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   8408篇
  免费   320篇
  国内免费   1篇
  2020年   103篇
  2019年   141篇
  2018年   157篇
  2017年   193篇
  2016年   216篇
  2015年   158篇
  2014年   203篇
  2013年   914篇
  2012年   326篇
  2011年   318篇
  2010年   234篇
  2009年   214篇
  2008年   311篇
  2007年   294篇
  2006年   280篇
  2005年   253篇
  2004年   264篇
  2003年   243篇
  2002年   293篇
  2001年   105篇
  2000年   102篇
  1999年   128篇
  1998年   138篇
  1997年   124篇
  1996年   111篇
  1995年   132篇
  1994年   109篇
  1993年   102篇
  1992年   107篇
  1991年   100篇
  1990年   91篇
  1989年   84篇
  1988年   66篇
  1987年   67篇
  1986年   69篇
  1985年   85篇
  1984年   106篇
  1983年   119篇
  1982年   115篇
  1981年   144篇
  1980年   104篇
  1979年   121篇
  1978年   125篇
  1977年   117篇
  1976年   102篇
  1975年   103篇
  1974年   105篇
  1973年   67篇
  1972年   63篇
  1969年   56篇
排序方式: 共有8729条查询结果,搜索用时 0 毫秒
951.
Prior knowledge in the domain of mathematics can sometimes interfere with learning and performance in that domain. One of the best examples of this phenomenon is in students’ difficulties solving equations with operations on both sides of the equal sign. Elementary school children in the U.S. typically acquire incorrect, operational schemata rather than correct, relational schemata for interpreting equations. Researchers have argued that these operational schemata are never unlearned and can continue to affect performance for years to come, even after relational schemata are learned. In the present study, we investigated whether and how operational schemata negatively affect undergraduates’ performance on equations. We monitored the eye movements of 64 undergraduate students while they solved a set of equations that are typically used to assess children’s adherence to operational schemata (e.g., 3 + 4 + 5 = 3 + __). Participants did not perform at ceiling on these equations, particularly when under time pressure. Converging evidence from performance and eye movements showed that operational schemata are sometimes activated instead of relational schemata. Eye movement patterns reflective of the activation of relational schemata were specifically lacking when participants solved equations by adding up all the numbers or adding the numbers before the equal sign, but not when they used other types of incorrect strategies. These findings demonstrate that the negative effects of acquiring operational schemata extend far beyond elementary school.  相似文献   
952.
Influenced by G. E. Moore, Russell broke with Idealism towards the end of 1898; but in later years he characterized his meeting Peano in August 1900 as ‘the most important event’ in ‘the most important year in my intellectual life’. While Russell discovered his paradox during his post-Peano period, the question arises whether he was already committed, during his pre-Peano Moorean period, to assumptions from which his paradox may be derived. Peter Hylton has argued that the pre-Peano Russell was thus vulnerable to (at least one version of) Russell's paradox and hence that the paradox exposes a pre-existing difficulty in Russell's Moorean philosophy. Contrary to Hylton, I argue that the Moorean Russell adhered to views which insulated him against the paradox. Further, I argue that Russell became vulnerable to his paradox as a result of changes in his Moorean position occasioned, first, by his acceptance of Cantor's theory of the transfinite, and, second, by his correspondence with Frege. I conclude with some general comments regarding Russell's acceptance of naïve set theory.  相似文献   
953.
Neuroimaging research indicates that human intellectual ability is related to brain structure including the thickness of the cerebral cortex. Most studies indicate that general intelligence is positively associated with cortical thickness in areas of association cortex distributed throughout both brain hemispheres. In this study, we performed a cortical thickness mapping analysis on data from 182 healthy typically developing males and females ages 9 to 24 years to identify correlates of general intelligence (g) scores. To determine if these correlates also mediate associations of specific cognitive abilities with cortical thickness, we regressed specific cognitive test scores on g scores and analyzed the residuals with respect to cortical thickness. The effect of age on the association between cortical thickness and intelligence was examined. We found a widely distributed pattern of positive associations between cortical thickness and g scores, as derived from the first unrotated principal factor of a factor analysis of Wechsler Abbreviated Scale of Intelligence (WASI) subtest scores. After WASI specific cognitive subtest scores were regressed on g factor scores, the residual score variances did not correlate significantly with cortical thickness in the full sample with age covaried. When participants were grouped at the age median, significant positive associations of cortical thickness were obtained in the older group for g-residualized scores on Block Design (a measure of visual-motor integrative processing) while significant negative associations of cortical thickness were observed in the younger group for g-residualized Vocabulary scores. These results regarding correlates of general intelligence are concordant with the existing literature, while the findings from younger versus older subgroups have implications for future research on brain structural correlates of specific cognitive abilities, as well as the cognitive domain specificity of behavioral performance correlates of normative gray matter thinning during adolescence.  相似文献   
954.
