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   33703篇
  免费   1223篇
  国内免费   16篇
  2018年   519篇
  2017年   523篇
  2016年   567篇
  2015年   405篇
  2014年   485篇
  2013年   2662篇
  2012年   896篇
  2011年   963篇
  2010年   640篇
  2009年   644篇
  2008年   933篇
  2007年   901篇
  2006年   842篇
  2005年   760篇
  2004年   729篇
  2003年   786篇
  2002年   759篇
  2001年   786篇
  2000年   778篇
  1999年   656篇
  1998年   397篇
  1997年   396篇
  1996年   395篇
  1995年   383篇
  1992年   602篇
  1991年   586篇
  1990年   552篇
  1989年   520篇
  1988年   540篇
  1987年   521篇
  1986年   550篇
  1985年   536篇
  1984年   500篇
  1983年   459篇
  1982年   373篇
  1981年   389篇
  1979年   525篇
  1978年   455篇
  1977年   397篇
  1976年   421篇
  1975年   442篇
  1974年   530篇
  1973年   559篇
  1972年   417篇
  1971年   426篇
  1970年   391篇
  1969年   408篇
  1968年   488篇
  1967年   453篇
  1966年   448篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
821.
822.
823.
824.
825.
826.
Certain investigators have found that recognition is impaired when a recall test is interpolated during the retention interval. One possible explanation of this finding is that interpolated recall leads subjects to employ a more stringent recognition criterion. In the two experiments reported here, the influence of the recognition criterion was eliminated by using a multiple-response test requiring subjects to rank a recognition list consisting of old and new items. Nevertheless recall impaired subsequent recognition in both experiments, the effect being most marked for lowly ranked items. The recognition test in the first experiment was carried out in two stages. This made possible a direct examination of whether recall has an effect on the recognition criterion. No evidence for such an effect was obtained. Other ways in which recall may affect the recognition criterion are discussed.  相似文献   
827.
This note describes a way of modifying a tape recorder for producing accurately controllable delays for experiments with delayed auditory feedback. Any value of delay from 80 millisec. to 1.2 sec. can be obtained to the nearest millisec., and the range could be extended by some minor changes. The delay is continuously monitored on a digital electronic timer.  相似文献   
828.
The data used in this study were made available through the Center for Interest Measurement Research and the Student Counseling Bureau, University of Minnesota. Computer analysis was provided by the Numerical Analysis Center, University of Minnesota. While attempting to increase the number of A and B+ scores on the women's SVIB by varying the composition of the criterion group on marital status, it was found that the desired effect was achieved by using a different item selection and weighting system from Strong's original one and not by varying the marital status of the criterion group. The experimental scoring keys developed in the study also acted selectively on original scores of B and B—, raising or lowering them, and generally reducing their number. These findings went beyond the original hypotheses and intent of the study and suggested an explanation for the apparent heterogeneity of women's interests and the resulting difficulty in measuring them.  相似文献   
829.
Judgments were made of the size of a small, luminous (inner) square appearing in the center of a somewhat larger, variable (outer) square, the whole pattern appearing in the dark. Accuracy of judgment was greatest when the outer square was constant from trial to trial but deteriorated when the outer square also varied in size, reaching a lower limit less than the accuracy produced under the absolute judgment condition (no outer square presented). An application of multiple discriminant analysis and the use of a maximum likelihood observer model provided estimates of the extent to which Os responded to inner and outer size variation as separate aspects of stimulation. Although Os differed markedly in this respect, their ability to identify inner square size under the various conditions did not reflect this difference.  相似文献   
830.
The effects of chronic hypothalamic lesions and various drugs on the viscero-visceral reflexes of cats have been investigated, utilizing measurement of the bioelectrical activity of the cerebral cortex. After coagulation of the posterolateral hypothalamus the heart rate decreased by 40–60 beats per minute, but eventually it regained its initial value. The viscero-visceral reflexes from the gallbladder to the heart were preserved after the operative procedure. Chlorpromazine and atropine blocked both arousal and the cardiorespiratory response to stimulation of the gallbladder. Similar effects were produced by novocaine and pantocaine.  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