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   2446篇
  免费   50篇
  国内免费   1篇
教育   1604篇
科学研究   152篇
各国文化   60篇
体育   301篇
综合类   1篇
文化理论   16篇
信息传播   363篇
  2023年   9篇
  2022年   19篇
  2021年   37篇
  2020年   66篇
  2019年   126篇
  2018年   136篇
  2017年   142篇
  2016年   104篇
  2015年   77篇
  2014年   92篇
  2013年   561篇
  2012年   76篇
  2011年   69篇
  2010年   72篇
  2009年   68篇
  2008年   79篇
  2007年   73篇
  2006年   63篇
  2005年   60篇
  2004年   51篇
  2003年   47篇
  2002年   36篇
  2001年   38篇
  2000年   26篇
  1999年   31篇
  1998年   39篇
  1997年   17篇
  1996年   13篇
  1995年   20篇
  1994年   19篇
  1993年   18篇
  1992年   14篇
  1991年   13篇
  1990年   22篇
  1989年   18篇
  1988年   7篇
  1987年   9篇
  1986年   6篇
  1985年   6篇
  1984年   9篇
  1983年   13篇
  1982年   6篇
  1981年   10篇
  1980年   9篇
  1978年   4篇
  1977年   7篇
  1974年   5篇
  1972年   4篇
  1867年   3篇
  1852年   3篇
排序方式: 共有2497条查询结果,搜索用时 140 毫秒
1.
Purpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.  相似文献   
2.
3.
As a part of efforts to evaluate and monitor the increasing public investment in early childhood education, teachers are being asked to assess children's school readiness. In this study, preschool teachers and kindergarten teachers rated children's skills in three areas (kindergarten readiness, academic skills, and communication skills), and these ratings were compared with direct assessments of the children's skills. Ratings by both groups of teachers tended to be more highly related to basic skills, such as counting and number naming, than to abilities such as solving applied problems and using expressive and receptive vocabulary. Preschool teachers' ratings had a lower association with children's observed skills and abilities than kindergarten teachers' ratings. Ratings of children attending Head Start were systematically inflated, but this relationship was mediated to a significant extent by the teachers' levels of education. More educated teachers rated children in a manner consistent with the children's directly assessed skills. Implications of these findings for informing future efforts to assess school readiness by using teacher ratings are discussed.  相似文献   
4.
Objective: To determine whether information retrieval might be enhanced by making each component of a structured abstract a separately searchable field. Design: Parallel searches on records arranged so that each abstract could either be searched in its entirety or as a collection of structured fields. Subjects: Records about cardiovascular disease downloaded from MEDLINE and tested against clinical questions derived from a concurrent survey of CD-ROM use in three health science libraries. Intervention: The investigators identified terms used to structure abstracts on MEDLINE and imported the abstracts into an Idealist database prior to searching using keywords from clinical questions. Measurements and main results: recall and precision rates are given for each question in the ‘structured’ and the ‘unstructured’ set of records. Conclusions: Use of structured, rather than unstructured, abstracts improves precision at the ex-pense of recall and places heavier demands upon the searcher’s skill in choosing the correct fields within the abstract to search. Further investigation requires more accurate simulation of MEDLINE software that utilizes features such as MeSH terms, explode, facilities and delimiters.  相似文献   
5.
Thepractice of evidence-based health care requires that information on methodology be identifiedfrom databases such as MEDLINE. Up until this year there have been no designated medicalsubject headings (MeSH) for evidence-based health care. ‘EVIDENCE-BASEDMEDICINE’ appears as a MeSH term from 1997. The absence of designated MeSH forthis concept prior to 1997 provides a challenge to the searcher. This paper describes the creationof a MEDLINE search strategy to retrieve articles on the methods of evidence-based health carepublished prior to the introduction of the new term, where an optimal combination of free-textand MeSH terms is required to identify relevant material. The study examines both free-text andsubject heading searching and attempts an optimal balance of sensitivity and specificity. It beginsby examining separate free-text and subject heading searches. Sensitivity of the subject headingsearch was 33% and specificity 80%, while the free-text search produced asensitivity of 50% and a specificity of 67%. The final strategy, combining bothapproaches, was more successful with sensitivity reaching between 82 and 90% andspecificity 83%. It is therefore possible to devise a search strategy to retrieve articles on themethods of evidence-based health care with relatively successful rates of sensitivity andspecificity. The limitations of MEDLINE, however, necessitate the use of additional approachesin identifying articles on the methods of evidence-based health care.  相似文献   
6.
7.
Higher education in the United Kingdom is centrally funded, centrally planned, and insulated from market forces. It bears many similarities to the non-market centrally planned economies (CPEs) of the former Soviet Union and Eastern Europe while they struggled to reform but to retain a system of planning and central control. Examination of UK higher education and the CPEs before the transformation to market based systems highlights some of the issues facing higher education today. It also highlights the need for reforms, as well as the difficulties involved in them. Such comparison can also bring home problems faced by reformers in the transition economies.
Despite allegedly extensive reforms in UK higher education, the sector faces problems like those facing the centrally planned economies of Eastern Europe and the former USSR in the 1970s and 80s. Parallels in a number of areas are particularly striking.  相似文献   
8.
Design-based research for LIS   总被引:2,自引:0,他引:2  
Design-based research is a methodology emerging from the field of education that may hold potential for research in library and information science (LIS). Based upon the assumption that learning is situated in a real-world context, design-based research combines research, design, and practice into one process. It results in usable products that are supported by a theoretical framework. While definitional and methodological issues do exist, the method holds some promise for research into “user-centered” information systems and services. In the field of LIS, design-based research might contribute to our understanding of how people find, choose, understand, and use information in context. The method is also of interest to professionals concerned with “evidence-based practice.” This article will first explain and describe the method as it has been used in the allied field of education. Issues related to definition and methodology will be explored, as well as some of the solutions that have been proposed. The method will then be related to LIS, using the bonded design work of Large, Nesset, Beheshti, and Bowler [Large, A., Nesset, V., Beheshti, J., & Bowler, L. (2006a). Bonded design: a methodology for designing with children. In S. Kurniawan & P. Saphiris (Eds.), Advances in Universal Web Design and Evaluation: Research, Trends and Opportunities. London: Idea Group., Large, A., Nesset, V., Beheshti, J., & Bowler, L. (2006b). “Bonded design”: a novel approach to intergenerational information technology design. Library and Information Science Research, 28, 64–82] as a case study to demonstrate the applicability of design-based research to LIS inquiry.  相似文献   
9.
10.
Hayes, Glynn, and Shanahan (2005) defined self-censorship asthe withholding of one’s opinion around an audience perceivedto disagree with that opinion. They argued that people differin their willingness to self-censor and introduced an 8-itemself-report instrument, the Willingness to Self-Censor scale,to measure this individual difference. The results of an experimentalstudy presented here provide further evidence of the constructvalidity of the scale. Each participant in the study was presentedwith a hypothetical scenario that contained information suggestinga group of people the participant was conversing with abouta controversial topic held opinions that were either uniformlysimilar to or different from the participant’s own opinion.Four weeks prior, each participant had responded to the Willingnessto Self-Censor scale and a measure of dispositional shyness.As expected, the manipulation of the climate of opinion affectedwillingness to express an opinion to the group, but more soamong those who scored relatively high on the Willingness toSelf-Censor scale. These results support the notion that somepeople rely on information about the climate of opinion moreso than do others when they decide whether or not to voice theiropinion publicly, and they suggest that the Willingness to Self-Censorscale measures this individual difference.  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