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   38042篇
  免费   1489篇
  国内免费   11篇
  39542篇
  2019年   479篇
  2018年   658篇
  2017年   671篇
  2016年   662篇
  2015年   477篇
  2014年   593篇
  2013年   2786篇
  2012年   1126篇
  2011年   1183篇
  2010年   688篇
  2009年   700篇
  2008年   1026篇
  2007年   1023篇
  2006年   957篇
  2005年   864篇
  2004年   834篇
  2003年   749篇
  2002年   800篇
  2001年   1199篇
  2000年   1101篇
  1999年   839篇
  1998年   431篇
  1997年   358篇
  1996年   362篇
  1992年   652篇
  1991年   643篇
  1990年   632篇
  1989年   622篇
  1988年   615篇
  1987年   580篇
  1986年   620篇
  1985年   662篇
  1984年   544篇
  1983年   507篇
  1982年   395篇
  1981年   383篇
  1979年   609篇
  1978年   442篇
  1977年   363篇
  1976年   408篇
  1975年   491篇
  1974年   562篇
  1973年   600篇
  1972年   474篇
  1971年   442篇
  1970年   448篇
  1969年   469篇
  1968年   582篇
  1967年   486篇
  1966年   501篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
This study addresses the demands of alternating bimanual syncopation, a coordination mode in which the two hands move in alternation while tapping in antiphase with a metronomic tone sequence. Musically trained participants were required to engage in alternating bimanual syncopation and five other coordination modes: unimanual syncopation where taps are made (with the left or right hand) after every tone; unimanual syncopation where taps are made after every other tone; bimanual synchronization with alternating hands; unimanual synchronized tapping with every tone; and unimanual tapping with every other tone. Variability in tap timing was greatest overall for alternating bimanual syncopation, indicating that it is the most difficult. This appears to be due to instability arising from the simultaneous presence of two levels of antiphase coordination (one between the pacing sequence and the hands, the other between the two hands) rather than factors relating to movement frequency or dexterity limits of the nonpreferred hand.  相似文献   
22.
23.
24.
25.
26.
27.
Following Altman's privacy regulation model, this research was based on the assumption that the relationship between achieved and desired levels of privacy is a major determinant of the experience of crowding in small groups. Further, on the basis of evidence that advancing age is associated with a chronic lack of communicative interaction, it was assumed that the achieved level of privacy among elderly persons generally is greater than that experienced by young adults. Given these assumptions, it was predicted that the crowding threshold of young adults would be significantly lower than that of older persons. To test this hypothesis, the research varied conversation distance (close, far) and density (small room, large room) and assessed the quality of communicative interaction and task performance among small groups of college-age females and retired women over 60 years of age. Results showed that task performance among younger subjects deteriorated in close interaction conditions, whereas the performance of older subjects was improved by spatial intrusion. Further, older subjects exhibited positive communication behaviors in response to close conversation, high-density conditions, while younger subjects responded either with negative communication behaviors or were unaffected by spatial restriction. Finally, the research confirmed previous findings that conversation distance is a more important determinant of the experience of crowding in small groups than physical density. The significance of the results for Altman's privacy regulation model and their implications for the study of human communication behaviors were discussed.  相似文献   
28.
A growing literature has observed a significant reduction in pain sensitivity among hypertensive animals and humans. It is uncertain whether a reduced sensitivity to pain can be observed in nonnotensive individuals who go on to develop high blood pressure. Blood pressure (BP) was reassessed in one hundred fifteen 19-year-old boys initially tested at age 14, when they were also presented with a pain stimulus (mechanical finger pressure). Hierarchical regression analyses indicated that information regarding pain tolerance improved prediction of changes in systolic and diastolic blood pressure beyond that afforded by differences in BP at age 14, parental history of hypertension, and body mass index. These analyses suggest that pain sensitivity may be associated with physiological processes involved in the development of sustained high blood pressure.  相似文献   
29.
Suicides among older adults in the United States and Canada in the last decade have accounted for an increasing share of all suicides. In both countries the use of firearms among older adults has steadily increased. Despite these trends, little is known about the extent to which crisis centers are prepared to prevent elder suicide. A survey of AAS-listed crisis prevention centers examined the training, knowledge, and current practices relevant to elder suicide among personnel in 321 crisis prevention centers in both countries. Results revealed insufficient training, a lack of familiarity with recent suicide trends, and limited outreach to older adults.  相似文献   
30.
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