也谈体育本质与体育教学问题——与《从体育本质看体育教学》作者商榷   总被引：1，自引：0，他引：1  

奚明秋  赵晓飞  张晓义 《体育学刊》2008,15(12)

对《从体育本质看体育教学》一文的相关论断提出质疑,指出该文的逻辑起点存在错误;论述自相矛盾;言语自我标榜;认识及说法上存在偏颇等,并就体育科学研究应遵循的态度及应承担的责任提出了看法。  相似文献   

4×100米接力跑的技战术分析   总被引：1，自引：0，他引：1  

丁新兴 《渭南师范学院学报》2003,18(2):77-78

影响4×100米接力跑成绩的主要因素有:短跑能力、高速跑进中的传接棒技术、合理的棒次安排等.教学中应以此为重点  相似文献   

PLC在电动机控制系统中的应用     

夏勇 《郧阳师范高等专科学校学报》2003,23(3):47-49

介绍了PLC与一台自耦变压器组成的启动设备在对多台电动机启动和控制电路中的应用，用一台自耦变压器不同时启动多台异步电动机的控制方法。  相似文献   

Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts     

Darrin Richards  B. Johan Ivarsson  Irving Scher  Ryan Hoover  Kathleen Rodowicz  Peter Cripton 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(4):385-396

Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p < 0.05) reduced peak resultant linear head accelerations of the stationary ATD by 35–56%. The integrated shoulder pads reduced linear head accelerations by an additional 18–21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.  相似文献   

The effect of different foot and hand set-up positions on backstroke start performance     

Karla de Jesus  Kelly de Jesus  J. Arturo Abraldes  Luis Mourão  Márcio Borgonovo-Santos  Alexandre I. A. Medeiros 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(4):481-496

Foot and hand set-up position effects were analysed on backstroke start performance. Ten swimmers randomly completed 27 starts grouped in trials (n = 3) of each variation, changing foot (totally immersed, partially and totally emerged) and hand (lowest, highest horizontal and vertical) positioning. Fifteen cameras recorded kinematics, and four force plates collected hands and feet kinetics. Standardised mean difference and 95% confidence intervals were used. Variations with feet immersed have shown lower vertical centre of mass (CM) set-up position (0.16 m), vertical impulse exerted at the hands, horizontal and vertical impulse exerted at the feet (0.28, 0.41, 0.16 N/BW.s, respectively) than feet emerged with hands horizontal and vertically positioned. Most variations with feet partially emerged exhibited higher and lesser vertical impulse exerted at hands than feet immersed and emerged (e.g. vertical handgrip, 0.13, 0.15 N/BW.s, respectively). Variation with feet emerged and hands on the lowest horizontal handgrip depicted shorter horizontal (0.23, 0.26 m) and vertical CM positioning at flight (0.16, 0.15 m) than the highest horizontal and vertical handgrip, respectively. Start variations have not affected 15-m time. Variations with feet partially or totally emerged depicted advantages, but focusing on the entry and underwater biomechanics is relevant for a shorter start time.  相似文献   

Are the new starting block facilities beneficial for backstroke start performance?     

Karla de Jesus  Kelly de Jesus  J. Arturo Abraldes  Alexandre Igor Araripe Medeiros  Ricardo J. Fernandes  João Paulo Vilas-Boas 《Journal of sports sciences》2016,34(9):871-877

We aimed to analyse the handgrip positioning and the wedge effects on the backstroke start performance and technique. Ten swimmers completed randomly eight 15 m backstroke starts (four with hands on highest horizontal and four on vertical handgrip) performed with and without wedge. One surface and one underwater camera recorded kinematic data. Standardised mean difference (SMD) and 95% confidence intervals (CI) were used. Handgrip positioning did not affect kinematics with and without wedge use. Handgrips horizontally positioned and feet over wedge displayed greater knee angular velocity than without it (SMD = ?0.82; 95% CI: ?1.56, ?0.08). Hands vertically positioned and feet over wedge presented greater take-off angle (SMD = ?0.81; 95% CI: ?1.55, ?0.07), centre of mass (CM) vertical positioning at first water contact (SMD = ?0.97; 95% CI: ?1.87, ?0.07) and CM vertical velocity at CM immersion (SMD = 1.03; 95% CI: 0.08, 1.98) when comparing without wedge use. Swimmers extended the hip previous to the knee and ankle joints, except for the variant with hands vertically positioned without wedge (SMD = 0.75; 95% CI: ?0.03, 1.53). Swimmers should preserve biomechanical advantages achieved during flight with variant with hands vertically positioned and wedge throughout entry and underwater phase.  相似文献   

开端计划对我国低收入家庭幼儿接受学前教育的启示     

张芬 《学前教育研究》2008,(11)

在我国学前教育事业快速发展、人民群众日益追求优质学前教育的同时,低收入家庭幼儿接受学前教育的问题日益突出,甚至制约了我国学前教育事业的进一步发展,务必得到解决。美国历时四十多年的开端计划是一个面向美国低收入家庭学前儿童的综合性项目,它所取得的成功对我国解决这一问题具有很大的借鉴价值。  相似文献   

螺纹编程指令介绍及多头螺纹的编程技巧     

陈银清  冯旭强 《茂名学院学报》2008,18(1):32-34

详细介绍了在数控车床上加工螺纹的编程指令G32、G92、G76的具体含义,并分析多头螺纹的加工原理,通过实例说明单头螺纹和多头螺纹的编程方法,说明加工多头螺纹主要是需在Z轴方向上改变起点位置来实现分度.  相似文献   

Literacy and language outcomes of comprehensive and developmental-constructivist approaches to early childhood education: A systematic review     

《Educational Research Review》2016

This systematic review of research on early childhood programs seeks to identify effective approaches capable of improving literacy and language outcomes for preschoolers. It applies consistent standards to determine the strength of evidence supporting a variety of approaches, which fell into two main categories: comprehensive approaches, which include phonemic awareness, phonics, and other skills along with child-initiated activities, and developmental-constructivist approaches that focus on child-initiated activities with little direct teaching of early literacy skills. Inclusion criteria included use of randomized or matched control groups, evidence of initial equality, a minimum study duration of 12 weeks, and valid measures of literacy and language. Thirty-two studies evaluating 22 programs found that comprehensive early childhood programs that have a balance of skill-focused and child-initiated activities programs had significant evidence of positive literacy and language outcomes at the end of preschool and on kindergarten follow-up measures. Effects were smaller and not statistically significant for developmental-constructivist programs.  相似文献   

齐抓共管,开创我校学生管理工作新局面     

董大校 《临沧师范高等专科学校学报》2007,(3):1-3

新时期,我校发展机遇与挑战并存,希望和困难同在,学生管理工作必须开创新的局面。为此,在学生管理工作上,我们必须采取相关措施,对班主任工作提出新的要求,只有这样才能真正使学校发展再跃新台阶。  相似文献