Heisenberg and ferromagnetism

Heisenberg’s contributions to the understanding of ferromagnetism are reviewed. The special features of ferromagnetism, vis-a-vis dia and para magnetism, are introduced and the necessity of a Weiss molecular field is explained. It is shown how Heisenberg identified the quantum mechanical exchange interaction, which first appeared in the context of chemical bonding, to be the essential agency, contributing to the co-operative ordering process in ferromagnetism.     

试论中国商业足球的美学魅力

在改革开放的大潮中,中国商业足球由于新闻媒体的宣扬,亿万球迷的忠诚,足球赛制的改革,足球健儿的拼搏,企业团体的赞助,正在展示着她无比诱人的美学魅力。     

竞技武术功能刍议

竞技武术近年来发展迅速。本文通过对相关文献资料的查阅,对竞技武术功能的积极方面和消极方面进行了分析。结果表明,竞技武术必须贯彻“以人为本”的理念才能持续健康地发展。     

Introducing novel approaches for examining the variability of individuals’ physical activity

Tudor-Locke and colleagues previously assessed steps/day for 1 year. The aim of this study was to use this data set to introduce a novel approach for the investigation of whether individual’s physical activity exhibits periodicity fluctuating round a mean and, if so, the degree of fluctuation and whether the mean changes over time. Twenty-three participants wore a pedometer for 365 days, recorded steps/day and whether the day was a workday. Fourier transform of each participant’s daily steps data showed the physical activity had a periodicity of 7 days in half of the participants, matching the periodicity of the workday pattern. Activity level remained stable in half of the participants, decreased in ten participants and increased in two. In conclusion, the 7-day periodicity of activity in half of the participants and correspondence with the workday pattern suggest a social or environmental influence. The novel analytical approach introduced herein allows the determination of the periodicity of activity, the degree of variability in activity that is tolerated during day-to-day life and whether the activity level is stable. Results from the use of these methodologies in larger data sets may enable a more focused approach to the design of interventions that aim to increase activity.     

Temporal specificity of training: intra-day effects on biochemical responses and Olympic-Weightlifting performances

The aim of this study was to investigate the performance of an Olympic-Weightlifting session training at three times of the day on the performance related to biochemical responses. Nine weightlifters (21 ± 0.5 years) performed, in randomised order, on three Olympic-Weightlifting training (snatch, clean and jerk) sessions (08:00 a.m., 02:00 p. m., 06:00 p. m.). Blood samples were collected: before, 3 min and 48 h after each training session. Haematological parameters and markers of muscle injury were assessed. Resting oral temperature and rating of perceived exertion (RPE) were also assessed during each session. ANOVA showed that the performance was better (P < 0.001) at 02:00 p. m. with a less RPE (P < 0.01) compared to the morning and the evening sessions while there was higher (P < 0.05) oral temperature at 06:00 p. m. versus 08:00 a.m. and 02:00 p. m. Muscle damage changed immediately (without significant effect after 48 h) after the training sessions with lower values ??in the evening compared to the morning. In conclusion, the afternoon training is more effective than morning or evening sessions for weightlifters. Therefore, coaches and weightlifters should be advised to schedule their training session in the afternoon hour.