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901.
中哈跨境河流的水量与水质,是双方共同关注的重要问题。对比了中哈跨境河水质标准及评价方法的差异性。中国采用的是单因子水质评价方法,哈萨克斯坦采用的是综合评价方法。中国与哈萨克斯坦跨境河水质监测指标数不同,但相同指标的标准限值在同一数量级。讨论了综合评价法与单因子评价法优势与不足。指出中哈跨境河水质标准与评价方法的统一,是双方合作研究急需解决的问题。建议综合两个标准体系,组成双方共同的地表水标准限值指标体系。建议对两国执行的评价方法,采各家之长优势互补,对环境及人体健康有严重影响的毒理性指标,必须执行单因素评价方法,在此基础上,对其他指标进行综合评价。 相似文献
902.
上海市水环境质量考核方法研究 总被引:1,自引:0,他引:1
提出了一种综合的水环境质量考核方法——水环境综合评价指数法。方法对综合水质指数、水质改善率和水质达标率三个参数进行标准化及加权平均,其中综合水质指数反映水环境质量状况,水质改善率反映水环境治理工作成效,水质达标率反映水环境功能区划要求。通过设置适当的权重系数,评价结果可较为全面和科学的反映区域水环境质量状况、水环境治理工作成效和水环境功能区划要求,为城市环境综合整治定量考核、水环境绩效评价等工作提供参考。 相似文献
903.
王晓雯 《中国环境管理干部学院学报》2014,(6):66-68
分别用三种不同的酸消解方法进行土壤标准样品的前处理,用原子吸收分光光度法测定其中铜、铅、锌、镉、镍、锰、总铬元素的含量。结果表明,电热板/硝酸-过氧化氢-氢氟酸消解方法耗酸量少,消解时间短,适用于土壤中铜、铅、锌、镉、镍、锰元素的前处理,相对标准偏差为1.0%~5.0%;而使用电热板/硝酸-硫酸-氢氟酸方法针对土壤中总铬元素进行消解前处理,准确度更高,相对标准偏差为2.7%~5.1%。 相似文献
904.
Jacob D. Wiseman Michael R. Burchell Garry L. Grabow Deanna L. Osmond T.L. Messer 《Journal of the American Water Resources Association》2014,50(3):653-664
Riparian buffers have been used for many years as a best management practice to decrease the effects of nonpoint pollution from watersheds. The NC Conservation Reserve Enhancement Program (NC CREP) has established buffers to treat groundwater nitrate‐nitrogen (NO3?‐N) from agricultural sources in multiple river basins. A maturing 46 m wide riparian buffer enrolled in NC CREP was studied to determine its effectiveness in reducing groundwater NO3?‐N concentrations from a cattle pasture fertilized with poultry litter. Three monitoring blocks that included groundwater quality wells, water table wells, and soil redox probes, were established in the buffer. NO3?‐N concentrations decreased significantly across the buffer in all of the monitoring blocks with mean reductions of 76‐92%. Many biological processes, including denitrification and plant uptake, may have been responsible for the observed NO3?‐N reductions but could not be differentiated in this study. However, mean reductions in Cl? concentrations ranged from 48‐65% through the blocks, which indicated that dilution was an important factor in observed NO3?‐N reductions. These findings should be carefully considered for future buffer enrollments when assigning nitrogen removal credits. 相似文献
905.
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907.
环境法课程教学中存在低效且脱离职业岗位需求的困境,而模块化教学是提高《环境法实务》教学效果并切合职业岗位需求的有效途径。详细阐述了《环境法实务》课程模块化设计的理念、思路以及具体的实施路径,包括课程内容的模块化设置、学法与教法的模块化构建以及成绩评定的模块化构建。 相似文献
908.
The impact of the extreme heat wave that affected Melbourne, Australia, in two distinct phases in January and February 2009 was severe, with 374 (heat) and 173 (bushfire) excess deaths. Whilst the human health issues have been covered in detail in policy and academic arenas, much less attention has been paid to the adverse impacts on urban infrastructure. Analysis of this event, underpinned by participatory actor-based research, has shown that the impacts were experienced disproportionately across different infrastructure types. For water, telecommunications and airports, the impacts were relatively minor and the impact on rail transport and roads (and to a lesser extent, seaports) was of moderate significance, whereas research findings indicate that the electricity sector was found to be the most vulnerable. This paper focuses on the sectors that were worst impacted: electricity, rail and road transport. Commentary identifies the direct and indirect impacts of the heat event, including associated cascading effects, as well as considering actual and potential adaptation responses both before and after the event. Concluding, the authors reflect on the implications of the heat wave for urban resilience, emphasising the crucial importance of understanding the urban environment as a complex and interconnected system. 相似文献
909.
Krzysztof Baszczyński Zygmunt Zrobek 《International journal of occupational safety and ergonomics》2013,19(3):313-331
Retractable type fall arresters are designed to protect against falls from a height of people who need freedom of vertical movement. The practice of fall protection shows that the devices are also used to protect people who work on flat roofs. This application creates quite different operating conditions for the devices. In some situations those conditions can be dangerous for users. The article presents a theoretical analysis of phenomena occurring during a fall arrest with retractable type fall arresters arranged horizontally. The analysis was verified with laboratory tests. The article presents a proposal for the construction of a test stand and a test method for estimating retractable type fall arresters intended for horizontal use. 相似文献
910.
Lidia Zapór Jolanta Skowroń Małgorzata Gołofit-Szymczak 《International journal of occupational safety and ergonomics》2013,19(1):121-129
The cytotoxic effects of volatile and water-insoluble organic solvents (ethylbenzene, tetrachloroethylene, n-hexane) were tested on isolated hepatocytes in monolayer culture by using the 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) reduction assay. All of the tested compounds inhibited metabolic activity of hepatocytes and this effect depended on the concentration of solvents in the incubatory medium. The presence of fetal calf serum in the medium did not change the cytotoxicity of xenobiotics. IC50 values calculated on the basis of the MTT assay indicated that ethylbenzene was more cytotoxic than tetrachloroethylene and n-hexane. Using hepatocyte monolayer culture and the MTT assay to assess cytotoxicity of organic solvents causes many technical problems. It seems that it cannot be used as a rapid, cheap, and credible method. 相似文献