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Transactions of Nonferrous Metals society of China 2014年第3期24卷 665-672页

作者： M.MOHAMMADI RAHVARD M.TAMIZIFAR M.A.BOUTORABI s.gholami shiri school of Materials science and Engineering and Center of Excellence for High strength Alloys Technology Iran University of Science and Technology school of Materials science and Engineering Sharif University of TechnologyAzadi Ave. P.O. Box 11365-9466 Tehran Iran Damavand Petrochemical Company Phase 2 Pars Special Economic Energy Zone Asaloye Boshehr Iran

The cast-decant-cast is a new method for the preparation of the functionally graded components that has been developed in recent years. The functionally graded cylindrical shape component with a radial gradient, e.g. the first alloy （A390） with high wear resistance on the surface of the piece and toughness and the second alloy （A356） of low machining costs in the core of the piece can be produced via this melt process. The effect of the second alloy superheat at temperatures of 750, 820 and 860 ℃ as well as the effect of the first alloy solidified layer at 25, 35 and 45 s decanting time on achieving the perfect interface between the two alloys was investigated. The characterization of the interface was carded out by optical microscopy and scanning electron microscopy, and its width was measured by the microhardness test. The results showed that the best interface was obtained at 860 ℃ and 35 s decanting time with a width of 500 ~tm. Also, the wear resistance test was performed to measure and compare the surface wear resistance to the core.

关键词： A390 alloy A356 alloy functionally graded material cast-decant-cast process

Preparation of in-situ Cu/NbC nanocomposite and its functionally graded behavior for electrical contact applications

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Transactions of Nonferrous Metals society of China 2015年第3期25卷 863-872页

作者： s.gholami shiri P.ABACHI K.POURAZARANG M.MOHAMMADI RAHVARD Department of Materials science and Engineering Sharif University of Technology Damavand Petrochemical Company Phase 2Pars Special Economic Energy Zone school of Materials science and Engineering and Center of Excellence for High strength Alloys Technology Iran University of Science and Technology

Cu–15%NbC (volume fraction) powder was synthesized using the starting powders of Cu, Nb and graphite in a high energy vibratory disc mill for 7 h of milling under argon atmosphere. A composite sample and a Cu/NbC functionally graded material (FGM) sample were produced by using the two-step press and sintering at 900 °C for 1 h under vacuum. The microstructure and physical and mechanical properties of the specimens were investigated. The field emission scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analysis confirmed the synthesis of the nanostructure matrix of 18–27 nm with the nanoparticles reinforcement of 42 nm after sintering, verifying the thermal stability of this composite at high temperature. The hardness of Cu–15%NbC was five times greater than that of the pure Cu specimen. The volume reduction of the sample after the wear test decreased in comparison with the pure Cu specimen. The electrical conductivity of the composite specimen decreased to 36.68% IACs. The FGM specimen exhibited high electrical conductivity corresponding to 75.83% IACs with the same hardness and wear properties as those of the composite sample on the composite surface. Thus, Cu/NbC FGM with good mechanical and electrical properties can be a good candidate for electrical contact applications.

关键词： Cu/NbC nanocomposite in-situ composite mechanical alloying electrical contact wear behavior

Diffusion in FsW Joints by Inserting the Metallic Foils

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Journal of Materials science & Technology 2013年第11期29卷 1091-1095页

作者： s.gholami shiri A.sarani s.R.Elmi Hosseini G.Roudini school of Materials science and Engineering Department of EngineeringShiraz University Department of Materials science & Engineering Faculty of EngineeringUniversity of Sistan and Baluchestan

The aims of this investigation were to study diffusion phenomenon in friction stir welding （FsW） joints and its influence on the tensile strength of joints. To study diffusion in stir zone, various metallic foils were inserted between two pure aluminium plates. The thin foils of pure copper, pure zinc, brass and Cu-Zn-Ni alloy with the thickness of 250 μm were used as metallic foils. The transversal cross sections of welds were observed by optical microscopy and scanning electron microscopy （sEM） equipped with an energy dispersive X-ray spectroscopy （EDs） system. The spot analyses near the metallic foils indicated that diffusion occurs from foils into the aluminium plates during welding; consequently, the strength of stir zone increases even by 50%. Besides, the metallic foils could reveal the flow of metal after FsW process.

