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End-Permian catastrophic event of marine acidification by hydrated sulfuric acid:Mineralogical evidence from Meishan Section of South China 被引量:21
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作者 LIANG HandongKey Laboratory of Coal Resources, China University of Mining and Technology, Beijing 100083, China (e-mail: hdl6688@sina.com) 《Chinese Science Bulletin》 SCIE EI CAS 2002年第16期1393-1397,共5页
The event Permian-Triassic boundary (EPTB) is well marked by the famous 'white clay' of bed 25 in Mei-shan Section located in Changxing county, Zhejiang province of China. In this note, the white clay as well ... The event Permian-Triassic boundary (EPTB) is well marked by the famous 'white clay' of bed 25 in Mei-shan Section located in Changxing county, Zhejiang province of China. In this note, the white clay as well as its overlying and underlying sequences is investigated particularly for mineralogical records. The investigation yields three findings that contribute to better understanding the scenario of the EPTB mass extinction. (i) A red goethite-rich microlayer (0.3 mm) is first recognized to be horizontally widespread on the base of the white clay in the section. The microlayer should be considered as a macro geochemical indicator naturally tracing a catastrophic initiation at the EPTB. (ii) An interruption of marine carbonate deposition is discovered due to blank of carbonate minerals in the white clay. The discovery provides significant evidence of a marine acidification event that would occur in the paleo-ocean with marine acidity estimated at pH【4.0 at least and be triggered by the ultimate 展开更多
关键词 mass extinction MARINE acidIFICATION hydrated sulfuric acid MEISHAN Section GOETHITE carbonate blank catastrophic event.
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灵芝多糖提取条件优化的快速方法 被引量:5
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作者 熊东林 姚跃飞 《中南林业科技大学学报》 CAS CSCD 北大核心 2010年第9期170-172,共3页
应用苯酚—硫酸法直接快速测定灵芝多糖提取液中的多糖含量,并对影响灵芝多糖提取的因素进行单因子分析和正交试验,确定了灵芝多糖的最优提取条件。灵芝多糖最优提取条件为:温度90℃,时间3.5 h,料水比1∶30。试验证明这种方法快速且准确。
关键词 灵芝 多糖 苯酚—硫酸法 正交试验
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