全文获取类型
收费全文 | 31114篇 |
免费 | 233篇 |
国内免费 | 367篇 |
专业分类
安全科学 | 512篇 |
废物处理 | 1706篇 |
环保管理 | 3694篇 |
综合类 | 4528篇 |
基础理论 | 8793篇 |
环境理论 | 4篇 |
污染及防治 | 7257篇 |
评价与监测 | 2486篇 |
社会与环境 | 2599篇 |
灾害及防治 | 135篇 |
出版年
2022年 | 241篇 |
2021年 | 198篇 |
2020年 | 159篇 |
2019年 | 199篇 |
2018年 | 1702篇 |
2017年 | 1641篇 |
2016年 | 1624篇 |
2015年 | 503篇 |
2014年 | 657篇 |
2013年 | 1796篇 |
2012年 | 1139篇 |
2011年 | 2229篇 |
2010年 | 1501篇 |
2009年 | 1411篇 |
2008年 | 1811篇 |
2007年 | 2160篇 |
2006年 | 852篇 |
2005年 | 777篇 |
2004年 | 780篇 |
2003年 | 785篇 |
2002年 | 789篇 |
2001年 | 939篇 |
2000年 | 655篇 |
1999年 | 347篇 |
1998年 | 247篇 |
1997年 | 276篇 |
1996年 | 293篇 |
1995年 | 344篇 |
1994年 | 306篇 |
1993年 | 254篇 |
1992年 | 267篇 |
1991年 | 252篇 |
1990年 | 272篇 |
1989年 | 243篇 |
1988年 | 212篇 |
1987年 | 226篇 |
1986年 | 201篇 |
1985年 | 208篇 |
1984年 | 210篇 |
1983年 | 198篇 |
1982年 | 177篇 |
1981年 | 178篇 |
1980年 | 157篇 |
1979年 | 169篇 |
1978年 | 130篇 |
1977年 | 143篇 |
1975年 | 117篇 |
1974年 | 116篇 |
1973年 | 133篇 |
1972年 | 128篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
951.
Protected areas’ role in climate-change mitigation 总被引:1,自引:0,他引:1
952.
Marjut Rajasilta Mikael Elfving Jari Hänninen Päivi Laine Ilppo Vuorinen Jorma Paranko 《Ambio》2016,45(2):205-214
953.
Anouk N’Guyen Philipp E. Hirsch Irene Adrian-Kalchhauser Patricia Burkhardt-Holm 《Ambio》2016,45(3):280-289
Managing invasive species is a major challenge for society. In the case of newly established invaders, rapid action is key for a successful management. Here, we develop, describe and recommend a three-step transdisciplinary process (the “butterfly model”) to rapidly initiate action for invasion management. In the framing of a case study, we present results from the first of these steps: assessing priorities and contributions of both scientists and decision makers. Both scientists and decision makers prioritise research on prevention. The available scientific knowledge contributions, however, are publications on impacts rather than prevention of the invasive species. The contribution of scientific knowledge does thus not reflect scientists’ perception of what is essentially needed. We argue that a more objective assessment and transparent communication of not only decision makers’ but also scientists’ priorities is an essential basis for a successful cooperation. Our three-step model can help achieve objectivity via transdisciplinary communication. 相似文献
954.
Maartje J. Klapwijk Anna J. M. Hopkins Louise Eriksson Maria Pettersson Martin Schroeder Åke Lindelöw Jonas Rönnberg E. Carina H. Keskitalo Marc Kenis 《Ambio》2016,45(2):223-234
Intensifying global trade will result in increased numbers of plant pest and pathogen species inadvertently being transported along with cargo. This paper examines current mechanisms for prevention and management of potential introductions of forest insect pests and pathogens in the European Union (EU). Current European legislation has not been found sufficient in preventing invasion, establishment and spread of pest and pathogen species within the EU. Costs associated with future invasions are difficult to estimate but past invasions have led to negative economic impacts in the invaded country. The challenge is combining free trade and free movement of products (within the EU) with protection against invasive pests and pathogens. Public awareness may mobilise the public for prevention and detection of potential invasions and, simultaneously, increase support for eradication and control measures. We recommend focus on commodities in addition to pathways, an approach within the EU using a centralised response unit and, critically, to engage the general public in the battle against establishment and spread of these harmful pests and pathogens. 相似文献
955.
