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   5196篇
  免费   480篇
  国内免费   478篇
  2024年   15篇
  2023年   101篇
  2022年   81篇
  2021年   109篇
  2020年   199篇
  2019年   213篇
  2018年   199篇
  2017年   198篇
  2016年   180篇
  2015年   141篇
  2014年   205篇
  2013年   535篇
  2012年   141篇
  2011年   196篇
  2010年   178篇
  2009年   181篇
  2008年   278篇
  2007年   340篇
  2006年   315篇
  2005年   282篇
  2004年   266篇
  2003年   179篇
  2002年   163篇
  2001年   93篇
  2000年   79篇
  1999年   49篇
  1998年   38篇
  1997年   34篇
  1996年   23篇
  1995年   21篇
  1994年   17篇
  1993年   19篇
  1992年   9篇
  1991年   10篇
  1990年   8篇
  1989年   12篇
  1987年   5篇
  1985年   80篇
  1984年   93篇
  1983年   59篇
  1982年   74篇
  1981年   70篇
  1980年   82篇
  1979年   75篇
  1978年   107篇
  1977年   84篇
  1976年   92篇
  1975年   79篇
  1974年   77篇
  1973年   66篇
排序方式: 共有6154条查询结果,搜索用时 15 毫秒
121.
An adaptive up-down tracking procedure was used in combination with a visually reinforced head turn response to examine auditory sensitivity for 500, 2000, and 8000-Hz tone bursts in infants 6 to 18 months of age. Six- and 10-month-old infants were tested with headphone presentation of stimuli, while 10-, 14, and 18-month-olds were tested in sound field. Infant threshold estimates for both headphone and sound field were within 15 dB of adult comparisons for all frequencies and age groups. Six-month-olds were significantly less sensitive to the 8000-Hz tone than to either of the lower frequency stimuli, but older infants demonstrated approximately equal sensitivity for all three frequencies tested.  相似文献   
122.
The hypothesis of this study is that an assumption of speaker credibility affects children's judgments of the external consistency of statements. In two experiments, first and third grade children (6 and 8 years of age, respectively) and college adults were read short paragraphs containing contradictory information from a contextual source and a speaker. The contextual source was described as either authoritative or nonauthoritative and discredited. The speaker was either an adult or child. Thus the contextual source was either more or less reliable than the speaker. Subjects were asked to affirm or contradict the speaker's statement, and to choose either the source or the speaker as most believable. The results showed that adult responses varied with the contextual source alone, while the responses of the first graders varied primarily with the speaker's age. The responses of the third graders varied with both factors. The results suggest young children can assess the external consistency of statements but frequently do not because of their assumptions about speakers and other performance factors.  相似文献   
123.
Four baboons (Papio cynocephalus) were tested using food as reward for ear advantages in the monaural discrimination of pure tones, three-tone musical chords, synthetically constructed consonant-vowels, and vowels. All four animals showed highly significant and reproducible ear advantages for each class of acoustic stimulus with marked individual differences in the direction of their ear asymmetry. The results obtained in these experiments represent the first evidence of ear asymmetries for different classes of acoustic stimuli in a nonhuman species. Further, the ear advantages found in these animals under monaural conditions resemble those obtained with dichotic presentation in human subjects and thus suggest that the baboon may be a valuable model of central auditory processing of various types of acoustic stimuli in man.  相似文献   
124.
The capacity to selectively attend to only one of multiple, spatially separated, simultaneous sound sources—the “cocktail party” effect—was evaluated in normal subjects and in those with anterior temporal lobectomy using common environmental sounds. A significant deficit in this capacity was observed for those stimuli located on the side of space contralateral to the lobectomy, a finding consistent with the hypothesis that within each anterior temporal lobe is a mechanism that is normally capable of enhancing the perceptual salience of one acoustic stimulus on the opposite side of space, when other sound sources are present on that side. Damage to this mechanism also appears to be associated with a deficit of spatial localization for sounds contralateral to the lesion.  相似文献   
125.
Two studies were conducted to determined the effects of specific learning centers on preschoolers' functional uses of language. In Study 1, preschoolers in three separate same-age classrooms (2-, 3-, and 5-year-olds) were observed on a time sampling scheduling during their free play periods for four weeks. Preschoolers' individual utterances were coded as serving one or more than one function; functions were defined following Halliday. The housekeeping and block centers tended to elicit the most individual and multifunctional utterances. The fantasy play and social interaction among children in these centers were thought to be responsible for this mature use of language.In Study 2, same-age and same-sex dyads from two age groups (4- and 5-year-olds) were observed in experimental settings playing with blocks alone and with dramatic props alone. Both contexts elicited a predominance of imaginative language, though the dramatic context elicited more imaginative language than the blocks. With age, children generated more individual functions and multifunctional utterances.  相似文献   
126.
