Determination of Platinum-Group Elements and Gold in Two Russian Candidate Reference Materials SCHS-1 and SLg-1 by ICP-MS after Nickel Sulfide Fire Assay Preconcentration   总被引：1，自引：0，他引：1  

Chunsheng Li  Chifang Chai  Xiaolin Li  Xueying Mao 《Geostandards and Geoanalytical Research》1998,22(2):195-197

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单轴压力下有补给水岩石电阻率变化各向异性研究   总被引：18，自引：1，他引：18  

安金珍  修济刚 《中国地震》1996,12(3):300-306

将两种规格的长方体水饱和花岗岩标本，以标本一个面的中心点为中心，对称布置成互成４５°角的４条对称四极法电阻率测线。标本电极面和相邻面的一小部分用防水环氧胶密封，使标本在装有水的承压水箱中，沿标本长轴方向受压，观测标本视电阻率随压力的变化。实验结果为：（１）有补给水实验与无补给水实验，电阻率变化整体形态相似，即电阻率随压力的变化先上升，后下降，但有补给水实验的电阻率下降幅度要大一些。（２）电阻率变化出现明显的方向性，可以用电阻率变化最大的各向异性主轴方向表示；实验中，用４条测线、４种组合（每３条测线组合可以确定１个视电阻率变化各向异性主轴方向）方法确定的４个电阻率变化各向异性主轴方向基本一致。（３）加压期间，电阻率各向异性主轴方向随压力增加发生变化，这种变化不是渐变和乱变，而是有规律的跃变，即整个实验过程，多数标本只跃变１—３次，每次跃变形成一个主方向，在主方向内，角度变化不大。（４）有补给水岩石电阻率变化整体形态与美国Ｂｒａｃｅ等（１９６８）所作的围压和孔隙压的岩石电阻率变化形态相似。  相似文献   

试论土地侵蚀     

柴宗新 《山地学报》1996,(2)

建议用“土地侵蚀”一词取代“水土流失”这个术语．土地侵蚀是地球陆地表面的固体组成物质（岩土体）在内外营力和人为作用下，发生的风化、运移和堆积过程．按土地利用实情，土地侵蚀分为土壤侵蚀、矿山侵蚀、道路侵蚀、城镇侵蚀、岸坡侵蚀和本利用地侵蚀等．  相似文献   

我国南方土地侵蚀特点     

柴宗新 《山地学报》1996,(4)

境内土地侵蚀严重，以水蚀为主，其面积６８３３２０ｋｍ２，占全国水蚀面积的３８％．讨论了：滑坡、泥石流侵蚀；碳酸盐岩、花岗岩和红层各具特色的侵蚀；土地侵蚀的危害严重，石化面积在扩大，中小河道淤高；塘库、湖泊遭淤，容积缩小；南方土地侵蚀泥沙输移比较小．  相似文献   

甘改—玉树断裂带的近代地震与未来地震趋势估计   总被引：3，自引：1，他引：3  

周荣军 《地震地质》1997,19(2):115-124

通过对甘改－玉树断裂带上近代地震的震级，震中位置和地震地表破裂的空间展布特征的研究，采用Ｎｉｓｈｅｎｋｏ和Ｂｕｌａｎｄ发展的“特征地震复发时间通用分布”概率模型，即“ＮＢ”模型，对甘孜玉树断裂带各段落未来５０ａ内强震趋势进行了估计。  相似文献   

石油资源的定量评价预测          下载免费PDF全文

刘承祚  陶起  柴俊杰  吴泰然  英定文 《地质科学》1988,(2):170-177

本文涉及石油资源的定量评价预测。文中介绍了六种方法:随机过程法、搜索区分析法、油田规模分布的极大似然估计法、蒙特卡洛法、经验分布变换法、模糊综合评判法。这些方法在我国中部一个油田石油资源评价预测中得到应用并获得了满意的结果。  相似文献   

Convection and cloud formation over snow-covered surface     

Steven K. Chai 《Atmospheric Research》1986,20(1)

