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Transactions of Nonferrous Metals Society of China 2019年第6期29卷 1127-1137页

作者： a.r.khodabakhshi M.KAZEMINEZHAD Department of Materials Science and Engineering Sharif University of Technology

In order to investigate the evolution of microstructure and flow stress during non-isothermal annealing,aluminum samples were subjected to strain magnitudes of 1, 2 and 3 by performing 2, 4 and 6 passes of multi-directional forging. Then, the samples were non-isothermally annealed up to 150, 200, 250, 300 and 350 ℃. The evolution of dislocation density and flow stress was studied via modeling of deformation and annealing stages. It was found that 2, 4 and 6 passes multi-directionally forged samples show thermal stability up to temperatures of 250, 250 and 300 ℃, respectively. Modeling results and experimental data were compared and a reasonable agreement was observed. It was noticed that 2 and 4 passes multi-directionally forged samples annealed non-isothermally up to 350 ℃ have a lower experimental flow stress in comparison with the flow stress achieved from the *** underlying reason is that the proposed non-isothermal annealing model is based only on the intragranular dislocation density evolution, which only takes into account recovery and recrystallization phenomena. However, at 350℃ grain growth takes place in addition to recovery and recrystallization,which is the source of discrepancy between the modeling and experimental flow stress.

关键词： severe plastic deformation multi-directional forging non-isothermal annealing dislocation density-based model microstructure mechanical properties

On the dielectric response function and dispersion relation in strongly coupled magnetized dusty plasmas

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Chinese Physics B 2018年第10期27卷 465-470页

作者： M Shahmansouri N khodabakhshi Department of Physics Faculty of ScienceArak University

Using the generalized viscoelastic fluid model, we derive the dielectric response function in a strongly coupled dusty magnetoplasma which reveals two different dust acoustic（DA） wave modes in the hydrodynamic and kinetic limits. The effects of the strong interaction of dust grains and the external magnetic on these DA modes, as well as on the shear wave are examined. It is found that both the real and imaginary parts of DA waves are significantly modified in strongly coupled dusty magnetoplasmas. The implications of our results to space and laboratory dusty plasmas are briefly discussed.

关键词： dusty plasma strongly coupled plasma magnetoplasma dielectric response function

Tightening the Penrose inequality

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Science China(Physics,Mechanics & Astronomy) 2022年第12期65卷 122-130页

作者： Hossein khodabakhshi Hong Lü run-Qiu Yang Center for Joint Quantum Studies Department of PhysicsSchool of ScienceTianjin UniversityTianjin300350China

The Penrose inequality estimates the lower bound of the mass of a black hole in terms of the area of its *** bound is relatively loose for extremal or near extremal black *** propose a new Penrose-like inequality for static black holes involving the mass,area of the black hole event horizon and *** inequality includes the Penrose inequality as its corollary,and it is saturated by both the Schwarzschild and reissner-Nordstr?m black *** the spherically symmetric case,we prove this new inequality by assuming both the null and trace energy conditions.

关键词： black hole Penrose-like inequality trace energy condition

A rapid Access to Novel and Known Benzimidazole Derivatives Using Silica Chloride as a reusable Catalyst

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Chinese Journal of Chemistry 2012年第4期30卷 959-964页

作者： Karami, Bahador Ghashghaee, Vahideh khodabakhshi, Saeed Department of Chemistry Yasouj University Yasouj Zip Code: 75918-74831 P. O.Box 353 Iran Department of Chemistry Gachsaran Branch Islamic Azad University Gachsaran Iran

A new application of silica chloride as an easily available and reusable solid acid catalyst for the synthesis of benzimidazole and its derivatives through the condensation of o-phenylenediamines and orthoesters under thermal and solvent-free conditions is described. This novel and eco-friendly method is very cheap and has many advan- tages including excellent yields, short reaction time, and simple work-up procedure.

关键词： silica chloride orthoesters o-phenylenediamine benzimidazole

A discrete model for response estimation of soil-structure systems with embedded foundations

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 263-276页

作者： P.khodabakhshi H.Jahankhah M.A.Ghannad Department of Civil Engineering Sharif University of Technology

The need for simplified physical models representing frequency dependent soil impedances has been the motivation behind many researches throughout history. Generally, such models are generated to capture impedance functions in a wide range of excitation frequencies, which leads to relatively complex models. That is while there is just a limited range of frequencies that really influence the response of the structure. Here, a new methodology based on the response-matching concept is proposed, which can lead to the development of simpler discrete models. The idea is then used to upgrade an existing simple model of surface foundations to the case of embedded foundations. The applicability of the model in both frequency domain and time domain analyses of soil-structure systems with embedded foundations is discussed. Moreover, the accuracy of the results is compared with another existing discrete model for embedded foundations.

关键词： discrete model embedded foundation spectral matching

Effects of initial wettability and different surfactant-silica nanoparticles flooding scenarios on oil-recovery from carbonate rocks

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Petroleum 2022年第4期8卷 499-508页

作者： Amin rezaei Amin khodabakhshi Amir Esmaeili Mehdi razavifar Abdal Industrial Projects Management Company(MAPSA) Pardis Technology ParkPardisTehranIran Department of Chemical Engineering Faculty of EngineeringMahshahr BranchIslamic Azad UniversityMahsharIran Department of Petroleum Engineering Amirkabir University of Technology(Tehran Polytechnic)TehranIran Enhanced Oil recovery(EOr)research Centre IOR/EOR Research InstituteShiraz UniversityShirazIran

