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11.
羟基多溴联苯醚对鲤鱼急性毒性及定量结构活性关系 总被引:1,自引:0,他引:1
羟基多溴联苯醚是一类具有环境风险的新兴污染物,它们已经在众多环境介质甚至人体内广泛存在。参照GB/T13267-91标准方法,采用静态生物急性毒性试验,测定了6种羟基多溴联苯醚(2′-OH-BDE7、4′-OH-BDE17、2′-OH-BDE28、2′-OH-BDE68、4′-OH-BDE90和2′-OH-BDE123)对普通鲤鱼的急性毒性96 h-LC50值,分别为697、1 130、854、550、644和522 ng.mL-1。除4′-OH-BDE17为高毒物质外,其他5种OH-PBDEs均为剧毒物质,高溴代的2′-OH-BDE123毒性最大。选用OH-PBDEs的KOW参数及由MOPAC软件PM3算法计算出的16个量子化学参数(EHomo、qBr+、ELumo等)为描述符,运用一元线性回归分析分别研究了96 h-LC50与他们之间的相关关系。结果表明:lgKOW和ELumo与6种羟基多溴联苯醚的96 h-lg LC50表现出较好的相关性,复相关系数均大于0.96,根据方程得到的96 h-lg LC50预测值与实验值基本相同,进一步对环境中广泛检出的其它OH-PBDEs的96 h-LC50值也进行了预测。 相似文献
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The humanitarian common logistic operating picture: a solution to the inter‐agency coordination challenge 下载免费PDF全文
Although significant progress has been made in developing the practice of humanitarian logistics, further improvements in efficiency and effectiveness have the potential to save lives and reduce suffering. This paper explores how the military/emergency services’ concept of a common operating picture (COP) can be adapted to the humanitarian logistics context, and analyses a practical and proven approach to addressing the key challenge of inter‐agency coordination and decision‐making. Successful adaptation could provide the mechanism through which predicted and actual demands, together with the location and status of material in transit, are captured, evaluated, and presented in real time as the basis for enhanced decision‐making between actors in the humanitarian supply network. Through the introduction of a humanitarian logistics COP and its linkages to national disaster management systems, local communities and countries affected by disasters and emergencies will be better placed to oversee and manage their response activities. 相似文献
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Makkimane B. Nataraj Sannanegunda V. Krishnamurthy 《Journal of environmental science and health. Part. B》2013,48(2):67-73
This study was undertaken to determine the effect of environmentally realistic concentrations of two commonly used pesticides viz., malathion and cypermethrin, using a fully 3 × 3 factorial experiments on the survivability and time of metamorphosis in a common rice paddy field frog (cricket frog) Fejervarya limnocharis under laboratory conditions. The results suggest that cypermethrin is more toxic than malathion and combinations of higher concentrations of cypermethrin (50 μg/L) with malathion (250 and 500 μg/L) are more deleterious to the survivability of tadpoles. With increasing cypermethrin concentration, the survivability of tadpole decreased (r = ?0.986, P = 0.108). But cypermethrin alone induced early metamorphosis among the surviving tadpoles. However, there was a delay in the time required for metamorphosis induced by malathion and its combination with cypermethrin. The delay in metamorphosis may indicate the altered physiological fitness of the individual. The emergent froglets will be subjected to environmental stressors like high temperature and less humidity of post-monsoon tropical climate that could enhance negative influence triggered by pesticides. 相似文献
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JOHAN A. OLDEKOP ANTHONY J. BEBBINGTON DAN BROCKINGTON RICHARD F. PREZIOSI 《Conservation biology》2010,24(2):461-469
Abstract: The lack of concrete instances in which conservation and development have been successfully merged has strengthened arguments for strict exclusionist conservation policies. Research has focused more on social cooperation and conflict of different management regimes and less on how these factors actually affect the natural environments they seek to conserve. Consequently, it is still unknown which strategies yield better conservation outcomes? We conducted a meta‐analysis of 116 published case studies on common resource management regimes from Africa, south and central America, and southern and Southeast Asia. Using ranked sociodemographic, political, and ecological data, we analyzed the effect of land tenure, population size, social heterogeneity, as well as internally devised resource‐management rules and regulations (institutions) on conservation outcome. Although land tenure, population size, and social heterogeneity did not significantly affect conservation outcome, institutions were positively associated with better conservation outcomes. There was also a significant interaction effect between population size and institutions, which implies complex relationships between population size and conservation outcome. Our results suggest that communities managing a common resource can play a significant role in conservation and that institutions lead to management regimes with lower environmental impacts. 相似文献
16.
Jan Narveson 《Journal of Agricultural and Environmental Ethics》1995,8(2):145-156
Environmental Ethics is the ethics of how we humans are to relate to each other about the environment we live in. The best way to adjust inevitable differences among us in this respect is by private property. Each person takes the best care of what he owns, and ownership entails the free market, which enables people to make mutually advantageous trades with those who might use it even better. Public regulation, by contrast, becomes management in the interests of the regulators, or of special interests, such as lovers of rare species-not the people they're supposed to be serving. 相似文献
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PWM变频器的广泛应用大大改善了电机调速性能,但是,由于PWM变频器共模电压在电机内部耦合电容作用下,形成轴电压和轴电流,会引起轴承早期失效危及系统安全运行。轴电流问题的研究包括对轴电流的分析、预测和抑制。然而这些过程需要轴电压和轴电流的准确测量进行验证和比对分析。设计合理而有效的测量装置和测量方法是非常重要的一环。在分析轴电流产生机理的基础上,对现有的各种轴电流测量方法和轴承阻抗特性测试方法进行介绍,总结对比这几种方法的优缺点,为轴电流的测试平台的新设计提供参考。 相似文献
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三生共赢:可持续发展的根本目标与行为准则 总被引:5,自引:0,他引:5
明确可持续发展的行为目标。制定相应的评价准则,是可持续发展思想从理念探讨向实践操作延伸的必由之路,也是进行社会行为选择的依据。在系统分析生活、生产与生态之间的关系后,提出应将“生活水平不断提高,生产能力不断增长和生态环境不断改善”(简称“三生共赢”)作为可持续发展的行为目标和评价准则,并从理论上对这一命题进行了阐述。 相似文献
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