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Synergistic Effect of Electro-magnetically Coupled Field in Polishing with the EMR Effect-based Tiny-grinding Wheel
电磁流变效应微磨头抛光加工电磁协同作用机理

LU Jia-bin,YAN Qiu-sheng,TIAN Hong,GAO Wei-qiang,
路家斌
,阎秋生,田虹,高伟强

摩擦学学报 , 2010,
Abstract: Based on the electro-magneto-rheological (EMR) effect, the Fe3O4-based EMR fluid dispersed with micron-sized finishing abrasives is used as a polishing fluid to form a dynamical tiny-grinding wheel under electro-magnetically coupled field. Using this EMR effect-based tiny-grinding wheel, polishing experiments were conducted to investigate the material removal amount of normal glass under the different electro-magnetically coupled fields, and revealed the machining performance of the tiny-grinding wheel. A mechanical model of dispersed particles in the EMR fluid was presented based on the theoretical analysis of materialogy and electromagnetism, and the synergistic effect of the coupled field in polishing with the tiny-grinding wheel was investigated in detail. Experimental results indicated that the material removal amount of the EMR effect-based tiny-grinding wheel was 1.74 times that of the ER effect-based tiny-grinding wheel and 5.71 times that of the MR effect-based tiny-grinding wheel due to the marked synergistic effect of the coupled field. The combined effect of the electric field force, the magnetic field force and the spin couple generated by the Lorentz force determined the stability of the chains of EMR particles and the machining performance of the EMR effect-based tiny-grinding wheel, and a good synergistic effect of EMR fluid can be obtained under appropriate electro-magnetically coupled field.
Asymptotic estimation for the system of electro-rheological fluids
电流变液系统流动的渐近估计

Ouyang Cheng,
欧阳成

物理学报 , 2004,
Abstract: By the movement model of ball particles in electro rheological(ER) fluids, the asymptotic behavior of the movement of the particles in ER fluids is considered when the mass of the particles is small. Using the theory of differential inequalities, the expression of asymptotic estimation is given and proved.
The Electronic Medical Record (EMR)  [PDF]
PeterChris Okpala
Journal of Applied Medical Sciences , 2013,
Abstract: The electronic medical record (EMR) comprises a system of recording, processing, storing, recording and transferring health information electronically. Through the use of the EMR, several limitations that are associated with the paper-based medical record system are clearly overcome. For example, in contrast to the paper record, the EMR can play a larger role in medical decision-making, integrating the services of various departments, customizing care to the patients, reducing medical errors, improving quality, reducing costs, etc. In addition, the EMR can effectively help to transfer patient information from one organization to another and in this way help in referrals and improving the access to healthcare. This article examines the problems associated with the implementation of EMR systems, and later discusses the uses of EMRs and its benefits. If EMR system is implemented and used properly, it will help in the improvement of community health.
基于格子Boltzmann方法的电流变液动力学建模及数值模拟 Dynamic modeling and numerical simulation of electro-rheological fluids based on Lattice Boltzmann Method
Dynamic modeling and numerical simulation of electro-rheological fluids based on Lattice Boltzmann Method
 [PDF]

