另一个单摆周期近似公式

利用"局部常化"方法及MATLAB计算软件,推导出了一个近似程度高且比较简洁的单摆周期公式.     

高校自然科学学报发表学科教学研究论文的必要性 ——基于L省的初步调查

对L省55家高校学报进行调查,发现高校自然科学学报很少发表学科教学研究论文.其原因有对教学研究学术属性认识的偏差,也有"重科研、轻教学"的科研评价取向对期刊工作的影响.从学科教学研究的学术属性、学报的特殊功能、现有可发表学科教学研究论文期刊数量、学报的综合性与学术质量的关系及高校教学属性的回归等方面分析,高校自然科学学报,尤其是地方高校学报,可以发表学科教学研究论文,从而引导、鼓励教师开展教学研究,促进优秀教研成果的传播和交流.     

关于单摆实验最大摆角的讨论

在利用单摆测重力加速度实验中,有复摆、空气浮力、空气阻力、摆角等多种误差因素。最大摆角的选择应将这些因素综合起来分析,否则将有失偏颇。在一种普通的实验方案下,本文针对两种情况,借助Mathematica软件,计算出了最大摆角的值。     

抛射体运动的飞行路径与抛射角的关系

在忽略空气阻力的情况下,抛射体运动的飞行路径长度与抛射初速度的平方成正比.运用Matlab可比较容易地证明,当抛射角为56.49°时,飞行路径最长.     

Effects of Cylinder Radius, Setover and Heel-Toe Difference on Cylinder-Flat Gauge of a Card

In order to provide manufacturers of carding machines and relevant accessories with theoretical references, how cylinder radius, setover and heel-toe difference affect cylinder-flat gauge of a carding machine was theoretically studied. The relationship between cylinder-flat gauge and cylinder radius, setover and heel-toe difference was geometrically discussed. Numerical calculation and illustration about the relationship were made with MATLAB in accordance with practical settings. A general formula about the relationship is derived. A concept, the small-gauge zone length, has been defined for the first time, and some relevant results thus obtained. Given setover and heel-toe difference, the greater the cylinder radius, the greater the average gauge. If a smaller overall cylinder-flat gauge is desirable, it is not necessary to emphasize the tangential direction of the heel of clothed surface to the cylinder. Their intersection within a small zone is acceptable. In many cases, small-gauge zone can reduce average gauge which may be helpful to the carding action; given cylinder radius and setover, the smaller the heel-toe difference, the more helpful to reduce the overall gauge; given cylinder radius and heel-toe difference, the small-gauge zone length will increase with the increase of setover, so does the difference between the smallest gauge and outlet gauge.