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．     

旅游对民族旅游地文化影响探析

跨学科研究是旅游研究中一种重要的手段,文章从社会学、传播学和旅游学三角度出发,主要就跨民族文化传播、文化冲突和文化控制三方面,分析了民族旅游目的地因旅游产生的正、负影响,进而提出了加强法制建设、加强教育、加强舆论导向和发挥群体作用等具体措施,以图促进民族旅游的健康发展和民族旅游目的地文化的进步.     

A comparison of methods to determine bilateral asymmetries in vertical leg stiffness

Whilst the measurement and quantification of vertical leg stiffness (K_vert) asymmetry is of important practical relevance to athletic performance, literature investigating bilateral asymmetry in K_vert is limited. Moreover, how the type of task used to assess K_vert may affect the expression of asymmetry has not been properly determined. Twelve healthy males performed three types of performance tasks on a dual force plate system to determine K_vert asymmetries; the tasks were (a) bilateral hopping, (b) bilateral drop jumping and (c) unilateral drop jumping. Across all the three methods, K_vert was significantly different between compliant and stiff limbs (P < 0.001) with a significant interaction effect between limb and method (P = 0.005). Differences in K_vert between compliant and stiff limbs were ?5.3% (P < 0.001), ?21.8% (P = 0.007) and ?15.1% (P < 0.001) for the bilateral hopping, bilateral drop jumping and unilateral drop jumping methods, respectively. All the three methods were able to detect significant differences between compliant and stiff limbs, and could be used as a diagnostic tool to assess K_vert asymmetry. Drop jumping tasks detected larger K_vert asymmetries than hopping, suggesting that asymmetries may be expressed to a greater extent in acyclic, maximal performance tasks.     

Dribbling determinants in sub-elite youth soccer players

Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s^?1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.     

湖北省体育旅游产业现状分析与绿色创新发展研究

通过对湖北省体育旅游资源、体育消费现状、区位发展定位等体育旅游产业相关因素进行调查分析,发现湖北省体育旅游资源相对丰富,但是,体育旅游产业的拓展相对滞后。运用比较研究法、专家访谈法以及SWOT分析法等方法,对湖北省体育旅游资源开发提出绿色创新发展理念和产业发展对策,力图为湖北省体育旅游产业的发展提供理论参考和借鉴。     

社区居家养老服务中心体育服务需求与供给研究——以武汉市为例

运用文献资料法、问卷调查法、数理统计法等,对武汉市社区居家养老服务中心的体育服务需求与供给现状进行研究。研究表明:社区老年人有较强的参与体育活动愿望,且参与体育活动在时段选择、时间长度、时间频率、活动强度等方面有着自身的规律;而养老服务中心的体育服务在场地设施、健身指导、信息宣传等方面与老年人的需求存在差距。建议:社会转型期的社区居家养老服务中的体育服务应做到体育服务供给主体多元化、体育服务内容多样化、体育服务人员专业化、体育志愿服务常态化。     

黔南生态产业的发展策略

依据可持续发展战略,结合生态学原理,根据黔南实际,发展生态产业非常必要和有效。黔南可优先发展生态农业和休闲生态旅游业,以带动其它生态产业的发展,从而为壮大黔南经济实力奠定坚实基础。     

大众文化的兴起

“大众文化”作为一个20世纪新兴的文化现象,有着独特的内涵和特征,对于这一文化现象兴起的原因历来众说纷纭,大众文化兴起的原因主要表现为：（1）科技时代机械复制技术的成果;（2）大众精神层面需求的滋生推进了这一文化现象的产生与发展;（3）产业利润的驱使也推动了这一现象的产生。     

文史遗产与古为今用的创新--从爱晚亭、阅江楼到公主馆

在学、史学的丰富遗产中，有一些作品可派生出一些名胜景点，爱晚亭、阅江楼即是典型二例，在伊犁发掘汉代的史典籍，关于细君、解忧两位公主的史料，使人们盼望着出现一处汉家公主纪念馆，成为两千多年来各民族和睦团结的象征。     

哈尔滨城市旅游开发研究

本文从城市旅游开发的一般理论认识出发，通过对哈尔滨市地方风格的分析，确定了哈尔滨市城市旅游形象，并对哈尔滨市旅游产品的设计，政府主导开发策略及旅游发展的相关问题进行了讨论，以期为哈尔滨市旅游开发与规划提供借鉴。