排序方式: 共有56条查询结果,搜索用时 15 毫秒
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实现资源信息GIS辅助决策系统方案的探讨 总被引:1,自引:0,他引:1
GIS技术和网络技术的发展,为资源信息海量数据管理、资源信息共享的社会化服务和综合利用提供了技术保障,建立一个以国家资源信息基础数据库建设为依托的,集海量资源信息管理、查询、应用、服务为一体的计算机应用系统,对全国或区域性资源信息进行管理和监控,提高处理效率,为多尺度、多类型的资源信息提供海量存储工具,为资源评价多目标综合分析和管理提供网络操作对资源信息的空间特征,阐述资源信息GIS系统运行机制、空间数据库数据模型、专业空间分析GIS集成技术、资源信息可视化的实现方案。 相似文献
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构造-地貌-气候耦合是现代地球系统科学研究的热点之一。大量地质事实表明,构造、地貌、气候与地质灾害的发生密切相关,而三者的阶段性耦合,即地文期-构造节律-气候旋回耦合,在很大程度上决定了地质灾害在时间分布上的群发和空间上的群集。从地文期-构造节律-气候旋回的关系及耦合作用的分析入手,通过地文期、构造节律、气候旋回与地质灾害的关系论述,建立了地文期、构造节律、气候旋回与地质灾害的耦合关系模式。依据现有资料,对三峡地区滑坡的群(高)发与地文期、构造、气候的耦合关系进行了初步分析,并就如何加强这方面的研究进行了讨论。 相似文献
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通过对三因素统计法数学模型的改进,使之能够适用于矿产定位和资源定量预测.并用改进的理论依据与特征分析对比,预测效果相似,其方法简单、易懂. 相似文献
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科克苏-穹库什太古生代构造-岩浆作用及其对西南天山造山时代的约束 总被引:3,自引:3,他引:3
天山造山带是古生代多期碰撞增生作用的产物,其确切的造山时代是当前争议较多的热点问题。分布在西南天山的科克苏-穹库什太剖面经历了复杂的构造变形,最明显的两期变形事件分别为朝北的推覆作用和 NE-SW 韧性走滑作用。本剖面可分为伊犁岩浆岛弧、伊犁结晶基底、高压变质杂岩三个岩石-构造单元。野外可见黑云母花岗闪长岩侵入到绿片岩相变质岩中,岩脉切穿绿片岩中面理构造。通过锆石 U-Pb LA-ICPMS 测年,科克苏剖面钾长花岗岩的年龄为341±6Ma 和338±8Ma,穹库什太黑云母花岗闪长岩的年龄为313±4Ma。其中,花岗闪长岩发生了黑云母定向排列,通过对黑云母进行~(40)Ar/~(39)Ar 测年,获得坪年龄为263.4±0.6Ma,表明该花岗闪长岩受过后期热事件的干扰。地球化学分析表明,黑云母花岗闪长岩属于钙碱性系列,Nb 和 Ta 含量低而 Rb,Ba 和 Th 含量很高,与俯冲作用有关的岛弧岩浆岩地球化学组成非常相似。结合前人对该地区高压变质岩、花岗岩和火山岩的研究成果,本文提出,西南天山俯冲-碰撞造山作用发生在晚石炭世之前,研究区后碰撞区域走滑作用标志着西南天山碰撞造山作用在二叠纪之前全部结束。 相似文献
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To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussées. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on re... 相似文献
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IS THE GRENVILLE PROVINCE AN ANCIENT ANALOGUE OF THE HIMALAYAN BELT?1 All埁greCJ ,2 4others.StructureandevolutionoftheHimalayan Tibetorogenicbelt[J].Nature ,1984,30 7:17~ 2 2 .
2 BurgJP ,DavyP ,MartinodJ .Shorteningofanaloguemodelsofthecontinentallithosphere :Newhypothesisforthefor mationoftheTibetanplateau[J].Tectonics ,1994,13:475~ 483.
3 BurtmanVS ,MolnarP .GeologicalandgeophysicalevidencefordeepsubductionofcontinentalcrustbeneaththePamir[C]… 相似文献
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Lagring R Degraer S de Montpellier G Jacques T Van Roy W Schallier R 《Marine pollution bulletin》2012,64(3):644-652
Over the years many policy measures have been taken to prevent illegal oil discharges from ships, like the MARPOL 73/78 Convention (1983) and the Bonn Agreement (1969/1983). However, the number of discharges remained high, leading to chronic oiling of seabirds and sensitive coastlines, therefore further measures were taken. The aim of this study is to quantify the effectiveness of two key legislative regulations: the IMO-designation of the North Sea as MARPOL Special Area which took effect in 1999, and the adoption of the EU Directive on Port Reception Facilities in 2000. Under study is the heavily navigated Belgian Surveillance Area, monitored since 1991, characterised by shallow waters with ecologically important sandbanks. The aerial surveillance data from 1991 to 2010 show a stepwise decrease in ship-source oil pollution. Three time periods can be distinguished with two turning points coinciding with the actual implementation of these key legislative measures, confirming their effectiveness. 相似文献
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