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1.
The possible uses of thermoluminescence in mineral exploration are summarised. The methodology is described and some applications for gold exploration are developed with regard to the district of St-Yrieix (Limousin, France), the district of Salsigne (Herault, France) and some occurrences in the Ardenne massif (Belgium). From these cases, different possibilities may be mentioned: the distinction of various types of mineralized structures (St-Yrieix); the evaluation of the potential of mineralized districts from samples collected in the old mining works or in the superficial formations, etc. (St-Yrieix; Ardenne massif), and the determination of a genetic affiliation between different types of mineralizations (e.g. between stratiform deposits and vein-type deposits: the comparison between the districts of St-Yrieix and Salsigne). Finally new possibilities using the TL sensitivity and the equation of the straight lines NTL (natural TL) and ATL (induced TL) are evaluated. 相似文献
2.
A five-step procedure involving mathematical formulation, identification and determination of parameters and verification is presented for development and selection of appropriate and reliable constitutive law(s) for geologic media. Comprehensive analyses are performed toward determination of an appropriate law for a (artificial) soil. The most suitable model is obtained by critical evaluation of four different plasticity models; here verification and comparisons of predictions with observations from laboratory tests, and with those from two boundary value problems are used as the basis of the selection. The model thus selected is found to be appropriate for applications to relevant practical problems. 相似文献
3.
A. M. Oskoorouchi B. Novrouzian
G. De Roeck
J. Van Den Broeck 《Computers and Geotechnics》1991,11(4):265-294The technique of Finite Strip method has been extended for zoned strips. One strip can have several different materials in horizontal direction including dummy materials. The new developed zoned Finite Strip (Z.F.S.) method has many engineering applications, particularly in geomechanical problems. The formulation is presented and three different geotechnical problems have been solved using the new Z.F.S. method, which could not be solved by the original Finite Strip method. The results are compared with the solution for the same problems obtained by analytical and/or numerical (Finite Element) methods. The reduced input and output for the Z.F.S. method compared to the Finite Element method makes this method attractive particularly for practising engineers. However the results can be as good as the well known Finite Element method. 相似文献
4.
This article deals with the topical problems related to studies of recent tectonic structures of the East European Craton and Scythian Plate. These are, in particular, broad development of cover formations above neotectonic structures (such covers complicate the estimation of amplitudes of tectonic movements); discontinuous distribution and insufficient degree of preservation of deposits correlative to the recent stage; overestimated denudation cut from recent uplifts; different points of view on the type of structural forms (block or bend); character and type of boundaries between structural forms; neotectonic implications of buried valleys; change of structural plans during the recent stage; and geodynamic conditions and sources of tectonic stresses during the formation of recent structures. 相似文献
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The Remeshing and Interpolation Technique with Small Strain (RITSS) approach has been developed to deal with 3-D geotechnical problems in this paper. Unstructured 20-node hexahedral element is found to work well for predicting collapse loads accurately for 3-D undrained geotechnical problems involving material incompressibility. Remeshing is automatically accomplished by ANSYS program. With remeshing and interpolation, small fluctuations appear in the load–deformation results. In order to minimize these fluctuations, different increment sizes and remeshing frequencies are explored. Meanwhile, various 3-D interpolation methods are compared, and the unique element division method is found to work best. The results of two numerical applications are presented for a 3-D strip footing penetrating deeply into uniform clay and a square foundation into normally consolidated clay. The computed bearing capacity responses are compared with other numerical or conventional results. The results show that the present method is accurate and efficient for 3-D large displacement foundation penetration problems. 相似文献
7.
It is a critical issue to assess landslide hazard degree in the risk analysis of mountain geo-hazards. Currently, different
kinds of approaches to assess landslide hazard degree are developed and utilized from single quantitative analysis to integrated
quantitative analysis. However, several problems of these approaches impede further applications. These problems include (1)
the methods are complex and mathematic background is required sometimes; (2) the methods are hard to utilize. This study comes
up with a new approach to assess landslide hazard degree: a set pair analysis method (SPAM). The SPAM takes the fuzzy property
of grade standards into full account and avoids the values of discrepancy uncertainty coefficient in connection degree formula.
