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991.
五氯酚对环境污染及居民健康影响研究 总被引:2,自引:0,他引:2
中国长期以来使用五氯酚纳盐杀灭亡血吸虫的中间宿主──—钉螺.为评价它对环境的污染及居民健康危害,1990-1993年在我省开展了五氯酚环境污染及对居民健康影响研究.在研究区采集环境样品(空气、水体、土壤及底泥、蔬菜、肉、蛋、鱼等)共173份;生物材料(人血、尿)共457份,分析五氯酚浓度.结果在明,在五氯酚使用区,环境中PCP浓度稍高于对照区,而生物材料尿、血中PCP浓度明显高于对照区.全血胆碱脂酶活性用药区明显低于对照区,统计学分析有显著差异(P<0.001),证实了长期低剂量使用可造成环境及生物蓄积. 相似文献
992.
993.
A hierarchical approach to fisheries planning and modeling in the Columbia River Basin 总被引:1,自引:0,他引:1
The Columbia River Basin is the scene of a massive effort to restore populations of Pacific salmon (Oncorhynchus spp.) and steelhead (O. mykiss). Efficient restoration is confounded by a high level of complexity, competing sociopolitical goals and values, and uncertainty
about key system properties. Simulation models and other tools of systems analysis are important to development of a comprehensive,
regionally acceptable strategy. Hierarchy theory provides a useful paradigm for organized complexity within the Columbia Basin
and the basis for a trilevel hierarchical structure for organizing and integrating models. Life-stage models compose the most
basic simulation units at the lowest level in the proposed hierarchical modeling structure. Each life-stage model simulates
a distinct period in the life cycle of anadromous salmonids. Population models at the intermediate level simulate the complete
life cycles of salmon and steelhead populations. At the highest level in the hierarchy, interpopulation models simulate extensive,
long-term processes that affect multiple species and stocks. A hierarchical system of models is preferable to a single model
or to a group of models lacking formal structure. A principal advantage is that models have the correct spatial and temporal
resolution for analyzing questions at different scales. A hierarchical structure also facilitates the flow of information
among models, and aids in understanding the impacts of uncertainty. Constructing a hierarchy of models should involve both
bottom-up and top-down perspectives that maintain logical consistency among models, while allowing unique model structures
appropriate for each level in the hierarchy. 相似文献
994.
在研究汕头市地震、风、洪潮、火等多种灾害的危险性、成灾模式和损失估计的基础上,应用地理信息系统(GIS)技术建立可视化的计算机综合防灾系统,可以提高城市的防灾能力。本文针对基于GIS的城市综合防灾系统的建立,提出了较为具体的研究方案和实施框架,便于课题组各项研究工作的开展和统一。 相似文献
995.
地球系统是宇宙系统的全息缩影,地球上的灾害和天体之间具有全息关系,同样有恒定的周期性。本文根据全息理论对灾害进行分析预测,并建议在灾害研究中应用全息理论. 相似文献
996.
分形块体理论及其在三峡高边坡稳定分析中的应用 总被引:4,自引:0,他引:4
把分形几何与块体理论相结合,提出了分形块体理论,建立了分形块体理论赤平解析法,并将其应用于三峡永久船闸高边坡稳定性分析中。结果表明:分形块体理论符合工程实际,是分析裂隙岩体工程稳定性行之有效的可靠方法。 相似文献
997.
Brian G. Field 《Journal of Environmental Planning and Management》1984,27(2):68-78
This paper focuses on the development plan activities of the London Boroughs and simply seeks to explain the relatively limited progress that has been made in the preparation and adoption of statutory local plans, by showing how production was constrained as local planners were caught up in the shifting ground of contemporary planning theory. The author suggests that uncertainty about the acceptable scope and content of local plans, at a time when planners were being encouraged to extend the emphasis of their work beyond the purely physical, led to serious problems as planners began to experiment with new approaches to local planning but failed to appreciate the operational implications of each approach. 相似文献
998.
E. M. White 《Journal of the American Water Resources Association》1983,19(4):649-653
ABSTRACT A stepwise multiple regression was used to evaluate the relative importance of antecedent-, event-, and high-intensity-precipitation amounts; runoff volume; and precipitation nutrient contents and concentrations in determining nutrient losses in runoff. Plots were fertilized at high, medium, and low rates and had cultivation ridges oriented up-and-down slope or on the contour. Runoff volume was the important factor in determining the loss of NO3, soluble PO4, total PO4, and soluble K ions in runoff from fallow, corn, or soybean plots. NH4-N loss was controlled mainly by the precipitation content and antecedet precipitation since fertilizer had been applied. Nutrient losses were greater from plots fertilized at the high rate and from plots with cultivation ridges oriented up-and-down slope rather than on the contour. 相似文献
999.
This article investigates the impact of ISO 14001 certification on the compliance with environmental regulations by Korean companies. The impact of ISO 14001 certification on the industry was studied through a questionnaire survey and the compliance of environmental regulations were investigated using government-released data. The motivation for an environment management system was a result of the current international situation and the need to maintain fair competition. ISO 14001 certification has been recognized as an essential strategy for industrial competition and to improve company/product recognition. The certified and non-certified companies' environmental regulation violation (ERV) rates were 3.5% and 11.6%, respectively, in 1997. In 1998, the ERV rate had an eight-time difference with 1.0% and 8.5% for certified and non-certified companies, respectively. Annual regulation violation rates were reduced from 3.5% in 1997 to 1.0% in 1998 with certified companies and from 11.6% in 1997 to 8.5% in 1998 with their non-certified counterparts, respectively. ISO 14001 certified companies showed more improvement than non-certified companies in regards to environmental performance. 相似文献
1000.
Kwawe DB 《Journal of environmental management》2002,66(4):345-359
Records in public archives were evaluated for the period 1981-1991. Simple surveys of peoples and of technology and physical premises provided insight to gauge the attitudes of a local community in the Melbourne municipality and the Melbourne City Council towards composting of organic waste materials. There is a lag in perception and attitudes between the local community and the local government towards composting of organic refuse as a solid waste treatment option. The simple methodology of the study still made it possible to verify past and present perceptions and attitudes. 相似文献