全文获取类型
收费全文 | 4906篇 |
免费 | 82篇 |
国内免费 | 5篇 |
专业分类
教育 | 3615篇 |
科学研究 | 285篇 |
各国文化 | 92篇 |
体育 | 424篇 |
综合类 | 1篇 |
文化理论 | 44篇 |
信息传播 | 532篇 |
出版年
2023年 | 19篇 |
2022年 | 27篇 |
2021年 | 61篇 |
2020年 | 112篇 |
2019年 | 159篇 |
2018年 | 207篇 |
2017年 | 214篇 |
2016年 | 191篇 |
2015年 | 114篇 |
2014年 | 180篇 |
2013年 | 1107篇 |
2012年 | 141篇 |
2011年 | 126篇 |
2010年 | 105篇 |
2009年 | 125篇 |
2008年 | 152篇 |
2007年 | 138篇 |
2006年 | 126篇 |
2005年 | 116篇 |
2004年 | 101篇 |
2003年 | 92篇 |
2002年 | 88篇 |
2001年 | 78篇 |
2000年 | 81篇 |
1999年 | 70篇 |
1998年 | 52篇 |
1997年 | 46篇 |
1996年 | 67篇 |
1995年 | 52篇 |
1994年 | 56篇 |
1993年 | 35篇 |
1992年 | 58篇 |
1991年 | 41篇 |
1990年 | 47篇 |
1989年 | 40篇 |
1988年 | 34篇 |
1987年 | 32篇 |
1986年 | 30篇 |
1985年 | 27篇 |
1984年 | 24篇 |
1983年 | 16篇 |
1982年 | 28篇 |
1981年 | 32篇 |
1980年 | 27篇 |
1979年 | 24篇 |
1978年 | 24篇 |
1976年 | 21篇 |
1975年 | 16篇 |
1974年 | 21篇 |
1973年 | 16篇 |
排序方式: 共有4993条查询结果,搜索用时 31 毫秒
51.
David S. Haydon Ross A. Pinder Paul N. Grimshaw William S. P. Robertson 《Sports Engineering》2016,19(3):177-184
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost. 相似文献
52.
While scholars have increasingly engaged with the (micro)political and emotional experiences of coaches in professional and semi-professional football, little attention has been given to grass-roots coaches’ understandings of these issues. The aim of this paper is to outline one possible research agenda that could contribute to the development of a rich and increasingly nuanced understanding of the everyday realities of being a grass-roots football coach. In particular, we consider (volunteer) coaches’ participation in grass-roots football to be an inherently relational endeavour. Following the presentation of a creative fiction that is based upon our shared experiences of being grass-roots football coaches, we then illustrate how relational thinking might be productively applied to exploring the social, (micro)political and emotional features of grass-roots football coaching. 相似文献
53.
Moataz Eltoukhy Adam Kelly Chang-Young Kim Hyung-Pil Jun Richard Campbell 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(1):89-102
Cost effective, quantifiable assessment of lower extremity movement represents potential improvement over standard tools for evaluation of injury risk. Ten healthy participants completed three trials of a drop jump, overhead squat, and single leg squat task. Peak hip and knee kinematics were assessed using an 8 camera BTS Smart 7000DX motion analysis system and the Microsoft Kinect® camera system. The agreement and consistency between both uncorrected and correct Kinect kinematic variables and the BTS camera system were assessed using interclass correlations coefficients. Peak sagittal plane kinematics measured using the Microsoft Kinect® camera system explained a significant amount of variance [Rangehip = 43.5–62.8%; Rangeknee = 67.5–89.6%] in peak kinematics measured using the BTS camera system. Across tasks, peak knee flexion angle and peak hip flexion were found to be consistent and in agreement when the Microsoft Kinect® camera system was directly compared to the BTS camera system but these values were improved following application of a corrective factor. The Microsoft Kinect® may not be an appropriate surrogate for traditional motion analysis technology, but it may have potential applications as a real-time feedback tool in pathological or high injury risk populations. 相似文献
54.
