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   842篇
  免费   3篇
  国内免费   1篇
教育   696篇
科学研究   20篇
各国文化   4篇
体育   65篇
综合类   2篇
文化理论   7篇
信息传播   52篇
  2023年   4篇
  2020年   9篇
  2019年   19篇
  2018年   17篇
  2017年   25篇
  2016年   28篇
  2015年   22篇
  2014年   23篇
  2013年   220篇
  2012年   16篇
  2011年   14篇
  2010年   22篇
  2009年   15篇
  2008年   13篇
  2007年   13篇
  2006年   22篇
  2005年   15篇
  2004年   14篇
  2003年   17篇
  2002年   15篇
  2001年   6篇
  2000年   17篇
  1999年   10篇
  1998年   16篇
  1997年   14篇
  1996年   12篇
  1995年   18篇
  1994年   8篇
  1993年   7篇
  1992年   16篇
  1991年   6篇
  1990年   12篇
  1989年   11篇
  1988年   9篇
  1987年   4篇
  1986年   6篇
  1985年   7篇
  1984年   5篇
  1983年   10篇
  1982年   11篇
  1981年   5篇
  1980年   8篇
  1979年   13篇
  1978年   6篇
  1975年   5篇
  1974年   4篇
  1972年   4篇
  1970年   8篇
  1968年   6篇
  1967年   4篇
排序方式: 共有846条查询结果,搜索用时 121 毫秒
1.
2.
3.
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   
4.
<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   
5.
A comparison of 1,096 professional journalists in China and the United States on attitudes toward attribution and plagiarism reveals Chinese journalists were more likely to see attribution as a practice to be embraced regardless of career longevity and culture, suggesting journalistic norms are more important than a collectivist orientation. Attribution was more likely to be embraced by those who see principles as more important than expediency, affirming research that plagiarism is hardly a monolithic concept. Overall, journalists in the two nations did not vary significantly in their attitudes toward plagiarism, despite vast differences in culture and politics as well as evidence that in some other fields China is more accepting of reusing material without attribution. The data show that among journalists, attitudes toward plagiarism are shared across national boundaries, reinforcing related research showing that a journalism culture exists and is shared at least in part across national boundaries.  相似文献   
6.
7.
Students with Attention Deficit Hyperactivity Disorders (ADHD) frequently experience significant difficulty mastering basic academic skills. This meta‐analysis focuses on one specific potential area of learning difficulties for these students: namely, writing. To identify the extent and depth of the potential writing challenges faced by students with ADHD, we conducted a meta‐analysis comparing the writing performance of grade 1 to 12 students with ADHD to their normally achieving peers. We located 44 papers, yielding 45 studies with 87 effect sizes. The average weighted effect sizes showed that students with ADHD obtained lower scores than their normally achieving peers for writing quality (–0.78), output (–0.64), number of genre elements (–0.69), vocabulary (–0.76), spelling (–0.80), and handwriting (–0.62). Contrary to expectations, moderator analyses found that neither study quality nor the source from which ADHD students were drawn (i.e., school/community vs. clinic/hospital) accounted for variability above sampling error alone.  相似文献   
8.
9.
Rats are typically less accurate in their arm selections in the radial maze over successive trials in a session (Roberts & Dale, 1981). In the present study, rats’ choice accuracy declined when such trials were separated by 2-min (massed) but not by 2-h (spaced) intertriai intervals. Changing intramaze visual/tactile arm stimuli (Experiments 1 and 3) or extramaze landmark stimuli (Experiment 4) between trials weakened the massed-trials effect, but changing the number of food pellets per arm, either alone or in conjunction with changes in intramaze cues (Experiments 2 and 3), did not. The rats also tended to avoid the spatial locations of their last four choices on a previous trial during their first four choices on a current trial, and more so with massed than with spaced trials. These findings indicate that intertriai proactive interference (PI) occurred only with massed trials and was weakened by changing intra- and extramaze cues between such trials.  相似文献   
10.
Animals were presented with (1) one solution which differed from that of the test solution, (2) a series of distinctly flavored solutions whose flavors differed from that of the test solution, or (3) with a flavored solution whose flavor was the same as that of the test solution. When animals received the solution whose flavor was the same as that of the test solution prior to a test for neophobia and prior to a conditioning trial, neophobia was reduced and aversions were weakened. However, when animals received a solution or a series of solutions whose flavors differed from that of the test solution, neophobia was reduced but conditioned aversions were unaffected. Presentations of solutions that differed from the test solution following aversion formation left the association between the taste of the test solution and the effects of the aversion-inducing treatment intact. In a final experiment it was discovered that neophobia was reduced as much when animals drank solutions whose flavors changed every third day as when they drank the same solution throughout testing.  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