高校业余足球运动员体能训练方法研究

运用文献资料法、专家访谈、比较分析等方法对高校业余足球运动员的供能特点进行了分析,根据高校业余足球运动员身体特点,对高校业余足球运动员体能水平构成因素进行分析,寻找符合高校业余足球运动员体能训练方法。     

试论无氧阈跑速作为耐力测试指标的必要性及可行性

800 m、1 000 m跑测试是在用一个以无氧代谢供能为主的运动项目评测人的有氧耐力,成绩不能客观反映机体的有氧耐力水平,不能引导学生科学锻炼,还会让受试者承受较大的心理负荷,不利于运动兴趣培养和终生体育生活方式的养成,且在800 m、1 000 m跑测试中频频发生意外。研究认为,可用无氧阈跑速做耐力评测指标,它能确切反映人的有氧耐力水平,引导人们科学锻炼,强度由低到中,安全、简单,可在跑步机或场地上完成。     

KPSF-35传动用自动控制系统设计中电流自适应与平波电抗器的组合应用

传动用自控系统设计,传统设计采用平波电抗器维持电流连续确保控制对象的工作,但铜耗多、体积大。电流自适应也可解决问题但效果欠佳,＂电流自适应＋平波电抗器＂解决方案,充分利用各自特点,即降低铜耗又最大限度满足系统的要求,提高了性能价格比。     

Energy system contribution to 400-metre and 800-metre track running

As a wide range of values has been reported for the relative energetics of 400-m and 800-m track running events, this study aimed to quantify the respective aerobic and anaerobic energy contributions to these events during track running. Sixteen trained 400-m (11 males, 5 females) and 11 trained 800-m (9 males, 2 females) athletes participated in this study. The participants performed (on separate days) a laboratory graded exercsie test and multiple race time-trials. The relative energy system contribution was calculated by multiple methods based upon measures of race [Vdot]O₂, accumulated oxygen deficit (AOD), blood lactate and estimated phosphocreatine degradation (lactate/PCr). The aerobic/anaerobic energy system contribution (AOD method) to the 400-m event was calculated as 41/59% (male) and 45/55% (female). For the 800-m event, an increased aerobic involvement was noted with a 60/40% (male) and 70/30% (female) respective contribution. Significant (P <?0.05) negative correlations were noted between race performance and anaerobic energy system involvement (lactate/PCr) for the male 800-m and female 400-m events (r = ? 0.77 and ??0.87 respectively). These track running data compare well with previous estimates of the relative energy system contributions to the 400-m and 800-m events. Additionally, the relative importance and speed of interaction of the respective metabolic pathways has implications to training for these events.     

Energy system contribution to 1500- and 3000-metre track running

The aim of the present study was to quantify the contributions of the aerobic and anaerobic energy systems to 1500- and 3000-m track running events during all-out time-trials performed individually on a synthetic athletic track. Ten 3000-m (8 males, 2 females) and fourteen 1500-m (10 males, 4 females) trained track athletes volunteered to participate in the study. The athletes performed a graded exercise test in the laboratory and two time-trials over 1500 or 3000?m. The contributions of the energy systems were calculated by measures of race oxygen uptake, accumulated oxygen deficit (AOD), race blood lactate concentration, estimated phosphocreatine degradation and some individual muscle metabolite data. The relative aerobic energy system contribution (based on AOD measures) for the 3000?m was 86% (male) and 94% (female), while for the 1500?m it was 77% (male) and 86% (female). Estimates of anaerobic energy expenditure based on blood lactate concentrations, while not significantly different (P?>?0.05), were generally lower compared with the AOD measures. In conclusion, the results of the present study conform with some recent laboratory-based measures of energy system contributions to these events.     

Transient VO2 Characteristics in Children at the Onset of Steady-Rate Exercise

Abstract

The transient oxygen uptake (VO₂) response during the initial phase of exercise was investigated in 28 children (mean age ± SD = 10.2 ± 2.28 years) during constant load submaximum bicycle ergometer exercise (mean power output ± SD = 56 ± 4.0 watts; mean VO₂ ± SD = .92 ± .141 [mdot] min^-1). The VO₂ half-time (VO₂ - t½) averaged (± SD) 34.8 (± 12.70) sec which is similar to that observed in adults. Examination of the VO₂-t ½ response as it related to age (7 to 14 years) showed that younger children attained steady-rate VO₂ more quickly than older children (r = .77 between age and VO₂-t½, P < .05). Body size, maturational level, exercise intensity, cardiorespiratory factors, and anaerobic potential are suggested as possible factors accounting for the positive age vs VO₂-t ½ relationship.     

Novel photocatalytic reactor for degradation of DDT in water and its optimization model

A novel photocatalytic reactor was developed to remove （1,1-bis（4-chlorophenyl）-2,2,2-trichloroethane） （DDT） from water. In the reactor, a cenosphere was used to support TiO2 film made by means of sol-gel. Because the cenospheres were coated with TiO2, their specific gravity was slightly increased from the original 0.6-0.8 to 0.8-0.9, so that they were able to be suspended in water. With the mixed operation of a bubbler, the water in the reactor was in a well-fluidized state. The bottom of the reactor is a sand filter bed, which can be used to prevent the photocatalyst from being lost. A mathematical model of the reactor has been developed in the two primary influential factors： ultraviolet （UV） light intensity and photocatalyst concentration. With such a model, the reactor can be designed more reasonably.     

Pb-17Li回路技术的初步分析

本文综合国外有关Pb-17Li回路的经验,结合本人的实践,就聚变堆包层(包括Iter-HCLL)的Pb-17Li回路,主要是对实验用Pb-17Li回路的设计和运行的诸要点做一评述,同时介绍一些设计中的普遍原则和一些重要数据.     

自行车运动员专项体能研究进展

自行车是一项集速度、力量和耐力于一身的运动项目,对运动员的体能,特别是专项体能要求较高。自行车运动员的专项体能主要包括有氧代谢能力、无氧代谢能力和专项力量,以及骑行技术与有氧、无氧能力的关系等。对国内外自行车运动员专项体能研究中的热点问题和主要研究成果进行分析讨论。