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Journal of Materials Science & Technology 2010年第12期26卷 1078-1082页

作者： S.Ahmadi h.arabi A.Shokuhfar Department of Material Science Faculty of EngineeringTarbiat Modares UniversityTehranIran Center of Excellence of Advanced Materials and Processing(CEAMP) Department of Metallurgy and Materials Science and EngineeringIran University of Science & Technology(IUST)NarmakTehranIran Department of Material Science Faculty of Mechanical EngineeringK.N.Toosi University of TechnologyTehranIran

Effects of multiple strengthening treatments （i.e. ag mechanical properties and stability of nanoscale prec in this research. Various tests such as hardness, tensi ng either at three or four consecutive temperatures） on pitated phases in an AA2090 alloy have been evaluated e, electrical resistance, differential scanning calorimetric （DSC）, and transmission electron microscopy （TEM） have been performed. The results show that the ultimate tensile strength （UTS） and the yield strength of the samples aged at four consecutive temperatures （i.e. natural aging＋190℃＋150℃＋100℃） can be increased approximately to 660 and 610 MPa, respectively. It is also found that precipitation of T1 phase occurs during multiple aging process of the alloy and the higher amounts of enthalpies shown in DSC charts are linked to higher volume fraction of this precipitate. Furthermore, TEM observations reveal that T1 phase has plate shape morphology and its crystal structure is in the form of hcp with lattice parameters of a=0.467 nm and c=0.878 nm.

关键词： Multiple strengthening Thermo mechanical treatment (TMT) Selected area electron diffraction (SAED) pattern Inter planar spacing (d)

Evaluation of the Electroslag Remelting Process in Medical Grade of 316LC Stainless Steel

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Journal of Materials Science & Technology 2009年第5期25卷 592-596页

作者： S.Ahmadi h.arabi A.Shokuhfar A.Rezaei Institute of Advanced Technologies for Metallic Materials Tarbiat Modares University Center of Excellence of Advanced Materials and Processing(CEAMP) Department of Metallurgy and Materials Science and EngineeringIran University of Science&Technology(IUST) Department of Material Science Faculty of Mechanical EngineeringK.N.Toosi University of Technology

This study is focused on the effects of electroslag remelting by prefused slag （CaO, Al2O3, and CaF2） on macrostructure and reduction of inclusions in the medical grade of 316LC （316LVM） stainless steel. Analysis of the obtained results indicated that for production of a uniform ingot structure during electroslag remelting, shape and depth of the molten pool should be carefully controlled. high melting rates led to deeper pool depth and interior radial solidification characteristics, while decrease in the melting rates caused more reduction of nonmetallic inclusions. Large shrinkage cavities formed during the conventional casting process in the primary ingots were found to be the cause of the fluctuation in the melting rate, pool depth and extension of equiaxed crystals zone.

关键词： Ultra clean steel Electroslag Radial solidification remelting Prefused slag Vertical solidification

Comparison of microstructural stability of IN939 superalloy with two different manufacturing routes during long-time aging

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Transactions of Nonferrous Metals Society of China 2014年第6期24卷 1717-1729页

作者： M.R.JAhANGIRI h.arabi S.M.A.BOUTORABI Metallurgy Department Niroo Research Institute School of Metallurgy and Materials Engineering Iran University of Science and Technology

Microstructural stability of IN939 superalloy with two different manufacturing routes was investigated during long-term aging at elevated temperatures by light optical microscope（OM） and scanning electron microscope（SEM） equipped with an EDS *** results show mat the coarsening behavior of γ＇ particles is primarily impacted by the initial heat treatment conditions,and the effect of the prior manufacturing route（casting or hot forming） is found to be insignificant,if any,on the γ＇ particles coarsening *** the temperature range of 790-827 ℃,IN939 cast/wrought-hT2 alloys have more microstructural stability,while in the temperature range of 827-910 ℃,the initial heat treatment marked as hT1 provides more stable microstructure for the cast or wrought IN939 superalloy.

关键词： nickel-based superalloy IN939 superalloy long-term coarsening manufacturing route heat treatment γ particles carbides

A Comparative Study of the Electronic and Magnetic Properties of Gd_5Ge_4 and Gd_5Si_4 Compounds

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Communications in Theoretical Physics 2014年第12期61卷 903-908页

作者： Z.Momeni Larimi A.Amirabadizadeh A.Yazdani h.arabi Department of Physics Faculty of Science University of Birjand P.O.Box 97175-615 Birjand Iran Tarbiat Modares University Tehran P.O.Box 14115-175 Iran Department of Physics Faculty of Basic Science Ferdowsi University Mashhad Iran

We present a comparative study of electronic structure and magnetic properties of Gd5Si4 and Gd5Ge4compounds using first principles full potential linearized augmented plane wave(FP-LAPW) method based on density functional theory(DFT) using the WIEN2 k code. The local-spin density approximation with correlation energy(LSDA+U) method has been used as the exchange-correlation potential. The optimized lattice constants are in good agreement with the experimental data. The total and partial density of states(DOS) of Gd5Si4 and Gd5Ge4show the difference in Si 3p-Gd 5d and Ge 4p-Gd 5d hybridization, which have an effective role in indirect exchange *** addition, the magnetic moments of Gd, Si, and Ge atoms and the compounds are calculated to clarify the differences in the magnetic properties of these compounds.

