全文获取类型
收费全文 | 2230篇 |
免费 | 174篇 |
国内免费 | 61篇 |
专业分类
安全科学 | 126篇 |
废物处理 | 17篇 |
环保管理 | 1048篇 |
综合类 | 580篇 |
基础理论 | 367篇 |
环境理论 | 2篇 |
污染及防治 | 44篇 |
评价与监测 | 57篇 |
社会与环境 | 132篇 |
灾害及防治 | 92篇 |
出版年
2023年 | 18篇 |
2022年 | 39篇 |
2021年 | 48篇 |
2020年 | 51篇 |
2019年 | 49篇 |
2018年 | 59篇 |
2017年 | 84篇 |
2016年 | 93篇 |
2015年 | 93篇 |
2014年 | 78篇 |
2013年 | 120篇 |
2012年 | 79篇 |
2011年 | 130篇 |
2010年 | 90篇 |
2009年 | 106篇 |
2008年 | 97篇 |
2007年 | 114篇 |
2006年 | 108篇 |
2005年 | 82篇 |
2004年 | 70篇 |
2003年 | 77篇 |
2002年 | 52篇 |
2001年 | 57篇 |
2000年 | 53篇 |
1999年 | 68篇 |
1998年 | 42篇 |
1997年 | 38篇 |
1996年 | 42篇 |
1995年 | 40篇 |
1994年 | 27篇 |
1993年 | 17篇 |
1992年 | 23篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 22篇 |
1986年 | 22篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 20篇 |
1977年 | 14篇 |
1975年 | 11篇 |
1973年 | 16篇 |
1972年 | 14篇 |
1971年 | 16篇 |
排序方式: 共有2465条查询结果,搜索用时 528 毫秒
971.
972.
王卫国 《防灾科技学院学报》2011,13(4):73-76
应急避难场所是通过规划和建设从而具有应急避难生活服务设施、可供居民紧急疏散和能够临时生活的场所。应急避难场所的规划建设是城市防灾规划的重要内容,在应对地震等突发灾害事件中能起到关键作用,是城市公共安全的一项重要内容。本文结合唐山市应急避难场所规划建设工作,阐述了城市应急避难场所规划建设在城市防灾中的必要性。论述了应急避难场所的规划建设、管理与使用的原则。本文可为其他城市应急避难场所的规划建设提供参考。 相似文献
973.
区域环境风险评价相比单个项目的评价具有信息相对缺乏、风险因素多,风险叠加难度大等特点.信息扩散法可有效应对评价信息不足问题,通过构建和运行风险信息矩阵实现对多个环境风险源的风险值叠加,并最终形成风险分区图以指导区域布局优化和风险管理.本研究结合广州南沙地区发展规划,应用信息扩散法对区域现有及规划风险源进行综合评估,并得出区域综合环境风险4级分区.评价结果显示,规划的石化基地布局不合理,将大幅增加区域环境风险等级,提出放弃该产业规划或重新选址,该建议得到最终决策的支持.建议区域开发在规划的初始阶段就考虑开展环境风险评价,以此论证区域功能划分和产业布局的环境合理性,实现优化区域开发和加强区域环境风险防控的目的. 相似文献
974.
苏州河的功能定位与综合整治目标 总被引:3,自引:2,他引:3
苏州河水“变情”,是上海人民长期以来的一个美好愿望。根据市委、市府确定的苏州河环境综合整治目标,该文论述了苏州河环境综合整治总体规划方案的基本思想,提出苏州河的功能定位要从实际出发,并全面考虑迈向21世纪的上海城市发展需要,使苏州河综合整治成为上海环境建设的标志性工程。 相似文献
975.
以某大型工业开发区为研究对象,在生态调查的基础上建立三级生态适宜度评价指标体系,采用多因子组合对土地利用进行评价,并借助地理信息系统技术将评价结果和图形叠置,实现了工业开发区土地利用生态适宜度评价的定量化,为工业开发区的环境保护规划和环境影响评价提供决策依据。 相似文献
976.
977.
“三水”统筹视角下京津冀地区城市水生态环境保护策略分析 总被引:1,自引:0,他引:1
明确京津冀地区水生态环境保护方向与策略,对于实现京津冀水生态环境保护和高质量协同发展,以及2035年美丽中国建设目标具有重大意义.在水资源、水环境、水生态的“三水”统筹视角下,面向京津冀地区水生态环境管理问题和需求,以重点城市作为基本分析单元,从“三水”以及社会经济发展水平、污染物排放量和环境治理力度这6个维度研究构建水生态环境保护策略分析体系,为量化水生态环境保护水平提供逻辑框架.在设立理想值的基础上应用PROMETHEE-GAIA方法分析京津冀各城市水生态环境现状与理想值之间的差距,因地制宜制定各个城市水生态环境保护策略.结果显示水生态环境保护综合水平从高到低依次为:北京市>天津市>秦皇岛市>衡水市>张家口市>廊坊市>净流(Phi)均值>邯郸市>承德市>沧州市>保定市>唐山市>石家庄市>邢台市,各城市水生态环境保护水平距离理想值仍有不小的差距;分别从单维度和单指标层次分析得到各城市水生态环境保护的优势和劣势,在此基础上,提出京津冀区域城市未来水生态环境保护策略,助力京津冀地区水生态环境保护. 相似文献
978.
