爆发力训练与有氧耐力评价指标的相关性研究

为研究同时进行爆发力训练与有氧耐力训练所产生的效果,本研究以14名耐力运动员为实验组(E)、14名耐力运动员为控制组(C)进12周的训练,实验组除15%爆发力训练代替传统耐力训练外,其余训练内容相同。结果发现:5 km跑成绩与RE在实验组明显提高(P<0.05),控制组无差异;5 J在实验组有非常显著性提高(P<0.01),控制组下降显著(P<0.05);VO2max在控制组显著性提高(P<0.01),对实验组变化不明显。混合控制组与实验组数据发现:5km跑时间与RE存在中度负相关(r=-0.54)。结论:同时进行爆发力与耐力训练在不改变VO2max的情况下可以提高5 km跑的成绩。     

游泳训练对Ⅱ型糖尿病Wistar大鼠肠系膜动脉舒张功能改善作用的研究

目的:通过建立wistar大鼠Ⅱ型糖尿病动物模型,观察Ⅱ型糖尿病(T2DM)模型大鼠,经游泳训练后肠系膜动脉舒张功能的变化,并探讨其内在影响机制。方法:实验材料wistar大鼠60只,造模完成后随机分成3组:正常对照组(CON),Diabetes模型组(DI),游泳运动组(SEX),每组15只。进行游泳训练共计8周。结果:T2DM可造成肠系膜动脉血管舒张功能降低(P<0.05),且存在内皮依赖性。舒张功能的降低与eNOS-NO系统活性降低直接相关。游泳训练可有效维持内皮依赖性舒张功能(P<0.05),其上调eNOS-NO系统。另外,T2DM造成的eNOS-NO系统活性降低与该系统上游蛋白PI-3K,Akt降低有关,且在加入上游蛋白抑制剂(PI-3K)LY294002及eNOS阻断剂L-NAME后保护效应消失。结论:游泳训练能改善T2DM wistar大鼠肠系膜舒动脉舒张功。其内在保护作用可能是通过部分激活PI-3K-Akt-eNOS信号通路而实现。     

低氧运动干预对大鼠心肌细胞自噬作用的探讨

目的:探讨常压低氧(13.6%氧含量)运动对大鼠心肌核转录因子NF-κB、Cyt c和自噬相关基因Beclin1的影响,为运动与低氧适应机制的研究和高原训练方案的制定提供理论依据。方法:采用酶联免疫吸附技术(ELISA)分别测大鼠心肌NF-κB、Cyt c和Beclin1的含量。结果:通过运动训练、低氧适应或者是低氧运动适应,都能使NF-κB和Beclin1不同程度升高,其中以HC和HiLo较为显著,Cyt c变化不明显,提示运动训练、低氧适应或者低氧运动适应都能诱导自噬的发生。结论:自噬相关基因Beclin1在低氧训练中产生的低氧适应机制可能是低氧刺激后细胞内产生ROS,ROS激活了NF-κB信号通路,使得Beclinl与NF-κB活性增高;通过长期的运动与低氧适应,可能ROS降低有效抑制NF-κB信号通路,使Beclinl和NF-κB产生了适应性变化,Cyt c从线粒体释放较少,提示细胞凋亡率减少,从而保护心肌细胞的作用。     

运动训练对自发性高血压大鼠心肌细胞凋亡蛋白表达的影响

目的:研究运动训练对SHR心肌细胞中HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3)的影响,以探讨其对运动引起心肌细胞凋亡的作用。方法:以SHR大鼠中等强度训练为实验模型,采用Western bloting技术检测了大鼠心肌细胞中调控蛋白HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3)的表达。结果:长期中等强度训练可以提高心肌细胞中抑凋亡蛋白HSP-72、Bcl-2和蛋白激酶β(PKB)的表达,凋亡蛋白Bax、糖原合成激酶-3(GSK-3)表达显著降低,Bcl-2/Bax的表达没有显著变化,从而抑制心肌细胞的凋亡。结论:心肌细胞中HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3),Bcl-2/Bax在运动后的不同表达对心肌细胞凋亡的发生有明显的抑制作用。     

局部文本特征选取算法的比较和改进研究

本文通过实验比较了互信息、χ2统计算法和优势率三种算法在用于局部文本特征选取时对文本分类性能的影响.实验结果显示,在应用于局部特征选择的情况下,文本特征选取算法仍然可以将特征空间的维度降低90%以上,而不降低文本分类的性能.同时,我们发现在应用于局部文本特征选取时,优势率算法的性能不如互信息和χ2统计算法.另外,对于K最近邻分类算法,随着K值的增大,文本分类的查准率在增加,而查全率在降低.最后,本文详细分析了造成这三种算法性能差异的原因,并提出了一种改进算法,来提高优势率算法应用于局部文本特征选取时的性能.     

