Joint effects of Penta-BDE and heavy metals on Daphnia magna survival, its antioxidant enzyme activities and lipid peroxidation

The joint toxicity of Penta-BDE (Pe-BDE) and heavy metals including cadmium and copper on Daphnia magna (D. magna) was evaluated on the basis of determining the 48 h survival, antioxidative enzyme responses, and lipid peroxidation. The response was classified as additive, greater than additive, or less than additive by comparing the measured ??toxic units, TU?? with one. Based on the survival of D. magna, less-than-additive interactions were found in most of mixtures treatments. This may be attributed to the different toxicity mechanism between Pe-BDE and metals. Cu and Cd played a greater role in toxicity than what Pe-BDE did. As for the superoxide dismutase (SOD) and catalase (CAT) activity, most response was less than additive. For the glutathione S-transferases (GST) activity, most of the greater-thanadditive responses were found in the Cu plus Pe-BDE treatments, but the additive responses occurred in Cd plus Pe-BDE treatments and binary metal treatments. For lipid peroxide levels, which were measured as malondialdehyde (MDA) levels, less-than-additive response occurred in the 50% Cd plus 50% Cu and ternary mixture treatments. Results suggested that Pe-BDE, Cd, and Cu could induce different patterns of antioxidant enzyme responses, such as antioxidant/prooxidant responses, depending on their capability to produce reactive oxygen species and antioxidant enzymes to detoxify them.     

Assessment of heavy metals in sediments from a typical catchment of the Yangtze River, China

An intensive investigation was conducted to study the accumulation, speciation, and distribution of various heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in sediments from the Yangtze River catchment of Wuhan, China. The potential ecological risks posed by these heavy metals also were estimated. The median concentrations of most heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) were higher than the background values of soils in Wuhan and were beyond the threshold effect level (TEL), implying heavy metal contamination of the sediments. Carbonate-bound Cd and exchangeable Cd, both of which had high bioavailability, were 40.2% and 30.5% of the total for Cd, respectively, demonstrating that Cd poses a high ecological risk in the sediments. The coefficients of the relationship among Pb, Hg, and Cu were greater than 0.797 using correlation analysis, indicating the highly positive correlation among these three elements. Besides, total organic carbon content played an important role in determining the behaviors of heavy metals in sediments. Principal component analysis was used to study the distribution and potential origin of heavy metals. The result suggested three principal components controlling their variability in sediments, which accounted for 36.72% (factor 1: Hg, Cu, and Pb), 28.69% (factor 2: Cr, Zn, and Ni), and 19.45% (factor 3: As and Cd) of the total variance. Overall, 75% of the studied sediment samples afforded relatively low potential ecological risk despite the fact that generally higher concentrations of heavy metals relative to TEL were detected in the sediments.     

灰色关联法在危险化学品事故分析中的应用

根据2008-2011年全国危险化学品事故资料的统计分析,运用灰色关联分析方法,建立以事故起数、死亡人数为参考数列,以事故不同类别为比较数列的灰色关联体系.得出了火灾、灼烫、容器爆炸、其他爆炸、中毒与窒息等不同事故类别与事故死亡人数之间的关联度,结果显示其他爆炸与死亡人数之间的关联度最大.     

3种草皮缓冲带对农田径流污染物的净化效果及其最佳宽度研究

通过对照试验,研究了百慕大、白花三叶草和高羊茅3种草皮缓冲带对农田径流污染物的净化效果.结果表明,空白对照带对径流水SS几乎没有去除效果,百慕大草皮缓冲带对径流水SS的去除率最高,达84%.其次为白花三叶草和高羊茅草皮缓冲带,对径流水SS的去除率分别为81%、73%;进水TN质量浓度在10 mg/L以内时,3种草皮缓冲带出水TN质量浓度都低于2mg/L,均达到<地表水环境质量标准>(GB 3838-2002)V类标准;进水TP质量浓度为0.54～1.50 mg/L时,3种草皮缓冲带出水TP质量浓度均为0.08～0.34 mg/L,也均低于GB 3838-2002V类标准规定的限值;3种草皮缓冲带径流水SS去除率和沿程距离具有显著的相关性,在径流水SS去除率为80%时.通过计算可知3种草皮缓冲带的最佳宽度为16.1～20.4 m.其中百慕大草皮缓冲带最低,为16.1 m.     

我国水产科学研究状况及发展战略浅谈

根据我国的国情，内陆水体水产学的研究重心应从发展渔业转移到保护水质上来，这种转移是与国际潮流相一致的，也是符合国民经济需求和民族长远利益的，必须努力促进这个学科方向的转移，并通过科学导向将我国水产开发的重点转向海洋，给我们的子孙后代留下了赖以生存的清洁水源。     

生态系统数据管理中的数据文档文件

生态系统的数据结构不同于商用数据结构。本文参考美国ＬＴＥＲＮ的Ｓｅｖｉｌｌｅｔａ站生态系统的数据管理模式，结合中国科学院封丘农业生态实验站的实际情况，着重介绍了生态系统的数据文档文件的特点、结构和应用，而这些都是研究生态系统数据管理的最基础工作。     

沙尘暴应急监测方法研究

在沙尘暴应急监测方法研究中，通过对总悬浮颗粒物采样仪器及各种采样参数的研究确定和降尘采样器的研制，制定出沙尘暴应急监测方法。