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Modification of Analytical Expression of Electron Dynamical Diffraction

Canying CAI , Qibin YANG , Hongrong LIU

材料科学技术(英)

Assuming that the wave function , the Schrodinger equation can be written as . Neglecting the last two terms, an analytical expression of electron dynamical diffraction was derived by Qibin YANG et al. In this paper, the analytical expression is modified by further considering the second-order differential term . When the accelerating voltage is not very high, or the sample is not very thin, the reciprocal vector ɡ is large, the modification of the second-order differential is necessary; otherwise it can be neglected.

关键词: Electron dynamical diffraction , null

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....

关键词:

Atomic and electronic structures of the lattice mismatched metal-ceramic interface

Journal of Physics-Condensed Matter

This research purposes to investigate the atomic and electronic structures of the Al/TiC(001) interface with lattice misfit using the ab initio pseudopotential approach. A detailed analysis of the relaxed atomic structure reveals that the atoms over the initial unfavourable sites relax to the favourable sites along the lateral plane. The properties of the semicoherent interface can be taken as averages over the different coherent sites. In addition, the interface atoms in relatively favourable regions are dragged near to the interface, while those in unfavourable regions are pushed away from the interface. Therefore, a large war-ping near the interface is made perpendicular to the lateral plane. The calculated adhesions explain the different wetting results from the viewpoint of structural transition. The subsequent analysis of electronic properties demonstrates that adhesions dominate mainly via the strong Al-C covalent bond.

关键词: first-principles;1st principles;adhesion;surfaces;misfit;1st-principles;wettability;al

STUDY ON THE PREDICTIVE METHOD OF BUCKLING DEFORMATIONS OF THIN-PLATE WELDED STRUCTURES

X. Q. Yang , L. X. Huo , Y. F. Zhang and J. X. Yan (School of Material Science and Engineering , Tianjin University , Tianjin 300072 , China)

金属学报(英文版)

The buckling formation and influence factors during welding thin - plated structures were investigated based on finite element methods, An engineering treatment method for prdicating the buckling distor- tion was proposed in here. It was used the equivalent applied thermal - load to simulate the welding residual stress,therefore the calculation of complex welding distoriton can be transformed into 3D elas- tic structural applied- load analyses, which can reduce the quantities of calculating works effectively. The validation of the method was verified by comparison of the numerical simulation and experimental results. The simulation of buckling distorition for side - walled structrues of paseenger train was per- formed and the calculation was in agreement with measuring results in general. It was shown that the main factors for producing the buckling were the intermittent fillet and ping the during welding the stiffened beams and columns to the panel.The existence of the free edge of panels would reduce the crit- ical buckling stress and enlarge the deflection obviously,but the continuous weld in closed frames didn' t degrade the buckling situation.

关键词: welding buckling distortion , null , null

连铸结晶器弯月面处保护渣的流动行为

颜慧成 , 郭征 , 张孟亭 , 张洪平

钢铁研究学报

引入变量m(冲量密度)和Yang-Mills型规范变换m=u+gradφ,将原始变量的N-S方程转化为规范-不变量形式,用自由质点法处理Voronoi元,对连铸结晶器弯月面处保护渣流动行为进行数学模拟.输出振动周期内的动态流场,然后结合一组试验数据进行计算,计算结果与实际情况相吻合,进而讨论了渣圈对液渣流动行为的影响,为研究结晶器弯月面处保护渣的行为和铸坯振痕的形成提供了一定的依据.

关键词: 连续铸钢 , 保护渣 , 流动行为 , 数学模拟

快速床动力学统一模型-由A型噎塞向C型噎塞的连续转变Ⅰ:模型构建

章明川 , 张楚 , 林郁郁 , 徐旭常

工程热物理学报

根据快速流化床的基本流动特性、A 型噎塞和 C 型噎塞的特征与定义,建立了一个统一,自恰的快速床模型一分相共存模型.模型以 A 型噎塞的修正Yang公式为‘本构方程',合理预报了快速床的最小固体流率Gsm,以及在固体流率不变的条件下降低操作气速时床层由A型噎塞向C型噎塞的连续过渡.模型中的稀相有效气流速度函数幂次n为可调参数,根据 C 型噎塞速度预报的Yousfi and Gau公式,初步确定模型参数n=4.

关键词: 快速流态化 , 噎塞速度 , A 型噎塞 , C 型噎塞 , 分相共存模型

NCl(a1 △)泵浦碘原子化学激光综述及可行性分析

多丽萍 , 李国富 , 李健 , 闵祥德

量子电子学报 doi:10.3969/j.issn.1007-5461.2001.05.001

自1990年Bower和Yang报告了NCl(a1△)/I的传能,引起了人们的极大关注.由NCl(a1△)泵浦I原子的全气相化学激光器能否产生和放大以及该体系的相关动力学的研究近几年也广泛展开.本文在综述了有关NCl(a 1△)及其与I的传能和发展现状基础上,理论上进行了分析和计算.最后对NCl(a 1△)泵浦I化学激光器可行性做了展望并提出具体探索和解决的途径.

关键词: 亚稳态NCl(a1△) , I原子化学激光

STUDY ON THE SiC_p./Al-ALLOY COMPOSITE AUTOMOTIVE BRAKE ROTORS

Z.L. Ding , Y.C. Fan , H.B. Qi , D.L. Ren , J.B. Guo and Z.Q. Jiang Shijiazhuang Railway Institute , Shijiazhuang 050043 , China

金属学报(英文版)

The SiC_p/Al-alloy composite front broke rotors designed for SHANGHAI SANTANA cars were prepared by semi-solid stirring+liquid for ping process. The properties of the composite rotors were examined. The composite brake rotors were subjected to dynamometer tests on a SCHENCK broke testing system, referring to TLll0 standard of VOLKSWAGEN Company. The friction coefficient and thermal response during fade testing and the wear performance of the composite rotors were studied as the function of various parameters, such as braking pressures, initial speeds, initial temperatures, torque and decelerations, and compared with that of conventional cast iron rotors. The results showed that the properties of SiC_p,/Al-alloy composite rotors can achieve the requirements of commercial cast iron rotor.s. The results also suggested that the friction coefficients of composite rotors under different broking conditions are within the deviation band specified by the TLll0 standard, and the temperature rise of the composite rotors at the cud of each fade stop is lower than that of the cast iron rotors. The wear resistance of composite rotors was higher than that of cast iron rotors. The friction and wear mechanism are analyzed.

关键词: SiC_p/Al-alloy composite , null , null , null

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