全风化花岗岩全岩和粘粒中粘土矿物含量变化对比

工程实践和理论研究中常用全岩和粘粒中粘土矿物绝对和相对含量。对同一样品探求两者关系,便于数据对比,有利于工程应用。以采自香港九龙的2处边坡3个探坑中51个全风化花岗岩样品为例,作者用同一套仪器、测试方法,先后采用了颗分法测粘粒质量百分比、物理化学方法测比表面积、XRD方法测矿物成分,分别得出了全岩和粘粒中粘土矿物的绝对含量和相对含量,以及用粘粒质量百分比乘以相对含量得出的换算含量。另外还将全岩XRD矿物成分同薄片统计结果进行了相关分析。对粘土矿物绝对含量基本为20%～45%的全风化花岗岩,对比分析不同含量结果表明:全岩中的某些粘土矿物,如高岭石、蛭石的绝对含量远大于换算含量;不同样品中高岭石和蛭石的相对含量变化幅度远大于它们在全岩中绝对含量变化,两者变化呈现某种一致性;全岩中粘土矿物含量远大于粘粒(粒径<2μm和<5μm两个界限)的含量。后两者相对而言变化基本一致,差值不大;同全岩中粘土矿物含量相关性较好的是比表面积;同薄片统计结果相比,全岩XRD粘土矿物含量受对风化矿物处理不确定性的影响,结果往往偏大。     

现代生物磷灰石及化石磷灰石研究

本文对现代脊椎动物牙齿及骨骼以及埋藏于黄土中的化石进行了矿物学研究。它们主要由磷灰石组成,含ＯＨ、ＣＯ３＾２－和有机质,结晶程度很差。现代生物磷灰石为羟基磷灰石。化石磷灰石具ＣＯ３＾２－含量高,ＣＯ３＾２－占据ＰＯ４＾３－位置,并发生重结晶等特点,属碳羟磷灰石。化石化总趋势是有机质丢失,其它钙的磷酸盐溶解,ＣＯ３＾２－一增中并置换ＰＯ４＾３－进入晶格的磷灰石重结晶作用。生物磷石加热至１２００℃,红     

蒙脱石晶体结构构型及其XRD、IR的分子模拟

利用Cerius2软件分别构建了15种含有0～96个水分子的Li-、Na-、K-蒙脱石超晶格模型。分析了模型结构中的键长和键角,运用分子力场方法—UFF力场构型优化得到蒙脱石的最优构型及其总能量等参数,在此基础上计算了3种蒙脱石含有32、64和96个水分子时晶体结构的X射线衍射(XRD)和红外吸收光谱(IR)。结果表明,蒙脱石结构模型中键长和键角等参数说明其结构具有合理性;当蒙脱石的结构达到能量最小构型时,体系的总能量随着水含量的增加而降低;XRD的模拟结果和实验结果相一致;IR的模拟结果与实验结果有所偏离,可能是由选取的分子力场和分子位能模型所致。     

氧化铬-铝混杂柱支撑蒙脱石的制备和性能

以浙江和新疆的膨润为原料合成了氧化铬－铝混杂柱支撑蒙脱石。分别用铝盐及铬盐溶液,经碱水解生成的聚羟基铬－铝混杂阳离子的成柱溶液,聚羟基铬－铝混杂阳离子通过阳离子交换引入蒙脱石,所得产物的性质用Ｘ射线衍射、热分析、红外光谱和ＢＥＴ比表面及孔径分布测量等方法研究并与氧化铬柱支撑脱石（简称铬蒙脱石）的性能进行比较,所得氧化铬－铝混杂柱支撑蒙脱石（简称铬－名蒙脱石）,其基面间距较高（２．１ｎｍ＾２／ｇ,这     

从高岭土中富集地开石和珍珠陶石的实验研究

本文报道了用氢氟酸溶蚀的方法，从天然高岭土中分离和富集地开石或珍珠陶石。研究表明，用适当的氢氟酸溶蚀处理，与高岭石伴生的微生地开石或珍珠陶石被富集于残余粘土中，从而达到分离和富集地开石或珍珠陶石的目的．在高岭石、地开石和珍珠陶石中，以珍珠陶石耐氢氟酸的稳定性最好，地开石次之，高岭石最易被溶蚀。     

Heavy meals in urban roadside soils, part 1: effect of particle size fractions on heavy metals partitioning

Urban roadside soils are important environmental media for assessing heavy metal concentrations in urban environment. However, among other things, heavy metal concentrations are controlled by soil particle grain size fractions. In this study, two roadside sites were chosen within the city of Xuzhou (China) to reflect differences in land use. Bulk soil samples were collected and then divided by particle diameter into five physical size fractions, 500–250, 250–125, 125–74, 74–45, < 45 μm. Concentrations of metals (Ti, Cr, Al, Ga, Pb, Ba, Cd, Co, Cu, Mn, Ni, V, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) were determined for each individual fraction. These metals could be roughly classified into two groups: anthropogenic element (Pb, Ba, Cd, Cu, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) and lithophile element (Ti, Cr, Al, Ga, Co, Mn, Ni, V) in terms of values of enrichment factor. As expected, higher concentrations of anthropogenic heavy metals (Cu, Zn, Mo, As, Hg, Bi, Ag) are observed in the finest particle grain size fraction (i.e. < 45 μm). However, heavy metals Se, Sb and Ba behave independently of selected grain size fractions. From the viewpoint of mass loading, more than 30% of the concentrations for all anthropogenic heavy metals are contributed by the particle grain size fractions of 45–74 μm at site 1 and more than 70% of the concentrations for all heavy metals are contributed by the particle grain size fractions of 45–74 and 74–125 μm at site 2. These results are important for transport of soil-bound heavy metals and pollution control by various remedial options.     

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．     

Mineralogical Characterization of Graphite Deposits from Thodupuzha-Kanjirappally Belt, Madurai Granulite Block, Southern India

Graphite from deposits occurring in the high-grade metamorphic rocks and their larteritized equivalents of the Thodupuzha-Kanjirappally Belt in Madurai Granulite Block, southern India is structurally fully ordered (crystallite size, Lc₍₀₀₂₎ ranging from 469 to 749 Å), possess high degree of graphitization (DG value ranging from 105 to 267 Å) and reflect crystallization at high temperature (700±100°C). Raman spectra of graphite display profiles corresponding to high crystallinity and high structural ordering. The high temperature crystallinity characteristics of graphite were not obliterated during retrogression of granulites to amphibolite facies gneisses. Preliminary carbon stable isotope results show a spread in isotope values from —11.8 to —26.8 %, which suggest more than one sources for carbon. The lighter carbon isotope values are suggestive of biogenic origin, whereas the heavier ones are probably fluid precipitated graphite.     

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。