全文获取类型
| 收费全文 | 23864篇 |
| 免费 | 431篇 |
| 国内免费 | 32篇 |
专业分类
| 教育 | 17175篇 |
| 科学研究 | 2071篇 |
| 各国文化 | 221篇 |
| 体育 | 1946篇 |
| 综合类 | 34篇 |
| 文化理论 | 237篇 |
| 信息传播 | 2643篇 |
出版年
| 2022年 | 153篇 |
| 2021年 | 280篇 |
| 2020年 | 454篇 |
| 2019年 | 656篇 |
| 2018年 | 881篇 |
| 2017年 | 943篇 |
| 2016年 | 853篇 |
| 2015年 | 526篇 |
| 2014年 | 653篇 |
| 2013年 | 4680篇 |
| 2012年 | 622篇 |
| 2011年 | 684篇 |
| 2010年 | 525篇 |
| 2009年 | 486篇 |
| 2008年 | 539篇 |
| 2007年 | 530篇 |
| 2006年 | 471篇 |
| 2005年 | 404篇 |
| 2004年 | 380篇 |
| 2003年 | 347篇 |
| 2002年 | 391篇 |
| 2001年 | 434篇 |
| 2000年 | 407篇 |
| 1999年 | 412篇 |
| 1998年 | 219篇 |
| 1997年 | 238篇 |
| 1996年 | 264篇 |
| 1995年 | 223篇 |
| 1994年 | 218篇 |
| 1993年 | 201篇 |
| 1992年 | 309篇 |
| 1991年 | 299篇 |
| 1990年 | 329篇 |
| 1989年 | 293篇 |
| 1988年 | 278篇 |
| 1987年 | 229篇 |
| 1986年 | 246篇 |
| 1985年 | 304篇 |
| 1984年 | 242篇 |
| 1983年 | 224篇 |
| 1982年 | 163篇 |
| 1981年 | 172篇 |
| 1980年 | 151篇 |
| 1979年 | 223篇 |
| 1978年 | 189篇 |
| 1977年 | 174篇 |
| 1976年 | 148篇 |
| 1975年 | 120篇 |
| 1974年 | 110篇 |
| 1973年 | 137篇 |
排序方式： 共有10000条查询结果，搜索用时 302 毫秒
51.
52.
D A Sedlock 《Research quarterly for exercise and sport》1991,62(2):213-216
This study was designed to examine the magnitude and duration of excess postexercise oxygen consumption (EPOC) following upper body exercise, using lower body exercise for comparison. On separate days and in a counterbalanced order, eight subjects (four male and four female) performed a 20-min exercise at 60% of mode-specific peak oxygen uptake (VO2) using an arm crank and cycle ergometer. Prior to each exercise, baseline VO2 and heart rate (HR) were measured during the final 15 min of a 45-min seated rest. VO2 and HR were measured continuously during the postexercise period until baseline VO2 was reestablished. No significant difference between the two experimental conditions was found for magnitude of EPOC (t [7] = 0.69, p greater than .05). Mean (+/- SD) values were 9.2 +/- 3.3 and 10.4 +/- 5.8 kcal for the arm crank and cycle ergometer exercises, respectively. Duration of EPOC was relatively short and not significantly different (t [7] = 0.24, p greater than .05) between the upper body (22.9 +/- 13.7 min) and lower body (24.2 +/- 19.4 min) exercises. Within the framework of the chosen exercise conditions, these results suggest EPOC may be related primarily to the relative metabolic rate of the active musculature, as opposed to the absolute exercise VO2 or quantity of active muscle mass associated with these two types of exercise. 相似文献
53.
54.
55.
Wilson C Simpson SE van Emmerik RE Hamill J 《Sports biomechanics / International Society of Biomechanics in Sports》2008,7(1):2-9
The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump. Relative motion plots and a modified vector coding technique were used to quantify the coordination variability across the trials. The results were consistent with a U-shaped curve, representing coordination variability, as skill increases. The high coordination variability in less skilled athletes is present while the appropriate characteristics defining the movement coordination patterns are acquired. This coordination variability may not be beneficial to performance. As the refinement of these characteristics is achieved, coordination variability decreases, resulting in a more consistent or regulated performance. In the final stages of developing a skilled performance, a functional variability is accessed that brings flexibility to the system allowing it to cope with perturbations. This study highlights the need to address the learning effect when analysing coordination variability from a dynamical systems perspective. 相似文献
56.
Renáta Tichá Christine A. Espin Miya Miura Wayman 《Learning disabilities research & practice》2009,24(3):132-142
The validity and reliability of curriculum‐based measures in reading as indicators of performance and progress for secondary‐school students were examined. Thirty‐five grade 8 students completed reading aloud and maze‐selection measures weekly for 10 weeks. Criterion measures were the state standards test in reading and the Woodcock–Johnson III Test of Achievement. Different time frames for each measure were compared. Most alternate‐form reliability coefficients were above .80. Criterion‐related validity coefficients ranged from .77 to .89. No differences related to time were found. Only maze selection reflected significant growth, with an average increase of 1.29 correct choices per week. Maze growth was related to the reading performance level and to change on the Woodcock–Johnson III from pre‐ to posttest. 相似文献
57.
A.F. Zahm 《Journal of The Franklin Institute》1948,245(4):331-336
58.
59.
60.