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Dislocation Velocity Exponent and the Strain Rate

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Journal of materials Science & Technology 2001年第3期17卷 363-366页

作者： Hongyan LIU and Xiaowei WANG international Center for Material physics, Institute of Metal Research, chinese academy of sciences, shenyang 110016, china E-mail: liu@*** chinese Acad Sci Met Res Inst Int Ctr Mat Phys Shenyang 110016 Peoples R China

The process of dislocation multiplication has been described hv chaos theory, trying to reveal the connection between the microstructures on the mesoscopic scale and the mechanical properties of material on the macroscopic scale. The relationship between the dislocation velocity exponent and the maximum of strain rate is given. The results obtained from logistic equation with exponent and the dislocation multiplication dynamic equation are compared. A scale law in one-dimension-map model with exponent is shown when the exponents of equations are changed.

关键词： Dislocation Velocity Exponent and the Strain Rate

Vacancies and Antisites in B2 FeAl and DO_3 Fe_3Al with a Modified Analytic EAM Model

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Journal of materials Science & Technology 2001年第6期17卷 601-604页

作者： Xiaolin SHU, Wan gyu HU, Hanning XIAO and Huiqiu DENG College of materials Science and Engineering, Hunan University, Changsha 410082, china Ban gwei ZHANG international centre of materials physics, chinese academy of sciences, S Hunan Univ Coll Mat Sci & Engn Changsha 410082 Peoples R China chinese Acad Sci Int Ctr Mat Phys Shenyang 110016 Peoples R China

A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of ... 详细信息

A simple modified analytic EAM model for bcc Fe and fcc Al was used to calculate the lattice constant and elastic constants of B2 FeAl and DO3 Fe3Al alloys. The formation energies of vacancy and antisite were also calculated. The present calculations are in agreement with the experimental data and the theoretical results obtained by other authors.

关键词： Al DO Fe Vacancies and Antisites in B2 FeAl and DO3 Fe3Al with a Modified Analytic EAM Model EAM

INVESTIGATION OF BEHAVIOUR OF B IN Ni_3Al ALLOYS BY POSITRON ANNIHILATION TECHNIQUE

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Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 125-128页

作者： DENG Wen XIONG Liangyue LONG Qiwei international centre for materials physics Institute of Metal Research,Academia Sinica,shenyang,chinaWANG Shuhe GUO Jianting Institute of Metal Research,Academia Sinica,shenyang,china Institute of Metal Research,Academia Sinica,shenyang 110015,china Inst of Metal Research Acad Sinica Shenyang China

The behuviour of B atoms added to mono-and poly-crystalline Ni_3AI alloys has been investi- gated hy positron annihilation technique(PA T).If the additive of B was less than 1.37 at-%, some of B atoms solid-solutioned interstitially into matrix and distorted the lattice,thus the lifetime (τ) of positron (e^+) Or matrix dilated:the others of them segregated on vacancy-like defects and formed "filling effect",thus the mean lifetime (τ)and S parameters *** B added was increased up to 2.22 at-%,more defects having larger free volume were induced by horide eutectic occurred along grain boundaries and grain interior,thus the τ in vacancy-like defects.τ and S parameters increased remarkably.

关键词： Ni_3Al positron annihilation B additive defect

Biomimetic Design and Test of Composite materials

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Journal of materials Science & Technology 1993年第1期9卷 9-19页

作者： Benlian ZHOU international centre for materials physics,Institute of Metal Research,Academia Sinica,shenyang,110015,china

A series of superior properties will make composites the most important structural materials in the next *** they are difficult to design owing to the complexity of structure and processing. Biomaterials had been naturally selected and evolved for millions of years,a great variety of their ra- tional composite structures could be taken as our reference in the biomimetic design of composite *** are many difficult problems in the current study on composite materials such as: brittleness of continuous fibers and difficulties in interface design;easy pull-out of short fibers from matrix causing failure in reinforcing;being less easy in selecting the aspect ratio of whiskers and dif- ficulties in finding the way of toughening composites of ceramic matrices as well as the way of heal- ing inner *** describing the distinct composite features,the functional adaptability and self-healing ability of biomaterials,several examples o.f biomimetic design of composite materials have been listed in this paper:the optimum design of composites simulating bamboo structure;the fine structure of bamboo fibers;the dumb-bell model simulating animal bone;the model on the pull-out of fiber with fractal-tree structure and some tentative works on the healing of inner damage in composite materials The methodology of biomimetic design and its future have been given at the ast part of this paper.

关键词： composite material biomimetic fiber

Enhanced Bamboo Reinforced Aluminum Laminates

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Journal of materials Science & Technology 1994年第5期10卷 355-358页

作者： Shihong LI Shaoyun FU and Benlian ZHOU (Int. centre for Mater. Phys., Institute of Metal Research, chinese academy of Science, shenyang, 110015, china)Qiyun ZENG and Xianrong BAO (Institute of Applied Ecology, chinese academy of sciences, shenyang, 11 Inst of Metal Research Shenyang China

A new technique has been developed for flattening circular natural bamboo culm to plate form for remarkably enhancing its mechanical properties, The enhanced bamboo, cheaper than Al, is then used to reinforce an aluminum alloy for civilian applications. The properties of the composite are greatly enhanced compared to those of the Al alloy. The Al protects bamboo from bioerosion and improves hygroscopicity

关键词： Laminated composites

Energy Spectra of the Tunable Laser Crystal Gd3GasO12:Cr3+ and Their Pressure-Induced Shifts