关键词： magnetocaloric compound density functional theory electronic and magnetic properties exchange interaction

Microstructural evolution of copper-titanium alloy during in-situ formation of TiB_2 particles

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Transactions of Nonferrous Metals Society of China 2013年第10期23卷 2994-3001页

作者： M.SOBhANI h.arabi A.MIRhABIBI R.M.D.BRYDSON Center of Excellence for Advanced Materials and Processing School of Metallurgy and Materials Engineering Iran University of Science and Technology Center of Excellence for Ceramic Materials in Energy and Environmental Applications Iran University of Science and Technology Institute for Materials Research University of Leeds

Bulk Cu-Ti alloy reinforced by TiB2 nano particles was prepared using in-situ reaction between Cu 3.4%Ti and Cu-0.7%B master alloys along with rapid solidification and subsequent heat treatment for 1-10 h at 900 ℃. high-resolution transmission electron microscopy （hRTEM） characterization showed that primary TiB2 nano particles and TiB whiskers were formed by in-situ reaction between Ti and B in the liquid copper. The formation of TiB whiskers within the melt led to coarsening of TiB2 particles. Primary TiB2 particles were dispersed along the grain boundaries and hindered grain growth at high temperature, while the secondary TiB2 particles were formed during heat treatment of the alloy by diffusion reaction of solute titanium and boron inside the grains. Electrical conductivity and hardness of the composite were evaluated during heat treatment. The results indicated that the formation of secondary TiB2 particles in the matrix caused a delay in hardness reduction at high temperature. The electrical conductivity and hardness increased up to 8 h of heat treatment and reached 33.5% IACS and hV 158, respectively.

关键词： in-situ reaction TiB whiskers TiB2 particles Cu-Ti alloy composite

Thermal noise-driven resonant sensors

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Microsystems & Nanoengineering 2024年第3期10卷 259-271页

作者： Yan Qiao Alaaeldin Elhady Mohamed arabi Eihab Abdel-Rahman Wenming Zhang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghaiChina Department of Systems Design Engineering University of WaterlooWaterlooONCanada

MEMS/NEMS resonant sensors hold promise for minute mass and force ***,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the ***,this restriction becomes increasingly pronounced as sensors shrink to the *** this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’*** sensors employ the dynamically amplified response to thermal noise at resonances for stimulus *** demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of *** overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are *** validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature ***-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.

关键词： noise resonant overcome

Niosome-encapsulated auraptene reduced the mRNA expression of VEGF-A and PDGFs genes in human retinaderived RPE cell line

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1028-1035页

作者： Akram Vahidi Teymoor Khosravi Farzad Dastaviz Mehdi Sheikh.arabi Ayyoob Khosravi Morteza Oladnabi Student Research Committee Golestan University of Medical SciencesGorgan ***Iran Department of Medical Nanotechnology Faculty of Advanced Medical TechnologiesGolestan University of Medical SciencesGorgan ***Iran Stem Cell Research Center Golestan University of Medical SciencesGorgan ***Iran Department of Molecular Medicine Faculty of Advanced Medical TechnologiesGolestan University of Medical SciencesGorgan ***Iran Gorgan Congenital Malformations Research Center Golestan University of Medical SciencesGorgan ***Iran

AIM:To evaluate the effect of auraptene(AUR)treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor(VEGF)-A and platelet-derived growth factors(PDGFs)in human retinal pigment epithelium(RPE)cell ***:Niosome nanocarriers were produced using two surfactants Span 60 and Tween *** cell line was treated with both free AUR and *** dosage of treatments was calculated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)*** of VEGF-A and PDGF-A,PDGF-B,PDGF-C,PDGF-D genes was measured after total RNA extraction and cDNA synthesis,using real-time polymerase chain reaction(RT-PCR).RESULTS:The highest entrapment efficiency(EE)was achieved by Span 60:cholesterol(1:1)with 64.3%.The half maximal inhibitory concentration(IC50)of free and niosome-encapsulated AUR were 38.5 and 27.78µg/mL,*** study revealed that niosomal AUR had more gradual delivery to the ***-PCR results showed reduced expression levels of VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D after treatment with both free and niosomal ***:Niosomal formulation of Span 60:cholesterol(1:1)is an effective drug delivery approach to transfer AUR to RPE ***-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D are four angiogenic factors,inhibiting which by niosomal AUR may be effective in age-related macular degeneration.

