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Elastic and optical properties of zinc-blende CrSb and its effective mass

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Rare Metals 2014年第5期33卷 615-621页

作者： Sahar Rezaee Arash Boochani Masoud Majidiyan Atefeh Ghaderi shahram solaymani Mosayeb Naseri Department of Physics College of ScienceIslamic Azad University Physics Department Sabzevar Tarbiat Moallem University Young Researchers and Elite Club Islamic Azad University

The elastic, optical, and effective mass properties of CrSb in zinc-blende（ZB） phase were *** calculations were carried out using the full-potential linearized augmented plane wave plus local orbital according to the density functional theory. The results of elastic calculations by generalized gradient approximation and local density approximation approximations indicate that ZB CrSb is a ductile material and its Debye temperature is rather low. Band structure and density of state calculations introduce the ZB CrSb as a half-metal with spin polarization of100 %. In metal state, 16 th and 17 th bands cut off the Fermi level. Calculations study the effective mass, Fermi velocity,and Fermi surface at 16 th and 17 th bands. In continue,optical quantities such as dielectric function, energy loss function, and optical conductivity were investigated.

关键词： Half-metal CrSb Elastic properties Optical properties

Gap States of ZnO Thin Films by New Methods:Optical Spectroscopy,Optical Conductivity and Optical Dispersion Energy

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Chinese Physics Letters 2018年第2期35卷 107-110页

作者： Vali Dalouji shahram solaymani Laya Dejam Seyed Mohammad Elahi TSahar Rezaee Dariush Mehrparvar Department of Physics Faculty of ScienceMalayer UniversityMalayerIran Department of Physics Science and Research BranchIslamic Azad UniversityTehranIran Department of Physics West Tehran BranchIslamic Azad UniversityTehranIran Department of Physics Kermanshah BranchIslamic Azad UniversityKermanshahIran

The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°*** values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 *** values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.

关键词： Zn Gap States of ZnO Thin Films by New Methods:Optical Spectroscopy,Optical Conductivity and Optical Dispersion Energy OC

Calculation of Half-Metal, Debye and Curie Temperatures of Co_2 VAl Compound: First Principles Study

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Communications in Theoretical Physics 2015年第5期63卷 641-647页

作者： Arash Boochani Heidar Khosravi Jabbar Khodadadi shahram solaymani Masoud Majidiyan Sarmazdeh Rohollah Taghavi Mendi Sayed Mohammad Elahi Department of Physics Kermanshah Branch Islamic Azad University Young Researchers and Elite club Kermanshah Branch Islamic Azad University Department of Physics Payame Noor University Department of Physics Mashhad Branch Islamic Azad University

By FP-LAPW calculations, the structural, elastic, Debye and Curie temperatures, electronic and magnetic properties of Co2 VAl are investigated. The results indicate that Ferromagnetic （FM） phase is more stable than Anti- Ferromagnetic （AFM） and Non-magnetic （NM） ones. In addition, C11-C12 〉 0, C44 〉 0, and B 〉 0 so Co2 VAl is an elastically stable material with high Debye temperature. Also, the BIG ratio exhibits a ductility behavior. The relatively high Curie temperature provides it as a favorable material for spintronic application. It＇s electronic and magnetic properties are studied by GGA ＋U approach leading to a 100% spin polarization at Fermi level.

关键词： exchange energy Debye temperature Curie temperature Co2VAl GGA+U

q–differ-integral operator on p–valent functions associated with operator on Hilbert space

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Applied Mathematics(A Journal of Chinese Universities) 2023年第3期38卷 458-466页

作者： shahram Najafzadeh Department of Mathematics Payame Noor UniversityP.O.Box 19395-3697TehranIran

Making use of multivalent functions with negative coefficients of the type f (z)=z^(p)-~(∑)_(k=p+1)^(∞)a_(k)z^(k),which are analytic in the open unit disk and applying the q-derivative a q–differintegral operator is *** by using the familiar Riesz-Dunford integral,a linear operator on Hilbert space H is introduced.A new subclass of p-valent functions related to an operator on H is *** estimate,distortion bound and extreme points are *** convolution-preserving property is also investigated.

关键词： multivalent function fractional q–derivative operator fractional q–integral operator Hilbert space coefficient estimate distortion bound extreme point convolution(or Hadamard product)

Domestic PV System with Feedback Linearization-based Control Strategy for Module-level MPPT under Partial Shading Condition

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Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1530-1539页

作者： Hamidreza Toodeji shahram Aghaei Department of Electrical Engineering Yazd University

A partial shading condition can adversely affect the energy conversion efficiency of domestic photovoltaic(PV) systems. Connecting each PV module to a microinverter and performing module-level maximum power point tracking(MPPT)are proposed as promising solutions. In this paper, a feedback linearization-based control strategy is designed for the nonlinear system by a novel straightforward approach. The obtained nonlinear control law can independently govern each microinverter, providing module-level MPPT for PV modules without DC optimizer. Moreover, PV modules can be easily connected or disconnected due to the lug-and-play ability of the proposed controller. As a result, the proposed PV system can be easily maintained and extended even by non-expert users. Moreover,any module failure in the proposed PV system can be tolerated without impacts on the normal operation of other PV *** advantages of the proposed control strategy are verified by the simulation of a test PV system in MATLAB/Simulink under various partial shading conditions as well as adding or removing PV modules.

