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   41824篇
  免费   1796篇
  国内免费   20篇
  2020年   526篇
  2019年   642篇
  2018年   949篇
  2017年   1043篇
  2016年   989篇
  2015年   726篇
  2014年   825篇
  2013年   3720篇
  2012年   1365篇
  2011年   1501篇
  2010年   968篇
  2009年   971篇
  2008年   1333篇
  2007年   1274篇
  2006年   1136篇
  2005年   995篇
  2004年   925篇
  2003年   936篇
  2002年   872篇
  2001年   1342篇
  2000年   1343篇
  1999年   982篇
  1998年   487篇
  1997年   414篇
  1996年   409篇
  1995年   390篇
  1994年   403篇
  1993年   368篇
  1992年   818篇
  1991年   768篇
  1990年   723篇
  1989年   668篇
  1988年   635篇
  1987年   632篇
  1986年   593篇
  1985年   670篇
  1984年   541篇
  1983年   424篇
  1982年   380篇
  1981年   377篇
  1979年   518篇
  1978年   395篇
  1977年   397篇
  1975年   466篇
  1974年   464篇
  1973年   523篇
  1972年   425篇
  1971年   350篇
  1968年   395篇
  1966年   403篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
43.
44.
45.
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   
46.
Cancellation tests are commonly used in the clinical assessment of visuospatial function, but there has been little study of task characteristics influencing performance. This study was designed to assess factors which affect cancellation performance. Sixteen healthy subjects sequentially performed four random-array letter cancellation tasks. The forms contained 50 and 100 stimuli and target:distractor (T/D) ratios of 1:4 and 1:9 with target letter “A” and randomly selected letter distractors. The primary performance measure was calculated as the number of correctly cancelled targets divided by the time to complete the task, corrected for accuracy. This measure revealed a strong effect of T/D ratio (p< .0001), with performance adversely affected by higher proportion of distractors. There was no effect of stimulus number. This suggests that T/D ratio should be considered in cancellation test design and interpretation.  相似文献   
47.
48.
49.
50.
The token economy has been the primary model for the behavioral management of inpatient populations. However, this basically operant approach seldom emphasizes the development of cognitive-coping skills to help patients more effectively manage stressors that result in hospitalization. The Therapeutic Contract Program (TCP) is described as an inpatient-treatment strategy that is designed to help foster such cognitive-coping and self-control skills. While external structure is provided by components of this program, subprograms of the TCP have as their goal the development of internally-attributed coping skills and self-perceptions of competence. This preliminary report describes the structure of the TCP, as well as planned and in-progress measures of program participation and treatment outcome.  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