岩土材料弹塑性动本构模型研究概况     

徐干成  谢定义 《岩土力学》1993,14(3):81-93

本文介绍了砂土本构模型研究的历史及现状,特别是对国内较少涉及的动弹塑性本构模型研究情况作了详细的介绍,并就作者的理解体会作了一些评价。  相似文献   

Isotopic compositional Characteristics of Terrigenous Natural Gases in China   总被引：1，自引：1，他引：1  

沈平  徐永昌 《中国地球化学学报》1993,12(1):14-24

The C and H isotopic compositions of the methane in more than 160 gas samples from 10 basins in China are presented in this paper.The natural gases are classified as four types: biogenic gas ,bio-thermocatalytic transitional gas, gas associated with condensate oil ,and coal-type gas. The isotopic compositions of these gases closely related to the depositional basins, the types of organic matter,the stages of thermal evolution and the genetic characteristics of different gas reservoirs.Studies of the C and H isotopic compositions of terrigenous natural gases will provide valua-ble information on the prospecting and development of natural gases of different genetic types.  相似文献   

The Partitioning of Tungsten bwtween Aqueous Fluids and Silicate Melts     

Xu Yongsheng  Zhang Benren  Han Yinwen 《中国地球化学学报》1993,12(2):128-136

An experimental study has been carried out to determine the partition coefficients of tungsten between aqueous fluids and granitic melts at 800 °C and 1.5 kb with natural granite as the starting material. The effects of the solutions on the partition coefficients of tungsten show a sequence of P > CO ₃ ²⁻ > B > H₂O. The effects are limited (generallyK _D < 0.3) and the tungsten shows a preferential trend toward the melt over the aqueous fluid. The value ofK _D increases with increasing concentration of phosphorus; theK _D increases first and then reduces with the concentration of CO ₃ ²⁻ when temperature decreases, theK _D between the solution of CO ₃ ²⁻ and the silicate melt increases, and that between the solution of B₄O ₇ ²⁻ and the silicate melt decreases. The partition coefficients of phosphorus and sodium between fluids and silicate melts have been calculated from the concentrations of the elements in the melts. TheK _D value for phosphorus is 0.38 and that for sodium is 0.56. Evidence shows that the elements tend to become richer and richer in the melts.  相似文献   

Types and distribution of silver ore deposits in China   总被引：2，自引：0，他引：2  

C. Y. Wu  G. Bai  L. M. Xu 《Mineralium Deposita》1993,28(4):223-239

Silver is generally recovered as a by- and co-product along with Au, Pb, Zn, Cu, Sb, Bi, Hg, Sn and W from polymetallic and gold mines in China. Chinese silver deposits can be classified into five principal types according to host rocks. These types and their host rocks are: (1) marine volcanic-sedimentary rocks hosting (la) massive sulfide Pb-Zn-(Cu)-Ag ores and (1b) stratiform Ag-(Au) ores; (2) continental volcanic-sedimentary rocks containing (2a) various polymetallic-silver veins and/or stockworks, and (2b) Ag-(Au) veins in pyroclastic rocks; (3) rocks affected by metasomatic processes including (3a) complex Sn-polymetallic-Ag ores, (3b) Pb-Zn-(Cu)-Ag skarns, (3c) associated W-Ag quartz veins and/or skarns, and (3d) Ag-(Au) zones and veins in altered carbonate rocks; (4) metamorphic-intrusive rocks, principally Ag-(Au) veins in sheared and brecciated metamorphic rocks; and (5) sedimentary rocks including (5a) stratiform Pb-Zn-Ag ores in carbonate rocks, (5b) Ag-V mantos in black shales, and (5c) Cu-(Ag) layers in red sandstones. A sixth grouping includes gossans. The tectonic settings, geological features, and temporal and spatial distribution of these different types of silver occurrences indicate that silver mineralization reflects to a great extent the evolution of tectonic environments in China throughout geological time. Type 1 is generally developed in association with several fold belts from the Caledonian to Yanshanian orogens, while types 2, 3 and 4 correlate with rejuvenation of the eastern China continent during the Mesozoic period. The three subgroups of type 5 are recognized in different stages and various sedimentry and diagenetic environments during the development of paraplatforms and fold belts. Type 6 results from recent weathering of existing sulfide ores or protores. Editorial handling: DR  相似文献   

