Do you find getting up in the morning so diffcultthat it’s painful? This might be called laziness, butDr. Nathaniel Kleitman, University of Chicago physio-logist, has a new explanation. He has proved thateveryone has...Do you find getting up in the morning so diffcultthat it’s painful? This might be called laziness, butDr. Nathaniel Kleitman, University of Chicago physio-logist, has a new explanation. He has proved thateveryone has a daily energy cycle.展开更多
以固定机翼式微型飞行器(miniature air vehicle,MAV)的气动设计为研究背景,对小展弦比低雷诺数下不同长短轴比值(long-short axis ratios,LSARs)的齐默曼和反齐默曼机翼流场进行数值分析.采用人工压缩性方法求解不可压粘性绕流,应用三...以固定机翼式微型飞行器(miniature air vehicle,MAV)的气动设计为研究背景,对小展弦比低雷诺数下不同长短轴比值(long-short axis ratios,LSARs)的齐默曼和反齐默曼机翼流场进行数值分析.采用人工压缩性方法求解不可压粘性绕流,应用三阶迎风格式离散对流项,湍流模型为Baldwin-Barth一方程模型.通过对比齐默曼和反齐默曼两种布局机翼的数值结果与实验值,验证了数值方法的正确性.通过分析不同长短轴比值齐默曼和反齐默曼机翼的气动性能,揭示出在长短轴比值相同的情况下,反齐默曼机翼有较高的升力,且其升阻比随着长短轴比值的减小而增大.展开更多
1 Introduction Endeavours on learning methods have long occupied the mind spaces of scholars and there have been theories abound on how people learn and in what way organisations can use some of the knowledge gained i...1 Introduction Endeavours on learning methods have long occupied the mind spaces of scholars and there have been theories abound on how people learn and in what way organisations can use some of the knowledge gained in the art of learning to maximise human productivity.While the theories by themselves are not solutions to problems,they are steps of inquiry that provide us with interesting perspectives that we can use to extend our knowledge of the dimensions of learning.This paper is an exploratory work on the theories postulated by three notable scholars including展开更多
British linguist Wilkins(1972)points out,"Without grammar,little can be conveyed;without vocabulary,nothing can be conveyed."Grammar provides the overall patterns,and vocabulary is the material to put in the...British linguist Wilkins(1972)points out,"Without grammar,little can be conveyed;without vocabulary,nothing can be conveyed."Grammar provides the overall patterns,and vocabulary is the material to put in the patterns.Zimmerman(1997)also stated the idea that vocabulary is central to language.So vocabulary is the building展开更多
文摘Do you find getting up in the morning so diffcultthat it’s painful? This might be called laziness, butDr. Nathaniel Kleitman, University of Chicago physio-logist, has a new explanation. He has proved thateveryone has a daily energy cycle.
文摘以固定机翼式微型飞行器(miniature air vehicle,MAV)的气动设计为研究背景,对小展弦比低雷诺数下不同长短轴比值(long-short axis ratios,LSARs)的齐默曼和反齐默曼机翼流场进行数值分析.采用人工压缩性方法求解不可压粘性绕流,应用三阶迎风格式离散对流项,湍流模型为Baldwin-Barth一方程模型.通过对比齐默曼和反齐默曼两种布局机翼的数值结果与实验值,验证了数值方法的正确性.通过分析不同长短轴比值齐默曼和反齐默曼机翼的气动性能,揭示出在长短轴比值相同的情况下,反齐默曼机翼有较高的升力,且其升阻比随着长短轴比值的减小而增大.
文摘1 Introduction Endeavours on learning methods have long occupied the mind spaces of scholars and there have been theories abound on how people learn and in what way organisations can use some of the knowledge gained in the art of learning to maximise human productivity.While the theories by themselves are not solutions to problems,they are steps of inquiry that provide us with interesting perspectives that we can use to extend our knowledge of the dimensions of learning.This paper is an exploratory work on the theories postulated by three notable scholars including
文摘British linguist Wilkins(1972)points out,"Without grammar,little can be conveyed;without vocabulary,nothing can be conveyed."Grammar provides the overall patterns,and vocabulary is the material to put in the patterns.Zimmerman(1997)also stated the idea that vocabulary is central to language.So vocabulary is the building
