短跑摆动技术分析与力量训练

通过对短跑技术摆动动作的分析，特别是对短跑过程中髋部动作一以髋为轴的高速摆动一平动运动的特征分析，认为短跑力量训练应以发展专项摆动力量为主，一般力量训练为辅，紧紧围绕摆动动作的肌群力量着手，在优先发展髋部屈肌肌群力量与上下肢力量均衡协调的基础上，改进短跑技术，并提供了短跑摆动专项力量训练的相应手段．     

女子400米运动员核心力量训练研究

运用文献资料法、运动实验法、逻辑分析法等方法,以广东省女子400m运动员核心力量训练为主要研究对象,以探讨核心力量训练的主要内容、方法和手段。结果表明:(1)核心是腰椎-骨盆-髋关节形成的一个整体,是人体的中间环节,是连接上下肢的纽带,把起止点、起点或止点在这一区域的肌群称为核心肌群,包括41对+1块肌肉;(2)核心力量训练主要起稳定身体姿势和重心、为上下肢运动创造支点、提高身体的平衡和控制能力、提高能量由核心向四肢的输出以及预防运动损伤等作用;(3)核心力量训练的方法主要有稳态和非稳态条件下的静力性和动力性练习。     

腿部核心肌群力量训练对高校足球业余运动员专项素质影响的实验研究

结合足球运动项目特点,对高校足球业余运动员采取腿部核心肌群力量训练效果进行研究,仔细分析实验前后足球业余运动员专业素质发生的改变.结果说明,借助腿部核心肌群力量训练,业余运动员原地正脚背射门和凌空正脚背射门的准度与速度都得到了提升.可见,科学应用腿部核心肌群力量训练,有利于业余足球运动员提高上下肢统一发力的能力,可以更好地控制身体.相较于传统基础训练,实验训练科学性更强,同时采取各种训练手段,提升了训练的趣味性.     

浅析加强上肢肌肉力量训练对提高短跑运动成绩的作用

众所周知,决定短跑运动成绩的主要因素是步长和步频,而跑动中的摆臂可起到调节步长和步频的作用,同时对维持身体平衡,增加两腿蹬摆力量,提高蹬摆速度,也有很明显的影响。因此,加强上肢肌肉力量训练可辅助提高短跑运动成绩。其实上肢力量一直被短跑教练员所认可,但未能引起足够的重视,在基层的兼职教练员对此重视的程度更为不足,以至造成队员上下肢肌肉力量比例失调,从而影响到潜在运动能力的挖掘。针对以上情况,我认为青少年加强上肢肌肉的力量训练是亟待解决的问题,就此问题进行了研究。     

体育运动力量训练的理论研究

力量训练的效果,取决于方法和负荷的有机统一,科学地控制力量训练,其根本就在于对力量训练方法的选择和负荷的优化.方法和负荷的优化组合,体现出力量训练的科学性.力量训练是一种动态的控制系统,方法和负荷结构的结合,处在一种不断调整和变化中,对人体的运动中枢和肌肉施以变化着的刺激去追求训练上的不断突破.     

核心力量训练在河北省女子铁饼备战第十三届全运会中的应用

核心区稳定性之所以重要,主要在于它是完成绝大多数技术动作力量产生和传递的核心区域,是人体动作链的中心环节。只有核心区稳定性提高,肢体的活动才能有支撑,才会更协调。核心力量训练本着运动链(动力链)理论,在完成技术动作过程中,将参与完成动作的肢体连成一个链,参与完成动作的每一个部分则是链上的一个环节,技术动作的完成是依靠动量在各个环节间的传递实现的,核心力量就是动量在动力链的传递过程中发挥着核心作用,在上下肢的动量传递过程中起承上启下的枢纽作用。因此,在投掷运动员力量训练的过程中要充分重视核心力量的训练,这才有可能使得运动员得成绩取得更大的突破。     

浅谈影响立定跳远成绩的主要因素

立定跳远是一项考核学生下肢爆发力、腰腹力量和上下肢协调能力的运动项目。从运动技术方面看，主要通过展腹、收腹举腿、团身落地动作来完成。通过对相关肌肉的科学训练，能够有效地提高立定跳远成绩。以朝阳师专学生为研究对象，分析影响立定跳远成绩的主要因素。     

田径运动训练中核心力量发展认识

一、核心力量 核心力量是指核心部位的肌肉、韧带和结缔组织的力量以及他们之间的协作。核心力量是以稳定人体核心部位、控制重心运转、传递上下肢肌肉力量的力量能力。核心力量是核心稳定性的形成的主要能力。     

浅谈教学中有关推铅球的技术要领

推铅球是田径运动的投掷项目之一,它对增强体质,特别是发展躯干和上下肢力量有显著的作用。铅球项目对学生的素质和技术有很高的要求,而且在体育教学中的训练占有相当大的比重,但是铅球的技术很不容易被掌握,这使学生和教师都很头疼,学生的运动成绩不理想,也影响了学生的考试成绩。因此在教学过程中要勤加练习,但也要注意练习过程中技术的掌握。     

现代武术散打运动训练理论与方法应用

采用文献法和数理计算法对武术散手的程序训练进行了研究，认为训练检测和评定所组成的反馈通道是程序训练的关键，并提出了散打专项力量影响因素的排序，还分析了腾空后摆腿专项力量训练手段对训练内容系统的影响．     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to