A case study is presented to assess the landslide hazard degree of 24 typical landslides in Fengjie County, Chongqing City,
where the Three Gorges Dam is located. The proposed method is simple in concept and easy in calculation and application. Its
results are credible. 相似文献
8.
花岗质岩石成因分类研究述评 总被引：5，自引：0，他引：5
由于花岗质岩石类型多 ,分布广 ,差异大 ,因此 ,国内外学者依据不同的判别标准提出了多种花岗质岩石的分类方案。通过对 2 0多种有代表性的分类方案的分析和对比 ,笔者认为 ,Barbarin(1999)提出的花岗岩类成因分类方案较为合理 ,但应补充橄榄玄粗质花岗岩类这一重要类型。文中较详细地介绍了Barbarin (1999)的分类方案 ,论述了含白云母的过铝质花岗岩类 (MPG)、含堇青石的过铝质花岗岩类 (CPG)、富钾的钙碱性斑状钾长石花岗岩类 (KCG)、富角闪石钙碱性花岗岩类(ACG)、岛弧拉斑系列花岗岩类 (ATG)、洋中脊拉斑质花岗岩类 (RTG)、过碱性和碱性花岗岩类(PAG)以及橄榄玄粗质花岗岩类 (SHG)的特征及其形成的地球动力学环境 ,并简要讨论了这种分类方法的优点和意义。 相似文献
9.
冰工程对于断裂力学是一个相对较新的应用领域.对不同工程领域中广泛存在的涉冰断裂力学问题进行了列举归纳,然后从冰的自然特性诸方面论证了冰工程分析中引入断裂力学方法的必要性及其适用性,最后综述了主要的研究成果和进展. 相似文献
10.
MARGOT BÖSE 《Boreas: An International Journal of Quaternary Research》1990,19(3):217-226
Till stratigraphical investigations in Berlin have been evaluated using the gravel counting method (4–12.5 mm). The results are compared with studies of several authors from the coastal area north of Berlin (Rügen and Stoltera Cliff near Warnemünde); the gravel counting results from Stoltera Cliff (Cepek 1973) are re-evaluated by means of cluster analysis, and a new stratigraphical interpretation of the sequence in the cliff is given. These results, together with a discussion of correlation problems of Weichselian and especially Saalian tills south of the Baltic Sea, lead to the following hypothesis: it is proposed that the ice margin of each glaciation has been nourished by several ice flows coming from different directions, for the most part turning from north-northeast at onset to east-northeast in later phases. Consequently, differences of composition are found in tills of the same age. 相似文献
11.
Abed Salih Al Dulaymie Bayan Muhie Hussien Moshtaq Ahmed Gharbi Husam Naji Mekhlif 《Arabian Journal of Geosciences》2013,6(3):801-816
This research examined the balneological characteristics of spring waters within the area of Abu-Jir Fault Zone throughout the hydrogeologic aspects explained by the setting of the hydrogeologic units including the water-bearing horizons of Euphrates, Ana, and Baba Formations. The groundwater flow in the hydrogeologic system correlated with the trends of enrichment or depletion case processes of mineralization (spatial distribution maps of TDS and other components) show different phenomena of groundwater source and interconnection, which helps in the classification springs into two potential site. The physicochemical characteristics of the water flow from springs indicate a hydrochemical approach throughout the spatial variation of important parameters (using Rockware software) related to the balneological study. The monitoring network of the spring waters performed by seven field measurements and 33 variables (totaling to 720 detected measurements) in 18 springs approved the after desk study and water point inventory using a GPS apparatus (GARMIN SUMMIT-e TREX). The study examined the integrated hydrogeological aspects and spring water properties for evolutions and the classification of minero-medicinal water. The traditional hydrochemical information of the spring waters and their sediment properties correlated with balneological limits (standards and definitions) are used in the selection of springs characterized by balneotherapeutic applications. A suggested screening and ranking technique has been developed for evaluating preferable springs selected for natural therapy. The application of ranking technique indicates four graded consequent preferable springs for balneotherapeutic investment: first grade spring represented by Kubaiysa spring (S-4); second grade springs represented by Tawila spring (S-12); third grade springs represented by Mamora spring (S-15), Arnab spring (S-10), Zazoe spring (S-5), and Maqtoom spring (S-13); and fourth grade springs represented by Khalidiya spring (S-16) and Layeg spring (S-7). 相似文献
12.
