,而影响了服务器虚拟技术在实际生活中的应用。本文说明了服务器虚拟技术的构成,并阐述了其优点,也分析了其存在的不足。  相似文献   

7.
本叙述了Internet来自外部,内部,硬件,软件方面的十种安全威胁和攻击,给出了防火墙的限制,隔离,筛选,过滤和屏蔽作用,介绍了防火墙的六种基本结构类型,论滤了过滤路由器,双宿主主机,主机过滤,过滤子网和吊带式五种安全结构,分析了传统防火墙的七种不足,给出了目前防火墙混合应用包过滤技术,代理服务技术和其他一些技术的发展趋势。  相似文献   

8.
我校"信号与系统"课程的改革与建设   总被引:17,自引:3,他引:14  
信号与系统是电气信息类专业重要的技术基础课程。近年来,课程组对“信号与系统”课程进行了全面的改革与建设,造就了一支高素质的教师队伍,提出了具有鲜明时代特征的教育教学思想,重构了课程体系,更新了教学内容,出版了高水平教材,改革了教学方法与手段,取得了丰硕成果,2003年被评为国家精品课程。  相似文献   

9.
为了解决泥浆泵液力端泵头1:6锥孔表面加工精度不高,在使用中出现锥孔表面剌蚀而报废的问题,本文介绍了一种性价比较高,简单易行,安全可靠的锥孔滚压工艺方法,通过该工艺方法的实施,提高了锥孔表面加工精度和硬度,达到了设计要求,保证了泵头质量,延长了泵头的使用寿命,减少了阀及阀组件更换频次,大大的降低了运行成本,为用户安全生产提供了优质的产品保障。  相似文献   

10.
项立刚 《通信世界》2004,(33):M004-M004
在家里收拾屋子,手机的充电器竞有十多个,两个人用了七八年的手机,坏了、丢了、换了的手机也有七八个,一部手机还常有双充,可不就十多个充电器了。经常的情况是手机坏了,充电器却并不坏,买了新的手机,当然也配有新的充电器,旧的充电器扔了,是个浪费,不扔,能有什么用?我想这样的情况,其他手机用户也都一样,数数家里手机充电器,可能都不少。  相似文献   

11.
Recent research progresses in Multi-Beam Klystron(MBK)in IECAS are briefly introduced in the letter,The S-band MBKs of IECAs have peak power of 120-250kW,average power of 4-9kW,efficiency of 35-45%,gain of 41-46dB.beam voltage of 15-19kV,and weight of 40-45kg.Some key technical problem of MBK are also described and discussed.Among them,improving the design of MBK to botain the required bandwidth,raising beam transmission to increase average power,eliminating oscillation and spray spectrum,overcoming window breakdown caused by magic mode,reducing breakdown times of electron gun,are most important things for the practical MBK.Besides,further research owrk in MBK in IECAS is commented.  相似文献   

12.
针对在VHDL语言教学过程中,如何进行算术运算的VHDL描述问题进行了探讨.文中首先论述了VHDL语言描述算术运算的局限性;重点阐述了加运算、减运算、乘运算、除运算、取模运算、取余运算的VHDL描述方法;由于设计的结果是一个专用的算式电路,不运行任何程序,工作的可靠性和稳定性都优于用CPU设计.  相似文献   

13.
高速下行分组接入(HSDPA)技术是针对第三代移动通信系统上、下行链路业务量不平衡的特点提出的,能够大幅提高下行传输速率。在R5版本中WCDMA和TD-SCDMA分别引入了HSDPA。两系统中的HSDPA技术在MAC层、物理层和技术上有一致性,但同时二者在物理层信令参数、物理信道种类、时隙调整、技术和整体性能上存在着一些差异,而差异的产生源于WCDMA和TD-SCDMA系统本身特点的不同。主要阐述了WCDMA和TD-SCDMA HSDPA的异同,并进行分析。  相似文献   

