Sequence　Stratigraphic　Features　of　Mesozoic－Cenozoic　Nonmarine　Sediments　in　Eastern　China     

Xu Huaida  Wei Kuisheng 《中国地质大学学报(英文版)》1994,(1)

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Prospector II: Towards a knowledge base for mineral deposits   总被引：1，自引：0，他引：1  

Richard B. McCammon 《Mathematical Geology》1994,26(8):917-936

What began in the mid-seventies as a research effort in designing an expert system to aid geologists in exploring for hidden mineral deposits has in the late eighties become a full-sized knowledge-based system to aid geologists in conducting regional mineral resource assessments. Prospector II, the successor to Prospector, is interactive-graphics oriented, flexible in its representation of mineral deposit models, and suited to regional mineral resource assessment. In Prospector II, the geologist enters the findings for an area, selects the deposit models or examples of mineral deposits for consideration, and the program compares the findings with the models or the examples selected, noting the similarities, differences, and missing information. The models or the examples selected are ranked according to scores that are based on the comparisons with the findings. Findings can be reassessed and the process repeated if necessary. The results provide the geologist with a rationale for identifying those mineral deposit types that the geology of an area permits. In future, Prospector II can assist in the creation of new models used in regional mineral resource assessment and in striving toward an ultimate classification of mineral deposits.  相似文献   

Simulation and modeling of rainfall radar measurements for hydrological applications     

Dino Giuli  Luca Baldini  Luca Facheris 《Natural Hazards》1994,9(1-2):109-122

A procedure is described for the simulation of rainfall radar reflectivity (absolute and differential) measurements by dual linear polarization meteorological radars. The basic requirement that the proposed procedure aims at satisfying is that radar data obtained at the end of the process be correlated in a physically plausible manner to the rainfall field at ground, the latter being generated by means of a stochastic space-time rainfall model. The main goal of the model is to give the possibility to easily check the accuracy of radar rainfall estimates derived by means of procedures and algorithms aimed at minimizing or compensating for the effects of measurement errors associated with several types of meteorological events, with particular reference to requirements of hydrogeological forecast systems. Within the limits imposed by the validity of the adopted model, an analysis was carried out indicating general criteria that may be adopted to achieve a better accuracy in rainfall estimates and a full exploitation of the advantages offered by the radar dual polarization measurement technique.  相似文献   

SOME EMPIRICAL EXAMPLES OF CENTRAL PLACE MODEL IN CHINA''S RURAL AND URBAN STUDIES     

《地理学报(英文版)》1994,(Z1)

Sincethe195Os,theCentralPlaceTheory(Cpp)hasbeenprevailingallovertheWest.Nevertheless,theaPplicationofthismodelinChinasplanningworkusedtobeanargUableproblem.Negativeviewswerefl.thehyPothesisabouttl1enatUralandhumanhomogeneityisdevoicedfromthereality;2.thetheorytvasge11eratedfrol11caPitalistsociety,wherethehistorical,socialandeconomicconditionsaredifferentfromChina's.Inrecentyears,theauthorshavetriedtoapplyCppmode1toChina'Surbanal1dregionalplanning,thesatisfactoryresu1tsprovedthegenera1ada…  相似文献   

红碱淖—沟岔地区地下水流系统研究   总被引：3，自引：0，他引：3  

武选民  王树棕 《水文地质工程地质》1993,20(6):30-34

本文根据对红碱淖－沟岔地区地下水形成的背景条件、水化学特征、环境同位素组成的分析和剖面地下水势的计算，把研究区划分为２个区域地下水流系统和３个局部地下水流系统，对不同等级地下水流系统的边界、系统的循环作了详细探讨，深刻揭示了这种复合地形区、均质含水介质中地下水流的循环模式。  相似文献   

