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   507篇
  免费   24篇
  国内免费   7篇
  2023年   9篇
  2022年   12篇
  2021年   10篇
  2020年   16篇
  2019年   13篇
  2018年   31篇
  2017年   12篇
  2016年   25篇
  2015年   12篇
  2014年   11篇
  2013年   39篇
  2012年   29篇
  2011年   33篇
  2010年   29篇
  2009年   21篇
  2008年   23篇
  2007年   23篇
  2006年   18篇
  2005年   21篇
  2004年   10篇
  2003年   18篇
  2002年   8篇
  2001年   10篇
  2000年   8篇
  1999年   7篇
  1998年   5篇
  1997年   9篇
  1996年   3篇
  1995年   2篇
  1993年   2篇
  1991年   7篇
  1990年   3篇
  1989年   4篇
  1987年   3篇
  1985年   6篇
  1984年   6篇
  1983年   3篇
  1982年   3篇
  1981年   2篇
  1979年   4篇
  1978年   5篇
  1976年   1篇
  1975年   2篇
  1974年   2篇
  1973年   4篇
  1972年   1篇
  1971年   2篇
  1970年   2篇
  1968年   2篇
  1967年   1篇
排序方式: 共有538条查询结果,搜索用时 140 毫秒
411.
This study examines sex differences in the risk threshold for adolescent delinquency. Analyses were based on longitudinal data from the Pittsburgh Youth Study (n?=?503) and the Pittsburgh Girls Study (n?=?856). The study identified risk factors, promotive factors, and accumulated levels of risks as predictors of delinquency and nondelinquency, respectively. The risk thresholds for boys and girls were established at two developmental stages (late childhood: ages 10–12 years, and adolescence: ages 13–16 years) and compared between boys and girls. Sex similarities as well as differences existed in risk and promotive factors for delinquency. ROC analyses revealed only small sex differences in delinquency thresholds, that varied by age. Accumulative risk level had a linear relationship with boys’ delinquency and a quadratic relationship with girls’ delinquency, indicating stronger effects for girls at higher levels of risk.  相似文献   
412.
We investigated whether the mere presentation of single-digit Arabic numbers activates their magnitude representations using a visually-presented symbolic same–different task for 20 adults and 15 children. Participants saw two single-digit Arabic numbers on a screen and judged whether the numbers were the same or different. We examined whether reaction time in this task was primarily driven by (objective or subjective) perceptual similarity, or by the numerical difference between the two digits. We reasoned that, if Arabic numbers automatically activate magnitude representations, a numerical function would best predict reaction time; but if Arabic numbers do not automatically activate magnitude representations, a perceptual function would best predict reaction time. Linear regressions revealed that a perceptual function, specifically, subjective visual similarity, was the best and only significant predictor of reaction time in adults and in children. These data strongly suggest that, in this task, single-digit Arabic numbers do not necessarily automatically activate magnitude representations in adults or in children. As the first study to date to explicitly study the developmental importance of perceptual factors in the symbolic same–different task, we found no significant differences between adults and children in their reliance on perceptual information in this task. Based on our findings, we propose that visual properties may play a key role in symbolic number judgements.  相似文献   
413.
This study, involving 139 employees from a variety of industries, organizations, and positions in Singapore, measured the effects of mood on the intentions of employees to contribute actions that are organizationally desirable but are not part of their formal job requirements (organizational citizenship behavior). After effects of established patterns of historical organizational citizenship behavior, demographic characteristics, and employee positive and negative affectivity had been controlled, stepwise regression analysis revealed that the amount of positive affect currently experienced by an employee significantly influenced the employee's intention to perform specific acts of organizational citizenship.  相似文献   
414.
Reliability and external validity are two fundamental values that pose incompatible constraints on neurobiological experiments. The more reliability an experimental result achieves, the less external validity it earns, and vice versa. In this article, I propose an externalist interpretation of external validity: the external validity of an experimental result depends not only on how much complexity is built into an experimental design, but also on the relationship between the experimental result and other related experiments. This externalist interpretation, which explains how a neurobiological experiment can be reliable and externally valid simultaneously, suggests a new way to understand the epistemology of neurobiological experimentation.  相似文献   
415.
Objective: To determine the usefulness of Q methodology to locate and describe shared subjective influences on clinical decision making among participant physicians using hypothetical cases containing common ethical issues.

Design: Qualitative study using by-person factor analysis of subjective Q sort data matrix.

Setting: University medical center.

Participants: Convenience sample of internal medicine attending physicians and house staff (n = 35) at one midwestern academic health sciences center.

