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Quantitative analysis of COH fluids synthesized at HP–HT conditions: an optimized methodology to measure volatiles in experimental capsules
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The quantitative assessment of COH fluids is crucial in modeling geological processes. The composition of fluids, and in particular their H2O/CO2 ratio, can influence the melting temperatures, the location of hydration or carbonation reactions, and the solute transport capability in several rock systems. In the scientific literature, COH fluids speciation has been generally assumed on the basis of thermodynamic calculations using equations of state of simple H2O–nonpolar gas systems (e.g., H2O–CO2–CH4). Only few authors dealt with the experimental determination of high‐pressure COH fluid species at different conditions, using diverse experimental and analytical approaches (e.g., piston cylinder + capsule piercing + gas chromatography/mass spectrometry; cold seal + silica glass capsules + Raman). In this contribution, we present a new methodology for the synthesis and the analysis of COH fluids in experimental capsules, which allows the quantitative determination of volatiles in the fluid by means of a capsule‐piercing device connected to a quadrupole mass spectrometer. COH fluids are synthesized starting from oxalic acid dihydrate at P = amb and T = 250°C in single capsules heated in a furnace, and at P = 1 GPa and T = 800°C using a piston‐cylinder apparatus and the double‐capsule technique to control the redox conditions employing the rhenium–rhenium oxide oxygen buffer. A quantitative analysis of H2O, CO2, CH4, CO, H2, O2, and N2 along with associated statistical errors is obtained by linear regression of the m/z data of the sample and of standard gas mixtures of known composition. The estimated uncertainties are typically <1% for H2O and CO2, and <5% for CO. Our results suggest that the COH fluid speciation is preserved during and after quench, as the experimental data closely mimic the thermodynamic model both in terms of bulk composition and fluid speciation. 相似文献
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随着旅游市场竞争日趋激烈,目的地定位的重要性愈加突出。然而,国内研究和实践对"把握旅游者兴趣和需求"这一定位首要工作普遍认识不足,且实施不到位。鉴于此,本研究对目的地定位中"击中消费者心灵"这一关键环节的实施从理论和实证上进行了阐释。理论上,分析了目的地突出属性与定位之间的关系及当前国内误区。实证上,引入轮换方格分析法,以国内十大海滨城市目的地为要素,阐释了识别旅游者对竞争目的地相比较的目的地突出属性的方法程序。此外,对旅游者访谈结果与目的地业界代表访谈结果的比较发现,供需双方在旅游者需求的认识上不吻合。文章最后还对本研究的应用价值和局限做了总结。 相似文献
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在商周的青铜器中,许多都铸有扉棱,但最早出现扉棱的青铜器,应该是商中期的圆形尊,而商早期所有的青铜器都没有扉棱.在西周的圆形尊中,除了没有铸扉棱的尊外,其余多是铸有三段扉棱.青铜器上为什么要铸造扉棱?这是我们需要研究的问题.在西周一些圆形尊的表面纹饰中,常出现翘起的牛角纹饰.这些纹饰是怎么制作的?这也是我们需要解决的问题.通过范铸模拟实验,使得上述两个问题有了较为合理的解释. 相似文献
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为研究出土墓葬青铜器铸造地,利用X射线荧光光谱法对湖北襄樊的余岗、沈岗、团山、陈坡四处墓地出土的部分青铜器泥芯、陶片进行测试分析,试验结果与山西侯马、武汉盘龙城遗址进行比较分析。对比研究显示,襄樊地区泥芯与当地墓土、陶片在常量元素上具有高度一致性,而与黄河流域的侯马和长江中下游的盘龙城有明显区别,说明襄樊地区这部分铜器应为本地铸造,暗示江汉流域存在自己特有文化。本项研究工作首次尝试利用同墓葬陶器化学成分探索青铜器铸造地,是泥芯研究青铜器铸造地的重要补充,泥芯和陶器相互配合,为青铜器铸造地研究提供了一种新思路。 相似文献
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本文评述了与殷墟青铜礼器铸造工艺研究相关的技术史、考古学和艺术史文献,概述了殷墟治铸遗址的发现和研究状况,分析取得的认识和存在的局限,探讨了在技术演进、文化传播及治铸业的组织管理等方面值得深入的问题. 相似文献
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Chloë N. Duckworth Julian Henderson Frank J.M. Rutten Kalliopi Nikita 《Journal of archaeological science》2012
Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is applied to the study of four samples of opaque glass of Late Bronze Age date. The technique is uniquely capable of identifying compositional heterogeneity at a sub-micron resolution within the crystalline opacifiers dispersed through homogeneous glass matrices. It is shown that this provides crucial information on the possible raw ingredients of the opacifying inclusions used, and has the potential for highlighting regional variations in the production technology involved in creating different colours of opaque glass. 相似文献
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《Journal of Geography in Higher Education》2012,36(2):155-171
The authors reflect critically on their experiences of teaching research methods/methodology/techniques (MMT) courses in human geography for the first time. Through a highly reflexive process involving journaling, they engage with the broader scholarship of teaching and learning approach. Three themes characterize commonalities in their instructional experiences: (1) prior knowledge, (2) preparation, and (3) confidence. Specifically, they were challenged by needing to teach particular MMTs that they had not previously applied in their own research, by not knowing how best to prepare for teaching such courses, and by a lack of confidence with their approaches that stemmed from numerous issues. 相似文献
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"明永乐宣德文物特展"是一个全面展现明早期艺术的综合性文物大展。展览的最终目的是要激发大众对传统艺术的兴趣,令其得到文化的熏陶与艺术的启迪,因此,展览陈列设计所要考虑的是一个多层次的体系。首先提炼装饰元素作为视觉主题,将艺术品的美感尽可能展现给观众,同时还要向观者传递时代背景、皇帝的思想境界等信息。此外,设计者还精心挑选不同的装饰材料以营造新颖的展示环境,达到衬托文物高超工艺水平的目的。 相似文献
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本文作者根据从事拓片工作30多年的实践经验,就拓片技术以及制作方法进行全面总结,从拓印工具、主要材料、拓印步骤、基本方法等方面做了系统论述。 相似文献
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