全文获取类型
收费全文 | 1562篇 |
免费 | 145篇 |
国内免费 | 316篇 |
专业分类
安全科学 | 130篇 |
废物处理 | 12篇 |
环保管理 | 259篇 |
综合类 | 934篇 |
基础理论 | 250篇 |
环境理论 | 1篇 |
污染及防治 | 82篇 |
评价与监测 | 91篇 |
社会与环境 | 158篇 |
灾害及防治 | 106篇 |
出版年
2024年 | 6篇 |
2023年 | 31篇 |
2022年 | 57篇 |
2021年 | 58篇 |
2020年 | 47篇 |
2019年 | 53篇 |
2018年 | 49篇 |
2017年 | 68篇 |
2016年 | 78篇 |
2015年 | 86篇 |
2014年 | 63篇 |
2013年 | 107篇 |
2012年 | 130篇 |
2011年 | 139篇 |
2010年 | 100篇 |
2009年 | 78篇 |
2008年 | 71篇 |
2007年 | 86篇 |
2006年 | 106篇 |
2005年 | 81篇 |
2004年 | 67篇 |
2003年 | 75篇 |
2002年 | 48篇 |
2001年 | 35篇 |
2000年 | 51篇 |
1999年 | 44篇 |
1998年 | 29篇 |
1997年 | 34篇 |
1996年 | 34篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 14篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有2023条查询结果,搜索用时 15 毫秒
891.
892.
Gisela García-Morales Renato Arturo Mendoza-Salgado Jaqueline García-Hernández Pedro Rosales-Grano Alfredo Ortega-Rubio 《Journal of Environmental Planning and Management》2018,61(1):161-175
Recreational beaches are strategic ecosystems for tourism and should be used in a sustainable manner. We studied three beaches in the municipality of Guaymas (NW Mexico), in order to assess their beach quality and identify key management issues. The evaluation was based on the perceptions of users concerning: (1) the user profile; (2) the recreational habits of users; and (3) the biophysical characteristics, infrastructure, services, and cleanliness of each beach. The results showed that the beaches were of different quality. The key management issues identified were the need to design and apply specific management programs for each beach, specifically in regards to improving infrastructure and services, and obtaining certification as a sustainable beach. The evaluation of the beaches as perceived by users suggests that it would be useful to assess beach quality in order to support management goals and be applicable to other beaches, both nationally and internationally. 相似文献
893.
Lauric Thiault Matthew I. Curnock Georgina G. Gurney Scott F. Heron Nadine A. Marshall Erin Bohensky Nao Nakamura Petina L. Pert Joachim Claudet 《Conservation biology》2021,35(2):598-609
Managing human use of ecosystems in an era of rapid environmental change requires an understanding of diverse stakeholders’ behaviors and perceptions to enable effective prioritization of actions to mitigate multiple threats. Specifically, research examining how threat perceptions are shared or diverge among stakeholder groups and how these can evolve through time is increasingly important. We investigated environmental threat perceptions related to Australia's Great Barrier Reef and explored their associations before and after consecutive years of mass coral bleaching. We used data from surveys of commercial fishers, tourism operators, and coastal residents (n = 5254) conducted in 2013 and 2017. Threats perceived as most serious differed substantially among groups before bleaching but were strongly aligned after bleaching. Climate change became the most frequently reported threat by all stakeholder groups following the coral bleaching events, and perceptions of fishing and poor water quality as threats also ranked high. Within each of the 3 stakeholder groups, fishers, tourism operators, and coastal residents, the prioritization of these 3 threats tended to diverge in 2013, but convergence occurred after bleaching. These results indicate an emergence of areas of agreement both within and across stakeholder groups. Changes in perceptions were likely influenced by high-profile environmental-disturbance events and media representations of threats. Our results provide insights into the plasticity of environmental-threat perceptions and highlight how their convergence in response to major events may create new opportunities for strategic public engagement and increasing support for management. 相似文献
894.