Spatial,socio‐economic,and ecological implications of incorporating minimum size constraints in marine protected area network design
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kristian Metcalfe Gregory Vaughan Sandrine Vaz Robert J. Smith 《Conservation biology》2015,29(6):1615-1625
Marine protected areas (MPAs) are the cornerstone of most marine conservation strategies, but the effectiveness of each one partly depends on its size and distance to other MPAs in a network. Despite this, current recommendations on ideal MPA size and spacing vary widely, and data are lacking on how these constraints might influence the overall spatial characteristics, socio‐economic impacts, and connectivity of the resultant MPA networks. To address this problem, we tested the impact of applying different MPA size constraints in English waters. We used the Marxan spatial prioritization software to identify a network of MPAs that met conservation feature targets, whilst minimizing impacts on fisheries; modified the Marxan outputs with the MinPatch software to ensure each MPA met a minimum size; and used existing data on the dispersal distances of a range of species found in English waters to investigate the likely impacts of such spatial constraints on the region's biodiversity. Increasing MPA size had little effect on total network area or the location of priority areas, but as MPA size increased, fishing opportunity cost to stakeholders increased. In addition, as MPA size increased, the number of closely connected sets of MPAs in networks and the average distance between neighboring MPAs decreased, which consequently increased the proportion of the planning region that was isolated from all MPAs. These results suggest networks containing large MPAs would be more viable for the majority of the region's species that have small dispersal distances, but dispersal between MPA sets and spill‐over of individuals into unprotected areas would be reduced. These findings highlight the importance of testing the impact of applying different MPA size constraints because there are clear trade‐offs that result from the interaction of size, number, and distribution of MPAs in a network. 相似文献
979.
Samuel Veloz Leonardo Salas Bob Altman John Alexander Dennis Jongsomjit Nathan Elliott Grant Ballard 《Conservation biology》2015,29(4):1217-1227
Systematic conservation planning aims to design networks of protected areas that meet conservation goals across large landscapes. The optimal design of these conservation networks is most frequently based on the modeled habitat suitability or probability of occurrence of species, despite evidence that model predictions may not be highly correlated with species density. We hypothesized that conservation networks designed using species density distributions more efficiently conserve populations of all species considered than networks designed using probability of occurrence models. To test this hypothesis, we used the Zonation conservation prioritization algorithm to evaluate conservation network designs based on probability of occurrence versus density models for 26 land bird species in the U.S. Pacific Northwest. We assessed the efficacy of each conservation network based on predicted species densities and predicted species diversity. High‐density model Zonation rankings protected more individuals per species when networks protected the highest priority 10‐40% of the landscape. Compared with density‐based models, the occurrence‐based models protected more individuals in the lowest 50% priority areas of the landscape. The 2 approaches conserved species diversity in similar ways: predicted diversity was higher in higher priority locations in both conservation networks. We conclude that both density and probability of occurrence models can be useful for setting conservation priorities but that density‐based models are best suited for identifying the highest priority areas. Developing methods to aggregate species count data from unrelated monitoring efforts and making these data widely available through ecoinformatics portals such as the Avian Knowledge Network will enable species count data to be more widely incorporated into systematic conservation planning efforts. 相似文献
980.
Just sustainabilities has emerged as a powerful discourse to guide local action towards sustainability. As an overarching discourse, it prescribes four policy principles: (1) addressing well-being and quality of life; (2) meeting the needs of present and future generations; (3) enabling justice and equity in terms of recognition, process, procedure, and outcome; and (4) living within ecosystem limits. Following previous calls for engaging public and private actors in just sustainabilities, this paper inquiries about the extent to which these principles can be realistically integrated in local environmental governance. A database of 400 sustainability initiatives in more than 200 cities in all world regions is analysed to examine whether just sustainabilities principles are already enshrined, explicitly or implicitly, in local sustainability initiatives. This analysis suggests that, in this sample, there is a significant deficit in terms of addressing the principles of justice and equity, and ecosystem limits. However, the data also suggest that local action may already be delivering some aspects of just sustainabilities, even if this is not always explicit. The paper concludes with a call for a coordinated effort to translate a just sustainabilities discourse to local actors leading action on the ground. 相似文献