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   785篇
  免费   17篇
  802篇
  2020年   9篇
  2019年   12篇
  2018年   12篇
  2017年   16篇
  2016年   15篇
  2014年   17篇
  2013年   85篇
  2012年   19篇
  2011年   21篇
  2010年   21篇
  2009年   12篇
  2008年   19篇
  2007年   21篇
  2006年   25篇
  2005年   16篇
  2004年   18篇
  2003年   21篇
  2002年   23篇
  2001年   11篇
  2000年   19篇
  1999年   11篇
  1998年   13篇
  1997年   9篇
  1995年   6篇
  1994年   6篇
  1993年   9篇
  1992年   13篇
  1991年   11篇
  1990年   14篇
  1989年   8篇
  1988年   13篇
  1987年   17篇
  1986年   10篇
  1985年   19篇
  1984年   15篇
  1983年   15篇
  1982年   15篇
  1981年   23篇
  1980年   10篇
  1979年   11篇
  1978年   11篇
  1977年   7篇
  1976年   8篇
  1974年   16篇
  1973年   9篇
  1972年   8篇
  1971年   9篇
  1970年   9篇
  1968年   13篇
  1966年   6篇
排序方式: 共有802条查询结果,搜索用时 15 毫秒
101.
We report two experiments that investigate practice effects on Stroop color-word interference in older and younger adults. Both experiments employed a computerized, single-item version of the Stroop task with a voice response, and both involved practice over hundreds of trials. Both experiments showed generally similar practice patterns, including a practice-related reduction in the size of the color-word interference effect. However, the older group continued to show a larger interference effect throughout practice. These findings indicate that older adults show the same trend in practice-related improvement on the Stroop task as younger adults.  相似文献   
102.
103.
Is a concept of either reversibility or of hierarchical forms of combination necessary for skilled seriation? We examined this question by presenting seriating cups to adult capuchin monkeys and chimpanzees and to 11‐, 16‐ and 21‐month‐old children. Capuchins and chimpanzees consistently created seriated sets with five cups, and placed a sixth cup into a previously seriated set. Children of all three ages created seriated five‐cup sets less consistently than the capuchins and chimpanzees, and were rarely able to place a sixth cup into a seriated set. Twenty‐one‐month‐olds produced more structures containing three or more cups than did the younger age groups, and these children also achieved seriated sets more frequently. Within all participant groups, success at seriating five cups was associated with the frequency of combining three or more cups, regardless of form. The ability to integrate multiple elements in persistent combinatorial activity is sufficient for the emergence of seriation in young children, monkeys and apes. Reliance on particular methods of combination and a concept of reversibility are later refinements that can enhance skilled seriation.  相似文献   
104.
105.
106.
107.
CONTEXT: Evaluating the efficacy of pediatric weight loss treatments is critical. OBJECTIVE: This is the first meta-analysis of the efficacy of RCTs comparing pediatric lifestyle interventions to no-treatment or information/education-only controls. DATA SOURCES: Medline, PsycINFO, and Cochrane Controlled Trials Register. STUDY SELECTION: Fourteen RCTs targetting change in weight status were eligible, yielding 19 effect sizes. DATA EXTRACTION: Standardized coding was used to extract information on design, participant characteristics, interventions, and results. DATA SYNTHESIS: For trials with no-treatment controls, the mean effect size was 0.75 (k = 9, 95% confidence interval [CI] = 0.52-0.98) at end of treatment and 0.60 (k = 4, CI = 0.27-0.94) at follow-up. For trials with information/education-only controls, the mean ES was 0.48 (k = 4, CI = 0.13-0.82) at end of treatment and 0.91 (k = 2, CI = 0.32-1.50) at follow-up. No moderator effects were identified. CONCLUSIONS: Lifestyle interventions for pediatric overweight are efficacious in the short term with some evidence for extended persistence. Future research is required to identify moderators and mediators and to determine the optimal length and intensity of treatment required to produce enduring changes in weight status.  相似文献   
108.
The conversations of 100 mother-child (mean age4.5 years) dyads about the children's school experienceswere examined for their emotional content. Dyads variedalong the dimensions of gender of child (53 girls; 57 boys), ethnicity (31African-American, 39 Anglo-American, and 40Mexican-American), and SES (55 lower and 55 higher).When compared to mother-son dyads, mother-daughter dyadsmade more emotional references, particularly when discussing topicsrelated to interpersonal relationships and whendiscussing emotions experienced by the daughters.Higher-SES dyads made more emotional references than did lower-SES dyads. While there was no main effectof ethnicity associated with the overall tendency todiscuss emotions, relative to other dyads,African-American dyads made more emotional referenceswhen discussing noninterpersonal, nonacademic topicsthan did other dyads, Anglo-American dyads made moreemotional references during the discussing of learningtopics, and Mexican-American dyads discussed emotion more in relation to interpersonal topics thandid African-American dyads.  相似文献   
109.
A geometrical analysis of the unfolding model: General solutions   总被引:1,自引:0,他引:1  
Given the complete setR of rank orders obtained from any configuration ofn stimulus points inr dimensions in accordance with the unfolding model, a configuration from which just these orders may be derived will be described as a solution forR. The space is assumed to be Euclidean. Necessary and sufficient conditions are derived for a configuration to be a solution forR. The geometrical constraints which are necessary and sufficient to determine the subset of pairs of orders and opposites contained inR are also identified and constitute the constraint system for the ordinal vector model. The relationship between the two models is discussed.  相似文献   
110.
A typical trial of this masking experiment involves, in quick succession, presentation of five letters, evocation of an eye movement, and presentation of a spatially localized mask, either a visual-pattern mask or a metacontrast ring. The effect of the mask is to sappress the report of the letter that stimulates the same retinal location, even though the mask appears to cover or surround the letter whose position in real space it shares. Masking is. however, weaker when the eyes move than when they do not. An auxiliary experiment suggests that the spatial aspects of observable (reportable by S) stimulus persistence are unaffected by eye movements, and therefore that observable persistence differs from that susceptible to masking.  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