This paper discusses the vapor-driven convection over snow and its limitations. It is shown on the basis of the moist convective plume model that vapor flux from the evaporating snow surface can drive convection, and maintain a super-cooled water cloud layer, without the assistance of heat flux from the surface, or entrainment or radiative cooling, at cloud top.Since the saturation vapor pressure over water is higher than that over ice, the base of the super-cooled water cloud has a lower limiting height. When the cloud base is lowered to this height, the air at the bottom of the convective layer is just saturated with respect to ice and the evaporation of snow stops, as does the vapor-driven convection. This limiting cloud base height varies with snow-surface temperature. The lower the snow temperature, the higher the cloud base height limit for continued convective transfer from the surface.  相似文献   

Experimental Study of Synthesis Processing System for Rock Acoustical Measurement     

Wang Gaizheng  Cheng Leping  Xie Qing  Luo Xiao  Yang Yanjun  LiBaohua  Chai Zhongli  Liu Ke 《岩土力学》1985,6(1):85-92

The system consists of SYC rock acoustical measurement instrument, microcomputer and single board computer. It is a building block system used in both laboratory and field testing to measure rock acoustical data. In this paper the main performances, the fundamental configuration, the interface technique and software design methods are presented, and measurement result analysis is made. An idea was proposed of the automatic acquisition and processing of test data by means of micro-computer control over the test device.  相似文献   

Thermochemistry of carbonate-pyroxene equilibria     

Liang Chai  Alexandra Navrotsky 《Contributions to Mineralogy and Petrology》1993,114(2):139-147

The enthalpies of drop solution of calcite, magnesite, dolomite, wollastonite and diopside have been measured in a lead borate solvent at 977 K in a Calvettype microcalorimeter. The carbonate calorimetry was done under flowing gas atmosphere. Both natural and synthetic samples were used. From these calorimetric data, the enthalpies of several reactions of carbonate with quartz were calculated. The enthalpies of these reactions (kJ/mol) at 298 K are: calcite+quartzwollastonite+CO₂, 92.3±1.0; magnesite+quartzenstatite+CO₂, 82.9±2.8; dolomite+quartzdiopside+CO₂, 163.0±1.9. These values generally are in agreement with those calculated from Robie et al., Helgeson et al., Berman and Holland and Powell. The enthalpy of dolomite-quartz reaction overlaps marginally with those from Berman and Holland and Powell. The enthalpy of formation of dolomite from magnesite and calcite (-11.1±2.5 kJ/mol) was also derived from the measured enthalpies, and this value is consistent with that from acid solution calorimetric measurements as shown by Navrotsky and Capobianco, but different from values in the earlier literature. These results support the premise that drop-solution of carbonates into molten lead borate results in a well-defined final state consisting of dissolved oxide and evolved CO₂. This was also confirmed by weight change experiments. Thus, oxide melt calorimetry is applicable to carbonates.  相似文献   

Assessment of seismic performance of extended pile‐shafts     

Y. H. Chai  S. T. Song 《地震工程与结构动力学》2003,32(12):1937-1954

The seismic performance of extended pile‐shafts subjected to the current level of displacement ductility demand is assessed for different soil conditions. Local curvature ductility demand is compared with the curvature ductility capacity provided by the current level of confining steel. Parameters in the assessment of extended pile‐shafts include the undrained shear strength of cohesive soils, relative density of cohesionless soils, aboveground height, longitudinal reinforcement ratio, axial force level and pile diameter. Results indicate that the curvature ductility demand in the pile decreases with increased soil stiffness but increases with increased aboveground height. The curvature ductility demand however is not sensitive to the longitudinal reinforcement ratio or axial force level, and is independent of the pile diameter. Results further indicate that the curvature ductility capacity available from the current level of confining steel may not be adequate for tall extended pile‐shafts, especially for piles with large longitudinal reinforcement ratio and embedded in soft or loose soils. Limits on the maximum longitudinal reinforcement ratio are suggested in the paper. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献