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   193篇
  免费   5篇
安全科学   15篇
废物处理   8篇
环保管理   20篇
综合类   37篇
基础理论   38篇
污染及防治   45篇
评价与监测   15篇
社会与环境   20篇
  2023年   1篇
  2021年   3篇
  2020年   2篇
  2019年   3篇
  2018年   10篇
  2017年   1篇
  2016年   11篇
  2015年   3篇
  2014年   6篇
  2013年   5篇
  2012年   14篇
  2011年   13篇
  2010年   13篇
  2009年   8篇
  2008年   13篇
  2007年   10篇
  2006年   8篇
  2005年   9篇
  2004年   14篇
  2003年   9篇
  2002年   5篇
  2001年   2篇
  2000年   4篇
  1999年   1篇
  1998年   2篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   4篇
  1992年   3篇
  1991年   4篇
  1990年   2篇
  1987年   1篇
  1985年   2篇
  1981年   1篇
  1978年   1篇
  1973年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有198条查询结果,搜索用时 31 毫秒
121.
122.
This paper reviews empirical evidence on psychological detachment from work during nonwork time. Psychological detachment as a core recovery experience refers to refraining from job‐related activities and thoughts during nonwork time; it implies to mentally disengage from one's job while being away from work. Using the stressor‐detachment model as an organizing framework, we describe findings from between‐person and within‐person studies, relying on cross‐sectional, longitudinal, and daily‐diary designs. Overall, research shows that job stressors, particularly workload, predict low levels of psychological detachment. A lack of detachment in turn predicts high strain levels and poor individual well‐being (e.g., burnout and lower life satisfaction). Psychological detachment seems to be both a mediator and a moderator in the relationship between job stressors on the one hand and strain and poor well‐being on the other hand. We propose possible extensions of the stressor‐detachment model by suggesting moderator variables grounded in the transactional stress model. We further discuss avenues for future research and offer practical implications. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
123.
124.
Does nitrogen deposition increase forest production? The role of phosphorus   总被引:2,自引:0,他引:2  
Effects of elevated N deposition on forest aboveground biomass were evaluated using long-term data from N addition experiments and from forest observation plots in Switzerland. N addition experiments with saplings were established both on calcareous and on acidic soils, in 3 plots with Fagus sylvatica and in 4 plots with Picea abies. The treatments were conducted during 15 years and consisted of additions of dry NH4NO3 at rates of 0, 10, 20, 40, 80, and 160 kg N ha−1 yr−1. The same tree species were observed in permanent forest observation plots covering the time span between 1984 and 2007, at modeled N deposition rates of 12-46 kg N ha−1 yr−1. Experimental N addition resulted in either no change or in a decreased shoot growth and in a reduced phosphorus concentration in the foliage in all experimental plots. In the forest, a decrease of foliar P concentration was observed between 1984 and 2007, resulting in insufficient concentrations in 71% and 67% of the Fagus and Picea plots, respectively, and in an increasing N:P ratio in Fagus. Stem increment decreased during the observation period even if corrected for age. Forest observations suggest an increasing P limitation in Swiss forests especially in Fagus which is accompanied by a growth decrease whereas the N addition experiments support the hypothesis that elevated N deposition is an important cause for this development.  相似文献   
125.
126.
Stickler syndrome or hereditary progressive arthro-ophthalmopathy, is an autosomal dominant condition characterized by ocular manifestations, arthritic changes, orofacial features and deafness, in variable degrees. We report the first case of prenatal diagnosis of Stickler syndrome in a child with a Pierre–Robin sequence (PRS) causing a polyhydramnios. When isolated polyhydramnios is not explained by immunological, metabolic or infectious causes, swallowing difficulty due to PRS must be considered. As PRS is aetiologically heterogenous, the prognosis depends on the cause. Genetic investigations and familial history must be taken into account. Here, in a context of familial Stickler syndrome, making the prenatal diagnosis of PRS as part of Stickler syndrome allowed us to reassure the parents and to anticipate airway trouble at the child's birth. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
127.
128.
On the basis of the embryo transfer new and developing biotechnologies including cryopreservation of embryos, sex predetermination and sex diagnosis (sexing), in vitro fertilization, cloning and production of chimaeras and of transgenic animals are discussed.  相似文献   
129.
130.
Data in the literature suggest that confined placental mosaicism might be associated with intrauterine growth retardation. However, this association may be coincidental and due to bias of ascertainment. We therefore started a prospective study based on the cytogenetic evaluation of placentae derived from growth-retarded newborns. We further minimized possible bias by excluding those small-for-date infants displaying findings which already could explain intrauterine growth retardation (mothers who are smokers, multiple pregnancies, gestosis, dysmorphic infants). In a collection of 71 small-for-gestational age newborns, we did not see a single case of true confined placental mosaicism.  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