14.
We report on temperature dependencies of the electron mobility in the two-dimensional electron gas (2DEG) in AIGaN/GaN heterostructures and in doped bulk GaN. Calculations and experimental data show that the polar optical scattering and ionized impurity scattering are the two dominant scattering mechanisms in bulk GaN for temperatures between 77 and 500K. In the 2DEG in AIGaN/GaN heterostructures, the piezoelectric scattering also plays an important role. Even for doped GaN, with a significant concentration of ionized impurities, a large volume electron concentration in the 2DEG significantly enhances the electron mobility, and the mobility values close to 1700 cm2/Vs may be obtained in the GaN 2DEG at room temperature. The maximum measured Hall mobility at 80K is nearly 5000 cm2/Vs compared to approximately 1200 cm2/Vs in a bulk GaN layer. With a change in temperature from 300 to 80K, the 2DEG in our samples changes from nondegenerate and weakly degenerate to degenerate. Therefore, in order to interpret the experimental data, we propose a new interpolation formula for low field mobility limited by the ionized impurity scattering. This formula is valid for an arbitrary degree of the electron gas degeneracy. Based on our theory, we show that the mobility enhancement in the 2DEG is related to a much higher volume electron concentration in the 2DEG, and, hence, to a more effective screening.  相似文献   

15.
文章介绍了高职院校DSP课程的教学改革情况。以培养应用性人才为目标,根据实际情况整合课程体系内容,通过实验教学、项目教学以及创新实践结合提高DSP课程教学成效。特别突出DSP硬件设计调试能力培养,同时兼顾Matlab及C语言软件的熟练应用。在高职院校开设DSP课程,是信息社会的必然需求,同时也给教学过程带来了新的问题与挑战。  相似文献   

16.
模电教学中的形象思维   总被引:1,自引:0,他引:1  
阐述了形象思维在认识客观世界时的重要作用,同时以大量的实例说明形象思维在模电课程中的应用,并论述了如何在模电教学中利用形象思维提高教学质量,同时培养学生的形象思维能力。  相似文献   

17.
The use of incentive regulation in telecommunications in the United States requires accurate measurement of the change in productivity. An approach to measuring productivity change, the Malmquist index approach, is introduced that not only provides a measure of that change but also allows for a decomposition into two mutually exclusive and exhaustive components – changes in technical efficiency over time and shifts in technology over time. Using annual data on four output measures and six input measures for the period 1988–1999 for nineteen local exchange carriers, the results indicate that productivity increased by about 5.5% per year. This growth is due primarily to innovation rather than improvements in efficiency. Of the nineteen LECs in the sample, eleven were operating efficiently throughout the entire 1988–1999 period. Of the remaining eight, four showed a slight improvement in efficiency while the efficiency of four declined. In the aggregate, however, there was virtually no change in efficiency. Finally, a comparison is made between two methods of estimating the change in productivity. The conventional growth accounting approach yields a lower estimate of the rate of change in productivity than does the Malmquist index approach.  相似文献   

18.
在DCT域中,存在AC,DC两个分量,通常在图像加密过程中,将水印嵌入AC分量,特别是中频系数上。本文从鲁棒性角度出发,通过实验证明,在实际应用中,DC分量比AC分量更适合嵌入水印。DC分量嵌入水印是有效的,且具有很好的鲁棒性,能抵御加在已嵌入水印的图像上的剪切、有损压缩的攻击。  相似文献   

19.
The authors describe the development trends and results of millimeter-wave systems in Japan in such fields as communication, radar, and measurement systems. The applications included are the W-40G waveguide transmission communication system, an automobile traffic control system using the 60-GHz band, a collision avoidance radar system for an automobile, a plasma electron density measuring system, and satellite communication. The authors describe the development of devices such as high-power FET amplifiers, traveling wave tube amplifiers (TWTAs), IMPATT amplifiers, low-noise amplifiers, and monolithic microwave integrated circuit (MMIC) devices used in constructing the millimeter-wave systems  相似文献   

20.
This paper reports the use of planar aluminum-PI-aluminum capacitors, in which the variation of low frequency dielectric permittivity is shown to be proportional to absorbed moisture, to carry out in-situ studies of moisture uptake and diffusion in PMDA-ODA device-grade polyimide films. It is found that the equilibrium amount of moisture uptake depends on ambient relative humidity in the temperature range 20-80‡C, and that the diffusion kinetics obey a Fickian model with a diffusion coefficient in the range 3-5 x 10-9 cm2 /sec at room temperature. The diffusion coefficient is temperature dependent, with an activation energy of 0.32-0.34 eV, and is weakly dependent on absorbed moisture at fixed temperature. An asymmetry is observed between absorption and desorption kinetics which correlates with the moisture-dependent diffusion coefficient.  相似文献   

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