A Comprehensive Method for Precise Determination of Re,Os, Ir,Ru, Pt,Pd Concentrations and Os Isotopic Compositions in Geological Samples   总被引：2，自引：0，他引：2       下载免费PDF全文

Zhuyin Chu  Yan Yan  Zhi Chen  Jinghui Guo  Yueheng Yang  Chaofeng Li  Yanbin Zhang 《Geostandards and Geoanalytical Research》2015,39(2):151-169

A comprehensive method for the precise determination of Re, Os, Ir, Ru, Pt and Pd concentrations as well as Os isotopic compositions in geological samples is presented. Samples were digested by the Carius tube method, and the Os was extracted by conventional CCl₄ method. The Re, Ir, Ru, Pt and Pd were first subgroup separated from the matrix elements into Re‐Ru, Ir‐Pt and Pd by a 2‐ml anion exchange column. Subsequently, the Re‐Ru was further purified by a secondary 0.25 ml anion exchange column or by microdistillation of Ru using CrO₃‐H₂SO₄ as an oxidant followed by a secondary 0.25 ml anion exchange separation of Re. The Pd and Ir‐Pt were further successively purified by an Eichrom‐LN column to completely remove Zr and Hf, respectively. Rhenium, Ir, Ru, Pt and Pd were individually measured by multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS), except for Ru after microdistillation purification was analysed by negative‐thermal ionisation mass spectrometry (N‐TIMS). The analytical results for peridotite reference material WPR‐1 agree well with the previously published data. Finally, several mafic rock reference materials including TDB‐1, WGB‐1, BHVO‐2, BCR‐2, BIR‐1a and DNC‐1a were analysed for Re‐Os isotopes and platinum‐group element concentrations to test their suitability for certification.  相似文献   

Winter performance of an urban stormwater pond in southern Sweden     

Annette Semadeni‐Davies 《水文研究》2006,20(1):165-182

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Vertical profiles of hydrogen chloride in the troposphere     

B. Vierkorn-Rudolph  K. Bächmann  B. Schwarz  F. X. Meixner 《Journal of Atmospheric Chemistry》1984,2(1):47-63

Vertical profiles of gaseous hydrogen chloride have been measured in the lower and middle troposphere. For sampling, denuder tubes coated with porous silica were used. Hydrogen chloride was determined by gas chromatography in combination with a derivatization method. The samples were collected over the Atlantic Ocean northwest of Norway in early September 1981 and over the Mediterranean Sea and north-eastern Spain in December 1981 at altitudes between 0.1 and 7 km. Above the 3 km altitude the mixing ratios are generally very low and relatively uniform with values of 50–100 ppt. Below 3 km, the variations of the HCl-mixing ratios are larger with maximum values of up to 500 ppt. The profiles are discussed with respect to the vertical and horizontal transport conditions and the possible sources and sinks of gaseous hydrogen chloride.  相似文献   

‘frost and salt’ weathering: Further experimental results     

J. P. McGreevy 《地球表面变化过程与地形》1982,7(5):475-488

A laboratory experiment has been conducted to examine the effects of ‘frost and salt’ weathering (i.e. physical breakdown by the freezing of salt solutions) on a limestone. Results show that the presence of certain salts in solution can inhibit frost damage. These findings are in direct conflict with those presented by Goudie (1974) and, more recently, Williams and Robinson (1981). Comparison of the experimental methods used in each of these three studies suggests that opposing results can be explained in terms of the different experimental procedures which were employed. If salt supply is frequent and plentiful then it seems likely that rock breakdown will be enhanced-this is the case represented by the experiment of Williams and Robinson. Conversely if the salt supply is limited and the amounts of salt remain more or less constant then rock breakdown will be inhibited-the case of the present experimental study. Caution is therefore advocated when attempting to extrapolate laboratory-derived results to infer on the behaviour of rocks under natural conditions. Several environmental situations in which ‘frost and salt’ weathering may be a possibility are dsiscussed, but it is concluded that further field data, especially concerning temperature regimes and salt availability at and below rock surfaces in cold regions, would be necessary before more definite statements could be made about the efficacy of this process.  相似文献   

Single-crystal electronic absorption spectroscopy of synthetic chromium-, cobalt-, and vanadium-bearing pyropes at different temperatures and pressures     

M. N. Taran  K. Langer  C. A. Geiger 《Physics and Chemistry of Minerals》2002,29(5):362-368

 Single crystals of synthetic vanadium-, chromium- and cobalt-bearing garnets, Pyr:V0.06, Pyr:V0.13, Pyr:Cr0.04, Pyr:Co0.10, and Gt:Co3.00, and a natural vanadium-bearing grossular, Gross:V0.07 (Cr³⁺ < 0.005), were studied by electronic absorption spectroscopy in the wavenumber range 35 000–5000 cm⁻¹ under ambient conditions and at temperatures up to 600 K and pressures up to 8 GPa. The T and P behavior of the absorption band energies and intensities shows the following for the different transition metal-bearing garnets: Cr: The thermal expansion of chromium octahedra are similar to and the Racah parameter the same in synthetic Cr-doped pyrope, α_poly≅ 1.3 × 10⁻⁵ K⁻¹, and in natural pyrope, α_poly≅ 1.5 × 10⁻⁵ K⁻¹, and B=655 cm⁻¹, respectively. Ca^2+[8]-free garnets have a slightly stronger crystal field at the Y^[6] site and, therefore, the energies of the two spin-allowed Cr³⁺ dd bands are ca. 300 cm⁻¹ higher in Mg-pyrope than in natural Ca-bearing pyrope. Co: Increasing temperature causes only a small thermal expansion of the cobalt dodecahedra. Increasing pressure gives rise to appreciable compression, which is similar to that of the Fe²⁺-dodecahedra in almandine, where k=125 ± 25 GPa. T and P dependence of the Co band intensities may be caused by strong spin-orbit coupling. V: Occurs in at least two valence states and structural sites: (1) V³⁺ in octahedral sites gives rise to two spin-allowed bands, at 17 220 cm⁻¹ and 24 600 cm⁻¹, whose temperature dependence is typical for spin-allowed dd transitions in centrosymmetric sites. (2) V⁴⁺, which causes a set of dd absorption bands similar to those observed in the spectrum of V⁴⁺-doped Zr[SiO₄]. The P behavior of the V absorption bands indicates an interaction between V³⁺ and V⁴⁺ species. Received: 27 June 2001 / Accepted: 19 December 2001  相似文献   

