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Ab-initio calculations of bandgap tuning of In1-xGaxY(Y=N,P)alloys for optoelectronic applications

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Chinese Physics B 2021年第11期30卷 467-474页

作者： muhammad Rashid Jamil m mahmood q Shahid m Ramay Asif mahmood A Ghaithan H m Department of Physics Ghazi University City CampusDera Ghazi Khan32200Pakistan Department of Physics COMSATS University IslamabadIslamabad 44000Pakistan Basic and Applied Scientific Research Center(BASRC) College of Science of DammamImam Abdulrahman Bin Faisal UniversityP.O.Box 383Dammam 31113Saudi Arabia Department Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam 31441Saudi Arabia Physics and Astronomy Department College of ScienceKing Saud UniversityRiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few *** the present article,the bandgap tuning and its influence on optical properties of In1-xGaxN/P,where(x=0.0,0.25,0.50,0.75,and 1.0)alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method(FP-LAPW)and modified Becke and Johnson potentials(TB-mBJ).The direct bandgaps turn from 0.7 eV to 3.44 eV,and 1.41 eV to 2.32 eV for In1-xGaxN/P alloys,which increases their potentials for optoelectronic *** optical properties are discussed such as dielectric constants,refraction,absorption,optical conductivity,and *** light is polarized in the low energy region with minimum *** absorption and optical conduction are maxima in the visible region,and they are shifted into the ultraviolet region by Ga ***,static dielectric constant e1(0)is in line with the bandgap from Penn’s model.

关键词： density functional theory direct bandgap III-V semiconductors tuning of optical band gap solar cell applications

Typical atmospheric haze during crop harvest season in northeastern China：A case in the Changchun region

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Journal of Environmental Sciences 2017年第4期29卷 101-113页

作者： Wei Wei Chen Daniel q.Tong mo Dan Shi Chun Zhang Xue Lei Zhang Yue peng Pan Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130102 China . Cooperative Institute for Climate & Satellites University of Maryland College Park MD 20740 USA Center for Spatial Information Science and Systems George Mason University Fairfax VA 22030 USA Beijing municipal Institute of Labor Protection Beijing 100054 China State key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

This study presents the mass concentrations of Pm（2.5）,O3,SO2 and NOxat one urban,one suburban and two rural locations in the Changchun region from September 25 to October 272013. major chemical components of Pm（2.5）at the four sites were daily sampled and analyzed. most of daily concentrations of SO2（7–82 μg/m^3）,O3（27–171 μg/m^3） and NOx（14–213 μg/m^3） were below the limits of the National Ambient Air quality Standard（NAAqS）in China. However,Pm（2.5）concentrations（143–168 μg/m^3） were 2-fold higher than *** Pm（2.5）concentrations（~ 150 μg/m^3） were measured during the pre-harvest and harvest at the urban site,while Pm（2.5）concentrations significantly increased from 250 to400 μg m^（-3） at suburban and rural sites with widespread biomass burning. At all sites,Pm（2.5）components were dominated by organic carbon（OC） and followed by soluble component sulfate（SO4^（2-））,ammonium（NH4~＋） and nitrate（NO3^-）. Compared with rural sites,urban site had a higher mineral contribution and lower potassium（K~＋and K） contribution to Pm（2.5）.Severe atmospheric haze events that occurred from October 21 to 23 were attributed to strong source emissions（e.g.,biomass burning） and unfavorable air diffusion ***,coal burning originating from winter heating supply beginning on October 18 increased the atmospheric pollutant emissions. For entire crop harvest period,the Positive matrix Factorization（PmF） analysis indicated five important emission contributors in the Changchun region,as follows： secondary aerosol（39%）,biomass burning（20%）,supply heating（18%）,soil/road dust（14%） and traffic（9%）.

关键词： Aerosol Air quality Agriculture Biomass burning Pm(2.5) PmF

A Geometric Distortion Solution Specifically for Historical Observations and its Implementation

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Research in Astronomy and Astrophysics 2024年第11期24卷 85-94页

作者： F.R.Lin q.Y.peng Z.J.Zheng B.F.Guo School of Software Jiangxi Normal UniversityNanchang 330022China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China Department of Computer Science Jinan UniversityGuangzhou 510632China Guangdong Ocean University Zhanjiang 524000China

Geometric distortion(GD)critically constrains the precision of *** well-established methods to correct GD requires calibration observations,which can only be obtained using a special dithering strategy during the observation ***,this special observation mode is not often used,especially for historical observations before those GD correction methods were *** a result,some telescopes have no GD calibration observations for a long period,making it impossible to accurately determine the GD *** limits the value of the telescope observations in certain astrometric scenarios,such as using historical observations of moving targets in the solar system to improve their *** investigated a method for handling GD that does not rely on the calibration *** this advantage,it can be used to solve the GD models of telescopes which were intractable in the *** method was implemented in Python and released on *** was then applied to solve GD in the observations taken with the 1 m and 2.4 m telescopes at Yunnan *** resulting GD models were compared with those obtained using well-established methods to demonstrate the ***,the method was applied in the reduction of observations for two targets,the moon of Jupiter(Himalia)and binary GSC 2038-0293,to show its *** GD correction,the astrometric results for both targets show ***,the mean residual between the observed and computed position(O-C)for binary GSC 2038-0293 decreased from 36 to 5 mas.