主要目的是通过对同位素在流域水文模拟应用中的一些假定、限制条件以及方法进行澄清和系统化,从而促进同位素在流域水文模拟中一些新的研究方向和研究热点.主要从三个方面,即同位素流量过程线分割、流域平均滞时与不同水源混合、与水文模型耦合,讨论同位素示踪剂在流域水文模拟中的研究进展情况.同时指出了同位素在流域水文模拟中应用存在的一些主要问题,包括:①降雨同位素含量的时空变化;②不同径流成分的采样;③径流输出同位素含量的空间变化;④流域平均滞时分布函数的确定;⑤水文同位素耦合模型. 相似文献
13.
离散元法及其在岩土工程中的应用综述 总被引：16，自引：0，他引：16
离散元法是基于不连续性假设的数值方法,它特别适合于求解节理岩体中的非连续性问题。在介绍离散元法基本原理的基础上,着重对离散元法在岩土工程领域的应用现状作了叙述和分析,并对其发展趋势进行了探讨。 相似文献
14.
厚度和品位是矿体的主要参数,两者既有区别又有联系.在解决某些地质问题时,把两者统一起来进行研究,能使问题更合理、有效地得到解决.通过提出MC参数概念,分析MC参数的特征,讨论了该参数在矿体矿化富集规律的研究、矿体资源/储量估算或资源/储量检验、估计资源/储量误差及确定合理勘探网度等方面的应用,说明了MC参数对矿床勘探应用的意义,并指出该参数的应用条件. 相似文献
15.
We consider the applications of existing mathematical models to heat and mass transfer dynamics in different zones of mantle-crust magmatic systems and discuss problems concerning quantitative modeling of mineralization associated with fractional crystallization of mafic melts in magma chambers, with or without crustal contamination. 相似文献
16.
《地学前缘(英文版)》2016,7(1)
Learning incorporates a broad range of complex procedures. Machine learning(ML) is a subdivision of artificial intelligence based on the biological learning process. The ML approach deals with the design of algorithms to learn from machine readable data. ML covers main domains such as data mining, difficultto-program applications, and software applications. It is a collection of a variety of algorithms(e.g. neural networks, support vector machines, self-organizing map, decision trees, random forests, case-based reasoning, genetic programming, etc.) that can provide multivariate, nonlinear, nonparametric regression or classification. The modeling capabilities of the ML-based methods have resulted in their extensive applications in science and engineering. Herein, the role of ML as an effective approach for solving problems in geosciences and remote sensing will be highlighted. The unique features of some of the ML techniques will be outlined with a specific attention to genetic programming paradigm. Furthermore,nonparametric regression and classification illustrative examples are presented to demonstrate the efficiency of ML for tackling the geosciences and remote sensing problems. 相似文献
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介绍了内陆湖泊水质遥感监测的特点及遥感监测水质的机理;总结了国内外近年来用于内陆湖泊水质参数反演的3种常用方法:经验模型、半经验法和机理模型法,并分析了3种模型的优缺点;讨论了目前遥感在水质监测应用中存在的问题和未来该领域研究的重点。 相似文献
19.
地球各向异性介质中地震波动理论、检测与应用研究 总被引：11，自引：0，他引：11
地下岩石的各向异性主要表现在地震波速度随传播方向发生变化,不同类型体波间相互耦合,横波发生分裂,波速度频散依赖于传播方向等。薄互层与裂隙定向分布等产生视各向异性,它在石油地震勘探、地震预测和岩石圈物理与动力学研究中有极大潜力和应用前景,并受到广泛重视。为此,文中讨论了地震各向异性研究在解决地球科学问题中的重要性与必要性;系统地介绍了中国在地震各向异性研究领域的各个方面,如波动传播、波场激发、数值模拟、偏移与反演成像,以及应用于油气资源探测、深部地球物理研究和地质灾害监测等方面所取得的新进展。结合笔者参加的第八届地震各向异性国际学术讨论会,及ＳＥＧ,ＩＡＳＰＥＩ,ＩＵＧＧ等有关学术会议情况,综述了国际上在该领域内的主要成果与发展动向,分析了国际上各国地震各向异性研究现状及存在问题,并对我国在该领域研究的进一步开展提供了主攻问题与相应建议。 相似文献