RADISS——面向CIMS／MIS的快速开发平台

介绍了一个ＣＩＭＳ环境下的管理信息系统的快速开发平台。该平台采用ＣＬＩＥＮＴ／ＳＥＲＶＥＲ体系结构，在ＵＮＩＸ及ＷＩＮＤＯＷＳ操作系统和支持ＴＣＰ／ＩＰ网络协议的环境下，提供了一组快速开发ＣＩＭＳ／ＭＩＳ的主包括ＭＲＰ、ＢＯＭ处理在内的集成支持环境，可以极大地提高应用系统的开发效率，缩短应用系统的开发周期，并使应用系统具有较好的集成性和开放性。     

AlN陶瓷衬底的SIMS和XRD测量

ＡｌＮ陶恣成分怀发对于ＡｌＮ的性能具有决定性作用，用二次离子质谱（ＳＩＭＳ）和Ｘ射线衍（ＸＲＤ）对清华大学材料系电子封装用的ＡｌＮ陶瓷进行了研究。ＳＩＭＳ谱表明ＡｌＮ衬底中除Ａｌ，Ｎ以我有Ｃ，Ｏ，Ｓｉ，Ｃａ，Ｙ等元素，其中有些是表面污染。衬底的ＳＩＭＳ深度分析表明样品Ｏ，Ｃａ，Ｙ信号都很强，且分布均匀，说明样口 含有Ｙ２Ｏ３，ＣａＯ添加剂，ＡｌＮ样品的ＸＲＤ谱与ＡｌＮ的ＪＣＰＤＳ卡片对照，在测量范     

聚氨酯／环氧树脂互穿网络聚合物相行为与粘接剪切性能的研究

制备了一系列聚氨酯／环氧树脂互穿聚合物网络ＰＵ／ＥＰＩＰＮｓ。由ＤＳＣ、ＴＭＡ和ＤＤＶ研究表明，ＩＰＮｓ在高温区存在单一的玻璃化转变温度Ｔｇ，ＩＰＮｓ的相行为与其粘接剪切强度相关。并确认接枝共聚物的存在增强了ＩＰＮｓ的互穿效应     

REPORT ON ELECTROMAGNETIC METROLOGY IN CHINA DURING 1990-1992

ＲＥＰＯＲＴＯＮＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＭＥＴＲＯＬＯＧＹＩＮＣＨＩＮＡＤＵＲＩＮＧ１９９０－１９９２￥ＹａｎｇＸｉａｏｒｅｎ；ＲｅｎＤｉａｎｑｉｎｇ；ＬｉＺｉｚｈｏｎｇ（ＣｏｍｍｉｓｓｉｏｎＡ，ＣｏｍｍｉｔｔｅｅｆｏｒＣｈｉｎｅｓｅＵＲＳＩ）...     

聚氨酯／环氧树脂互穿网络聚合物相行为与粘接剪切性…

制备了一系列聚氨酯／环氧树脂互穿聚合物网络ＰＵ／ＥＰ ＩＰＮｓ，由ＤＣＳ、ＴＭＡ和ＤＤＶ研究表明，ＩＰＮｓ在高温区存在单一的玻璃化转变温度，Ｔｇ，ＩＰＮｓ的相行为与其粘接剪切强度相关，并确认接枝共聚物的存在增强了ＩＰＮｓ的互穿效应。     

ISO/IEC16500《全世界兼容的端一端数字电视系统标准》

ＩＳＯ／ＩＥＣ１６５００：１９９９,通常称为ＤＡＶＩＣ１－３－１,是一个全世界兼容的端—端数字ＴＶ系统标准。该标准由ＤＡＶＩＣ（数字视听委员会）制定并由ＩＳＯ／ＩＥＣＪＴＣ１ＰＡＳ交换投票批准作为国际标准。ＩＳＯ／ＩＥＣ１６５００标准的实施,多媒体生产厂家能获得更多的听众,载体能提供有效的传输,用户可通过天衣无缝的通路及时得到信息并进行通信。ＩＳＯ／ＩＥＣ１６５００对跨国的相互干扰的数字视听系统取得了端—端兼容性,除参照ＩＳＯ、ＩＥＣ、ＩＴＵ及ＡＮＳＩ标准外,它还参照了１８个组织的规范。目前,…     

聚醚型聚氨酯／乙烯基酯树脂互穿聚合物网络结构？…

以聚氨酯（ＰＵ）为组分Ｉ,乙烯工酯树脂（ＶＥＲ）为组分Ⅱ,采用二步法制备了聚氨酯／乙烯基酯树脂互穿聚合物网络（ＰＵ／ＶＥＲ－ＩＰＮ）采用透射电镜（ＴＥＭ）和原子显微镜观察了ＰＵ／ＶＥＲ－ＩＰＮ的微观形态,用调制ＤＳＣ（Ｍ－ＤＳＣ＾ＴＭ）动态力学分析方法（ＤＭＡ）研究了ＩＰＮ的玻璃化转变行为及动态力学性能,结果表明,ＰＵ网络与ＶＥＲ网络形成了多相微区结构,在界面处互穿和缠结,形成类似胞状的结构,ＰＵ     

