Correlation between optical, chemical and micro-structural parameters of high-rank coals and graphite     

M. Marques  I. Surez-Ruiz  D. Flores  A. Guedes  S. Rodrigues 《International Journal of Coal Geology》2009,77(3-4):377-382

In order to identify the parameters that best characterize the chemical and structural evolution of organic matter during coalification, the relationships between optical, chemical and micro-structural parameters in high-rank coals and natural graphite were studied. The samples include anthracites from Peñarroya–Belmez–Espiel Basin (Spain), Douro Basin (Portugal), and Alto Chicama Basin (Peru); and natural graphite from Canada, Mozambique, and Austria.Correlations between the following optical parameters were assessed: vitrinite random reflectance (R_r), Reflectance Indicating Surfaces (RIS) axis (R_MAX, R_INT and R_MIN), and RIS parameters (R_am, R_ev and R_st), as well as B_w and AI anisotropy parameters. Furthermore, the chemical parameters used were chosen according to their significant variation in coals, namely volatile matter, carbon, and hydrogen contents calculated in dry ash free basis (VM_daf, C_daf, H_daf), as well as the H/C atomic ratio. Structural organization was characterized by micro-Raman spectroscopy and XRD. Raman parameters used were the full width at half maximum (FWHM) and position of G and D1 bands on the first-order Raman spectrum, and the ID1/IG intensity area ratio. The selected XRD parameters were interlayer spacing d₀₀₂, and crystallite sizes L_a and L_c.Results show that: (i) R_MAX RIS axis seems to correlate best with chemical and micro-structural parameters; (ii) for the majority of studied samples, H_daf and H/C atomic ratio are the only chemical parameters with significant correlations with R_MAX; (iii) the FWHM of the G band of Raman spectrum shows good linear correlation with the XRD parameter d₀₀₂; and, (iv) structural organization of carbon materials, as measured by trends in their optical and crystalline parameters, is influenced by their hydrogen content (daf basis) and therefore by the H/C atomic ratio.  相似文献   

Spatial and seasonal variation of salt ions under the influence of halophytes,in a coastal flat in eastern China   总被引：1，自引：0，他引：1  

Yanyou Wu  Rongcheng Liu  Yuguo Zhao  Pingping Li  Congqiang Liu 《Environmental Geology》2009,57(7):1501-1508

The high salinity of coastal saline field is a key factor limiting the reclamation. Halophytes have been utilized in the reclamation of saline land. The study area is in Yancheng, China. An analysis of the concentrations of Rb, Cs, Sr, and Ba, the ratio of Rb/Cs, and Sr/Ba in soils in autumn shows that the soil of this study area has great homogeneity. Artemisia halodendron, Gossypium hirsutum, and Sesbania cannabina were selected as the reclamation plants in the present study. In order to know the spatial-temporal distribution of soil salinity, the influence of plant-specific vegetation, and the difference of desalination among these halophytes in coastal flat, the authors analyze the soil-layers and seasonal variation in salt ions. Sodium chloride was accumulated in 0–5 cm topsoil with no vegetation during the winter and spring. The effect of desalinization of halophytes is significant. Of the three plant species, Sesbania cannabina has the greatest desalinization. The difference of ions composition of soils covered with various plant species is significant. It can be concluded that halophytes have better amelioration of coastal soil salinity. Special attention should be paid to the selection of plant species and measures to plant and cultivate crops in the reclamation of saline land.  相似文献   

化学物相分析在物料成分全分析数据处理中的应用   总被引：1，自引：0，他引：1  

黄宝贵 《岩矿测试》2009,28(5):439-443

讨论了化学物相分析在物料成分全分析数据加合平衡计算中的作用。根据对不同类型、不同共生组合且具有代表性的物料成分全分析数据平衡计算过程中所推荐的计算程序和计算结果,介绍了化学物相分析在物料成分全分析数据处理中的实际应用。同时阐述了具体应用对象、应用规则、应用模式以及应用过程中需要注意的问题等。  相似文献   

Geochemistry characterization of groundwater in an agricultural area of Razan,Hamadan, Iran     

Mohsen Jalali 《Environmental Geology》2009,56(7):1479-1488

This study was conducted to evaluate factors regulating groundwater quality in an area with agriculture as main use. Thirty groundwater samples have been collected from Razan area (Hamadan, Iran) for hydrochemical investigations to understand the sources of dissolved ions and assess the chemical quality of the groundwater. The chemical compositions of the groundwater are dominated by Na⁺, Ca²⁺, HCO₃ ⁻, Cl⁻ and SO₄ ²⁻, which have been derived largely from natural chemical weathering of carbonate, gypsum and anthropogenic activities of fertilizer’s source. The production of SO₄ ²⁻ has multiple origins, mainly from dissolution of sulphate minerals, oxidation of sulphide minerals and anthropogenic sources. The major anthropogenic components in the groundwater include Na⁺, Cl⁻, SO₄ ²⁻ and NO₃ ⁻, with Cl⁻ and NO₃ ⁻ being the main contributors to groundwater pollution in Razan area.  相似文献   

