全文获取类型
收费全文 | 4254篇 |
免费 | 67篇 |
国内免费 | 14篇 |
专业分类
教育 | 3128篇 |
科学研究 | 295篇 |
各国文化 | 75篇 |
体育 | 265篇 |
综合类 | 2篇 |
文化理论 | 31篇 |
信息传播 | 539篇 |
出版年
2023年 | 20篇 |
2022年 | 29篇 |
2021年 | 72篇 |
2020年 | 131篇 |
2019年 | 167篇 |
2018年 | 216篇 |
2017年 | 216篇 |
2016年 | 198篇 |
2015年 | 136篇 |
2014年 | 181篇 |
2013年 | 1036篇 |
2012年 | 145篇 |
2011年 | 140篇 |
2010年 | 131篇 |
2009年 | 125篇 |
2008年 | 129篇 |
2007年 | 121篇 |
2006年 | 113篇 |
2005年 | 72篇 |
2004年 | 45篇 |
2003年 | 67篇 |
2002年 | 68篇 |
2001年 | 54篇 |
2000年 | 52篇 |
1999年 | 43篇 |
1998年 | 32篇 |
1997年 | 42篇 |
1996年 | 39篇 |
1995年 | 39篇 |
1994年 | 39篇 |
1993年 | 49篇 |
1992年 | 29篇 |
1991年 | 32篇 |
1990年 | 26篇 |
1989年 | 27篇 |
1988年 | 12篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 30篇 |
1984年 | 17篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 14篇 |
1978年 | 18篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1974年 | 9篇 |
1973年 | 7篇 |
排序方式: 共有4335条查询结果,搜索用时 21 毫秒
1.
Jee-Hyub Kim Byung-Kwan Kwak Seungwoo Lee Geunbae Lee Jong-Hyeok Lee 《Information Retrieval》2001,4(2):115-132
In Korean information retrieval, compound nouns play an important role in improving precision in search experiments. There are two major approaches to compound noun indexing in Korean: statistical and linguistic. Each method, however, has its own shortcomings, such as limitations when indexing diverse types of compound nouns, over-generation of compound nouns, and data sparseness in training. In this paper, we propose a corpus-based learning method, which can index diverse types of compound nouns using rules automatically extracted from a large corpus. The automatic learning method is more portable and requires less human effort, although it exhibits a performance level similar to the manual-linguistic approach. We also present a new filtering method to solve the problems of compound noun over-generation and data sparseness. 相似文献
2.
3.
4.
5.
Jane Harrison 《Health information and libraries journal》1997,14(1):33-42
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
6.
7.
8.
9.
10.
Gill Needham Jane Holdsworth Denise Miles 《Health information and libraries journal》1991,8(3):170-171
相似文献