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   13850篇
  免费   202篇
  国内免费   22篇
教育   9738篇
科学研究   1535篇
各国文化   128篇
体育   1162篇
综合类   8篇
文化理论   101篇
信息传播   1402篇
  2021年   139篇
  2020年   198篇
  2019年   275篇
  2018年   373篇
  2017年   357篇
  2016年   368篇
  2015年   250篇
  2014年   329篇
  2013年   2426篇
  2012年   297篇
  2011年   321篇
  2010年   283篇
  2009年   223篇
  2008年   271篇
  2007年   242篇
  2006年   237篇
  2005年   215篇
  2004年   234篇
  2003年   211篇
  2002年   179篇
  2001年   446篇
  2000年   301篇
  1999年   258篇
  1998年   128篇
  1997年   162篇
  1996年   134篇
  1995年   136篇
  1994年   149篇
  1993年   116篇
  1992年   193篇
  1991年   194篇
  1990年   202篇
  1989年   205篇
  1988年   172篇
  1987年   160篇
  1986年   170篇
  1985年   211篇
  1984年   163篇
  1983年   153篇
  1982年   136篇
  1981年   125篇
  1980年   119篇
  1979年   172篇
  1978年   139篇
  1977年   118篇
  1976年   96篇
  1975年   116篇
  1974年   105篇
  1973年   112篇
  1971年   103篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
71.
72.
73.
You are invited to Seattle for the 1977 Annual Meeting, its theme to be "Change, Comparison, and Controversy." Suggestions are made for activities in Seattle and the Pacific Northwest, including the cohost city, Vancouver, British Columbia.  相似文献   
74.
Indexing consistency in MEDLINE   总被引:3,自引:0,他引:3  
The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases.  相似文献   
75.
76.
<正> 尽管图书馆有着漫长的历史,但是"图书馆学校除美国早期的以外,却主要是二十世纪的产物".在布赖姆莱(G. Bramley)的这个论断之外,还应该加上丹顿(J. P. Danton)的观察,即在美国、欧洲以外的世界其它地方的图书馆学校显然都是在第二次世界大战之后才兴办起来的.对世界各地图书馆学校进行研究、比较,就会发现以下一些问题,诸如专业协会的影响逾越了国界;改变高等教育的形式影响一些国家图书馆学校的建立;学校数量的递增产生了对师资的需  相似文献   
77.
The present study examined three hypotheses regarding the consequences of early brain damage for academic achievement: First, early brain insults will have a negative impact on achievement, even in children with normal intelligence. Second, underachievement in these children will be at least partially independent of IQ (i.e., not fully accounted for by a lowering of IQ within the average range). Third, normally intelligent children with histories of brain insult will also manifest selective cognitive dysfunctions. To test these hypotheses, we compared two groups of children who had recovered from Haemophilus influenzae type b meningitis. The "complicated" group consisted of children who, as a consequence of having sustained neurologic complications during their illness, were more likely to have had brain insults. Children in the "uncomplicated" group did not have complications with their illness and were regarded as having escaped significant central nervous system (CNS) pathology. Only children with normal hearing and a prorated Full Scale IQ of at least 80 (WISC-R) were considered. Group differences on the Wide Range Achievement Test-Revised were consistent with the first two hypotheses. Although the two groups had similar Verbal IQs, the complicated group also had a lower mean Performance IQ and performed less well on perceptually demanding neuropsychological tasks. Findings suggest that learning disabilities may have selective, brain-related cognitive antecedents; but they challenge the practice of using IQ criteria for clinical diagnosis.  相似文献   
78.
79.
80.
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