量热学和热动力学研究进展概况

对量热学的发展历史作了简要介绍,并就近年来利用量热法进行各种反应的热动力学研究的进展进行了概述。根据将微量热新技术引入到地质、地球化学领域研究矿物溶解的阶段性成果,展望了地球化学反应热动力学研究的广阔前景。     

工程物探在我国的发展前景

本文介绍了地矿部１９９６年度工程物探的技术进步和综合应用,指出工程物探在我国具有良好的发展前景。     

Water-related defects and oxygen diffusion in albite: a computer simulation study

 Computer simulation techniques have been used to investigate the energetics of defect formation in Albite and to calculate O and (OH) migration activation energies. We find that the Na Frenkel defect has the lowest formation energy, whilst interstitials associated with impurities are the most favourable O defects. Water can be accommodated in the albite structure as both OH groups and as H₂O molecules with solution energy of 0.73 eV and 0.9 eV respectively. The activation energies for O migration is reduced by up to 50% when the O is migrating as part of an (OH) group. In addition, we find a marked diffusional anisotropy for both O and (OH) in albite. Received: 15 September 1995 / Accepted: 29 April 1996     

国外勘查地球物理的若干进展——1996年

本文根据1996年国外发表的勘查地球物理文献,概要列举了物探方法发展的新前沿。在矿产勘查方面介绍了金属矿预测和普查工作的新进展以及金伯利岩、滑石矿床的找矿方法和实例。在环境勘察方面,回顾了电法在水质调查中的应用,介绍了物探方法在城市垃圾场调查、煤矿闭坑善后工作、城市人工物理场环境效应调查中的应用以及滑坡和洞穴调查中新采用的方法。在区域和深部地球物理调查方面,概述了西方国家近年来实施的矿产勘查开创计划、大规模的电导率结构研究和南极磁异常图的编制。在新技术新方法方面,介绍了新的航空电磁系统———FLAIRTEM、电(磁)法中非接触数据采集技术、谱激发极化法在环境调查中的应用、探测油气蚀变柱的区域勘查新方法和海洋重力仪。     

矿物热力学数据的获取

简介矿物热力学数据获取方法发展现状,重点评述量热法和相平衡法的近期发展状况。     

九十年代固体地球科学及超大型矿床研究若干进展

90年代，国内外地学工作者将现代科学的新方法、新技术应用于地球科学研究中，通过深海钻探、高温高压技术与地球物理手段等多种方法综合研究，致使在：地球的核-幔组分；CO2的起源、全球变化及其与成矿的关系；岩石圈的演化与缺氧事件、生物灭绝、海底扩张及成矿的相关性等诸多固体地球科学研究领域，均取得了若干最新的认识和重要进展。本文还对超大型矿床及分散元素成矿机制等的研究新进展分别作了阐述，并提出在华南和西南地区要重视晋宁期和喜山期成矿作用的研究。     

Trace Element Determination by ICP‐AES and ICP‐MS: Developments and Applications Reported During 2006 and 2007

This review describes developments in trace element determination using inductively coupled plasma‐atomic emission spectrometry (ICP‐AES) and inductively coupled plasma‐mass spectrometry (ICP‐MS) that were reported in 2006 and 2007. It focuses on the application of ICP techniques to geological and environmental samples; fundamental studies in ICP‐MS and ICP‐AES instrumentation have largely been ignored. New advances in ICP‐MS and ICP‐AES were incremental over this period, partly because both techniques are now well‐established. A continuing shift towards the hyphenation of low‐flow separation techniques has sparked activity in the development of appropriate low‐flow interfaces, and papers discussing interference removal also contribute significantly to the volume of research for both ICP‐AES and ICP‐MS. Whereas the majority of new ICP publications concerned advances in ICP‐MS analysis rather than ICP‐AES, development for ICP‐AES still occurs in almost all areas, particularly in sample introduction and hyphenated techniques.     

Progress and new directions in high temperature calorimetry

Calorimetry at 600–900° C, using Calvet-type microcalorimeters, has provided data in several areas of interest to geology. The best-developed application is solution calorimetry in molten oxide solvents (lead borate, sodium molybdate) to determine the enthalpies of formation of anhydrous silicates and related minerals, the enthalpies of phase transformations and order-disorder reactions, and the enthalpies of mixing in molten salts, glasses, and solid solutions. An attractive feature of the technique is the ability to use rather small samples; ～ 300 mg total often being sufficient for the study of a phase synthesized at high pressure. Current developments include the improvement of precision by careful control of solvent composition and water content, the development of alkali borate or borosilicate solvents for use under atmospheres of controlled oxygen fugacity, and the study of compounds containing fluorine as well as oxygen. In addition, direct-reaction calorimetry at high temperature has been used to study rapid phase transformations and gas-solid reactions. The latter include the oxidation of metals and the thermodynamics of oxides having wide homogeneity ranges, for example wüstite. A recent development is calorimetry at pressures up to 2 kb, using a cold-seal pressure vessel inserted in the calorimeter. Applications include the study of geothermal fluids and, eventually, the study of equilibria involving hydrous phases and water-containing melts and glasses.     

