全文获取类型
收费全文 | 3459篇 |
免费 | 51篇 |
国内免费 | 2篇 |
专业分类
教育 | 2566篇 |
科学研究 | 195篇 |
各国文化 | 28篇 |
体育 | 474篇 |
文化理论 | 70篇 |
信息传播 | 179篇 |
出版年
2023年 | 36篇 |
2022年 | 62篇 |
2021年 | 83篇 |
2020年 | 132篇 |
2019年 | 205篇 |
2018年 | 266篇 |
2017年 | 256篇 |
2016年 | 189篇 |
2015年 | 126篇 |
2014年 | 130篇 |
2013年 | 729篇 |
2012年 | 134篇 |
2011年 | 93篇 |
2010年 | 92篇 |
2009年 | 87篇 |
2008年 | 75篇 |
2007年 | 68篇 |
2006年 | 73篇 |
2005年 | 58篇 |
2004年 | 45篇 |
2003年 | 55篇 |
2002年 | 32篇 |
2001年 | 34篇 |
2000年 | 29篇 |
1999年 | 23篇 |
1998年 | 27篇 |
1997年 | 20篇 |
1996年 | 28篇 |
1995年 | 23篇 |
1994年 | 28篇 |
1993年 | 19篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 20篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1979年 | 8篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 6篇 |
1972年 | 6篇 |
排序方式: 共有3512条查询结果,搜索用时 328 毫秒
101.
102.
The aim of this study was to assess the effect of stress on a previously acquired motor coordination. Following a longitudinal learning experiment, four participants performed oscillations on a ski simulator, either in normal or stressful conditions. The results showed that the amplitude of the oscillations decreased under stress, but no significant effect was seen regarding coordination, suggesting the strong resistance to stress of overlearned behaviour. Nevertheless, for one participant, a transient regression towards a former stage of learning was observed. This result was consistent with the regression hypothesis formulated by Fuchs (1962). 相似文献
103.
104.
The aim of this study was to determine the physiological responses to orienteering by examining the interrelationships between the information provided by a differential global positioning system (dGPS) about an orienteer's route, speed and orienteering mistakes, portable metabolic gas analyser data during orienteering and data from incremental treadmill tests. Ten male orienteers completed a treadmill threshold test and a field test; the latter was performed on a 4.3 km course on mixed terrain with nine checkpoints. The anaerobic threshold, threshold of decompensated metabolic acidosis, respiratory exchange ratio, onset of blood lactate accumulation and peak oxygen uptake (VO2peak) were determined from the treadmill test. Time to complete the course, total distance covered, mean speed, distance and timing of orienteering mistakes, mean oxygen uptake, mean relative heart rate, mean respiratory exchange ratio and mean running economy were computed from the dGPS data and metabolic gas analyser data. Correlation analyses showed a relationship between a high anaerobic threshold and few orienteering mistakes (r = - 0.64, P < 0.05). A high threshold of decompensated metabolic acidosis and VO2peak were related to a fast overall time (r = -0.70 to -0.72, P < 0.05) and high running speed (r = 0.64 to 0.79, P < 0.05 and P < 0.01, respectively), and were thus the best predictors of performance. 相似文献
105.
The aim of this paper is to present a motivational model of the coach-athlete relationship that describes how coaches may influence athletes' motivation. In line with cognitive evaluation theory (Deci and Ryan, 1980, 1985) and the hierarchical model of intrinsic and extrinsic motivation (Vallerand, 1997, 2000), a motivational sequence is proposed where coaches' personal orientation towards coaching, the context within which they operate, and their perceptions of their athletes' behaviour and motivation influence coaches' behaviours. Also, coaches' behaviours in the form of autonomy-supportive behaviours, provision of structure and involvement have a beneficial impact on athletes' needs for autonomy, competence and relatedness, which, in turn, nurture athletes' intrinsic motivation and self-determined types of extrinsic motivation. Here, we first review coaches' autonomy-supportive behaviours. We then describe the psychological processes through which coaching behaviours have a positive influence on athletes' intrinsic and self-determined extrinsic motivation. Finally, we identify social and personality processes that determine coaching behaviours. 相似文献
106.
The effects of query structures and query expansion (QE) on retrieval performance were tested with a best match retrieval system (InQuery1). Query structure means the use of operators to express the relations between search keys. Six different structures were tested, representing strong structures (e.g., queries with facets or concepts identified) and weak structures (no concepts identified, a query is a bag of search keys). QE was based on concepts, which were first selected from a searching thesaurus, and then expanded by semantic relationships given in the thesaurus. The expansion levels were (a) no expansion, (b) a synonym expansion, (c) a narrower concept expansion, (d) an associative concept expansion, and (e) a cumulative expansion of all other expansions. With weak structures and Boolean structured queries, QE was not very effective. The best performance was achieved with a combination of a facet structure, where search keys within a facet were treated as instances of one search key (the SYN operator), and the largest expansion. 相似文献
107.
108.
109.
110.
Gérald Séguin 《Journal of The Franklin Institute》1980,309(3):179-189
A sequence of metrics {DN} is said to be additive and matched to a discrete memoryless channel (DMC) if DN is the sum on its coordinates of N single letter metrics and if the maximum likelihood decoder for sequences of length N is a minimum DN-distance decoder. Necessary and sufficient conditions on the transition probabilities of a DMC for the existence of a sequence of additive metrics matched to it are given. In the case of the binary channel these are shown to be equivalent to the channel being symmetric. Explicit transition probabilities are given for a large class of ternary DMCs with an associated sequence of additive matched metrics. The problem solved here may be considered a generalization of the problem of finding the DMCs matched to the Lee metric solved by Chiang and Wolf in 1971 (2). 相似文献