全文获取类型
| 收费全文 | 215篇 |
| 免费 | 18篇 |
| 国内免费 | 7篇 |
专业分类
| 教育 | 35篇 |
| 科学研究 | 12篇 |
| 体育 | 172篇 |
| 综合类 | 21篇 |
出版年
| 2022年 | 1篇 |
| 2021年 | 4篇 |
| 2020年 | 4篇 |
| 2019年 | 13篇 |
| 2018年 | 16篇 |
| 2017年 | 12篇 |
| 2016年 | 13篇 |
| 2015年 | 6篇 |
| 2014年 | 13篇 |
| 2013年 | 51篇 |
| 2012年 | 5篇 |
| 2011年 | 5篇 |
| 2010年 | 13篇 |
| 2009年 | 7篇 |
| 2008年 | 11篇 |
| 2007年 | 10篇 |
| 2006年 | 16篇 |
| 2005年 | 13篇 |
| 2004年 | 4篇 |
| 2003年 | 6篇 |
| 2002年 | 5篇 |
| 2001年 | 2篇 |
| 2000年 | 1篇 |
| 1999年 | 1篇 |
| 1998年 | 2篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1993年 | 3篇 |
| 1991年 | 1篇 |
排序方式： 共有240条查询结果，搜索用时 15 毫秒
81.
Emma Kate Zadow Cecilia Marie Kitic Sam Shi Xuan Wu James William Fell Murray John Adams 《European Journal of Sport Science》2018,18(3):367-375
Exercise has been demonstrated to have considerable effects upon haemostasis, with activation dependent upon the duration and intensity of the exercise bout. In addition, markers of coagulation and fibrinolysis have been shown to possess circadian rhythms, peaking within the morning (0600–1200?h). Therefore, the time of day in which exercise is performed may influence the activation of the coagulation and fibrinolytic systems. This study aimed to examine coagulation and fibrinolytic responses to short-duration high-intensity exercise when completed at different times of the day. Fifteen male cyclists (VO2max: 60.3?±?8.1?ml?kg?1?min?1) completed a 4-km cycling time trial (TT) on five separate occasions at 0830, 1130, 1430, 1730 and 2030. Venous blood samples were obtained pre- and immediately post-exercise, and analysed for tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombin–anti-thrombin complexes (TAT) and D-Dimer. Exercise significantly increased plasma concentrations of TF (p?p?p?p?p?=?.004) and TFPI (p?=?.031), with 0830 greater than 1730 (p .001), while 1730 was less than 2030?h (p?=?.008), respectively. There was no significant effect of time of day for TAT (p?=?.364) and D-Dimer (p?=?.228). Power output, TT time and heart rate were not significantly different between TTs (p?>?.05); however, percentage VO2max was greater at 1730 when compared to 2030 (p?=?.04). Due to a time-of-day effect present within TF, peaking at 0830, caution should be applied when prescribing short-duration high-intensity exercise bout within the morning in populations predisposed to hypercoagulability. 相似文献
82.
Dajo Sanders Mathieu Heijboer Matthijs K. C. Hesselink Tony Myers Ibrahim Akubat 《Journal of sports sciences》2018,36(12):1385-1391
This study evaluated the changes in ratios of different intensity (rating of perceived exertion; RPE, heart rate; HR, power output; PO) and load measures (session-RPE; sRPE, individualized TRIMP; iTRIMP, Training Stress Score?; TSS) in professional cyclists. RPE, PO and HR data was collected from twelve professional cyclists (VO2max 75 ± 6 ml?min?kg?1) during a two-week baseline training period and during two cycling Grand Tours. Subjective:objective intensity (RPE:HR, RPE:PO) and load (sRPE:iTRIMP, sRPE:TSS) ratios and external:internal intensity (PO:HR) and load (TSS:iTRIMP) ratios were calculated for every session. Moderate to large increases in the RPE:HR, RPE:PO and sRPE:TSS ratios (d = 0.79–1.79) and small increases in the PO:HR and sRPE:iTRIMP ratio (d = 0.21–0.41) were observed during Grand Tours compared to baseline training data. Differences in the TSS:iTRIMP ratio were trivial to small (d = 0.03–0.27). Small to moderate week-to-week changes (d = 0.21–0.63) in the PO:HR, RPE:PO, RPE:HR, TSS:iTRIMP, sRPE:iTRIMP and sRPE:TSS were observed during the Grand Tour. Concluding, this study shows the value of using ratios of intensity and load measures in monitoring cyclists. Increases in ratios could reflect progressive fatigue that is not readily detected by changes in solitary intensity/load measures. 相似文献
83.
