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Normal Mode Analysis on Three Different Structures of a Duplex DNA d(CGCGAATTCGCG) 被引量:1
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作者 LIN Dong-hai LIAO Xin-li 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1998年第3期67-71,共5页
Normal mode analysis in dihedral angle space was carried out on two X ray crystal structures and one model structure responded to the same sequence of duplex DNA: d(CGCGAATTCGCG). Comparing these results indicates th... Normal mode analysis in dihedral angle space was carried out on two X ray crystal structures and one model structure responded to the same sequence of duplex DNA: d(CGCGAATTCGCG). Comparing these results indicates that it is reliable and meaningful to carry out normal mode analysis on model structures. The reliability is greater except for the ends of helix. 展开更多
关键词 normal mode analysis Duplex DNA Atomic fluctuation Molecular dynamics
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Thomson effect with hyperbolic two-temperature on magneto-thermo-visco-elasticity 被引量:1
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作者 A.M.ALHARBI M.I.A.OTHMAN H.M.ATEF 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第9期1311-1326,共16页
The study considers a homogeneous isotropic thermo-visco-elastic solid with hyperbolic two-temperature to cope up with its two-dimensional(2 D)deformations.The heat conduction equation is influenced by the Thomson coe... The study considers a homogeneous isotropic thermo-visco-elastic solid with hyperbolic two-temperature to cope up with its two-dimensional(2 D)deformations.The heat conduction equation is influenced by the Thomson coefficient.Lord-Shulman’s theory is used to modify the basic governing equations.A method called"normal mode analysis"is utilized to attain the magnetic field,stress,conductive and thermodynamic temperature,and displacement components.Also,a number of numerical calculations are performed and discussed to understand the impact of hyperbolic two-temperatures,Thomson parameter,and viscosity on the material mentioned above. 展开更多
关键词 thermo-visco-elasticity magnetic field hyperbolic two-temperature Lord-Shulman’s theory Thomson coefficient normal mode analysis
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Research on coupled thermo-hydro-mechanical dynamic response characteristics of saturated porous deep-sea sediments under vibration of mining vehicle 被引量:1
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作者 Wei ZHU Xinyu SHI +2 位作者 Rong HUANG Liyue HUANG Wenbo MA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第9期1349-1362,共14页
The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-m... The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-mechanical problem for saturated porous deep-sea sediments subject to the vibration of the mining vehicle is investigated.Based on the Green-Lindsay(G-L)generalized thermoelastic theory and Darcy’s law,the model of thermo-hydro-mechanical dynamic responses for saturated porous deep-sea sediments under the vibration of the mining vehicle is established.We obtain the analytical solutions of non-dimensional vertical displacement,excess pore water pressure,vertical stress,temperature,and change in the volume fraction field with the normal mode analysis method,and depict them graphically.The normal mode analysis method uses the canonical coordinate transformation to solve the equation,which can quickly decouple the equation by ignoring the modal coupling effect on the basis of the canonical mode.The results indicate that the vibration frequency has obvious influence on the vertical displacement,excess pore water pressure,vertical stress,and change in volume fraction field.The loading amplitude has a great effect on the physical quantities in the foundation,and the changes of the physical quantities increase with the increase in loading amplitude. 展开更多
关键词 deep-sea sediment thermo-hydro-mechanical dynamic generalized thermoelastic theory normal mode analysis dynamic response characteristic
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Rotational Effect on the Propagation of Waves in a Magneto-Micropolar Thermoelastic Medium
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作者 A.M.Abd-Alla S.M.Abo-Dahab +1 位作者 M.A.Abdelhafez A.M.Farhan 《Computers, Materials & Continua》 SCIE EI 2021年第10期205-220,共16页
