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61.
Pierre Hudon In-Ho Jung Don R. Baker 《Physics of the Earth and Planetary Interiors》2002,130(3-4):159-174
Melting relations of β-quartz were experimentally determined at 1.0 GPa (1900±20 °C), 1.5 GPa (2033±20 °C), and 2.0 GPa (2145±20 °C) using a new high-pressure assembly in a piston–cylinder apparatus and substantial differences were found with data previously reported. The new melting data of β-quartz were combined and optimized with all available thermodynamic, volumetric, and phase equilibria data for β-cristobalite, β-quartz and coesite to produce a P–T liquidus diagram for silica valid up to 6.0 GPa. Using the new optimized thermodynamic parameters, the invariant point β-cristobalite+β-quartz+liquid and β-quartz+coesite+liquid were determined to lie at 1687±17 °C and 0.457 GPa, and 2425±25 °C and 5.00 GPa, respectively. 相似文献
62.
超临界二氧化碳(ScCO2)–H2O–煤地球化学反应可造成煤物理结构和化学结构的改变,对煤层注CO2增采甲烷的有效性尤为关键。为了探讨ScCO2-H2O-煤反应对不同变质程度煤化学结构的影响,选择3个不同煤化程度煤样,在自主研制的ScCO2-H2O-煤地球化学反应模拟实验装置中模拟1000m埋深条件下煤样与ScCO2和去离子水反应240h,并对反应前后的煤样分别进行了X射线衍射和拉曼光谱实验,对比分析了反应前后煤样晶体结构和碳有序度的变化特征。测试结果表明:ScCO2-H2O反应破坏了煤的晶体完整性和碳有序度,改变了煤的大分子结构,且对低阶煤和中–高阶煤具有不同的影响,反应提高了低阶煤的平行定向程度,使其结构更加紧凑,减小了面网间距,而使中–高阶煤中无序单元增加,面网间距增大。该研究结果为CO2-ECBM项目实施中ScCO2-H2O作用对煤储层吸附解吸特征和孔渗特征影响的研究奠定了微观尺度基础。 相似文献
63.
Thomas Pichler 《Environmental Geology》2005,47(2):215-224
The application of sulfur isotope (34S) values of sulfate in groundwater provided the information necessary to evaluate the source, transport and fate of battery acid and associated contaminants at the Gulf Coast Recycling (GCR) facility. The chemical and isotopic composition of groundwater beneath the (GCR) property, a battery recycling facility in east Tampa, Florida, varies more than expected for an area of comparable size. Sulfate (SO42–) values, for example, range from 1.2 to 11,500 mg/L and oxygen and hydrogen isotopes do not attenuate towards the weighted annual mean. Those samples that are high in sulfate generally have a low pH, which immediately indicates battery acid (H2SO4) contamination as a potential source for the sulfate. The low pH and high reactivity of the sulfuric acid groundwater cause the formation of hydrogeological microenvironments due to preferential dissolution of carbonate minerals, which in turn causes enhanced recharge and groundwater flow in certain areas; thus, the extreme scatter in the data set. Because of the difficult hydrogeology it is not straightforward to delineate the point-sources of contamination and up to five potential scenarios have to be evaluated: (1) seawater intrusion, (2) upwelling of high-sulfate groundwater, (3) local dissolution of gypsum, (4) an up-gradient contaminant source to the northeast of the GCR property and (5) battery acid contamination. 相似文献
64.
含Ti硅酸盐玻璃在基础科学研究和应用技术开发上均有重要价值,亟需对其进行准确的成分分析,为进一步的科研工作提供重要的数据支撑.对玻璃进行电子探针分析时,由于样品的易损性和其中(Na和K)阳离子在电子束轰击下极易发生迁移和扩散,因此往往需要经过条件实验来确定合适的分析条件,确保样品在该条件下能够保持尽量稳定的状态,才能获... 相似文献
65.
Alfredo Alberto Muxel Sonia Maria Nobre Gimenez Flaveli Aparecida de Souza Almeida Rení Ventura da Silva Alfaya Antonio Alberto da Silva Alfaya 《洁净——土壤、空气、水》2011,39(3):289-295
The natural cotton fiber was used to synthesize an anion exchange, containing ZrO2 film on its surface, NCFZC (natural cotton fiber/ZrO2 composite). This anion exchanger was produced by the reaction of the zirconium oxychloride and hydroxyl groups on surface of the natural cotton fiber. The material was used for Cr(VI) ions adsorption studies. Adsorption equilibrium time and optimum pH for Cr(VI) adsorption were found to be 6 h and 4.0, respectively. The Langmuir and Temkin isotherms were used to models adsorption equilibrium data. The adsorption capacity of NCFZC was found to be 1.33 mmol/g. Kinetic studies showed that the rate of adsorption of Cr(VI) on NCFZC obeyed a pseudo‐second‐order kinetic model. 相似文献
66.
使用COSMIC掩星提供的NmF2数据,利用傅里叶分析方法,研究全球F2层峰值电子密度的周年和半年分布特征,分析2010年LT12:00 14:00 NmF2周年和半年变化幅度及2008-2011年年平均值变化.结果显示,电离层NmF2周年和半年变化幅度在中高纬地区相对较大;在赤道和低纬地区相对较小,且NmF2以半年变化为主.太阳活动增强期间,NmF2年平均值增大. 相似文献
67.
Marcel Guillong Kathrin Hametner Eric Reusser Stephen A. Wilson Detlef Günther 《Geostandards and Geoanalytical Research》2005,29(3):315-331
New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP. 相似文献
68.
小良试验站三种植被类型地表径流效应的对比研究 总被引:13,自引:0,他引:13
本文分析研究了3种植被类型下的地表径流在汇流、洪峰及径流过程上的特征,差异是巨大的。在径流过程上桉树林和裸地的变地剧烈,几乎没有什么调蓄作用,洪峰流量占一次性降水径流量的绝大部分,涨水和退水流量都较小。本文应用灰色系统GM(2,1)模型,成功地预测了以年和以月为时间尺度的地表径流序列,其预测模型可以用来对这些时间尺度的地表径流进行预报。 相似文献
69.
70.