首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   856篇
  免费   3篇
  国内免费   3篇
安全科学   16篇
废物处理   16篇
环保管理   133篇
综合类   268篇
基础理论   149篇
污染及防治   201篇
评价与监测   47篇
社会与环境   25篇
灾害及防治   7篇
  2020年   7篇
  2018年   16篇
  2017年   10篇
  2016年   16篇
  2015年   13篇
  2014年   20篇
  2013年   68篇
  2012年   23篇
  2011年   31篇
  2010年   23篇
  2009年   22篇
  2008年   33篇
  2007年   35篇
  2006年   19篇
  2005年   21篇
  2004年   35篇
  2003年   19篇
  2002年   24篇
  2001年   12篇
  2000年   13篇
  1999年   18篇
  1998年   8篇
  1997年   12篇
  1996年   17篇
  1995年   13篇
  1994年   25篇
  1993年   7篇
  1991年   7篇
  1990年   8篇
  1988年   6篇
  1983年   6篇
  1982年   6篇
  1981年   8篇
  1980年   9篇
  1979年   7篇
  1978年   7篇
  1977年   7篇
  1968年   6篇
  1965年   6篇
  1964年   9篇
  1963年   6篇
  1962年   6篇
  1961年   6篇
  1960年   8篇
  1959年   11篇
  1957年   7篇
  1956年   11篇
  1954年   9篇
  1939年   6篇
  1924年   6篇
排序方式: 共有862条查询结果,搜索用时 0 毫秒
271.
272.
273.
The environmental radioactivity surveillance program of the Federal Republic of Germany is briefly described. Some results of intercomparative measurements carried out by the Federal Milk Research Institute are presented.  相似文献   
274.
275.
Land use changes which affect the hydrological cycle encompass a broad field of agricultural, forestry, and engineering activity. A variety of research methods, ranging from the very simple to the very complex, have been used in attempting to evaluate the effects of such changes. Because of the complexity of the hydrological process, it is difficult to distinguish the effects of changes in land use from natural variations in quality, quantity, peak rates, and other characteristics of runoff. The use of plots, experimental catchments, barometer watersheds, representative basins, benchmark and vigil networks, and other methods for the collection of data, and methods of data analysis ranging from simple graphical correlations to multivariate analysis and mathematical catchment models are reviewed and classified. Current methods of research are mainly of an ad hoc nature and the major deficiency is in the study of fundamental physical processes.  相似文献   
276.
277.
This paper seeks to verify the usefulness of selected multivariate statistical techniques for exploring new dose-response relationships between human health and air pollution. We do so by comparing our results with those already established in the literature through hypothesis testing procedures or laboratory work. This use of multivariate techniques is pretheoretical and should be interpreted as suggesting relationships which warrant further investigation with more traditional methodologies. Our results conform very well with those existing in the literature and lend credence to the use of such pretheoretical statistical methods.  相似文献   
278.
279.
ABSTRACT: Levee sump systems are used by many riverine communities for temporary storage of urban wet weather flows. The hydrologic performance and transport of stormwater pollutants in sump systems, however, have not been systematically studied. The objective of this paper is to present a case study to demonstrate development and application of a procedure for assessing the hydraulic performance of flood control sumps in an urban watershed. Two sumps of highly variable physical and hydraulic characteristics were selected for analysis. A hydrologic modeling package was used to estimate the flow hydrograph for each outfall as part of the flow balance for the sump. To validate these results, a water balance was used to estimate the total runoff using sump operational data. The hydrologic model calculations provide a satisfactory estimate of the total runoff and its time‐distribution to the sump. The model was then used to estimate pollutant loads to the sump and to the river. Although flow of stormwater through a sump system is regulated solely by flood‐control requirements, these sumps may function as sedimentation basins that provide purification of stormwater. A sample calculation of removals of several conventional pollutants in the target sumps using a mass balance approach is presented.  相似文献   
280.
A pilot project in Tijuana brings together government, industry, and the community to identify and solve environmental problems. © 2001 John Wiley & Sons, Inc.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号