一种基于非线性弹簧新的球轴承接触有限元模型

基于Hertz接触理论和非线性弹簧模型提出了一种新的球轴承有限元建模方法。所提方法在沟道圆心间设置非线性弹簧,采用Hertz理论建立非线性弹簧力与变形关系,通过非线性弹簧长度判断球体是否与套圈发生接触。数值算例表明该方法人计算结果与Hertz理论解一致,说明该方法可行有效,并且此方法精度较高。     

椭圆偏振光谱中的主角测量条件分析

对椭圆偏振光谱中的主角测量条件进行了分析。当入射角等于主角 θp 时 ,椭偏参数的相位为 90°,据此给出了当材料的介电函数已知时对θp 进行数值和解析计算的公式和方法 ,并可相应地计算出椭偏参数的幅值 ρp0 。在θp 入射角下测量可获得较高的数据精度。主角条件下椭偏参数 ρp0 及其相位Δp 的实验测量结果与计算值符合得很好。本工作给出的计算公式和方法可在其他光谱实验中获得应用。     

Co-Ni/FeMn双层膜中磁化强度对交换偏置的影响

固定CoNiFeMn双层膜中反铁磁层的厚度,改变CoNi铁磁层的成分来调节磁化强度,从而研究铁磁层的饱和磁化强度对CoNiFeMn双层膜中交换偏置的影响.研究表明,CoNiFeMn界面的交换耦合能U不是一个常量,而是随(MFM)12的增加而线性增加.其原因是铁磁层磁矩通过界面相互作用在反铁磁层中形成的局域交换磁场,在磁场冷却时影响反铁磁层的自旋结构或磁畴结构及双层膜中的交换偏置 关键词： 交换偏置 磁化强度     

Spin-Wave Modes in Exchange-Coupled FePt/FeNi Bilayer Films

A simple magnetic modulation structure of the exchange-coupling FePt/FeNi bilayer film is fabricated and studied for its magnetization dynamics using time-resolved magneto-optical polar Kerr spectroscopy. It is found that two spin-wave modes can be excited. One is fixed at -3.2 GHz in frequency for any external field and may serve as a frequency-stabilized spin-wave filter, while the other is external field dependent. In contrast, only the external field-dependent mode is excited in single-layer FeNi, supporting the localized origin of the mode at -3.2 GHz, which is confined to a thin exchange-coupling region. The other external field-dependent mode in frequency is attributed to the Kittel mode.     

均布扭力矩作用下圆截面圆环的稳定性分析

圆环在均布扭力矩作用下的变形特殊且容易发生跳跃,不考虑稳定性而得到的一些结论将可能不存在。本文利用最小势能原理导出圆截面圆环在均布扭力矩作用下的平衡路径,并根据系统稳定性的能量判据,对圆环的平衡稳定性、变形与运动过程进行分析,最后得到稳定平衡状态下圆环横截面上的内力最大值。     

The subwavelength tuned magneto-optical Kerr effect in L1_0-FePt films with perpendicular magnetic anisotropy

For L10-FePt films with strong perpendicular anisotropy covered by arrays of hexagonal close-packed polystyrene spheres(PSSs),fine structures are observed in magneto-optical Kerr rotation spectra in the visible spectral range.The reflection minima are found to be located at the same wavelengths as the Kerr rotation peaks.The Kerr rotation enhancement is attributed to the excitation of both the surface plasmon polariton in the dielectric PSS/metal interface and the guide waves(guide mode)in the PSS array.The two-dimensional PSSs/SiO2/FePt system exhibiting a tunable magneto-optical Kerr effect and a high perpendicular magnetic anisotropy will be helpful for designing and fabricating magneto-optics devices.     

基于元模型与聚类算法的设计空间减缩策略及工程应用

提出了一种基于元模型建模和聚类算法的设计空间减缩策略,能直接将设计空间减小到相对小的子空间。建议的方法分为三步:首先,进行低精度元模型建模,其次重新设计样本点并基于元模型求解样本点函数值和导数,应用最短距离层次聚类算法确定样本点聚类数与聚类中心,采用模糊c均值算法完成设计空间划分,生成设计空间子空间;最后,求解子空间目标函数的均值,确定保留子空间,并在保留子空间中对函数进行优化,达到目标函数全局最优解。测试函数和工程算例表明,该方法能够有效减小设计空间。     

Thickness dependence of the anomalous Hall effect in disordered face-centered cubic FePt alloy films

The anomalous Hall effect in disordered face-centered cubic(fcc) FePt alloy films is experimentally studied. The longitudinal resistivity independent term of the anomalous Hall conductivity(AHC) increases and approaches saturation with increasing film thickness. The contribution of side jump scattering is suggested to decrease monotonically with increasing film thickness, which can be ascribed to the variation of the surface scattering with the film thickness. The sign of the skew scattering contribution to the AHC is opposite to that of the intrinsic contribution in the system.