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   2510篇
  免费   100篇
  国内免费   1篇
  2023年   21篇
  2022年   17篇
  2021年   22篇
  2020年   50篇
  2019年   61篇
  2018年   84篇
  2017年   73篇
  2016年   69篇
  2015年   66篇
  2014年   56篇
  2013年   259篇
  2012年   99篇
  2011年   98篇
  2010年   71篇
  2009年   55篇
  2008年   81篇
  2007年   95篇
  2006年   82篇
  2005年   53篇
  2004年   70篇
  2003年   45篇
  2002年   51篇
  2001年   121篇
  2000年   118篇
  1999年   77篇
  1998年   18篇
  1997年   29篇
  1996年   23篇
  1994年   19篇
  1992年   40篇
  1991年   54篇
  1990年   39篇
  1989年   44篇
  1988年   42篇
  1987年   28篇
  1986年   18篇
  1985年   23篇
  1984年   22篇
  1983年   18篇
  1981年   15篇
  1979年   22篇
  1976年   15篇
  1975年   14篇
  1974年   16篇
  1973年   16篇
  1971年   17篇
  1970年   14篇
  1969年   15篇
  1968年   16篇
  1967年   16篇
排序方式: 共有2611条查询结果,搜索用时 158 毫秒
221.
222.
Rheumatoid arthritis (RA) prevalence increases with age and old people are special patient population. The recognition of functional disability related to RA could be challenging in elderly patients because aging itself and potential co-morbid disease may also cause functional disability. In this study, we aimed to look at the correlation between disease activity and functional disability in elderly RA patients. Elderly RA patients, ≥65 years old at their routine visits were included in the study. The composite ‘disease activity score’ in 28 joints (DAS-28) was used to determine disease activity groups. Health assessment questionnaire (HAQ) scores were calculated to describe the functional disability and compared across the disease activity groups. Two hundred and fifty-eight RA patients with the mean age of 71 ± 5 (65–90) and a total disease duration of 8.4 ± 8.5 (.5–50) years were recruited. The proportion of patients with high and moderate disease activity was 70%. HAQ scores were significantly correlated with disease activity (p < .05). Functional disability estimated by HAQ was correlated with disease activity in elderly patients with RA  相似文献   
223.
The Hidden Markov Modeling approach for eye-movement data analysis is able to quantitatively assess differences and similarities among individual patterns. Here we applied this approach to examine the relationships between eye-movement patterns in face recognition and age-related cognitive decline. We found that significantly more older than young adults adopted “holistic” patterns, in which most eye fixations landed around the face center, as opposed to “analytic” patterns, in which eye movements switched among the two eyes and the face center. Participants showing analytic patterns had better performance than those with holistic patterns regardless of age. Interestingly, older adults with lower cognitive status (as assessed by the Montreal Cognitive Assessment), particularly in executive and visual attention functioning (as assessed by Tower of London and Trail Making Tests) were associated with a higher likelihood of holistic patterns. This result suggests the possibility of using eye movements as an easily deployable screening assessment for cognitive decline in older adults.  相似文献   
224.
225.
Examining how animals direct social learning during skill acquisition under natural conditions, generates data for examining hypotheses regarding how transmission biases influence cultural change in animal populations. We studied a population of macaques on Koram Island, Thailand, and examined model-based biases during interactions by unskilled individuals with tool-using group members. We first compared the prevalence of interactions (watching, obtaining food, object exploration) and proximity to tool users during interactions, in developing individuals (infants, juveniles) versus mature non-learners (adolescents, adults), to provide evidence that developing individuals are actively seeking information about tool use from social partners. All infants and juveniles, but only 49% of mature individuals carried out interacted with tool users. Macaques predominantly obtained food by scrounging or stealing, suggesting maximizing scrounging opportunities motivates interactions with tool users. However, while interactions by adults was limited to obtaining food, young macaques and particularly infants also watched tool users and explored objects, indicating additional interest in tool use itself. We then ran matrix correlations to identify interaction biases, and what attributes of tool users influenced these. Biases correlated with social affiliation, but macaques also preferentially targeted tool users that potentially increase scrounging and learning opportunities. Results suggest that social structure may constrain social learning, but the motivation to bias interactions towards tool users to maximize feeding opportunities may also socially modulate learning by facilitating close proximity to better tool users, and further interest in tool-use actions and materials, especially during development.  相似文献   
226.
This article investigates how test-takers change their strategies to handle increased test difficulty. An adult sample reported their test-taking strategies immediately after completing the tasks in a reading test. Data were analyzed using structural equation modeling specifying a measurement-invariant, ability-moderated, latent transition analysis in Mplus (Muthén & Asparouhov, 2011). It was found that almost half of the test-takers (47%) changed their strategies when encountering increased task-difficulty. The changes were characterized by augmenting comprehending-meaning strategies with score-maximizing and test-wiseness strategies. Moreover, test-takers' ability was the driving influence that facilitated and/or buffered the changes. The test outcomes, when reviewed in light of adjusted test-taking strategies, demonstrated a form of process-based validity evidence.  相似文献   
227.
228.
Following war and war captivity, many combat veterans and former prisoners of war (ex-POWs) may suffer from posttraumatic psychopathologies, and these may be transmitted to their offspring. Though there are considerable individual differences between offspring in this respect, the mechanisms underlying such differences remain unclear. The current longitudinal study examined the role that veterans’ offspring’s Big Five personality traits may play within this intergenerational transmission. One hundred and twenty-three dyads consisting of veterans (79 ex-POWs and 44 combat veterans) and their adult offspring were examined. Fathers’ posttraumatic stress symptoms (PTSS) and global psychiatric distress (GD) were assessed 30 and 35 years after the war, and offspring’s PTSS, GD, and Big Five personality traits were assessed 40 years after the war. Findings indicate that veterans’ psychopathologies were associated with those of their offspring. Furthermore, analyses revealed significant positive associations between offspring’s psychopathologies and their Neuroticism, and negative associations with their Agreeableness and Conscientiousness. Finally, a mediation effect was found wherein the fathers’ PTSS and GD were related to their offspring’s Neuroticism levels, and the offspring’s Neuroticism was related to their PTSS and GD levels. These findings suggest that offspring’s personality traits may indeed play a role in the transmission of posttraumatic psychopathologies from veterans to their offspring, and may explain individual differences in this respect. Specifically, high levels of Neuroticism may place offspring at risk for secondary traumatization. Possible explanations and limitations are discussed, and future research directions are suggested.  相似文献   
229.
230.
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