GIS空间目标的广义Hausdorff距离模型

分析了GIS中常用的空间距离度量及其存在的问题,这些距离度量没有顾及空间目标的整体形状、位置分布等特征。基于此,引入了Hausdorff距离的概念,给出了Hausdorff距离的计算方法,分析指出了Hausdorff距离容易受空间目标局部几何形状的影响。进而从统计学的角度分析了现有的距离度量并不能有效地表达空间目标间距离的整体分布,并提出了一种广义Hausdorff距离模型,这种距离模型能够度量空间目标间距离分布的中心趋势和离散度。实际算例证明了此模型在GIS环境下的实现方法。     

中国北方东部沙质荒漠化的地学观

中国北方东部的土地荒漠化主要受新构造运动以来的构造-沉积特征、青藏高原隆升所引起的全球气候变化、尤其是亚洲季风等地质背景控制。北方东部沙质荒漠化区域地质分类,按其成因可分为就地起沙型、风沙型和土地粗粒化型等3种类型。其中,就地起沙型沙质荒漠化主要分布在东部毛乌素、科尔沁、浑善达克、呼伦贝尔等沙地内,流经这些沙地的古河道,广泛发育河湖相砂质沉积物以及以砂质沉积物为母质的土壤分布区。风沙型沙质荒漠化主要分布在上述沙地的边缘地带,如毛乌素沙地以南的覆沙黄土区等。土地粗化主要分布在内蒙古锡林郭勒草原-河北坝上草原,其土壤类型多为含砾沙土,其土壤母质为基岩风化壳、残坡积或冲洪积物。荒漠化发展趋势上,尽管就地起沙型沙质荒漠化在毛乌素、科尔沁和浑善达克沙地的局部地区均有所逆转,但总体上,在北方广大地区,主要以地表土壤粗化为主的荒漠化和风沙型荒漠化等均有不同程度的扩大。上述不同类型的沙质荒漠化,总体上受地质背景控制。其中,第四纪以来的构造-沉积特征控制着不同类型荒漠化的区域分布,气候变化控制着荒漠化的进程,人类活动则是在上述背景的基础上进行。     

青藏高原东南部第四纪右旋剪切运动

通过对藏东南嘉黎断裂和滇西北断裂实地考察研究，表明青藏高原南部不存在统一的边界走滑断裂。嘉黎断裂的西段位于青藏高原南部，是一个南北挤压作用下的东西向伸展构造区，发育近南北向的地堑系，嘉黎断裂西段是这些地堑之间的转换断层，具有较高的右旋走滑速率。滇西北断裂与红河断裂构成川滇菱形块体的西南边界，该块体具有向东南逃逸和顺时针旋转运动。     

山东地区水化学短临跟踪标志体系的研究

在系统整理山东地区水化学观测资料的基础上,对山东菏泽５．９级地震、苍山５．２级地震及大同６．１级地震和南黄海５．３级地震前的地震异常特征进行了分析和总结。认为水化学多组分的同步异常变化,同震源应力场孕育过程,多组分的同步异常变化,具有统一的物理力学机制,是震前源兆异常的重要标志,这些异常基本同步出现,相互印证,增强了异常的可信度,为短临异常的判定提供了较为充分的依据。某一井孔水化学多发出现同步异常     

Study on financial loss and its adjustment in earthquake insurance

Introduction Earthquake often brings large catastrophe to the mankind, especially in recent years when a large number of destructive earthquakes occur in the whole globe, which have caused tremendous casualties and losses to the people. Obviously, it is not very reasonable to make up financial losses and carry out post-seismic reconstruction by the government only for such kind of huge earth- quake losses. Therefore, as an effective measure to raise fund and make up financial losses, earth- qu…     

The Impact of Aqueous Medium on Gas Yields and Kinetic Behaviors of Hydrogen Isotope Fractionation during Organic Matter Thermal Degradation

