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   41857篇
  免费   452篇
  国内免费   20篇
教育   30397篇
科学研究   3579篇
各国文化   411篇
体育   3189篇
综合类   10篇
文化理论   692篇
信息传播   4051篇
  2021年   296篇
  2020年   488篇
  2019年   736篇
  2018年   3031篇
  2017年   2941篇
  2016年   2469篇
  2015年   736篇
  2014年   862篇
  2013年   6023篇
  2012年   918篇
  2011年   1483篇
  2010年   1426篇
  2009年   999篇
  2008年   1343篇
  2007年   1759篇
  2006年   661篇
  2005年   907篇
  2004年   979篇
  2003年   842篇
  2002年   605篇
  2001年   586篇
  2000年   636篇
  1999年   543篇
  1998年   352篇
  1997年   364篇
  1996年   413篇
  1995年   367篇
  1994年   367篇
  1993年   313篇
  1992年   455篇
  1991年   470篇
  1990年   435篇
  1989年   426篇
  1988年   380篇
  1987年   366篇
  1986年   355篇
  1985年   397篇
  1984年   324篇
  1983年   335篇
  1982年   285篇
  1981年   281篇
  1980年   295篇
  1979年   385篇
  1978年   274篇
  1977年   251篇
  1976年   232篇
  1975年   203篇
  1974年   193篇
  1973年   188篇
  1971年   172篇
排序方式: 共有10000条查询结果,搜索用时 687 毫秒
1.
As medical programs place increasing importance on competency-based training and surgical simulations for residents, anatomy laboratories, and body donation programs find themselves in a position of adapting to changing demands. To better assess the demand for “life-like” cadaveric specimens and evaluate the possible impacts that competency-based medical education could have upon the body donation program of McGill University, Canada, the authors tracked, over the course of the last 10 years, the number of soft-embalmed specimens, along with the number of teaching sessions and the residents enrolled in competency-based programs that are using cadaveric material. The results reveal that the number of soft-embalmed specimens used within residency training increased from 5 in 2009 to 35 in 2019, representing an increase from 6% of bodies to 36.5% of the total number of body donors embalmed in this institution. Correspondingly, the number of annual teaching sessions for residents increased from 19 in 2012 to 116 in 2019. These increases in teaching are correlated with increasing number of residents enrolled in competency-based programs over the last 3 years (Pearson r ranging from 0.9705 to 0.9903, and R2 ranging from 0.9418 to 0.9808). Those results suggest that the new skill-centered curricula which require residents to perform specific tasks within realistic settings, exhibit a growing demand for “life-like” cadaveric specimens. Institutions’ body donation programs must, therefore, adapt to those greater need for cadaveric specimens, which presents many challenges, ranging from the logistical to the ethical.  相似文献   
2.
  • Scientific publication has been a key part of the scientific method since the inception of Philosophical Transactions in 1665.
  • The scientific publications industry has grown exponentially along with science, incorporating technological innovations along the way, and adapting journal processes and practices to changing needs of science as it matured.
  • Of all the technological innovations over more than 300 years, the move to online journals may be the most significant, making open access to content practical for the first time.
  • The open‐access movement is disrupting the economics of journal publishing, which is hoped will make the industry more competitive: the ability of the publications industry to adapt to open access will be a measure of its resilience.
  • The demand for articles published in reputable journals continues to grow as readers trust the credibility of peer reviewed journal articles, and good authors value the prestige of publishing in the best journals.
  • It is difficult to predict what new functionalities may be included in articles of the future or what additional services publishers and editors will provide, but there is every reason to believe that scientific journal articles are here to stay.
  相似文献   
3.
ABSTRACT

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.  相似文献   
4.
David Kaldewey 《Minerva》2018,56(2):161-182
This article analyzes the concept of “grand challenges” as part of a shift in how scientists and policymakers frame and communicate their respective agendas. The history of the grand challenges discourse helps to understand how identity work in science and science policy has been transformed in recent decades. Furthermore, the question is raised whether this discourse is only an indicator, or also a factor in this transformation. Building on conceptual history and historical semantics, the two parts of the article reconstruct two discursive shifts. First, the observation that in scientific communication references to “problems” are increasingly substituted by references to “challenges” indicates a broader cultural trend of how attitudes towards what is problematic have shifted in the last decades. Second, as the grand challenges discourse is rooted in the sphere of sports and competition, it introduces a specific new set of societal values and practices into the spheres of science and technology. The article concludes that this process can be characterized as the sportification of science, which contributes to self-mobilization and, ultimately, to self-optimization of the participating scientists, engineers, and policymakers.  相似文献   
5.
6.
7.
Letters     
  相似文献   
8.
Editorial     
B. Sury 《Resonance》2018,23(7):723-725
  相似文献   
9.
10.
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