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   2497篇
  免费   47篇
  国内免费   4篇
教育   1967篇
科学研究   119篇
各国文化   39篇
体育   130篇
综合类   1篇
文化理论   18篇
信息传播   274篇
  2023年   10篇
  2022年   14篇
  2021年   32篇
  2020年   46篇
  2019年   70篇
  2018年   110篇
  2017年   100篇
  2016年   97篇
  2015年   55篇
  2014年   72篇
  2013年   535篇
  2012年   61篇
  2011年   78篇
  2010年   54篇
  2009年   57篇
  2008年   75篇
  2007年   74篇
  2006年   67篇
  2005年   48篇
  2004年   37篇
  2003年   38篇
  2002年   49篇
  2001年   31篇
  2000年   44篇
  1999年   41篇
  1998年   27篇
  1997年   37篇
  1996年   34篇
  1995年   36篇
  1994年   44篇
  1993年   41篇
  1992年   34篇
  1991年   28篇
  1990年   34篇
  1989年   24篇
  1988年   12篇
  1987年   14篇
  1986年   22篇
  1985年   22篇
  1984年   21篇
  1983年   20篇
  1982年   16篇
  1981年   17篇
  1980年   12篇
  1979年   8篇
  1978年   16篇
  1977年   7篇
  1976年   7篇
  1975年   9篇
  1974年   9篇
排序方式: 共有2548条查询结果,搜索用时 15 毫秒
1.
2.
Thepractice of evidence-based health care requires that information on methodology be identifiedfrom databases such as MEDLINE. Up until this year there have been no designated medicalsubject headings (MeSH) for evidence-based health care. ‘EVIDENCE-BASEDMEDICINE’ appears as a MeSH term from 1997. The absence of designated MeSH forthis concept prior to 1997 provides a challenge to the searcher. This paper describes the creationof a MEDLINE search strategy to retrieve articles on the methods of evidence-based health carepublished prior to the introduction of the new term, where an optimal combination of free-textand MeSH terms is required to identify relevant material. The study examines both free-text andsubject heading searching and attempts an optimal balance of sensitivity and specificity. It beginsby examining separate free-text and subject heading searches. Sensitivity of the subject headingsearch was 33% and specificity 80%, while the free-text search produced asensitivity of 50% and a specificity of 67%. The final strategy, combining bothapproaches, was more successful with sensitivity reaching between 82 and 90% andspecificity 83%. It is therefore possible to devise a search strategy to retrieve articles on themethods of evidence-based health care with relatively successful rates of sensitivity andspecificity. The limitations of MEDLINE, however, necessitate the use of additional approachesin identifying articles on the methods of evidence-based health care.  相似文献   
3.
4.
5.
6.
Policies for responding to allegations of fraud in research   总被引:1,自引:0,他引:1  
Greene PJ  Durch JS  Horwitz W  Hooper VS 《Minerva》1985,23(2):203-215
  相似文献   
7.
8.
Last year 1279 professional authors completed a lengthy questionnaire on their use of, and attitudes towards, technological tools for writing and publishing. The data were analysed quantitatively, by examining the most frequent responses to items on the questionnaire, and qualitatively, by looking closely at details illuminating the relationship between authors and publishers. The results, for present purposes, are divided into three broad bands of interest: first, what types of writing software authors are currently using; second, what the implications of using authors' disks in the publication chain are; and third, how technology alters perceptions of the copy as a unit of sale. Findings suggest that though authors are operating at basic levels, they have embraced technology with more enthusiasm than their publishers. The challenge facing those involved in books is to make provision for presenting and displaying work in electronic form: to improve contracts and licensing agreements, and to disseminate information on technology to authors.Funded by the British National Bibliography Reseach Fund.© Jane Dorner, 1991  相似文献   
9.
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   
10.
ABSTRACT

This paper examines how conservators engage with uncertainty when creating preventive conservation strategies. It argues that by recognising contexts in which uncertainty will be encountered conservators can develop effective management strategies. A typology of uncertainty explores a range of categories of uncertainty, their experience in preventive conservation and identifies distinct approaches to manage them. Managing uncertainty may include acts of defining its parameters, exposing and resolving through communication or protecting from with contingency. Whatever approach is adopted it must be accepted that uncertainty cannot be avoided. It is important therefore to aim to live well with uncertainty and the paper advocates for preventive conservation applications of strategies recommended in health care for patients with life-threatening illnesses. These strategies include working on things that can be controlled, goal setting, acceptance and factoring in emotions. The ability to identify contexts in which uncertainty is inbuilt should trigger those concerned with preventive conservation to activate strategies developed for managing and living well with uncertainty.  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