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energy dissipation mechanism of commensurate graphene layers

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Science China(Technological Sciences) 2021年第3期64卷 635-640页

作者： HUO ZhanLei CHEN Yang GUO ZhengRong CHANG TienChong Shanghai Key Laboratory of Mechanics in energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

The energy dissipation mechanism of graphene layers in commensurate contact is studied by molecular dynamics *** commensurability between graphene layers is controlled by misfit angles between graphene layers or an in-plane strain applied to one of the graphene *** find that for small size graphene,the main energy dissipation is not caused by *** propose two potential energy dissipation channels,the lattice distortion induced by the moirésuperlattice structure and variation of entropy of the contacting *** results provide an insight into the energy dissipation mechanism of commensurate contact graphene.

关键词： graphene commensurate energy dissipation molecular dynamics misfit angle

energy dissipation and Apparent Viscosity of Semi-solid Metal during Rheological Processes PartⅠ: energy dissipation

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Journal of Materials Science & Technology 2007年第6期23卷 342-346页

作者： Wen LIU Shuming XING Peiwei BAO Milan ZHANG Liming XIAO Beijing Jiaotong University Beijing 100044 China

The energy dissipation caused by the viscous force has great effects on the flow property of semi-solid metal during rheological processes such as slurry preparing, delivering and cavity filling. Experimental results in this paper indicate that the viscous friction between semi-solid metal and pipe wall, the collisions among the solid particles, and the liquid flow around particles are the three main types of energy dissipation. On the basis of the hydromechanics, the energy dissipation calculation model is built. It is demonstrated that the micro-structural parameters such as effective solid fraction, particle size and shape, and flow parameters such as the mean velocity, the fluctuant velocity of particles and the relative velocity between the fluid and solid phase, affect the energy dissipation of semi-solid metal.

关键词： Semi-solid metal energy dissipation Rheology Apparent viscosity Model

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energy dissipation of slot-type flip buckets

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Journal of Hydrodynamics 2018年第2期30卷 365-368页

作者： Jian-hua Wu Shu-fang Li Fei Ma College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China College of Water Conservancy and Hydropower Engineering Hebei University of Engineering Handan 056000 China

The energy dissipation is a key index in the evaluation of energy dissipation *** the present work,a flip bucket with a slot,called the slot-type flip bucket,is theoretically and experimentally investigated by the method of estimating the energy *** theoretical analysis shows that,in order to have the energy dissipation,it is necessary to determine the sequent flow depth h1 and the flow speed V1 at the corresponding position through the flow depth h2 after the hydraulic *** relative flow depth h2/ho is a function of the approach flow Froude numberFro,the relative slot widthb/Bo,and the relative slot angleθ/β.The expression for estimating the energy dissipation is developed,and the maximum error is not larger than 9.21%.

关键词： energy dissipation hydraulic jump slot-type flip bucket

energy dissipation of coal and rock during damage and failure process based on EMR

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International Journal of Mining Science and Technology 2015年第5期25卷 787-795页

作者： Song Dazhao Wang Enyuan Li Zhonghui Liu Jie Xu Wenquan School of Safety Engineering China University of Mining & Technology Postdoctoral Research Station Yongcheng Coal & Electricity Holding Group Co.Ltd. State Key Laboratory of Coal Resources & Safe Mining Shaanxi Coal and Chemical Technology Institute Co. Ltd.

The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy ***,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of *** the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing *** results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting *** type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak *** type Ⅱ trend energy is a W-shaped fluctuating one containing 6 *** load-control loading mode,there is one energy dissipation trend of shock downward-steady *** that,rock samples also present a trend of 4 *** energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive *** factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.

关键词： energy dissipation Electromagnetic radiation Coal and rock Damage and failure Rock burst

energy dissipation of cavity expansion based on generalized non-linear failure criterion under high stresses

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Journal of Central South University 2012年第5期19卷 1419-1424页

作者：邹金锋童无欺赵健 School of Civil Engineering Central Sou th University

Based on the compression mechanism for analyzing the cavity expansion problem in soil under high stresses,generalized non-linear failure criterion and large strain and energy conservation in plastic region during the cavity expanding were *** energy conservation equation was established and the limited pressure of cavity expansion under high stresses was given based on the energy dissipation analysis method,in which the energy generated from cavity expansion is absorbed by the volume change and shear strain caused in *** factors of large strain and dilatation were considered by the proposed *** analysis shows that the limited pressure is determined by failure criterion,stress state,large deformation characteristic,dilatation and strength of *** is shown from the comparison that the results with the proposed method approximate to those of the in-situ *** cavity expansion pressure first decreases and then increases nonlinearly with both of shear modulus and dilatation increasing.

