磁悬浮框架飞轮磁轴承技术研究与发展现状

对磁悬浮框架飞轮(MSGFW)和高精度磁轴承研究现状及其未来发展进行了详细阐述。根据转子悬浮力类型，将磁悬浮框架飞轮分为磁阻力构型、洛伦兹力构型和混合力构型，并结合三种构型论述了国内外框架飞轮的发展过程。在此基础上，对球面磁阻力磁轴承和洛伦兹力磁轴承进行了详细介绍，并结合磁路图分析其工作原理，比较了同类磁轴承的优劣。展望了磁悬浮框架飞轮与高精度磁轴承的未来发展方向，指出高动态响应检控共位平动球面磁阻力磁轴承，标准磁悬浮动量球和磁悬浮控制敏感球是磁悬浮框架飞轮的研究重点。     

基于遗传算法的地磁匹配搜索策略

为降低导航成本,提出仅利用磁测计和里程计的地磁场匹配定位方法.为解决搜索空间过大的问题,提出以遗传算法在匹配区域搜索可能路径的方法.该方法以相关性度量作为适应度函数,交叉与变异仅针对点列的相对关系完成,提出用局部适应度函数自适应调整交叉概率与变异概率.仿真结果表明,该方法可以有效完成地磁匹配导航中任意形状路径的匹配.     

人工辅助心脏用永磁轴承盘式无刷电机设计与研究

介绍了一种应用于人工辅助心脏的永磁轴承无位置传感器盘式无刷直流电动机的结构与电磁场仿真计算方法及结果,并对其温度场进行仿真计算。该电机体积重量小,无机械轴承,避免了对血液的破坏,且运行安全可靠。     

基于谱插值和奇异值差分谱的滚动轴承静电监测信号去噪方法

采用静电传感器进行滚动轴承故障监测实验研究.针对滚动轴承静电监测中各种强噪声、故障特征难以提取的问题,提出了基于谱插值和奇异值差分谱的联合去噪方法.首先采用谱插值抑制工频干扰,然后将所得信号构造Hankel矩阵,求取奇异值差分谱并自动确定有用分量个数,最后重构信号.仿真和实验结果表明:仅采用奇异值差分谱或者小波去噪方法,无法从含有强工频干扰的信号中提取有用成分;所提出的方法相比较谱插值和小波去噪方法能够凸显早期故障特征频率.     

中心承力筒数控加工工艺

通过制定合理的数控加工工艺方案,实现了中心承力筒的数控加工,有效保证了孔的加工精度和

表面质量,提高了零件的加工效率。通过在5 轴联动数控加工中心上实际加工,证明该数控加工工艺切实可

行。

     

最大熵磁共振成象理论

由于在实际磁共振成象系统中，只能得到有限的频谱数据，利用传统的ＦＦＴ方法重建磁共振图象，将导致截断的伪影和低的分辨率。本文提出了一种基于ＡＲ模型的最大熵磁共振成象算法，利用ＡＲ模型外推未知频谱数据，替代了ＦＦＴ方法的填零法重建，并利用了ＢＵＲＧ算法中的ＡＲ模型参数计算的有效性，不仅消除了截断伪影、抑制噪声、提高了分辨率，而且使重建时间与ＦＦＴ方法相当，完全适用于临床应用。     

Solar cycle and latitude dependence of high-beta suprathermal plasma conditions in interplanetary space between 1.3 and 5.4 AU

The analysis of energetic particles and magnetic field measurements from the Ulysses spacecraft has shown that in a series of events, the energy density contained in the suprathermal tail particle distribution is comparable to or larger than that of the magnetic field, creating conditions of high-beta plasma. In this work we analyze periods of high-beta suprathermal plasma occurrences (β_ep > 1) in interplanetary space, using the ratio (β_ep) of the energetic particle (20 keV to ∼5 MeV) and magnetic field energy densities from measurements covering the entire Ulysses mission lifetime (1990–2009) in order to reveal new or to reconfirm some recently defined interesting characteristics. The main key-results of the work are summarized as follows: (i) we verify that high-beta events are detected within well identified regions corresponding mainly to the vicinity of shock surfaces and magnetic structures, and associated with energetic particle intensity enhancements due to (a) reacceleration at shock-fronts and (b) unusually large magnetic field depressions. (ii) We define three considerable features for the high-beta events, concentrated on the next points: (a) there is an appreciable solar-activity influence on the high-beta events, during the maximum and middle solar-cycle phase, (b) the annual peak magnitude and the number of occurrences of high events are well correlated with the sunspot number, (c) the high-beta suprathermal plasma events present a spatial distribution in heliographic latitudes (HL) up to ∼±80°, and a specific important concentration on the low (−25° ? HL < −6°, 6° < HL ? 25°) and median (−45° ? HL < −25°, 25° < HL ? 45°) latitudes. We also reconfirm by a statistical analysis the results of Marhavilas and Sarris (2011), that the high-beta suprathermal plasma (β_ep > 1) events are characterized by a very large parameter β_ep (up to 1732.5), a great total duration (406 days) and a large percentage of the Ulysses-mission lifetime (which is equal to 6.34% of the total duration with usable measurements, and 11.3% of the duration in presence of suprathermal particles events).     

A heuristic derivation of an improved analytical theory for perpendicular diffusion of charged particles

A heuristic derivation of an improved nonlinear guiding center theory for perpendicular diffusion of charged particles is presented. This new derivation complements previous work which is based on an indirect solution of the Fokker–Planck equation. The new derivation confirms the improved theory for diffusion of charged particles and makes the validity of the theory plausible.     

电磁轴承及其应用 第二部分 电磁轴承工作原理和设计要点

第一部分简述了电磁轴承及电传动技术在国内外的发展及其在航空领域的应用前景.第二部分介绍了燃气涡轮发动机用电磁轴承的设计要求和主要设计问题及其解决方法.     

某型飞机平尾管梁轴承轴向间隙问题的分析

分析某型飞机平尾管梁安装轴承轴向间隙产生的原因及轴承间隙加大对飞机使用的影响，并提出了排故和设计改进措施。