全文获取类型
| 收费全文 | 332篇 |
| 免费 | 5篇 |
专业分类
| 教育 | 221篇 |
| 科学研究 | 21篇 |
| 各国文化 | 4篇 |
| 体育 | 25篇 |
| 文化理论 | 5篇 |
| 信息传播 | 61篇 |
出版年
| 2020年 | 5篇 |
| 2019年 | 5篇 |
| 2018年 | 5篇 |
| 2017年 | 6篇 |
| 2016年 | 13篇 |
| 2015年 | 9篇 |
| 2014年 | 8篇 |
| 2013年 | 106篇 |
| 2012年 | 6篇 |
| 2011年 | 9篇 |
| 2010年 | 6篇 |
| 2009年 | 8篇 |
| 2008年 | 4篇 |
| 2007年 | 12篇 |
| 2006年 | 11篇 |
| 2005年 | 4篇 |
| 2003年 | 5篇 |
| 2002年 | 4篇 |
| 2001年 | 2篇 |
| 2000年 | 5篇 |
| 1999年 | 4篇 |
| 1998年 | 4篇 |
| 1997年 | 6篇 |
| 1996年 | 6篇 |
| 1995年 | 2篇 |
| 1994年 | 4篇 |
| 1993年 | 8篇 |
| 1992年 | 2篇 |
| 1991年 | 3篇 |
| 1989年 | 4篇 |
| 1988年 | 2篇 |
| 1987年 | 3篇 |
| 1985年 | 2篇 |
| 1984年 | 6篇 |
| 1983年 | 3篇 |
| 1982年 | 3篇 |
| 1981年 | 3篇 |
| 1979年 | 4篇 |
| 1978年 | 3篇 |
| 1977年 | 2篇 |
| 1976年 | 2篇 |
| 1974年 | 2篇 |
| 1973年 | 2篇 |
| 1972年 | 2篇 |
| 1971年 | 2篇 |
| 1970年 | 2篇 |
| 1933年 | 1篇 |
| 1925年 | 1篇 |
| 1922年 | 1篇 |
| 1920年 | 1篇 |
排序方式： 共有337条查询结果，搜索用时 421 毫秒
91.
92.
93.
94.
95.
Julie M. Glanville Steven Duffy Rachael McCool Danielle Varley 《Journal of the Medical Library Association》2014,102(3):177-183
Background:
Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication.Objectives:
The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers.Methods:
A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources.Results:
On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews.Conclusions:
Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces.Implications:
For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.Clinical trials registers such as ClinicalTrials.gov and portals to trials registers such as the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) are increasingly used to identify ongoing or completed clinical trials. These resources offer important information on the methods and progress of trials likely to be of interest to a range of users, including researchers, clinicians, and patients. The extent to which these resources can be relied upon as a sole source of trials for inclusion in systematic reviews, including Cochrane systematic reviews (CSRs), is the subject of the research study reported here. This study also investigates the most efficient ways that librarians, information professionals, and other searchers can search these resources. Search efficiency was investigated by evaluating the overlap and unique yield of searches in the two resources and by testing four search approaches. The tested search approaches ranged from the very precise (single specific condition search term combined with a single specific intervention search term) to the very sensitive (at least two interventions terms). 相似文献96.
Hugh Finsten 《Government Information Quarterly》1985,2(1):13-25
The extent of government involvement in public activity and the highly technical aspects of the issues arising in our legislatures, points to the need for expert assistance for lawmakers. In Canada, this need was addressed at the federal level by the establishment of a research service as a unit of the Parliamentary Library in 1965. This article gives an insight into the structure and variety of services provided by the 50 professionals of the research unit and the new directions it is taking in addressing the challenges in its work for Canada's two Houses of Parliament. 相似文献
97.
98.
99.
100.