宇航元器件应用验证指标体系构建方法研究

通过分析宇航元器件应用验证指标体系的特点,建立了一套面向宇航元器件应用验证的指标体系构建方法,该方法分别应用专家遴选系统、头脑风暴法和德尔菲法,解决了宇航元器件应用验证指标体系构建中的专家遴选、因素识别和指标体系构建问题。最后,应用该方法建立了宇航元器件应用验证综合评价指标体系基本结构。     

Automation of the Measurement Process of the Parameters of the Sensitive Elements of the Gas Flow Rate Sensors

Russian Microelectronics - The study of the characteristics and errors of sensors is as difficult as designing and manufacturing them. The operation of sensors needs to be accurately studied in...     

图文电视的现状与发展

本文描述了数据广播的现状,探讨了图文电视的结构和特点及其在中国的发展状况和前景。     

浅析微模块数据中心的关键技术

经过集装箱数据中心、模块化数据中心的发展热潮后,微模块数据中心进入人们的视野。其制冷、供电和服务器定制技术都有鲜明的特点。文章通过分析这些技术以及案例,提出只要解决了标准化、产业化等问题之后,微模块数据中心将会得到更快的发展。     

On the Design of the Triple-Resonance Interstage Network

The triple resonance network has emerged as a promising candidate for interstage bandwidth enhancement in cascaded CMOS amplifiers. This paper presents several design procedures for such networks, subject to the condition of moderate (1 dB) or no peaking in the passband, for the case where the devices can be chosen or designed, as well as the case in which the devices are given.      

快速恢复外延二极管用硅外延片的工艺研究

利用化学气相沉积方法制备所需硅外延层,通过FTIR(傅里叶变换红外线光谱分析)、C-V(电容-电压测试)、SRP(扩展电阻技术)等多种测试方法获取外延层的几何参数、电学参数以及过渡区形貌。详细研究了本征层生长工艺与外延层厚度分布、电阻率分布以及过渡区形貌之间的对应关系。采用该优化设计的硅外延材料,成功提高了FRED器件的性能与成品率。     

紧凑型节能荧光灯高频参数测试系统研制

本文介绍了一种紧凑型节能荧光灯的高频工作特性测试系统。该系统成本低、功能强、具有自动清零、采集并处理数据、输出结果的功能；实验证明它能快速、准确、自动地一次完成荧光灯所有高频工作参数的测量。     

加强实验室开放,构建电工电子创新实验教学平台

结合电工电子实验教学内容,对创新实验教学平台的设计进行了讨论,结合实际提出了创新实验平台的建设理念与建设模式,并就平台主要建设内容、平台特色、平台的教学与研究功能、平台建设效果、平台建设存在的难点进行了阐述,对培养高素质的创新性人才有一定的参考价值。     

Analyzing the effect of the phase-jitter in the operation of second order phase-locked loops

Phase-locked loops (PLLs) are designed to extract timing signals in telecommunication networks. Noise, cross-talk, inter-symbol interference, quantization noise, and signal distortion are responsible for oscillations in the time between two successive transitions of the clock or data signal. It appears as an accidental phase modulation superposed to the original signal. This phenomenon is called timing jitter and affects the integrity of the data recovering process and, as a consequence, the error bit rate is increased. This problem has been studied by treating the jitter as a band limited noise process and tolerance masks for the jitter amplitude and frequency are recommended for several network architectures. Here, we develop a simple model with the continuous phase deviations of the clock signals considered as periodic signals in the band of the real disturbances. Comparisons with the stochastic approach are presented.     

基于CB的串行口和接口板端口程序应用

串行口及接口板端口是计算机通信的主要途径 ,也是目前计算机工程测控中通用的基本方法。C Builder (简称CB)编程语言以其功能完备、开发效率高的特点而成为目前流行的程序开发工具 ,介绍了利用CB语言编写串行口和端口通信的程序的方法 ,并对具体的各方法编写了相应的示例。     

On the generalized Cramer-Rao bound for the estimation of thelocation

It is shown that the generalized Gaussian distribution maximizes the generalized Cramer-Rao (CR) bound for the pth absolute central moment of any classical location parameter unbiased estimator. The underlying maximization is taken over the class of distributions with fixed and finite pth-order moment and exhibits particular utility in minimax designs as well as in worst-case performance analysis. The relationship between the generalized Gaussian density and the generalized CR bound is further examined for the model of a mixture of generalized Gaussian distributions as well as for scenarios where multiple independent generalized Gaussian observations are involved     

Investigation Into the Effects of the Patch-Type FSS Superstrate on the High-Gain Cavity Resonance Antenna Design

