飞秒激光行波泵浦BBO晶体光参量放大

采用飞秒钛宝石激光放大器二次谐波为泵浦源，行波泵浦ＢＢＯ晶体光参量放大器，获得了可调谐输出（０．４４～２．６μｍ），最大输出能量约４０μＪ／脉冲，测量了参量激光的调谐特性、能量分布和线宽，理论与实验符合较好。     

Charge recycling differential logic (CRDL) for low powerapplication

A novel logic family, called charge recycling differential logic (CRDL), has been proposed and analyzed. CRDL reduces power consumption by utilizing a charge recycling technique with the speed comparable to those of conventional dynamic logic circuits. It has an additional benefit of improved noise margin due to inherently static operation. The noise margin problem of true single-phase-clock latch (TSPC) is also eliminated when a CRDL logic circuit is connected to it. Two swing-suppressed-input latches (SSILs), which are introduced for use with CRDL, have better performance than the conventional transmission gate latch. Moreover, a pipeline configuration with CRDL in a true two-phase clocking scheme shows completely race-free operation with no constraints on logic composition. Eight-bit Manchester carry chains and full adders were fabricated using a 0.8 μm single-poly double-metal n-well CMOS technology to verify the relative performance of the proposed logic family. The measurement results indicate that about 16-48% improvements in power-delay product are obtained compared with differential cascode voltage switch (DCVS) logic     

一种接入信息高速公路的新技术ADSL

新近出现的非对称数字用户线（ＡＤＳＬ）技术利用用户网中现有的铜双绞线提供１．５～６Ｍｂ／ｓ的下行数字信道，为接入信息高速公路提供了一条新途径，本文首次论述ＡＤＳＬ的基本概念，技术，发展现状和应用，最后论述我们对发展我国ＡＤＳＬ接入设备的几点建议。     

Chopper stabilised ΠΔΣ analogue to digitalconversion

A chopper stabilised ΠΔΣ ADC architecture is proposed. A chopper stabilised version of ΠΔΣ ADC, which has identical performances to the regular ΠΔΣ ADC but is immune to low frequency noises such as DC offsets, can be obtained without adding hardware complexities     

一种抑制时频分布交插项的有效方法

文中提出了一种构造时频分布的新方法,这种方法能够有效地压缩相应谱图中的交插项,它能够满足大多数所期望的特性,并且具有很高的时频分辨率,数字实例给出几个特定信号的情况以及说明这种时频分布的特点。     

Traffic impacts of international roaming on mobile and personal communications with distributed data management

In this paper, we propose four network interconnection scenarios and the related signaling aspects for the international roaming traffic in mobile and personal communications. With or without international gateway relay nodes summarized from the proposed scenarios, we also derive three international roaming network sets {IR₁, IR₂, IR₃} for the observed signaling traffic model with twolevel databases. Based on the proposed performance metrics, analysis results show that under some reasonable assumptions the signaling traffic of international roaming is significantly impacted by the related gateway relay nodes and databases. In addition, the studied cache data management strategy at VLR can reduce the impacts of the signaling traffic of query operation, but the caching approach cannot improve the performance of update operation. Furthermore, the performance of proposed standalone STP scenario is better than that of integrated STP scenario for the international network connection.     

复杂背景下的人脸分割

针对复杂背景下人脸位置的不确定性和人脸轮廓边缘点的不连续性,本文提出一种新的人脸分割算法,能够在复杂背景下将人脸快速分割出来。本文算法包括三部分:首先设计了特征与模板相结合的人脸定位算法,在复杂背景中以双眼和嘴的坐标为基准确定人脸位置;其次,设计了自适应搜索算法,提取真正的人脸轮廓点,去除“假”轮廓点;最后利用人脸轮廓的平滑性通过曲线拟合来补充不确定轮廓点,完成人脸分割。本文算法综合利用了人脸的肤色、表面结构、轮廓边缘以及轮廓的平滑性等特征完成人脸分割,实验结果证明了算法的有效性。     

Finite-difference time-domain simulation of scattering from objectsin continuous random media

A three-dimensional (3D) finite-difference time-domain (FDTD) scheme is introduced to model the scattering from objects in continuous random media. FDTD techniques have been previously applied to scattering from random rough surfaces and randomly placed objects in a homogeneous background, but little has been done to simulate continuous random media with embedded objects where volumetric scattering effects are important. In this work, Monte Carlo analysis is used in conjunction with FDTD to study the scattering from perfectly electrically conducting (PEC) objects embedded in continuous random media. The random medium models under consideration are chosen to be inhomogeneous soils with a spatially fluctuating random permittivities and prescribed correlation functions. The ability of frequency averaging techniques to discriminate objects in this scenarion is also briefly investigated. The simulation scheme described in this work can be adapted and used to help in interpreting the scattered field data from targets in random environments such as geophysical media, biological media, or atmospheric turbulence     

Hg1-xCdxTe外延薄膜表面对红外透射光谱的影响

利用傅里叶红外光谱仪测量液相外延生长的Hg1-xCdxTe薄膜,发现未经腐蚀的原生薄膜材料红外透射光谱经本征吸收后有吸收边倾斜并伴有透射比值偏低的现象.对红外透射光谱的影响因素进行了分析,用扫描电子显微镜、电子探针及轮廓仪对样品表面腐蚀前后进行测试,结果表明腐蚀前后Hg1-xCdxTe薄膜表面(深度约1μm)汞含量和表面平整度的差别是导致这一现象的主要原因.运用带-带尾态之间的跃迁理论及表面散射对这一现象进行了解释.     

防空兵雷达系统效能综合评估

根据防空兵雷达的作战任务和基本功能,将防空兵雷达评估指标分为探测能力、定位能力、抗干扰能力、生存能力、数据处理能力、目标识别能力及可用性等七个方面,建立了防空兵雷达评估指标体系,并对评估指标进行了具体量化,建立了评估指标的数学模型,给出防空兵雷达系统的效能综合评估结果.