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Journal of Ocean University of China 2018年第2期17卷 305-310页

作者： NAZEER majid BILAL Muhammad Earth & Atmospheric Remote Sensing Laboratory (EARL) Department of Meteorology COMSATS Institute of Information Technology School of Marine Sciences Nanjing University of Information Science and Technology Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic University

Landsat-5 Thematic Mapper(TM) dataset have been used to estimate salinity in the coastal area of Hong Kong. Four adjacent Landsat TM images were used in this study, which was atmospherically corrected using the Second Simulation of the Satellite Signal in the Solar Spectrum(6S) radiative transfer code. The atmospherically corrected images were further used to develop models for salinity using Ordinary Least Square(OLS) regression and Geographically Weighted Regression(GWR) based on in situ data of October 2009. Results show that the coefficient of determination(R^2) of 0.42 between the OLS estimated and in situ measured salinity is much lower than that of the GWR model, which is two times higher(R^2 = 0.86). It indicates that the GWR model has more ability than the OLS regression model to predict salinity and show its spatial heterogeneity better. It was observed that the salinity was high in Deep Bay(north-western part of Hong Kong) which might be due to the industrial waste disposal, whereas the salinity was estimated to be constant(32 practical salinity units) towards the open sea.

关键词： Landsat Thematic Mapper water quality salinity remote sensing coastal water

Evaluating estimated sediment delivery by Revised Universal Soil Loss Equation(RUSLE)and Sediment Delivery Distributed(SEDD)in the Talar Watershed,Iran

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Frontiers of Earth Science 2020年第1期14卷 50-62页

作者： Mohammad Saeid MIRAKHORLO majid RAHIMZADEGAN Department of Water Resources Faculty of Civil EngineeringK.N.Toosi University of TechnologyTehranIran

The performance of the Revised Universal Soil Loss Equation(RUSLE)as the most widely used soil erosion model is a challenging ***,the objective of this study is investigating the estimated sediment delivery by the RUSLE method and Sediment Delivery Distributed(SEDD)*** this end,the Talar watershed in Iran was selected as the study ***,700 paired sediment-discharge measurements at Valikbon and Shirgah-Talar hydrometric stations between the years 1991 and 2011 were collected and used in sediment rating *** procedures were investigated to produce the required RUSLE *** estimated soil erosion by RUSLE was evaluated using sediment rating curve data by two methods including least squares and quantile *** average annual suspended sediment load was calculated for each sub-watershed of the study area using the SEDD ***,a sediment rating curve was estimated by least squares and quantile regression methods using paired discharge-sediment *** average annual suspended sediment load values were calculated for two hydrometric stations and were further evaluated by the SEDD *** results indicated that the first considered procedure,which utilized 15-min rainfall measurements for the rainfall factor(R),and the classification method of SENTINEL-2 MSI image for the cover management factor(C),offered the best results in producing RUSLE ***,the results revealed the advantages of utilizing satellite images in producing cover management layer,which is required in the RUSLE method.

关键词： Revised Universal Soil Loss Equation(RUSLE) sediment rating curve quantile regression Geographic Information System(GIS)

Isomorphisms of Finite Semi-Cayley Graphs

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Acta Mathematica Sinica,English Series 2015年第4期31卷 715-730页

作者： majid AREZOOMAND Bijan TAERI Department of Mathematical Sciences Isfahan University of Technology

Let G be a finite group. A Cayley graph over G is a simple graph whose automorphism group has a regular subgroup isomorphic to G. A Cayley graph is called a CI-graph （Cayley iso- morphism） if its isomorphic images are induced by automorphisms of G. A well-known result of Babai states that a Cayley graph F of G is a CI-graph if and only if all regular subgroups of Aut（F） isomorphic to G are conjugate in Aut（F）. A semi-Cayley graph （also called bi-Cayley graph by some authors） over G is a simple graph whose automorphism group has a semiregular subgroup isomorphic to G with two orbits （of equal size）. In this paper, we introduce the concept of SCI-graph （semi-Cayley isomorphism） and prove a Babai type theorem for semi-Cayley graphs. We prove that every semi-Cayley graph of a finite group G is an SCI-graph if and only if G is cyclic of order 3. Also, we study the isomorphism problem of a special class of semi-Cayley graphs.

