含氯取代基的聚间苯二甲酰间苯二胺的合成与表征

以 2 ,5 -二氯对苯二甲酰氯作为第三单体 ,将其与间苯二甲酰氯、间苯二胺在N ,N -二甲基乙酰胺中进行低温溶液共缩聚反应 ,合成了含氯取代基的聚间苯二甲酰间苯二胺。研究了单体摩尔浓度、反应初始温度、叔胺添加剂种类、第三单体用量等对共聚物相对分子质量的影响 ,并用红外光谱、热重分析等方法对共聚物进行了表征。     

浅析2020年前美军事战略重点的转变--从装备发展看美国军事战略重点可能的变化

美国21世纪前期的军事战略重点将是争夺外空优势，夺取制天权和制信息权。分析了美国夺取外空优势的原因，及其为夺取外空优势在国家政策、航天发展和技术准备等方面采取的措施。     

MB8镁合金薄板的搅拌摩擦焊

针对我国航空航天工业常用的MB8镁合金。采用搅拌摩擦焊工艺进行焊接，对其焊缝的成形特点、组织特征和力学性能进行分析。结果表明，采用搅拌摩擦焊焊接镁合金效果良好。     

模糊数学识别火山岩岩性

针对火岩地层岩性识别成功率低的状况，应用模糊数学原理，建立模糊数学识别火山岩岩性模式，识别和划分火山岩地层岩性，以便进一步深入研究火山岩油气藏储层，选择8个反映火山岩岩性测井参数，确定阈值；利用所建立的火山岩岩性识别模式，对火山岩岩性进行分类；依据最大隶属原则，识别火山岩岩性，应用实地研究资料，识别10种火山岩岩性，并与岩心鉴定统计分析结果对比，一致性达85％。表明该方法识别火山岩岩性精度较高，在地质上具有很好的应用前景。     

隔震结构在省防震减灾中心大楼工程中的应用

结合工程实例介绍了隔震结构在工程设计中的应用     

用迭代法消除数字图像放大后的模糊

用迭代法对数字图像经过插值放大后产生的模糊问题进行了研究，把数字图像插值放大造成的模糊看成是点扩散函数与清晰图像卷积的结果，根据插值算法可以得到点扩散函数，由于数字图像解卷积是典型的解线性方程组的问题，用雅可比（Jacobi）迭代法得到了很好的结果。与频谱空间变换的方法相比，迭代法没有分母为0的问题和空间变换过程造成的舍入误差。     

Discrete singular convolution and its application to the analysis of plates with internal supports. Part 2: Applications

Part 2 of this series of two papers presents the applications of the discrete singular convolution (DSC) algorithm. The main purpose of this paper is to explore the utility, test the accuracy and examine the convergence of the proposed approach for the vibration analysis of rectangular plates with internal supports. Both partial internal line supports and complex internal supports are considered for 21 square plates of various combinations of edge support conditions. The effects of different size, shape and topology of the internal supports and different boundary conditions on the vibration response of plates are investigated. The partial internal line supports may vary from a central point support to a full range of cross or diagonal line supports. Several closed‐loop supports, such as ring, square and rhombus, and their combinations are studied for complex internal supports. Convergence and comparison studies are carried out to establish the correctness and accuracy of the DSC algorithm. The DSC results are compared with those in the available literature obtained by using other methods. Numerical results indicate that the DSC algorithm exhibits controllable accuracy for plate analysis and shows excellent flexibility in handling complex geometries, boundary conditions and support conditions. Copyright © 2002 John Wiley & Sons, Ltd.     

数字电视传输流的实时码率变换系统

数字视频压缩后通常是打包成传输流的形式进行传送，年个传输流有其固定的发送码率，在某些应用场合，比如信道调制前端，需要对输入传输流码率进行改变以适应该信道要求，描述了一种全硬件实现，双路输出，实时，节目可选择的码率变换系统的原理及具体实现。     

Advances in the management and control of optical Internet

Given the ever increasing demand for network bandwidth, and the phenomenal advances in optical wavelength division multiplexing (WDM) networking technologies, a major component of the next generation Internet will be an Internet protocol (IP)-based optical WDM network. As IP over WDM networking technologies mature, a number of important architectural, management and control issues have surfaced. These issues need to be addressed before a true next generation optical Internet can emerge. We enumerate some of the key architectural, management and control issues and discuss corresponding approaches and advances made toward addressing these issues. We first review the different IP/WDM networking architectural models and their tradeoffs. We outline and discuss several management and control issues and corresponding approaches related to the configuration, fault, and performance management of IP over dynamic WDM networks. We present an analysis and supporting simulation results demonstrating the potential benefits of dynamic IP over WDM networks. We then discuss the issues related to IP/WDM traffic engineering in more detail, and present the approach taken in the NGI SuperNet Network Control and Management Project funded by DARPA. In particular, we motivate and present an innovative integrated traffic-engineering framework for reconfigurable IP/WDM networks. It builds on the strength of multiprotocol label switching for fine-grain IP load balancing, and on the strength of reconfigurable WDM networking for reducing the IP network's weighted-hop-distance, and for expanding the bottleneck bandwidth     

Synthesis and Characterization of Poly （L-lactide-co-ε-caprolactone） Copolymers

A series of random and block poly（ L-lactide-co-e-caprolactone ） （ PCLA ） copolymers whh different composition are prepared using stannous octaoate as catalyst.The effects of the amount of initiator on the intrinsic viscosity have been investigated. The structure of the PCLA copolymers is characterized by means of nuclear magnetic resonance（ NMR ）, Fourier transform infrared spectrum （ FTIR ）, differential scanning calorimetry （ DSC ） and X- ray diffraction （ XRD ） methods. It is shown that the synthesis condition and the composition of copolymers obrious influence on the structure of PCLA copolymers. Hydrolytic degradation of the copolymers in a PBS solution of pH 7.4 at 37.0℃ shows that the copolymers of different composhions degrade at different rates.