关于伊利石结晶度Kubler指数的误差计算

本文讨论了测量Ｋｕｂｌｅｒ指数时产生的误差来源;提出以统计学方法描述“Ｓｔｒｉｐ型”衍射峰的半高宽度及其误差大小;以衍射强度、衍射峰形态与测量条件关系式描述“Ｄｉｇｉｔａｌ型”衍射峰半高宽的测量误差大小。并特别提出了数字化衍射仪平滑操作产生的误差原理和总体趋势。提出的原理及公式,不仅适合半高宽的误差计算,并可用于数字化光谱分析计算中。     

关于伊利石结晶度诸指数的评价

本文根据结晶学原理、Ｓｃｈｅｒｒｅｒ定律、Ｗａｒｒｅｎ－Ａｖｅｒｂａｃｈ理论和Ｘ射线衍射峰形态学原理提出任何衍射峰都是由五个基本要素组成的,即：衍射峰位置;最大衍射强度;半高宽;衍射峰形态和对称性。各衍射峰要素都具有其自身的物理学意义,其中,只有半高宽和衍射峰形态是与晶体内部结构和大小即结晶度相联系的。据此,分析评价了与Ｘ射线衍射相关的Ｋüｂｌｅｒ指数、Ｗｅｂｅｒ－ＤｕｎｏｙｅｒｄｅＳｅｇｏｎｚａｃ－Ｅｃｏｎｏｍｏｕ指数、Ｗｅａｖｅｒ指数、Ｍｉｌｉｅｒｓ指数、Ｗｅｂｅｒ指数、分解ＨＷ及纯Ｃ轴厚度等伊利石结晶度指数的理论基础、使用前提和条件、特点及误差源。指出Ｋüｂｌｅｒ指数、Ｗｅｂｅｒ－ＤｕｎｏｙｅｒｄｅＳｅｇｏｎｚａｃ－Ｅｃｏｎｏｍｏｕ指数和分解ＨＷ为非条件性单一结晶度指数;Ｗｅａｖｅｒ指数、Ｗｅｂｅｒ指数和高宽比为条件性单一结晶度指数;消除晶体内部微应变影响的ｃ轴厚度为全面描述伊利石结晶度指数;而Ｍｉｌｉｅｒｓ指数不可描述伊利石结晶度。     

南黄海南部坳陷下第三系阜宁组、戴南组泥岩的粘土矿物与热成熟度的关系

粘土矿物在埋藏成岩过程中的重要变化是膨胀型粘土逐渐减少(如蒙脱石),伊利石、绿泥石结晶度逐渐增加(半高宽减小)。通过对具有代表性的常6—1—1井粘土矿物X衍射分析,系统研究了伊利石10A峰、绿泥石7A峰的半高宽、A/H值(背影峰面积/峰高)与镜质体反射率R_0以及有机质热变指数LOM的对应关系。研究结果表明伊利石(特别经乙二醇处理过)的10A峰半高度及A/H值可以估算有机质成熟与否;可以作为预测源岩生油门限以及油气保存阶段的指标。     

X射线衍射峰五基本要素的物理学意义与应用

本文根据Bragg衍射方程、Scherrer方程、衍射强度计算原理，研究讨论了X射线衍射5构成要素中的衍射峰位置、衍射峰宽度、衍射峰高度的物理学意义。根据实验研究证明了衍射峰不对称性的几何条件特征，并用地质事实验证了衍射形态变化与晶格应变和粒度大小的内在联系。从而阐明了单个衍射峰5基本构成要素的完整物理学意义，并以实例论证了5要素的实际应用价值。     

井径仪,井温仪测量精度分析

井径仪、井温仪有相似的测量原理和计算方法。由于仪器测量原理的限制,许多因素均可产生误差。本文根据历年工作经验,从仪器测量原理入手,分析了误差产生的各种原因,探讨了这些误差因素对测量值的影响,提出了提高仪器测量精度的具体措施。井径、井温的测量是煤田测井中必不可少的重要内容。但是在实际测量和校验时,常产生很大的误差;因此,如何保证两种方法的测量精度是一个值得研究的问题。本文拟分析煤田测井规程所规定的仪器精度,分析影响测量精度的因素以及提高测量精度的相应措施。     

