集中供热直埋管网事故的控制与预防

管网直埋敷设以其占地少、工程量小、施工快与热损失少等优点广泛应用到城市集中供热热网中。随着供热事业的发展,热用户不断增加,有的大城市一条热网的长度就达到几十公里,直埋管网分布于不同土壤条件的埋层中,在热网不断的延伸过程中,其发生事故的可能性增加了,可靠程度在降低,而人们对其的依赖程度却在不断增加,但直埋管网爆管事故的可能性在增加。本文通过对这一过程建立数学模型,对影响管网安全的可靠性的进行分析,提出相应的补救措施与建议。引起相关领域人员的重视,减少管网事故的发生,维护公共安全。     

吉林省肿瘤医院供热管网系统改造实践与分析

针对吉林省肿瘤医院供热管网的现状,分析了存在的问题及产生原因。在满足区域内现有及新建建筑物供热需求并兼顾原热网敷设条件的基础之上,提出了热网改造方案,进行了设计。重点加强了热网的热力平衡和调节手段的设置。并通过系统热力平衡分析和加设调节装置等技术手段解决了水力失衡问题,达到较满意的效果,为供热管网进行热力平衡积累了一定的经验。     

热网自动化系统的运行原理与应用

论述了热网自动化控制系统方案、功能和特点以及管网调节原则,分析了系统的各种运行需求及其应用,提出了选型和运作的原则、原理.采用热网自动化系统,达到了节能增效目的.     

供热管网噪音分析

为了调节热网平衡,在管网上增加调节和控制阀门,改变流速的变化,因此容易产生噪音。本文分析了管网噪音产生的原因及避免噪音产生的解决方法。     

基于Web的热网监控系统的应用研究

本文针对目前热网管理中存在的问题,以热电二厂热力公司所属管网换热站为例提出了一种基于Web的热网监控系统概念,详细论述了系统的功能,软、硬件的实现方法以及通讯方式。     

供热管网噪音分析

为了调节热网平衡,在管网上增加调节和控制阀门,改变流速的变化,因此容易产生噪音。本文分析了管网噪音产生的原因及避免噪音产生的解决方法。     

浅谈供热管网工程质量监督管理

集中供热是指以热水或蒸汽作为热媒,由一个或多个热源通过热网向城市、镇或其中某些区域热用户供应热能的方式。从施工过程质量管理与施工过程质量监督两方面,介绍了供热管网工程施工中质量监管的要点,以期对热力施工的发展有所启示。     

集中供热热力站微机监控系统的应用研究

随着城市供热管网的不断扩大,如何科学有效地控制和管理热网,提高热网的经济和社会效益,成为供热企业急需解决的重要课题.文章介绍利用先进的微机监控系统和可靠的网络通信技术,对热力站的运行参数进行实时监测,并采用智能控制仪对热力站施行本地智能控制,以适应室外温度与热网运行状况的变化,从而有效地解决热网的控制和管理问题.     

论城市供热管网的优化设计

供热管网的合理的布局是城市建设和发展的前提条件。本文首先对我国城市供热管网的特点与常用设计技术进行了探讨,指出在供热管网的设计和运行中,应从热网优化的具体要求出发。同时从7个方面来阐述如何搞好城市的供热管网优化设计问题。     

浅谈供热管网节能改造技术

作为集中供热效率控制的重要指标之,热网效率的提高目前已经成为了供热节能工作的焦点问题。本文分析了目前我国城市供热管网的现状,并由此提出了转变热网运行方式、提高设备的工作效率、推广多热源联产模式、应用各种节能新技术、以及注重建筑节能保暖等一系列富有针对性的管网改造对策,为充分发挥集中供热应有的节能效果提供了有力的技术支持。     

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.     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.