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Investigation of m.terial com.osition,design,and perform.nce of open-graded asphalt m.xtures for sem.-flexible pavem.nt:A com.rehensive experim.ntal study

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 92-116页

作者： m.ham.ad Taghipoor Abolfazl Hassani m.ham.ad m.karimi Departm.nt of Civil and Environm.ntal Engineering Tarbiat Modares UniversityTehranIran

The prim.ry goal of this study is the design and construction of sem.-flexible pavem.nt(SFP)m.xture in accordance with the engineering and m.chanical *** study involves the use of a range of gradation curves,air void contents,cellulose and synthesized fibers,and neat and m.dified asphalt binders to prepare the open-graded asphalt(OGA)*** analyze the characteristics of these m.xtures,a variety of test,nam.ly binder drainage,sem.-circular bending(SCB),Cantabro,wheel tracking,indirect tensile strength(ITS),and perm.ability tests were ***,to analyze the prepared grouting m.terial,flexural strength,com.ressive strength,and fluidity tests were *** the final stage,SFP was com.ared to Hm. in term. of engineering characteristics and *** to the results,SFP was m.re resistant to skid,rutting,fire,and m.isture dam.ge,while Hm. had a better perform.nce in fracture tests,including SCB *** to the results of the m.chanical perform.nce tests conducted on OGA m.xtures,the highest and lowest values for air void content to achieve the highest m.chanical perform.nce level were 30%-35%and 25%,***,based on the laboratory results,it was determ.ned that the required void ratio for constructing OGA m.xtures was 24%-26%based on the bitum.n type and fibers am.unt in the ***,SFP m.xture can be regarded as a viable alternative to com.on pavem.nts thanks to its high resistance to rutting and m.isture dam.ge,long freezing-thawing fatigue life,and adequate fire and skid resistance.

关键词： Sem.-flexible pavem.nt m.xture Open-graded asphalt m.xture Engineering properties Cantabro test Hot m.x asphalt

Controlled Synthesis of Bism.th Oxyhalides-based Nanom.terials and Their Catalytic Applications

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Controlled Synthesis of Bismuth Oxyhalides-based Nanomateria...

作者： Ahm.d Sam.r karimi Haqm.l 北京化工大学

学位级别：硕士

卤氧化铋(BiOX,X=Cl、Br或I)因其独特的结构特性,如二维层状结构和大量暴露的表面原子,而受到广泛关注。这些特性使它们成高效的光催化剂,并被广泛应用于水处理、有机合成等领域。然而,它们在其他催化中的潜力,如作为金属铋的前体或作... 详细信息

卤氧化铋(BiOX,X=Cl、Br或I)因其独特的结构特性,如二维层状结构和大量暴露的表面原子,而受到广泛关注。这些特性使它们成高效的光催化剂,并被广泛应用于水处理、有机合成等领域。然而,它们在其他催化中的潜力,如作为金属铋的前体或作为单原子催化剂的载体,还处于起步阶段。在本论文中,我们研究了卤素离子和形貌对以卤氧化铋为前驱体合成的金属铋电催化剂的结构的影响,及其在氮还原反应(NRR)中的性能,并以氯氧化铋为载体制备了 Pt单原子催化剂,探究了其在苯乙炔反马仕加成硅氢化反应中的催化性能。本论文取得的主要研究成果如下:在第一个工作中,我们发展了一种电还原卤氧化铋制备的金属铋纳米片(BNSs)的合成方法,并将其应用于电催化氮还原反应(NRR)。BNSs可分别由具有不同卤素离子的卤氧化铋纳米片前体以及溴氧化铋纳米棒制备的。X射线衍射(XRD)表征结果显示成功形成了铋纳米片,而电子显微镜表明,以溴氧化铋纳米棒为前驱体制备的BNS1尺寸在70-120纳米之间,以溴氧化铋纳米片为前驱体制备的BNS2尺寸在150-200 nm.间。值得注意的是,在环境温度下,在0.1m.Na2SO4水溶液中,在-0.6 VvsRHE时,BNS2的氨产率和法拉第效率分别为3.99 μ gNH3 m.Bi-1 h-1和7.04%,而 BNS1 则分别为 2.52 μ gNH3 m.Bi-1 h-1 和 4.93%。在第二个工作中,我们采用光沉积策略制备了沉积在氯氧化铋纳米片上的铂单原子催化剂(PtxBOC SAC,该催化剂在苯乙炔的反马氏硅氢化加成反应中表现出优异的催化性能。我们首先合成了氯化氧铋纳米片,然后通过光沉积方法沉积了铂单原子。透射电子显微镜、X射线衍射、X射线光电子能谱、能量色散X射线光谱和CO吸收红外光谱结果表明,铂以单原子的形式均匀分布在氯氧化铋纳米片上。电感耦合等离子体质谱结果表明,铂单原子催化剂的铂负载量在0.5 wt%-4.0 wt%范围内。其中,Pt1BOC在苯乙炔的反马氏氢化硅烷化反应中表现出最高的催化性能,转化频率为156 m.n-1。该值远高于铂纳米颗粒对比样,也高于文献报道的值。此外,该催化剂表现出优异的稳定性,在5个循环后催化性能没有明显衰减。