朱石沙,罗奇,刘金刚,唐涛
- , 2016, DOI: 10.7511/jslx201605003
Abstract: 电流变悬浮液内部结构对外电场的快速响应发生在指定的控制空间中,在这一特指的时间和空间尺度上电流变悬浮液的物理行为特征主要为剪切速率低和流动阻尼大,即Mach和Reynolds数一般不大,可以视为微尺度流动来加以研究。针对这一流动特征,基于介观动理论的格子Boltzmann方法,建立了电流变悬浮液两相流动的离散颗粒运动模型,通过该模型进行了动力学模拟,结果表明,该模型解决了分子动力学模型难以描述的因颗粒运动造成局部流场流变特性改变的难题,以及该流场双向耦合过程中对颗粒运动的影响。
Since the fast response of the internal structure of the electro-rheological (ER) suspension fluids occur in the controlled space (electrode distance is generally 1 mm~2 mm) of the applied electric field,where the main feature of the ER suspension fluids in the certain time and spatial scales is low shear rate but high flow resistance,which means the Mach number and the Reynolds number are generally small,it can be considered as micro-scale flow.According to this characteristic,the author proposed a discrete-particle-motion model of the ER suspension flows based on the Lattice Boltzmann Method(LBM) of the Mesoscopic kinetic theory.The results of the dynamic simulation showed that the model solved the problem of describing the changes of the rheological properties of some local flow fields and the influences on the particle movement during the two-way coupling in this flow field.
磁流变液夹层板隔声性能研究
Sound Insulation Performance of the Sandwich Panel Cored with Magneto-Rheological Fluid
 [PDF]

戚利利, 徐晓美, 石静, 刘凯, 陆安琪
Open Journal of Transportation Technologies (OJTT) , 2016, DOI: 10.12677/OJTT.2016.55015
Abstract:
本文基于波阻抗分析法建立了夹层板的传声损失数学模型,根据松弛时间谱间接估算了磁流变液的粘弹性模量,基于此理论模型,采用MATLAB编写相应的传声损失数值模拟程序,仿真研究了磁流变液夹层板的传声损失。研究结果表明,励磁电流对磁流变液夹层板的传声损失具有明显的影响,通过调节励磁电流,可以实现夹层板隔声能力的半主动控制;夹层板的芯层厚度并非越大越好,大的芯层厚度易于使吻合频率落入夹层板的常用工作频率范围,从而恶化夹层板的低频隔声性能;夹层板的面板材料选取要综合考虑夹层板的高、低频隔声能力,且要注意成本和轻量化的要求。
Mathematical model of the sound transmission loss (STL) of sandwich panels is firstly established based on the method of wave impedance analysis. And then, the viscoelastic moduli of magneto-rheological fluid are estimated indirectly according to the relaxation time spectrum. Finally, the simulation program of the STL of sandwich panels is coded by MATLAB and then the STL of sandwich panels is analyzed. Research results show that there are obvious effects of the field current on the STL, and semi-active control of the sound insulation performance of the sandwich panel can be realized by adjusting the field current; the core layer thickness of the sandwich panel is not the bigger the better because bigger thickness is easy to make the coincidence frequency fall into the common operating frequency range of sandwich panels and thus worsens the sound insulation performance of sandwich panel in low frequency range; selection of face sheet material should comprehensively consider the sound insulation performance of panels in both low and high frequency ranges, and the panel cost and lightweight requirements should also be considered.
Structure evolution features of electro-rheological fluids induced by particles'' mass
颗粒质量导致的电流变液结构演化特征

