如何控制数字地下地形图的空间占用     

黄华平 《四川测绘》2001,24(3):113-114

数字地形图的数据量的大小不但取决于采点密谋，而且也受AUTOCAD中的某些操作的影响。  相似文献   

形变反演模型的非线性平差   总被引：1，自引：0，他引：1  

陶本藻 《武汉大学学报(信息科学版)》2001,26(6):504-508

阐述了反演问题参数估计的质量要求，将反演理论中的分辨率和精度与平差中的良好统计性质作了对比分析，为使反演参数得到良好估计，提出平差处理对策。针对反演问题经常是非线性模型，提出了非线性平差的几种方法，最后给出参数筛选的原则和相应的统计检验方法。  相似文献   

远场和超远场前兆的模拟实验研究   总被引：7，自引：0，他引：7  

许昭永  梅世蓉  杨润海  赵晋明  王彬  华培忠 《地震研究》2001,24(4):332-338

在岩石试件、传压块体（包括岩石和钢块）和压机架上布设应变观测点，观测研究它们在岩石试样破裂孕育过程中的变化特征。结果发现，岩样临破坏前除岩样上各个测点都出现异常变化外，同时较远处的测力元件、传压块体和压机架上的应变也出现了突变或扰动前兆异常。岩石试样外部测点的应变特征变化在极临近主破裂时才有反映。而岩样上的测点除极临近主破裂时有突变和扰动外在离主破裂较早时已有反映。岩石试样外的测点距岩样约25－90cm，约为破裂尺度的3－10（多）倍。这表明在孕震区以外很远的地方都可能出现前兆异常。并初步探讨了形成远场前兆的原因。  相似文献   

随机-模糊处理方法在岩石力学指标统计及岩组划分中的应用   总被引：9，自引：0，他引：9  

章杨松  罗国煜  李晓昭  阎长虹 《工程地质学报》2001,9(2):182-187

探讨了随机 模糊处理方法在岩石力学指标统计和岩组定量划分中的应用。文中对计算中的隶属函数取值及迭代方式进行了深入讨论。通过计算结果的比较分析, 认为随机 模糊处理方法更符合实际, 并优于其他方法。最后作者提出了岩组定性划分 岩石样本参数的随机 模糊统计分析 岩组定量划分及参数重新统计的分析程序。  相似文献   

云南会泽麒麟厂铅锌矿床构造地球化学及定位预测   总被引：22，自引：1，他引：22  

韩润生  陈进  李元  马德云  高德荣  赵德顺 《矿物学报》2001,21(4):667-673

在论述构造地球化学基本理论与方法的基础上，深入讨论了会泽麒麟厂铅锌矿床构造地球化学特点，认为构造地球化学异常集中区是进行隐伏矿定位预测的重要依据，提出了1571中段44－62剖面线间的深部等重点定位找矿靶区，已被验证工程证实，新发现八号隐伏矿体。该方法对隐伏矿定位预测和评价具有重要指导意义。  相似文献   

电感耦合等离子体质谱法同时测定地质样品中痕量碘溴硒砷的研究：Ⅱ.土壤及沉积物标准物质分析   总被引：11，自引：8，他引：11  

李冰  史世云等 《岩矿测试》2001,20(4):241-246

样品用碳酸钠和氧化锌混合熔剂半熔，热水提取，然后用强酸性阳离子交换树脂将阴离子形式存在的分析元素与溶液中大量钠、锌等阳离子分离，采用电感耦合等离子体质谱法直接同时测定溶液中的碘、溴、硒、砷。用0.07mol/L的氨水溶液清洗进样系统，有效减少了碘等元素的记忆效应和清洗时间。方法检出限（10σ，DF=100）溴、碘分别为0.15和0.028μg/g，砷、硒分别为0.04和0.004μg/g。用土壤和沉积物等地质标准物质分析验证了方法的准确度和精密度，绝大多数分析结果在标准值的允许误差范围之内。样品10次测定的RSD为0.8%～2.8%。  相似文献   

