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41.
Environmental Science and Pollution Research - The present study was conducted to evaluate the impact of marble industry effluents on the accumulation of heavy metals in selected tissues of...  相似文献   
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A total of 411 milk samples were screened for the residues of the following chlorinated hydrocarbon insecticides using chromatographic methods: DDT insecticides (P,P'-DDT, P,P'-DDE, P,P'-DDD, O,P' -DDT); cyclodiene insecticides (aldrin, endrin, dieldrin, heptachlor, heptachlorepoxide, cis-and trans-chlordane); hexachlorocyclohexane (alpha-HCH, gamma-HCH) and hexachlorobenzene (HCB). The milk samples were obtained from lactating women selected randomly from five different geographical regions in Jordan. These regions were North and Middle Jordan Valley, Amman, Irbid and Zarqa. All of the studied insecticides were found to contaminate human milk in Jordan, but with high variations in the concentration and percentage of population occurrence. P,P'-DDE was the predominant contaminant occurring in 80.3% of studied population, followed by P,P'-DDT occurring in 53.5%. The regional results showed that the DDT residues were also the predominant contaminant in all regions and that the North and Middle Jordan Valley regions were the most affected. Infant's age (i.e. lactation period) had a significant inverse relationship with the concentration of insecticides in the milk fat.  相似文献   
44.
Gas-phase reaction of CFC-12 (CCl2F2) with methane was carried out in a plug flow reactor over the temperature range of 873-1123 K. The major organic halocarbons formed during the reaction were C2F4, C2H2F2, CHClF2, CH3Cl, C3H2F6 and CCl3F. The formation of all products except C2H2F2 decreased with temperature, while the selectivity to C2H2F2 (difluoroethylene) increased with temperature and reached approximately 80% at 1123 K. Under these reaction conditions, methane acts as hydrogen and carbon source, resulting in the formation of an unsaturated C2 hydrofluorocarbon from two C1 precursors.  相似文献   
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Environmental Science and Pollution Research - The pervasiveness of microplastics in aquatic ecosystems has become a major environmental issue in recent years. The gradual dumping of plastic...  相似文献   
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Environmental Science and Pollution Research - The ongoing COVID-19 outbreak, initially identified in Wuhan, China, has impacted people all over the globe and new variants of concern continue to...  相似文献   
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Environmental Science and Pollution Research - Though the incidence of several cancers in Western societies is regulated wisely, some cancers such as breast, lung, and colorectal cancer are...  相似文献   
48.
固定化蒽醌对偶氮染料生物降解促进作用研究   总被引:8,自引:3,他引:5  
采用非水溶性蒽醌固定化技术对偶氮染料生物降解促进作用进行了研究,对比了海藻酸钙,聚乙烯醇-硼酸,聚乙烯醇-海藻酸钙和琼脂4种固定化技术,探讨了溶解氧对脱色过程的影响和固定化蒽醌系统脱色广谱性.研究结果表明,固定化蒽醌可提高多种偶氮染料生物厌氧脱色速度1.5~2倍和降低偶氮染料脱色过程氧化还原电位-10~-15 mV;经4次循环使用后,其加速作用仍保持在90%以上;固定化蒽醌微生物系统具有很强抗氧冲击能力.  相似文献   
49.
最近 ,小型倾斜河流中的阶梯形鱼道建筑以它的简易与实用而变得日益重要。在这种鱼道中出现的滚动流将产生波涌 ,并继续向下传播 ,而且它的周期性滚动可能会严重危害鱼道。因此 ,我们着手研究了它的严重性以便设计者在设计鱼道时能考虑这些因素。由实验证实滚动流源于阶梯形鱼道的上游。滚动流在稳定流与半平滑流间转变 ,它在一定时间间隔内不断地从稳定流变成半平滑流 ,又从半平滑流变成稳定流。它的流量值随着阶梯形水道的几何形状变形而呈现上下限。流量值和时间间隔均随着水池长度的增加而增加。  相似文献   
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Environmental Science and Pollution Research - The Kyoto Protocol has stipulated array of national policies to combat the climate change. To tackle the global warming, governments embraced Paris...  相似文献   
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