检索结果-南通市图书馆

Electronic Band Structure and Optical Parameters of Spinel Snmg_(2)O_(4) by modified Becke–Johnson Potential

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第10期29卷 193-197页

作者： masood Yousaf m.a.saeed Ahmad Radzi mat Isa Amiruddin Shaari H.A.Rahnamaye Aliabad Physics Department Faculty of ScienceUniversiti Teknologi MalaysiaSkudai-81310JohorMalaysia Department of Physics Hakim Sabzevari UniversityIran

The electronic band structure and optical parameters of Snmg_(2)O_(4) are investigated by the first-principles technique based on a new potential approximation known as modified Becke–Johnson(mBJ).The direct band gap values by LDA,GGA and EV-GGA are underestimated significantly as compared to mBJ-GGA,which generally provides the results comparable to the experimental ***,the present band gap value(4.85 eV)using mBJ-GGA is greatly enhanced to the previous value by EV-GGA(2.823 eV).The optical parametric quantities(dielectric constant,index of refraction,reflectivity,optical conductivity and absorption coefficient)relying on the band structure are presented and *** first critical point(optical absorption's edge)in Snmg_(2)O_(4) occurs at about 4.85 eV.A strong absorption region is observed,extending between 5.4 eV to 25.0 *** Snmg_(2)O_(4),static dielectric constantε1(0),static refractive index n(0),and the magnitude of the coefficient of reflectivity at zero frequency R(0)are 2.296,1.515 and 0.0419,*** optoelectronic properties indicate that this material can be successfully used in optical devices.

关键词： absorption reflectivity dielectric

An Insight into the Structural, Electronic and Transport Characteristics of XIn_(2)S_(4) (X = Zn, Hg) Thiospinels using a Highly Accurate All-Electron FP-LAPW+Lo method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第7期30卷 205-209页

作者： masood Yousaf m.a.saeed Ahmad Radzi mat Isa H.A.Rahnamaye Aliabad m.R.Sahar Department of Physics Faculty of ScienceUniversiti Teknologi MalaysiaSkudai-81310JohorMalaysia Department of Physics Hakim Sabzevari UniversityIran

The highly accurate full-potential linearized augmented plane wave plus local orbital method is employed to calculate the structural,electronic and transport properties of HgIn_(2)S_(4) and ZnIn_(2)S_(4).For ZnIn_(2)S_(4),the calculated In–S bond length is in good agreement with the experimental *** moduli results suggest that ZnIn_(2)S_(4) can afford more compressional effects than HgIn_(2)S_(4).The present study confirms that both HgIn_(2)S_(4) and ZnIn_(2)S_(4) are indirect band gap materials with band gap values of 0.705 eV and 1.533 eV *** localized region existing in the most bottom valance band of both materials splits into states by 1 eV energy difference under the spin orbital coupling *** plots of charge density predict that chemical bonding in these compounds is a mixture of ionic and covalent *** mass results reveal that mobility of charge carriers in ZnIn_(2)S_(4) is greater than that in HgIn_(2)S_(4).

关键词： effect. orbital charge

Optoelectronic Properties of Pure and Co Doped Indium Oxide by Hubbard and modified Becke–Johnson Exchange Potentials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第12期30卷 107-111页

作者： H.A.Rahnamaye Aliabad m.Bazrafshan H.Vaezi masood Yousaf Junaid munir m.a.saeed Department of Physics Hakim Sabzevari UniversitySabzevarIran Department of Physics Khayyam Institute of Higher EducationMashhadIran Department of Physics Universiti Teknologi MalaysiaSkudai 81310JohorMalaysia

Structural and optoelectronic properties of pure and Co doped In2O3 are studied by employing the full-potential linearized augmented plane wave method,which is known to produce highly accurate *** principles calculations are performed with ordinary generalized gradient approximation(GGA)along with new Hubbard and modified Becke-Johnson exchange(mBJ)potential *** band gap results are obtained for In2O3 with GGA+U and *** the case of mBJ,the band gap values are 3.5 eV and 3.4 eV for rhombohedral and cubic phases,which are in close agreement with the experimental *** of In by Co 25%alters the energy gap and a spin splitting effect is observed in these *** the spin-up state,it remains semiconductor,whereas for the spin-down state it shows semimetallic *** value of static refractive index n(0)is 1.74 for the cubic phase,while in rhombohedral phase the values of n(0)are 1.77 and 1.74 along xx and zz optical axes,*** calculated optical properties conform anisotropy in the rhombohedral phase and these materials can be potential candidates for the optoelectronics applications.