The current literature on sex differences in values/preferences related to work appears polarized around two apparently contradictory sets of findings and conclusions. One set of studies fails to detect sex differences. The other set of studies indicates that males are more concerned about money, independence, security, and career goals, while females appear more concerned about people and environmental issues at work. Following W. D. Siegfried, I. MacFarlane, D. B. Graham, N. A. Moore, and P. L. Young (Journal of Vocational Behavior, 1981, 18, 30–42) it is suggested that level of analysis may be a crucial factor accounting for much of the prevailing confusion in the literature. This study investigated sex differences in values/preferences related to work at various levels of generality. A sample of 1081 senior high school students was administered the Work Aspect Preference Scale (WAPS). Complete-link cluster analyses were performed for males and females separately. Comparison of the two dendrograms reveals the substantial similarity of the preference patterns of males and females. However, the basic difference in the patterns focused on the Altruism and Physical Activity subscales. Females appeared more likely to associate helping others with personal achievement whereas males tended to see helping people in terms of controlling and organizing them. Females also linked physical activity with helping others and self-development whereas males tended to associate physical activity with extrinsic rewards of work. It is concluded that the use of cluster analysis techniques may provide the best procedure to effect an adequate reconciliation of the conflicting results to be found in the current literature.  相似文献   
127.
An analysis is provided detailing the conditions for the appropriate theoretical study of the object of educational science: pedagogy.  相似文献   
128.
This paper reports on experiments which test whether factors such as regret or disappointment influence taxpayer compliance decisions. Previous tests of regret and disappointment theory have been based upon the common-ratio effect in which probabilities vary while outcomes are held fixed. In contrast, our experiments involved trials in which the outcomes were allowed to vary. Previous tests had mainly found evidence of regret effects and to a lesser extent were supportive of disappointment. In contrast, we were able to reject simple theories of both regret and disappointment. A second experiment produced evidence which indicates that whether or not rejected risky alternatives are resolved has no significant influence on subjects' choices. One would expect that regret could only occur when a subject learns the outcome of a non-chosen option. Hence this result can be seen as evidence against regret theory. We shall argue that there is a possible interpretation of regret theory which is compatible with this result.  相似文献   
129.
In Experiments 1 and 2 rats were trained under two multiple schedules of reinforcement. In one, bar pressing during a tone-light compound stimulus was reinforced under a variable-interval food reinforcement schedule. In the other multiple schedule, bar pressing avoided grid shock on a free-operant schedule. In both multiple schedules, a discrimination was maintained by an extinction schedule that was operative during the absence of the tone-light compound. In Experiments 1 and 2 the intensity of the tone-light compound was manipulated over three levels. Subsequent extinction tests revealed that light was attended to, almost exclusively of the tone, when food reinforcement had maintained bar pressing. On the other hand, the tone gained considerable attentional control under the shock avoidance schedule. This stimulus-reinforcer interaction was maintained for all three levels of the compound intensity. In Experiment 3 it was investigated whether this interaction was associative by presenting shock during the absence of the tone-light compound when food reinforcement maintained responding, and food during the absence of the compound when shock avoidance maintained responding. Since both food and shock were presented during a single session for both schedules, nonassociative effects of the reinforcing stimuli were equivalent across the schedules. Nevertheless, the stimulus-reinforcer interaction was maintained, indicating that the interaction was an associative effect.  相似文献   
130.
Two experiments examined the relations among self-esteem, perceived competency to cope, and actual coping behaviors following a threat communication. Leventhal's “parallel response model” (in Advances in experimental social psychology, L. Berkowitz (Ed.), New York: Academic Press, 1970, Vol. 5) predicts that low-esteem subjects will show deficits in both competency and coping behaviors. Experiment 1 manipulated threat level of a tetanus communication. Low-esteem subjects showed coping deficits on measures of free associations, free recall, fatalism, and coping. Threat groups differed only on fear and danger measures. Experiment 2 manipulated the fear level of an antismoking film and used false feedback to alter perceived competency. Positive feedback increased perceived competency to quit smoking among low-esteem subjects only. Without feedback, low-esteem subjects reduced smoking less than high-esteem subjects; positive feedback reversed the pattern. The discussion argued that, consistent with Leventhal's model, the low-esteem coping deficit has two independent causes: (1) excessive concern with fear, and (2) inadequate perceived competency.  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