全文获取类型
收费全文 | 23514篇 |
免费 | 249篇 |
国内免费 | 125篇 |
专业分类
教育 | 16517篇 |
科学研究 | 2729篇 |
各国文化 | 251篇 |
体育 | 1827篇 |
综合类 | 16篇 |
文化理论 | 219篇 |
信息传播 | 2329篇 |
出版年
2021年 | 149篇 |
2020年 | 285篇 |
2019年 | 449篇 |
2018年 | 615篇 |
2017年 | 595篇 |
2016年 | 589篇 |
2015年 | 403篇 |
2014年 | 510篇 |
2013年 | 4532篇 |
2012年 | 459篇 |
2011年 | 498篇 |
2010年 | 408篇 |
2009年 | 391篇 |
2008年 | 437篇 |
2007年 | 475篇 |
2006年 | 449篇 |
2005年 | 452篇 |
2004年 | 420篇 |
2003年 | 394篇 |
2002年 | 372篇 |
2001年 | 365篇 |
2000年 | 386篇 |
1999年 | 397篇 |
1998年 | 250篇 |
1997年 | 257篇 |
1996年 | 292篇 |
1995年 | 307篇 |
1994年 | 244篇 |
1993年 | 235篇 |
1992年 | 322篇 |
1991年 | 316篇 |
1990年 | 326篇 |
1989年 | 354篇 |
1988年 | 300篇 |
1987年 | 316篇 |
1986年 | 294篇 |
1985年 | 341篇 |
1984年 | 307篇 |
1983年 | 296篇 |
1982年 | 277篇 |
1981年 | 243篇 |
1980年 | 214篇 |
1979年 | 311篇 |
1978年 | 254篇 |
1977年 | 259篇 |
1976年 | 209篇 |
1975年 | 182篇 |
1974年 | 199篇 |
1973年 | 190篇 |
1971年 | 158篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
41.
42.
43.
John Ashworth 《Higher Education Quarterly》1997,51(2):164-188
Since 1990, there has been considerable debate concerning the benefits of the expansion of higher education and the appropriate way to fund such an expansion. This paper demonstrates that three factors are decisive to the individual contemplating higher education: national economic growth; the relative earnings of graduates and non-graduates; the difference between the average and the marginal student. The results, of analysis based on rates of return, reaffirm the view that a proportion of the costs involved in higher education can be transferred to the graduates themselves in the form of loans. However, there appear to be limits to the costs that can be transferred if all students are to judge that undergraduate study is a worthwhile proposition. Notwithstanding this, most students could be lent more income to study than is now the case and indeed an average student would be advised to take any loans despite the greater debt. Marginal students, however, are making a risky private investment and, therefore, any decisions to further expand may result in students not taking up the places. 相似文献
44.
45.
46.
47.
48.
49.
50.
Time series analysis was used to investigate the hypothesis that during acquisition of a motor skill, knowledge of results (KR) information is used to generate a stable internal referent about which response errors are randomly distributed. Sixteen subjects completed 50 acquisition trials of each of three movements whose spatial-temporal characteristics differed. Acquisition trials were either blocked, with each movement being presented in series, or randomized, with the presentation of movements occurring in random order. Analysis of movement time data indicated the contextual interference effect reported in previous studies was replicated in the present experiment. Time series analysis of the acquisition trial data revealed the majority of individual subject response patterns during blocked trials were best described by a model with a temporarily stationary, internal reference of the criterion and systematic, trial-to-trial variation of response errors. During random trial conditions, response patterns were usually best described by a "White-noise" model. This model predicts a permanently stationary, internal reference associated with randomly distributed response errors that are unaffected by KR information. These results are not consistent with previous work using time series analysis to describe motor behavior (Spray & Newell, 1986). 相似文献