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   9143篇
  免费   1069篇
  国内免费   531篇
  2024年   30篇
  2023年   195篇
  2022年   140篇
  2021年   195篇
  2020年   428篇
  2019年   454篇
  2018年   412篇
  2017年   452篇
  2016年   375篇
  2015年   292篇
  2014年   353篇
  2013年   1163篇
  2012年   209篇
  2011年   328篇
  2010年   280篇
  2009年   357篇
  2008年   415篇
  2007年   454篇
  2006年   474篇
  2005年   409篇
  2004年   362篇
  2003年   294篇
  2002年   255篇
  2001年   175篇
  2000年   153篇
  1999年   159篇
  1998年   121篇
  1997年   104篇
  1996年   87篇
  1995年   88篇
  1994年   70篇
  1993年   70篇
  1992年   66篇
  1990年   32篇
  1989年   40篇
  1988年   29篇
  1987年   30篇
  1985年   165篇
  1984年   146篇
  1983年   120篇
  1982年   106篇
  1981年   84篇
  1980年   91篇
  1979年   86篇
  1978年   113篇
  1977年   86篇
  1976年   61篇
  1975年   43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
881.
This study explored the relationship between illegitimate birth and cognitive development among 513 boys on probation. Prior research has shown that being part of a single-parent household leads to diminished verbal capacities and often puts a child in greater danger of abuse and neglect. Frequent abuse is thought to lead to the enhancement of visual and spatial skills relative to verbal skills through a process of “frozen watchfulness”. I hypothesized that illegitimate boys from one-parent homes would have greater verbal-performance discrepancy scores than would boys from other combinations of birth status and family structure. These boys had the lowest verbal IQ and highest performance IQ scores and, hence, the largest discrepancy. These boys also suffered the highest degree of abuse and neglect of all four birth status/family structure combinations studied.  相似文献   
882.
This study was performed after the tradition of F. C. Bartlett (1932), who demonstrated that memory reconfigures over time. The authors investigated the memory of young and older adults to examine the degree to which the aging process influences reconfigurative tendencies. From an initial sample of 53 participants, 20 young and 19 older adults completed 6 tests of recall for Bartlett's original text materials over an 84-day period. Consistent with the broad conclusions of Bartlett's study, reconfiguration was observed: Both young and older adults introduced errors into memory. Older adult recall was lower overall than that of young adults, and recall performance diminished over time. However, there was no difference between the performances of young and older adults with respect to incorrectly recalled intrusive elements.  相似文献   
883.
Children’s other-oriented behaviors in distress situations, when observed, appear to be different depending on the kind of distress situations. The authors investigated developmental differences in children’s other-oriented behaviors by comparing two distress situations: participant-caused/other-victim and other-caused/participant-victim situations. The kinds of other-oriented behaviors younger and older children engaged in were observed under an experimental setting—two tasks that involved accidentally collapsing the object the other constructed. The results showed that other-oriented behaviors were observed irrespective of age and situations. However, the developmental changes of these behaviors were different between the two situations: Older children showed more kinds of other-oriented behaviors than younger children did in the participant-caused situation, whereas no differences between ages were observed in the participant-victim situation. Other-oriented behaviors toward the victim when the participants were at fault appeared to develop during the preschool years, whereas other-oriented behaviors toward those responsible for participants’ distress appeared to be difficult for preschoolers. The developmental origin of and changes in other-oriented behaviors in cases when children are victims should be further investigated, in additional age groups, as should the influence of cultural context.  相似文献   
884.
Research has suggested that women who experience postpartum depression are subsequently more likely to perceive their preschool-aged children as temperamentally difficult and maladjusted. However, previous studies have not controlled for the effects of concurrent depression levels on maternal ratings of child temperament or evaluated the accuracy of maternal reports. In the present study we assessed maternal and paternal ratings of child temperament 2 years after subjects had participated in a study of postpartum depression. The findings indicate that correlations between postpartum depression and subsequent child temperament ratings were accounted for statistically by concurrent levels of depression. Although fathers' ratings corroborated some aspects of maternal perceptions, levels of parental agreement were only moderately high. Moreover, discrepancies between the parents' reports were significantly associated with maternal depression, indicating that parental disagreement is more likely when the wife is dysphoric.  相似文献   
885.
