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   45113篇
  免费   1780篇
  国内免费   24篇
  2020年   454篇
  2019年   568篇
  2018年   797篇
  2017年   828篇
  2016年   821篇
  2015年   619篇
  2014年   715篇
  2013年   3416篇
  2012年   1293篇
  2011年   1361篇
  2010年   905篇
  2009年   878篇
  2008年   1229篇
  2007年   1196篇
  2006年   1091篇
  2005年   961篇
  2004年   883篇
  2003年   873篇
  2002年   859篇
  2001年   1714篇
  2000年   1693篇
  1999年   1209篇
  1998年   518篇
  1997年   448篇
  1996年   436篇
  1995年   419篇
  1992年   1002篇
  1991年   974篇
  1990年   958篇
  1989年   852篇
  1988年   826篇
  1987年   824篇
  1986年   771篇
  1985年   825篇
  1984年   683篇
  1983年   545篇
  1982年   432篇
  1979年   651篇
  1978年   495篇
  1977年   452篇
  1975年   575篇
  1974年   618篇
  1973年   678篇
  1972年   543篇
  1971年   482篇
  1970年   435篇
  1969年   477篇
  1968年   574篇
  1967年   497篇
  1966年   517篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Periadolescent rats exhibit a number of behavioral differences in comparison with younger or older animals. For instance, periadolescents tend to show enhanced acquisition of simple active avoidance tasks, but impaired acquisition of more complex appetitive and aversive discriminations. In this experiment, rats were trained on a simple passive avoidance task at one of three ages, as weanlings (25 days), periadolescents (35 days), or young adults (45 days). Training occurred in the presence of both a redundant discriminative stimulus and a specified, redundant contextual stimulus. The periadolescents did not differ from either younger or older rats in rate of learning the passive avoidance task. The retention performance of these animals was then tested following a change in either, neither, or both of the redundant cues. When a measure of performance that controls for baseline activity was used, it was observed that periadolescents were not disrupted by a change in the redundant discriminative stimulus, a cue change that clearly disrupted performance in 25- and 45-day-old animals, and tended to be more disrupted by the contextual change than younger or older rats. It is hypothesized that the alterations in performance exhibited by periadolescents may be related to an ontogenetic alteration in stimulus selection modulated by the catecholaminergic systems.  相似文献   
972.
Exposure to electric shock produces an analgesic reaction (SIA) that is reversed by opiate antagonists ("opioid" SIA) under some conditions but not under other conditions ("nonopioid" SIA). A number of studies using tail-flick to radiant heat as the measure of pain sensitivity have found that a small number of shocks lead to nonopioid SIA, while a large number of shocks produce opioid SIA. In contrast, a small number of shocks have been reported to produce opioid SIA when the Formalin test was used to measure pain reactivity. However, the Formalin test involves administering a chronic pain stimulus (injection of Formalin into the paw) for an extended period before the shocks. Here it is reported that this "preexperimental" stress is sufficient to convert the SIA after a small number of shocks measured by tail-flick to the opioid form.  相似文献   
973.
This paper reports the validation of brief, self-report measures of intrinsic enjoyment and boredom coping. Intrinsic enjoyment is characterized by intense involvement, interest and absorbed concentration; boredom coping is designed to reflect the disposition to restructure one's perceptions and participation in potentially boring activities so as to decrease boredom. Both traits are hypothesized to reflect the capacity for good attentional control across a variety of situations. Reliability was established by test-retest correlation and by an inter-item consistency measurement. Construct validity was established by comparison with previously-validated personality tests, real-life measures (such as Random Activities Experiential Sampling, which involves repeated self-report measures in daily life), as well as with laboratory measures of attention (including the averaged visual evoked potential (EP) and the Continuous Performance Test). Intrinsic enjoyment is significantly correlated with an independent measure of intrinsic involvement (low wish to be elsewhere in one's daily life), the affective experience of potency, self-reports of concentrating well with ease, high ego development, an internal locus of control, lack of boredom susceptibility and certain EP indices of attentional change and ‘cortical’ augmenting. Boredom coping is associated with a higher percent of time actually spent alone, high continuous performance task measures of attentional capacity, and low MMPI and Research Diagnostic Criteria indices of psychopathology.  相似文献   
974.
Three papers (V. A. Mann, Reading skill and language skill. Developmental Review, 1984, 4, 1–15; G. Wolford & C. A. Fowler, Differential use of partial information by good and poor readers. Developmental Review, 1984, 4, 16–35; F. J. Morrison, Reading disability: A problem in rule learning and word decoding. Developmental Review, 1984, 4, 36–47) are critiqued from the standpoint of their adequacy in advancing our understanding of a problem as complex as reading disability. Experimenters should be explicit about their guiding theoretical assumptions, and should think through the relations, if any, between their laboratory tasks and the actual processes of reading. The reading protocol of a dyslexic child is provided, and is interpreted within the frameworks of the Mann, Wolford and Fowler, and Morrison viewpoints.  相似文献   
975.
