基于HHD测试的男子羽毛球运动员肩关节旋转特征分析

目的:通过观察男子羽毛球运动员肩关节旋转活动度及肌力的特征,为羽毛球运动员肩关节损伤的预防和康复提供参考。方法:以16名专业羽毛球男子运动员为受试对象,同时以9名普通男子为对照,使用手持式测力计(HHD)测定优势侧及非优势侧肩关节的旋内、旋外肌力;同时,测量其旋转被动活动度。结果:(1)男子羽毛球运动员肩关节旋外被动活动度大于旋内被动活动度。(2)男子羽毛球运动员肩关节优势侧旋内、旋外肌力均大于非优势侧,但旋外/旋内比例不存在双侧差异。结论:(1)男子羽毛球运动员肩关节旋转活动度存在双侧差异。(2)男子羽毛球运动员优势侧肩关节旋内、旋外肌力均大于非优势侧。     

Guiding Low Spatial Ability Individuals through Visual Cueing: The Dual Importance of Where and When to Look

Research suggests that spatial ability may predict success in complex disciplines including anatomy, where mastery requires a firm understanding of the intricate relationships occurring along the course of veins, arteries, and nerves, as they traverse through and around bones, muscles, and organs. Debate exists on the malleability of spatial ability, and some suggest that spatial ability can be enhanced through training. It is hypothesized that spatial ability can be trained in low-performing individuals through visual guidance. To address this, training was completed through a visual guidance protocol. This protocol was based on eye-movement patterns of high-performing individuals, collected via eye-tracking as they completed an Electronic Mental Rotations Test (EMRT). The effects of guidance were evaluated using 33 individuals with low mental rotation ability, in a counterbalanced crossover design. Individuals were placed in one of two treatment groups (late or early guidance) and completed both a guided, and an unguided EMRT. A third group (no guidance/control) completed two unguided EMRTs. All groups demonstrated an increase in EMRT scores on their second test (P < 0.001); however, an interaction was observed between treatment and test iteration (P = 0.024). The effect of guidance on scores was contingent on when the guidance was applied. When guidance was applied early, scores were significantly greater than expected (P = 0.028). These findings suggest that by guiding individuals with low mental rotation ability “where” to look early in training, better search approaches may be adopted, yielding improvements in spatial reasoning scores. It is proposed that visual guidance may be applied in spatial fields, such as STEMM (science, technology, engineering, mathematics and medicine), surgery, and anatomy to improve student's interpretation of visual content. Anat Sci Educ. © 2018 American Association of Anatomists.     

Kinematic and kinetic analysis of overhand,sidearm and underhand lacrosse shot techniques

Lacrosse requires the coordinated performance of many complex skills. One of these skills is shooting on the opponents’ net using one of three techniques: overhand, sidearm or underhand. The purpose of this study was to (i) determine which technique generated the highest ball velocity and greatest shot accuracy and (ii) identify kinematic and kinetic variables that contribute to a high velocity and high accuracy shot. Twelve elite male lacrosse players participated in this study. Kinematic data were sampled at 250 Hz, while two-dimensional force plates collected ground reaction force data (1000 Hz). Statistical analysis showed significantly greater ball velocity for the sidearm technique than overhand (P < 0.001) and underhand (P < 0.001) techniques. No statistical difference was found for shot accuracy (P > 0.05). Kinematic and kinetic variables were not significantly correlated to shot accuracy or velocity across all shot types; however, when analysed independently, the lead foot horizontal impulse showed a negative correlation with underhand ball velocity (P = 0.042). This study identifies the technique with the highest ball velocity, defines kinematic and kinetic predictors related to ball velocity and provides information to coaches and athletes concerned with improving lacrosse shot performance.     

产教融合视阈下高职会计专业“会计工厂”的构建

基于产教融合的视角,针对高职会计专业学生实习实践中存在的问题,以人工智能、大数据及财经职业教育的转型等对财务人员知识体系与能力发展提出的要求为导向,构建了“会计工厂”这一产教融合新模式。其构建路径包括:明晰构建目标,搭建“互联网+”会计学徒平台,将会计工作流程化,引入人工智能技术、影像识别技术、财经机器人等技术,实现工作智能化。“会计工厂”实行“每月轮行”“每周轮岗”的运作模式,具有职业场景真实,学习资源丰富,多行业、多岗位、多模式训练学生实操能力等特点,可以让学生们体验做“真账”、做“准员工”的感觉。     

球坐标系中速度与加速度的转动参考系求法

应用转动参考系 ,给出了一种求解球坐标系中速度和加速度的简捷方法。该方法不仅图像清晰 ,简明直观 ,而且可应用到矢量力学教学中去     

适用于数据分类的极限学习机优化算法

针对极限学习机参数优化问题,提出量子遗传算法优化极限学习机的方法（QGA-ELM）。在该方法中,对ELM的输入权值和隐含层阈值采用量子比特编码,并将其映射为QGA的染色体,QGA的适应度函数为对应ELM的分类精度;通过QGA的量子旋转门优化出输入权值与隐含层阈值,以此训练出分类精度更高的ELM,从而改善ELM的泛化性能。通过ELM和QGA-ELM对数据集的仿真结果对比表明,QGA-ELM有效地提升了ELM网络的分类精度。     

矩阵乘法的来源和意义

本文依据矩阵的乘法规则探寻出它的实际意义 ,再联系理论上的价值 ,揭示了矩阵乘法的必要性     

静态箱法在甲烷排放及稻田甲烷减排策略研究中的应用

为揭示天然湿地与稻田甲烷排放特征的差异,采用静态箱法对闽江河口天然湿地和稻田甲烷排放特征进行了比较,并探讨了水旱轮作的甲烷减排模式。结果表明:早稻田平均甲烷排放量为17.03 mg/m2.h,高于相应季节的天然芦苇沼泽甲烷排放量(7.47 mg/m2.h);天然湿地和稻田土壤理化特征差异是导致甲烷排放量不同的主要原因;早稻田甲烷排放量日变化主要受温度影响,而潮汐是影响天然芦苇沼泽的关键因素;水旱轮作可有效降低稻田甲烷排放。     

主应力轴旋转情况下土的各向异性理论研究进展

从理论方面,对国内外主应力轴旋转情况下土的各向异性研究进行了对比和总结,并提出了一些研究建议。指出在理论方面,应当对屈服面方程采用应力分量表示的模型在三维空间里进行屈服面性状的描述,同时考虑不同加载方向下屈服面的变化特性以及旋转硬化的问题,并应开展对加载方向变化时土体屈服面变化特性的实验研究及理论验证。     

烟叶样品中主要碳水化合物研究

对云南省3个主要产烟区不同品种、不同部位烟叶中碳水化合物含量的变化规律以及不同施肥情况、连作和轮作对烟叶样品中碳水化合物含量的影响进行了分析研究.结果表明轮作烟叶样品中总糖和淀粉含量均高于连作烟叶样品;不同施肥情况的烟叶样品中总糖含量的变化规律与淀粉含量的变化规律正好相反;不同部位烟叶样品中总糖、淀粉和总细胞壁物质含量的变化规律也各不相同.