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   8991篇
  免费   837篇
  国内免费   410篇
  2024年   52篇
  2023年   255篇
  2022年   167篇
  2021年   205篇
  2020年   476篇
  2019年   438篇
  2018年   397篇
  2017年   467篇
  2016年   427篇
  2015年   324篇
  2014年   419篇
  2013年   1340篇
  2012年   175篇
  2011年   292篇
  2010年   255篇
  2009年   324篇
  2008年   404篇
  2007年   425篇
  2006年   421篇
  2005年   367篇
  2004年   319篇
  2003年   232篇
  2002年   210篇
  2001年   147篇
  2000年   113篇
  1999年   120篇
  1998年   106篇
  1997年   74篇
  1996年   57篇
  1995年   65篇
  1994年   45篇
  1993年   41篇
  1992年   35篇
  1991年   17篇
  1990年   25篇
  1989年   27篇
  1987年   17篇
  1985年   133篇
  1984年   125篇
  1983年   105篇
  1982年   89篇
  1981年   66篇
  1980年   74篇
  1979年   66篇
  1978年   94篇
  1977年   59篇
  1976年   43篇
  1975年   32篇
  1974年   24篇
  1973年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
241.
It is a common task to give children a picture containing implicit depth cues and to require them to extract depth information from it. The cues are always selected from the adult repertoire; little is known about children's production of their own cues. In this experiment, 5- to 10-year-old children were required to draw one object behind another in a situation in which adults invariably produce the further object partially occluded by the nearer. The results were an age-related decline in the tendency to segregate the objects and an increase in the tendency to group the objects using partial occlusion, with a cross-over at 8 years. At all ages some children drew one object inside the boundary of the other. It is argued that the results are composed of two tendencies, a gradual mastery of discrete scaling phenomena (e.g., “up” on the page means “further”) within a given style, and a set of decisions to be made between incompatible styles.  相似文献   
242.
Laboratory rats were given escape training in both arms of a Y maze followed by extinction in one of four conditions: regular (no shock), punished (both arms containing a shock mid-segment), choice, or forced (one arm containing a shock mid-segment, one arm shock free). Subjects in the punished and forced conditions required more extinction trials than those in the regular extinction condition. The choice condition was intermediate and not significantly different from the others. Choice subjects avoided the shock by choosing the safe alley early and consistently during extinction, but some continued to run for many trials without further punishment. It was suggested that the number of punished trials early in extinction is related to persistence of running, and the results were discussed in relation to the Mowrer-Brown and the discrimination hypotheses.  相似文献   
243.
The temporal characteristics of auditory memory were investigated using a reaction time paradigm. The study attempted to determine whether or not there are functionally distinct left and right hemisphere components of auditory memory with different capacities for the retention of nonlinguistic information, such as fundamental frequency, over the course of several seconds. The results indicated that fundamental frequency information in auditory memory remains substantially unchanged over the course of 2 sec. No evidence was found for the existence of separate left and right hemisphere components of auditory memory with different temporal characteristics. The implications of this finding for the organization of auditory memory in the brain are discussed.  相似文献   
244.
A Greek-born aphasic who had been able to speak four languages (Romanian, Russian, Greek, German) was tested quantitatively for verbal expression (standard interview indexes) and verbal reception (fifth part of the Token Test). The form of aphasia (qualitative aspect) was found to be identical for all four languages. Quantitatively, his performance in the four languages was different, with the languages used most during the past 20 years (Romanian and Russian) being less impaired. Nevertheless, verbal reception was equally impaired quantitatively in all four languages. Treatment with semantic-syntagmatic methods performed in Romanian had a beneficial effect on speech in the other languages as well. The authors feel that the expressive disturbance noted in aphasia reflects involvement of deep as well as of surface structures of language, but the receptive disturbance reflects involvement of the deep structures only. This may account for quantitative discrepancies in expression without discrepancy in reception among the four languages, as well as the qualitatively identical features of the disturbance in verbal expression and reception.  相似文献   
245.
246.
247.
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   
248.
249.
The effects of prompts and reinforcement to promote paper recycling were compared in six university dormitories. For a Prompt condition, residents were urged to recycle paper for ecological reasons via flyers distributed to each room. For a Raffle contingency, residents were given one raffle ticket for every pound of paper brought to a collection center. For a Contest contingency, two dorms were paired and the dorm whose residents delivered the most paper won $15 for its treasury. Contingency awareness was strengthened via a flyer placed under the door of each resident's room. Flyers alone had little effect in increasing paper-recycling behaviors, but the raffle (substantially) and the contest (somewhat) increased the amount of paper brought to a dorm's recycling center. Students whose rooms were closest to the collection center showed the greatest participation. Removal of the reinforcement contingencies resulted in a return to baseline levels.  相似文献   
250.
This study was designed to test the effects of both interaction distance and the quality of the interaction upon attraction. It was found that close interaction distances amplified the quality of the interaction so that for a positive interaction there was more liking for a close rather than a far partner, while for a negative interaction a close partner was liked less. The implications of this finding for research concerning crowding is discussed, as are possible explanatory mechanisms.  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