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   15198篇
  免费   186篇
  国内免费   11篇
教育   10347篇
科学研究   2008篇
各国文化   120篇
体育   1060篇
综合类   5篇
文化理论   102篇
信息传播   1753篇
  2021年   160篇
  2020年   210篇
  2019年   311篇
  2018年   475篇
  2017年   420篇
  2016年   407篇
  2015年   250篇
  2014年   389篇
  2013年   2679篇
  2012年   333篇
  2011年   364篇
  2010年   321篇
  2009年   288篇
  2008年   347篇
  2007年   288篇
  2006年   280篇
  2005年   250篇
  2004年   288篇
  2003年   208篇
  2002年   215篇
  2001年   308篇
  2000年   302篇
  1999年   276篇
  1998年   161篇
  1997年   192篇
  1996年   182篇
  1995年   133篇
  1994年   147篇
  1993年   150篇
  1992年   263篇
  1991年   230篇
  1990年   216篇
  1989年   232篇
  1988年   207篇
  1987年   191篇
  1986年   182篇
  1985年   189篇
  1984年   160篇
  1983年   174篇
  1982年   134篇
  1981年   123篇
  1980年   116篇
  1979年   180篇
  1978年   143篇
  1977年   131篇
  1976年   108篇
  1975年   94篇
  1974年   109篇
  1973年   101篇
  1972年   91篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
1.
2.
ABSTRACT

This forum brings together food, (in)security, and communication. The authors participating in this forum center communication as both process and tool for understanding, mitigating, and making meaning of food (in)security. The nine authors together discuss the role of communication in food (in)security, the central challenges for scholars and practitioners working on food (in)security, and the creative possibilities and impacts influencing the future of food (in)security. The forum produces a call for applied scholars to re-imagine communication frameworks in order to make meaningful differences in their communities.  相似文献   
3.
A significant number of archaeological finds of the 13th–16th century from the Tuscan sites of Germagnana and Gambassi in Valdelsa—FI, was studied by different physico-chemical investigations (SEM–EDS, ICP, Mössbauer spectroscopy, XRD, XRF, TG-DTA) in order to contribute to clarify the production methodology and the pre-industrial glass manufacture technology. The studied samples are mainly non-vitreous finds as production waste, refractory materials, crucibles and raw materials; also vitreous finds as frits, skims, glasses (glass masses, glass working waste and finished products) have been taken into consideration. The obtained petrographic and physico-chemical data strongly suggest that both Gambassi and Germagnana glass manufactures were strictly connected with the sources of vitrifiable materials, situated in Tuscan sand quarries. In particular a comparison between sands from the neighbouring quarries and appropriate finds of the two archaeological sites evidences that the employed vitrifiable materials possibly belong to La Casina La Cava resort. The archaeological classification, based on macroscopic observation and stratigraphic position, was compared and verified with the scientific classification of the examined finds of Germagnana and Gambassi sites based on their composition, morphology and physico-chemical properties.  相似文献   
4.
5.
6.
Gordon  R. S.  Franklin  K. L.  Baker  J.  Davies  B. 《Sports Engineering》2004,7(3):131-138
Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle...  相似文献   
7.
8.
The aim of this study was to investigate the effects of extensive endurance training (15-25 h per week) on the development of maximal oxygen uptake (VO2 max) in boys from puberty. Maximal oxygen uptake was measured a number of times each year from the age of puberty and for the next 6-9 years in seven young male elite cross-country skiers. Mean VO2 max was measured as 76.3 and 80.1 ml kg-1 min-1 at the ages of 14 and 15 years respectively. Despite the fast rate of growth during puberty, maximal aerobic power showed seasonal variations from the age of 14, reaching a plateau at the age of 15, whereas VO2 max (ml kg-2/3 min-1) increased continuously. It is concluded that, during puberty, boys probably attain significant increases in VO2 max when appropriate amounts of endurance training are undertaken.  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