全文获取类型
收费全文 | 14064篇 |
免费 | 151篇 |
国内免费 | 13篇 |
专业分类
教育 | 9670篇 |
科学研究 | 1613篇 |
各国文化 | 191篇 |
体育 | 1039篇 |
综合类 | 6篇 |
文化理论 | 131篇 |
信息传播 | 1578篇 |
出版年
2021年 | 95篇 |
2020年 | 172篇 |
2019年 | 260篇 |
2018年 | 300篇 |
2017年 | 358篇 |
2016年 | 304篇 |
2015年 | 210篇 |
2014年 | 313篇 |
2013年 | 2913篇 |
2012年 | 285篇 |
2011年 | 265篇 |
2010年 | 222篇 |
2009年 | 250篇 |
2008年 | 301篇 |
2007年 | 285篇 |
2006年 | 270篇 |
2005年 | 240篇 |
2004年 | 218篇 |
2003年 | 198篇 |
2002年 | 192篇 |
2001年 | 177篇 |
2000年 | 209篇 |
1999年 | 189篇 |
1998年 | 125篇 |
1997年 | 126篇 |
1996年 | 149篇 |
1995年 | 122篇 |
1994年 | 146篇 |
1993年 | 143篇 |
1992年 | 192篇 |
1991年 | 185篇 |
1990年 | 188篇 |
1989年 | 187篇 |
1988年 | 154篇 |
1987年 | 162篇 |
1986年 | 173篇 |
1985年 | 183篇 |
1984年 | 176篇 |
1983年 | 169篇 |
1982年 | 142篇 |
1981年 | 159篇 |
1980年 | 133篇 |
1979年 | 167篇 |
1978年 | 171篇 |
1977年 | 118篇 |
1976年 | 125篇 |
1975年 | 114篇 |
1974年 | 101篇 |
1973年 | 114篇 |
1971年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
This article reports on a large‐scale international survey of authors' perception and experience of the journals system conducted by ciber in association with National Opinion Polls (NOP). It explores the factors that inform authors' decisions where to publish and, in particular, which groups of readers they perceive to be most important. It probes readership behaviour and the values that underlie authors' attitudes towards copyright and emerging business models, notably open access. It is concluded that many aspects of author behaviour are highly conservative and that a significant shift towards open access is, in the short to medium term, highly unlikely. 相似文献
82.
In this essay, we respond to the narratives and essays in this issue by examining organizational power issues related to researchers and institutional research boards (IRBs). Rather than taking a singular perspective on power, we use multiple perspectives and suggest that the cumulative analyses provide the best understanding of IRBs and organizational power. 相似文献
83.
Question classification systems play an important role in question answering systems and can be used in a wide range of other domains. The goal of question classification is to accurately assign labels to questions based on expected answer type. Most approaches in the past have relied on matching questions against hand-crafted rules. However, rules require laborious effort to create and often suffer from being too specific. Statistical question classification methods overcome these issues by employing machine learning techniques. We empirically show that a statistical approach is robust and achieves good performance on three diverse data sets with little or no hand tuning. Furthermore, we examine the role different syntactic and semantic features have on performance. We find that semantic features tend to increase performance more than purely syntactic features. Finally, we analyze common causes of misclassification error and provide insight into ways they may be overcome. 相似文献
84.
Lucretia W McClure 《Journal of the Medical Library Association》2005,93(2):197-198
85.
86.
87.
88.
89.
90.