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   32309篇
  免费   358篇
  国内免费   465篇
安全科学   990篇
废物处理   1513篇
环保管理   3796篇
综合类   5671篇
基础理论   8330篇
环境理论   25篇
污染及防治   8566篇
评价与监测   2189篇
社会与环境   1871篇
灾害及防治   181篇
  2023年   145篇
  2022年   323篇
  2021年   342篇
  2020年   257篇
  2019年   309篇
  2018年   528篇
  2017年   525篇
  2016年   799篇
  2015年   609篇
  2014年   951篇
  2013年   2536篇
  2012年   1126篇
  2011年   1542篇
  2010年   1236篇
  2009年   1276篇
  2008年   1527篇
  2007年   1574篇
  2006年   1335篇
  2005年   1167篇
  2004年   1031篇
  2003年   1121篇
  2002年   983篇
  2001年   1278篇
  2000年   895篇
  1999年   539篇
  1998年   362篇
  1997年   376篇
  1996年   371篇
  1995年   438篇
  1994年   473篇
  1993年   363篇
  1992年   385篇
  1991年   367篇
  1990年   397篇
  1989年   352篇
  1988年   303篇
  1987年   283篇
  1986年   230篇
  1985年   257篇
  1984年   278篇
  1983年   264篇
  1982年   250篇
  1981年   237篇
  1980年   181篇
  1979年   201篇
  1978年   183篇
  1975年   148篇
  1974年   126篇
  1972年   138篇
  1971年   136篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
951.
952.
Nematode communities in the rooted soil layer under the crowns of introduced tree species on Valaam Island (Republic of Karelia) have been studied by conventional nematological methods to evaluate their taxonomic diversity, population density, and eco-trophic structure. On the whole, 49 nematode genera have been recorded, with their total abundance varying from 1209 to 2548 ind./100 g soil. The abundance and proportion of plant parasites in the soil nematode assemblage have proved to be higher under introduced trees, compared to natural forest biocenoses.  相似文献   
953.
We develop a landscape stewardship classification which distinguishes between farmers’ understanding of landscape stewardship, their landscape values, and land management actions. Forty semi-structured interviews were conducted with small-holder (<5 acres), medium-holders (5–100 acres), and large-holders (>100 acres) in South-West Devon, UK. Thematic analysis revealed four types of stewardship understandings: (1) an environmental frame which emphasized the farmers’ role in conserving or restoring wildlife; (2) a primary production frame which emphasized the farmers’ role in taking care of primary production assets; (3) a holistic frame focusing on farmers’ role as a conservationist, primary producer, and manager of a range of landscape values, and; (4) an instrumental frame focusing on the financial benefits associated with compliance with agri-environmental schemes. We compare the landscape values and land management actions that emerged across stewardship types, and discuss the global implications of the landscape stewardship classification for the engagement of farmers in landscape management.  相似文献   
954.
Russian Journal of Ecology - The genetic and phenotypic structure (according to the fur color) of 14 sable samples from the Baikal mountain land (BML) has been studied by analyzing 257 animals for...  相似文献   
955.
956.
957.
958.
Environmental restoration projects are commonly touted for their ecological positives, but such projects can also provide significant socioeconomic and cultural benefits to local communities. We assessed the social dimensions of a large-scale coral reef restoration project in Maunalua Bay, O‘ahu, where >1.32 million kg of invasive marine macroalgae was removed from 11 hectares (90,000 m2; 23 acres) of impacted coral reef in an urbanized setting. We interviewed 131 community stakeholders and analyzed both quantitative and qualitative data to assess human uses of the environment, assess perceptions of environmental health, and characterize social dimensions (+/?) associated with the invasive algae removal effort. Results indicate substantial direct economic benefits, including the creation of more than 60+ jobs, benefiting more than 250 individuals and 81 households. The project helped develop a skilled workforce in a local business dedicated to environmental restoration and increased the capacity of community organizations to address other threats to reefs and watersheds. Other major benefits include revitalization of Native Hawaiian cultural practices and traditions and the successful use of harvested invasive algae as compost by local farmers. Our results show the project heightened community awareness and a broader sense of stewardship in the area, creating enabling conditions for collective community action. Our findings show that restoration projects that explicitly incorporate efforts to build community awareness, involvement, and a shared responsibility for a site may ultimately create the long-term capacity for sustainable stewardship programs. We conclude by discussing lessons learned for engaging productively with communities in environmental restoration and stewardship, which remains a central focus in conservation worldwide.  相似文献   
959.
How species interact modulate their dynamics, their response to environmental change, and ultimately the functioning and stability of entire communities. Work conducted at Zackenberg, Northeast Greenland, has changed our view on how networks of arctic biotic interactions are structured, how they vary in time, and how they are changing with current environmental change: firstly, the high arctic interaction webs are much more complex than previously envisaged, and with a structure mainly dictated by its arthropod component. Secondly, the dynamics of species within these webs reflect changes in environmental conditions. Thirdly, biotic interactions within a trophic level may affect other trophic levels, in some cases ultimately affecting land–atmosphere feedbacks. Finally, differential responses to environmental change may decouple interacting species. These insights form Zackenberg emphasize that the combination of long-term, ecosystem-based monitoring, and targeted research projects offers the most fruitful basis for understanding and predicting the future of arctic ecosystems.  相似文献   
960.
While science advances technology, it is also true that technology advances science. Thus, the two bodies of knowledge are increasingly recognized as interdependent. Nonetheless, recent advances in information communication technology (ICT), in particular, may have profound implications for the norms by which science is conducted. For example, treatment of data will increasingly be in terms of probability distributions, rather than as point estimates, because the cost of computation is now so low that more robust approaches to treatment of uncertainty are within the grasp of normal science. Perhaps more importantly, the techniques by which scientists collaborate, communicate, and curate science are undergoing a rare period of rapid change. The papers in this special section exemplify the evolution of the relationship between technology and science in these two important ways: (1) treatment of data uncertainties and (2) participation in novel methods of publication and review. The latter was fostered by the 2016 meeting of the International Symposium on Sustainable Systems and Technologies (ISSST), at which all of the papers in this special section were presented. This editorial summarizes some of the trends in ICT that are the subject of experimentation in ISSST and introduces the idea that scientific societies in the information age are more likely to take the form of a network than they are likely to look like the societies of the last several centuries.  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