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Chinese Physics B 2019年第6期28卷 324-331页

作者： m Kurt h Yurtseven A Kurt s Aksoy Department of Physics Canakkale 18 Mart University17100 CanakkaleTurkey Department of Physics Middle East Technical University06531 AnkaraTurkey Lapseki ICDAs CIB mTAL high school 17100 CanakkaleTurkey

The ρ(Nh2) infrared(IR) frequencies and the corresponding full width at half maximum(FWhm) values for(Ch3)2 Nh2 FeⅢ m Ⅱ(hCOO)6(DmFe m, m = Ni, Zn, Cu, Fe, and mg) are analyzed at various temperatures by using the experimental data from the literature. For the analysis of the IR frequencies of the ρ(Nh2) mode which is associated with the structural phase transitions in those metal structures, the temperature dependence of the mode frequency is assumed as an order parameter and the IR frequencies are calculated by using the molecular field theory. Also, the temperature dependence of the IR frequencies and of the damping constant as calculated from the models of pseudospin(dynamic disorder of dimethylammonium(DmA+) cations)–phonon coupling(Ps) and of the energy fluctuation(EF), is fitted to the observed data for the wavenumber and FWhm of the ρ(Nh2) IR mode of the niccolites studied here. We find that the observed behavior of the IR frequencies and the FWhm of this mode can be described adequately by the models studied for the crystalline structures of interest. This method of calculating the frequencies(IR and Raman) and FWhm of modes which are responsible for the phase transitions can also be applied to some other metal organic frameworks.

关键词： infrared(IR) frequency full width at half maximum(FWhm) phase transitions ρ(Nh2) mode niccolites

Thermal vibration of functionally graded porous nanocomposite beams reinforced by graphene platelets

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Applied mathematics and mechanics(English Edition) 2020年第8期41卷 1209-1226页

作者： m.h.YAs s.RAhImI Department of mechanical Engineering Razi UniversityKermanshah 67346-67149Iran

The thermal vibration of functionally graded(FG)porous nanocomposite beams reinforced by graphene platelets(GPLs)is *** beams are exposed to the thermal gradient with a multilayer *** temperature varies linearly across the thickness *** different types of dispersion patterns of GPLs as well as porosity distributions are *** material properties vary along the thickness *** using the mechanical parameters of closed-cell cellular solid,the variation of Poisson’s ratio and the relation between the porosity coefficient and the mass density under the Gaussian random field(GRF)model are *** using the halpin-Tsai micromechanics model,the elastic modulus of the nanocomposite is *** equations of motion based on the Timoshenko beam theory are obtained by using hamilton’s *** equations are discretized and solved by using the generalized differential quadrature method(GDQm)to obtain the fundamental *** effects of the weight fraction,the dispersion model,the geometry,and the size of GPLs,as well as the porosity distribution,the porosity coefficient,the boundary condition,the metal matrix,the slenderness ratio,and the thermal gradient are presented.

关键词： thermal vibration functionally graded(FG) porous material graphene platelet(GPL) Timoshenko beam

Dynamic and buckling analysis of polymer hybrid composite beam with variable thickness

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Applied mathematics and mechanics(English Edition) 2020年第5期41卷 785-804页

作者： s.AFshIN m.h.YAs Department of mechanical Engineering Razi UniversityKermanshah 67149Iran

This work deals with a study of the dynamic and buckling analysis of polymer hybrid composite(PhC) beam. The beam has variable thickness and is reinforced by carbon nanotubes(CNTs) and nanoclay(NC) simultaneously. The governing equations are derived based on the first shear deformation theory(FsDT). A three-phase halpinTsai approach is used to predict the mechanical properties of the PhC. We focus our attention on the effect of the simultaneous addition of NC and CNT on the vibration and buckling analysis of the PhC beam with variable thickness. Also a comparison study is done on the sensation of three impressive parameters including CNT, NC weight fractions, and the shape factor of fillers on the mechanical properties of PhC beams,as well as fundamental frequencies of free vibrations and critical buckling load. The results show that the increase of shape factor value, NC, and CNT weight fractions leads to considerable reinforcement in mechanical properties as well as increase of the dimensionless fundamental frequency and buckling load. The variation of CNT weight fraction on elastic modulus is more sensitive rather than shear modulus but the effect of NC weight fraction on elastic and shear moduli is fairly the same. The shape factor values more than the medium level do not affect the mechanical properties.

关键词： polymer hybrid composite(PhC) halpin-Tsai carbon nanotube(CNT) nanoclay(NC) free vibration buckling load

Large scale silver nanowires network fabricated by meV hydrogen (h＋) ion beam irradiation

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Chinese Physics B 2016年第4期25卷 268-273页

作者： honey s Naseem s Ishaq A maaza m Bhatti m T Wan D Center of Excellence in solid state Physics University of the Punjab Lahore Pakistan National Center for Physics Quaid-i-Azam University Islamabad 44000 Pakistan UNEsCO-UNIsA Africa Chair in Nanosciences/Nanotechnology College of Graduate Studies University of South Africa Muckleneuk ridge P. O. Box 392 Pretoria South Africa Nanosciences African Network (NANOAFNET) iThemba LABS National Research Foundation Old Faure road P. O. Box 722 Somerset West 7129 South Africa Department of Physics Bahauddin Zakariya University Multan 60800 Pakistan school of materials science and Engineering Shanghai University Shanghai 201900 China

A random two-dimensional large scale nano-network of silver nanowires （Ag-NWs） is fabricated by meV hydrogen （h＋） ion beam irradiation. Ag-NWs are irradiated under h＋ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by h＋ ion beam-induced welding of Ag-NWs at intersecting positions. h＋ ion beam induced welding is confirmed by transmission electron microscopy （TEm） and scanning electron microscopy （sEm）. moreover, the structure of Ag NWs remains stable under h＋ ion beam, and networks are optically transparent. morphology also remains stable under h＋ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under meV h＋ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps： ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from meV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices.

关键词： Ag nanowires h+ ion irradiation nanowelding large scale nano-network optical properties

Effect of substitution group on dielectric properties of 4h-pyrano [3,2-c] quinoline derivatives thin films

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Chinese Physics B 2016年第7期25卷 440-449页

作者： h m Zeyada F m El-Taweel m m El-Nahass m m El-shabaan Department of Physics Faculty of Science Damietta University Department of Chemistry Faculty of Science Damietta University Department of Physics Faculty of Education Ain Shams University

The AC electrical conductivity and dielectrical properties of 2-amino-6-ethyl-5-oxo-4-（3-phenoxyphenyl）-5,6-dihydro-4h-pyrano[3, 2-c]quinoline-3-carbonitrile（Ph-hPQ） and 2-amino-4-（2-chlorophenyl）-6-ethyl-5-oxo-5,6-dihydro-4h-pyrano [3, 2-c] quinoline-3-carbonitrile（Ch-hPQ） thin films were determined in the frequency range of 0.5 k hz–5 mhz and the temperature range of 290–443 K. The AC electrical conduction of both compounds in thin film form is governed by the correlated barrier hopping（CBh） mechanism. some parameters such as the barrier height, the maximum barrier height, the density of charges, and the hopping distance were determined as functions of temperature and frequency. The phenoxyphenyl group has a greater influence on those parameters than the chlorophenyl group. The AC activation energies were determined at different frequencies and temperatures. The dielectric behaviors of Ph-hPQ and Ch-hPQ were investigated using the impedance spectroscopy technique. The impedance data are presented in Nyquist diagrams for different temperatures. The Ch-hPQ films have higher impedance than the Ph-hPQ films. The real dielectric constant and dielectric loss show a remarkable dependence on the frequency and temperature. The Ph-hPQ has higher dielectric constants than the Ch-hPQ.

关键词： thin films quinoline derivatives dielectrical properties correlated barrier hopping

f(T,B)gravity with statistically fitting of h(z)

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Communications in Theoretical Physics 2023年第9期75卷 79-90页

作者： s h shekh N myrzakulov A Bouali A Pradhan Department of mathematics S.P.M.Science and Gilani ArtsCommerce CollegeGhatanjiYavatmalMaharashtra 445301India L.N.Gumilyov Eurasian National University Astana 010008Kazakhstan Ratbay myrzakulov Eurasian International Center for Theoretical Physics Astana010009Kazakhstan Laboratory of Physics of matter and Radiation Mohammed I UniversityBP 717OujdaMorocco Centre for Cosmology Astrophysics and Space Science(CCASS)GLA UniversityMathura-281406Uttar PradeshIndia

some recent developments(accelerated expansion)in the Universe cannot be explained by the conventional formulation of general *** apply the recently proposed f(T,B)gravity to investigate the accelerated expansion of the *** parametrizing the hubble parameter and estimating the best fit values of the model parameters b_(0),b_(1),and b_(2)imposed from supernovae type la,Cosmic microwave Background,B aryon Acoustic Oscillation,and hubble data using the markov Chain monte Carlo method,we propose a method to determine the precise solutions to the field *** then observe that the model appears to be in good agreement with the observations.A change from the deceleration to the acceleration phase of the Universe is shown by the evolution of the deceleration *** addition,we investigate the behavior of the statefinder analysis,equation of state(Eos)parameters,along with the energy ***,to discuss other cosmological parameters,we consider some wellknown f(T,B)gravity models,specifically,f(T,B)=aT^(b)+cB^(d).Lastly,we find that the considered f(T,B)gravity models predict that the present Universe is accelerating and the Eos parameter behaves like the ACDm model.