狭缝系统与伊利石结晶度Kuebler指数的测定及相关问题讨论

根据实验结果,衍射峰半高宽随接收狭缝增大而呈二次工线线性增大。扫描速度与扫描步长的确定应遵守Ｗａｎｇ（１９９４）提出的关系式,并确定在相对误差小于〈５％的范围内。固定样品条件,选定最优实验条件下使用国际标样标定系统偏差是伊利石结晶测量中必不可少的重要步骤。不固定样品条件和实验条件,同一样品的伊利石工值将因条件的变化而不同;固定样品和实验条件而不使用国际标样标定系统偏差,则无法与他人数据进行对比,其     

关于《凹凸棒粘土中坡缕石的内标法X衍射定量分析研究》一文的修正

熊飞（2005）探讨了用内标曲线定量分析凹凸棒粘土中坡缕石含量的方法。但是原文中获得内标曲线的方法还有改进的余地。为确立内标曲线的数据点,原来的积分强度（峰面积）是按照半峰宽乘以峰高获得。这种方法求得的峰面积误差相对较大,导致了原文所提出的内标曲线在用于计算粘土纯度时有时会出现较大的误差,尤其是高纯样品往往出现坡缕石含量大于100％的情况。采用积分方法计算衍射峰的面积,对熊飞（2005）提出的曲线做出了必要的修正。本文所涉及的峰面积都是扣除背景后进行讨论。改进后的方法效果较好     

球粒陨石的冲击作用与热释光特征研究

测定了我国部分球粒陨石的自然热释光峰温、峰半高宽度和灵敏度, 强冲击型陨石的热释光灵敏度偏低,峰温、峰半高宽温度则偏高。岩庄陨石属天然冲击球粒陨石,具有强烈的冲击特征。测定岩庄陨石两种不同颜色冲击脉体的热释光,其强度明显地不一样,并发现该陨石的热释光具有β辐照诱发热释光位移和退火热释光位移现象。冲击作用明显地改变着热释光的各种特性。     

狭缝系统与伊利石结晶度Kübler指数的测定及相关问题讨论

根据实验结果,衍射峰半高宽随接收狭缝增大而呈二次曲线线性增大.扫描速度与扫描步长的确定应遵守Wang(1994)提出的关系式,并确定在相对误差小于＜5%的范围内.固定样品条件,选定最优实验条件和使用国际标样标定系统偏差是伊利石结晶度测量中必不可少的重要步骤.不固定样品条件和实验条件,同一样品的伊利石结晶度值将因条件的变化而不同;固定样品和实验条件而不使用国际标样标定系统偏差,则无法与他人数据进行对比,其结果常常错划近变质带的上下界限,造成成岩/变质界限及近变质/浅变质界限的混乱.     

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。     

θ扫描在粘土X射线定量分析中的应用

根据Ｘ射线衍射中θ扫描的基本原理，在理论分析的基础上认为θ曲线峰的形状能较精确地反映粘土矿物的定向水平和分层现象，而峰的积分面积比常规２θ曲线峰的积分面积更能客观地反映粘土矿物的含量。提出在粘土矿物Ｘ射线定量计算中用θ峰积分面积代替常规的２θ峰积分面积，并通过分析各粘土矿物的θ峰形了解样品中粘土矿物的分层情况     

X 射线粉末法晶胞参数修正的微计算机程序设计

X 射线粉末法,不仅可利用其粉末图来鉴定矿物,而且,可利用粉末法求出的晶胞参数来研究矿物的化学组成、结构和成因。晶胞参数计算和修正是 X 射线粉末法的一项不可缺少的重要工作之一。利用指标化的 d 值或θ角进行最小二乘方修正的方法,已经比较成熟.在晶系和空间群未知情况下,仅仅利用 d 值进行指标化并计算其晶胞常数,虽然已经进行了许多研究,并取得了很大进展,但成功率并不令人满意。     

石英单晶无衍射样品板的研制

本文介绍了由作者首创、以石英单晶片制成的一种用于粉晶X射线衍射仪上薄膜样品的底托——单晶无衍射样品板。与常规的玻璃板或者多孔素瓷板及银滤膜等样品底托相比,后二者因系结晶物质,会产生自身的衍射峰;玻璃板则在2?15—37°(Cu靶)间有一个宽大的衍射晕,这些都影响样品衍射花样的准确测定。以平行于石英(11.21)面网切割制成的单晶片,在所测定的2?3一135°范围内不存在任何衍射峰,背景值分布十分平稳,且明显低于玻璃样品板。使用这种新型的单晶无衍射样品板,将有助于提高粉晶X射线衍射仪测定的精确度。     

