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   451篇
  免费   9篇
  国内免费   9篇
安全科学   14篇
废物处理   14篇
环保管理   66篇
综合类   85篇
基础理论   92篇
环境理论   1篇
污染及防治   127篇
评价与监测   29篇
社会与环境   27篇
灾害及防治   14篇
  2023年   8篇
  2022年   12篇
  2021年   22篇
  2020年   16篇
  2019年   11篇
  2018年   18篇
  2017年   21篇
  2016年   36篇
  2015年   22篇
  2014年   29篇
  2013年   42篇
  2012年   26篇
  2011年   29篇
  2010年   16篇
  2009年   24篇
  2008年   21篇
  2007年   20篇
  2006年   13篇
  2005年   7篇
  2004年   13篇
  2003年   13篇
  2002年   14篇
  2001年   3篇
  2000年   2篇
  1999年   3篇
  1998年   2篇
  1997年   1篇
  1996年   4篇
  1995年   2篇
  1994年   3篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1982年   2篇
  1978年   1篇
  1977年   3篇
排序方式: 共有469条查询结果,搜索用时 890 毫秒
331.
The analysis of mitochondrial DNA in loggerhead sea turtles (Caretta caretta) from eight foraging grounds in the Mediterranean and the adjoining Atlantic revealed deep genetic structuring within the western Mediterranean. As a consequence, the foraging grounds off the North-African coast and the Gimnesies Islands are shown to be inhabited mainly by turtles of the Atlantic stocks, whereas the foraging grounds off the European shore of the western Mediterranean are shown to be inhabited mainly by turtles from the eastern Mediterranean rookeries. This structuring is explained by the pattern of sea surface currents and water masses and suggests that immature loggerhead sea turtles entering the western Mediterranean from the Atlantic and the eastern Mediterranean remain linked to particular water masses, with a limited exchange of turtles between water masses. As the north of the western Mediterranean comprises mostly individuals from the highly endangered eastern Mediterranean rookeries, conservation plans should make it a priority to reduce the mortality caused by incidental by-catch in these areas.  相似文献   
332.
333.
We investigated the possibility that male harassment of lactating females differed in relation to time of birth in the grey seal, Halichoerus grypus, on Sable Island, Nova Scotia. This was done by comparing the frequency of male disturbances, maternal performance and pup growth for females that either gave birth during the peak of the pupping season or after the peak. Of the females, 58% gave birth in a 7-day period near the beginning of the pupping period, when the operational sex ratio was 2–4 females per male. Late in the pupping period the operational sex ratio reversed to about 1 female for every 2 males. The relative frequency of disturbances by males was significantly greater for late-pupping mothers than for peak-pupping ones (1.9 vs. 1.4 encounters/h). Females that gave birth late also were disturbed by males 3 times more often than females that gave birth during the peak (3.4 vs. 1.1 % of observation time). Late-pupping mothers spent 22% less time suckling (4.0 vs. 5.1 % of observation time), had 30% slower growing pups (1.7 vs. 2.4 kg/d), and weaned pups that were 16% lighter (45.6 vs. 54.0 kg). The effect of birth time on pup mass gain and weaning mass was not attributable to factors such as maternal mass, pup birth mass or pup sex. We conclude that the reduced maternal performance is likely the result of the increased male harassment. As reduced weaning mass can lead to reduced juvenile survival, male harassment may have contributed to the enhanced reproductive synchrony in this species.  相似文献   
334.
The response of corticolous lichens, bryophytes, and vascular plants to anthropogenic edges in northern hardwood forest preserves is compared in east-coast and mid-west (NW Minnesota) sites, using micro-epiphytes on red oak (Quercus rubra) and sugar maple (Acer saccharum). The drastically attenuated lichen flora in the east, apparently due to regional air pollution, restricts the usefulness of these bioindicators, even 120 km from New York City. The forest edge is not necessarily equated with increased light. Established edges may have pronounced shoot growth that shades epiphytes. In the absence of air pollution, lichen and bryophyte species exhibit individual responses to light, humidity, and substrate chemistry. Thus summary variables such as total cover or species richness have limited value as bioindicators of forest integrity.  相似文献   
335.
336.
Within-city green infrastructure can offer opportunities and new contexts for people to become stewards of ecosystem services. We analyze cities as social–ecological systems, synthesize the literature, and provide examples from more than 15 years of research in the Stockholm urban region, Sweden. The social–ecological approach spans from investigating ecosystem properties to the social frameworks and personal values that drive and shape human interactions with nature. Key findings demonstrate that urban ecosystem services are generated by social–ecological systems and that local stewards are critically important. However, land-use planning and management seldom account for their role in the generation of urban ecosystem services. While the small scale patchwork of land uses in cities stimulates intense interactions across borders much focus is still on individual patches. The results highlight the importance and complexity of stewardship of urban biodiversity and ecosystem services and of the planning and governance of urban green infrastructure.  相似文献   
337.
