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   328篇
  免费   3篇
  国内免费   4篇
安全科学   12篇
废物处理   11篇
环保管理   56篇
综合类   82篇
基础理论   50篇
环境理论   1篇
污染及防治   102篇
评价与监测   6篇
社会与环境   15篇
  2022年   4篇
  2021年   13篇
  2020年   2篇
  2019年   4篇
  2018年   6篇
  2017年   7篇
  2016年   12篇
  2015年   7篇
  2014年   9篇
  2013年   35篇
  2012年   15篇
  2011年   17篇
  2010年   17篇
  2009年   5篇
  2008年   16篇
  2007年   11篇
  2006年   17篇
  2005年   10篇
  2004年   5篇
  2003年   9篇
  2002年   12篇
  2001年   5篇
  1998年   3篇
  1997年   5篇
  1995年   3篇
  1994年   3篇
  1993年   3篇
  1992年   3篇
  1991年   4篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1985年   3篇
  1983年   2篇
  1982年   3篇
  1981年   5篇
  1980年   4篇
  1978年   3篇
  1966年   2篇
  1964年   2篇
  1962年   4篇
  1961年   2篇
  1959年   2篇
  1958年   3篇
  1931年   2篇
  1924年   3篇
  1917年   1篇
  1916年   3篇
  1914年   1篇
  1913年   2篇
排序方式: 共有335条查询结果,搜索用时 0 毫秒
331.
332.
Abstract: For a number of years, best management practices (BMPs) have been implemented within the Town Brook watershed as part of a watershed wide effort to reduce phosphorus losses to the New York City water supply reservoirs. Currently, there are no quantitative indications of the effectiveness of these practices at the watershed scale. Additionally, work is needed to evaluate management practice solutions for costs in relation to effectiveness. In this study we develop a methodology for evaluating management solutions to determine the best way(s) to select and place management practices so that pollutant removal targets are met at minimum cost. The study combines phosphorus losses as simulated by the Soil and Water Assessment Tool (SWAT), management practice effectiveness estimates from a predeveloped characterization tool, and practice costs in optimizations using a genetic algorithm. For a user defined target phosphorus removal (60 percent for this study), optimization favors nutrient management plans, crop rotations, contour strip cropping, and riparian forest buffers; the most cost effective scenario achieves a cost effectiveness of 24/kg phosphorus removal per year compared to the 34/kg phosphorus removal per year associated with the current basic implementation scheme. The study suggests that there is a need to evaluate potential solutions prior to implementation and offers a means of generating and evaluating the solutions.  相似文献   
333.
<正>Pentachlorophenol(PCP)has been extensively used as a fungicide,bactericide,herbicide,molluscicide。algaecide and insecticide worldwide(Ahlborg and Thunberg,1980:Choudhury et al.,1986).Although PCP is primarily used as a preservative for wood and wood products,it has been also used in a variety of other products,including adhesives,construction materials,leather and paper.PCP is environmentally persistent with a half-life of up to 6-7 months in soil and water systems(Law  相似文献   
334.
Hepatitis A is the most common among all hepatitis worldwide in spite of an efficient vaccine and improved hygiene. Shellfish-borne outbreaks are still of major concern causing hundreds of cases and huge economical losses in the present context of global food trade. Hepatitis A virus (HAV) is a unique picornavirus with many differences in its molecular biology including both its incapacity to induce the inhibition of the cellular protein synthesis and a highly biased and deoptimized codon usage with respect the cell. The final goal of this intriguing strategy seems to be the need for a fine-tuning control of the translation kinetics, particularly at the capsid coding region, and the underlying mechanism is the use of a right combination of common and rare codons to allow a regulated ribosome traffic rate thus ensuring the proper protein folding. Capsid folding is critical to warrant a high environmental stability for a virus transmitted through the fecal–oral route with long extracorporeal periods.  相似文献   
335.
Environmental Fluid Mechanics - In this paper, we revisit a well-known formulation of temperature structure parameter ( $$C_T^2$$ ), originally proposed by V. I. Tatarskii. We point out its...  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