陕西勉略宁三角区基本地质组成及演化   总被引：5，自引：0，他引：5  

王根宝  崔继岗 《西北地质科学》1996,17(2):11-17

陕西勉略宁三角区发育４大套不同构造背景下所形成的岩石组合，表明区内经历了晚太古结晶基底与早中元古浅变质火山岩过渡基底形成、晚元古一早古生代扬子大陆边缘演化、勉略海槽演化及陆内造山４个大的复杂演化阶段，最终形成今日之基本构造格局与地质面貌．  相似文献   

深埋砂层取原状样技术研究          下载免费PDF全文

马明  祝德生  孙昕  岳雪波  刘祯荣 《探矿工程》1996,(5):42-45

针对砂（土）样易扰动的特点，研制了ＨＹＳ－１型单动回转压入式取砂器，并从钻取，退样，试样制作的全过程各工序对取样质量进行控制，解决了南水北调和三峡工程中深埋砂层取原状样的技术难题。  相似文献   

Evolutionary Stages of the Earliest Skeletal Fauna and Division and Correlation of the Precambrian-Cambrian Boundary Strata     

Yue Zhao 《《地质学报》英文版》1988,62(3):233-248

Through an analysis of the earliest fossils in the Precambrian-Cambrian boundary beds in various parts ofthe world, especially in the Yangtze and Siberia platforms, the author has found that the evolution of the ea-rliest skeletal animals may be divided from older to younger into three stages. The first stage (theAnabarites-Protohertzina fauna) is represented by the Anabarites-Protohertzina zone of the Meishucunian Stagein the Yangtze platform and the A. trisulcatus and P. cristata zones of the Manykayn Stage in Siberia. The sec-ond stage (the earliest orthothecimorphid and mollusc fauna) is represented by the Paragloborilus-Siphogonuchites zone of the Meishucunian Stage and the Aldanocyathus sunnaginicus zone of the TommotianStage. The third stage (the earliest hyolithimorphid and lapworthellid fauna) is represented by the Sinosachiteszone of the Meishucunian Stage and the D.regularis and D.lenaicus zones of the Tommotian Stage. The threeevolutionary stages can be used as a criterion for worldwide correlation.  相似文献   

胶东旧店金矿构造控矿特征研究   总被引：1，自引：0，他引：1       下载免费PDF全文

岳石  赵寅震 《地质找矿论丛》1988,(2):38-46

通过对胶东旧店金矿床的构造及其演化特征和成矿作用的研究,说明构造活动释放能量导致了金的活化,构造的分布和差异性所产生的能量不均匀性是金元素迁移、沉积的动因,是控制金矿形成的主导因素。  相似文献   

Geotechnical Shallow-Burial Disposal of Low-level Radioactive Wastes in USA     

Yue Huiguo 《岩土力学》1985,6(1):101-106

In this paper the current state of disposal of low-level radioactive wastes in U.S.A. is briefly introduced, the existing problems and influence are presented, some geotechnical designs for shallow-burial disposal are suggested so as to improve the prevention of contamination.  相似文献   

梅雨锋暴雨的Q矢量定性分析   总被引：6，自引：3，他引：6       下载免费PDF全文

岳彩军  寿绍文  姚秀萍 《气象科学》2003,23(1):55-63

本文利用1991年7月5日20时－6日20时一次江淮梅雨锋暴雨过程实部资料，结合地面降水分析，定性地比较分析了准地转Q矢量、半地转Q矢量及湿Q矢量的诊断特性。结果表明，半地转Q矢量比准地转Q矢量优越。非地转Q矢量与湿Q矢量相差不大，都明显比半地转Q矢量及准地转Q矢量优越。准地转Q矢量表现最差；700hPa各Q矢量的辐合场较各自在850hPa及500hPa的相应场对降水的反映更好，尤其是700hPa非地转Q矢量及湿Q矢量辐合场与同时刻地面降水的发生有很好的对应关系；与降水对应的Q矢量的辐合场基本位于槽前及气旋的中、前方，这对台站实际业务预报工作有参考价值。  相似文献   

镇江地区雷暴日的时空分布及雷暴日异常多年的特征分析   总被引：7，自引：0，他引：7       下载免费PDF全文

吴志伟  王镇江  朱筱英  徐焱  岳一洲 《气象科学》2003,23(2):245-252

对1959—2000年镇江地区4个县市年雷暴活动日数时间序列进行EOF分析，并在此基础上，分析了它们的时空分布特征，并用合成分析研究了雷暴活动日数异常多年同期及前期的500hPa高空环流背景场先兆特征和赤道东太平洋海温异常情况，为雷电预报和防雷减灾工作提供有参考意义的结果。  相似文献   

混合GM(1,1)模型预报季节性时间序列精度的方法探讨   总被引：3，自引：0，他引：3  

王琪洁  邹峥嵘  彭悦 《现代测绘》2003,26(6):11-14

灰色系统已被成功用于工程、经济、物理控制等许多领域。然而在预报具有季节性的时间序列时，直接应用GM(1，1)灰色模型往往精度不高。因为GM(1，1)灰色模型只能反映时间序列的总体变化趋势，不能很好反映其季节性波动变化的具体特征。因此，作者提出运用“滑动平均去季节性波动”与GM(1，1)混合建模的方法预报具有季节特征的时间序列。并以水文地质系统中地下水位预报和安装在混凝土中的测缝计测得的建筑物形变量为一组时间序列，基于均方差、平均绝对误差和平均绝对百分误差三个精度准则，比较了此方法与其它灰色建模法的结果。结果表明，此方法不仅能反映时间序列的总体变化趋势，而且能客观反映其波动变化的具体特征，有效提高了预报精度，减少了建模的复杂度。  相似文献   

哈密地区一次大降水天气过程分析     

屠月青  李如琦 《沙漠与绿洲气象(新疆气象)》2003,26(3):13-15

对哈密2001年10月大降水天气过程的降水成因进行了分析，表明低空急流和上升运动是其形成的重要机制，同时在哈密地区大降水天气短期预报着眼点方面获得了一些有益的启示。  相似文献   

Detrital and pedogenic magnetic mineral phases in the loess/palaeosol sequence at Lingtai (Central Chinese Loess Plateau)     

S. Spassov  F. Heller  R. Kretzschmar  M. E. Evans  L. P. Yue  D. K. Nourgaliev 《Physics of the Earth and Planetary Interiors》2003,140(4):255-275

A detailed rock magnetic investigation of loess/palaeosol samples from the section at Lingtai on the central Chinese Loess Plateau (CLP) is presented. Thermal demagnetisation of isothermal remanent magnetisation (IRM) and Curie temperature measurements suggest the presence of magnetite, maghemite and hematite as remanence carrying components. Bulk and grain size fractionated samples have been analysed using coercivity spectra of remanence acquisition/demagnetisation curves, which identify four main remanence carriers in different grain size fractions of loesses and palaeosols. A linear source mixing model quantifies the contribution of the four components which have been experimentally derived as dominating endmembers in specific grain size fractions. Up to two thirds of the total IRM of the palaeosols are due to slightly oxidised pedogenic magnetite. Two detrital components dominate up to 90% of the IRM of the loess samples and are ascribed to maghemite of different oxidation degree. Detrital hematite is present in all samples and contributes up to 10% of the IRM. The iron content of the grain size fractions gives evidence that iron in pedogenically grown remanence carriers does not originate from the detrital iron oxides, but rather from iron-bearing clays and mafic silicates. The contribution of pedogenic magnetite to the bulk IRM increases with the increasing degree of pedogenesis, which depends in turn on climate change.  相似文献