中国电子商务思考

网络经济持续走低，但电子商务的发展大方向是不会改变的。在中国，目前的主要问题是宽带网的重复建设、认证机构建设缺乏有效监管、电子商务立法滞后、物流配送系统不完善、标准化问题成为电子商务发展的障碍等，当前应做的主要是：政策的宏观引导、示范推广、加强对宽带网和认证机构建设的监管等。     

基于体全息技术的WDM器件

利用体全息技术制作波分复用器件是一种新方法。本文介绍了此种方法的基本原理和器件的基本性能，并报道了国外对该项技术的研究进展。     

基于CDMA智能网平台的增值业务--"位置服务"

本主要介绍基于CDMA智能网平台的一种增值业务——“位置服务”，阐述这个业务的网络结构、涉及到的技术问题和解决方案，并将这个整体思路投入到开发业务中去。     

Network topology and the theory of rubber elasticity

The earliest investigations on rubber elasticity, commencing in the 19th century, were necessarily limited to phenomenological interpretations. The realisation that polymers consist of very long molecular chains. commencing c. 1930, gave impetus to the molecular theory of rubber elasticity (1932-). according to which the high deformability of an elastomer, and the elastic force generated by deformation, stem from the configurations accessible to long molecular chains. Theories of rubber elasticity put forward from 1934-1946 relied on the assumption that the junctions of the rubber network undergo displacements that are affine in macroscopic strain. The theory of James and Guth (1947) dispensed with this premise, and demonstrated instead that the mean positions of the junctions of a ‘phantom’ network consisting of Gaussian chains devoid of material properties are affine in the strain. The vital significance of the distinction between the actual distribution of chain vectors in a network and their distribution if the junctions would be fixed at their mean positions went unnoticed for nearly 30 years. Experimental investigations, commencing with the incisive work of Gee in 1946. revealed large departures from the relationship of stress to strain predicted by the theories cited. This discrepancy prompted extensive studies, theoretical and experimental, during succeeding years. Inquiry into the fundamentals of polymer networks, formed for example by interlinking very long polymer molecules, exposed the need to take account of network imperfections, typically consisting of chains attached at only one end to a network junction. Various means were advocated to make corrections for these imperfections. The cycle rank ζ of the network has been shown (1976) to be the fundamental measure of its connectivity, regardless of the junction functionality and pattern of imperfections. Often overlooked is the copious interpenetration of the chains comprising typical elastomeric networks. Theories that attempt to represent such networks on a lattice are incompatible with this universal feature. Moreover, the dense interpenetration of chains may limit the ability of junctions in real networks to accommodate the fluctuations envisaged in the theory of phantom networks. It was suggested in 1975 that departures from the form predicted for the elastic equation of state are due to constraints on the fluctuations of junctions whose effect diminishes with deformation and with dilation. Formulation of a self-consistent theory based on this suggestion required recognition of the non-affine connection between the chain vector distribution function and the macroscopic strain in a real network, which may partake of characteristics of a phantom network in some degree. Implementation of the idea was achieved through postulation of domains of constraint affecting the equilibrium distribution of fluctuations of network junctions from their mean positions. This led in due course to a theory that accounts for the relationship of stress to strain virtually throughout the ranges of strain accessible to measurement. The theory establishes connections between structure and elastic properties. This is achieved with utmost frugality in arbitrary parameters.     

图书馆图书管理系统分析与设计

图书馆作为一个专门收集、整理、保存、传播文献 ,并提供利用的科学、文化、教育机构 ,是人们获取知识的主要来源之一。发展至今已有数千年的历史。然而 ,在信息技术迅速普及的今天 ,越来越多的读者希望通过网络更方便、更快捷地进行图书的查阅、借阅 ,获取自己的所需 ,因此图书馆的信息化建设尤为重要     

WLAN网管系统的现状和发展

2001年以来，全球WLAN（无线局域网）市场应用的瓶颈被打破，中国也迎来了WLAN商业化运作和服务的春天，WLAN为我们带来了一种全新的、灵活的工作方式，同时也带来了新的挑战，本文将对WLAN网络管理的主要内容和具体指标进行阐述，并对各大厂商的WLAN网管产品进行简单介绍和比较。     

一种语音混沌保密通信方案的研究与硬件实现

在硬件实验研究的基础上，建立一种环形蔡氏电路，提出用环蔡氏电路实现语音混沌保密通信的一种闭环逆系统方案，其特点是利用环形蔡氏电路的单向耦合原理，通过反馈的方法形成一个包括有用信号在内的极联闭合环路，从而实现改善端与接收端之间混沌系统的严格同步而不受有用信息调制的影响。理论分析与硬件实验结果证明，该方案同现有的其它混沌通信方案相比较，具有非线性失真小、保真度高的优点，完全能够满足传送语音信号的要求。     

第三代短波自动链路建立系统特性分析及仿真实现

分析了第三代短波自动链路建立系统的工作特性及技术特点，并对系统仿真实现的原则及一些细节问题进行了较深入的探讨，同时对仿真实现中涉及的链路质量分析（LQA）算法进行了研究。     

低潮时期宽带网建设需要注意的问题

宽带建设低潮期实际上是一次优胜劣汰的过程,宽带运营竞争的手段将由低价竞争转向服务质量和特色的竞争。应在重视宽带接入建设的同时,也要重视业务运营管理平台的建设。应从长远考虑,不应仅为了节省投资而降低对设备的要求。由于降低成本的主要方向是在线缆部分,因此EVDSL技术应用的速度将大大超过人们的预期。在网络建设上,IPDSLAM虽有优势但也有不足,还需要进一步的成熟、稳定和实践的检验。     

软交换技术的发展及其应用

软交换是下一代网络NGN的核心技术，本文从软交换的概念入手，介绍了软交换的基本功能及其优点．软交换的网络系统结构、软交换的对外接口等内容，并探讨了软交换技术的应用。