材料期刊网

Positron lifetime study of the single-phase B2Ni(100-x)Al(x) and Ni50-xCOxAl50 intermetallics

Rongshi CHEN , Jianting GUO , Wenlong ZHOU , Liangyue XIONG

材料科学技术（英文）

In order to understand the point defect structure in NiAl Intermetallic compound, the positron lifetime in binary Ni100-xAlx (53 greater than or equal to x greater than or equal to 45) and ternary B2 Ni50-xCoxAl50 (x=0, 5, 10, 15) intermetallic compounds as a function of composition were measured. It is shown that the positron lifetime spectra of these compounds can be consistently expressed by single-component lifetimes. The positron lifetime value in ternary Ni50-xCoxAl50 alloy is independent of Co content and equal to that detected in both stoichiometric and Al-rich NiAl. From an analysis of the present results, it is suggested that the constant lifetime of tau approximate to 180 ps should be ascribed to saturation trapping and annihilation of positron exclusively at Ni vacancy, no evidence for the presence of Al vacancy is available.

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Thermomechanical Processing and Superplasticity of AZ91 Magnesium Alloy

Rongshi CHEN , J.J.Bl , in , M.Sue'ry , Qudong WANG , Enhou HAN

材料科学技术（英文）

The effect of extrusion on grain refinement has been studied in the AZ91 cast ingots. It is found that grain size smaller than 10μm can be obtained by the extrusion processing. Vickers hardness measurements were also carried out to evaluate the effect of these processes on the room temperature mechanical properties. ...

关键词: Magnesium alloy , null

Microstructural Stability of a Multiphase Ni-25Al-15Cr (at. pct) Intermetallic Alloy

Rongshi CHEN , Jianting GUO , Jiyang ZHOU

材料科学技术（英文）

The microstructure of multiphase Ni-25Al-15Cr (at. pct) intermetallic alloy consists of dendritic arms (β-NiAl phase) and interdendritic regions (γ/γ´ two phases) under homogenization followed by air cooling condition. Furnace cooling following homogenization does not significantly influence its microstructure. However, the effects of aging treatment on the microstructure strongly depend on cooling rates following homogenization. A single phase g´ layer with a α-Cr `spouse' layer is observed surrounding the dendritic arms, the formation of this ‘couple’ is attributed to a four-phase invariant quasi-peritectoid, i.e: β+γ=γ´+α-Cr .

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Chen系统的状态变量周期性反馈控制

李开明 , 李亚洲 , 冯维贵 , 林长

量子电子学报 doi:10.3969/j.issn.1007-5461.2007.05.014

采用非线性反馈控制,用附加了带参数的正弦项对Chen系统进行了有效的控制.随着参数k的逐渐增大,系统的动力学行为呈现出一系列的变化.数值研究结果表明:随控制参数的增大,驱动信号的强度渐大,混沌系统由混沌运动到周期轨道,最终到一相点.

关键词: 混沌 , Chen系统 , 不动点 , Lyapunov指数 , 反馈控制

SIF expressions for center cracked strip loaded by uniformly distributed stress acting on central portion of crack - Corrections of Chen's results - Response

International Journal of Fracture

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Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

第27卷B辑作者索引

金属学报

Volu扣ne 27SeriesB1991AUTHOR INDEX CCAO Guanghan(曹光旱)············……6一B科6CAo weijie(曹卫恋)..················……5一B32oCAO Yilin(曹益林)··················……6一B443CHANG Xin(常听)···············……1一B48CHE Guang邻n(车广灿)·············一6一B科0CHEN Erbao(陈二保)···············……6一B410CHEN Jia....

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基于二氧化碳封存的超临界两相流动的数值研究

高诚 , 胥蕊娜 , 陈黎 , 姜培学

工程热物理学报

格子Boltzmann方法(LBM)在计算复杂结构物理模型时具有独特优势并在模拟两相流动过程中能够高效清晰捕捉相界面.本文介绍了基于Shan-Chen多相模型的格子Boltzmann方法的理论成果以及基于二氧化碳封存的超临界两相流的模拟研究.结果表明,Shan-Chen模型在模拟两相流时符合Laplace定律,且两相层流时的速度分布和相渗曲线均与理论值吻合.二氧化碳封存过程中,较大的注入速率在提高二氧化碳残余俘获量的同时会降低其化学俘获量.

关键词: 二氧化碳封存 , 超临界两相流 , Shan-Chen模型

A molecular dynamics study of the structural change differences between Au-225 and Au-369 clusters on MgO surfaces at low temperature

Chinese Physics B

The differences in structural change between Au-225 and Au-369 clusters with their (111) facets supported on MgO(100) surfaces at 5 K are studied by using molecular-dynamics simulations with the atomic interchange potentials of the Au/MgO interface. The parameters are obtained from the ab initio energies using the Chen-Mobius inversion method. Analyses of the pair distribution functions show that the two Au clusters use different deformation processes to adjust the distances between the interface atoms, owing to the misfit between the atom distances among the clusters and the substrates. The local structural changes are identified by atomic density profiles.

关键词: interfaces;nanostructures;computer modelling and simulation;molecular;dynamics;local-structure changes;mgo(001) surface;au;adsorption;cu;nanoclusters;dimers;models;ag

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....

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