PRELIMINARY ANALYSIS OF SKATING MOTION

A mechanical model of skating motion was founded, and its solution was obtained by using the Routh's equations in nonholonomic dynamics. The two kinds of common, local meaning and scleronomic motions were discussed in detail. The computational results turn out in good agreement with observations.

How ploughing and frictional melting regulate ice-skating friction

The slipperiness of ice is well known while,for ice skating,its mechanism still needs further investigation,where the complex interactions including the thermal conduction of the skate–meltwater–ice system,the ploughing and the frictional melting of ice to the friction force are still unclear.This study presents a theoretical framework and a simplified analytical solution to unveil the friction mechanism when a curved skate sliding on ice.The theory is validated by experiments and the effects of these various factors,including the sliding velocity,the ice temperature,the supporting weight,and the geometry of the skate blade to the friction are revealed in detail.This study finds that the contribution of friction force from the ploughing deformation through skate indentation and that from the fluid friction through the shear motion of the meltwater layer is comparable with each other,which thus clarifies how the ploughing deformation of the ice substrate together with its frictional melting regulates the friction during skating.

Green Construction of National Speed Skating Oval

1 Background As the basic principle of the world economy,environment,and social development,sustainable development is the focus of the international community today.In the Olympic Agenda 2020 published by the International Olympic Committee(IOC),sustainable development was officially listed as one of the core concepts of the Olympic Games.Since the beginning of the bid,the concept of ctathlete-centered,sustainable and economical”was proposed,which was highly consistent with the idea of the Olympic Agenda 2020.To implement the concept of holding“green”Olympic Games and meet the sustainability requirements of the IOC,the Organizing Committee of Beijing Winter Olympic Games issued a series of documents related to the sustainability of sports venues such as Sustainability Policies for 2022 Beijing Winter Olympic Games and Winter Paralympic Games,and strived to realize the sustainable development of sports venues in the whole life cycle of planning and design stage,construction stage,operation stage,and post-game utilization.

The Influence of the Oval, Lane and Simultaneous Entry on the Performance and Pacing Strategy of Speed Skating Men's 1500 m

Objective To explore the influence of the oval(plateau or plain),the lane(inner or outer),and simultaneous entry(long distance or sprint)on the result and pacing strategy in speed skating men’s 1500 m.Methods Multi-factor analysis of variance,independent sample T test,Spearman correlation coefficient method,paired T test and other statistical methods are used to analyze the relationship and differences between the oval(plateau or plain),the lane(inner or outer),and/or simultaneous entry(long distance or sprint)and the results of the top 8 athletes of the ISU event in the 2019-2020 season.Results Among the three factors of oval,lane,and simultaneous entry,only the altitude will improve the athlete’s perfor-mance of 1500 m,an increase of about 2.52%(2.65 s).Both the oval and the simultaneous entry will affect the athlete’s 1500 m pacing strategy.Athletes tend to adopt a more positive strategy when competing in plateau;the sprint athletes have a faster opening,but a slower ending.Conclusion At present,the level of speed skating in China and the world is in the highest period.Among the oval factors,the highland oval can significantly improve the athletes’performance of 1500 m;athletes tend to adopt a more positive pacing strategy in the plateau than in the plain.In the process of preparing for the 2022 Winter Olympic Games,we can predict the competitive level of the opponent through the plateau competition results and carry out targeted preparation.Different lanes do not affect the athlete’s 1500 m performance and pacing strategy but may affect the athlete’s final lap speed.There is no obvious difference between the sprint and long-distance athletes on the performance of 1500 m,but the sprint athletes have a faster opening and a slower ending,and the long-distance athletes have a faster final lap and a smaller drop between each lap.

The First Lakeview Place Skating Carnival——Your Ice Wonderland

On the inaugural day of the Lakeview Place ice rink, profes-sional skaters performed a fig-ure skating display for the audi-ence, including some popular skating routines such as The Butterfly Lovers, The Leut Day and The Blue

Skating on Thin Ice

There is something very odd about the weather in Beijing.It’s mid-February when, according to my experience ,my bones should be rattling and all the city’s lakes should be frozen solid.

