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   17651篇
  免费   758篇
  国内免费   8篇
  2020年   189篇
  2019年   203篇
  2018年   303篇
  2017年   277篇
  2016年   307篇
  2015年   236篇
  2014年   316篇
  2013年   1296篇
  2012年   543篇
  2011年   523篇
  2010年   353篇
  2009年   340篇
  2008年   468篇
  2007年   490篇
  2006年   437篇
  2005年   430篇
  2004年   382篇
  2003年   326篇
  2002年   366篇
  2001年   700篇
  2000年   697篇
  1999年   492篇
  1998年   209篇
  1997年   196篇
  1996年   189篇
  1995年   167篇
  1992年   397篇
  1991年   364篇
  1990年   378篇
  1989年   324篇
  1988年   314篇
  1987年   305篇
  1986年   278篇
  1985年   294篇
  1984年   274篇
  1983年   223篇
  1982年   182篇
  1981年   175篇
  1979年   246篇
  1978年   223篇
  1977年   189篇
  1975年   234篇
  1974年   267篇
  1973年   262篇
  1972年   201篇
  1971年   195篇
  1969年   191篇
  1968年   223篇
  1967年   205篇
  1966年   173篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
241.
Flicker fusion frequencies of 48 healthy controls and of 35 alcoholics were measured to detect possible associations between flicker fusion and signs of nonspecific brain damage, the aim of the study. FFF was statistically significantly lower in patients addicted to alcohol than in healthy subjects. Lower flicker fusion frequencies were associated with the severeness of organic psychosis as rated psychopathologically. The hypothesis that addiction to alcohol is a sign of diffuse, nonspecific, organic brain damage was discussed.  相似文献   
242.
243.
244.
16 learning-disabled second- and third-grade students were matched on previous years' achievement scores and grade and assigned at random to experimental and control conditions. Students in the experimental condition were given 8 20-min. sessions of training in test-taking skills particular to the Stanford Achievement Test. Analysis of test scores indicated trained students scored significantly higher on one subtest of a shortened version of the test than students who had not been trained.  相似文献   
245.
A national survey of behavior modification procedures used by school psychologists is reported. Usable questionnaires were received from 148 (49%) of 300 randomly selected members of the 1982 National Association of School Psychologists directory. Each respondent was asked to indicate the type of exposure, use, and inclusion of data collection procedures for each of 18 commonly used behavioral techniques. Conditional probabilities between type of exposure and use found strong relationships between supervision and subsequent use. The implications for the field of school psychology and future directions for training programs are discussed.  相似文献   
246.
We present four cases of Prader-Willi syndrome. Two of them have an abnormality of a chromosome 15, the other both show different chromosomal abnormalities. Translocations or deletions were found recently in the bands 15q11/12 in about 60% of the cases of Prader-Willi syndrome. The consequences for diagnosis, symptomatology and genetic counselling of the syndrome are discussed.  相似文献   
247.
Rats were used to determine whether stress-induced analgesia (SIA) can be produced by conditioning with interoceptive stimuli (LiCl) as with exteroceptive stimuli (footshock). SIA was measured using a tail-flick test. As expected, unavoidable footshock as well as conditioning with footshock produced SIA. In contrast, conditioning with LiCl failed to cause SIA. The findings support the notion of functional differences in neural substrates for conditioning by exteroceptive and interoceptive cue.  相似文献   
248.
For four of six autistic children who underwent intensive behavioral treatment, the nature of their self-stimulatory behavior changed from initial lowlevel motor behaviors (such as rocking, spinning, twirling) to differing kinds of higher-level behaviors (such as lining of objects, echolalic speech, and preoccupation with spelling and numerical values). The children who changed to the highest levels of self-stimulatory behavior also showed the largest gains in treatment (as determined by IQ scores, school placement, etc.). The changes in self-stimulatory behaviors were attributed to the intense teaching of appropriate social behaviors and the explicit therapeutic suppression of low-level, self-stimulatory behaviors. The long-term therapeutic effects of changing from lower-to higher-level forms of self-stimulatory behavior were discussed.This study was supported by a grant from the National Institute of Mental Health (grant MH 11440). We want to express our thanks to the parents who allowed us to study their children. We gratefully acknowledge the assistance of Maria Audero with the design of the weighted measure, and Tracee Parker with the collection of the data.  相似文献   
249.
Observers detected a briefly flashed target letter embedded in word, pronounceable nonword, and unpronounceable nonword contexts. The word context facilitated perception under both holistic and analytical processing strategies; the facilitative effect was enhanced when processing was analytical.  相似文献   
250.
Based upon perceptual studies, the present hypothesis was that different ranges of spatial-frequency information constitute different sources of information for recognition memory. In Experiment 1, 40 subjects were tested with sets of focused and unfocused pictures as inspection and test stimuli. In addition to reporting whether each test picture was believed to be a member of the inspection set or a novel picture, each subject was allowed to adjust the contrast of the stimulus until such a judgment could be made. In Experiment 2, subjects made similar judgments when inspection or test stimuli were flickered (perceptually enhancing low spatial frequencies) or unflickered. Results from both studies were consistent with the experimental hypothesis. Other studies were reviewed, which, together with the present data, lend converging evidence to the spatial-frequency hypothesis.  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