磁悬浮轴承-转子系统的分岔与混沌特性

研究磁悬浮轴承-转子系统主共振情形时的非线性动力学行为。由Taylor级数展开得到非线性电磁力的表达式。用Lung-Kutta法计算系统的运动响应。借助Poincare影射和Lyapunov指数对系统的运动形态进行分析。结果发现了在主共振情形下系统中由环面破裂产生的混沌现象及之后的由倍周期分岔导致的混沌现象。     

基于磁晶格的机械构件线应变在线检测技术

介绍了基于等间距磁晶格在线检测机械构件线应变的基本原理；提出了检测信号处理与波形转换方法；将机械构件线应变的检测转换为对检测信号波形高低电平持续时间的计测，并推导出时间计测值与构件线应变之间的数学关系式。为实现机械构件线应变的非接触式实时在线定量检测提供新的技术与方法。     

On the estimation variance for the specific Euler–Poincaré characteristic of random networks

The factors that determine the local magnetic properties of FeCo/SiO₂ nanocomposite powders and films have been analysed by electron energy‐loss spectroscopy (EELS) and transmission electron microscopy (TEM). Attention has been given to the chemical composition, the local electronic structure and the atomic arrangement. The results show that the nanoparticles from sol‐gel prepared powders are generally Fe‐rich, whereas they are Co‐rich in sol‐gel prepared films. In addition, a subnanometre oxide layer at the surface of the FeCo nanoparticles has been clearly observed in the powder sample. It is found that the magnetic moment should be partly governed by alloying effects. Numerical values of the near‐surface magnetic moment have been obtained using the ab‐initio layer‐KKR method. These values should be helpful in understanding the layer‐by‐layer changes of the white line ratio close to the surface of the nanoparticles.     

基于神经网络的磁悬浮球自适应控制器

建立了磁悬浮球系统的数学模型，讨论了系统的刚度阻尼和控制系统之间的关系。利用神经网络的学习功能在传统比例积分微分（PID）控制器的基础上构建了一种自适应PID控制器。用于磁悬浮球控制系统。实验结果表明，控制器结构简单，易于工程实现，可以实现磁悬浮球的稳定悬浮，并且系统具有快速响应性和良好的抗干扰性。     

无传感器磁轴承转子位置检测与研究

主要研究一种无传感器磁轴承转子位置自检测的方法,该方法不需要专用的位移传感器。由于线圈的电感是转子位移的函数,故其两端的电压也为转子位移的函数。在磁轴承系统的线性功率放大器的输入端注入一高频信号作为转子位置的测试信号,将线圈端电压经过谐振电路来提取含有位置信号的高频电压信号,再将电压信号进行精密半波整流后得到脉动的直流信号,最后通过低通滤波器得到平滑的转子位移直流信号,由PID控制器转换为转子位移的控制信号。仿真试验证明了该方法的可行性。     

变压器一次侧匝间短路参数与特征分析

变压器作为电力系统中传送电能的关键设备,其一次侧发生匝间短路产生的故障电流将对变压器本身、发电机和电网产生较大冲击,影响电力系统的电能质量和稳定性。针对变压器匝间短路电流计算问题,通过试验变压器的稳态和暂态实测数据在三维有限元软件FLUX中建立仿真模型,基于此模型,进行不同匝数和位置的匝间故障仿真。同时考虑绕组自感、互感与短路匝数及位置的关系,提出了一种根据回路电压方程组计算故障电流的方法。与FLUX得到的仿真结果对比,验证了计算方法的正确性。最后通过FLUX软件的后处理功能对比研究了变压器发生不同类型匝间短路后的内部电磁场变化规律。     

基于模糊综合评价的交易结算偏差电量处理方法

随着电力市场改革不断深化,市场化电力交易愈加复杂,交易结算偏差电量需要更加规范化的处置,因此,提出了一种基于模糊综合评价理论的偏差电量处理方法。该方法基于模糊综合评价方法,综合考虑每笔交易的交易类型、交易周期、交易电量和交易电价4项重要指标,依托业务人员工作经验运用层次分析法设定各项指标权重及交易类型和交易周期隶属度函数,最终确定每笔交易的综合评价得分,以得分为依据分摊偏差电量。最后通过算例分析验证了该方法的有效性和实用性。     

超高速数控精密磨床磁浮轴承主轴单元设计

本文介绍了磁浮轴承的优点，并提出了磁浮轴承作为磨床主轴轴承的设计方法。同时，首次提出了超高速数控精密外圆磨床磁浮轴承主轴单元设计方法和设计过程。并针对一台300m／s超高速数控精密外圆磨床磁浮轴承主轴单元进行了设计。经过实验证明，提出的设计方法是正确的。同时，应用了该技术的超高速数控精密磨床，虽然初期投资成本高，但其优越的使用性能使其综合效益高。     

Direct current bias applied to hot flame diamond deposition produces smooth low friction coatings

As-deposited diamond coatings generally have a high surface roughness which results in a high friction coefficient and extensive wear of the counter material in sliding contact. Therefore several methods for smoothening diamond coatings have been proposed, such as laser polishing, molten metal etching, thermochemical polishing and mechanical polishing. All these methods have some disadvantage e.g. long processing time or high processing temperature. Furthermore, they are all post-deposition treatments i.e. the manufacture of these coatings requires at least two processing steps, deposition and smoothening. With the present method which combines d.c. bias with hot flame diamond deposition, a smooth diamond surface is produced during the actual growth of the film. No post-deposition treatment is necessary. The surface roughness is not dependent on the coating thickness which means that thick coatings with smooth surface can be produced. In fact, the method has a smoothening effect, i.e. rough surfaces can be made smooth. The method is comparable to conventional hot flame deposition of diamond as to growth rate and cost of producing the coatings. The coatings have a nano-crystalline structure and a surface roughness of Ra = 25 nm, and result in a friction coefficient of 0.1 or less in dry sliding and about 0.05 in water-lubricated sliding against cemented carbide. Their wear resistance is virtually the same as that of conventional diamond films.     

磁场处理降低残余应力过程中应力应变的测量

在前期研究强脉冲磁场处理与低频交变磁场处理降低残余应力，并取得显著效果的基础上，进一步在磁场处理低碳钢制作的试样（包括单向拉伸试样和无应力试样）时，对应力应变过程进行测量。结果表明，单向拉伸试样经过低频交变磁场处理后，材料内部残余应力在下降的趋势，而且处理过程中具有磁振动现象。无应力试样与单向拉伸试验在磁场中，随场强的增加，试样中的应变逐渐由正值变为负值。克应力试验在不同频率的交变磁场中的应变各不