Initial wettability of rock surfaces plays a crucial role in displacement efficiency during core flooding *** this study,linear alkylbenzene sulfonic acid(LABSA)and silica nanoparticles(NPs)were utilized as enhanced oil recovery(EOr)agents to improve oil recovery from carbonate rock *** to the core flooding experiments,effects of the presence of LABSA and SiO_(2)NPs on oil-water interfacial tension(IFT),wettability alteration,and surfactant adsorption on the rock surfaces were *** results of IFT/contact angle measurements showed that by adding 0.03 wt%LABSA,the IFT,and contact angle reduced from the initial values of 36.9 mN/m and 115.6°±0.2°to 8.3 mN/m and 100.3°±0.4°,***,incorporating SiO_(2)NPs(0.1 wt%)into the system causes a further decrease in IFT value(dropped to 2.2 mN/m),along with a substantial reduction in contact angle(final contact angle after 6 h soaking into the solution was measured as 64.8°±0.3°).In addition,surfactant loss due to the adsorption on the rock surfaces decreased up to 35%in the presence of SiO_(2)NPs(0.1 wt%).Moreover,various core flooding scenarios in carbonate plugs with different initial wettability conditions were conducted,and the performance of the EOr agents in enhancing oil recovery from oilwet and water-wet core samples in the secondary and tertiary mode of flooding was *** outcomes revealed that the injection of a combination of chemicals,containing LABSA(0.03 wt%)and SiO_(2)(0.1 wt%)in the secondary mode leads to the highest ultimate oil recovery from sister carbonate core samples.

关键词： LABSA Enhanced oil recovery Silica nanoparticles IFT Contact angle Adsorption Carbonates

Modified Potential Around a Moving Test Charge in Strongly Coupled Dusty Plasma

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Communications in Theoretical Physics 2017年第7期67卷 111-116页

作者： M. Shahmansouri B.Farokhi N. khodabakhshi Department of Physics Faculty of Science Arak University Arak P.O. Box 38156-8-8349 Iran

The theory of dynamical （wa＆e） potential behind a moving test charge in a weakly coupled dusty plasma is extended to that including of strong interaction between dust grains. Such strong interaction is included in the dielectric response function by a generalized hydrodynamic （GH） fluid model. It is shown that the strong interaction between dusts including the lattice spacing correction has a significant effect on the wake potential in dusty plasma. This may be used to investigate basic features of phase transition and possibility of lattice formation of dusty plasma.

关键词： dusty plasma strongly coupled plasma generalized hydrodynamic fluid model

New approach for assessing the weldability of precipitation-strengthened nickel-base superalloys

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1183-1191页

作者： Homam Naffakh Moosavy Mohammad-reza Aboutalebi Seyed Hossein Seyedein Meisam khodabakhshi Carlo Mapelli School of Metallurgy and Materials Engineering Iran University of Science and Technology (IUST) MAPNA Turbine Engineering and Manufacturing Company (TUGA) Dipartimento di Meccanica Politecnico di Milano

A new procedure was proposed for evaluating the weldability of nickel-base superalloys. The theory is on the basis of two microstructural patterns. In pattern I, the weld microstructure exhibits severe alloying segregation, many low-melting eutectic structures, and low weldability. The weld requires a weaker etchant and a shorter time for etching. In pattern Ⅱ, the weld microstructure displays less alloying segregation, low quantity of eutectic structures, and high weldability. The weld needs a stronger etchant and a longer time for etching. Five superalloys containing different amounts of Nb and Ti were designed to verify the patterns. After welding operations, the welds were etched by four etchants with different corrosivities. The weldability was determined by TG-DSC measurements. The metallography and weldability results confirmed the theoretic patterns. Finally, the etchant corrosivity and etching time were proposed as new criteria to evaluate the weldability of nickel-base superalloys.

关键词： superalloys nickel alloys weldability metallography etching segregution eutectics

Fe_3O_4 nanoparticles:A powerful and magnetically recoverable catalyst for the synthesis of novel calix[4]resorcinarenes

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Chinese Chemical Letters 2012年第2期23卷 173-176页

作者： Bahador Karami S.Jafar Hoseini Shaghayegh Nikoseresht Saeed khodabakhshi Department of Chemistry Yasouj UniversityYasouj 75918-74831P.O.Box 353Iran Department of Chemistry Gachsaran BranchIslamic Azad UniversityGachsaran 75817lran

A simple synthesis of novel and known calix[4]resorcinarenes derivatives has been achieved by the condensation of resorcinol and different aromatic aldehydes in the presence of catalytic amounts of Fe_3O_4 nanoparticles under solvent-free *** experimental conditions have been thoroughly optimized and established,allowing significant rate enhancements and good to excellent *** reactions can be run safely without using any toxic organic solvents under mild reaction *** Fe_3O_4 nanoparticles were characterized by powdered X-ray diffraction（XrD）,transmission electron microscopy（TEM） and FT-Ir spectroscopy.

关键词： Fe_3O_4 nanoparticles Calixresorcinarenes resorcinol Arylaldehyde

利用磁性可回收的Fe_3O_4纳米颗粒催化剂合成苯并咪唑的新方法(英文)

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催化学报 2012年第2期33卷 298-301页

作者： Bahador KArAMI Shaghayegh NIKOSErESHT Saeed khodabakhshi Department of Chemistry Yasouj University Department of Chemistry Gachsaran BranchIslamic Azad University

Magnetically recoverable Fe3O4 nanoparticles have been synthesized as a catalyst for the cyclocondensation of 1,2-phenylenediamines with orthoesters under solvent-free *** loadings can be as low as 1 mol% to give high yields of the corresponding benzimidazole derivative at 80 °*** green method offers significant advantages in terms of its simplicity,low catalyst loadings,high product yields,and non-toxic *** Fe3O4 nanoparticles were characterized by X-ray diffraction,transmission electron microscopy,and Fourier transform infrared spectroscopy.

关键词： ferroferric oxide nanoparticle 1,2-phenylenediamine orthoester benzimidazole