Results of modeling, design, simulation and fabrication are presented for a high-gain cavity resonance antenna (CRA), employing highly-reflective patch-type superstrates. In order to determine the resonant conditions, the antenna is first analyzed using the transverse equivalent network (TEN) model, as well as the well known simple ray-tracing method. Prior to that, a highly-reflective patch-type frequency selective surface (FSS) is designed in order to be employed as the superstrate layer of the CRA. Next, a 2.5-D full-wave analysis software package, based on the method of moments (ANSOFT Designer v4.0), is utilized to analyze the antenna structure. Using this full-wave analyzer, the input impedance properties of an actual antenna are investigated as well. Then, a 3-D full-wave analyzer, based on the finite element method (ANSOFT HFSS), is used to extract the directivity and radiation patterns of the CRA, taking into account the finiteness of the substrate, superstrate and ground plane. Some previously unaddressed issues, such as the effects of the FSS superstrate on the input impedance characteristics of the probe-fed microstrip patch antenna, acting as the excitation source of the CRA are also studied. The effects of the highly-reflective FSS superstrate size on the CRA directivity, and explicitly its aperture efficiency, are investigated as well. A comparative study is also performed between CRAs with patch-type FSS and high permittivity dielectric superstrates. Measurement results are provided to support the modelings and simulations.      

Setting up as a consultant the devil is in the details

Making a success of a consultancy means finding a niche where you can offer clients an edge over competing consultants. You cannot be all things to all people. If, for instance, you want to function as a customer's representative reviewing process designs, project economics and schedules, be sure to portray yourself as such. If you want to specialize in particular unit operations, you should emphasize that forte. Among other choices, you may intend to make your name as an expert witness, or as an economic and market analyst, an adviser on educational curricula, a counselor to government or nongovernmental organizations, or to equipment vendors or technology licensors; whatever the choice, be sure to advertise yourself specifically as such. In any case, be objective and never stretch the facts as to your capabilities. Later in this article, we give recommendations on how to market your services.     

Modeling the nonlinear context dependency of the neural integrator in the vestibuloocular reflex

A neural integrator (NI) is presumed to exist in the oculomotor system to assist in numerous tasks such as maintaining gaze on imaginary targets in the dark. It is shared by all ocular reflexes including the vestibuloocular reflex (VOR). It has been widely accepted that the NI acts as a ldquoperfectrdquo integrator even in the dark with time constants as large as 1950s. However, the NI time constant is often less than ideal and its value can also be dependent on context [W. W. P. Chan and H. L. Galiana, ldquoIntegrator function in the oculomotor system is dependent on sensory context,rdquo J. Neurophysiol., vol. 93, pp. 3709--3717, Feb. 2005.]. In this paper, a nonlinear feedback model is postulated to model the context-dependent properties of the NI. Algorithms are first developed and validated to fit both linear and nonlinear NI models to experimental data in the presence of ocular nystagmus. Preliminary results indicate that even normal subjects can have a nonlinear VOR and NI.     

Resonance phenomena in the magnetized semiconductor plasma and their application for the design of the millimeter and submillimeter wave components

A review of physical principles of design as well as some ways of technical realization of controlled resonance semiconductor devices at millimeter and submillimeter wavelengths is presented. The operation of such devices is based on cyclotron and magnetoplasma resonances as well as on Fabry-Perot resonance. Such choice has been made due to the fact that these resonance phenomena are the most typical ones for the magnetized semiconductor plasma.     

基于校园网教学系统的研究

如何挖掘校园网资源潜力、开发网上教学系统进行探讨。对建立网上教学系统的必要性、可行性及网上教学系统的形式内容进行了分析说明。提出了包括网上作业、网上考试、网上课堂、网上实验等网上教学方式。构成符合现代教育思想的完整教学系统。     

WH-m/M相乘复合码扩频系统的互扰统计特性

本文建立了复合码ＤＳ－ＣＤＭＡ扩频系统的数学模型,推导了多址干扰的数学表示,定义了用户之间的互扰因子,并进行了计算,研究发现,在扩频比相同的上,若ＰＮ序列周期大小扩频比,且序列的伪随机性产好,则采用ＷＨ－ｍ／Ｍ复合序列与采用ｍ－Ｍ序列的扩频系统,其互扰因子均呈高斯分布,且数字特征相同,当ＰＮ序列周期等于扩频比时,互扰因子不具有高斯分布特性,该结论不要求扩频比足够大,而且对同步和异步ＤＳ－ＣＤＭＡ通     

MEMS微执行器平板运动稳定性研究

在MEMS静电执行器设计中,由于吸合效应的存在,导致微执行器调节范围受到限制.首先,对微执行器吸合效应产生的原因及其影响进行了分析与阐述.然后,针对吸合效应所带来的问题,给出了多种解决方法,以及与这些方法相关的技术进展.最后,对这些方法的性能及优缺点进行了总结.这些解决MEMS微执行器吸合效应的方法分为三种:利用反馈方...     

Application of the GSD technique to the analysis of slot-coupledwaveguides

The generalized spectral domain (GSD) technique is applied to the analysis of waveguide coupling by axially uniform slots. For a slotted-circular waveguide, cut off wavenumbers of TE and TM modes as well as the corresponding field distributions in the composite waveguide are determined and compared to that obtained by other methods. Plots of the field lines corresponding to the dominant as well as a number of higher order modes are presented. It is shown that considering the H₀₀ modes in the comprising waveguides is necessary. Furthermore, it is demonstrated how the efficiency of the method regarding accuracy and CPU time requirements can considerably be enhanced if infinite sums over eigenmodes which have to be evaluated are replaced by closed-form expressions