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Nano Research 2011年第5期4卷 511-521页

作者： Izabela Janowska Maria-Simona Moldovan Ovidiu Ersen Herve Bulou kambiz chizari Marc J. Ledoux Cuong Pham-Huu Laboratoire des MatEriaux Surfaces et ProcEdEs pour la Catalyse （LMSPC UMR 7515 CNRS） 25 rue Becquerel F-67087 Strasbourg Cedex 02 France Institut de Physique et Chimie des Materiaux de Strasbourg （IPCMS UMR 7504 CNRS） 23 rue du Loess F-67037 Strasbourg Cedex 08 France

Heterogeneous catalytic reactions involve the use of highly dispersed active phases such as metal, metal oxide, or metal sulphide nanoparticIes on thermally stable supports. Fluctuations of the reaction temperature during the reactions can induce sintering of the particles. The stability of such small particles represents a crucial parameter in the development of new families of catalysts with high activity in many fields. Here we report the stability of platinum nanoparticles （2-3 nm） on a few-layer graphene （FLG） surface as studied by in situ high temperature transmission electron microscopy.

关键词： Graphene platinium nanoparticles diffusion catalysis TEM annealing

Microwave Synthesis of Large Few-Layer Graphene Sheets in Aqueous Solution of Ammonia

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Nano Research 2010年第2期3卷 126-137页

作者： Izabela Janowska kambiz chizari Ovidiu Ersen Spyridon Zafeiratos Driss Soubane Victor Da Costa Virginie Speisser Christine Boeglin Matthieu Houllé Dominique Bégin Dominique Plee Marc-Jacques Ledoux Cuong Pham-Huu Laboratoire des Matériaux Surfaces et Procédés pour la Catalyse(LMSPC)UMR7515 CNRS-Universitéde Strasbourg 25rue Becquerel67087 Strasbourg Cedex 08France Institut de Physique et Chimie des Matériaux de Strasbourg(IPCMS) UMR7504 CNRS-Universitéde Strasbourg 23rue du Loess67037 Strasbourg Cedex 02France Arkema Groupement de Recherche de Lacq(GRL)BP 3464170 LACQFrance

Few-layer graphene (FLG) sheets with sizes exceeding several micrometers have been synthesized by exfoliation of expanded graphite in aqueous solution of ammonia under microwave irradiation, with an overall yield approaching 8 wt.%. Transmission electron microscopy (in bright-field and dark-field modes) together with electron diffraction patterns and atomic force microscopy confirmed that this graphene material consisted mostly of mono-, bi- or few-layer graphene (less than ten layers). The high degree of surface reduction was confirmed by X-ray photoelectron and infrared spectroscopies. In addition, the high stability of the FLG in the liquid medium facilitates the deposition of the graphene material onto several substrates via low-cost solution-phase processing techniques, opening the way to subsequent applications of the material.

关键词： Graphene transmission electron microscopy(TEM) expanded graphite exfoliation microwaves

Improving the hydrodynamic performance of the SUBOFF bare hull model: a CFD approach

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Acta Mechanica Sinica 2020年第1期36卷 44-56页

作者： kambiz Divsalar Department of Mechanical Engineering Imam Khomeini University of Maritime SciencesNowshahrIran

The main aims of this study are to investigate the hydrodynamic performance of an autonomous underwater vehicle(AUV),calculate its hydrodynamic coefficients,and consider the flow characteristics of underwater *** addition,three important parts of the SUBOFF bare hull,namely the main body,nose,and tail,are modified and redesigned to improve its hydrodynamic performance.A three-dimensional(3D)simulation is carried out using the computational fluid dynamics(CFD)*** simulate turbulence,the k-ωshear stress transport(SST)model is employed,due to its good prediction capability at reasonable computational *** the effects of the length-to-diameter ratio(LTDR)and the nose and tail shapes on the hydrodynamic coefficients,it is concluded that a hull shape with bullet nose and sharp tail with LTDR equal to 7.14 performs better than the SUBOFF *** final proposed model shows lower drag by about 14.9%at u=1.5 m·s^-***,it produces 8 times more lift than the SUBOFF model at u=6.1 m·s^-*** effects are due to the attachment of the fluid flow at the tail area of the hull,which weakens the wake region.

