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Chinese Journal of Chemical Engineering 2017年第9期25卷 1238-1248页

作者： Mohammad Mesbah Ebrahim Soroush Mashallah Rezakazemi young researchers and Elites club Science and Research Branch Islamic Azad University young researchers and Elites club Ahvaz Branch Islamic Azad University Department of Chemical Engineering Shahrood University of Technology

Hydrates always are considered as a threat to petroleum industry due to the operational problems it can *** problems could result in reducing production performance or even production stoppage for a long *** this paper, we were intended to develop a LSSVM algorithm for prognosticating hydrate formation temperature(HFT) in a wide range of natural gas mixtures. A total number of 279 experimental data points were extracted from open literature to develop the LSSVM. The input parameters were chosen based on the hydrate structure that each gas species form. The modeling resulted in a robust algorithm with the squared correlation coefficients(R^2) of 0.9918. Aside from the excellent statistical parameters of the model, comparing proposed LSSVM with some of conventional correlations showed its supremacy, particularly in the case of sour gases with high H_2S concentrations, where the model surpasses all correlations and existing thermodynamic models. For detection of the probable doubtful experimental data, and applicability of the model, the Leverage statistical approach was performed on the data sets. This algorithm showed that the proposed LSSVM model is statistically valid for HFT prediction and almost all the data points are in the applicability domain of the model.

关键词： Hydrate formation temperature(HFT) Natural gas Sour gases Least squares support vector machine Outlier diagnostics Leverage approach

Simultaneous Effects of Hydrostatic Pressure and Conduction Band Non-parabolicity on Binding Energies and Diamagnetic Susceptibility of a Hydrogenic Impurity in Spherical Quantum Dots

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Communications in Theoretical Physics 2011年第8期56卷 377-381页

作者： G.Rezaei N.A.Doostimotlagh B.Vaseghi Department of Physics College of SciencesYasouj University young research club Islamic Azad University

Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.

关键词： non-parabolic conduction band hydrostatic pressure quantum dots hydrogenic impurity diamagnetic susceptibility

Properties of Defect Modes in Periodic Lossy Multilayer with Negative-Index-Materials

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Communications in Theoretical Physics 2013年第7期60卷 80-86页

作者： Alireza Aghajamal Mahmood Barati Department of Physics Science and Research Branch Islamic Azad University young researchers club Science and Research Branch Islamic Azad University

Employing the characteristic matrix method, this study investigates transmission properties of onedimensional defective lossy photonic crystals composed of negative and positive refractive index layers with one lossless defect layer at the center of the crystal. The results of the study show that as the refractive index and thickness of the defect layer increase, the frequency of the defect mode decreases. In addition, the study shows that the frequency of the defect mode is sensitive to the incidence angle, polarization, and physical properties of the defect layer, but it is insensitive to the small lattice loss factor. The peak of the defect mode is very sensitive to the loss factor, incidence angle, polarization, refractive index, and thickness of the defect layer. This study also shows that the peak and the width of the defect mode are affected by the numbers of the lattice period and the loss factor. The results can lead to designing new types of narrow filter structures and other optical devices.

关键词： one-dimensional photonic crystal defect mode loss factor negative index material

Hydroxyapatite/alumina nanocrystalline composite powders synthesized by sol–gel process for biomedical applications

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1033-1036页

作者： S.Khors M.H.Fathi S.Salehi S.Amirkhanlou young researchers and Elite club Najafabad Branch Islamic Azad University Department of Materials Engineering Isfahan University of Technology German Textile research Centre North-West (DTNW) University of Duisburg-Essen young researchers and Elite club Behshahr Branch Islamic Azad University

Hydroxyapatite/alumina nanocrystalline composite powders needed for various biomedical applications were successfully synthe- sized by sol-gel process. Structural and morphological investigations of the prepared composite powders were performed using X-ray dif- fractometer （XRD）, scanning electron microscopy （SEM）, X＇Pert HighScore software, and Clemex Vision image analysis software. The re- suits show that the crystallite size of the obtained composite powders is in the range of 25 to 90 nm. SEM evaluation shows that the obtained composite powders have a porous structure, which is very useful for biomedical applications. The spherical nanoparticles in the range of 60 to 800 nm are embedded in the agglomerated clusters of the prepared composite powders.

关键词： nanocrystalline materials biomaterials hydroxyapatite alumina sol-gel process nanostructures

Creep rupture assessment for Level-2 PSA of a 2-loop PWR： accounting for phenomenological uncertainties

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Nuclear Science and Techniques 2017年第8期28卷 117-125页

作者： Faramarz Yousefpour Seyed Mohsen Hoseyni Seyed Mojtaba Hoseyni Seyed Ali Hashemi Olia Kaveh Karimi Nuclear Science and Technology research Institute TehranIran young researchers and Elite club East Tehran BranchIslamic Azad University Tehran Iran

The Level-2 probabilistic safety assessment(PSA) of pressurized water reactors studies the possibility of creep rupture for major reactor coolant system components during the course of high pressure severe accident sequences. The present paper covers this technical issue and tries to quantify its associated phenomenological uncertainties for the development of Level-2 PSA. A framework is proposed for the formal quantification of uncertainties in the Level-2 PSA model of a PWR type nuclear power plant using an integrated deterministic and PSA approach. This is demonstrated for estimation of creep rupture failure probability in station blackout severe accident of a 2-loop PWR, which is the representative case for high pressure sequences. MELCOR 1.8.6 code is employed here as the deterministic tool for the assessment of physical phenomena in the course of accident. In addition, a MATLAB code is developed for quantification of the probabilistic part by treating the uncertainties through separation of aleatory and epistemic sources of *** probability for steam generator tube creep rupture is estimated at 0.17.

