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   52753篇
  免费   1471篇
  国内免费   26篇
  2020年   395篇
  2019年   519篇
  2018年   3998篇
  2017年   3321篇
  2016年   2891篇
  2015年   681篇
  2014年   682篇
  2013年   2750篇
  2012年   1675篇
  2011年   3394篇
  2010年   3094篇
  2009年   2171篇
  2008年   2562篇
  2007年   3059篇
  2006年   869篇
  2005年   945篇
  2004年   895篇
  2003年   754篇
  2002年   735篇
  2001年   1102篇
  2000年   1128篇
  1999年   809篇
  1998年   365篇
  1997年   324篇
  1996年   311篇
  1995年   328篇
  1992年   645篇
  1991年   597篇
  1990年   581篇
  1989年   548篇
  1988年   546篇
  1987年   485篇
  1986年   487篇
  1985年   536篇
  1984年   434篇
  1983年   400篇
  1982年   320篇
  1979年   475篇
  1978年   332篇
  1976年   322篇
  1975年   364篇
  1974年   432篇
  1973年   463篇
  1972年   403篇
  1971年   345篇
  1970年   320篇
  1969年   339篇
  1968年   417篇
  1967年   376篇
  1966年   365篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The ability to make egocentric distance estimates of a single point source of light, seen in darkness and without the cues of changing size and luminance, was investigated in sixteen observers. The attenuation required to maintain constant luminance, when the target was viewed from different distances, was shown to follow the inverse square law providing the angle subtended by the light was less than 20 s arc. Distance changes were also simulated by means of a split mirror which produced vergence cues, or by test lenses to provide accommodation cues. Over the range 0.5 to 9.2 m distance estimates were surprisingly accurate, although there was some overestimation of near and underestimation of far distances. Most observers made good judgements when only convergence cues were varied, whereas no observers made consistently good judgements when only accommodation cues were varied. The difficulties are discussed in terms of the accommodation-convergence link. When distance was simulated by changing convergence and accommodation cues, estimates were not as good as when real distance was changed. Since good estimates were made with brief target exposures, these judgements were not based on subsequent convergence or accommodation changes. It is suggested that the metric or reference against which the apparently absolute judgements were made was the efferent demand signal associated with a 'resting' position of convergence in darkness.  相似文献   
42.
43.
44.
Drawing on terror management theory (TMT), we discuss the psychological motivations that shape personality at two levels: the characteristically human personality common to us all and the individual differences that distinguish some people from others. TMT posits that the motivation to protect the self against deep-rooted fears about mortality drives people to maintain meaningful, reliable conceptions of reality and positive evaluations of themselves, two broad tendencies that form the foundation of every person’s personality. We review studies showing that mortality reminders increase efforts to bolster cultural sources of meaning and self-esteem in similar ways across individuals and cultures. TMT also posits that individual differences in personality partly reflect the different sources of meaning and self-esteem that people invest in to assuage mortality fears. We review evidence that individual differences predict the degree and direction of people’s defensive responses to mortality reminders. Directions for future research are discussed.  相似文献   
45.
46.
This study examines the relationship of life stress, daily hassles, and perceived self-efficacy to adjustment in a community sample of 32 men and 32 women between ages 65 and 75. In a structured interview, negative life change events, daily hassles, self-efficacy, depression, psychosomatic symptoms, and negative well being were assessed. Both negative life events and daily hassles were related to psychological distress and physical symptoms for men, and hassles were associated with psychological distress and physical symptoms for women. An inverse relationship between self-efficacy and maladjustment was also found. Hassles showed the most powerful relationship to distress.  相似文献   
47.
A meta-analysis of published studies with adult human participants was conducted to evaluate whether physical fitness attenuates cardiovascular reactivity and improves recovery from acute psychological stressors. Thirty-three studies met selection criteria; 18 were included in recovery analyses. Effect sizes and moderator influences were calculated by using meta-analysis software. A fixed effects model was fit initially; however, between-studies heterogeneity could not be explained even after inclusion of moderators. Therefore, to account for residual heterogeneity, a random effects model was estimated. Under this model, fit individuals showed significantly attenuated heart rate and systolic blood pressure reactivity and a trend toward attenuated diastolic blood pressure reactivity. Fit individuals also showed faster heart rate recovery, but there were no significant differences in systolic blood pressure or diastolic blood pressure recovery. No significant moderators emerged. Results have important implications for elucidating mechanisms underlying effects of fitness on cardiovascular disease and suggest that fitness may be an important confound in studies of stress reactivity.  相似文献   
48.
This study examined the contributions of several important domains of functioning to attention‐deficit/hyperactivity disorder (ADHD) symptoms and conduct problems. Specifically, we investigated whether cognitive inhibition, emotion regulation, emotionality, and disorganized attachment made independent and specific contributions to these externalizing behaviour problems from a multiple pathways perspective. The study included laboratory measures of cognitive inhibition and disorganized attachment in 184 typically developing children (M age = 6 years, 10 months, SD = 1.7). Parental ratings provided measures of emotion regulation, emotionality, and externalizing behaviour problems. Results revealed that cognitive inhibition, regulation of positive emotion, and positive emotionality were independently and specifically related to ADHD symptoms. Disorganized attachment and negative emotionality formed independent and specific relations to conduct problems. Our findings support the multiple pathways perspective on ADHD, with poor regulation of positive emotion and high positive emotionality making distinct contributions to ADHD symptoms. More specifically, our results support the proposal of a temperamentally based pathway to ADHD symptoms. The findings also indicate that disorganized attachment and negative emotionality constitute pathways specific to conduct problems rather than to ADHD symptoms.  相似文献   
49.
Despite this virtue's history as an instrument of women's oppression, modesty, at its most basic, means voluntary restraint of one's power, undertaken for the sake of others. It is a mechanism that modifies unequal power relationships and encourages greater compassion and fairness. I use a Christian perspective with influences from Jewish and Muslim sources to examine modesty. The modest person, I argue, must be in relationship with others, must be honestly aware of her impacts on others, must be sensitive to those impacts, compassionate toward others, and willing to hold back for others' sakes. Moreover, modesty is not only a virtue that pertains to sexuality and clothing, but it also can promote virtuous environmental behavior, particularly as it leads to awareness of, and sensitivity to, the effects of everyday behaviors on vulnerable others.  相似文献   
50.
Although a great deal of research has been conducted on the relationship between social support and physical health, the contribution of personality characteristics to this relationship has rarely been assessed. Structural equation modeling was employed to derive and test a model of the direct and indirect relationships between personality characteristics, social network size, the perceived availability of support, socially supportive behaviors, and perceived physical health with a sample of Pennsylvania adults. Significant paths indicate that individuals who perceive themselves as affiliative and as help seekers and help givers report larger social networks, receive more socially supportive behaviors, and perceive that more support is available to them. The perception that support is available shared a direct relationship with perceived physical health. The utility of including multiple measures of social support and personality characteristics related to receiving support in investigations of the relationship between social support and physical health is 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