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   5429篇
  免费   281篇
  国内免费   1篇
  2023年   39篇
  2022年   56篇
  2021年   68篇
  2020年   133篇
  2019年   133篇
  2018年   231篇
  2017年   216篇
  2016年   226篇
  2015年   184篇
  2014年   203篇
  2013年   683篇
  2012年   258篇
  2011年   258篇
  2010年   165篇
  2009年   161篇
  2008年   217篇
  2007年   236篇
  2006年   190篇
  2005年   123篇
  2004年   152篇
  2003年   133篇
  2002年   105篇
  2001年   159篇
  2000年   187篇
  1999年   109篇
  1998年   42篇
  1997年   49篇
  1996年   42篇
  1995年   23篇
  1994年   33篇
  1993年   29篇
  1992年   56篇
  1991年   68篇
  1990年   48篇
  1989年   52篇
  1988年   49篇
  1987年   36篇
  1986年   23篇
  1985年   25篇
  1984年   33篇
  1983年   27篇
  1982年   26篇
  1981年   22篇
  1979年   30篇
  1975年   23篇
  1974年   23篇
  1973年   21篇
  1971年   28篇
  1970年   26篇
  1967年   22篇
排序方式: 共有5711条查询结果,搜索用时 15 毫秒
191.
Scores on three spatial tests (mental rotation, embedded figures, and gestalt completion) were significantly correlated with four same-different reaction-time tasks in a sample of 48 female university students. Scores on the Vandenberg-Kuse mental rotation test correlated best with a one-different-all-different task, embedded figures with a one-different-all-same task, and the gestalt completion with a one-same-all-same task, suggesting that the strategies subjects employ for each spatial test are similar to the strategies they use in each of the same-different tasks with which their scores correlate best. Present results support the position that stronger correlations than previously noted between scores on spatial tests and reaction-time tasks are observed when matching the tests and tasks in terms of hypothesized underlying processes.  相似文献   
192.
The purpose of this study was to examine the relationships among competitive worries, sport confidence, and performance of young athletes. Participants were 143 young swimmers aged 11 to 12 years. The athletes completed trait and state questionnaires (competitive worries and sport confidence) in noncompetitive and competitive conditions, respectively. The results indicated: (a) significant relationships among trait and state characteristics and between trait General Self-confidence and performance ratings in both races as well as between performance ratings in Races 1 and 2; (b) significant differences in state variables among athletes with moderate or high and low scores on the trait variables; (c) significant differences in performance among athletes with moderate or high and low scores on the trait General Self-confidence and trait Positive Thinking in Race 1 and on variables trait General Self-confidence, state General Self confidence, and state Positive Thinking Race 2; and (d) trait General Self-confidence and trait Confidence in Unfavorable Situations were the most important predictors of young swimmers' performances. These results may be useful in application to competitive sports for young athletes. They may help in psychodiagnostic procedures and may be used for both the content and the direction of individual programs for psychological preparation of young athletes.  相似文献   
193.
Factors determining why acts are regarded as aggressive were investigated in a sample of 303 subjects (140 males, 163 females, M age = 17.7 yr., SD = 1.4). A model was tested, according to which people base their attribution of aggression to acts on four factors: (1) intention (yes/no), (2) reason (attack/defense), (3) injury (death/injury/no injury), and (4) mode (weapon/bare hands/nonphysical means). All four factors contributed to the explanation of attribution of aggression, and the order of importance was the one mentioned above, intention being most important. The interaction between intention and reason was the second most important, contributing more than reason alone. The findings are consistent with the severity of punishment in sentences for different crimes of violence.  相似文献   
194.
A model of dual attitudes   总被引:66,自引:0,他引:66  
When an attitude changes from A1 to A2, what happens to A1? Most theories assume, at least implicitly, that the new attitude replaces the former one. The authors argue that a new attitude can override, but not replace, the old one, resulting in dual attitudes. Dual attitudes are defined as different evaluations of the same attitude object: an automatic, implicit attitude and an explicit attitude. The attitude that people endorse depends on whether they have the cognitive capacity to retrieve the explicit attitude and whether this overrides their implicit attitude. A number of literatures consistent with these hypotheses are reviewed, and the implications of the dual-attitude model for attitude theory and measurement are discussed. For example, by including only explicit measures, previous studies may have exaggerated the ease with which people change their attitudes. Even if an explicit attitude changes, an implicit attitude can remain the same.  相似文献   
195.