PU软段结构对PU／PMMA IPN中两组分相容性的影响

用同步法合成了４种聚氨酯／聚甲基两烯酸甲酯互穿聚合物网络／（ＰＵ／ＰＭＭＡ ＩＰＮ）利用ＤＤＣ、ＴＥＭ和动态力学谱（ＤＭＳ）等手段综合研究了ＩＰＮ中两组分的相容性和相态结构，用基团贡献加和方法计算了各种ＰＵ和ＰＭＭＡ的溶度参数δ，结合ＰＵ软段链结构讨论了各种ＩＰＮＫ呈现不同相容性和相态结构的原因。     

聚氨酯／环氧树脂互穿网络聚合物相行为与断裂拉伸强度

制备了一系列聚氨酯／环氧树脂互穿网络聚合物ＰＵ／ＥＰＩＰＮ，由ＤＳＣ，ＴＭＴ和动态粘弹仪研究表明，ＩＰＮ在高温区存在的单一玻璃化转变温度Ｔｇ，ＩＰＮ的的相行为与其断裂伸强度的相关，并确认接枝共聚物的存在增强了ＩＰＮ的互穿效应。     

聚环氧氯丙烷聚氨酯／聚苯乙烯IPN的玻璃化转变行为

用ＤＳＣ和动态弹粘谱（ＤＭＳ）研究了聚环氧氯丙烷聚氨酯／聚苯乙烯互穿聚合物网络「ＰＵ（ＰＥＣＨ）／ＰＳＩＰＮ」的玻璃化转变行为，发现，当ＩＰＮ中聚苯乙烯（ＰＳ）含量大于２０％（质量分数）时，ＩＰＮ是不相容体系，有两个玻璃化转变，ＰＳ交链度的增加，对应于ＰＵ的玻璃化转变（ＴｇＩ）不变，对应玻璃化转变（ＴｇＩＩ）向高温方向移动，转变越来越不明显，加入氨酯反应催化剂时，Ｔｇ明显内移，Ｔｇｆｆ内移超过２０     

支持综合服务和区分服务的MPLS路由器的总体设计

简要介绍了综合服务、区分服务、流量工程等技术，及其与MPLS间的相互关系。然后在一种通用的综合服务网、区分服务网和MPLS网互通的网络构架下，提出了支持综合服务和区分服务的MPLS边缘路由器（LER）和核心路由器（LSR）的功能设计，最后说明了网络的处理流程。     

Measurement of processing and queuing delays introduced by an open-source router in a single-hop network

Measurement of the main contributions to the single-hop delay introduced by an open-source router is dealt with. A new method is proposed, which is capable of distinguishing the time interval during which a generic packet stays in either input or output queue (queuing delay) of the router under analysis and the time interval characterizing the effective routing process (processing delay) the packet undergoes. Thanks to proper measurement probes, i.e., kernel-layer functions, the method makes the occurring time of events of interest available at the application layer, thus giving the possibility of separately evaluating the aforementioned delays and, ultimately, pursuing a deeper insight of the considered router. After brief remarks concerning various delays a packet experiences when passing through a generic router, the measurement principle underlying the method is presented in detail. Particular emphasis is put on its capability of locally monitoring the transit of each packet from the input to the output port of an open-source router along with main features and implementation issues of the proposed measurement probes. Results obtained in many experiments carried out on a suitable test bed in different operating conditions are then given in order to highlight the method's reliability and effectiveness.     

高性能路由器操作系统HEROS中的高可用性设计

为了保证路由器系统的整体性能和安全性，清华大学设计并实现了用于骨干网络路由器的高性能路由器操作系统HEROS（Highly Efficient Router Operation System）。骨干路由器是Internet的核心，为了保证网络的平稳运行，需要其具有相当高的可用性。本文首先分析了骨干路由器的高可用性要求，设计并实现了一种基于消息传递机的面向协议软件的高可用性系统。该系统具有对上层协议透明，独立于底层传输机制等优点，在采用主节点双机备份的硬件条件下，可以保证系统软件无故障地平稳运行。     

Feedline Separation for Independent Control of Simultaneously Different Tx/Rx Radiation Patterns

The shortcoming of Wi-Fi networks is that one user can access the router at a time. This drawback limits the system throughput and delay. This paper proposes a concept of Simultaneously Different Tx/Rx (SDTR) radiation patterns with only one antenna set at the router. Furthermore, these two patterns have to be simultaneously operated at the same time so that the system delay can be eased. An omni-directional pattern is employed at router for receiving mode so that the router can sense carrier signal from all directions. At the same time, the router launches a directional beam pointed to another user. A proposed circuit allows these two modes to be able to operate the same time. To evaluate the SDTR concept, a prototype is constructed for testing in real circumstance comparing to computer simulation. As a result, the SDTR concept can improve the system throughput while decreasing the system delay comparing to conventional system.     

