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1.
A low-flux reactor (SLOWPOKE II) may be used to determine a large number of trace elements by neutron activation. Details of this technique are given along with results for 22 elements in 22 international reference rocks. Our results are compared with published "best values"; the agreement is favourable in most cases. 相似文献
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N. T. Kamenikhin 《Geochemistry International》2010,48(2):163-177
The paper is devoted to the solution of a reverse problem: reproducing the zoning of ore mineralization based not on the production
of chemical elements at various depth levels (this can be done only late in the course of exploration) but by finding out
elements according to a model for geochemical zoning during early exploration phases. The model provides a basis for evaluating
the erosion level of ore mineralization based on a single section through an ore-hosting geochemical aureole. The tools used
in the calculations are pair correlation coefficients and ordered series (arranged in descending order) of the average concentrations
of indicator elements of a given mineralization type. The application of the method led to revealing rigorously defined combinations
of negative and positive pair correlation coefficients and an individual sequence of elements of the zoning in ordered series
for each level of the ore-hosting structure. Elements of zoning are distinguished among indicator elements, with the former
marking levels of ore mineralization. The relations established thereby make it possible to determine element sequence of
zoning elements of ore mineralization as a whole and the affiliation of a given section with a certain level of the ore mineralization.
The model of pair correlation reveals eight levels (from distant supraore to distant subore), and the model of ordered sequences
points to thirteen levels. The models are nonseparatable, they interact and complement each other. The proposed methods can
be applied in exploration operations at hydrothermal ore deposits with mineralogical-geochemical zoning. 相似文献
3.
An account is given of the formulation and preparation of synthetic standards suitable for the routine analysis of minerals, ores and ore concentrates by instrumental neutron activation. Fifteen standards were prepared, each containing from one to seven elements. The standards contain forty-four elements that produce isotopes with half-lives longer than 12 hours. An evaluation of the accuracy and precision of the method of preparation is given. 相似文献
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Instrumental neutron activation analysis has been applied to the analysis of recently issued NBS reference materials SRM 1633a Fly Ash and SRM 1632a Bituminous Coal. Only the nuclides with half-lives of less than 48 hours have been used. The results for the determination of 18 elements (Fly Ash) and 19 elements (Coal) are compared with the values given by NBS and with recent results obtained by other investigators. 相似文献
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Yu. A. Shchekinov 《Astronomy Reports》2009,53(7):605-610
A possibility of an efficient condensation of heavy elements, such as iron, on the surface of dust grains in interstellar molecular clouds is studied. A high rate of dust destruction in the interstellar medium from one side, and a high degree of heavy elements depletion from the other indicate that the freezing-out of metals should be efficient in interstellar (predominantly molecular) clouds. This is possible only due to betatron acceleration of dust grains behind shocks that originate under intersection of supersonic turbulent flow. Estimates of the heavy elements depletion due to condensation on the surface of dust grains are given. 相似文献
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An attempt has been made in this research paper to understand the groundwater quality of coastal stretch from Sirkazhi to Manampandal of Nagapattinum district, Tamil Nadu (India). A total of 47 samples were taken for the baseline study. The water samples collected in the field were analyzed for electrical conductivity, pH, total dissolved solids (TDS), major cations like calcium, magnesium, sodium, potassium, and anions like bicarbonate, carbonate, chloride, nitrate, and sulfate, in the laboratory using the standard methods given by the American Public Health Association. The groundwater locations were selected to cover the entire study area and attention was given to the area where contamination is expected. The expected groundwater contaminants were chloride, nitrate, TDS, Na, and K. The results were evaluated in accordance with the drinking water quality standards given by the World Health Organization. To know the distribution pattern of the concentration of different elements and to demarcate the higher concentration zones, the contour maps for various elements were also generated, discussed, and presented. 相似文献
9.
