纳米材料的产业化

纳米材料有着广泛的用途和巨大的市场，人们一直在力图寻求一种批量低价生产这种材料的方法，纳米相技术公司（Nanophase Technolgies Corp.）花费数年时间开发出一种工艺，即物理气相合成法（PVS）生产纳米材料。之后，公司大大改进了该工艺，使产品产量以及产品纯度大为提高，随后，公司又开发出了离散粒子封装法（DPE），用这种方法可以在纳米粒子的表面产生聚合物膜，使得产品的表面性质能迎合不同用户的需求，最后，介绍了几种采用该公司的新技术生产的产品。     

电压型馈线自动化设备的应用与实践

简要介绍了广州供电分公司实施馈线自动化系统的实践历程,阐述了电压型馈线自动化设备及系统的基本设计思路,并就其在实际应用中所遇到的一些技术问题和解决方法进行了探讨和分析。     

酶催化水溶性导电聚苯胺的模板导向合成与表征

对辣根过氧化物酶(HRP)催化水溶性导电聚苯胺的合成进行了研究.以聚乙烯磺酸钠(PVS)作为反应的聚阴离子模板.详细地研究了反应体系的pH值、H2O2浓度及苯胺与PVS的摩尔比对苯胺聚合的影响.用UV-vis-near-IR、FTIR及四探针电导率测试仪对产物进行了表征,并与其他模板聚合产物进行了比较.研究结果表明,PVS可作为HRP催化苯胺聚合的模板,合成的PVS/PANI的电导率为4.78×10-1S·cm-1,反应体系的pH值应控制在4.0～5.0,H2O2浓度以20 mmol·L-1为宜,PVS与苯胺的摩尔比应控制在1～1.5.     

A Complete Mechanization of Correctness of a String-Preprocessing Algorithm

We report on mechanization of a correctness proof of a string-preprocessing algorithm. This preprocessing algorithm is employed in Boyer-Moore’s pattern matching algorithm. The mechanization is carried out using the PVS system. The correctness proof being mechanized has been formulated in Linear Time Temporal Logic. It consists of fourteen lemmata which are related to safety properties and two additional lemmata dealing with liveness properties. The entire mechanization of the safety and liveness parts has been completed. Several small errors and omissions were found in the handwritten proof and corrected. Yet, the manual correctness proof of the string-preprocessing algorithm was found to satisfy the usual mathematical validity. We conclude that the string-preprocessing algorithm in Boyer-Moore’s pattern matching algorithm, corrected a number of times because of flaws, does not contain any more undiscovered errors. An extended abstract of this work appears in the Proceedings of the 8^th IEEE International Conference on Engineering of Complex Computer Systems (ICECCS ‘02).     

Cones and foci: A mechanical framework for protocol verification

We define a cones and foci proof method, which rephrases the question whether two system specifications are branching bisimilar in terms of proof obligations on relations between data objects. Compared to the original cones and foci method from Groote and Springintveld, our method is more generally applicable, because it does not require a preprocessing step to eliminate τ-loops. We prove soundness of our approach and present a set of rules to prove the reachability of focus points. Our method has been formalized and proved correct using PVS. Thus we have established a framework for mechanical protocol verification. We apply this framework to the Concurrent Alternating Bit Protocol.

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A Mechanized Proof Environment for the Convenient Computations Proof Method

A mechanized verification environment made up of theories over the deductive mechanized theorem prover PVS is presented, which allows taking advantage of the convenient computations method. This method reduces the conceptual difficulty of proving a given property for all the possible computations of a system by separating two different concerns: (1) proving that special convenient computations satisfy the property, and (2) proving that every computation is related to a convenient one by a relation which preserves the property. The approach is especially appropriate for applications in which the first concern is trivial once the second has been shown, e.g., where the specification itself is that every computation reduces to a convenient one. Two examples are the serializability of transactions in distributed databases, and sequential consistency of distributed shared memories. To reduce the repetition of effort, a clear separation is made between infrastructural theories to be supplied as a proof environment PVS library to users, and the specification and proof of particular examples. The provided infrastructure formally defines the method in its most general way. It also defines a computation model and a reduction relation—the equivalence of computations that differ only in the order of finitely many independent operations. One way to prove that this relation holds between every computation and some convenient one involves the definition of a measure function from computations into a well-founded set. Two possible default measures, which can be applied in many cases, are also defined in the infrastructure, along with useful lemmas that assist in their usage. We show how the proof environment can be used, by a step-by-step explanation of an application example.     

Specifying Cash-Point with DisCo

We describe how the cash-point service problem of Formal Methods ’99 is specified using DisCo [Dis, JKS91]. Received January 2000 / Accepted in revised form December 2000     

Synthesis of well-defined star-branched polymers by stepwise iterative methodology using living anionic polymerization

This article reviews the synthesis of regular and asymmetric star-branched polymers with well-defined structures by methodologies using living anionic polymerization, especially focusing on the synthetic approaches accessible for precisely controlled architectures of star-branched polymers concerning molecular weight, molecular weight distribution, arm number, and composition. The reason for selecting living anionic polymerization from many living/controlled polymerization systems so far developed is that this living polymerization system is still the best to meet the strict requirements for the precise structures of star-branched polymers. Furthermore, we herein mainly introduce a novel and quite versatile stepwise iterative methodology recently developed by our group for the successive synthesis of many-armed and multi-compositional asymmetric star-branched polymers. The methodology basically involves only two sets of the reaction conditions for the entire iterative synthetic sequence. The reaction sequence can be, in principle, limitlessly iterated to introduce a definite number of the same or different polymer segments at each stage of the iteration. As a result, a wide variety of many-armed and multi-compositional asymmetric star-branched polymers can be synthesized.     

一种基于OpenMP的并行混合PVS算法*

针对传统串行混合PVS(Principal Variation Search,主要变例搜索)算法的计算量大、执行耗时长和无法利用多核资源的不足,提出了一种基于OpenMP(Open Multi-Processing)的并行混合PVS算法,该算法应用了PVSplitting(主要变例分裂)策略,自底向上将博弈树每一层的首个PV结点的每个分支的搜索线程化,利用多核CPU并行执行,并对临界区和线程调度进行了合理设计,以提高搜索效率。最后,基于一个真实的中国象棋博弈系统进行了实验,结果表明该算法拥有较高的剪枝率和加速比,能够明显提升混合PVS算法的执行性能。