论高校财务岗位轮换

实行财务岗位轮换制度,是新形式下高校发展的必然要求,文章阐述了财务岗位轮换的重要作用及存在的问题,并对财务岗位轮换应采取的具体措施作了论述.     

轴向激光扫描淬火齿轮位置设计

本文讨论了采用宽带镜轴向扫描进行齿轮表面激光淬火时齿轮位置的一种确定方法,同时还讨论了激光入射角λ及光束带宽ι与齿轮转角θ、齿数Z及模数m的关系。     

旋转对乒乓球运动状态的影响

乒乓球的旋转种类很多,不同的旋转其运动状态不同,掌握旋转对乒乓球运动状态影响的规律,对提高乒乓球技术教学的效果和运动员实战能力的提高有着积极的促进作用.本文以上旋球和下旋球为例,对乒乓球旋转球的空中飞行的运动状态、接触台面后的运动状态及平挡触拍后的运动状态几个方面进行分析对比.结果表明:旋转球在空中飞行时,上旋球飞行弧线的弯曲度增大,边飞行边"下潜",下旋球飞行弧线的弯曲度减小,边飞行边"上浮";上旋球触台后的前冲速度加快,飞行方向为继续"下潜",下旋球触台后的前冲速度减慢,飞行方向为继续"上浮";平挡触拍后,上旋球向前上方反弹,下旋球向前下方反弹.     

基于FPGA的两相步进电机控制器设计

在介绍步进电机的控制原理及其工作原理的基础上,提出基于FPGA的步进电机正反转控制的设计方案,给出Verilog—HDL语言设计的两相步进电机的两相八拍工作方式的程序及其在QuartusⅡ进行仿真得到的结果。仿真结果表明,该设计控制灵活,易于调试。     

Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by applying maximum likelihood factor analysis subject to scaling and rotation constraints. As an illustrative example, an oblique 5-factor model will be fitted to the variance-covariance matrix of the 30 personality facets measured by the Revised NEO Personality Inventory, and confidence intervals will be estimated for all factor loadings and factor correlations, as well as for the associated reliability and validity coefficients.     

转动非惯性系中的力学方法

通过科氏惯性力与洛仑兹力的类比,并引入广义坐标、广义动量、广义能量等概念,采用广义动量-能量原理等若干非传统方法,讨论有关转动非惯性参考系中的相对运动学与动力学问题.     

微型直流电动机驱动试验分析

该文论述了微型直流电动机驱动电路的基本原理．分析了以51单片机控制微型直流电动机正反转和调速的驱动电路．文中给出了具体的试验电路和试验结果。     

排球发球中侧旋球的理论与实效性研究

本文运用刚体转动定律及流体伯努利方程对排球发侧旋球的弧线飞行原理和侧旋速度对飞行轨迹以及着地点进行理论分析研究,结果表明击球点于球体重心右侧1/3处、击球挥臂出手方位面向球网方向右转30度,用中等力量击球实效性较高。     

Snippets of physics

The Foucault pendulum is an elegant device that demonstrates the rotation of the Earth. After describing it, we will elaborate on an interesting geometrical relationship between the dynamics of the Foucault pendulum and Thomas precession discussed in the last installment¹. This will help us to understand both phenomena better. T Padmanabhan works at IUCAA, Pune and is interested in all areas of theoretical physics, especially those which have something to do with gravity.     

对角线法则计算四阶行列式的简便方法

阐述一种相对简便的对角线法来计算四阶行列式．