浅谈铅球最后用力的几个问题

通过查阅大量相关资料,从出手角度、最后用力的工作距离和时间、铅球最后用力上升的高度等方面,运用运动生物力学的原理进行分析研究.     

韦拔群同志入党时间再考证

韦拔群是广西农民运动的先驱和著名的领袖 ,中国共产党的优秀党员。但一些作者和老红军干部对其入党时间有不同的看法。本着尊重历史、实事求是和对韦拔群同志负责的原则 ,笔者经过多次反复考证 ,认为韦拔群入党时间应该在 1 92 6年冬。     

一种智能化NO输送系统的研制

为了满足临床吸入一氧化氮（NO）治疗安全与可靠的要求,研制一种和呼吸机同步的一氧化氮吸入装置是至关重要的．该装置使用气体流量计（GFM）检测呼吸机的吸气流量,通过气体稀释公式计算出在治疗条件下NO标气的流量,并由质量流量控制器（MFC）来控制NO标气送往呼吸回路,同时采用NO／NO2电化学传感器对进入人体前的治疗气中NO浓度和二氧化氮（NO2）浓度进行监测．试验结果表明：该一氧化氮吸入装置供N0标气相对于呼吸机供气滞后不到200ms,NO气体的用量相对于持续供气时节约了E／（I＋E）（吸呼比：I：E）、NO2的生成量〈2mg／L,从而不仅实现了监测与配气的智能化,而且也提高了NO治疗气精度、确保了治疗的可靠性与安全性．     

浅谈医学研究生高效自我管理策略

对医学研究生管理现状进行简要分析,从心态管理、目标管理、时间管理、知识管理和行动管理五大方面提出具体可行的研究生自我管理方法,引导医学研究生实现高效的自我管理,推进科研项目的高效实施。     

Adherence to 24-hour movement guidelines among Portuguese preschool children: the prestyle study

ABSTRACT

Purpose

The 24-Hour Movement Guidelines (24 hMG) provide specific recommendations, including physical activity (PA), screen-time and sleep-duration, which preschoolers should achieve for a healthy day (24 h). The aim of the current study was to analyse preschooler’s adherence with the 24-Hour Movement Guidelines.     

山西省农村中学课外体育活动的现状调查与分析

采用问卷调查法对山西省农村中学课外体育活动的现状进行研究,对促进山西省农村中学课外体育活动健康有序地开展提出建议,旨在进一步贯彻学校体育有关法规,为上级部门制定有关政策和深化学校体育改革提供有益参考。     

Different types of compression clothing do not increase sub-maximal and maximal endurance performance in well-trained athletes

Abstract

Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean ± s: age 27.1 ± 4.8 years, [Vdot]O_2max 63.7 ± 4.9 ml · min^?1 · kg^?1) performed four sub-maximal (～70%[Vdot]O_2max) and maximal tests with and without different compression stockings, tights, and whole-body compression suits. Arterial lactate concentration, oxygen saturation and partial pressure, pH, oxygen uptake, and ratings of muscle soreness were recorded before, during, and after all tests. In addition, we assessed time to exhaustion. Sub-maximal (P = 0.22) and maximal oxygen uptake (P = 0.26), arterial lactate concentration (P = 0.16; 0.20), pH (P = 0.23; 0.46), oxygen saturation (P = 0.13; 0.26), and oxygen partial pressure (P = 0.09; 0.20) did not differ between the types of clothing (effect sizes = 0.00–0.45). Ratings of perceived exertion (P = 0.10; 0.15), muscle soreness (P = 0.09; 0.10) and time to exhaustion (P = 0.16) were also unaffected by the different clothing (effect sizes = 0.28–0.85). This was the first study to evaluate the effect on endurance performance of different types of compression clothing with increasing amounts of compressive surface. Overall, there were no performance benefits when using the compression garments.     

Influence of sex and specialty on the prediction of middle-distance running performances using the Mercier et al.’s nomogram

The aim was to test the influence of sex and specialty (3000, 5000 and 10000 m) on the validity of middle-distance running performance predictions obtained from the Mercier et al.’s nomogram. Consequently, we examined all official French track running rankings for the 3000-, 5000- and 10000-m events (men and women) from 2006 to 2012. A scoring table was used to determine the runners’ specialties. Only runners who performed in the three distance events within the same year were included (75 women and 400 men). The Mercier et al.’s nomogram was used to predict one running performance from the other two. The results showed no significant difference between actual and predicted running performances (P = 0.77). Female runners had significantly lower performances than male runners (P < 0.001). Specialty did not influence performances (P = 0.11). Very high correlations were found between actual and predicted performances (0.91 < r < 0.99), with the exception of women (r = 0.85) in 5000 m. Moreover, low limits of agreement were obtained for male and female runners, whatever the specialty. These results support the validity of the nomogram to predict running performance in the 3000-, 5000- and 10000-m events for male and female runners, whatever the specialty. The predicted running performances may be used in training programmes (e.g., to prescribe tempo runs) and competitions (e.g., to establish split times).     

世界优秀速滑运动员弯道蹬冰技术的时间特征分析

揭示优秀速滑运动员蹬冰技术的时间特点，对明确clap式冰刀蹬冰技术动作结构具有重要的意义。通过运动学3维摄像方法分析后认为：在一个单步中右单步支撑时间大于左单步，而这种时值的延长体现在单支撑阶段；从蹬冰腿关节的伸展时机上看，踝关节的缓冲时间表现为右腿大于左腿，但缓冲时间占整个单步时间的百分比却相同，具有明显的规律性；从下肢三大关节伸展角速度达到最大值的时机上看，髋、膝关节具有相对的同步性，但踝关节却具有一定的延迟性。     

中国学习者英语语调单位特征研究——一项基于英语专业四级口语考试的研究

本研究采用某高等院校全国英语专业四级口语考试中的第一项（复述故事）任务作为研究对象语料,借助语音分析软件Praat对预料进行筛选、标注、分析,从而发现研究对象的独立语调单位特征主要表现在：用词量少,时长短;语调单位与句法结构的切分存在偏差;多个重读音节并存;调核音调单一,多降少升。