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Journal of Materials Science & Technology 2012年第1期28卷 73-82页

作者： Ali Khoshakhlagh Ali Nazari gholamreza khalaj Department of Materials Engineering Science and Research BranchIslamic Azad University Department of Materials Engineering Saveh BranchIslamic Azad University

In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.

关键词： Water permeability Fe203 nanoparticles Compressive strength Split tensilestrength Flexural strength

Artificial Neural Networks for Hardness Prediction of HAZ with Chemical Composition and Tensile Test of X70 Pipeline Steels

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Journal of Iron and Steel Research International 2015年第5期22卷 446-450页

作者： Hesam POURALIAKBAR Mohammad-javad khalaj Mohsen NAZERFAKHARI gholamreza khalaj Department of Advanced Materials World Tech Scientific Research Center(WT-SRC) Iranian Welding Research and Engineering Center(IWREC) University of Applied Science and Technology Young Researchers and Elites Club Saveh BranchIslamic Azad University Department of Materials Engineering Saveh BranchIslamic Azad University

A neural network with feed-forward topology and back propagation algorithm was used to predict the effects of chemical composition and tensile test parameters on hardness of heat affected zone （HAZ） in X70 pipeline steels. The mass percent of chemical compositions （i. e. carbon equivalent based upon the International Institute of Welding equation （CEIIw）, the carbon equivalent based upon the chemical portion of the ho-Bessyo carbon equivalent equation （CEecm）, the sum of the niobium, vanadium and titanium concentrations （CvTaNb）, the sum of the niobium and vanadium concentrations （CNbv）, the sum of the chromium, molybdenum, nickel and copper concentrations （CcrMoNiCu））, yield strength （YS） at 0. 005 offset, ultimate tensile strength （UTS） and percent elongation （El） were considered as input parameters to the network, while Vickers microhardness with 10 N load was considered as its output. For the purpose of constructing this model, 104 different data were gathered from the experimental re- ***. Scatter diagrams and two statistical criteria, i.e. absolute fraction of variance （R2 ） and mean relative error （MRE）, were used to evaluate the prediction performance of the developed model. The developed model can be fur- ther used in practical applications of alloy and thermo-mechanical schedule design in manufacturing process of pipe line steels.

关键词： artificial neural network chemical composition microalloyed steel mechanical property API X70 steel

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

Effect of postweld heat treatment on interface microstructure and metallurgical properties of explosively welded bronze–carbon steel

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Journal of Central South University 2018年第8期25卷 1849-1861页

作者： KHANZADEH GHARAHSHIRAN Mohammad Reza KHOSHAKHLAGH Ali khalaj gholamreza BAKHTIARI Hamid BANIHASHEMI Ali Reza Center for Advanced Engineering Research Majlesi Branch Islamic Azad University Young Researchers and Elites Club Science and Research Branch Islamic Azad University Young Researchers and Elites Club Saveh Branch Islamic Azad University Department of Materials Engineering Najafabad Branch Islamic Azad University Department of Materials Engineering Shahreza Branch Islamic Azad University

The effects of postweld heat treatment on the microstructure and metallurgical properties of a bronze–carbon steel(st37)explosively bonded interface were *** welding was done under 1.5-and 2-mm standoff distances and different conditions of explosive *** were postweld heat treated for 4 and 16 h in the furnace at 250°C and 500°C and then air *** studies using optical microscopy,scanning electron microscopy,and microhardness testing were used to evaluate the welded *** examinations showed that by increasing the standoff distance and the explosive charge,the interface of bronze to steel became *** microhardness test result showed that the hardness of the samples was higher near the joint interface compared with other areas because of the intensive plastic deformation,which was caused by the explosion *** results show that increasing the heat treatment temperature and time caused the intermetallic compounds’layer thickness to increase,and,because of the higher diffusion of copper and tin,the iron amount in the intermetallic compounds ***,because of the increase in heat treatment temperature and time,internal stresses were released,and the interface hardness decreased.