Alessandro Fornasiero Aldo Savoldelli Roberto Modena Gennaro Boccia Barbara Pellegrini Federico Schena 《Journal of sports sciences》2018,36(8):901-906
In the literature there is a lack of data about the development of top level athletes in cross-country mountain biking (XCO). The purpose of this study was to analyze anthropometric and physiological characteristics of some of the best XCO bikers aged between 13 and 16. The study involved 45 bikers (26 males and 19 females) belonging to a youth national team. The evaluations, consisting of anthropometric measures, incremental cycling tests (VO2max, PPO, P@RCP), and 30 s Wingate Tests (PMax, PMean), were conducted over a lapse of 4 years. Our findings showed in bikers, already at young age, a specific athletic profile advantageous for XCO performance. At the age of 16, just before entering the junior category and competing at international level, male and female bikers showed physiological values normalized to the body mass comparable to those reported in literature for high level athletes (VO2max>70 and >60 ml/kg/min, PPO >6.5 and >5.5 W/kg, respectively in males and females). The production of high power-to-weight ratios and high peaks of anaerobic power attests the presence of highly developed aerobic and anaerobic systems in young XCO cyclists reflecting the high physiological demand of this sport. 相似文献
84.
85.
86.
水圈包括海洋、湖沼、河流、冰川、地下水等,水圈中居住着地球上一半以上的微生物,包括细菌、古菌、真菌、藻类、病毒等,蕴含着地球上最大的微生物组。已有的研究表明,水圈微生物在重要元素生物地球化学循环中发挥关键驱动作用。但是,人们对水圈微生物组的核心科学问题,即微生物如何发挥驱动作用至今了解不多。最近,国家自然科学基金委员会"水圈微生物驱动地球元素循环的机制"重大研究计划(简称"水圈微生物计划")正式立项。该计划拟选择典型水圈环境,解析微生物群落构建及与环境之间的相互作用、微生物物质与能量代谢机制以及微生物代谢活动的生态学意义与贡献,从而揭示水圈微生物驱动碳、氮、硫等元素生物地球化学循环的机制。文章简述了该计划提出的背景与依据,以及涉及的主要科学问题和研究设想。 相似文献
87.
依据罗兰.巴特的符号学视角,结合符号消费的特点和低碳环保时代的要求,尝试性地从符号载体、符号编码、符号意义三个方面对自行车运动进行了解读。认为:自行车运动的符号载体,可以是有形的比赛、产品,也可以是无形的文化理念;自行车运动自身的特点、社会文化的影响和意识形态的引导在为自行车运动进行着编码;自行车运动的符号意义体现在:它是竞争、健康、交往和休闲娱乐的符号。 相似文献
88.
卢永明 《西安体育学院学报》1999,(4)
花式单车是澳门发展的新兴项目之一,目前,已能达到亚洲水平,此项运动在澳门极具发展潜力。为了找出发展该项目的优势,为进一步提高澳门花式单车运动水平,笔者认为,应将其列入学界竞赛计划以比赛促进普及与提高;注意科学选材,将身体条件好的运动员集中试训,以缩短训练周期,提高成材率。 相似文献
89.
90.