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   1599篇
  免费   25篇
  国内免费   24篇
安全科学   69篇
废物处理   19篇
环保管理   496篇
综合类   614篇
基础理论   100篇
污染及防治   113篇
评价与监测   63篇
社会与环境   133篇
灾害及防治   41篇
  2024年   1篇
  2023年   8篇
  2022年   10篇
  2021年   27篇
  2020年   31篇
  2019年   18篇
  2018年   21篇
  2017年   35篇
  2016年   37篇
  2015年   29篇
  2014年   51篇
  2013年   93篇
  2012年   41篇
  2011年   89篇
  2010年   43篇
  2009年   97篇
  2008年   113篇
  2007年   88篇
  2006年   75篇
  2005年   58篇
  2004年   61篇
  2003年   80篇
  2002年   65篇
  2001年   63篇
  2000年   85篇
  1999年   68篇
  1998年   64篇
  1997年   42篇
  1996年   17篇
  1995年   17篇
  1994年   17篇
  1993年   19篇
  1992年   17篇
  1991年   11篇
  1990年   4篇
  1989年   8篇
  1988年   3篇
  1987年   9篇
  1986年   6篇
  1985年   6篇
  1984年   5篇
  1983年   3篇
  1982年   7篇
  1981年   1篇
  1980年   2篇
  1974年   2篇
  1968年   1篇
排序方式: 共有1648条查询结果,搜索用时 203 毫秒
211.
The sustainability of large dams has been questioned on several grounds. One aspect that has been less explored is that the development of dams and reservoirs often enables agricultural expansion and urban growth, which in turn increase water consumption. As such, dam development influences, while being influenced by, the spatial and temporal distribution of both supply and demand of water resources. In this paper, we explore the interplay between large dams, patterns of population growth and agricultural expansion in the United States over the past two centuries. Based on a large-scale analysis of spatial and temporal trends, we identify three distinct phases, in which different processes dominated the interplay. Then, we focus on agricultural water use in the Southwest region (Arizona, California and Nevada) and explore chicken-and-egg dynamics where water supply partly meets and partly fuels water demand. Lastly, we show that the legacy of dams in the United States consists of a lock-in condition characterized by high levels of water consumption, especially in the Southwest, which leads to severe water crises and groundwater overexploitation when droughts occur.  相似文献   
212.
This paper investigates the current status and trends over time in the environmental performance of European ports. The research is based on the provision of data from 79 European ports on issues related to their environmental management, environmental priorities and current environmental monitoring practices. This study updates previous environmental reviews, so that the trends over time are drawn. For instance, 90% of respondent ports stated that they have an environmental policy and 94% of ports have designated environmental personnel. The percentage of ports that have an Environmental Management System has increased by +33% in the last 9 years. Air quality, port waste and energy consumption emerged as the three major environmental priorities of the European port sector in 2013. The research also reveals the diversity amongst European ports in terms of size and physical surroundings. Some examples are presented on specific initiatives carried out by sector organisations about the Top-10 port priority issues. The future expectations of European ports on data collection and reporting are described.  相似文献   
213.
The water–energy–food nexus is being promoted as a conceptual tool for achieving sustainable development. Frameworks for implementing nexus thinking, however, have failed to explicitly or adequately incorporate sustainable livelihoods perspectives. This is counterintuitive given that livelihoods are key to achieving sustainable development. In this paper we present a critical review of nexus approaches and identify potential linkages with sustainable livelihoods theory and practice, to deepen our understanding of the interrelated dynamics between human populations and the natural environment. Building upon this review, we explore the concept of ‘environmental livelihood security’ – which encompasses a balance between natural resource supply and human demand on the environment to promote sustainability – and develop an integrated nexus-livelihoods framework for examining the environmental livelihood security of a system. The outcome is an integrated framework with the capacity to measure and monitor environmental livelihood security of whole systems by accounting for the water, energy and food requisites for livelihoods at multiple spatial scales and institutional levels. We anticipate this holistic approach will not only provide a significant contribution to achieving national and regional sustainable development targets, but will also be effective for promoting equity amongst individuals and communities in local and global development agendas.  相似文献   
214.
