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   80081篇
  免费   2548篇
  国内免费   18篇
  82647篇
  2020年   611篇
  2019年   811篇
  2018年   4262篇
  2017年   3599篇
  2016年   3232篇
  2015年   1048篇
  2014年   1087篇
  2013年   4719篇
  2012年   2383篇
  2011年   4180篇
  2010年   3538篇
  2009年   2616篇
  2008年   3323篇
  2007年   3753篇
  2006年   1686篇
  2005年   1650篇
  2004年   1495篇
  2003年   1363篇
  2002年   1406篇
  2001年   2016篇
  2000年   2016篇
  1999年   1510篇
  1998年   732篇
  1997年   652篇
  1996年   635篇
  1993年   584篇
  1992年   1253篇
  1991年   1152篇
  1990年   1144篇
  1989年   1031篇
  1988年   1020篇
  1987年   971篇
  1986年   1050篇
  1985年   1058篇
  1984年   892篇
  1983年   805篇
  1982年   571篇
  1981年   564篇
  1979年   944篇
  1978年   671篇
  1975年   764篇
  1974年   817篇
  1973年   913篇
  1972年   772篇
  1971年   723篇
  1970年   642篇
  1969年   669篇
  1968年   858篇
  1967年   776篇
  1966年   651篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
261.
Relaxation therapy for tension headache in the elderly: a prospective study   总被引:1,自引:0,他引:1  
We evaluated the effects of an 8-week progressive muscle-relaxation therapy regimen on the headache activity of 10 elderly tension-headache subjects. Posttreatment assessment at 3 months revealed significant decreases in overall headache activity (50% or greater) in 7 subjects. Significant clinical or statistical prepost differences, or both, were also found for the number of headache-free days, peak headache activity, and medication index. This is the first prospective study of tension headache in an elderly population, and, unlike previous retrospective studies, it suggests that relaxation therapy may be an effective intervention in the treatment of such headaches.  相似文献   
262.
Although stress and anxiety have long been assumed to play an exacerbatory role in asthma, no study has systematically documented that daily exacerbations of asthma symptoms are related to stress and/or anxiety. In this study, 24 airways obstruction patients (12 asthmatics and 12 chronic obstructive pulmonary disease patients) were instructed to monitor the severity of daily respiratory symptoms. In addition, subjects recorded their daily anxiety level and the number and perceived impact of daily stressors. The results showed that although there were differences between high- and low-stress days for both groups, there were no differences between groups on symptom severity or between high- and low-anxiety days, as measured by the State-Trait Anxiety Inventory (STAI). Thus, although the number and impact of daily stressors were found to be directly associated with the severity of asthma symptoms, anxiety does not appear to have a direct role in the exacerbation of asthma. The findings failed to support the anxiety theory of asthma but provided an explanation for the poor results obtained in previous treatment studies which employed anxiety management with asthmatics.  相似文献   
263.
Two multidimensional mood-state inventories, the Profile of Mood States (POMS) and the Eight State Questionnaire (8SQ), were administered to 289 Australian college undergraduates. Intercorrelations for the combined 14 subscales were subjected to a higher-order factor analysis in order to elucidate the central clinical states within the mood-state sphere. Results suggested four major state dimensions pertaining to Neuroticism, Hostility/Anger, Vigor, and a combined Extroversion/Arousal-Fatigue entity. Both three- and five-factor solutions were taken out for comparative purposes. Furthermore, separate higher-order factorings of the POMS on normative samples of 350 male and 650 female psychiatric outpatients were conducted, corroborating three of the four central state dimensions, at least in the case of females. The implications of these findings for behavioral assessment are discussed.This study was supported by a Research Development Grant awarded to the author by the University of Melbourne.  相似文献   
264.
A comparison study is an experiment whose primary purpose is to compare directly (regardless of experimental design) at least two different procedures for changing behavior or two or more components of such a procedure. This paper argues that, in spite of their popularity, such studies typically lead to inappropriate inferences with poor generality based on improper evidence gathered in support of the wrong question, thus wasting the limited experimental resources. The discussion considers problems concerning the functions of comparison studies, the nature of the comparisons that are attempted, the generality of their findings, and the limited role that they can play in technological research.  相似文献   
265.
266.
267.
268.
269.
270.
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