新一代无铅兼容PCB基板的研究进展（Ⅰ）

本文回顾了环氧树脂用酚醛树脂固化剂的历史，介绍了无铅兼容PCB基板的两种主要的酚醛树脂固化剂．比较了酚醛固化环氧和双氰胺固化环氧的板材性能，分析了酚醛固化剂对覆铜板耐CAF性能的影响。同时，评析了区分板材是否无铅兼容的技术手段和标准，列举了当前典型的新一代无铅兼容PCB基板的产品性能。     

新一代无铅兼容PCB基板的研究进展（Ⅱ）

本文回顾了环氧树脂用酚醛树脂固化剂的历史．介绍了无铅兼容PCB基板的两种主要的酚醛树脂固化剂。比较了酚醛固化环氧和双氰胺固化环氧的板材性能。分析了酚醛固化剂对覆铜板对CAF性能的影响，同时，评析了区分板材是否元铅兼容的技术手段和标准。列举了当前典型的新一代元铅兼容PCB基板的产品性能。     

无铅兼容PCB基板的研究进展——无铅兼容PCB基板的性能及其表征

无铅焊料产生的高温高热对PCB基板的制造技术具有很大的冲击力和影响力，本文介绍了无铅焊料及其与Sn63／Pb37的对比特点，总结了无铅兼容PCB基板的性能表征方法。     

新一代无铅兼容PCB基板材料的最新研究进展（2）

（续上期）2.1.22 各种覆铜板的热分层时间 图16为各种覆铜板的T288比较,各覆铜板包括聚苯醚／环氧、加填料聚苯醚／环氧、热心性聚苯醚、加填料180℃Tg Non-Dicy FR-4、加填料150℃Tg Non-Dicy FR-4、加填料150℃Tg Dicy周化FR-4、加填料170℃Tg无卤FR-4、未加填料175℃Tg Dicy固化FR-4、无铅热稳定性175℃Tg Dicy固化FR-4。     

无铅兼容PCB基板的研究进展（2）——无铅兼容PCB基板的固化剂

本文回顾了环氧树脂用酚醛树脂固化剂的发展历史，介绍了两种主要的酚醛树脂固化剂，即线性苯酚酚醛树脂（Phenolic Novolac）和双酚A线性酚醛树脂（BPA—Novolac），概括了兼容无铅焊料环氧基板的酚醛一一环氧反应机理，同时，对酚醛固化环氧和双氰胺固化环氧的板材性能进行了对比，列举了世界主要的无铅兼容板材。     

绿色无铅PCB

绿色环保生产促进无铅焊料需求，天津将建电子垃圾回收和处理中心，Calumet Electronics开出符合RollS指令的PCB产线。     

新一代无铅兼容PCB基板材料的最新研究进展（1）

在实施两个指令的促进下,当前世界覆铜板的制造技术出现了迅猛的发展,笔者以2006年以来的文献为基础,概述了无铅安装对环氧基覆铜板用固化剂的促进,分析了无铅兼容覆铜板的性能以及性能之间的关系。同时,对无铅兼容覆铜板去钻污特点、导电阳极丝(CAF)与互连应力测试(IST)等研究热点进行了评述。     

推进无铅焊接应用

虽然国际国内都在不同程度地应用无铅技术，但目前还处于过渡和起步阶段，从理论到应用都还不成熟，没有统一的标准，对无铅焊接的焊点可靠性还没有统一的认识，因此无论国际国内无铅应用技术都非常混乱，大多企业虽然焊接材料无铅化了，但元器件焊端仍然有铅。究竟哪一种无铅焊料更好，哪一种PCB焊盘镀层对无铅焊更有利，哪一种元器件焊端材料对无铅焊接焊点可靠性更有利，什么样的温度曲线最合理、     

PCB用高耐热性基板材料的技术进展

提高印制电路板(PCB)用基板材料的耐热性，既是覆铜板业技术开发中的一个“老课题”，又是当前基板材料技术发展中的新课题。近半个世纪以来，随着电子安装技术和PCB制造技术的快速推进，总是不断给基板材料的耐热性能增添着新的内涵，对其有更新方面的要求。     