辽东辽河群大石桥组碳酸盐岩稀土元素地球化学及其对Lomagundi事件的指示   总被引：6，自引：4，他引：2  

汤好书  陈衍景  武广  杨涛 《岩石学报》2009,25(11):3075-3093

2.33～2.06Ga期间发生了全球性大气圈充氧作用及其相关的占δ~(13)C_(carb)正异常,被称为Lomagundi事件.2.2～2.174Ga的辽河群大石桥菱镁矿及其围岩显示了δ~(13)C_(carb)正异常,是运用REY(REE+Y)指纹技术研究Lomagundi事件的良好对象.本文研究表明,6件白云岩围岩样品∑REE为0.988×10-6～2.744×10-6;Y/Ho比值为37.9～49.4(平均42.5±4.7);(La/La~*)_(SN)为1.075±0.317,(Gd/Gd~*)_(SN)为1.390±0.166,均为正异常;HREE富集(Nd_(SN)/Yb(_SN)=0.38～0.78).所有上述特征与现代海水REY配分模式一致,表明这些样品记录了Lomagundi时期海水的REY特征.6件菱镁矿样品∑REE为4.549±2.239,高于围岩白云岩;HREE弱亏损(Nd_(SN)/Yb_(SN)=1.141±0.265),Y/Ho平均值为40.2±3.2;(La/La~*)_(SN)为0.657～1.149(平均0.919±0.203),(Gd/Gd~*)_(SN)=1.036±0.081,正异常程度弱于白云岩,但仍显示以海水来源为主.矿体顶板滑石白云岩∑REE含量最高(10.758);页岩标准化稀土配分模式为平坦型,(Eu/Eu~*)_(SN)正异常高达1.97,Gd和Y正异常最小,Y/Ho比值最低(31.3),(Nd/Yb)_(SN)为0.89,显示受后期热流体交代影响.菱镁矿(Sm/Yb)_(CN)值(2.61±0.45)高于白云岩(1.19±0.27),指示海水由深变浅,大石桥菱镁矿及其围岩白云岩REY主要来自陆源溶解物,洋底热液贡献微弱,制约REY特征的主导因素为大气圈-水圈的性质,如fO_2,pCO-2等.白云岩和菱镁矿(Ce/Ce~*)_(SN)值平均分别为1.11±0.13和1.04±0.08,表明2.2～2.174Ga期间大陆风化作用加剧,海水呈碱性,pH值＞8.2.2.33Ga前的化学沉积物(Eu/Eu~*)_(SN)＞1.53,2.06Ga后的化学沉积物(Eu/Eu~*)_(SN)＜1.53,大石桥组白云岩和菱镁矿(Eu/Eu~*)_(SN)均值分别为1.44±0.11和1.58±0.20.表明2.2～2.174Ga时海相沉积物(Eu/Eu~*)_(SN)≈1.53,2.33～2.06Ga是地球水圈-气圈系统由还原向氧化转变的关键时期.  相似文献   

2000年春季北京特大沙尘暴物理化学特性的分析   总被引：52，自引：9，他引：43  

张仁健  王明星  浦一芬  刘强  符建中  张文 《气候与环境研究》2000,5(3):259-266

2000年春季北京频频发生沙尘天气,严重影响了北京市大气环境状况.对4月6日北京地区发生的特大沙尘暴化学元素成分的分析表明北京春季沙尘污染极为严重.沙尘暴期间,20种元素总质量浓度高达1536μg/m3,是1999年同期的31.4倍.即使沙尘暴过后,污染依然严重,元素总质量浓度仍高达338.7μg/m3,是1999年春季的7倍.研究还发现,沙尘暴期间来自远方的大粒子占了很大的比例,绝大多数的元素浓度在粒径大于16μm处出现一个非常高值,远高于其他谱段的浓度;在沙尘暴后及其他时间,还没有观测到这种谱分布.沙尘暴期间的粗粒子(d>2μm)数浓度是沙尘暴后的20倍以上,细粒子(d<2μm)的数浓度是沙尘暴后的7倍.  相似文献   