关键词： energy dissipation energy conservation large strain cavity expansion high stress ,,

energy dissipation in atomic-scale friction

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Friction 2013年第1期1卷 24-40页

作者： Yuan-zhong HU Tian-bao MA Hui WANG State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

The mechanisms of energy dissipation are discussed in this paper by reviewing the models and research in atomic-scale *** study is undertaken to answer a fundamental question in the study of friction:How is frictional work dissipated,particularly in cases where material damage and wear are not *** initiation of energy dissipation,the role of structural commensurability,and the estimation of the interfacial shear strength have been examined in detail by introducing the Tomlinson model,the Frenkel-Kontorova model,and the cobblestone model,*** discussion is extended to energy dissipation progress described in terms of phononic and electronic *** contributions from other mechanisms of dissipation such as viscoelastic relaxation and material wear are also *** an example,we analyzed a specific process of dissipation in multilayer graphene,on the basis of results of molecular dynamics(MD)simulations,which reveal a reversible part of energy that circulates between the system and the external *** leads us to emphasize that it is crucial in future studies to clearly define the coefficient of dissipation.

关键词： energy dissipation atomic-scale friction phononic damping viscoelastic relaxation

energy dissipation FOR WEAK SOLUTIONS OF INCOMPRESSIBLE MHD EQUATIONS

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Acta Mathematica Scientia 2013年第3期33卷 865-871页

作者：高真圣谭忠吴国春 School of Mathematical Sciences Huaqiao University School of Mathematical Sciences Xiamen University

In this article, we mainly study the local equation of energy for weak solutions of 3D MHD equations. We define a dissipation term D（u, B） that steins from an eventual lack of smoothness in the solution, and then obtain a local equation of energy for weak solutions of 3D MHD equations. Finally, we consider the 2D case at the end of this article.

关键词： energy dissipation incompressible MHD equations

energy dissipation through wind-generated breaking waves

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Chinese Journal of Oceanology and Limnology 2012年第5期30卷 822-825页

作者：张书文曹瑞雪谢玲玲 College of Ocean and Meteorology Guangdong Provincial Key Laboratory of ClimateResources and Environment in Continental Shelf and Deep SeaGuangdong Ocean University

Wave breaking is an important process that controls turbulence properties and fluxes of heat and mass in the upper oceanic layer.A model is described for energy dissipation per unit area at the ocean surface attributed to wind-generated breaking waves,in terms of ratio of energy dissipation to energy input,windgenerated wave spectrum,and wave growth *** advanced is a vertical distribution model of turbulent kinetic energy,based on an exponential distribution *** result shows that energy dissipation rate depends heavily on wind speed and sea *** results agree well with predictions of previous works.

关键词： near-surface dynamics energy dissipation wave breaking

energy dissipation Analysis of Bended SMA Bar in Isothermal State

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Journal of Wuhan University of Technology(Materials Science) 2004年第4期19卷 95-98页

作者：彭刚 China Three Gorges University

The theory calculation formula is deduced about stress distribution in cross section and changes in Martensite percentages with the section height of random section shape bar under the action of the bending moment according to the Brinson's Constitutive *** bar's energy dissipation capability under circulation of bending moment was analyzed and the calculation theory was set up. By using MATLAB program and the numerical calculation for uniform rectangle cross section bar, the relationships among the maximal stress and strain on cross section edge with bend load, the stress and Martensite percent's with cross section height, the energy dissipation capability with cross section height, and the energy dissipation capability with maximal strain on cross section edge are gained, also those curves are discused. It is put forward that the SMA material can be used for passive structure vibration control to dissipate energy of bend load.

关键词： shape memory alloys energy dissipation constitutive relation thermodynamics equation pseudo-elasticity