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Communications in Theoretical physics 2004年第1期 141-150页

作者： MA Dong-Ping~(1,2) 1 Department of Applied physics,Sichuan University,Chengdu 610065,china 2 international centre for materials physics,Academia Sinica,shenyang 110015,china

By means of both the theory for pressure-induced shifts（PS）of energy spectra and the theory for shiftsof energy spectra due to electron-phonon interaction（EPI）,at 300K,the‘pure electronic’contributions and the contri-butions from EPI to R1line,R2line,and U band of GGG:Cr3+as well as their PS have been calculated,*** total calculated results are in good agreement with all the experimental *** physical origins have *** is found that the mixing-degree of|t（2～2）(3T1)e4T2〉and|t232E〉base-wavefunctions in the wavefunctions ofR1level of GGG:Cr3+is considerable under normal pressure,and the mixing-degree rapidly decreases with *** change of the mixing-degree with pressure plays a key role for PS of R1line or *** 300K,boththe temperature-independent contribution to R1line（or R2line or U band）from EPI and the temperature-dependentone are *** remarkable difference between pressure-dependent behaviors of PS of R1lines of GGG:Cr3+andGSGG:Cr3+results from the differences of their microscopic *** features of emission spectra of GGG:Cr3+at various pressures have satisfactorily been explained.

关键词： high-pressure effect line shift spin-orbit interaction electron-phonon interaction d-orbital coupling between t22(3T1)e4T2 and t23 2E tunable laser crystal

High-pressure synthesis and properties of CeO_2-ZrO_2 solid solution

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chinese Science Bulletin 2001年第10期46卷 801-806页

作者： XU Dapeng, WANG Quanyong, LU Zhe, LIU Zhiguo, ZHANG Gongmu & SU Wenhui1. Department of physics, Jilin University, Changchun 130023 china 2. international Center for materials physics, chinese academy of sciences, shenyang 110015, china 3. Center for Condensed Matter and Radiation physics, china Center of Advanced Science and Technology (World Laboratory), Beijing 100080, china Department of physics Jilin University Changchun China international Center for materials physics Chinese Academy of Sciences Shenyang China Center for Condensed Matter and Radiation physics China Center of Advanced Science and Technology (World Laboratory) Beijing China

Using nanoparticles of CeO2 and ZrO2 prepared by the chemical precipitation method as starting materials, the single-phase cubic Ce0.5Zr0.5O2 solid solution (c-Ce0.5Z0.5O2) has been synthesized under 3.1 GPa at 1073 K for the first time. The structure of the c-Ce0.5Zr0.5O2 has not been changed before and after annealing at 773 K for 1 h. Only an unknown EPR signal (g =1.990) has been observed in the c-Ce0.5Zr0.5O2 and not varied after annealing at 773 K for 1 h, which exhibited that there exists no Ce3+ in the c-Ce0.5Zr0.5O2 and the Ce4+ has not been reduced into Ce3+ after annealing. The transport mechanism is ionic for the c-Ce0.5Zr0.5O2. The bulk conductivity (a =1.2×10-5 S/cm at 823 K, σ=2.1 ×10-3 S/cm at 1123 K) is the same as that of CeO2, but smaller than that of Y2O3-stabilized ZrO2. A marked curvature at T = 823 K has been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 823 K is lower than that above 823 K, and the reason has been discussed.

关键词： CeO2-ZrO2 nanocrystalline high-pressure and -temperature solid-state reaction solid solution.

Laser-induced Chemical VaporDeposited Nanosized Silicon Nitridewith Double Optical Beams

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chinese Journal of Lasers 1996年第1期B5卷 67-71页

作者： WANG Weixiang (Institute of Quantum Electronices, South china Normal Unicersity, Guangzhou 510631, china international centre for materials physics, Academia Sinica, shenyang, 110015, china)LIU Songhao(Institute of Quantum Electronices, South china Normal South china Normal Univ Guangzhou China

It was studied that how the CO2laser lines affect the characteristics of silicon nitride powders synthesized by laser-induced chemical vapor deposition （LICVD）. A new method was proposed for nanosized silicon nitride synthesis, and it is called double optical beam LICVD. The stoichiometric silicon nitride nanopowders with high purity were produced by using this new method. The ratio of N/Si of the powder is as high as 1. 321 which is very close to the ideal value of 1. 333.

关键词： laser-induced chemical vapor deposition nanosized silicon nitride

Solitary Magnon Localization in Antiferromagnet RbFeBr_3

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Journal of materials Science & Technology 1994年第3期10卷 225-228页

作者： Wuming LIU and Benlian ZHOU(international centre for materials physics, Institute of Metal Research, Academia Sinica, shenyang, 110015, china)Liming GUO(Dept. of Mathematics, Institute of Yunnan Nationality, Xunming, 650031, china) Inst of Metal Research Academia Sinica Shenyang China

Introducing the Dyson-Maleev transformation. the coherent state ansatz and the time-dependent variation principle, we obtain two partial different equations of motion from Hamiltonian. Employing the method of multiple scales. we reduce these equations into the envelope function equations and force the amplitude function to satisfy a nonlinear Schrodinger equation. Using the inverse- scat-tering transformation, we obtain the single soliton solution and discuss the solitary magnon localization in antiferromagnet RbFeBr3

关键词： Rev Solitary Magnon Localization in Antiferromagnet RbFeBr3