全文获取类型
收费全文 | 533篇 |
免费 | 11篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 19篇 |
废物处理 | 23篇 |
环保管理 | 64篇 |
综合类 | 86篇 |
基础理论 | 163篇 |
环境理论 | 1篇 |
污染及防治 | 139篇 |
评价与监测 | 28篇 |
社会与环境 | 23篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 10篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 15篇 |
2017年 | 18篇 |
2016年 | 18篇 |
2015年 | 19篇 |
2014年 | 20篇 |
2013年 | 27篇 |
2012年 | 34篇 |
2011年 | 47篇 |
2010年 | 28篇 |
2009年 | 32篇 |
2008年 | 20篇 |
2007年 | 36篇 |
2006年 | 18篇 |
2005年 | 18篇 |
2004年 | 14篇 |
2003年 | 6篇 |
2002年 | 21篇 |
2001年 | 19篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1972年 | 1篇 |
1962年 | 1篇 |
1957年 | 1篇 |
1941年 | 1篇 |
1937年 | 3篇 |
1918年 | 1篇 |
排序方式: 共有549条查询结果,搜索用时 15 毫秒
471.
Erik Meijaard Marcel Cardillo Emily M. Meijaard Hugh P. Possingham 《Conservation biology》2015,29(3):920-925
We investigated whether the impact of conservation science is greater for research conducted in countries with more pressing conservation problems. We quantified research impact for 231 countries based on 2 citation metrics (mean cites per paper and h index) and fitted models predicting research impact based on number of threatened bird and mammal species (as a measure of conservation importance of a country) and a range of demographic variables. Citation rates of conservation research increased as a country's conservation need increased and as human population, quality of governance, and wealth increased. Even after accounting for these factors, citation rates among regions and countries within regions varied significantly. The conservation research community needs to consider ways to begin addressing the entrenched disadvantages some countries have when it comes to initiating projects and producing high‐quality research. 相似文献
472.
Gregor Kalinkat Juliano S. Cabral William Darwall G. Francesco Ficetola Judith L. Fisher Darren P. Giling Marie‐Pierre Gosselin Hans‐Peter Grossart Sonja C. Jähnig Jonathan M. Jeschke Klaus Knopf Stefano Larsen Gabriela Onandia Marlene Pätzig Wolf‐Christian Saul Gabriel Singer Erik Sperfeld Ivan Jarić 《Conservation biology》2017,31(2):481-485
473.
474.
Routti H Letcher RJ Born EW Branigan M Dietz R Evans TJ Fisk AT Peacock E Sonne C 《Journal of environmental monitoring : JEM》2011,13(8):2260-2267
Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg(2+)-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. 相似文献
475.
Rasmussen JJ Baattrup-Pedersen A Larsen SE Kronvang B 《Journal of environmental monitoring : JEM》2011,13(4):943-950
The combination of intensive agricultural activities and the close connectivity between land and stream emphasise the potential risk of pesticide exposure in Danish streams. Benthic macroinvertebrates are applied in the assessment of stream ecological status, and some sensitive species have been shown to respond strongly to brief pulses of pesticide contamination. In this study we investigate the impact of agriculturally derived pesticides on stream macroinvertebrate communities in Denmark. As a measure of toxic pressure we apply the Runoff Potential. We investigated a total of 212 streams. These were grouped into distinct classes according to the magnitude of pesticide contamination in the period from 2003-2006. A total of 24 different macroinvertebrate indices were applied to detect effects of pesticide runoff (e.g. the SPEAR-index and the number of EPT taxa). We found high predicted pesticide runoff in 39% of the streams, but we found no significant effect of predicted pesticide exposure on stream macroinvertebrate indices. We, additionally, examined the influence of a series of environmental parameters ranging from site scale to catchment scale on the macroinvertebrate community. Relative proportions of gravel, sand and silt in bed sediments explained most of the variation in macroinvertebrate indices as well as the upstream riparian habitat quality. We suggest that the Runoff Potential model overestimate pesticide runoff contamination in Danish streams due the presence of buffer strips enforced by Danish legislation. When pesticide runoff contamination is low to moderate, poor physical properties (indirectly related to agricultural activity) are the main impediment for the ecological quality of Danish streams. 相似文献
476.
Lore Lannoo Karuna R. M. van der Meij Mireille N. Bekker Luc De Catte Sarah Deckers Koenraad Devriendt Nele Roggen Robert-Jan H. Galjaard Janneke Gitsels-van der Wal Merryn V. E. Macville Linda Martin Erik A. Sistermans Kristel Van Calsteren Joachim Van Keirsbilck Neeltje Crombag Lidewij Henneman 《黑龙江环境通报》2023,43(3):294-303
Background
The Netherlands and Belgium have been among the first countries to offer non-invasive prenatal testing (NIPT) as a first-tier screening test. Despite similarities, differences exist in counseling modalities and test uptake. This study explored decision-making and perspectives of pregnant women who opted for NIPT in both countries.Methods
A questionnaire study was performed among pregnant women in the Netherlands (NL) (n = 587) and Belgium (BE) (n = 444) opting for NIPT, including measures on informed choice, personal and societal perspectives on trisomy 21, 18 and 13 and pregnancy termination.Results
Differences between Dutch and Belgian women were shown in the level of informed choice (NL: 83% vs. BE: 59%, p < 0.001), intention to terminate the pregnancy in case of confirmed trisomy 21 (NL: 51% vs. BE: 62%, p = 0.003) and trisomy 13/18 (NL: 80% vs. BE: 73%, p = 0.020). More Belgian women considered trisomy 21 a severe condition (NL: 64% vs. BE: 81%, p < 0.001). Belgian women more frequently indicated that they believed parents are judged for having a child with trisomy 21 (BE: 42% vs. NL: 16%, p < 0.001) and were less positive about quality of care and support for children with trisomy 21 (BE: 23% vs. NL: 62%, p < 0.001).Conclusion
Differences in women's decision-making regarding NIPT and the conditions screened for may be influenced by counseling aspects and country-specific societal and cultural contexts. 相似文献477.
478.
Didac Pascual Jonas kerman Marina Becher Terry V. Callaghan Torben R. Christensen Ellen Dorrepaal Urban Emanuelsson Reiner Giesler Dan Hammarlund Edward Hanna Annika Hofgaard Hongxiao Jin Cecilia Johansson Christer Jonasson Jonatan Klaminder Jan Karlsson Erik Lundin Anders Michelsen David Olefeldt Andreas Persson Gareth K. Phoenix Zofia Rczkowska Riikka Rinnan Lena Strm Jing Tang Ruth K. Varner Philip Wookey Margareta Johansson 《Ambio》2021,50(2):375
Arctic and subarctic ecosystems are experiencing substantial changes in hydrology, vegetation, permafrost conditions, and carbon cycling, in response to climatic change and other anthropogenic drivers, and these changes are likely to continue over this century. The total magnitude of these changes results from multiple interactions among these drivers. Field measurements can address the overall responses to different changing drivers, but are less capable of quantifying the interactions among them. Currently, a comprehensive assessment of the drivers of ecosystem changes, and the magnitude of their direct and indirect impacts on subarctic ecosystems, is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years, and is one of the most studied sites in the Arctic. In this study, we summarize and rank the drivers of ecosystem change in the Torneträsk area, and propose research priorities identified, by expert assessment, to improve predictions of ecosystem changes. The research priorities identified include understanding impacts on ecosystems brought on by altered frequency and intensity of winter warming events, evapotranspiration rates, rainfall, duration of snow cover and lake-ice, changed soil moisture, and droughts. This case study can help us understand the ongoing ecosystem changes occurring in the Torneträsk area, and contribute to improve predictions of future ecosystem changes at a larger scale. This understanding will provide the basis for the future mitigation and adaptation plans needed in a changing climate.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01381-1) contains supplementary material, which is available to authorized users. 相似文献
479.
480.