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   44778篇
  免费   1939篇
  国内免费   31篇
  2020年   496篇
  2019年   583篇
  2018年   832篇
  2017年   786篇
  2016年   885篇
  2015年   610篇
  2014年   763篇
  2013年   3429篇
  2012年   1437篇
  2011年   1387篇
  2010年   868篇
  2009年   907篇
  2008年   1199篇
  2007年   1233篇
  2006年   1096篇
  2005年   983篇
  2004年   935篇
  2003年   837篇
  2002年   885篇
  2001年   1598篇
  2000年   1598篇
  1999年   1163篇
  1998年   473篇
  1997年   450篇
  1995年   435篇
  1992年   931篇
  1991年   876篇
  1990年   877篇
  1989年   797篇
  1988年   777篇
  1987年   724篇
  1986年   701篇
  1985年   751篇
  1984年   635篇
  1983年   583篇
  1982年   448篇
  1979年   667篇
  1978年   481篇
  1977年   439篇
  1976年   435篇
  1975年   530篇
  1974年   644篇
  1973年   671篇
  1972年   554篇
  1971年   506篇
  1970年   448篇
  1969年   491篇
  1968年   597篇
  1967年   536篇
  1966年   491篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
871.
When an imperative visual stimulus is paired with an auditory (accessory) stimulus, RT is generally faster than with the imperative stimulus alone. Three experiments using additive-factors logic tested an energy-summation view of the accessory, where effects are due to increased rate of information build-up in sensory stages, and a preparation-enhancement view which holds that the accessory serves an alerting function. Experiment 1 found no interaction between the accessory presence and (visual) stimulus brightness, suggesting no role of the accessory in stimulus identification. Experiment 2 found no interaction between accessory presence and spatial S-R compatibility, arguing that the accessory operated in stage(s) other than response selection. Experiment 3 produced an interaction between the accessory and movement complexity, arguing for accessory effects in a response-programming stage. The data generally favored preparation-enhancement, and offered no support for an energy-summation view.  相似文献   
872.
The authors recently proposed that adverse effects of material rewards on Wechsler subscale performance may be the result of a reward-produced developmental regression. The present study further explores that idea through an attempt to replicate earlier findings with adults and to extend the inquiry to children. Selected Wechsler subscales were administered to 32 subjects at each of three ages (5, 10, and 18 years) under either reward or nonreward conditions. Subscales were chosen to represent both algorithmic and heuristic types of tasks. Reward and nonreward groups (8 males and 8 females per group at each age) were matched initially on age and ability. For adults, consistent with earlier findings, reward had an adverse effect on performance on the heuristic subscales and tended to facilitate performance on the algorithmic subscales. However, rewards generally had no effect at the fourth-grade level and had a reverse effect at the nursery school level, i.e., rewards facilitated heuristic and hampered algorithmic performance. These findings appear to be more consistent with an explanation based on developmental regression than on any available alternative mechanism.  相似文献   
873.
874.
Full-time employed (N = 255), partly employed (N = 48), and unemployed (N = 43) male and female university graduates completed a questionnaire that included measures designed to assess expected job levels and current job levels and two measures of potential social action (willingness to volunteer actions and hours to a fictional Campaign to Assist Unemployed Youth). Comparisons between groups and the results of multiple regression analyses provided mixed support for the prediction that larger negative gaps between expected and current employment status would be associated with a greater willingness to assist the Campaign. The unemployed respondents tended to volunteer more actions and more hours to the Campaign than did the other two groups. A multiple regression analysis showed that the current level by expected level interaction term was statistically significant as predicted, but only for the fully employed graduates. Within the full-time employed group, female graduates and those from the humanities/social sciences/education schools expressed more willingness to assist the Campaign than did male graduates and those from the sciences/medicine schools of the university. Results were discussed in relation to current research on relative deprivation and reported affect and to recent studies of job satisfaction.  相似文献   
875.
876.
The purpose of the present study was to evaluate the predictive validity of the Yellow Brick Road Test (YBRT) relative to performance in reading as measured by the Metropolitan Achievement Test (MAT). A full prediction-performance comparison matrix was employed to compare three different cutoff scores for the YBRT for the identification of “at-risk” children. Four hundred and fourteen kindergarten-aged children were administered the YBRT, 214 of whom were followed to the end of second grade. It was concluded that the YBRT is a moderately valid instrument for predicting the level of reading achievement in a population with a different average performance level from the normative sample. However, the results of this study failed to support the utility of the test author's suggested use of a score of 120 as the cutoff score. Finally, it is recommended that a prediction-performance comparison study be considered standard methodology for the evaluation of the validity and efficiency of screening instruments.  相似文献   
877.
Induction by reinforcer schedules.   总被引:1,自引:1,他引:0       下载免费PDF全文
Traditional strategies for determining whether a reinforcer schedule enhances the occurrence of an activity are reviewed and critically evaluated. A basic assumption underlying these strategies is that it is possible to isolate the effect of reinforcer intermittency on schedule induction. It is concluded that this is not, in fact, possible. An alternative approach is proposed that emphasizes the inductive effects of the reinforcer schedule as a unit and the effects of particular aspects of the reinforcer schedule (e.g., interreinforcer interval, repetition of the reinforcer, reinforcer magnitude).  相似文献   
878.
Editorial: Conceivable book reviews   总被引:1,自引:1,他引:0       下载免费PDF全文
  相似文献   
879.
Rats' lever pressing produced sucrose reinforcers on a variable-interval schedule where, in different conditions, the duration of a stimulus presented immediately after reinforcement was either correlated or uncorrelated with the duration of the current interreinforcement interval. Under the baseline schedule, in which no stimulus was presented, the minimum interreinforcement interval was 8 s and the mean postreinforcement pause of each subject approximated this value. Response rates increased slowly over the first 10 to 15 s and then remained roughly constant throughout the remainder of the interval. In both the correlated and uncorrelated conditions, the added stimulus resulted in the postreinforcement pauses lengthening to values in excess of the duration of the preceding stimulus. This resulted in a poststimulus pause which was, in most cases, roughly constant irrespective of the duration of the preceding stimulus, or of the reinforcement contingencies prevailing immediately after stimulus offset. Local response-rate patterns in the uncorrelated conditions were similar to those obtained under the baseline schedule in which no stimulus was presented. However, in the correlated condition local response rates increased across the remainder of the interreinforcer interval. Further, the rate of acceleration was inversely related to the duration of the preceding stimulus. These results show that a correlation between stimulus duration and the ensuing time to reinforcement can control behavior—a type of temporal control not previously reported.  相似文献   
880.
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