Stability analysis and modeling for the three-dimensionalDarcy-Forchheimer stagnation point nano?uid ?owtowards a moving surface?

正Yuming CHU1,2, M. I. KHAN3,, M. I. U. REHMAN4, S. KADRY5,S. QAYYUM4, M. WAQAS6     

Preface

The 7th World Congress on Recovery, Recycling and Re-integration (R’05) was held in Beijing, China from September 25 to 29, 2005. Over 600 papers from 60 countries, and 6 plenary lecturers on achievements and future needs in various areas of 3R were pre- sented in 15 parallel sessions. In addition, two forums and four workshops were arranged for in-depth discussions on specific topics. The 3R World Congress series originated from the Rio Earth Summit, 1992, at which the need for a globa…     

小问题?

105.重量为P的物块系在可绕铰链A旋转的轻杆AD上,杆AD搁置在平板ABC上,设平板与物块D之间的摩擦系数为μ=0.4,AD和AC边的夹角为θ,OA=40cm,OB=20cm,OC=30cm,不计物块D的尺寸(图1)。求物块能放在平板上无滑动时θ角的最小值。(南通纺织专科学校黄又珩,引自R.C.希伯勒,工程力学)     

小问题?

129.半径为R的水平圆盘绕通过盘心的铅垂轴匀速转动,测得一质点通过盘心时相对圆盘的速度为v,离开盘缘时相对速度为2v。设运动过程中质点不受水平外力且摩擦可忽略。求质点通过盘心时,相对于圆盘的加速度的大小。(蒋持平,哈尔滨工业大学844信箱) 130.质量分别为m_1,m_2,半径分别为r_1,r_2的两均质圆盘,分别可绕其垂直轴O_1及O_2轴转动。若开始     

小问题? (34)

105.重量为P的物块系在可绕铰链A旋转的轻杆AD上,杆AD搁置在平板ABC上,设平板与物块D之间的摩擦系数为μ=0.4,AD和AC边的夹角为θ,OA=40cm,OB=20cm,OC=30cm,不计物块D的尺寸(图1)。求物块能放在平板上无滑动时θ角的最小值。(南通纺织专科学校黄又珩,引自R.C.希伯勒,工程力学) ...     

Combining ?eld-modulating electroosmotic vortex and insulatingpost to manipulate particles based on dielectrophoresis?

正School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Wuhan 430074, China(Received Aug. 17, 2020/Revised Dec. 7, 2020)     

Ce0.8Zr0.2O2固溶体磨料对ZF7光学玻璃抛光性能的改善

采用改进的湿固相机械化学反应法制备出超细锆掺杂氧化铈磨料Ce1-xZrxO2(x=0,0.2),运用X射线衍射(XRD)、透射电镜(TEM)等手段表征其物相类型、外观形貌、比表面积、粒度、表面电位等物理性质,通过测定抛光速率和观察表面的微观形貌考察它们对ZF7光学玻璃的抛光性能影响.结果表明,Ce0.8Zr0.2O2固溶体磨料对ZF7光学玻璃抛光性能比纯CeO2磨料有明显的提高,抛光速率达到463 nm/min,5.0 μm×5.0 μm的范围内微观表面粗糙度Rα值达到1.054 nm,而纯CeO2磨料的抛光速率只有292 nm/min,Rα值却增大到1.441 nm.Ce0.8Zr0.2O2固溶体的抛光速率的明显增大和表面粗糙度Rα的下降主要与其负表面电位的增大和颗粒尺寸、粒度的减小密切相关.     

Annual Index to Vol. 1, 2003

l Forum …………Arthur M. Squires, Kui Wang, John F. Davidson, Qingru Chen, John R. Grace, Kefa Cen, Terry A. Ring, Guilin Yang and George E. Klinzing No.1, 2-6 …………Dianzuo Wang, Lothar Reh and Ying Hu No.3, 94 l Articles Characteristic Dimensionless Numbers in Multi-scale and Rate-De-pendent Processes …………Yilong Bai, Mengfen Xia and Haiying Wang et al. No.1, 7-12 Particle Properties Promise and Neglect ……………Wolfgang P…     

Compensated compactness applied to perturbed fourth and sixth order P. D. E.

I.Introducti0nlnthearticle,wemainlydiscussthefollowingequations:wherej(.)isasmoothnonlinearmapfromRtoR,l'l2andlI'if2.denotethenormofH'(R)andthenormofL'"(R),respectively,C0isaconstant.Asdandsgotozero,theconvergenceandregularityforthesolutionsofEq.(l.l)andE…     

On the boundedness and periodicity of the solutions of a certain vector differential equation of third-order

IntroductionWeshallbeconcernedherewiththird-ordersystemofnon-lineardifferentialequationsoftheformX F(X,X)X Ba H(X)=P(t,X,X,X),(l)whereX6R",R"denotestherealn-dimensionalEuclldeanspaceRxRx'xR(nfactors),R=(--ac,ac),Fisannxn-matrixfunction,Bisarealnxn-constantsymmetricmatrix,H:R"~R"1andp:RxR"xR"xR"~R".ThedotsindicatCdifferentiationwithrespeCttot.ThefunctionsF,HandParecontinuousforallvaluesoftheirrespeCtivearguments.Moreover,theexistenceandtheuniquenessofthesolutionsof(l)willbeassu…     

Four-point explicit difference schemes for the dispersive equation

A class of three-level explicit difference schemes for the dispersive equationu_1=au_(xxx)are established These schemes have higher stability and involve four meshpoints at the middle level.Their local truncation errors are O(τ+h)and stabilityconditions are from|R|≤0.25 to|R|≤10,where|R|=|a|τ/h~3,which is muchbetter than|R|≤0.25.     

