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   370篇
  免费   11篇
  国内免费   2篇
安全科学   13篇
废物处理   13篇
环保管理   65篇
综合类   29篇
基础理论   90篇
污染及防治   100篇
评价与监测   30篇
社会与环境   38篇
灾害及防治   5篇
  2023年   4篇
  2022年   3篇
  2021年   6篇
  2020年   4篇
  2019年   4篇
  2018年   11篇
  2017年   7篇
  2016年   18篇
  2015年   17篇
  2014年   8篇
  2013年   21篇
  2012年   11篇
  2011年   26篇
  2010年   18篇
  2009年   20篇
  2008年   20篇
  2007年   21篇
  2006年   15篇
  2005年   25篇
  2004年   15篇
  2003年   20篇
  2002年   17篇
  2001年   8篇
  2000年   4篇
  1999年   7篇
  1998年   3篇
  1997年   3篇
  1996年   7篇
  1995年   5篇
  1994年   5篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1984年   3篇
  1982年   4篇
  1981年   2篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1975年   3篇
  1974年   2篇
  1971年   1篇
排序方式: 共有383条查询结果,搜索用时 156 毫秒
91.
The time-series correlation between ambient levels, indoor levels, and personal exposure to PM2.5 was assessed in panels of elderly subjects with cardiovascular disease in Amsterdam, the Netherlands, and Helsinki, Finland. Subjects were followed for 6 months with biweekly clinical visits. Each subject's indoor and personal exposure to PM2.5 was measured biweekly, during the 24-hr period preceding the clinical visits. Outdoor PM2.5 concentrations were measured at fixed sites. The absorption coefficients of all PM2.5 filters were measured as a marker for elemental carbon (EC). Regression analyses were conducted for each subject separately, and the distribution of the individual regression and correlation coefficients was investigated. Personal, indoor, and ambient concentrations were highly correlated within subjects over time. Median Pearson's R between personal and outdoor PM2.5 was 0.79 in Amsterdam and 0.76 in Helsinki. For absorption, these values were 0.93 and 0.81 for Amsterdam and Helsinki, respectively. The findings of this study provide further support for using fixed-site measurements as a measure of exposure to PM2.5 in epidemiological time-series studies.  相似文献   
92.
Zinc is an essential metal for all living organisms. However, so far, little or no attention has been paid to the consequences of zinc deficiency or acclimation to this metal during culturing and testing on toxicity test results. In this study, the cladoceran Ceriodaphnia dubia was acclimated for 10 generations to four zinc concentrations ranging from 0 to 100 microg Zn/l and changes in zinc tolerance were monitored using acute (48 h) and chronic (9 days) assays. C. dubia deprived of zinc and acclimated to 13 microg Zn/l had a lower fitness in comparison with organisms acclimated to 50 and 100 microg Zn/l. In the two lowest versus the two highest acclimation concentrations the 9dEC50 values (on immobility) were 358-387 microg Zn/l versus 486-489 microg Zn/l; the mean number of young per female was 11-18 versus 25-32; and the time to first brood was 4.7-5.0 days versus 4.0-4.3 days. Moreover, the coefficient of variation of all parameters tested was highest in the two lowest acclimation concentrations. The results indicate that culturing test animals in media lacking trace metals such as zinc could give rise to animals that are unnaturally sensitive to those same metals daring toxicity tests.  相似文献   
93.
A global three-dimensional Lagrangian chemistry-transport model STOCHEM is used to describe the European regional acid deposition and ozone air quality impacts along the Atlantic Ocean seaboard of Europe, from the SO2, NOx, VOCs and CO emissions from international shipping under conditions appropriate to the year 2000. Model-derived total sulfur deposition from international shipping reaches over 200 mg S m(-2) yr(-1) over the southwestern approaches to the British Isles and Brittany. The contribution from international shipping to surface ozone concentrations during the summertime, peaks at about 6 ppb over Ireland, Brittany and Portugal. Shipping emissions act as an external influence on acid deposition and ozone air quality within Europe and may require control actions in the future if strict deposition and air quality targets are to be met.  相似文献   
94.