关键词：模型不确定性蠕变断裂 PSA 压水堆断裂评价二级现象学反应堆冷却剂系统

Effects of heat treatment on the intermetallic compounds and mechanical properties of the stainless steel 321–aluminum 1230 explosive-welding interface

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International Journal of Minerals,Metallurgy and Materials 2017年第11期24卷 1267-1277页

作者： Mohammadreza Khanzadeh Gharah Shiran Gholamreza Khalaj Hesam Pouraliakbar Mohamma dreza Jandaghi Hamid Bakhtiari Masoud Shirazi Center for Advanced Engineering research Majlesi Branch Islamic Azad University Isfahan *** Iran young researchers and Elite club Saveh Branch Islamic Azad University Saveh *** Iran young researchers and Elite club Science and Research Branch Islamic Azad University Tehran *** Iran Advanced Materials research Center Faculty of Materials Engineering Najafabad Branch Islamic Azad University Najafabad *** Iran

The effects of heat treatment on the microstructure and mechanical properties of intermetallic compounds in the interface of stainless steel 321 explosively bonded to aluminum 1230 were investigated in this study. Experimental investigations were performed by optical microscopy, scanning electron microscopy, and microhardness and shear tensile strength testing. Prior to heat treatment, increasing the stand-off distance between samples from 1 to 2.5 mm caused their interface to become wavy and the thickness of intermetallic layers to increase from 3.5 to 102.3 μm. The microhardness increased from HV 766 in the sample prepared at a stand-off distance of 1 mm to HV 927 in the sample prepared at a stand-off distance of 2.5 mm; in addition, the sample strength increased from 103.2 to 214.5 MPa. Heat treatment at 450°C for 6 h increased the thickness of intermetallic compound layers to 4.4 and 118.5 μm in the samples prepared at stand-off distances of 1 and 2.5 mm, respectively. These results indicated that increasing the duration and temperature of heat treatment decreased the microhardness and strength of the interface of explosively welded stainless steel 321-Al 1230 and increased the thickness of the intermetallic region.

关键词： intermetallic compounds explosive welding heat treatment stand-off distance mechanical properties

Influence of Annealing Temperature on Berthelot-Type Hopping Conduction Mechanism in Carbon-Nickel Composite Films

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Chinese Physics Letters 2016年第8期33卷 92-95页

作者： V.Dalouji S.M.Elahi A.Ghaderi S.Solaymani Department of Physics Malayer University Plasma Physics research Center Science and Research BranchIslamic Azad University young researchers and Elite club Kermanshah BranchIslamic Azad University

Electrical conductivity of carbon-nickel composite films annealed at temperatures 300, 500 and 800℃ is studied over a temperature range of 50 300 K. While the conductivity data above room temperature show extended state conduction, lowering the temperature from 150 to 50 K leads to the Berthelot-tvpe conduction mechanism. It can be seen that the films annealed at 500℃ have the maximum conductivity. The extent of the carrier wave function at 500℃ has the minima 2.87 × 10-7 cm and 2.45 ×10-7 cm in octahedral-metal stretching vibrations and intrinsic stretching vibrations of the metal at the tetrahedral site, respectivel. The average distances between two vibration octahedral and tetrahedral sites at 500℃ also have the minima 1.13 × 10-7 cm and 0.97×10 7 cm, respectivel3： The Berthelot temperature for fihns annealed at 800℃ ha^s the minimum of 9-1.3 K.

关键词： of it is be for FESEM in on

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Interacting viscous dark energy in a Bianchi type-Ⅲ universe

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research in Astronomy and Astrophysics 2014年第9期14卷 1121-1134页

作者： Hassan Amirhashchi young researchers and Elite club Mahshahr Branch Islamic Azad University Mahshahr Iran

We study the evolution of the equation of state of viscous dark energy in the scope of Bianchi type III space-time. We consider a case where the dark energy is minimally coupled to the perfect fluid, as well as in direct interaction with it. The viscosity and the interaction between the two fluids are parameterized by constants 40 and σ, respectively. We have made a detailed investigation of the cosmological implications of this parametrization. To differentiate between different dark energy models, we have performed a geometrical diagnostic by using the statefinder pair {s, r}.

关键词： Bianchi type-III models -- dark energy -- statefinder

Control over hysteresis curves and thresholds of optical bistability in different semiconductor double quantum wells

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Chinese Physics B 2015年第8期24卷 373-380页

作者： Hamedi H R Mehmannavaz M R Afshari Hadi Institute of Theoretical Physics and Astronomy Vilnius University young researchers and Elite club Mashhad Branch Islamic Azad University research Institute for Applied Physics University of Tabriz

The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing.

关键词： optical bistability semiconductor double quantum wells K-type Y-type and inverted Y-type schemes OB threshold intensity

Effect of Quantum Interference from Incoherent Pumping Field and Spontaneous Emission on Controlling the Optical Bistability and Multi-Stability

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Communications in Theoretical Physics 2013年第2期59卷 199-204页

作者： H.R. Hamedi Ali Sari M. Sahrai S.H. Asadpour research Institute for Applied Physics and Astronomy University of Tabriz Department of Electrical Engineering Islamic Azad University young researchers club Islamic Azad University

Optical bistability （0t3） and optical multi-stability （OM） of a four-level A-type atomic system with two fold lower levels inside a unidirectional ring cavity is investigated. The effect of quantum interference arising from spontaneous emission and incoherent pumping on 013 and OM is discussed. It is found that the threshold of OB and OM can be controlled by quantum interference mechanisms. In addition intensity of coupling field and the rate of an incoherent pumping field on behavior of OB and OM are then discussed.

关键词： optical bistability optical multistability quantum interference incoherent pumping