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   16116篇
  免费   619篇
  国内免费   4篇
  16739篇
  2019年   214篇
  2018年   258篇
  2017年   219篇
  2016年   260篇
  2015年   169篇
  2014年   263篇
  2013年   1277篇
  2012年   434篇
  2011年   485篇
  2010年   292篇
  2009年   312篇
  2008年   416篇
  2007年   443篇
  2006年   421篇
  2005年   343篇
  2004年   372篇
  2003年   334篇
  2002年   329篇
  2001年   452篇
  2000年   510篇
  1999年   342篇
  1998年   205篇
  1997年   154篇
  1996年   166篇
  1995年   164篇
  1992年   276篇
  1991年   285篇
  1990年   296篇
  1989年   276篇
  1988年   267篇
  1987年   234篇
  1986年   246篇
  1985年   259篇
  1984年   191篇
  1983年   207篇
  1982年   158篇
  1980年   156篇
  1979年   248篇
  1978年   216篇
  1977年   150篇
  1975年   215篇
  1974年   242篇
  1973年   268篇
  1972年   225篇
  1971年   210篇
  1970年   162篇
  1969年   195篇
  1968年   248篇
  1967年   239篇
  1966年   209篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Congenital hypothyroidism (CH) is a neonatal disorder that is caused by a prolonged loss of thyroid hormone, which is essential for early brain development. While CH was once the leading cause of mental retardation, newborn screening for CH now allows for early identification and treatment. As a result, affected children now show normal physical and psychological development. Nevertheless, because they still undergo a brief but circumscribed period of thyroid hormone insufficiency, they are at risk for subtle selective impairments. This paper examines several of the persisting deficits observed in children with CH that was identified early in life by newborn screening as well as the relevant disease- and treatment-related factors contributing to such deficits. Highlighted will be (a) a weakness in visuospatial processing, which is associated with prenatal thyroid hormone insufficiency, (b) selective memory deficits associated with postnatal thyroid hormone insufficiencies, (c) a weakness in sensorimotor abilities also reflecting postnatal thyroid hormone insufficiencies, and (d) attention deficits, which are due to abnormal thyroid hormone levels at time of testing. Because these four disabilities implicate different neural substrates, the findings described presently will provide insights as to the specific time windows when different brain structures in the human critically need thyroid hormone.  相似文献   
952.
The Demise of the Doomsday Argument   总被引:1,自引:0,他引:1  
Sowers  George F.  jr 《Mind》2002,111(441):37-46
  相似文献   
953.
954.
The social combination theory of group problem solving is used to extend existing psychometric models to collaborative settings. A model for pairwise group work is proposed, the implications of the model for assessment design are considered, and its estimation is addressed. The results are illustrated with an empirical example in which dyads work together on a twelfth-grade level mathematics assessment. In conclusion, attention is given to avenues of research that seem most fruitful for advancing current initiatives concerning the assessment of collaboration, teamwork, and related constructs.  相似文献   
955.
In two experiments, we investigated the role of apparent motion in discriminating left/right gaze deviation judgments. We demonstrated that discrimination accuracy and response confidence was significantly higher when the eyes were moved to the left or right, compared to when the eyes were presented in their final shifted position (static images). To dissociate the role of motion signals from luminance signals, gaze stimuli were also presented in reverse contrast. Replicating past studies polarity reversal had a profound and detrimental effect on gaze discrimination in static images, although, intriguingly, while response confidence remained low, participant performance improved as gaze angle increased. In striking contrast to these data, polarity reversal had no negative effect on performance when the eyes were moved. We discuss these findings in the context of a multiple-cue account of gaze perception.  相似文献   
956.
This research investigated how and for whom experiences of the workday spill over into relationship functioning at home. Two correlational studies and one experimental study were conducted among Dutch dual‐earners with children. Moderated mediation analyses showed that work demands spill over into relationship behavior through the depletion of temporary self‐regulatory resources and subsequently a decrease in psychological availability for the partner. Whether work demands spill over into relationship behavior was dependent on dispositional self‐control in that evidence for negative spillover was only found for individuals low in dispositional self‐control. The experimental study showed that the induction of gratitude for the partner after the workday helped individuals low in dispositional control to prevent negative spillover into the partner relationship.  相似文献   
957.
Research on the division of cognitive labor has found that adults and children as young as age 5 are able to find appropriate experts for different causal systems. However, little work has explored how children and adults decide when to seek out expert knowledge in the first place. We propose that children and adults rely (in part) on “mechanism metadata,” information about mechanism information. We argue that mechanism metadata is relatively consistent across individuals exposed to similar amounts of mechanism information, and it is applicable to a wide range of causal systems. In three experiments, we show that adults and children as young as 5 years of age have a consistent sense of the causal complexity of different causal systems, and that this sense of complexity is related to decisions about when to seek expert knowledge, but over development there is a shift in focus from procedural information to internal mechanism information.  相似文献   
958.
Adolescent decision‐making is highly sensitive to input from the social environment. In particular, adult and maternal presence influence adolescents to make safer decisions when encountered with risky scenarios. However, it is currently unknown whether maternal presence confers a greater advantage than mere adult presence in buffering adolescent risk taking. In the current study, 23 adolescents completed a risk‐taking task during an fMRI scan in the presence of their mother and an unknown adult. Results reveal that maternal presence elicits greater activation in reward‐related neural circuits when making safe decisions but decreased activation following risky choices. Moreover, adolescents evidenced a more immature neural phenotype when making risky choices in the presence of an adult compared to mother, as evidenced by positive functional coupling between the ventral striatum and medial prefrontal cortex. Our results underscore the importance of maternal stimuli in bolstering adolescent decision‐making in risky scenarios.  相似文献   
959.
Parental overcontrol (OC), behavior that intrusively or dominantly restricts child autonomy, has been identified as a transdiagnostic risk factor for youth. However, it is as yet unknown whether the association between parental OC and child maladjustment remains even when OC is exerted infrequently or by attuned parents. Rather, the selective use of OC might steer children away from danger. Taking a developmental psychopathology approach, this study focuses on the larger parent–child relationship context, testing whether either the dose at which parents demonstrate OC or the degree to which children perceive their parents as attuned determines whether OC is risky or protective for adolescents’ adjustment. Among a community sample of 114 families of children followed from the ages of 12–18, we examine whether OC, behaviorally coded from triadic mother–father–child discussions in middle childhood, is associated with later risky behavior and anxiety symptoms in adolescence. Overcontrol exerted by either mothers or fathers had a curvilinear effect on adolescent risky behaviors, and this effect was moderated by children's perceived attunement. Although OC generally was associated with increased risky behaviors, low doses of OC or OC exerted by highly attuned parents protected against engagement in risky behaviors. No main effect of OC was observed on adolescent anxiety; however, mothers’ OC interacted with perceived parental attunement, such that OC exerted by less attuned parents predicted greater anxiety. Results underscore that the effect of parenting behaviors depends on the larger parent–child relationship context.  相似文献   
960.
To inform ethical procedures for human subjects research using mobile health (mHealth), we examined perceived risks and benefits of study participation among emerging adults (= 54) with drug use who completed text message assessments of substance use and sexual behaviors. Most participants reported comfort with participation and some reported perceived benefits, such as improved relationships. Perceived risks were infrequently reported, including negative emotions and legal or financial concerns. In conclusion, participants from a vulnerable population reported few perceived harms of participation in longitudinal mHealth assessments of sensitive behaviors. Researchers should continue characterizing participants’ perspectives on ethical aspects of mHealth research.  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