下一代卫星网络发展研究

卫星网络发展到今天,技术日益成熟、国际标准逐渐完善、市场蓬勃发展,但当前卫星网络的高延时弯管架构、不具备标准的星上IP功能以及缺乏兼容性与扩展性等局限性,导致其不能像地面Internet一样高速而迅猛地发展。下一代卫星网络只有利用成熟的IP技术组建IP卫星网络和地面Internet无缝对接,才能突破卫星网络发展的瓶颈,满足用户廉价和方便的服务需求。本文在总结当前卫星网络局限性的基础上,探讨了下一代卫星网络IP化的必然性、架构及优势,并阐述了下一代卫星网络面临的挑战及机遇。     

下一代互联网在湖南电信网络的试商用部署实践

本文介绍了在长株潭两型社会建设综合配套改革试验区部署下一代互联网技术的背景,并对下一代互联网技术在湖南的实践部署和应用情况进行了重点说明,阐述了中国电信湖南分公司在IPv6网络和业务方面的主要创新成果,并提出了深化下一代互联网研究实践的建议。     

从第十届世界电子电路大会管窥PCB基板的研究进展（1）

介绍了世界电子电路大会发展的历史,首先围绕ECWC10论文集的范围,剖析了日本两大PCB基板研发的技术特点,两公司的研发产品具有主要性能优越,综合性能平衡的特点,适应当前高频化和无铅化的发展要求。同时,也介绍了纳米技术在基板中的综合运用,最后,分析了导热性基板的研究进展。希望通过对以上有代表性的基板的剖析了解世界基板的发展趋势。     

美国空、海军下一代战斗机信息征询书概要和比较

介绍了美国空军和海军发布的下一代战斗机信息征询书, 即“下一代战术飞机能力要求信息”和“2030 年舰载攻击战斗机的关键能力需求调研”, 并对这两份信息征询书进行了比较。认为: 这两份信息征询书都代表了美国军方的观点, 通过比较分析, 可以从实证的角度得到很多美国军方关于六代机的真实想法, 另外, 这种基于实证的研究方法为国外六代机的研究提供了一个新的研究途径。     

pMOSFET中栅控产生电流的衬底偏压影响研究

研究了pMOSFET中栅控产生电流(GD)的衬底偏压特性。衬底施加负偏压后,GD电流峰值变小;衬底加正向偏压后,GD电流峰值增大。这归因于衬底偏压VB调制了MOSFET的栅控产生电流中最大产生率,并求出了衬底偏压作用系数为0.3。考虑VB对漏PN结的作用,建立了包含衬底偏压的产生电流模型。基于该模型的深入分析,很好地解释了衬底负偏压比衬底正偏压对产生电流的影响大的实验结果。     

