基于现场总线技术的分布式控制系统的设计与实现

随着现场总线技术的发展,传统的控制系统结构开始向大规模的分布式控制系统方向发展。本文在神经元芯片技术的基础上,研究探讨了分布控制系统的开发技术,对基于现场总线技术的分布式控制系统的软件设计作了详细介绍。     

分布式控制系统中CAN总线通讯性能改进方法

通讯的可靠性研究一直是航空发动机分布式控制系统研究的关键问题。在基于CAN总线的分布式通讯中,ID标识符的分配和数据的编码解码问题尤为突出,针对以往的ID标识符分配存在结构层次不明晰,不利于系统扩展,而数据编码解码则存在编程复杂、执行效率不高等缺点,设计了结构层次清晰的ID标识符,设计了精简、执行效率高的数据编码解码方案,将设计应用于航空发动机分布式控制系统中,试验结果表明设计方案能够满足航空发动机分布式控制系统通讯要求。     

基于TrueTime的涡扇发动机分布式控制系统及数字仿真平台设计

国内外航空发动机分布式控制系统研究往往脱离实际发动机,分布式控制系统的控制性能好坏很难定量地表现出来。本文以一实际的涡扇发动机为被控对象,分析了被控对象的特点及控制需求,设计了分布式控制方案,在MATLAB/TrueTime环境搭建了分布式控制系统数字仿真平台,仿真平台采用CAN总线通讯方案,通过时间与事件触发解决通讯同步问题,最终完成了发动机各个状态下的主燃油、加力燃油、尾喷口喉部面积控制,仿真结果表明所搭建的数字仿真平台控制性能良好,能满足航空发动机控制要求。     

分布式控制系统关键技术研究

分布式控制系统解决了以往以传统仪表、可编程控制器(PLC)为基础的控制系统所存在的信息传送实时性差、数据无法共享、管理难度大等诸多难题.该文以糖厂控制管理系统为例,对分布式控制系统的组成及其功能进行了分析,并对相关的关键技术进行了研究.实现了高效、可靠的控制点数据的上传及下载,对控制点数据结构定义与管理,I/O设备管理,数据处理流程等做了深入的分析,并设计了实现数据库存取的部分代码.     

现场总线的工厂分布式显示控制系统

研究了分布式显示控制系统中应用CAN总线的软硬件设计,作出了SJA1000的初始化方法和通信程序设计,并得出现场总线的工厂分布式显示控制系统设计方法。     

分布式控制系统及其在智能建筑上的应用

针对工业过程中普遍存在的“孤岛”现象，讨论了分布式控制系统的原理结构，应用中应注意的问题以及现存的问题。提出了分布式控制系统的发展方向，以分布式控制系统在智能建筑上的应用为例，说明分布式控制是实现管控集成一体化的有效手段，克服孤岛现象后效益明显，管理功能大大加强。     

敏捷制造企业的分布式质量控制系统

总结了敏捷制造企业对质量控制系统的需求,提出分布式计算机辅助质量控制系统的设计思想、功能模型和总体结构,并讨论了系统原型的应用。     

中央空调智能监控器的设计与实现

传统的中央空调控制系统能源浪费严重、温度调节能力差,针对这个问题,该文提出中央空调智能控制器的设计方法,真正实现了中央空调分布式控制系统的“分散控制、集中管理”。文中对智能控制器硬件系统和软件系统分别进行了详尽地描述,给出了以单片机MSC1210为中央处理器,以DS1820芯片为温度数据采集器、转换器智能控制器硬件设计方案,研究了软件的功能需求,阐述了温度控制流程。该设计方案为中央空调分布式控制系统以及楼宇自动化系统的实现给予了有益的参考。     

DCS系统在水厂滤池自动控制中的应用及优化

目前,自动化控制系统在全国各水厂应用较为广泛,本篇主要描述了分布式控制系统（DCS）在水厂滤池的应用,并通过对控制系统的深入改造,使水厂滤池运行更加稳定、可靠,达到滤池全自动控制的要求。     

分布式档案库房智能控制系统研究

档案库房的现代化改造中,智能控制系统是核心。本文在对档案库房控制系统需求分析的基础上,以RS485总线和ARM处理器为基础,辅以多传感器、多控制接口、多通信接口,构建了一种分布式档案库房智能控制系统,并对系统的具体实现进行了初步阐述。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.