检索结果-南通市图书馆

Research on the Heat-Conduction Enhancement for Liquid with Nano-Particle Suspensions

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2002年第3期11卷 214-219页

作者： b.X.Wang H.Li X.f.Peng Department of Thermal Engineering Tsinghua University Beijing P.R. China

by measuring the effective thermal conductivity, taking photos of the distribution of the nano-particles in the fluids and photos that reflect the interfacial phenomena between nano-particles and fluids, we try to exp... 详细信息

关键词： Nano-particle suspension effective thermal conductivity brownian motion affinity heat-conduction enhancement.

Tuning the fields focused by a high NA lens using spirally polarized beams(Invited Paper)

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2017年第3期15卷 51-54页

作者： f.Wackenhut b.Zobiak A.J.Meixner A.V.failla Eberhard Karls University Tübingen Institute of Physical and Theoretical Chemistry University Medical Center Hamburg-Eppendorf UKE Microscopy Imaging Facility

We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture （NA） lens. Different and relevant states of polarization as well as field distributions can be created by the simple turning of a λ/2 retardation wave plate placed in the excitation path of a micro- scope. The realization of such a versatile excitation source can provide an essential tool for nanotechnology investigations and biomedical experiments.

关键词： Tuning the fields focused by a high NA lens using spirally polarized beams high

Neumann boundary Conditions Inhibiting SSb in Coleman-Weinberg Mechanism

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2010年第12期54卷 1071-1074页

作者： f.N.fagundes R.O.francisco b.b.Dilem J.A.Nogueira Universidade federal do Espírito Santo

In this work we show that homogeneous Neumann boundary conditions inhibit the Coleman-Weinberg mechanism for spontaneous symmetry breaking in the scalar electrodynamics if the length of the finite region is small enou... 详细信息

关键词： scalar electrodynamics Neumann boundary conditions spontaneous symmetry breaking

A computational study of the role of particle size standard deviation on the collision frequency in differential settling

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2013年第1期28卷 34-45页

作者： C.HEILIGER N.b.KAYE f.Y.TESTIK Civil Engineering Clemson UniversityClemsonSC29634USA

The results of a simple computational model for differential settling are presented illustrating the significant role that particle size distribution plays in collision frequency and sedimentation rate of particles in a quiescent environment. The model tracks a large number of particles（order 10;） with log-normally distributed diameters,as they settle at their Stokes settling *** collisions are detected and result in larger particles that fall more rapidly.A number of simplifying assumptions are made in the model in order to avoid empirical correlations for phenomena such as collision efficiency and particle *** simplifying assumptions were needed to isolate and quantify the role of the particle size *** concentration profiles indicate that,even in the absence of collisions, the standard deviation（σ;） of the particle size strongly influences the bulk mass settling rate as,for largerσ;, more mass is concentrated in larger,faster falling *** collision frequency is also a strong function ofσ;. for a given mass concentration the collision frequency first increases linearly with increasingσ;as greater variation in particle size leads to greater variation in particle velocity,and shorter times for particles to catch each *** largerσ;more mass is concentrated in larger particles,so,for a given mass concentration,there are fewer particles per unit volume,increasing the mean distance between the particles and reducing the collision *** implications of these results for sedimentation measurement using optical attenuation techniques are discussed.

关键词： Settling Sediment size distribution Sediment collision frequency Coefficient of variation

Resonance Conversion as the Effective Way of Triggering the ^（178m2）Hf Isomer Energy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2006年第8期23卷 2049-2051页

作者： f. feodor KARPESHIN M. b.TRZHASKOVSKAYA 张景波 Science Center and Department of Physics Harbin Institute of Technology Harbin 150001 fock Institute of Physics St. Petersburg State University RU-198504 St. Petersburg Russia PNPI RU-198355 St. Petersburg Leningrad District Russia

Experiments on photo-induced de-excitation triggering of ^（178m2）Hf are revisited. We present an alternative and more effective way of triggering by exploiting the resonance internal conversion. full theoretical description of a possible channel is presented. It is therefore revisited the impact itself produced by those experiments.

关键词： Resonance Conversion Effective Way

fractographic analysis of the overload effect on fatigue crack growth in 2024-T3 and 7075-T6 Al alloys

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 83-90页

作者： A.Albedah b.bachir bouiadjra S.M.A.K.Mohammed f.benyahia Mechanical Engineering Department College of EngineeringKing Saud UniversityP.O.Box 800Riyadh 11421Saudi Arabia LMPM Department of Mechanical EngineeringUniversity of Sidi Bel AbbesBP 89CitéBen M’hidiSidi Bel Abbes 22000Algeria Department of Mechanical and Industrial Engineering Ryerson UniversityTorontoOntario M5B 2K3Canada

The effect of single overload on the fatigue crack growth in 2024-T3 and 7075-T6 Al alloys was *** tests under constantamplitude loading with overload peak were carried out on V-notched *** analysis was used as a principal approach to explain the crack growth retardation due to the *** electron microscopy(SEM)analyses were conducted on the fractured surface of failed specimens to study the retardation *** obtained results show that the overload application generates a plastic zone in both aluminum *** generated plastic zone is three times larger in the case of 2024-T3 compared to 7075-T6,and thus,a significant crack retardation was induced for *** retardation effect due to the overload for 2024-T3 and 7075-T6 lasted for about 10 mm and 1 mm,respectively,from the point of overload application.

