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The vibron dressing in α-helicoidal macromolecular chains

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Chinese Physics B 2013年第6期22卷 218-227页

作者： D.evizovi s. Galovi A. Reshetnyak Z. Ivi University of Belgrade Vina Institute of Nuclear Sciences Laboratory for Theoretical and Condensed Matter PhysicsP. O. Box 522 11001 Belgrade Serbia Joint Institute for Nuclear Research Bogoliubov Laboratory for Theoretical Physics Dubna Russia Laboratory of Non-Linear Media Physics Institute of Strength Physics and Materials ScienceTomsk 634021 Russia

We present a study of the physical properties of the vibrational excitation in α-helicoidal macromolecular chains, caused by the interaction with acoustical and optical phonon modes. The influence of the temperature and the basic system parameters on the vibron dressing have been analyzed by employing the simple mean-field approach based on the variational extension of the Lang-Firsov unitary transformation. The applied approach predicts a region in system parameter space where one has an abrupt transition from a partially dressed （light and mobile） to a fully dressed （immobile） vibron state. We found that the boundary of this region depends on system temperature and the type of bond among structural elements in the macromolecular chain.

关键词： vibron small-polaron α-helix partial dressing

Analytical and approximate solutions of nonlinear schrödinger equation with higher dimension in the anomalous dispersion regime

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Journal of Ocean Engineering and science 2022年第2期7卷 143-154页

作者： Lanre Akinyemi Mehmet senol M.s.Osman Department of Mathematics Lafayette CollegeEastonPAUSA Nev¸s ehir HacıBekta¸s Veli University Department of MathematicsNev¸s ehirTurkey Department of Mathematics Faculty of ScienceCairo UniversityGiza 12613Egypt

The generalized Riccati equation mapping method(GREMM)is used in this paper to obtain different types of soliton solutions for nonlinear schrödinger equation with higher dimension that existed in the regimes of anomalous ***,we use the q-homotopy analysis method combined with the Laplace transform(q-HATM)to obtain approximate solutions of the bright and dark optical *** q-HATM illustrates the solutions as a rapid convergent *** addition,to show the physical behavior of the solutions obtained by the proposed techniques,the graphical representation has been provided with some parameter *** findings demonstrate that the proposed techniques are useful,efficient and reliable mathematical method for the extraction of soliton solutions.

关键词： q-homotopy analysis method Generalized Riccati equation mapping method Laplace transform

Mathematical model of micropolar fluid in two-phase immiscible fluid flow through porous channel

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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 993-1006页

作者： P.K.YADAV s.JAIsWAL B.D.sHARMA Department of Mathematics Motilal Nehru National Institute of Technology Allahabad

This paper is concerned with the flow of two immiscible fluids through a porous horizontal channel. The fluid in the upper region is the micropolar fluid/the Eringen fluid, and the fluid in the lower region is the Newtonian viscous fluid. The flow is driven by a constant pressure gradient. The presence of micropolar fluids introduces additional rotational parameters. Also, the porous material considered in both regions has two different permeabilities. A direct method is used to obtain the analytical solu- tion of the concerned problem. In the present problem, the effects of the couple stress, the micropolarity parameter, the viscosity ratio, and the permeability on the velocity profile and the microrotational velocity are discussed. It is found that all the physical parameters play an important role in controlling the translational velocity profile and the microrotational velocity. In addition, numerical values of the different flow parameters are computed. The effects of the different flow parameters on the flow rate and the wall shear stress are also discussed graphically.

关键词： micropolar fluid immiscible fluid porous medium couple stress microp=olarity parameter

Hydromagnetic thin film flow of Casson fluid in non-Darcy porous medium with Joule dissipation and Navier＇s partial slip

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Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1613-1626页

作者： G.s.sETH R.TRIPATHI M.K.MIsHRA Department of Applied Mathematics Indian Institute of Technology (India School of Mines) Dhanbad 826004 India

In this paper, the effects of viscous and Ohmic heating and heat genera- tion/absorption on magnetohydrodynamic flow of an electrically conducting Casson thin film fluid over an unsteady horizontal stretching sheet in a non-Darcy porous medium are investigated. The fluid is assumed to slip along the boundary of the sheet. similar- ity transformation is used to translate the governing partial differential equations into ordinary differential equations. A shooting technique in conjunction with the 4th order Runge-Kutta method is used to solve the transformed equations. Computations are car- ried out for velocity and temperature of the fluid thin film along with local skin friction coefficient and local Nusselt number for a range of values of pertinent flow parameters. It is observed that the Casson parameter has the ability to enhance free surface velocity and film thickness, whereas the Forchheimer parameter, which, is responsible for the inertial drag has an adverse effect on the fluid velocity inside the film. The velocity slip along the boundary tends to decrease the fluid velocity. This investigation has various applications in engineering and in practical problems such as very large scale integration （VLsI） of electronic chips and film coating.