利用地震多参数预测油水边界     

徐守余 《地质论评》1993,39(7):83-87

为了解奂徐集复杂断块地区含油范围预测问题，使用了地震多参数分 析法。多参数分析法是充分利用各种地球物理参数(振幅、频率、相位及 速度等)，并将各参数测定结果与地质因素相结合，引用判别函数以判定 其含油性，进而预测早期油水边界。利用地震多参数分析法，在徐集地区 预测早期油水边界已取得了较好的效果。  相似文献   

海南岛石碌群中双峰火山岩Sm—Nd同位素特征兼论石碌铁矿成矿背景   总被引：9，自引：1，他引：9  

方中  赵建新 《地球化学》1993,(4):326-336

对海南岛石碌群第６层及其相当层位中海相双峰火山岩Ｓｍ－Ｎｄ同位素，微量和稀土元素的研究表明，位于火山岩带西段军营和石碌的细碧岩具有Ｎ－ＭＯＲＢ特征，在中段和东段芙蓉田和兰洋的变拉斑玄武岩具有Ｅ－ＭＯＲＢ和ＩＲＴ（初始裂谷拉斑玄武岩）特征。石碌群的玄武岩和石碌Ｆｅ－Ｃｏ－Ｃｕ矿床分别与红海裂谷中南段的新生代玄武岩和Ａｔｈａｎｔｉｓ Ⅱ ＤｅｅＰ多金属矿床有许多相同之处。双峰火山岩的另一端元为壳源型石  相似文献   

内蒙狼山-渣尔泰山中元古代拉张型过渡壳的形成、形变及成矿          下载免费PDF全文

牛树银  孙爱群  许传诗 《地质找矿论丛》1993,8(1):28-39

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近40年中国区域的气候型变化与北半球大气环流特征10年际时空变化的关系   总被引：3，自引：0，他引：3  

徐祥德  苗峻峰  章基嘉 《热带气象学报》1994,10(1):38-36

根据１８００－１９８９年（１１０年）的资料，分析研究了新加坡地区月平均和年平均降雨量的一些特征。主要结论是：新加坡年平均降雨量存在准２－６年和１８年的周期振荡；亚洲季风以及ＥＮＳＯ对新加坡降雨量有明显的影响。新加坡年雨量的谷值出现在西南季风期而峰值在东北季风期。在Ｅｌ Ｎｉｎｏ年，新加坡降雨量多为负距平；而在反Ｅｌ Ｎｉｎｏ年，新加坡降雨量多为正距平。  相似文献   

我国热带气旋灾害的分析研究   总被引：2，自引：1，他引：2  

蔡则怡  徐良炎  徐元太 《大气科学》1994,18(Z1):826-836

本文对１９４９—１９９１年４３年的热带气旋资料，以及１９５６—１９９２年３７年的热带气旋灾情资料进行了分析，说明了热带气旋灾害的主要特征和发展趋势。提出了关于热带气旋灾情评估的３项指标，表明灾情与热带气旋系统强度、大小、天气，登陆率，预报准确率，热带气旋系统影响地区社会经济活动的发达程度，物质财富积累水平，以及防抗措施的水平等有密切的关系，为我国今后防台减灾提供了依据。  相似文献   

宁芜地区三个辉长岩的全岩和矿物Rb-Sr等时线年龄   总被引：9，自引：0，他引：9       下载免费PDF全文

徐祥  邢凤鸣 《地质科学》1994,(3):309

 从南京到芜湖有许多辉长岩体分布,如南京蒋庙岩体、高古山岩体、大栏杆岩体,马鞍山阳湖塘岩体,当涂姑山岩体和芜湖市区的辉长岩体等。  相似文献