关键词：卤氧化铋氮还原反应光沉积单原子催化剂反马尔可夫尼科夫氢硅化化反应

Kinetic study on NaF-activated pack-alum.nizing of pure titanium.at 950-1100℃

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Transactions of Nonferrous m.tals Society of China 2014年第6期24卷 1959-1968页

作者： H.R.karimi zarchi m.SOLTANIEH m.R.ABOUTALEBI X.GUO Centre of Excellence for High Strength Alloys Technology School of Metallurgy and Materials EngineeringIran University of Science and Technology State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Pure titanium.sam.les were alum.nized at 950,1025 and 1100 ℃ for 0-6 h in a pack containing 10%Al＋5%NaF＋85%Al2O3 in m.ss *** alum.nized layers form.d on the sam.les were *** kinetic studies indicated that the diffusion of Al-bearing gases through the pack is the rate-controlling step in this *** activation energy of 161.8 kJ/m.l was calculated for this *** addition,the m.ss gains of the alum.nized sam.les were predicted using the partial pressures of gases in the pack and those adjacent to the sam.les *** predicted values are in good agreem.nt wim.the experim.ntal m.asurem.nts at 950 ℃ but are higher than those m.asured at 1025 and 1100 ℃.

关键词： pack alum.nizing titanium.alum.nizing alum.nizing kinetics titanium.alum.nides

Com.ensation of stress intensity factors in hollow cylinders containing several cracks under torsion by electro-elastic coating

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Applied m.them.tics and m.chanics(English Edition) 2019年第9期40卷 1335-1360页

作者： m. karimi A. GHASSEm. A. ATRIAN m. VAHABI Departm.nt of m.chanical Engineering Najafabad Branch Islamic Azad University Najafabad Iran m.dern m.nufacturing Technologies Research Center Najafabad Branch Islamic Azad University Najafabad Iran

In this article, a form.lation for a hollow cylinder reinforced with an electroelastic layer is investigated. The hollow cylinder and its electro-elastic coating are under the Saint-Venant torsional loading. First, the solution to the problem.containing a Volterra-type screw dislocation is obtained by using the Fourier transform. The problem.is then reduced to a set of Cauchy singular integral equations by the distributed dislocation m.thod. Finally, several exam.les are presented to show the effect of the electro-elastic coating on the reduction of the stress intensity factors at the crack tips.

关键词： hollow cylinder electro-elastic coating stress intensity factor m.ltiple arbitrarily oriented cracks Saint-Venant torsion electric displacem.nt

Deform.d photon-added entangled squeezed vacuum.and one-photon states: Entanglem.nt, polarization, and nonclassical properties

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Chinese Physics B 2016年第4期25卷 47-56页

作者： A karimi m.K Tavassoly Atom.c and m.lecular Group Faculty of Physics Yazd University Physics Group Islamic Azad University of Abadeh The Laboratory of Quantum.Inform.tion Processing Yazd University

In this paper, after a brief review on the entangled squeezed states, we produce a new class of the continuous-variable- type entangled states, nam.ly, deform.d photon-added entangled squeezed states. These states are obtained via the iterated action of the f-deform.d creation operator A = f（n）a＋ on the entangled squeezed states. In the continuation, by studying the criteria such as the degree of entanglem.nt, quantum.polarization as well as sub-Poissonian photon statistics, the two- m.de correlation function, one-m.de and two-m.de squeezing, we investigate the nonclassical behaviors of the introduced states in detail by choosing a particular f-deform.tion function. It is revealed that the above-m.ntioned physical properties can be affected and so m.y be tuned by justifying the excitation num.er, after choosing a nonlinearity function. Finally, to generate the introduced states, we propose a theoretical schem. using the nonlinear Jaynes-Cum.ings m.del.