云南个旧卡房锡矿田花岗岩黑云母矿物化学特征及其成岩成矿意义          下载免费PDF全文

马莲花  蔡永丰  刘希军  许继峰  周云  苏小倩 《高校地质学报》2018,24(5):692

黑云母作为花岗岩中含量最高的暗色矿物,其成分特征对指示岩石成因与成矿起着重要作用。云南个旧卡房锡多 金属矿床的形成与花岗质岩浆活动密切相关,卡房花岗岩包含有大量黑云母,通过电子探针测试方法,对该花岗岩中的 黑云母成分进行了系统的研究。结果显示,黑云母为富铁黑云母,具有富硅、铁、铝、钾、钛,贫锰、镁、钙、钠等特 征,含铁指数为0.67~0.83。黑云母的成分特征暗示其结晶温度为500~708 ℃,结晶压力为202~538 MPa,对应的结晶深度为 7.64~20.35 km,表明卡房花岗岩形成于中低温环境、属于中深成相。综合研究认为,卡房锡矿田花岗岩具有高铁指数以及 氧逸度由高到低变化趋势等特征是锡成矿的有利条件,可以作为在本区寻找锡矿的重要标志。  相似文献   

流体包裹体中微量气体组成及其成矿示踪体系研究新进展   总被引：2，自引：0，他引：2  

孙晓明  王敏  薛婷  孙凯 《地学前缘》2004,11(2):471-478

N2 Ar He体系可用以示踪成矿流体及温泉等与火山有关的水流体的来源 ,当体系中He含量低于检出限 ,N2 Ar He体系不能用时 ,CO2 /CH4 N2 /Ar体系可用于识别成矿流体中岩浆水、建造水和大气降水 ,CO2 CH4 H2 体系可以鉴别成矿流体是否发生过沸腾作用以及沸腾是在开放体系还是封闭体系中形成 ,一般开放体系中沸腾有利于成矿。CO2 CH4 C2 H6体系可用于判别岩浆作用是否直接影响成矿或对成矿流体的贡献 ,从而确定热液矿床的成因。CH4 C2 H6 C3 H8体系可用来示踪一些与干酪根热解有关的成矿流体长距离、大规模迁移过程。C2 H6 C3 H8 C6H6体系可用于判定成矿流体的大地构造环境 ,因岛弧与裂谷环境下C2 H6/C3 H8比值有明显差异。以广东长坑 (Au Ag)和嵩溪 (Ag Sb)矿床为例 ,概述了这些体系各自的应用  相似文献   

A comparison analysis of chemical composition of aerosols in the dust and non-dust periods in Beijing   总被引：5，自引：0，他引：5  

ZHANG Renjian  XU Yongfu  HAN Zhiwei 《大气科学进展》2004,21(2):300-305

Dust events occurred frequently in Beijing in recent years. In this work, 120 aerosol samples werecollected in two typical dust events (21-22 March and 15 May) and a non-dust period in Beijing fromMarch to May 2001. Samples were analyzed for major elemental components by the Proton Induced X-ray Emission (PIXE) method. Results show that the enrichment factors of crustal elements such as Mg,A1, and Ti had little differences between the dust period and the non-dust period in Beijing, while theenrichment factors of other elements that have a relation to anthropogenic emissions were very low duringthe dust period. The results derived by using multivariate factor analysis from the observation data showthat the sources such as soil dust, industry, and fuel combustion were among the major contributors tothe particles in Beijing.  相似文献   

多粒度时空对象组成结构表达研究     

李锐  石佳豪  董广胜  刘朝辉 《地球信息科学学报》2021,23(1):113-123

全空间信息系统、智慧城市的构建,需要将地理实体抽象成时空对象,而时空对象的多粒度性,体现在时空对象具有多尺度、多维度、多层次的特点。如何在当今海量数据中,对多粒度时空对象的信息进行有序组织成为时空对象研究中的难点。本文基于面向对象的思想,提出了一套时空对象组成的表达与操作方法,为时空对象信息的有序组织提供了新思路。该方法基于概念分类理论,将时空对象的组成分为实体对象组成与关系组成,在此基础上,通过构建时空对象信息集族、对象组成集族、关系组成集族,对时空对象组成结构的形式化描述,并基于时空对象的生命周期,给出构建、更新、析构、组合、分解等时空对象组成表达的相关操作,进一步完善多粒度时空对象组成结构的表达。最后,以城市道路的组成信息管理为例,将武昌区珞喻路作为研究的时空对象,对城市道路时空对象组成结构的表达及操作进行举例说明。该方法的提出,实现了多粒度时空对象组成结构的表达,减少时空对象组成的冗余。  相似文献