On the Use of Multiple Hops in Next Generation Wireless Systems

Traditional cellular networks provide a centralized wireless networking paradigm within the wireless domain with the help of fixed infrastructure nodes such as Base Stations (BSs). On the other hand, Ad hoc wireless networks provide a fully distributed wireless networking scheme with no dependency on fixed infrastructure nodes. Recent studies show that the use of multihop wireless relaying in the presence of infrastructure based nodes improves system capacity of wireless networks. In this paper, we consider three recent wireless network architectures that combine the multihop relaying with infrastructure support – namely Integrated Cellular and Ad hoc Relaying (iCAR) system, Hybrid Wireless Network (HWN) architecture, and Multihop Cellular Networks (MCNs), for a detailed qualitative and quantitative performance evaluation. MCNs use multihop relaying by the Mobile Stations (MSs) controlled by the BS. iCAR uses fixed Ad hoc Relay Stations (ARSs) placed at the boundaries to relay excess traffic from a hot cell to cooler neighbor cells. HWN dynamically switches its mode of operation between a centralized Cellular mode and a distributed Ad hoc mode based on the throughput achieved. An interesting observation derived from these studies is that, none of these architectures is superior to the rest, rather each one performs better in certain conditions. MCN is found to be performing better than the other two architectures in terms of throughput, under normal traffic conditions. At very high node densities, the variable power control employed in HWN architecture is found to be having a superior impact on the throughput. The mobility of relay stations significantly influences the call dropping probability and control overhead of the system and hence at high mobility iCAR which uses fixed ARSs is found to be performing better. This work was supported by Infosys Technologies Ltd., Bangalore, India and the Department of Science and Technology, New Delhi, India. B. S. Manoj received his Ph.D degree in Computer Science and Engineering from the Indian Institute of Technology, Madras, India, in July 2004. He has worked as a Senior Engineer with Banyan Networks Pvt. Ltd., Chennai, India from 1998 to 2000 where his primary responsibility included design and development of protocols for real-time traffic support in data networks. He had been an Infosys doctoral student in the Department of Computer Science and Engineering at the Indian Institute of Technology-Madras, India. He is a recipient of the Indian Science Congress Association Young Scientist Award for the Year 2003. Since the beginning of 2005, he has been a post doctoral researcher in the Department of Electrical and Computer Engineering, University of California, San Diego. His current research interests include ad hoc wireless networks, next generation wireless architectures, and wireless sensor networks. K. Jayanth Kumar obtained his B.Tech degree in Computer Science and Engineering in 2002 from the Indian Institute of Technology, Madras, India. He is currently working towards the Ph.D degree in the department of Computer Science at the University of California, Berkeley. Christo Frank D obtained his B.Tech degree in Computer Science and Engineering in 2002 from the Indian Institute of Technology, Madras, India. He is currently working towards the Ph.D. degree in the department of Computer Science at the University of Illinois at Urbana-Champaign. His current research interests include wireless networks, distributed systems, and operating systems. C. Siva Ram Murthy received the B.Tech. degree in Electronics and Communications Engineering from Regional Engineering College (now National Institute of Technology), Warangal, India, in 1982, the M.Tech. degree in Computer Engineering from the Indian Institute of Technology (IIT), Kharagpur, India, in 1984, and the Ph.D. degree in Computer Science from the Indian Institute of Science, Bangalore, India, in 1988. He joined the Department of Computer Science and Engineering, IIT, Madras, as a Lecturer in September 1988, and became an Assistant Professor in August 1989 and an Associate Professor in May 1995. He has been a Professor with the same department since September 2000. He has held visiting positions at the German National Research Centre for Information Technology (GMD), Bonn, Germany, the University of Stuttgart, Germany, the University of Freiburg, Germany, the Swiss Federal Institute of Technology (EPFL), Switzerland, and the University of Washington, Seattle, USA. He has to his credit over 120 research papers in international journals and over 100 international conference publications. He is the co-author of the textbooks Parallel Computers: Architecture and Programming, (Prentice-Hall of India, New Delhi, India), New Parallel Algorithms for Direct Solution of Linear Equations, (John Wiley & Sons, Inc., New York, USA), Resource Management in Real-time Systems and Networks, (MIT Press, Cambridge, Massachusetts, USA), WDM Optical Networks: Concepts, Design, and Algorithms, (Prentice Hall, Upper Saddle River, New Jersey, USA), and Ad Hoc Wireless Networks: Architectures and Protocols, (Prentice Hall, Upper Saddle River, New Jersey, USA). His research interests include parallel and distributed computing, real-time systems, lightwave networks, and wireless networks. Dr.Murthy is a recipient of the Sheshgiri Kaikini Medal for the Best Ph.D. Thesis from the Indian Institute of Science, the Indian National Science Academy (INSA) Medal for Young Scientists, and Dr. Vikram Sarabhai Research Award for his scientific contributions and achievements in the fields of Electronics, Informatics, Telematics & Automation. He is a co-recipient of Best Paper Awards from the 1st Inter Research Institute Student Seminar (IRISS) in Computer Science, the 5th IEEE International Workshop on Parallel and Distributed Real-Time Systems (WPDRTS), and the 6th and 11th International Conference on High Performance Computing (HiPC). He is a Fellow of the Indian National Academy of Engineering.     

美第六代战斗机研究进展情况

目前, 美国F-22已经列装、F-35即将装备, 俄罗斯等航空大国紧随其后, 正在加紧第五代战斗机的研制。美国为了牢牢把握绝对制空权, 其第六代战斗机的研发已经悄然起步, 2030年前后空中优势的争夺战已经打响。从美军战略构想出发, 研究美军发展第六代战斗机的动因, 梳理美空军六代机的研究进展, 系统描述了目前美空军对六代机的能力需求和相关技术支撑。