共查询到20条相似文献，搜索用时 31 毫秒
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The fluorine content in twenty-nine reference samples of geological interest has been determined using a well tried and tested method which has been previously reported. The analytical method uses fast neutron activation involving the reaction 19 F(n,a)16 N and gamma spectrometry. Interferences have been found to be negligible for the experimental conditions used. The method involves minimal sample preparation, is rapid and can easily measure concentrations down to 5 parts per million in a 5 g sample. 相似文献
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Different Results in Pressuremeter Theories 总被引：2，自引：2，他引：0
Radhi M. Alzubaidi 《Geotechnical and Geological Engineering》2014,32(4):965-972
The limit pressure that evaluated from pressuremeter tests has been shown to represent a key constitutive relationship for bearing capacity and shallow foundation design. The theoretical and the conventional limits pressure have been evaluated from different methods of interpretation using different theories. This paper provides a new method for interpretation the conventional limit pressure, the new method showed very good agreements with other methods used for evaluating the conventional limit pressure. The new method named as conventional limit pressure. The results of Menard pressuremeter conducted in Abu-Dhabi site been analyzed in five methods of interpretation for conventional and theoretical limit pressure. The deduced results from different methods showed some discrepancies for the same tests. The tested soil can be described as poorly graded sand with silt. 相似文献
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微波溶样-自动电位滴定法测定铬矿石中三氧化二铬 总被引：3，自引：2，他引：1
样品经硫酸-磷酸-氟硼酸分解,在30～60 kPa条件下进行微波溶样,用自动电位滴定仪测定铬矿石中三氧化二铬的含量。对两个不同三氧化二铬含量的铬矿石国家一级标准物质测定20次,测定的平均值与标准值的相对误差为0.015%～0.021%,相对标准偏差为0.09%～0.10%。选取主要进口国的不同含量的铬矿石进行主含量的测定,与经典法对比,分析结果均在合理允差范围之内。方法具有简便、快速、低耗、污染小等优点,可应用于大批铬矿石样品的分析及检测。 相似文献
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提出了用ａ－ｒ联测法探测采油区油水分布的新设想，在采油区进行了首次试验，获得成功。介绍了判别油水分布的理论依据、方法技术和成果资料分析方法。 相似文献
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The decrease of density contrast with depth in sedimentary basins is approximated by an exponential function. The anomaly
equation, in frequency domain, of a prismatic model with an exponential density function is derived. The method has been extended
to derive the Fourier transforms of the gravity anomalies of the sedimentary basin, wherein the basin is viewed as vertical
prisms placed in juxtaposition. The gravity anomalies of the sedimentary basin are obtained by taking the inverse Fourier
transforms. Filon’s method has been extended for calculating accurate inverse Fourier transforms. The accuracy of the method
has been tested using a synthetic example. A combination of space and frequency domain methods have been developed for inversion
of gravity anomalies over the sedimentary basin. The method has been applied to interpret one synthetic profile and one field
profile over the Godavari basin. The method developed in this paper to calculate the inverse Fourier transforms yields continuous
spectrum with accurate values. The maximum depth deduced from the gravity anomalies is of the same order as the depth encountered
to the basement at the Aswaraopeta borewell. 相似文献
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高应变动测法目前得到了越来越广泛的应用,研究其测试结果的可靠性对实际工程具有重要意义。对PHC桩应用高应变法、竖向静载方法进行试验,以确定桩基的单桩极限承载力。首先对2组不同直径的6根试桩进行高应变测试,采用国际上推荐的GOBLE-CAPWAPC-CASE方法,得到试桩的单桩极限承载力; 然后按慢速维持荷载法进行竖向抗压静载试验,将所得极限承载力与高应变法所得结果进行对比,高应变法所得结果高于静载试验的结果, 2种方法结果不同是由于2种方法的测试原理、计算方法、影响因素等不同所致。高应变法的理想化桩-土体系以及主要参数的设定对结果都有很大的影响,实际试验中应充分考虑如何取值。 相似文献
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地貌单位线(GIUH)基于流域地貌特征和概率方法，在我国许多地区得到广泛应用。针对面雨量分布不均问题，通过分析初始概率的变化，考虑GIUH的非线性改正，并用实际资料进行了验证。 相似文献
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从Ｐα的基本概念出发，分析了影响凡计算的因素，并针对现行马两层计算法存在的问题，提出了改进计算方法。经实际资料验证，效果较好，具有一定的实用价值和推广意义。 相似文献
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基于供需成因分析和供需水量平衡的旱情评价方法研究 总被引：2，自引：0，他引：2
以水资源的供需差值为旱情综合评价的基础,提出了两种旱情综合评价方法,即供需成因分析评价方法和供需水量平衡评价方法,应用山东省的实际资料对评价方法进行了检验,评价结果与实际相符。 相似文献
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The determination of indium in geological materials is difficult by usual analytical techniques because of their lack of sensitivity. Neutron activation analysis with special irradiation and counting conditions allows to determine indium ultra-traces with a quantitative detection limit about a few parts per billion. The method developed is fast and very sensitive and has been tested successfully for several American and French geochemical standards. 相似文献
