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   8815篇
  免费   172篇
  国内免费   3篇
  2021年   45篇
  2020年   71篇
  2019年   97篇
  2018年   238篇
  2017年   235篇
  2016年   305篇
  2015年   194篇
  2014年   169篇
  2013年   601篇
  2012年   477篇
  2011年   475篇
  2010年   135篇
  2009年   153篇
  2008年   193篇
  2007年   225篇
  2006年   209篇
  2005年   1438篇
  2004年   800篇
  2003年   569篇
  2002年   236篇
  2001年   89篇
  2000年   71篇
  1999年   93篇
  1998年   61篇
  1997年   46篇
  1996年   38篇
  1995年   43篇
  1994年   51篇
  1993年   46篇
  1992年   62篇
  1991年   70篇
  1990年   98篇
  1989年   70篇
  1988年   64篇
  1987年   72篇
  1986年   79篇
  1985年   72篇
  1984年   66篇
  1983年   58篇
  1982年   39篇
  1981年   37篇
  1980年   40篇
  1979年   65篇
  1978年   49篇
  1976年   47篇
  1975年   68篇
  1974年   71篇
  1973年   59篇
  1972年   49篇
  1971年   39篇
排序方式: 共有8990条查询结果,搜索用时 15 毫秒
131.
Aggressivity, inattention, hyperactivity, and impulsivity are cardinal dimensions of externalizing behavior problems of childhood. They are diagnostic and clinical features of childhood disorders, and are thought to be linked to the subsequent development of adult disorders such as substance abuse (SA). Little is known, however, about the convergent and discriminant validity of these four constructs. We used multiple measures to develop indices of aggressivity, inattention, hyperactivity, and impulsivity in a sample of 10- to 12-year-old boys (N=183) with and without a family history of SA. Data were taken from mother reports, child reports, teacher reports, and laboratory tasks. The study aims were (1) to test the convergent and discriminant validity of aggressivity, inattention, hyperactivity, and impulsivity; (2) to examine whether the data were consistent with a model specifying the four constructs as indicators of one superordinate factor; and (3) to differentiate boys with and without a family history of SA in construct scores. The results supported the convergent and discriminant validity of the four constructs. Although discriminable, the constructs covaried strongly and were consistent with a model specifying them as indicators of a single superordinate factor. Boys with a family history of substance abuse scored higher than control boys on aggressivity, inattention, and impulsivity scores, but the groups did not differ on hyperactivity scores. The results are discussed in terms of the role of childhood behavior problems in vulnerability to SA.This work was supported by the National Institute on Drug Abuse grant No. DA 05605.  相似文献   
132.
Two experiments are reported addressing the preparation and initiation of movements with equal or unequal timing properties for both hands. Temporal coordination was examined in two movement tasks: one in which both hands performed the movements simultaneously (simultaneous aiming task) and one in which only one alternative of two possible movements was executed (choice aiming task). For each task a different group of subjects was used. Besides the timing relationships between both movements, the effects of preparation interval (1, 3, and 5 s), the average velocity (7, 14, 17.5, and 70 cm/s), the presence of advance information about the required velocity of the movement(s), and practice were investigated. Based on the common- and the specific-timing notions, distinct hypotheses were tested as to the effects of the variables on the temporal coordination as revealed by reaction time. A main result was that the effects of timing differences between the hands was task specific. For the choice task the data are in agreement with the common-timing notion of coordination, i. e., only one timing demand at a time can be prepared, whereas in the simultaneous task evidence was obtained for the specific-timing notion, i. e., independent preparation and initiation of different timing properties for the hands. However, it is argued that the results of the choice task probably do not reflect a general inability to prepare movements of different timing requirements for both hands, but is related to a task-specific strategy of selective preparation.  相似文献   
133.
Summary This study investigated the relation between psychometric mental-ability test scores and several reaction-time measures; a simple-reaction task, a choice-reaction task, the Posner and Mitchell (1967) letter-identification task, and a variation of the sentence-verification task. Scores on the Raven Advanced Progressive Matrices and the Verbal Subtest of the Scholastic Aptitude Test (SATV) were obtained. The less complex information-processing tasks replicate earlier studies in which general intelligence was only marginally related to reaction-time measures. The sentence-verification task systematically varied task complexity. Several direct and derived measures from the task were significantly correlated with psychometric mentalability measures. However, even though a number of precautions were taken to ensure that the sentence-verification task assessed purely verbal-processing efficiency, there was little evidence for an important task-specific relation between verification measures and verbal ability. Moreover, despite its relative verbal complexity, sentence verification did not reflect a greater relationship to verbal ability than other tasks did. Overall, the information-processing efficiency measures used in this study suggested a fairly general, rather than a task-specific, relationship to intellectual ability.The research presented in this paper was conducted while the first author was affiliated with the University of Georgia, U. S. A.  相似文献   
134.
