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   67101篇
  免费   2657篇
  国内免费   26篇
  69784篇
  2020年   711篇
  2019年   945篇
  2018年   1244篇
  2017年   1328篇
  2016年   1338篇
  2015年   942篇
  2014年   1169篇
  2013年   5184篇
  2012年   2136篇
  2011年   2196篇
  2010年   1372篇
  2009年   1321篇
  2008年   1949篇
  2007年   1932篇
  2006年   1793篇
  2005年   1597篇
  2004年   1521篇
  2003年   1404篇
  2002年   1451篇
  2001年   2023篇
  2000年   1885篇
  1999年   1476篇
  1998年   746篇
  1997年   660篇
  1992年   1201篇
  1991年   1129篇
  1990年   1157篇
  1989年   1064篇
  1988年   1089篇
  1987年   1038篇
  1986年   1052篇
  1985年   1060篇
  1984年   898篇
  1983年   864篇
  1982年   677篇
  1981年   658篇
  1979年   1032篇
  1978年   741篇
  1977年   637篇
  1976年   658篇
  1975年   861篇
  1974年   924篇
  1973年   972篇
  1972年   762篇
  1971年   736篇
  1970年   691篇
  1969年   764篇
  1968年   905篇
  1967年   803篇
  1966年   729篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
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   
53.
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   
54.
55.
56.
57.
58.
59.
60.
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