/ This study examines similarities and differences between organic and conventional farmers. We explore the factors that underlie farmers' conservation attitudes and behaviors, including demographic and farm characteristics, awareness of and concern for environmental problems associated with agriculture, economic orientation toward farming, and self-reported conservation practices. A series of intensive personal interviews was conducted with 25 farmers in Washtenaw County, Michigan, USA, using both qualitative and quantitative survey methods. The findings indicate that both groups of farmers share a concern for the economic risks associated with farming, although the organic farmers reported a significantly greater concern for long-term sustainability and a greater willingness to incur present risk to gain future benefits. Organic farmers expressed a greater awareness of and concern for environmental problems associated with agriculture. Organic farmers also scored significantly higher on a multifaceted measure of conservation practices, although both groups had a fairly high adoption rate. Implications of these findings are discussed, relative to economic risks of farming, implications for new farmers, effectiveness of conservation education and government programs, and impact of farm size and crop diversity.KEY WORDS: Environmental attitudes; Conservation behaviors; Organic farming; Agricultural sustainability  相似文献   
215.
Fish production and marketing are as old as the rural communities involved in the lucrative occupation in Badagry area of Lagos State, Nigeria. A random sampling of 200 fishermen using Participatory Rural Appraisal techniques (PRA) in five Badagry villages was used to explore coastal fishing and socio-economic development in the study area with a view to enhancing local productivity and sustainability. The findings show that an average fisherman in Badagry is aware of the resources available in his environment, and can affect productivity levels positively if given adequate incentives. There are two lessons from this study; one has to do with what PRA tells us about the fishing community, the other is the importance of facilitators that have, amongst other things, good listening skills. The experience also revealed that field workers’ ability to listen and learn from local fishermen was a critical factor in collecting in-depth information that could be used for rural community planning.  相似文献   
216.
The distance between where food is produced and consumed is increasing, and is often taken as evidence of an unsustainable global food system. Seafood is a highly traded commodity yet seafood sustainability assessments do not typically consider the impacts of the movement of products beyond the fishery or farm. Here we use life cycle assessment to examine the carbon footprint of the production and distribution of select seafood products that are consumed in Australia and determine differences in the sustainability of imports and their domestically produced counterparts. We found that the distance food is transported is not the main determinant of food sustainability. Despite the increased distance between production and consumption, carbon footprints of meals from imported seafood are similar to meals consisting of domestically produced seafood, and sometimes lower, depending on the seafood consumed. In combining LCA with existing seafood sustainability criteria the trade-offs between sustainability targets become more apparent. Carbon ‘footprinting’ is one metric that can be incorporated in assessments of sustainability, thereby demonstrating a broader perspective of the environmental cost of food production and consumption.  相似文献   
217.
The concepts of sustainable agriculture, organic agriculture, regenerative agriculture, and alternative agriculture are receiving increasing attention in the academic and popular literature on present trends and future directions of agriculture. Whatever the reasons for this interest, there nevertheless remain differences of opinion concerning what counts as a sustainable agriculture. One of the reasons for these differences is that the moral underpinnings of a policy of sustainability are not clear. By understanding the moral obligatoriness of sustainability, we can come to understand precisely what must be sustained, and by implication, how. This article discusses the arguments that can be advanced for sustaining anything and initially concludes that our obligations to future generations entail sustaining more than just sufficient food production or an adequate resource base. Indeed, a tradition of care and community must underlie whatever agricultural and resource strategies we are to develop under the rubric of sustainability. A consideration of the larger social and environmental system in which agriculture operates and the constraints this system places on agriculture forces us to recognize that sustainability has to do with larger institutional issues, including our ability to incorporate our common morality democratically into our institutions, practices, and technologies.  相似文献   
218.
本文从生态文明内涵和可持续发展本质出发,对生态文明和可持续发展之关系进行了初步探讨,这对于坚持科学发展观、走可持续发展道路,提高生态文明和尊重自然的认识,建设和谐社会,促进生态文明建设具有重要意义。  相似文献   
219.
The implementation of urban sustainability practices is affected by political obstacles, and diverse political ideologies may defend different city models. Sustainable policy design could also be affected by several factors that cause the deflection of resources initially allocated to other groups that are contrary to the concerns pursued and have the power to veto sustainable plans by exerting pressure on the party in power.In this sense, the aim of this paper is to show the impact that political factors have on cities’ sustainability, and the effect of both on cities’ economic development. To do so, we used the 78 Spanish cities with a population over 100,000 studied by MERCO (Spanish Corporate Reputation Monitor) as regards their levels of sustainability for the fiscal years 2008 and 2009. Both relationships have been tested empirically through two dependence models using linear regression techniques.The results obtained show that political competition improves cities’ sustainability, while a leftist ideology has an inverse impact. On the other hand, a significant direct relationship has been observed between urban sustainability and municipal economic activity.  相似文献   
220.
大连地区水资源可持续利用问题思考   总被引:2,自引:0,他引:2  
从水资源可用的战略高度,从生命之源-水入手,较详细地分析了大连地区水危急资源开发利用问题,从而,较全面地论述了大连地区水资源可持续利用的战略措施。  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