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   1105篇
  免费   26篇
教育   768篇
科学研究   73篇
各国文化   14篇
体育   181篇
文化理论   33篇
信息传播   62篇
  2023年   10篇
  2022年   13篇
  2021年   17篇
  2020年   37篇
  2019年   68篇
  2018年   92篇
  2017年   85篇
  2016年   67篇
  2015年   51篇
  2014年   44篇
  2013年   233篇
  2012年   48篇
  2011年   29篇
  2010年   29篇
  2009年   15篇
  2008年   29篇
  2007年   23篇
  2006年   31篇
  2005年   16篇
  2004年   9篇
  2003年   16篇
  2002年   7篇
  2001年   12篇
  2000年   10篇
  1999年   5篇
  1998年   6篇
  1997年   6篇
  1996年   8篇
  1995年   11篇
  1994年   9篇
  1993年   6篇
  1992年   7篇
  1990年   5篇
  1989年   6篇
  1986年   3篇
  1981年   2篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
  1977年   2篇
  1976年   3篇
  1974年   5篇
  1973年   2篇
  1972年   5篇
  1969年   2篇
  1968年   2篇
  1956年   3篇
  1872年   4篇
  1871年   2篇
  1870年   4篇
排序方式: 共有1131条查询结果,搜索用时 15 毫秒
1.
2.
The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.  相似文献   
3.
4.
Against the backdrop of Spain’s Transparency Act, this article discusses the presence or otherwise of a series of document types, proposed as management-related transparency indicators, on 61 (8 national and 53 provincial) historic archive websites. Although examples of good practice were identified, the information provided was found to be scant, in particular as regards lines of action, organisational objectives and yearly reports. The information most commonly provided on the websites included the collection classification chart, service use regulations and citizen charters. The inference drawn was that archives, so intently focused on their role in the application of the Act by the organisations they serve, neglect their own administrative obligations in respect of its provisions. The recommendation is that as government-funded and subsidised public service institutions, historic archives should exercise transparency by furnishing the information stipulated in the Act on their websites.  相似文献   
5.
6.
English-Spanish cognates are an important subset of words in both the English and Spanish languages. Cognates are words that possess identical or nearly identical spellings and meanings in both languages as a result of being derived from Latin and Greek. Of major importance is the fact that many of the more than 20,000 cognates in English are academic vocabulary words, terms essential for comprehending school texts.

?The Pura Belpré Children's Book Award has been given since 1996 to outstanding children's and young adult literature that represents, affirms, and celebrates the Latino cultural experience. The books are judged for their literary and artistic quality.

?There are many English-Spanish cognates in each of the Pura Belpré picture books. The purpose of this article is to introduce the Pura Belpré Cognate Database, which lists all of the English-Spanish cognates for each of the children's picture books that have won the award or have been designated as honor books. Ideas for vocabulary, spelling, and morphology lessons or mini-lessons are also presented.  相似文献   
7.
Myokines may play a role in the health benefits of regular physical activity. Secreted protein acidic rich in cysteine (SPARC) is a pleiotropic myokine that has been shown to be released into the bloodstream by skeletal muscle in response to aerobic exercise. As there is evidence suggesting that SPARC release may be linked to glycogen breakdown and activation of 5’ adenosine monophosphate-activated protein kinase, we hypothesised that brief supramaximal exercise may also be associated with increased serum SPARC levels. In the present study, 10 participants (3 women; mean?±?SD age: 21?±?3 y, body mass index (BMI): 22?±?3?kg?m?2, and V˙O2max: 39?±?6?mL?kg?1?min?1) performed an acute bout of supramaximal cycle exercise (20-s Wingate sprint against 7.5% of body mass, with a 1-min warm-up and a 3-min cool-down consisting of unloaded cycling). Serum SPARC levels were determined pre-exercise as well as 0, 15, and 60?min post-exercise and corrected for plasma volume change. To determine whether regular exercise affected the acute SPARC response, participants repeated the acute exercise protocol three times per week for four weeks, and serum SPARC response to supramaximal exercise was reassessed after this period. Acute supramaximal exercise significantly decreased plasma volume (?10%; p?<?.001), but was not associated with a significant change in serum SPARC levels at either the pre-training or post-training testing sessions. In conclusion, in contrast to aerobic exercise, a single brief supramaximal cycle sprint is not associated with an increase in serum SPARC levels, suggesting that SPARC release is not related to skeletal muscle glycogen breakdown.  相似文献   
8.
Sedentary behaviour (SB) has recently emerged as an independent risk factor for different health outcomes. Older adults accumulate long time in SB. Understanding the role that SB plays on health is crucial for a successful aging. This short systematic review summarizes the current evidence related to the effects of objectively measured SB on frailty, physical performance and mortality in adults ≥60?years old. The literature search produced 271 records for physical performance (n?=?119), frailty (n?=?31), and mortality (n?=?121). Finally, only 13 articles fulfilled the inclusion criteria and were included in this review. All articles but one included in the physical performance section (n?=?9) showed a negative association between longer time spent in SB and physical performance. A significant association of SB with higher odds of frailty was found, however this association disappeared after adjusting for cognitive status. Lastly, two of the three included studies showed positive associations between SB and mortality, but this effect decreased or even disappeared in the more adjusted models. In conclusion, there is consistency that SB is negatively associated with physical performance. However, the relationship between objectively measured SB and frailty incidence and mortality rates remains unclear and deserves further research. The use of homogenous criteria to assess SB and the inclusion of more robust research designs will help clarifying the independent effects that SB could have on physical performance, frailty, and mortality. This will ultimately help designing more efficient and comprehensive physical activity guidelines for older adults.  相似文献   
9.
ABSTRACT

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (< .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.  相似文献   
10.
ABSTRACT

This research adapted the Life Skills Scale for Sport (LSSS) into Portuguese and provided evidence for its construct validity. Study 1 included four translators and five academics who developed a Portuguese version of the LSSS (P-LSSS). During this study, evidence for the content and substantive aspects of construct validity was provided using an expert panel and 25 sports participants. Study 2 included 413 participants that completed the P-LSSS. Within this study, evidence for the structural aspect of construct validity was provided via factor analyses. Study 3 included 134 participants who completed the P-LSSS and a measure of motivation. This study provided evidence for the external aspect of construct validity, with results showing more self-determined motivation had positive relationships with participant’s life skills development. Overall, our findings provided evidence for the construct validity of P-LSSS scores. Researchers and practitioners can use the P-LSSS to assess life skills development within sports participants.  相似文献   
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