Every year, millions of migratory shorebirds fly through the East Asian–Australasian Flyway between their arctic breeding grounds and Australasia. This flyway includes numerous coastal wetlands in Asia and the Pacific that are used as stopover sites where birds rest and feed. Loss of a few important stopover sites through sea‐level rise (SLR) could cause sudden population declines. We formulated and solved mathematically the problem of how to identify the most important stopover sites to minimize losses of bird populations across flyways by conserving land that facilitates upshore shifts of tidal flats in response to SLR. To guide conservation investment that minimizes losses of migratory bird populations during migration, we developed a spatially explicit flyway model coupled with a maximum flow algorithm. Migratory routes of 10 shorebird taxa were modeled in a graph theoretic framework by representing clusters of important wetlands as nodes and the number of birds flying between 2 nodes as edges. We also evaluated several resource allocation algorithms that required only partial information on flyway connectivity (node strategy, based on the impacts of SLR at nodes; habitat strategy, based on habitat change at sites; population strategy, based on population change at sites; and random investment). The resource allocation algorithms based on flyway information performed on average 15% better than simpler allocations based on patterns of habitat loss or local bird counts. The Yellow Sea region stood out as the most important priority for effective conservation of migratory shorebirds, but investment in this area alone will not ensure the persistence of species across the flyway. The spatial distribution of conservation investments differed enormously according to the severity of SLR and whether information about flyway connectivity was used to guide the prioritizations. With the rapid ongoing loss of coastal wetlands globally, our method provides insight into efficient conservation planning for migratory species. Gestión Óptima de una Ruta Migratoria de Múltiples Especies de Aves Costeras Sometida a Incremento del Nivel del Mar 相似文献
895.
896.
Coastal zone management is inconceivable without the mobilization and integration of different types of knowledge – that is, without knowledge co-production practices. This article applies the concept of knowledge co-production to analyze the process of emergence, standardization, and enculturation of environmental management systems (EMSs) within port communities in the Dutch Wadden Sea. Moreover, it is a report from the field in which we reflect on the participatory practices conducted to facilitate the knowledge arrangements required to develop EMSs for a group of ports. The article concludes that this type of knowledge arrangement and co-production practices (involving different types of actors and knowledge) might become mandatory in the near future to stabilize the EMS phenomenon in the practices of ports. 相似文献
897.
The 11 th Five Year Plan has divided national functional zones in the basic unit of county-level administrative region. Af- ter implementation of national Major Function-oriented Zones (MFOZ) at prefec... 相似文献
898.
三峡库区(重庆段)涨落带土地资源的开发利用模式初探 总被引:17,自引:0,他引:17
三峡水库是我国特大型水利枢纽工程,到2009年水库全部建成运行后将出现一个落差达30m的涨落带。涨落带土地肥沃,出露水面的时间长,光、热、水、土条件匹配好,有较大的开发价值。对涨落带进行保护性的开发利用,将缓解库区的人地矛盾、促进库区小康进程与可持续发展。论文以三峡库区的主体--重庆段为例,论述了三峡重庆库区涨落带土地资源的分布、特征及开发价值;阐明了涨落带土地资源开发利用应注意的5个原则问题;结合库区气候、地貌及水位变动等条件,初步探讨了涨落带土地资源开发利用的6种模式;对开发利用中可能存在的生态与环境问题进行了分析,提出了有针对性的建议;为合理制定涨落带的土地资源利用与保护规划提供科学依据。 相似文献
899.
江苏王港海岸湿地的围垦现状及湿地资源可持续利用 总被引:8,自引:0,他引:8
海岸湿地是全球生物生产量最高的生态系统之一,具有极高的资源开发价值和环境调节功能。王港地区是江苏沿海盐沼湿地发育的典型地区之一,随着盐沼湿地围垦的进行,湿地面积减少,环境退化。为了实现盐沼湿地资源的可持续利用,必须改变盐沼湿地开发利用的方式,发展科学的、有利于生态环境健康发展的产业,如开辟科研基地保护区、发展花卉、草坪业、滩涂生态旅游业、建立盐沼林牧复合生态系统、实行盐沼湿地的综合管理等,同时,还要严格执行相关的法律法规。 相似文献
900.
An analysis of tritium and 36Cl data collected at Yucca Mountain, Nevada suggests that fracture flow may occur at high velocities through the thick unsaturated zone. The mechanisms and extent of this “fast flow” in fractures at Yucca Mountain are investigated with data analysis, mixing models and several one-dimensional modeling scenarios. The model results and data analysis provide evidence substantiating the weeps model [Gauthier, J.H., Wilson, M.L., Lauffer, F.C., 1992. Proceedings of the Third Annual International High-level Radioactive Waste Management Conference, vol. 1, Las Vegas, NV. American Nuclear Society, La Grange Park, IL, pp. 891–989] and suggest that fast flow in fractures with minimal fracture–matrix interaction may comprise a substantial proportion of the total infiltration through Yucca Mountain. Mixing calculations suggest that bomb-pulse tritium measurements, in general, represent the tail end of travel times for thermonuclear-test-era (bomb-pulse) infiltration. The data analysis shows that bomb-pulse tritium and 36Cl measurements are correlated with discrete features such as horizontal fractures and areas where lateral flow may occur. The results presented here imply that fast flow in fractures may be ubiquitous at Yucca Mountain, occurring when transient infiltration (storms) generates flow in the connected fracture network. 相似文献