Continued development of personal air pollution monitors is rapidly improving government and research capabilities for data collection. In this study, we tested the feasibility of using GPS-enabled personal exposure monitors to collect personal exposure readings and short-term daily PM2.5 measures at 15 fixed locations throughout a community. The goals were to determine the accuracy of fixed-location monitoring for approximating individual exposures compared to a centralized outdoor air pollution monitor, and to test the utility of two different personal monitors, the RTI MicroPEM V3.2 and TSI SidePak AM510. For personal samples, 24-hr mean PM2.5 concentrations were 6.93 μg/m3 (stderr = 0.15) and 8.47 μg/m3 (stderr = 0.10) for the MicroPEM and SidePak, respectively. Based on time–activity patterns from participant journals, exposures were highest while participants were outdoors (MicroPEM = 7.61 µg/m3, stderr = 1.08, SidePak = 11.85 µg/m3, stderr = 0.83) or in restaurants (MicroPEM = 7.48 µg/m3, stderr = 0.39, SidePak = 24.93 µg/m3, stderr = 0.82), and lowest when participants were exercising indoors (MicroPEM = 4.78 µg/m3, stderr = 0.23, SidePak = 5.63 µg/m3, stderr = 0.08). Mean PM2.5 at the 15 fixed locations, as measured by the SidePak, ranged from 4.71 µg/m3 (stderr = 0.23) to 12.38 µg/m3 (stderr = 0.45). By comparison, mean 24-h PM2.5 measured at the centralized outdoor monitor ranged from 2.7 to 6.7 µg/m3 during the study period. The range of average PM2.5 exposure levels estimated for each participant using the interpolated fixed-location data was 2.83 to 19.26 µg/m3 (mean = 8.3, stderr = 1.4). These estimated levels were compared with average exposure from personal samples. The fixed-location monitoring strategy was useful in identifying high air pollution microclimates throughout the county. For 7 of 10 subjects, the fixed-location monitoring strategy more closely approximated individuals’ 24-hr breathing zone exposures than did the centralized outdoor monitor. Highlights are: Individual PM2.5 exposure levels vary extensively by activity, location and time of day; fixed-location sampling more closely approximated individual exposures than a centralized outdoor monitor; and small, personal exposure monitors provide added utility for individuals, researchers, and public health professionals seeking to more accurately identify air pollution microclimates.

Implications: Personal air pollution monitoring technology is advancing rapidly. Currently, personal monitors are primarily used in research settings, but could they also support government networks of centralized outdoor monitors? In this study, we found differences in performance and practicality for two personal monitors in different monitoring scenarios. We also found that personal monitors used to collect outdoor area samples were effective at finding pollution microclimates, and more closely approximated actual individual exposure than a central monitor. Though more research is needed, there is strong potential that personal exposure monitors can improve existing monitoring networks.  相似文献   
338.
This paper is concerned with the ways in which Danish municipalities seek to mitigate climate change through a range of governance strategies. Through the analysis of ten municipal climate plans using the framework of Mitchell Dean, as well as extensive ethnographic fieldwork in two municipalities, this paper explores how local climate change mitigation is shaped by particular rationalities and technologies of government, and thus seeks to illustrate how the strategies set out in the plans construe climate change mitigation from a certain perspective, thereby rendering some solutions more likely than others and recasting citizens as passive consumers who are to be guided to consume in more climate-friendly ways in the process.  相似文献   
339.
Anticipatory governance for social-ecological resilience   总被引:1,自引:0,他引:1  
Anticipation is increasingly central to urgent contemporary debates, from climate change to the global economic crisis. Anticipatory practices are coming to the forefront of political, organizational, and citizens’ society. Research into anticipation, however, has not kept pace with public demand for insights into anticipatory practices, their risks and uses. Where research exists, it is deeply fragmented. This paper seeks to identify how anticipation is defined and understood in the literature and to explore the role of anticipatory practice to address individual, social, and global challenges. We use a resilience lens to examine these questions. We illustrate how varying forms of anticipatory governance are enhanced by multi-scale regional networks and technologies and by the agency of individuals, drawing from an empirical case study on regional water governance of Mälaren, Sweden. Finally, we discuss how an anticipatory approach can inform adaptive institutions, decision making, strategy formation, and societal resilience.  相似文献   
340.
Environmental Science and Pollution Research - The present work is to evaluate the neurotoxicity induced by pyrethroid insecticide “Deltamethrin” at 0.32 mg/kg/day in two main...  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