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41.
Determination of Lithium, Beryllium and Boron at Trace Levels by Laser Ablation-Inductively Coupled Plasma-Sector Field Mass Spectrometry 总被引:1,自引:2,他引:1
Massimo Tiepolo Alberto Zanetti Riccardo Vannucci 《Geostandards and Geoanalytical Research》2005,29(2):211-224
The analytical capabilities of laser ablation (LA)-ICP-MS in determining Li, Be and B at trace levels in geological samples have been tested on a series of glass reference materials and natural samples. The LA-ICP-MS instrument used consisted of a sector-field ICP-MS coupled with a laser ablation microprobe operating at either 266 or 213 nm wavelength. Reference glasses from NIST (SRM 612, 614 and 616) and MPI-DING (KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, T1-G and ATHO-G) were selected to develop the analytical method and to assess the best instrumental configuration. A series of calcic amphiboles with different Li, Be and B concentrations were also analysed using both LA-ICP-MS and SIMS to test the applicability of the method to natural minerals. Results indicated that with a spot size of 40 μm the agreement between measured and reference values of Li, Be and B is generally better than 10% for NIST SRM 612 and 20% for NIST SRM 614. Average reproducibility at the 2s level was 10% for Li, 20% for Be and 15% for B. Limits of detection were approximately 100 ng g-1 for Be and B and 200 ng g-1 for Li. These results were confirmed by analyses carried out on natural amphiboles and compared well in terms of precision and accuracy with those commonly achieved by SIMS. 相似文献
42.
Roger Guérin 《Hydrogeology Journal》2005,13(1):251-254
43.
文章介绍区域地质背景、矿区地物化特征,对成矿时代、流体包裹体特征进行初步研究,并指出找矿远景,希望对矿区的矿产勘查具有借鉴和指导意义。 相似文献
44.
罗辛矿床为世界级白岗岩型铀矿床,存在SJ、SH、SK、Z17、Z19等多个矿(化)带,各矿(化)带矿物组合存在较大差异,但系统的矿物学研究程度不高。本次工作通过岩矿鉴定、扫描电镜观察、电子探针分析等方法,系统研究罗辛地区主要矿(化)带铀矿物共生组合及赋存状态。结果显示,白岗岩矿化按矿物组合可划分为3类: ①晶质铀矿+锆石+磷灰石组合,主要分布在Z17、Z19、SJ矿床(带);②铀石 、铀钍石+榍石+磷灰石组合,主要分布在SH矿床;③贝塔石组合,主要分布在SK、SH矿床。研究区铀成矿可划分为3个期次:岩浆期、热液期、表生淋积期。岩浆期为主成矿期,研究区晶质铀矿电子探针化学年龄为505±11 Ma,代表岩浆期成矿年龄。SH应进一步寻找铀石、铀钍石+榍石+磷灰石组合矿化白岗岩。 相似文献
45.
改进的能量守恒方法及其在CHAMP重力场恢复中的应用 总被引:1,自引:0,他引:1
XU Tianhe HE Kaifei Xi’an Research Institute of Surveying Mapping Middle Yanta Road Xi’an China. 《地球空间信息科学学报》2008,11(3):168-173
An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year's worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S. 相似文献
46.
Building damage in Dujiangyan during Wenchuan Earthquake 总被引:2,自引:1,他引:1
A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were seismically designed achieved the desired seismic fortification target; they sustained less damage than the non-seismically designed buildings. Among the seismically designed buildings investigated, RC frame buildings performed the best in terms of seismic resistance. Masonry buildings with a ground story of RC frame structure were the second best, and masonry buildings performed the worst. Considering building height, multistory buildings sustained more severe damage than high-rise buildings and 2- and 3-story buildings. Compared to residential buildings, public buildings, such as schools and hospitals, suffered more severe damage. 相似文献
47.
48.
49.
海相沉积成因的黑滑石矿床是近年来在我国发现的新的成因类型矿床,本文除着重介绍在川东南发现的海相沉积成因的黑滑石矿床地质特征和矿床成因外,还引进非金属矿床含矿建造和成矿系列的概念,提示黑滑石矿及与其共生伴生的其它非金属矿的找矿方向。 相似文献
50.
Improved Platinum-Group Element Extraction by NiS Fire Assay from Chromitite Ore Samples Using a Flux Containing Sodium Metaphosphate 总被引:1,自引:0,他引:1
Many chromite-rich rocks contain relatively high concentrations of the platinum-group elements (PGE). In many cases, the phases carrying PGE occur as either platinum-group minerals (PGM) or as base metal sulfides in solid solution in sulfides. In some cases, such as the UG-2 unit of the Bushveld Complex, the PGM are occluded inside chromite grains. Chromites are notably difficult to dissolve in most fluxes and if the chromite contains some PGM the possibility exists that not all the PGE will be recovered during fusion. In this work, shortcomings in published methods of analysis based on the nickel sulfide fire assay procedure were investigated and a new procedure developed based on the addition of sodium metaphosphate to the fusion mixture. Optimum composition of the fusion mixture was found to be 10 g sodium metaphosphate and 9 g silica to 10 g sample, 15 g sodium carbonate, 30 g lithium tetraborate, 7.5 g nickel and 4.5 g sulfur to achieve complete dissolution of chromite grains. The new flux mixture was evaluated by the analysis of reference material CHR-Pt+ (which is known to contain PGM inside chromite grains) and no undissolved chromite grains were found in the glassy slag. Analysis of the nickel sulfide beads from this fire assay using neutron activation analysis showed similar results for Rh and Ru when compared with published conventional true (or accepted) values, while Au, Ir, Os, Pd and Pt values determined here were 10 to 30% higher than the corresponding published conventional true values. It was concluded that the addition of sodium metaphosphate improved chromite dissolution in the flux and appears to improve PGE recovery. 相似文献