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   341篇
  免费   8篇
教育   244篇
科学研究   56篇
体育   23篇
文化理论   1篇
信息传播   25篇
  2023年   4篇
  2022年   4篇
  2021年   3篇
  2020年   13篇
  2019年   10篇
  2018年   10篇
  2017年   20篇
  2016年   11篇
  2015年   5篇
  2014年   13篇
  2013年   60篇
  2012年   9篇
  2011年   7篇
  2010年   13篇
  2009年   6篇
  2008年   7篇
  2007年   5篇
  2006年   7篇
  2005年   5篇
  2004年   7篇
  2003年   12篇
  2002年   16篇
  2001年   8篇
  2000年   4篇
  1999年   7篇
  1998年   2篇
  1997年   3篇
  1996年   4篇
  1995年   4篇
  1994年   4篇
  1993年   4篇
  1992年   2篇
  1991年   4篇
  1988年   4篇
  1985年   4篇
  1983年   3篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1973年   4篇
  1968年   2篇
  1966年   2篇
  1925年   1篇
  1923年   1篇
  1922年   2篇
  1920年   1篇
  1899年   1篇
  1897年   2篇
  1850年   1篇
排序方式: 共有349条查询结果,搜索用时 15 毫秒
301.
Working memory in a bottlenosed dolphin was tested in both indirect and direct auditory delayed-discrimination tasks in which a correct spatial response was conditional upon the nature of a preceding sound. In the indirect task, either one of two possible sounds was briefly presented. After a prescribed delay, the dolphin was cued to go either to a left-hand or right-hand paddle pair. Responses to the outer paddle of a pair were rewarded following sound A, and responses to the inner paddle of a pair were rewarded after sound B. In the direct delayed-discrimination task, only one paddle pair was used in each session. In both tasks, the delay interval between the discriminative sound stimulus and the opportunity for a spatial response was progressively increased over sessions until the animal failed to meet a specified performance criterion or self-terminated a session. Delay limits of about 30 and 60 sec were obtained in the indirect and direct tasks, respectively. The increase in delay limit in the latter task was attributable to the use of an overt mediational response during the longer delays. In both cases, however, the obtained delay limits fell considerably short of the 2- to 3-min limits obtained in auditory delayed-matching studies using the same test sounds and the same subject. The task differences indicate that working memory functions cannot depend upon memory of the predelay stimulus alone, but must be determined in part by additional processes.  相似文献   
302.
The ability to understand false beliefs is critical to a concept of mind. Chandler, Fritz, and Hala challenge recent claims that this ability emerges only at around 4 years of age. They report that 2- and 3-year-olds remove true trails and lay false ones to mislead someone about the location of a hidden object. Experiment 1 confirmed that 2- and 3-year-olds produce apparently deceptive ploys, but they produce them less often than 4-year-olds, require prompting, and rarely anticipate their impact on the victim's beliefs or search. In addition, Experiment 2 showed that 3-year-olds produce deceptive and informative ploys indiscriminately, whether asked to mislead a competitor or inform a collaborator. By contrast, 4-year-olds act selectively. The results support earlier claims that an understanding of false beliefs and deceptive ploys emerges at around 4 years of age. 2- and 3-year-olds can be led to produce such ploys but show no clear understanding of their effect.  相似文献   
303.
Because ethnicity is a basis for defining peer crowds in ethnically diverse American high schools, some may question whether crowds foster discrimination and stereotyping or affirm minority youths' positive ties to their ethnic background. Through examination of both self- and peer ratings of crowd affiliation among 2,465 high school youth aged 14–19 years, this study assesses the likelihood that African American, Asian American, Latino, and multiethnic adolescents are associated with ethnically defined crowds. Crowd affiliations are related to friendship patterns among all groups, positive features of ethnic orientation for Asian and Latino youth, but also some aspects of stereotyping and discrimination for Latinos. Results emphasize ethnic diversity in the role that peer crowds play in minority adolescents' social experiences.  相似文献   
304.
This article reports on the findings of an international online survey of early career researchers (ECRs) with regard to their authorship and peer review, attitudes, and practices, which sought to discover how the new wave of researchers were utilizing these key aspects of the scholarly communications system. A questionnaire was developed on the back of a 3‐year longitudinal, qualitative study and was distributed through publisher lists, social media networks, university networks, and specialist ECR membership organizations. Identical English, Polish, Russian, Chinese, Spanish, and French versions of the questionnaire were used. Results from 1,600 respondents demonstrated that 82.7% had co‐authored a paper, and most had performed a variety of authorship tasks. Almost half the respondents reported being subject to various authorship policies, although a quarter said they were not aware of any such policies. Almost all Chinese ECRs reported being subject to authorship policies, but only a third of UK ECRs reported the same. Three‐quarters of ECRs had experience in responding to peer review, and half had been peer reviewers. Half the respondents had a good experience of review and viewed it as a valuable way to improve their authorship skills. However, there was some criticism of some shortcoming such as lengthy peer review and superficial or uninformed comments by reviewers. Double‐blind review was the preferred methodology, and there were few suggestions for how to improve the review process.  相似文献   
305.
A study from the Harbingers research project provides a comprehensive assessment of the main features of the scholarly communications system as viewed by early career researchers (ECRs) in the final year of the study (2018). Aspects covered are: discovery and access, authorship practices, peer review, publishing strategies, open access publishing, open data, sharing, collaboration, social media, metrics, impact, reputation, libraries, publishers, and scholarly transformations. Nearly 120 science and social science researchers from seven countries were questioned about these 16 aspects. It was found that some scholarly features work well for ECRs, and in this category can be included: discovery and access, authorship practices, sharing, collaboration, and publishers. Reputation, publishing strategies, and impact are more problematical, and they, in turn, cause tensions regarding some other factors – social media, open access, and open data. Of the rest, libraries are largely invisible, and ECRs have conflicting views concerning ethical behaviour. Few envisage that transformational change will take place in the next 5 years.  相似文献   
306.
This exploratory study of elementary school science examines questions central to policy, practice and research on formative assessment: What is the quality of teachers’ content-pedagogical and assessment knowledge? What is the relationship between teacher knowledge and assessment practice? What is the relationship between teacher knowledge, assessment practice and student learning? Drawing on multiple measures, hierarchical linear modelling and path analysis, results suggest that despite weaknesses in teachers’ content-pedagogical and assessment knowledge, teachers’ formative assessment practices are positively related to student learning. Relationships between teachers’ knowledge and assessment practices are mixed. Findings underscore both the potential and challenge of bringing effective formative practice to fruition as well as the need for continued research.  相似文献   
307.
308.
All too often, curriculum development had lead to the self-destructive situation of the overloading of the curriculum. To address such a situation in post-War Germany, Josef Derbolav discusses one criterion of selection, the exemplary, drawing on the every-day sense of the word 'example'. Those themes that are worth teaching become examples for others. They must open up a part of humanity. Classroom work has to disclose these possibilities to the students.  相似文献   
309.
310.
Matrix and operational methods together provide a compact, convenient and systematic solution of transients. This paper illustrates the application of these methods to the solution of active four-terminal networks. First, the matrices are written with the Laplacian operator, s, as the parameter. Second, the vacuum tube as a four-terminal network is reviewed. Third, an example is given which illustrates the use of the method.  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