全文获取类型
收费全文 | 3560篇 |
免费 | 60篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 200篇 |
废物处理 | 120篇 |
环保管理 | 947篇 |
综合类 | 323篇 |
基础理论 | 864篇 |
环境理论 | 7篇 |
污染及防治 | 798篇 |
评价与监测 | 230篇 |
社会与环境 | 133篇 |
灾害及防治 | 31篇 |
出版年
2023年 | 14篇 |
2022年 | 21篇 |
2021年 | 28篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 44篇 |
2017年 | 66篇 |
2016年 | 83篇 |
2015年 | 73篇 |
2014年 | 75篇 |
2013年 | 446篇 |
2012年 | 135篇 |
2011年 | 176篇 |
2010年 | 122篇 |
2009年 | 135篇 |
2008年 | 161篇 |
2007年 | 202篇 |
2006年 | 136篇 |
2005年 | 118篇 |
2004年 | 125篇 |
2003年 | 128篇 |
2002年 | 108篇 |
2001年 | 64篇 |
2000年 | 78篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 44篇 |
1996年 | 59篇 |
1995年 | 57篇 |
1994年 | 64篇 |
1993年 | 52篇 |
1992年 | 46篇 |
1991年 | 39篇 |
1990年 | 38篇 |
1989年 | 31篇 |
1988年 | 40篇 |
1987年 | 30篇 |
1986年 | 34篇 |
1985年 | 33篇 |
1984年 | 30篇 |
1983年 | 37篇 |
1982年 | 48篇 |
1981年 | 47篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 25篇 |
1977年 | 29篇 |
1976年 | 13篇 |
1974年 | 10篇 |
1972年 | 11篇 |
排序方式: 共有3653条查询结果,搜索用时 15 毫秒
71.
Grace B. Villamor Robert Gilmore Pontius Jr. Meine van Noordwijk 《Regional Environmental Change》2014,14(2):825-834
This paper examines the size and intensity of changes among five land categories during the two time intervals in a region of Indonesia that is pioneering negotiations concerning reducing emissions from deforestation and forest degradation (REDD). Maps at 1973, 1993, and 2005 indicate that land-cover change is accelerating, while carbon loss is decelerating in Jambi Province, Sumatra. Land dynamics have shifted from Forest loss during 1973–1993 to Agroforest loss during 1993–2005. Forest losses account for most reductions in aboveground carbon during the both time intervals, but Agroforest plays an increasingly important role in carbon reductions during the more recent interval. These results provide motivation for future REDD policies to count carbon changes associated with all influential land categories, such as Agroforests. 相似文献
72.
Michael J. Manfredo Jeremy T. Bruskotter Tara L. Teel David Fulton Shalom H. Schwartz Robert Arlinghaus Shigehiro Oishi Ayse K. Uskul Kent Redford Shinobu Kitayama Leeann Sullivan 《Conservation biology》2017,31(4):772-780
The hope for creating widespread change in social values has endured among conservation professionals since early calls by Aldo Leopold for a “land ethic.” However, there has been little serious attention in conservation to the fields of investigation that address values, how they are formed, and how they change. We introduce a social–ecological systems conceptual approach in which values are seen not only as motivational goals people hold but also as ideas that are deeply embedded in society's material culture, collective behaviors, traditions, and institutions. Values define and bind groups, organizations, and societies; serve an adaptive role; and are typically stable across generations. When abrupt value changes occur, they are in response to substantial alterations in the social–ecological context. Such changes build on prior value structures and do not result in complete replacement. Given this understanding of values, we conclude that deliberate efforts to orchestrate value shifts for conservation are unlikely to be effective. Instead, there is an urgent need for research on values with a multilevel and dynamic view that can inform innovative conservation strategies for working within existing value structures. New directions facilitated by a systems approach will enhance understanding of the role values play in shaping conservation challenges and improve management of the human component of conservation. 相似文献
73.
Sánchez-Arcilla Agustín Sierra Joan Pau Brown Sally Casas-Prat Mercè Nicholls Robert James Lionello Piero Conte Dario 《Regional Environmental Change》2016,16(8):2471-2484
Regional Environmental Change - The potential impact of climate change on port operations and infrastructures has received much less attention than the corresponding impact for beach systems.... 相似文献
74.
Bolliger Janine Schmatz Dirk Pazúr Robert Ostapowicz Katarzyna Psomas Achilleas 《Regional Environmental Change》2017,17(8):2265-2277
Regional Environmental Change - Understanding drivers of forest-cover change is essential for a broad range of ecosystem properties. In this work, we assessed changes in forest cover using... 相似文献
75.
