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   25276篇
  免费   350篇
  国内免费   72篇
教育   18195篇
科学研究   2137篇
各国文化   260篇
体育   2061篇
综合类   50篇
文化理论   175篇
信息传播   2820篇
  2021年   250篇
  2020年   347篇
  2019年   513篇
  2018年   718篇
  2017年   764篇
  2016年   695篇
  2015年   471篇
  2014年   646篇
  2013年   4936篇
  2012年   628篇
  2011年   646篇
  2010年   558篇
  2009年   532篇
  2008年   568篇
  2007年   573篇
  2006年   561篇
  2005年   501篇
  2004年   386篇
  2003年   400篇
  2002年   353篇
  2001年   498篇
  2000年   426篇
  1999年   389篇
  1998年   221篇
  1997年   221篇
  1996年   279篇
  1995年   210篇
  1994年   241篇
  1993年   220篇
  1992年   342篇
  1991年   344篇
  1990年   353篇
  1989年   340篇
  1988年   274篇
  1987年   290篇
  1986年   303篇
  1985年   300篇
  1984年   274篇
  1983年   291篇
  1982年   237篇
  1981年   231篇
  1980年   216篇
  1979年   342篇
  1978年   266篇
  1977年   214篇
  1976年   219篇
  1975年   183篇
  1974年   187篇
  1973年   164篇
  1971年   181篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
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   
104.
105.
106.
107.
108.
109.
The literature of medical librarianship of Nigeria is reviewed. The staff structure of Nigerian univeristy libraries and, in particular, of the medical libraries attached to them is restrictive, unprogressive, and unconducive to the development of medical librarianship in Nigeria. These medical libraries should cease to be administered and regarded as just unavoidable appendages of the main university libraries. They should be independent, full-fledged libraries of their own, recognixed as full academic departments of their respective colleges or faculties, with their heads being in no way inferior in status to other heads of academic departments.The granting of faculty status to Nigerian unviersity librarians should go the whole way and let the principle of multiple professorships be applied to the staff structure of unviersity libraries. Efforts are being made to effect bibliographic organization of Nigerian medical literature. A national library of medicine for Nigeria, however, humble its beginning, should be established.  相似文献   
110.
This paper describes the procedures used at the Library of the College of Physicians of Philadelphia to divide its ninety-year-old dictionary card catalog. The division was necessitated by overcrowding, obsolete subject headings, and lack of a complete authority list which resulted in like materials being scattered throughout the catalog under several headings. Two catalogs were created: the historical-biographical catalog, representing all works published before 1950 and all works of historical or biographical nature; and the current catalog, containing all works published from 1950 on, excepting historical or biographical materials. The 1950- catalog was further divided into name and subject catalogs, and the subject section was revised according to MeSH. The project was completed in about two years. As a result, searching time has been much reduced, and the library is able to take advantage of the annual revisions of MeSH to update the subject catalog.  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