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421.
V. E. Sytnikov P. I. Dolgosheev G. G. Svalov N. V. Polyakova D. I. Belij 《Physica C: Superconductivity and its Applications》1998,310(1-4):387-391
The work presents the basic principles of the multilayer cable conductor design to achieve the maximum current-carrying capacity and the minimum losses in a superconductor and constructive cable elements. The multilayer conductors of two to ten layers are analyzed. The results show that the traditional core design with alternative winding directions from layer to layer is useful only for two-layer conductor. The conductor with more layers must have either the layers wound in one direction but with different pitch lengths or two layer groups wound with different pitch lengths. Only for these cases, the balanced design can be realized and current distribution will be uniform. In such balanced design, the interlayer electrical voltage and as a result, the coupling losses, are absent and interlayer electrical insulation is not needed. The recommendations to achieve the maximum critical current as a function of conductor dimensions are derived. 相似文献
422.
E. Ahmed 《Il Nuovo Cimento D》1991,13(2):151-155
Summary Fluctuations in anisotropic high-temperature superconductors are studied in the presence of antiferromagnetic order. Their
effects on the coherence lengths and the critical fields are studied using perturbation theory.
The author of this paper has agreed to not receive the proofs for correction. 相似文献
423.
F. Abbattista R. Albanese C. Delprete G. Genta R. Gerbaldo G. Ghigo L. Gozzelino E. Mezzetti A. B. Mosolov S. Ronchetti M. Vallino 《Il Nuovo Cimento D》1994,16(12):2087-2094
Summary This paper deals with a comparison of chemical, physical and mechanical characterisation of YBCO samples obtained with Temporary-Liquid-Densification
Melt Growth (TLDMG). Ba2YCu3O7-x
+50% excess BaY2CuO5 pellets were prepared from different Ba-Y-Cu-O system phases, suitable to produce during the heat treatment temporary liquids
at temperatures lower than 1000°C. A mechanical characterisation was performed in zero-field-cooling and field-cooling condition,
showing hysteretic behaviour and creep of the levitation force. Measurements of magnetic hysteresis cycles in low fields and
a.c. susceptibility were also performed. Some mechanical applications (high-speed electric motor and flywheel energy accumulator)
were built and tested. The work now proceeds on two new industrial applications of melt-processed HTSC materials.
Paper presented at the “VII Congresso SATT? Torino, 4–7 October 1994. 相似文献
424.
冷质部件的支撑是FAIR二极超导磁体样机中的关键部件,它们对于保持线圈的空间位形起到至关重要的作用,因此,对其开展稳定性的研究是十分必要的。为此,文中基于压杆稳定的理论和有限元法,对支撑进行了稳定性的研究,为支撑力学性能的评估、结构的优化设计和磁体样机的工程设计提供了参考依据。 相似文献
425.
R. De Luca A. Fedullo V. A. Gasanenko 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,58(4):461-467
The dynamical properties of symmetric quantum interferometers with equal
junctions of negligible capacitance have been studied by means of
perturbation analysis in the limit of small values of the parameter β. In
this limit, two characteristic time constants arise. These quantities may be
linked to two different dynamical processes in the system: the first is
related to the time evolution of the average superconducting phase
difference across the two junctions; the second defines the time scale for
flux motion. The response of the system to constant and time-dependent
externally applied magnetic fields is considered and a general perturbed
solution for the average superconducting phase difference and the fluxon
number variable is derived to first order in β. 相似文献
426.
427.
R. De Luca A. Fedullo 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(1):59-66
The magnetic states of multi-junction superconducting quantum interference
device containing 2N identical conventional Josephson junctions are studied by
means of a perturbation analysis of the non-linear first-order ordinary
differential equations governing the dynamics of the Josephson junctions in
these devices. In the zero-voltage state, persistent currents are calculated
in terms of the externally applied magnetic flux Φex . The
resulting d.c. susceptibility curves show that paramagnetic and diamagnetic
states are present, depending on the value of Φex . The stability
of these states is qualitatively studied by means of the effective potential
notion for the system. 相似文献
428.
G.T. Ma J.S. Wang Q.X. Lin M.X. Liu Z.G. Deng X.C. Li H.F. Liu J. Zheng S.Y. Wang 《Physica C: Superconductivity and its Applications》2009,469(21):1954-1957
The lateral restorable characteristics of a translational symmetry high-Tc superconducting maglev system are investigated by measuring its resonant frequency (fRF) after a lateral displacement. The difference between whether this lateral displacement is restorable, meaning elastic or inelastic, is determined by whether or not the maglev body returns to its original position after a lateral displacement. The maximum restorable lateral displacement (δMRLD) is determined by the sudden change of the fRF vs. the maximum lateral displacement (δMLD) curve. The fRF of the high-Tc superconducting maglev system with different field-cooling height (FCH) and working height (WH) was obtained from the frequency domain vibration curve which was measured by a vibration measurement system. The results showed that, the δMRLD was reduced when the WH was decreased. The maximum restorable guidance force (FMRGF) was found to not always increase with the lowering of the WH for the same FCH. The lateral restorable stiffness (kLRS) was always enhanced with the decrease of the WH. The decrease of the δMRLD with the WH is interpreted by the fact that, the tangential field component (ΔH) across the surface of the high-Tc superconductor (HTSC) is easier to exceed the Jcλ value (Jc is the critical current density and λ is the London penetration depth) when the WH is lowered, and this makes the trapped flux lines become more susceptible in escaping its pinning sites. 相似文献
429.
430.
Zhi-Bo Feng Yuan-Min Zhang Guo-Zhi Wang Hongpei Han 《Physica E: Low-dimensional Systems and Nanostructures》2009,41(10):1859-1863
We propose a feasible scheme to detect the noncommutative feature of non-Abelian geometric phases (NAGP) with superconducting nanocircuits. The induced NAGP associated with two-fold degenerate states naturally arises in the chosen four-level subsystem interacting with the microwave pulses. We explicitly show the noncommutative effect of the NAGP by considering the difference between the level populations at the end of the composed evolution loops l2l1 and the counter-ordered one l1l2. The scheme opens the new possibility for detecting the fundamental characteristics of the NAGP with superconducting circuit devices. 相似文献