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991.
课堂节奏如同音乐的轻重缓急,绘画的浓淡疏密。抑扬顿挫是音乐之美,错落有致乃书画之美,张弛有度则是课堂之美。处理好课堂节奏的几个成分、以“教为主导,学为主体”构建多元师生互动课堂、谱写好课堂的五线谱才能演奏出动听的课堂交响乐。 相似文献
992.
人际交往障碍往往是影响人成才的重要因素,而这种情况在大学生中更是普遍。对于人际交往障碍来访者,运用认知疗法、合理情绪疗法等来改变求助者的不合理看法和认知,从而引导求助者消除人际交往障碍心理,重新树立人际交往的自信心。 相似文献
993.
994.
Sara M. Brice Kevin F. Ness Doug Rosemond 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):174-184
The purpose of this study was to investigate the relationship between the cable force and linear hammer speed in the hammer throw and to identify how the magnitude and direction of the cable force affects the fluctuations in linear hammer speed. Five male (height: 1.88 ± 0.06 m; body mass: 106.23 ± 4.83 kg) and five female (height: 1.69 ± 0.05 m; body mass: 101.60 ± 20.92 kg) throwers participated and were required to perform 10 throws each. The hammer's linear velocity and the cable force and its tangential component were calculated via hammer head positional data. As expected, a strong correlation was observed between decreases in the linear hammer speed and decreases in the cable force (normalised for hammer weight). A strong correlation was also found to exist between the angle by which the cable force lags the radius of rotation at its maximum (when tangential force is at its most negative) and the size of the decreases in hammer speed. These findings indicate that the most effective way to minimise the effect of the negative tangential force is to reduce the size of the lag angle. 相似文献
995.
Mark McDowell 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):185-194
There is currently much debate about the safety of the sport of softball. Batted‐ball speed and average pitcher reaction time are factors often used to determine safe performance. Batted‐ball speed is shown to be the most important factor to consider when determining safe play. Average pitcher reaction time is explained and directly correlated to batted‐ball speed. Eleven aluminum multi‐wall, three aluminum single‐wall and two composite softball bats were tested with mid‐compression polyurethane softballs averaging 1721 ±62 N/6.4 mm to represent the relative bat‐ball performance for the sport of slow‐pitch softball. Nine men and six women were chosen for this study out of a test group of over three hundred slowpitch softball players. On average, aluminum bat performance results were within the recommended safety limits established by the national softball associations. However, when composite bats were used, their performance results exceeded the recommended safety limits which can pose a significant safety risk. Using aluminum softball bats, batted‐ball speeds ranged from 80 to 145 km.h‐1. Using composite softball bats, batted‐ball speeds ranged from 146 to 161 km.h‐1. The scientific relevance of this study is to provide performance information that can lead to injury prevention in the sport of softball. 相似文献
996.
N. Loock D. E. Du Toit D. J. L. Ventner R. A. Stretch 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):15-22
The aim of this study was to compare a batsman's running and turning speed during three runs while wearing either traditional batting pads or one of two models of newly designed cricket batting pads. Fifteen cricketers participated. The running and turning speeds were measured on three different days with players using the three pairs of batting pads for each trial in random order. The weights of the pads were 1.85 kg, 1.70 kg and 1.30 kg for P1, P2 and P3 respectively. Each player had to run three runs (3 × 17.68m), with the times recorded at the completion of each run, as well as the time to cover the distance from 5 m before and after the turn at the end of the first run. The fastest time from two trials for each pair of pads was retained for analysis. An analysis of variance (ANOVA) with repeated measures was used to determine the differences between the mean times of the three trials. The results showed no significant differences between the types of batting pads and the time to complete the run‐three‐runs test (P1 = 10.67 ± 0.48 s; P2 = 10.67 ± 0.43; P3 = 10.69 ± 0.44 s), the turning time (P1 = 2.34 ± 0.18 s; P2 = 2.32 ± 0.18 s; P3 = 2.35 ± 0.19 s) and to complete the third run (P1 = 3.49 ± 0.44 s; P2 = 3.53 ± 0.34 s; P3 = 3.51 ± 0.36 s). Of the 45 trials of three runs used for analysis, P, recorded the fastest time on 16 trials (36%), P2 on 19 trials (42%) and P3 on 10 trials (22%). The results showed no significant differences in the running or turning speeds, although there may be some practical relevance to using the newly designed cricket batting pads. 相似文献
997.
Thomas Stöggl Lars Karlöf 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):365-380
The purpose of this study was to evaluate the behaviour of cross-country ski poles during double poling on a treadmill using three-dimensional kinematics. The results were compared with standard laboratory tests of the pole manufacturers. A total of 18 skiers were analysed at two speeds (85% and 95% of the maximal speed) at grades of 1.5% and 7%. Variables describing cycle characteristics, bending stiffness, bending behaviour, and trajectories of the pole markers were analysed. Triangular-shaped poles demonstrated the greatest stiffness and lowest variability in maximal bending. Softer poles demonstrated greater variability in bending behaviour and lost ground contact at high skiing speeds, which for some skiers resulted in failure to complete high-speed tests. Considerable variations in pole behaviour for similar poles between skiers were observed, which might be attributed to differences in technique, indicating that mechanical properties of the poles did not exclusively determine pole behaviour in the dynamic situation. The greatest magnitude of pole bending was in the middle part of the pole, which differed from the standard static pole analysis of the manufacturer. Increases in grade demonstrated the greatest effect on pole bending. Distinct differences from the pole manufacturers' laboratory measures were apparent, suggesting that basic pole testing might be adapted. 相似文献
998.
Christopher Joyce Angus Burnett Jodie Cochrane Kevin Ball 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):108-120
The aims of this study were (i) to determine whether significant three-dimensional (3D) trunk kinematic differences existed between a driver and a five-iron during a golf swing; and (ii) to determine the anthropometric, physiological, and trunk kinematic variables associated with clubhead speed. Trunk range of motion and golf swing kinematic data were collected from 15 low-handicap male golfers (handicap = 2.5 ± 1.9). Data were collected using a 10-camera motion capture system operating at 250 Hz. Data on clubhead speed and ball velocity were collected using a real-time launch monitor. Paired t-tests revealed nine significant (p ≤ 0.0019) between-club differences for golf swing kinematics, namely trunk and lower trunk flexion/extension and lower trunk axial rotation. Multiple regression analyses explained 33.7–66.7% of the variance in clubhead speed for the driver and five-iron, respectively, with both trunk and lower trunk variables showing associations with clubhead speed. Future studies should consider the role of the upper limbs and modifiable features of the golf club in developing clubhead speed for the driver in particular. 相似文献
999.
1000.
论高等教育系统的生态平衡 总被引:8,自引:0,他引:8
高等教育生态系统像人类社会一样面临着生态危机,目前我国高等教育内部出现的发展区域失重、科学教育与人文教育失衡、规模与质量的冲突等种种问题都源于高等教育系统的生态失衡。因此,用一种生态平衡的观念来引领我国高等教育系统的发展是一种理性的选择,同时,实现高等教育系统与环境相互适应、自然性与社会性的相互耦合、主体与客体的相互共生、结构与功能的相互协调。 相似文献