Sediment and mysids from the Scheldt estuary, one of the largest and most polluted estuaries in Western Europe, were analyzed for a number of contaminants that have been shown to possess endocrine-disrupting activity, i.e. organotins, polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), nonylphenol ethoxylates (NPE) and transformation products, nonylphenol (NP) and nonylphenol ether carboxylates (NPEC). In addition, in vitro estrogenic and androgenic potencies of water and sediment extracts were determined. Total organotin concentrations ranged from 84 to 348 ng/g dw in sediment and 1110 to 1370 ng/g dw in mysid. Total PBDE (excluding BDE-209) concentrations ranged from 14 to 22 ng/g dw in sediment and from 1765 to 2962 ng/g lipid in mysid. High concentrations of BDE-209 (240-1650 ng/g dw) were detected in sediment and mysid (269-600 ng/g lipid). Total HBCD concentrations in sediment and mysid were 14-71 ng/g dw and 562-727 ng/g lipid, respectively. Total NPE concentrations in sediment were 1422 ng/g dw, 1222 ng/g dw for NP and 80 ng/g dw for NPEC and ranged from 430 to 1119 ng/g dw for total NPE and from 206 to 435 ng/g dw for NP in mysid. Significant estrogenic potency, as analyzed using the yeast estrogen assay, was detected in sediment and water samples from the Scheldt estuary, but no androgenic activity was found. This study is the first to report high levels of endocrine disruptors in estuarine mysids.  相似文献   
95.
A simple and cheap device, which allows a controlled and continuous food supply of suspension feeding animals in long term experiments, has been developed and is described.  相似文献   
96.
97.
Spatial planners around the world need to make climate change adaptation plans. Climate adaptation planning requires combining spatial information with stakeholder values. This study demonstrates the potential of geodesign tools as a mean to integrate spatial analysis with stakeholder participation in adaptation planning. The tools are interactive and provide dynamic feedback on stakeholder objectives in response to the application of spatial measures. Different rationalities formed by underlying internalized values influence the reasoning of decision-making. Four tools were developed, each tailored to different rationalities varying between a collective or individual viewpoint and analytical or political arguments. The tools were evaluated in an experiment with four groups of participants that were set around an interactive mapping device: the touch table. To study how local decision-making on adaptation can be supported, this study focuses on a specific case study in the Netherlands. In this case study, multiple different stakeholders need to make spatial decisions on land use and water management planning in response to climate change. The collaborative use of four geodesign tools was evaluated in an interactive experiment. The results show that the geodesign tools were able to integrate the engagement of stakeholders and assessment of measures. The experiment showed that decision-making on adaptation to climate change can benefit from the use of geodesign tools as long as the tool is carefully matched to the rationality that applies to the adaptation issue. Although the tools were tested to support the design of adaptation plans in a Dutch setting, the tools could be used for regional adaptation planning in other countries such as the development of regional adaptation strategies (RAS) as required by the European Union or on a national scale to support developing national adaptation plans of action (NAPAs) as initiated by the United Nations Framework Convention on Climate Change (UNFCCC) for least developed countries.  相似文献   
98.
99.
Abstract: If logging is to be compatible with primate conservation, primate populations must be expected to recover from the disturbance and eventually return to their former densities. Surveys conducted over 28 years were used to quantify the long-term effects of both low- and high-intensity selective logging on the density of the five common primates in Kibale National Park, Uganda. The most dramatic exception to the expectation that primate populations will recover following logging was that group densities of Cercopithecus mitis and C. ascanius in the heavily logged area continued to decline decades after logging. Procolobus tephrosceles populations were recovering in the heavily logged areas, but the rate of increase appeared to be slow (0.005 groups/km2 per year). Colobus guereza appeared to do well in some disturbed habitats and were found at higher group densities in the logged areas than in the unlogged area. There was no evidence of an increase in Lophocebus albigena group density in the heavily logged area since the time of logging, and there was a tendency for its population to be lower in heavily logged areas than in lightly logged areas. In contrast to the findings from the heavily logged area, none of the species were found at a lower group density in the lightly logged area than in the unlogged area, and group densities in this area were not changing at a statistically significant rate. The results of our study suggest that, in this region, low-intensity selective logging could be one component of conservation plans for primates; high-intensity logging, however, which is typical of most logging operations throughout Africa, is incompatible with primate conservation.  相似文献   
100.
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