鄂北膨胀土的矿物组成和化学成分分析

首先利用X射线衍射（XRD）对鄂北膨胀土中的不同矿物组成进行了鉴定,并根据衍射峰的强度和半高宽定量分析了各成分的含量,然后利用X射线能谱（EDX）对膨胀土中的化学元素组成进行了测定和分析,最后对膨胀土的结核现象进行了分析。其研究成果对评价膨胀土的潮解特性,揭示了膨胀土和改性膨胀土特性以及强度形成机理具有重要的意义,并为今后膨胀土的研究和应用提供了一定的理论依据。     

Organic matters and acid‐sulfate alteration in Itomuka mercury mine,Hokkaido, Japan: Implications for the transportation and deposition mechanisms of Hg

In order to examine the transportation and deposition mechanisms of Hg, we investigated the ore and hydrothermal alteration minerals and solid organic matters from Itomuka mercury mine located in the eastern part of central Hokkaido. In addition to the ore minerals, native mercury and cinnabar, quartz, marcasite, alunite, kaolinite, and minor amounts of pyrite and smectite were identified in the Hg ore by powder X‐ray diffraction (XRD) analysis. This mineral assemblage of acid sulfate alteration was likely developed under the conditions of low temperature (≤100°C) and low pH (≤2) in the steam‐heated environment. The H₂SO₄ was produced above the water table by the oxidation of H₂S separated from deep, near‐neutral fluids by boiling. The dominance of native mercury over cinnabar in Hg ore indicates that the greater part of mineralized Hg was transported as Hg⁰ in aqueous solution and vapor with low sulfur fugacity. The solid organic matters found in the Hg ore were analyzed with SEM‐EDS, micro‐XRD, and micro‐Fourier transform infrared (FTIR) spectroscopy, and these results suggest that the organic matters contributed to keeping the low fO₂ of the Hg‐bearing fluid and transportation of Hg as Hg⁰ in S‐poor condition. Because the solubility of Hg in acidic fluid is low, neutral to alkaline fluid seems to have leached Hg from the basement sedimentary rocks of Hidaka Group which also supplied the organic matters to the fluid. The oxidation and cooling of Hg‐bearing solution and vapor triggered the deposition of liquid Hg as a primary phase.     

LiCl化学剥离辉钼矿的实验研究

为了制得超细化的二硫化钼,采用LiCl剥离辉钼矿。在室温下,将一定量的二硫化钼加入到氯化锂水溶液中,经搅拌、超声振荡,得到有沉淀的溶液。经过滤、水洗、干燥,用XRD,SEM表征,结果表明二硫化钼的径厚比明显减小,层厚达到约19nm。其原因可能是锂离子进入到MoS2的层间,撑开了二硫化钼层化学剥离所致。     

Mineralogical characteristics of airborne particles collected in Beijing during a severe Asian dust storm period in spring 2002

Asian dust storm (ADS) samples were collected on March 20,2002 in Beijing,China. High-resolution field emission scanning electron microscopy with energy dispersive X-ray detector (FESEM-EDX) and X-ray diffraction (XRD) were used to study the morphology,chemical compositions,number-size dis-tributions and mineralogical compositions of ADS particles. The mineral particles were major compo-nents in the ADS samples,accounting for 94% by number. The XRD analysis indicated that the dust particles were dominated by clay (40.3%),and quartz (19.5%),followed by plagioclase (8.4%),calcite (7.5%),K-feldspar (1.5%),hematite (0.9%),pyrite (0.9%),hornblende (0.4%) and gypsum (0.3%),with a certain amount of noncrystalline materials (20.3%). Clay minerals were mainly illite/smectite mixed lay-ers (78%),followed by illite (9%),kaolinite (6%),and chlorite (7%). In addition to these main minerals,FESEM-EDX also detected some trace minerals,such as dolomite,pyrite,thenardite,as well as heavy minerals represented by rutile,ilmenite and apatite. The mineralogical compositions of the 2002-03-20 Asian dust storm and the Saharan dust plumes were similar but the clay mineralogy showed a great distinction,with the illite/smectite mixed layers being common in the Asian dust storm but illite being common in the Saharan dust plumes.     

翡翠制品的无损伤鉴定

翡翠是玉石中的珍品，其主要组成矿物是硬玉，翡翠制品中所含矿物的种类和数量是决定其真伪、质量和价值的主要因素。通过几个典型的鉴定翡翠制品的实例，系统地说明用Ｘ射线衍射分析方法无损伤鉴定翡翠制品的原理及方法，并对此进行了讨论。     

Comparing the Success Rate of Raman Spectroscopy and Powder XRD for Routine Mineral Identification

This study provides a measurement of success rate of Raman spectroscopy for mineral identification, and a direct comparison of powder X‐ray diffraction (PXRD) is provided by applying the same procedure for measuring its success rate against the identical set of samples. Consistent, standardised analytical procedures were applied to a set of fifty‐five minerals, and a success score was assigned to the results of each analytical method for each sample. For each analytical method, an average success rate (on a scale of 0–100) was calculated from these success scores. The success rate measured for powder XRD is 89, while the success rate for Raman spectroscopy came to 77. As the most common analytical challenge in Raman spectroscopy is specimen photoluminescence (PL), an estimate of the impact of technological advances that would eliminate this interference is provided by recalculating the success rate after removing the samples that produced PL interference from consideration. The resulting no‐PL success rate of 90 indicates that the success rate of Raman spectroscopy would be quite comparable to powder XRD if PL interference could be removed from Raman spectra.     

