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   19181篇
  免费   274篇
  国内免费   123篇
教育   13359篇
科学研究   2294篇
各国文化   182篇
体育   1665篇
综合类   12篇
文化理论   156篇
信息传播   1910篇
  2021年   147篇
  2020年   272篇
  2019年   420篇
  2018年   556篇
  2017年   518篇
  2016年   511篇
  2015年   329篇
  2014年   437篇
  2013年   3491篇
  2012年   408篇
  2011年   431篇
  2010年   321篇
  2009年   336篇
  2008年   364篇
  2007年   391篇
  2006年   368篇
  2005年   363篇
  2004年   343篇
  2003年   322篇
  2002年   308篇
  2001年   304篇
  2000年   330篇
  1999年   333篇
  1998年   182篇
  1997年   191篇
  1996年   240篇
  1995年   217篇
  1994年   179篇
  1993年   172篇
  1992年   266篇
  1991年   259篇
  1990年   273篇
  1989年   289篇
  1988年   239篇
  1987年   249篇
  1986年   244篇
  1985年   272篇
  1984年   243篇
  1983年   226篇
  1982年   200篇
  1981年   194篇
  1980年   185篇
  1979年   262篇
  1978年   210篇
  1977年   192篇
  1976年   167篇
  1975年   146篇
  1974年   170篇
  1973年   148篇
  1971年   130篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
26.
Duchenne Muscular Dystrophy (DMD) is a neurogenetic developmental disorder that presents with progressive muscular weakness. It is caused by a mutation in a gene that results in the absence of specific products that normally localize to muscle cells and the central nervous system (CNS). The majority of affected individuals have IQs within the normal range, generally with lower verbal than performance IQ scores. Prior work has demonstrated selective deficits on tests of verbal span and immediate memory. For the current study, 26 boys with DMD (and normal intellectual function) and their unaffected siblings were evaluated. Paired comparisons demonstrated that the children with DMD had significantly poorer academic achievement scores than their siblings, even though their vocabulary levels and home and educational environments were comparable. Children with DMD also had more behavioral concerns, physical disabilities, and poorer verbal memory spans. Linear regression indicated that behavioral concerns, executive function, and physical disability did not contribute substantially to academic performance, whereas performance on verbal span did. DMD presents with a selective developmental aberration in verbal span that has wide‐ranging consequences on learning skills.  相似文献   
27.
美国运动员米斯蒂·海曼在悉尼奥运会女子200m蝶泳比赛中击败了该项世界纪录保持者澳大利亚苏珊 ?奥尼尔,爆出了2000年一大新闻。米斯蒂的成功,首先在于确立训练目标:增强肌肉力量,改善身体组成成份。虽然,那时她的体魄已经非常健康、匀称了,体内只有16%的脂肪,但计划要她降到12%。教练员探索她发展肌肉的突破口,为她制订了符合饮食习惯的各组食谱。训练中,主要做带有力量性、平衡性、多关节的和全身的练习,如:下蹲,静力举重,大步行进中的扩胸等练习,以增大肺活量。教练员还为她设计了提高肩后部和上背部的力量、提高腰腹部的力量和改善四头…  相似文献   
28.
Book reviews     
  相似文献   
29.
For centuries publishers have acted as intermediaries between author and audience. Copyright, like freedom of expression, is an essential element of freedom in this role, because without it authors' rights are not fully protected. Only when they are protected against theft and other economic or moral infringements are authors free to express themselves without fear. Publishers, too, rely on copyright to protect their investments and their freedom Paul Nijhoff Asser has been secretary of the International Group of Scientific, Technical and Medical Publishers (STM), Amsterdam, since 1970. He has been active in publishing and bookselling for more than forty years. This article was adapted from a presentation at the seminar “East Meets West: Copyright and the Publisher in a Market Economy”, Hamburg, March 1991.  相似文献   
30.
This article focuses on several conceptual and structural issues that are central to copyright compliance in the electronic age. It presumes the development of a national electronic network for storing, organizing, accessing, managing, and charging for information. The article first discusses the implications of constructing a comprehensive electronic “highway,” or Digital Library System (DLS), which would link information to the widespread community of users. It then presents the ramifications of a highly decentralized set of subsystems serving rights holders and users, linked by protocols established by the DLS. A discussion of the implications of digital interchangeability for copyright follows. The article ends with an analysis of alternatives to existing intellectual property rights conveyance systems, and concludes that current ownership structures, and systems for conveying rights and royalties, will remain the foundation for copyright in the electronic world. This article appeared in a slightly different form in theProceedings of the Twelfth National Online Meeting—1991, and is published here with the permission of Learned Information, Inc., Medford, N.J.  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