首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2147篇
  免费   63篇
  国内免费   28篇
安全科学   139篇
废物处理   85篇
环保管理   516篇
综合类   238篇
基础理论   563篇
环境理论   2篇
污染及防治   446篇
评价与监测   136篇
社会与环境   77篇
灾害及防治   36篇
  2023年   16篇
  2022年   25篇
  2021年   23篇
  2020年   32篇
  2019年   32篇
  2018年   52篇
  2017年   69篇
  2016年   78篇
  2015年   69篇
  2014年   66篇
  2013年   144篇
  2012年   94篇
  2011年   165篇
  2010年   111篇
  2009年   97篇
  2008年   125篇
  2007年   137篇
  2006年   128篇
  2005年   79篇
  2004年   79篇
  2003年   89篇
  2002年   66篇
  2001年   44篇
  2000年   35篇
  1999年   36篇
  1998年   32篇
  1997年   17篇
  1996年   30篇
  1995年   22篇
  1994年   23篇
  1993年   22篇
  1992年   22篇
  1991年   13篇
  1990年   16篇
  1989年   7篇
  1988年   13篇
  1987年   18篇
  1986年   12篇
  1985年   7篇
  1984年   10篇
  1983年   10篇
  1982年   15篇
  1981年   6篇
  1980年   7篇
  1979年   7篇
  1974年   4篇
  1969年   3篇
  1967年   3篇
  1935年   3篇
  1926年   2篇
排序方式: 共有2238条查询结果,搜索用时 15 毫秒
991.
Mark Liechty 《Disasters》2022,46(1):185-205
What causes a disaster's aftermath? Scholars have increasingly turned to historical approaches that link outcomes to pre-disaster sociopolitical dynamics. Disasters lead to ‘critical junctures’ that ‘trigger’ events that unfold in the wake of the initial phenomenon. This paper argues that the ‘critical junctures’ paradigm shares limitations with ‘path dependency’ theory from which it is derived, namely a tendency towards historicism—a functionalist teleology better able to explain continuity than change. As an alternative, this analysis draws on Michel Foucault's understanding of ‘conditions of possibility’ as a way of rethinking agency/causation, moving away from individual subjects, events, or even historical conditions towards, instead, the new, radically destabilised ‘epistemological field’ emerging in the disaster's aftermath. This paper examines a series of devastating earthquakes in Nepal to consider how post-disaster ‘epistemological fields’ present new ‘conditions of possibility’ within which new ideas, actions, and outcomes become thinkable and possible in ways that pre-disaster historical conditions could not have predicted.  相似文献   
992.
993.
本实验利用标准短期(48- 96 h)实验室测试测定了包括初级生产者,底栖无脊椎动物,水蚤类动物,软体动物和鱼类在内的15种水生生物对于MON 0818的敏感性。MON 0818是一种商业表面活性剂,由多种聚氧乙烯牛脂胺混合而成。此外本实验使用模糊网纹蚤(Ceriodaphnia dubia)潜在的长期(8 d)毒性,确定了暴露浓度。长期毒性测试中未在任何终端指标中发现显著效果。利用得出的数据和文献记载得到物种敏感度在4种暴露条件下的分布,通过对比物种敏感度分布进行了tier-1危害评估。评估显示在本研究规划下(以综述为原型,研究林业除草剂;12 L标准每公顷,等于4.27 kg每公顷) 最差的情况(无意中以最大标签使用速率直接过量喷洒到15 cm深的水体中)会造成中等危害(43.1%的物种处于暴露中,高于中位有效浓度水平)。在更多以最大使用速率使用的典型情况下,受到损害的物种降至20.9%(6 L标准每公顷,相当于2.14 kg每公顷),在更频繁的雇佣施用速率(2.5 L标准每公顷,相当于0.89 kg每公顷)下,受损物种比例降至6.9%。通过草甘膦在环境中的最大测定浓度计算得到MON 0818的浓度,最终受损物种比例(3.8%)则小于此浓度下受损物种比例(5%)。
精选自Jose L. Rodriguez-Gil, Ryan Prosser, David Poirier, Linda Lissemore, Dean Thompson, Mark Hanson, Keith R. Solomon. Aquatic hazard assessment of MON 0818, a commercial mixture of alkylamine ethoxylates commonly used in glyphosate-containing herbicide formulations. Part 1: Species sensitivity distribution from laboratory acute exposures. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 501–511, July 2017. DOI: 10.1002/etc.3559
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3559/full
  相似文献   
994.
In this paper we consider uses of value of information studies in conservation biology. It is a common assumption that more and better quality data will lead to better conservation management decisions. Indeed, this assumption lies behind, and motivates, a great deal of current work in conservation biology. Of course, more data can lead to better decisions in some cases but decision-theoretic models of the value of information show that this need not always be the case: sometimes the cost of data collection is too high. While such value of information studies are well known in economics and decision theory circles, their applications in conservation biology are relatively new. These studies are a valuable tool for conservation management, and we outline some of the potential applications. We also offer some advice about, and problems with, implementing value of information studies in conservation settings.  相似文献   
995.
This paper develops and applies an integrated model of mortality and morbidity valuation that is consistent with the principles of welfare economics. To obtain the integrated model, the standard one-period expected utility model of one person facing the prospect of either being alive or dead is extended to incorporate (1) a third health state (sick) with a utility level that is intermediate to utility if healthy and utility if dead, (2) a family perspective in which a parent makes choices about risk exposure both for herself and for a child, and (3) a multi-period framework that allows for possible parent/child differences in illness latency. Monetary benefits of health risk reduction obtained from the integrated model are compared with those that would be computed using the standard model. The integrated model then is applied using data obtained from two field studies of skin cancer and leukemia to demonstrate how it can be used to estimate health benefits of reduced illness and death risks.  相似文献   
996.
997.
998.
999.
1000.
Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner’s behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher (Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号