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排序方式: 共有1035条查询结果,搜索用时 15 毫秒
101.
Ying Li Jianguo Du Fukuan Wang Xiaocheng Zhou Xiaodong Pan Ruqing Wei Institute of Earthquake Science China Earthquake Administration Beijing China Inner Mongolia Corporation Ltd.of Geologic Engineering Hohhot China Earthquake Administration of Jilin Province Changchun China Liaocheng Seismology Hydro-chemistry Test Station Liaocheng China 《地震学报(英文版)》2009,(1):93-100
The geochemical backgrounds and origins of soil gases in the Yanhuai basin are discussed based on the regional seismogeological data and concentrations of Rn,Hg,CO2,H2,He and CH4 in soil gas measured at 422 investigating sites in field during September to October 2007.The geochemical background values of Rn,Hg,CO2,H2,He and CH4 are(8105.8±5937.4) Bq/m3,(9.7±5.8) ng/m3,(395.9±35.3)×10-6,(4.0±2.3)×10-6,(15.9±10.4)×10-6 and(12.7±8.1)×10-6,respectively.The geochemical backgrounds of the soil gases are higher in... 相似文献
102.
MATHEMATICAL MODELS FOR LIQUID-SOLID TWO-PHASE FLOW 总被引:2,自引:0,他引:2
Weiming Wu Sam S.Y. Wang National Center for Computational Hydroscience Engineering The University of Mississippi MS U.S.A. 《国际泥沙研究》2000,(3)
I INTRODUCTIONTurbulence models for single-phase fluid flows have been developed and widely applied in mechanical,aeronautical, environmental and hydraulic engineering, and other fields. The closure techniques for theReynolds-averaged Navier-Stokes equations for various levels of models including the simple turbulencemodel, one-equation turbulence model, k-s turbulence model and turbulence stress/flux model have beenverified to be physically reasonable and have acceptable accuracy in app… 相似文献
103.
We highlighted the flexibility of using unstructured mesh together with the local refinement by a resistivity model with complicated topography. The effect of topography is emphasized. Based on this, we calculated a specific class of layered models and found that the accuracy is not always satisfactory by utilizing the standard approach. As an improvement, we employed the layered earth as the reference model to calculate the wavenumbers. The comparison demonstrates that the accuracy is considerably improved... 相似文献
104.
大沟湾滑坡是瞿家湾滑坡群中相对高差最大的滑坡体, 洞坪水库蓄水后滑坡体产生了较大变形且变形机制表现出一定的特殊性.野外调查研究表明: 蓄水前该滑坡体稳定性良好; 蓄水至452m后, 滑坡后缘堆积体与基岩交界处产生贯通滑坡两侧冲沟的连续裂缝, 剪出口位于整个滑体中部580m高程附近, 由于下部坡体的抗滑作用而使整个坡体仍处于稳定状态; 蓄水至488m后, 从整个滑体前缘到570m高程附近又形成另一滑坡体, 与先前上部滑坡呈梯级分布, 分析得出大沟湾滑坡为上部牵引-下部推移的复合式滑坡, 两个滑坡共同作用导致整个滑体发生明显变形.分析并利用FLAC3D模拟再现整个变形过程, 对滑坡体变形破坏机制做出了很好解释. 相似文献
105.
Characteristics of Scour and Deposition in Front of Breakwaters Under Irregular Broken Clapotis 总被引:1,自引:0,他引:1
First the scour and deposition patterns of the sandy seabed in front of a vertical breakwater under the action of irregular broken clapotis are investigated experimentally and classified into five types: scour type Ⅰ , scour type Ⅱ, scour type Ⅲ, deposition type Ⅰ, and deposition type Ⅱ . Secondly, the processes of formation of scour and deposition patterns are probed in comparison with those induced by regular broken clapotis and standing waves. Thirdly, the criteria for distinguishing scour and deposition patterns under irregular broken clapotis are presented. 相似文献
106.
三峡库区奉节县宝塔坪小区大型复杂滑坡特征及成因机制 总被引:11,自引:1,他引:11
奉节县新城宝塔坪小区的地质灾害问题是当前学术界关注的焦点,也是库区具有普遍性问题。本文首次提出,在小区发育有5个复杂结构的滑坡。滑坡具3种成因:(1)碎裂-溶蚀-杏黄色泥质条带发育-滑坡;(2)碎裂-溶蚀-T2b^2粉砂质泥岩顶层泥化-滑坡;(3)T2b^4泥岩溶蚀-滑坡。岩溶蚀作用为主导作用。断裂的发育为溶蚀作用提供了通道。 相似文献
107.
108.
土壤环境中化学定时炸弹的研究现状与展望 总被引:1,自引:0,他引:1
土壤环境中的化学定时炸弹对生态环境乃至人类自身危害极大,国内外均有大规模发生化学定时炸弹的实例,但是,由于其不易发现而常常被忽略,这将造成更为严重的后果。化学定时炸弹的分类问题比较复杂,目前较为妥当的做法是对各种分类方案进行有益的探索。化学定时炸弹的触爆机制研究十分重要,是进行地球化学灾害评价、预测和防治的基础;地球化学工程技术是将来预防和治理化学定时炸弹最主要手段。从科学的严密性和严肃性考虑,化学定时炸弹的概念应该由具有更深刻内涵和更广泛外延的“缓变型地球化学灾害”来替代。 相似文献
109.
The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results show that the mooring system has an annual reliab 相似文献
110.