Generalized derivatives of a region function and its applications

This paper is based on some fundamental concepts im [7], Clarke’s generalizedderivatives,as well as Lasotra’s and Strauss’s definitions of differential D(x) of amultivalued function f(x).Thereby,the generalized derivatives of a region function F(x) isdefined asD_F(x)=U∩{G(x)(?)B(R), (?)x∈B(R); G(x)=F’_x=F’(x)}The existence of the generalized derivatives of a region function F(x) is discussed:thenecessary and sufficient conditions of existence of the Fréchet generalized derivatives ofsuch a function is established.     

Space-time correlations of passive scalar in Kraichnan model

We consider the two-point, two-time(space-time) correlation of passive scalar R( r, τ) in the Kraichnan model under the assumption of homogeneity and isotropy. Using the fine-gird PDF method, we find that R( r, τ) satisfies a diffusion equation with constant diffusion coefficient determined by velocity variance and molecular diffusion. Its solution can be expressed in terms of the two-point, one time correlation of passive scalar, i.e., R( r, 0). Moreover, the decorrelation of R( k, τ), which is...     

介绍“Wiley工程中数值方法丛书”之一:生物力学中的有限元

《生物力学中的有限元》(Finitc Elements in Biomechanics)一书由R.H.Gallagher,B.R.Simon,P.C.Johnson和J.F.Gross主编,1982年John Wile & Sons出版。本书是R.H.Gallagher和O.C.Zienkiewicz主编的“Wiley工程中数值方法丛书”之一。丛书包括:《工程实践中的岩体力学》;《优化结构设计:理论和应用》;《流体中的有限元》(卷一,粘性流和流体动力学;卷二,数学基础、空气动力学和润滑);【基　金】      

多肢墙的线性方程解

本文去掉了R.Rossman方法中连梁连续化这一基本假定,给出了一种更符合实际的解法,该方法可以直接处理多肢墙,进而解决了R.Rossman方法中弯矩分配系数的确定问题。     

北京国际实验力学会议(ICEM)

由中国力学学会和日本非破坏检查协会联合召开的国际实验力学会议已于1985年10月7-10日在北京科学会堂举行。出席这次会议的近300人(包括展出和工作人员),其中外宾近150人。他们分别来自日本、美国、英国、西德、瑞士、意大利、加拿大、埃及、印度、朝鲜等十多个国家,其中有美国实验力学学会(SEM)主席R.J.Rinn,英国应变测量学会(BSSM) ...     

THE FIRST-ORDER APPROXIMATION OF NON-KIRCHHOFF-LOVE THEORY FOR ELASTIC CIRCULAR PLATE WITH FIXED BOUNDARY UNDER UNIFORM SURFACE LOADING (Ⅲ)──NUMERICAL RESULTS

1ShanghaiUniversity;ShanghaiInstituteofAppliedMathematicsandMechanics,Shanghai200072P.R.ChinaIX.NondimensionalEquationsandBoundaryConditionsoftheFirstOrderApproximateTheoryFortheconvenienceofnumericalcomputation,webeginbytransformingthedifferentialequatio…     

The asymptotic solution to the antiplane shear dynamic crack-tip field in an elastic strain-softening viscoplastic material

ProjectsupportedbytheNationalNaturalScienceFoundationofHeilongiianginP.R.ChinaI.Introductionlnthatengineering,thereisakindofmaterials.Somesofteninganddamagephenomenaa1waysappearwhenthedeformationbecomeslargeenough.Forstudyingthisprocess.asofteningmode1oft…     

SOLUTION FOR PLANE STRAIN FORWARD AND BACKWARD EXTBUSIONS WITB A FRACTIONAL REDUCTION R=0.5 BY THE INTEGARTION DEPENDING ON A PARAMETER

A parameter t is introduced to boundary slip line of rigid regions for plane strain and indirect extrusions with a fractional reduction R=0.5. Integration by substitution has been used along the boundary slip line in order to obtain the extrusion pressure. By the integration depending on a pararneter, the following results are obtained, (?)/2R=1.29 and die pressure is 5.14k for backward extrusion, (?)/2R=1.29 and pad average pressure is 2.57k for forward extrusion. All the results from this method are the same as those of the conventional solution.     

NONLINEAR COMPLEX DYNAMIC PHENOMENA OF THE PERTURBED METALLIC BAR CONSIDERING DISSIPATING EFFECT

IntroductionTotheweaklydamped ,periodicallyforcedsine_Gordonequation ,A .R .Bishop[1～ 3]analyzeditssolutionunderperiodicboundaryconditionandconcludedthatitssolutionwouldshowdifferentspatialstructuresandlong_timeasymptoticstatesalongwiththevariationofpara…