VHF/UHF天线宽带匹配网络的优化设计与实验研究

本文系统地研究了VHF/UHF天线宽带匹配网络的设计与制作.提出遗传算法与模拟退火法相结合的优化设计方法,解决VHF/UHF天线宽带匹配网络制作过程中元件值随频率较大变化引发的难题.最后,利用该方法研制了30~450MHz全向宽带小型化天线的宽带匹配网络.实验表明,带内VSWR＜3.0,且计算结果与测试结果十分吻合.     

用DWDM系统闲置资源恢复2.5 Gbit/s SDH传输系统

对部分厂家２．５Ｇｂｉｔ／ｓＳＤＨ设备接入波分复用系统进行了试验,为发生光缆中断等突发性事件时终端站间迅速恢复电路提供了有益参考。     

线源激励二维理想导体角反射器辐射场严格解

采用模式匹配法,对平行电流丝或磁流丝作用下二维理想导体角反射器的电磁辐射进行了严格地电磁场分布。推导出了以散射场展开系数为未知量的矩阵方程,给出了计算实例,其中张角为１８０℃（即平板）的计算结果与文献［４］的结果是一致的。     

Confocal Microscopy Studies of Trypsin Immobilization on Porous Glycidyl Methacrylate Beads

The immobilization of trypsin on porous glycidyl methacrylate (GMA–GDMA) beads has been investigated. In particular, the distribution within the beads of trypsin and of dextran used for hydrophilizing the bead surface prior to protein immobilization was investigated with confocal microscopy. For the system investigated, the fluorescence intensity profiles obtained when using borate buffer as an ambient solution displayed a distinct minimum at the center of the beads, irrespective of the observation depth. However, by reduction of the refractive index difference between the solution and the beads through the addition of glucose to the aqueous solution, artifacts relating to optical length differences could be reduced. For both low molecular weight fluorescein isothiocyanate (FITC), FITC-labeled trypsin, and FITC-labeled dextran, an essentially homogeneous distribution throughout the beads was observed. This simple “contrast matching” method seems therefore to be an interesting tool when investigating the distribution of immobilized protein in porous chromatography media.     

基于PC机的虚拟现实技术研究

本文利用所需额外硬件很少的立体显示技术,研制了一种基于微机平台的虚拟现实系统。这个系统利用最新推出的微机版的三维图形标准Open GL建模,以实时动画形式实现了真正的交互性,立体视觉效果明显,可以给观赏者提供真实的临场感和亲自控制的参与感。与已研制出的“三维立体显示系统”相比,有了实质性的进步。     

A novel quasi-phase-matching frequency doubling technique

A new quasi-phase-matching technique for efficient second-harmonic generation is reported. It is based on the spatial periodic modulation of the light intensity along the propagation direction, rather than the conventional spatial periodic modulation of the nonlinear optical coefficients. It can be realized by using a novel dual-channel waveguide frequency doubler structure for the desired light intensity distribution. This dual-channel waveguide device has major advantages including very small beam size, high light intensity within long nonlinear-waveguide interaction length, highly efficient second-harmonic generation, ease in fabrication of the nonlinear channel waveguides without any spatially periodic poling, and low waveguide propagation losses. The new quasi-phase-matching technique can also be applied to third-harmonic generation and other nonlinear optics processes.     

车灯配光性能在线检测系统研究

本文介绍一种能够对车灯光度、色度性能同时进行在线测试的计量仪器。它操作方便，精度较高，符合国标对车灯配光性能检测的要求。     

热成像温差分辨率与微分光谱匹配因数的关系

由近距离低温面目标热成像系统的信号方程和噪声等效温差ＮＥＴＤ的定义，导出了ＮＥＴＤｏｃ１／Ｍ，并由此得到ＭＲＴＤｏｃ１／Ｍ，ＭＤＴＤｏｃ１／Ｍ，从而证明了热成像系统的温差分辨率；ＮＥＴＤ、ＭＲＴＤ、ＭＤＴＤ均要求微发光谱匹配因数Ｍ要大，这为选用光谱区配因数Ｍ和Ｍ作为热成像系统的综合评价参数奠定了理论基础。     

Phase-matched high-order harmonics by interaction of Ar atoms with high-repetition-rate low-energy femtosecond laser pulses

High-order harmonics are generated by coherent interaction of an intense laser and atoms or molecules[1]. With the development of the intense ultrashort pulse laser, the research of high-order harmonic generation has reached the water-window in spectral region[2] and subfemtosecond in time domain[3]. Especially, the generation and application of subfemtosecond pulse led the study of high-order harmonic generation into a completely new world[4, 5]. It has made the study of ultrafast science fro…     

Computational Modeling of Organizations Comes of Age

As they are maturing—i.e., as they are becoming validated, calibrated and refined—computational emulation models of organizations are evolving into: powerful new kinds of organizational design tools for predicting and mitigating organizational risks; and flexible new kinds of organizational theorem-provers for validating extant organization theory and developing new theory. Over the past 50 years, computational modeling and simulation have had enormous impacts on the rate of advancement of knowledge in fields like physics, chemistry and, more recently, biology; and their subsequent application has enabled whole new areas of engineering practice. In the same way, as our young discipline comes of age, computational organizational models are beginning to impact behavioral, organizational and economic science, and management consulting practice. This paper attempts to draw parallels between computational modeling in natural sciences and computational modeling of organizations as a contributor to both social science and management practice.To illustrate the lifecycle of a computational organizational model that is now relatively mature, this paper traces the evolution of the Virtual Design Team (VDT) computational modeling and simulation research project at Stanford University from its origins in 1988 to the present. It lays out the steps in the process of validating VDT as a computational emulation model of organizations to the point that VDT began to influence management practice and, subsequently, to advance organizational science. We discuss alternate research trajectories that can be taken by computational and mathematical modelers who prefer the typical natural science validation trajectory—i.e., who attempt to impact organizational science first and, perhaps subsequently, to impact management practice.The paper concludes with a discussion of the current state-of-the-art of computational modeling of organizations and some thoughts about where, and how rapidly, the field is headed.