955.
Research on disgust in neuroscience, medicine, and psychology often relies on a disgust facial expression from a standardized set. Two studies (N = 60 and N = 160) compared this standard disgust face to a new facial expression called the “sick face” posed by three different actors asked to look as if they were sick and about to vomit. Relative to the standard disgust face, the sick face was significantly more likely to be endorsed as disgust, less likely to be endorsed as another emotion, and rated as conveying disgust more intensely. Disgust may not have a facial signal, but various faces may serve as cues to disgust.  相似文献   
956.
This study examined the long-held, but empirically untested assumption that emotional display rules at work are different from more general display rules. We examined whether the effect of context (work vs. non-work) on display rules depended on rater gender, rater country (i.e., Singapore, United States), and discrete emotion (anger, contempt, disgust, fear, sadness, and happiness). Results revealed that display rules at work involved less expressivity of emotion than did display rules outside of work for all six emotions. Further, display rules in Singapore involved less expressivity of anger, sadness, and fear than display rules in the US, with no country differences being observed for the emotions of happiness, contempt, and disgust. These results were qualified by significant country-by-gender interactions for anger, contempt, and disgust, a significant country-by-context interaction for fear, and a three-way interaction (i.e., country-by-gender-by-context) for sadness.  相似文献   
957.

This report examines the public use of personal nicknames for notorious American Twentieth Century Deviants. The analysis documents the frequency of nicknames by decade in the twentieth century, the category of the deviant act committed by the person nicknamed, and the connotations of the nicknames. The relationship between the use of nicknames for deviants, and deviants as folk heroes is explored. The data indicate that the public use of personal nicknames for deviants peaks in the 1920's and 1930's and has been declining ever since. This phenomenon parallels the decline in American's belief in the “rags to riches” type of folk hero.  相似文献   
958.
Although it is known that state initiatives can help produce moral panics, the role policy rhetoric assumes in creating, sustaining, and terminating moral panics has not been theoretically addressed. This article offers a typology of drug policies and illustrates how each is used at varying stages of a moral panic. It is argued that moral panics begin when proactive and punitive statements are used in combination. Moral panics subside when reactive and rehabilitative rhetorical statements are issued concurrently. The argument is empirically tested by analyzing the presidential addresses of the Reagan and Bush administrations for drug-related statements. Regression analysis, analysis of variance, and crosstabular analyses are used to test several hypotheses derived from the theoretical discussion. The empirical evidence supports the theoretical discussion and the constructionist perspective of social problems.  相似文献   
959.
Practical information about culturally appropriate interventions with children of incarcerated parents (CIPs) of color and their families is notably sparse. This study uses a cultural–ecological perspective to contextualize individual, family, and legal issues inherent in many intervention programs for CIPs of color. The authors highlight demographic trends, review research limitations, and discuss ways that therapeutic models can help counselors address their clients' needs. Recommendations are provided for future interventions with this underserved population. La información práctica sobre intervenciones culturalmente apropiadas con hijos de personas de color encarceladas (CIPs) por sus siglas en inglés y sus familias es notablemente escasa. Este estudio usa una perspectiva cultural‐ecológica para contextualizar los asuntos individuales, familiares y legales inherentes a muchos programas de intervención para CIPs. Los autores destacan las tendencias demográficas, las limitaciones en la investigación de reseñas, y discuten formas en las que los modelos terapéuticos pueden ayudar a los consejeros a abordar las necesidades de sus clientes. Se proporcionan recomendaciones para intervenciones futuras con esta población desatendida.  相似文献   
960.
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