高频燃烧—红外碳硫仪测定地质样品中的碳和硫   总被引：7，自引：6，他引：7  

史世云  温宏利李冰何红蓼  吕彩芬 《岩矿测试》2001,20(4):267-271

应用HIR-944B型高频-红外碳硫分析仪,对不同地质样品中碳、硫的测定进行了研究,称样30～60mg,加入0.4g纯铁屑及1.7g钨粒助熔剂,高温燃烧分解试样,红外检测,可定量地质样品中质量为0～O.9mg的硫及质量为0～15mg的碳.用该仪器测定地质标样中碳、硫的结果与标准值符合,碳和硫11次测定的RSD分别是＜2.6%和＜3.0%.  相似文献   

An experimental investigation of water level effects on the dynamic behaviour of a large arch dam     

Jean Proulx  Patrick Paultre  Julien Rheault  Yannick Robert 《地震工程与结构动力学》2001,30(8):1147-1166

The need for full‐scale dynamic tests, which are recognized as the most reliable method to evaluate a structure's vibration properties, is increasing as new analysis techniques are developed that take into account the complex interaction phenomenons that occur in dam–reservoir–foundation systems. They are extremely useful to obtain reliable data for the calibration of newly developed numerical methods. The Earthquake Engineering and Structural Dynamics Research Center (CRGP) at the University of Sherbrooke has been developing and applying dynamic testing methods for large structures in the past 10 years. This paper presents the experimental evaluation of the effects of the varying water level on the dynamic response of the 180 m Emosson arch dam in Switzerland. Repeated forced‐vibration tests were carried out on the dam during four different periods of the reservoir's filling cycle during a one‐year span. Acceleration and hydrodynamic pressure frequency responses were obtained at several locations while the dam was subjected to horizontal harmonic loading. The variation of the resonant frequencies as a function of the reservoir level is investigated. A summary of the ongoing numerical correlation phase with a three‐dimensional finite element model for the dam–reservoir–foundation system is also presented. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Correlation of hydraulic conductivity with stratigraphy in a fractured-dolomite aquifer, northeastern Wisconsin, USA     

M. Muldoon  J. Simo  K. Bradbury 《Hydrogeology Journal》2001,9(6):570-583

This study integrated surface and subsurface stratigraphic data with geophysical logs and hydrogeologic data in order to characterize the hydraulic properties of the Silurian dolomite in northeastern Wisconsin. Silurian stratigraphy consists of predictable alternations of characteristic facies associations. A vertical profile of hydraulic conductivity, obtained from short-interval packer tests in a core hole that penetrates a majority of the Silurian section, indicates that hydraulic conductivity ranges over five orders of magnitude (10^–1 to 10^–6 cm/s). Matrix conductivity is generally low and varies with texture; the finer-grained restricted-marine and transitional facies being less permeable than the coarser-grained open-marine facies. High-conductivity values are generally associated with bedding-plane fractures, and fracture frequency is greater in the restricted-marine facies. High-flow features in 16 wells were identified using fluid-temperature/resistivity and heat-pulse flowmeter logs. Natural-gamma logs were used to identify the stratigraphic position of flow features in each well and to correlate flow features to specific stratigraphic horizons. By combining stratigraphic, geophysical, and hydrogeologic data, 14 high-permeability zones within the Silurian aquifer have been identified and correlated in wells more than 16 km apart. These zones parallel bedding, appear most pronounced at contacts between contrasting lithologies, and are most abundant in restricted-marine lithologies. Electronic Publication  相似文献   

水文水井抽水试验参数自动监测系统的研制与应用   总被引：1，自引：0，他引：1       下载免费PDF全文

吴翔　张涛鄢泰宁  龚元明徐永齐 《探矿工程》2001,(4):43-44

将现代计算机检测技术与水文水井抽水试验相结合，开发研制了多参数自动监测系统，可对抽水试验中孔内水位、水温和出水量进行实时同步检测，该系统在实际工程中得到了应用与验证。介绍了该系统的组成、检测原理、主要性能参数及生产试验情况。  相似文献