Interventions: Presented with four hypothetical cases involving urgent decision making near the end of life, participants selected one of three specific clinical actions offered for each case. Immediately afterward and while considering their decision, each respondent sorted twenty-five subjective self-referent items in terms of the influence of each statement on their decision-making process. By-person factor analysis, where participants are defined as variates, yielded information about the attitudinal background the physicians brought to their consideration of each hypothetical case. We performed a second-order factor analysis on all of the subjective viewpoints to determine if a smaller core of shared attitudes existed across some or all of the four case vignettes. Factor scores for each item and post-sort comments from interviews conducted individually with each respondent guided the interpretation of ethical perspective used by these respondents in making clinical decisions about the cases.

Measurements and Main Results: Second-order factor analysis on seventeen viewpoints used by physicians in the four hypothetical urgent decision cases revealed three moderately correlated (r 2 < 40%) subjective core attitudinal guides used broadly among all the cases and among sixteen of the seventeen original factors. Across all the cases, our participants were guided in general by: (1) patient-focused beneficence, (2) a patient- and surrogate-focused perspective that includes risk avoidance, and (3) best interest of the patient guided by ethical values. Economic impact on the physician, expediency in resolution of the situation, and the expense of medical treatment were not found to be influential determinants in this study.

Conclusions: Q sorting and by-person factor analysis are useful qualitative methodological tools to study the complex structure of subjective attitudes that influence physicians in making medical decisions. This study revealed the subjective viewpoints used by our physician participants as they made ethically challenging treatment decisions. The three second-order factors identified here are grounded in current bioethical values as well as the personal traits of physicians. The participants' decision methods appear to resemble casuistry more than principle-based decision making. Generalizability of results will require further studies.  相似文献   
416.
417.
In this article, we review past studies comparing randomized experiments to regression discontinuity designs, mostly finding similar results, but with significant exceptions. The latter might be due to potential confounds of study characteristics with assignment method or with failure to estimate the same parameter over methods. In this study, we correct the problems by randomly assigning 588 participants to be in a randomized experiment or a regression discontinuity design in which they are otherwise treated identically, comparing results estimating both the same and different parameters. Analysis includes parametric, semiparametric, and nonparametric methods of modeling nonlinearities. Results suggest that estimates from regression discontinuity designs approximate the results of randomized experiments reasonably well but also raise the issue of what constitutes agreement between the 2 estimates.  相似文献   
418.
This article describes Let's Talk, a counseling center outreach program. Counselors hold walk‐in hours across campus to engage students who might not otherwise seek counseling. Locations are chosen to reach underserved communities. Counselors offer informal consultation, a less formal alternative to traditional counseling. Este artículo describe Let's Talk (Hablemos), un programa de acercamiento a los centros de consejería. Los consejeros mantienen horas de puertas abiertas sin cita previa en distintos lugares del campus para atraer a estudiantes que de otra forma no buscarían acceso a la consejería. Las ubicaciones se eligen para alcanzar comunidades con servicios insuficientes. Los consejeros ofrecen consultas informales, una alternativa menos formal a la consejería tradicional.  相似文献   
419.
The impact of context reinstatement (CR) on eyewitness recall and identification was explored in this study. Participants viewed a video of a staged theft and, following a 1‐week interval, were asked to identify the culprit and recall the event in either the same or in a different physical environment. Results suggested that CR enhanced the perceived familiarity of the lineup members, which in turn increased participants' willingness to identify someone in the lineup. Although CR significantly improved facial discrimination and identification accuracy when the target was present, it also increased confidence ratings beyond that warranted by the increase in accuracy. In terms of recall, reinstating the study context improved participants' free recall of both central and peripheral details and cued recall of peripheral details. The results were consistent with a (mis)attribution of familiarity and the outshining hypothesis. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
420.
The Child Behaviour Checklist (CBCL) and Youth Self‐Report (YSR) are widely used measures of internalising and externalising problems in children and adolescents, but cross‐cultural differences in these problems have not been examined in Australian children of Chinese and Anglo‐Celtic ancestry. Fifty‐nine Chinese (27 boys and 32 girls) and 65 Anglo‐Celtic Australian (35 boys and 30 girls) children aged 10–13 years completed the YSR, and one of their parents completed the CBCL. Cross‐informant agreement between these two measures was also examined. No differences were found between the Chinese and Anglo‐Celtic groups on parents' and children's ratings on any syndrome or overall scales. The overall level of agreement between YSR and CBCL scores was poor in the Anglo‐Celtic group (intraclass correlation coefficient for total problems = 0.33), but there was no agreement between these scores in the Chinese group. Results highlight the need to obtain multiple sources of information in assessments of mental health problems in children from different cultural backgrounds.  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