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   36949篇
  免费   1511篇
  国内免费   10篇
  2020年   380篇
  2019年   487篇
  2018年   671篇
  2017年   693篇
  2016年   753篇
  2015年   491篇
  2014年   648篇
  2013年   2913篇
  2012年   1135篇
  2011年   1217篇
  2010年   726篇
  2009年   756篇
  2008年   1078篇
  2007年   1051篇
  2006年   1019篇
  2005年   870篇
  2004年   881篇
  2003年   804篇
  2002年   820篇
  2001年   1088篇
  2000年   993篇
  1999年   770篇
  1998年   450篇
  1997年   374篇
  1996年   360篇
  1992年   588篇
  1991年   582篇
  1990年   557篇
  1989年   573篇
  1988年   570篇
  1987年   534篇
  1986年   552篇
  1985年   616篇
  1984年   496篇
  1983年   465篇
  1982年   404篇
  1981年   379篇
  1979年   552篇
  1978年   424篇
  1976年   403篇
  1975年   472篇
  1974年   517篇
  1973年   533篇
  1972年   425篇
  1971年   397篇
  1970年   387篇
  1969年   421篇
  1968年   495篇
  1967年   428篇
  1966年   427篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
191.
After 12-15 ejaculatory series, each consisting of several short intromissions (2- to 3-s vaginal penetration) and an ejaculation, male golden hamsters adopt an altered copulatory pattern consisting of long intromissions (5- to 25-s penetration with intravaginal thrusting). Receptivity declines and the tendency for the female to attack the male increases at about the time of this shift in copulatory pattern. Because the mean interintromission interval (III) between short intromissions is about 8 s compared to 100 s between long intromissions, it is possible that females detect this difference and adjust their mating accordingly. When the III between short intromissions from a rested male was experimentally increased to 100 s by use of a halter and lead device, the duration of lordosis was significantly less than that displayed by females paired with control males (8-s III) and virtually the same as that displayed by females paired with males that produced only long intromissions. This suggests that the female uses the temporal patterning of intravaginal stimulation as one criterion for terminating mating with a particular male.  相似文献   
192.
193.
Business organizations have become interested in recent years in the role of social support in reducing the negative effect of stress. The purpose of this research is to examine the effects of two types of social support (i.e., job and life support) on the relationships between job and life stress and burnout. Participants consisted of 270 males and 254 females. For both males and females job stress and life stress correlate positively with burnout, while job and life support were negatively correlated with burnout. The hypothesis that social support would moderate stress-burnout relationships was not supported. Neither job support nor life support moderated job stress or life stress-burnout relationships. Females exhibited significantly higher levels of burnout, job stress, and life stress than males; however, there was no difference between males and females in the amount of social support received.  相似文献   
194.
A philosophical movement, correctly called logical pragmatism, is growing up around the philosophy of W. V. O. Quine, Soviet scholars follow this development with clear and well-grounded understanding of the origins and tenets of the system. This essay continues the dialogue between contemporary Marxism-Leninism and logical pragmatism recommended by Soviet scholars.A Russian translation of this article is being published inFilosofskie nauki (Moscow).  相似文献   
195.
Attitudes toward older and younger adults: a meta-analysis   总被引:3,自引:0,他引:3  
Attitudes toward the elderly have been examined in a number of empirical studies, yet the question of whether the elderly are viewed more negatively than younger persons has not been resolved. A meta-analysis of the literature was conducted to examine this question; results demonstrated that attitudes toward the elderly are more negative than attitudes toward younger people. However, smaller differences between the evaluations of elderly and younger targets were found when (a) the study used measures of personality traits (compared with measures of competence), (b) there were a larger number of dependent measures included in the effect size, (c) specific information was provided about the target person (compared with when a general target such as old person was used), and (d) a between-subjects design (compared with a within-subjects design) was used. These results support Lutsky's (1981) conclusion that age, in and of itself, seems to be less important in determining attitudes toward the elderly than other types of information. The methodological limitations within the literature and a need to consider multiple components of attitudes toward older individuals are discussed.  相似文献   
196.
Surviving members of the Berkeley Older Generation Study were interviewed and tested with the Wechsler Adult Intelligence Scale in 1969-1970 and again in 1983-1984, when subjects' ages ranged from 73 to 93. Health was assessed by self-reports at both measurement periods. Although many individuals showed some decline in intellectual functioning, substantial individual differences were apparent at all age levels. More than one half of the subjects showed no reliable change, and a minority showed a reliable increase in verbal scores. The role of self-reported health has increasing importance in the maintenance of intellectual functioning in advanced old age.  相似文献   
197.
Clinical judgments on the treatability and prognosis of mentally disordered offeenders (MDO) may strongly influence legal dispositions and the availability of treatment resources. This study examined 1,238 discharge summaries for MDOs referred for court assessments. Psychiatrists evidenced marked variability in how often they recommended treatment and how frequently they judged patients to have a poor prognosis. Two logit analyses suggested that diagnosis and consultation by other clinicians were associated with (a) treatment recommendations (i.e., Axis I diagnosis and social work consultations) and (b) prognosis (i.e., Axis II diagnosis and psychology consultations).  相似文献   
198.
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   
199.
200.
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