Long-term seasonal rainfall forecasting: efficiency of linear modelling technique

Using the lagged (past) climate indices, including El Nino–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) as input parameters and long-term spring rainfall as outputs, calibration and validation of the linear multiple regression (MR) models have been performed. Since Australian rainfall varies both temporally and spatially, the analysis on the linear MR models was performed on regional scale. These models show the capability of linear MR technique for long-term predictions of Western Australian spring rainfall. The emphasis was given to assess the statistical correlations between Western Australian spring rainfall and dominating large-scale climate modes. The efficiency of linear modelling technique was evaluated to predict seasonal rainfall forecasting. At the same time, the Pearson correlation (R), mean absolute error, root-mean-square error and Willmott index agreement (d) were used to assess the capability of MR models. The models which fulfilled the limits of statistical significances were used for the prediction of future spring rainfall using independent data set. The results indicate that during calibration periods maximum achievable correlations varied from 0.47 to 0.53 for the selected stations. In regard to predict peaks and troughs of rainfall time series, it was found that correlations between predicted and actual peaks varied from 0.82 to 0.94 and between predicted and actual troughs varied from 0.53 to 0.91.     

Error in digital network and basin area delineation using d8 method: A case study in a sub-basin of the Ganga

Digital elevation model (DEM) is one of the input data derived from different satellite sensors for hydrologic and hydraulic modelings. Two prime questions could be answered before using these DEMs. First, the acceptability of datasets for our use and second appropriate resolution of the dataset. Three widely used DEMs SRTM 30m, ASTER 30m and SRTM 90m are analyzed to evaluate their suitability to delineate river network and basin boundary area. The hydrology tool of spatial analyst extension inbuilt in ArcGIS 10.2 (which uses the D8 method for calculation of flow direction) has been used for the delineation of both river networks and basin boundary. The assessment of river network alignment and boundary delineation is carried out in the seven sub-catchments of Gandak river basin having different morphological characteristics. The automatically delineated boundary area for all the three DEMs reflects a significant difference when compared with the digitized basin area from the Ganga flood control commission (GFCC) map. The maximum boundary area delineation error is 39137.20 km₂ forASTER 30m, and minimum delineation error of 13239.28 km₂ for SRTM 90m. In the stream network, delineation accuracy is good for SRTM 90m while, except Gandak trunk, ASTER 30m DEM shows better delineation accuracy indicated by mean absolute error (MAE) and standard deviation (SD).     

数字黑河的思考与实践1:为流域科学服务的数字流域

多学科数据的收集和积累、多学科模型的集成以及现代化的观测系统是发展流域科学的必要前提。"数字黑河"是为黑河流域科学研究和流域集成管理而搭建的集数据、模型和观测系统于一体的信息化平台,是"数字地球"在流域尺度上的一次实践性尝试。数字黑河由数据平台、模型平台和数字化观测系统组成,其核心是观测、数据和模型平台中的信息基础设施建设,但同时也外延而扩展为以流域综合模型为骨架的各种应用。"数字黑河"已阶段性地完成了数据集成,在线数据量超过1 000 GB,并实现了完全共享,有力地支持了黑河流域的各项研究工作;在模型集成方面已初步建成了流域综合模型和空间决策支持系统。"数字黑河"的进一步构想是在e-Science的框架下将数据系统、观测系统、模型系统、信息发布系统、高性能计算及科学计算可视化集成为一个整体。     

Identification of Microfabric of Kaolinite Clay Mineral Using X-ray Diffraction Technique

A new method is introduced in this study to identify the microfabric (geometric arrangement of platelets) of cohesive soil using standard X-ray diffractometer. Various sampling techniques are used to prepare the Kaolinite clay samples with different microfabrics to assess the consistency and versatility of the proposed method. This method is based on identifying the presence of basal and prism peaks from the X-ray diffraction pattern and corresponding relative intensity values. The present study also demonstrates the conditions for which Scanning Electron Micrographs (SEM) are not capable of accurately identifying the microfabric of cohesive soils. The method proposed in this study uses relative amplitudes of basal and prism peaks avoiding difficult sample and surface preparation procedures, as used by previous researchers in their microfabric identification methods. The proposed method is found to be a rapid and accurate method for identifying the microfabric of Kaolinite clay and should prove to be valuable for routine implementation for studying structured natural clays.     

