基于可接受间隙理论的交汇段次航道通过能力

为研究内河交汇段航道通过能力,分析了内河交汇段船舶流特性。讨论了可接受间隙理论在内河交汇段实行"分道通航"规则下分析应用的可行性。借鉴公路无信号交叉口通过能力计算方法建立交汇段航道通过能力计算模型。以长江尹公洲"十字型"交汇航段为例,在条件相同下计算比较交汇段航道、基本段航道和船闸三种航段的通过能力。比较结果表明:交汇段通过能力小于基本段通过能力,但大于船闸通过能力;为内河航道设计、交通运输规划等相关领域的人员提供参考。     

天津港大沽沙航道交通组织优化

为保障天津港大沽沙航道通航安全畅通,对该航道通航环境和交通现状进行了研究,统计分析了大沽口港区和南疆南港区泊位及到港船舶情况,通过分析通航时间和通航密度,计算了航道实际通航能力,指出该航道交通组织优化的必要性.依据港口发展规划,对港区货物吞吐量及到港船舶数量进行了预测,在此基础上提出了大沽沙航道交通组织优化模式和安全保障措施及建议.     

浅谈内河航道数字化建设的意义

进入21世纪、我国内河航道建设飞速发展,如何加强内河航道数字化、信息化建设是当前研究的热点和难点,该文通过对航道信息化系统结构进行介绍,对航道信息化综合平台进行分析,从而为内河航道信息化具体实现打下了基础;通过对航道信息化建设的意义进行了分析,加强了提高航运管理能效的信心。     

海上突发事件下的航道通航效率分析

为研究海上交通突发事件对港口航道通航效率的影响,以交通波理论为基础,结合港口航道船舶交通流特性,分析突发事件时航道内船舶的聚集和消散过程,建立海上交通突发事件时空影响模型。以厦门港超大型船舶进港单向通航为例,定量计算出单向通航时最大排队长度及阻塞时间,为海事主管部门在超大型船舶进港时制定相应措施提供理论参考依据。     

上海港集装箱内河集疏运网络优化

对上海的内河网络做了比较全面深入的分析研究.首先,把上海内河航运网简化成网络结构图,把比较关键的航道交汇点抽象成结点并分配相应的集装箱数;其次,结合“一环十射”规划综合分析航道运输能力,力图与实际情况相符合;最后,采用Dijkstra算法计算出各节点到目的港区的最短途径,分析计算结果与各河段的运输能力,修正运输途径以得出航运系统比较满意的内河运输集疏运网络方案.     

测量技术在内河航道养护工程中的应用

江苏省地处我国大陆东部沿海中心,位于著名的长江三角洲经济发达地区,同时也是全国内河水运最为发达的省份之一。它为内河航道的发展提供了广阔的空间,但对航道养护和管理提出了更高的要求。测量技术在内河航道养护工程施工中发挥着重要的作用,因此本文主要阐述了内河航道养护工程主要测量工作内容及测量仪器设备,并重点分析了测量技术要点,最后通过对新通扬运河航道疏浚工程的测量放样进行了分析。     

依靠科技进步再创天津港辉煌

天津港位于华北平原海河入海口,处于京津城市带和环渤海经济圈的交汇点,是环渤海中与华北、西北等内陆地区距离最短的港口,是首都北京和天津市的海上门户,也是亚欧大陆桥的起点之一,背靠三北,面向东亚。 天津港是中国最大的人工港,由海港和河港两部分组成,港区现有陆域面积37平方公里,港口陆域规划面积80平方公里,航道为10万吨级,15万吨级航道正在建设中。天津港     

内河电子航道图数据交换技术研究

基于内河电子航道图相关标准与规范,开展数据交换技术研究,通过数据交换模型建立、基础数据与过程数据分层、分类与编码设计,在统一的数据处理平台下实现数据交换过程,为内河电子航道图数据组织、交换与应用提供有效的方法和手段,促进内河航道空间数据资源共享与信息交换。     

江苏辐射沙洲小庙洪水道深水航道冲淤观测分析

吕四10万吨级进港航道为江苏辐射沙洲首条人工开挖深水航道,关于其建设环境、冲淤特点的研究分析对整个辐射沙洲建港都有重要意义。根据对吕四进港航道实测水文、泥沙及地形资料的分析表明:正常天气下航道竣工后月平均淤强约为0.05 m,淤积原因主要为航道疏浚后过水断面增加造成航槽内流速有所减小,使进入水体的浅滩细颗粒泥沙在航道内落淤。但由于深槽区域航道段潮流动力条件较强,泥沙难以大量落淤,从而使得航道整体淤强不大。     

浅谈内诃航道维护与管理

内河航道维护管理的重要任务是做好日常维护管理工作，保障航道及其设施符合标准和技术要求，做到保尺度．保航标、保畅通，既满足目前航运管理的需要，又为航运发辰创造条件。本文简要介绍了内河航道堆护与管理的重点内容，供同行业管理人员参考。     

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.