汕尾500 kV茅湖变电站主变防火墙施工技术

结合具体工程防火墙的概况，从基础施工、模板拼装和安装、钢筋绑扎、混凝土浇筑、表面处理多方面介绍了防火墙的施工工艺要点，施工结果显示，其整体外观质量较好，满足了工程结构的要求。     

7‐Azidomethoxy‐Coumarins as Profluorophores for Templated Nucleic Acid Detection

Templated nucleic acid detection is an emerging bioanalytical method that makes use of the target DNA or RNA strand to initiate a fluorogenic reaction. The Staudinger reduction holds particular promise for templated sensing of nucleic acids because the involved functional groups are highly chemoselective. Here, the azidomethoxy group, which can be removed under Staudinger conditions, is used to cage 7‐hydroxycoumarin fluorophores. Reduction by phosphines and subsequent loss of the azidomethoxy substituent induce a significant bathochromic shift of the major absorbance band in the near UV region. When excited at the appropriate wavelength, this change in the absorbance spectrum translates into a substantial fluorescence turn‐on signal. The described profluorophores are readily conjugated to amino‐modified DNAs and are rapidly uncaged by a triphenylphosphine–DNA probe under the control of a DNA template. In addition, turnover of the probes on the target strand occurs and yields substantial signal amplification.     

后向攻击技术方案的对比与选择

以空战前向攻击为参照，以对比的方式分析，论证了导弹越肩发射后向攻击和后向发射后向攻击技术方案的特点和存在的问题，在此讨论的基础上，提出了选择空战导弹后向攻击技术方案的倾向性意见。     

The initiation mechanism of corrosion of zinc by sodium chloride particle deposition

This study details the mechanism of attack by sodium chloride particles on zinc. The dissolution and subsequent reaction of a single micro-particle of salt on zinc has shown explicitly the mechanism by which attack occurs. Following the initial formation of a hemispherical droplet when the particle wets in humid air, a secondary spreading effect occurs. The rate and potential associated with this spreading process has been measured using a Kelvin probe, and the chemistry of the compounds formed as a result of the corrosion mechanism have been determined using spectrographic techniques.     

Securing Threshold Cryptosystems against Chosen Ciphertext Attack

For the most compelling applications of threshold cryptosystems, security against chosen cipher text attack is a requirement. However, prior to the results presented here, there appeared to be no practical threshold cryptosystems in the literature that were provably chosen ciphertext secure, even in the idealized random oracle model. The contribution of this paper is to present two very practical threshold cryptosystems, and to prove that they are secure against chosen ciphertext attack in the random oracle model. Not only are these protocols computationally very efficient, but they are also non-interactive, which means they can be easily run over an asynchronous communication network. Received November 2000 and revised September 2001 Online publication 11 March 2002     

一种代理多重数字签名方案的安全性分析

对Qi和Harn的代理多重数字签名方案，提出了一种伪造攻击，利用该伪造攻击,n个原始签名者中任何一个签名者都能伪造出一个有效代理多重数字签名，并对Qi和Harn的代理多重数字签名方案进行了改进，提出了一种新的安全的代理多重数字签名方案。     

A generalized correlation attack on a class of stream ciphers based on the Levenshtein distance

A statistical approach to cryptanalysis of a memoryless function of clock-controlled shift registers is introduced. In the case of zero-order correlation immunity, an algorithm for a shift register initial state reconstruction based on the sequence comparison concept is proposed. A constrained Levenshtein distance relevant for the cryptanalysis is defined and a novel recursive procedure for its efficient computation is derived. Preliminary experimental results are given and open theoretic problems are discussed.Following [11], a Boolean function f(x ₁,..., x _n) is said to be mth-order correlation immune if m is the maximum integer such that the random variable f(X ₁,..., X _n) is statistically independent of every set of m random variables chosen from the balanced and independent binary random variables X ₁,..., X _n.     

注射模CAPP技术研究与开发

在分析注射模具工艺设计和CAPP特点的基础上 ,提出了面向注射模具的CAPP开发方法。即以针对归纳总结出的抽象零件而建立的工艺模板为基础 ,开发了基于网络和数据库的具有企业集成层、项目管理层和工艺设计层3层结构的模具CAPP系统。该系统能够满足模具零件特别是非成型零件的工艺设计工作要求 ,界面友好 ,可针对不同企业非常容易地完成定制。     

计算机辅助生成控制系统故障树

有关故障树生成方法的研究已经成为故障树分析研究中的一个重要分支，故障树的完善程度将直接影响系统可靠性的定性分析和定量计算。因此，故障树及故障树自动生成方法的开发研究具有非常现实和极其广泛的应用价值。本文分析了已有的控制系统故障树生成方法特点，提出一种计算机辅助故障树生成方法。通过系统元件的逻辑关系对所建立的元件故障模式数据库的搜索生成系统的故障树。该方法给出了元件故障模式的建立、元件问的关联方法、控制回路模板的建立方法以及故障树自动生成算法。最后，结合一个复杂系统故障树的生成验证了该方法的可行性和有效性。     

非对称数字水印系统研究

针对传统对称水印的不足,设计并实现了一种用于版权保护的非对称图像水印系统。该系统采用三级认证结构:用户和认证机构分别拥有由私钥变换而成的不同的公钥,他们可以利用各自的公钥对数字产品进行两层检测,并且无法去除和伪造水印,只有掌握私钥的版权所有者才能进行最终的认证。实验表明:该水印的检测性能良好,同时对常规的图像处理方法具有较强的顽健性。与其它非对称水印相比,该水印系统不但抵御公开攻击的能力较强,而且可防止认证机构的欺骗行为,因而具有更高的安全性。