排序方式: 共有55条查询结果,搜索用时 16 毫秒
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样品采自伊敏褐煤盆地中一个因次火山活动形成的烟煤区,包含了从褐煤到瘦煤的变质系列。红外光谱分析表明,煤的含氧基团在褐煤阶段已开始消失,烷基和芳环同步增加,在R°=1.10%时达最大值。顺磁共振自由基浓度和X-衍射参数La/Lc介于区域变质煤和岩浆接触热变质煤之间,芳核外官能团的热演化超前于芳核骨架及R°的演化。 相似文献
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Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse ef fects on human activities.Organic carbon in marine sediments is an indispensable part of the global carbon reservoir in global carbon cycling.Evaluating such a reservoir calls for quantitative studies of marine carbon burial,which closely depend on quantifying total organic carbon and black carbon in marine sediment cores and subsequently on obtaining their high-resolution temporal sequences.However,the conventional methods for detecting the contents of total organic carbon or black carbon cannot resolve the following specific difficulties,i.e.,(1)a very limited amount of each subsample versus the diverse analytical items,(2) a low and fluctuating recovery rate of total organic carbon or black carbon versus the reproducibility of carbon data,and(3)a large number of subsamples versus the rapid batch measurements.In this work,(i)adopting the customized disposable ceramic crucibles with the microporecontrolled ability,(ii)developing self-made or customized facilities for the procedures of acidification and chemothermal oxidization,and(iii)optimizing procedures and carbon-sulfur analyzer,we have built a novel Wang-Xu-Yuan method(the WXY method)for measuring the contents of total organic carbon or black carbon in marine sediment cores,which includes the procedures of pretreatment,weighing,acidification,chemothermal oxidation and quantification;and can fully meet the requirements of establishing their highresolution temporal sequences,whatever in the recovery,experimental efficiency,accuracy and reliability of the measurements,and homogeneity of samples.In particular,the usage of disposable ceramic crucibles leads to evidently simplify the experimental scenario,which further results in the very high recovery rates for total organic carbon and black carbon.This new technique may provide a significant support for revealing the mechanism of carbon burial and evaluating the capacity of marine carbon accumulation and sequestration. 相似文献
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煤成甲烷、乙烷碳同位素动力学研究和应用--以鄂尔多斯盆地上古生界煤成气为例 总被引:10,自引:0,他引:10
同位素动力学模型的发展和应用使天然气的研究工作进入了一个动态的研究阶段。迄今为止,大多数研究工作集中在甲烷的碳同位素动力学模拟。而少有地球化学家对乙烷及其他重烃气组分的碳同位素组成的动力学模拟加以重视。本文在甲烷碳同位素动力学模型基础上,编制了限定体系下乙烷的同位素动力学模拟软件。并在热解模拟实验的基础上对鄂尔多斯盆地上古生界煤成气甲烷、乙烷的同位素演化进行了模拟,获得长期累积甲烷、乙烷的同位素值分别为δ^1C1=-33.46‰3、δ^13C2=-23.1‰,与上古生界储层中天然气的组分特征(δ^13C1=-32.95%。、δ^13C2=-23.41‰)基本一致,与下古生界天然气的同位素组成存在着明显的差别,说明上古生界煤与上古生界天然气存在着源—气的对应关系;而对下古生界天然气来说,上古生界煤系不是主要的气源岩。 相似文献
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样品采自伊敏褐煤盆地中一个因次火山活动形成的烟煤区,包含了从褐煤到瘦煤的变质系列。红外光谱分析表明,煤的含氧基团在褐煤阶段已开始消失,烷基和芳环同步增加,在R^O=1.10%时达最大值。顺磁共振自由其浓度和X-衍射参数La/Lc介于区域变质和岩浆接触热变质煤之间,芳核外官能团的热演化超前于芳核骨架及R^o的演化。 相似文献
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Century-scale high-resolution black carbon records in sediment cores from the South Yellow Sea,China
Black carbon(BC)has received increasing attention in the last 20 years because it is not only an absorbent of toxic pollutants but also a greenhouse substance,preserving fire-history records,and more importantly,acting as an indicator of biogeochemical cycles and global changes.By adopting an improved chemothermal oxidation method(WXY),this study reconstructed the century-scale high-resolution records of BC deposition from two fine-grained sediment cores collected from the Yellow Sea Cold Water Mass in the South Yellow Sea.The BC records were divided into five stages,which exhibited specific sequences with three BC peaks at approximately 1891,1921,and 2007 AD,representing times at which the first heavy storms appeared just after the termination of long-term droughts.The significant correlation between the times of the BC peaks in the cores and heavy storms in the area of the Huanghe(Yellow)River demonstrated that BC peaks could result from markedly strengthened sedimentation due to surface runof f,which augmented the atmospheric deposition.Stable carbon isotope analysis indicated that the evident increase in carbon isotope ratios of BC in Stage 5 might have resulted from the input of weathered rock-derived graphitic carbon cardinally induced by the annual anthropogenic modulation of water-borne sediment in the Huanghe River since 2005 AD.Numerical calculations demonstrated that the input fraction of graphitic carbon was 22.97% for Stage 5,whereas no graphitic carbon entered during Stages 1 and 3.The obtained data provide new and important understanding of the source-sink history of BC in the Yellow Sea. 相似文献