山东地质调查信息网络节点建设与示范应用

山东省地质调查院节点网络采用以太网星型拓扑结构,主干提供百兆带宽,完成了1栋楼4个楼层共70个信息点、1个中心机房的综合布线。部署了服务器、主干交换机、支交换机、路由器、防火墙、UPS等网络设备,以及网络操作系统、网络防病毒系统和网络数据服务系统等软件。该节点网络已通过了中国地质调查局组织的专家验收,实现了与国家地质骨干网的连接,满足了新形势下地质调查工作的信息传输、存储和共享服务的需求。     

起伏地形条件下固定点源测深法定量解释研究

采用有限元法对起伏地形下存在不均匀极化体时的多种地电断面进行了固定点源测深的正演数值模拟计算;提出并实现了在起伏地形下利用固定点源测深法资料作相对强度断面图、确定极化体空间位置的方法;通过对不同条件下数值模拟结果的定量解释计算和分析,证明了该方法的有效性;初步总结出了地形对定量解释结果的影响规律。     

Moving shoreline boundary condition for nearshore models

The paper develops and analyzes two fully nonlinear boundary conditions that incorporate the motion of the shoreline in nonlinear time domain nearshore models. A moving shoreline essentially means the computational domain is changing with the solution of the flow. The problem is solved in two steps. The first is to establish an equation that determines the motion of the shoreline based on the local momentum balance. The second is to develop and implement into a shoreline model the capability of accommodating a changing computational domain. The two models represent two different ways of addressing this step: one is to track the position of the shoreline in a fixed grid by establishing a special shoreline point which generally is not a fixed grid point. The second is by a coordinate transformation that maps the changing domain onto a fixed domain and solves the basic equations in the mapped domain. The two shoreline conditions are tested against three known solution for nonlinear shoreline motion. Two are the 1-D solutions to the nonlinear shallow water (NSW) equations by Carrier and Greenspan [J. Fluid Mech. 4 (1958) 97], one representing the response to a transient change in the offshore water level, the other the motion due to a periodic standing wave, both on slopes steep enough to allow full reflection. The third is the 2-D horizontal (2DH) computational solution by Zelt [Coast. Eng. 15 (1991) 205] for the run-up of a solitary wave on a cusped beach. In all cases, both models are shown to behave well and give high accuracy results for suitably chosen grid and time spacings.     

Structural Analysis of Platforms with the Effect of Joint Flexibility

- A modified space beam element is presented in this paper to consider the local joint flexibility of T, Y tubular joints subjected to axial forces and in- plane bending moments for analysis of platforms. Two numerical examples are shown to verify the efficiency and validity of the method presented here.     

基于改进聚类分裂的动态R-树实现方法

在R*-树的构建过程中引入聚类技术能够有效地提高索引的性能,传统的k-means聚类算法对初始值非常敏感,聚类过程较为复杂。基于此,文中提出一种改进聚类分裂的动态R*-树实现方法,在节点分裂的过程中引进聚类技术,对R*-树的基本结构加以改进,从而获得动态的结构重组。实验表明,动态R*-树以略高的构建开销换取较高的查询效率,大幅度提高索引树的空间利用率,在批量数据动态加载和处理等方面具有较高的实用价值。     

Experimental investigation of pressure distribution on a cylinder due to the wave diffraction in a finite water depth

The experimental investigations on the pressure distribution around a large vertical cylinder fixed on a wave channel, piercing the free surface and subjected to regular waves have been carried out. Recently, considerable advances have been made in the development of analytical techniques for studying non-linear wave loading phenomena on large structures. However, there is a lack of high quality experimental data that may be used for validating the analytical and numerical solutions obtained. This paper describes the design and execution of an experiment conducted at the Hydraulics Laboratory in the Civil Engineering Department of the Istanbul Technical University. Experimental measurements of pressures at different locations are presented including comparisons with the computational results. This study showed that the experimental and computational results generally exhibited better correlation, however, the measured pressure values diverged from the computational results while approaching the free surface.     

“一带一路”倡议下中国与重要节点地区的贸易格局及影响因素--以外高加索国家为例

外高加索国家地处欧亚十字路口,是古丝绸之路上的重要国家,也是“一带一路”的核心节点,区位战略意义重大。该文分析了外高加索三国自1991年独立以来中国与其贸易发展历程,借助HM指数和贸易互补性指数,从贸易总体格局和贸易商品特征两个角度分析双向贸易关系,并探究了影响其贸易发展的因素。结果表明:1)中国与外高加索三国长期保持贸易往来,贸易总额呈波动攀升趋势,阶段性特征明显;贸易差额起伏变化,整体长期维持贸易顺差状态;外高加索三国对中国的贸易依赖性显著大于中国对其依赖性。2)中国对外高加索三国出口商品互补性显著高于进口互补性,说明与作为中国进口商品来源国相比,外高加索三国作为中国商品的消费市场更具优势;中国对外高加索三国出口商品类型较为相似,结构呈集中与多元并存态势,主要出口商品逐步由资源、劳动密集型的低附加值商品向技术密集型等高附加值商品转变,而中国自外高加索三国进口的商品类型虽有所扩展,但主要类型仍较为单一,高度集中于未加工或半加工类资源型商品。3)地理距离、政局稳定性、产业结构、地缘关系、贸易环境及便利性是影响中国与外高加索三国贸易发展的主要因素。     

京津冀城市群经济网络结构分析

分析京津冀城市群经济网络对京津冀协同发展具有重要的指导意义。从综合经济实力和交通联系2个方面分析了经济网络的节点与线路,采用社会网络分析法研究经济网络的结构,以剖析其经济网络空间结构的现状特征。研究结果表明,京津冀城市群的经济网络处于起步阶段,中部联系紧密区的经济网络最为紧密,南部联系稳定区的经济网络初具雏形,北部联系薄弱区的经济网络尚未形成。基于经济网络中存在的问题,提出优化经济网络的建议。     

三维前方交会在大型金属网架结构中的应用

探讨了三维前方交会法在大型无支撑金属网架结构屋面施工的质量监测方法,并对实测数据进行了分析,结果表明该方法保证施工质量,达到设计要求,为今后的安全运营提供了可靠的依据。同时为大型无支撑建筑屋顶的变形监测提供了一种测量监测依据。     

基于GIS的城郊物流规划

指明了城郊物流的特殊性和规划的基本要求,明确了可用于城郊物流规划中的G IS技术。采用G IS手段,制作了区位图,界定了城郊的性质,展现了本区的空间结构、交通体系和物流现状,结合模型分析预测出物流需求。重点探讨了3级物流结点的体系架构,阐述了各级结点的规划依据,设计了对应的算法,定位了物流园区、物流中心、配送中心的具体位置;以上位规划原则和可视化分析,提出对内、对外物流通道建设方案。