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   16754篇
  免费   1343篇
  国内免费   959篇
  2023年   203篇
  2022年   181篇
  2021年   265篇
  2020年   491篇
  2019年   574篇
  2018年   538篇
  2017年   647篇
  2016年   653篇
  2015年   414篇
  2014年   521篇
  2013年   1744篇
  2012年   346篇
  2011年   434篇
  2010年   363篇
  2009年   557篇
  2008年   733篇
  2007年   781篇
  2006年   737篇
  2005年   628篇
  2004年   541篇
  2003年   445篇
  2002年   421篇
  2001年   259篇
  2000年   246篇
  1999年   212篇
  1998年   171篇
  1997年   142篇
  1996年   118篇
  1995年   107篇
  1994年   98篇
  1993年   81篇
  1992年   61篇
  1991年   45篇
  1990年   48篇
  1989年   26篇
  1988年   39篇
  1987年   26篇
  1985年   394篇
  1984年   445篇
  1983年   377篇
  1982年   474篇
  1981年   468篇
  1980年   470篇
  1979年   421篇
  1978年   481篇
  1977年   372篇
  1976年   373篇
  1975年   291篇
  1974年   297篇
  1973年   254篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
In the present study, the discourse interaction between adult and child was examined in terms of the content of their utterances, and the linguistic and contextual relations between their messages, in order to investigate how children use the information from adults' input sentences to form contingent responses. The analyses described were based on longitudinal data from four children from approximately 21 to 36 months of age. Categories of child discourse, their development and their interactions with aspects of prior adult utterances form the major results of the study. Child utterances were identified as adjacent (immediately preceded by an adult utterance), or as nonadjacent (not immediately preceded by an adult utterance). Adjacent utterances were either contingent (shared the same topic and added new information relative to the topic of the prior utterance), imitative (shared the same topic but did not add new information), or noncontingent (did not share the same topic). From the beginning, the adjacent speech was greater than nonadjacent speech. Contingent speech increased over time; in particular, linguistically contingent speech (speech that expanded the verb relation of the prior adult utterance with added or replaced constituents within a clause) showed the greatest developmental increase. Linguistically contingent speech occurred more often after questions than nonquestions. The results are discussed in terms of how the differential requirements for processing information in antecedent messages is related to language learning.  相似文献   
952.
The relationship between career maturity and self-concepts of 252 sixth-grade black males was investigated. Student samples of suburban and urban middle- and urban lower-class were drawn from 42 different school settings located in Monroe, Erie, and Westchester Counties of New York State. The Attitude Scale of the Career Maturity Inventory and the Coopersmith Self-Esteem Inventory were used to assess the association of career maturity and self-concepts. Results indicated relatively weak-positive relationships between career maturity and self-concepts. Significant career maturity differences were found. However, self-concepts of the three groups were not statistically significantly different. Of the set of independent variables predicting and estimating variance accounted for (socioeconomic status, family intactness, place of residence, and reading), socioeconomic status was found to have the strongest predictive value on career maturity. It was suggested that researchers examine elementary school black students' career development in view of the group with whom they identify most.  相似文献   
953.
Ordered recall of auditory digits was obtained from children of 4, 7, 9, and 11 years of age. Lists had one of three types of sound pattern: melody, prosody, or monotone. For each sound pattern condition, half the lists were temporally grouped. Effects of sound pattern were minor, and not obviously age-specific. Profound effects of temporal grouping and clear-cut primacy effects appeared for all age groups and all conditions. These results render less plausible the popular hypothesis that the increase of memory span with age is due to the emergence of active strategies. It is suggested that the development of span may be due to an increase in the ease with which children can identify the individual items and encode information about their order.  相似文献   
954.
