Precision measurement of the Newtonian gravitational constant

The Newtonian gravitational constant G, which is one of the most important fundamental physical constants in nature, plays a significant role in the fields of theoretical physics, geophysics, astrophysics and astronomy. Although G was the first physical constant to be introduced in the history of science, it is considered to be one of the most difficult to measure accurately so far. Over the past two decades, eleven precision measurements of the gravitational constant have been performed, and the latest recommended value for G published by the Committee on Data for Science and Technology (CODATA) is (6.674 08 ± 0.000 31) × 10⁻¹¹ m³ kg⁻¹ s⁻² with a relative uncertainty of 47 parts per million. This uncertainty is the smallest compared with previous CODATA recommended values of G; however, it remains a relatively large uncertainty among other fundamental physical constants. In this paper we briefly review the history of the G measurement, and introduce eleven values of G adopted in CODATA 2014 after 2000 and our latest two values published in 2018 using two independent methods.     

Understanding the relative contribution of technical and tactical performance to match outcome in Australian Football

ABSTRACT

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009–2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.     

我国少数民族运动会的发展现状及对策研究

文章运用文献资料研究法和逻辑分析法对我国七届民运会的表演项目、竞赛项目的设置以及对民运会单个项目进行比较分析,得出我国民运会在以:"发展民族体育,增强民族体质,加强民族团结,振奋民族精神"的宗旨的指导下,本着"平等、团结、繁荣、进步"的原则,正逐步迈上健康的发展轨道,但同时我们也发现其所存在的问题和不足,并由此提出了相应的发展对策和建议。     

《功夫熊猫》对中国武术的影响

《功夫熊猫》的成功使我们意识到我国传统文化的传承应具有新的时代性,武术动漫的创作不仅仅是国内传统文化的＂拷贝＂,更是对传统文化和现代流行元素有力的结合而走出一条发展道路;中国武术的发展不能照搬西方体育发展模式,应在借鉴他人成功经验的基础上,开辟一条符合自己特点的道路。这是弘扬中国文化、发展中国武术的正确选择,也是时代发展的必然要求。     

浅析武术健身发展现状与对策

中国武术是中华民族传统文化的瑰宝,也是东方文化的一颗灿烂的明珠.武术可以强身健体、益寿延年,是一个很好的健身运动.文章对武术健身发展现状进行了分析,武术健身在党和政府的高度重视下飞速发展,但武术健身发展方面仍然存在着许多问题:武术相关健身项目还没有自己的一席之地,没有被国内外完全接受;武术健身运动推广范围还很少,武术健身发展有许多自身的不足之处.文章就武术健身发展出现的问题提出了相应发展对策,为武术健身发展起到了参考作用,并为今后武术健身运动更好的发展指出道路     

仡佬族传统体育“打篾鸡蛋”的变迁及发展现状

打篾鸡蛋是仡佬族的传统活动。每逢重大节日,仡佬人都会以此活动表示庆祝,表达喜悦。文章通过文献资料法、田野调查法、走访法等对打篾鸡蛋这一运动形式的起源和变迁进行追索,以此了解仡佬族的传统体育文化以为其今后的发展展开探索之路。     

我国民族传统体育产业化进程的思考

文章在详细阐述我国民族传统体育在国民经济中的定位及其发展历程的基础上,采用文献研究、归纳演绎等方法,详细分析了我国民族传统体育产业化进程中存在的问题。通过对这些问题的总结和深入探讨,提出了促进我国民族传统体育产业化进程的针对性应对措施：（1）加强民族传统体育的自身改造;（2）加大民族传统体育的宣传力度;（3）加快民族传统体育产业领域高级人才的培养;（4）加强相关的法律法规建设;（5）发展民族传统体育俱乐部;（6）积极构建民族传统体育产业的发展战略。     

对我国体育院校足球专项班学生学习裁判动机的研究

就目前中国足球裁判员队伍建设的热点,把全国部分体育院校足球专项班作为研究对象,通过调查问卷法、个人访谈法,结合图像、资料、数据的统计和分析,对足球专项学生学习裁判动机进行研究。     

现代汉语教学应关注现实的语言应用问题

针对当前现实中存在的语言应用中的一些问题,提出高校现代汉语教学应高度关注现实中的语言应用问题,让学生通过对这些问题的反思获取知识,培养和提高学生应用语言的能力。     

危机情境中的决策信息流分析

动态变化的危机情境,使危机决策面临诸多不确定性,对决策信息流的认知与控制是有效决策的前提.本文在界定危机情境基础上,对危机决策信息流模型、特点和控制机制等问题进行了探讨.