材料期刊网，材料期刊，材料类期刊，材料期刊投稿

钛合金中的正交相变及其应用

金属学报 doi:10.3724/SP.J.1037.2010.00483

本文概述了钛合金及Ti3Al经过渡族元素合金化形成的正交相的联系与区别,简要总结了作者研究组近期针对这些正交相变的研究结果,分析了需进一步澄清的科学问题.结合低弹性模量超弹性钛合金研制、冷镦紧固件丝材超细网篮显微组织制备以及Ti2AINb基合金板材和箔材研发3个实例,展示了正交相变规律的实际应用.

关键词: β类钛合金 , 应力诱发马氏体相变 , 相稳定性 , Ti2AlNb

Energy spectra, g factors and their pressure-induced and/or thermal shifts of SrTiO3 : Cr3+ and SrTiO3 : Mn4+ II: Pressure effects on ground-state g factor and splittings of t(2)(3) E-2 and t(2)(3) (4)A(2) of SrTiO3 : Cr3+

Communications in Theoretical Physics

By using the wavefunctions obtained from diagonalizing the complete d(3) energy matrix at normal and various pressures, the g factor of the ground state of SrTiO3:Cr3+ and its pressure-induced shift have been microscopically calculated. Only by taking the local strains around Cr3+ in SrTiO3:Cr3+ (which are about twice the bulk ones) and corresponding P-chi dependence, can we obtain a good agreement between the calculated result of pressure-induced shift of ground-state g factor and the experimental one. The physical origins of this pressure-induced shift have been explained. It is found that the change of Dq(-1) with pressure makes main contribution to the pressure-induced shift of ground-state g factor of SrTiO3:Cr3+. By using the wavefunctions obtained from diagonalizing the complete d3 energy matrix at normal pressure, the relevant matrix elements and accordingly strain-induced splittings of t(2)(3) E-2 and t(2)(3) (4)A(2) of SrTiO3:Cr3+ have been calculated. The important results of Y-c, Z(c), P-c and Q(c) have also been evaluated. It is the admixtures of basic wavefunctions resulted from the spin-orbit interaction and/or Coulomb interaction and/or Kramers degeneracy that make the strain-induced splittings of the levels nonzero. It is found that there are nonvanishing matrix elements of operators T2 xi, T2 eta and T2 zeta between wavefunctions with positive M-s and those with negative M-s', which have important effects on the strain-induced splittings of the levels.

关键词: crystal fields;energy spectrum;g factors;high-pressure effect;strain-induced splitting;theoretical calculations;ruby;crystal

E型环氧树脂的NMR研究

冀克俭 , 刘元俊 , 张银生

高分子材料科学与工程

利用1H-NMR测定了E型环氧树脂的数均分子量,并利用13C-NMR表征了E型环氧树脂的微观结构.

关键词: 环氧树脂 , 核磁共振谱 , 微结构

低能电子碰撞Ar(e, 3e)双电离实验

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

屏栅电离室+△E-E望远镜探测器系统

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

R7E拖车轮E级热处理工艺的研究及应用

张振国 , 刘英 , 邹东红

机械工程材料 doi:10.3969/j.issn.1000-3738.2004.09.010

根据英国BS5892-1992标准中的R7E拖车轮E级热处理要求和力学性能要求,研究了温度、冷却介质、车轮形状等对拖车轮整体力学性能的影响,确定了R7E拖车轮E级热处理工艺为(830士10)℃×(3.5～4)h+(530±10)℃×(3.5～4)h,该工艺可以满足BS5892-1992的要求,按此工艺规程生产的车轮达到了标准中规定的力学性能要求.

关键词: 车轮 , E级热处理 , 力学性能

A study of the temperature dependence of g factor for MgO:V2+ crystal

Physica B-Condensed Matter

The temperature dependence of EPR g factor for MgO:V2+ crystal has been studied theoretically by considering both the static contribution due to the thermal expansion of crystal and the vibrational contributions due to the electron-phonon interaction of the acoustic and optical branches. The static contribution is calculated from the high-order perturbation formula of g factor and the thermal expansion coefficients alpha(T) at various temperatures. The vibrational contribution of acoustic phonons is obtained by using a Debye model for the lattice vibrations and that of optical phonons is calculated by use of a single frequency model. The calculated results show that for the g factor at various temperatures, the static contribution is dominant, but for the temperature dependence of g factor, i.e., (dg/dT)(p) or Delta g(T) = g(T) - g(0), the vibrational contributions from the acoustic and optical phonons are comparable with the static contribution due to thermal expansion. It appears that a reasonable theoretical explanation for the temperature dependence of g factor should take all of these contributions into account.

关键词: impurities

PP/PP-g-MAH/Talc/EP复合材料的性能

罗筑 , 陈梅红 , 涂兴文 , 孙华伟

高分子材料科学与工程

通过熔融共混制备聚丙烯（PP）/马来酸酐接枝聚丙烯（PP-g-MAH）/滑石粉（Talc）/环氧树脂（EP）复合材料,研究了E-51/504/554（55.6/42.4/2,E1）、E-51/EDA/554（92.2/7.8/0.01,E2）、E-20/2E4MZ（100/4,E3）三种EP体系及其含量对复合材料力学性能的影响,结果表明,E-1对复合材料的弯曲模量改善最显著,当加入4%的E1时,复合材料的弯曲模量达到最大值,提高了29.1%。傅里叶红外光谱（FT-IR）分析表明,EP与PP-g-MAH发生了酯化反应。观察复合材料的微观结构,发现EP阻止Talc的凝聚,加强了两相界面作用力。