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Some key technics of drop tower experiment device of national Microgravity laboratory ({2.) (NMLC)

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Science china(Technological Sciences) 2005年第3期48卷 305-316页

作者： ZHANG Xiaoqian 1 , YUAN Longgen 1 , WU Wendong 1 , TIAN Lanqiao 2.& YAO Kangzhuang 2.1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080, china 2. Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, china 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China

Drop tower is an important ground based facility for microgravity science experiment. The technical performances of the drop tower NMLC are advanced compared with similar facilities in the US, Germany and Japan. The main components such as drop capsule, deceleration devices, release mechanism present its advantages and creativities.

关键词： drop tower facility,drop capsule,deceleration devices,release mechanism.

Trend and Development of Semi-Solid Metal Processing

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Journal of Materials Science & Technology 2000年第5期16卷 453-460页

作者： Xianfeng PAN, Haifeng ZHANG, Aimin WANG, Bingzhe DING, Keqiang QIU and Zhuangqi HU (State Key laboratory of Rapidly solidified {2.equilibrium alloys, Institute of Metal Research, Chinese Academy of Sciences, shenyang 110015, china) State Key laboratory of Rapidly solidified {2.equilibrium alloys Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

This paper reviewed the trend and development of semi-solid metal technique. The processes and mechanisms for producing slurry of SSM and its industrial applications have been summarized and discussed. Discussions on the basic rheological theory are presented for more applications. Further consideration of the development and application of SSM technique is also proposed.

关键词： SSM Trend and Development of Semi-Solid Metal Processing

An Examination on Atomic-level Stress Calculations by Nanoindentation Simulation via the Quasicontinuum Method

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Journal of Materials Science & Technology 2010年第1期26卷 56-64页

作者： Yufei Shao and Shaoqing Wang shenyang national {2. for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, shenyang 110016, china [a] shenyang national {2. for Materials Science Institute of Metal Research Chinese Academy of Sciences shenyang 110016 china

Nanoindentation simulations on single crystals AI and Cu via the quasicontinuum method have been performed. Two kinds of atomic-level local stress calculation methods, i.e. the coarse-grained local stress and the virial local stress, are employed to calculate the stress state of the contact area. Various comparisons between the coarse-grained local stress and the virial local stress have been made. Firstly, the averaged normal stress beneath the contact surface calculated by coarse-grained method agrees well with continuum mechanical pressure measurement, while the virial method gives unphysical results sometimes. Secondly, the coarsegrained results reflect the indenter size effect on the critical shear stress quite accurately, while the virial calculations fail. Thirdly, the distribution of maximum shear stress of the coarse-grained method predicts the defects nucleation locations reliably, while the distribution of virial local stress gives an incorrect prediction sometimes. Thus it is concluded that the coarse-grained method can offer a more reliable description of the local stress states of atoms in spatially inhomogeneous solids.

关键词： Nanoindentation Atomistic stress Quasicontinuum

Vibration Effects on the Structural Stability of Al-Ti Intermetallics by First-principles Calculations

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Journal of Materials Science & Technology 2010年第12期26卷 1071-1077页

作者： Hui Zhang and Shaoqing Wang shenyang national {2. for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,shenyang 110016,china [a] shenyang national {2. for Materials Science Institute of Metal Research Chinese Academy of Sciences shenyang 110016 china

The structural stability of the intermetallics AlTi3, Al2.i, Al3Ti4 and Al3Ti in the Al-Ti system has been investigated using density functional theory （DFT） and density functional perturbation theory （DFPT）. The calculated ground-state convex hull is in agreement with the experimental researches. Al3Ti4 （hP7） is metastable at 0 K and may be stabilized as the temperature increases due to the effects of the vibration entropy. For Al2.i, r-Al2.i is stable at 0 K and h-Al2.i is stabilized by the vibration entropy at high temperatures. Al3Ti （tI16） is unstable considering vibration effects and Al3Ti （tI8） is the most stable structure at 0 K.

关键词： First-principles Al-Ti Vibration Crystal structure

Strain-induced Microstructure Refinement in a Tool Steel Subjected to Surface Mechanical Attrition Treatment

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Journal of Materials Science & Technology 2010年第3期26卷 258-263页

作者： Shoudan Lu,Zhenbo Wang and Ke Lu shenyang national {2. for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,shenyang 110016,china [a] shenyang national {2. for Materials Science Institute of Metal Research Chinese Academy of Sciences shenyang 110016 china

A nanostructured surface layer has been fabricated on an AISI H13 tool steel by means of surface mechanical attrition treatment （SMAT）.Strain-induced refinement processes of ferrite grains and carbide particles have been investigated by transmission electron microscopy （TEM） and scanning electron microscopy （SEM） in the SMAT surface *** refinement of ferrite is found to be dominated by dislocation activities and greatly facilitated by a large number of carbide particles at a depth 〉2. μ*** comparisons with microstructure refinement processes in other SMAT ferrite steels indicate that a larger volume fraction of carbide particles with a lower shear strength is expected to facilitate the refinement process of ferrite grains.