In this study the authors investigated associations among children's observed responses to failure in an analogue entry situation, their attention deployment patterns, and skills and processes associated with self-regulation. Participants were 54 kindergarten and first-grade students who were either aggressive-rejected or low aggressive-popular based on peer nominations. Inhibitory control predicted the tendency to respond to entry failure by stopping and watching the group's activity. Baseline vagal tone and other-directed attention predicted children's tendency to change entry strategies after failure. Parent-rated attention skills moderated the relation between children's attention deployment patterns during the entry task and their responses to entry failure. Children who engaged in more other-directed attention were less likely to turn to solitary play after entry failure but only if they had high or moderate levels of attentional control. Other-directed attention was related to repeating previous entry bids without modification after entry failure but only when children had high levels of attention problems.  相似文献   
886.
In this article the authors compared chimpanzees’ executive function with that of children. They developed a nonverbal dimensional change card sorting task, which indexed the development of executive function. Three pairs of mother and offspring chimpanzees and 30 typically developed 5-year-old children were presented with 2 target stimuli and a test stimulus comprising 2 dimensions (size and shape) on a display; they were required to sort the test stimulus according to 1 dimension (e.g., shape). After 5 consecutive correct trials, the participants had to sort the test stimulus according to the other dimension (e.g., size). The results showed that the chimpanzees often failed to sort the test stimuli according to the first and reversed dimensions. On the other hand, the children were correctly able to use both dimensions. These results indicate that chimpanzees may have less developed executive skills than children.  相似文献   
887.
In the present work the effect of two task variables on transfer were studied: shape of the track-circular or triangular; and target speed-constant or variable. One or both of these variables was changed on transfer. Experimental conditions were (a) 10 preshift and 10 post-shift trials, and (b) 20 single-trial alternations of two tasks. 22 groups of 12 Ss each were tested. Condition (a) showed positive transfer with single variable change and zero or negative transfer with simultaneous change in two variables, and condition (b) annulled all transfer effects. Results are discussed in terms of commonality between tasks and receptor and perceptual anticipation.  相似文献   
888.
The authors studied the development of postural adjustments associated with the initiation of gait in children by using kinematic and electromyographic (EMG) analysis. Participants (N = 28) included infants with 1-4 and 9-17 months of walking experience, children 4-5 years of age, and adults. Anticipatory postural adjustments (APA) were present in the youngest age groups, including a clear anticipatory lateral tilt of the pelvis and the stance leg, which enabled the child to unload the opposite leg shortly before its swing phase. An anticipatory activation of the hip abductor of the leg in stance phase prior to heel-off was found, suggesting pelvis stabilization. APA did not appear consistently until 4-5 years of age. A decrease in segmental oscillations occurred across the ages, indicating better control of intersegmental coordination in the frontal and sagittal planes during the postural phase of gait initiation. Young walkers presented APA involving movements of both the upper and the lower parts of the body, whereas, like adults, 4- to 5-year-olds were able to laterally shift only the pelvis and the stance leg. The oldest children and the adults also showed lower activation levels of hip and knee muscles but higher activation at the ankle level. Those kinematic and EMG results taken together suggest a clear developmental sequence from an en bloc operation of the body through an articulated operation with maturation, walking experience, or both.  相似文献   
889.
ABSTRACT

Studies of sensory-motor performance, including those concerned with changes because of age, disease, or therapeutic intervention, often use measures based on jerk, the time derivative of acceleration, to quantify smoothness and coordination. However, results have been mixed: some researchers report sensitive discrimination of subtle differences, whereas others fail to find significant differences even when they are obviously present. One reason for this is that different measures have been used with different scaling factors. These measures are sensitive to movement amplitude or duration to different degrees. The authors show that jerk-based measures with dimensions vary counterintuitively with movement smoothness, whereas a dimensionless jerk-based measure properly quantifies common deviations from smooth, coordinated movement.  相似文献   
890.
Methodological and empirical issues in research on action information feedback (AIF) are discussed, with particular reference to the procedures and results of Annett (1970). Positioning responses practiced under conditions of AIF training are learned, though generally less well than under terminal IF conditions. Effects obtained as a result of AIF training may be subject to variations in movement extent required, gain and other transformations, frequency, temporal locus, and mode of augmentation, many aspects of which remain to be systematically studied.  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