Avalanche photodiode with sectional InGaAsP/InP charge layer

An InGaAs/InP avalanche photodiode (APD) with a sectional InGaAsP/InP charge layer at the heterointerface between the InGaAs absorption and InP multiplication region has been designed, fabricated and tested. We demonstrate a new APD structure that utilizes the sectional 140 nm thin charge layer and a 500 nm thin multiplication layer. The band diagram, electrical field distribution and current-voltage (I-V) characteristics up to punch-through voltage have been simulated. The fabricated mesa structure photodiode shows responsivity 0.9 A/W at 1310 nm at 20 V and avalanche gain up to 10 near breakdown voltage 36 V. The measured results revealed that the sectional charge layer could be used for control of the electric field profile in the APD structure.     

基于0.35 μm高压CMOS工艺的横向线性雪崩光电二极管

提出了一种基于0.35 μm高压CMOS工艺的线性雪崩光电二极管（Avalanche Photodiode, APD）。APD采用了横向分布的吸收区-电荷区-倍增区分离（Separate Absorption, Charge and Multiplication, SACM）的结构设计。横向SACM结构采用了高压CMOS工艺层中的DNTUB层、DPTUB层、Pi层和SPTUB层,并不需要任何工艺修改,这极大的提高了APD单片集成设计和制造的自由度。测试结果表明,横向SACM线性APD的击穿电压约为114.7 V。在增益M = 10和M = 50时,暗电流分别约为15 nA和66 nA。有效响应波长范围为450 ~ 1050 nm。当反向偏置电压为20 V,即M = 1时,峰值响应波长约为775 nm。当单位增益 （M = 1） 时,在532 nm处的响应度约为最大值的一半。     

热处理对SACM645销轴力学性能的影响

对直径110mm的SACM645销轴进行了不同的热处理工艺试验,试验结果表明经910±10℃油淬(保温1.5min/mm)及630±10℃水冷(保温3min/mm)热处理后SACM645销轴的力学性能可满足厂标30.85.089中对38CrMoAlA的要求。     

2016年国外空空导弹发展动态研究

全面介绍了2016年国外空空导弹最新发展情况, 重点论述了美国的AIM-9X、 AIM-120、 小型先进能力导弹(SACM)和微型自卫弹药(MSDM), 欧洲的ASRAAM和"流星", 印度的"阿斯特拉"等空空导弹最新研制进展和试验情况, 最后总结空空导弹的最新发展特点.     

Ge/Si SACM-APD器件分析

Ge/Si吸收区-电荷区-倍增区分离(SACM)结构的APD作为一种新型光电探测器已成为硅基APD器件研究的重点.对SACM Ge/Si型APD器件的基本结构及其主要特性参数,包括量子效率、响应度、暗电流等进行了理论分析及仿真验证.实验结果表明:在给定的器件参数条件下,所设计的APD器件的雪崩击穿电压为25.7 V,最大内部量子效率为91%,单位增益下响应度峰值为0.55 A/W,在750~1 500 nm范围内具有较高响应度,其峰值波长为1 050 nm;在高偏压以及高光照强度情况下,倍增区发生空间电荷效应从而导致增益降低.     

An extended systematic literature review on provision of evidence for safety certification

ContextCritical systems in domains such as aviation, railway, and automotive are often subject to a formal process of safety certification. The goal of this process is to ensure that these systems will operate safely without posing undue risks to the user, the public, or the environment. Safety is typically ensured via complying with safety standards. Demonstrating compliance to these standards involves providing evidence to show that the safety criteria of the standards are met.ObjectiveIn order to cope with the complexity of large critical systems and subsequently the plethora of evidence information required for achieving compliance, safety professionals need in-depth knowledge to assist them in classifying different types of evidence, and in structuring and assessing the evidence. This paper is a step towards developing such a body of knowledge that is derived from a large-scale empirically rigorous literature review.MethodWe use a Systematic Literature Review (SLR) as the basis for our work. The SLR builds on 218 peer-reviewed studies, selected through a multi-stage process, from 4963 studies published between 1990 and 2012.ResultsWe develop a taxonomy that classifies the information and artefacts considered as evidence for safety. We review the existing techniques for safety evidence structuring and assessment, and further study the relevant challenges that have been the target of investigation in the academic literature. We analyse commonalities in the results among different application domains and discuss implications of the results for both research and practice.ConclusionThe paper is, to our knowledge, the largest existing study on the topic of safety evidence. The results are particularly relevant to practitioners seeking a better grasp on evidence requirements as well as to researchers in the area of system safety. As a major finding of the review, the results strongly suggest the need for more practitioner-oriented and industry-driven empirical studies in the area of safety certification.     

一种基于层次化兴趣的非结构化P2P拓扑形成模型

在非结构化P2P系统中有两个根本性的问题需要研究:拓扑的自动生成和查询算法.其中前者更为重要:虽然查询算法通常是独立于拓扑结构的,但一个结构良好的拓扑会极大地改善查询算法的性能.提出一种基于层次化兴趣表达的拓扑生成模型(self adaptive community-based model,简称SACM).在这种模型里,每个节点由自身的资源整体类型倾向决定自己的兴趣(interest),并且采用树形结构来表达兴趣;然后节点由兴趣产生一个二进制序列的CID(community ID),CID将成为拓扑形成的主要依据--具有相近CID的节点能聚集成一个连通性较高的子图(社区).SACM不仅提供了生成聚类拓扑的算法,更为重要的是,它通过兴趣的定义及维护从统计上在资源和网络拓扑之间建立了联系.是否存在这种联系正是结构化P2P于非结构化P2P的本质区别.