许兆龙 《华东地质学院学报》2006,29(1):92-96
利用半开元等半拓扑概念引入拓扑分子格的S紧化与S次紧化概念,给出了它们的刻画,推广了王国俊(1990)拓扑分子格的紧化与次紧化概念,得出了拓扑分子格与其最简单点S紧化关于分离性(半分离性)的性质,以及正统拓扑分子格与其最简单点S紧化(S次紧化)关于分离性(半分离性)的性质等。 相似文献
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《International Journal of Coal Geology》1987,9(2):171-186
Thirty-three coal samples from the Northumberland Coalfield were investigated for thirty-six major and minor elements with a view to interpreting the mode of inorganic formation or association and their enrichment or depletion in relation to the published data for other coals.It was generally observed that the interelement correlation did not confirm a total dependency of the elements either on the inorganic or organic matter. However, the association of some of the minor elements tend to constitute a more satisfactory reference to the first phase of coalification (i.e. organo-metallic complexes). Principal components and factor analyses given for the elements confirm the mode of formation and provide the basis for suggesting three significant modes of concentration and association: (a) biological fixation; (b) mineral sorption; and (c) localized concentration.Comparison of the chemical data for this coal with published data appears to show similarity with the averages quoted for a “rich coal ash”. 相似文献
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Kuppusami GOVINDARAJU 《Geostandards and Geoanalytical Research》1982,6(1):91-159
All data reported by 200 analysts (106 laboratories) are presented for the four ANRT samples: Diorite DR-N, Serpentine UB-N, Bauxite BX-N and Disthène DT-N. Recommended values are given for the major and minor elements. As far as the as trace elements are concerned, DR-N has been characterized for 35 elements whereas the other three samples have been for only 20 elements. Wherever possible, brief comments have been inserted so as to explain our way of assigning recommended or proposed values.
After more than a decade of existence the total number of data reported for all the four samples reach only 3200 units which are not sufficient enough for a valid evaluation of compiled data. It is also pointed out that these samples are most likely to be available even during the next century as they have been prepared in large quantities of the order of one ton. A plea is therefore made for contribution of more data particularly for trace elements and for major elements which are present as trace elements in UB-N, BX-N and DT-N. 相似文献
After more than a decade of existence the total number of data reported for all the four samples reach only 3200 units which are not sufficient enough for a valid evaluation of compiled data. It is also pointed out that these samples are most likely to be available even during the next century as they have been prepared in large quantities of the order of one ton. A plea is therefore made for contribution of more data particularly for trace elements and for major elements which are present as trace elements in UB-N, BX-N and DT-N. 相似文献
13.
The origin of the Noril’sk and Talnakh sulfide PGE-Cu-Ni deposits that are associated with Triassic basaltic traps of Siberia
is considered. It has been shown that ore elements of these deposits (with the probable exception of iron) are of a crustal
origin rather than a mantle one. They entered the basalts owing to the remobilization (recycling) of ore elements from Early
Proterozoic sediments and rocks that are presented in the basement of the Siberian Craton. The criteria for prospecting for
analogous deposits are given. 相似文献
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首先基于布西奈斯克解,将表面作用有集中荷载时半无限弹性体的应力变形解在荷载作用区域利用复合辛普森公式进行数值积分,得到了表面处于不同形式的分布荷载作用下土体自由场水平及竖直方向应力和变形的计算公式。结合有限差分法及Mindlin位移解分别推导出弹性地基中桩顶作用有集中荷载时单桩桩、土单元的位移,两者结合便得到主动桩的分析方法。通过将堆载作用下的土体自由场位移施加于桩上把上述自由场分析及主动桩分析结合起来,推导出堆载作用下被动单桩的竖向和水平向承载特性的分析方法。选取地表附近作用有矩形均布荷载的计算工况,通过与有限元计算结果的对比验证了所提出的分析方法的正确性;将所提出的方法计算结果与某处工程案例中实测数据结果进行对比,分析表明利用该方法分析堆载对邻近桩基的水平及竖向影响是合理可靠的。 相似文献
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燃煤产物中有害元素淋滤实验的研究现状 总被引：8，自引：0，他引：8
对燃煤产物矿物学、元素地球化学以及显微岩石学特征、燃煤产物淋滤试验的研究现状进行了评述;对燃煤产物淋滤实验的类型、淋滤试验的有效性及条件选择、影响有害元素可溶性(淋滤行为)的因素进行了讨论;并给出了当前淋滤实验最为关心的元素种类。 相似文献
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万渝生 《吉林大学学报(地球科学版)》1991,(2)
批式熔融是大洋玄武质岩石形成的主要机制之一。本文建立了批式熔融作用中元素间的线性关系模型,并应用于北秦岭宽坪群变玄武质岩石化学分析资料的研究,对变异图解、相关矩阵、源区成分计算和估计等问题作了讨论。给出了一些具体应用的方法。 相似文献
19.
电子探针能谱矿物定量分析 总被引：4，自引：1，他引：4
文章以不同类型矿物作为分析实例，说明电子探针能谱仪和谱仪在矿物分析中的作用。实验表明使用能谱各类矿物主元素进行定量分析，既满足精密要求又能缩短分析时间，提高工效约２０倍，对能谱用于定量分析过程中的若干技术问题进行了讨论，以期获得最佳精密度的分析结果。 相似文献