Paul S. R. Goods Brian Dawson Grant J. Landers Christopher J. Gore Kevin Croft Peter Peeling 《European Journal of Sport Science》2016,16(8):1047-1054
This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?.001), with a large effect (d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response. 相似文献
55.
We identified the perceptual–cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n?=?127) completed an adapted participation history questionnaire and video-based assessments of perceptual–cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual–cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual–cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification. 相似文献
56.
Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% FIO2). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnrMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO2 occurred with reduced FIO2, along with a rise in heart rate (Cohen’s d?=?1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% FIO2. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% FIO2) decrease in lnTP (d?=?1.84 [1.74–1.94]), and SampEn (d?=?0.98 [0.83–1.12]) and an increase in DFA-α1 (d?=?0.72 [0.60–0.84]) from normoxia at 9.8% FIO2. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ~9.8% FIO2 (~6000?m equiv.), below which significant alterations in autonomic control occur. 相似文献
57.
Objective
The purpose of this study was to investigate the relative effectiveness of three web-scale discovery (WSD) tools in answering health sciences search queries.Methods
Simple keyword searches, based on topics from six health sciences disciplines, were run at multiple real-world implementations of EBSCO Discovery Service (EDS), Ex Libris''s Primo, and ProQuest''s Summon. Each WSD tool was evaluated in its ability to retrieve relevant results and in its coverage of MEDLINE content.Results
All WSD tools returned between 50%–60% relevant results. Primo returned a higher number of duplicate results than the other 2 WSD products. Summon results were more relevant when search terms were automatically mapped to controlled vocabulary. EDS indexed the largest number of MEDLINE citations, followed closely by Summon. Additionally, keyword searches in all 3 WSD tools retrieved relevant material that was not found with precision (Medical Subject Headings) searches in MEDLINE.Conclusions
None of the 3 WSD products studied was overwhelmingly more effective in returning relevant results. While difficult to place the figure of 50%–60% relevance in context, it implies a strong likelihood that the average user would be able to find satisfactory sources on the first page of search results using a rudimentary keyword search. The discovery of additional relevant material beyond that retrieved from MEDLINE indicates WSD tools'' value as a supplement to traditional resources for health sciences researchers. 相似文献58.
59.
Dr. Richard W. Thoreson CarolAnne M. Kardash David A. Leuthold Kelly A. Morrow 《Research in higher education》1990,31(2):193-209
This study examines sources of satisfaction, indicators of stress, academic performance, and reward structure in the academic careers of male and female faculty at a major midwestern state university. Faculty pairs were selected from five academic divisions. A total of 58 matched pairs were identified. Of these, 63 faculty responded, yielding data for 23 matched pairs. Subjects were mailed the Academic Career Development Survey, consisting of 144 items. Results indicated that self-reported physical and mental health, and professional and personal life satisfaction were high for both males and females. Both males and females placed high importance on their career and on marriage/other intimate relationships; however, both reported high levels of dissatisfaction with these factors. Gender differences were found in both satisfaction and type of stress reported; no gender differences were found in composite teaching and research performance indices. Salary data, obtained for 42 matched pairs, indicated similar salary levels for men and women. Results were discussed with respect to prior research on gender differences and the academic career. 相似文献
60.
This article describes results of an empirical investigation of the relationship between research and undergraduate teaching in Australian higher education. Two research indexes (weighted number of publications, and number of research activities) were used. Scores on a Likert-type scale of reported commitment to teaching undergraduate students formed the main criterion of teaching effectiveness. This was supplemented by student ratings in one of the aggregate-level analyses. The results revealed typically no relation or a negative relation between teaching and research at the level of the individual and at the level of the department, across all subject areas. The only exceptions concerned one group of former colleges of education. Further analysis by staff self-rating of academic quality showed that there existed one group of staff, mainly in the universities, who were committed to teaching and highly active researchers. However, the data did not support a causal interpretation of the association. It is concluded that there is no evidence in these results to indicate the existence of a simple functional association between high research output and the effectiveness of undergraduate teaching. Some implications for policy and student course choice are discussed. 相似文献