电路原件实物图片磁力贴

1制作理由 在初中八年级物理教学中,电路的连接既是重点,又是难点。为了使学生能很好的掌握这一知识点,老师们找规律、想方法,但都离不开一定量的习题训练,而在进行习题训练时,一道实物电路图习题,图就要画好半天,一节课讲练不到几道题。基于这些原因,我设计并制作了一套电路原件实物图片磁力贴,使用后觉得很方便,学生也觉得很有趣,极大地调动了学生的学习积极性,其他物理老师借用后,反响也特别好。下面我就介绍一下电路原件实物图片磁力贴的制作方法。     

《电铃响丁当》教学片段与分析

片段一:设计实验方案师:我们在前面认识了电磁铁并做了一个,谁还记得刚才你制作的电磁铁吸起了多少大头针?生:3个。生:5个。生:6个。师:观察这些数字,它们说明了什么?生:电磁铁吸起的大头针个数不一样。生:磁力大小不一样。师:哪些因素会影响电磁铁的     

自控电路的探讨

自控电路是实现自动化的一个基本的要求，是实现自动化的重要前提和保证。在科技高度发展的时代，自动控制电路一天天地广泛应用干生产、生活和工作中，它的使用非常简单，但它的原理却不是人人知晓，尤其是非专业人员。现在，笔者怀着对电工电子的极大兴趣，对几个简单常见的自控电路进行了总结和探索，以飨读者。     

Design and analysis of superconducting magnets of a new mixed Maglev model

A new electromagnetic suspension model using a combination of high temperature superconductors (HTS) and copper conductors is proposed in this paper. A feasibility study showed that the magnets of our model can generate the 250 kg vertical suspension force. Three dimensional FEM and Design Sensitivity Analysis using the levitation gap length and cross sectional dimensions of the HTS magnets as design parameters were conducted to obtain the optimal shape of the cross section and the configuration of the HTS magnet. It was found that the gap length when optimized HTS magnet was used was much larger than that when copper conductor magnet was used, while the HTS coil volume was minimum, and the perpendicular field along the outer surface of the HTS coil was less than 0.12 T.     

Hysteresis model of magnetostrictive actuators and its numerical realization

This paper presents two numerical realization of Preisach model by Density Function Method (DFM) and F Function Method (FFM) for a giant magnetostrictive actuator (GMA). Experiment and simulation showed that FFM is better than DFM for predicting precision of hysteresis loops. Lagrange bilinear interpolation algorithm is used in Preisach numerical realization to enhance prediction performance. A set of hysteresis loops and higher order reversal curves are predicted and experimentally verified. The good agreement between the measured and predicted curves shows that the classical Preisach model is effective for modelling the quasi-static hysteresis of the GMA.     

圆形载流线圈沿一直径折成直角可看作磁偶极子

从磁偶极子的特点出发，用毕奥一萨伐尔定律、安培力公式和力矩的定义，推导出用磁矩表示的圆形载流线圈沿一直径折成直角的远场及其在均匀磁场中所受的磁力和磁力矩，指出此非平面栽流线圈可看作磁偶极子．     

A linear rotary magnetorheological damper for vehicles

1.IntroductionOneofthemostimportantperformanceparameterofautomobilesisthecushioningability.Soallkindsofvibrationdampersareassembledinvehicles,amongwhichthefullest-blownoneisthehydraulicdamperworkingthroughreciprocatingmovementofhinderedpistoninahydrauliccylinderabsorbingvibrationwithself-containedspring.Butsuchkindofdampercannotchangewiththechangeincharacteristicsofavibrationsource(suchasamplitudeofvibrationandphase),lackingofenoughself-adaptingability.Magnetorheologicaldamperfluid(MRF)isaty…     

从一道力学题看一类题目的机械能守恒

用机械能守恒定律求解两相互作用物体(接触面光滑)的加速这类题时，一般只从系统的受力分析得出机械能守恒的结论，而忽略了物体间正压力作功的情况。本文对两物体间正压力作功的情况进行分析，用矢量法证明了物体间正压力对系统(由相互作用的两物体及地球组成)作功的代数和为零，故系统的机械能守恒。     

增强现实系统中基于神经网络的磁力跟踪器校正

Nonlinear errors always exist in data obtained from tracker in augmented reality （AR）, which badly influence the effect of AR. This paper proposes to rectify the errors using BP neural network. As BP neural network is prone to getting into local extrema and convergence is slow, genetic algorithm is employed to optimize the initial weights and threshold of neural network. This paper discusses how to set the crucial parameters in the algorithm. Experimental results show that the method ensures that the neural network achieves global convergence quickly and correctly. Tracking precision of AR system is improved after the tracker is rectified, and the third dimension of AR system is enhanced.     

隐藏在地下的吸铁石

青藏高原上，有一座奇怪的山峰。大雁飞到这儿，常常会迷失方向，从半空中掉下来。大雁在天上飞得好好的，怎么会迷失方向掉下来呢？如果这是真的，说不定这座山上藏着一个磁铁矿，南于它受到强烈的磁力干扰，大雁才会迷航的。