用CryptoAPI生成密钥的方法

加密技术是电子商务信息安全的重要手段，而密钥生成算法是加密能否安全的关键技术。本文通过程序例子详细介绍了用微软的加密应用程序接口(CryptoAPI)来生成和管理密钥的方法。     

The property of being polynomial for Mal’tsev constraint satisfaction problems

A combinatorial constraint satisfaction problem aims at expressing in unified terms a wide spectrum of problems in various branches of mathematics, computer science, and AI. The generalized satisfiability problem is NP-complete, but many of its restricted versions can be solved in a polynomial time. It is known that the computational complexity of a restricted constraint satisfaction problem depends only on a set of polymorphisms of relations which are admitted to be used in the problem. For the case where a set of such relations is invariant under some Mal’tsev operation, we show that the corresponding constraint satisfaction problem can be solved in a polynomial time. __________ Translated from Algebra i Logika, Vol. 45, No. 6, pp. 655–686, November–December, 2006.     

The Direct Resolution of the Enantiomers of Four Chiral Pesticides

Cellulose-tris(3,5-dimethylphenylcarbamate)(CDMPC) were synthesized as highperformance liquid chromatography (HPLC) chiral stationary phase(CSP). The successful resolution of four chiral pesticides on the CSP was realized and the influence of the temperature on the separation was studied.     

Chromatographic evaluation of perphenylcarbamoylated β-cyclodextrin bonded stationary phase for micro-high performance liquid chromatography and pressurized capillary electrochromatography

Application of mono (6^A-N-ethylenediamine-6^A-deoxy) perphenylcarbamoylated β-cyclodextrin (β-CD) bonded stationary phase (CSP) in micro-high performance liquid chromatography (micro-HPLC) and pressurized capillary electrochromatography (p-CEC) was firstly presented. A series of racemic α-amidophosphonates were resolved in reversed- and normal-phase modes on this CSP. The investigated chromatographic parameters include retention factor (k′), separation factor (α) and resolution (Rs) of solutes. In addition, the structural variation of the solutes and the experimental factors affecting chiral separations have been examined, including the percentage of alcohol modifier, the linear velocity (u) of the mobile phase, electrical field strength, etc. Baseline separation was achieved for most of the entities. Hydrophobic interaction, steric effect and π-π interaction contribute to the possible mechanism. Comparative results indicate that higher Rs value up to 3.1 was found in micro-HPLC, higher efficiency up to 29,970 in p-CEC.     

Chiral separation of triazole pesticide enantiomers by high performance liquid chromatography

Four triazole enantiomers of diclobutrazol (erythro form) (1), paclobutrazol (erythro form) (2), diniconazole (3) and uniconazole (4) have been separated by high performance liquid chro-matography (HPLC) on chiral stationary phase (CSP) OA-4700. Chromatographic data and a chiral recongnition model are presented for the separation of these pesticide enantiomers. The influence of column temperature and composition of mobile phase have been described.     

一类约束满足问题及其算法

针对具有解析约束形式、同一变量多赋值的约束满足问题,提出了一种新的约束满足问题定义·通过一种特殊约束满足问题的研究提出一套建立在这个定义基础之上的概念和三种算法:整数规划法、不等式组法和直接求解不定方程法,详细研究了其中的第三种算法,并给出了最坏情况下的时间复杂度,从而能够比较清晰地描述一类约束满足问题的一般分析过程,揭示了约束满足问题同经典的整数规划、数论和整数环论的联系·     

基于通信顺序进程的计算机网络通信协议形式化描述

描述和设计计算机网络通信协议时，使用抽象的同步通信机制最为方便。但在实际中，使用异步通信机制将不可避免。基于霍尔的“通信顺序进程”和其他对通信协议描述与设计的理论研究结果，本文提出一个形式化方法，这个方法在不论使用何种实现通信机制的情况下都将保证通信协议的正确性     

基于UPPAAL的虚拟生产系统仿真

虚拟生产系统(VPSs)是一种为应对易变的和不确定的制造环境而提出的新型生产资源结构形式.针对VPSs的特点,提出了基于自治与协调机制的控制结构.应用赋时自动机理论以及在UPPAAL的辅助下,对VPSs进行了DEDS的建模.为获得期望的性能(生产流程和时间)和行为特性(避免冲突和死锁),设计了基于启发式调度规则的自治与协调监控器,并进行了系统分析和时间最优调度的计算与仿真,从而构建起兼顾控制和调度问题的VPSs闭环监控系统.     

一种改进的实时系统可达性分析算法

首先简介了时间自动机、时钟区域、区域等价、时钟带的概念.利用时钟带,可以将时间自动机的无穷状态空间转化为有穷.实时系统的绝大多数安全性和部分活性可以通过可达性分析算法来验证.然而,当系统时钟个数较多时,用DBM存储时钟带,会造成内存空间的很大耗费.该文提出了用邻接表存储时钟带,给出了改进的算法,并对算法的空间复杂度作了分析.实验表明,当时钟个数大于5时能节约很大的内存空间,从而在一定程度上缓解了状态爆炸.     

CSP热轧低碳钢板轧制过程中析出行为分析

采用H-800透射电镜研究CSP热轧低碳钢轧制过程中析出物形貌、尺寸、及分布等，结果表明：累积变形量较小，变形温度较高时，第二相粒子主要在晶界或相界上形成，数量较少且比较粗大，尺寸多在150nm以上；随着轧制过程的进行，累积变形量的增大和轧制温度的降低，第二相粒子主要在晶内析出，细小、弥散且数量较多，尺寸大多数在20～100nm之间，析出物主要为Al2O3、MnS、Cu7S4和Fe3C。