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   194865篇
  免费   8398篇
  国内免费   157篇
  2020年   2803篇
  2019年   3465篇
  2018年   3828篇
  2017年   4201篇
  2016年   4848篇
  2015年   3960篇
  2014年   4813篇
  2013年   23504篇
  2012年   5359篇
  2011年   4688篇
  2010年   4220篇
  2009年   4964篇
  2008年   4726篇
  2007年   4278篇
  2006年   4646篇
  2005年   4525篇
  2004年   4102篇
  2003年   3689篇
  2002年   3483篇
  2001年   4372篇
  2000年   4101篇
  1999年   3742篇
  1998年   2928篇
  1997年   2725篇
  1996年   2646篇
  1995年   2472篇
  1994年   2433篇
  1993年   2392篇
  1992年   3133篇
  1991年   2944篇
  1990年   2780篇
  1989年   2687篇
  1988年   2623篇
  1987年   2604篇
  1986年   2644篇
  1985年   2894篇
  1984年   2810篇
  1983年   2526篇
  1982年   2452篇
  1981年   2416篇
  1980年   2249篇
  1979年   2571篇
  1978年   2355篇
  1977年   2298篇
  1976年   2108篇
  1975年   2301篇
  1974年   2409篇
  1973年   2355篇
  1972年   1908篇
  1971年   1850篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
781.
This study examined the independent and joint effects of cigarette smoking and caffeine consumption on blood pressure (BP) and heart rate (HR) reactions to stress in male and female college students. Following an initial physiological baseline, participants received one of four experimental treatments (paced smoking, caffeine, smoking plus caffeine, or neither) and had BP and HR measured before, during, and after two stressful tasks. The results revealed that, compared with the control condition, caffeine ingestion enhanced the magnitude of stress-induced systolic BP and HR reactions. Smoking combined additively with stress, and the joint effect of smoking and caffeine was no greater than either taken alone. Males and females were generally similar in their BP and HR responses to smoking, caffeine, and stress. Inconsistencies with previous research and possible physiological mechanisms underlying the observed effects are discussed.  相似文献   
782.
Group work as an integral part of counsellor training appears to have been under-utilised. Certainly it is the case that empirical evaluations of such group work appear rarely in guidance and counselling journals. An attempt is made to remedy these deficiencies by reviewing studies relevant to counsellor training and to report on 17 years of research and experience with group work within a counsellor training programme at a New Zealand university.  相似文献   
783.
The vocationally-indecisive individual presents a major counselling problem. The theory and research behind career indecision is discussed and a counselling approach based on identity formation is outlined. Four identity statuses — Identity Achievements, Foreclosures, Identity Diffusions, and Moratoriums — are described and counselling approaches for each are explored.  相似文献   
784.
785.
786.
Two different types of stimulus objects, a live female quail artificially adorned with bright orange feathers and an inanimate toy dog, served as conditioned stimuli. For subjects in experimental groups, the conditioned stimuli were presented shortly before access to a sexually receptive normal female quail. For subjects in control groups, exposure to the conditioned stimuli was unpaired with copulatory opportunity. Subjects in the experimental but not in the control groups quickly came to approach the location of the conditioned stimulus objects. When an adorned female quail served as the conditioned stimulus, the conditioned approach behavior was controlled by a combination of the presence of the orange adornments and the visual cues of the head and neck of the female bird, and the approach behavior persisted as the adorned female moved to new locations. When the toy dog served as the conditioned stimulus, the conditioned approach behavior was limited to the spatial cues that surrounded the toy dog during conditioning trials. Although both types of stimulus objects evoked conditioned approach behavior, only the adorned female stimulus supported copulatory behavior. This last finding indicates that copulatory behavior can become redirected toward novel stimuli as a result of conditioning, but only under special circumstances. The results are consistent with the suggestion that appetitive components of reproductive behavior are more susceptible to conditioning than consummatory components. Possible reasons for this are discussed, together with implications of the results for the contribution of conditioning processes to sexual selection.  相似文献   
787.
In a study of air traffic controllers, religious differences are found in the way Type A behavior is associated with several health status indicators. Associations between the Jenkins Activity Survey (JAS) and physical illness incidence, health-promotive behavior, diastolic and systolic blood pressure, subjective distress and impulse control problems, and alcohol consumption are examined by religious attendance, religious affiliation, and change in affiliation. Findings confirm that Type A does not vary significantly by religion. However, there are several significant findings between Type A and various health indicators. Type A is associated with illness incidence, overall and more strongly in several religion, subgroups. Type A and alcohol consumption are related positively in Protestants and converts, and negatively in churchgoing Catholics. Type A is related to impulse control problems in churchgoing Protestants and to subjective distress in churchgoing Catholics. Finally, in individuals with weak or no religious ties, Type A is associated with lower blood pressure. This last finding suggests that in some people (for example, the irreligious or unchurched), the coronary-prone behavior pattern may have cardiovascular effects which are salutary in at least one respect.The authors wish to thank Dr. Kyriakos S. Markides and Laura A. Ray for their assistance with this study. Address requests for reprints to Dr. Levin at the Institute of Gerontology, 300 North Ingalls, Ann Arbor, MI 48109.  相似文献   
788.
789.
790.
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