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Transactions of Nonferrous metals Society of China 2010年第3期20卷 425-431页

作者： m.ALIOFKHAZRAEI sh.AHANGAR ANI A.SABOUR ROUHAGHDAm Department of materials Engineering Faculty of EngineeringTarbiat Modares University Department of Advanced materials and Renewable Energies Iranian Research Organization for Science and Technology(IROST)

Size distribution of nano-carbides produced by duplex treatments of surface nanocrystallization(by surface severe plastic deformation) and plasma electrolytic carburizing on CP-Ti was *** and kurtosis of Gussian shape distribution curves were studied and the effect of time was *** usage of longer time is more suitable for achieving less size of complex *** roughness of treated samples was *** is observed that there is an optimum level for time on surface roughness increasing(difference between two measured data).

关键词： surface nanocrystallization hard layer roughness CP-Ti

Sorption of certain lanthanides by kieselguhr loaded with Cyanex 572 from sulfate medium

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Journal of Rare Earths 2020年第3期38卷 299-305页

作者： sh.sh.Emam m.S.Gasser N.E.El-Hefny W.H.mahmoud H.F.Aly Hot Laboratories Centre Atomic Energy AuthorityCairo 13759Egypt Department of Chemistry Faculty of ScienceAin Shams UniversityCairoEgypt

Kieselguhr for chromatography was loaded with Cyanex 572 extractant and characterized using X-ray diffraction(XRF),scanning electron microscopy(SEm),Fourier transform infra-red(FT-IR),and thermal *** of some heavy lanthanides together with yttrium by the prepared kieselguhr/Cy-572 sorbent was investigated by batch experiment in terms of initial metal ions concentrations,volume to solid mass ratio(V/m),sulfuric acid concentration as well as *** sorption equilibrium of Cy-572 loaded kieselguhr was satisfactorily explained by the pseudo second-order kinetic model and Langmuir isotherm ***,the values of thermodynamic parameters △G°,△H°,and △S°at25℃of the studied metal ions show that the process is spontaneous and endothermic in nature.2.0 mol/L HNO3 is promising to desorb these metal ions.

关键词： Sorption Cyanex 572 Lanthanides Kieselguhr Sulfate medium Rare earths

Nanoscale potential barrier distributions and their effect on current transport in Ni/n type Si Schottky diode

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Journal of Semiconductors 2015年第12期36卷 74-80页

作者： m.Yeganeh N.Balkanian sh.Rahmatallahpur West North Research Complex

We have experimentally studied the Ni/n-Si nano Schottky barrier height （SBH） and potential difference between patches in the nano Schottky diodes （SD） using contact atomic force microscopy （C-AFm） in tapping mode and scanning tunneling microscopy （STm）. Topology measurement of the surface with C-AFm.sh.wed that, a single Ni/n-Si SD consists of many patches with different sizes. These patches are sets of parallel diodes and electrically interacting contacts of 5 to 50 nm sizes and between these individual diodes, there exists an additional electric field. In real metal semiconductor contacts （mSC）, patches with quite different configurations, various geometrical sizes and local work functions were randomly distributed on the surface of the metal. The direction and intensity of the additional electric field are distributed in homogenously along the contact metal surface. SBH controls the electronic transport across the mS interface and therefore, is of vital importance to the successful operation of semiconductor devices.

关键词： nano Schottky diode additional electrical field nanopatch STm and C-AFm

Tameness and Artinianness of Graded Generalized Local Cohomology modules

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Algebra Colloquium 2015年第1期22卷 131-146页

作者： m. Jahangiri N. shirmohammadi sh. Tahamtan Faculty of mathematical sciences and Computer Kharazmi University rlbhran Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 Tehran Iran School of mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 rlbhran Iran Department of Mathematics University of Tabriz Tabriz Iran Islamic Azad University Borujerd Branch Boroujerd Iran

Let R = ⊙n〉0 Rn be a standard graded ring, a ∩ ⊙n〉0 Rn an ideal of R, and m, N two finitely generated graded R-modules. This paper studies the homogeneous components of graded generalized local cohomology modules. We show that for any i 〉 0, the n-th graded component Hiα（m, N）n of the i-th generalized local cohomology module of m and N with respect to a vanishes for all n 〉〉 0. Some sufficient conditions are pro- posed to satisfy the equality sup{end（Hiα （m, N）） [ i _〉 0} = sup{end（HiR＋（m, N））｜ i 〉 0}. Also, some sufficient conditions are proposed for the tameness of Hiα（m, N） such that i = fRα＋（m,N） or i = cdα（m,g）, where fRα＋（m,N） and cdα（m,g） denote the R＋- finiteness dimension and the cohomological dimension of m and N with respect to a, respectively. Finally, we consider the Artinian property of some submodules and quotient modules of Hjα（m, N）, where j is the first or last non-minimax level of Hiα（m, N）.

