游泳年龄组运动员的训练

本文中简述了年龄组运动员能量代谢和肌肉力量的差异与游泳运动成绩的关系,提出了不同年龄组的训练重点,对培养少年优秀游泳运动员有重要的参考作用。

欧洲混合泳冠军弗朗西斯科的赛前训练

本文详细介绍两次欧洲混合泳冠军弗朗西斯科的赛前的训练方法。在训练季节开始,教练员就决定安排好年度负荷量,使弗朗西斯科在1983年8月罗马举行的欧洲冠军赛上达到最佳竞技状态。在欧洲锦标赛选拔赛之前的冬训时期,

“直臂”与“曲臂”划水练习对少儿仰泳初学者转肩技术的影响

转肩技术是仰泳中一个重要的技术环节,游进时肩转动与否、转动的方式等,直接影响人体在水中的身体姿势、手臂划水效果和游进的速度。与俯卧状态下的自由泳等泳姿相比,仰泳时两臂动作无论从力学角度还是从人体解剖学角度来看,其用力条件、动作的自然性等,都处于不利状态。因此,转肩技术对仰泳动作效率等各方面的影响更为显著。实践中可以看到,高水平仰泳运动员都拥有良好的转肩技术。

仰泳

目前我国在四种游泳姿式比赛中,仰泳的差距很大,从1978年8月至邯郸比赛止的我国最高成绩与世界纪录比较100米仰泳男子差6秒41,女子差8秒9,200米仰泳男子差13秒61,女子差19秒8,是四种姿式当中差距最大的项目(表1)。现就仰泳的一些问题谈谈自己的看法。

探索成人学习游泳的方法和技术(九) 仰泳的分解游及与自由泳的组合

第八课时：仰泳的分解游技（练习13~15）练习13.仰泳的滑行,移臂及两侧平衡转换首先在陆上做出正确的仰泳移臂动作：手臂从体侧大拇指领先上抬,同时侧身,手臂要完全伸直,大臂紧紧贴着身体上举至耳侧,要达到之前练习陆上流线型的位置,大臂和耳朵及头颈之间最好不留一点空隙。

让游泳意外不再发生

夏天到了,又要过两个月的暑假生活,同学们一定很兴奋吧!不过,暑假里的安全可千万不能忽略啊!几乎每年这个时候,全国都有不少中小学生因游泳而死亡的报道。大头恐龙真是很担心,所以在这里想说说游泳安全的事情,大家一定要警惕哟!

游泳 水中的行走

悠久的历史游泳运动是男女老幼都喜欢的体育项目之一。古代游泳,根据现有史料的考证,国内外较一致的看法是产生于居住在江、河、湖、海一带的古代人。他们为了生存。

漂浮的红宝石项链

十多米的瀑布倾泻而下,将水面拍得哗哗作响。即便是站在岸边,也能感受到水花带来的丝丝凉爽与惬意。可是,此刻站在岸边的斯科特,感到的却是一股股寒意。中午时分,警长接到报案：道恩在这个小湖中淹死了!说起道恩,他可是本市的风云人物,常年排行全市富豪榜的前三位!他的死亡,引起了斯科特很大的关注。

娃娃天地 婴儿学游泳

教你的小宝贝学游泳吧!出生后两星期至3个月的时间是婴儿学游泳的最佳时机。从洗澡就可以开始他们的游泳生涯。 一个月的婴儿刚开始学游泳时的水温在38℃左右,以后每个月下降1℃,到12个月时只要27℃就可以了。练习时间则根据婴儿出生体重(2.5-4KG)来定,以持续6-10分钟。

大自然的空调——蒸发

当我们剧烈运动时,总会大汗淋漓。但在炎热的夏天,人即使不运动,也会不自觉地流汗,你知道流汗对人体起到什么作用吗？另外,你注意过夏天的狗吗？它们总会伸出长长的舌头,大口喘气!这又是为什么？当天气干旱时,植物总是卷起叶子,卷起叶子又是为什么呢？其实,这些都是蒸发现象。那么蒸发有什么神奇的作用呢？下面,就让我们一起来研究蒸发的奥秘吧!

Depressive-like behavior in mice recently recovered from motor disorders after 3-nitropropionic acid intoxication

Objective Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid （3- NP）, a widely known toxin that selectively damages the striatum in the brain. Methods Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test （FST）. Results When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST （at day 16 post-intoxication）, and the mice presented a normal ＂learned helplessness＂. Conclusion A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.

Effects of an artificial reef system on demersal nekton assemblages in Xiangshan Bay, China

In 2012,an artificial reef system was deployed in Xiangshan Bay,China,to enhance its fishery resources. To determine the effect of the artificial reef system on the demersal nekton assemblages,a beforeafter-control-impact study design was applied. Comparisons of assemblages from impact and control habitats revealed that the assemblage in the impact area had a gradual response to reef deployment. The assemblages in the impact and control areas changed in different ways after reef deployment. During the study period,total biomass,species richness and average body weight in the control area remained relatively stable,whereas there were significant increases in these indicators in the impact area. Responses to the reefs differed among nekton species,inducing assemblage succession in the reefs post-deployment. Sparus macrocephalus and Cynoglossus abbreviat us benefited most from reef deployment. Conversely,smallsized shrimp Palaemon gravieri showed a progressive decrease in biomass following reef deployment. Overall,the artificial reef system diversified the demersal nekton assemblage,enhanced the total biomass,and increased the proportion of large-sized species.

Swimming of motile gyrotactic microorganisms and suspension of nanoparticles in a rheological Jeffery fluid with Newtonian heating along elastic surface

Bioconvection plays an inevitable role in introducing sustainable and environment-friendly fuel cell technologies.Bio-mathematical modelling of such designs needs continuous refinements to achieve strong agreements in experimental and computational results.Actually,microorganisms transport a miscellaneous palette of ingredients in manufacturing industrial goods particularly in fertilizer industries.Heat transfer characteristics of molecular structure are measured by a physical phenomenon which is allied with the transpiration of heat within matter.Motivated by bioinspired fuel cells involved in near-surface flow phenomena,in the present article,we examine the transverse swimming of motile gyrotactic microorganisms numerically in a rheological Jeffery fluid near a stretching wall.The leading physical model is converted in a nonlinear system of ODEs through proper similarity alterations.A numerical technique called shooting method with R-K Fehlberg is applied via mathematical software and graphical presentations are obtained.The influence of all relative physical constraints on velocity,temperature,concentration,and volume fraction of gyrotactic microorganisms is expressed geometrically.It is found that heat and mass flux at the surface as well as density of motile microorganism’s declines for Brownian motion and thermophoresis parameter.Comparison in tabular form is made with existing literature to validate the results for limiting cases with convective boundary conditions.

Age, Growth and Distribution of the Antarctic Fish Pseudochaenichthys georgianus Based on Otolith Morphometry

The Ps. georgianus （Pseudochaenichthys georgianus） were sampled in the summer between 1979 and 2009 at South Georgia Island, and at South Shetland Island. The otoliths ofPs. georgianus contained microincrements similar to daily increments in the otoliths of fishes from temperate and tropical waters. The estimated age from microincrements was similar to that inferred from the body length distribution and otoliths mass： age （years） = 81.98 × Otolith Mass （g） - 0.483. Ps. georgianus like all Channichthyidae due to their adoption to cold water, attain rapidly large body in accordance with the parameters of the von Bertalanffy growth equation： L∞ （asymptotic length） = 66.1 cm; K （constant related to coefficient of catabolism） = 0.28; to （age of the fish at initial length） = 0.008 year; L0 （length of the fish at initial age） = 0.15 cm. That fast growth rate （despite the difference in hatching periods between regions at South Georgia Island, and at South Shetland Island） were not changed, confirming, that it is established to cold water by natural selection. Changes of the microincrements growth pattern are described that appear to be related to larval, hatching and metamorphosis, and have similar pattern to those ones previewed in C. aceratus （Chaenocephalus aceratus） and C. gunnarii （Champsocephalus gunnarii）. Larvaes and postlarvaes of that species have similar habitats during early life history, which is reflected in similar otoliths morphology. Width of their daily increments is： 0.0018-0.0028 mm for Ps. georgianus, 0.0015-0.0024 mm for C. gunnarii and 0.001-0.0016 mm for C. aceratus. The age and developments periods of South Georgia＇s icefish （common name and the abbreviation = SGI for Ps. georgianus as this species was found only there in the past） estimated from otolith was validated by their different geographical distribution depending on the currents and the presence of their food-krill in them. Postlarvae and early juvenile stages were concentrated at the south-western side of the island shelves deeper than 200 m, where currents are weaker in comparison to surface and where juvenes and small krill prevail. Older and mature fish, over 3 or 4 years old, were numerous on the north-eastern side of the islands shelves in regions of strong vortices that concentrate krill to high densities. As life in the currents needs greater ability to swimming as a large, mature and 4 years old fish had increased their ability to swim up to 4 times growing and developing from inshore larvae. During that, their otoliths become more flattened （up to 3 times） and elongated for better fulfil its functions in the higher swimming speed. However, similar species C. aceratus and C. gunnari have more flattened and elongated otoliths than Ps. georgianus and have larger geographical occurrence from Palmer Archipelago to Kerguelen. The least elongated means the highest otolith, which reflects the highest body of Ps. georgianus, which help this species to stay on the shelf during swimming. High body gives less drifting during swimming in the currents. Evolution of otolith shape is linked with a body shape to decrease resistance and achieve high speed of swimming. During development, Ps. georgianus use different currents and countercurrents to catch different krill stages. System of current is natural environment of life ofPs. georgianus.