The present paper aims to explore how the magnetic field,ramp parameter,and rotation affect a generalized micropolar thermoelastic medium that is standardized isotropic within the half-space.By employing normal mode a... The present paper aims to explore how the magnetic field,ramp parameter,and rotation affect a generalized micropolar thermoelastic medium that is standardized isotropic within the half-space.By employing normal mode analysis and Lame’s potential theory,the authors could express analytically the components of displacement,stress,couple stress,and temperature field in the physical domain.They calculated such manners of expression numerically and plotted the matching graphs to highlight and make comparisons with theoretical findings.The highlights of the paper cover the impacts of various parameters on the rotating micropolar thermoelastic half-space.Nevertheless,the non-dimensional temperature is not affected by the rotation and the magnetic field.Specific attention is paid to studying the impact of the magnetic field,rotation,and ramp parameter of the distribution of temperature,displacement,stress,and couple stress.The study highlighted the significant impact of the rotation,magnetic field,and ramp parameter on the micropolar thermoelastic medium.In conclusion,graphical presentations were provided to evaluate the impacts of different parameters on the propagation of plane waves in thermoelastic media of different nature.The study may help the designers and engineers develop a structural control system in several applied fields. 展开更多
关键词 Magnetic field MICROPOLAR THERMOELASTIC ROTATION ramp parameter normal mode analysis
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Product Vibrational State Distributions of F+CH_(3)OH Reaction on Full-Dimensional Accurate Potential Energy Surface
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作者 Meng Zhang Yongfa Zhu Jun Li 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第1期153-166,I0064,共15页
The hydrogen abstraction reaction of methanol with fluorine atoms can produce HF and CH_(3)O or CH_(2)OH radicals,which are important in the environment,combustion,radiation,and interstellar chemistry.In this work,the... The hydrogen abstraction reaction of methanol with fluorine atoms can produce HF and CH_(3)O or CH_(2)OH radicals,which are important in the environment,combustion,radiation,and interstellar chemistry.In this work,the dynamics of this typical reaction is investigated by the quasi-classical trajectory method based on a recently developed globally accurate full-dimensional potential energy surface.Particularly,the vibrational state distributions of the polyatomic products CH_(3)O and CH_(2)OH are determined by using the normal mode analysis method.It is found that CH_(3)O and CH_(2)OH are dominantly populated in the ground state when the reactants are at the ground ro-vibrational state.The OH stretching mode,torsional mode,H_(2)CO out-of-plane bending mode and their combination bands in the CH_(2)OH product can be effectively excited once the OH stretching mode of the reactant CH_(3)OH is excited to the first vibrationally excited state.Most of the available energy flows into the HF vibrational energy and the translational energy in both channels,while the radical products,CH_(3)O or CH_(2)OH,receive a small amount of energy,consistent with experiment,which is an indication of its spectator nature. 展开更多
关键词 normal mode analysis Potential energy surface CH_(3)OH Product energy partitioning Hydrogen abstraction reaction
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Mode-I crack in a two-dimensional fibre-reinforced generalized thermoelastic problem
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作者 Kh.Lotfy 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期244-253,共10页
A general model of the equations of the Lord-Sulman theory including one relaxation time and the Green-Lindsay theory with two relaxation times, as well as the classical dynamical coupled theory, are applied to the st... A general model of the equations of the Lord-Sulman theory including one relaxation time and the Green-Lindsay theory with two relaxation times, as well as the classical dynamical coupled theory, are applied to the study of the influence of reinforcement on the total deformation for an infinite space weakened by a finite linear opening mode- I crack. We study the influence of reinforcement on the total deformation of rotating thermoelastic half-space and their interaction with each other. The material is homogeneous isotropic elastic half space. The crack is subjected to prescribed temperature and stress distributions. The normal mode analysis is used to obtain the exact expressions for displacement components, force stresses, and temperature. The variations of the considered variables with the horizontal distance are illustrated graphically. Comparisons are made with the results obtained in the three theories with and without rotation. A comparison is also made between the two theories for different depths. 展开更多
关键词 mode-I crack Lord -Sulman theory THERMOELASTICITY normal mode analysis.
