硅酸盐体系的化学平衡:(1)物质平衡原理   总被引：6，自引：5，他引：6  

马鸿文  杨静  刘贺  李贺香  白志民  王庆华 《现代地质》2006,20(2):329-339

通过具体应用实例,系统介绍了在硅酸盐体系的化学平衡研究中,依据物质平衡原理,求解“相混合方程”(PME)而进行物相定量分析的“相混合计算”(PMC)方法。应用实例包括矿物原料和结晶岩物相的定量分析,复杂固溶体矿物的端员组分计算,多组分硅酸盐陶瓷的配料比例计算,以及硅酸盐陶瓷制品物相的定量分析。物相定量分析结果是结晶岩和工业岩石原料分类命名的基础,可以为改进矿物原料预处理工艺提供依据,也是研究硅酸盐体系的化学平衡、对材料制备过程进行热力学分析的基础。实际计算中必须合理估计各种分析数据的累积误差。优化计算结果的理论依据主要有矿物晶体化学原理、矿物共生组合规律和次要组分分配的固溶体矿物相优先原则。  相似文献   

锡石的原位高压X射线衍射研究     

隋兴伟  秦善  李海建  李玉娟  刘景  李晓东  李晖 《矿物岩石》2006,26(2):10-15

利用同步辐射能量色散X射线衍射(EDXD)方法和金刚石对顶砧(DAC)高压技术对采于四川平武的锡石进行原位高压(达24.0 GPa)结构研究发现:压力加载过程中,锡石在13.8 GPa时发生了从金红石型结构(P 42/m nm)到C aC l2型结构(P nnm)的位移式相变;在19.9 GPa时又由C aC l2型结构相变为黄铁矿型结构(P a3),此相变为重构式相变。对于第Ⅳ主族元素氧化物(S iO2,G eO2,SnO2和PbO2)及过渡金属氧化物(M nO2和R uO2)的高压行为进行了讨论,它们具有相似的高压相变序列,这些成果对与斯石英同构氧化物的高压行为研究提供了有价值的参考。  相似文献   

基于三维有限元分析的土钉支护结构优化设计研究     

张远芳  高盟 《水文地质工程地质》2006,33(5):106-109

通过建立三维有限元模型，对土钉支护的变形和受力性能进行分析，得出土钉力的合理分布。在此基础上，考虑土钉支护的水平位移，采用遗传算法＋复合形法，对土钉支护的结构优化设计进行研究，建立了土钉支护结构的优化设计数学模型，并编制了相应的计算程序。通过算例分析，并与基于极限平衡分析的优化结果相比较，得出合理的土钉支护结构设计的参考结论。  相似文献   

大姚铜矿白垩系马头山组砂岩类的地球化学特征及成岩成矿背景分析     

甘凤伟  方维萱  王训练  韩润生 《矿产与地质》2006,20(4):340-347

分析大姚铜矿砂岩类的常量元素，反映其成岩成矿的构造背景，砂岩铜矿中碎屑岩的常量元素特征主要受物源区控制。大姚砂岩铜矿成矿受氧化-还原环境控制，分析大姚六苴矿床岩石和矿石样品的Fe^2＋／Fe^3＋值与铜元素含量之间的关系，探讨砂岩铜矿的氧化-还原环境特征，从而建立大姚砂岩铜矿的地球化学相。  相似文献   

电吸附找矿法在捕获常规化探方法难以发现的异常时的有效性     

杨芳芳  卢宗柳  周奇明  陆一敢 《矿产与地质》2006,20(4):479-483

电吸附找矿法是一种针对寻找隐伏矿而研制的找矿新方法，它属金属活动态提取法的一种，其找矿原理是：深埋藏隐伏矿在地电化学作用下发生溶解，溶解出来的矿物质在各种迁移动力的驱动下，从地下深部向上运移到地表，进入土壤形成后生异常。后生异常组分多属活动态，但活动态组分不仅存在于后生异常中，也存在于同生异常——原生晕异常和次生晕异常中，因此，应用电吸附找矿法寻找露头矿和浅埋藏矿时，其效果与常规化探方法是一样的；但电吸附找矿法的主要作用是可应用于寻找深埋藏隐伏矿，因由隐伏矿引起的后生异常活动态组分含量很低，常规化探方法很难发现它，而电吸附找矿法却能捕获它。  相似文献   

西太平洋副高活动指数的吸引子维数计算     

董兆俊  张韧 《热带气象学报》2006,22(4):400-404

基于NCEP／NCAR再分析资料计算出的西太平洋副高活动的三种特征指数，利用相空间重构方法对副高活动的三种特征指数的混沌特性和分数维进行了计算。计算结果表明，副高的短期活动存在混沌吸引子，副高脊线指数和面积指数动力系统的独立变量数目的上、下限分别为3和6，分析结果为副高动力系统的重构研究奠定了基础。  相似文献   