Seasonal changes in the demersal nekton community off the Changjiang River estuary

The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A total of 95 species(56 teleosts,11 cephalopods,and 28 decapod crustaceans)from 69 genera,49 families and 15 orders were collected.These species could be classifi ed into six groups on the basis of temporal distribution patterns.The resident crab Ovalipes punctatus dominated the community,both in number and biomass.A clear seasonal succession was observed in the species composition.Cluster analysis revealed three primary seasonal groups corresponding to the samples collected in winter-spring,late spring-summer and late summer-autumn.The highest biomass and lowest diversity were observed in summer,while the lowest biomass and highest diversity in winter.The abundance-biomass comparison curves and community composition suggested that the investigated community was moderately disturbed.The results suggest that reduction in fi shing pressure and in the degree of seasonal hypoxia are essential for sustainable resource management off the Changjiang River estuary.

Finite element model updating for large span spatial steel structure considering uncertainties

In order to establish the baseline finite element model for structural health monitoring,a new method of model updating was proposed after analyzing the uncertainties of measured data and the error of finite element model.In the new method,the finite element model was replaced by the multi-output support vector regression machine(MSVR).The interval variables of the measured frequency were sampled by Latin hypercube sampling method.The samples of frequency were regarded as the inputs of the trained MSVR.The outputs of MSVR were the target values of design parameters.The steel structure of National Aquatic Center for Beijing Olympic Games was introduced as a case for finite element model updating.The results show that the proposed method can avoid solving the problem of complicated calculation.Both the estimated values and associated uncertainties of the structure parameters can be obtained by the method.The static and dynamic characteristics of the updated finite element model are in good agreement with the measured data.

Investigation and Research on the Scientific Selection of the Swimming Athletes

Scientific selection is the key factors of the success of the athletes. Nowadays, the level of competitive swimming is in a time of rapid advance. How to make a scientific selection is a task which is worth deeply researching. It is quite important to make a scientific and modem selection according to the features and trends of swimming events. To carry out specific and scientific selection according to the athletes in Liaoning＇ s characteristic is the basis for bringing up first-class athletes. Hope that this study can provide some theoretical support for the scientific selection of swimmers.

Anguilliform Fish Propulsion of Highest Hydrodynamic Efficiency

It is hypothesized that steady anguilliform swimming motion of aquatic animals is purely reactive such that no net vortex wake is left downstream. This is versus carangiform and tunniform swimming of fish, where vortex streams are shed from tail, fins, and body. But there the animal movements are such to produce partial vortex cancellation downstream in maximizing propulsive efficiency. In anguilliform swimming characteristic of the eel family, it is argued that the swimming motions are configured by the animal such that vortex shedding does not occur at all. However, the propulsive thrust in this case is higher order in the motion amplitude, so that relatively large coils are needed to produce relatively small thrust; the speeds of anguilliform swimmers are less than the carangiform and tunniforrn, which develop first order thrusts via lifting processes. Results of experimentation on live lamprey are compared to theoretical prediction which assumes the no-wake hypothesis. Two-dimensional analysis is first performed to set the concept. This is followed by three-dimensional analysis using slender-body theory. Slender-body theory has been applied by others in studying anguilliform swimming, as it is ideally suited to the geometry of the lamprey and other eel-like animals. The agreement between this new approach based on the hypothesis of wakeless swimming and the experiments is remarkably good in spite of the physical complexities.

Research on the current situations and countermeasures of the swimming elective course in colleges and universities in Chengdu

In college physical education, swimming elective course is one of the important contents of college physical education. By analyzing the current situation of the college swimming elective course in Chengdu city, the author of this article found that the characteristics of the elective courses of the college students are that the elective courses are diversified, showing the non competitive characteristics. And the author analyzes the characteristics of the swimming elective course, how to better combine with the implementation, and further discusses how to further carry on the reform of the PE teaching, and construct the elective course of the type of the sports club teaching mode. Using the questionnaire survey, the mathematical statistics and other methods, the author analyzes and researches on the status of the teaching of the swimming elective course in 7 universities in Chengdu. The results show that in the current teaching of the swimming elective course, there are some problems existing in the setting of the teaching goals and the curriculum contents, the present situation of the teams of teachers, the guarantee of the teaching materials and the teaching evaluation and other aspects. Aiming at these problems, the author puts forward the reasonable suggestions and the countermeasures, to make the teaching of the swimming elective course more perfect, and also to provide referential significance for the teaching reform of the swimming elective course in the colleges and universities in Chengdu.

个人混合泳项目中的泳式转换转身技术

近年来,我国选手,特别是女选手个人混合泳项目水平迅速提高。1992年,林莉在巴塞罗那奥运会上创造了2′11″65的女子200米个人混合泳的世界纪录;以4′36″73的佳绩,夺得400米个人混合泳比赛的银牌。1993年12月,辽宁选手戴国宏在第一届世界短池游泳锦标赛上,创造了4′29″00的女子400米个人混合泳世界纪录,获得该项世界冠军。个人混合泳已成为我国优势游泳项目之一。个人混合泳项目是我国年龄组比赛必赛项目之一,也就是说,任何主项的年龄组运动员,都必须参加个人混合泳项目的比赛。个人混合泳项目比赛已引起运动员。