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A general solution for one dimensional chemo-mechanical coupled hydrogel rod

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Acta Mechanica Sinica 2018年第2期34卷 392-399页

作者： Xing-quan wang Qing-Sheng Yang Department of Engineering Mechanics Beijing University of Technology

Smart hydrogels are environmentally sensitive hydrogels, which can produce a sensitive response to external stimuli, and often exhibit the characteristics of multi filed coupling. In this paper, a hydrogel rod under chemomechanical coupling was analytically studied based on a poroelastical model. The already known constitutive and governing equations were simplified into the one dimensional case, then two different boundary conditions were considered. The expressions of concentration, displacement,chemical potential and stress related to time were obtained in a series form. Examples illustrate the interaction mechanism of chemical and mechanical effect. It was found that there was a balance state in the diffusion of concentration and the diffusion process could lead to the expansion or the stress change of the hydrogel rod.

关键词： Chemo-mechanical coupling Analytical solution One dimensional hydrogel rod

VGQ-Vor： extending virtual grid quadtree with Voronoi diagram for mobile k nearest neighbor queries over mobile objects

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Frontiers of Computer Science 2013年第1期7卷 44-54页

作者： Botao wang Jingwei qu Xiaosong wang Guoren wang Masaru KITSUREGAWA Department of Information Science and Engineering Northeastern University Shenyang 110004 China Institute of Industrial Science the University of Tokyo Tokyo 153-8505 Japan

Performing mobile k nearest neighbor （MkNN） queries whilst also being mobile is a challenging problem. All the mobile objects issuing queries and/or being queried are mobile. The performance of this kind of query relies heav- ily on the maintenance of the current locations of the objects. The index used for mobile objects must support efficient up- date operations and efficient query handling. This study aims to improve the performance of the MkNN queries while re- ducing update costs. Our approach is based on an observa- tion that the frequency of one region changing between being occupied or not by mobile objects is much lower than the frequency of the position changes reported by the mobile ob- jects. We first propose an virtual grid quadtree with Voronoi diagram （VGQ-Vor）, which is a two-layer index structure that indexes regions occupied by mobile objects in a quadtree and builds a Voronoi diagram of the regions. Then we propose a moving k nearest neighbor （kNN） query algorithm on the VGQ-Vor and prove the correctness of the algorithm. The ex- perimental results show that the VGQ-Vor outperforms the existing techniques （Bx-tree, Bdual-tree） by one to three or- ders of magnitude in most cases.

关键词： location based services mobile k nearest neigh- bor query mobile object index Voronoi diagram

A crucial role of heme-regulated eIF2α kinase in maintaining cytoskeletal meshwork under an oxygen deficient condition

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Science Bulletin 2017年第15期62卷 1045-1047页

作者： Guangbo qu Xiaoyan wang Sijin Liu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

During erythroid differentiation,heme-regulated e IF2α kinase(Hri)is necessary to coordinate translation of globin mRNAs with the availability of heme for the production of large amounts of hemoglobin in red blood ce... 详细信息

关键词：血红素 f2α 细胞骨架激酶 el 氧气血红蛋白 mRNA

Temperature and velocity dependent friction of a microscale graphite-DLC heterostructure

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Friction 2020年第2期8卷 462-470页

作者： Yujie GONGYANG Wengen OUYANG Cangyu qu Michael URBAKH Baogang quan Ming MA quanshui ZHENG Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China Center for Nano and Micro Mechanics Tsinghua UniversityBeijing 100084China School of Chemistry and The Sackler Center for Computational Molecular and Materials Science Tel Aviv UniversityTel Aviv 69978Israel The Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv UniversityTel Aviv 69978Israel Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China

One of the promising approaches to achieving large scale superlubricity is the use of junctions between existing ultra-flat surface together with superlubric graphite *** we studied the frictional properties of microscale graphite mesa sliding on the diamond-like carbon,a commercially available material with a ultra-flat *** interface is composed of a single crystalline graphene and a diamond-like carbon surface with roughness less than I *** an integrated approach,which includes Argon plasma irradiation of diamond-like carbon surfaces,X-ray photoelectron spectroscopy analysis and Langmuir adsorption modeling,we found that while the velocity dependence of friction follows a thermally activated sliding mechanism,its temperature dependence is due to the desorption of chemical groups upon *** observations indicate that the edges have a significant contribution to the *** results highlight potential factors affecting this type of emerging friction junctions and provide a novel approach for tuning their friction properties through ion irradiation.

关键词： friction graphite diamond like carbon irradiation desorption

Simulated Calculations of Strain Induced Precipitation Behaviorin a Nb-Ti-V Steel

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Journal of Materials Science & Technology 1998年第6期14卷 571-573页

作者： qu, Jinbo wang, Zhaodong Liu, Xianghua wang, Guodong NE Univ Technol State Key Lab Rolling & Automat Shenyang 110006 Peoples R China

On the basis of regular solution sublattice model and classical nucleation and growth theory, strain induced precipitation kinetics in Nb-Ti-V combined treated microalloying steels has been calculated. The calculated precipitation-time-temperature diagram is in reasonable agreement with experimental results obtained from isothermal stress relaxation method. (Edited author abstract) 11 Refs.