关键词： Semi-Cayley graph Cayley graph CI-graph semiregular subgroup

Synthesis of nanocrystalline γ-Al_2O_3 by sol-gel and precipitation methods for methanol dehydration to dimethyl ether

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Journal of Natural Gas Chemistry 2011年第2期20卷 128-134页

作者： Zahra Hosseini majid Taghizadeh Fereydoon Yaripour Chemical Engineering Department Babol University of Technology Catalyst Research Group Petrochemical Research and Technology Company NPC

The capability of sol-gel and conventional precipitation techniques for the synthesis of nanocrystalline γ-alumina was investigated. These catalysts were used for vapor-phase dehydration of methanol to dimethyl ether in a fixed-bed reactor under the same operating conditions （T = 300 ？C, P = 1 bar, LHSV = 2.8, 11.7, 26.1 h？1） and characterized by means of N2 adsorption-desorption, NH3-TPD, XRD, TGA and SEM techniques. According to the experimental results, the catalysts prepared using sol-gel method in non-aqueous medium showed better performance compared with those prepared by other methods.

关键词： γ-Al2O3 sol-gel precipitation methanol dehydration dimethyl ether

CFD-DEM simulation of the hole cleaning process in a deviated well drilling： The effects of particle shape

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Particuology 2016年第2期14卷 72-82页

作者： Siamak Akhshik Mehdi Behzad majid Rajabi Department of Mechanical Engineering Sharif University of Technology Azadi Avenue Tehran Iran School of Mechanical Engineering lran University of Science and Technology Narmak Tehran Iran

We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. This numerical method allows us to incorporate the fluid-particle interactions （drag force, contact force, Saffman lift force, Magnus lift force, buoyancy force） using momentum exchange and the non-Newtonian behavior of the fluid. The interactions of particle-particle, particle-wall, and particle-drill pipe are taken into account with the Hertz-Mindlin model. We compare the transport of spheres with non-spherical particles （non-smooth sphere, disc, and cubic） constructed via the multi- sphere method for a range of fluid inlet velocities and drill pipe inclination angles. The simulations are carried out for laboratory-scale drilling configurations. Our results demonstrate good agreement with published experimental data. We evaluate the fluid-particle flow patterns, the particle velocities, and the particle concentration profiles. The results reveal that particle sphericity plays a major role in the fluid-solid interaction. The traditional assumption of an ideal spherical particle may cause inaccurate results.

关键词： CFD-DEM method Deviated well drilling Particles transport Two-way coupling scheme Particle-fluid Interaction

Perturbation,symmetry analysis,Bäcklund and reciprocal transformation for the extended Boussinesq equation in fluid mechanics

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Communications in Theoretical Physics 2021年第4期73卷 21-28页

作者： Gangwei Wang Abdul-majid Wazwaz School of Mathematics and Statistics Hebei University of Economics and BusinessShijiazhuang050061China Department of Mathematics Saint Xavier UniversityChicagoIL 60655United States of America

In this work,we study a generalized double dispersion Boussinesq equation that plays a significant role in fluid mechanics,scientific fields,and ocean *** equation will be reduced to the Korteweg-de Vries equation via using the perturbation *** derive the corresponding vectors,symmetry reduction and explicit solutions for this *** readily obtain Bäcklund transformation associated with truncated Painlevé*** also examine the related conservation laws of this equation via using the multiplier ***,we investigate the reciprocal Bäcklund transformations of the derived conservation laws for the first time.

关键词： Boussinesq equation perturbation and symmetry analysis Bäcklund transformation conservation laws

Influence of B source materials on the synthesis of TiB_2-Al_2O_3 nanocomposite powders by mechanical alloying

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1214-1220页

作者： majid Abdellahi Javad Heidari Rahman Sabouhi Materials Engineering Department Islamic Azad University

