首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   115798篇
  免费   1860篇
  国内免费   234篇
教育   79737篇
科学研究   13261篇
各国文化   1972篇
体育   9248篇
综合类   171篇
文化理论   1052篇
信息传播   12451篇
  2021年   897篇
  2020年   1653篇
  2019年   2541篇
  2018年   3013篇
  2017年   3302篇
  2016年   3349篇
  2015年   2290篇
  2014年   3165篇
  2013年   27181篇
  2012年   2319篇
  2011年   2646篇
  2010年   2291篇
  2009年   2591篇
  2008年   2329篇
  2007年   2050篇
  2006年   2306篇
  2005年   2289篇
  2004年   2970篇
  2003年   2308篇
  2002年   2021篇
  2001年   1890篇
  2000年   1476篇
  1999年   1335篇
  1998年   1266篇
  1997年   1334篇
  1996年   1543篇
  1995年   1353篇
  1994年   1335篇
  1993年   1334篇
  1992年   1343篇
  1991年   1241篇
  1990年   1273篇
  1989年   1170篇
  1988年   1020篇
  1987年   971篇
  1986年   983篇
  1985年   1226篇
  1984年   1140篇
  1983年   1074篇
  1982年   1065篇
  1981年   998篇
  1980年   960篇
  1979年   1035篇
  1978年   1028篇
  1977年   942篇
  1976年   862篇
  1975年   690篇
  1974年   687篇
  1973年   661篇
  1972年   495篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Recent theories suggest that negative effects of fatigue on performance are determined by perception of effort and motivation rather than being directly caused by reaching physiological limits. In the current experiment, the influence of motivation on fatigue-induced decrements in soccer performance was experimentally investigated. Sixty amateur soccer players performed a validated soccer-passing test before and after a fatigue protocol. Results showed that players’ motivation and performance decreased after the fatigue protocol for players in the control group. In contrast, players in the motivation group (i.e., with motivation experimentally induced after the fatigue protocol) were able to uphold their motivation and increase their performance. These results indicate that motivation plays a crucial role in performance under fatigue, as fatigue-induced decrements in soccer passing performance can be counteracted by high levels of motivation. Future research may explore the limits of this counteracting effect and extend findings to other relevant performance aspects.  相似文献   
52.
53.
54.
Hypocalcemia is a laboratory and clinical abnormality that is observed especially in neonates and paediatric patients. Laboratory hypocalcaemia is often asymptomatic but it can manifest as central nervous system irritability, paraesthesia, tetany (i.e. contraction of hands, arms, feet, larynx, bronchioles), seizures, and even psychiatric changes in children. Cardiac function may also be impaired because of poor muscle contractility. We report a unique case of an eleven year old male child who presented with chronic kidney disease associated with severe hypocalcemia, tonic-clonic seizures, hypovitaminosis D but normal electroencephalogram and electrocardiography. The child required prolonged intravenous calcium gluconate therapy to correct his ionised calcium levels.  相似文献   
55.
56.
Purpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.  相似文献   
57.
ABSTRACT

Nearly everyone agrees that physical pain is bad. Indeed, if anything merits the status of a platitude in our everyday thinking about value, the idea that pain is bad surely does. Equally, it seems clearly true that emotional suffering – despair, loneliness, grief, disappointment, guilt, shame, lovesickness, and the like – are all bad as well. We are strongly inclined to pity and feel sorry for those who suffer emotionally in these ways; we are motivated, at least some of the time, to do what we can to alleviate their suffering. Given this, it might seem curious that pain and suffering are so integral to sport – whether one is a participant or a spectator. There’s nothing particularly puzzling about pain and suffering that is inadvertently related to sport – as when an athlete injures her hamstring and has to miss her chance at Olympic glory, or when supporters face the misery of getting up at 6am because an away game has been scheduled to start at noon. But there does seem to be something curious about the extent to which pain and suffering are voluntarily embraced by participants and spectators, as the quotation from Nick Hornby aptly illustrates. Why do people willingly engage in something that brings about so much suffering? In this paper, I’ll attempt to answer this question.1  相似文献   
58.
The central objective of Dewey's Democracy and Education is to explain ‘what is needed to live a meaningful life and how can education contribute?’ While most acquainted with Dewey's educational philosophy know that ‘experience’ plays a central role, the role of ‘situations’ may be less familiar or understood. This essay explains why ‘situation’ is inseparable from ‘experience’ and deeply important to Democracy and Education’s educational methods and rationales. First, a prefatory section explores how experience is invoked and involved in pedagogical practice, especially experience insofar as it is (a) experimental, (b) direct, and (c) social‐moral in character. The second and main section on situations follows. After a brief introduction to Dewey's special philosophical use of ‘situation’, I examine how situations are implicated in (a) student interest and motivation; (b) ‘aims’ and ‘criteria’ in problem‐solving; and (c) moral education (habits, values, and judgements). What should become abundantly clear from these examinations is that there could be no such thing as meaningful education, as Dewey understood it, without educators’ conscious, intentional, and imaginative deployment of experience and situations.  相似文献   
59.
60.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号