非相关文献知识发现的关键技术研究

本文在对非相关文献知识发现中的关键技术进行界定的基础上,对11个国外主要的非相关文献知识发现研究中所涉及的关键技术,即初始文本集的构建、信息抽取及中间关联词的确定与排序等进行了比较研究,认为B集合质量低是非相关文献知识发现目前存在的主要问题.针对该问题,作者提出以提高B集合的质量为主要目标,从B集合形成的前过程,即初始文本集的质量以及B集合本身的质量,即B词的排序两个方面的改进策略.前者包括初始文本集的合理结构及综合过滤机制,后者包括双向词频法、基于MeSH加权和基于文献内聚力加权.并对部分改进策略进行了试验.     

对足球训练中运用Yo-Yo测试的原理、作用和方法的研究

作为一种体能测试方法和手段，Yo—Yo目前已被中国足协作为对国内职业足球俱乐部的体能测试的内容。使用文献资料，观察、实验等方法，对Yo-Yo测试的原理及其作用方法进行了探讨和研究，为Yo-Yo测试提供理论和实践上的依据。     

Activity profile of top-class association football referees in relation to performance in selected physical tests

Abstract

The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r ² = 0.30; P < 0.05), the 200-m sprint (r ² = 0.05; P < 0.05), or the 50-m sprint (r ² = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.     

Alterations in Strength and Maximal Oxygen Uptake Consequent to Nautilus Circuit Weight Training

Abstract

The purpose of this study was to determine the effects of a Nautilus circuit weight training program on muscular strength and maximal oxygen uptake ([Vdot]O ₂ max) by comparing these effects to those produced by adhering to either a free weight (FW) strength training program or a running (R) program. Male college students who voluntarily enrolled in either a FW training class (n = 11), a Nautilus (N) circuit weight training class (n= 12), or a R conditioning class (n= 13) were subjects for this investigation. All groups participated in their respective programs 3 days per week for 10 weeks. Strength was assessed using a Cybex II isokinetic dynamometer set at an angular velocity of 60° · s ^?1 and a damping of 2. The FW group served as the control group for the assessment of [Vdot]O ₂ max changes, while the R group served as controls for the assessment of strength differences. ANCOVA revealed that the N and R groups experienced significant (p < .01) increases in [Vdot]O ₂ max expressed in L · min ^?1 (10.9 and 11.4%), ml · kg ^?1 · min ^?1 (10.8 and 11.7%), and ml · kgLBW ^?1 · min ^?1 (7.1 and 7.5%) when compared to the FW group. There were no significant differences between the N and R groups. There were no significant differences among groups in final peak torque values (after covariance), and torque at the beginning and end of the range of motion for the knee extensors, knee flexors, elbow extensors, and elbow flexors. In general, isokinetic strength values elicited by the N group compared favorably to those generated by the FW group. It was concluded that for a training period of short duration, Nautilus circuit weight training appears to be an equally effective alternative to standard free weight (strength) and aerobic (endurance) training programs for untrained individuals.     

颜元与科南特教育思想之比较

颜元是我国明末清初著名的一位教育家,针对当时八股教育的弊端和不足,一心一意改革教育,实现教育创新,为了实现其培养专门人才和通才结合的思想,提出了"实文、实行、实体、实用"实学教育思想体系,倡导"习行"教学方法,采取全面评价学生等教育思想。科南特作为美国著名的教育家,是一位以要素主义流派为代表的教育家,提出了中等教育改革、师范教育改革、大学通识教育等重要的教育思想,影响了当时美国教育改革。通过比较发现,两个教育家在教育经验、教育理念、教育目的、教育内容、教育评价等方面既有分歧,也存在一定的共同之处。在今天,两位教育家的教育思想对我们的教育家的成长有很大启示价值。