关键词： Friction stir welding Diffusion Metallic foil Pure aluminium Tensile strength

Tracing suspended and bed sediments during high and low water periods using geochemical characteristics-Case study:Vazrood watershed,northern Iran

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Journal of Mountain science 2024年第2期21卷 470-483页

作者： KARIMI Nabiyeh gholami Leila KAVIAN Ataollah KHALEDI DARVIsHAN Abdulvahed Department of Watershed Management Faculty of Natural ResourcesSari Agricultural Sciences and Natural Resources UniversitySari ***Iran Department of Watershed Management Engineering Faculty of Natural ResourcesTarbiat Modares UniversityNoor ***Iran

Complete and comprehensive information about sediment dynamic and identification of hotspots of sediment production and transport are necessary for understanding the erosion processes and increasing the efficiency of soil and water conservation *** studies used the sediment fingerprint techniques to investigate the contribution of different sources in suspended and bed sediment yield of the ***,the contribution of various land use/land covers in suspended and bed sediment yield for the great Caspian sea basin is in an aura of ambiguity and the present study was conducted to gather information about an important part of this area in northern Iran,where rangelands are located upstream of Hyrcanian forests and dense agricultural lands are located *** surface soil of different land use/land covers including forest,rangeland,agriculture and streambank lands were sampled in 30 *** and bed sediments were sampled in the watershed outlet in two high and low water *** characteristics of soil and sediment samples containing 59 elements were measured using ICP-OEs GBC *** reliable and suitable tracers from 59 elements were then selected using Range test,Kruskal-Wallis and Discriminant Function Analysis,respectively,in FingerPro package of R *** results showed that for suspended sediment,streambank and rangeland had the highest contributions of 86.2%and 47.5%,respectively,in two high and low water *** bed sediment,in two high and low water periods,rangeland and streambank had the highest contributions of 73.8%and 84.4%,*** use change and especially human activities such as agriculture,road construction and development of residential areas along the main river riparian zone has led to a significant increase in suspended and bed sediments.

关键词： Caspian sea basin FingerPro Geochemistry sediment transport Tracer combination

The nature and movement of thrusts in the eastern Iranian orogen:sechengi Area on the northern border of Lut and sistan

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Journal of Mountain science 2024年第9期21卷 3157-3171页

作者： shahriar KEsHTGAR Mahmoud Reza HEYHAT sasan BAGHERI Ebrahim gholami seyed Naser RAIsOssADAT Department of Geology Faculty of ScienceUniversity of BirjandBirjand ***Iran Department of Geology Faculty of ScienceUniversity of Sistan and BaluchestanZahedan 98167-45845Iran

The eastern Iranian range,known as the sistan suture zone in the past,has recently been identified as the sistan *** Paleogene orogeny is located between the Lut and Afghan *** structural analysis shows that most of the thrusts dip towards the NW so that the Permo-Triassic sediments and Jurassic micro-diorites of the Lut Block overthrusted over the younger *** studies show that the tectonic vergence was from the NW to the sE of the sechengi area in the NW part of sistan *** recognized three deformation phases in eastern *** first N-s deformation event(D1)resulted in the formation of tight E-W folds(F1)and associated cleavages(s1).The second E-W deformation event(D2),which occurred in the late Paleogene led to the bending of older structures,including the axial plane of the first-generation folds giving them a new northwest direction(F2).Additionally,the ramp of the first-phase thrusts(striking E-W)was reactivated,acquiring a new NNW orientation and exhibiting ssE tectonic *** third deformation event(D3)resulted in the formation of NNE and WNW conjugate faults in eastern *** consecutive deformation events perpendicular to each other are inconsistent with the models of simple linear orogen presented for eastern Iran(*** of eastern Iran continental crust and subsequence linear collision)and seem more consistent with the buckling orogeny(Orocline).

关键词： Thrust Tectonic vergence Orocline Buckling sechengi Eastern Iranian ranges.

Gas tungsten arc welding of CP-copper to 304 stainless steel using different filler materials

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Transactions of Nonferrous Metals society of China 2012年第12期22卷 2937-2942页

作者： sajjad gholami shiri Mohsen NAZARZADEH Mahmood sHARIFITABAR Mehdi shafiee AFARANI Materials science and Engineering Division School of Engineering University of Sistan and Baluchestan Zahedan Iran Department of Materials science and Engineering Ferdowsi University of Mashhad Mashhad Iran

The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper filler material. But, the presence of some defects like solidification crack and lack of fusion caused decreasing tensile strength of other joints. In the optimum conditions, the tensile strength of the joint was 96% of the weaker material. Also, this joint was bent till to 180° without any macroscopic defects like separation, tearing or fracture. It was concluded that copper is a new and good candidate for gas tungsten arc welding of copper to 304 stainless steel.

