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   4996篇
  免费   306篇
  2023年   46篇
  2022年   63篇
  2021年   102篇
  2020年   155篇
  2019年   162篇
  2018年   229篇
  2017年   230篇
  2016年   215篇
  2015年   155篇
  2014年   162篇
  2013年   535篇
  2012年   286篇
  2011年   262篇
  2010年   146篇
  2009年   155篇
  2008年   209篇
  2007年   211篇
  2006年   170篇
  2005年   139篇
  2004年   126篇
  2003年   112篇
  2002年   115篇
  2001年   73篇
  2000年   84篇
  1999年   59篇
  1998年   61篇
  1997年   40篇
  1996年   34篇
  1995年   25篇
  1994年   31篇
  1993年   37篇
  1992年   41篇
  1991年   55篇
  1990年   35篇
  1989年   40篇
  1988年   27篇
  1987年   31篇
  1986年   29篇
  1985年   35篇
  1984年   25篇
  1983年   23篇
  1982年   35篇
  1981年   34篇
  1980年   33篇
  1979年   29篇
  1978年   27篇
  1975年   33篇
  1974年   36篇
  1973年   26篇
  1972年   24篇
排序方式: 共有5302条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
It is widely assumed that reinforcers are biologically relevant stimuli, or stimuli that have been associated with biologically relevant stimuli. However, brief, arbitrary stimuli have also been reported to have reinforcement-like effects, despite being unrelated to biologically relevant stimuli like food. The present study explored the potential reinforcement-like effects of brief stimuli across 5 experiments. In Experiments 1 through 4, pigeon subjects responded for food reinforcement and brief stimulus presentations in a 2-component multiple schedule. Neither baseline response rates nor resistance to change during disruption tests were systematically greater in a component with versus without brief stimulus presentations. Increasing the rate and duration of brief stimulus presentations in Experiment 4 did not reveal reinforcement-like effects when compared directly with food. In Experiment 5, pigeons chose between independent terminal links in a concurrent-chains procedure. Across conditions, varying the location, duration, and rate of brief stimulus presentations in the terminal links had no systematic effects on preference. In contrast, varying rates of food reinforcers resulted in large and reliable shifts in preference. Therefore, the present study found no systematic evidence that brief stimuli unrelated to food reliably increase response rates, resistance to change, or preference. These data demonstrate the value of systematic replication, and a behavioral momentum approach to assessing potential reinforcement-like effects.  相似文献   
5.
This study examined the role of illness uncertainty in pain coping among women with fibromyalgia (FM), a chronic pain condition of unknown origin. Fifty-one FM participants completed initial demographic and illness uncertainty questionnaires and underwent 10-12 weekly interviews regarding pain, coping difficulty, and coping efficacy. Main outcome measures included weekly levels of difficulty coping with FM symptoms and coping efficacy. Multilevel analyses indicated that pain elevations for those high in illness uncertainty predicted increases in coping difficulty. Furthermore, when participants had more difficulty coping, they reported lower levels of coping efficacy. Results were consistent with hypothesized effects. Illness uncertainty accompanied by episodic pain negatively influenced coping efficacy, an important resource in adaptation to FM.  相似文献   
6.
7.
How do speakers design what they say in order to communicate effectively with groups of addressees who vary in their background knowledge of the topic at hand? Prior findings indicate that when a speaker addresses a pair of listeners with discrepant knowledge, that speakers Aim Low, designing their utterances for the least knowledgeable of the two addressees. Here, we test the hypothesis that speakers will depart from an Aim Low approach in order to efficiently communicate with larger groups of interacting partners. Further, we ask whether the cognitive demands of tracking multiple conversational partners' perspectives places limitations on successful audience design. We find that speakers can successfully track information about what up to four of their partners do and do not know in conversation. When addressing groups of 3–4 addressees at once, speakers design language based on the combined knowledge of the group. These findings point to an audience design process that simultaneously represents the perspectives of multiple other individuals and combines these representations in order to design utterances that strike a balance between the different needs of the individuals within the group.  相似文献   
8.
Native Hawaiian high school students, N = 1779, were surveyed for symptoms of psycho-pathology and suicide attempts in the previous 6 months. Seventy-seven (4.3%) of the students reported making a suicide attempt. There were no significant differences in prevalence rates for males and females. Depression, anxiety, aggression, substance abuse symptoms, and low family support, but not peer support, were significantly correlated with suicide attempts. On logistic regression, depression, substance abuse, and family support independently predicted attempts. The lack of gender difference may indicate a cultural characteristic of the Hawaiian population that differentiates it from mainstream American populations but likens it to the Native American population.  相似文献   
9.
Three recent books focus, in different ways, on the idea of human rights and its relation to religion and religious ethics. All three books discussed here address criticisms of the human rights idea and seek to establish the relationship of religion and human rights with regard to the field of policy. The present discussion begins with an overview that places these three books in the larger context of the development of the human rights idea and its historical relationship with religion. It then turns to Little's book, next to the collection of essays edited by Twiss, Simion, and Petersen, which is described internally as a Festschrift for Little, and then to Hogan's book, and in the final section it explores comparisons among the books.  相似文献   
10.
Twenty-six suicide attempters, 9 to 18 years of age, were compared with 725 nonattempters on measures of school achievement, educational goals, socioeconomic status, and depression. As has been found in studies using clinical samples, suicide attempters in our communitybased sample had significantly lower school achievement than nonattempters. The relationship between attempted suicide and low school achievement seemed to be explained by the effects of depression. Lower-SES youth tended to be more likely to attempt suicide than higher-SES youths. However, SES appeared to have little effect on the relationship between attempted suicide and school achievement. Results also suggest that children of mothers with low educational goals for them may be more at risk for attempted suicide than youths whose mothers have higher educational goals for their children.This research was supported by the National Institute of Mental Health, Grant No. MH36971.  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