关键词： isotropic homogeneous space-time f(T,B)gravity statistical fitting of h(z)data cosmology

microstructures of InN film on 4h-siC(0001) substrate grown by RF-mBE

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Journal of semiconductors 2015年第8期36卷 37-41页

作者： P.Jantawongrit s.sanorpim h.Yaguchi m.Orihara P.Limsuwan Department of Physics Faculty of Science King Mongkut’s University of Technology Thonburi Thailand Center of Excellence in Physics CHE Ministry of Education Department of Physics Faculty of Science Chulalongkorn University Graduate school of science and Engineering Saitama University

InN film was grown on 4h-siC （0001） substrate by RF plasma-assisted molecular beam epitaxy （RF- mBE）. Prior to the growth of InN film, an InN buffer layer with a thickness of ～5.5 nm was grown on the substrate. surface morphology, microstructure and structural quality of InN film were investigated. micro-structural defects, such as stacking faults and anti-phase domain in InN film were carefully investigated using transmission electron microscopy （TEm）. The results show that a high density of line contrasts, parallel to the growth direction （c-axis）, was clearly observed in the grown InN film. Dark field TEm images recorded with diffraction vectors g = 1120 and g = 0002 revealed that such line contrasts evolved from a coalescence of the adjacent rnisoriented islands during the initial stage of the InN nucleation on the substrate surface. This InN nucleation also led to a generation of anti-phase domains.

关键词： RF-mBE TEm InN threading dislocation anti-phase domain crystal polarity

Crashworthiness performance of hybrid kenaf/glass fiber reinforced epoxy tube on winding orientation effect under quasi-static compression load

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Defence Technology（防务技术） 2020年第5期16卷 1051-1061页

作者： A.B.m.supian s.m.sapuan m.Y.m.Zuhri E.s.Zainudin h.h.Ya Advanced Engineering materials and Composites Research Centre Department of Mechanical and Manufacturing EngineeringUniversiti Putra Malaysia43400UPM SerdangSelangorMalaysia Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products(INTROP)Universiti Putra Malaysia43400UPM SerdangSelangorMalaysia Department of mechanical Engineering Universiti Teknologi Petronas32610Seri IskandarPerakMalaysia

This research was aimed to study the effect winding orientation on the crashworthiness performance of hybrid *** specimens tested under quasi-static compression load involve of three winding parameters(q?30,45and 70)of hybrid kenaf/glass fiber reinforced epoxy and glass fiber reinforced epoxy as contrast *** automated filament winding technique has been used in fabrication of hybrid and non-hybrid composite tube and crashworthiness performance was investigated *** effects of winding orientation on energy absorption capabilities and crashworthiness characteristic were investigated through quasi-static compression load and the result are compared with the glass fiber composite tube to justify the capability of hybrid natural/synthetic as energy absorption *** samples proved to enhancing the progressive crushing capability as combination of local buckling,delaminate and brittle fracturing as progressive crushing *** the view of winding orientation aspect,the results of high winding orientation of hybrid composite tube elevated the crush load efficiency,specific energy absorption and energy absorption capability compared to glass composite tube(GFRP).The hybrid kenaf/glass composite tube with high winding orientation showed the best winding orientation to enhance the energy absorber characteristics as energy absorption application.

关键词： composite laminate winding

Barrier height and ideality factor dependency on identically produced small Au/p-si schottky barrier diodes

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Journal of semiconductors 2010年第7期31卷 16-21页

作者： m.A.Yeganeh s.h.Rahmatollahpur Faculty of Physics Baku State UniversityAcademic Zahid X■lilov ksi-23AZ 1148BakuAzerbaijan Departments of Physics Sharif University of Technology11365-9567TehranIran

small high-quality Au/P-si schottky barrier diodes（sBDs） with an extremely low reverse leakage current using wet lithography were *** effective barrier heights（Bhs） and ideality factors from current-voltage （Ⅰ-Ⅴ） characteristics were measured by a conducting probe atomic force microscope（C-AFm）.In spite of the identical preparation of the diodes there was a diode-to-diode variation in ideality factor and barrier height *** extrapolating the plots the built in potential of the Au /p-si contact was obtained as V_（bi）=0.5425 V and the barrier height valueΦ_（b（c-V）） was calculated to beΦ_（B（C-V））=0.7145 V for Au/*** is found that for the diodes with diameters smaller than 100μm,the diode barrier height and ideality factor dependency to their diameters and correlation between the diode barrier height and its ideality factor are nonlinear,where similar to the earlier reported different metal semiconductor diodes in the literature,these parameters for the here manufactured diodes with diameters more than 100μm are also *** on the very obvious sub-nanometer C-AFm produced pictures the scientific evidence behind this controversy is also explained.

关键词： schottky barrier diodes conducting probe-atomic force microscope barrier height and ideality factor

Landau damping in a dipolar Bose–Fermi mixture in the Bose–Einstein condensation(BEC) limit

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Chinese Physics B 2016年第12期25卷 367-376页

作者： s m moniri h Yavari E Darsheshdar Department of Physics University of Isfahan

By using a mean-field approximation which describes the coupled oscillations of condensate and noncondensate atoms in the collisionless regime, Landau damping in a dilute dipolar Bose-Fermi mixture in the BEC limit where Fermi superfluid is treated as tightly bounded molecules, is investigated. In the case of a uniform quasi-two-dimensional （2D） case, the results for the Landau damping due to the Bose-Fermi interaction are obtained at low and high temperatures. It is shown that at low temperatures, the Landau damping rate is exponentially suppressed. By increasing the strength of dipolar interaction, and the energy of boson quasiparticles, Landau damping is suppressed over a broader temperature range.

关键词： Landau damping mixtures of Bose and Fermi superfluids dipole-dipole interaction