First-grade children were given either empathy instructions (in which they were told to imagine themselves in the target person's place) or neutral instructions (in which they were told to listen to what the target person did). For half the subjects, the target person was of the same sex; for the other half, the target person was of the opposite sex. Subjects were then given a chance to anonymously donate money to the target child, who was presented as being in need. Liking for the target child, subject's perceptions of the target child's emotional state, and subjects' report of their own emotional states were also assessed. Empathic instructions increased donating behavior for males, but not for females. Accuracy of perception of the target person's state was generally high. Self-reports of emotional states congruent with that of the target tended to be associated with increased donating behavior only for males, but these self-reports were greater for females than males, and greater for both sexes with same-sex target persons. Liking also was enhanced by gender similarity. These results are discussed in terms of a proposed relationship among empathy, prosocial behavior, sex, and age.We wish to express our gratitude to the staff and students of Wannamaker and North Fairview Elementary Schools of Topeka, Kansas, for their assistance in carrying out this research, and also thank C. Daniel Batson for his helpful suggestions and comments.  相似文献   
976.
Odor recognition: familiarity, identifiability, and encoding consistency   总被引:8,自引:0,他引:8  
The investigation examined the association between the perceived identity of odorous stimuli and the ability to recognize the previous occurrence of them. The stimuli comprised 20 relatively familiar odorous objects such as chocolate, leather, popcorn, and soy sauce. Participants rated the familiarity of the odors and sought to identify them. At various intervals up to 7 days after initial inspection, the participants sought to recognize the odors among sets of distractor odors that included such items as soap, cloves, pipe tobacco, and so on. The recognition response entailed a confidence rating as to whether or not an item had appeared in the original set. At the time of testing, the participants also sought to identify the stimuli again. The results upheld previous findings of excellent initial recognition memory for environmentally relevant odors and slow forgetting. The results also uncovered, for the first time, a strong association between recognition memory and identifiability, rated familiarity, and the ability to use an odor label consistently at inspection and subsequent testing. Encodability seems to enhance rather than to permit recognizability. Even items identified incorrectly or inconsistently were recognized at levels above chance.  相似文献   
977.
We report two free recall experiments and a cued recall experiment in which a new two-stage model was used to obtain numerical measurements of age changes in various aspects of storage and retrieval. The subjects in all three experiments were 7-year-olds (second graders) and 11-year-olds (sixth graders). The major findings in the free recall experiment were that getting a trace into storage posed less of a problem for elementary schoolers than learning how to get it out on test trials, that retrieval development is more rapid during the elementary school years than storage development, and that the superiority of older children's storage and retrieval abilities tends to become more pronounced as learning progresses. A similar pattern of results was obtained under different conditions in the cued recall experiment.  相似文献   
978.
Two experiments examined whether individuals who ascribe the disparity in the performances of two actors to situational constraints adequately adjust their dispositional inferences to reflect their own perceptions of causality. Using the quiz-game format of L. D. Ross, T. M. Amabile, and J. L. Steinmetz (1977, Journal of Personality and Social Psychology, 35, 485–494), the effects of the subjects' awareness of the role-determined, self-presentation advantage of the questioner on their dispositional inferences concerning the quiz-game participants are noted. It is hypothesized that subjects who indicated full awareness of the determining force of the situation would nevertheless draw more favorable dispositional inferences about the questioner than about the contestant. The prediction is confirmed. Although the situationally aware subjects rate the questioner and contestant more similarly than do the other subjects, they still rate the questioner higher in knowledge, memory, and education. The results of Experiment 2 indicate that increasing the salience of the subjects' assessment of the situational advantage of the questioner does not eliminate the disparity. It is proposed that the fudamental attribution error represents more a failure to adjust trait inferences for causal attributions than a misperception of causality. Implications concerning the relationship between knowledge of causality and social judgment and the utility of the distinction between “perceived causality” and “higher order causal inferences” are discussed.  相似文献   
979.
In this paper we discuss a method for assessing agreement among raters who are scoring the number of times, a specified event occurs. In such cases, it seems reasonable to define agreement in terms of raters' behaviours in correctly identifying responses which have in fact occurred, and in their falsely counting responses which have not. We exploit the discrete nature of the response variable, and examine a class of models for mean response assuming an underlying Poisson distribution. Test statistics are given for deciding on the applicability of the models, and whether there is agreement with respect to correctly detecting responses, as well as with falsely scoring responses.  相似文献   
980.
The five stages of family development and their phase-specific tasks as delineated by Michael A. Solomon in an article that appeared in this journal (1973) are given dramatic representation by Virginia Woolf in her novel To the Lighthouse (1927). The novel begins with the Ramsay family system arrested at the third stage of development; and it is only after the death of Mrs. Ramsay that the remaining family members begin to attend to the phase-specific tasks of stages four and five, and family development commences.  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