一种新型绝对式多磁极磁电编码器

提出了一种绝对式多磁极磁电编码器的实现方案,采用线性霍尔和开关霍尔组合使用的方式去测量2组极对数互质的多磁极永磁体之间的位置关系和绝对角度。结合现有的磁电编码器成果,确定了磁电编码器的绝对角度计算方案。通过理论分析、作图分析以及与理论推导结合的方式确定了永磁体磁极的数量关系、霍尔元件的布置方式以及具体的磁极识别过程。并利用MATLAB软件模拟磁电编码器的工作过程,证明了绝对角度计算方案的可行性。     

多铁性复合材料动态耦合响应的有限元分析

多铁性材料在实际应用中往往需要考虑多场动态耦合效应。为研究磁电多铁性复合材料的动态耦合效应及其界面的影响,建立了在动态激励下磁电耦合响应的有限元分析模型,其中采用内聚力模型单元模拟压电和压磁材料间界面,以表征其刚度和强度。对多个算例进行了磁电动态耦合响应分析,考察了界面刚度以及边界条件对动态磁电耦合响应的影响。结果显示,界面刚度和边界约束对磁电多铁性复合材料的动态耦合效应有较大影响,界面刚度越大,耦合效应越强。     

Magneto hydrodynamic buoyant convection of an electrically conducting fluid in a tilted square cavity

A numerical investigation of steady‐natural convection of an electrically conducting fluid, enclosed in a tilted square cavity, subjected to a uniform magnetic field applied perpendicular to the plane of cavity is presented. A comprehensive understanding of the effects of controlling parameters on the flow and heat transfer is delineated for a wide range of parameters. Correlations for the average Nusselt number are presented specifically for fluids with low Prandtl numbers pertaining to liquid metals. It is made known that when the applied magnetic field is perpendicular to the plane of the cavity, the magneto hydrodynamic drag is greatest as compared to any other direction of the applied magnetic field and consequently the suppression of convection is also at its maximum, irrespective of all other controlling parameters. 8 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20326     

汽车剪切阀式磁流变减振器的阻尼特性研究

介绍了汽车磁流变减振器的定义及其减振控制过程,描述了汽车磁流变减振器的基本工作模式;着重阐述了汽车剪切阀式磁流变减振器的工作原理,分析了汽车剪切阀式磁流变减振器的阻尼特性,揭示了汽车剪切阀式磁流变减振器阻尼力的构成及其相互关系,提出了实现可调阻尼控制的关键问题。     

永磁同步发电机极限电磁功率的分析计算

永磁同步发电机的极限电磁功率是发电机的重要性能指标,是选择发电机类型重要的依据之一。文章推导了确定永磁同步发电机极限电磁功率 的计算公式,并对不同类型转子的发电机极限电磁功率进行了分析计算,为正确选择发电机的形式提供了重要的依据。     

Sequential Magneto-Actuated and Optics-Triggered Biomicrorobots for Targeted Cancer Therapy

Micro/nanorobots have the potential to be remotely propelled and manipulated in complex biological fluid and organ tissue. However, the combination of the sophisticated physiological barriers, remote-controlled navigation, real-time motion tracking, and diagnostic/therapeutic effects are tremendous challenges for application and translation. An unique sequential magneto-actuated and optics-triggered biomicrorobot (AI microrobot) for actively targeted cancer treatment is prepared. The AI microrobot consists of two components, magnetospirillum magneticum (AMB-1), providing the ability to autonomously swim toward the tumor site via internal hypoxia-driven effects and an external applied magnetic field, and indocyanine green nanoparticles, acting as a fluorescence imaging agent and photothermal therapy. The AI microrobots are tracked in vivo by fluorescence and magnetic resonance imaging. It is found that the AI microrobots can sequentially migrate to the hypoxic internal area of tumors and then effectively eradicate solid tumors through photothermal therapy under NIR laser irradiation. The sequential magneto-actuated and optics-triggered AI microrobots platform described here presents a bioinspired strategy toward remotely controlled propulsion, actively targeted cargo delivery, and satisfactory therapeutic performance in the circulatory system.     

磁流变胶泥流变学特性测试装置研究

现有的商用磁流变仪不能满足磁流变胶泥高剪切率和高剪切应力测试的要求,对比设计了密闭圆筒剪切模式的磁流变胶泥流变特性测试装置。在完成总体结构设计的基础上,建立了剪切通道励磁磁路的分析模型,得出了剪切通道磁场强度与励磁电流的关系,并进行了有限元仿真验证。考虑转子与外筒存在倾斜,建立了磁流变胶泥转矩传递的力学模型,得到了转子与外筒倾斜角度与传递转矩误差的理论关系。完成了测量装置样机的制作,开展了磁流变胶泥流变学特性测试,在低剪切率下测量装置测试结果与安东帕流变仪测试结果能较好吻合。研究表明,测试装置能够实现25 000 s-1的高剪切率和200 k Pa的高剪切应力测试。     

基于巨磁阻的金融机具传感器

与传统的磁敏传感器比较，巨磁阻传感器具有灵敏度高、可靠性好、测量范围宽、体积小、价格低等优点。介绍了巨磁阻传感器的工作原理和输出特性。以巨磁阻传感器为磁敏元件，研发成功国家专利产品点钞机的巨磁阻传感器。实践表明，采用巨磁阻传感器可以检测到各国不同纸币上的微小磁信号。     

基于磁阻芯片和MSP430单片机的电子罗盘设计

电子罗盘是一种获取载体姿态航向的设备。介绍磁电子罗盘的工作原理及其具体实现,利用Honeywell的HMC1022双轴磁阻传感器设计了一种小型化的电子罗盘,利用AD623高精密度放大器作信道调理电路,利用低功耗的MSP430微处理器完成A／D转换、方位角计算以及数字化输出等工作。采用置位／复位电路配合微处理器有效解决了传感器失调和漂移的影响。实验表明该系统具有良好的获取航向能力,且运行稳定,功耗低,误差小于1°。     

应用PMO提高低碳钢φ300 mm连铸圆坯心部质量

在芜湖新兴φ300 mm圆坯连铸机上引入脉冲磁致振荡技术(Pulsed Magneto-Oscillation, 简称PMO)以提高铸坯心部质量,探索了PMO电源参数和连铸机拉速对低碳20钢连铸坯质量的影响。结果表明,采用合适的PMO参数处理可显著降低20钢径向碳分布,碳极差比对比坯平均降低50%,且效果稳定。不采用PMO技术,将连铸机拉速从0.75 m/min提高至0.85 m/min后,对比坯低倍不合格,碳极差达到0.12%。采用PMO技术的铸坯仍保持了较好的心部质量,碳极差降低至0.03%,生产效率提高13.3%。