Lauren Patterson Jennifer Phelan Chris Goudreau Robert Dykes 《Journal of the American Water Resources Association》2017,53(1):56-66
The health of freshwater biota is dependent on streamflow, yet identification of the flow regimes required to maintain ecological integrity remains challenging to states in the United States seeking to establish ecological flows. We tested the relationship between decreases in streamflow and Shannon‐Weaver diversity index of fish species for four flow‐based habitat guilds: riffle, riffle‐run, pool‐run, and pool in North Carolina. We found species that prefer shallow habitats, such as riffles and riffle‐runs were the most sensitive to decreases in streamflow; whereas no significant relationships were found for pool or pool‐run species. The sensitivity to decreases in streamflow was greatest during summer and fall, when streams are naturally lower. When all fish habitat guilds were included in the assessment of flow‐biology relationships, there were no significant relationships to decreases in streamflow. As the sensitivity of fish to reductions in streamflow is not constant across habitat guilds, combining all fish species together for flow‐biology analyses may greatly underestimate the response of fish species to decreases in flow and should be acknowledged when establishing ecological flows. 相似文献
76.
de Grenade Rafael Rudow Joshua Taboada Hermoza Rossi Adauto Aguirre Maria Elena Scott Christopher A. Willems Bram Schultz Jennifer L. Varady Robert G. 《Regional Environmental Change》2017,17(3):789-802
Regional Environmental Change - Mountainous areas with extreme elevation gradients and corresponding ranges of biophysical and socioeconomic conditions are highly vulnerable to global change. We... 相似文献
77.
To analyze the factors affecting US public concern about the threat of climate change between January 2002 and December 2013, data from 74 separate surveys are used to construct quarterly measures of public concern over global climate change. Five factors should account for changes in levels of concern: extreme weather events, public access to accurate scientific information, media coverage, elite cues, and movement/countermovement advocacy. Structural equation modeling indicates that elite cues, movement advocacy efforts, weather, and structural economic factors influence the level of public concern about climate change. While media coverage exerts an important influence, it is itself largely a function of elite cues and economic factors. Promulgation to the public of scientific information on climate change has no effect. Information-based science advocacy has had only a minor effect on public concern, while political mobilization by elites and advocacy groups is critical in influencing climate change concern. 相似文献
78.
William S. Fisher Leska S. Fore Leah M. Oliver Charles Lobue Robert Quarles Jed Campbell Peggy Harris Becky Hemmer Sherry Vickery Mel Parsons Aaron Hutchins Kent Bernier Danny Rodriguez Patricia Bradley 《Environmental monitoring and assessment》2014,186(11):7165-7181
States may protect coral reefs using biological water quality standards outlined by the Clean Water Act. This requires biological assessments with indicators sensitive to human disturbance and regional, probability-based survey designs. Stony coral condition was characterized on a regional scale for the first time in the nearshore waters of the US Virgin Islands (USVI). Coral composition, abundance, size, and health were assessed at 66 stations in the St. Croix region in fall 2007 and at 63 stations in the St. Thomas and St. John region in winter 2009. Indicators were chosen for their sensitivity to human disturbance. Both surveys were probability-based (random) designs with station locations preselected from areas covered by hardbottom and coral reef substrate. Taxa richness was as high as 21 species but more than half the area of both regions exhibited taxa richness of <10 species in the 25 m2 transect area. Coral density was as high as 5 colonies m?2 but more than half the area of both regions had <2 colonies m?2. Both regions showed similar dominant species based on frequency of occurrence and relative abundance. Because of large colony sizes, Montastrea annularis provided more total surface area and live surface area than more abundant species. The surveys establish baseline regional conditions and provide a foundation for long-term regional monitoring envisioned by the USVI Department of Planning and Natural Resources. The probabilistic sampling design assures the data can be used in Clean Water Act reporting. 相似文献
79.
80.
Damon M. Hall Gerardo R. Camilo Rebecca K. Tonietto Jeff Ollerton Karin Ahrné Mike Arduser John S. Ascher Katherine C. R. Baldock Robert Fowler Gordon Frankie Dave Goulson Bengt Gunnarsson Mick E. Hanley Janet I. Jackson Gail Langellotto David Lowenstein Emily S. Minor Stacy M. Philpott Simon G. Potts Muzafar H. Sirohi Edward M. Spevak Graham N. Stone Caragh G. Threlfall 《Conservation biology》2017,31(1):24-29
Research on urban insect pollinators is changing views on the biological value and ecological importance of cities. The abundance and diversity of native bee species in urban landscapes that are absent in nearby rural lands evidence the biological value and ecological importance of cities and have implications for biodiversity conservation. Lagging behind this revised image of the city are urban conservation programs that historically have invested in education and outreach rather than programs designed to achieve high‐priority species conservation results. We synthesized research on urban bee species diversity and abundance to determine how urban conservation could be repositioned to better align with new views on the ecological importance of urban landscapes. Due to insect pollinators’ relatively small functional requirements—habitat range, life cycle, and nesting behavior—relative to larger mammals, we argue that pollinators put high‐priority and high‐impact urban conservation within reach. In a rapidly urbanizing world, transforming how environmental managers view the city can improve citizen engagement and contribute to the development of more sustainable urbanization. 相似文献