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Nonlocal thermoelastic analysis of a functionally graded material microbeam

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Applied Mathematics and Mechanics(English Edition) 2021年第6期42卷 855-870页

作者： wei peng Like CHEN Tianhu HE Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province Lanzhou University of TechnologyLanzhou 730050China School of Civil Engineering and Mechanics Lanzhou UniversityLanzhou 730000China School of Science Lanzhou University of TechnologyLanzhou 730050China

In extreme heat transfer environments, functionally graded materials(FGMs)have aroused great concern due to the excellent thermal shock resistance. With the development of micro-scale devices, the size-dependent effect has become an important issue. However, the classical continuum mechanical model fails on the micro-scale due to the influence of the size-dependent effect. Meanwhile, for thermoelastic behaviors limited to small-scale problems, Fourier's heat conduction law cannot explain the thermal wave effect. In order to capture the size-dependent effect and the thermal wave effect, the nonlocal generalized thermoelastic theory for the formulation of an FGM microbeam is adopted in the present work. For numerical validation, the transient responses for a simply supported FGM microbeam heated by the ramp-type heating are *** governing equations are formulated and solved by employing the Laplace transform techniques. In the numerical results, the effects of the ramp-heating time parameter, the nonlocal parameter, and the power-law index on the considered physical quantities are presented and discussed in detail.

关键词： nonlocal thermoelastic theory functionally graded material(FGM) size-dependent microbeam ramp-type heating dynamic response

Evaluation of thermophoretic effects on graphite dust coagulation in high-temperature gas-cooled reactors

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Particuology 2020年第4期18卷 45-52页

作者： Kaiyuan Wang Suyuan Yu wei peng Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Advanced Nuclear Energy Technology Cooperation Innovation CenterKey Laboratory of Advanced Nuclear Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China

In high-temperature gas-cooled reactors,graphite dust particles within the reactor core and the heat transfer equipment experience large temperature *** such conditions,thermophoresis may play an important role in determining aerosol *** study presents a theoretical and numerical analysis of the thermophoretic effects on aerosol coagulation within these *** coagulation rates for Brownian versus thermophoretic coagulation are calculated and compared for various temperature *** results show that thermophoretic coagulation dominates over Brownian coagulation for large temperature *** defined an enhancement factor to evaluate the role of thermophoretic coagulation under various reactor *** enhancement factor increased dramatically with increasing temperature gradient,decreasing pressure and increasing particle diameter,but was not very sensitive to temperature *** time evolution of the particle size distribution related to combined Brownian and thermophoretic coagulation was simulated using a log-skew-normal method of *** simulation results indicate that aerosol evolution can be strongly accelerated by thermophoretic coagulation under large temperature gradients.

关键词： Graphite dust High-temperature gas-cooled reactor Thermophoretic coagulation Log-skew-normal method of moments Particle size distribution

Experimental and mechanistic study of dispersed micrometer-sized particle resuspension in a square straight duct with rough walls

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Particuology 2023年第12期83卷 101-114页

作者： Qi Sun Suyuan Yu wei peng Institute of Nuclear and New Energy Technology Cooperation Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing100084China Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of the Ministry of EducationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing100084China

The resuspension of graphite dust is an important phenomenon in the release of radioactivity and the safety of nuclear reactors during severe *** this study,a visualization experimental platform is constructed to study effects of particle size,flow velocity,and wall roughness on the resuspension characteristics of graphite particles.A statistical model of particle resuspension applicable to monolayer dispersed particles is developed based on the moment equilibrium of the particles and the flow field characteristics,as calculated by the large-eddy simulation *** results show that particle resuspension can be divided into short-and long-term resuspension *** particle resuspension occurs during the short-term *** increases in flow velocity and particle diameter,the aerodynamic or adhesion force acting on the particles increases,and corresponding particle resuspension fraction *** influence of rough walls on particle resuspension is related to both the force on the particles and the arm ratio between the wall morphology and the particle diameter.A comparison with the experimental results demonstrates that the particle resuspension model developed in this study accurately predicts the impact of flow velocity,particle size,and wall roughness on particle resuspension.

关键词： Particle resuspension Statistical model Moment equilibrium High temperature gas-cooled reactor(HTGR)

A modified fractional-order thermo-viscoelastic model and its application to a polymer micro-rod heated by a moving heat source

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Applied Mathematics and Mechanics(English Edition) 2022年第4期43卷 507-522页

Classical thermo-viscoelastic models may be challenged to predict the precise thermo-mechanical behavior of viscoelastic materials without considering the memorydependent ***,with the miniaturization of devices,the size-dependent effect on elastic deformation is becoming more and more *** capture the memory-dependent effect and the size-dependent effect,the present study aims at developing a modified fractional-order thermo-viscoelastic coupling model at the microscale to account for two fundamentally distinct fractional-order models which govern the memory-dependent features of thermal conduction and stress-strain relation,***,the modified theory is used to study the dynamic response of a polymer micro-rod heated by a moving heat *** governing equations are obtained and solved by the Laplace transform *** calculation,the effects of the fractional-order parameter,the fractional-order strain parameter,the mechanical relaxation parameter,and the nonlocal parameter on the variations of the considered variables are analyzed and discussed in detail.

