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铀及其衰变产物引起的土壤污染是全球关注的重大环境问题,不仅会引起生态风险,还会对人体健康造成威胁。因此,如何有效地解决铀污染、完善铀污染土壤修复技术体系,是实现铀矿冶行业可持续发展的关键。目前,铀污染土壤的修复技术主要有物理-化学修复、生物修复以及联合修复3种方式。本文首先介绍了铀在土壤中的赋存形态及其危害,然后对各种修复技术的研究现状及优缺点进行了详细综述,阐述了铀污染修复的影响因素,最后总结了目前铀污染土壤修复技术存在的挑战,并展望了该领域修复技术未来的发展方向,以期在实际应用中充分结合环境因素和各种修复方法的适用性,选择合适的修复技术实现污染土壤中铀的高效去除。 相似文献
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含铀硼镁铁矿综合利用过程中除铀方法的探讨 总被引:1,自引:0,他引:1
在对含铀硼镁铁原矿中铀的存在形式以及各种综合利用工艺实现铁硼分离后铀的分布及价态改变进行分析后,针对不同的工艺探讨了除铀方法的可行性。 相似文献
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阐述了化工流化床技术在铀燃料循环工业各个过程中的具体应用,包括铀矿石浸析、铀化学转化、铀同位素富集、水堆燃料元件制备、高温气冷堆燃料元件制造、乏燃料后处理、铀燃料工业三废处理以及新型流化床核反应堆概念设计等过程。概述了各种应用流化床的类型和构造,结合具体应用过程评价了各种流化床的设计特性和优缺点,展望了流化床技术在铀燃料循环工业中的未来发展方向和广阔应用前景。指出必须结合我国核电快速发展的新趋势和新要求,加大针对铀燃料工业中的流化床应用技术研究,特别是气固流化床的基础研究工作。 相似文献
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近年来,随着世界铀价格和铀需求量的不断变化,铀的勘查和开发也随之发生新的变化。根据近几期”红皮书”及相关资料,综述了近期世界铀资源、勘查与生产情况,并对世界主要产铀国进行分别的说明。通过对世界铀矿的分布规律、铀勘查和铀生产的分析,对国内的铀矿找矿工作进行指导。 相似文献
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Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders,
but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled
VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-2H3]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s
syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting
that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the
ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the
corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured.
A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis
and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994. 相似文献
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为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。 相似文献
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The proportions of the different lecithin fractions have been determined in HeLa and KB tissue culture cells and Ehrlich Ascites
tumor. 82.8% of the total phosphatidyl choline phosphorus is found in fraction 3 of HeLa cells. The major phosphatidyl cholines
found in KB cells and Ehrlich Ascites tumor are in fractions 3 and 4 and representing 66.6% and 88.7% of the total phosphatidyl
choline P, respectively. The incorporation of 1,2-14C-choline and 1,2-14C-ethanolamine into the various phosphatidyl choline fractions has been assayed to determine their biosynthesis in Ehrlich
Ascites tumor. The incorporation of 1,2-14C-choline into fractions 3 and 4 is 100 times the 1,2-14C-ethanolamine. This evidence indicates that the methylation pathway of phosphatidyl choline synthesis is very low in HeLa,
KB and Ehrlich Ascites cells.
One of 13 papers presented at the symposium “Lipid Metabolism in Cells in Culture,” AOCS Meeting, Houston, May 1971.
Part of a thesis submitted to the Graduate School of the University of North Dakota in partial fulfillment of the Degree of
Master of Science. 相似文献
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