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The analytical hierarchy process (AHP) is one of the most effective methods for criteria ranking/weighting to have been successfully incorporated into GIS analyses. We present a new method for optimizing pairwise comparison decision-making matrices in AHP method, which has been developed on the basis of an interval pairwise comparison matrix (IPCM) derived from expert knowledge. The method has been used for criteria ranking in land subsidence susceptibility mapping (LSSM) as a practical test case, for which an interval matrix was generated by pairwise comparison. To compare the capability of the AHP method (a traditional approach) with that of the proposed IPCM method (a novel approach), 11 creations of LSSM were ranked using each approach in turn. The criteria weightings obtained were then used to produce LSSM maps based on each of these approaches. The results were tested against a data set of known land subsidence occurrences, indicating an improvement in accuracy of about 14% in the LSSM map that was developed using the IPCM method. This improvement was achieved by minimizing the uncertainty associated with criteria ranking/weighting in a traditional AHP and could form a basis for future research into minimizing the uncertainty in weightings derived using the AHP method. Our results will be of considerable importance for researchers involved in GIS-based multi-criteria decision analysis (MCDA) and those dealing with GIS-based spatial decision-making methods. 相似文献
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The recharge of a karst aquifer, in terms of its quantity and spatial distribution, depends on various natural factors such
as climate, topography, vegetation, soil, and geology. Selection of an adequate method for assessing recharge in karst is
often a matter of dispute. Multi-parameter methods using Geographical information systems tools have recently been successfully
developed and applied in karstic terrains of Spain and Lebanon. Specific local conditions such as highly karstified terrains
could additionally complicate such an assessment. The Montenegro karstified terrains in the southern part of the External
Dinarides are characterized by a very high precipitation rate, irregular seasonal distribution, and absence of surface waters
(extremely high infiltration capacity of karst). Considering such conditions, an attempt to apply existing knowledge and experiences
to the development of an appropriate multi-parameter method for assessing spatial distribution of autogenous recharge has
been made. The KARSTLOP method has been developed, applied, and calibrated at catchments of several large karst springs of
Montenegro. Obtained results in tested catchment areas confirm that with some further improvements the KARSTLOP method could
be a useful tool to support research of karstic aquifers in similar highly karstified terrains. 相似文献
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A. K. Raina A. K. Chakraborty M. Ramulu J. L. Jethwa 《Fragblast: International Journal for Blasting and Fragmentation》2000,4(2):103-125
Rock mass damage due to blasting (BID) is important for the personnel working underground and also for rock reinforcement costs. Therefore, about 20 methods for damage assessment have been developed. The methods are shortly presented. Often several methods have to be used in combination to achieve good quantitative estimate of the damage. Some blast damage indices have been developed and one of them, the Dib (Yu & Vongpaisal 1996) after a modification of the Index was tested in field with good result. The ultrasonic method used both in lab and field tests has limited value and can only used with good accuracy to a depth of ~0.5 m. This method is not therefore recommended for blast damage measurements where damage depth could be up to 2.5 m. 相似文献
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Geochemical methods of prospecting for oil and gas have been developed by measuring the content of hydrocarbon gases in drill core and drilling mud obtained from key stratigraphic horizons. The samples may be recovered during the drilling of shallow structural wells. The method has been tested in the Ukraine, South Mangyshlak and West Uzbekistan. The results show distinct methane anomalies over oil and gas pools located in both anticline and monocline structures. 相似文献
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An approach for predicting swelling pressure of bentonites based on thermodynamic relationships between swelling pressure and suction is presented in this paper. The proposed method requires sorption isotherm data of the bentonites. A series of swelling pressure tests were performed on compacted specimens of bentonite-sand mixtures with different bentonite contents, water contents, and dry densities. The sorption isotherm of the pure bentonite was measured using a chilled-mirror hygrometer. It is found that the method works well for the bentonite-sand mixtures tested. Several published data on bentonites that have been proposed to be used as buffer and sealing material for nuclear waste repository were collected and used to verify the method. The proposed method is found to be also applicable for other bentonites of different types and therefore, can be used to predict swelling pressure of bentonites. 相似文献