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Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in surface sediment and bivalve from the Changjiang Estuary, China 总被引:1,自引:0,他引:1
Surface sediments and bivalves were collected from the Changjiang Estuary in December 2003 and November 2004, respectively. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in these samples were measured with high-resolution chromatography (HRGC)/High Resolution Mass Spectrometer (HRMS). The concentrations of total PCDD/Fs and toxic equivalent (TEQ) were 169.83±119.63 and 0.81±0.36 pg/g dry weight (dw) in sediments, and 580.33±240.17 and 7.24±3.65 pg/g dw in bivalves. The homolog compositions of PCDD/Fs were similar among samples, the most abundant congener was octa-chlorinated dibenzo-p-dioxin (OCDD) and then octa-chlorinated dibenzofuran (OCDF) and 1,2,3,4,6,7,8-hepta-chlorinated dibenzo-p-dioxin (HpCDD). The herbicide pentachlorophenol (PCP) and sodium pentachlorophenol (Na-PCP) were proved the main source of PCDD/Fs in this area. 相似文献
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有利降水因素最多的地方降水的可能性最大,在其附近,降水强度往往比较大。从这一思路出发,把各种降水系统和物理参数叠合在一张底图上——即急流轴和系统配置综合图(以下简称综合图),圈出有利降水因素最多的地区,并从而探讨未来24小时强降水的落区预报。通过对1973—1975年4—6月江南有西南低空急流的近180天图次的初步分析,找到了一些初步规律,并在1977年5—6月进行试报,效果较好。 相似文献
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