关键词： auraptene niosome age-related macular degeneration angiogenesis nanocarrier

Impact of umbelliprenin-containing niosome nanoparticles on VEGF-A and CTGF genes expression in retinal pigment epithelium cells

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 7-15页

作者： Farzad Dastaviz Akram Vahidi Teymoor Khosravi Ayyoob Khosravi Mehdi Sheikh.arabi Abouzar Bagheri Mohsen Rashidi Morteza Oladnabi Stem Cell Research Center Golestan University of Medical SciencesGorgan ***Iran Department of Medical Genetics School of Advanced Technologies in MedicineGolestan University of Medical SciencesGorgan ***Iran Student Research Committee Golestan University of Medical SciencesGorgan ***Iran Department of Molecular Medicine Faculty of Advanced Medical TechnologiesGolestan University of Medical SciencesGorgan ***Iran Department of Medical Nanotechnology Faculty of Advanced Medical TechnologiesGolestan University of Medical SciencesGorgan ***Iran Department of Clinical Biochemistry and Genetics Faculty of MedicineMazandaran University of Medical SciencesSari ***Iran Department Pharmacology Faculty of MedicineMazandaran University of Medical SciencesSari ***Iran Gorgan Congenital Malformations Research Center Golestan University of Medical SciencesGorgan ***Iran

AIM:To investigate the impact of niosome nanoparticles carrying umbelliprenin(UMB),an anti-angiogenic and anti-inflammatory plant compound,on the expression of vascular endothelial growth factor(VEGF-A)and connective tissue growth factor(CTGF)genes in a human retinal pigment epithelium(RPE)-like retina-derived cell ***:UMB-containing niosomes were created,optimized,and ***-like cells were treated with free UMB and UMB-containing *** IC_(50)values of the treatments were determined using an MTT *** expression of VEGF-A and CTGF was evaluated using real-time polymerase chain reaction after RNA extraction and cDNA ***’characteristics,including drug entrapment efficiency,size,dispersion index,and zeta potential were *** UMB had an IC_(50)of 96.2μg/mL,while UMB-containing niosomes had an IC_(50)of 25μg/***:Treatment with UMB-containing niosomes and free UMB resulted in a significant reduction in VEGF-A expression compared to control cells(P=0.001).Additionally,UMB-containing niosomes demonstrated a significant reduction in CTGF expression compared to control cells(P=0.05).however,there was no significant reduction in the expression of both genes in cells treated with free ***:Both free UMB and niosome-encapsulated UMB inhibits VEGF-A and CTGF genes ***,the latter demonstrates significantly greater efficacy,potentially due to the lower UMB dosage and gradual *** findings have implications for anti-angiogenesis therapeutic approaches targeting age-related macular degeneration.

关键词： umbelliprenin niosome age-related macular degeneration vascular endothelial growth factor-A connective tissue growth factor

分子印迹表面增强拉曼散射传感器的构建与应用

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科学通报 2024年第11期69卷 1429-1446页

作者：陈璇温宇浩周娜曹晓林 Maryam arabi 纪灵张志阳陈令新李金花中国科学院烟台海岸带研究所山东省海岸带环境工程技术研究中心中国科学院海岸带环境过程与生态修复重点实验室山东省海岸带环境过程重点实验室烟台264003 烟台大学生命科学学院烟台264006 中国科学院大学海洋学院北京100049 国家海洋局烟台海洋环境监测中心站烟台264006 滨州医学院药学院烟台264003

分子印迹表面增强拉曼散射(MI-SERS)传感器,将具有构效预定性、识别特异性和应用普遍性的分子印迹聚合物(MIPs)作为识别元件,结合表面增强拉曼散射(SERS)光谱检测技术的指纹识别、无损、高灵敏和快速的优良特性,提高了传感器的分析性能... 详细信息

分子印迹表面增强拉曼散射(MI-SERS)传感器,将具有构效预定性、识别特异性和应用普遍性的分子印迹聚合物(MIPs)作为识别元件,结合表面增强拉曼散射(SERS)光谱检测技术的指纹识别、无损、高灵敏和快速的优良特性,提高了传感器的分析性能,为复杂基质痕量分析提供了新方法.MI-SERS传感器凭借高效、精确、无损等成为新兴的研究热点,在环境监测、食品安全、生物医药等领域显示了广阔的发展前景.本文综述了MI-SERS传感器构建与应用的新进展.首先,介绍了基本的传感机理,以及根据使用场景、操作过程和检测模式进行的结构分类.然后,从MIPs制备策略和SERS基底改良入手,阐述了提高传感器性能的印迹策略和条件优化方法,并探讨了传感器的即时检验应用.最后,提出了MI-SERS传感器在稳定性、增强机理、普适性、绿色可持续性方面可能面临的挑战,展望了其构建和应用前景.

关键词：分子印迹表面增强拉曼散射传感器构建策略

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.M.FEIZABAD M.h.YAS Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQM)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQM)