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Determinationofpolychlorinatedbiphenylcongenersinenvironmentalsamples¥ChuShaogang;YangChun;XuXiaobai(ResearchCenterforEco-Env... 相似文献
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The effects of land use and its patterns on soil properties in a small catchment of the Loess Plateau 总被引:3,自引:0,他引:3
Due to relatively strong human activities in the hilly area of Loess Plateau,the natural vegetation has been destroyed,and landscape pattern based on agricultural land matrix was land use mosaic composing of shrub land,grassland,woolland and orchard.This pattern has an important effect on soil moisture and soil nutrients.The Danangou catchment,a typical small catchment,was selected to study the effects of land use and its patterns on soil moisture and nutrients in this paper.The results are as follows:The comparisons of soil moisture among seven land uses for wet year and dry year were performed:(1)the average of soil moisture content for whole catchment was 12.11% in wet year,while it was 9.37% in dry year;(2)soil moisture among seven land uses was significantly different in dry year,but not in wet year;(3) form wet year to dry year,the profile type of soil moisture changed from decreasing type to fluctuation-type and from fluctuant type to increasing type;(4)the increasing trend in soil moisture from the top to foot of hillslope occurred in simple land use along slope,while complicated distribution of soil moisture was observed in multiple land uses along slope.The relationships between soil nutrients and land uses and landscape positions were analysed:(1)five nutrient contents of soil organic matter(SOM),total N(TN),available N(AN),total P(TP) and available P(AP) in hilly area were lower than that in other areas.SOM content was less than 1%,TN content less than 0.07%,and TP fallow land and cropland,and higher level in soil fertility was found in crop-fruit intercropping land among croplands;(3)soil nutrient distribution and responses to landscape positions were variable depending on slope and the location of land use types. 相似文献
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Transformation of chlorophenols by nanoscale bimetallic particles represents one of the latest innovative technologies for environmental remediation. Nanoscale Pd/Fe bimetallic particles were synthesized in the laboratory for treatment of o-chlorophenol. Most of the nanoscale particles are in the size range of 20-100 nm. BET specific surface area of the nanoscale Pd/Fe particles is 12.4 m2/g. In comparison, a commercially available Fe powder( < 100 mesh) has a specific surface area of just 0.49 m2/g. Batch experiments demonstrated that the nanoscale Pd/Fe bimetallic particles can effectively dechlorinate o-chlorophenol. Dechlorination efficiency is affected by the mass fraction of Pd in the bimetal, nanoscale Pd/Fe mass concentration and mixing intensity. 相似文献
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我国纳米科技研究应用现状及发展趋势分析 总被引:2,自引:0,他引:2
综合介绍了国内纳米材料及其技术在诸多领域的开发应用现状,并对纳米科技未来的发展趋势和市场前景进行了预测和展望。 相似文献
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陶瓷微滤膜过滤黑液的清洗与再生 总被引:4,自引:0,他引:4
对无机陶瓷微滤膜过滤草桨黑液的膜清洗及再生的方法进行了研究。考察了物理和化学方法的再生效果、单种清洗剂的清洗效果、复合方法的清洗效果和效果的可重复性。结果表明物理冲洗、高温灼烧、单一的化学清洗剂清洗均可以提高陶瓷膜的再生通量;但是复合方法对陶瓷微滤膜的再生效果较好,其中按氢氧化钠溶液清洗、硝酸溶液清洗、次氯酸钠溶液清洗的实验步骤,膜的再生渗透通量高.且重复性强,可望在工业生产的在线清洗中应用。 相似文献
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