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   50727篇
  免费   651篇
  国内免费   977篇
安全科学   1632篇
废物处理   2257篇
环保管理   6641篇
综合类   8602篇
基础理论   13103篇
环境理论   28篇
污染及防治   12979篇
评价与监测   3350篇
社会与环境   3423篇
灾害及防治   340篇
  2023年   242篇
  2022年   534篇
  2021年   537篇
  2020年   438篇
  2019年   464篇
  2018年   810篇
  2017年   836篇
  2016年   1215篇
  2015年   940篇
  2014年   1426篇
  2013年   4149篇
  2012年   1772篇
  2011年   2417篇
  2010年   1935篇
  2009年   2029篇
  2008年   2385篇
  2007年   2436篇
  2006年   2085篇
  2005年   1764篇
  2004年   1699篇
  2003年   1726篇
  2002年   1560篇
  2001年   1920篇
  2000年   1416篇
  1999年   856篇
  1998年   585篇
  1997年   612篇
  1996年   605篇
  1995年   723篇
  1994年   669篇
  1993年   581篇
  1992年   575篇
  1991年   579篇
  1990年   607篇
  1989年   535篇
  1988年   466篇
  1987年   450篇
  1986年   409篇
  1985年   432篇
  1984年   489篇
  1983年   432篇
  1982年   441篇
  1981年   410篇
  1980年   335篇
  1979年   376篇
  1978年   286篇
  1977年   249篇
  1975年   247篇
  1974年   245篇
  1972年   262篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
1.
Environment, Development and Sustainability - The current study explores the role of green trust, green perceived risk and green perceived quality in changing green purchase intention....  相似文献   
2.
Russian Journal of Ecology - A study of the anthropogenic impacts on the on-shore aggregation of true seals was carried out at a haul-out located at the mouth of Piltun Bay (the northeastern part...  相似文献   
3.
Environmental Science and Pollution Research - Heavy metals are well known for their toxicity and become significant environmental pollution with a continually rising technology and public outcry...  相似文献   
4.
Environmental Science and Pollution Research - A current environmental problem is the uncontrolled use of various pesticides that are harmful to the environment and public health. The herbicide...  相似文献   
5.
Russian Journal of Ecology - Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study,...  相似文献   
6.
针对2018年3月9—15日京津冀地区的一次空气重污染过程,进行了基于地基颗粒物激光雷达组网的星载-地基联合观测分析。颗粒物激光雷达观测到污染前期为局地污染累积过程,中期有明显的污染物区域传输过程,北京受太行山沿线城市污染输送影响较大。风廓线激光雷达观测结果表明:此次污染过程近地面主要为偏南风且风力较弱,冷空气到来时风向转为较强东北风,导致污染消散。微波辐射计观测到保定在污染过程中出现持续6 d的逆温层,同时在污染过程中近地面相对湿度较高,逆温层被打破后污染开始消散。在污染过程的各个阶段中,污染团的空间分布与变化特征均被很好地反映出来,可见地天联合观测对污染物的累积与输送研究有较大的意义,能对京津冀及周边地区的大气污染联防联控提供有力支持。  相似文献   
7.
Journal of Material Cycles and Waste Management - Power generation from municipal solid waste plays significant role to mitigate the environmental pollution. The power generation potential of...  相似文献   
8.
The current study is interested in evaluating the decay of cotton, Whatman and chemical pulp caused by Trichoderma harzianum and Paecilomyces variotii. The structural changes of the paper were evaluated by Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). The SEM results show differences in hyphae colonization and paper decay patterns between studied species under the current study; P. variotii caused an eroded structure in the cotton (cavity forming), whereas the initial T. harzianum colonization produced rupture and erosion (soft-rot decay type II) for the three types of paper ,the gaps were elongated with sharp pointed ends, which consisted either of individual cavities or in chains. Moreover, FTIR results confirmed that there a relationship could be observed between fungal decay and crystalline cellulose content because the intensity of peaks at 1335 and 1111 cm?1 significantly decreased due to the fungal decay. Furthermore, the intensity of O–H stretching absorption slightly decreased, and this may be attributed to hydrolysis of cellulose molecules.  相似文献   
9.
Objective: There have been substantial reductions in motor vehicle crash–related child fatalities due to advances in legislation, public safety campaigns, and engineering. Less is known about non-traffic injuries and fatalities to children in and around motor vehicles. The objective of this study was to describe the frequency of various non-traffic incidents, injuries, and fatalities to children using a unique surveillance system and database.

Methods: Instances of non-traffic injuries and fatalities in the United States to children 0–14 years were tracked from January 1990 to December 2014 using a compilation of sources including media reports, individual accounts from families of affected children, medical examiner reports, police reports, child death review teams, coroner reports, medical professionals, legal professionals, and other various modes of publication.

Results: Over the 25-year period, there were at least 11,759 events resulting in 3,396 deaths. The median age of the affected child was 3.7 years. The incident types included 3,115 children unattended in hot vehicles resulting in 729 deaths, 2,251 backovers resulting in 1,232 deaths, 1,439 frontovers resulting in 692 deaths, 777 vehicles knocked into motion resulting in 227 deaths, 415 underage drivers resulting in 203 deaths, 172 power window incidents resulting in 61 deaths, 134 falls resulting in 54 deaths, 79 fires resulting in 41 deaths, and 3,377 other incidents resulting in 157 deaths.

Conclusions: Non-traffic injuries and fatalities present an important threat to the safety and lives of very young children. Future efforts should consider complementary surveillance mechanisms to systematically and comprehensively capture all non-traffic incidents. Continued education, engineering modifications, advocacy, and legislation can help continue to prevent these incidents and must be incorporated in overall child vehicle safety initiatives.  相似文献   

10.
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