关键词： Nanostructured and nanocrystalline material AISI H13 tool steel Grain refinement Surface mechanical attrition treatment (SMAT) Carbides

Pressure-induced color change arising from transformation between intra-and inter-band transitions in LuH_(2.x)N_(y)

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Science china(Physics,Mechanics & Astronomy) 2024年第2期67卷 161-166页

作者： Zhe Liu Yingjie Zhang shenyang Huang Xue Ming Qing Li Chenghao Pan Yaomin Dai Xiaoxiang Zhou Xiyu Zhu Hugen Yan Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China State Key laboratory of Surface Physics Key Laboratory of Micro and Nano-Photonic Structures of the Ministry of EducationDepartment of PhysicsFudan UniversityShanghai 200433China

The pressure-induced color change in the nitrogen-doped lutetium hydride has triggered extensive discussions about the underlying physics and potential ***,we study the optical response of LuH_(2.x)N_(y)in a broad frequency range at ambient pressure and its evolution with pressure in the visible spectral *** broad-band optical spectra at ambient pressure reveal a Drude component associated with intra-band electronic transitions and two Lorentz components(L1 and L2.arising from inter-band electronic *** application of pressure causes a spectral weight transfer from L1 to the Drude component,leading to a blue shift of the plasma edge in the reflectivity spectrum alongside a reduction of the high-frequency *** results suggest that the pressure-induced color change in LuH_(2.x)N_(y)is closely related to the transformation between intra-and inter-band electronic transitions,providing new insights into the mechanism of the pressure-induced color change in LuH_(2.x)N_(y).

关键词： nitrogen-doped lutetium hydride optical spectroscopy high-pressure technique color change

Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2126-2136页

作者： Xiaoyu Zhang Zirui Mao Floyd W.Hilty Yulan Li Agnes Grandjean Robert Montgomery Hans-Conrad zur Loye Huidan Yu shenyang Hu Purdue University IndianapolisIN46202USA Pacific Northwest national laboratory RichlandWA99352USA CEA DESISECDMRCUniv.MontpellierMarcouleFrance Department of Chemistry and Biochemistry University of South CarolinaColumbiaSC29208USA

Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste *** improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material *** this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous *** structures are created using the phase field method(PFM)to precisely control pore *** our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population *** address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)*** of the developed model involves examining the flow and diffusion fields in porous ***,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,***,all three parameters exert an influence on the diffusion-advection *** background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,***,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore *** comprehensive parametric study provides valuable insights into the kinetics of isotope

关键词： Volumetric lattice Boltzmann method(VLBM) Phase field method(PFM) Pore-scale diffusion-advection Nuclear waste treatment Porous media flow Graphics processing unit(GPU) parallelization

Microstructure Investigation on the Triple Junction with an Adjoining Twin Boundary in Nanocrystalline Palladium

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Journal of Materials Science & Technology 2010年第11期26卷 1047-1050页

作者： Yuchen Wang,Zhenxing Su and Dehai Ping shenyang national {2. for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,shenyang 110016,china [a] shenyang national {2. for Materials Science Institute of Metal Research Chinese Academy of Sciences shenyang 110016 china

By using high-resolution transmission electron microscopy,a [110] triple junction （TJ） containing a twin boundary （TB） in nanocrystalline palladium has been observed along the common axis *** statics calculation and imaging simulation were performed to determine the atomic structure of the *** modeling structure exhibits that the adjoining TB is a distorted one,whilst other two adjoining grain boundaries （GBs） exist in steady equilibrium *** present observation gives a clear example demonstrating that the adjoining TB can release the larger stresses residing at the junction.

关键词： Triple junction Grain boundary Molecular statics High-resolution transmission electron microscopy (HRTEM)

A Novel Deflection Method for Measuring the Growth Stress of Thermally Growing Oxide Scales

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Journal of Materials Science & Technology 2003年第3期19卷 231-234页

作者： Yuhai QIAN Meishuanshenyang national {2. for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, shenyang 110016, china Lab. for Mat. Sci. Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

A kind of new deflection technique has been developed for measuring the growth stress of thermally growing oxide scales during high temperature oxidation of alloys. The average growth stresses in oxide scales such as Al2.3, NiO and Cr2.3 formed on the surface of the superalloys can be investigated by this technique. Unlike the comventional deflection method, the novel method does not need to apply a coating for preventing one main face of thin strip specimen from oxidizing and can be used under the condition of longer time and higher temperature.

关键词： Oxide film Growth stress Deflection method