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   929篇
  免费   77篇
  1006篇
  2024年   5篇
  2023年   11篇
  2022年   15篇
  2021年   25篇
  2020年   36篇
  2019年   50篇
  2018年   72篇
  2017年   75篇
  2016年   64篇
  2015年   37篇
  2014年   43篇
  2013年   131篇
  2012年   52篇
  2011年   55篇
  2010年   35篇
  2009年   30篇
  2008年   40篇
  2007年   44篇
  2006年   39篇
  2005年   27篇
  2004年   15篇
  2003年   9篇
  2002年   24篇
  2001年   4篇
  2000年   5篇
  1999年   5篇
  1998年   5篇
  1997年   7篇
  1996年   2篇
  1995年   4篇
  1994年   1篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   5篇
  1987年   2篇
  1986年   2篇
  1985年   6篇
  1984年   1篇
  1983年   2篇
  1982年   3篇
  1981年   4篇
  1979年   3篇
  1976年   2篇
  1975年   2篇
  1974年   1篇
  1972年   1篇
排序方式: 共有1006条查询结果,搜索用时 15 毫秒
911.
Graphs illustrating complex scientific relationships require students to integrate multiple concepts and visual features into a coherent understanding. We investigate ways to support students in integrating their understanding of density concepts through a graph that is linked to a simulation depicting the relationship between mass, volume, and density. We randomly assigned 325 8th-grade students to 1 of 2 graphing activities. In the analyze condition, students plotted a set of data points selected to help clarify the relationship between mass, volume, and buoyancy, and then interacted with a guided simulation to improve their plotting accuracy. In the generate condition, students chose their own data points, and then interacted with a guided simulation to test and revise their choices. We found that, although analyze participants were more likely to construct accurate graphs, generate participants were more likely to develop a coherent understanding of density and buoyancy. Analyses of process data and interviews suggest that generate participants grappled with the mass-volume ratio by deliberately testing points and identifying patterns as they updated their understanding of science concepts. In contrast, analyze participants displayed less deliberate exploration of the graph space. We discuss how activities that integrate graph interpretation and concept refinement can deepen science learning.  相似文献   
912.
Many service members in need of mental health treatment do not seek such treatment. This study investigated the frequency of Army soldiers’ exposure to specific types of deployment stressors and whether different event-types were associated with willingness to seek and actual receipt of treatment. Male soldiers who were married (n = 600) completed online surveys that assessed posttraumatic stress disorder (PTSD), willingness to seek treatment for PTSD, actual receipt of PTSD treatment, and the frequency of exposure to 4 types of potentially traumatizing warzone experiences: committing a moral injury, observing a moral injury, threats to life, and traumatic loss. Soldiers who reported greater exposure to moral injury experiences (committed or observed) were less likely to be willing to seek treatment, regardless of PTSD symptom severity. Although exposure to moral injury did not differentiate actual treatment receipt, soldiers who endorsed loss were more likely to have received treatment, regardless of PTSD symptom severity. These results suggest that the types of trauma experienced during deployment may be a factor in postdeployment treatment-seeking attitudes and behaviors.  相似文献   
913.
This research demonstrates that a consumer's physical appearance—and, more specifically, his or her body size—predictably influences the product(s) that the consumer is recommended. Four studies conducted in both field and lab settings show that agents more frequently recommend round (vs. angular) shaped products to heavier targets, notably for products and categories in which body size is irrelevant (e.g., lamps and perfume). We attribute this to a combination of shape‐congruency and trait‐congruency, whereby individuals choose products for others based on shared dimensions of the person and product.  相似文献   
914.
Repeated and orthographically similar words are vulnerable in RSVP, as observed using the repetition blindness (RB) paradigm. Prior researchers have claimed that RB is increased for emotion words, but the mechanism for this was unclear. We argued that RB should be reduced for words with properties that capture attention, such as emotion words. Employing orthographic repetition blindness, our data showed that words with negative emotional valence had a report advantage when they were the second of two similar words (e.g., less RB occurred with HORSE curse than with HORSE purse). This renders emotion RB similar to the use of emotion words in the attentional blink phenomenon. The findings demonstrate the neglected role of competition in conscious recognition of multiple words under conditions of brief display and masking.  相似文献   
915.
Object names are a major component of early vocabularies and learning object names depends on being able to visually recognize objects in the world. However, the fundamental visual challenge of the moment‐to‐moment variations in object appearances that learners must resolve has received little attention in word learning research. Here we provide the first evidence that image‐level object variability matters and may be the link that connects infant object manipulation to vocabulary development. Using head‐mounted eye tracking, the present study objectively measured individual differences in the moment‐to‐moment variability of visual instances of the same object, from infants’ first‐person views. Infants who generated more variable visual object images through manual object manipulation at 15 months of age experienced greater vocabulary growth over the next six months. Elucidating infants’ everyday visual experiences with objects may constitute a crucial missing link in our understanding of the developmental trajectory of object name learning.  相似文献   
916.
Statistical learning (SL), sensitivity to probabilistic regularities in sensory input, has been widely implicated in cognitive and perceptual development. Little is known, however, about the underlying mechanisms of SL and whether they undergo developmental change. One way to approach these questions is to compare SL across perceptual modalities. While a decade of research has compared auditory and visual SL in adults, we present the first direct comparison of visual and auditory SL in infants (8–10 months). Learning was evidenced in both perceptual modalities but with opposite directions of preference: Infants in the auditory condition displayed a novelty preference, while infants in the visual condition showed a familiarity preference. Interpreting these results within the Hunter and Ames model (1988), where familiarity preferences reflect a weaker stage of encoding than novelty preferences, we conclude that there is weaker learning in the visual modality than the auditory modality for this age. In addition, we found evidence of different developmental trajectories across modalities: Auditory SL increased while visual SL did not change for this age range. The results suggest that SL is not an abstract, amodal ability; for the types of stimuli and statistics tested, we find that auditory SL precedes the development of visual SL and is consistent with recent work comparing SL across modalities in older children.  相似文献   
917.
The purpose of this pilot study was to examine the mediating effect of posttraumatic stress disorder (PTSD) symptom clusters on the association between trauma exposure and attachment behaviors. Results from bootstrapped mediation analyses with a sample of 116 married adults revealed that total PTSD, avoidance, negative alterations in cognition/mood, and arousal symptoms partially mediated the effect of trauma exposure on perceived attachment behaviors in men only; the intrusion symptom cluster was not significant and there were no significant mediation effects for women. Findings shed light on possible gender variant mechanisms by which trauma may threaten secure attachment bonds in couples.  相似文献   
918.
Growing research links Traumatic Brain Injury (TBI) with greater posttraumatic stress disorder (PTSD) symptoms. Much of this research has focused on the influence of the presence or severity of a single TBI while neglecting the potential cumulative effects of multiple TBIs incurred across an individual’s lifetime on combat-related PTSD. The present study addressed this gap using a sample of 157 military service members and 4 civilian contractors who underwent structured TBI interviews at a military hospital in Iraq and completed the Combat Experiences Scale (CES) and Posttraumatic Checklist – Military (PCL-M). Results indicated that a greater number of lifetime TBIs were associated with greater PTSD symptoms when accounting for the presence and severity of a recent, deployment-related TBI. Additionally, a significant interaction of number of lifetime TBIs and combat exposure emerged, indicating that exposure to combat yielded greater PTSD symptoms among those with multiple lifetime TBIs compared to those with one or zero lifetime TBIs. These data suggest that incurring multiple TBIs may amplify the link between combat exposure and PTSD and underscore the need to screen for lifetime TBI history.  相似文献   
919.
The ability to quickly detect and respond to visual stimuli in the environment is critical to many human activities. While such perceptual and visual–motor skills are important in a myriad of contexts, considerable variability exists between individuals in these abilities. To better understand the sources of this variability, we assessed perceptual and visual–motor skills in a large sample of 230 healthy individuals via the Nike SPARQ Sensory Station, and compared variability in their behavioral performance to demographic, state, sleep and consumption characteristics. Dimension reduction and regression analyses indicated three underlying factors: Visual–Motor Control, Visual Sensitivity, and Eye Quickness, which accounted for roughly half of the overall population variance in performance on this battery. Inter-individual variability in Visual–Motor Control was correlated with gender and circadian patters such that performance on this factor was better for males and for those who had been awake for a longer period of time before assessment. The current findings indicate that abilities involving coordinated hand movements in response to stimuli are subject to greater individual variability, while visual sensitivity and occulomotor control are largely stable across individuals.  相似文献   
920.
Caregiver social support has been shown to be protective for caregiver mental health, parenting and child psychosocial outcomes. This is the first known analysis to quantitatively investigate the relationship between caregiver social support and adolescent psychosocial outcomes in HIV‐endemic, resource–scarce Southern African communities. A cross‐sectional household survey was conducted over 2009–2010 with 2,477 South African adolescents aged 10–17 and their adult caregivers (18 years or older) in one urban and one rural community in South Africa’s KwaZulu‐Natal province. Adolescent adjustment was assessed using adult caregiver reports of the Strengths and Difficulties questionnaire (SDQ), which measures peer problems, hyperactivity, conduct problems, emotional symptoms and child prosocial behavior. Hierarchical linear regressions and multiple mediation analyses, using bootstrapping procedures, were conducted to assess for: (a) direct effects of more caregiver social support on better adolescent psychosocial wellbeing; and (b) indirect effects mediated by better parenting and caregiver mental health. Direct associations (p < .001), and indirect associations mediated through better parenting, were found for all adolescent outcomes. Findings reinforce the importance of social support components within parenting interventions but also point to scope for positive intervention on adolescent psychosocial wellbeing through the broader family social network.  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