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中子活化分析测定不同粒径大气颗粒物中的元素含量 总被引:1,自引:0,他引:1
一、前言颗粒物是大气环境中组成复杂、危害较大的污染物之一。颗粒物本身可以是有毒或有害的物质,也可能是其它污染物的运载体或反应林。它的来源很多,地区特性较强,物化特性多变,因此它已成为大气污染研究的重要内容。不同粒径的颗粒物对人体的危害作用是不同的。大于10微米粒径的颗粒主要沉积在鼻腔、咽喉;而小于1微米的颗粒则大部分沉积在支气管和肺泡中。许多有害金属元素绝大部分富集在小于2微米的细颗粒上,对人体和生物的影响较大。因此研究不同粒径颗粒中的元素组分及其与时、空的关系,对大气污染状况的评价和污染源对大气颗粒物贡献率的估算有着重要的实际意义。 相似文献
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The chief aim of this preliminary work is to investigate the weathering process of the bed rock and moraine in Antarctic by the method of sedimentology. Microfractures, the depth of which is less than 1 cm, and macrofissures are formed through frost weathering process. The chemical composition of the weathering products are observably related to their size due to migration process. Weathering materials are relatively rich in rare-earth elements of Ce family. Weathering clay minerals are mainly illite hydromica which can considerably absorb the elements of Ti, K, Cs, Rb, Sc, Sb, As and Fe. The weathering crust of the bed rock has hardly any CaCO_3 component, it belongs to primigenial debris weathering crust, with only a slight As pollution. 相似文献
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GEOCHEMISTRY OF SEDIMENTS AND ENVIRONMENT IN XIHU LAKE OF GREAT WALL STATION OF CHINA, ANTARCTICA 总被引:3,自引:0,他引:3
The determined results in this paper, which were obtained by the multielement analysis of the 260 cm-deep core sediments under the water of Xihu Lake in the Great Wall Station area, are as follows: The Cenozoic volcanic rocks around Xihu Lake are the main source of sediments in the lake. The chemical differentiation in very fine particles is still detectable. From the variation of ratios of the Cs/Rb, Br/CI and La/Yb in the clay fraction with depth and from the variation or CaCO_3 contained in the sediments, cation replacing amount in the clay grains and the sediment grain sizes in time, it can be seen that since 3600 a. B. P., there has existed the climatic variation of warm-cold-warm, which embodies the advance and retreat history of the ice sheet in this area. 相似文献
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