关键词： Autonomous underwater vehicle Computational fluid dynamics Hydrodynamic performance Drag Turbulence model Hull shape

The design of electroabsorption modulators with negative chirp and very low insertion loss

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Journal of Semiconductors 2012年第6期33卷 14-19页

作者： kambiz Abedi Department of Electrical Engineering Faculty of Electrical and Computer EngineeringShahid Beheshti University

Electroabsorption modulators（EAMs） with negative chirp and very low insertion loss are numerically designed with asymmetric intra-step-barrier coupled double strained quantum wells（AICD-SQWs） based on InGaAlAs *** this purpose,the electroabsorption coefficient is calculated over a range of wells layer strain from compressive（CS） to tensile（TS）.The chirp parameter and insertion loss for TE input light polarization are evaluated from the calculated electroabsorption spectra,and their Kramers-Kronig transformed refractive index *** results of the numerical simulation show that the best range of left and right wells strain for EAMs based on AICD-SQWs with negative chirp and very low insertion loss are from 0.032%to 0.05%（TS） and-0.52% to-0.50%（CS）,respectively.

关键词： electroabsorption modulators AICD-SQW strain chirp insertion loss

High-performance traveling-wave electroabsorption modulators utilizing mushroom-type waveguide and periodic transmission line loading

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Optoelectronics Letters 2012年第3期8卷 176-178页

作者： kambiz Abedi Department of Electrical Engineering Faculty of Electrical and Computer Engineering Shahid Beheshti University

For the first time, periodic loaded electrodes and mushroom-type waveguide are combined to improve the performance of traveling-wave electroabsorption modulators (TWEAMs) based on the asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQW). The electrical modulation response of periodic mushroom-type TWEAM is obtained by using equivalent circuit model, and is compared with simulation result of conventional mushroom-type TWEAM counterpart. The equivalent circuit model simulation results indicate that for the exemplary modulation length of 300 mm, the mushroom-type TWEAM with periodic transmission line loading can achieve much wider bandwidth about 99.7 GHz and 43.1 GHz than the conventional counterpart with about 43 GHz and 33 GHz for 35 W and 45 W terminations, respectively.

关键词：行波电吸收调制器输电线路蘑菇性能负荷波导等效电路模型应变量子阱

High-performance optical wavelength-selective switch-es based on double ring resonators

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Optoelectronics Letters 2013年第3期9卷 185-188页

作者： kambiz Abedi Department of Electrical Engineering Faculty of Electrical and Computer Engineering Shahid Beheshti University

In order to improve the performance of optical wavelength-selective switches based on double micro-ring resonators, an asymmetric intra-step-barrier coupled double strained quantum wells (AICD-SQWs) structure is utilized as the active light guiding medium. The AICD-SQW active layer has advantages, such as large change range in absorption coefficient, high extinction ratio, large Stark shift and very low insertion. For predicting the switching characteristics of double ring resonators structure, the absorption coefficient and real refractive index changes of the AICD-SQW active layer are calculated for different applied electric fields for TE input light polarization. Simulation results show that switching characteristics strongly depend on changes in absorption coefficient and real refractive index of active layer. In addition, isolations of 37.44 dB and 26.84 dB are realized between drop and through ports, when drop and through ports are ON and OFF, respectively, and vice versa.

