西宁和贵德盆地新生代沉积物重矿物变化对构造活动的响应   总被引：1，自引：0，他引：1  

孟庆泉  吴小斌  刘善品  闫宝华  吴松  张洒  宋春晖 《沉积学报》2013,31(1):139-148

位于青藏高原东北缘的西宁、贵德盆地的新生代沉积序列较完整的记录了盆地周围物源区构造变形过程。重矿物是碎屑物质的重要组成部分,是最直观、有效揭示源区母岩、构造-沉积过程的重要手段。通过重矿物的系统分析,结合沉积-构造变形,揭示出始新世-上新世末西宁-贵得盆地及其源区经历了几个构造活动阶段:古新世-始新世早期的隆升阶段、始新世中期-渐新世晚期的构造稳定阶段、渐新世末-中新世初的构造隆升阶段、中中新世构造稳定阶段和晚中新世以来的强烈隆升阶段。并结合特征矿物（绿泥石）及古水流分析,推断古近纪西宁-贵德盆地是东昆仑山前一个统一盆地。中新世早期青藏高原的扩张导致了拉脊山开始隆起,使原型盆地解体;约8.5 Ma以来拉脊山强烈隆升,两侧盆地逐渐转变为山间盆地。这为正确理解青藏高原东北缘盆山格局的形成和演化提供了重要依据。  相似文献   

青藏高原近60年来气候变化及其环境影响研究进展     

杨耀先  胡泽勇  路富全  蔡英  于海鹏  郭瑞霞  付春伟  樊威伟  吴笛 《高原气象》2022,41(1):1-10

作为全球能量水分循环的关键区域,青藏高原(下称高原)气候变化对高原及周边地区气候与环境变化具有重要影响.本文从高原表面增暖、辐射变化、降水的多尺度变率、表面风速及环境变化方面回顾了高原近60年来气候变化及其环境效应与物理机制的研究进展,并基于再分析和台站观测资料讨论了近10余年来高原表面温度和风速变化的特征及原因.最后...  相似文献   

Numerical Study Of The Impact Of Coherent Structures On Vertical Transfers In The Atmospheric Boundary Layer     

F. Lohou  A. Druilhet  B. Campistron  J.-L. Redelspergers  F. Saïd 《Boundary-Layer Meteorology》2000,97(3):361-383

In two preceding papers, coherent structures of theatmospheric boundary layer (ABL), such as rollvortices or cells, were investigated through radar andaircraft observations collected during the TRAC-93(Turbulence Radar Aircraft Cells) experiment held inFrance in June 1993. The analysis of this experimentaldata set provided information on the spatialcharacteristics of these organisations (length scale,orientation, type ... ), their temporal and verticalevolution, and their relation with the dynamic andthermodynamic conditions of the ABL. For the thirdpaper in this series, a large eddy simulation model is used to examine the impact of thecoherent structures on the ABL vertical fluxes. Theanalysis of the simulated horizontal fields is madewith two-dimensional auto and cross-correlationsapplied on different pertinent ABL variables. Theresults emphasise a directional anisotropy of theseorganised fields throughout the ABL, much morepronounced in the heat flux fields, not only at thelength scale of organisations but also at theturbulence scales. This finding has an importantconsequence for traditional ABL flux measurementsbased on the hypothesis of isotropic and homogeneousturbulence. It can explain part of the underestimationof the surface fluxes often mentioned in theliterature. This approach makes it possible tomodify the concept of diffusion time (in chemicalmodelling) and could also lead to revised ABLparameterisations in Range Scale models.  相似文献   

韧性剪切带位移量统计方法评述——以西秦岭元家坪韧性剪切带为例     

赵仁夫  何芳  丁仨平 《甘肃地质》2000,(2)

韧性剪切带位移量的计算方法较多 ,每一种方法都有它适用的范围 ,应根据区域地质特点选择适宜的方法进行计算。在对元家坪韧性剪切带位移量的计算中 ,对其方法进行了比较 ,认为应用多种方法计算及验证 ,能得出较准确的位移量。  相似文献   

韧性剪切带位移量统计方法评述——以西秦岭元家坪韧性剪切带为例     

赵仁夫  何芳 《甘肃地质》2000,9(2):37-42

韧性剪切带位移量的计算方法较多 ,每一种方法都有它适用的范围 ,应根据区域地质特点选择适宜的方法进行计算。在对元家坪韧性剪切带位移量的计算中 ,对其方法进行了比较 ,认为应用多种方法计算及验证 ,能得出较准确的位移量。  相似文献   