关键词： fatigue crack growth overload retardation fractography crack tip plasticity

Soil Pore Characterization Using free Software and a Portable Optical Microscope

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2013年第4期23卷 503-510页

作者： L. f. PIRES f. S. bORGES S. PASSONI A. b. PEREIRA Department of Physics State University of Ponta Grossa (UEPG) Department of Soil Science State University of Ponta Grossa (UEPG)

Total porosity （TP）, determined by image analysis, pore type and pore size distribution were evaluated on impregnated soil blocks from an undisturbed brazilian sandy loam soil using a digital portable optical microscope. The free software Image J （version 1.40g） was used for image analysis. Procedures for soil image collection and analysis were presented. The image analysis allowed the evaluation of pore sizes with diameters ranging from 20 to 〉 1 000 μm. The following types of pores were also obtained： rounded, elongated and intermediate. The results M[owed the characterization of the soil as moderately porous （TP = 21.6%）. Rounded, intermediate and elongated pores were responsible for 11.6%, 31.7% and 56.7% of TP. In relation to pore size 51.1% of TP was in the 100-500μm size class and a third of TP came from the pores larger than 500μm.

关键词： image analysis soil porosity soil structure pore size distribution

bound in continuum states and induced transparency in mesoscopic demultiplexer with two outputs

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2020年第12期29卷 429-437页

作者： Z Labdouti T Mrabti A Mouadili E H El boudouti f fethi b Djafari-Rouhani LPMR Dèpartement de PhysiqueFacultèdes SciencesUniversitèMohammed IOujdaMorocco LSTA Dèpartement de PhysiqueFacultèPolydisciplinaire de LaracheUniversitèAbdelmalek EssaadiTètouanMorocco LPMCER Dèpartement de PhysiqueFacultèdes Sciences et Techniques de MohammediaUniversitèHassan IICasablancaMorocco IEMN UMR CNRS 8520UFR de PhysiqueUniversitède Lille59655 Villeneuve d'AscqFrance

We investigate the electronic transport in a simple mesoscopic cross structure made of two wires(stubs)grafted at the same point along a quantum *** show that the structure may exhibit important phenomena such as bound in continuum(bIC)*** states are transformed into electromagnetically induced transparency(EIT)resonance by detuning slightly the lengths of the *** last phenomenon is used to propose and study a mesoscopic demultiplexer device with an input waveguide and two output *** give closed-form expressions of the geometrical parameters that allow a selective transfer of a given state in the first waveguide without perturbing the second *** effect of temperature on the transmission resonances is also examined by using Landauer-büttiker *** analytical results of the dispersion relation and transmission and reflection coefficient are obtained using the Green's function method.

关键词： mesoscopic structure demultiplexer device bound states in continuum(bIC) EIT resonance

Dynamics of Sutterby fluid flow due to a spinning stretching disk with non-fourier/fick heat and mass flux models

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第9期42卷 1247-1258页

作者： f.MAbOOD J.MACKOLIL b.MAHANTHESH A.RAUf S.A.SHEHZAD Department of Information Technology Fanshawe College LondonON N5Y 5R6Canada Department of Mathematics CHRIST(Deemed to be University)Bangalore 560029India Department of Mathematics COMSATS University IslamabadSahiwal 57000Pakistan

The magnetohydrodynamic Sutterby fluid flow instigated by a spinning stretchable disk is modeled in this *** Stefan blowing and heat and mass flux aspects are incorporated in the thermal *** conventional models for heat and mass flux,i.e.,fourier and fick models,are modified using the Cattaneo-Christov(CC)model for the more accurate modeling of the *** boundary layer equations that govern this problem are solved using the apt similarity *** subsequent system of equations is tackled by the Runge-Kutta-fehlberg(RKf)*** graphical visualizations of the results are discussed with the physical *** rates of mass and heat transmission are evaluated for the augmentation in the pertinent *** Stefan blowing leads to more species diffusion which in turn increases the concentration field of the *** external magnetism is observed to decrease the velocity ***,more thermal relaxation leads to a lower thermal field which is due to the increased time required to transfer the heat among fluid *** heat transport is enhanced by the stretching of the rotating disk.

关键词： Sutterby fluid Stefan blowing Cattaneo-Christov(CC)theory magnetic field rotating stretching disk