Effective passivation of defects in Ge-rich SiGe-on-insulator substrates by Al2O3 deposition and subsequent post-annealing

A method of Al₂O₃ deposition and subsequent post-deposition annealing (Al₂O₃-PDA) was proposed to passivate electrically active defects in Ge-rich SiGe-on-insulator (SGOI) substrates, which were fabricated using Ge condensation by dry oxidation. The effect of Al₂O₃-PDA on defect passivation was clarified by surface analysis and electrical evaluation. It was found that Al₂O₃-PDA could not only suppress the surface reaction during Al-PDA in our previous work [Yang H, Wang D, Nakashima H, Hirayama K, Kojima S, Ikeura S. Defect control by Al-deposition and the subsequent post-annealing for SiGe-on-insulator substrates with different Ge fractions. Thin Solid Films 2010; 518: 2342-5.], but could also effectively passivate p-type defects generated during Ge condensation. The concentration in the range of 10¹⁶-10¹⁸ cm⁻³ for defect-induced acceptors and holes in Ge-rich SGOI drastically decreased after Al₂O₃-PDA. As a result of defect passivation, the electrical characteristics of both back-gate p-channel and n-channel metal-oxide-semiconductor field-effect transistors fabricated on Ge-rich SGOI were greatly improved after Al₂O₃-PDA.     

线状WSN中基于概率分流的负载均衡路由协议

针对线状无线传感器网络中节点能量消耗不均衡现象,本文提出基于概率分流的负载均衡路由协议,以一定规则建立多条路由路径,通过使负载较轻路径上的节点以一定概率分担负载较重路径上节点的数据传输任务,均衡网络中各个节点的负载。仿真结果表明,本协议能有效地改善各个节点能量消耗的均衡性,延长网络生存时间。     

空间用元器件热真空试验评价方法研究

空间用元器件热真空试验是空间环境模拟试验中非常重要的一项试验,文章通过对空间用元器件热真空环境应力的分析,给出了不同轨道的温度范围以及不同真空度下空间用元器件的物理效应;对空间用元器件热真空试验评价方法进行了研究和探讨,在参照组件、分系统、整星热真空试验方法的基础上,提出了器件级热真空试验程序。介绍了已开展的DC/DC混合集成电路和双向收发器单片集成电路的热真空试验情况和试验结果。试验结果表明,通过热真空试验,可以对空间用元器件热真空环境下的性能和可靠性进行试验评价,为航天用户单位合理选用空间用元器件提供科学依据。     

一种改进的核相关滤波目标跟踪方法研究

针对目标跟踪领域视频图像序列经常出现遮挡、光照变化和快速移动等难点,提出了一种融合目标上下文信息和超像素级特征的核相关滤波跟踪方法,目标与其周围的信息存在相关性,利用中层视觉特征(超像素)构建目标的上下文滤波模型,在相关滤波框架下,实现对目标的快速训练和定位。实验结果表明,和其他相关滤波类算法相比,所提出的算法在处理以上跟踪难点时,精确度更高,且鲁棒性更强,同时能以较快的速度运行,满足实时性的要求。     

基于MSC双声路SAW器件的设计仿真平台

利用模块化设计思想,在Matlab编程环境下实现了基于多条耦合器双声路声表面波器件的设计仿真平台。为了提高MSC双声路SAW器件的性能,该平台将多条耦合器、分裂指及假指设计方案融合到器件设计中。多条耦合器不仅实现了两个变迹换能器传递函数的乘积,而且消除了体声波对器件性能的影响。假指消除了通过变迹换能器引起的波前畸变。分裂指可以最小化换能器内部的声波反射问题。通过一个频率为203.559MHz的基于多条耦合器双声路声表面波器件的设计和实际测试结果的对比分析,证明了该设计仿真平台不仅可以进行器件版图结构的设计和模拟,而且设计平台所得到的版图和数据可以用于器件的掩膜版制作和器件封装尺寸参考。另外,该仿真设计平台可以很好地实现对器件的脉冲特性、频率响应特性的模拟和仿真。     

机载三维成像激光雷达实时探测精度分析

为了提高机载增益调制型三维成像激光雷达系统实时探测时的测距精度,推导了该激光雷达的测距公式,可以得出距离精度与探测器探测到的光强密切相关,机载实时探测时各种运动引起的像移会通过强度图来影响测距精度和成像质量。基于光学成像原理和坐标变换矩阵原理,分析了该激光雷达实时探测时飞行器姿态变化对成像质量的影响,分析结果显示,飞行器姿态变化对z方向的位移影响最大为0.0298个像素,可以忽略不计,而对x,y方向像移影响比较大。研究了飞行器同一个姿态变化对地面点的像移影响,研究结果表明,像移会随着地面物点对光轴的夹角和飞行方向的夹角改变而改变。     

升华法生长AlN体单晶初探

研究了高温升华法(PVT)生长AlN体单晶的技术和材料的性质.使用陶瓷BN坩埚,加热温度约在1900℃左右,生长结果为AlN晶须或致密多晶,难以生长出较大的AlN晶粒.用钨坩埚加热生长温度达到2200℃左右时,在AlN陶瓷片和6H-SiC片上生长了直径22mm的AlN晶体,最大的晶粒尺寸长10mm、直径5mm.利用X射线粉末衍射分析了几种不同AlN样品的结构和组成.讨论了PVT法生长AlN晶体所涉及的化学热力学过程和现象.     

An Analysis of Consumer Preferences among Wireless LAN and Mobile Internet Services

Wireless data communication (WDC) services are increasingly penetrating the market. The two main alternative WDC technologies are wireless LAN and mobile Internet. Services based on these technologies display differences in quality attributes such as terminal device, data transmission speed, pricing scheme and so on. How consumers choose between these two alternatives will be determined by their preferences regarding such quality attributes. In turn, their preferences will affect the evolution of WDC services and related technologies. This study employs a conjoint analysis of consumer valuations of quality attributes of wireless LAN and mobile Internet services. Respondents rate hypothetical service alternatives featuring various combinations of quality attributes. By estimating consumer willingness to pay for the attributes of WDC services, the authors predict the evolution of WDC services and related technologies along various quality dimensions, make a comparison with the results of a previous study, and draw policy implications for national‐and company‐level R&D strategies.     

An Analysis of Citation Counts of ETRI‐Invented US Patents

From its foundation until 2004, ETRI has registered over 1,000 US patents. This letter analyzes the characteristics of these patents and addresses the explanatory factors affecting their citation counts. For explanatory variables, research team related variables, invention specific variables, and geographical domain related variables are suggested. Zero‐altered count data models are used to test the impact of independent variables. A key finding is that technological cumulativeness, the scale of invention, outputs in the electronic field, and the degree of dependence on the US technology domain positively affect the citation counts of ETRI‐invented US patents. The magnitude of international presence appears to negatively affect the citation counts of ETRI‐invented US patents.     

RS码类的构建及在数据链模拟系统中的应用

Reed-Solomon码(RS码)具有强大的纠错能力,在数据通信中得到了广泛的应用,如RS(31,15)码已经成为美军数据链系统的标准码。为了实现应用于数据链模拟系统中的RS编译码类,从分析RS纠错编译码原理入手,在研究了RS编译码模型的基础上,重点对RS编译码的编程实现方法进行了详细分析。以VC++为编程实现平台,采用面向对象的程序设计方法,构建且封装了RS编译码类,最后对RS编译码类的纠错性能进行了验证,结果表明,设计的RS编译码类能够有效纠错且正确恢复发端发送的信息,满足模拟系统的设计要求。