Diversity reception of 16STAR-QAM in frequency-selective Ricianfading

Bit error rate (BER) performance of differential 16STAR-QAM in frequency-selective Rician fading channels with diversity reception is theoretically analysed for three different types of delay profiles: double spike, one-sided exponential and Gaussian profiles. The effect of time delay between line-of-sight (LOS) and multipath components is also included in the analysis, and is shown to degrade the system performance significantly     

IS—95CDMA系统的容量分析

容量的需求是推动ＣＤＭＡ数字蜂窝移动通信开发的主要动力。系统的容量受许多因素的影响，本文针对ＩＳ－９５ＣＤＭＡ系统在采用了功率控制、话音激活和扇区划分技术的情况下，对系统的容量进行了分析，同时也分析了功率控制精度对容量的影响。     

深亚微米薄膜SOI MOSFET的二维数值模拟

本文介绍了适合于薄膜亚微米、深亚微米ＳＯＩＭＯＳＦＥＴ的二维数值模拟软件。该模拟软件同时考虑了两种载流子的产生－复合作用，采用了独特的动态二步法求解泊松方程和电子、空穴的电流连续性方程，提高了计算效率和收敛性。利用此模拟软件较为详细地分析了薄膜ＳＯＩＭＯＳＦＥＴ不同于厚膜ＳＯＩＭＯＳＦＥＴ的工作机理及特性，发现薄膜ＳＯＩＭＯＳＦＥＴ的所有特性几乎都得到了改善。将模拟结果与实验结果进行了对比，两者吻合得较好。     

新型陶瓷刀具材料JX－2－I界面结构的实验研究

利用ＴＥＭ和电子衍射图谱分析，研究了新型陶瓷刀具材料ＪＸ－２－Ｉ的界面微观结构。ＴＥＭ分析表明，ＪＸ－２－Ｉ刀具材料的界面结合状态较好，Ａｌ＿２Ｏ＿３／ＳｉＣｗ界面上形成了具有较高强度的“钢筋混凝土”结构，在Ａｌ＿２Ｏ＿３／ＳｉＣｗ和Ａｌ＿２Ｏ＿３／ＳｉＣｐ界面上没有剧烈的化学反应发生；通过ＴＥＭ和电子衍射图分析，发现在Ａｌ＿２Ｏ＿３的晶粒边界上有尖晶石（ＭｇＡｌ＿２Ｏ＿４）生成，这有利于控制Ａｌ＿２Ｏ＿３晶粒的长大，提高复合材料的强度。     

玛西斜坡侏罗系八道湾组油气成藏特征及勘探方向

玛西斜坡AH12井在侏罗系八道湾组首获高产工业油流,开辟了玛西斜坡油气勘探新领域。该区八道湾组成藏条件、油气富集规律及油水关系认识不清,导致后期部署多口预探井均告失利。综合运用地质、地震及分析化验等资料,对油气藏类型、成藏特征及模式进行研究,并指出有利勘探方向。结果表明:八道湾组油气主要来自二叠系风城组烃源岩;八道湾组一段一砂组辫状河三角洲水下分流河道优质砂体与上部湖泛泥岩形成良好的储盖组合;海西—印支与印支—燕山2期高角度断裂构成直通源型和接力型2类高效输导体系。研究区油藏类型为断块和断层-岩性油藏,受继承性鼻状构造、岩相及断裂与砂体的有效配置等因素控制,具有"烃源岩供烃、断裂跨层输导、鼻凸聚集、断裂岩性控藏"的成藏模式。该区中浅层油气勘探应以构造背景为基础,寻找有效输导断裂为重点,围绕鼻凸带进行勘探,克拉玛依组、八道湾组及三工河组湖泛泥岩之下储层为油气勘探的有利方向。     

IMS系统特点与需求分析

本文主要分析了IMS的用户需求和运营商需求、系统结构与特点、应用情况和引入机制,并论证了基于IMS融合的优势.     

Thermal Annealing and Propagation of Shockley Stacking Faults in 4H-SiC PiN Diodes

Stacking faults within 4H-SiC PiN diodes are known to be detrimental to device operation. Here, we present electroluminescence (EL) images of 4H-SiC PiN diodes providing evidence that electrically and optically stimulated Shockley stacking fault (SSF) propagation is a reversible process at temperatures as low as 210°C. Optical beam induced current (OBIC) images taken following complete optical stressing of a PiN diode and that lead to a small number of completely propagated SSFs provide evidence that such defects propagate across the n–/p+ interface and continue to grow throughout the p+ layer. These observations bring about questions regarding the validity of the currently accepted driving force mechanism for SSF propagation.     

一种全桥ZVZCS DC/DC变换器的研究

提出了一种全桥零电压零电流(FB-ZVZCS)DC/DC变换器拓扑,副边采用电容和二极管构成了两个辅助电路,它们与谐振电感谐振形成的阻断电压源相串联,实现了滞后臂较大范围的ZCS,同时此种结构抑制了副边整流二极管尖峰电压;针对高输出电压设计,输出采用双全桥串联整流电路以降低整流二极管的高电压应力和解决它们的均压问题。变换器控制简单、没有辅助开关和缓冲电路。文中详细分析了工作原理和参数设计,仿真和样机实验验证了方案的正确性。     

空间网络中基于身份的分布式密钥管理研究

为解决在空间网络中实施集中式密钥管理困难以及维护公钥证书开销过大等问题,论文设计了一种基于身份的分布式密钥管理方案。结合空间网络特点,给出了分布式私钥生成中心的构建方法。并利用Boneh和Franklin提出的基于身份的公钥加密体制,设计了私钥更新、主密钥分量更新和会话密钥协商等策略。分析和仿真验证,该方案能满足安全要求,具有较好的扩展性。     

Transfer of GaN-Based Light-Emitting Diodes From Silicon Growth Substrate to Copper

III-nitride light-emitting diodes (LEDs) grown on Si (111) substrates have the potential of low-cost manufacturing for solid-state lighting and display, by taking advantage of the well-developed IC technologies of silicon. In this letter, LEDs grown on silicon substrates were transferred onto copper substrates, to maximize light extraction and heat dissipation. On Si substrates, $hbox{300} times hbox{300} muhbox{m}^{2}$ multiple quantum well InGaN LEDs were first grown and processed. The top surface of the fabricated devices was then temporarily bonded to a sapphire wafer and the Si substrate was chemically etched. Ti/Al/Ti/Au layers were deposited on the backside of LEDs. An 80-$muhbox{m}$ -thick copper layer was electroplated and the temporary bonding was removed, resulting in LEDs on copper substrate. The optical output power of LEDs on copper increased by $sim$ 70% as compared to that of the LEDs on silicon. The improved performance was attributed to the removal of the light-absorbing Si substrate and the good thermal conductivity of copper.