过载及其表示方法

笔者查阅了航空航天类期刊32种,发现"过载"的表示方法不当,因此,有必要对此进行讨论. 过载(也称过载因数或载荷因数)是飞行器在飞行过程中受力计算及其结构强度计算的依据.     

学业负担过重:归因分析与解决路径

我国中小学生学业负担过重问题自建国以来一直备受人们关注,优质教育资源的相对匮乏引起的过度与无序的竞争和教育行政部门采取的学业质量评价机制的错位与失衡以及教师能力素质与家庭传统教育观念的掣肘是造成学生学业负担过重的主要原因。加强优质教育资源的建设与均衡配置,大力推进学业质量评价机制的改革,促进家校合作,提高教育教学的有效性是解决中小学生学业负担过重的有效途径。     

Effect of hand paddles and parachute on backstroke coordination and stroke parameters

Hand paddles and parachutes have been used in order to overload swimmers, and consequently increase the propulsive force generation in swimming. However, their use may affect not only kinematical parameters (average speed, stroke length and stroke rate), but also time gaps between propulsive phases, assessed through the index of coordination (IdC). The objective of this study was to assess the effects of hand paddles and parachute use, isolated or combined, on kinematical parameters and coordination. Eleven swimmers (backstroke 50-m time: 29.16 ± 1.43 s) performed four 15-m trials in a randomised order at maximal intensity: (1) without implements (FREE), (2) with hand paddles (HPD), (3) with parachute (PCH) and (4) with hand paddles plus parachute (HPD+PCH). All trials were video-recorded (60 Hz) in order to assess average speed, stroke rate, stroke length, five stroke phases and index of coordination. When average swimming speed was compared to FREE, it was lower in PCH and HPD+PCH, and higher in HPD. Stroke rate decreased in all overloaded trials compared to FREE. The use of hand paddles and parachute increased and decreased stroke length, respectively. In addition, propulsive phase duration was increased when hand paddles were used, and time gaps shifted towards zero (no time gap), especially when hand paddles were combined with parachute. It is conceivable that the combined use of hand paddles and parachute, once allowing overloading both propulsive and resistive forces, provides a specific stimulus to improve muscle strength and propulsive continuity.     

Theory-based model of factors affecting information overload

As the volume of available information increases, individuals and organisations become overwhelmed by the plethora of information. This can reduce productivity and performance, hinder learning and innovation, affect decision making and well-being and cost organisations large amounts of money. This paper develops a new theory-based model of factors affecting information overload and provides a formula for calculating the extent of overload, potentially of use as a diagnostic tool supporting individual or organisational development.     

浅谈低压配电线路设计中断路器的选择方法

断路器作为供配电设计中低压配电回路和控制回路使用最频繁、最重要的保护电器元件,也是保护配电网安全、可靠、经济运行和人身安全及人们生产生活用电的关键电器设备。以《低压配电设计规范》(GB50054-2011)为依据,简要阐述了低压配电线路设计中断路器的选择方法。     

大负荷训练对大鼠骨生物力学特性影响的实验研究

】实验以２０只ＳＤ大鼠，进行１０～３０天反复长时间的跑台训练。训练后取其双侧股骨、胫骨、肱骨、尺骨为样本，拍Ｘ光片后制成测试试件，在日产万能力学实验机上做四点弯曲实验，测定其破坏能量、弹性模量、屈服载荷、最大载荷等１０个生物力学参数，然后做统计学处理和比较。在本实验负荷下，大鼠的股骨、胫骨、肱骨、尺骨的各项生物力学特性都受到不同程度的影响，经历了损害和适应的过程，其中胫骨和尺骨的生物力学参数下降较股骨和肱骨出现得早且适应差，甚至有再次受到损害的表现。这与它们在机体中所处的位置特点有关。实验揭示，在Ｘ光片无应力骨折迹象的情况下，骨的生物力学特性仍有改变（Ｐ＜０．０５，Ｐ＜０．０１）。     

概观C++及Java程序设计语言的特征

随着计算机技术的发展，程序设计语言也越来越多，其中C 、Java可以说是目前应用最为广泛的语言，其原因与它们优良的特性密不可分。本着重探讨这两种程序语言的特征，分别总结和阐述了它们优越于其他语言的、自身所独有的特点及为实现这些特点而采取的有效机制。     

四川草地超载原因及对策分析

四川牧区地处长江、黄河上游的特殊地理位置,是青藏高原以至整个西部地区水资源的屏障,保护好这一地区的生态环境具有十分重要的现实意义。本文通过测算1990—2001年四川草原实际载畜量和超载率可看出四川草原已出现严重超载放牧。传统的思想观念、粗放式的畜牧经营方式,频发的自然灾害以及过快的人口增长都是导致草原超载的重要根源,如何在保证牧民既得利益的前提下,保护好生态环境,实现生态与经济并重、草畜平衡,是当前亟需解决的问题。     

信息过载视角下用户创建资源列表扩散效果的影响因素研究——以网易云音乐为例

[目的/意义]选取歌单这一典型用户自发组织平台资源创建资源列表模式，探索"什么样的用户创建资源列表更受欢迎"的问题，揭示用户创建资源列表内容丰富度可能引发的信息冗余现象。[方法/过程]基于信息接受理论与信息过载视角，构建用户创建资源列表扩散的信息接受模型，借助爬虫软件获取网易云音乐歌单相关数据，研究资源列表创建者特征、资源列表质量特征对资源列表扩散效果的影响。[结果/结论]网易云音乐中用户社交网络具有无标度特征；创建者活跃度和贡献度对网络中心性产生正向影响；创建者网络中心性、网络活跃度、网络贡献度、资源列表介绍长度对资源列表有用性和资源列表扩散效果均有显著正向影响；资源列表内容丰富度与资源列表有用性、资源列表扩散效果均存在倒U型关系；在资源列表质量特征对资源列表扩散效果的影响中，资源列表有用性起到了中介作用。     

The concept of information overload: A preliminary step in understanding the nature of a harmful information-related condition

The amount of content, both on and offline, to which people in reasonably affluent nations have access has increased to the point that it has raised concerns that we are now suffering from a harmful condition of ‹information overload.’ Although the phrase is being used more frequently, the concept is not yet well understood – beyond expressing the rather basic idea of having access to more information than is good for us. This essay attempts to provide a philosophical explication of the concept of information overload and is therefore what philosophers call ‹conceptual analysis’ – a task that, along with normative ethical analysis, is distinctive to Anglo-American style analytic philosophy. I will begin with an analysis of the atomic concepts expressed by the terms ‹information’ and ‹overload’ and then attempt to give a philosophical explanation of the concept of information overload that more precisely identifies exactly what the condition amounts to.