煤中微量元素研究进展   总被引：30，自引：3，他引：30  

刘桂建  彭子成  王桂梁  杨萍月  Chou Chenglin 《地球科学进展》2002,17(1):53-62

煤炭是我国的主要能源，在煤炭开采、运输、洗选、淋溶（滤）、燃烧等其它加工利用过程中，煤中的微量元素要发生迁移、析出，并入侵到大气、水、土壤和生态环境中，最终影响人类生存和生活环境。煤中微量元素十分重要，是因为它们与环境问题、动、植物及人类健康密切相关。在研究微量元素时必须考虑微量元素的性质及毒性，它们主要依靠其含量、种类、存在形式、pH值、氧化-还原条件及其它因素。在全面综合国内外研究文献的基础上，分析了煤中微量元素的发现、分布规律、赋存状态、成因机理及微量元素的应用等方面研究的历史、现状，并对今后研究的重点内容和发展方向进行了较为详细的论述和分析，并指出在进一步深入研究煤中微量元素地球化学的基础上，加强微量元素环境学方面的研究是今后煤中微量元素环境地球化学研究的重要内容。  相似文献   

建立地质-地球化学找矿模型 ——以西藏甲玛铜多金属矿床为例   总被引：1，自引：0，他引：1  

龚鹏  胡小梅  李娟  仇一凡 《地质通报》2013,32(10):1601-1612

区域地球化学定量预测是全国重要矿产资源潜力评价项目的组成部分之一。为了提高其预测结果的可信度,科学合理的地质-地球化学找矿模型是关键,也是地球化学找矿预测区圈定和资源量估算过程中相似类比的“标准样本”。在中国地球化学找矿模型历史沿革的基础上,提出了地质-地球化学找矿模型建立的基本思路、理论基础和主要内容。通过收集、整理、归纳西藏冈底斯成矿带甲玛“三位一体”（夕卡岩型-角岩型-斑岩型）铜多金属矿床的最新资料,构建了甲玛典型铜多金属矿床的地质-地球化学找矿模型。该模型由区域地质特征、矿床地质特征、矿床地球化学特征、地球化学异常特征、地质-地球化学特征、重要控矿因素6个方面组成。  相似文献   

Re-equilibration of CO₂ fluid inclusions at controlled hydrogen fugacities     

G. B. MORGAN VI  I-MING CHOU  J. D. PASTERIS  S. N. OLSEN 《Journal of Metamorphic Geology》1993,11(1):155-164

Abstract Natural, pure CO₂ inclusions in quartz and olivine (c. Fo₉₀) were exposed to controlled f_H2 conditions at T= 718–728°C and P_total= 2 kbar; their compositions were monitored (before and after exposures) by microsampling Raman spectroscopy (MRS) and microthermometry. In both minerals exposed at the graphite–methane buffer (f_H2= 73 bar), fluid speciations record the diffusion of hydrogen into the inclusions. In quartz, room-temperature products in euhedral isolated (EI type) inclusions are carbonic phases with molar compositions of c. CO₂(60) + CH₄(40) plus graphite (Gr) and H₂O, whereas anhedral inclusions along secondary fractures (AS type) are Gr-free and contain H₂O plus carbonic phases with compositions in the range c. CO₂(60) + CH₄(40) to CO₂(10) + CH₄(90). EI type inclusions in olivine evolved to c. CO₂(90–95) + CH₄(5–10) without Gr, whereas AS type inclusions have a range of compositions from CO₂(90) + CH₄(10) ± Gr to CH₄(50) + H₂(50) ± Gr; neither H₂O nor any hydrous species was detected by optical microscopy or MRS in the olivine-hosted products. Differences in composition between and among the texturally distinct populations of inclusions in both minerals probably arise from variations in initial fluid densities, as all inclusions apparently equilibrated with the ambient f_H2. These relations suggest that compositional variability among inclusions in a given natural sample does not require the entrapment of multiple generations of fluids. In addition, the absence of H₂O in the olivine-hosted inclusions would require the extraction of oxygen from the fluids, in which case re-equilibration mechanisms may be dependent on the composition and structure of the host mineral. Many of the same samples were re-exposed to identical P–T conditions using Ar as the pressure medium, yielding ambient f_H2= 0.06 bar. In most inclusions, the carbonic fluids returned to pure CO₂ and graphite persisted in the products. Reversal of the mechanisms from the prior exposure at f_H2= 73 bar did not occur in any inclusions but the AS types in olivine, in which minor CO₂ was produced at the expense of CH₄ and/or graphite. The observed non-reversibility of previous mechanisms may be attributed to: (1) slower fluid–solid reactions compared to reactions in the homogeneous fluid phase; (2) depressed activities of graphite due to poor ordering; and/or (3) low ambient f_O2 at the conditions of the second run.  相似文献   

