Application of Numerical Method to Soil Mechanics

This is a summing-up report based on 48 papers on the applications of numerical method to soil mechanics. Recently, there is a new development of coupling of finite element with other numerical ones in soil mechanics. The dynamic numerical analyses have found further application to nonlinear stress-strain relationship, effective stress, and three dimensional problems. The suitable contact element or conjunct element could be used for contact conditions in finite element calculation. It is an important direction to combine usual numerical method with probabilistic method, which has been used in evaluations of consolidation effect, slope stability, dam, seepage, deformation calculation, interaction, and the performance analyses of pole and foundation.     

热释光断代技术测定断层活动时代可能性的研究

本文根据多年来研究断层活动所积累的热释光年龄资料和断层运动过程中各种温、压条件变化的模拟实验结果,阐述了断层运动所产生的摩擦升温有可能使断层面上乃至断层带内某些矿物原有的热释光“退火”,初步探讨了用热释光测年技术测定断层活动年代的可能性     

铈硼硅石的微量化学分析法

铈硼硅石是一种罕见的稀土矿物,由于它含有某些化学性质近似的元素,故分析难度较大。本文研究了应用纸色层法和离子选择性电极法对铈硼硅石中某些主要成分和微成分的分离和测定条件,设计了较合理的铈硼硅石微量全分析流程。该流程也适合类似矿物的分析,与常法比较,本法具有快速、准确、成本低和用样少等优点。     

长江流域旱涝典型年大气水汽输送

利用我国125个探空站一日两次自地面至100hpa共11个层次上的观测资料,对长江流域典型夏涝年(1980年)和夏旱年(1985年)我国大气中水汽总输送场、涡动输送场及散度场进行了计算分析。结果表明:当水汽总输送场从西北、西南和东南三支气流携带的水汽交汇于长江流域,且整个水汽输送场稳定持久,则在水汽辐合带附近导致大量降水,形成洪涝;反之,当三支气流微弱不稳定,不能形成水汽辐合带条件,则形成干旱。涡动输送亦反映出类似的特征。稳定且强盛的西南气流水汽输送是形成降水的主要条件和原因。     

Discussion on the Relation Between the Probabilistic Distribution of Magnitude in a Seismic Province and That in an Area with Potential Seismic Source

According to the joint probabilistic distribution model of magnitude and space,the author discusses the relationship between the probabilistic distribution of magnitude in a seismic province and that in an area with potential seismic sources.The results show that if the magnitude probabilistic distribution follows the truncated exponential form in a seismic province,there must be some potential source in which the magnitude probabilistic distribution does not conform to that form.The result is consistent with the concept of "characteristic earthquake" derived from the study of actual records of seismicity and the study of geology.The author suggests that the relationship between the probabilistic distribution of magnitude in a seismic province and that in a seismic potential area must be considered in the study of the analysis of seismicity,seismic zonation and engineering seismology,for the purpose of the evaluation of the probabilistic distribution of magnitude correctly in every area with potential s     

Ultra-high pressure metamorphic rocks in the Dabie-Su-Lu region, China: Their formation and exhumation

Abstract Based on petrological, structural, geological and geochronological research, the authors summarize the progress of ultra-high pressure (UHP) metamorphic rock study since 1989 by Chinese geoscientists and foreign geoscientists in the Dabie-Su-Lu region. The authors introduce and discuss a two-stage exhumation process for the UHP metamorphic rocks that have various lithologies; eclogite, ultramafics, jadeitic quartzite, gneiss, schist and marble. The metamorphic history of UHP metamorphic rocks is divided into three stages, that is, the pre-eclogite stage, coesite eclogite stage, and retrograde stage. Prior to UHP metamorphism, the ultramafics had a high temperature environment assemblage of mantle and others had blueschist facies assemblages. The granulite facies assemblages, which have recorded a temperature increase event with decompression, have developed locally in the Weihai basaltic rocks. Isotopic ages show a long range from > 700 Ma to 200 Ma. The diversity in protoliths of UHP metamorphic rocks may be related to the variation of isotopic ages older than 400 Ma. The Sm-Nd dating of ~ 220 Ma could reflect the initial exhumation stage after the peak UHP metamorphism in relation to the collision between the Sino-Korean and Yangtze blocks and subsequent events. Petrological and structural evidence imply a two-stage exhumation process. During the initial exhumation, the UHP metamorphic rocks were sheared and squeezed up in a high P/T regime. In the second exhumation stage the UHP metamorphic rocks were uplifted and eventually exposed with middle crustal rocks.     

祁雨沟地区金矿床稳定同位素研究

对河南嵩县祁雨沟地区角砾岩型金矿床和蚀变岩型金矿床稳定同位素研究表明，两类矿床具有同一成矿流体来源－岩浆水；在早期－主期成矿阶段成矿流体以岩浆水为主，晚期矿化流体加入了相当数量的大气水。铅同位素组成表明金矿床的成矿物质与区内钙碱性花岗岩成岩皆主要来源自上地幔，混合铅的存在指示了上地壳地矿物质加入岩浆热液中，参与了金床床的成矿作用。     

β修正新光度法测定环境水中银

在酸性介质中，银（Ⅰ）与碘化钾和丁基罗丹明Ｂ（ＢＲＢ）反应、显色液由红色变紫色．本文研究β修正光度法定量痕量银，该方法能消除显色体系中过量ＢＲＢ干扰，提高分析准确度和精密度。２５ｍｌ溶液中，银在０─１μｇ／ｍｌ浓度范围内遵循Ｌａｍｂｅｒｔ－Ｂｅｅｒ定律。样品分析表明，银最低测定量０．０４ｍｇ／Ｌ，加标回收率９５．３─１０６％。     

旋转电极法研究盐类溶解─LiCl、NaCl、KCl在水中的溶解动力学

利用旋转盘装置结合离子选择电极研究了ＬｉＣｌ、ＮａＣｌ、ＫＣｌ在２０℃～３５℃水中溶解动力学，得到了溶解动力学方程．     

渭河平原地下水分布特征与环境同位素研究——以白杨水源地为例

白杨水源地座落在渭河下游重镇——渭南市西北约5km处，为渭河冲积平原的一部分。区内第四纪松散堆积物巨厚，地形平坦，降水充沛，地表水丰富，为地下水储存提供了良好的空间。按含水介质的埋藏条件可划分为潜水、浅层承压水、中层承压水和深层承压水4个含水岩组。为了进一步研究地下水的补给形成机制、储存运移过程、排泄开采条件，本文结合环境同位素（包括14C、13C、3H、D和18O）对水源地地下水年龄、地下水运动速率以及一些水文地质参数进行研究和探讨。而同位素测定表明：水源地潜水为现代水，3H含量较高，河水补给量占1/2