Zhao Xiao-Peng,Gao Xiu-Min,Gao Dan-Jun,Zhong Hong-Fei,
赵晓鹏
,高秀敏,郜丹军,钟鸿飞

物理学报 , 2002,
Abstract: Considering the mass effect and the short-range interaction of multi-particles, we conducted a molecular dynamic simulation of the structural evolution features of electro-rheological (ER) fluids based upon the equivalent conduction model. We also devised and constructed an equipment, then observed the Poiseuille flow. The results of the experiment were compared with those of simulation. The conclusion is that, when the mass effect is considered, the peak-value of the changing velocity in transition zone decreases, and the period to form the plug zone prolongs. The effect becomes remarkable with the increasing particles' mass and the width of the plug zone. The Poiseuille flow observed in the experiment is in accord with the simulation. The particles clinging to the electrodes are stationary, which testifies the prophecy (particles clinging to the electrodes are stationary).
Modeling of Magnetoelectric Interaction in Magnetostrictive-Piezoelectric Composites  [PDF]
M. I. Bichurin,V. M. Petrov
Advances in Condensed Matter Physics , 2012, DOI: 10.1155/2012/798310
Abstract: The paper dwells on the theoretical modeling of magnetoelectric (ME) effect in layered and bulk composites based on magnetostrictive and piezoelectric materials. Our analysis rests on the simultaneous solution of elastodynamic or elastostatic and electro/magnetostatic equations. The expressions for ME coefficients as the functions of material parameters and volume fractions of components are obtained. Longitudinal, transverse, and in-plane cases are considered. The use of the offered model has allowed to present the ME effect in ferrite cobalt-barium titanate, ferrite cobalt-PZT, ferrite nickel-PZT, and lanthanum strontium manganite-PZT composites adequately. 1. Introduction The magnetoelectric (ME) effect in a material consists in inducing the electric polarization in an applied magnetic field, or vice versa, inducing the magnetization in an applied electric field. The effect was first observed in antiferromagnetic Cr2O3 with a room temperature ME voltage coefficient of 20?mV/cm?Oe [1]. Using magnetostrictive-piezoelectric composites gives rise to an enhancement of ME effects [2, 3]. A composite is expected to be magnetoelectric since the ME coupling is the product of the magnetostrictive deformation and the piezoelectric field generation [4–6]. The ME voltage coefficient where and are the applied magnetic and induced electric AC fields, correspondingly. Lead zirconate titanate- (PZT-) ferrite and PZT-Terfenol-D are the most studied composites to date [7, 8]. One of largest ME voltage coefficients of 500?V/(cm·Oe) was reported recently for a high permeability magnetostrictive piezofiber laminate [9]. The thorough investigation of ME materials is stipulated by potential application for novel devices. In our earlier works, ME effect has been studied for low-frequency, electromechanical resonance (EMR) and magnetic resonance (FMR) regions. In addition, we have first studied ME interaction at the coincidence of EMR and FMR, that is, magneto-acoustic resonance (MAR). In this paper, we discuss detailed mathematical modeling approaches that are used to describe the dynamic behavior of ME coupling in magnetostrictive-piezoelectric composites at low-frequencies and in EMR region. Expressions for ME coefficients are obtained using the solution of elastostatic/elastodynamic and electrostatic/magnetostatic equations. The ME voltage coefficients are estimated from the known material parameters. The basic methods developed for decreasing the resonance frequencies are analyzed. 2. Modeling of Magnetoelectric Effect in Low-Frequency Region 2.1. Symmetric Layered
Design and Properties of a scanning EMR probe Microscope  [PDF]
S. A. Solin
Physics , 2006,
Abstract: The design, fabrication, and predicted performance of a new type of magnetic scanning probe microscope based on the newly discovered phenomenon of extraordinary magnetoresistance (EMR) is described. It is shown that the new probe should advance the state of the art of both sensitivity and spatial resolution by an order of magnitude or more.
New pure shear acoustic surface waves guided by cuts in magneto-electro-elastic materials  [PDF]
Arman Melkumyan
Physics , 2006,
Abstract: It is shown that new pure shear acoustic surface waves with five different velocities can be guided by stress free plane cuts with different magneto-electrical properties in magneto-electro-elastic materials. The possibility for the surface waves to be guided by a cut in pairs, which is reported in this paper, is new in magneto-electro-elastic materials and has no counterpart in piezoelectric materials. The five velocities of propagation of the surface waves are obtained in explicit forms. It is shown that the possibility for the surface waves to be guided in pairs disappears and the number of surface waves decreases from 5 to 1 if the magneto-electro-elastic material is changed to a piezoelectric material.
New pure shear elastic surface waves in magneto-electro-elastic half-space  [PDF]
Arman Melkumyan
Physics , 2006,
Abstract: Pure shear surface waves guided by the free surface of a magneto-electro-elastic material are investigated. Three surface waves are obtained for various magneto-electrical conditions on the free surface of the magneto-electro-elastic half-space. The velocities of propagation and the existence conditions for each of these waves are obtained in explicit exact form.
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