全文获取类型
收费全文 | 485篇 |
免费 | 8篇 |
专业分类
教育 | 336篇 |
科学研究 | 45篇 |
各国文化 | 8篇 |
体育 | 73篇 |
综合类 | 1篇 |
文化理论 | 6篇 |
信息传播 | 24篇 |
出版年
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 20篇 |
2018年 | 21篇 |
2017年 | 24篇 |
2016年 | 18篇 |
2015年 | 10篇 |
2014年 | 21篇 |
2013年 | 100篇 |
2012年 | 17篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 13篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 12篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1955年 | 1篇 |
1954年 | 1篇 |
1902年 | 1篇 |
排序方式: 共有493条查询结果,搜索用时 15 毫秒
101.
102.
Sheikhattari P Stephenson R Assasi N Eftekhar H Zamani Q Maleki B Kiabayan H 《Child abuse & neglect》2006,30(3):231-245
OBJECTIVE: This study examines the determinants of three types of child maltreatment: physical maltreatment, mental maltreatment, and child neglect among school children in the Kurdistan Province of Iran. The analysis examines the impact of socioeconomic, familial, demographic, and household dynamic factors on the three child maltreatment outcomes, and compares the differential impact of these factors across the three types of child maltreatment. A greater understanding of the factors associated with child maltreatment has the potential to inform public health interventions aimed at reducing specific forms of maltreatment and at identifying at risk populations. METHODS: Data were collected from 1,370 school students, age 11-18. Separate logistic models are fitted for six binary outcomes examining self-reported experiences of physical maltreatment in the home or school, mental maltreatment in the home or school, and child neglect in the home or school. RESULTS: Male children were more likely to report experiencing any kind of child maltreatment than girls. Residency in a rural area, poor parental relationships and the use of addictive substances by household members were associated with increased odds of reporting child maltreatment. Poor school performance was associated with the reporting of experiencing maltreatment at school. CONCLUSION: Each of the forms of child maltreatment is highly correlated with socioeconomic, demographic, and living condition factors. The results point to the strong influence that familial factors have in shaping a child's likelihood of reporting maltreatment. Characteristics of the mother were associated with maltreatment, but not characteristics of the father. The results highlight a number of mechanisms through which public health interventions may seek to reduce the prevalence of child maltreatment in Kurdistan; different approaches are needed to reduce child maltreatment in the home and school environments. 相似文献
103.
The sweet spot of a cricket bat for low speed impacts 总被引:2,自引:1,他引:1
Rob Bower 《Sports Engineering》2012,15(2):53-60
The impact location of a cricket ball on a cricket bat has a large influence on the resulting rebound velocity of the ball. To measure this, a cricket bat was swung in a pendulum motion towards a cricket ball suspended in space. The position of the ball was modified so that it impacted the bat at 24 different positions on the face of the bat. This included six positions longitudinally and four positions laterally. The speed of the bat and each rebound were measured by a radar gun so that the apparent coefficient of restitution (ACOR) could be calculated. Impacts occurring centrally and 1?cm either side of the midline produced significantly higher rebound speeds and ACOR??s than impacts occurring 2 and 3cm off centre (p?<?0.01). Impacts occurring 15?C20?cm from the base of the bat produced the highest rebound speeds (p?<?0.01) and impacts occurring 20?C30?cm from the base of the bat produced the highest ACOR values. Implications for higher speed impacts and game scenarios are discussed. 相似文献
104.
105.
Adrian Mackenzie 《Journal of Cultural Economy》2018,11(1):36-53
Platforms are important actors in contemporary cultural economic processes. They include social network sites, online content management systems, streaming media platforms, mobile communication infrastructures, supply chain logistics solutions, and cryptocurrencies. Analysis of platforms and their capitalization should take into account the ways they structure social practice as assets and the constitutive opacity of platforms as configured realities. It explores capitalization by focusing on the problems of counting people and things on platforms. Via a case study of the software repository platform [Github.com] (https://github.com), it analyzes how 'platform numbers’ participate in capitalization. It describes attempts to enumerate the elements of the platform by counting, mapping or listing them. The paper shows how attempts to enumerate people and things encounter forms of association, duplication, combination, imitation and configuration that are crucial to the ensemble but remain refractory to capitalization. It proposes configurative enumeration of the platform numbers as a way of conceptualizing these un-enacted excesses. In a configurative enumeration, the composition, the rhythms of imitation, variation and commutation, and constant relating, repairing and adjusting of configurations crucial to the ongoing formation of platforms come into view. Configurative enumerations engage the inventive realities of platformization, realities that precede and sometimes overflow their capitalization. 相似文献
106.
This paper introduces an experimental model to measure the holistic performance of professional football clubs. The model utilizes a selection of established financial and sporting indicators, which are weighted in accordance with their perceived relative importance and in relation to components of financial management and governing body regulations. The paper uses data pertaining to clubs competing in the English Premier League to demonstrate the outputs of the model. The authors argue that although the model is experimental, it still provides a useful platform to analyse performance of football clubs through further scientific investigation. 相似文献
107.