关键词： size-dependent effect fractional-order strain fractional-order thermal conduction generalized thermo-viscoelasticity moving heat source

Three new species of Genus Cryptonatica (Gastropoda,Naticidae) from Huanghai Sea Cold Water Mass

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Acta Oceanologica Sinica 2010年第1期29卷 52-57页

作者： ZHANG Suping wei peng Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

This report based on the results of investigations conducted in June 2007 and July 2008, respectively, on the benthic community structure and characteristic diversity of the Huanghai Sea （Yellow Sea） Cold Water Mass, as well as that in July 1959 during the national oceanic survey. The Naticidae specimens collected from Cold Water Mass in middle and northern Huanghai Sea were studied through morphological classification and the internal anatomy on radula. Three new species of Naticidae, i.e., Cryptonatica purpurfunda sp. nov., Cryptonatica sphaera sp. nov., and Cryptonatica striatica sp. nov. were identified. The morphological characteristics of the new species are described, and the similarties and differences between the new species and similar species are compared and discussed.

关键词： Mollusca Gastropoda Naticidae Cryptonatica new species Huanghai Sea Cold Water Mass

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells

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Chinese Journal of Natural Medicines 2018年第9期16卷 693-699页

作者： peng wei CHEN Bao-An Department of Medical Oncology Jiangsu Cancer HospitalJiangsu Institute of Cancer ResearchNanjing Medical University Affiliated Cancer Hospital Department of Hematology and Oncology (Key Department of Jiangsu Medicine) Medical Schoolthe Affiliated Zhongda HospitalSoutheast University

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma(ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid(GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time-and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress(ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

关键词： Gambogic acid Apoptosis Extranodal NK/T-cell lymphoma Endoplasmic reticulum stress

Long-time Asymptotics for the Reverse Space-time Nonlocal Hirota Equation with Decaying Initial Value Problem:without Solitons

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 708-727页

作者： wei-qi peng Yong CHEN School of Mathematical Sciences East China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this work,we mainly consider the Cauchy problem for the reverse space-time nonlocal Hirota equation with the initial data rapidly decaying in the solitonless *** from the Lax pair,we first construct the basis Riemann-Hilbert problem for the reverse space-time nonlocal Hirota ***,using the approach of Deift-Zhou nonlinear steepest descent,the explicit long-time asymptotics for the reverse space-time nonlocal Hirota is *** the reverse space-time nonlocal Hirota equation,since the symmetries of its scattering matrix are different with the local Hirota equation,the v(λ_(i))(i=0,1)would like to be imaginary,which results in theδ_(λi)^(0)contains an increasing t(±Imv(λ_(i)))/2,and then the asymptotic behavior for nonlocal Hirota equation becomes differently.

关键词： Riemann-Hilbert problem reverse space-time nonlocal Hirota equation long-time asymptotics nonlinear steepest descent method

Eutectic reaction and cored dendritic morphology in yttrium doped Zr-based amorphous alloys

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 747-751页

作者： wei-jie peng Yong Zhang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing100083China

The microalloying effect of yttrium on the crystallization behaviors of （Zr0.525Al0.10Ti0.05Cu0.179Ni0.146）100-xYx, and （Zr0.55Al0.15- Ni0.10Cu0.20）100-xYx （x=0, 0.4, and 1, thus the two alloy systems were denoted as Zr52.5, Zr52.5Y0.4, Zr52.5Y1, and Zr55, Zr55Y0.4, Zr55Y1, respectively） was studied. Transmission electron microscopy （TEM） results suggested that the crystalline phases were different in the two Zr-based alloys and with different yttrium contents. ZrNi-phase and Al3Zr5 phase precipitations can be well explained by the mechanisms of nucleation and growth. Al3Zr5 phase is mainly formed by a peritectic-like reaction, while ZrNi-phase by a eutectic reaction. The contents of elements Y, A1, and Ti may dominate the reaction types. The orientation relationship between Y203 particles and A13Zr5 phase is also discussed.

关键词： zirconium alloys amorphous alloys bulk metallic glasses yttrium eutectic structure dendritic structure

A modified stiffness spreading method for layout optimization of truss structures

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Acta Mechanica Sinica 2018年第6期34卷 1072-1083页

作者： Mingjie Cao Haitao Ma peng wei State Key Laboratory of Subtropical Building Science School of Civil Engineering and TransportationSouth China University of TechnologyGuangzhou 510640China Earthquake Engineering Research and Test Center Guangzhou UniversityGuangzhou 510405China

The stiffness spreading method (SSM) was initially proposed for layout optimization of truss structures,in which an artificial elastic material of low modulus is uniformly distributed in the design domain to create connections between discrete *** this paper,a modified stiffness spreading method is proposed by replacing the artificial elastic material with auxiliary bars to connect real members of the truss *** the background continuum mesh for the elastic material is no longer required,the computational cost is significantly *** SSM,the new method is advantageous in that an initial design may consist of disconnected bars allocated in the design domain,and mathematical programming methods can be applied for the efficient solution of the formulated optimization problem.A number of solution strategies are also developed to achieve more practical designs with lower computational *** examples of both 2-D and 3-D truss structures are presented to demonstrate the feasibility,robustness and effectiveness of the proposed method.

关键词： Stiffness spreading method Modified stiffness spreading method Layout optimization Truss structure Optimization strategy