M.D. Starostenkov
,
B. F. Demyanov
,
E.A. Kuklina and E. G. Sverdlova General Physics Department
,
Altai State Technical University
,
Lenin st 46
,
Barnaul
,
656099
,
Russia
金属学报(英文版)
Computer simulation of grain boundaries(GB) was carried out in Fe and ordered alloys NiAl and FeAl with B2 superlattice. In this work symmetrical tilt grain boundaries =5[100](012) and = 5[100](013) are studied. The atomic interaction has been described by Morse empirical central- force potentials.The atomic structure and energy of GB were investigated by means of construction of -surface using full atomic relaxation by method of molecular statics. It is shown that = 5 tilt GBs in Fe, Ni3Al and NiAl have several steady states. Comparison of our results with geometrical model of coincidence site lattice (CSL) was carried out. GBs in model CSL are unstable, the stabilization is achieved by additional displacement at some vector along the plane of defect.
关键词:
grain boundary
,
null
,
null
,
null
,
null
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
,
null
,
null
,
null
贾昌春
,
A.Lahmam-Bennani
,
A.Duguet
,
L.Avaldi
,
M.Lecas
,
Dal Cappello
原子核物理评论
doi:10.3969/j.issn.1007-4627.2002.z1.007
通过Ar(e, 3e)五重微分截面3维图的理论与实验比较发现, 在低能电子入射的情况下, 理论与实验存在较大的偏差.
关键词:
(e,3e)
,
双电离
,
五重微分截面
王涛峰
,
朱丽萍
,
孟庆华
,
王黎明
,
韩洪银
,
夏海鸿
,
黎光武
,
屈从会
,
顾先宝
原子核物理评论
doi:10.3969/j.issn.1007-4627.2007.03.008
研制了屏栅电离室+△E-E望远镜探测器系统,系统的屏栅电离室用来测定252Cf自发裂变碎片的能量和相对于探测器系统轴线的发射角,与屏栅电离室耦合安装的△E-E望远镜探测器由一个薄的屏栅电离室(气体△E)和一个金硅面垒探测器(E)组成,用来确定互补碎片的电荷.用本系统对252Cf自发裂变碎片电荷分布进行了4个参数的关联测量,结果表明,这个探测器系统的电荷分辨能力Z/△Z好于40:1.
关键词:
屏栅电离室
,
△E-E望远镜
,
电荷分辨能力
贾昌春
,
A.Lahmam-Bennani
,
A.Duguet
,
L.Avaldi
,
M.Lecas
,
C.Dal Cappello
原子核物理评论
doi:10.3969/j.issn.1007-4627.2002.02.018
通过比较Ar在低碰撞能量下的(e,3e)双电离实验结果和基于包含一次作用机制SO和TS1的一阶波恩近似的理论计算结果, 表明在动量转移方向上对称性的破坏显示非一次效应(例如二型两步作用机制)起非常重要的作用.
关键词:
(e,3e)
,
双电离
,
五重微分截面
闫永娜
,
王利娟
,
杨更亮
,
侯文欣
,
张巧霞
色谱
doi:10.3321/j.issn:1000-8713.2009.06.025
采用胶束电动毛细管色谱法(MECC)对硫酸多粘菌素E药物中的主要成分多粘菌素E1和E2进行了分离,并测定了多粘菌素E1、E2的含量.分别考察了电泳电压、表面活性剂种类、Brij-35(月桂醇聚氧乙烯醚)浓度、乙腈含量、磷酸盐缓冲液的pH值、氯化钠浓度等实验参数对实验结果的影响,从而确定了最佳的分离条件:电泳电压为10 kV,运行缓冲液为含有30 mmol/L Brij-35、5%(体积分数)乙腈、0.167 mol/L氯化钠的磷酸二氢钠缓冲液(0.01 mol/L,pH 4.1).在优化的实验条件下,E1和E2得到了较好的分离,分离度达到1.94.以多粘菌素E1为例,柱效和峰面积的日间及日内测定的相对标准偏差(RSD)均小于5% .E1和E2在硫酸多粘菌素E药物中的含量分别为67%和32% .该方法简便、快速、准确、重现性好.
关键词:
胶束电动毛细管色谱
,
多粘菌素E1
,
多粘菌素E2
,
硫酸多粘菌素E
