少年儿童不同年龄阶段力量训练特点

通过对不同年龄阶段的少年儿童的生理特点和进行力量训练的方法进行分析、讨论 ,认为对少年儿童进行科学合理的早期力量训练 ,不但对其健康无害 ,而且还可以使其运动器官达到良好的发育状态。     

农村剩余劳动力转移:一个新视角

乡镇企业吸纳农村剩余劳动力后继乏力,城市和农业内部吸纳能力有限,导致农村剩余劳动力转移滞缓,使得我国小农生产方式与市场经济的矛盾日趋尖锐,农业劳动者的资源难以增加,农民收入增长缓慢,严重制约了工业品需求的扩张和就业的扩大,进而又影响了农村剩余劳动力的转移。这种宏观胶着状态可通过微观主体重塑,即农业企业化经营和资本化运作,在一个企业内部实现一、二、三产业的同时发展来转移农村剩余劳动力,对此,政府必须给予相应的制度安排和财力支持。     

亚运情境下广州民生举措满意度对知觉与凝聚力的中介作用

以广州亚运会为个案.采用自行设计的民生举措知觉和满意度量表及居民凝聚力量表,探讨亚运情境下当地居民对政府民生举措满意度,及其对居民民生举措知觉、居民凝聚力是否具有中介作用.结果显示:当地居民时政府在举办亚运情境下所采取的能源、安全、就业、全民健身、生态环保、民生服务等举措的知觉,显著影响居民凝聚力;由于民生举措满意度的加入使该影响变小或变得不显著.说明民生举措满意度对民生举措知觉与居民凝聚力具有中介作用.     

质点组内力的功改变质心动能的条件

讨论了质点组内力的功是可以改变质心动能的，以及所满足的条件．     

Remote effects of lower limb stretching: preliminary evidence for myofascial connectivity?

The skeletal muscles and the fibrous connective tissue form an extensive, body-wide network of myofascial chains. As fascia can modify its stiffness, strain transmission along these meridians is supposable. The goal of this trial therefore was to collect pilot data for potential remote effects of lower limb stretching on cervical range of motion (ROM). Twenty-six healthy participants (30 ± 6 years) were included in the matched-pairs intervention study. One group (n = 13) performed three 30 s bouts of static stretching for the gastrocnemius and the hamstrings, respectively. An age- and sex-matched control group (CG; n = 13) remained inactive. Pre- and post-intervention, maximal cervical ROM in flexion/extension was assessed. A repeated measures ANOVA revealed systematic differences between groups (P < .05). ROM increased following stretching (143.3 ± 13.9 to 148.2 ± 14°; P < .05) but remained unchanged in the CG (144.6 ± 16.8 to 143.3 ± 16.8°; P > .05). Our data point towards existence of a strain transfer along myofascial meridians. Further randomised controlled studies on conditions, factors and magnitude of tensile transmission are warranted.     

卢瑟福模型中电子运动分析

关于卢瑟福模型中电子的运动是加速还是减速,不同文献给出不同描述,甚至是截然相反的描述.本文分别从能量和力的角度定量、定性地分析了卢瑟福模型中电子的运动情况,得出了卢瑟福模型中电子绕原子核旋转、辐射能量时作加速运动的结论.     

试析当前湖北劳动力素质结构

近年来，湖北经济增长率结束了长时期的下降而开始出现回升，经济发展的状况对全省劳动力就业形势构成了较大影响。表现为经济结构的调整带来了就业形势的变化，并进而影响劳动力素质结构的变化。     

The influence of shoe drop on the kinematics and kinetics of children tennis players

This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12?mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p?=?.004) and the ankle was less dorsiflexed at foot strike (p?=?.037). In D0 compared with D12, the peak impact force was reduced by 17% (p?=?.049), the ankle was less dorsiflexed at foot strike (p?=?.045) and the knee was more flexed at foot strike (p?=?.007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p?=?.658) or the peak ankle plantarflexor moment (p?=?.071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.     

如何正确理解和分析摩擦力

就高中学生在学习摩擦力概念易出现的三方面误区谈一谈高中物理教学过程中应如何引导学生正确理解摩擦力的方向、大小以及做功引起能的转化.     

离体器官静息张力检测装置的优化设计与应用

在离体器官实验中，标本悬挂、静息张力调节是实验成功的关键，为此，我们首创并研制了离体器官实验的关键设备——离体器官静息张力检测装置。该文介绍了该装置的构造、技术原理以及在教学、科研中的具体应用。该装置操作简便，能灵敏、准确的调节离体器官标本的静息张力，可更客观、更准确地反映各种理化及药物因素对离体器官平滑肌的影响。