Determination of aquifer susceptibility to pollution using statistical analysis

 The use of statistical techniques in studying the causes of geochemical variations in aquifers can provide important results which cannot be derived in other ways. In this study, data from the Wadi Shueib catchment area in Jordan is evaluated, using principle component factor and multivariate factor analysis in order to better understand the variablility in groundwater chemistry and evaluate the sources of pollution and the susceptibility of these aquifers to the different sources of pollution. This study clearly demonstrates that these statistical techniques can help determine the various mechanisms causing chemical variation in the aquifers and the relative susceptibility of each aquifer to different types of pollution. Received: 13 March 1996 · Accepted: 18 June 1996     

The use of laboratory experiments for the study of conservative solute transport in heterogeneous porous media

 Laboratory experiments on heterogeneous porous media (otherwise known as intermediate scale experiments, or ISEs) have been increasingly relied upon by hydrogeologists for the study of saturated and unsaturated groundwater systems. Among the many ongoing applications of ISEs is the study of fluid flow and the transport of conservative solutes in correlated permeability fields. Recent advances in ISE design have provided the capability of creating correlated permeability fields in the laboratory. This capability is important in the application of ISEs for the assessment of recent stochastic theories. In addition, pressure-transducer technology and visualization methods have provided the potential for ISEs to be used in characterizing the spatial distributions of both hydraulic head and local water velocity within correlated permeability fields. Finally, various methods are available for characterizing temporal variations in the spatial distribution (and, thereby, the spatial moments) of solute concentrations within ISEs. It is concluded, therefore, that recent developments in experimental techniques have provided an opportunity to use ISEs as important tools in the continuing study of fluid flow and the transport of conservative solutes in heterogeneous, saturated porous media. Received, December 1996 · Revised, July 1997 · Accepted, August 1997     

Thermochemistry of the new silica polymorph moganite

Samples of microcrystalline silica varieties containing variable amounts of the new silica polymorph moganite (up to R~82 wt.%) have been studied by a combination of high temperature solution calorimetry using lead borate (2 PbO · B₂O₃) solvent and transposed temperature drop calorimetry near 977 K, in order to investigate the thermochemical stability of this new silica mineral. The enthalpy of solution at 977 K and the heat content (H₉₇₇ — H₂₉₈) of “pure” moganite phase were estimated to be -7.16 ± 0.35 kJ/mol and 43.62 ± 0.50 kJ/mol, respectively. The standard molar enthalpy of formation is-907.3 ± 1.2 kJ/mol. Thus, calorimetry strongly supports results of previous X-ray and Raman spectroscopic studies that moganite is a distinct silica polymorph. Its thermochemical instability relative to quartz at 298 K of 3.4 ± 0.7 kJ/mol is marginally higher than those of cristobalite and tridymite. Structurally, this instability may be related to the presence of distorted 4-membered rings of SiO₄ tetrahedra, which are not found in the quartz structure. The metastability relative to quartz may also explain the apparent scarcity of moganite in altered rocks and in rocks that are older than 130 my.     

Application of Laser Ablation ICP-MS to U-Th-Pb Dating of Monazite

Recent advances in laser ablation ICP-MS techniques allow accurate U-Th-Pb age dating of monazites that are as young as several tens of million years to a precision better than 2%. Accuracy of the age determinations has been improved by true real-time mass bias correction via nebulisation of a solution containing enriched ²³³U and natural Tl isotopes. The Tl-U tracer solution eliminates possible effects of variable sample matrices on the precision and accuracy of measured isotopic ratios. Mass bias corrections based on measured ²⁰⁵Tl/²³³U ratios in the tracer solution allow direct measurement of ²³⁵U in monazite. Combined with high-sensitivity laser ablation ICP-MS measurements, direct measurement of ²³⁵U particularly improves the precision of U-Pb dating of young monazites. Correction for laser-induced Pb/U and Pb/Th elemental fractionation is based on a mathematical treatment of time resolved count-rate data that is independent of laser ablation characteristics, does not require external standardisation and allows variable laser pit size or raster patterns for each measurement. The new procedures make the LA ICP-MS technique more flexible for in situ U-Th-Pb analysis.     

Synthesis of nitrate sodalite: An in situ scanning calorimetric study

The formation of nitrate sodalite, an important constituent of the resilient heels at DOE nuclear waste storage sites, was closely followed by oven synthesis, in situ calorimetry as a function of heating rate from 0.01 to 0.1 °C/min and X-ray diffraction. A transition sequence of amorphous-zeolite A-sodalite-cancrinite was confirmed. For in situ synthesis calorimetry, the heat flow peaks related to zeolite A formation are shifted to higher temperatures as heating rate increases. Although the end products are mostly nitrate sodalite, no calorimetric signals associated with zeolite A to sodalite conversion are detected. This suggests that the enthalpy of formation of zeolite A and sodalite are very similar and the zeolite A to sodalite conversion enthalpy is small. This conclusion is in accord with previous measurements by oxide melt solution calorimetry.     

