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   20849篇
  免费   236篇
  国内免费   121篇
安全科学   524篇
废物处理   895篇
环保管理   2778篇
综合类   3435篇
基础理论   5868篇
环境理论   12篇
污染及防治   5393篇
评价与监测   1296篇
社会与环境   873篇
灾害及防治   132篇
  2021年   143篇
  2019年   128篇
  2018年   237篇
  2017年   263篇
  2016年   416篇
  2015年   318篇
  2014年   481篇
  2013年   1620篇
  2012年   591篇
  2011年   846篇
  2010年   679篇
  2009年   669篇
  2008年   847篇
  2007年   876篇
  2006年   774篇
  2005年   672篇
  2004年   651篇
  2003年   633篇
  2002年   616篇
  2001年   765篇
  2000年   576篇
  1999年   328篇
  1998年   261篇
  1997年   279篇
  1996年   281篇
  1995年   332篇
  1994年   306篇
  1993年   288篇
  1992年   278篇
  1991年   278篇
  1990年   295篇
  1989年   278篇
  1988年   249篇
  1987年   240篇
  1986年   222篇
  1985年   201篇
  1984年   256篇
  1983年   211篇
  1982年   272篇
  1981年   221篇
  1980年   184篇
  1979年   202篇
  1978年   184篇
  1977年   154篇
  1976年   138篇
  1975年   143篇
  1974年   160篇
  1973年   163篇
  1972年   148篇
  1971年   147篇
排序方式: 共有10000条查询结果,搜索用时 757 毫秒
471.
472.
Results of a recent intercomparison on the determination of trace elements in simulated air filter samples are reported. A large scatter of results is obtained for some elements and systematic differences between laboratories are observed. The performance of different methods, in particular neutron activation analysis and atomic absorption spectrophotometry, used by the various laboratories is discussed (air filter analysis; intercomparison; trace elements; control charts).  相似文献   
473.
474.
475.
476.
Dimock  R. V.  Groves  K. H. 《Marine Biology》1975,33(4):301-308
Marine Biology - The combined effects of temperature and salinity on the rate of oxygen consuption by the estuarine crab Panopeus herbstii Milne-Edwards (Crustacea: Decapoda: Xanthidae) were...  相似文献   
477.
478.
Oil/Suspended Particulate Material Interactions and Sedimentation   总被引:1,自引:0,他引:1  
The interactions of physically dispersed oil droplets with suspended particulate material (SPM) can be important for the transport of bulk quantities of spilled crude oil and polycyclic aromatic hydrocarbons (PAH) to subtidal sediments. The literature regarding oil/SPM interactions is reviewed, and results from whole-oil droplet/SPM interaction kinetics and pure-component (Prudhoe Bay crude oil distillate cut) equilibrium partitioning experiments are presented. The effects of oil type, SPM characteristics, and salinity on the interaction rates are examined, and the importance of whole-oil droplet/SPM interactions on particle agglomeration and settling behavior are discussed. Whole-oil droplet/SPM interactions are retarded as oil droplet dispersion into the water column is inhibited by oil viscosity increases due to evaporation weathering and water-in-oil emulsification. Compared to whole oil droplet/SPM interactions, dissolved-component/SPM adsorption is not as significant for transport of individual components to sediments. The information presented in this paper can be used to augment computer-based models designed to predict oil-spill trajectories, oil-weathering behavior, and spilled oil impacts to the marine environment.  相似文献   
479.
Enhanced bioremediation is quickly developing into an economical and viable technology for the remediation of contaminated soils. Until recently, chlorinated organic compounds have proven difficult to bioremediate. Environmentally recalcitrant compounds, such as polychlorinated biphenyls (PCBs) and persistent organic pesticides (POPs) such as dichlorodiphenyl trichloroethane (DDT) have shown to be especially arduous to bioremediate. Recent advances in field‐scale bioremedial applications have indicated that biodegradation of these compounds may be possible. Engineers and scientists at the Savannah River Site (SRS), a major DOE installation near Aiken, South Carolina, are using enhanced bioremediation to remediate soils contaminated with pesticides (DDT and its metabolites, heptachlor epoxide, dieldrin, and endrin) and PCBs. This article reviews the ongoing remediation occurring at the Chemicals, Metals, and Pesticides (CMP) Pits using windrow turners to facilitate microbial degradation of certain pesticides and PCBs. © 2003 Wiley Periodicals, Inc.  相似文献   
480.
In the UK for the period 1994-99, a broad range of environmental projects were given financial support through the European Agriculture Guidance and Guarantee Fund under the Objective 1 and Objective 5b programmes. This paper is concerned with the ex-post evaluation of these projects set within a Sustainable Development framework. The aim was to identify project types or characteristics that offered the greatest return on investment. A classification of six broad project types was adopted. The evaluation revealed that there were significant differences between individual projects with respect to the type and scale, and temporal and social distribution of the benefits they delivered. In particular, as well as delivering environmental and economic benefits, many projects made a significant contribution to the development of human and social capital. The paper concludes that it is possible to improve the basis for future project selection in order to maximise the returns on environmental investments in the context of sustainable development.  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