Analysis of spatial clustering optimization

Spatial clustering is widely used in many fields such as WSN (Wireless Sensor Networks), web clustering, remote sensing and so on for discovery groups and to identify interesting distributions in the underlying database. By discussing the relationships between the optimal clustering and the initial seeds, a clustering validity index and the principle of seeking initial seeds were proposed, and on this principle we recommend an initial seed-seeking strategy: SSPG (Single-Shortest-Path Graph). With SSPG strategy used in clustering algorithms, we find that the result of clustering is optimized with more probability. At the end of the paper, according to the combinational theory of optimization, a method is proposed to obtain optimal reference k value of cluster number, and is proven to be efficient.     

硅酸盐熔体包裹体均匀化过程的动力学性质

硅酸盐熔体包裹体的研究,和以模拟实验为主的实验岩石学,实验矿物学一样,已经成为现代岩浆岩石学,尤其是理论岩浆岩石学研究的一个必不可少的组成部分。均匀化测温研究,是硅酸盐熔体包裹体研究的一个重要组成部分。其方法是对于呈封闭系统的硅酸盐熔体包裹体进行加热,在反方向上,再造这些包裹体从结晶到熔融的所有阶段,直至其完全均匀化,也就是恢复到它们被生长着的矿物包含、捕获时的状态,借以测量矿物近液相线或固相线的结晶温度。     

Mid-Late Neoproterozoic rift-related volcanic rocks in China: Geological records of rifting and break-up of Rodinia

Early Cambrian and Mid-Late Neoproterozoic volcanic rocks in China are widespread on several Precambrian continental blocks,which had aggregated to form part of the Rodinia supercontinent by ca.900 Ma....     

The potential of contribution of mangrove-derived organic matter in intertidal sediments as a proxy of mangrove development in the northern Beibu Gulf

University of Maryland, College Park     

The nonlinear time lag multivariable grey prediction model based on interval grey numbers and its application

Natural Hazards - The linear relationship of the original grey prediction model is too single, and the original grey prediction model does not consider the time delay of the effect of the current...     

2005年1月18日乳山ML4.3地震序列

对2005年1月18日乳山ML4.3地震序列特征及烈度分布进行了介绍, 认为乳山ML4.3地震序列是一次能量衰减较快、频度起伏衰减的主-余型地震序列, 序列本身不具有明显的前兆意义.     

三门湾表层沉积物黏土矿物特征及来源分析

利用XRD方法分析了三门湾表层沉积物中的黏土矿物组成和含量,结合沉积物粒径趋势分析及长江和三门湾流域中小河流的黏土矿物组合特征,开展了三门湾沉积物的来源分析。结果表明,三门湾表层沉积物中黏土矿物以伊利石为主,其次为高岭石和绿泥石,蒙脱石含量最低。其中,伊利石高值区位于海湾中部,高岭石和绿泥石高值区分布在港汊附近,蒙脱石则在近岸呈斑块状分布。三门湾现代表层沉积物主要来源于长江入海物质,海湾周边短源山溪性河流带来的物质仅影响了河口近岸区。     

A micro–macro investigation of the capillary strengthening effect in wet granular materials

Wet granular materials are three-dimensionally simulated by the discrete element method with water bridges incorporated between particles. The water bridges are simplified as toroidal shapes, and the matric suction is constantly maintained in the material. A comparison with experimental tests in the literature indicates that the toroidal shape approximation may be one of the best choices with high practicability and decent accuracy. Mechanical behaviours of wet granular materials are studied by triaxial tests. Effects of particle size distributions and void ratios are investigated systematically in this study. The hydraulic limit of the pendular state is also discussed. It gives the capillary cohesion function which is not only determined by the degree of saturation but also positively correlated to relative density and particle size polydispersity and inversely proportional to mean particle size. Furthermore, the capillary strengthening effect is also analysed microscopically in aid of the Stress–Force–Fabric relationship, mainly in fabric anisotropy, coordination number and stress transmission pattern, which revealed the micro-mechanisms of the additional effective stress induced by capillary effect.     

我国断层气测量在地震科学研究中的应用现状

氢气被认为是反应断裂活动最灵敏的地球化学组分之一。研究影响断裂带氢浓度动态变化的主要因素,是科学分析断裂带氢与构造活动关系的基础工作。本文基于河南内乡马山口断层气氢气浓度与辅助测项的连续观测资料,重点分析了氢浓度变化与地温、气温、气压的相关关系,确定了主要影响因素。结果表明,氢气浓度日变化极值介于气温和地温之间,极值点靠近地温一侧。使用逐步回归方法分析进一步证明,地温、温度对氢气浓度均有影响,但地温影响更显著,气压影响不显著。总体来讲,氢浓度会受到地温和气温的双重影响,但与地温关系更为密切。     

公路资产数据库的设计与可视化研究

公路资产包括基础设施及其附属设施等有形资产和相关的设备资源、人力调配等无形资产两部分。实现公路资产的数字化管理是数字交通、智慧交通的基础。本文以辽宁某县为实验区,研究提出了公路资产数据的分类体系及数据标准,基于地理信息系统(GIS)技术构建了公路资产数据库,实现了公路资产数据的可视化表达与管理,为该县公路的信息化管理奠定了坚实的地理空间数据基础,具有推广应用价值。