关键词： gas tungsten arc welding CP-copper 304 stainless steel dissimilar joint microstructure mechanical properties

Molecular investigation of exoU and exoY virulence genes in Pseudomonas aeruginosa collected from hospitalized patients in North of Iran:A descriptive-analytical study

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Journal of Acute Disease 2024年第2期13卷 74-80页

作者： Ahmad Reza Moradi Mehrdad gholami Lotfollah Davoodi Negar Hajilou Hamid Reza Goli sana Institute of Higher Education SariIran Department of Medical Microbiology and Virology Faculty of MedicineMazandaran University of Medical SciencesSariIran Antimicrobial Resistance Research Center Faculty of MedicineMazandaran University of Medical SciencesSariIran Molecular and Cell Biology Research Center Faculty of MedicineMazandaran University of Medical SciencesSariIran

Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa ***:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospitalized in educational-therapeutic hospitals and were identified using standard microbiological ***,the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion *** bacterial DNAs were extracted by the alkaline lysis ***,the presence of exoU and exoY genes was evaluated by the PCR ***:In this study,47%,72%,29%,39%,40%,and 44%of the isolates were non-susceptible to piperacillin,aztreonam,ceftazidime,imipenem,tobramycin,and ciprofloxacin,*** addition,95%and 93%of the clinical isolates carried the exoU and exoY *** and fecal isolates had both virulence genes,while only one wound isolate had neither ***,all urinary isolates contained the exoY gene and only one isolate lacked the exoU ***,88 isolates simultaneously had both exoU and exoY ***:High prevalence of exoU and exoY genes in this region indicates a significant role of typeⅢsecretion system in pathogenesis of Pseudomonas *** typeⅢsecretion system may be a suitable target to reduce the pathogenicity of this bacterium.

关键词： Pseudomonas aeruginosa exoU exoY Virulence gene TypeⅢsecretion system PCR

Unexpected Effect of Nb Addition as a Microalloying Element on Mechanical Properties of δ-TRIP steels

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Journal of Iron and steel Research International 2016年第9期23卷 988-996页

作者： sajad gholami shiri seyed Ahmad Jenabali JAHROMI Yahya PALIZDAR Majid BELBAsI Department of Materials science & Engineering School of Engineering Shiraz University Shiraz 115019 Iran Nanotechnology and Advanced Materials Department Materials and Energy Research Center Karaj 128747 Iran Department of Materials Engineering Islamic Azad University Central Tehran Branch Tehran 009821 Iran

The concept of microalloying was applied to the δ-TRIP （transformation-induced plasticity） steel to inves- tigate the feasibility of increasing the mechanical properties and understanding the effect of microalloying on the morphology and structure of the steel. A hot rolled δ-TRIP steel with three different contents of Nb （0, 0.03, 0.07 mass%） was subjected to the microstructural and mechanical examination. The high Al and si concentration in these steels guaranteed the presence of the considerable δ-ferrite phase in the microstructure after the casting and the subsequent hot rolling. The obtained results showed that Nb dramatically affects the microstructure the dynamic re- covery and recrystallization behavior, as well as the grain shape and thus the stability of austenite after the thermo- mechanical process of hot rolling. The results also revealed an unexpected effect of Nb on the mechanical properties. The addition of Nb to the δ-TRIP steel led to a significant decrease in the ultimate strength （from 1144 to 917 MPa） and an increase in ductility （from 24% to 28%）. These unconventional results could be explained by the change in the steel microstructure. The work-hardening＇behaviors of all samples exhibit three stages of the work-hardening rate evolution. At the stage 2, the work-hardening rate of the studied steels increased, being attributed to the TRIP effect and the transformation of austenite to martensite.

关键词： δ-TRIP steel Nb microalloying high Al steel mechanical property work-hardening

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

First evidence for chiral wobbling of triaxial nuclei

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Nuclear science and Techniques 2024年第7期35卷 4-7页

作者： s.Frauendorf Department of Physics and Astronomy University of Notre DameNotre DameIN 46556USA

Chirality(Greek“handiness”)is a property of many com-plex *** molecules exist in two forms,one being the mirror image of the *** for our hands,it is impossible to make the images identical by a suitable *** two forms are called left-handed and *** have the same binding energy,because the electro-magnetic interaction,which holds the molecule together,does not change under a *** properties that are insensitive to the geometry are also the *** different geometry is the reason why the left-handed form turns the polarization plane of transmitted light in one direction by some angle while the right-handed form turns it in the oppo-site direction by the same ***,the geometrical differences between the two species may have other *** two species of the carvon molecule shown in Fig.1 taste quite differently.

关键词： turns Chiral mirror