Drug states, flavors, and contextual cues were each trained as conditional discriminative stimuli to control a saccharin-LiCl association. In transfer tests, drug states transferred control over consumption to other flavored solutions and to food. Contexts and flavors transferred control only to other flavored solutions. Pavlovian control groups given direct pairings of context-LiCl or flavor-LiCl did not show reliable transfer. However, these control groups did show greater or the same aversion to the specific context or flavor predicting LiCl compared to the context or flavor discrimination groups. The dissociation of the discrimination and Pavlovian groups on transfer versus preference tests suggests that performance on the occasion setting task cannot be due to simple excitation or learning about a unique compound cue. Data from extinction procedures provide further support for the dissociation between simple excitation and occasion setting.  相似文献   
135.
Abstract— Schachter and Singer (1962) showed that people search the immediate environment for emotionally relevant cues to label and interpret unexplained physiological arousal We investigated how unobtrusively activated cognitions and physiological arousal interact to produce emotional experience when the immediate environment is devoid of relevant cues Subjects were primed with positive, negative, or neutral concepts They then either exercised or sat still and, either immediately or after a delay, rated their emotional state Consistent with what Schachter and Singer found, subjects in the exercise, delayed-rating condition, who lacked an obvious explanation for their arousal, made the most extreme affective self-ratings, which were consistent with the valence of the primed concepts These subjects apparently interpreted their residual arousal in terms of the primed concepts Subjects in the exercise, immediate-rating condition, who had an explanation for their arousal (i e, the exercise), were not influenced by the primes Subjects in the no-exercise condition showed typical priming effects, with prime-consistent self-ratings that decayed over time Implications for emotion formation, misattnbution of arousal, and cognition are discussed  相似文献   
136.
This study examined the relationship between high and low quality counselor responses in four response modes and client cognitions. Twenty-one university students participated in two sessions of brief counseling that included high and low quality counselor responses in paraphrasing, questioning, reflection of feeling, and self-disclosure. After each counseling session, participants used Kagan's (1975) interpersonal process recall method to report their cognitions in response to these counselor responses. Results indicated that the participants had more favorable cognitions toward the counselor associated with high quality counselor paraphrasing and reflection of feeling responses. Participants' cognitions directed toward themselves did not differ in response to any of the four high and low quality counselor responses. Implications of the results are discussed.  相似文献   
137.
This paper addresses a problem in reporting scientific research. The problem is how to distinguish between justifiable and unjustifiable data selection. Robert Millikan is notorious for an infamous remark that he used all his data when in fact he had used a selection. On this basis he has been accused of fraud. There is a tension here — historians and his defenders see his selection as understandable and legitimate, while current statements about the Responsible Conduct of Research imply his selection was illegitimate. This paper discusses two main issues that arise in assessing his conduct, whether he was intentionally misleading and whether he actually did mislead the scientific community about some facts of nature. It is argued that he was not intentionally misleading, and that it is unlikely that he misled the scientific community.  相似文献   
138.
139.
The inhibitory and facilitatory effects of context on word recognition were investigated in 24 8-to 10-year-old children with a specific reading disability in comparison with a group of 24 children matched for reading ability and a group of 24 children matched for chronological age. To avoid confounding the effects of reading level with those of word difficulty, target words of equivalent relative familiarity for each participant were presented in congruous, neutral, and incongruous sentence contexts. In agreement with previous studies, there was clear evidence of both general inhibitory and facilitatory effects. In contrast to previous findings, however, reading level did not have a major impact on the inhibition of word recognition in incongruous contexts compared with neutral contexts, although it may have led to greater facilitation in congruous contexts compared with neutral contexts. Although further research is required, these results suggest that if reading-age appropriate materials are selected, less skilled readers and those with a reading disability may not be as influenced by context as has been claimed previously.  相似文献   
140.
A longitudinal study is reported of relocating employees ( n = 51) and their partners ( n = 31) who relocated between two cities in England. A nonmoving comparison group of employees from the same organization ( n = 58) was included. The subjects completed a questionnaire before (approximately 6 weeks) and after (approximately 10 weeks) the relocation. Results showed that relocating employees' pre-move general stress was similar to that of nonmoving employees. Moreover, male relocators' stress reduced significantly following the move, while female relocators stayed the same. Stress specific to relocation was very high for relocating employees and partners, and remained so following the move. Evidence was found to show a relationship between attributions of the causes of relocation problems and the experience of stress.  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