关键词： Domestic photovoltaic(PV)system microinverter power optimizer module-level maximum power point tracking(MPPT) plug-and-play feedback linearization-based control strategy

Internal Combustion Engine as a New Source for Enhancing Distribution System Resilience

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Journal of Modern Power Systems and Clean Energy 2021年第5期9卷 1130-1136页

作者： Ahad Abessi shahram Jadid Department of Electrical Engineering Iran University of Science and TechnologyTehranIran

Enhancing distribution system resilience is a new challenge for *** distribution loads,especially the residential customers and high-priority loads after disasters,is vital for this *** this paper,the internal combustion engine(ICE)vehicles are firstly introduced as valuable backup energy sources in the aftermath of disasters and the use of this technology is ***,the improvement of distribution system resilience is investigated through supplying smart residential customers and injecting extra power to the main *** this method,it is assumed that the infrastructure of distribution system is partially damaged(common cases)and it can be restored in less than one *** extra power of residential customer can be delivered to other loads.A novel formulation for increasing the injected power of the smart home to the main grid using ICE vehicles is ***,the maximum backup duration in case of extensive damages in the distribution system is calculated for some commercial ICE *** this case,the smart home cannot deliver extra energy to the main grid because of its *** results demonstrate the effectiveness of the proposed method for increasing backup power during power *** is also shown that ICE vehicles can supply residential customers for a reasonable amount of time during a power outage.

关键词： Internal combustion engine(ICE) smart home building energy management system(BEMS) distribution system resilience

Developing energy forecasting model using hybrid artificial intelligence method

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Journal of Central South University 2015年第8期22卷 3026-3032页

作者： shahram Mollaiy-Berneti Young Researchers and Elites Club Bandar Abbas Branch Islamic Azad University

An important problem in demand planning for energy consumption is developing an accurate energy forecasting model. In fact, it is not possible to allocate the energy resources in an optimal manner without having accurate demand value. A new energy forecasting model was proposed based on the back-propagation(BP) type neural network and imperialist competitive algorithm. The proposed method offers the advantage of local search ability of BP technique and global search ability of imperialist competitive algorithm. Two types of empirical data regarding the energy demand(gross domestic product(GDP), population, import, export and energy demand) in Turkey from 1979 to 2005 and electricity demand(population, GDP, total revenue from exporting industrial products and electricity consumption) in Thailand from 1986 to 2010 were investigated to demonstrate the applicability and merits of the present method. The performance of the proposed model is found to be better than that of conventional back-propagation neural network with low mean absolute error.

关键词： energy demand artificial neural network back-propagation algorithm imperialist competitive algorithm

HEAT-RESISTANT,PYRIDINE-BASED POLYAMIDES CONTAINING ETHER AND ESTER UNITS WITH IMPROVED SOLUBILITY

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Chinese Journal of Polymer Science 2010年第1期28卷 29-37页

作者： Hassan Ebadi shahram Mehdipour-Ataei Islamic Azad University of Shahreza P.O.Box 81145-311 ShahrezaIsfahanIran Iran Polymer and Petrochemical Institute P.O.Box 14965/115 TehranIran

A diamine containing ether and ester units, as basic monomer for the preparation of polyamides, was prepared via three consecutive reactions. Nucleophilic substitution reaction of 1,4-dihydroxy benzene with 4-nitrobenzoyl chloride produced 4-hydroxyphenyl 4-nitrobenzoate （HPNB）. Reduction of nitro groups to amino groups using Fe and HC1 resulted in preparation of 4-hydroxyphenyl 4-aminobenzoate （HPAB）. The diamine was synthesized through nucleophilic substitution reaction of HPAB with 2,6-dichloropyridine. The precursors and diamine were fully characterized by common methods, and the diamine was polycondensed with different diacid chlorides in the presence of an acid scavenger to prepare new polyamides. The polyamides were characterized, and their physical properties including thermal stability and behavior, inherent viscosity and solubility were studied.

关键词： Polyamide Polycondensation Diamine Ester Ether.

HEAT-RESISTANT PYRIDINE-BASED POLY(ETHER-ESTER)S: SYNTHESIS, CHARACTERIZATION AND PROPERTIES

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Chinese Journal of Polymer Science 2013年第1期31卷 171-178页

作者： shahram Mehdipour-Ataei Ali Mahmoodi Department of Chemistry Islamic Azad University

A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6- dichloropyridine in the presence of potassium carbonate. The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis. Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene, 1,5-dihydroxy naphthalene, bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly（ether-ester）s. The polymers were characterized and their physical and thermal properties including inherent viscosity, molecular weight, solubility, thermal stability, thermal behavior and crystallinity were studied. They revealed high heat-resistance and improved solubility in polar solvents. Structure-property relations for the prepared polyester were also studied.

关键词： Polyester Polymer synthesis and characterization Thermal properties Structure-property relations.