Crane and Ross reported that second graders learned more than sixth graders about attributes made relevant after solution of a discrimination task. Here two experiments are reported that enlighten the sources of this developmental difference. Both make use of an experimental technique whereby children verbalize their hypotheses during solution of a discrimination problem. The results indicate that ten-year-olds do not learn about incidental attributes that they tested while irrelevant in the pre-solution period, but that five-year-olds and seven-year-olds do. Children of all three ages process incidental information about attributes that they did not sample pre-solution. With some qualification, the incidentally processed information is retained throughout a five-minute delay interval. The results bear on developmental trends in the distribution of attention and on theoretical accounts of incidental learning in discrimination tasks.  相似文献   
955.
956.
The proposition that impulsive children inhibit expressive behavior less than reflective children was investigated by providing third grade impulsive and reflective boys with either differential or nondifferential forms or successive discrimination training prior to tests for stimulus generalization. Consistent with specific predictions derived from Spence's theory on the roles of excitation and inhibition, it was found that: (a) Reflectives acquired the discrimination more rapidly, (b) reflectives achieved a higher level of discriminative performance, (c) impulsives exhibited more variable response reates during the nonreinforced stimulus, and (d) the type of training interacted with the child's conceptual tempo to determine the elevation and shape of the post-discrimination generalization gradients. The results provide support for the construct validity of the Matching Familiar Figures Test of reflectivity-impulsivity.  相似文献   
957.
Retardate use of retention strategies and the independence of color and form retention were compared with predictions of the Attention-Retention theory of retardate discrimination learning. Lists of two-choice discrimination problems were increased in length from one to capacity, which was defined through criterion retention across a 20-sec interval. It was demonstrated that (a) capacity and rate of adjustment of retentional strategy were directly related to intelligence, (b) at capacity limits the retention of problems in one dimension interfered with retention in a second dimension, and (c) results consistent with a capacity allocation strategy were obtained. The results were interpreted as reflecting short-term memory capacity constraints on the use of rehearsal.  相似文献   
958.
Human infants' discrimination of changes in internal and external elements of compound visual patterns was investigated in four experiments employing a familiarization-novelty paradigm in which visual reinforcing patterns were presented contingent upon rate of high-amplitude nonnutritive sucking. In Experiment 1, 4-month infants discriminated changes in the shape of internal, external and both internal and external figures. One-month infants discriminated external changes in both internal and external figures, but failed to show reliable response recovery when only internal figures were changed. Experiments 2 and 3 failed to explain the 1-month results on the basis of poor resolution of internal figures by showing comparable discrimination of small and large singly-presented figures and by failing to find improved internal discrimination with large separation between internal and external figures. In Experiment 4, 1-month infants showed response recovery to figure additions made adjacent to the initial figure, but not to internal additions. The results are interpreted in terms of attentiveness by young infants to external pattern elements and may indicate early processing of figure-ground information. The developmental differences observed suggest an increased breadth of attention to pattern elements.  相似文献   
959.
To assess the development of monocular slant perception as well as the relative effectiveness of different sources of information, children in first, third, and fifth grades and college adults were asked to make judgments of surface slant on the basis of monocular texture gradient information. Accuracy of judgment increased with increasing age. In addition, differences in gradient effectiveness were found. Compression gradients were relatively ineffective sources of information, whereas perspective and multiple gradients resulted in greater accuracy. The results suggest limitations on the specificity of certain forms of gradients.  相似文献   
960.
A total of 400 children at ages 5, 9, and 12 years were given a component selection task with stimuli differing in color and shape. Relative salience of these two stimulus components was manipulated across subjects in two ways: the standard shapes and colors from previous studies were compared with standard shapes in fluorescent colors, and the latter materials were compared with nonsense shapes in fluorescent colors. While fluorescence of color had little effect, the replacement of standard shapes with nonsense figures caused attention to be redirected from shape to color as the primary cue for learning. This effect was more pronounced at age 9 than at age 5. Apparently there is a greater tendency for older than for younger children to withdraw attention from a normally dominant component such as shape, when it is advantageous to adopt another feature such as color as the primary functional cue. An additional variable was integration of components (color within shape vs color as background for shape). Integration produced generally greater attention to color but did not affect the general pattern of salience effects.  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