关键词：环形谐振器波长选择选择开关性能折射率变化光学开关特性斯塔克位移

Enhancement of current density using effective membranes electrode assemblies for water electrolyser system

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Journal of Energy Chemistry 2016年第1期25卷 77-84页

作者： Swaminathan Seetharaman Subash Chandrabose Raghu kambiz Ansari Mahabadi Institute of Materials Research & Engineering A*STAR (Agency for Science Technology and Research) 3 Research Link Singapore 117 602 Singapore School of Civil and Environmental Engineering Nanyang Technological University Block N1 Nanyang Avenue Singapore 639 798 Singapore

The goal of this study was to develop and design a composite proton exchange membrane（PEM） and membrane electrode assembly（MEA） that are suitable for the PEM based water electrolysis system. In particular,it focuses on the development of sulphonated polyether ether ketone（SPEEK） based membranes and caesium salt of silico-tungstic acid（Cs Si WA） matrix compared with one of the transition metal oxides such as titanium dioxide（TiO2）, silicon dioxide（SiO2） and zirconium dioxide（ZrO2）. The resultant membranes have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ion exchange capacity（IEC）, water uptake and atomic force microscopy. Comparative studies on the performance of MEAs were also conducted utilizing impregnation-reduction and conventional brush coating methods. The PEM electrolysis performance of SPEEK-Cs Si WA-ZrO2 composite membrane was more superior than that of other membranes involved in this study. Electrochemical characterization shows that a maximum current density of 1.4 A/cm^2 was achieved at 60 °C, explained by an increased concentration of protonic sites available at the interface.

关键词： Composite membrane Membrane electrode assembly Impregnation reduction method Brush coating method Electrolysis

A polymer electro-optic modulator with ultra wide-band and low driving voltage

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Optoelectronics Letters 2011年第6期7卷 423-426页

作者： kambiz Abedi Habib Vahidi Department of Electrical and Computer Engineering Shahid Beheshti University

In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element technique is used to obtain modulator response thoroughly. From the numerical analysis, frequency dispersions of modulator's important parameters, such as microwave effective index nm , microwave characteristic impedance ZC and microwave loss a, are extracted. Our design exhibits electrical bandwidth of 260 GHz and drive voltage of about 2.8 *** in this frequency.

关键词：电光调制器低驱动电压聚合物矢量有限元方法超宽带频率调制器有效折射率调制响应

Quantum-dot Semiconductor Optical Amplifiers in State Space Model

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计算物理 2013年第4期30卷 605-612页

作者： Hussein Taleb kambiz Abedi Saeed Golmohammadi Department of Electrical Engineering Faculty of Electrical and Computer Engineering Shahid Beheshti University G. C. Evin ***Tehran Iran Nanophotonics Group School of Engineering-Emerging Technologies University of Tabriz Tabriz *** Iran

A state space model(SSM) is derived for quantum-dot semiconductor optical amplifiers(QD-SOAs).Rate equations of QD-SOA are formulated in the form of state update equations,where average occupation probabilities along QD-SOA cavity are considered as state variables of the *** show that SSM calculates QD-SOA′s static and dynamic characteristics with high accuracy.

关键词： quantum-dot rate equation model semiconductor optical amplifiers state space model

Fischer-Tropsch Reaction Kinetics of Cobalt Catalyst in Supercritical Phase

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Journal of Natural Gas Chemistry 2007年第2期16卷 115-120页

作者： Abdullah Irankhah Ali Haghtalab Ebrahim Vasheghani Farahani kambiz Sadaghianizadeh Department of Chemical Engineering Tarbiat Modarres UniversityP.O.Box 14115-111TehranIran Department of Gas Research Research Institute of Petroleum IndustryP.O.Box 18745-4163TehranIran

Fischer-Tropsch synthesis under supercritical phase condition was examined in a continuous and a high-pressure fixed bed reactor by employing a cobalt catalyst （Co-Ru/γ-Al2O3）. An integral reactor model involving Fischer-Tropsch reaction kinetics in the supercritical fluid n-hexane was used to describe the overall performance. On the basis of Langmuir-Hinshelwood-Hougen-Watson （LHHW） model, the reaction rate constants were obtained for the rate equations of CO conversion to CH4 formation under supercritical conditions.

关键词： Fischer-Tropsch synthesis supercritical phase n-hexane kinetics cobalt