XRD定量分析技术在大坪岩堆固结灌浆量检测中的应用

XRD定量分析技术,是根据水泥中所特有的粉末微晶物相组合,测试硅酸二钙、硅酸三钙等水泥指示矿物2.78特征谱线变化,精确测定被灌体内外来水泥指示矿物的质量分数,而不受原有岩土矿物所含原地相同化学成份的干扰及影响。通过测定水泥质量分数计算灌浆率,最终确定灌浆量。     

An XRD, TEM and Raman study of experimentally annealed natural monazite

 The healing of radiation damage in natural monazite has been experimentally studied in annealing experiments using XRD, TEM, Raman microprobe and cathodoluminescence analysis. The starting material was a chemically homogeneous monazite from a Brazilian pegmatite with a concordant U–Pb age of 474 ± 1 Ma and a U–Th/He age of 479 Ma. The monazite shows nm-scale defects induced by radioactive decay. The X-ray pattern of the unheated starting material revealed two distinct monazite “phases” A and B with slightly different lattice parameters. Monazite A shows sharp reflections of high amplitudes and slightly expanded lattice parameters (1% in volume) compared to a standard monazite. Phase B exhibits very broad reflections of low amplitudes. Two sets of experiments were performed. First, dry monazite powder was annealed at 500, 800 and 1000 °C for 7 days. Each run product was analysed by X-ray diffractometry. Second, monazite grains were hydrothermally annealed at temperatures from 500 to 1200 °C for 5 to 15 days. TEM observations show that partial healing of the monazite lattice already occurred at 500 °C and increased gradually with temperature, so that after 10 days at 900 °C complete healing was achieved. The observations are interpreted accordingly: the starting material has a mosaic structure consisting of two domains, A and B, which are basically two monazite crystals with different lattice parameters. We suggest that the A domains correspond to well-crystallised areas where helium atoms are trapped. The accumulation of He causes expansion of the A monazite lattice. Diffraction domains B are interpreted as a helium-free distorted monazite crystal lattice, which can be referred to old alpha-recoil tracks. These B domains are composed of “islands” with an expanded lattice, induced by the presence of interstitials, and “islands” of a compressed monazite lattice, induced by presence of vacancies. Both the islands will pose stress on the lattice in the vicinity of the islands. The broadening of the B reflections is due to the expanded or compressed diffraction domains and to the different amount of the distortion. With increasing temperature the unit-cell volume of monazite A decreases, i.e. the position of the A reflections shifts towards smaller d _hkl values. This was interpreted as a relaxation of the monazite lattice due to helium diffusion out of the monazite lattice. Simultaneously, the nm-sized defect domains B are healed. At 900–1000 °C only a monazite with well-crystallised lattice and minimum unit-cell volume is observed. Received: 7 May 2001 / Accepted: 11 October 2001     

东南太平洋热液区硫化物样品富集培养物中Fe3＋还原细菌的多样性分析

采集了东南太平洋热液区DYl15-20V一$35一TVGl7站位的沉积物硫化物样品,其含有76．717％（m／m）强还原性的磁性良好的黄铁矿．以乳酸钠为电子供体,不溶性的氢氧化铁为电子受体,对该样品进行Fe¨还原细菌的定向富集培养．通过构建该茵群的16SrDNA基因文库,随机挑选82个阳性克隆子进行群落结构多样性分析．研究结果表明：82个克隆代表的6种基因型分别属于4个主要类群,其中ε一变形杆菌占有绝对优势,达到55．2％．此外其还包括厚壁菌门、β一变形杆菌和仅．变形杆菌,克隆子比例依次为27．6％、10．3％、6．9％．在富集产物中还原氢氧化铁的功能菌群主要是具有硫还原作用的ε一变形菌中的硫还原菌．     

海洋油气渗漏烃蚀变带的地球物理检测及在中国海区的应用

针对海洋油气渗漏可以在近地表沉积层中引起的一系列烃蚀变效应,本文讨论了利用不同手段,分层次进行检测的几种方法.利用烃蚀变带所产生的磁异常现象,在平面上圈定油气渗漏的分布范围,进而寻找海底油气藏.同时,钻井岩芯岩屑的磁性质测量结果可以从剖面上预测下伏岩层的含油气性.最终利用X射线衍射方法(XRD)对典型层位岩石样品的物相测量,进行烃蚀变矿物组合分析并通过镜下鉴定作进一步的综合判断.对渤海海域烃蚀变效应的磁法检测研究结果与遥感及其他方法的研究结果有很好的一致性.对南海3口钻井岩芯岩屑的磁性测量结果表明：两口有油气前景而另一口没有异常.这与实际结果十分一致,同时表明该方法在海区同样可以具有良好效果.