论农村公路桥梁的养护与管理

桥梁是公路的重要组成部分,其养护质量的好坏直接关系到整条公路的使用功能和服务水平。文中针对目前农村公路桥梁现状,分析了在管养过程中存在的问题,并根据多年的桥梁管养经验,对如何进一步提高桥梁管养水平进行了探讨。     

高速公路管养体制探讨

本文以宁宿徐高速公路养护管理体制为模式,重点阐述管养结合体制中养护中心的人员和设备配置、管养里程、管养职责等,并就与社会化养护公司的合作进行了分析。     

新时期公路养护管理体制改革方向的探讨

阐述了现行公路养护管理体制的不足，并根此探讨了新时期公路养护管理体制的改革方向，包括实现政企分开及管养分开、组建养护机械化专业队伍、引入竞争机制、使用公路养护管理系统和专家决策系统、制定配套的政策与措施、为养护队伍人员分流建立社会保障体系等。     

浅谈特殊结构桥梁的管养

该文在总结借鉴国内和发达国家桥梁管养经验基础上,依据国家现行规范、标准,以及城市交通发展趋势,对目前桥梁管养存在的问题进行了分析,并提出对特殊结构桥梁管养相关建议,供从事桥梁建设、管理、养护的专业技术人员参考.     

对《水利工程维修养护定额标准》的应用实践

2004年7月29日,水利部、财政部联合发文颁布《水利工程维修养护定额标准》(以下简称"定额标准"),《定额标准》的出台一方面为水管体制改革和水利工程管养分离的顺利实施提供经费核定依据,保证了水利工程维修养护资金足额到位;另一方面为建立市场化、专业化和社会化的水利工程维修养护体系,提高养护水平,降低运行成本,培育维修养护市场主体,规范维修养护市场环境提供支持。     

市场经济条件化下公路养护管理对策谈

公路是国民经济建设的重要基础设施,公路养护管理的发展越来越重要。公路养护体制改革的进程,使公路养护这块蛋糕逐渐从行业保护翼下浮出市场。＂十一五＂期间我国公路养护总里程达到230万公里,在这巨大市场即将成型的阶段,必将有一番优胜劣汰的过程。如何在竞争中站稳脚跟,是几十万养护从业人员都面临的非常紧迫的问题,笔者根据近几年工作中的一些体会,分析了加强公路养护与管理的重要性,探讨一下传统公路养护部门的在市场化条件下生存发展的一些策略,供大家探讨。目前,公路的重要性已经被我国各级政府所认识,并且给予了足够的重视,公路建设正在全国各地如火如荼地开展,里程增加,技术等级提高,路面状况改善,公路建设呈现出良好的发展态势,但由于农村公路的使用极不规范以及县际和农村公路的养护项目分散,涉及面广,基层和一线技术力量、管理力量都比较薄弱,在养护中遇到的技术问题较多,资金投入也受到限制;再加上养护管理部门的设置还不完善,乡镇又没有较全面的养护机构,致使乡镇道路养护管理脱节,以至大量道路毁坏,严重影响道路的使用寿命和服务质量,阻碍农村交通事业的发展。因此,加快建立乡村道路养护管理机制,积极筹集乡村道路养护资金,加强对乡村道路养护管理的领导,对加快农村交通建设步伐,促进农村经济健康发展有着重要意义。     

对大通县农村公路管理与养护工作的思考

我县是全省农村公路管养体制改革的试点县。本文分析了大通县农村公路的现状，按照全省《农村公路管理与养护体制改革试点工作方案》的要求，启动了农村公路管养体制改革方案，从不同层面阐述了农村公路管理与养护工作的组织与实施，并得出了养护与管理工作的成功经验。     

浅谈公路养护的科学管理

公路是国民经济建设中的重要基础设施,公路养护的管理在公路建设中显得越发重要.本文分析了公路养护科学管理的重要性,指出了我国在现阶段中公路养护管理工作的不足之处,并提出相应的对策来解决这些问题,把公路养护的管理做的更加出色.     

城市沥青路面养护维修措施探讨

随着城市建设的飞速发展,作为城市组成并占有重要位置的市政基础设施城市道路来讲,其功能性、使用性能每时每刻对城市的社会发展、经济发展、人民生活都有着不可分割的依存关系。对这些路面如何进行科学的、系统的养护与施工管理,是道路养护管理系统最基本的组成部分。文章对沥青路面常见的病害作了分析,并提出针对性的养护措施。     

考虑不确定性的既有桥梁网络管养对策优化

为了实现辖区桥梁整体的优化管理,提出一种考虑不确定性的既有桥梁网络整体管养策略优化分析方法。采用可靠度指标评价桥梁构件、个体与网络的多级性能层次;构建了网级桥梁管养策略的优化框架;并分别建立了寿命期内桥梁性能演变的概率模型,以及养护策略效应和网络养护成本的数学模型;基于Visio网络图形建模方法,发展了一种桥梁网络拓扑结构的自动识别技术;提出一种基于失效分枝矩阵的网络性能概率评价方法,并以运营荷载和环境作用状况下的网络路径连通性能为例进行优化及分析。研究结果表明:该方法强化了对大节点数复杂网络的分析能力;该技术与多目标优化算法结合,实现了考虑不确定性的网级管养策略优化的全程计算机化;网级优化的Pareto前缘给出的都是全局最优解,网级管养优化策略明显提高了桥梁网络的整体性能,有效避免了传统决策引起的木桶短板效应,实现了资金的全局最优分配。     

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.