岩石圈塑性流动网络与多层构造变形的物理模拟   总被引：15，自引：2，他引：15       下载免费PDF全文

李建国  周永胜 《地震地质》1997,19(3):57-258

采用塑化松香作为岩石圈延性下层的相似材料，进行了板内塑性流动网络及多层构造变形的物理模拟实验。延性单层模型的实验表明，在边界挤压或“高原”重力势的作用下，依赖于延性层粘度的高低不同，主要形成剪切网络、压性褶皱以及二者过渡型式等一级构造。在延性／脆性双层模型中（脆性上层和延性下层分别相当于岩石圈上、下层），边界驱动力的远程传递，主要借助于延性下层的网络状流动，岩石圈下层（含下地壳和岩石圈地幔）的剪切网络，即塑性流动网络，控制着板内构造变形，导致脆性上层内剪切破裂网络、逆推断裂、纵向张裂以及其它次级断裂和褶皱的发育。实验还表明，上、下层之间非连续分布的软弱夹层（模拟壳内低速、高导层）并不妨碍下层塑性流动网络的扩展，但影响牵引力的向上传递及上层构造变形的强弱分布  相似文献   

泽当、景洪大气气溶胶粒子的物理、化学特性   总被引：9，自引：1，他引：9  

杨军  朱彬  李子华 《气象学报》2001,59(6):795-802

利用 1 997～ 1 999年在西藏泽当、云南景洪观测地飞得到的大气气溶胶资料 ,分析了气溶胶粒子的物理化学特性 ,包括质量浓度、数浓度、光学吸收系数和化学组成 ,初步讨论了有关的影响因子 ,并同国内外其它地区的观测结果进行了比较。结果表明 ,大气气溶胶粒子在以上两地以及与其它地区之间存在明显的差异  相似文献   

黄土土性参数的统计分析   总被引：16，自引：2，他引：16  

倪万魁  韩启龙 《工程地质学报》2001,9(1):62-67

讨论了土性参数不确定性的主要来源, 并对黄土高原典型地段黄土土性参数进行了详细地统计分析, 结果表明黄土土性参数的均值、标准差和变异系数具有明显的区域性特点, 土性参数的统计必须针对具体的工程进行。黄土的物理力学指标的分布多服从正态分布, 在边坡可靠度计算中各指标均可用正态分布近似。  相似文献   

A study on geology,geomorphology, hydrology,groundwater, and physical resources of the desertified Badia environment in Jordan towards sustainable development   总被引：1，自引：0，他引：1  

A. S. Al-Homoud  R. J. Allison  B. F. Sunna  K. White 《Environmental Geology》1996,27(3):198-209

This paper summarizes information on geomorphology and physical resources as a part of the Jordan Badia Research and Development Program. The research focused on the issue of the environment in arid lands as an aid to providing practical options for sustainable development, for the benefit not only of the Hashemite Kingdom of Jordan but of other arid regions of the world. The research is significant in that there is a need to identify usable natural resources and establish a framework for their effective exploitation and management in a marginal, fragile environment, which is sensitive to change. Pressure for development of the Badia stems from the fact that the great majority of the population in Jordan is compressed into less than 10% of the country by environmental constraints. It is hoped that the Jordan Badia Research and Development Program will provide the required framework to ease current environmental pressures, encourage migration to the Badia, a sparsely populated region, and establish economically and ecologically self-supporting communities. This paper discusses the following areas that are related to the sustainable development of the Jordan Badia with special emphasis on the Safawi area in the northern Jordan Badia; geomorphology, including landform, processes, and hazards; geology and physical resources; hydrology; surface water and water engineering; and groundwater.  相似文献   

沽源——多伦地区航空磁场特征研究     

樊艾 《铀矿地质》1996,12(2):100-103

本文以区内岩矿石物性及地质资料为基础，对沽源—多伦地区航空磁场进行了分析和研究，依据磁场的分布特征及幅值大小将其划分为８个磁场分区，并对各分区磁场进行了地质解释，为在该地区应用航磁资料预测铀矿远景区提供了基础材料。  相似文献   