关键词： Steel

Cyclic behavior of stiffened joints between concrete-filled steel tubular column and steel beam with narrow outer diaphragm and partial joint penetration welds

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Frontiers of Structural and Civil Engineering 2016年第3期10卷 333-344页

作者： Chunyan quan Wei wang Jian ZHOU Rong wang State Key Laboratory of Disaster Reduction in Civil Engineering TongJi University Shanghai 200092 China Department of Structural Engineering TongJi University Shanghai 200092 China East China Architectural Design & Research Institute Shanghai 200002 China

This paper presented an investigation on a stiffened joint in practical engineering which was between concrete-filled steel tubular column and steel beam with narrow outer diaphragm and partial joint penetration welds. Through the low-frequency cyclic loading test, the cyclic behavior and failure mode of the specimen were investigated. The results of the test indicated the failure mode and bearing capacity of the specimen which were influenced by the axial compression ratio of the concrete-filled tubular column. On the contrary, the inner diaphragm and inner stiffeners had limited impacts on the hysteretic behavior of the joint. There was no hysteresis damage fracture on the narrow outer diaphragm connected to the concrete-filled steel tubular column with partial joint penetration welds. Due to the excellent ductility and energy dissipating capacity, the proposed joint could be applied to the seismic design of high-rise buildings in highly intensive seismic region, but axial compression ratio should be controlled to avoid unfavorable failure modes.

关键词： narrow outer diaphragm concrete-filled tubular column joint inner and outer stiffening cyclic behavior

High-entropy intermetallics:from alloy design to structural and functional properties

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Rare Metals 2022年第6期41卷 1989-2001页

作者： Hang wang quan-Feng He Yong Yang Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Department of Materials Science and Engineering.City University of Hong Kong Hong Kong 999077China Department of Advanced Design and System Engineering.City University of Hong Kong Hong Kong 999077China

Conventional intermetallics are strong but ***,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,some of which even show appreciable ductility and fracture toughness at room *** this article,we provide a focused review on the recent researches on HEIs,from the fundamentals,such as the concept of HEIs,the formation rules to the structural and functional properties of *** results hitherto reported clearly show that the HEIs with distinct properties could be a promising material for future structural and functional applications.

关键词： Internetallics High-entropy alloys Phase formation Mechanical properties Functional properies

Influence of External Interface Normal Stress on the Growth of Cu-Sn IMC During Aging

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Acta Metallurgica Sinica(English Letters) 2020年第10期33卷 1388-1396页

作者： Changchang wang Yinbo Chen Zhi-quan Liu Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shenzhen Institute of Advanced Electronic Materials Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

A U-shape clamp was designed to apply stress perpendicular to the interface of Cu/Sn/Cu solder joints,and its influence on the growth behavior of Cu-Sn intermetallic compound(IMC)during thermal aging at 150℃ was *** results show that compared with the sample at general stress-free state,the growth rate of IMC under compression is faster,while that under tension is ***,the interface between IMC and Sn is smoother under compressive stress,and the corresponding IMC grains are smaller and more uniform than that under tensile *** to the growth kinetic analysis,the growth of IMC under general,compressive and tensile states is all controlled by the combination of grain boundary diffusion and volume diffusion with a similar growth exponent(n≈0.4).However,external stress can affect the Ostwald ripening process of grain growth,causing a change of grain size and grain boundary density in the IMC *** a result,the IMC growth behavior at the interface of the solder joint will be affected by the applied external normal stress.

关键词： Cu-Sn IMC Growth behavior External stress effect Isothermal aging

Applicability of discrete element method with spherical and clumped particles for constitutive study of granular materials

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 240-251页

作者： Tongming qu Min wang Yuntian Feng Zienkiewicz Centre for Computational Engineering College of EngineeringSwansea UniversitySwanseaWales SA18EPUK T-3 Fluid Dynamics and Solid Mechanics Group Theoretical DivisionLos Alamos National LaboratoryLos AlamosNM87545USA

Discrete element method(DEM)has been intensively used to study the constitutive behaviour of granular ***,to what extent a real granular material can be reproduced by virtual DEM simulations remains *** study attempts to answer this question by comparing DEM simulations with typical features of experimental granular *** groups of models with spherical and clumped particles are investigated from four perspectives:(i)deviatoric stress and volumetric behaviour;(ii)critical state behaviour;(iii)stress-dilatancy relationship;and(iv)the evolution of principal stress ratio against axial *** results demonstrate that DEM with spherical or clumped particles is capable of qualitatively describing macroscopic deviatoric stress responses,volumetric behaviour,and critical state behaviour observed in experiments for granular *** the other hand,some qualitative deviations between experiments and the investigated DEM simulations are also observed,in terms of the stress-dilatancy behaviour and principal stress ratio against axial strain,which are proven to be critical for constitutive *** results demonstrate that DEM with spherical or clumped particles may not necessarily fully capture experimental features of granular materials even from a qualitative *** is thus encouraged to thoroughly validate DEM with experiments when developing constitutive models based on DEM observations.

关键词： Discrete element method(DEM) Granular materials Constitutive behaviour Deviatoric hardening model Rolling resistance model Irregular particles