全文获取类型
收费全文 | 263篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 8篇 |
环保管理 | 6篇 |
综合类 | 96篇 |
基础理论 | 66篇 |
环境理论 | 1篇 |
污染及防治 | 57篇 |
评价与监测 | 17篇 |
社会与环境 | 5篇 |
出版年
2021年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2013年 | 11篇 |
2012年 | 14篇 |
2011年 | 7篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 15篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 14篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 10篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 6篇 |
1965年 | 4篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1962年 | 4篇 |
1961年 | 2篇 |
1960年 | 7篇 |
1959年 | 4篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1956年 | 1篇 |
1955年 | 5篇 |
1954年 | 1篇 |
1935年 | 1篇 |
1931年 | 1篇 |
1925年 | 1篇 |
排序方式: 共有266条查询结果,搜索用时 31 毫秒
1.
Mehaffey MH Nash MS Wade TG Ebert DW Jones KB Rager A 《Environmental monitoring and assessment》2005,107(1-3):29-44
The Catskill/Delaware reservoirs supply 90% of New York City’s drinking water. The City has implemented a series of watershed protection measures, including land acquisition, aimed at preserving water quality in the Catskill/Delaware watersheds. The objective of this study was to examine how relationships between landscape and surface water measurements change between years. Thirty-two drainage areas delineated from surface water sample points (total nitrogen, total phosphorus, and fecal coliform bacteria concentrations) were used in step-wise regression analyses to test landscape and surface-water quality relationships. Two measurements of land use, percent agriculture and percent urban development, were positively related to water quality and consistently present in all regression models. Together these two land uses explained 25 to 75% of the regression model variation. However, the contribution of agriculture to water quality condition showed a decreasing trend with time as overall agricultural land cover decreased. Results from this study demonstrate that relationships between land cover and surface water concentrations of total nitrogen, total phosphorus, and fecal coliform bacteria counts over a large area can be evaluated using a relatively simple geographic information system method. Land managers may find this method useful for targeting resources in relation to a particular water quality concern, focusing best management efforts, and maximizing benefits to water quality with minimal costs.The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to Agency’s administrative review and approved for publication as an EPA document. 相似文献
2.
Gary H. Heinz David S. Miller Brian J. Ebert Kenneth L. Stromborg 《Environmental monitoring and assessment》1994,33(3):175-182
From 1977–1978 to 1990, concentrations of polychlorinated biphenyls (PCBs) and most organochlorine pesticides declined in eggs of red-breasted mergansers (Mergus serrator) nesting on islands in northwestern Lake Michigan. Total PCBs decreased 60% (from 21 ppm in 1977–1978 to 8.5 ppm in 1990) and p,p-DDE decreased 66% (from 6.5 to 2.2 ppm). Dieldrin decreased only 16% (from 0.82 to 0.69 ppm). In 1990, 79.1% of incubated eggs hatched, which was not significantly different from the 83.5% that hatched in 1977–1978.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
3.
4.
5.
6.
7.
8.
9.
10.