青海察尔汉盐湖深水盐田光卤石矿物化特性研究总结报告   总被引：4，自引：1，他引：4       下载免费PDF全文

王石军 《盐湖研究》1997,5(1):7-20

虽然国家“七五”重点工程一青海钾肥厂已转入生产阶段近九个年头，但对用盐湖卤水通过大面积深水盐田（池内水深1M左右）晒制光卤石在我国至今缺乏成熟的经验。本文就是通过对青海钾肥厂十平方公里盐田的西光卤石池光卤石矿六年的定期取样分析资料，总结出深水盐田光卤石矿的物化特性及其形成机理，以便为其它与将来特别是青钾二期工程更大面积的盐田生产和盐田管理提供基础和指导。本文是目前对深水盐田光卤石矿物化特性进行全面描述的唯一资料。  相似文献   

黄海物理海洋学的主要特征     

郭炳火 《海洋科学进展》1993,(3)

本文概述了黄海物理海洋学主要特征,其中包括温、盐结构,环流和潮汐、潮流。在第二部分中重点说明黄海某些突出的海洋现象。诸如:黄海冷水团及环流,黄海暖流,海洋锋及底层流,最后一部分讨论海区的营养盐输送机制。  相似文献   

Neural network modelling of wave overtopping at coastal structures     

Marcel R.A. van Gent  Henk F.P. van den Boogaard  Beatriz Pozueta  Josep R. Medina 《Coastal Engineering》2007

A method has been developed to estimate wave overtopping discharges for a wide range of coastal structures. The prediction method is based on Neural Network modelling. For this purpose use is made of a data set obtained from a large number of physical model tests (collected within the framework of the European project CLASH, see e.g. [Steendam, G.J., Van der Meer, J.W., Verhaeghe, H., Besley, P., Franco, L. and Van Gent, M.R.A. (2004). The international database on wave overtopping. World Scientific, Proc. 29th ICCE, vol. 4, pp. 4301–4313, Lisbon, Portugal.]). Moreover, a method was developed to obtain confidence intervals for the overtopping predictions of the neural network.  相似文献   

An overview of the ecosystems of the Barents and Norwegian Seas and their response to climate variability     

Harald Loeng  Ken Drinkwater 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2478

The principal features of the marine ecosystems in the Barents and Norwegian Seas and some of their responses to climate variations are described. The physical oceanography is dominated by the influx of warm, high-salinity Atlantic Waters from the south and cold, low-salinity waters from the Arctic. Seasonal ice forms in the Barents Sea with maximum coverage typically in March–April. The total mean annual primary production rates are similar in the Barents and Norwegian Seas (80–90 g C m⁻²), although in the Barents, the production is higher in the Atlantic than in the ice covered Arctic Waters. The zooplankton is dominated by Calanus species, C. finmarchicus in the Atlantic Waters of the Norwegian and Barents Seas, and C. glacialis in the Arctic Waters of the Barents Sea. The fish species in the Norwegian Sea are mostly pelagics such as herring (Clupea harengus) and blue whiting (Micromesistius poutassou), while in the Barents Sea there are both pelagics (capelin (Mallotus villosus Müller), herring, and polar cod (Boreogadus saida Lepechin)) and demersals (cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus)). The latter two species spawn in the Norwegian Sea along the slope edge (haddock) or along the coast (cod) and drift into the Barents Sea. Marine mammals and seabirds, although comprising only a relatively small percentage of the biomass and production in the region, play an important role as consumers of zooplankton and small fish. While top-down control by predators certainly is significant within the two regions, there is also ample evidence of bottom-up control. Climate variability influences the distribution of several fish species, such as cod, herring and blue whiting, with northward shifts during extended warm periods and southward movements during cool periods. Climate-driven increases in primary and secondary production also lead to increased fish production through higher abundance and improved growth rates.  相似文献   

中韩黄海海洋学联合研究新进展     

刘瑞玉  赵一阳  翁学传  顾宏堪  郭玉洁  杨纪明 《海洋与湖沼》1996,27(6):657-666

根据中国科学院海洋研究所１９９２年５月和９月，韩国仁荷大学校海洋科学技术研究所１９９２年９－１０月在南海调查所获资料及双方过去积累的多年资料进行多学科研究。首次编绘出潮能分布图和渔业捕捞，水产养殖图，取得的新进展和结果烛海洋学研究，资料开发和渔业持续发展提供新的重要依据。  相似文献