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Structural, electronic, and optical studies of chalcogenides stannite Cu2CdSnX4（X=S, Se, and Te）: insights from the DFT study

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Optoelectronics Letters 2025年第2期21卷 69-76页

作者： Jamal GUERROUM Mohamed AL-HATTAB Lhoucine MOUDOU Khalid rahmani Youssef LACHTIOUI Omar BAJJOU Laboratory of Engineering in Chemistry and Physics of Matter Faculty of Sciences and Technics Sultan Moulay Slimane University Ecole Normale Supérieure Mohammed V University in Rabat College of Graduate Studies University of South Africa

In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu2CdSnX4（X=S,Se,Te） *** calculations are based on the density functional theory （DFT） method and are performed using the Cambridge sequential total energy package （CASTEP） code included in the Biovia Material Studio 20 *** optical properties have been studied in a domain that extends energetically from 10 meV to 40 *** results show that Cu2CdSnX4（X=S,Se,Te） stannite exhibits absorption in the visible region,the refractive index decreases with increasing energy,and the refractive index values are n=3.2,3.73 and 3.75 for Cu2CdSnS4,Cu2CdSnSe4and Cu2CdSnTe4,*** show also high conductivity,which implies that this material is promising for solar *** results argue in favor of the use of these materials in various potential *** density of state,band structures,and structural properties of Cu2CdSnX4（X=S,Se,and Te） stannite are also studied in this work.

关键词： Refractive index

Catalytic process modeling and sensitivity analysis of alkylation of benzene with ethanol over MIL-101(Fe) and MIL-88(Fe)

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 1100-1111页

作者： Ehsan rahmani Mohammad rahmani Department of Chemical Engineering Amirkabir University of TechnologyTehran 158754413Iran

A solvothermal method was used to synthesize MIL-101(Fe)and MIL-88(Fe),which were used for alkylation of *** synthesized catalysts were characterized by X-ray diffraction,Fourier transform infrared spectroscopy,field emission scanning electron microscope,dynamic light scattering,and BET ***-organic frameworks(MOFs)were modeled to investigate the catalytic performance and existence of mass transfer *** effectiveness factors revealed absence of internal a nd external mass *** analysis revealed best operating conditions over MIL-101 at 120℃ and 5 bar and over MIL-88 at 142℃ and 9 bar.

关键词： MOFs alkylation ethylbenzene catalysts pellet model kinetic model sensitivity analysis

Data-Based Filters for Non-Gaussian Dynamic Systems With Unknown Output Noise Covariance

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 866-877页

作者： Elham Javanfar Mehdi rahmani the Department of Electrical Engineering Imam Khomeini International UniversityQazvin ***Iran

This paper proposes linear and nonlinear filters for a non-Gaussian dynamic system with an unknown nominal covariance of the output *** challenge of designing a suitable filter in the presence of an unknown covariance matrix is addressed by focusing on the output data set of the *** that data generated from a Gaussian distribution exhibit ellipsoidal scattering,we first propose the weighted sum of norms(SON)clustering method that prioritizes nearby points,reduces distant point influence,and lowers computational ***,by introducing the weighted maximum likelihood,we propose a semi-definite program(SDP)to detect outliers and reduce their impacts on each *** these weights paves the way to obtain an appropriate covariance of the output ***,two filtering approaches are presented:a cluster-based robust linear filter using the maximum a posterior(MAP)estimation and a clusterbased robust nonlinear filter assuming that output noise distribution stems from some Gaussian noise resources according to the ellipsoidal *** last,simulation results demonstrate the effectiveness of our proposed filtering approaches.

关键词： Data-based filter maximum likelihood estimation unknown covariance weighted maximum likelihood estimation weighted sum-of-norms clustering

Mechanical characterization of Mg-B4C nanocomposite fabricated at different strain rates

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International Journal of Minerals,Metallurgy and Materials 2020年第2期27卷 252-263页

作者： Gholam Hossein Majzoobi Kaveh rahmani Mechanical Engineering Department Bu-Ali Sina University

Magnesium has wide application in *** main purpose of this investigation was to improve the properties of magnesium by reinforcing it using B4C *** reinforced nanocomposites were fabricated using a powder compaction technique for 0,1.5vol%,3vol%,5vol%,and 10vol% of *** compaction was conducted using a split Hopkinson bar(SHB),drop hammer(DH),and Instron to reach different compaction loading *** compressive stress–strain curves of the samples were captured from quasi-static and dynamic tests carried out using an Instron and split Hopkinson pressure bar,*** revealed that,to achieve the highest improvement in ultimate strength,the contents of B4C were 1.5vol%,3vol%,and 3vol% for Instron,DH,and SHB,*** results also indicated that the effect of compaction type on the quasi-static strength of the samples was not as significant,although its effect on the dynamic strength of the samples was *** improvement in ultimate strength obtained from the quasi-static stress–strain curves of the samples(compared to pure Mg)varied from 9.9% for DH to 24% for *** dynamic strength of the samples was improved(with respect to pure Mg)by 73%,116%,and 141%for the specimens compacted by Instron,DH,and SHB,*** improvement in strength was believed to be due to strengthening mechanisms,friction,adiabatic heating,and shock waves.

关键词： powder compaction B4C magnesium strain rate ultimate strength sintering

Programmable structured surfaces can change the future of wireless communications

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Light(Science & Applications) 2022年第7期11卷 1341-1342页

作者： Lei Xu Mohsen rahmani Advanced Optics and Photonics Laboratory Department of EngineeringSchool of Science and TechnologyNottingham Trent UniversityNottingham NG118NSUK

An innovative time-varying metasurface has been reported to realise dual-channel data transmissions for light-to-microwave signal *** a novel technique is a remarkable step forward to realise full-spectrum networks for catering for the growing demand for wireless ***,this technique enriches the functionalities of tunable metasurfaces and stimulates new information-oriented applications.