气候变化影响中国粮食安全研究的新思路北大核心CSCD     

丑洁明  董文杰  徐洪  涂钢 《气候与环境研究》2022,27(1):206-216

鉴于气候变化影响粮食安全问题的特殊性和复杂性,本文试图从自然科学和社会科学的交叉研究入手,提出一种新的研究的思路和方法,即:运用计量经济学模型对气候变化数据进行统计分析,使用计量经济学方法来评估气候这一外部驱动因素引发的社会经济系统变化与观测到的气候变化引发的社会经济系统变化之间的关系;在厘清“气候变化影响量”对粮食产量的影响的基础上,预估我国未来30年特别是经济社会发展两个关键节点2035年和2050年的粮食生产的气候变化风险,文章给出了一种新的研究视角,构建了研究内容和研究方法,力争实现定性研究与定量研究相结合,以科学预测为政策指导提供有力支撑。  相似文献   

Application of an Economy--Climate Model to Assess the Impact of Climate Change   总被引：1，自引：0，他引：1  

CHOU Jieming  DONG Wenjie  FENG Guolin 《大气科学进展》2010,27(4):957-965

An interdisciplinary investigation was conducted to assess the impact of climate change on grain yields using an economy--climate model (C-D-C). The model was formulated by incorporating climate factors into the classic Cobb-Douglas (C-D) economic production function model. The economic meanings of the model output elasticities are described and elucidated. The C-D-C model was applied to the assessment of the impact of climate change on grain yields in China during the past 20 years, from 1983 through 2002. In the study, the land of China was divided into eight regions, and both the C-D-C and C-D models were applied to each individual region. The results suggest that the C-D-C model is superior to the classic C-D model, indicating the importance of climate factors. Prospective applications of the C-D-C model are discussed.  相似文献   

两种四维SVD同化方法的比较及误差分析   总被引：3，自引：3，他引：0  

王金成  李建平  丑纪范 《大气科学》2008,32(2):277-288

4DSVD是最近提出的一种新的资料同化方法。目前还存在一些需要解决的问题,比如如何选取样本,如何得到支撑大气吸引子的基向量以及选取基向量的个数问题等等。作者利用奇异值分解(SVD)与经验正交函数分解(EOF)两种方法来获得支撑大气吸引子的基向量,推导了基于这两种方法的4DSVD分析场的理论公式,并用简单的数值试验比较了基于这两种方法的4DSVD分析场的空间相关系数和误差,初步分析了分析场与基向量个数的关系以及与样本选取的关系和分析误差的来源及各种误差对分析误差影响的相对大小。结果表明,用SVD方法作为获得支撑大气吸引子基向量的方法得到的分析场较EOF方法稳定,分析场与基向量个数有密切关系,观测误差、模式误差和观测代表性误差是分析误差的主要来源,且其引起的分析误差随着基向量个数增多而增大。  相似文献   

Numerical Study on Breaking Criteria for Solitary Waves     

Chung-ren CHOU  Ruey-syan SHIH  John Z. YIM 《中国海洋工程》2003,17(4):589-604

Studies of the breaking criteria for solitary waves on a slope are presented in this paper. The boundary element method is used to model the processes of shoaling and breaking of solitary waves on various slopes. Empirical formulae that can be used to characterize the breaking of solitary waves are presented. These include the breaking index, the wave height, the water depth, and the maximum particle velocity at the point of breaking. Comparisons with the results of other researches are given.  相似文献   

A Study of Wind Statistics Through Auto-Regressive and Moving-Average (ARMA) Modeling     

John  Z.YIM 《中国海洋工程》2001,(1):61-72

Statistical properties of winds near the Taichung Harbour are investigated. The 26 years'incomplete data of wind speeds, measured on an hourly basis, are used as reference. The possibility of imputation using simulated results of the Auto-Regressive (AR), Moving-Average (MA), and/ or Auto-Regressive and Moving-Average (ARMA) models is studied. Predictions of the 25-year extreme wind speeds based upon the augmented data are compared with the original series. Based upon the results, predictions of the 50- and 100-year extreme wind speeds are then made.  相似文献   

A Numerical Wave Tank for Nonlinear Waves with Passive Absorption   总被引：1，自引：2，他引：1  

Chung-Ren CHOU 《中国海洋工程》2001,(2):253-268

  相似文献   

当前流体包裹体研究和应用概况   总被引：12，自引：7，他引：12  

池国祥周义明  卢焕章 《岩石学报》2003,19(2):201-212

本文概要总结近年来流体包裹体研究和应用的发展情况，包括流体包裹体岩相学，PVTX研究，分析技术和应用等四个方面。岩相学方面的主要进展反映在“流体包裹体组合”概念的提出和应用。在PVTX研究方面，人工包裹体和热液金刚石压腔的应用极大地促进了我们对地质流体体系相特征的了解。各种分析技术不断涌现或改进，其中以Laser-Raman对气体成分和LA-ICP—MS对溶质成分的分析尤其有用。流体包裹体的应用领域一直以矿床学研究为主，当前和今后一段时间仍将如此。但是，流体包裹体在地球科学的其它领域，尤其是石油地质以及岩浆和地球内部过程的研究等方面，正得到越来越多的应用。  相似文献