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Influence of glycine additive on corrosion and wear performance of electroplated trivalent chromium coating

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International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 544-554页

作者： Navid Mehdipour Milad rezaei Zeynab Mahidashti Department of Materials and Metallurgical Engineering Amirkabir University of Technology(Tehran Polytechnic)Hafez Ave.P.O.Box 15875-4413TehranIran

The aim of this study is to evaluate the effect of various molar ratios of glycine to chromium salt(Gly:Cr)and different current densities on the corrosion and wear behaviors of Cr(III)electroplated *** morphology and thickness of the coatings were investigated by scanning electron *** wear properties of the coatings were studied using pin on disk and hardness tests,while corrosion behavior of the coatings was identified using linear polarization,small amplitude cyclic voltammetry,and electrochemical impedance spectroscopy *** increasing the glycine concentration,a structure with low crack density was *** all molar ratios,maximum thickness and current efficiency was observed at a current density of 150 mA·cm?*** the electrochemical methods had a consistent result,and maximum corrosion resistance of approximately 16000Ω·cm2 was obtained in the case of Gly:Cr=3:1 and current density of 200 mA·cm?2.

关键词： electrodeposition trivalent chromium glycine corrosion resistance

Movement of Intransitive Permutation Groups Having Maximum Degree

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Chinese Annals of Mathematics,Series B 2012年第1期33卷 143-148页

作者： Mehdi ALAEIYAN Mehdi rezaei School of Mathematics Iran University of Science and Technology

Let G be a permutation group on a set Ω with no fixed points in,and m be a positive *** the movement of G is defined as move(G):=sup Γ {|Γg\Γ| | g ∈ G}.It was shown by Praeger that if move(G) = m,then |Ω| 3m + t-1,where t is the number of G-orbits *** this paper,all intransitive permutation groups with degree 3m+t-1 which have maximum bound are ***,a positive answer to her question that whether the upper bound |Ω| = 3m + t-1 for |Ω| is sharp for every t > 1 is given.

关键词：置换群运动正整数固定点出版社 tgt 移动

Effect of Ni loadings on the activity and coke formation of MgO-modified Ni/Al_2O_3 nanocatalyst in dry reforming of methane

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Journal of Energy Chemistry 2014年第5期23卷 633-638页

作者： Zahra Alipour Mehran rezaei Fereshteh Meshkani Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan

MgO-modified Ni/Al2O3 catalysts with different Ni loadings were prepared and employed in dry reforming of methane （DRM）. The effect of Ni loadings on the activity and coke formation of Ni/MgO-A1203 catalysts were investigated. The synthesized catalysts were characterized by XRD, N2 adsorption-desorption, SEM, TPO and TPR techniques. The obtained results showed that increasing nickel loading decreased the BET surface area and increased the catalytic activity and amount of deposited carbon. In addition, the effect of gas hourly space velocity （GHSV） and feed ratio were studied.

关键词： nickel catalyst MgO modifier syngas dry reforming coke formation

Distributed output feedback stationary consensus of multi-vehicle systems in unknown environments

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Control Theory and Technology 2018年第2期16卷 93-109页

作者： Vahid rezaei Margareta STEFANOVIC Department of Electrical and Computer Engineering University of Denver Denver CO 80208 U.S.A.

In the traditional distributed consensus of multi-vehicle systems, vehicles agree on velocity and position using limited information exchange in their local neighborhoods. Recently, distributed leaderless stationary consensus has been proposed in which vehicles agree on a position and come to a stop. The proposed stationary consensus schemes are based on all vehicles＇ access to their own absolute velocity measurements, and they do not guarantee this collective behavior in the presence of disturbances that persistently excite vehicles＇ dynamics. On the other hand, traditional distributed disturbance rejection leaderless consensus algorithms may result in an uncontrolled increase in the speed of multi-vehicle system. In this paper, we propose a dynamic relative-output feedback leaderless stationary algorithm in which only a few vehicles have access to their absolute measurements. We systematically design the distributed algorithm by transforming this problem into a static feedback robust control design challenge for the low-order modified model of vehicles with fictitious modeling uncertainties. We further propose dynamic leader-follower stationary consensus algorithms for multi-vehicle systems with a static leader, and find closed-form solutions for the consensus gains based on design matrices and communication graph topology. Finally, we verify the feasibility of these ideas through simulation studies.

关键词： Multi-vehicle system distributed control stationary consensus disturbance accommodation

Effects of 946-nm thermal shift and broadening on Nd^(3+):YAG laser performance

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Chinese Physics B 2015年第12期24卷 342-345页

作者： Seyed Ebrahim Pourmand Ghasem rezaei Department of Optics and Laser Engineering Estahban Branch Islamic Azad University Department of Physics College of Sciences Yasouj University

Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with *** lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.

