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421.
THE EDDY LOSSES OF A MAGNETIC THRUST BEARING 总被引:1,自引:0,他引:1
Accurate calculations of losses associated with the operation of magnetic bearings are particularly important for high speed applications where the rotor losses are expected to be large and for some particular applications where even low power losses will be critical. Power losses in the magnetic thrust bearing is often neglected, but if there is misaligned in the rotor and bearing, the magnetic field in the thrust bearing is no longer axisymmetric one, or the dynamic control current in the winding is time dependent one, eddy currents are caused to flow inside the conducting material, then the power losses are very important for magnetic bearing design. This paper presents an analytical model of a thrust magnetic bearing, and the magnetic fields, forces and losses of thrust magnetic bearing are calculated. In the calculations the frequency of dynamic control current is up to 1 000 Hz, rotating speed is from 60 rpm to 1 200 rpm, and the non-linearity of material is also taken into consideration. The results shows that if the magnetic field is not saturation, the eddy losses is proportional to dynamic control current frequency and a square function of dynamic control current, and also 5/2 power function of shafts speed. 相似文献
422.
本文以包括钢轨、轨枕、道床在内的轨道作为双层结构模型。分析了轨道在移动简谐荷载作用下的动力响应,并与定点荷载作用的结果作了比较,指出了二者的差异,并建议在分析高速铁路轨道动力响应时考虑到车速度的影响,以及转向架邻轮和阻尼的作用。 相似文献
423.
A new local search method with hybrid neighborhood for Job shop scheduling problem is developed. The proposed hybrid neighborhood is not only efficient in local search, but also can help overcome entrapments while search procedure get trapped at local optima and carry the search to areas of the feasible set with better prospect. New strategies used for breaking out of entrapments are presented and they are helpful for the procedure to improve local optima. A performance comparison of the proposed method with some best-performing algorithms on all 10-job, 10-machine benchmark problems and the other two problems generated by Fisher and Thompson ( ie. , FT6 and FT20) is made. The experiment results show the better optimal performance of the proposed algorithm. 相似文献
424.
汤康民 《西南交通大学学报》1993,(3)
本文提出了高承台桥台桩基础设计中关于Q_q和M_f的计算公式,它比现有《桥规》公式要简单得多。 相似文献
425.
According to the researches on theoretic basis in part I of the paper,the spanning tree algorithms solving the maximum independent set both in even network and in odd network have been developed in this part,part Ⅱ of the paper.The algorithms trans form first the general network into the pair sets network,and then decompose the pair sets network into a series of pair subsets by use of the characteristic of maximum flow passing through the pair sets network.As for the even network,the algorithm requires only one time of trans formation and decomposition,the maximum independent set can be gained without any iteration processes,and the time complexity of the algorithm is within the bound of O(|V|^3).However,as for the odd network,the algorithm consists of two stages.In the first stage,the general odd network is transformed and decomposed into the pseudo-negative envelope graphs and generalized reverse pseudo-negative envelope graphs alternately distributed at first;then the algorithm turns to the second stage,searching for the negative envelope graphs within the pseudo-negative envelope graphs only.Each time as a negative envelope graphhas been found.renew the pair sets network by iteration at once.and then tum back to the first stage.So both stages form a circulation process up to the optimum.Two available methods,the adjusting search and the picking-off search are specially developed to deal with the problems resulted from the odd network.Both of them link up with each other harmoniously and are embedded together in the algorithm.Analysis and study indicate that the time complexity of this algorithm is within the bound of O(|V|^5). 相似文献
426.
Endothelialcells (ECs)functionasthebarrierofthebrainandrelatetothesecretionofsomeendo crines.Theirdysfunctioniscloselyrelatedtotheoccurrenceanddevelopmentofcerebralvasculardiseases[1] .DamagetoECsisthefirstsignandaba sicfactorofcerebralischemia .Therefore ,… 相似文献
427.
青岛远洋船员学院学报编辑部 《青岛远洋船员学院学报》2000,21(1):55-58
大编辑学是揭示编辑学与其它学科间运动关系的学说。大编辑学概念是大编辑学观念的逻辑概括,它由现代编辑工作实践产生,由大编辑学的编辑体制所体现。大编辑学机制充分体现事物运动的规律性,是最适于高校学报这种非产业化编辑体系特点的。学报编辑体制必须适应大编辑学机制。 相似文献
428.
SATA GmbH & Co.KG 《汽车维修与保养》2012,(6):108-108
拥有超过100年历史的德国萨塔公司,其著名品牌SATA(萨塔)自1988年进入中国市场以来,一直坚持高端定位,以人性化和创新领先的技术和设计、优越的品质和周到的服务在广大OEM汽车制造厂4S店、汽车维修厂和广大漆工朋友中树立了良好的品牌形象,在喷涂行业内赢得了极高的信誉。随着德国萨塔品牌知名度的不断提升,一些不法厂商制造和销售假冒SATA喷枪意图鱼目混珠,混淆消费者视听,以只有外观相似但质量差 相似文献
429.
标准化是城市轨道交通实现一体化、网络化的基础和前提。介绍了城市轨道交通客运服务的内容,从列车运营、票制设定、车辆设施、站厅环境、信息服务以及主管部门等方面总结了纽约、伦敦、巴黎和东京等主要大城市的地铁客运服务方面的成果和经验。指出服务标准化是保证和提高轨道交通客运服务水平的必要手段,提出制定我国地铁客运服务标准化的建议。 相似文献
430.
Research Group 《河北交通科技》2008,(3)
分析了对大学生开展社会主义核心价值体系教育的意义,指出了高校社会主义核心价值体系教育的主要内容,提出了高等学校开展社会主义核心价值体系教育的保障措施。 相似文献