几类特殊图的圆色数性质

圆色数是图的色数概念的推广 .与色数相比 ,圆色数包含了更多有关图本身结构的信息 ,因而更加难以确定 .本文推导了 2类特殊图———图Ctk 和图Ctk-v的圆色数 ;并给出了图Hm ,n圆色数的一个简单证明 .     

范德瓦尔斯频移及线型畸变现象

从理论上研究了囚禁于两电介质间薄原子蒸汽的频率调制吸收光谱中范德瓦尔斯频移及线型畸变现象,发现在频率调制情形下频移很明显,线型则由对称类色散型转为非对称类吸收型。采用频率调制的方法解决了在很多情形下采用直接法或吸收法不易实现对vdW作用势进行精确测量的难题。     

m维欧氏空间中正则单形的不变量

证明了M维欧氏空间中以正则单形的中心为球心的M维球面上任一点到各顶点及至各(M—1)维面距离平方之和均为不变量，从数量关系方面揭示了正则单形的一个性质．文末提出了一个猜想。     

现行直道跨栏跑训练理论与普通大学生训练计划的比较研究

为寻求和探索中国普通高校优秀跨栏跑大学生运动员赛前训练是否具有科学性,运用观察、生物力学测量、数理统计及逻辑分析等方法,对江苏省优秀跨栏跑大学生运动员张亚菲市运会赛前一个月训练计划进行分析,对比中国现行跨栏跑训练理论得出,张亚菲的训练计划符合当今直道跨栏跑训练理论,以速度为核心,高度重视栏间节奏跑,重视快速力量训练;在训练方法与手段上,以间歇和重复的训练方法为主,以及与专项紧密结合的栏性练习;在训练结构上,增加每周强度课次数,以达到提高训练强度比重这一目标。这一研究旨在为中国普通高校教练员科学训练提供参考依据。     

The effect of the bend on technique and performance during maximal effort sprinting

This study investigated changes in performance and technique that occur during maximal effort bend sprinting compared with straight-line sprinting under typical outdoor track conditions. Utilising a repeated measures design, three-dimensional video analysis was conducted on seven male sprinters in both conditions (bend radius: 37.72 m). Mean race velocity decreased from 9.86 to 9.39 m/s for the left step (p = 0.008) and from 9.80 to 9.33 m/s for the right step (p = 0.004) on the bend compared with the straight, a 4.7% decrease for both steps. This was mainly due to a 0.11 Hz (p = 0.022) decrease in step frequency for the left step and a 0.10 m (p = 0.005) reduction in race step length for the right step. The left hip was 4.0° (p = 0.049) more adducted at touchdown on the bend than the straight. Furthermore, the bend elicited significant differences between left and right steps in a number of variables including ground contact time, touchdown distance and hip flexion/extension and abduction/adduction angles. The results indicate that the roles of the left and right steps may be functionally different during bend sprinting. This specificity should be considered when designing training programmes.     

游泳200m项目的分段体能分配矩阵分析

以200m竞技游泳项目为切入点,采用速度系数的数理统计方法对优秀游泳运动员的体能分配方式进行矩阵分析。结果表明：（1）大多数顶尖选手采用了第一个50m最快,第三个分段最慢的体能分配方式;（2）中国运动员多在第一个分段速度系数较高,游速较快,对后程冲刺阶段的速度耐力的重视程度不如开始和途中游阶段;国际顶尖选手,前分段与后分段相差较小,体力分配比较均匀。     

Influence of test duration on oxygen uptake attained during treadmill running

Abstract

Previous investigations have revealed that in well-trained middle-distance runners, oxygen uptake (VO₂) does not attain maximal values (VO_2max) in exhaustive treadmill trials where the VO₂ demand exceeds VO_2max. To date, this shortfall in the VO₂ attained has been demonstrated in trials as short as 2 min in duration. In this study, we investigated whether a reduction in exhaustive test duration influences the VO₂ attained during running on a treadmill. Six middle-distance runners participated in the study, completing an exhaustive 400 m and 800 m trial. These trials, together with a progressive test to determine VO_2max, were completed in a counterbalanced order. Oxygen uptakes attained during the 400 m and 800 m trials were compared to examine the influence of exhaustive test duration. A plateau in VO₂ was observed in all participants for the progressive test, demonstrating the attainment of VO_2max. The mean speed, duration, and resulting distance in the constant-speed exhaustive trials were 25.8 km · h^?1 (s=1.2), 55.8 s (s=2.3), and 400.2 m (s=20.2) for the 400 m trial, and 24.3 km · h^?1 (s=0.8), 108.4 s (s=21.2), and 730.1 m (s=129.1) for the 800 m trial, respectively. A paired-samples t-test revealed a significantly different (P=0.018)%VO_2max was attained for the 400 m (85.7%, s=3.0) and 800 m (89.1%, s=5.0) trials. In conclusion, VO₂ did not reach VO_2max during the exhaustive constant-speed 400 m and 800 m trials, but the test duration does influence the%VO_2max achieved. Specifically, the VO₂ attained becomes progressively further below VO_2max as trial duration is reduced, such that 89% and 86% VO_2max is achieved in exhaustive 800 m and 400 m constant-speed trials, respectively.     

现代110米栏的技术特点

通过查阅大量技术资料和观看比赛录像,对110米跨栏跑现代和过去技术的研究,得出跨栏跑的摆动腿技术、起跨腿技术、着地技术、腿臂配合等技术方面的不同,构成了现代技术与过去技术质的不同,而使现代技术更趋完善和合理。     

400米研究现状分析

近些年来我国体育工作者对400m的研究颇多,主要集中在400m的能量供应、速度能力、速度分配（节奏控制）、400m的训练等方面,分别就这几方面给予归纳总结。     

防护装备影响防化单兵运动的实验研究

经过深入调查分析,通过对防化单兵在徒手状态和穿着个人防护装备条件下通过400 m障碍物的测试数据进行对比,找到个人防护装备对单兵通过不同障碍物时的影响因素及各因素的影响程度,为防化兵体能训练提供理论依据并对个人防护装备的改进提出建议.