关键词： heat treatment explosive welding intermetallic compound standoff distance diffusion layer

Synthesis of boron nitride nanorod and its performance as a metalfree catalyst for oxidative desulfurization of diesel fuel

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Chinese Journal of Chemical Engineering 2024年第4期68卷 120-132页

作者： Tanaz Ghanadi gholamreza Moradi Alimorad Rashidi Catalyst Research Center Faculty of Chemical and Petroleum EngineeringRazi UniversityKermanshahIran Nanotechnology Research Center Research Institute of Petroleum Industry(RIPI)TehranIran

In order to reduce the sulfur compounds in diesel fuel,boron nitride(BN)has been used as a novel metal-free catalyst in the present *** nanocatalyst was synthesized via template-free approach followed by heating treatment at 900℃ in nitrogen atmosphere that the characteristics of the sample were identified by the X-ray diffraction,Fourier-transform infrared spectroscopy,Raman spectroscopy,field emission scanning electron microscopy,transmission electron microscopy,atomic force microscopy,and N2 adsorption-desorption *** results of structural and morphological analysis represented that BN has been successfully *** efficacy of the main operating parameters on the process was studied by using response surface methodology based on the Box-Behnken design *** prepared catalyst showed high efficiency in oxidative desulfurization of diesel fuel with initial sulfur content of 8040 mg·kg^(-1)*** statistical analysis,a significant quadratic model was obtained to predict the sulfur removal as a function of efficient *** maximum efficiency of 72.4%was achieved under optimized conditions at oxidant/sulfur molar ratio of 10.2,temperature of 71℃,reaction time of 113 min,and catalyst dosage of 0.36 ***,the reusability of the BN was studied,and the result showed little reduction in activity of the catalyst after 10 times ***,a plausible mechanism was proposed for oxidation of sulfur compounds on the surface of the *** present study shows that BN materials can be selected as promising metal-free catalysts for desulfurization process.

关键词： Desulfurization Boron nitride(BN)nanostructure Experimental design BoxeBehnken

Suspended particulate matter promotes epithelial-to-mesenchymal transition in alveolar epithelial cells via TGF-β1-mediated ROS/IL-8/SMAD3 axis

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Journal of Environmental Sciences 2024年第7期141卷 139-150页

作者： Shahrzad Molavinia Dian Dayer Mohammad Javad Khodayar gholamreza Goudarzi Maryam Salehcheh Cellular and Molecular Research Center Medical Basic Sciences Research InstituteAhvaz Jundishapur University of Medical SciencesAhvazIran Department of Toxicology School of PharmacyAhvaz Jundishapur University of Medical SciencesAhvazIran Student Research Committee Ahvaz Jundishapur University of Medical SciencesAhvazIran Toxicology Research Center Medical Basic Sciences Research InstituteAhvaz Jundishapur University of Medical SciencesAhvazIran Air Pollution and Respiratory Diseases Research Center Ahvaz Jundishapur University of Medical SciencesAhvazIran Iranian Scientific Association of Clean Air TehranIran

Epidemiological evidence presents that dust storms are related to respiratory diseases,such as pulmonary fibrosis(PF).However,the precise underlying mechanisms of SPM-elicited adverse effects still need to be ***-mesenchymal transition(EMT)process is a characteristic of *** discussed whether suspended particulate matter(SPM)is involved in EMT induction via transforming growth factor-β1(TGF-β1).In this study,a detailed elemental analysis(55 elements),particle size,and morphology were *** investigate the toxicity of SPM,an MTT test was performed to detect cell ***,A549cells were exposed to selected concentrations of SPM(20 and 40μg/mL)for single and repeated *** DCFH-DA assay showed that exposure to SPM could produce reactive oxygen species(ROS).The ELISA assay demonstrated increased levels of interleukin-8(IL-8)and TGF-β1 in the *** blot was used to detect the expression of proteins associated with EMT and the SMAD3-dependent *** of western blot demonstrated that E-cadherin was reduced,whereas p-SMAD3,vimentin,andα-smooth muscle actin were *** findings indicated that SPM triggered EMT by induction of oxidative stress,inflammation,and the TGF-β1/SMAD3 pathway activation.

关键词： Particulate matter TGF-β1 Oxidative stress Epithelial-mesenchymal transition Pulmonary fibrosis Cells

Using satellite-derived land surface temperatures to clarify the spatiotemporal warming trends of the Alborz Mountains in northern Iran

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Journal of Mountain Science 2024年第2期21卷 449-469页

作者： ROSHAN gholamreza SARLI Reza GHANGHERMEH Abdolazim TAHERIZADEH Mehrnoosh NIKNAM Arman Department of Geography Golestan UniversityGorgan 49138-15759Iran Department of Forest Resources Management Faculty of ForestryUniversity of Agriculture in KrakowAL.29 Listopada 4631-425 KrakówPoland Department of Geoinformatics Physical and Environmental GeographyUniversity of SzegedSzeged 6722Hungary

