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   250篇
  免费   10篇
  国内免费   2篇
安全科学   15篇
废物处理   11篇
环保管理   51篇
综合类   42篇
基础理论   77篇
环境理论   1篇
污染及防治   37篇
评价与监测   12篇
社会与环境   14篇
灾害及防治   2篇
  2023年   7篇
  2022年   5篇
  2021年   19篇
  2020年   11篇
  2019年   17篇
  2018年   12篇
  2017年   15篇
  2016年   17篇
  2015年   12篇
  2014年   13篇
  2013年   8篇
  2012年   16篇
  2011年   25篇
  2010年   13篇
  2009年   13篇
  2008年   11篇
  2007年   6篇
  2006年   13篇
  2005年   6篇
  2004年   3篇
  2003年   2篇
  2002年   3篇
  2001年   4篇
  1999年   2篇
  1998年   2篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1988年   1篇
  1985年   1篇
  1980年   1篇
排序方式: 共有262条查询结果,搜索用时 15 毫秒
241.
Book reviews     
Factor Four: Doubling Wealth, Halving Resource Use. Ernst von Weizacker, Amory Lovins & L. Hunter Lovins, 1997, London, Earthscan, ISBN 1 85383 407 6, £15.99 (hbk)

Local and Global: Management of Cities in the Information Age,. Jordi Borja & Manuel Castells, 1997, London, Earthscan, 277pp. ISBN 1 85383 441 6, £19.95 (pbk)

Wasted: counting the costs of global consumption. Michael Redclift, 1996, Earthscan, London, 173pp. ISBN 1 85383 360 6, £32.50(hbk), 1 85383 355 X, £12.95(pbk)

Eco-feminist Natures: race, gender, feminist theory and political action. Noel Sturgeon, 1997, New York, Routledge, ISBN 0 415 912504, £12.99 (pbk)

Global Warming and Global Politics. Matthew Paterson, 1996, London and New York, Routledge, ISBN 0 415 13871 X, US$85.00, UK£50.00, (hbk) ISBN 0 415 13872 8, US$20.99, UK£12.88, (pbk)

Managing for Local Sustainability: policy, problem-solving, practice and place. Valerie M. Brown (Ed.), 1997, Commonwealth of Australia, 314 pp. ISBN 0642 26464 3, Copies of the report can be obtained from: National Office of Local Government Commonwealth Department of the Environment, Sports and Territories, GPO Box 9834, Canberra ACT 2601. Tel: (06) 289 2222; fax (06) 289 2436.

Local Agenda 21, Local Authorities and Tourism: a United Kingdom perspective. David Leslie & Fiona Muir, 1996, Glasgow, Caledonian University, ISBN 0 948255 52 8, £9.00

Straws in the Wind: medieval urban environmental law — the case of Northern Italy. Ronald E. Zupko & Robert A. Laures, 1996, Boulder, CO, Westview Press, 152 pp. ISBN 0 8133 2972 8, £10.00 (pbk)  相似文献   
242.
243.
This study outlines the development of an approach to evaluate the sources, sinks, and magnitudes of greenhouse gas emissions from a grazed semiarid rangeland dominated by mulga (Acacia aneura) and how these emissions may be altered by changes in management. This paper describes the modification of an existing pasture production model (GRASP) to include a gas emission component and a dynamic tree growth and population model. An exploratory study was completed to investigate the likely impact of changes in burning practices and stock management on emissions. This study indicates that there is a fundamental conflict between maintaining agricultural productivity and reducing greenhouse gas emissions on a given unit of land. Greater agricultural productivity is allied with the system being an emissions source while production declines and the system becomes a net emissions sink as mulga density increases. Effective management for sheep production results in the system acting as a net source (approximately 60-200 kg CO2 equivalents/ha/year). The magnitude of the source depends on the management strategies used to maintain the productivity of the system and is largely determined by starting density and average density of the mulga over the simulation period. Prior to European settlement, it is believed that the mulga lands were burnt almost annually. Simulations indicate that such a management approach results in the system acting as a small net sink with an average net absorption of greenhouse gases of 14 kg CO2 equivalents/ha/year through minimal growth of mulga stands. In contrast, the suppression of fire and the introduction of grazing results in thickening of mulga stands and the system can act as a significant net sink absorbing an average of 1000 kg CO2 equivalents/ha/year. Although dense mulga will render the land largely useless for grazing, land in this region is relatively inexpensive and could possibly be developed as a cost-effective carbon offset for greenhouse gas emissions elsewhere. These results also provide support for the hypothesis that changes in land management, and particularly, suppression of fire is chiefly responsible for the observed increases in mulga density over the past century.  相似文献   
244.
245.
246.
Human dimensions research focuses on the interrelationships between humans and the environment. To date, human dimensions research in arctic regions has concentrated primarily on local events and contexts. As such, it complements analysis elsewhere of adaptation and sustainable development within broad institutional, social, and environmental contexts. This paper reviews five projects from the Human Dimensions of the Arctic System (HARC) initiative, established by the US National Science Foundation in 1997. Common themes and findings are highlighted: climatic variations or change affect societies through interactions with human activities; population dynamics provide key quantitative indicators of social impacts and well being; and specific impacts and responses are the result of complex, context-sensitive interactions. Congruent approaches to the challenges of interdisciplinary research are also identified: multivariate time plots aid the integration of data, retrospective and prospective studies are part of a continuum and reinforce one another, comparative studies are essential for understanding general principles of human dimensions, and arctic residents can play a vital role in research and action.  相似文献   
247.
Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales.  相似文献   
248.
We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however.  相似文献   
249.
Environmental Geochemistry and Health - The contamination of bodies of water by potentially hazardous elements has in recent decades become an environmental problem that poses serious risks to...  相似文献   
250.
The Benguela Current Large Marine Ecosystem off southwest Africa is a regionally valued system because of its biological productivity, which supports high biomass throughout the foodweb, and a rich diversity of habitats and species. However, the region is exposed to numerous anthropogenic pressures that are likely to escalate under future economic growth. In response, the Benguela Current Commission called for a spatial biodiversity assessment (BCC-SBA) to identify conservation priorities, including potential areas for marine protected areas. The systematic conservation-planning approach to this assessment requires a fine-scale map of coastal habitats, which was not previously available for the region. Our aim was to undertake this mapping, within tight logistic and resource limitations. We used a previously derived methodology for mapping the distribution of coastal habitats from aerial imagery. The Benguela coast is approximately 5,047 km long. Half of this extent is sandy beach, a third is rocky and mixed shores, 13 % comprises lagoonal features, and the remainder (4 %) comprises estuaries and offshore islands. The distribution and extent of these coastal habitats differs substantially alongshore (i.e. with latitude), with conditions ranging north–south from hot, humid mangrove-lined lagoons, to hyper-arid coastal desert sandy beaches. Patterns in regional geology, climate and oceanography are proposed as the main drivers of spatial heterogeneity in coastal habitat types. The resulting ecological and socio-economic wealth requires proactive protection (supported through the BCC-SBA, for example), to ensure sustainable utilization of the rich natural resources, and persistence of these resources for the benefit of current and future generations.  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