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A Normal Mode Stability Analysis of Numerical Interface Conditions for Fluid/Structure Interaction
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作者 J.W.Banks B.Sjogreen 《Communications in Computational Physics》 SCIE 2011年第7期279-304,共26页
In multi physics computations where a compressible fluid is coupled with a linearly elastic solid,it is standard to enforce continuity of the normal velocities and of the normal stresses at the interface between the f... In multi physics computations where a compressible fluid is coupled with a linearly elastic solid,it is standard to enforce continuity of the normal velocities and of the normal stresses at the interface between the fluid and the solid.In a numerical scheme,there are many ways that velocity-and stress-continuity can be enforced in the discrete approximation.This paper performs a normal mode stability analysis of the linearized problem to investigate the stability of different numerical interface conditions for a model problem approximated by upwind type finite difference schemes.The analysis shows that depending on the ratio of densities between the solid and the fluid,some numerical interface conditions are stable up to the maximal CFL-limit,while other numerical interface conditions suffer from a severe reduction of the stable CFL-limit.The paper also presents a new interface condition,obtained as a simplified characteristic boundary condition,that is proved to not suffer from any reduction of the stable CFL-limit.Numerical experiments in one space dimension show that the new interface condition is stable also for computations with the non-linear Euler equations of compressible fluid flow coupled with a linearly elastic solid. 展开更多
关键词 Finite difference method normal mode analysis fluid/structure interaction compressible fluid interface condition
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Three-phase-lag functionally graded thermoelastic model having double porosity and gravitational effect
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作者 Kapil Kumar Kalkal Aarti Kadian Sunil Kumar 《Journal of Ocean Engineering and Science》 SCIE 2023年第1期42-54,共13页
In the present article,we have used the three-phase-lag model of thermoelasticity to formulate a two dimensional problem of non homogeneous,isotropic,double porous media with a gravitational field im-pact.Thermal shoc... In the present article,we have used the three-phase-lag model of thermoelasticity to formulate a two dimensional problem of non homogeneous,isotropic,double porous media with a gravitational field im-pact.Thermal shock of constant intensity is applied on the bounding surface.The normal mode procedure is employed to derive the exact expressions of the field quantities.These expressions are also calculated numerically and plotted graphically to demonstrate and compare theoretical results.The influences of non-homogeneity parameter,double porosity and gravity on the various physical quantities are also ana-lyzed.A comparative study is done between three-phase-lag and GN-III models.Some limiting cases are also deduced from the current study. 展开更多
关键词 Three-phase-lag Pores FISSURES GRAVITY normal mode analysis
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Study of micro-elongated thermoelastic medium loaded with a piezoelectric layer under the influence of gravity using the dual-phase-lag model
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作者 Mohamed I.A.Othman Ebtesam E.M.Eraki Mohamed F.Ismail 《International Journal of Mechanical System Dynamics》 2023年第2期136-145,共10页
This paper aims to examine the influence of gravity on a thermoelastic microelongated layer when a piezoelectric layer is above it,utilizing the theory of Lord–Shulman(L–S)and also the model of dual‐phase‐lag(DPL)... This paper aims to examine the influence of gravity on a thermoelastic microelongated layer when a piezoelectric layer is above it,utilizing the theory of Lord–Shulman(L–S)and also the model of dual‐phase‐lag(DPL).A partial differential equation was transformed into an ordinary differential equation using the normal mode analysis.Aluminum epoxy numerical computations are carried out,and the results are presented in graphical format.The L–S theory and the model of DPL are compared in the presence and absence of gravity and it is found that gravity has quite a massive influence on all the physical quantities. 展开更多
关键词 PIEZOELECTRICS normal mode analysis GRAVITY micro‐elongated thermoelastic DPL model
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On the Generalized Thermoelasticity Problem for an Infinite Fibre-Reinforced Thick Plate under Initial Stress 被引量:1
