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   8288篇
  免费   29篇
  国内免费   59篇
安全科学   187篇
废物处理   431篇
环保管理   723篇
综合类   1209篇
基础理论   2421篇
环境理论   1篇
污染及防治   1914篇
评价与监测   582篇
社会与环境   881篇
灾害及防治   27篇
  2023年   42篇
  2022年   78篇
  2021年   66篇
  2020年   30篇
  2019年   44篇
  2018年   186篇
  2017年   206篇
  2016年   290篇
  2015年   121篇
  2014年   159篇
  2013年   440篇
  2012年   578篇
  2011年   449篇
  2010年   238篇
  2009年   248篇
  2008年   302篇
  2007年   313篇
  2006年   305篇
  2005年   593篇
  2004年   703篇
  2003年   613篇
  2002年   216篇
  2001年   291篇
  2000年   179篇
  1999年   130篇
  1998年   45篇
  1997年   67篇
  1996年   57篇
  1995年   70篇
  1994年   69篇
  1993年   61篇
  1992年   61篇
  1991年   68篇
  1990年   70篇
  1989年   56篇
  1988年   56篇
  1987年   54篇
  1986年   55篇
  1985年   41篇
  1984年   47篇
  1983年   47篇
  1982年   48篇
  1980年   30篇
  1979年   32篇
  1978年   29篇
  1977年   28篇
  1976年   28篇
  1974年   33篇
  1973年   31篇
  1972年   29篇
排序方式: 共有8376条查询结果,搜索用时 484 毫秒
771.
772.
773.
774.
775.
Seat belt use habit has been investigated according to the education level of drivers. Copies of a questionnaire were distributed to 1000 participants of four different education levels. Factors such as seat belt usage habit, restricting factors and crash data have been investigated. Data have been analyzed with SPSS 15.0 software. Increased level of education leads to increased seat belt usage, lower numbers of crashes and crash severities. The factors restricting seat belt use are lack of habit, discomfort and short distance driving. The use of precaution signal and increases in comfort can increase seat belt usage. The primary and high school education on traffic safety and seat belt usage has been serving the purpose.  相似文献   
776.
777.
778.
779.
Climate change alone may deeply impact air quality levels in the atmosphere because the changes in the meteorological conditions will induce changes on the transport, dispersion and transformation of air pollutants. The aim of this work was to evaluate the impact of climate change on the air quality over Europe and Portugal, using a reference year (year 1990) and a IPCC SRES A2 year (year 2100). The Hadley Centre global atmospheric circulation model (HadAM3P) was used to provide results for these two climatic scenarios, which were then used as synoptic forcing for the MM5-CHIMERE air quality modelling system. In order to assess the contribution of future climate change on O3 and PM concentrations, no changes in regional emissions were assumed and only climate change forcing was considered. The modelling results suggest that the O3 monthly mean levels in the atmosphere may increase almost 50 μg m?3 across Europe in July under the IPCC SRES A2 scenario. In Portugal, this increase may reach 20 μg m?3. The changes of PM10 monthly average values over Europe will depend on the region. The increase in PM10 concentrations during specific months could be explained by the average reduction of the boundary layer height and wind speed.  相似文献   
780.
Fire fighters are normally overprotected during their working hours because of the tendency to keep the personal protection level sufficiently high in case of the worst possible scenarios. This study investigated the effects of task-fitted protective clothing on thermal strain in fire fighters as compared to EN 469:2005 protective clothing during a prolonged (2 1/2 hrs) job-related rescue drill under neutral and hot climates. The subjects were 23 healthy, physically fit professional male fire fighters aged 26-44 years. Measurements included cardiovascular and thermal responses and subjective assessments. Wearing task-fitted clothing during rescue tasks in a neutral climate considerably reduced total thermal and cardiovascular strain in prolonged rescue work. The fire fighters also perceived physical work as significantly harder on average, and reported more intense subjective discomfort while wearing EN 469:2005 as compared to task-fitted clothing.  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