An Al2O3-TiB2 nanocomposite was successfully synthesized by ball milling of Al, TiO2 and two B source materials of B2O3 （system （1）） and H3BO3 （system （2））. Phase identification of the milled samples was examined by Xray diffraction. The morphology and microstructure of the milled powders were monitored by scanning electron microscopy and transmission electron microscopy. It was found that the formation of this composite was completed after 15 and 30 h of milling time in systems （1） and （2）, respectively. More milling energy was required for the formation of this composite in system （2） due to the lubricant properties of HaBO3 and also its decomposition to HBO2 and B2O3 during milling. On the basis of X-ray diffraction patterns and thermodynamic calculations, this composite was formed by highly exothermic mechanically induced self-sustaining reactions （MSR） in both systems. The MSR mode took place around 9 h and 25 h of milling in systems （1） and （2）, respectively. At the end of milling （15 h for system （1） and 30 h for system （2）） the grain size of about 35-50 nm was obtained in both systems.

关键词： nanocomposites powders alumina titanium diboride mechanical alloying

Multi-objective optimization of molten carbonate fuel cell system for reducing CO2 emission from exhaust gases

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Frontiers in Energy 2015年第1期9卷 106-114页

作者： Ramin ROSHANDEL majid ASTANEHI Farzin GOLZAR Department of Energy Engineering Sharif University of TechnologyTehran 14565114 Iran

The aim of this paper is to investigate the implementation of a molten carbonate fuel cell （MCFC） as a CO2 separator. By applying multi-objective optimization （MOO） using the genetic algorithm, the optimal values of operating load and the corresponding values of objective functions are obtained. Objective functions are minimiza- tion of the cost of electricity （COE） and minimization of CO2 emission rate. CO2 tax that is accounted as the pollution-related cost, transforming the environmental objective to the cost function. The results show that the MCFC stack which is fed by the syngas and gas turbine exhaust, not only reduces CO2 emission rate, but also produces electricity and reduces environmental cost of the system.

关键词： molten carbonate fuel cell (MCFC) multi-objective optimization (MOO) Pareto curve geneticalgorithm CO2 separation

Effects of external fields on a two-dimensional Klein-Gordon particle under pseudo-harmonic oscillator interaction

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Chinese Physics B 2012年第11期21卷 68-73页

作者： Sameer M.Ikhdair majid Hamzavi Physics Department Near East University Department of Basic Sciences Shahrood BranchIslamic Azad University

We study the effects of the perpendicular magnetic and Aharonov-Bohm （AB） flux fields on the energy levels of a two-dimensional （2D） Klein Gordon （KG） particle subjected to an equal scalar and vector pseudo-harmonic oscillator （PHO）. We calculate the exact energy eigenvalues and normalized wave functions in terms of chemical potential param- eter, magnetic field strength, AB flux field, and magnetic quantum number by means of the Nikiforov Uvarov （NU） method. The non-relativistic limit, PHO, and harmonic oscillator solutions in the existence and absence of external fields are also obtained.

关键词： Klein-Gordon equation two-dimensional pseudo-harmonic oscillator (PHO) potential,magnetic and Aharonov-Bohm (AB) flux fields Nikiforov-Uvarov method

Spin and pseudospin symmetric Dirac particles in the field of Tietz-Hua potential including Coulomb tensor interaction

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Chinese Physics B 2013年第9期22卷 233-244页

作者： Sameer M. Ikhdair majid Hamzavi Department of Physics Faculty of ScienceAn-Najah National UniversityNew CampusJunaidNablusWest BankPalestine Department of Electrical and Electronic Engineering Near East University Department of Science and Engineering Abhar BranchIslamic Azad University

Approximate analytical solutions of the Dirac equation for Tietz-Hua （TH） potential including Coulomb-like tensor （CLT） potential with arbitrary spin-orbit quantum number K are obtained within the Pekeris approximation scheme to deal with the spin-orbit coupling terms K（K± 1）r^-2. Under the exact spin and pseudospin symmetric limitation, bound state energy eigenvalues and associated unnormalized two-component wave functions of the Dirac particle in the field of both attractive and repulsive TH potential with tensor potential are found using the parametric Nikiforov-Uvarov （NU） method. The cases of the Morse oscillator with tensor potential, the generalized Morse oscillator with tensor potential, and the non-relativistic limits have been investigated.

关键词： Dirac equation Tietz-Hua (TH) potential Coulomb-like tensor (CLT) potential generalizedMorse potential