水资源系统管理的广义保证率与多目标模糊优化          下载免费PDF全文

陈守煜  邱林 《水科学进展》1993,4(3):215-220

综述了水资源系统管理可靠性研究现状,指出水资源系统管理中存在着两种不确定性——随机性和模糊性.从一般情况出发,在同时考虑随机性与模糊性的基础上,提出了广义保证率概念、定义及其分析计算方法,并用多目标模糊优选随机动态规划(MOFOSDP)模型研究了一类带广义保证率目标的水资源系统运行管理多目标优化问题.实例计算结果表明,提出的带广义保证率目标的MOFOSDP模型合理可行,优于传统方法.  相似文献   

泰安市城区—旧县水源地岩溶地面塌陷历程及影响因素分析     

吴亚楠 《中国岩溶》2020,39(2):225-231

文章总结泰安市城区—旧县水源地内岩溶塌陷的发生发展历程，综合前人研究成果及最新的野外调查统计结果，对影响研究区岩溶塌陷的分布及影响因素进行了剖析，探明了岩溶塌陷的发育条件及诱发因素。结果表明:(1)研究区内岩溶塌陷主要发生在岩溶发育较强、断裂带附近、土层厚度小于30 m的区域；发生塌陷区域的土层结构以二元结构为主，其次是多元结构；塌陷大多发生在汛期，尤其是在大型降雨之后；(2)强烈的地下水开采活动引发的岩溶水大幅度波动是塌陷发生的最主要诱发因素，且岩溶地下水位在基岩面附近波动时最易引发塌陷；外界对土体的扰动也对塌陷有一定的影响，泰安城区旧镇铁路交汇处的塌陷与列车行车震动有密不可分的联系。综合分析以往岩溶塌陷的研究方向和程度，建议今后的研究重点应为塌陷过程演化监测与模拟、塌陷预警预报方法探索及数据库建设。   相似文献   

一次连续性冰雹天气过程的诊断分析   总被引：6，自引：4，他引：2  

王琎董安祥  沈治广 《干旱气象》2004,22(1):44-48

对2000年秋季发生在甘肃庆阳的一次连续性冰雹天气过程进行了诊断分析。结果表明：这次冰雹天气过程是由于低层大气能量不断积累、低空切变线触发不稳定能量释放而产生的。冰雹出现在中低层对流不稳定和低层暖平流、高层冷平流以及低层辐合、高层辐散的上升运动区。冰雹落区与高低空温度平流和总温度平流的分布有着较好的对应关系。  相似文献   

Non-integrability of a Weakly Integrable Hamiltonian System     

Giuseppe Pucacco  Kjell Rosquist 《Celestial Mechanics and Dynamical Astronomy》2004,88(2):185-207

The geometric approach to mechanics based on the Jacobi metric allows to easily construct natural mechanical systems which are integrable (actually separable) at a fixed value of the energy. The aim of the present paper is to investigate the dynamics of a simple prototype system outside the zero-energy hypersurface. We find that the general situation is that in which integrability is not preserved at arbitrary values of the energy. The structure of the Hamiltonian in the separating coordinates at zero energy allows a perturbation treatment of this system at energies slightly different from zero, by which we obtain an analytical proof of non-integrability.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

Effective Community Engagement for Sustainability: Wombat Community Forest Management Case Study     

ANITRA NELSON  CHRISTOPHER PETTIT 《The Australian geographer》2004,35(3):301-315

The first significant government sponsored community‐based forest management project in Australia was initiated in Central Victoria in 2002. This paper analyses the initial stage of the Wombat Community Forest Management Pilot Project. The paper develops a functional concept of ‘effective community’ for structuring community engagement in these kinds of natural resource management projects. The effective community has characteristics in common with a community of interest, adopts a bioregional perspective, embodies the values of environmental stewardship and interacts in a fully informed way as a ‘discursive community’ (Meppam 2000 Meppam, T. 2000. ‘The discursive community: evolving institutional structures for planning sustainability’, Ecological Economics, 34: 47–61.  [Google Scholar]). The paper offers general advice for organising effective community engagement in such projects and 12 recommendations for governments developing similar initiatives elsewhere.  相似文献