全文获取类型
收费全文 | 21497篇 |
免费 | 351篇 |
国内免费 | 139篇 |
专业分类
教育 | 14975篇 |
科学研究 | 2280篇 |
各国文化 | 187篇 |
体育 | 1459篇 |
综合类 | 274篇 |
文化理论 | 100篇 |
信息传播 | 2712篇 |
出版年
2022年 | 165篇 |
2021年 | 337篇 |
2020年 | 316篇 |
2019年 | 404篇 |
2018年 | 557篇 |
2017年 | 587篇 |
2016年 | 531篇 |
2015年 | 482篇 |
2014年 | 688篇 |
2013年 | 3616篇 |
2012年 | 794篇 |
2011年 | 864篇 |
2010年 | 740篇 |
2009年 | 740篇 |
2008年 | 728篇 |
2007年 | 773篇 |
2006年 | 779篇 |
2005年 | 705篇 |
2004年 | 407篇 |
2003年 | 398篇 |
2002年 | 339篇 |
2001年 | 471篇 |
2000年 | 377篇 |
1999年 | 355篇 |
1998年 | 205篇 |
1997年 | 205篇 |
1996年 | 209篇 |
1995年 | 160篇 |
1994年 | 174篇 |
1993年 | 153篇 |
1992年 | 231篇 |
1991年 | 219篇 |
1990年 | 248篇 |
1989年 | 224篇 |
1988年 | 175篇 |
1987年 | 183篇 |
1986年 | 187篇 |
1985年 | 177篇 |
1984年 | 183篇 |
1983年 | 170篇 |
1982年 | 134篇 |
1981年 | 136篇 |
1980年 | 132篇 |
1979年 | 190篇 |
1978年 | 160篇 |
1977年 | 113篇 |
1976年 | 119篇 |
1975年 | 111篇 |
1973年 | 104篇 |
1971年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
901.
902.
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
903.
904.
905.
906.
907.
908.
909.
For postsecondary students with disabilities influencing reading performance, printed class materials pose a substantial barrier and have a negative impact on academic achievement. Digital technologies offer alternative ways of accessing print materials for students with print‐related disabilities. Alternative media is a broad term that encompasses a variety of formats into which printed text is converted. Alternative media, together with assistive computer technologies designed to read aloud the text, provide a means to access textual information and bypass the difficult reading process. The purpose of this article is to provide an overview of model programs and pertinent research on the use of alternative media by postsecondary students with print disabilities; we will identify promising practices for students whose disabilities negatively influence reading performance. 相似文献
910.
谢慧松 《成都体育学院学报》2007,33(5):76-79
通过文献资料、高速摄像和对比分析的方法,对中外男运动员百米途中跑一个单步的步长、步时及人体重心轨迹进行研究,制定了短跑运动员所应达到的步频、步幅范围与跑速之间关系的模式表,为教练员科学训练提供了依据. 相似文献