全文获取类型
收费全文 | 129篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
教育 | 69篇 |
科学研究 | 18篇 |
体育 | 32篇 |
综合类 | 13篇 |
信息传播 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 14篇 |
2013年 | 14篇 |
2012年 | 18篇 |
2011年 | 9篇 |
2010年 | 11篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有133条查询结果,搜索用时 19 毫秒
21.
22.
23.
JOHN MORRIS MARY NEVILL DYLAN THOMPSON JASON COLLIE CLYDE WILLIAMS 《Journal of sports sciences》2013,31(5):371-381
Nine male student games players consumed either flavoured water (0.1 g carbohydrate, Na+ 6 mmol · l?1), a solution containing 6.5% carbohydrate-electrolytes (6.5 g carbohydrate, Na+ 21 mmol · l?1) or a taste placebo (Na+ 2 mmol · l?1) during an intermittent shuttle test performed on three separate occasions at an ambient temperature of 30°C (dry bulb). The test involved five 15-min sets of repeated cycles of walking and variable speed running, each separated by a 4-min rest (part A of the test), followed by 60 s run/60 s rest until exhaustion (part B of the test). The participants drank 6.5 ml · kg?1 of fluid as a bolus just before exercise and thereafter 4.5 ml · kg?1 during every exercise set and rest period (19 min). There was a trial order effect. The total distance completed by the participants was greater in trial 3 (8441 ± 873 m) than in trial 1 (6839 ± 512, P < 0.05). This represented a 19% improvement in exercise capacity. However, the trials were performed in a random counterbalanced order and the participants completed 8634 ± 653 m, 7786 ± 741 m and 7099 ± 647 m in the flavoured water (FW), placebo (P) and carbohydrate-electrolyte (CE) trials, respectively (P = 0.08). Sprint performance was not different between the trials but was impaired over time (FW vs P vs CE: set 1, 2.41 ± 0.02 vs 2.39 ± 0.03 vs 2.39 ± 0.03 s; end set, 2.46 ± 0.03 vs 2.47 ± 0.03 vs 2.47 ± 0.02 s; main effect time, P < 0.01). The rate of rise in rectal temperature was greater in the carbohydrate-electrolyte trial (rise in rectal temperature/duration of trial, °C · h?1; FW vs CE, P < 0.05; P vs CE, N.S.). Blood glucose concentrations were higher in the carbohydrate-electrolyte than in the other two trials (FW vs P vs CE: rest, 4.4 ± 0.1 vs 4.3 ± 0.1 vs 4.2 ± 0.1 mmol · l?1; end of exercise, 5.4 ± 0.3 vs 6.4 ± 0.6 vs 7.2 ± 0.5 mmol · l?1; main effect trial, P < 0.05; main effect time, P < 0.01). Plasma free fatty acid concentrations at the end of exercise were lower in the carbohydrate-electrolyte trial than in the other two trials (FW vs P vs CE: 0.57 ± 0.08 vs 0.53 ± 0.11 vs 0.29 ± 0.04 mmol · l?1; interaction, P < 0.01). The correlation between the rate of rise in rectal temperature (°C · h?1) and the distance completed was ?0.91, ?0.92 and ?0.96 in the flavoured water, placebo and carbohydrate-electrolyte conditions, respectively (P < 0.01). Heart rate, blood pressure, plasma ammonia, blood lactate, plasma volume and rate of perceived exertion were not different between the three fluid trials. Although drinking the carbohydrate-electrolyte solution induced greater metabolic changes than the flavoured water and placebo solutions, it is unlikely that in these unacclimated males carbohydrate availability was a limiting factor in the performance of intermittent running in hot environmental conditions. 相似文献
24.
通过对北京市残疾田径运动员在云南昆明进行为期五周的高原训练进行跟踪,观察运动员在平原—高原—平原交叉环境下肺功能的变化规律,分别对MVV、VC、FVC、FEV1%、PEF、PEF25~75%用力肺活量平均呼吸流速各指标进行测试。结果显示:高原残疾田径运动员训练后肺功能各指标有明显上升,高原训练有利于残疾田径运动员肺通气功能的提高。 相似文献
25.
Effects of Ventilation on Segmental Bioimpedance Spectroscopy Measures Using Generalizability Theory
A. Allan Turner Albert Lozano-Nieto Marcel Bouffard 《Measurement in physical education and exercise science》2013,17(2):116-129
The purpose of this study was to examine the effect of three ventilation conditions (i.e., normal, regimented, and no-ventilation) on the reproducibility of bioimpedance scores in humans for the forearm and trunk segments. One hundred able-bodied North American men and women, from 18 to 71 years of age, volunteered as participants. The experimenters used a Xitron Bio-Impedance Analyzer System model 4200 instrument with Hydra software (Xitron Technologies, San Diego, California, USA) to collect bioimpedance data on extracellular fluid and intracellular fluid scores. The experimenters analyzed the data using the generalizability theory,with persons as the facet of differentiation and time as the facet of generalization. The major findings were (a) ventilation conditions did not have a significant impact on the reproducibility of the test scores, (b) the forearm segment produced consistently higher intracellular fluid generalizability coefficients across three ventilation conditions for both gender groups when compared to the trunk segment, (c) the trunk segment produced intracellular fluid generalizability coefficients that were higher for the male group, and (d) the measurement error affected extracellular fluid scores less than segmental intracellular fluid scores. 相似文献
26.
通过了解体育与非体育专业学生健康体适能状况及其差异,探讨运动对女大学生心肺适能的影响。采用随机抽样的方法从体育与非体育专业的男生中分别各抽取16人,使用台阶试验和肺功能测试仪分别对他们进行心肺适能的有关指标,按要求进行一一测试,并采用检验对其差异的显著性进行检验。结果显示:体育专业女生台阶指数明显高于非体育专业女生(P<0.01);体育专业女生台阶负荷后心率变化幅度相对于非体育女生比较小、恢复较快,均存在非常显著的差异(P<0.01);在肺功能测试中,体育专业女生的肺活量、用力肺活量、每分钟最大通气量均高于非体育专业女生,其中在肺活量、用力肺活量的比较中(P<0.01)、每分钟最大通气量比较中(P<0.05),与非体育女生比较都存在显著的差异性。得出结论,经常参加体育运动可以提高心肺适能,从而获得更好的体适能。 相似文献
27.
针对单线双竖井机械通风的铁路隧道,以流体力学的恒定流理论为计算依据,推导出在隧道内列车活塞风计算方法. 相似文献
28.
室内^222 Rn/^220 Rn危害的评估与防护中,^222 Rn/^220 Rn浓度水平与空间分布的准确计算是一个关键问题。通过对室内^222 Rn/^220 Rn水平影响因素的分析,建立较真实的物理模型,运用CFD技术研究固定外界^222 Rn/^220 Rn浓度与壁面析出率时,不同通风状况下室内^222 Rn/^220 Rn浓度的平均值与三维分布情况。 相似文献
29.
针对风道抽出式和压入式隧道通风系统风量难以平衡的问题。提出采用改变隧道与风道交角的方法.通过理论分析和模型实验得出风道抽出式和压入式隧道通风系统的性能差异,采用隧道与风道不同交角的方法能有效解决风量不均衡问题,并为其应用到实际工程中提供了实验依据. 相似文献
30.
矿井通风难易程度采用矿井等积孔的大小进行评估,并不能准确反映其真实的通风难易程度,应考虑矿井总风量是否够、井下各用风区域间的风量调配是否容易、矿井瓦斯涌出量的大小、矿井开采强度、采煤方法等影响因素,进行综合评定。 相似文献