全文获取类型
收费全文 | 377篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 12篇 |
环保管理 | 48篇 |
综合类 | 152篇 |
基础理论 | 56篇 |
污染及防治 | 78篇 |
评价与监测 | 15篇 |
社会与环境 | 10篇 |
灾害及防治 | 1篇 |
出版年
2020年 | 3篇 |
2018年 | 7篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2013年 | 41篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 23篇 |
2007年 | 15篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 11篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1995年 | 6篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1975年 | 6篇 |
1974年 | 3篇 |
1971年 | 3篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1965年 | 3篇 |
1964年 | 4篇 |
1963年 | 3篇 |
1962年 | 5篇 |
1959年 | 3篇 |
1957年 | 8篇 |
1956年 | 3篇 |
1940年 | 3篇 |
1939年 | 3篇 |
1937年 | 3篇 |
1935年 | 4篇 |
1934年 | 3篇 |
1932年 | 3篇 |
1925年 | 2篇 |
1921年 | 3篇 |
排序方式: 共有383条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
25.
26.
Roger H. Willsie Harry L. Ratt 《Journal of the American Water Resources Association》1974,10(2):360-371
ABSTRACT: The paper outlines both the methods used and the results obtained in a study of the demand for municipal and industrial water for the Seattle region. The study was made as part of a regional water management study program, one objective of which is to “… identify, quantify, and set priorities for all current and future water uses …”. A basic concept in the study of municipal and industrial water use is that the demand for water is derived from the demand for output and the direct services that water provides. Principal characteristics of the study are: (1) Water use is studied by type - residential, commercial, industrial and public -with identification of factors affecting each; (2) Water demands are studied by season as well as on an annual basis; (3) Projections of future water use are tied directly to projections of economic change in the service area; and (4) The effects of alternative policies on water use are estimated. Water use levels are projected under alternative regional growth assumptions provided by the Puget Sound Governmental Conference, a regional planning agency. Thus, the water use planning is consistent with other regional planning programs in this respect. The results can be varied according to changes in specific factors affecting water use. The factors considered in the present study include: single-family residential lot size, distribution of population between single- and multi-family units, per capita water use by multi-family unit residents, and industrial and commercial water use per employee. An income elasticity of demand was estimated for single-family residential water use. 相似文献
27.
28.
Handling intensity and the short- and long-term survival of elephant seals: addressing and quantifying research effects on wild animals 总被引:3,自引:0,他引:3
This study addresses the consequences of repeated human handling on the survival of an endangered phocid, the southern elephant seal and the implications for wildlife research. Southern elephant seal pups were repeatedly handled during the first six weeks of their lives. The possibility that such anthropogenic research may have altered the very parameters that were being investigated is a topical and relevant study area that we address here. Our results show that there were no measurable effects on pups that were repeatedly handled and subjected to invasive research methods with respect to survivorship in the short term (the 24-day nursing period) nor in the long term (the first year of life and beyond) and hence fitness one year after handling. In support of this conclusion we were unable to detect any significant differences in the survival rates of the most intensively handled seals and the least intensively handled seals. 相似文献
29.
30.