关键词： 946-nm Nd:YAG laser thermal broadening thermal shift flashlamp pump slope efficiency threshold power

Bearing capacity of thin-walled shallow foundations： an experimental and artificial intelligence-based study

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第4期17卷 273-285页

作者： Hossein rezaei Ramli NAZIR ehsan MOMENI Faculty of Engineering Lorestan University Khorram A bad 68151-44316 Iran Department of Geotechnics and Transportation Faculty of Civil Engineering Universiti Teknologi Malaysia Johor 81310 Malaysia

目的:薄壁扩展式地基已被广泛应用于土壤强度相对较低的沿海工程。目前,已有很多学者对其进行了人工神经网络的适用性研究,希望用此对地基的承重能力进行预测。但是这些研究多数是基于传统的人工神经网络,学习速度慢且受困于局部极小值... 详细信息

目的:薄壁扩展式地基已被广泛应用于土壤强度相对较低的沿海工程。目前,已有很多学者对其进行了人工神经网络的适用性研究,希望用此对地基的承重能力进行预测。但是这些研究多数是基于传统的人工神经网络,学习速度慢且受困于局部极小值。本文拟提出一种改进的基于人工神经网络的预测薄壁浅地基承重能力的模型。方法:1.整合145组关于地基承重测试的文献数据和实验数据(包括承重能力、摩擦角、沙的单位重量、基脚宽度和长宽比等);除了承重能力,其他参数都是模型输入;2.研究各参数对地基承重能力的影响,确定最优的人工神经网络模型参数,并对不同的人工神经网络模型进行比较。结论:1.当基脚长宽比从0.5变为1.12时,地基的承重能力增加了大约一半;2.基于粒子群优化算法的人工神经网络模型表现最好;在测试数据中,承重能力的预测值和测量值之间高达0.98的相关系数也表明,在无粘性土中,基于人工神经网络的预测模型适用于薄壁浅地基的承重能力预测。

关键词：薄壁地基沙承重能力人工神经网络粒子群优化

Microwave promoted rapid dehydration of aldoximes to nitriles using melamine-formaldehyde resin supported sulphuric acid in dry media

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Chinese Chemical Letters 2011年第7期22卷 815-818页

作者： Ramin rezaei Marzeih Karami Department of Chemistry Islamic Azad UniversityFirouzabad BranchP.O.Box 74715-117FirouzabadIran

A simple and convenient procedure for the synthesis of nitriles by dehydration of aldoxime using supported sulphuric acid on melamine-formaldehyde resin （MFR） under solvent-free condition has been developed. A variety of aromatic and aliphatic aldoximes were converted to the corresponding nitriles. The resin was recovered and reused for subsequent reactions. ~ 2011 Ramin rezaei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Aldoximes Nitriles Melamine-formaldehyde resin Sulphuric acid Solvent-free

A predictive,simple and rapid method for thermodynamic study on the binding of copper ion with Alzheimer's amyloid β peptide

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Chinese Chemical Letters 2009年第6期20卷 751-754页

作者： G.rezaei Behbehani Chemistry Department Imam Khomeini International University

The interaction of CuCl2 to the first 16 residues of the Alzheimer＇s amyliod β peptide, Aβ（1-16） was studied by isothermal titration calorimetry at pH 7.2 and 37℃ in aqueous solution.

关键词： Alzheimer's amyloid β peptide Isothermal titration calorimetry Solvation parameters

Optimization of preparation conditions of Fe-Co nanoparticles in low-temperature CO oxidation reaction by taguchi design method

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Journal of Natural Gas Chemistry 2012年第4期21卷 415-420页

作者： Abolfazl Biabani Mehran rezaei zohreh Fattah Catalyst and Advanced Materials Research Laboratory Chemical Engineering DepartmentFaculty of EngineeringUniversity of KashanKashan P.O.Box ***Iran Institute of Nanoscience and Nanotechnology University of KashanKashan P.O.Box ***Iran

Mixed iron-cobalt oxide （Co/Fe molar ratio = 1/5） are prepared using a simple co-precipitation procedure and studied for the catalytic oxidation of carbon monoxide. In particular, the effects of a range of preparation variables such as pH value when precipitation, aging temperature, precipitation agent type and aging time are investigated on the catalytic performance of synthesized Fe-Co oxides in CO oxidation reaction. In addition, the preparation factors were optimized by Taguchi design method. The optimized sample was characterized by XRD, N2 adsortion/desorption, TEM and TGA/DTA techniques. The results reveal that the optimized sample shows a mesoporous structure with a narrow pore size distribution centered in the range of 2-7 nm. The sample prepared under optimized conditions has high activity and stability toward removal of carbon monoxide at lower temperatures. It is shown that different preparation variables influence the catalytic performance of Fe-Co oxide in CO oxidation reaction.

关键词： Fe Co nanoparticles experimental design CO oxidation