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提出水污染综合多目标规划思路,把治理投资,运行费用,收益和污染物削减量作为规划目标,对多种方案进行优化选择,建立了实现多目标规划的数学模型,对方案的产生组合,初选和优化等建模过程作了系统介绍,并以泾河水质规划为例,将模型予以应用。 相似文献
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Ian Brotherton 《Journal of Environmental Planning and Management》1989,32(2):121-127
This paper appraises, in the context of the current debate concerning national parks for Scotland, factors that may have contributed to the achievement of national park purposes in England and Wales. Voluntary support, presumptions and resources are seen as crucial to the achievement of those purposes; while the few extra powers available to the national park authorities and the plan making process are seen to be of some importance. In contrast, it is argued that the much‐debated nature of the administrative authority has had little effect on the extent to which park purposes are achieved. 相似文献
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Falusi Bamidele Ayodeji Olanipekun Edward Olorunsola Olanisebe Deborah Olukemi 《毒物与环境化学》2013,95(9):1665-1672
Transfer coefficients of the four metals As, Cd, Hg, and Pb were determined in the leaves and barks of Morinda lucida collected in Nigeria, with the view to quantify relative differences in the bioavailability of the metals to these parts of the plant. Samples were acid digested and the levels of the metals in the digestates were determined using an atomic absorption spectrophotometer. Certain properties of the soils, i.e., pH, clay fraction, electrical conductivity, cation exchange capacity, and organic matter, were also determined. The latter influence the bioavailability of the metals. All parameters correlated with the concentrations of the metals in soils. Transfer coefficient values recorded for Cd and Pb in various tissues of M. lucida Benth were within the expected ranges, while those of As and Hg showed elevated topsoil concentrations of metals. The order of bioavailability of the metals and their bioaccumulation in the tissues of M. lucida Benth was Hg > Cd > As > Pb. Stem barks of the plant showed the least bioaccumulation of all four metals and hence are most suitable for therapeutic purposes. Vegetative parts of M. lucida Benth used for therapeutic purposes should be sourced at sites that will give low transfer coefficient in order to reduce human exposure to toxicity associated with ingestion of heavy metals. 相似文献
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我国土地用途管制之耕地保护绩效的定量研究--以山东省为例 总被引:16,自引:4,他引:12
本文采用虚拟变量模型。以软件Eviews为分析工具。以农业大省山东省为例。首次对土地用途管制在耕地保护中的绩效进行了定量研究。结果表明,实施土地用途管制后。每1万元基本建设投资可节约占用耕地0.00195hm^2。1998-2002年。山东省共节约建设占用耕地80430.48hm^2。但GM(1,1)预测结果表明。到2010年,山东省耕地保护形势仍然非常严峻。据此文章提出了政策建议。 相似文献
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蔡先凤 《中国人口.资源与环境》2007,17(4):116-120
随着核能和平利用的发展。核能的安全性日益引起人们的关注,核损害及其赔偿已经成为无法回避的问题。我国现行核损害责任制度存在重大缺陷.应该尽快建立和完善我国大陆的核损害责任制度。建议:①在民事基本法的层次上,对核损害责任做出全面而具体的规定。②制定核领域的基本法《原子能法》或《核设施法》。③制定《核损害赔偿法》或《核损害责任法》或《核损害赔偿条例》。最后提出我国大陆核损害责任立法的主要内容。 相似文献
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