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   548篇
  免费   3篇
  国内免费   1篇
安全科学   32篇
废物处理   35篇
环保管理   40篇
综合类   67篇
基础理论   108篇
污染及防治   201篇
评价与监测   42篇
社会与环境   25篇
灾害及防治   2篇
  2023年   7篇
  2021年   10篇
  2020年   12篇
  2019年   5篇
  2018年   12篇
  2017年   21篇
  2016年   28篇
  2015年   12篇
  2014年   14篇
  2013年   45篇
  2012年   20篇
  2011年   37篇
  2010年   19篇
  2009年   18篇
  2008年   35篇
  2007年   35篇
  2006年   18篇
  2005年   37篇
  2004年   21篇
  2003年   28篇
  2002年   20篇
  2001年   14篇
  2000年   4篇
  1999年   7篇
  1998年   5篇
  1996年   5篇
  1995年   3篇
  1994年   4篇
  1993年   5篇
  1992年   3篇
  1991年   3篇
  1989年   3篇
  1988年   6篇
  1987年   1篇
  1985年   4篇
  1984年   4篇
  1983年   1篇
  1982年   3篇
  1981年   2篇
  1980年   1篇
  1979年   5篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1963年   1篇
  1939年   1篇
  1938年   1篇
  1935年   1篇
  1934年   2篇
  1931年   1篇
排序方式: 共有552条查询结果,搜索用时 337 毫秒
551.
Almås AR  Lombnaes P  Sogn TA  Mulder J 《Chemosphere》2006,62(10):1647-1655
A pot experiment was carried out to investigate the impact of Cd and Zn extractability in soil and speciation in pore water of industrial contaminated soils, on metal concentration in a metal sensitive species like spinach (Spinacia oleracea) and a more metal tolerant species like Italian ryegrass (Lolium multiflorum). For chemical speciation of Cd and Zn in pore water, WHAM/Model VI version 6.0 was used. The DGT technique was used to determine the effective concentration, C(E), of Cd and Zn in soils. The free ion activity in pore water correlated well with the contents in plants, and there was a linear relationship between the C(E) values and the concentration of Cd and Zn in both spinach and ryegrass in the non-toxic range. However, the C(E) values usually overestimated the plant contents when plants, particularly the spinach plants, were subjected to toxic concentration in the pore water. Metal uptake decreased in plants affected by toxicity, whereas metal binding to the Chelex resin did not. Thus, we found no linear relationship between the C(E) and metal contents in spinach, whereas a linear relationship was found between C(E)-Zn and the Zn concentration in ryegrass (r2=0.96, p<0.001). For Cd in ryegrass this relationship was weak (r2=0.53, p=0.18). This study indicates that the transport of metals from labile metal pools to the DGT-resin is linearly related to plant uptake only when plants are growing well, and that the applicability of DGT as an indicator for plant uptake seems species dependent.  相似文献   
552.
Speed choice versus celeration behavior as traffic accident predictor   总被引:1,自引:0,他引:1  
INTRODUCTION: The driver celeration behavior theory predicts that this variable is superior to all other variables as a predictor of individual traffic accident involvement, including the ever-important speed parameter. The study was undertaken to test this prediction. Also, it was expected that most variables would associate fairly strongly. METHOD: The use of speed choice as a predictor of individual traffic accident record was discussed, and four different variants of this variable (maximum, net mean, gross mean, and standard deviation of speed) identified. These variables were then compared to celeration behavior as predictors of accident record of bus drivers in the same set of data. RESULTS: Celeration behavior was found to be slightly superior, in accordance with the prediction made from the driver celeration behavior theory, although the differences were not significant. Furthermore, the predictor variables were found to associate fairly strongly between themselves, with the exception of gross mean speed, and to have fair stability over time, especially when aggregated. CONCLUSIONS: These results tentatively confirm some of the predictions made from the driver celeration behavior theory. As the results for accidents were in the expected direction, but not significant, and the maximum speed variable may have suffered from a ceiling effect, the conclusion is provisional. Impact on industry: The correlations found were strong enough to warrant the use of celeration behavior as a predictive variable for transportation companies in their safety work.  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