我国老年认知心理研究综述

认知老化是老年心理学研究的重要领域之一。我国学者对它的研究主要在老年认知活动的认知速度,认知能力的感知觉、记忆、思维和智力,日常认知,认知功能障碍等方面。随着测量理论、方式以及科技的发展,在研究内容、统计分析方法、研究工具、研究结果的推广等方面会发现更多值得思考和探讨的新颖点,从而更有效地利用研究结果,不断提高老年人的生活质量和心理健康水平。     

基于PIC16F72单片机无刷直流电机控制器设计

随着人们生活水平的提高和现代化生产、办公自动化的发展,家用电器、工业机器人等设备都越来越趋向于高效率化、小型化及高智能化,作为执行元件的重要组成部分,电机必须具有精度高、速度快、效率高等特点,无刷直流电机的应用也因此而迅速增长,本设计是通用无刷电机的控制器设计,以PIC16F72单片机为控制电路,单片机采集比较电平及电机霍尔反馈信号,通过软件编程控制无刷直流电动机,实验表明具有较好的参考价值。     

月球的起源和演进

由于月球是环绕地球运行的唯一的一颗自然卫星。对月球起源的研究不仅能够发现太阳系星球卫星的形成规律。而且可以揭示字宙星系的演进规律,进而控制星球的演进。因此许多人研究过月球,但是关于月球的起源仍然是一个不解之谜。于是本文作者通过分析和研究地球的演进过程,发现了地球卫星的形成机制．即地球岩石圈在水的长期侵蚀下分裂成一些断块．有的断块外部被溶蚀成许多溶洞,而内部又变成浮石结构,以致比重很小;当共中一个这样的断块的岩基被海水蚀透。使大量的水进入地慢与炽热的岩浆接触时．就会产生巨大的爆炸,将断块炸裂成多个浮石碎块,其中有些浮石碎块在巨大的岩浆喷射力的推动下经过大而深的岩洞可获得第一宇宙速度以上的飞行速度．从而进入绕地球运行的轨道。在这些进入绕地轨道的浮石碎块中有一块体积最大的浮石碎块就是后来形成月球的雏形。后来月雏不断地吸收地球周围的残余物质而变得越来越大．并渐渐地远离地球。     

800m跑运动员训练方法浅谈

现代中长跑的训练内容很多，凡是能够决定和影响运动员竞技运动能力及专项运动成绩的因素，郁应列为训练的内容，800m跑属于极限强度很强的项目，运动中能量的供应主要以肌糖的酵解为主，无氧代谢高达84％，比赛后程的血乳酸浓度可达到270-300mm%，氧债可达到20-30L。因此，800m跑的运动员必须提高在运动中产生乳酸的能力，而这些能力的提高必须经过艰苦科学合理的训练。     

影响优秀男子标枪运动员标枪出手时状态的各因素分析

通过对影响优秀男子标枪运动员标枪出手时状态的各因素的分析，明确了各因素对运动成绩的影响程度，其中起主导作用的是出手速度和出手角度。在平时的训练中，应以速度为中心，不断完善投掷技术，全面发展运动员的身体素质和专项素质。     

Book reviews

Women, sport and performance, C.L. Wells, Human Kinetics, Champaign, Illinois, 1985. xi+333 pp, $24.00 (hb), ISBN 0 931250 87 0

Research designs and statistics for physical education, Anne L. Rothstein, Prentice Hall, New York, 1985. xiii + 353 pp, £31 (hb), ISBN 0 13 774142 1

Limits of human performance, American Academy of Physical Education Papers No. 18, D.H. Clarke and H.M. Eckert (eds), Human Kinetics, Champaign, Illinois, 1985. 144 pp, £14.50 (pb), ISBN 0 931250 99 4

Sports physiology, (2nd edn) E.L. Fox, Holt Saunders, Eastbourne, 1984. xii+418 pp, £18.95 (hb), ISBN 0 03 063771 6

Sport management ‐ macro perspectives, P. Chelladurai, Sports Dynamics, London, Ontario, 1985. 191 pp, $11.95 (pb), ISBN 0 9691619 0 5

Microelectronics in the sport sciences, Charles F. Cicciarella, Human Kinetics, Champaign, Illinois (distributed in the UK by Eddington Hook & Co.), 1986. 105 pp, $12.00 (pb), ISBN 0 87322 056 0

The biomechanics of sports techniques, (3rd edn) J.G. Hay, Prentice Hall, New Jersey, 1985. xvii+539 pp, £15.95 (pb), ISBN 0 13 078304 8     

Concurrent validity and test–retest reliability of a global positioning system (GPS) and timing gates to assess sprint performance variables

Abstract

There has been no previous investigation of the concurrent validity and reliability of the current 5 Hz global positioning system (GPS) to assess sprinting speed or the reliability of integrated GPS–accelerometer technology. In the present study, we wished to determine: (1) the concurrent validity and reliability of a GPS and timing gates to measure sprinting speed or distance, and (2) the reliability of proper accelerations recorded via GPS–accelerometer integration. Nineteen elite youth rugby league players performed two over-ground sprints and were simultaneously assessed using GPS and timing gates. The GPS measurements systematically underestimated both distance and timing gate speed. The GPS measurements were reliable for all variables of distance and speed (coefficient of variation [CV] = 1.62% to 2.3%), particularly peak speed (95% limits of agreement [LOA] = 0.00 ± 0.8 km · h^?1; CV = 0.78%). Timing gates were more reliable (CV = 1% to 1.54%) than equivalent GPS measurements. Accelerometer measurements were least reliable (CV = 4.69% to 5.16%), particularly for the frequency of proper accelerations (95% LOA = 1.00 ± 5.43; CV = 14.12%). Timing gates and GPS were found to reliably assess speed and distance, although the validity of the GPS remains questionable. The error found in accelerometer measurements indicates the limits of this device for detecting changes in performance.     

Measurement in speed skating tournaments

Twenty principal components analyses were performed on the results of 10 European and 10 World male speed skating championships. The first principal component obtained was defined as ‘the ability to skate well at all tournament distances’. Therefore the rank order of the participants’ skating ability could be estimated in an alternative way to allow validation of the scoring method currently in force. This validity coefficient turned out to be so high (r = 0.967) that it does not seem necessary to adopt a more sophisticated method, despite a few demonstrable shortcomings of the one in use. However, there remains a considerable proportion of variance (10–34%) that can not be explained by systematic aspects of skating ability.     

NIC Express v4.0双网卡绑定实现以太网设备冗余的安装、配置与测试

服务器作为计算机网络信息平台的核心,稳定性、安全性和网络带宽至关重要.采用双网卡绑定是提高服务器网络链路(网卡、网线、交换机)热备份冗余、保障服务器链路通畅、降低故障率的重要技术方案.本文详尽分析了双网卡绑定软件NIC Express Enterprise Edition v4.0的安装与配置,并进行了网络传输速率的测试.     

基于单片机实现摄像机运动控制系统的设计

本文以AT89S52单片机为核心构成云台控制器,通过8279键盘、显示接口芯片实现外部控制信息的输入以及步进电机转速的显示,控制摄像机进行上、下、左、右各方向的行进动作.为保证控制的可靠性,步进电机控制信号的发出不是由单片机完成,而是由专用步进电机驱动模块产生.