广西游泳后备人才基本情况的调查与分析

采用文献资料、专家访谈、问卷调查及数理统计等方法,对广西省15个竞技游泳后备人才培养基地的人才培养情况进行调查分析.结果显示:广西各地的县级游泳训练的人数比以前少了许多,这一现象对整个广西游泳训练及人才培养体系的建设来说是一种损失.希望通过此次调查,对广西竞技游泳事业的进一步发展提供帮助.     

Dynamics and manipulation of ferroelectric domain walls in bismuth ferrite thin films

Ferroelectric domain walls differ from domains not only in their crystalline and discrete symmetry, but also in their electronic, magnetic, and mechanical properties. Although domain walls provide a degree of freedom to regulate the physical properties at the nanoscale, the relatively lower controllability prevents their practical applications in nano-devices. In this work, with the advantages of 3D domain configuration detection based on piezoresponse force microscopy, we find that the mobility of three types of domain walls (tail-to-tail, head-to-tail, head-to-head) in (001) BiFeO₃ films varies with the applied electrical field. Under low voltages, head-to-tail domain walls are more mobile than other domain walls, while, under high voltages, tail-to-tail domain walls become rather active and possess relatively long average lengths. This is due to the high nucleation energy and relatively low growth energy for charged domain walls. Finally, we demonstrate the manipulation of domain walls through successive electric writings, resulting in well-aligned conduction paths as designed, paving the way for their application in advanced spintronic, memory and communication nano-devices.     

论课程品质及课程力自增的哲学理据

新课程品质及课程力自增,是新课程改革呈旺盛势态的标志。充实哲学理据以接近本质,建议从三个方面着力解决问题:一是理顺新课程改革的结构性问题,能正确理解课程与课程力之间的主体和载体的关系,全面实现自增的旨趣;二是针对课程品质及课程力自增的合理性论证与追述,能着力于内生长与外发展中存在的历史流变,发现不合理存在的原因,从而全...     

从“文斗”到“武斗”:礼法约束下“斗秧歌”田野调查

以海阳大秧歌中的民俗武术活动“斗秧歌”仪式为个案,运用田野调查等方法,从民俗学视角对“斗秧歌”的过程及民俗语境进行分析。认为:海阳大秧歌吸收了军事武术中的兵法谋略与民间武术技术动作,族群生存斗争与比武较技是“斗秧歌”吸收武术元素的重要动因,其逻辑形式表现为礼法约束下由“文斗”到“武斗”的递进,“文斗”体现兵法谋略智慧,武术是“武斗”的主要支撑力量。“斗秧歌”受到礼法约束,以强化乡间社会秩序的稳定,反映了中国传统社会治理中的礼法并施思想。剖析其民俗语境发现,“斗秧歌”是族群生存抗争的仪式手段、护卫生存环境的民间演习、展示个人魅力的艺术舞台,也是地域武术传播的民俗载体。武术与“斗秧歌”之间的融合互动关系,显示武术与民俗活动深厚的历史渊源及武术具有的多元价值属性。     

现时代，求变革，开启体育新篇章——基于校园足球发展研究

本文通过梳理中国知网近十年的相关文献和书籍以及专业足球教师的讲解,解读习近平新时代校园足球的时代背景、发展历程以及取得的成果,进而发现校园足球的困境及解决办法,使其注入新鲜的生命力,在全面深化改革的背景下一马当先承担起世界第一大运动的责任,开启体育新篇章。     

加快新农村建设强化农村转移劳动力培训

新农村建设是国家为了实现农业、农村经济建设全面发展而制订的一个宏观目标。最终目的是要解决三农问题,实现农村的发展和农民的共同富裕。要想使农民富裕,根本出路是农村剩余劳动力向城镇和非农产业转移。但是农民文化水平较低成为农村剩余劳动力有效转移的最大障碍。因此,对农村转移劳动力进行有效的培训成为必须;如何充分利用有限的培训资源,开展有效的转移劳动力培训成为必须考虑的问题。     

Postural balance and rifle stability in a standing shooting position after specific physical effort in biathletes

The aim of the study was to evaluate the effect of maximal specific physical effort on postural balance and rifle stability in biathletes in a standing shooting position. The study included 10 junior elite biathletes. The measurements were taken with the Vicon system and AMTI force platform. Postural balance and rifle stability characteristics were determined at rest as well as 1 and 5 min post maximal specific physical effort which was performed on a ski ergometer and continued until exhaustion. Maximal physical effort exerted a significant effect on all examined postural sway and rifle sway characteristics. The duration of the post-exercise changes was longer than 5 minutes. Higher post-effort rifle sway was observed in the vertical direction than in the across the shooting line direction. Post-effort postural balance impairment in the shooting line was much greater than in the across the shooting line direction. Moreover, a strong correlation was found between postural balance and rifle stability. Maximal physical effort influenced postural balance and rifle stability during aiming. Rifle sway during aiming in a standing shooting position seems to be coordinated with the postural sway of the biathlete’s body. Thus, an increase in postural sway contributes to greater sway and lesser stability of the rifle.     

上肢康复机器人主动康复训练控制策略

近年来,脑卒中和交通事故造成上肢损伤的人数逐年上升,医疗领域对康复器械的需求越来越大。为满足实际需求,开发以气动人工肌肉为驱动器的4自由度（肩关节外收/内展（被动）、前驱/后伸、肘关节屈曲、腕关节屈曲）可穿戴上肢康复机器人。首先设计上肢康复机器人的结构,并采用气动人工肌肉作为肘关节与腕关节的驱动器。然后针对该上肢康复机器人,研究主动康复训练控制策略,设计两种控制策略。通过穿戴实验验证控制策略的有效性和实际应用价值。     

圆形载流线圈沿一直径折成直角可看作磁偶极子

从磁偶极子的特点出发,用毕奥—萨伐尔定律、安培力公式和力矩的定义,推导出用磁矩表示的圆形载流线圈沿一直径折成直角的远场及其在均匀磁场中所受的磁力和磁力矩,指出此非平面载流线圈可看作磁偶极子.     

干旱区绿洲土地利用景观空间格局动态变化研究——以渭干河—库车河三角洲绿洲为例

渭干河—库车河三角洲绿洲地处世界第二大沙漠塔克拉玛干沙漠的北缘，该绿洲现已成为新疆主要的农业区和棉花基地。但随着经济的快速发展，土地资源开发强度开始加大。本研究利用1989年和2001年的遥感影像数据，借助RS和GIS技术，运用景观生态学原理，通过计算多样性指数、优势度指数、分离度指数、均匀度指数、破碎度指数等指标，对渭干河—库车河三角洲绿洲的景观格局及土地利用变化进行动态分析，得出：多样性指数从1.304降低到1.190，优势度指数从0.305升高到0.419，均匀度指数从0.8104降低到0.7396，破碎度指数从0.0177升高到0.0225，并揭示出土地利用类型三增两减(盐碱地、水体、红柳增加，绿洲、荒地减少)的变化特征。同时，利用SPSS软件对土地利用变化的驱动机制进行了分析，结果表明：人口，经济，政策因子仍然是占主导地位的。