The Alborz Mountains are some of the highest in Iran,and they play an important role in controlling the climate of the country’s northern *** land surface temperature(LST)is an important variable that affects the ecosystem of this *** study investigated the spatiotemporal changes and trends of the nighttime LST in the western region of the Central Alborz Mountains at elevations of 1500-4000 m above sea *** data were extracted for the period of 2000-2021,and the Mann-Kendall nonparametric test was applied to evaluating the changes in the *** results indicated a significant increasing trend for the monthly average LST in May-August along the southern *** the northern and southern aspects showed decreasing trends for the monthly average LST in October,November,and March and an increasing trend in other *** all elevations,the average decadal change in the monthly average LST was more severe along the southern aspect(0.60°C)than along the northern aspect(0.37°C).The LST difference between the northern and southern aspects decreased in the cold months but increased in the hot *** the same elevation,the difference in the lapse rate between the northern and southern aspects was greater in the hot months than in the cold *** increasing elevation,the lapse rate between the northern and southern aspects *** change was concluded to greatly decrease the difference in LST at different elevations for April-July.

关键词： Global warming Mountainous areas Lapse rate Surface air temperatures Alborz

OPERATOR NORM AND LOWER BOUND OF FOUR-DIMENSIONAL GENERALIZED HAUSDORFF MATRICES

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Acta Mathematica Scientia 2022年第1期42卷 429-436页

作者： gholamreza TALEBI Department of Mathematical sciences Vali-e-Asr University of RafsanjanRafsanjanIslamic Republic of Iran

The problem addressed is the exact determination of the operator norm and lower bound of four-dimensional generalized Hausdorff matrices on the double sequence spaces L_(p).A Hardy type formulae is found as an exact value for their operator norm and a Copson type formulae is established as a lower estimate for their lower ***,exact values are found for the operator norm and lower bound of the transpose of generalized Hausdorff matrices.

关键词： four-dimensional Hausdorff matrices

Effect of transparency on Josephson junction between s+g-wave superconductors

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Chinese Physics B 2010年第10期19卷 499-504页

作者： gholamreza Rashedi Department of Physics University of Isfahan

In this paper, a dc Josephson junction between borocarbide superconductors has been studied theoretically. The s＋g-wave pairing symmetry which is observed in rare earth complex of borocarbides has a huge anisotropy and is an interesting form of unconventional superconductivity. We calculate the Josephson current in a superconductorinsulator-superconductor （SIS） Josephson junction with s＋g-wave superconducting pairing symmetry. In our planar junction c-axis is parallel to an interface with finite transparency but ab-planes of two tetragonal superconductors are misorientated by angle α. We obtain that the Josephson current is strongly dependent on mis-orientation between the left and the right ab-planes. An insulator sandwiched between two superconductors which acts as a potential barrier is demonstrated by a transparency coefficient. The effects of the potential barrier and the mis-orientation on the current are studied analytically and numerically. Occurrence of 0-θ transition in this s＋g-wave junction is investigated in this paper. A comparison between d-wave Josephson junction and s＋g-wave one is also made in the present paper.

关键词： Josephson junction unconventional superconductor borocarbides

Evaluation of pressure oscillations by a laboratory motor

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Chinese Journal of Aeronautics 2020年第3期33卷 805-825页

作者： Roohollah TAHERINEZHAD gholamreza ZAREPOUR Department of Mechanical Engineering University of GuilanRasht 51665-315Iran

Aeroacoustic pressure oscillation is one of the important challenges in segmented solid rocket motors with high slenderness *** reason for these oscillations can be searched in vortex shedding due to grain burning surfaces, holes and *** this paper, a novel sub-scaled motor was used for evaluation of aeroacoustic pressure ***, the related parameters to scale down using Buckingham's Pi-theorem were determined and then the sub-scaled motor was designed and *** this, Strouhal number in various grain forms and vortex shedding prediction criteria have been ***, one-dimensional linear and non-linear solution approaches have been *** understand the motor internal flow and vortex shedding formation, steady state computational fluid dynamic performed for seven regression steps and finally, two static tests have been *** show that various definitions for Strouhal number are useful only for primarily glance on vortex shedding and pressure oscillations and so CFD solution and the test program are inevitable for a correct understanding of the ballistic operational condition of the *** results demonstrated the existence of such oscillations with frequencies nearly equal to axial *** seems that non-linear parameters have small effects on aeroacoustic pressure oscillation and therefore the linear solution is acceptable to obtain approximate *** course,it should be emphasized that linear solution represents oscillations on overall motor action time,whereas the output of non-linear solution depends on thermochemistry properties of solid propellant and combustion ***, with a non-linear solution, oscillations maybe occur in some intervals of action ***(Fast Fourier Transformation) results demonstrated that although both first and second acoustic modes have been excited, the position of longitudinal oscillation has an important role on which one is dominant.

关键词： Aeroacoustic Pressure oscillation Solid rocket motor Strouhal number Sub-scale Vortex shedding