3G技术4D集成在云南边防信息系统中的应用   总被引：2，自引：1，他引：2  

李圣权  胡鹏  杨传勇  吴艳兰 《测绘信息与工程》2004,29(3):37-39

讨论了 4D集成的空间数学框架、空间与非空间数据库组织方式、数据模型设计以及 3G技术结合的可能性与可行性 ,并介绍了其在云南边防信息系统中的集成及应用情况。  相似文献   

GML空问数据存储映射模型研究     

李俊关佶红  李玉珍 《武汉大学学报(信息科学版)》2004,29(12):1071-1074

提出了一种将GML文档存储到空间数据库的存储映射模型G2SDB ,同时通过定义边表 ,保留GML文档的部分结构信息 ,有利于处理GML查询中的路径表达式 ,提高查询操作的效率 ,也有利于GML文档的重构。  相似文献   

Isotope Dilution MC-ICP-MS Rare Earth Element Analysis of Geochemical Reference Materials NIST SRM 610, NIST SRM 612, NIST SRM 614, BHVO-2G, BHVO-2, BCR-2G, JB-2, WS-E, W-2, AGV-1 and AGV-2     

Adam J.R. Kent  Benjamin Jacobsen  David W. Peate  Tod E. Waight  Joel A. Baker 《Geostandards and Geoanalytical Research》2004,28(3):417-429

We present data for the concentrations of eleven rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb, Lu) in eleven international geochemical reference materials obtained by isotope dilution multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). We have analysed both rock powders and synthetic silicate glasses, and the latter provide precise data to support the use of these as reference materials for in situ trace element determination techniques. Our data also provide precise measurements of the abundance of mono-isotopic Pr in both glasses and powders, which allows more accurate constraints on the anomalous redox-related behaviour of Ce during geochemical processes. All materials were analysed in replicate providing data that typically reproduce to better than one percent. Sm/Nd ratios in all these materials also reproduce to better than 0.2% and are accurate to < 0.2% and can thus be used as calibrants for Sm-Nd geochronology. Our analyses agree well with existing data on these reference materials. In particular, for NIST SRM 610, USGS BHVO-2, AGV-1 and AGV-2, our measured REE abundances are typically within < 2% (and mostly 1%) of REE concentrations previously determined by isotope dilution analysis and thermal ionisation mass spectrometry, consistent with the higher degree of precision and accuracy obtained from isotope dilution techniques. Close agreement of results between basaltic glass reference materials USGS BHVO-2G and BCR-2G and the BHVO-2 and BCR-2 powders from which they were created suggests that little fractionation, concentration or dilution of REE contents occurred during glass manufacture.  相似文献   

基于地学G~4I系统的元数据分类方法   总被引：1，自引：0，他引：1  

韩聪  路来君 《吉林大学学报(地球科学版)》2006,(Z1)

以实现空间数据的标准化为前提,对空间数据库中元数据管理系统的作用和分类原则进行了探讨,指出了传统的分类方法对于以矿产资源预测为目标的地学系统而言存在着弊端。需要结合矿产资源预测的特点,对空间数据库建设中元数据的分类原则进行补充,提出了面向客户应用即按矿产资源预测目标进行分类,实现对空间数据查询的高效利用。该方法可以在地学G4I系统中得以实施和应用。  相似文献   

Analysis of oil lens removal by extraction through a seepage face     

M.I.J. van Dijke  S.E.A.T.M. van der Zee 《Computational Geosciences》1998,2(1):47-72

Removal of LNAPL (oil) from an aquifer is described using a multiphase flow model. At the well boundary seepage face conditions are imposed. These conditions are implemented in a numerical model and withdrawal in a twodimensional domain is simulated for two different geometries of the oil lens and for varied values of the physical parameters. Assuming vertical equilibrium, the oil flow equation is reduced by vertical integration. The well boundary condition is approximated by imposing zero oil lens thickness. Similarity solutions of the reduced equations for the two geometries show good agreement with the numerical results in most cases.  相似文献   

An alternative explanation of the EUV spectrum of the white dwarf G191–B2B invoking a stratified H+He envelope including heavier elements     

M. A. Barstow  & I. Hubeny 《Monthly notices of the Royal Astronomical Society》1998,299(2):379-388

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Distance determination and low-resolution spectroscopy of the planetary nebula M1-79     

W. Saurer 《Monthly notices of the Royal Astronomical Society》1998,299(1):51-59

In this paper we present the first individual distance to the Galactic planetary nebula (PN) M1-79 determined using the reddening–distance method. Our result is 2.7 ± 0.9 pc (i.e. an accuracy of ≈ 30 per cent). By means of optical low-resolution spectroscopy spanning a usable range of ≈ 3650–7100 Å, the chemical composition of this PN is studied. Elemental abundances are given for O, N, and Ne, along with ionic abundances for several ions for three different regions within the nebula. The ionic abundances can be attributed to the effects of ionization stratification. There is no evidence for internal variations of O and N. From its chemical composition, morphology and kinematics, M1-79 is most probably a type I PN.  相似文献   

地球节律的成因   总被引：1，自引：0，他引：1  

杨学祥  王成金  郑文瑞  刘淑琴 《地学前缘》1997,(Z2)

地球节律主要受地球内部能量间歇性的释放所控制。旋转系统有不同于非旋转系统的位能、热能和旋转能的相互转换方式。在重力分异和热对流过程中，地核不仅有巨量热能，而且有巨量的旋转能和放射性蜕变能。这是地球能量释放的内因。天文因素使地球内核周期性地南北振动，使地球轨道、体积，形状、自转速度、公转速度和差异旋转状态周期性地变化。这是地球能量间歇性释放的外因。对作差异旋转的内核而言，万有引力常数Ｇ的变化可以改变太阳辐射量和太阳系体积，影响核幔的角动量交换和地壳地幔容积，造成热幔柱的形成与喷发，控制了核幔边界的能量交换过程。这是天文周期与地质旋回一一对应的原因，也是地球节律产生的根本原因。这使人们可以从天文周期预测地质变动。  相似文献   

吉林省1∶20万数字地质图空间数据库的应用     

梁伟杰  庄毓敏 《吉林地质》2003,(1)

1∶20万数字地质图空间数据库中存在着大量的地质矿产信息,有效地利用这些数据进行空间分析,研究矿产与控矿因素之间的关系,总结找矿地质特征,利用GIS系统可非常快捷、方便的在成矿预测工作中起到十分重要的作用。  相似文献   

G308、YJ2.1R硬质合金在复合钎头上的应用          下载免费PDF全文

张汉斌  童志伟  张国榉 《探矿工程》2002,(2):24-27

介绍了G308、YJ2．1R新型凿岩硬质合金的物理机械性能，并就镶嵌该2 种硬质合金的飞龙φ40、φ42－4PIC锥体连接复合钎头，与我国目前广泛流行的镶YG11C硬质合金片的φ40、42mm“一”字形钎头在同一场的进行了对比应用。  相似文献