We examined the differential impact of chronic versus acute economic stress on depressive mood among a sample of 1241 low-income, single, European and African American women. Based on Hobfoll's (1988, 1989) conservation of resources (COR) theory, we predicted that acute resource loss would be more distressing than chronic economic lack. That is, although chronically impoverished conditions are stressful, the attendant resource losses created will be more distressing. We further predicted that mastery and social support would be more beneficial in offsetting the negative consequences of acute resource loss than the negative consequences of chronic economic lack, because acute loss creates identifiable demands that resources may address. Hence, we hypothesized that mastery and social support would show stress buffering effects only for material loss, not chronic lack. The findings generally supported the hypotheses, but mastery buffered only European American women's resource loss and social support buffered only African American women's resource loss. The findings are discussed in light of implications for prevention within theoretical and cultural contexts.  相似文献   
196.
The N-end rule is one ubiquitin-proteolytic pathway that relates the in vivo half-life of a protein to the identity of its N-terminal residue. NTAN1 deamidates N-terminal asparagine to aspartate, which is conjugated to arginine by ATE1. An N-terminal arginine-bearing substrate protein is recognized, ubiquitylated by UBR1/E3α, and subsequently degraded by 26S proteasomes. Previous research showed that NTAN1-deficient mice exhibited impaired long-term memory in the Lashley III maze. Therefore, a series of studies, designed to assess the role of NTAN1 in short- and intermediate-term memory processes, was undertaken. Two hundred sixty mice (126 −/−; 134 +/ +) received Lashley III maze training with intertrial intervals ranging from 2–180 min. Results indicated that inactivation of NTAN1 amidase differentially affects short-, intermediate-, and long-term memory.  相似文献   
197.
The emergence of new technologies to study brain function in vivo has resulted in an explosion of interest in cognitive neuroscience within the last ten years. While most research in functional neuroimaging has been geared toward adult normal volunteers, the development of functional magnetic resonance imaging (fMRI) has made it possible to study neural development in normal children, as well as those with developmental disorders. This technology provides an unprecedented opportunity to expand our knowledge of brain function throughout childhood. A variety of technological, experimental, and practical difficulties are amplified when imaging children. This paper reviews some of the more challenging theoretical and practical concerns and provides suggestions for their management.  相似文献   
198.
In accelerated longitudinal design, one samples multiple age cohorts and then collects longitudinal data on members of each cohort. The aim is to study age-outcome trajectories over a broad age span during a study of short duration. A threat to valid inference is the Age x Cohort interaction effect. S. W. Raudenbush and W. S. Chan (1993) developed a test for such interactions in the context of 2 cohorts by using a hierarchical model. The current article extends this approach to include any number of cohorts. Using the National Youth Survey, the authors combine data collected on 7 cohorts over 5 years to approximate change in antisocial attitudes between 11 and 21 years of age. They show how to test for cohort differences in trajectories, how to calculate the power of the test, and how to use graphical procedures to aid understanding. The approach allows unbalanced designs and the clustering of participants within families, neighborhoods, or other social units.  相似文献   
199.
In order to assess the effects of glucose on drug-induced spatial learning deficits, three experiments were conducted using the Morris water maze. Scopolamine and glucose were injected ip at various stages of training. Rats of Wistar strain served as subjects. In Experiment 1, scopolamine (0.4 mg/kg) and 10, 100, or 500 mg/kg of glucose were administered every day from the start of training, and the effect on acquisition was evaluated. In Experiment 2, scopolamine and 100 or 500 mg/kg of glucose were administered after 6 days of training, and the effect on performance was assessed. In Experiment 3, scopolamine and 500 mg/kg of glucose were injected after 2 days of training, and the effect on the following trial was tested. In all experiments, scopolamine impaired acquisition/performance of the task. Glucose at 500 mg/kg showed a significant enhancing effect on acquisition regardless of scopolamine injection only when injected daily from the start of training (Experiment 1). Glucose injected after the performance has reached asymptote (Experiment 2) did not affect performance, and glucose in the middle of training showed a slight but insignificant enhancing effect (Experiment 3). These results may suggest that the effect of glucose changes as a function of the degree of learning of the spatial learning task. The possibility of task specificity of the glucose effect was also discussed in relation to the cholinergic systems and local cerebral glucose utilization.  相似文献   
200.
This article considers an analytic strategy for measuring and modeling child and adolescent problem behaviors. The strategy embeds an item response model within a hierarchical model to define an interval scale for the outcomes, to assess dimensionality, and to study how individual and contextual factors relate to multiple dimensions of problem behaviors. To illustrate, the authors analyze data from the primary caregiver ratings of 2,177 children aged 9-15 in 79 urban neighborhoods on externalizing behavior problems using the Child Behavior Checklist 4-18 (T. M. Achenbach, 1991a). Two subscales, Aggression and Delinquency, are highly correlated, and yet unidimensionality must be rejected because these subscales have different associations with key theoretically related covariates.  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