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1.
本文分析了稀土永磁同步电机直轴电枢反应。主要分析了负载时由直轴电枢反应引起的漏磁通,其中包括合群漏磁和“曾氏漏磁”,并推导了这些漏磁通的定性计算公式,完善了永磁同步电机的电磁设计计算。  相似文献   
2.
《Journal of Natural History》2012,46(32):2997-3011
Species in the colonial subfamily Polyzoinae demonstrate a range of colonial organisations. Colony form appears to be significant at species level but not to have a phylogenetic significance at genus level, species in both speciose genera Polyandrocarpa and Stolonica having colonies either of separate zooids joined by basal stolons or they have completely embedded zooids. Polyandrocarpa and Oculinaria have characters that indicate a close affinity with solitary styelinid genera Polycarpa and Cnemidocarpa, respectively, and suggest that the subfamily is polyphyletic. Stolonica and other genera in the Polyzoinae, in which zooids and body organs are small and simplified, also appear to be polyphyletic assemblages of taxa but their relationships are masked by parallel evolution and convergence associated with replication and colony development. Previously overlooked in the siphonal linings of Oculinaria australis are overlapping spines possibly analagous with the rounded scales (see Kott 1985 Kott, P. 1985. The Australian Ascidiacea Pt 1, Phlebobranchia and Stolidobranchia.. Memoirs of the Queensland Museum, 23: 1440.  [Google Scholar]) in siphons of Stolonica diptycha (Hartmeyer, 1919 Hartmeyer, R. 1919. Ascidien. In: Results of Dr E. Mjöberg's Swedish scientific expeditions to Australia 1910–13.. Kungliga Svenska Vetenskapsakademiens Handlingar, 60(4): 1150.  [Google Scholar]). Similar armature appears to be significant at species level in Pyuridae and occasionally Styelidae and it may be further evidence of polyphyly in Polyzoinae. One of the seven species reported (Stolonica vermiculata sp. nov. from Lord Howe I.) is new; one (Oculinaria australis from a range of locations around the southern half of the Australian continent) is recorded often; and five (Polyandrocarpa colemani known only from the Queensland–New South Wales border, P. colligata, Stolonica styeliformis and S. duploplicata all from the tropical western Pacific and Botryllocarpa elongata from Tasmania) are seldom recorded.  相似文献   
3.
建立了一维固体电枢溶化波烧蚀计算模型,采用有限差分法计算电磁场的扩散,得到了溶化波烧蚀速度和烧蚀深度的变化特性。数值计算结果表明,暴露于强磁场环境下的烧蚀表面产生较高的磁场梯度,电流密度集中在烧蚀表面,焦耳热的剧增导致电枢发生烧蚀。将伪烧蚀算法应用于有限差分的计算,证实其不相容。计算结果对溶化波烧蚀问题的理论及试验研究有重要的指导作用。  相似文献   
4.
永磁同步电机的电枢反应电抗和同步电抗   总被引:1,自引:0,他引:1  
蒋文选 《贵州科学》1998,16(1):52-58
分析永磁同步电机的电枢反应电抗、同步电抗、定子漏抗、齿顶互感漏抗和合群漏抗,导出了齿顶互感漏抗和合群漏抗的计算公式,进一步完善了永磁同步电机的电磁设计参数的计算。  相似文献   
5.
A possible two-dimensional viscous magnetohydrodynamics (MHD) model is applied to investigating the plasma armature in a railgun. The space-time conservation element and solution element (CE/SE) method for solving the coupled Navier-Stokes equations and Maxwell equations was devised. The distributions of physical parameters of the plasma may thus be evaluated. The results show that extremely high pressure can always be observed ahead of the projectile, and the Lorentz force is the main propulsion. The distribution of temperature is in a good agreement with the results predicted by the law of radiation at the boundaries. Due to convection, the circulation patterns of velocity are evident in both the cases considering inviscid and viscous effect. Furthermore, the velocity and acceleration oscillate over time until a new steady state is achieved. This model efficiently captures the salient features of the physical phenomena, and contributes to further studies of MHD problems in plasma armature. Supported by the National Natural Science Foundation of China (Grant No. 10672080)  相似文献   
6.
利用8031实现电枢电流控制的卷取机恒张力控制,同时研究了卷径滤波,动态电流滤波的必要性和实现方法,该模型已成功地在工厂使用。  相似文献   
7.
根据麦克斯韦方程和热传导方程,建立了电磁导轨炮导轨、电枢二维非稳态电磁场和温度场的计算模型,运用有限差分P-R算法进行了耦合计算.数值结果显示了导轨及固体电枢内部磁感强度、电流密度和温度分布;同时由于电枢运动,电流趋向导体表面流动并在电枢尾部与轨道接触面上趋于集中,使电枢尾部焦耳热剧增导致出现高温烧蚀.研究工作为改进电枢设计,避免电枢在快速滑动中发生转捩并抑制烧蚀提供了理论依据.  相似文献   
8.
针对机械振动对机器的性能和寿命的影响,对所研制的机械式振动保护开关进行了工作原理及结构的分析,为在线性状态振动监测提出了一种新方法。  相似文献   
9.
阐述了直流电机固有参数的测量对于直流调速系统设计的重要意义,给出了直流电机固有参数的测量方法和计算公式  相似文献   
10.
 中西医整合发展态势愈加明确,多学科交叉融合趋势引领医学向更深层次、更高水平发展。针灸是中医学的重要组成部分,作为中医学的先导学科,针灸器具和技术的改革创新将成为促进中医针灸现代化的关键。从耳迷走神经刺激仪的研发看整合针灸医学的发展趋势,“古术新知”的核心就是用现代科技知识推动中医药的发展。  相似文献   
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