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   426篇
  免费   18篇
  国内免费   9篇
  2023年   3篇
  2022年   5篇
  2021年   6篇
  2020年   8篇
  2019年   7篇
  2018年   10篇
  2017年   12篇
  2016年   19篇
  2015年   19篇
  2014年   11篇
  2013年   35篇
  2012年   19篇
  2011年   17篇
  2010年   13篇
  2009年   16篇
  2008年   24篇
  2007年   24篇
  2006年   25篇
  2005年   17篇
  2004年   14篇
  2003年   8篇
  2002年   24篇
  2001年   9篇
  2000年   7篇
  1999年   7篇
  1998年   6篇
  1997年   4篇
  1996年   2篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   5篇
  1991年   3篇
  1990年   10篇
  1989年   3篇
  1988年   5篇
  1987年   3篇
  1986年   3篇
  1985年   7篇
  1984年   3篇
  1982年   4篇
  1981年   4篇
  1980年   3篇
  1979年   1篇
  1978年   3篇
  1977年   3篇
  1976年   4篇
  1975年   3篇
  1974年   1篇
  1973年   2篇
排序方式: 共有453条查询结果,搜索用时 15 毫秒
61.
62.
The primary auditory cortex is now known to be involved in learning and memory, as well as auditory perception. For example, spectral tuning often shifts toward or to the frequency of the conditioned stimulus during associative learning. As previous research has focused on tonal frequency, less is known about how learning might alter temporal parameters of response in the auditory cortex. This study addressed the effects of learning on the fidelity of temporal processing. Adult male rats were trained to avoid shock that was signaled by an 8.0 kHz tone. A novel control group received non-contingent tone and shock with shock probability decreasing over days to match the reduced number of shocks received by the avoidance group as they mastered the task. An untrained (nai ve) group served as a baseline. Following training, neuronal responses to white noise and a broad spectrum of tones were determined across the primary auditory cortex in a terminal experiment with subjects under general anesthesia. Avoidance conditioning significantly improved the precision of spike-timing: the coefficient of variation of 1st spike latency was significantly reduced in avoidance animals compared to controls and nai ves, both for tones and for noise. Additionally, avoidance learning was accompanied by a reduction of the latency of peak response, by 2.0-2.5 ms relative to nai ves and approximately 1.0 ms relative to controls. The shock-matched controls also exhibited significantly shorter peak latency of response than nai ves, demonstrating the importance of this non-avoidance control. Plasticity of temporal processing showed no evidence of frequency specificity and developed independently of the non-temporal parameters magnitude of response, frequency tuning and neural threshold, none of which were facilitated. The facilitation of temporal processing suggests that avoidance learning may increase synaptic strength either within the auditory cortex, in the subcortical auditory system, or both.  相似文献   
63.
While recent research using peer ratings demonstrates positive relations between youth's reputations for aggression and popularity, it is not clear whether aggressive youth themselves make these links. Using youth's self‐reports, this study assessed the associations of relational and physical aggression with indicators of both personal gains in peer relations (perceived popularity and receipt of prosocial attention) and personal costs in terms of retaliation or depressive responses (peer victimization and depressive symptoms) in a large sample (n=455) of eighth‐ to tenth‐grade students. Regression analyses reveal that more relationally aggressive youth report more prosocial attention but also more relational (but not physical) victimization. In contrast, more physically aggressive youth report more depressive symptoms and physical (but not relational) victimization. Findings suggest that some costs of aggression (victimization) are higher for boys while others (depressive symptoms) are greater for girls. Group differences were also found for aggressive, victimized, and aggressive/victimized youth compared to the typical low aggressive/low victimized youth. These data suggest that the costs of relational and physical aggression may outweigh benefits except for aggressive non‐victimized boys. Aggr. Behav. 32:409–419, 2006. © 2006 Wiley‐Liss, Inc.  相似文献   
64.
通过对以未病先防为主导的中国古代主要辟疫思想及方法的回顾与思考,探讨了其对今天传染病预防的参考价值。认识到在当代传染病预防工作中,借鉴中国古代医学的思想与实践之精粹或许可为当代新发传染病的防治另辟新径,以期能对现代传染病的预治有所启示。  相似文献   
65.
66.
Adolescents spend a substantial amount of time using social networking sites (SNSs); however, little is known regarding whether such use is associated with indicators of adjustment. The present study employed a multidimensional measure of SNS use to investigate the link between Australian adolescent SNS use and indicators of adjustment. Youth (N = 1,819, 55% female) from 34 diverse high schools across Western Australia were surveyed. The results showed that frequency of SNS use was linked to higher social self‐concept while investment in SNSs was associated with lower self‐esteem and higher depressed mood. Furthermore, having an SNS was linked to more negative indicators for female adolescents compared with male adolescents, although the link between frequency of use and investment in SNSs to indicators of adjustment was not moderated by gender. The present study highlights the complexity of the relationship between adolescent SNS use and indicators of adjustment, and offers insight into the diverse types of adolescent use of SNSs.  相似文献   
67.
Compassion fatigue is a phenomenon that occurs when a caregiver feels overwhelmed by repeated empathic engagement with distressed clients (Figley, 2002). Research demonstrates its existence among nurses, physicians, and mental health professionals, but to date no published study has specifically investigated the nature and prevalence of compassion fatigue among genetic counselors. The present study was an initial attempt to identify and describe the phenomena in genetic counseling by conducting focus group interviews with 12 genetic counselors. Data analysis yielded several themes: a) compassion fatigue occurs and may compromise professional and personal functioning; b) prevalent triggers include delivering bad news and difficult patient issues (e.g., terminal illness, anger, psychopathology); c) effective coping strategies include consulting with colleagues, setting boundaries, and humor; and d) risk factors include personality characteristics and traumatic memories. Training, practice, and research recommendations are provided.  相似文献   
68.
69.
Psychometric properties, particularly predictive validity, of scales in the General Nordic Questionnaire for Psychological and Social Factors at Work (QPSNordic) were assessed. The analysis is confined to the scales in the QPSNordic, and 24 of the 26 scales are included. A large group of Swedish county council employees ( n = 3,976; response rate = 65%) participated in a study and were given the QPSNordic. Register data for long-term sick leave (>90 days), with diagnosis, were used for predictive analysis. The following main results were obtained: Reliability was generally satisfactory, confirmatory factor analysis indicated good fit, concurrent validity was good, some less often investigated organizational variables predicted sickness absence, and scales were differentially associated with absence due to psychiatric and musculoskeletal disorders. In conclusion, the psychometric testing of the QPSNordic so far suggests that it is a good instrument for assessing health-related factors at work.  相似文献   
70.
In the context of Question Answering (QA) on free text, we assess the value of answer comparison and information fusion in handling multiple answers. We report improvements in answer re-ranking using fusion on a set of location questions and show the advantages of considering candidates as allies rather than competitors. We conclude with some observations about answer modeling and evaluation methodology, arising from a more recent experiment with a larger set of questions and a greater diversity of question types and candidates.  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