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   136篇
  免费   0篇
教育   101篇
科学研究   6篇
各国文化   1篇
体育   5篇
信息传播   23篇
  2020年   1篇
  2019年   4篇
  2018年   5篇
  2017年   5篇
  2016年   8篇
  2014年   5篇
  2013年   37篇
  2012年   2篇
  2011年   3篇
  2010年   2篇
  2009年   2篇
  2008年   4篇
  2007年   3篇
  2006年   2篇
  2005年   2篇
  2004年   4篇
  2003年   1篇
  2002年   1篇
  2001年   11篇
  2000年   1篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1990年   4篇
  1989年   1篇
  1988年   1篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1977年   1篇
  1971年   1篇
  1970年   1篇
  1965年   1篇
  1939年   2篇
排序方式: 共有136条查询结果,搜索用时 31 毫秒
1.
2.
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the co-localization of organic and inorganic species in specific layers (e.g. egg yolk paint atop a glue ground). Because of this ability to localize the analytical signal to approximately 6?µm or less, the mass spectral information can be used to produce mass-resolved and spatially-resolve images which can be correlated to previous studies of the same samples. In this study, ToF-SIMS was used to analyze a paint cross section obtained from a painting attributed to Raphael, and another from a painting by the Sienese artist Matteo di Giovanni.  相似文献   
3.
4.
This article describes the first half century of the Communist government’s supervision and management of the central-government archives of the last two dynasties. Immediately with the Communist ascent to power in 1949, the new government took great interest in assembling and protecting the country’s archival documents, readying the Ming-Qing archives for access to scholars, and preparing for publication of selected materials. By the 1980s Beijing’s Number One Historical Archives, in charge of the largest holding of Ming-Qing documents, had become the first Chinese authority to complete a full sorting and preliminary catalogues for such a collection. Moreover, to facilitate searches, an attempt has recently begun to create a subject-heading system for these and other holdings in the country. In the first half century’s final decades, foreign researchers were admitted for the first time and tours and international exchanges began to take place.
Beatrice S. BartlettEmail:
  相似文献   
5.
6.
7.
8.
9.
A review of publications in Teaching and Teacher Education over ten years (2000-2010) on teacher professional development is the subject of the paper. The first part synthesises production referred to learning, facilitation and collaboration, factors influencing professional development, effectiveness of professional development and issues around the themes. The second part, selects from the production nine articles for closer examination. The paper concludes by noting how the production brings out the complexities of teacher professional learning and how research and development have taken cognisance of these factors and provided food for optimism about their effects, although not yet about their sustainability in time.  相似文献   
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