关键词： behavior Hubbard cubic

B(E2) value of even-even ^(108-112)Pd isotopes by interacting boson model-1

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2014年第2期38卷 24-28页

作者： I.Hossain H.Y.Abdullah I.m.Ahmad m.a.saeed Department of Physics Rabigh College of Science and Arts King Abdulaziz University Department of Physics College of Education Scientific Department Salahaddin University Department of Physics College of Education Mosul University Department of Physics Faculty of Science Universiti Teknologi Malaysia

This work studies the systematic reduced transition probabilities B（E2）↓, intrinsic quadrupole moments and deformation parameters of Pd isotopes with even neutrons from N =62 to 66. The downward reduced transition probabilities B（E2）↓from gamma transition 8^＋to 6^＋, 6^＋ to 4^＋, 4^＋ to 2^＋ and 2^＋ to 0＋states of even-even108 112Pd isotopes were calculated by the Interacting Boson model（IBm-1） and compared with the available previous experimental results. The ratio of the excitation energies of the first 4＋and the first 2＋excited states, R4/2, is also studied for the classification of symmetry of these nuclei. Furthermore we have studied systematically the transition rate R = B（E2： L＋ →（L 2）＋）/B（E2 ： 2＋ →0＋） of some of the low-lying quadrupole collective states in comparison with the available experimental data. The associated quadrupole moments and deformation parameters have been calculated. The results of this calculation are in good agreement with the corresponding available experimental data. The108 112Pd isotopes show the O（6） symmetry.

关键词： B(E2) ground-states Pd isotopes.quadrupole moments deformation parameter

Experimental study on the dynamic response of a 3-D wedge under asymmetric impact

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 263-274页

作者： saeed Hosseinzadeh Kristjan Tabri maritime Engineering Research Group School of EngineeringUniversity of SouthamptonSouthamptonUK Department of Civil Engineering and Architecture Tallinn University of TechnologyTallinnEstonia marine Technology Competence Center Tallinn University of TechnologyKuressaareEstonia

Water entry problems represent complex multiphase flows involving air,water,and structure interaction,occurring rapidly in rough seas,and potentially effecting structural integrity of floating *** paper experimentally investigates asymmetric slamming loads acting on a 3-D elastic wedge *** specimen,featuring two different bottom plates(stiffened and unstiffened),each 4 mm thick,aims to assess the effect of structural stiffness on dynamic *** experiments are conducted at different drop heights of 25 cm and 50 cm and varying heel angles from 5°to 25°.The paper describes the experimental conditions,including wedge geometry,material properties,and the test *** study explores the influence of heel angle on impact acceleration,revealing an increase in peak acceleration with a higher inclination angle,particularly in the vertical ***,the hydrodynamic pressure resulting from asymmetric slamming is *** pressure results analyzed and compared at different locations along the length of the *** experimental findings indicate that,despite the leeward side(stiffened)experiencing a smaller hydrodynamic load,the heel angle significantly affects pressure results on the windward side(unstiffened),leading to a more pronounced dynamic *** time history of pressure results emphasizes the effect of elastic vibrations,particularly noticeable on the unstiffened bottom *** study contributes to a deeper understanding of asymmetric slamming on aluminum structures,facilitating the enhancement of mathematical models and the validation of numerical simulations.

