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排序方式: 共有1406条查询结果,搜索用时 15 毫秒
91.
X射线荧光技术用于西秦岭地区金矿勘查 总被引:1,自引:0,他引:1
本文根据用轻便型X射线荧光仪在西秦岭数个金异常区测量金的伴生元素——砷的荧光强度,间接找寻金矿的实践,阐明用该仪器可快速圈定金矿远景区和揭示隐伏金矿体,提高找矿效果。并对使用X射线荧光技术进行现场测量及配合金异常查证工作,作了初步探讨。 相似文献
92.
Hsueh-Yu Lu 《Environmental Geology》2007,51(6):1029-1041
A new method has been developed to estimate the hydraulic conductivity in unconsolidated aquifers. The method uses bulk geochemical
compositions correlated with hydraulic conductivities measured by pumping tests. The concept is based on a general rule that
hydraulic conductivity is principally controlled by grain-size distribution and particle shape,both of which relate to mineralogical
composition. Using a MINLITH algorithm, normative mineralogical compositions can be derived from bulk geochemical compositions
economically and expediently, and then correlated to the hydraulic conductivity determined by pumping tests in the field.
In this study, 202 sediment samples from nine unconsolidated aquifers were analyzed by X-ray fluorescence. Although hydraulic
conductivity does not show a definite relationship with geochemical compositions, it does demonstrate a linear logarithmic
equation to the content of normative earthy minerals. However, linear regressed equations should not be applied to aquifers
composed of medium to coarse sand and gravel sizes due to interference from lithic fragments. In addition, this equation tends
to overestimate hydraulic conductivity possibly because the effect of compaction is ignored in this study. 相似文献
93.
氢化物发生—原子荧光光谱法测定煤样中的硒 总被引:6,自引:2,他引:6
采用氢化物发生原子荧光光谱法测定了煤样中的总Se。煤样选用高压闷罐强酸消解的方法进行处理,所得消解液经6mol/L HCl将Se(Ⅵ)还原为Se(Ⅳ),然后进行测定。标准工作曲线的线性范围为0-400μg/L Se,检测限为0.4μg/L Se。用标准参考物质煤飞灰对方法进行了验证,所得总Se含量与标准值相符,对ω为10^-6级Se的4次测定,RSD≤4.5%。 相似文献
94.
95.
Fault-controlled dolomitization at Swan Hills Simonette oil field (Devonian), deep basin west-central Alberta, Canada 总被引:6,自引:0,他引:6
The partly dolomitized Swan Hills Formation (Middle‐Upper Devonian) in the Simonette oil field of west‐central Alberta underwent a complex diagenetic history, which occurred in environments ranging from near surface to deep (>2500 m) burial. Five petrographically and geochemically distinct dolomites that include both cementing and replacive varieties post‐date stylolites in limestones (depths >500 m). These include early planar varieties and later saddle dolomites. Fluid inclusion data from saddle dolomite cements (Th=137–190 °C) suggest that some precipitated at burial temperatures higher than the temperatures indicated by reflectance data (Tpeak=160 °C). Thus, at least some dolomitizing fluids were ‘hydrothermal’. Fluorescence microscopy identified three populations of primary hydrocarbon‐bearing fluid inclusions and confirms that saddle dolomitization overlapped with Upper Cretaceous oil migration. The source of early dolomitizing fluids probably was Devonian or Mississippian seawater that was mixed with a more 87Sr‐rich fluid. Fabric‐destructive and fabric‐preserving dolostones are over 35 m thick in the Swan Hills buildup and basal platform adjacent to faults, thinning to less than 10 cm thick in the buildup between 5 and 8 km away from the faults. This ‘plume‐like’ geometry suggests that early and late dolomitization events were fault controlled. Late diagenetic fluids were, in part, derived from the crystalline basement or Palaeozoic siliciclastic aquifers, based on 87Sr/86Sr values up to 0·7370 from saddle dolomite, calcite and sphalerite cements, and 206Pb/204Pb of 22·86 from galena samples. Flow of dolomitizing and mineralizing fluids occurred during burial greater than 500 m, both vertically along reactivated faults and laterally in the buildup along units that retained primary and/or secondary porosity. 相似文献
96.
Abstract: Synchrotron X-ray fluorescence analyses on individual hypersaline fluid inclusions were tested to using synchrotron source at Tsukuba (KEK), Japan. The XRF instrumentation at KEK meets the purpose of fluid inclusion analysis, nondestructive, multi–element, ppm detection limits, with micro spatial resolution. In practice, however, the quantitative chemical analysis of fluid inclusion requires further considerable data accumulation. Semi-quantitative distribution of elements (mass number > 25) in single fluid inclusion was obtained. 相似文献
97.
98.
应用放射性同位素x射线荧光分析仪测定各种元素含量在许多文献中均有报道。本文主要介绍84A86型轻便x射线荧光分析仪首次在福建省紫金山铜矿区测定粉末样、块状岩心、坑道壁中铜矿的含量及其所取得的经济效益。 相似文献
99.
X射线荧光光谱分析检出限问题的探讨与建议 总被引:12,自引:5,他引:7
对有关X射线荧光光谱分析低含量元素的检出限问题进行了多方面的探讨。从检出限的定义及其定义下的相对标准偏差到各种不同测量、校准与校正方法的检出限及其相对应的相对标准偏差进行计算。提出了以定义检出限的相对标准偏差为基准,对各种测量方法计算出的检出限进行重新界定,从而确认一个具有可比性的、精度一致的检出限。同时还讨论了仪器与X光管固有杂质元素谱线对该元素检出限的影响;测量仪器、测量条件与测量时间对检出限的影响;不同岩性试样对检出限的影响;检出限与测定限等问题。 相似文献
100.