Chen Lu Rewrites the History of Figure Skating

ON March 11, 1995, 18-year-old Chinese athlete Chen Lu took first place in the women’s singles of the World Figure Skating Championship held in Birmingham, Britain. For the first time, the name of a Chinese was recorded on the list of single skating champions.

我国花样滑冰双人滑运动员自信心培养策略研究

根据花样滑冰双人滑运动的特点和现状,提出了对我国花样滑冰双人滑运动员自信心培养的策略,通过科学训练完善技术,加强运动员的艺术修养和对比赛成功情景的体验及加强赛前心理干预和赛后心理恢复等手段,帮助运动员在训练和比赛中提高自信心水平及专项心理能力,从而提高运动员竞技水平和运动成绩。

Definition and Development of a Control Concept Applied in Elements Distributed for Manage Them Using IoT

In recent years,the Internet has gradually developed into a mature tool,which can integrate technologies involved in different application scenarios.The Internet allows the integration of solutions to different problems,which benefits both users and companies.The Internet of Things is a further development of the Internet,which can further realize the interconnection of people,machines,and things.The work of this paper mainly focuses on the use of Internet of Things technology to achieve efficient management.A wireless device is designed in the paper,which can be integrated in a helmet.This helmet can be used in some specific scenarios.Managers can use the Internet of Things technology to call the data generated by the hearing equipment and lighting equipment in the helmet to identify users.These helmets can be managed through a network platform.On the network platform,in addition to the helmet,some other components can be allowed to access,making the platform more universal and convenient.This paper elaborates on the design and development of the project and shows how to use it for effective time management in the skating rink.

CROOKED TONGUES x adidas 泰式大餐

Adidas Super Skate绝对是近些年最令人期待推出别注的鞋款之一。回想到2004年．BAPE正值品牌创立10周年之际，当时BAPE分别挑选了adidas中最经典的Superstar以及滑板鞋SuperSkate为素材．分别推出名为Super APE Star及Super APE Skate两个鞋款．一经推出炒价就瞬间破万，绝对要佩服BAPE的影响力。在adidas或Superstar 35周年庆典上，仓石一树就曾穿着过一双蛇皮幻彩staff版Super APE Skate、因为这双鞋只作BAPE内部员工穿用，并不做公开发售而且数量又非常有限．顿时令这双的价格瞬间达到五位数，但仍然造成有价无市的场面，由于流入市面上的数量极少，很多人都是只见过图片没见过实物．所以都愿意称其为“传奇”鞋款、于是很多潮人就更加期待下一次Super Skate会跟何品牌合作再创奇迹：但可惜的是。

Skate V960开启联通2012年终端战略 “由低到中”已成定局

凭借一款千元智能手机BladeV880,中国联通和中兴通讯在2011年可谓大放异彩。一方面,中国联通推出"600MHz主频处理器、3.5英寸电容触摸屏"的千元智能手机新标准,重新定义了3G移动互联网手机,并通过定制终端实现用户数的大幅提升;另一方面,中兴通讯也创造了"第一次单款智能手机订单超过100万、第一次由运营商买断包销除iPhone以外的单款手机"等一系列记录。而近日,双方再次携手推出Skate V960智能手机,试图将重点转移至中端市场。

中兴通讯发布Skate与Racer-II智能手机

中兴通讯股份有限公司发布两款全新智能手机——skate和Racer-II，再次彰显了其将高性能智能手机推向大众市场的决心。

Non-enzymatic antioxidant blood plasma profile in the period of high training loads of elite speed skaters in the altitude

At the altitude,hypoxia and training load are key factors in the development of oxidative stress.Altitude-induced oxidative stress is developed due to the depletion of antioxidant potential.In the current study,we examined the non-enzymatic antioxidant profile of blood plasma in 7 males and 5 females specializing in speed skating at a 21-day training camp at 1850m above sea level.Training included:cycling,roller skating,ice skating,strength training,and special training.At the start point and the endpoint,total hemoglobin mass(tHb-mass),hemoglobin concentration,and circulating blood volume were determined.Antioxidant profiles,hypoxic doses,hypoxic impulses,and training impulses were assessed at 3,6,10,14,and 18 days.Antioxidant profiles consisting of“urate”and“thiol”parts were registered with chemiluminometry.In the training dynamics,antioxidant parameters changed individually,but in total there was a decrease in the“urate”capacity by a factor of 1.6(p=0.001)and an increase in the“thiol”capacity by a factor of 1.8(p=0.013).The changes in“urate”capacity positively correlated(r_(S)=0.40)and the changes in“thiol”capacity negatively correlated(r_(S)=−0.45)with changes in tHb-mass.Both exercise and hypoxic factors affect the antioxidant parameters bidirectionally.They correlated with a decrease in thiol capacity and with an increase in urate capacity.The assessment of the non-enzymatic antioxidant profile can be a simple and useful addition to screening the reactive oxygen species homeostasis and can help choose the personalized training schedule,individualize recovery and ergogenic support.