关键词： fluid thin film non-Darcy medium velocity slip unsteady stretching sheet,Joule dissipation heat generation/absorption

EXACT sOLUTIONs FOR MAGNETOHYDRODYNAMIC FLOW IN A ROTATING FLUID

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Acta Mechanica sinica 2002年第3期18卷 244-251页

作者： s. Asghar Masood Khan A.M. siddiqui T. Hayat Department of Mathematics Quaid-i-Azam University Islamabad Pakistan Department of Mathematics Pennsylvania State University York Campus 1031 Edgecomb Avenue New York PA 17403 USA

An analytical solution is obtained for the flow due to solid-body rotations an oscillating porous disk and of a fluid at infinity. Neglecting the induced magnetic field, the effects of the transversely applied magnetic field on the flow are studied. Further, the flow confined between two disks is also discussed. It is found that an infinite number of solutions exist for the flow confined between two disks.

关键词： rotating fluid porous disk double disks magnetohydrodynamic flow

Microstructures and Mechanical Properties of Al/Mg Alloy Multilayered Composites Produced by Accumulative Roll Bonding

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Journal of Materials science & Technology 2011年第1期27卷 15-21页

作者： H.s. Liu B. Zhang G.P. Zhang shenyang National Laboratory for Materials science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education School of Materials & Metallurgy Northeastern University Shenyang 110004 China

Al/Mg alloy multilayered composites were produced successfully at the lower temperature（280 C） by accumulative roll bonding（ARB） processing *** microstructures of Al and Mg alloy layers were characterized by scanning electron microscopy and transmission electron *** hardness and three-point bending tests were conducted to investigate mechanical properties of the *** is found that Vickers hardness,bending strength and stiffness modulus of the Al/Mg alloy multilayered composite increase with increasing the ARB *** and crack propagation along the interface are the two main failure modes of the multilayered composite subjected to bending *** and fracture mechanisms of the composite are analyzed.

关键词： Accumulative roll bonding(ARB) Al/Mg alloy multilayered composite Ultra-fine grains Hardness Bending properties

Factors associated with crash severity on rural roadways in Wyoming

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Journal of Traffic and Transportation Engineering(English Edition) 2016年第4期3卷 308-323页

作者： Debbie s.shinstine shaun s.Wulff Khaled Ksaibati Wyoming Technology Transfer Center University of Wyoming Department of statistics University of Wyoming

The ability to identify risk factors associated with crashes is critical to determine appropriate countermeasures for improving roadway safety. Many studies have identified risk factors for urban systems and intersections, but few have addressed crashes on rural roadways, and none have analyzed crashes on Indian Reservations. This study analyzes crash severity for rural highway systems in Wyoming. These rural systems include interstates, state highways, rural county local roads, and the roadway system on the Wind River Indian Reservation （WRIR）. In alignment with the Wyoming strategic highway safety goal of reducing critical crashes {fatal and serious injury}, crash severity was treated as a binary response in which crashes were classified as severe or not severe. Multiple logistic regression models were developed for each of the highway systems. Five effects were prevalent on all systems including animals, driver impairment, motorcycles, mean speed, and safety equipment use. With the exception of animal crashes, all of these effects increased the probability that a crash would be severe. Based upon these results, DOTs can pursue effective policies and targeted design decisions to reduce the severity of crashes on rural highways.

关键词： Crash dataCrash analysisLogistic regressionRoadway safetyIndian reservationsHighway system

Influence of Zn^(2+)or Cu^(2+) on Reduction and Recalcination Behavior of Fe_2TiO_5

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Journal of Materials science & Technology 2007年第5期23卷 697-702页

作者： M.Bahgat M.H.Khedr H.s.Abdelmaksoud CMRDI P.O.Box 87-HelwanCairoEgypt Chemistry Department Faculty of ScienceBenisuef UniversityEgypt

Fe2O3, TiO2, CuO and ZnO powders were mixed according to the formula of （1-x）TiO2 xCuO-Fe2O3 or （1-x）TiO2 xZnO-Fe2O3 （x=0, 0.2 0.4, 0.6, 0.8, 1）, and well ball-milled with H2O for 3 h to ensure homogeneity of the powdered solids, then fired at 1200℃ for 4 h. The fired samples were reduced at 500℃ with hydrogen gas. The reduced samples were subjected to recalcination at 500℃ in CO2 atmosphere. Both of fired, reduced and calcined samples were characterized by X-ray diffraction, vibrating sample magnetometry, reflected light microscopy and scanning electron microscopy. Different phases were formed after firing of Cu^＋2 or Zn^2＋ substituted Fe2TiO5. Magnetization （Bs） of the formed phases after firing are very low corresponding to diluted magnetic semiconductors （DMs） and increases with increasing the substituted cations （Cu^＋2 or Zn^2＋）. The reduction of the fired samples enhanced the Bs values whereas the reducibility increases with increasing the Cu^＋2 or Zn^2＋ content. samples show different tendency toward CO2 decomposition which is very important for environmental minimization for CO2.

关键词： Nanosized ferrite Titanate Reduction Magnetic properties Reduction-recalcin-ation CO2 decomposition

Review of deployment technology for tethered satellite systems

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Acta Mechanica sinica 2018年第4期34卷 754-768页

作者： B.s.Yu H.Wen D.P.Jin state Key Laboratory of Mechanics and Control of Mechanical structures Nanjing University of Aeronautics and Astronautics

Tethered satellite systems（Tsss） have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a Tss. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. Hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

关键词： Tethered satellite Deployment Dynamics Control Experiment