Danielle T. Gescheit Rob Duffield Melissa Skein Neil Brydon Stuart J. Cormack Machar Reid 《Journal of sports sciences》2017,35(20):1988-1994
Elite tennis is characterised by repeated bouts of up to 5-set match play, yet little is known about the technical requirements of shots played. This study therefore investigated technical performance changes over consecutive days of prolonged, simulated tennis match play. A total of 7 well-trained men tennis players performed 4 consecutive days of competitive 4-h match play. Matches were notated to determine between-day changes in groundstroke and serve performance, as well as point and match durations. Changes ≥75% likely to exceed the smallest important effect size (0.2) were considered meaningful and represented as effect size ± 90% confidence interval. Effective playing time reduced on days 3 and 4, alongside likely increases in “stretch” groundstrokes over the 4 days (mean effect size ± 90% confidence interval; 0.57 ± 0.38) and “stretch” backhand returns on days 2 and 3 (0.39 ± 0.54 and 0.67 ± 0.55). Relative unforced errors increased on day 4 (vs. day 2; 0.36 ± 0.22) and second-serve winning percentage reduced after day 1 (?0.47 ± 0.50). Further, a likely increase in emotional outbursts characterised day 3 (vs. day 2; 0.73 ± 0.57). Consecutive-day match play impairs hitting accuracy, stroke positioning and emotional responses; an understanding of which prepares players for elite-standard tennis tournament play. 相似文献
108.
有人把体育运动中的兴奋剂归咎于参赛运动员违背了体育运动精神的价值取向,从不太严格的意义上讲,体育精神可以这样来描述,即运动员通过努力的训练及顽强的意志(而不是使用违禁物质与方法),来实现对体育运动的热爱、卓越的追求,并由此获取相应的物质回报。另一方面,运动员是否以为他(她)的对手在使用兴奋剂也会影响他们的态度,因为他们往往会为了取得同等的竞争条件而做同样的事情;另外一些影响运动员是否使用兴奋剂的因素来自于他(她)的同伴、支持者、赞助商、媒体、公众舆论等,这些因素都有可能左右他(她)们的决定,即在比赛当中是否应使用提高运动成绩的违禁药物或措施。 相似文献
109.
Respiratory muscle fatigue has been reported following short bouts of high-intensity exercise, and prolonged, moderate-intensity exercise, as evidenced by decrements in inspiratory and expiratory mouth pressures. However, links to functionally relevant outcomes such as breathing effort have been lacking. The present study examined dyspnoea and leg fatigue during a treadmill marathon in nine experienced runners. Maximal inspiratory and expiratory pressure, peak inspiratory and expiratory flow, forced vital capacity, and forced expiratory volume in one second were assessed before, immediately after, and four and 24 hours after a marathon. During the run, leg effort was rated higher than respiratory effort from 18 through 42 km (P < 0.05). Immediately after the marathon, there were significant decreases in maximal inspiratory pressure and peak inspiratory flow (from 118 +/- 20 cm H(2)O and 6.3 +/- 1.4 litres x s(-1) to 100 +/- 22 cm H(2)O and 4.9 +/- 1.5 litres x s(-1) respectively; P < 0.01), while expiratory function remained unchanged. Leg maximum voluntary contraction force was significantly lower post-marathon. Breathing effort correlated significantly with leg fatigue (r = 0.69), but not inspiratory muscle fatigue. Our results confirm that prolonged moderate-intensity exercise induces inspiratory muscle fatigue. Furthermore, they suggest that the relative intensity of inspiratory muscle work during exercise makes some contribution to leg fatigue. 相似文献
110.
The physical demands of elite English rugby union 总被引:1,自引:1,他引:0
The aim of this study was to assess the physical demands of elite English rugby union match-play. Player movements were captured by five distributed video cameras and then reconstructed on a two-dimensional plane representing the pitch. Movements based on speeds were categorized as standing, walking, jogging, and medium-intensity running (low-intensity activity), and high-intensity running, sprinting, and static exertion (scrummaging, rucking, mauling, and tackling) (high-intensity activity). Position groups were defined as forwards (tight and loose) and backs (inside and outside). Backs travelled more total distance than forwards (6127 m, s=724 vs. 5581 m, s=692; P<0.05) and greater distances in walking (2351 m, s=287 vs. 1928 m, s=2342; P<0.001) and high-intensity running (448 m, s=149 vs. 298 m, s=107; P<0.05). Forwards performed more high-intensity activity than backs (9:09 min:s, s=1:39 vs. 3:04 min:s, s=1:01; P<0.001), which was attributable to more time spent in static exertion (7:56 min:s, s=1:56 vs. 1:18 min:s, s=0:30; P<0.001), although backs spent more time in high-intensity running (0:52 min:s, s=0:19 vs. 1:19 min:s, s=0:26; P=0.004). Players travelled a greater distance in the first 10 min compared with 50-60 and 70-80 min, but there was no difference in the amount of high-intensity activity performed during consecutive 10-min periods during match-play. These results show the differing physical demands between forwards and backs with no evident deterioration in high-intensity activity performed during match-play. 相似文献