全文获取类型
收费全文 | 3846篇 |
免费 | 311篇 |
国内免费 | 192篇 |
专业分类
安全科学 | 486篇 |
废物处理 | 68篇 |
环保管理 | 1093篇 |
综合类 | 1952篇 |
基础理论 | 210篇 |
环境理论 | 2篇 |
污染及防治 | 131篇 |
评价与监测 | 142篇 |
社会与环境 | 193篇 |
灾害及防治 | 72篇 |
出版年
2024年 | 6篇 |
2023年 | 27篇 |
2022年 | 49篇 |
2021年 | 91篇 |
2020年 | 133篇 |
2019年 | 83篇 |
2018年 | 63篇 |
2017年 | 95篇 |
2016年 | 102篇 |
2015年 | 140篇 |
2014年 | 194篇 |
2013年 | 181篇 |
2012年 | 222篇 |
2011年 | 295篇 |
2010年 | 214篇 |
2009年 | 194篇 |
2008年 | 150篇 |
2007年 | 233篇 |
2006年 | 269篇 |
2005年 | 198篇 |
2004年 | 194篇 |
2003年 | 178篇 |
2002年 | 159篇 |
2001年 | 172篇 |
2000年 | 170篇 |
1999年 | 110篇 |
1998年 | 84篇 |
1997年 | 81篇 |
1996年 | 52篇 |
1995年 | 55篇 |
1994年 | 28篇 |
1993年 | 44篇 |
1992年 | 18篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 1篇 |
排序方式: 共有4349条查询结果,搜索用时 375 毫秒
21.
Osowski SL Swick JD Carney GR Pena HB Danielson JE Parrish DA 《Environmental monitoring and assessment》2001,66(2):159-185
Swine Concentrated Animal Feeding Operations (CAFOs) have received much attention in recent years. As a result, a watershed-based screening tool, the Cumulative Risk Index Analysis (CRIA), was developed to assess the cumulative impacts of multiple CAFO facilities in a watershedsubunit. The CRIA formula calculates an index number based on: 1) the area of one or more facilities compared to the area of the watershed subunit, 2) the average of the environmental vulnerability criteria, and 3) the average of the industry-specific impact criteria. Each vulnerability or impact criterion is ranked on a 1 to 5 scale, with a low rank indicating low environmental vulnerability or impact and a high rank indicating high environmental vulnerability or impact. The individual criterion ranks, as well as the total CRIA score, can be used to focus the environmental analysis and facilitate discussions with industry, public, and other stakeholders in the Agency decision-making process. 相似文献
22.
Diazinon contamination of California's rivers has resulted in placing several rivers on the federal Clean Water Act § 303d list of impaired waterways. Impaired water body listing requiresthe development of Total Maximum Daily Loads (TMDL). Previous studies identified stormwater related diazinon pulses in California rivers. This study was conducted to monitor diazinonconcentrations in the Sacramento River watershed after rainfallevents, to ascertain whether pulses could be identified and, ifconcentrations of concern were observed, to estimate loadings anddetermine geographic origins of the insecticide. TMDL developmentrequires knowledge of contaminant sources, loadings, and geographic origins. Flow and diazinon concentrations peaked in the Sacramento River at Sacramento after the three largest stormsduring January and February 1994. Diazinon concentrations peakedconsequent to each of three storms. Diazinon concentrationsmeasured in the Sacramento River at Sacramento exceeded theCalifornia Department of Fish and Game acute and chroniccriteria for protection of aquatic life during January andFebruary for nine and nineteen days, respectively. Multipleexceedances were observed throughout the watershed. Diazinon loading and geographic origin differed with each of the three storms. The design of this study provides a useful template for others attempting to identify loadings and sources of contaminants in surface waters and to rectify aquatic ecosystemcontamination from various land use practices. 相似文献
23.
滨州沿海湿地生物多样性保护探讨 总被引:1,自引:0,他引:1
重点研究了该区域海洋生物多样性、淡水生物多样性、陆生和海岛等高等植物多样性、陆栖动物多样性与特点。分析了其破坏现状及原因,提出了生物多样性保护对策和可持续利用途径。 相似文献
24.
25.
26.
环境保护的两种重要手段-政府决策与公众参与 总被引:1,自引:0,他引:1
综述了目前我国环境保护的两种重要手段-政府决策和公众参与的现状及必要性,将政府决策与公众参与结合起来,以推动我国环保事业的进一步发展. 相似文献
27.
西藏公路建设过程中的生态保护 总被引:1,自引:1,他引:1
针对西藏独特的高原生态环境特征,分析了公路建设的生态影响,提出了不同生态系统类型的生态恢复和保护措施。 相似文献
28.
29.
寓资源环境保护于发展之中 总被引:5,自引:0,他引:5
本文从四个方面阐述了中国的环境与发展问题。要改善中国目前生态状况的关键在于树立生态道德观念,扭转贫困地区的面貌,寓资源环境保护于发展之中。 相似文献
30.
Ma Shijun 《环境科学学报(英文版)》1990,2(2):57-62
This paper concisely introduced the eco-environmental survey in China and the Chinese scientific programme for environmental research which is being practiced or being planned. China has established a nation-wide system relating to environmental scientific research and environmental administration and has taken the following strategies for solving the environment problems: (1) a series of laws and regulations for environmental protection has been promulgated so as to strengthen the legal administration and economic punishment. (2) the idea of ecological construction has been proposed for the purpose of taking the environmental protection work into the consideration of the national and provincial (or regional) economic construction planning. (3) spreading ecological engineering and ecological technologies have reduced the pollutant sources and have increased the industrial and agricultural economic profit. 相似文献