关键词： graded rings and modules generalized local cohomology Artinian modules,tameness

Effect of Sulfur Precursor on Dimensions of One-dimensional CdS Nanocrystals

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Journal of materials Science & Technology 2009年第4期25卷 462-464页

作者： m.maleki sh.mirdamadi R.Ghasemzadeh m.Sasani Ghamsari Department of metallurgy and material Engineering Iran University of Science & Technology Solid State Lasers Research Group Laser & Optics Research School

One-dimensional CdS nanocrystals have been prepared by solvothermal method using cadmium acetate as a cadmium precursor, elemental sulfur and Na2S, as a sulfur precursor, and ethylenediamine as a solvent at 150℃ for 5 h. The nanocrystals were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEm）, transmission electron microscopy （TEm） and UV-Vis absorption spectroscopy. XRD patterns indicate that both Na2S and elemental sulfur as the sulfur precursor result in CdS nanorods with wutzite phase （hexagonal structure）. SEm and TEm images show that diameter of CdS nanorods can be decreased using Na2S instead of elemental sulfur. For the growth of CdS nanorods, a mechanism has been proposed. Uv-Vis absorption of CdS nanorods （sulfur precursor： Na2S） was shown blue shift to 485 nm due to the quantum size effect.

关键词： Nanomaterials Semiconductors CdS nanorods Na2S Solvothermal method

Comparative studies on Y(Ⅲ)and Dy(Ⅲ)extraction from hydrochloric and nitric acids by Cyanex 572 as a novel extractant

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Journal of Rare Earths 2018年第12期36卷 1342-1350页

作者： N.E.El-Hefny m.S.Gasser sh.sh.Emam W.H.mahmoud H.F.Aly Hot Laboratories Centre Atomic Energy Authority Faculty of Science Ain Shams University

Extraction of Y(III) and Dy(III) from hydrochloric and nitric acids by Cy-572 in kerosene was studied. The factors affecting the extraction were separately investigated. The stoichiometry of the extracted species was deduced on the basis of slope analysis method. Evaluation of extraction equilibrium and stripping investigation was studied as well as saponification effect of Cy-572. The composition of the extracted metal species in the organic phase was found to be [mA·(HA)] for Y(III) or Dy(III) in both media.1.0 mol/L HCI is the best stripping agent for each metal ion from the studied acidic media in one *** Cy-572 does not exhibit any selectivity towards the extraction of Y(III) or Dy(III) from both HCI and HNOsolutions. Based on the obtained results, the data were compared and the separation feasibility between lanthanides and Y(III) in the two media was discussed.

关键词： Extraction Cyanex-572 Yttrium Lanthanides Separation factor Saponification

Damage prediction of 7025 aluminum alloy during equal-channel angular pressing

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International Journal of minerals,metallurgy and materials 2014年第10期21卷 990-998页

作者： m.Ebrahimi sh.Attarilar C.Gode F.Djavanroodi Department of mechanical Engineering Iran University of Science and Technology Department of materials Engineering Sahand University of Technology School of Denizli Vocational Technology Program of Machine Pamukkale University Department of mechanical Engineering Imperial College

Equal-channel angular pressing （ECAP） is a prominent technique that imposes severe plastic deformation into materials to en- hance their mechanical properties. In this research, experimental and numerical approaches were utilized to investigate the mechanical prop- erties, strain behavior, and damage prediction of ECAPed 7025 aluminum alloy in various conditions, such as die channel angle, outer comer angle, and friction coefficient. Experimental results indicate that, after the first pass, the yield strength, ultimate tensile strength, and hardness magnitude are improved by approximately 95%, 28%, and 48.5%, respectively, compared with the annealed state, mainly due to grain re- finement during the deformation. Finite element analysis shows that the influence of die channel angle is more important than that of outer comer angle or friction coefficient on both the strain behavior and the damage prediction. Also, surface cracks are the main cause of damage during the ECAP process for every die channel angle except for 90°; however, the cracks initiated from the neighborhood of the central re- gions are the possible cause of damage in the ECAPed sample with the die channel angle of 90°.

