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Correlation of Shear Viscosity of Nanofluids Using the Local Composition Theory 被引量:5
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作者 M.S. Hosseini A. Mohebbi S Ghader 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第1期102-107,共6页
In this study,a new method is presented to correlate the shear viscosity of nanofluids by local composition theory.The Eyring theory and nonrandom two-liquid(NRTL)equation are used for this purpose.The effects of temp... In this study,a new method is presented to correlate the shear viscosity of nanofluids by local composition theory.The Eyring theory and nonrandom two-liquid(NRTL)equation are used for this purpose.The effects of temperature and particle volume concentration on the viscosity are investigated.The adjustable parameters of NRTL equation are obtained by fitting with experimental data.The calculated shear viscosities for nanofluids of CuO/water with 29 nm particle size,Al2O3/water with two different particle diameters,36 nm and 47 nm,and CuO/(ethylene glycol,water)are compared with experimental data and the average absolute deviation(AAD)is 1.2%,while the results from some conventional models yield an AAD of 190%.The results of this study are in excellent agreement with experimental data. 展开更多
关键词 NANOFLUID VISCOSITY local composition theory nonrandom two-liquid equation Eyring theory
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A Study on the Development of Rural Tourism in Qianshan Scenic Spot in Liaoning Province from the Perspective of Local Theory
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作者 Yang YU Liang ZHAO 《Asian Agricultural Research》 2017年第9期7-8,共2页
This paper first explains the local theoretical knowledge,and then analyzes the local foundation of the development of rural tourism in Qianshan scenic area,and finally puts forward the conception of the development o... This paper first explains the local theoretical knowledge,and then analyzes the local foundation of the development of rural tourism in Qianshan scenic area,and finally puts forward the conception of the development of rural tourism in Qianshan scenic area. 展开更多
关键词 Rural tourism Local theory Liaoning Qianshan
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Theory of passive localization for underwater sources based on acoustic ray modeling 被引量:2
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作者 SUN Zhenge (National Laboratory of Acoustics Beijing 100080)MA Yuanliang TU Qingping and JIANG Xiaoquan(College of Marine Engineering, NPU Xi’an 710072) 《Chinese Journal of Acoustics》 1997年第3期250-259,共10页
The theory of passive localization for underwater sources based on acoustic ray channel modeling is discussed. The principles of channel modeling in Ray-theory, determination of eigenrays which connect source and rece... The theory of passive localization for underwater sources based on acoustic ray channel modeling is discussed. The principles of channel modeling in Ray-theory, determination of eigenrays which connect source and receiver, analysis of DOA arriving structure and time delay spectrum arriving structure, their relationship to source location are given in the paper. Source location is estimated by matching measured DOA and TDS to their calculated counterparts. The method of Ray-theory based passive localization features its simplicity, less calculation, short array aperture and robust performance to environment parameters, as compared with those methods based on Normal Mode theory. 展开更多
关键词 theory of passive localization for underwater sources based on acoustic ray modeling
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An Obliquely Propagating Electromagnetic Lower-Hybrid-Drift Instability in Plasmas with Negative Ions
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作者 王飞虎 张宙 +1 位作者 陈银华 黄凤 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第4期388-393,共6页
In this study, by employing a local fluid theory for warm plasma containing negative ions, an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field currents or rel... In this study, by employing a local fluid theory for warm plasma containing negative ions, an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field currents or relative drifts between electrons and ions was investigated. It is found that the growth rate of the lower-hybrid-drift instability (LHDI) can be controlled by appropriate selection of the propagation direction, the wave number and the relative population of the negative ions. 展开更多
关键词 lower-hybrid-drift frequency INSTABILITY negative ions local fluid theory
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Accurate treatments of electrostatics for computer simulations of biological systems: A brief survey of developments and existing problems
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作者 衣沙沙 潘聪 胡中汉 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期1-7,共7页
Modern computer simulations of biological systems often involve an explicit treatment of the complex interactions among a large number of molecules. While it is straightforward to compute the short-ranged Van der Waal... Modern computer simulations of biological systems often involve an explicit treatment of the complex interactions among a large number of molecules. While it is straightforward to compute the short-ranged Van der Waals interaction in classical molecular dynamics simulations, it has been a long-lasting issue to develop accurate methods for the longranged Coulomb interaction. In this short review, we discuss three types of methodologies for the accurate treatment of electrostatics in simulations of explicit molecules: truncation-type methods, Ewald-type methods, and mean-field-type methods. Throughout the discussion, we brief the formulations and developments of these methods, emphasize the intrinsic connections among the three types of methods, and focus on the existing problems which are often associated with the boundary conditions of electrostatics. This brief survey is summarized with a short perspective on future trends along the method developments and applications in the field of biological simulations. 展开更多
