Superconductor Science & Technology
In this paper we report the transport properties of c-axis-oriented superconducting La(1.44)Nd(0.4)Sr(0.16)CuO(4) films on LaSrAlO(4) substrates with different thicknesses in various magnetic fields parallel and perpendicular to the c axis of the films. It is found that with decreasing film thickness there is a crossover from the parallel shift to fan-shape broadening in the resistive transitions. Moreover, for both field configurations, the flux pinning potential U(0)(H) of the film shifts upward with an order of magnitude with increasing in-plane compressive strain. These results indicate that the compressive epitaxial strain and strain-induced destabilization of the static charge stripes are important aspects for the promotion of superconducting transition temperature as well as the flux pinning potential.
关键词:
high-temperature superconductors;crystal thin-films;flux motion;la2-xsrxcuo4;strain;insulator;dependence;behavior
程开甲
,
程漱玉
稀有金属材料与工程
应用Cheng-Born能带对称破缺理论和TFDC(Thomas-Fermi-Dirac-Cheng)电子理论研究了薄膜层内电子的特性.对金属铂上的TiO2膜层来说,TFDC理论指出电子(或空穴)将由金属与膜的间界面一侧迁移到另一侧.根据Cheng-Born对称破缺理论,当能带中只有很少的电子时,则只有极少的角区中存在电子,动量空间即产生对称破缺,从而导致超导电性,并由热力学估算出薄膜超导体的转变温度.结果显示薄膜超导体的转变温度至少比块材超导体的转变温度高一个量级.作者还设计了一个研究薄膜超导电性的实验.
关键词:
超导电性
,
薄膜
,
对称破缺
,
TFDC
JIANG Qichuan LI Zhang WANG Shoushi HE Zhenming Jilin University of Technology
,
Changchun
,
China
金属学报(英文版)
The majority of Ti is found to be preferentially precipitated in the form of TiC from medium manganese steel melt.The TiC may contribute to the heterogeneous nuclei of fine austenite crystallization,to the retardation of dislocation movement as well as to pile-up and proliferate the dislocations,thus,the matrix of the as-cast steel will be effectively strength- ened.It was also found that the TiC can be acted as the heterogeneous nuclei of the nodular eutectic carbide formation and caused the dispersion o fan abundance of the carbide in the interstices between austenite dendrite arms.
关键词:
TiC
,
null
,
null
D.R.Huang
,
T.F.Ying
,
L.T.Kuo
,
S.J.Wang
,
H.C.Huang
,
C. Y.Huang
材料科学技术（英）
A single phase brushless spindle motor with innovative design has been developed for application in a DVD drive. The methods used to reduce the cogging torque and to improve the dynamic performance of this new design motor are proposed in this paper. The single phase brushless spindle motor is usually applied for cooling fan, pump and blower before the performance is improved by the reengineering process. The stator configuration and the drive circuit have been remodeled in order to meet the requirements of the spindle motor used in the DVD applications.
关键词:
Xiang XUE
,
Zhiliang NING
,
Bide ZHOU
,
Chunhui ZHANG
材料科学技术（英）
In this study, the Solidworks was used as pre-processor, which performed the three- dimensional solid construction and automatic enmeshment. The COSMOS was adopted as post- processor to display the temperature distribution and further to simulate the thermal stress distribution of dies. A software package for three-dimensional temperature fields of complicated die casting and its dies was developed and the temperature distributions of a fan cover casting were simulated by the software.
关键词:
