全文获取类型
收费全文 | 21691篇 |
免费 | 291篇 |
国内免费 | 59篇 |
专业分类
教育 | 16033篇 |
科学研究 | 1495篇 |
各国文化 | 281篇 |
体育 | 1508篇 |
综合类 | 47篇 |
文化理论 | 134篇 |
信息传播 | 2543篇 |
出版年
2021年 | 213篇 |
2020年 | 274篇 |
2019年 | 444篇 |
2018年 | 589篇 |
2017年 | 670篇 |
2016年 | 601篇 |
2015年 | 408篇 |
2014年 | 547篇 |
2013年 | 4562篇 |
2012年 | 549篇 |
2011年 | 549篇 |
2010年 | 496篇 |
2009年 | 500篇 |
2008年 | 529篇 |
2007年 | 496篇 |
2006年 | 506篇 |
2005年 | 457篇 |
2004年 | 353篇 |
2003年 | 337篇 |
2002年 | 308篇 |
2001年 | 418篇 |
2000年 | 349篇 |
1999年 | 302篇 |
1998年 | 210篇 |
1997年 | 216篇 |
1996年 | 232篇 |
1995年 | 201篇 |
1994年 | 214篇 |
1993年 | 200篇 |
1992年 | 268篇 |
1991年 | 273篇 |
1990年 | 302篇 |
1989年 | 285篇 |
1988年 | 231篇 |
1987年 | 237篇 |
1986年 | 249篇 |
1985年 | 225篇 |
1984年 | 235篇 |
1983年 | 238篇 |
1982年 | 188篇 |
1981年 | 192篇 |
1980年 | 192篇 |
1979年 | 241篇 |
1978年 | 227篇 |
1977年 | 163篇 |
1976年 | 163篇 |
1975年 | 152篇 |
1974年 | 132篇 |
1973年 | 141篇 |
1971年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
George L. Parker 《Publishing Research Quarterly》1990,6(1):65-73
Historical research benefits students of publishing in three ways. First, it provides an accurate account of what happened
in the past. Second, by setting contemporary issues in a historical context, it helps identify trends. Finally, it encourages
curiosity and learning about one’s cultural and intellectual heritage. Parker provides examples of research that serve these
purposes.
George L. Parker is professor and head of the Department of English and Philosophy at the Royal Military College of Canada,
Kingston, Ontario. He teaches Canadian and American literature, has coedited an anthology,The Evolution of Canadian Literature in English: Beginnings to 1970, has contributed to theDictionary of Canadian Biography, and has publishedThe Beginnings of The Book Trade in Canada (1985). 相似文献
952.
953.
954.
Robert L. Brennan 《Educational Measurement》2000,19(1):5-10
In what sense is generalizability theory an extension of classical test theory? In what sense is generalizability theory an application of analysis of variance. 相似文献
955.
956.
G W Gayle R L Pohlman R M Glaser G M Davis 《Research quarterly for exercise and sport》1990,61(3):224-232
The purpose of the present study was to determine the effects of 10-in [0.25-m] versus 16-in [0.41-m] wheelchair handrims on cardiorespiratory and psychophysiological exercise responses during wheelchair propulsion at selected velocities. Fifteen male paraplegics (27.0 +/- 5.5 yrs) performed three discontinuous exercise tests (ACE = arm crank ergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, VO2, VE, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km.h-1. In contrast, at 8 km.h-1 subjects demonstrated a 13% lower steady state VO2 (p less than .05) using the 10-in handrims, coincident with a 23% lower VE. Steady state HR during WERG at 8 km.h-1 using the 10-in (124.4 +/- 3.9 b.min-1) or 16-in (130.6 +/- 4.6 b.min-1) handrims were not significantly different. There were also no significant differences between ACE or WERG conditions during maximal effort for VO2 or VE. However, HRpeak during ACE was 7% higher than HRpeak during WERG16 (183 +/- 15 b.min-1 vs. 171 +/- 12 b.min-1, p less than .05), and whole blood HLa during ACE was also significantly higher (by 2.3-2.5 mmol; p less than .05) compared to WERG. There were no significant differences for HR, performance time, or RPE between trials using different handrim diameters during the 1600-m event.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
957.
958.
959.
960.