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   21616篇
  免费   37篇
  国内免费   1篇
  2020年   14篇
  2018年   3495篇
  2017年   2825篇
  2016年   2259篇
  2015年   199篇
  2014年   93篇
  2013年   256篇
  2012年   582篇
  2011年   2402篇
  2010年   2532篇
  2009年   1500篇
  2008年   1731篇
  2007年   2209篇
  2006年   61篇
  2005年   250篇
  2004年   208篇
  2003年   147篇
  2002年   99篇
  2001年   53篇
  2000年   73篇
  1999年   34篇
  1998年   43篇
  1997年   40篇
  1996年   25篇
  1995年   19篇
  1994年   16篇
  1993年   15篇
  1992年   29篇
  1991年   21篇
  1990年   19篇
  1988年   10篇
  1987年   18篇
  1986年   10篇
  1985年   10篇
  1984年   16篇
  1983年   19篇
  1982年   25篇
  1981年   25篇
  1980年   13篇
  1979年   18篇
  1978年   14篇
  1977年   13篇
  1976年   12篇
  1975年   15篇
  1974年   20篇
  1973年   20篇
  1972年   13篇
  1971年   14篇
  1970年   13篇
  1969年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
The number, amplitude, duration, and bout structure of isolation-induced ultrasonic vocalization (USV) of infant rats (Rattus norvegicus) were measured on postnatal Day 10. Measurements were made before and after a brief, 1-min, active interaction with their mother or before and after a "pick-up" control procedure. Consistent with prior studies, the number of USVs emitted was significantly increased in the period following the maternal reunion but not after the control procedure. The average amplitude of USVs was also greater following maternal reunion. Finally, analyses characterizing the bout structure of USV production indicated that the average bout size (i.e. number of USVs/bout) was increased severalfold following the reunion with the mother, accounting for the greater rate of USV production during the second isolation period.  相似文献   
142.
Attentional selection of an object in the visual field degrades processing of neighboring stimuli in young adults. A pair of experiments examined the effects of aging on such localized attentional interference. In Experiment 1, younger and older observers made speeded same-different judgments of target shapes that varied in spatial separation. Performance declined for both age groups as the distance between targets decreased, but an Age x Distance interaction indicated that the magnitude of this effect was larger for older adults. Experiment 2 ruled out sensory masking as an explanation for these findings. Results indicate that older observers experience losses in the ability to attend to multiple spatially proximal stimuli within the visual field.  相似文献   
143.
This study examined the stability and continuity of early-identified behavior problems and the factors associated with this stability. Children and their mothers (N=125) were seen when the children were 2 and 4 years of age. Maternal reports of child externalizing behavior and laboratory observations of child noncompliance were stable from age 2 to age 4. Early externalizing behaviors decreased over time; however, child noncompliance in the laboratory did not. Although few associations were found between maternal positive behavior and child behavior problems, maternal controlling behavior was related to increases in child behavior problems, particularly at high levels of both prior noncompliance and prior maternal control. Child noncompliance was predictive of increases in maternal controlling behavior over time.  相似文献   
144.
Faculty members at Canadian business schools were surveyed regarding their ethical perceptions of behaviours related to undergraduate instruction. Fifty-five behavioural statements were listed and respondents were asked to rate the extent to which they felt each behaviour was ethical or unethical. The only item that respondents endorsed as unequivocally unethical (90% indicated it was definitely unethical) was Becoming sexually involved with an undergraduate in one of your classes. We also compared the results of our sample to those of an American sample. Overall, an interesting pattern of differences emerged between the responses obtained in Canada and the U.S. In general, the direction of the significant differences was such that Canadian professors viewed the behaviours in question as less ethical than did their American counterparts.  相似文献   
145.
Threats to the physical safety and psychological well-being of mental health professionals present serious problems, according to 1,131 licensed mental health professionals in the state of Georgia. The professionals included clinical social workers, marriage and family therapists, professional counselors, psychiatrists, psychologists, and social workers. From a total of 6,431 surveys sent out, 1,131 (18%) were returned. The results revealed 2.696 separate accounts of 14,120 acts of physical or psychological assaults committed by 8,292 perpetrators. The results also showed that 61% of the respondents had been victimized in violent acts of a psychological or physical nature and that 29% had feared for their lives at least once during their professional careers. These data are consistent with other research that indicates that 6 out of 10 professionals will be assaulted during their professional careers.  相似文献   
146.
147.
In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus–response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus–response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus–response mappings, causing a compatibility effect from the avatar’s point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants’ sense of agency over the avatar, a spatial compatibility effect from the avatar’s perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.  相似文献   
148.
This article focuses on the development of adolescent resilience and protective factors within a sample of 86 inner-city high school students in Chicago. Resilience was considered present when (a) children living in conditions of risk (b) show better-than-predicted outcomes (c) presumably due to some intervening process. Conditions (a) and (b) were met using quantitative comparisons. Condition (c), the intervening process, was examined using autobiographical essays to begin to understand protective factors youth consider salient in overcoming adversity. Internal attributes such as perseverance, determination, and having the awareness to learn from the risk-attrition process surfaced in the content analyses. Motivational support from family members and teachers was also highly valued for promoting successful adjustment.  相似文献   
149.
The mechanisms used to convey parents' and teachers' educational expectations for the academic achievement of low-income African American children were explored using data from the Chicago Longitudinal Study. A total of 712 children were studied. A model of mediated effects was used to test the processes of influence from parents' and teachers' expectations to sixth-grade outcomes. Children's perceptions of expectations were hypothesized to mediate the effect of expectations to school outcomes. Study findings revealed that these perceptions only partially mediated the effects of expectations to sixth-grade reading and math outcomes, yet added unique independent variance to these outcomes. Prior achievement emerged as a powerful mediator of the effects of early educational intervention and sociodemographic variables to sixth-grade outcomes. These findings suggest a need to further investigate the processes of communicating parent and teacher expectations.  相似文献   
150.
In this paper we explore parallels between Rational Emotive Behaviour Therapy (REBT) and the applications of Stoic philosophy. We look especially at the foundations of the philosophy in Chrysippus, rather than just at the writings of the better known Roman Stoics. Similarities are found against very different historical backgrounds, although there are also important differences. Our investigation highlights some peculiarly modern aspects of Ellis's philosophy, which may be inessential to the practice of REBT. At the same time REBT provides a model for interpreting Stoic practices to modern audiences.  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