GaAs异质结材料BOA光开关特性分析

本文较为详细地讨论了GaAs异质结材料BOA型光开关的特性;并应用转移矩阵理论和有效折射率法计算和分析了电极结构与器件半波电压和串音度的关系.结果表明:通过优化设计电极的宽度可以获得BOA型光开关最小的半波电压;电极位置的对称性对器件串音度起决定性的影响.采用自对准工艺技术可以比较准确的控制电极的位置.分析表明:要得到<-40dB的串音度,电极位置偏差必须小于0.3μm.     

利用变压器研究两个互感线圈的串并联

利用变压器研究了两个互感线圈串并联的等效电感。     

ELECTRON TRANSPORT BEHAVIOURS IN THE NITROGEN DIRECT CURRENT GLOW DISCHARGE

A Monte Carlo simulation is presented to describe the electron transport behaviours in the nitrogen direct current glow discharge. The energy and angular distributions of the electrons at different positions of the cathode dark space are calculated; their energy and density distribution features throughout the entire discharge are discussed. The influence of molecular vibrational excitation, typical for electron－molecule collisions, has been studied and the elementary process of active species generation has been illustrated. The simulated results reveal that, in the cathode dark space, the high-energy electrons are mainly forward scattering and behave as a high-energy ‘electron beam'. The sharp increase of the number of secondary electrons plays an important role in producing active species at the interface between the cathode dark space and the negative glow region. The vibrational excitation enhances the energy loss of electrons in the negative glow region.     

基于运动跟踪匹配技术的视频对象提取

本文提出一种自动分割VOP的技术。其方法是：先对初始帧使用形态运动滤波技术提取出初始运动对象的二值轮廓模型,并在后继帧中使用豪斯道夫对象跟踪器跟踪运动以对象模型;而为了适应对象的形状变化,本文使用活动轮廓模型（snake）技术对运动心合匹配;最后根据一系列精确的二值轮廓引导提取运动对象序列。实验结果表明,我们的算法可有效地提取视频对象平面。     

Photocatalytic Characterization of TiO_2 Supported on Active Carbon

Photocatalysis on TiO2, with a promising application to the elimination of organic contaminants from air and water, has been a particularly active area1. For such application, it is important to improve the efficiency of TiO_2 photocatalysts. In the most cases, the concentration of organic contaminants in water is extremely dilute (ppm level or below) and TiO_2 itself has low adsorbabilities for them, it usually takes a long time to complete their decomposition. One of the effective ways to …     

Baker's Yeast Mediated Reduction of Optically Active Diketone

Baker's yeast (BY) mediated reduction of synthetic substrate is a useful method for preparing chiral intermediate in synthesis chemistry1,2, because it is readily available and inexpensive. The selectivity is generally predicted by Prelog rule3, that is, a hydride is transferred to the re face of the prochiral ketone.The baker's yeast mediated reduction of bicyclic diketones was previously reported by several groups4-6, but to our knowledge, no application of this reduction to sesquiter-pene-…     

行波电极型BOA光开关的研制

设计了行波电极型GaAs异质结材料BOA光开关;采用谱域法分析和设计了平面微带线结构(PMS),并应用转移矩阵理论和有效折射率法计算和分析了电极结构与器件半波电压和串音度的关系。结果表明,采用PMS结构器件的3dB带宽可达到20GHz;电极位置的对称性对器件串音度起决定性的影响,采用本文提出的电极对准工艺,能够得到小于—40dB的串音度。     

激光中的涡旋与孤子

本文概述了在有源非线性光学共振腔中形成的图样类型及特点,这些特征可用激光流体动力学描述;介绍了在这一领域内的最新发展和应用前景。     

航空CCD电光侦察系统的发展现状与展望

CCD电光照相系统是继机载航空胶片航空侦察系统之后迅速发展起来的一门新兴的技术。本文对其发展现状、发展趋势及其对航空侦察系统的重大意义作了介绍和分析。     

A High-Speed Active Switch Routing Architecture

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