In order to recognize the impact of aqueous medium on gas yields and the kinetic behaviors of hydrogen isotope fractionation during organic matter thermal degradation, the gold tube apparatus was used to conduct thermal simulation experiments by mixing the nC18 with the water of different properties and proportions. The yields of natural gas components, the relation among hydrogen isotope composition of each component and the experimental temperatures vs. heating rates have been obtained, and the results indicate that under the higher temperature conditions, the hydrous experiment has obvious impact on gas yields, such as when more water is added, higher amounts of hydrocarbon gas and H2 are yielded, and the existence of water obviously prolongs the temperature interval with the existence of heavy hydrocarbon gas. It also shows that the hydrogen isotope of hydrocarbon gas generated by the hydrous experiment is obviously lighter than that generated by the anhydrous experiment, and with the increasing amount of added water, the δD value of hydrocarbon gas gradually decreases. Compared with gas yields, the variation of δD value is more sensitive to aqueous medium in the thermal simulation experiment. However, compared with the amount of the added water, the aqueous medium property has smaller impact on the gas yields, which still shows the inherit effect on hydrogen isotope composition of aqueous medium. Through the model simulation and the isotope fractionation behavior analysis, it is validated that the hydrogen isotope fractionation process can be well described by the chemical kinetic model. The difference of reaction fraction of normal methane and D-containing methane is large, corresponding to the same activation energy. The content of normal methane is obviously higher in the part with lower activation energy, while the content of D-containing methane is higher in the part with higher activation energy. Therefore, it will result in larger hydrogen isotope fractionation amplitude, and the δD values will be more sensitive to the variation of maturity. Meanwhile, the average activation energy of methane generation from nC18 in the hydrous experiment is higher than that in the anhydrous experiment, and the greater amount of added water, the larger the average activation energy of methane generation reaction. This has laid foundation for its exploratory application in the study of gas reservoir forming history and the gas-source correlation, which indicates the research and application prospects in this orientation.     

Thermal simulation of basic volcanic fluid influence on different source rocks

Based on thermal simulation experiment, interactions between volcanic fluids and source rocks were studied. Gas generations in the dry system and fluid system under different temperatures were analyzed. The results showed that the various types of source rocks are similar in composition, containing gaseous C1-C5 hydrocarbons, H2 and CO2 whose gas yields increase with increasing temperature. The gas yield of source rocks of type I is the high- est, followed by type II, and that of source rocks of type III is the lowest, indicating that the yield of hydrocarbon gases is related to their hydrocarbon generating potential. Although the generating potential of type III is the lowest, it can still be regarded as a useful gas source when it is buried deeply enough. The basic volcanic fluid restrains the generation of gaseous hydrocarbons in different types of source rocks, but promotes the generation of inorganic gases.     

基于实际材料图的三维断层模型动态构建方法

三维地质模型是地质调查信息表达从传统二维平面向三维空间转变的一次重大突破。中国正在开展的三维地质填图作为国家的重要基础地质调查工作部署,将调查与研究相结合,在推动三维地质建模从研究走向实践具有重大意义。三维地质填图过程中如何准确、快速地构建三维断层模型是其中的关键点及难点。通过对数字填图过程不同阶段数据源的分析,详细分析了实际材料图建立断层数据以及与野外路线数据的关系映射规则,提出并实现了由线及面的断层模型构建方法。该方法强调断层模型构建与业务流程的一致性、动态性和快速性,构建模型的数据源始于野外第一手资料,充分利用填图业务过程中不同阶段数据的关联、约束与继承关系,能够满足在填图过程中根据地质认识的深入快速、动态地重构模型的要求,同时也可根据直观的三维断层模型时时验证地质连图的合理性。算法已在实际野外三维地质填图工作进行了多次实验,获得较好的成果。实验说明,基于实际材料图的三维断层模型构建方法与实际业务过程同步,具有操作便捷性,可直接应用于三维地质填图的实际工作要求。     

沿海与内陆地下卤水对比分析

分析对比我国滨海与内陆地下卤水的分布、成因及其水文地球化学特征，指出不同成因的地下卤水具有不同的水质．     

Tectonique transpressive en terre Adélie au Paléoprotérozoı̈que (Est Antarctique)Palaeoproterozoic transpression in Terre Adélie (East Antarctica)

The Palaeoproterozoic units of Terre Adélie show two types of structural domains associated with HT–LP metamorphic conditions: domes and NS–N340° striking vertical shear zones. Shear zones reflect dextral transpressive motions. Domes reflect sub-vertical shortening and principal stretching subparallel to shear zones. They could partly result from longitudinal flow coeval with transpression. Deformations are comparable to those described along the eastern and western boundaries of the Archean Gawler Craton (South-East Australia), which underlines the continuity between these two areas before opening of the Austral Ocean. To cite this article: A. Pelletier et al., C. R. Geoscience 334 (2002) 505–511.