基于弹性薄板的不规则采动地表沉陷预计模型

文章借助弹性薄板理论,建立地表沉陷变形的预计模型,并给出任意点地表变形的预计表达式。针对地下开挖空间形状的不规则性,推导出了水平空间、倾斜面空间以及不规则开挖空间：椭圆抛物面空间、二次柱面空间以及二次曲面空间地表沉陷的预计公式。本文的研究结果对该类开采沉陷问题的研究具有一定指导意义。     

一种基于似最小生成树的空间聚类算法

根据空间邻近目标的距离变化情况,定义了边长变化因子概念,给出了一种似最小生成树的构建方法。在此基础上,提出了一种基于似最小生成树的空间聚类算法。模拟数据和实际数据分析发现,基于似最小生成树的空间算法能够发现任意形状的空间簇和异常点,并能够很好地适应空间数据分布不均匀的特点。通过与经典的DBSCAN算法比较,发现基于似最小生成树的空间聚类算法比DBSCAN算法更具有实用性。     

Sandy gravel accumulation in a fluvial environment

Particle size, pebble shape, pebble fabric, discharge and flow velocity data are used to introduce a model of sandy gravel formation in Welsh gravel-bed rivers. The development of contact-imbrication of the typically very bladed and very platy cobbles and larger pebbles subsequently acts to significantly affect the depositional modes and patterns of small pebbles and sand particles. An important distinction is drawn between sand deposition, which can occur at or below the bed surface, and pebble and cobble deposition, which is merely a surface phenomenon.     

多尺度空间线状实体形状相似关系的表达与度量

本文对空间数据多尺度表达中线状实体综合前后的形状相似性进行了描述、分析和研究。通过调查统计,得出了衡量线状实体形状相似程度的两个重要参量SIMⅠ、SIMⅡ,基于这两个参量给出了空间线状实体形状相似性的定义以及在不同尺度下线状实体形状相似性的度量方法,并用实例进行验证。为空间数据多尺度表达时线状实体的形状表达提供了一种分析和评价手段。     

车贝雪夫多项式约简算法的研究

解释了车贝雪夫多项式化整计算通用算法中关于化整后的车贝雪夫多项式约简处理的技术原理,给出了一种可快速实现多项式约简处理的实用求算方法。     

基于视觉的水雷目标识别方法研究

水下目标识别一直是目标识别领域的研究热点,为此,以水雷目标识别为需求背景提出了一种基于视觉的水雷目标识别方法。该方法从水雷目标形状的本质特征出发,根据几何矩的物理意义,结合区域特征和边界特征构造了三个适合于水雷目标形状描述子,采用阈值判决的方法,实现水雷目标的识别。实验结果表明,该方法比基于不变矩的方法识别率更高,具有较好的稳定性,尤其适用于水下特定形状的目标识别和目标受到部分遮挡的情况。其中水下图像处理和特征的定义方法对水下目标识别具有指导和借鉴意义。     

多尺度地理空间线状目标形状相似性的度量

本文研究了多尺度地理空间线状目标相似关系的表达与度量问题.基于Douglas-Peucker算法,通过对线状目标形状的分析,从几何学的角度,给出了衡量基本图形中折线与线段之间形状相似度的两个重要参量.按照图形特征,利用分类讨论的方法,建立了多尺度地理空间线状目标形状相似性的计算模型.最后通过实例的计算验证了该度量方法的可行性.     

COMPARISON OF AEROSOL CHARACTERISTICS OVER MAINLAND OF CHINA AND WESTERN PACIFIC AND ITS LONG-RANGE TRANSPORT

Based on the aerosol data obtained at Shangdianzi regional background monitoring station together withthe air trajectory analysis,the chemical constituents of the aerosol from the different sources are discussed andcompared with the aerosol samples collected over the western Pacific.The results show that the relative massconcentrations of the crustal and pollutant elements in the aerosol collected over the ocean are higher than thosebeing observed at Shangdianzi in particle size above 4.7 μm and below 0.65μm in diameter.The variationsof the enrichment factors of these elements in marine aerosol with particle size are different from those in shang-dianzi's samples.The former enrichment factors are evidently higher than the latter above 1.1 μm in diameter.On the basis of the comparative research,the long-range transport processes of aerosol particles are discussed.     

澳大利亚西部哈默斯利铁成矿省BIF富铁矿的成矿特征与控矿因素

澳大利亚西部哈默斯利铁成矿省含有世界级高品位的赤铁矿体。主要铁矿床包括芒特维尔贝克、汤姆普莱斯山、帕拉伯杜等,它们均产于元古宙早期布罗克曼BIF型含铁建造中。高品住铁矿体的空间分布明显受到元古宙区域隆起和拉张环境下形成的古老正断层系统的控制。该成矿省高品位铁矿层的形成可分为3个阶段：第1阶段为深层阶段,该阶段硅从含铁建造中淋滤出来,留下薄层状富含铁氧化物、碳酸盐岩、硅酸镁和磷灰石的残余物;第2阶段为深部大气水氧化阶段,该阶段含铁建造的磁铁矿-菱镁矿组合被氧化为赤铁矿-铁白云石,并以发育假象赤铁矿为特征;第3阶段为浅层风化作用。通过对成矿特征和成矿模式的总结,认为成矿时代、断层、褶皱等构造特征及流体和表生风化作用是富铁矿床形成的主要控矿因素。     

Using numerical modelling to evaluate tsunami hazard near the Kuril Island

A sequence of computer experiments is used to study questions concerning the tsunami problem as a quantitative estimate of tsunami danger, detailed geographical tsunami classification, determination of the parameters of critical tsunami waves, and the conditions of their development. We call a wave critical, if its impact on the coast is most hazardous.Using the Middle Kuril Island as an example, we present the results of a computer experiment which includes determining the wavefields on the shelf and estimating the effects connected with the deep-water Bussol and Diana Straits.Numerical simulation of tsunami waves of different sources permits the assessment of the extent of tsunami danger in different areas of the coastal zone of Simushir Island, depending on the location of the focus zone and their geometry.The major singularities of the wavefield arise in the zones of the deep-water straits. The distribution of the amplification factors is determined by both the global parameters of the wavefields and the local properties of individual harbours. The results obtained for a particular harbour in the northern part of Simushir Island, formed the basis for the quantitative estimate of tsunami danger for this area.