SIMD implementation of a non-linear transient shell program with partially structured meshes

The implementation of an explicit transient program for the three-dimensional non-linear finite element analysis of shells on a massively parallel SIMD computer, the CONNECTION Machine, is described. Particular emphasis is placed on interprocessor communication using router and NEWS schemes. A hybrid communication scheme, where NEWS is used within structured subdomains and the router is used to exchange nodal forces between subdomains, is examined. It is shown that the ‘mesh-structure index’ of most large meshes is sufficient to make hybrid schemes effective and this is verified by computer runs. Some benchmark non-linear calculations with 8K to 32K elements are also presented.     

Towards a service-enabled distributed router architecture

Modelling is an essential tool in the development and assessment of new concepts. The authors propose an architecture for the next-generation gigabit distributed active router that was designed and implemented in the IST project, FlexiNET. In the FlexiNET project, a service called 'dynamic service deployment' dynamically installs, monitors and uninstalls new services on user demand or by default configuration. The proposed distributed router architecture achieves scalability of performance, functional flexibility and reliability. Scalability is achieved by adding new modules that have identical interfaces in an extensible function block. New services can easily be added by inserting modules that have the appropriate functionality. Another significant aspect of the model presented is that a failure in one module does not affect the other modules because they operate independently.     

基于扩展服务路由器的主动网络体系结构

结合当前主要的两种主动网络实现策略的优点提出了一种新的基于扩展服务路由器的主动网络体系结构,该体系结构由扩展服务路由器,主动扩展组件服务器和密钥分发中心KDC组成,用户可以使用编程接口编写可扩展组件,为了保证安全性,设计了一种简化的身份认证协议,目前,基于分布式实时操作系统VxWorks的扩展服务路由器原型系统和基于Solaris的主动扩展组件服务器和KDC原型系统已经设计完成。     

Supporting vertical handover between universal mobile telecommunications system and wireless LAN for real-time services

The provisioning of the seamless handovers for real-time services in-between UMTS/ WLAN loose-interworking by the network-layer technologies has been studied. Issues are how to execute such a vertical handover in a fast and efficient manner as well as how to achieve it in a viable way. To resolve such issues, a novel scheme called 'designated crossover point' (DCP) within the existing IP end-to-end quality of service (QoS) architecture has been proposed. The DCP is an agent at the edge router in the customer's premise to join the old RSVP signalling path and new RSVP signalling path. With the DCP in place, the vertical handover can be greatly accelerated. Besides, by enabling the DCP to handover to the edge router in the customer's network currently visited by the mobile, lower charging cost can be achieved. Finally, there is no modification required for the devices in the provider's network and thus the viability is much improved. It is then end up with a topology for resource management in IP backbone for UMTS/WLAN loose-interworking to support the idea of DCP. To determine when to perform the rerouting to remove the possible derouting caused by DCPs, use of an adaptive rule has been suggested. Simulation results show in general that the adaptive rule is effective.     

一种路由器多操作系统平台的设计与实现

为了实现路由器软件在操作系统间的移植,并且扩展原有操作系统的功能,设计和实现了一种路由器多操作系统平台(RMOS).该RMOS基于微内核体系结构,设计了统一的系统调用接口,它不仅隐藏原有操作系统的内部细节,还加强了内存操作的安全性,对系统资源进行监控,并为非实时操作系统虚拟了实时调用接口.通过使用RMOS,路由器厂商能够根据市场需求,提供基于不同操作系统的多性价比产品,同时大大降低软件移植的成本.目前,RMOS可在VxWorks和Linux上顺利运行.     

高性能安全路由器BW7000的设计与实现

高性能和安全是计算机网络研究的两个主要问题。路由器在保证转发性能的前提下提供网络安全保护已经成为当前的研究热点。文章介绍了在完成国家"八六三"计划重大课题"高性能安全路由器"的过程中解决的若干关键技术问题。高性能安全路由器BW7000基于自主设计的高性能路由器操作系统HEROS。为保证高性能的路由转发,设计实现了基于RAM的高性能路由查找算法;为支持服务质量控制和安全管理,设计实现了基于无冲突HashTrie树的分组分类算法和基于反馈的分布式分组调度算法;为保证网络安全,提出了基于分布式密钥管理的路由器安