关键词： Flexible fluid structure interactions(FFSI) experimental study asymmetric impact hydrodynamic pressure slamming loads

Time-dependent effects in transient liquid phase bonding of 304L and Cp-Ti using an Ag-Cu interlayer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2024年第7期31卷 2237-2255页

作者： saeed VAZIRIAN mohammad mOSHKBAR BAKHSHAYESH Ali FARZADI Department of materials and metallurgical Engineering Amirkabir University of Technology(Tehran Polytechnic)Tehran 15916-34311Iran

One of the challenges for bimetal manufacturing is the joining ***,transient liquid phase(TLP)bonding was performed between 304L stainless steel and Cp-Ti using an Ag-Cu interlayer with a thickness of 75μm for bonding time of 20,40,60,and 90 *** bonding temperature of 860℃ was considered,which is under the β transus temperature of *** TLP bonding,various intermetallic compounds(ImCs),including Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe),Ti_(2)(Cu,Ag),and Ti_(2)Cu from 304L toward Cp-Ti formed in the ***,on the one side,with the increase in time,further diffusion of elements decreases the blocky ImCs such as Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe)in the 304L diffusion-affected zone(DAZ)and reaction zone,and on the other side,Ti_(2)(Cu,Ag)ImC transformed into fine morphology toward Cp-Ti *** microhardness test also demonstrated that the(Cr,Fe)_(2)Ti+Ti_(5)Cr_(7)Fe_(17) ImCs in the DAZ on the side of 304L have a hardness value of HV 564,making it the hardest *** maximum and minimum shear strength values are equal to 78.84 and 29.0 mPa,*** cleavage pattern dominated fracture surfaces due to the formation of brittle phases in dissimilar joints.

关键词： diffusion brazing transient liquid phase bonding dissimilar material joints microstructural evolution mechanical properties grade 2 titanium

Coupling of RANS and BEm Solvers for Simulation of Propeller Behind the Hull in Full Appended model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第3期38卷 424-438页

作者： saeed NAJAFI mehdi POURmOSTAFA LIU Peng-fei Iranian National Institute for Oceanography and Atmospheric Science(INIOAS) Tehran 14155-4781Iran Department of maritime Engineering Amir Kabir University of TechnologyTehran 15875-4413Iran marine Offshore and Subsea TechnologySchool of EngineeringNewcastle UniversityNewcastle upon TyneNE17RUUK

To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into *** main concern is to apply the wake effect of ship stern on the propeller *** this paper,a coupled BEm(Boundary Element method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion *** motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational *** unsteady boundary element method which is also known as panel method is chosen to estimate the propeller *** wakes are treated using a time marching wake alignment ***,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS *** on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPm in every time *** of the solver is carried out using the towing tank test report of a 50 m oceanography research *** factor and trust deduction coefficient are estimated ***,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.

关键词： RANS BEm coupled method ship propeller self-propulsion wake sheet pattern

Quantum dense coding with gravitational cat states

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第3期76卷 84-90页

作者： saeed Haddadi mehrdad Ghominejad Artur Czerwinski Faculty of Physics Semnan UniversityP.O.Box 35195-363SemnanIran Centre for Quantum Optical Technologies Centre of New TechnologiesUniversity of WarsawBanacha 2c02-097 WarszawaPoland

A protocol of quantum dense coding with gravitational cat states is *** explore the effects of temperature and system parameters on dense coding capacity and provide an efficient strategy to preserve the quantum advantage of dense coding for these *** results may open new opportunities for secure communication and insights into the fundamental nature of gravity in the context of quantum information processing.

关键词： quantum dense coding gravitational cat states quantum advantage

Quantum speedup and non-markovianity of an atom in structured reservoirs:pseudomodes as a good description of environmental memory

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第8期76卷 60-66页

作者： maryam Hadipour Soroush Haseli saeed Haddadi Faculty of Physics Urmia University of TechnologyUrmiaIran School of Physics Institute for Research in Fundamental Sciences(IPM)PO Box 19395-5531TehranIran Faculty of Physics Semnan UniversityPO Box 35195-363SemnanIran

Following the recent paper(Teittinen et al 2019 New J. Phys. 21 123041), one can see that in general there is no simple relation between non-markovianity and quantum speed limit. Here, we investigate the connection between quantum speed limit time and non-markovianity of an atom in structured environments(reservoirs) whose dynamics is governed by an exact pseudomode master equation(Garraway 1997 Phys. Rev. A 55 2290). In particular, we find an inverse relation between them, which means that the non-markovian feature of the quantum process leads to speedup of evolution. Thus, there is a link between quantum speedup and memory effects for specific cases of dynamical evolution. Our results might shed light on the relationship between the speedup of quantum evolution and the backflow of information from the environment to the system.

关键词： quantum speed limit non-markovianity pseudomode method structured environments