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   47280篇
  免费   1939篇
  国内免费   34篇
  2020年   514篇
  2019年   646篇
  2018年   893篇
  2017年   964篇
  2016年   923篇
  2015年   686篇
  2014年   794篇
  2013年   3733篇
  2012年   1401篇
  2011年   1577篇
  2010年   988篇
  2009年   954篇
  2008年   1323篇
  2007年   1242篇
  2006年   1127篇
  2005年   970篇
  2004年   908篇
  2003年   929篇
  2002年   905篇
  2001年   1755篇
  2000年   1719篇
  1999年   1217篇
  1998年   533篇
  1997年   462篇
  1996年   431篇
  1992年   1017篇
  1991年   974篇
  1990年   949篇
  1989年   901篇
  1988年   852篇
  1987年   822篇
  1986年   815篇
  1985年   865篇
  1984年   687篇
  1983年   557篇
  1981年   426篇
  1979年   640篇
  1978年   493篇
  1977年   455篇
  1976年   433篇
  1975年   591篇
  1974年   654篇
  1973年   664篇
  1972年   570篇
  1971年   478篇
  1970年   442篇
  1969年   512篇
  1968年   568篇
  1967年   486篇
  1966年   557篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
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   
112.
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   
113.
Cardiovascular reactivity to video game and mental arithmetic stressors was compared among three groups of men: aerobically trained mild hypertensives, untrained mild hypertensives, and a comparison group of untrained normotensives. Relative to the untrained hypertensives, the trained hypertensives reacted to the video game with marginally smaller systolic blood pressure and diastolic blood pressure, but there were no significant differences between these groups in reactivity during the mental arithmetic task. Comparisons between each hypertensive group and the normotensive group showed that blood pressure (BP) reactivity of normotensives during the video game was generally similar to that of trained hypertensives but smaller than that of untrained hypertensives. These results indicate that aerobic training, which has been found to reduce resting BP in mild hypertensives, may also exert a favorable impact in reducing cardiovascular reactivity of hypertensives during some stressful situations.  相似文献   
114.
115.
116.
Ohne Zusammenfassung Mit 117 Abbildungen im Text.  相似文献   
117.
118.
119.
120.
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