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   61756篇
  免费   1668篇
  国内免费   24篇
  2020年   487篇
  2019年   644篇
  2018年   4130篇
  2017年   3475篇
  2016年   3013篇
  2015年   834篇
  2014年   852篇
  2013年   3736篇
  2012年   1899篇
  2011年   3696篇
  2010年   3351篇
  2009年   2392篇
  2008年   2959篇
  2007年   3343篇
  2006年   1241篇
  2005年   1250篇
  2004年   1174篇
  2003年   1112篇
  2002年   1023篇
  2001年   1391篇
  2000年   1390篇
  1999年   1031篇
  1998年   559篇
  1997年   461篇
  1996年   402篇
  1995年   429篇
  1994年   432篇
  1993年   410篇
  1992年   836篇
  1991年   800篇
  1990年   769篇
  1989年   704篇
  1988年   686篇
  1987年   680篇
  1986年   626篇
  1985年   703篇
  1984年   575篇
  1983年   452篇
  1982年   399篇
  1981年   395篇
  1979年   560篇
  1978年   445篇
  1977年   414篇
  1976年   393篇
  1975年   473篇
  1974年   493篇
  1973年   533篇
  1972年   414篇
  1968年   394篇
  1966年   387篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
113.
114.
115.
116.
117.
118.
119.
The purpose of this study was to determine the effects of Type A behavior and family history of hypertension on cardiovascular reactivity to mental stress in a group of employed black women. Measures of heart rate and of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were taken at rest, during a mental arithmetic task, and during the Type A Structured Interview (SI). Results indicated that the Type A behavior pattern was associated with SBP and DBP hyperresponsivity during the SI but not during mental arithmetic. Additionally, certain speech components of the Type A pattern, as well as features of the potential-for-hostility component, were also related to cardiovascular responses during the SI. Family history of hypertension did not influence the cardiovascular parameters either alone or in combination with Type A behavior. The results suggest that many of the cardiovascular response characteristics of the Type A pattern that have been observed in predominantly white samples also hold true for blacks. Replication of these findings with other subgroups of blacks, such as young females and middle-aged males, will help document the generality of these findings within the black population.  相似文献   
120.
We examined the effects of acute psychological stress on lymphocyte proliferation and circulating levels of interleukin-1 and -2. Healthy men were exposed to two viewings of a gruesome surgery film and were asked to recall details of the film twice during a 30-min period. These subjects were compared to a nonstress control group. Lymphocyte proliferation to the mitogen concanavalin A (Con A; 5 micrograms/ml) was decreased during and after exposure to the stressor when compared to the control group. This decrease was more pronounced in subjects exhibiting greater blood pressure reactivity while viewing the film than in subjects showing smaller blood pressure responses. None of the other immunological measures was significantly affected by the stressor. Cortisol was not correlated with lymphocyte responsiveness. Possible explanations for these results and implications for further research are discussed.  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