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作者 Ahmed E.Abouelregal Ashraf M.Zenkour 《Advances in Applied Mathematics and Mechanics》 SCIE 2014年第6期783-796,共14页
In this paper,the generalized thermoelasticity problem for an infinite fiberreinforced transversely-isotropic thick plate subjected to initial stress is solved.The lower surface of the plate rests on a rigid foundatio... In this paper,the generalized thermoelasticity problem for an infinite fiberreinforced transversely-isotropic thick plate subjected to initial stress is solved.The lower surface of the plate rests on a rigid foundation and temperature while the upper surface is thermally insulated with prescribed surface loading.The normal mode analysis is used to obtain the analytical expressions for the displacements,stresses and temperature distributions.The problem has been solved analytically using the generalized thermoelasticity theory of dual-phase-lags.Effect of phase-lags,reinforcement and initial stress on the field quantities is shown graphically.The results due to the coupled thermoelasticity theory,Lord and Shulman’s theory,and Green and Naghdi’s theory have been derived as limiting cases.The graphs illustrated that the initial stress,the reinforcement and phase-lags have great effects on the distributions of the field quantities. 展开更多
关键词 Dual-phase-lag theory fiber-reinforced initial stress normal mode analysis thick plate.
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Memory-dependent magneto-thermoelasticity for perfectly conducting two-dimensional elastic solids with thermal shock
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作者 Sarhan Y.Atwa Nantu Sarkar 《Journal of Ocean Engineering and Science》 SCIE 2019年第3期289-298,共10页
Recently,Yu et al.(2014)proposed a new model in generalized thermoelasticity based on heat conduction with the memory-dependent derivative.The magneto-thermoelastic responses in a perfectly conducting thermoelastic so... Recently,Yu et al.(2014)proposed a new model in generalized thermoelasticity based on heat conduction with the memory-dependent derivative.The magneto-thermoelastic responses in a perfectly conducting thermoelastic solid half-space is investigated in the context of the above new theory.Normal mode analysis together with an eigenvalue expansion technique is used to solve the resulting non-dimensional coupled governing equations.The obtained solutions are then applied to a specific problem for thermoelastic half-space whose boundary is subjected to a time-dependent thermal shock and zero stress.The effects of the kernel function,time-delay parameter,magnetic field and thermoelastic coupling parameter on the variations of different field quantities inside the half-space are analyzed graphically.The results show that these parameters has significant influence on the variations of the considered variables. 展开更多
关键词 Magneto-thermoelasticity Memory-dependent derivative TIME-DELAY normal mode analysis
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Rayleigh wave propagation with two temperature and diffusion in context of three phase lag thermoelasticity
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作者 Mandeep Singh Sangeeta Kumari 《Journal of Ocean Engineering and Science》 SCIE 2024年第4期317-325,共9页
The primary objective of this research problem is to analyze the Rayleigh wave propagation in homogeneous isotropic half space with mass diffusion in Three Phase Lag(TPL)thermoelasticity at two temperature.The governi... The primary objective of this research problem is to analyze the Rayleigh wave propagation in homogeneous isotropic half space with mass diffusion in Three Phase Lag(TPL)thermoelasticity at two temperature.The governing equations of thermodiffusive elastic half space have been solved using the normal mode analysis in order to obtain the Rayleigh wave frequency equation at relevant boundary conditions.The variation of various parameters like non-dimensional speed,attenuation coefficient,penetration depth and specific loss corresponding to thermodiffusion parameter,relaxation time,wave number and frequency has been obtained.The effect of these parameters on Rayleigh wave propagation in thermoelastic half space are graphically demonstrated and variations of all these parameters have been compared within Lord-Shulman(L-S),Green-Nagdhi(GN-III)and Three Phase Lag(TPL)theory of thermoelasticity. 展开更多
关键词 Rayleigh waves Attenuation coefficient normal mode analysis Thermoelasticity Diffusion Three phase lag
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