Lucy Rist Adam Felton Erland Mårald Lars Samuelsson Tomas Lundmark Ola Rosvall 《Ambio》2016,45(2):140-151
There is a growing demand for alternatives to Sweden’s current dominant silvicultural system, driven by a desire to raise biomass production, meet environmental goals and mitigate climate change. However, moving towards diversified forest management that deviates from well established silvicultural practices carries many uncertainties and risks. Adaptive management is often suggested as an effective means of managing in the context of such complexities. Yet there has been scepticism over its appropriateness in cases characterised by large spatial extents, extended temporal scales and complex land ownership—characteristics typical of Swedish forestry. Drawing on published research, including a new paradigm for adaptive management, we indicate how common pitfalls can be avoided during implementation. We indicate the investment, infrastructure, and considerations necessary to benefit from adaptive management. In doing so, we show how this approach could offer a pragmatic operational model for managing the uncertainties, risks and obstacles associated with new silvicultural systems and the challenges facing Swedish forestry. 相似文献
956.
Martyn N. Futter Lars Högbom Salar Valinia Ryan A. Sponseller Hjalmar Laudon 《Ambio》2016,45(2):188-202
We present a framework for evaluating and communicating effects of human activity on water quality in managed forests. The framework is based on the following processes: atmospheric deposition, weathering, accumulation, recirculation and flux. Impairments to water quality are characterized in terms of their extent, longevity and frequency. Impacts are communicated using a “traffic lights” metaphor for characterizing severity of water quality impairments arising from forestry and other anthropogenic pressures. The most serious impairments to water quality in managed boreal forests include (i) forestry activities causing excessive sediment mobilization and extirpation of aquatic species and (ii) other anthropogenic pressures caused by long-range transport of mercury and acidifying pollutants. The framework and tool presented here can help evaluate, summarize and communicate the most important issues in circumstances where land management and other anthropogenic pressures combine to impair water quality and may also assist in implementing the “polluter pays” principle. 相似文献
957.
Ryan A. Sponseller Michael J. Gundale Martyn Futter Eva Ring Annika Nordin Torgny Näsholm Hjalmar Laudon 《Ambio》2016,45(2):175-187
Nitrogen (N) availability plays multiple roles in the boreal landscape, as a limiting nutrient to forest growth, determinant of terrestrial biodiversity, and agent of eutrophication in aquatic ecosystems. We review existing research on forest N dynamics in northern landscapes and address the effects of management and environmental change on internal cycling and export. Current research foci include resolving the nutritional importance of different N forms to trees and establishing how tree–mycorrhizal relationships influence N limitation. In addition, understanding how forest responses to external N inputs are mediated by above- and belowground ecosystem compartments remains an important challenge. Finally, forestry generates a mosaic of successional patches in managed forest landscapes, with differing levels of N input, biological demand, and hydrological loss. The balance among these processes influences the temporal patterns of stream water chemistry and the long-term viability of forest growth. Ultimately, managing forests to keep pace with increasing demands for biomass production, while minimizing environmental degradation, will require multi-scale and interdisciplinary perspectives on landscape N dynamics. 相似文献
958.
We examine the wider social knowledge domain that complements technical and environmental knowledge in enabling adaptive practices through two case studies in Tanzania. We are concerned with knowledge production that is shaped by gendered exclusion from the main thrusts of planned adaptation, in the practice of irrigation in a dryland village and the adoption of fast-maturing seed varieties in a highland village. The findings draw on data from a household survey, community workshops, and key informant interviews. The largest challenge to effective adaptation is a lack of access to the social networks and institutions that allocate resources needed for adaptation. Results demonstrate the social differentiation of local knowledge, and how it is entwined with adaptive practices that emerge in relation to gendered mechanisms of access. We conclude that community-based adaptation can learn from engaging the broader social knowledge base in evaluating priorities for coping with greater climate variability. 相似文献
959.
Highly erratic rainfall patterns in northern Benin complicate the ability of rural farmers to engage in subsistence agriculture. This research explores gender-specific responses to climate variability in the context of agrarian Benin through a household survey (n = 260) and an experimental gaming exercise among a subset of the survey respondents. Although men and women from the sample population are equally aware of climate variability and share similar coping strategies, their specific land-use strategies, preferences, and motivations are distinct. Over the long term, these differences would likely lead to dissimilar coping strategies and vulnerability to the effects of climate change. Examination of gender-specific land-use responses to climate change and anticipatory learning can enhance efforts to improve adaptability and resilience among rural subsistence farmers. 相似文献
960.