关键词 Ewald sum local molecular field theory symmetry-preserving mean field theory
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Spatially Resolved Analytical Electron Microscopy at Grain Boundaries of α-Al_2O_3
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作者 S.Nufer, A.G.Marinopoulos, C.Elsasser, W.Kurtz and M.RuhleMax-Planck-Institut fur Metallforschung, Seestr. 92, D-70174 Stuttgart, Germany 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2002年第2期189-190,共2页
In this work the electronic structure and the impurity excess of the basal and rhombohedral twin grain boundaries are investigated, using electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectrosco... In this work the electronic structure and the impurity excess of the basal and rhombohedral twin grain boundaries are investigated, using electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDXS). The measurability of electronic structures of the twin grain boundaries are discussed by comparing theoretical density of states (DOS) from bulk material with interfacial DOS, obtained from local density functional theory (LDFT) calculations. 展开更多
关键词 Grain boundaries Alumina (α-Al2O3) Local density function theory (LDFT) Electron energy loss spectroscopy (EELS)
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Theoretical Study of Electron Paramagnetic Resonance Spectra and Local Lattice Distortion for Mn^(2+) in Zn(ClO_4)_2·6(H_2O)Mg(ClO_4)_2·6(H_2O)
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作者 李菊芬 HUO Jianli WU Xinhui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第3期571-574,共4页
The electron paramagnetic resonance(EPR) spectra of trigonal Mn^(2+) centers in Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals were studied on the basis of the complete energy matrices for a d^5... The electron paramagnetic resonance(EPR) spectra of trigonal Mn^(2+) centers in Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals were studied on the basis of the complete energy matrices for a d^5 configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn^(2+) center has an compressed distortion along the crystalline c3 axis, and when Mn^(2+) is doped in the Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 ?, for Zn(ClO4)2·6(H2O), R=2.130 2 ?, for Mg(ClO4)2·6(H2O) have been determined. 展开更多
关键词 Zn(ClO4)2·6(H2O):Mn^2+ Mg(ClO4)2·6(H2O):Mn^2+ systems local lattice structure distortion EPR spectrum ligand-fields theory
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Common Properties of the Operator Products in Local Spectral Theory
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作者 Kai YAN Xiao Chun FANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2015年第11期1715-1724,共10页
Let X,Y be Banach spaces, A,D : X - Y and B,C : Y - X be the bounded linear operators satisfying operator equation set ACD=DBD DBA=ACAIn this paper, we show that AC and BD share some basic operator properties such a... Let X,Y be Banach spaces, A,D : X - Y and B,C : Y - X be the bounded linear operators satisfying operator equation set ACD=DBD DBA=ACAIn this paper, we show that AC and BD share some basic operator properties such as the injectivity and the invertibility. Moreover, we show that AG' and BD share many common local spectral properties including SVEP, Bishop property (β) and Dunford property (C). 展开更多
关键词 Jacobson's lemma operator equation set common property local spectral theory
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The Decomposability for Operator Matrices and Perturbations
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作者 Xiao Li WANG ALATANCANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2023年第3期497-512,共16页
Let X and Y be Banach spaces.For A∈L(X),B∈L(Y),C∈L(Y,X),let MCbe the operator matrix defined on X⊕Y by M_(C)=(AC0B)∈L(X⊕Y).In this paper we investigate the decomposability for MC.We consider Bishop’s property(... Let X and Y be Banach spaces.For A∈L(X),B∈L(Y),C∈L(Y,X),let MCbe the operator matrix defined on X⊕Y by M_(C)=(AC0B)∈L(X⊕Y).In this paper we investigate the decomposability for MC.We consider Bishop’s property(β),decomposition property(δ)and Dunford’s property(C)and obtain the relationship of these properties between M_(C) and its entries.We explore how σ_(*)(M_(C))shrinks from σ_(*)(A)∪σ_(*)(B),where σ_(*)denotes σ_(β),σ_(δ),σ_(C),σ_(dec).In particular,we develop some sufficient conditions for equality σ_(*)(MC)=σ_(*)(A)∪σ_(*)(B).Besides,we consider the perturbation of these properties for MCand show that in perturbing with certain operators C the properties for MCkeeps with A,B.Some examples are given to illustrate our results.Furthermore,we study the decomposability for(0AB0).Finally,we give applications of decomposability for operator matrices. 展开更多
关键词 Bishop’s property(β) decomposition property(δ) Dunford’s property(C) DECOMPOSABILITY operator matrix PERTURBATION local spectral theory
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Aeroelastic stability analysis of heated flexible panel subjected to an oblique shock 被引量:7
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作者 Liuqing YE Zhengyin YE Xiaochen WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第8期1650-1666,共17页
