共查询到17条相似文献,搜索用时 43 毫秒
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银包套Bi2223多芯带材局部临界电流的变化对整个长样带材性能的影响 总被引:3,自引:0,他引:3
本文研究了Bi2223高温超导带材在自场和77K温度下,局部临界电流的统计特性对整根长样带材临界电流特性的影响,一般地,超导带材的Ⅰ-Ⅴ特性由标准的幂指数模型参数Ic和n值来描述,并以1μV/cm作为临界电流的判据;通过测量局部带材的临界电流Ⅰ-Ⅴ特性,得到了整根带材的临界电流特性;并通过统计方法,得到了局部带材临界电流分布的高斯几率分布函数,结果表明,带材局部临界电流分布不均匀,局部临界电流的变化对整个带材的临界电流影响很大;并用统计学的方法对长样带材的临界电流性能进行了分析和讨论。 相似文献
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本文研究了30K温区和工频下81芯Bi2223/Ag带材的临界电流特性和没背场下的交流损耗,临界电流是用SQUID磁化法和标准四引法测量;交流损耗理在样品通以正弦电流情况下采用电测法进行测量,结果发现交流损耗随背场的增加而增大,同时与频率的关系是非线性的,并且偏离基于Bean模型所预言的结果;表明30K温区多芯带材Ag基中的涡流损耗的芯间的耦合损耗不可忽略。 相似文献
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Nadia Nibbio Svetlomir Stavrev Bertrand Dutoit 《Physica C: Superconductivity and its Applications》1998,310(1-4):208-212
We have made a software electromagnetic simulation of eddy current effects in Bi(2223)Ag sheathed tapes with applied AC transport current in a broad frequency range. We have used simple models of monocore and multicore tapes. Calculated is the power distribution (W/m3) within the metal sheath using the geometry of real tapes. The numerical simulation is carried out with Finite-element-method software. The paper also describes the influence of the tape cross-sectional architecture and the sheath resistivity on the eddy current loss. 相似文献
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Svetlomir Stavrev Bertrand Dutoit 《Physica C: Superconductivity and its Applications》1998,310(1-4):86-89
The AC self-field loss in Bi(2223)Ag-sheathed tapes with different number of filaments has been measured between 59 and 2500 Hz by means of a dual lock-in amplifier. Due to the wide frequency range of the measurements, we have been able to dissociate quantitatively the different self-field loss contributions: hysteretic, eddy current and resistive loss (near Ic). This is an important advantage compared to single frequency measurements where such loss dissociation is only qualitative. The hysteresis losses of the different tapes fall between Norris' predictions for elliptical and strip cross-section. The relative weight of eddy current loss is found to be inversely proportional to the current ratio—the higher the i, the less is their contribution. Frequency-independent resistive loss due to flux-creep is observed for high currents at low frequencies; this loss becomes quickly negligible with the increasing frequency. 相似文献
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A theoretical model for the angular dependence of the critical current of BSCCO/Ag tapes 总被引:1,自引:0,他引:1
Guo Min Zhang Liang Zhen Lin Li Ye Xiao Yun Jia Yu 《Physica C: Superconductivity and its Applications》2003,390(4):321-324
A theoretical model describing the angular dependence of critical current was proposed based on the critical state model and the effective mass theory. The critical currents of single-tape and a stack of three BSCCO/Ag tapes were measured under DC magnetic fields with different orientations and strength. The comparison of the theoretical and experimental results is presented. 相似文献
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H. Utsunomiya T. Sakai Y. Saito T. Matsuo 《Physica C: Superconductivity and its Applications》1995,250(3-4):340-348
Silver-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox (Bi(2223)) tapes were fabricated by the “oxide-powder-in-tube” technique. After the tapes were shaped and sintered, an additional cold rolling and a re-sintering were applied in order to enhance the critical current density Jc. The influence of the additional rolling conditions (roll diameter, number of passes, lubrication) on the Jc (77 K, 0 T) was made clear. The influence of the sintering conditions (temperature, heating rate) on Jc was also investigated. As for the rolling conditions, a small redundant shear deformation or a small contact angle leads to a good grain alignment, texturing, and a higher Jc value. As for the temperature of the first sintering, 1113 K is superior to 1118 K because of the volume fraction of the Bi(2223) phase. 相似文献