关键词： aluminum alloys equal-channel angular pressing materials damage strain distribution mechanical properties

Thermal-hydraulic and stress analysis of AP1000 reactor containment during LOCA in dry cooling mode

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Nuclear Science and Techniques 2017年第6期28卷 73-85页

作者： sh.sheykhi S.Talebi m.Soroush E.masoumi Department of Energy Engineering and Physics Amirkabir University of Technology(Tehran Polytechnic) Young Researchers and Elite Club Islamic Azad UniversitySouth Tehran Branch

Some kinds of break in the reactor coolant system may cause the coolant to exit rapidly from the failure site,which leads to the loss of coolant accident(LOCA).In this paper,a stress analysis of an AP1000 reactor containment is performed in an LOCA,with the passive containment cooling system(PCCS) being available and not available for cooling the wall's *** variations in the mechanical properties of the wall's containment,including elastic modulus,strength,and stress,are analyzed using the ABAQUS code.A general two-phase model is applied for modeling thermal-hydraulic behavior inside the *** pressure and temperature from thermal-hydraulic models are considered as boundary conditions of the ABAQUS code to obtain distributions of temperature and stress across steel shell of the containment in the *** results indicate that if the PCCS fails,the peak pressure inside the containment exceeds the design ***,the stress would still be lower than the yield stress value,and no risk would threaten the integrity of the containment.

关键词： Two-phase flow LOCA Containment integrity AP1000 reactor

Lanthanide amino acid Schiff base complexes:synthesis,spectroscopic characterization,physical properties and in vitro antimicrobial studies

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Journal of Rare Earths 2013年第7期31卷 715-721页

作者： Samir Alghool m.sh.Zoromba Hanan F.Abd El-Halim Department of Chemistry Faculty of SciencePort Said UniversityPort Said 42521Egypt Department of Chemistry Faculty of PharmacyMisr International UniversityIsmailia RoadKm 28 CairoEgypt

Complexes of La （III）, Nd（III）, Gd（III）, Sm（III）, and Ce（IV） were synthesized with Schiff base [（3,5-di-tert-butyl-2-hy- droxybenzyl） amino] acetic acid （H3L）. The ligand and its complexes were synthesized and characterized based on the following analysis： elemental analyses, FAB-mass, molar conductance measurements, magnetic measurement, UV-visible, IR, and NmR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to metal ion through ONO donor sequence. Thermal degradation studies of the ligand and its complexes showed that the previous lanthanide complexes were more thermally stable than the ligand itself. The Schiff base and its complexes were screened for their antibacterial （Escherichia coli, Staphylococcus aureus） and antifungal （Aspergillus flavus and Candida Albicans）.

关键词： lanthanide Schiffbase complexes physical properties biological activity rare earths

Experimental and numerical study on plasma nitriding of AISI P20 mold steel

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International Journal of minerals,metallurgy and materials 2016年第9期23卷 1065-1075页

作者： N.Nayebpashaee H.Vafaeenezhad sh.Kheirandish m.Soltanieh materials Processing Simulation Laboratory(mPS-LAB) School of Materials and Metallurgical EngineeringIran University of Science and Technology(IUST) School of materials and metallurgical Engineering Iran University of Science and Technology(IUST)

In this study, plasma nitriding was used to fabricate a hard protective layer on AISI P20 steel, at three process temperatures（450℃, 500℃, and 550℃） and over a range of time periods（2.5, 5, 7.5, and 10 h）, and at a fixed gas N2：H2 ratio of 75vol%：25vol%. The morphology of samples was studied using optical microscopy and scanning electron microscopy, and the formed phase of each sample was determined by X-ray diffraction. The elemental depth profile was measured by energy dispersive X-ray spectroscopy, wavelength dispersive spectroscopy, and glow dispersive spectroscopy. The hardness profile of the samples was identified, and the microhardness profile from the surface to the sample center was recorded. The results show that ε-nitride is the dominant species after carrying out plasma nitriding in all strategies and that the plasma nitriding process improves the hardness up to more than three times. It is found that as the time and temperature of the process increase, the hardness and hardness depth of the diffusion zone considerably increase. Furthermore, artificial neural networks were used to predict the effects of operational parameters on the mechanical properties of plastic mold steel. The plasma temperature, running time of imposition, and target distance to the sample surface were all used as network inputs; Vickers hardness measurements were given as the output of the model. The model accurately reproduced the experimental outcomes under different operational conditions; therefore, it can be used in the effective simulation of the plasma nitriding process in AISI P20 steel.

关键词： tool steel plasma nitriding sputtering neural networks