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   15803篇
  免费   54篇
  国内免费   4篇
教育   12059篇
科学研究   1486篇
各国文化   71篇
体育   741篇
综合类   4篇
文化理论   422篇
信息传播   1078篇
  2023年   19篇
  2022年   26篇
  2021年   50篇
  2020年   83篇
  2019年   146篇
  2018年   2303篇
  2017年   2222篇
  2016年   1699篇
  2015年   209篇
  2014年   259篇
  2013年   1072篇
  2012年   343篇
  2011年   801篇
  2010年   916篇
  2009年   534篇
  2008年   764篇
  2007年   1256篇
  2006年   181篇
  2005年   493篇
  2004年   541篇
  2003年   443篇
  2002年   224篇
  2001年   77篇
  2000年   92篇
  1999年   66篇
  1998年   53篇
  1997年   63篇
  1996年   64篇
  1995年   48篇
  1994年   55篇
  1993年   39篇
  1992年   53篇
  1991年   44篇
  1990年   48篇
  1989年   39篇
  1988年   33篇
  1987年   27篇
  1986年   30篇
  1985年   24篇
  1984年   22篇
  1983年   15篇
  1982年   25篇
  1981年   31篇
  1980年   27篇
  1979年   18篇
  1978年   21篇
  1976年   21篇
  1975年   16篇
  1974年   21篇
  1973年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
997.
Diana Barnes 《Metascience》2010,19(2):255-257
  相似文献   
998.
The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (2002–2005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation.  相似文献   
999.
Organic acid disorders are inherited metabolic disorders in which organic acids accumulate in tissues and biological fluids of affected individuals. Classical organic acidurias include methylmalonic aciduria, propionic aciduria, isovaleric aciduria and maple syrup urine disease (MSUD). They are considered the most frequent metabolic disorders among severely ill children. Patients frequently present with acute symptoms early in life. 420 cases clinically suspected to have organic aciduria, with upper age limit of 12 years for a 2-year period (January 2007–December 2008) were enrolled into this study. Metabolic acidosis and neurological symptoms were the most common signs. Screening tests and thin layer chromatography were done for detection of organic acidurias. Identification and quantitation of organic acids in urine and quantification of amino acids in blood were done by high performance liquid chromatography. Out of 420 patients, 45 patients (10.7%) were found to have organic acidurias. 15 cases of methylmalonic aciduria, 16 cases of propionic aciduria, 13 cases of MSUD, and one case of isovaleric aciduria were diagnosed. Results demonstrate the importance of testing for organic acidurias. Since organic aciduria may cause irreversible brain damage if not treated, we recommend selective screening amongst severely ill children despite implied extra costs.  相似文献   
1000.
Problem solving is an important skill in the knowledge economy. Research indicates that the development of problem solving skills works better in the context of instructional approaches centered on real-world problems. But students need scaffolding to be successful in such instruction. In this paper I present a conceptual framework for understanding the effects of scaffolding. First, I discuss the ultimate goal of scaffolding—the transfer of responsibility—and one way that scholars have conceptualized promoting this outcome (fading). Next, I describe an alternative way to conceptualize transfer of responsibility through the lens of distributed cognition and discuss how this lens informs how to promote transfer of responsibility. Then I propose guidelines for the creation of problem solving scaffolds to support transfer of responsibility and discuss them in light of the literature.  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