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   24191篇
  免费   426篇
  国内免费   15篇
教育   17272篇
科学研究   2140篇
各国文化   227篇
体育   2038篇
综合类   13篇
文化理论   182篇
信息传播   2760篇
  2022年   184篇
  2021年   271篇
  2020年   410篇
  2019年   658篇
  2018年   893篇
  2017年   862篇
  2016年   740篇
  2015年   451篇
  2014年   698篇
  2013年   4713篇
  2012年   665篇
  2011年   670篇
  2010年   488篇
  2009年   511篇
  2008年   565篇
  2007年   497篇
  2006年   458篇
  2005年   426篇
  2004年   394篇
  2003年   377篇
  2002年   358篇
  2001年   497篇
  2000年   424篇
  1999年   376篇
  1998年   213篇
  1997年   225篇
  1996年   247篇
  1995年   240篇
  1994年   197篇
  1993年   212篇
  1992年   333篇
  1991年   311篇
  1990年   306篇
  1989年   312篇
  1988年   267篇
  1987年   310篇
  1986年   275篇
  1985年   315篇
  1984年   261篇
  1983年   222篇
  1982年   196篇
  1981年   173篇
  1980年   160篇
  1979年   271篇
  1978年   188篇
  1977年   173篇
  1976年   155篇
  1975年   143篇
  1974年   154篇
  1971年   148篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
162.
ABSTRACT

Press credentialing practices are a vital, yet understudied site of scholarly research on journalistic norms and practices. Press credentialing not only structures internal professional hierarchies, but they also signify the boundaries of the journalistic field itself. This paper explores the legal and theoretical implications of press credentialing to cover the United States Congress, drawing on the concepts of boundary work and journalistic authority to demonstrate the material impact of the space between fields on professional legitimation in journalism. Using WorldNetDaily (WND) as a case study, I argue that the Standing Committee of Correspondents (SCC) occupies a hybrid boundary zone between the journalistic and political fields, generating a unique tension in First Amendment jurisprudence that places journalists in a paradoxical role as both the professional embodiments of free speech and its constitutional steward. The resulting jurisdictional conflict between the SCC and WND extends the relational model of journalistic authority by articulating how journalist-state relations can fundamentally augment the process of legitimation at its fuzzy boundaries. The relevance and implications for press credentialing practices in the digital age are discussed.  相似文献   
163.
164.
165.
166.
167.
ABSTRACT

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.  相似文献   
168.
Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   
169.
ABSTRACT

With increasing demand for improved medical equipment and healthcare, next-generation biomedical engineers need strong design skills. Equipping biomedical engineering students with tools for idea generation and development can increase student design success. Design Heuristics are an ideation tool developed through empirical studies of product designs. While identified in the mechanical engineering space, Design Heuristics may be applicable in biomedical engineering design. In our study, we implemented a Design Heuristics session during upper-level undergraduate and first-year graduate biomedical engineering design courses. We examined the applicability of Design Heuristics within individual and team concept generation contexts. The findings demonstrated that biomedical engineering students were able to use Design Heuristics to generate multiple concepts, and that initial concepts produced using Design Heuristics were carried over into final team design. The results support the applicability of Design Heuristics to student idea generation in biomedical engineering design.  相似文献   
170.
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