The critical conditions for aeroelastic stability and the stability boundaries of a flexible two-dimensional heated panel subjected to an impinging oblique shock are considered using theoretical analysis and numerical... The critical conditions for aeroelastic stability and the stability boundaries of a flexible two-dimensional heated panel subjected to an impinging oblique shock are considered using theoretical analysis and numerical computations, respectively. The von-Karman large deflection theory of isotropic flat plates is used to account for the geometrical nonlinearity of the heated panel, and local first-order piston theory is employed in the region before and after shock waves to estimate the aerodynamic pressure. The coupled partial differential governing equations, according to the Hamilton principle, are established with thermal effect based on quasi-steady thermal stress theory.The Galerkin discrete method is employed to truncate the partial differential equations into a set of ordinary differential equations, which are then solved by the fourth-order Runge-Kutta numerical integration method. Lyapunov indirect method is applied to evaluate the stability of the heated panel. The results show that a new aeroelastic instability(distinct from regular panel flutter) arises from the complex interaction of the incident and reflected wave system with the panel flexural modes and thermal loads. What's more, stability of the panel is reduced in the presence of the oblique shock. In other words, the heated panel becomes aeroelastically unstable at relatively small flight aerodynamic pressure. 展开更多
关键词 AerothermoelasticityHeated panel Local piston theory Shock waves STABILITY Thermal flutter
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The vertical distribution characteristics of integral turbulence statistics in the atmospheric boundary layer over an urban area in Beijing 被引量:7
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作者 LIU Yang LIU HuiZhi WANG Lei 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第8期1533-1545,共13页
Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Be... Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Beijing city according to similarity theory. The conclusions were as follows.(1) Normalized standard deviations of wind speeds/ui * were plotted as a function only of a local stability parameter. The values under near-neutral conditions were 2.15, 1.61, and 1.19 at 47 m, 2.39, 1.75,and 1.21 at 140 m, and 2.51, 1.77, and 1.30 at 280 m, showing a clear increase with height. The normalized standard deviation of wind components fitted the 1/3 law under unstable stratification conditions and decreased with height under both stable and unstable conditions.(2) The normalized standard deviation of temperature fitted the.1/3 law in the free convection limit, but was quite scattered with different characteristics under near-neutral conditions. The normalized standard deviations of humidity and the CO2 concentration fitted the.1/3 law under unstable conditions, and remained constant under near-neutral and stable stratification. The normalized standard deviation of scalars, i.e., temperature, humidity, and CO2 concentration, all increased with height.(3) Compared with momentum, and the water vapor and CO2 concentrations, the turbulence correlation coefficient for heat was smaller under near-neutral conditions, but larger under both stable and unstable conditions. A dissimilarity between heat, and the water vapor and CO2 concentrations was observed in urban areas. The relative correlation coefficients between heat and each of momentum, humidity, and CO2 concentration(|rwT/ruw|, |rwT/rwc| and |rwT/ruq|) in the lower layers were always larger than in higher layers, except for the relative correlation coefficient between heat and humidity in an unstable stratification. Therefore, the ratio between heat and each of momentum, humidity, and CO2 concentration decreased with height. 展开更多
关键词 Urban boundary layer Local similarity theory Integral turbulence statistics
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Mechanical theorem proving in the surfaces using the characteristic set method and Wronskian determinant 被引量:1
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作者 FENG RuYong YU JianPing 《Science China Mathematics》 SCIE 2008年第10期1763-1774,共12页
In this paper, we generalize the method of mechanical theorem proving in curves to prove theorems about surfaces in differential geometry with a mechanical procedure. We improve the classical result on Wronskian deter... In this paper, we generalize the method of mechanical theorem proving in curves to prove theorems about surfaces in differential geometry with a mechanical procedure. We improve the classical result on Wronskian determinant, which can be used to decide whether the elements in a partial differential field are linearly dependent over its constant field. Based on Wronskian determinant, we can describe the geometry statements in the surfaces by an algebraic language and then prove them by the characteristic set method. 展开更多
关键词 mechanical theorem proving Wu-Ritt’s characteristic set method local theory of surface Wronskian determinant 12H99 53A05
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VERTICAL STRUCTURE OF SECOND-MOMENT TURBULENT VARIABLES
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作者 AL-JIBOORI.M.H. 徐玉貌 钱永甫 《Acta meteorologica Sinica》 SCIE 2001年第2期218-232,共15页
Two kinds of observational data,fluctuation and mean profile measurements,from a 325 m meteorological tower in Beijing,China,are used to evaluate local scales of velocity and temperature for higher heights by flux-gra... Two kinds of observational data,fluctuation and mean profile measurements,from a 325 m meteorological tower in Beijing,China,are used to evaluate local scales of velocity and temperature for higher heights by flux-gradient mean profiles and eddy-correlation techniques.A comparison of these methods each other was made in terms of vertical turbulence fluxes for momentum and beat at the same heigbt.The vertical profiles of non-dimensional second moments. such as vertical turbulent fluxes of momentum and heat.velocity and temperature standard deviations,were derived by local similarity theory.The local similarity relations expressed that the vertical distributions of non-dimensional second moment variables were found to be functions of z/Λ and z/h in the stable boundary layer and the function of z/Z_i for the convective boundary layer,where A the local Monin Obukhov(M-O)length.h the height of stable boundary layer and Z_i the height of mixed-layer.These relations are shown to agree well with the observational data. 展开更多
关键词 vertical turbulence fluxes local similarity theory standard deviations of velocity and temperature
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