含氯盐和硫酸盐类盐渍土膨胀特性的研究   总被引：5，自引：2，他引：5  

高民欢  李斌 《冰川冻土》1997,19(4):346-353

对含氯盐和硫酸盐类盐渍土的盐胀规律及影响因素进行了较为系统的试验研究，得出了盐胀随温度变化的若干规律，即盐胀随温度变化的关系式，起胀温度与各影响因素之间的关系式，盐胀与降温速度的关系式，成型温度对盐胀规律的影响等。分析了Ｎａ２ＳＯ４含量，ＮａＣｌ含量，Ｃｌ＾－／ＳＯ４＾２－，含水量对盐胀的影响，给出了盐胀与各影响因素之间的关系式。  相似文献   

山谷、盆地酸雨形成的特点及分析   总被引：3，自引：0，他引：3  

洪正昉 《水文地质工程地质》2001,28(3):28-30

通过多年来对酸雨监测资料的研究，根据酸雨的发展情况，分析了山谷、盆地的酸雨形成特点，提出了山谷和盆地酸雨形成的新观点，认为其酸雨的形成主要是来自当地自身环境所产生的大气污染，其次才是外界的污染因素，中和离子也是酸雨污染加重的原因之一。  相似文献   

重金属离子对中华绒螯蟹肝胰脏和鳃丝SOD,CAT活力的影响   总被引：14，自引：3，他引：14  

潘鲁青  任加云  吴众望 《中国海洋大学学报(自然科学版)》2004,34(2):189-194

研究了 3种重金属离子 (Cu2 ,Zn2 ,Cd2 )对中华绒螯蟹肝胰脏和鳃丝 SOD,CAT活力的影响。实验结果表明 ,肝胰脏和鳃丝 SOD,CAT活力在 3种重金属离子作用下分别随取样时间变化显著 (P<0 .0 5 ) ,对 2种抗氧化酶活力的抑制均为肝胰脏 <鳃丝。 3种重金属离子在实验时间内对肝胰脏 2种抗氧化酶活力的影响呈峰值变化 ,低浓度组表现为促进作用 ,高浓度组在 96 h时为抑制作用 ;低浓度组在 72 h内能提高鳃丝 2种抗氧化酶活力 ,随后下降 ,至 96 h时表现为抑制作用 ,而高浓度组一直为明显的抑制作用 ,2种抗氧化酶活力表现出明显的时间、剂量效应关系。因此 ,肝胰脏和鳃丝SOD,CAT2种抗氧化酶可作为中华绒螯蟹毒理学的评价指标。  相似文献   

Transfer of manganese and ferro ions by manganese bacteria     

Shi Junxian  Chen Zhongyuan 《海洋学报(英文版)》1996,15(3):355-363

Ｔｒａｎｓｆｅｒｏｆｍａｎｇａｎｅｓｅａｎｄｆｅｒｒｏｉｏｎｓｂｙｍａｎｇａｎｅｓｅｂａｃｔｅｒｉａ￥ＳｈｉＪｕｎｘｉａｎａｎｄＣｈｅｎＺｈｏｎｇｙｕａｎ（ＴｈｅＳｅｃｏｎｄｉｎｓｔｉｔｕｔｅｏｆＯｃｅａｎｏｇｒａｐｈｙ，ＳｔａｔｅＯｃｅａｎｉｃＡｄ...  相似文献   

4种重金属离子对彩虹明樱蛤(Moerella iridescens)的急性致毒效应   总被引：2，自引：0，他引：2       下载免费PDF全文

王志铮  王伟定  杨阳  卢振锋 《海洋与湖沼》2007,38(4):373-378

以彩虹明樱蛤养殖壳高优势组(平均壳高为17.35±1.01mm)为实验动物,进行4种重金属离子Hg2 、Cr6 、Cu2 、Zn2 对彩虹明樱蛤的急性毒性和加和等毒性强度联合毒性试验。结果表明,彩虹明樱蛤对重金属的耐药性均随实验时间延长而缓慢降低,4种重金属离子毒性大小依次为Cu2 、Hg2 、Zn2 、Cr6 ,其对彩虹明樱蛤96h的半致死质量浓度分别为0.0554mg/L、0.1099mg/L、2.2605mg/L、19.6277mg/L;Hg2 、Cr6 、Cu2 、Zn2 离子两两组合在加和等毒性强度下对彩虹明樱蛤96h联合急性毒性所呈现的致毒特征与离子间毒性强度匹配情形密切相关。  相似文献