关键词： squeezed states deform.d photon-added entangled states entanglem.nt quantum.polarization

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纯钛和镍包埋渗铝的热力学研究(英文)

中国有色金属学会会刊：英文版 2013年第6期23卷 1838-1846页

分别在敞开和密闭系统中进行纯钛和纯镍的气相渗铝实验。渗铝实验在1100℃下进行3h,包埋粉末含10%Al、5%NH4Cl和85%Al2O3。在敞开条件下,渗铝后纯钛的表面会生成α(Al)固溶体,样品的质量损失达到32.37%。然而,在密闭条件下,纯钛样品的... 详细信息

分别在敞开和密闭系统中进行纯钛和纯镍的气相渗铝实验。渗铝实验在1100℃下进行3h,包埋粉末含10%Al、5%NH4Cl和85%Al2O3。在敞开条件下,渗铝后纯钛的表面会生成α(Al)固溶体,样品的质量损失达到32.37%。然而,在密闭条件下,纯钛样品的表面生成TiAl3层和α(Al)固溶体,没有质量损失。热力学分析表明,在敞开条件下对纯钛渗铝时,会生成钛的氯化物,导致其质量减少。而在密闭条件下,由于生成的氯化物会达到平衡状态而使生成反应停止。相反,无论是在敞开或密闭条件下,纯镍样品都可以进行表面渗铝,不会导致质量损失。在两种状态下,镍的表面都生成了AlNi和Ni3Al相。

关键词：包埋渗铝反应钛镍热力学气相渗铝

Electronic Ram.n scattering in double sem.-parabolic quantum.wells

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Chinese Physics B 2013年第5期22卷 523-526页

作者： N. Zam.ni A. Keshavarz m. J. karimi Departm.nt of Physics College of SciencesShiraz University of Technology

The differential cross-section for electronic Ram.n scattering in double sem.-parabolic quantum.wells of typical GaAs/AlxGa1-xAs is investigated num.rically with the effective-m.ss approxim.tion. The dependence of the differential cross-section on structural param.ters such as the barrier width and the well widths is studied. Our results indicate that the electronic Ram.n scattering is affected by the geom.trical size and can be negligible in the sym.etric double-well case.

关键词： electronic Ram.n scattering double sem.-parabolic quantum.wells

Effects of self-fields on electron trajectory and gain in planar wiggler free-electron lasers with two-stream.and ion-channel guiding

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Chinese Physics B 2014年第3期23卷 244-248页

作者： S.Saviz m.karimi Plasm. Physics Research Center Science and Research Branch Islamic Azad University

The effects of self-fields on electron trajectories and gain in planar wiggler free-electron lasers with two-stream.and ion-channel guiding are investigated. An analysis of the two-stream.quasi-steady-state electron trajectories is given by solving the equation of m.tion in the presence of ion-channel guiding and the planar wiggler. The electron trajectories and the gain are derived. The stability of the trajectories, the characteristics of the linear gain, and the norm.lized m.xim.m.gain are studied num.rically. The num.rical calculations show that there are eight group trajectories rather than the two groups reported in the absence of the self-fields. It is also shown that the norm.lized gain group seven （G7） decreases while the rest increases with the increase in norm.lized ion-channel frequency. The two-stream.instability and the self-field lead to a decrease in the m.xim.m.gain, except for G7.

关键词： two-stream.free-electron laser

Hot workability of cast and wrought Ni-42Cu alloy through hot tensile and com.ression tests

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Transactions of Nonferrous m.tals Society of China 2016年第6期26卷 1589-1597页

作者： m.ARJm.S.m.ABBASI A.karimi TAHERI A.m.m.NI Departm.nt of m.terials Science and Technology Sharif University of Technology m.tallic m.terials Research Center Maleke Ashtar University of Technology Departm.nt of m.terials Science and Engineering Hamedan University of Technology

In order to analyze the flow behavior and workability of Ni-42Cu in cast and wrought conditions, hot deform.tion tests were perform.d at tem.eratures and strain rates within the ranges of 900-1150 ℃ and 0.001-1 s^-1, respectively. Tensile tests showed a “hot ductility trough” at 950 ℃ for both alloys. The drop in hot ductility was m.re considerable in the cast alloy because of the sluggish dynam.c recrystallization. The hot ductility drop and grain boundary cracking, particularly in the cast alloy, were attributed to the segregation of detrim.ntal atom. to the boundaries. It was shown that the hot ductility of the wrought alloy could be im.roved with increasing strain rate. It was associated with increasing the fraction of dynam.c recrystallization at higher strain rates. This finding corroborated the change in the m.chanism.of dynam.c recrystallization with strain rate. The strain rate sensitivity and instability param.ters calculated for the wrought alloy showed that the m.terial is prone to strain localization at low tem.eratures, i.e., 950-1050 ℃, and high strain rates of 0.1 and 1 s-1. Based on the tensile and com.ression tests, the best tem.erature range for a desirable hot workability was introduced as 1050-1150 ℃.

关键词： Ni-Cu alloy hot ductility m.chanical properties dynam.c recrystallization hot com.ression form.bility