Longitudinal Changes in Athletic Performance in Competitive Figure Skaters

Purpose To measure changes in strength,power,and agility over consecutive seasons based on competition level in figure skaters.Methods A total of 197 competitive singles figure skaters(age range=9-25 years old)completed combines with United States Figure Skating on two consecutive seasons between 2011 and 2018.Skaters either remained in the same competitive on-ice level or increased by one level on consecutive seasons.All athletes completed the hexagon agility test,maximal verti-cal jump,timed tuck jumps,push-ups,and bent knee v-ups.Repeated-measures analyses of variance separated by sex with Tukey’s post hoc were performed for each dependent variable and Cohen’s d effect sizes were calculated for all significant differences.Results Female skaters who remained in the same level demonstrated improved performance on vertical jump(3.66 cm higher),timed tuck jumps(3.77 more jumps),v-ups(1.59 more v-ups),and hexagon jump(1.17 s faster).There was an interaction for female skaters who remained in the same level(P=0.004),with senior and junior levels outperforming inter-mediate level skaters on the hexagon jump test.Female skaters who increased level demonstrated improved performance on the vertical jump(2.24 cm higher),hexagon jump(1.16 cm faster),and tuck jump(3.03 more jumps).Male skaters did not demonstrate any changes in performance except v-ups(2.86 more v-ups)for those who increased level.Conclusions The greatest changes were in lower level female skaters who remained in the same level,supporting the impor-tance of participating in strength and conditioning programs earlier in skating careers to maximize athleticism before reaching the senior level,when changes in off-ice performance plateau.

最美的旋律——送给年轻朋友的音乐礼物

最美的旋律诞生在何处呢?在古典音乐史上，层出不穷的杰出作曲家们饱含着对生活对生命的感悟，用毕生谱写出数之不尽的伟大篇章。从18世纪的贝多芬到20世纪的格什温，音乐让平淡乏味中的人们得以滋润、得以宣泄，甚至到达了一个至高无上的精神世界，在这个世界中畅游、欢娱。

Release of unwanted flat-bodied fish from a horizontal-bar grid system as revealed through comparative fishing trials and underwater video observations

Grid systems separate fish species primarily through physical means:fish size and body shape.On Georges Bank off the northeast USA,many species of flounders are overfished,and their catch needs to be reduced.Flat-bodied skates are also often discarded.We tested a European style horizontal-bar grid system to reduce these flat-bodied low quota species in a trawl targeting the haddock(Melanogrammus aeglefinus),whose population is robust.The grid system consisted of 4 grid sections,two on each side,with horizontal bars 70 mm apart.The alternating tow method was used to compare the catch characteristics between a trawl with a grid section and the same trawl without a grid section.A video camera was used to observe fish escape in the grid section.The results indicate that the grid system reduced the flounder catch rate(mainly winter flounder,Pseudopleuronectes americanus)by 51.3%,and skates(mainly winter skate,Leucoraja ocellata and little skate,Leucoraja erinacea)by 29.4%,while there were no differences in the catch of Atlantic cod(Gadus morhua).While haddock was reduced by 37%by weight,the reduction was primarily small undersized individuals.There was no reduction in large haddock greater than 50 cm.Video observations indicates that flounders and cod mainly escaped from the bottom half of the grid while haddock were from the top half.These finding suggest that this system reduced low quota flounders,as well as discarded skates and small haddock,while retaining Atlantic cod and large size haddock.Underwater observations indicate that differential spacing(narrower on the top and wider on the bottom)may improve the system performance by releasing more flat-bodied fish,that were observed to escape from the bottom part of the grid,while retaining more haddock,which typically escape from the top part of the grid.