北京市春夏季大气气溶胶的单颗粒分析表征   总被引：9，自引：0，他引：9  

肖锐刘成德  梁汉东董树屏 F．Adams 《岩矿测试》2004,23(2):125-131

采集了北京市2000年春夏季大气气溶胶样品5个，采用扫描电镜X射线能谱技术分析大气气溶胶单颗粒约2500个。研究结果表明，沙尘期间，矿物尘是最主要的颗粒物种类，非沙尘期间，北京市大气气溶胶中主要检出矿物尘和含硫颗粒物。夏季随着颗粒物污染的加重，含硫颗粒物的数目百分数增加。是北京市大气颗粒物污染的重要特征。重点讨论了Ca-S颗粒、K-S颗粒和Ca-K-S颗粒三类典型含硫颗粒物的化学组成和粒径分布特征。数目可观的Ca-K-S颗粒以及其他硫酸盐颗粒的生成与相对湿度和云量等气象条件相关，这些颗粒物可能是云中过程的产物。减少SO2排放，减少含硫颗粒物，对于控制北京市的大气颗粒物浓度水平具有重要意义。  相似文献   

广东茂名高岭土煅烧实验研究   总被引：1，自引：0，他引：1  

朱粉利  曾伟能  王勤燕  周汉文 《矿产与地质》2004,18(2):168-172

对茂名高岭土进行煅烧，结合X-射线衍射、扫描电子显微镜分析，得到了茂名高岭土在不同温度点煅烧的性能参数，并确定出其非晶化转变的温度是550℃。同时对煅烧过程中的煅烧温度、恒温时间等影响因素进行探讨，结果表明，在茂名高岭土的煅烧过程中，适当延长恒温时间可降低非晶化转变的温度，缩短恒温时间，则非晶化转变温度升高。  相似文献   

四川新康风化淋滤型海泡石的热相变研究   总被引：3，自引：0，他引：3  

王吉中  李胜荣  江永宏 《矿物学报》2004,24(1):55-60

以四川新康风化淋滤型海泡石为研究对象，利用X射线衍射分析和红外光谱分析技术，对海泡石的热相变过程及特征进行了研究。结果发现，四川新康风化淋滤型海泡石的相变过程与沉积型、热液型海泡石相变过程明显不同，其相变过程可以划分为两个阶段：800℃以下保持海泡石相；800℃以上海泡石相转化为斜顽辉石相。  相似文献   

糜棱岩化过程中绿泥石多型与结晶度的演变--以郯庐断裂带南段为例     

王勇生  朱光  刘国生 《矿物学报》2004,24(3):271-277

摘要：根据郯庐断裂带南段韧性剪切带糜棱岩中同构造矿物组合、黑云母的存在以及长石的变形行为，推测其变形．变质温度为400一450oC。bo值分析表明．这些糜棱岩是在低压环境下形成的。在流体作用下。糜棱岩中的绿泥石既可以交代其它矿物而形成，也可以直接从流体中结晶形成。交代其它矿物所形成的绿泥石为Ⅱ型绿泥石，其结晶度值介于0．21^。一0．23^。20．与温度具有较好的对应关系。直接从流体中结晶而产生的绿泥石初始时刻为工型．其结晶度值介于0．236^。-0．341^。20之间，多屑于近变带范畴。其指示温度要低于实际所经历的环境温度。由于糜棱岩化过程中工型绿泥石的不断产生以及工型绿泥石向Ⅱ型绿泥石转化的不充分。导致了在400以上仍然出现工型绿泥石与Ⅱ型绿泥石混合的现象．并且实测的结晶度是不同时刻形成的、具不同结晶度的绿泥石的混合结晶度。  相似文献   

Subsurface Occurrence of Natural Gas Hydrate in the Nankai Trough Area: Implication for Gas Hydrate Concentration   总被引：2，自引：0，他引：2  

