金属结单电子晶体管的模型建立及实验验证

在正统理论的基础上，使用主方程法建立了金属结单电子晶体管的器件模型和算法流程．将电容、电阻和温度等参数代入器件模型得到的I-V特性曲线与实验结果吻合较好，从而验证了模型、算法以及程序流程的正确性．此外，通过详细讨论模拟与实验的三组曲线差别，得到模型使用主方程的稳态解是导致模拟与实验之间结果存在差别的主要原因，即求解含有时间的主方程将增加模拟精度；而且，指出镜像电荷引起的电势使电流随电压呈现指数增加的主要影响因素，明显偏离理论模拟的线性增加趋势．     

三种纵向结构的AlGaN/GaN HFET性能比较

对AlGaN/GaN HFET纵向的常规结构、倒置结构和双异质结进行了研究,结果表明:常规结构的材料生长简单、容易控制,倒置结构的直流性能低于常规结构,而双异质结虽然在材料生长方面较为复杂,但它可以获得较常规结构更为优良的直流特性.     

An investigation on thermal reliability of underfilled PBGA solder joints

The failure mechanism, as well as cycles to failure, of two groups of PBGA samples (with/without underfill) for thermal shock in the range of -40/spl square/-125/spl square/ were presented. The experiment shows that the solder ball in the samples without underfill cracked after 500 times cycle, while no crack was found in the underfilled samples even after 2700 cycles. However, the die attach layer delaminated after 500 cycles and the PCB cracked in the underfilled samples after long time cycling. C-SAM is employed to investigate the delamination in the underfilled samples. Highly concentrated stress-strain induced by the CTE mismatch between the BGA component and the PCB, coarsened grain and two kinds of intermetallic compounds (Ni/sub 3/Sn/sub 2//NiSn/sub 4/) which formed during reflow and thermal cycling and their impact on the reliability of solder joints are discussed in this paper. The initiation of the crack and its propagation are also presented in this paper. By means of dye penetrant test, the authors reveal the distribution of microcracks in the solder ball array. In addition, this paper includes results of simulation, which further verified its conclusions.     

Mitigation of polarization-mode dispersion in multichannel lightwave transmission systems

We propose a novel polarization-mode dispersion (PMD) compensation scheme for wavelength-division-multiplexing (WDM) systems, in which many WDM channels share one or a few PMD compensators at receiver site. It is shown, both analytically and numerically, that this scheme can achieve virtually the same performance as that using per-channel-based PMD compensation.     

航空发动机温度控制放大器激励信号源设计

介绍一种基于LMI17的温度控制放大器激励信号源,阐述了信号源的设计原理与工程实现.该激励信号源可以提供线性可调的正负毫伏直流电压信号,精度高、稳定性好,很好地满足了实际工程的需要.     

High‐Strength Laminated Copper Matrix Nanocomposites Developed from a Single‐Walled Carbon Nanotube Film with Continuous Reticulate Architecture

A critical challenge in nanocomposite fabrication by adding SWCNTs as reinforcement is to realize an effective transfer of the excellent mechanical properties of the SWCNTs to the macroscale mechanical properties of the matrix. Using directly grown SWCNT films with continuous reticulate structure as the template, Cu/SWCNTs/Cu laminated nanocomposites are fabricated by an electrodepositing process. The resulting Cu/SWCNTs/Cu laminated nanocomposites exhibit extremely high strength and Young's modulus. The estimated Young's modulus of the SWCNT bundles in the composite are between 860 and 960 GPa. Such a high strength and an effective load‐transfer capacity are ascribed to the unique continuous reticulate architecture of SWCNT films and the strong interfacial strength between the SWCNTs and Cu matrix. Raman spectroscopy is used to characterize the loading status of the SWCNTs in the strained composite. It provides a route to investigate the load transfer of SWCNTs in the metal matrix composites.     

基于MATLAB的信号处理网络实验室

随着网络技术的发展,高校教学越来越倚重于 Web 技术所带来的各项应用.为了降低成本和易于扩展,在网络上实现了信号处理实验.本文介绍了信号处理网络实验的设计步骤,该网络实验室主要应用MATLAB Web Server和Web技术,将Web应用的灵活性与MATLAB强大的科学计算能力结合在一起.通过在Web环境下MATLAB程序的应用,达到教学实验远程共享的目的,展示了MATLAB Web应用的良好发展前景.     

基于AT89C51和BH1417F芯片的数字化调率发射机设计

文章介绍的调频发射机设计是将单片机AT89C51和调频发射机相结合,用单片机P3.0、P3.1、P3.2、P3、3作为与BH1417F的通讯端口,通过改变P3.0、P3.1、P3.2、P3、3传送的高低电平从而改变BH1417F发射频率.同时又用单片机去控制四个数码管动态的去显示调频发射机所发送频率.     

水浴沉积法制备硫化镉薄膜的初步研究

采用化学水浴沉积法制备了半导体薄膜硫化镉（CdS）太阳能电池材料,对影响成膜的因素以及薄膜的结构和光学性能进行了初步测试研究。结果表明,反应溶液的pH值以及薄膜的退火温度是影响成膜的重要因素。实验中pH值范围控制在10．5—10．8之间,最佳退火温度为400℃。另外退火时滴加CdCl2溶液并将其涂抹于薄膜表面,可以使薄膜在可见光范围的透过率得到进一步的提高。     

无高架地板的“洞洞板”系统在大面积高洁净等级厂房中的应用

以目前国内一家光电厂的华夫板设计为例,介绍华夫板设计方案,对两类不同华夫板的设计方案进行比选,阐述了无高架地板"洞洞板"系统的特点,设计的重点、难点和解决方案,并通过项目的实际运行得以验证,无高架地板"洞洞板"系统值得在类似厂房中使用。