FAN Zhanguo
,
JI Chunlin
,
WANG Kuihan
,
CUI Chuanmeng
,
LIU Sulan
,
Northeast University of Technology
,
Shenyang
,
China
金属学报(英文版)
A unidirectional reaction for synthesis of the high T_c superconductor YBa_2Cu_3O_x has been proposed, Its T_c is 90-94.5 K and △T is 1 K. The phase relationships in the system Y_2BaCuO_5-Y_2Cu_2O_5-CuO-YBa_2Cu_3O_x were studied and discussed.
关键词:
unidirectional reaction
,
null
,
null
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
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（英文）
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（英文）
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:
陈云传
,
刘晓亚
,
熊万斌
,
陈明清
,
李华伟
材料保护
doi:10.3969/j.issn.1001-1560.2003.11.008
以酚醛型环氧树脂为原料,合成出低粘度环氧丙烯酸酯(EA)树酯,讨论了环氧树脂类型、催化剂用量等因素对反应及产物性能的影响,并用柔性单体--己内酯改性丙烯酸酯(FAn)替代通常的单官能度单体,对树脂产物进行了涂料配方的研究.
关键词:
紫外光(UV)固化
,
罩光涂料
,
环氧丙烯酸树脂
,
应用
Journal of Physics D-Applied Physics
A large magnetoresistance (MR) is observed in a double helical CoMnSi compound over the entire temperature region from 5 K to the maximum measuring temperature of 380 K, with the largest MR ratio of -18.3% at 245 K and the smallest MR ratio of -5.5% at 85 K at 5 T. This phenomenon is ascribed to two different mechanisms in different temperature regions. The suppressed spin fluctuations of the double helical structure are responsible for the MR below 110 K. However, in consideration of the natural multilayer superstructure of CoMnSi, the larger MR above 110 K is ascribed to the decrease in K-space restrictions when the change in magnetic structure from double helical order to fan order occurs.
关键词:
giant magnetoresistance;magnetic-structure;crystal;metals
Materials and Corrosion-Werkstoffe Und Korrosion
The low cycle fatigue behavior of a low-alloy reactor pressure vessel (RPV) steel was investigated in high temperature water. Main attention was paid to the effects of surface finish of specimens on fatigue cracking behavior. It was found that the influence of surface finish on fatigue resistance of the steel was strain-rate dependent in high temperature water. Pretty obvious degradation of fatigue resistance appeared at fast strain rate with rougher surface finish. At slow strain rate, surface circumferential scratches promoted crack initiation and propagation. The fracture surface showed relatively flat and slight crack-arrest features. At fast strain rate, surface scratches also promoted crack initiation, but seemed not to dominate crack propagation. The fracture surface showed typical terraced and fan-like features. The above fatigue cracking behavior can be rationalized by a strain-rate dependent environmentally assisted cracking process of low-alloy RPV steel in high temperature water.
关键词:
environmentally assisted cracking;low-cycle fatigue;low-alloy;corrosion-fatigue;growth-behavior;carbon