Takashi Uchida    Hailong Lu  Hitoshi Tomaru 《Resource Geology》2004,54(1):35-44

Abstract. The Nankai Trough runs along the Japanese Islands, where extensive BSRs have been recognized in its forearc basins. High resolution seismic surveys and site-survey wells undertaken by the MITI have revealed the gas hydrate distribution at a depth of about 290 mbsf. The MITI Nankai Trough wells were drilled in late 1999 and early 2000. The highlights were successful retrievals of abundant gas hydrate-bearing cores in a variety of sediments from the main hole and the post survey well-2, keeping the cored gas hydrate stable, and the obtaining of continuous well log data in the gas hydrate-dominant intervals from the main hole, the post survey well-1 and the post survey well-3. Gas-hydrate dominant layers were identified at the depth interval from 205 to 268 mbsf. Pore-space hydrate, very small in size, was recognized mostly filling intergranular pores of sandy sediments. Anomalous chloride contents in extracted pore water, core temperature depression, core observations as well as visible gas hydrates confirmed the presence of pore-space hydrates within moderate to thick sand layers. Gas hydrate-bearing sandy strata typically were 10 cm to a meter thick with porosities of about 40 %. Gas hydrate saturations in most hydrate-dominant layers were quite high, up to 90 % pore saturation.
All the gas hydrate-bearing cores were subjected to X-ray CT imagery measurements for observation of undisturbed sedimentary textures and gas-hydrate occurrences before being subjected to other analyses, such as (1) petrophysical properties, (2) biostratigraphy, (3) geochemistry, (4) microbiology and (5) gas hydrate characteristics.  相似文献   

Characteristics of Energy Accumulation and Release of Seismogenic Tectonics and Seismic Risk Analysis in Some Areas in the Tianshan Mountains, Xinjiang1     

Shen Jun 《中国地震研究》2005,19(1):1-11

INTRODUCTIONHowtocombinethestudyofseismogenictectonicswithearthquakepredictionisanurgentscientificdifficulty .Thereexistbiggapsbetweenstudymethodsandcurrentknowledgeonseismogenitectonics ,earthquakeprediction ,seismogenesisandthephysicsofearthquakeoccurre…  相似文献   

Structural properties of (Mn1-x Fe x )Nb2O6 columbites from X-ray diffraction and IR spectroscopy     

S. C. Tarantino  M. Zema  F. Maglia  M. C. Domeneghetti  M. A. Carpenter 《Physics and Chemistry of Minerals》2005,32(8-9):568-577

A suite of (Mn_1-x Fe _x )Nb₂O₆ (x=0, 0.05, 0.25, 0.50, 0.75, 1) columbite samples has been prepared by solid-state reaction from oxides. X-ray diffraction and spectroscopic investigations have been carried out in order to gain different perspectives on how the solid solution adapts at different length scales to cation mixing. X-ray powder diffraction and powder absorption IR spectroscopy data are presented. The powder diffraction data show that there is no significant excess volume of mixing on the Fe–Mn columbite join. All the unit-cell parameters decrease linearly as a function of increasing Fe content. Substitution of Fe²⁺ for the larger Mn²⁺ cation causes a decrease in the volume of the A polyhedron, which also becomes more regular with respect to both bond-length and edge-length distortion parameters. No significant variation of the B site has been observed. Wavenumber shifts of the IR peaks nearly all vary linearly with composition, consistent with linear variations of the lattice parameters. Line broadening has been quantified by autocorrelation analysis of the IR spectra. This is interpreted as suggesting that there is some element of local strain or positional disorder at the length scale of second or third nearest neighbours around sites occupied by Fe.  相似文献   

Prediction of creep characteristic of rock under varying environment   总被引：2，自引：0，他引：2  