关键词： wireless tunable surfaces

Exploiting Bivariate Dependencies to Speedup Structure Learning in Bayesian Optimization Algorithm

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Journal of Computer Science & Technology 2012年第5期27卷 1077-1090页

作者： Amin Nikanjam Adel rahmani School of Computer Engineering Iran University of Science and Technology

Bayesian optimization algorithm （BOA） is one of the successful and widely used estimation of distribution algorithms （EDAs） which have been employed to solve different optimization problems. In EDAs, a model is learned from the selected population that encodes interactions among problem variables. New individuals are generated by sampling the model and incorporated into the population. Different probabilistic models have been used in EDAs to learn interactions. Bayesian network （BN） is a well-known graphical model which is used in BOA. Learning a propel model in EDAs and particularly in BOA is distinguished as a computationally expensive task. Different methods have been proposed in the literature to improve the complexity of model building in EDAs. This paper employs bivariate dependencies to learn accurate BNs in BOA efficiently. The proposed approach extracts the bivariate dependencies using an appropriate pairwise interaction-detection metric. Due to the static structure of the underlying problems, these dependencies are used in each generation of BOA to learn an accurate network. By using this approach, the computational cost of model building is reduced dramatically. Various optimization problems are selected to be solved by the algorithm. The experimental results show that the proposed approach successfully finds the optimum in problems with different types of interactions efficiently. Significant speedups are observed in the model building procedure as well.

关键词： evolutionary computation Bayesian optimization algorithm Bayesian network model building bivariate interaction

Smart Bubble Sort:A Novel and Dynamic Variant of Bubble Sort Algorithm

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Computers, Materials & Continua 2022年第6期71卷 4895-4913页

作者： Mohammad Khalid Imam rahmani College of Computing and Informatics Saudi Electronic UniversityRiyadhSaudi Arabia

In the present era,a very huge volume of data is being stored in online and offline *** houses,research,medical as well as healthcare organizations,and academic institutions store data in databases and their subsequent retrievals are performed for further *** the required data from a given database within the minimum possible time is one of the key factors in achieving the best possible performance of any computer-based *** the data is already sorted,finding or searching is comparatively *** real-life scenarios,the data collected from different sources may not be in sorted *** algorithms are required to arrange the data in some order in the least possible *** this paper,I propose an intelligent approach towards designing a smart variant of the bubble sort algorithm.I call it Smart Bubble sort that exhibits dynamic footprint:The capability of adapting itself from the average-case to the best-case *** is an in-place sorting algorithm and its best-case time complexity isΩ(n).It is linear and better than bubble sort,selection sort,and merge *** averagecase and worst-case analyses,the complexity estimates are based on its static footprint *** complexity in worst-case is O(n2)and in average-case isΘ(n^(2)).Smart Bubble sort is capable of adapting itself to the best-case scenario from the average-case scenario at any subsequent stages due to its dynamic and intelligent *** Smart Bubble sort outperforms bubble sort,selection sort,and merge sort in the best-case scenario whereas it outperforms bubble sort in the average-case scenario.

关键词： Sorting algorithms smart bubble sort footprint dynamic footprint time complexity asymptotic analysis

Dynamics of an ensemble of clumps embedded in a magnetized ADAF

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Research in Astronomy and Astrophysics 2015年第12期15卷 2187-2192页

作者： Fazeleh Khajenabi Mina.rahmani Department of Physics Golestan University Department of Physics Damghan University

We investigate the effects of a global magnetic field on the dynamics of an ensemble of clumps within a magnetized advection-dominated accretion flow by ignoring interactions between the clumps and then solving the collisionless Boltzman equation. In the strong-coupling limit, in which the averaged radial and rotational velocities of the clumps follow dynamics described by an Advection-Dominated Accretion Flow （ADAF）, the root mean square radial velocity of the clumps is cal- culated analytically for different magnetic field configurations. The value of the root mean square radial velocity of the clumps increases by increasing the strength of the radial or vertical components of the magnetic field, but a purely toroidal magnetic field geometry leads to a reduction in the value of the root mean square radial velocity of the clumps in the inner parts by increasing the strength of this component. Moreover, dynamics of the clumps strongly depend on the amount of advected energy so that the value of the root mean square radial velocity of the clumps increases in the presence of a global magnetic field as the flow becomes more advective.

关键词： accretion -- accretion disk -- black hole physics -- magnetohydrody- namics

Towards automated software model checking using graph transformation systems and Bogor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第8期10卷 1093-1105页

作者： Vahid RAFE Adel T.rahmani Department of Computer Engineering Iran University of Science and Technology

Graph transformation systems have become a general formal modeling language to describe many models in software development *** modeling of dynamic systems and model-to-model transformations are only a few examples in which graphs have been used to software *** even the perfect graph transformation system must be equipped with automated analysis capabilities to let users understand whether such a formal specification fulfills their *** this paper,we present a new solution to verify graph transformation systems using the Bogor model *** attributed graph grammars(AGG)-like graph transformation systems are translated to Bandera intermediate representation(BIR),the input language of Bogor,and Bogor verifies the model against some interesting properties defined by combining linear temporal logic(LTL) and special-purpose graph *** results are encouraging,showing that in most cases our solution improves existing approaches in terms of both performance and expressiveness.

关键词： Graph transformation Verification Bogor Attributed graph grammars (AGG) Software model checking