郑桂丽
,
姜丽
,
张志东
液晶与显示
doi:10.3969/j.issn.1007-2780.2010.06.001
根据Erickson-Leslie流体动力学理论,研究了混合排列向列相-共面转换液晶盒的引流效应.在强锚定边界条件下,经过理论推导,得出液晶指向矢与流速的关系方程,进一步通过数值计算得出指向矢分布与时间的关系.发现引流效应加快了指向矢达到平衡态的速度,而且破坏了指向矢分布的瞬态对称性,特别在加电压的初始几毫秒这种现象非常明显.
关键词:
混合排列向列相
,
共面转换
,
引流效应
,
指向矢分布
LIN Jialiu ZHU Shigen YU Zhenzong Tsinghua University
,
Beijing
,
China
金属学报(英文版)
The stress-strain relation for cast low alloy carbon steel at solidification temperature has been examined by the authors' own desingned apparatus for rheological properties measurement.The rheology model,the stress-strain constitutive equation and the rheological parameters therefrom of the cast steel were proposed.Thus the theoretical basis and calcula- ting data for computerized s#nulation on the stress-strain relation and thermal cracking of the cast steel were suggested.
关键词:
rheological behaviour
,
null
,
null
,
null
,
null
JIANG Laizhu CUI Kun Huazhong University of Science and Technology
,
Wuhan
,
China
金属学报(英文版)
Studies were made of the calculation of fractal dimension of transverse impact fracture sur- face,and of the correlation between impact toughness of steel and parameters of free-cutting phase by means of the developed fractal geometry model of crack propagation.It is believed that the area fraction,f,of free-cutting phase is negligibly influential to the longitudinal im- pact toughness,as f1 .While the aspect ratio,saying ratio of length to width,of free-cut. ting phase is inversely influential to the transverse impact toughness.This may .be the reason why the transverse impact toughness of free-cutting steel containing more rare earth contrast to sulphur is even higher than the low sulphur containing steel.
关键词:
fractal geometry
,
null
,
null
Liu Zhengyi Fu Jian Zhuang Yuzhi South China University of Technology
,
Guangzhou
,
China Correspondent:LIU Zhengyi professor
,
Dept.of Mechanical Engineering No.2
,
South China University of Technology
,
Guangzhou
,
China
金属学报(英文版)
The nature of“white layer”found in 55SiMnMo steel subjected to friction test has been stu- died using TEM,SEM,X-ray diffraction and EPMA techniques.It is shown that the struc- ture of the“white laver”on the rubbing surface is duplex,consisting of a special martensite and some austenite.This layer may be 25—50 μm thick.It is ultrafine,with grain diametric approximately 30 nm.Its micro-hardness may be as high as Hm 1500 and is capable of cut- ting glass.It has superb corrosion resistance and resists tempering.Its mierostructure and hardness undergo changes only when the steel is tempered above 500℃.
关键词:
friction
,
null
,
null
余永刚
,
王玉强
,
周彦煌
,
陆欣
工程热物理学报
为了探索液体火箭发动机的新型点火方法,设计了一种周期性序列脉冲放电火花的模拟点火装置,该装置采用电机驱动电极转动,在圆周上形成放电火花的时空分布.采用高速录像系统,开展了HAN基液体推进剂LP1846液雾在不同条件下电点火特性的实验研究,结果表明,电极转速在3-5 r/s时,电火花在圆周放电空间内的分布比较密集,电能时空分布比较均匀,LP1846液雾点火效果较好.喷雾场流速、液雾细度与周向放电火花能量分布存在一个最佳匹配关系.
关键词:
液体推进剂
,
喷雾
,
电点火
,
瞬态测量
