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   30883篇
  免费   750篇
  国内免费   11篇
  31644篇
  2020年   204篇
  2019年   210篇
  2018年   1733篇
  2017年   1617篇
  2016年   1262篇
  2015年   259篇
  2014年   304篇
  2013年   1643篇
  2012年   842篇
  2011年   1681篇
  2010年   1468篇
  2009年   959篇
  2008年   1303篇
  2007年   1568篇
  2006年   501篇
  2005年   535篇
  2004年   499篇
  2003年   434篇
  2002年   477篇
  2001年   737篇
  2000年   764篇
  1999年   555篇
  1998年   258篇
  1997年   218篇
  1992年   448篇
  1991年   406篇
  1990年   445篇
  1989年   414篇
  1988年   396篇
  1987年   399篇
  1986年   404篇
  1985年   421篇
  1984年   333篇
  1983年   299篇
  1982年   237篇
  1981年   212篇
  1979年   386篇
  1978年   278篇
  1977年   251篇
  1976年   223篇
  1975年   341篇
  1974年   372篇
  1973年   351篇
  1972年   328篇
  1971年   287篇
  1970年   260篇
  1969年   321篇
  1968年   358篇
  1967年   321篇
  1966年   325篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
The testing of Convulsofin carried out in 220 patients at 14 clinics over a period of six months confirms the international experience gained with valproic acid and sodium valproinate. The main field of application of Convulsofin according to the experience gained will again be the treatment of fits in generalised primary epilepsy for which it permits to carry out a monotherapy to a remarkable extent. The favourable effect of the preparation in photosensitivity could be confirmed. Also in generalised secondary epilepsy and in fits of partial epilepsy. Convulsofin is partly effective, so that it can recommended as a co-medication in the treatment of therapy-resistant forms of these epilepsies which are difficult to treat. Decrease in thrombocytes, transient increase in serum transaminases, gastrointestinal disorders, loss of hair and undesired increases in body-weight were the more frequently occurring side-effects.  相似文献   
992.
A simple stochastic model is formulated in order to determine the optimal time between the first test and the second test when the test-retest method of assessing reliability is used. A forgetting process and a change in true score process are postulated. The optimal time between tests is derived by maximizing the probability that the respondent has not remembered the response on the first test and has not had a change in true score. The resulting test-retest correlation is then found to be a linear function of the true reliability of the test, where the slope of this function is the key probability of not remembering and having no change in true score. Some numerical examples and suggestions for using the results in empirical studies are given. Specific recommendations are presented for improved design and analysis of intentions data.This research was made possible by a grant from the Center for Food Policy Research, Graduate School of Business, Columbia University, New York, New York, 10027.  相似文献   
993.
The family and the child with epilepsy   总被引:7,自引:0,他引:7  
Reports documenting psychosocial epiphenomena of chronic illness in individuals with that illness have been common in recent years. Few studies, however, have been concerned with how illness might affect the family. Those that have appeared in the literature often lack critical controls (i.e., control groups) and often fail to investigate possible links between illness-specific variables (i.e. chronicity, inhibition of mobility) and psychosocial outcomes on the family. The present study of 45 families focused on how children with epilepsy affect their families' functioning relative to families with a child with diabetes and families with no chronically ill members. The results suggest several areas of child and family adjustment (i.e. child self-concept, family communication, family cohesion) in which the families of epileptic children have great difficulty. Implications of these results are discussed with regard to differential influences of various chronic illnesses on families and family-based preventive and remedial treatment programs.  相似文献   
994.
995.
996.
A coaching strategy to decrease errors in swimming strokes with swimmers who had not improved under "standard" coaching procedures was investigated using a multiple baseline design across subjects and swimming strokes. The procedure resulted in a large decrease in errors on swimming strokes during sessions in a training pool. Stimulus generalization of improved performance to normal practice conditions in the regular pool was observed with all but one swimmer. This improvement was maintained during two maintenance phases lasting approximately 2 weeks, as well as under standard coaching conditions during at least a 2-week follow-up. For two swimmers, error rates on one of the strokes showed a gradual increase between the third and fifth week of follow-up, but brief remedial prompting sessions immediately corrected their performance. Some beneficial response generalization to other components of the stroke being trained was observed, but no improvements were found on untrained strokes. The error correction package did not disrupt practice, require excessive amounts of the coach's time, or necessitate the use of cumbersome apparatus. In addition, the coach and the swimmers considered the procedures to be effective, and expressed their willingness to participate in them again in the future.  相似文献   
997.
998.
999.
Further to the debate between Kearins (1978) and Drinkwater (1978), visual memory skills of Aboriginal and white Australian children were examined using Drinkwater's version of Kim's game with desert Aboriginal and rural white children. Older children remembered more than younger ones, and Aboriginal children recalled more natural objects than white children. There was no difference between the groups in recall of manufactured objects, nor between recall of manufactured and natural objects within each group. Aboriginal children remembered significantly more objects overall than white children when the task was first administered. On a second occasion, after a procedure designed to orient children towards the use of predominantly visual rather than verbal memorising strategies, there was no significant difference between the groups.  相似文献   
1000.
Stimulus generalization is suggested as an alternative method for examination of the "novelty" problem in motor learning. These experiments demonstrated that stimulus generalization occurs using simple movements as stimuli. The phenomenon of the "peak shift" in post-discrimination generalization gradients was also examined. The first experiment demonstrated that a peak shift occurred using linear movements as stimuli and that the magnitude of the peak shift increased as the difference between the training stimuli decreased. The second experiment showed similar results when the stimuli consisted of a range of movements rather than single movement length. The final experiment provided evidence that perception of movement length is influenced by the magnitude of an immediately preceding movement. The relevance of these studies to current motor-learning theory is discussed.  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