颅颌面外科与三维重建技术   总被引：16，自引：1，他引：15  

归来  戴汝平 《CT理论与应用研究》2000,9(3):31-34

目的 探讨电子束ＣＴ三维重建技术在颅颌面外科的适应症和应用价值。方法 采用美国Ｉｍａｔｒｏｎ公司的电子束ＣＴ（ｅｌｅｃｔｒｏｎ ｂｅａｍ ＣＴ,以下简称ＥＢＣＴ）Ｃ－１５０,对７６例严重颅颌面病人实行薄层ＣＴ容积扫描。将所获ＣＴ 象经数字接口传至加拿大ＩＳＧ公司生产的Ａｌｌｅｇｒｏ工作站进行三维重建。结果 ＥＢＣＴ成像技术能立体的、详尽和精确的显示机体组织三维解剖结构极其相互关系。其再现畸形或病体  相似文献   

Salinity Distribution at Canal Istanbul and Its Possible Impacts on the Northern Marmara Sea     

Saçu  Şehriban  Erdik  Tarkan  Şen  Olgay 《中国海洋工程》2020,34(6):881-888

China Ocean Engineering - Turkey has announced its plan to construct a new waterway, Canal Istanbul, parallel to the Bosphorus. In this study, the influence of Canal Istanbul on salinity...  相似文献   

钙质土中重力串锚水平承载力特性有限元研究     

徐保照  李飒  苏洪路 《中国海洋大学学报(自然科学版)》2019,(5):108-115

目前没有规范给出串锚的水平承载力计算公式,为了利用有限元法研究串锚水平承载力特性,采用相关理论计算以及室内试验的方法来验证有限元法模拟计算的可靠性。实践证明,有限元法具有较高的计算精度。利用有限元分析软件ABAQUS建立了串锚-土体模型,模拟串锚在水平荷载作用下破坏过程,研究了串锚在水平荷载作用下破坏机理,从而得到了串锚水平承载力特性。在相同的工况条件下,串锚的水平承载力与其锚链长度有关,在一定范围内,增加锚链的长度可以提高串锚的水平承载力;串锚的水平承载力不是相应的单个锚的水平承载力相加,其水平承载力小于相应的单个锚水平承载力之和,在进行串锚水平承载力设计计算时应给与相应的考虑。  相似文献   

Biodegradation in numerical basin modelling: a case study from the Gifhorn Trough,N-Germany     

I. O. Blumenstein  B. M. Krooss  R. di Primio  W. Rottke  E. Müller  C. Westerlage  R. Littke 《International Journal of Earth Sciences》2008,97(5):1115-1129

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Fragmentation Energy in Rock Blasting     

Essaïeb Hamdi  Najla Bouden Romdhane  Jean du Mouza  Jean Michel Le Cleac’h 《Geotechnical and Geological Engineering》2008,26(2):133-146

The theoretical explosive energy used in blasting is a common issue in many recent research works (Spathis 1999; Sanchidrian 2003). It is currently admitted that the theoretical available energy of the explosives is split into several parts during a blast: seismic, kinetic, backbreaks, heave, heat and fragmentation energies. Concerning this last one, the energy devoted to the breakage and to the creation of blocks within the muckpile can be separated from the microcracking energy which is devoted to developing new and/or extending existing micro cracks within the blocks (Hamdi et al. 2001; López et al. 2002). In order to investigate these two types of energy, a first and important task is to precisely study the main parameters characterising the two constitutive elements of the rock mass (rock matrix and discontinuity system). This should provide useful guidelines for the choice of the blasting parameters (type of explosive, blasting pattern, etc.), in order to finally control the comminution process. Within the frame of the EU LESS FINES research project, devoted to the control of fines production, the methodology was developed in order to: (1) characterize the in situ rock mass, by evaluating the density, anisotropy, interconnectivity and fractal dimension of the discontinuity system and (2) evaluate fragmentation (both micro and macro) energy spent during the blasting operation. The methodology was applied to three production blasts performed in the Klinthagen quarry (Sweden) allowing to estimate the part of the fragmentation energy devoted to the formation of muck pile blocks on one side and to the muckpile blocks microcracking on the other side.  相似文献