Effects of power variation on cycle performance during simulated hilly time-trials

It has previously been shown that cyclists are unable to maintain a constant power output during cycle time-trials on hilly courses. The purpose of the present study is therefore to quantify these effects of power variation using a mathematical model of cycling performance. A hypothetical cyclist (body mass: 70?kg, bicycle mass: 10?kg) was studied using a mathematical model of cycling, which included the effects of acceleration. Performance was modelled over three hypothetical 40-km courses, comprising repeated 2.5-km sections of uphill and downhill with gradients of 1%, 3%, and 6%, respectively. Amplitude (5–15%) and distance (0.31–20.00?km) of variation were modelled over a range of mean power outputs (200–600?W) and compared to sustaining a constant power. Power variation was typically detrimental to performance; these effects were augmented as the amplitude of variation and severity of gradient increased. Varying power every 1.25?km was most detrimental to performance; at a mean power of 200?W, performance was impaired by 43.90?s (±15% variation, 6% gradient). However at the steepest gradients, the effect of power variation was relatively independent of the distance of variation. In contrast, varying power in parallel with changes in gradient improved performance by 188.89?s (±15% variation, 6% gradient) at 200?W. The present data demonstrate that during hilly time-trials, power variation that does not occur in parallel with changes in gradient is detrimental to performance, especially at steeper gradients. These adverse effects are substantially larger than those previously observed during flat, windless time-trials.     

基于仙人掌发展模型的“晒”的隐喻性词义演变

"晒"是现代汉语中的基本词汇,在词义演化过程中,"晒"的隐喻性语义演化不仅能体现出词义辐射型的优势,各种引申义能直接指向"晒"的基本义,而且发挥了连锁型的优势,加强了各引申义之间的紧密联系。"晒"的不同语义之所以能纳入到统一的语义框架中,是因为它们之间存在着差异的同时又表现出某种程度的相似性,这种相似性可通过仙人掌发展模型进行分析,显示了词语语义链发展的新特征。     

程序民主的完美典范:雅典陪审法庭

本文借助文本资料和考古资料,重现了古代雅典陪审法庭的运作过程。在此基础上,作者提出,雅典人以平等、公平、公正为目标,通过把陪审员名额分配上的硬性规定与分配法庭时的弹性机率、程序的公开性与投票的秘密性相结合,并配以对程序协助者的监督,从而创造了古典社会中程序民主的典范。     

面向在校大学生培养党政后备人才模式纵论

在实施人才强国战略中,建立党政后备人才培养体系是加强党的执政能力建设,从更高的战略层面推进人才队伍建设可持续发展的重要举措。面对日益激烈的人才竞争,大学生成为党政后备人才资源群体有其历史的合理性;面向在校大学生培养党政后备人才要立足于当代大学生的现实特点和后备人才的未来的双重视角,充分关注其特殊性,着重培养强化他们的政治思维素质、社会责任感、理论联系实际能力、健全的个性心理品质、完善和谐的人格。面向在校大学生培养党政后备人才模式,对广大经济欠发达地区具有普适性。     

开放型实验室管理模式探讨

讨论了开放型实验室需要解决的问题及其管理模式，并介绍了实践经验。     

应用管理系统在局域网中的总体设计

随着计算机关系型数据库语言的丰富与完善,特别是FOXBASE最新一代的数据库管理系统软件的出现,以及各种管理系统开发工具软件的使用,使得在开发一个计算机系统时,最感困难和复杂的已不再是具体程序的编写,而是整个系统的规划。大连市委组织部开发的《大连市组织工作信息管理网络系统》即是整个系统的规划在局域网络中的总体设计的想法和思路。     

High-extensible scene graph framework based on component techniques

INTRODUCTION With the tremendous growth of the digital en- tertainment industry in the past decades, the scale of game scene is becoming more gigantic. To effectively manage and organize the massive data, game engine usually uses hierarchical scene graph. Many popular 3D modelling tools, such as Maya, 3D Studio Max, use scene graph to manage the scene content (Sowizral, 2000). 3D modelling software—Houdini directly edits scene graph to create and modify the virtual environment. Most v…     

接受反应文论中的读者概念解析

伴随读者在文学活动中主体地位的突显而来的是各种读者概念的出现。本文主要分析西方接受反应文论中有代表性的读者概念,它们是里法德尔的“超级读者”,伊瑟尔的“隐含的读者”,费什的“有知识的读者”和艾柯的“标准读者”,指出这些读者概念在理论上的成就以及在实践中的不足之处。     

基于网络环境下协作学习模式的构建和实践

随着信息技术的发展，网络环境已成为学习者学习的重要环境之一。基于网络环境下的协作学习，能够激发学习者的学习动机，消除学习的孤独感，有利于培养学习者之间的合作交流能力和创新能力，增强互助意识，提高学习效率。文章从协作学习的概念和特点入手，介绍了协作学习的四个基本要素，分析了协作学习的几种模式，探讨了基于网络环境下协作学习的教学设计和实施。     

对初中生数学形象思维中直感能力的调查研究

直感是形象思维中一个很重要的方面,为了提高学生的形象思维水平,就要提高学生的直感能力.直感可分为4个维度即形象识别、模式补形、形象相似、象质转换.而初中生数学直感能力总体处于中下等水平,培养学生数学直感能力可以从以下几个方面入手:加强变图、变式训练,丰富表象模式,形成知识“相似块”,重视象质关联图的应用.