T. N. Singh  A. K. Verma 《Environmental Geology》2005,48(4-5):559-568

The strain developed due to creep is mainly proportional to the logarithm of the time under load, and is mostly proportional to the stress and temperature. At higher temperature the creep rate falls slowly with respect to time, and the creep strain is proportional to a fractional power of time, with the exponent increasing as the temperature increases and reaching a value approximately one-third at temperatures of about 0.5°C. At these temperatures, the creep increases with stress according to a power greater than unity and possibly exponentially. It increases with temperature as (−U/kT), where U is an activation energy and k is Boltzman’s constant. There are different methods to determine the creep strain and the energy of Jog (B) including experimental methods, multivariate regression analysis, and by numerical simulation. These methods are less cumbersome and time consuming. In the present investigation, artificial neural network technique has been used for prediction of the creep strain and energy of Jog (B). Two different networks have been tested and validated. Both the networks have four input neurons and one hidden layer with five neurons, and one output neuron. The data for different rocks at temperatures up to 750°C under conditions of compressive or tortional stress are taken from the literatures. The training and testing data sets used were 163 and 14, respectively. To deal with the problem of overfitting of data, Bayesian regulation has been used and network is trained with suitable training epochs. The coefficients of correlation among the predicted and observed values are found high and they improve the confidence of the users. The mean absolute percentage error obtained are also very low.  相似文献   

福建大田—漳平地区构造-热对煤系石墨成矿及赋存的控制探讨     

丁正云  王路  曾欢  李阳  陈泉霖  邓瑞锦  程乔  林晓炎  曹代勇 《煤田地质与勘探》2020,48(1):55-61

福建省大田—漳平地区位于东部滨太平洋构造带上，不同时期的岩浆热液作用和复杂多变的构造形变格局，为该地区形成丰富的石墨矿床提供了良好的成矿条件。为了查明大田—漳平地区煤系石墨的成矿控制因素及分布规律，通过工业分析、元素分析、X射线衍射和激光拉曼光谱等实验，对不同矿区不同变质程度的煤和煤成石墨的化学组成及微观结构特征等煤成石墨化特征进行了研究，并将不同变形特征的样品划分为煤成石墨、煤成半石墨和石墨化无烟煤三大类。研究表明:煤的变形特征与煤成石墨的演化类型基本一致，且韧性变形样品的石墨化程度最高，说明构造应力作用能促进煤的石墨化作用；煤成石墨的分布受到岩浆-构造活动的控制，石墨矿床多产出于岩浆岩侵入体外接触带或附近断裂带的有利围岩地层中，且大田—漳平地区煤系石墨矿具有明显的成区、成带分布特点，煤成石墨成矿区主要集中在闽西南坳陷南部的漳平一带；而北部大田一带分布的矿区矿体石墨化程度较漳平一带低，多为煤成半石墨或石墨化无烟煤，研究结果可为该地区煤系石墨矿产综合勘探开发利用提供有利依据。   相似文献   

X射线荧光光谱法分析不同类型岩石中10种主量元素的测试能力验证   总被引：4，自引：3，他引：1  

王建其  柳小明 《岩矿测试》2016,35(2):145-151

以28个不同类型岩石标样作外标,用玻璃熔片法制样,采用经验系数法进行基体校正,建立了X射线荧光光谱法(XRF)测定不同类型岩石中硅铝钙镁等10种主量元素的分析方法。该方法被用于参与GeoPT分析测试能力验证,15年来分析了23个不同类型的岩石验证样品。经验证该方法对SiO_2、Al_2O_3、K_2O和CaO具有非常好的分析效果(所有测定结果的|Z|2);对于MgO、MnO、TiO_2和Na_2O四个元素,尽管各有一个样品的分析结果的|Z|2,这主要是样品与标样的基体差异较大造成了低含量样品测定结果超差,但依然可获得好的分析效果;当TFe_2O_31.0%,P_2O_5含量在0.08%~0.80%区间时,分析结果的|Z|2,满足分析期望。总体上所建立的XRF分析方法稳定,可满足应用地球化学实验室测试不同类型岩石中10种主量元素的分析期望。  相似文献