Removal of perchlorate （ClO4^-） contaminants by calcined Zn-Al layered double hydroxides     

Liang LU Yulin WANG Jing HE 《中国地球化学学报》2006,25(B08):255-255

Layered double hydroxides （LDHs） are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions, giving rise to positively charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDHs is based on a very interesting property of these materials, the so-called memory effect： Calcination of LDHs produces intermediate non-stoichiometric oxides （CLDH） which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Perchlorate＇s （ClO4^-） strong oxidizing capabilities make it ideally suited for use as a propellant in solid rocket fuel. However, this use in rocket fuel has led to the ClO4^- contamination of considerable amounts of water throughout the United States. ClO4^- has been shown to inhibit iodide uptake by the thyroid gland; and in large doses, it has been linked to anemia and fetal brain damage. This is especially a problem in China. With the recent emergence of perchlorate contamination as an important drinking water quality issue, adsorption by calcined LDHs was studied for ClO4^- removal. In this work, the effect of various factors such as （a） CLDH structure, （b） conditions for removal of ClO4^- ion, such as dosage of adsorbent, initial concentration of ClO4^-, and temperature and （c） co-existing anions in perchlorate contamination on the removal of ClO4^-, have been investigated, respectively.  相似文献   

Wave velocities in a pre-stressed anisotropic elastic medium     

M. D. Sharma  Neetu Garg 《Journal of Earth System Science》2006,115(2):257-265

Modified Christoffel equations are derived for three-dimensional wave propagation in a general anisotropic medium under initial stress. The three roots of a cubic equation define the phase velocities of three quasi-waves in the medium. Analytical expressions are used to calculate the directional derivatives of phase velocities. These derivatives are, further, used to calculate the group velocities and ray directions of the three quasi-waves in a pre-stressed anisotropic medium. Effect of initial stress on wave propagation is observed through the deviations in phase velocity, group velocity and ray direction for each of the quasi-waves. The variations of these deviations with the phase direction are plotted for a numerical model of general anisotropic medium with triclinic/ monoclinic/orthorhombic symmetry  相似文献   

Pseudo-dynamic approach of seismic active earth pressure behind retaining wall   总被引：4，自引：2，他引：4  

Deepankar Choudhury  Sanjay S. Nimbalkar 《Geotechnical and Geological Engineering》2006,24(5):1103-1113

Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. Commonly used Mononobe-Okabe method considers pseudo-static approach, which gives the linear distribution of seismic earth pressure in an approximate way. In this paper, the pseudo-dynamic method is used to compute the distribution of seismic active earth pressure on a rigid retaining wall supporting cohesionless backfill in more realistic manner by considering time and phase difference within the backfill. Planar rupture surface is considered in the analysis. Effects of a wide range of parameters like wall friction angle, soil friction angle, shear wave velocity, primary wave velocity and horizontal and vertical seismic accelerations on seismic active earth pressure have been studied. Results are provided in tabular and graphical non-dimensional form with a comparison to pseudo-static method to highlight the realistic non-linearity of seismic active earth pressures distribution.  相似文献   

Determination of the Trace Refractory Elements V, Nb and Ta in Environmental Samples by ICP-MS After Separation and Preconcentration with Nanometre-Sized Alumina Microcolumns Following Chemical Modification by Gallic Acid     

Xuli Pu  Chaozhang Huang  Bin Hu  Zucheng Jiang 《Geostandards and Geoanalytical Research》2006,30(2):97-105

Nanometre-sized alumina was chemically modified with gallic acid (GA) and used as a solid phase adsorption material for the determination of trace amounts of V, Nb and Ta in natural water, soil and stream sediment samples by inductively coupled plasma-mass spectrometry. The effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes were investigated. The results showed that V, Nb and Ta could be adsorbed at pH 4.0 and recovered with 1 ml of 2.0 mol l^-1 HCl. Under optimised conditions, the adsorption capacity of GA-modified nanometre-sized Al₂O₃ was found to be 7.0, 8.9, 13.3 mg g^-1 for V, Nb and Ta, respectively. The limits of detection were as low as 0.25, 0.24 and 0.66 ng l^-1 for V, Nb and Ta, respectively with a concentration factor of fifty. The recovery of V, Nb and Ta for spiked water samples was between 85.7 and 116%. The developed method has also been applied to the determination of trace V, Nb and Ta in soil and stream sediment certified materials, and the determined values were in a good agreement with the certified values.  相似文献