平行线束法的仿射研究

用 3 个仿射图的投射方向构成 1 个仿射坐标系,同时也构成 1 个三棱锥,在此仿射坐标系中用球面三角重新研究由两个仿射图求第 3 个仿射图的投影作图理论 ——平行线束法。进一步还给出了由两个仿射图得到正投影的条件、由两个正投影得到第 3 个正投影的条件、以及由 V,H 两投影得到指定方向上的正投影的条件,简化了研究过程,得到了更简单的公式。     

射频板条CO_2激光器并联谐振技术的研究

本文利用周期性网络模型计算了射频板条CO2激光器电极的纵向电压分布．探讨了并联谐振技术在板条器件中获得成功运用的原因．提出了利用并联谐振技术进一步提高电压分布均匀性的两个途径．     

A survey of parallel execution strategies for transitive closure and logic programs

An important feature of database technology of the nineties is the use of parallelism for speeding up the execution of complex queries. This technology is being tested in several experimental database architectures and a few commercial systems for conventional select-project-join queries. In particular, hash-based fragmentation is used to distribute data to disks under the control of different processors in order to perform selections and joins in parallel. With the development of new query languages, and in particular with the definition of transitive closure queries and of more general logic programming queries, the new dimension of recursion has been added to query processing. Recursive queries are complex; at the same time, their regular structure is particularly suited for parallel execution, and parallelism may give a high efficiency gain. We survey the approaches to parallel execution of recursive queries that have been presented in the recent literature. We observe that research on parallel execution of recursive queries is separated into two distinct subareas, one focused on the transitive closure of Relational Algebra expressions, the other one focused on optimization of more general Datalog queries. Though the subareas seem radically different because of the approach and formalism used, they have many common features. This is not surprising, because most typical Datalog queries can be solved by means of the transitive closure of simple algebraic expressions. We first analyze the relationship between the transitive closure of expressions in Relational Algebra and Datalog programs. We then review sequential methods for evaluating transitive closure, distinguishing iterative and direct methods. We address the parallelization of these methods, by discussing various forms of parallelization. Data fragmentation plays an important role in obtaining parallel execution; we describe hash-based and semantic fragmentation. Finally, we consider Datalog queries, and present general methods for parallel rule execution; we recognize the similarities between these methods and the methods reviewed previously, when the former are applied to linear Datalog queries. We also provide a quantitative analysis that shows the impact of the initial data distribution on the performance of methods. Recommended by: Patrick Valduriez     

绝对时钟智能控制器的研制

介绍了一种日常参数智能控制器的研制及研制过程中的几个重要问题的解决方法。特别是用于城市照明及美化城市的彩灯的开、关时间智能控制方面，给出了依据当地绝对时间、经度、纬度进行昼夜时间计算的方法，使之在不接光电传感器情况下可跟踪季节的昼夜变化。控制系统采用８９Ｃ２０５１单片机，配有时钟日历芯片ＤＳ１２８８７，系统体积小、功能强、可靠性高。     

多Transputer系统上的并行消隐算法及其图形显示

本文讨论了三维物体隐面消除的并行处理问题。给出了一类ＭＩＭＤ并行深度缓冲器算法，并在多Ｔｒａｎｓｐｕｔｅｒ系统上实现。文中还对这些算法的效率进行了比较。     

DGPSL：A DISTRIBUTED GRAPHICS LIBRARY

ＤＧＰＳＬ：ＡＤＩＳＴＲＩＢＵＴＥＤＧＲＡＰＨＩＣＳＬＩＢＲＡＲＹＳｈｉＪｉａｏｙｉｎｇ；ＰａｎＺｈｉｇｅｎｇ；ＺｈｅｎｇＷｅｎｔｉｎｇＤＧＰＳＬ：ＡＤＩＳＴＲＩＢＵＴＥＤＧＲＡＰＨＩＣＳＬＩＢＲＡＲＹ￥ＳｈｉＪｉａｏｙｉｎｇ；ＰａｎＺｈｉｇｅｎｇ；...     

Transputer在高速雷达视频回波采集系统中的应用

介绍以ＴｒａｎｓｐｕｔｅｒＴ４２５单片高速并行计算机为中心控制环境，与高速Ａ／Ｄ（３５ＭＨｚ，８ｂｉｔ相结合构成的实时高速雷达回波采集系统。该系统的特点是：采集速度高，存贮量大；利用标准的Ｔｒａｎｓｐｕｔｅｒ链路实时完成处理器间的数据传输和通讯；系统采用并行Ｏｃｃａｍ语言编程。这样既充分发挥处理器的并行功能，又使数据采集和数据处理同步进行，这在实时信号采集与处理系统中具有特别重要的意义。     

银河－Ⅱ气象应用并行库

本文着重介绍“银河－Ⅱ气象应用并行库”的设计思想、技术特点和使用方法。     

Efficient Parallel Algorithms for Some Graph Theory Problems

In this paper,a sequential algorithm computing the aww vertex pair distance matrix D and the path matrix Pis given.On a PRAM EREW model with p,1≤p≤n^2,processors,a parallel version of the sequential algorithm is shown.This method can also be used to get a parallel algorithm to compute transitive closure array A^* of an undirected graph.The time complexity of the parallel algorithm is O(n^3/p).If D,P and A^* are known,it is shown that the problems to find all connected components,to compute the diameter of an undirected graph,to determine the center of a directed graph and to search for a directed cycle with the minimum(maximum)length in a directed graph can all be solved in O(n^2/p logp)time.     

Effect of γ-Irradiation on Phenolic Acids in Strawberries

ABSTRACT: The content of phenolic acids in strawberries was determined before and after gamma-irradiation in the dose range 1 to 10 kGy. Fresh whole strawberries were irradiated, acid-base-hydrolyzed, and purified on polyamide columns. The compounds were analyzed by reversed-phase chromatography and detected with a diode-array detector. Dose/concentration relationships were obtained for gallic acid, 4-hydroxybenzoic acid, cinnamic acid, p-coumaric acid, and caffeic acid. Whereas radiolysis of the individual acids in aqueous solutions led to their efficient degradation and to a notable hydroxylation, in the complex matrix of food no hydroxylation products were formed and only the amount of 4-hydroxybenzoic acid was affected by irradiation (build up: 0.68 ± 0.04 mg kg⁻¹kGy⁻¹).