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1.
微通道板非晶态Al2O3电子透射膜   总被引:17,自引:5,他引:12  
文中介绍了MCP非晶态Al2O3电子透射膜在成像器件中的作用,阐述了膜层的选择,形成条件与方法,给出了膜层形成及其与辉光气体放电的关系,测量了膜层及带膜MCP的些特性,并进行了初步分析了讨论。  相似文献   

2.
甘仲民  李平辉 《电子学报》1996,24(6):72-76,66
本文提出了一种利用测量AM-AM,AM-PM特性对微波GaAsFET大信号建模式的方法。此外,利用测量或理论求得的AM-AM、AM-PM非线性特性,可进一步分析放大器的增益、互调性能,避免多音激励下进行测量或理论分析的麻烦。结果表明,理论与实验甚为一致。  相似文献   

3.
本文研究了各种实验参数对O-SIMS和Cs-SIMS中GaAs二次离子发射的影响,和样品室中氧分压对GaAs二次离子发射的增强效应.实验表明,与Ar-SIMS不同,O-SIMS和Cs-SIMS中随Ep增加二次离子的强度反而有所下降,而样品室注入氧可以提高正二次离子产额,但需要达到较高的氧分压:10-3Pa.二次离子能量分布测量表明,对O-SIMS,二次离子强度在Vbias=30V左右达到最大值,对Cs-SIMS,二次离子强度在Vbias=-20V左右达到最大值.  相似文献   

4.
本文提出了一种利用测量AM-AM、AM-PM特性对微波GaAsFET大信号建模的方法.此外,利用测量或理论求得的AM-AM、AM-PM非线性特性,可进一步分析放大器的增益、互调性能,避免多音(射频)激励下进行测量或理论分析的麻烦.结果表明,理论与实验甚为一致.  相似文献   

5.
用化学和电学研究测试了6H-SiC与元素金属(Ni,Mo)和硅化物(MoSi2,TaSi2和TiSi2)的接触特性。用俄歇电子光谱(AES)化学分析技术研究了由热处理引起的界面反应,在退火过程中,用电学测量方法(电流-电压和电容-电压)测量了整流特性或欧姆接触特性。并尽可能地计算了势垒高度及接触电阻值。  相似文献   

6.
根据Hg1-xCdxTe本征吸收系数的经验公式及Hougen模型,建立了一种用室温红外透射谱研究Hg1-xCdxTe外延薄膜组份均匀性的方法,用这种方法检测了LPE、MBE、MOCVD薄膜的组份分布,并与二次离子质谱(SIMS)测量结果进行了比较  相似文献   

7.
根据Hg1-xCdxTe本征吸收系数的经验公式及Hougen模型,建立了一种用室温红外透射谱研究Hg1-xCdxTe外延薄膜组份均匀性的方法,用这种方法检测了LPE、MBE、MOCVD薄膜的组份分布,并与二次离子质谱(SIMS)测量结果进行了比较。  相似文献   

8.
在2000年世界无线电大会上,第3代移动通信系统(3G)的地面系统被确定可使用5种无线传输技术,它们是CDMA-DS、CDMA-MC、CDMA-TDD、TDMA-SC和TDMA-TDD。其中前3种基于CDMA(码分多址)技术,后两种基于TDMA(时分多址)技术。可见,在3G标准中,CDMA是主流技术。CDMA(Code Division Multiple Access)蜂窝系统由于采用了一种称之为扩频的通信技术,所以与采用TDMA和FDMA(频分多址)的GSM蜂窝系统相比,具有抗干扰性好、系统容量…  相似文献   

9.
两种改进的适用于多目标情况的恒虚警检测算法   总被引:1,自引:0,他引:1  
本文基于筛选平均和无偏筛选平均提出了两种改进的恒虚警检测器-MCM-CFAR和MUCM-CFAR,并应用了何友提出的自动筛选技术,在SwerlingⅡ型目标似假设下,并考虑瑞利分布杂波和单脉冲检测情形,本文推导出了MCM-CFAR和MUCM-CFAR检测器的Pfα,Pd和平均判决门限的解析表达式,并与其它方案进行了比较。  相似文献   

10.
红外透射光谱在HgCdTe外延薄膜性能评价中的应用   总被引:8,自引:2,他引:6  
用最新发表的HgCdTe材料的光学常数对MBE工艺生长的HgCdTe/CdTe/GaAs材料的透射光谱进行了理论计算,对受生长工艺破坏的衬底背面再次进行抛光处理,消除因表面不平整引起的漫反射效应,使实验测量得到的光谱曲线与理论计算结果很好地吻合,由此得到的HgCdTe和CdTe外延层的厚度和解理面上用显微镜测量的数值相同。  相似文献   

11.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

12.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

16.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

17.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

18.
正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first  相似文献   

19.
20.
LI Shaoqian 《中国通信》2014,(6):I0001-I0002
The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave (ram-wave) frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.  相似文献   

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