有机岩石学的研究现状与进展

介绍了有机岩石学的产生与发展。并系统地论述了有机岩石学在分散有机质的分类、成熟度研究方法、热模拟实验、油气潜力评价、新技术与新手段的应用等几方面的研究现状与进展。     

Thermodynamics of the kaolinite-group minerals

The enthalpies of formation of kaolinite and dickite were determined by high-temperature melt solution calorimetry to be ΔfH°(298.15 K) = −4118 ± 10 and −4127 ±10 kJ/mol, respectively. These data represent the first calorimetric confirmation of the metastability of kaolinite with respect to dickite.     

Energetics of nanoparticle oxides: interplay between surface energy and polymorphism†

Many oxides tend to form different structures (polymorphs) for small particles. High temperature oxide melt solution calorimetry has been used to measure the enthalpy as a function of polymorphism and surface area for oxides of Al, Ti, and Zr. The results confirm crossovers in polymorph stability at the nanoscale. The energies of internal and external surfaces of zeolitic silicas with open framework structures are an order of magnitude smaller than those of oxides of normal density.     

Investigation of landslides with natural lineaments derived from integrated manual and automatic techniques applied on geospatial data

Lineament extraction has long been performed through extensive field mapping. Recent advances in the field of remote sensing have made possible the availability of imageries from earth observation satellites with different Spatio-temporal resolutions, paving way for new automatic, semi-automatic, and manual techniques for the extraction of natural lineaments. The study focuses on the extraction of lineaments representing tectonic fault zones; the lineaments are extracted automatically and semi-automatically/manually. Results show that indirect information about the tectonic lineaments can be derived through automatic techniques whereas, the semi-automatic techniques are more effective to directly identify them. Detailed analyses of lineaments and landslides revealed that areas near lineaments, in general, experienced higher frequency of landslides. Moreover, it is also observed that lineaments are not the only factor that affects landslide density; other parameters like slope and lithology were also found to be the controlling factors in determining the spatial landslide distribution. Lastly, some recommendations have been made based on observations.

     

硼同位素分析方法研究进展

硼具有两种稳定同位素10B和11B,其在自然界的丰度分别是19.90%和80.10%。自然界硼同位素组成变化很大, δ11B变化可达90‰以上(－30‰～＋60‰)。硼同位素的分析精度优于0.2‰,因此被广泛应用于多种地质过程的示踪研究。近年来,硼元素的提取、分离纯化和仪器测定技术均取得了可喜的进展,分析精度不断提高,为硼同位素地球化学研究奠定了良好的基础。本文从样品分解、化学分离和仪器测定等方面对硼同位素分析测试方法进行了归纳总结。     

Thermodynamic properties of synthetic calcium-free carbonate cancrinite

Calcium-free carbonate cancrinite with formula unit Na_8.28[Al_5.93Si_6.07O₂₄](CO₃)_0.93(OH)_0.49·3.64H₂O (CAN) has been synthesized under hydrothermal conditions. The product has been characterized by the methods of scanning electronic microscopy and energy dispersive X-ray analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis with FTIR of evolved gases (TGA–FTIR), and X-ray powder diffraction. The heat capacity of CAN has been measured from 6 to 259 K via low-temperature adiabatic calorimetry. A linear combination of Einstein functions has been used to approximate the obtained data on the heat capacity. The thermal contributions to the entropy and enthalpy of CAN in the temperature range 0–300 K have been calculated from these data. The heat capacity and third-law absolute entropy of CAN at 298.15 K are 1,047 ± 30 and 1,057 ± 35 J mol^?1 K^?1, respectively. High-temperature oxide-melt solution calorimetry has been used to determine the enthalpy of formation from elements of CAN at 298.15 K; the value equals ?14,684 ± 50 kJ mol^?1. The Gibbs energy of formation from elements at 298.15 K has been calculated and totaled ?13,690 ± 51 kJ mol^?1.     

孔隙网络模型在土壤水文学中的应用研究进展

非饱和土壤的水力性质是采用模型定量模拟水分和溶质在非饱和带中运动的最重要的物理参数,可以用网络模型来预测。孔隙网络模型的主要优点在于可以对发生在土壤孔隙尺度上的物理、化学过程进行直观的表达和模拟。目前,国内外研究者已在样品图像获取、图像分析、模型建立以及求解等方面取得了一定的进展。在对其进行综合评述的基础上,指出了已有网络模型在建立过程中存在的不足之处,并进一步明确了今后的研究方向。