Quantitative X-Ray diffraction of carbonate sediments: mineralogical analysis through fitting of Lorentzian profiles to diffraction peaks

A new automatic method for quantitative mineralogical analysis of carbonate sediments by X-Ray diffraction is described. Percentage analysis has been carried out by means of the reference intensities method from integrated areas of the diffraction peaks. Diffraction peaks were fitted by means of Lorentzian profiles. The addition of an internal standard allows the determination of data on the stoichiometric disequilibrium of the carbonate phases and the existence of non-carbonate phases and/or non-crystalline phases simultaneously. Relative errors of the quantitative estimates of carbonate phases are always less than 15%, even though real percentage differences between actual and calculated values are less than 3·8% in all cases.     

Electronic and optical properties of Fe, Zn and Pb sulfides

Ab initio quantum-chemical calculations of the spatial and electronic structures of sphalerite (ZnS), pyrite (FeS₂) and galena (PbS), using the density functional theory (DFT) local density approximation (LDA) and generalized gradient approximation (GGA), the Hartree–Fock (HF) method and the hybrid functional B3LYP, have been carried out. For galena, the DFT LDA and GGA functionals provided the best estimate of the band gap, from within –0.1 eV to +0.4 eV of the measured value. B3LYP and RHF gave rise to errors of +1.3 and +5.4 eV, respectively. The unit cell parameter error varied from between –1.1% and +2.3% for all the functionals examined. For sphalerite the B3LYP functional provided the best estimate of the band gap (error +0.3 eV). The unit cell parameter error varied between –2.1% and +2.0% for the various DFT functionals and B3LYP. RHF gave rise to an error of +3.8%. For FeS₂, the DFT-GGA approach provides the best results for both the unit cell and the band gap. This may be due to mutual cancellation of the crystal field splitting and band separation force, which are of equal but opposite magnitudes. The calculated density of states (DOS) for the conduction band is used to interpret the experimental features of the S 1s XANES (X-ray absorption near-edge structure) spectra obtained using synchrotron radiation. Because of the l = ±1 selection rule for electron excitation, the S K-edge XANES spectra represent a transition of the S 1s electron to conduction band S p-like orbitals. The near-edge region, up to 15 eV past the edge is approximated well by the DOS. Individual peaks in the DOS correlate with peaks in the XANES spectra. In addition, the imaginary part of the dielectric function, which reflects the transitions from occupied to unoccupied levels, is used to model the near-edge region of the XANES, using the DFT-GGA formalism. Individual peaks in the XANES spectrum are moderately well resolved using the dielectric function, especially for ZnS and FeS₂, while the DOS for the conduction band is more successful in predicting the shape of the XANES spectra for all three minerals.     

X射线粉晶衍射法在变粒岩鉴定与分类中的应用

变粒岩的鉴定通常以显微镜鉴定技术为主,但在显微镜下区分颗粒细小的长石、石英及绿泥石、蒙脱石、云母等层状硅酸盐矿物十分困难,仅通过显微鉴定技术对变粒岩进行定名可能产生较大误差,这对地质填图和原岩恢复工作会造成一些偏差,导致得出错误的地质结论。随着X射线衍射分析技术的发展,该技术已广泛应用于矿物学和岩石学的研究,本研究将结合X射线粉晶衍射技术,对显微镜下难以区分的细小矿物进行鉴定。共选用23件变粒岩样品,利用X射线粉晶衍射分析和显微镜岩石薄片鉴定技术,对变粒岩矿物组分进行检测,用X射线粉晶衍射矿物半定量分析结果验证岩石薄片鉴定结果准确性。显微镜岩石薄片鉴定结果与X射线粉晶衍射物相分析结果对比显示,10件样品定名一致,其余13件样品详细定名有差异。通过分析产生差异的原因,可以认为显微镜岩石薄片鉴定优势在于能确定岩石结构和构造,以及常见矿物组分;X射线粉晶衍射法的优势在于能检测出显微镜下较难区分的细小石英和长石颗粒的相对含量,并能检测出颗粒较小的绿泥石、蒙脱石及云母等层状硅酸盐矿物,该方法对含量较少、颗粒较细的矿物检测效果较好。实验证明将显微岩石薄片鉴定技术和X射线粉晶衍射技术相结合,才能更准确对变粒岩进行定名,为地学研究提供更符合客观实际的技术数据和分析结论。