关键词： astrometry-methods data analysis-techniques image processing

LOW TEmPERATURE THERmODYNAmIC STUDY OF THE STABLE AND mETASTABLE PHASES OF SILVER

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Acta metallurgica Sinica(English Letters) 2007年第5期20卷 355-362页

作者： X.B. Li Y.q. Xie Y.Z. Nie H.J. peng Research Center of Advanced materials Xiangtan University Xiangtan 411105 China School of material Science and Engineering University Changsha 410083 China Central South

The low temperature thermodynamics of the stable phase of silver was assessed by the polynomial model and Debye model from the experimental data available in the literature. By means of the constrained non-linear least squares curve fitting arithmetic, two sets of parameter values were determined. The expression of the thermodynamic functions cp（T） and G（T）-H （298.15K） at 0-298.15K were presented. Only the low temperature thermodynamics of the metastable phase of silver can be extrapolated by the Debye model The expression of the thermodynamic functions cp（T） at 0- 298.15K was presented.

关键词： silver thermodynamic heat capacity SGTE (Scientific Group Thermodata Europe)

NUmERICAL STUDY OF THE NOTCH EFFECT ON THE CREEP BEHAVIOR AND LIFE OF NICKEL-BASE SINGLE CRYSTAL SUPERALLOYS

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Acta metallurgica Sinica(English Letters) 2004年第4期17卷 487-492页

作者： q.m.Yu Z.F.Yue Department of Engineering mechanics Northwestern Polytechnical University Xi'an 710072 ChinaDepartment of Engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China

Numerical calculations of creep damage development and life behavior of circular notched specimens of nickel-base single crystal had been performed. The creep stress distributions depend on the specimen geometry. For a small notch radius, von mises stress has an especial distribution. The damage distribution is greatly influenced by the notch depth, notch radius as well as notch type. The creep crack initiation place is different for each notched specimen. The characteristics of notch strengthening and notch weakening depend on the notch radius and notch type. For the same notch type, the creep rupture lives decrease with the decreasing of notch radius. A creep life model has been presented for the multiaxial stress states based on the crystallographic slip system theory.

关键词： creep damage life model notched specimen nickel-base single crystal superalloys

A generalized synthesis load model considering network parameters and allvanadium redox flow battery

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Protection and Control of modern Power Systems 2018年第1期3卷 324-336页

作者： L Zhou Z W peng C R Deng X Z qi P q Li Guangdong Power Grid Corporation Information Center GuangzhouChina College of Electrical and Information Engineering Hunan UniversityChangsha 410082China

The simulation precision of the classic load model(CLm)is affected by the increasing proportion of installed energy storage capacity in the *** paper studies the all-vanadium redox flow battery(VRB)and proposes an equivalent model based on the measurement-based load modeling method,which can simulate the maximum output of the VRB energy storage system and fit the external characteristic of the system precisely in the occurrence of large disturbance and continuous small *** equivalent model is connected to CLm to form a generalized synthesis load model(GSLm),which considers the parameters of distribution network and reactive power *** with CLm,GSLm has better structures and can describe the load characteristics of distribution network with energy storage system more *** results validate the effectiveness and good parameter stability of GSLm,and show that the higher the proportion of energy storage in the grid is the better description ability GSLm has.

关键词： All-vanadium redox flow battery Classic load model Network parameter Parameter identification Reactive compensation

Numerical investigation of Dufour and Soret effects on unsteadymHD natural convection flow past vertical plate embedded innon-Darcy porous medium

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Applied mathematics and mechanics(English Edition) 2012年第2期33卷 195-210页

作者： m.q.AL-ODAT A.AL-GHAmDI mechanical Engineering Department Faculty of EngineeringUmm Al-Qura UniversityMakkahKingdom of Saudi Arabia mechanical Engineering Department Al-Huson University CollegeAl-Balqa Applied UniversityIrbidJordan

The Dufour and Soret effects on the unsteady twodimensional magnetonyaro dynamics （mHD） doublediffusive free convective flow of an electrically conducting fluid past a vertical plate embedded in a nonDarcy porous medium are investigated numeri cally. The governing nonlinear dimensionless equations are solved by an implicit finite difference scheme of the CrankNicolson type with a tridiagonal matrix manipulation. The effects of various parameters entering into the problem on the unsteady dimension less velocity, temperature, and concentration profiles are studied in detail. Furthermore, the time variation of the skin friction coefficient, the Nusselt number, and the Sherwood number is presented and analyzed. The results show that the unsteady velocity, tem perature, and concentration profiles are substantially influenced by the Dufour and Soret effects. When the Dufour number increases or the Soret number decreases, both the skin friction and the Sherwood number decrease, while the Nusselt number increases. It is found that, when the magnetic parameter increases, the velocity and the temperature decrease in the boundary layer.

关键词： double-diffusive free convection non-Darcy model magnetohydrodynamic(mHD) porous medium Dufour effect Soret effect numerical solution

STABILITY OF mICROSTRUCTURES DURING COOLING PROCESSES OF Al LIqUID mETAL

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中国有色金属学会会刊：英文版 1998年第4期8卷 2-7页

作者： Liu, RS Li, JY Zhou, Z Dong, KJ peng, P Xie, q Zheng, CX Hunan Univ Dept Phys Changsha 410012 Peoples R China Hunan Univ Dept Chem Changsha 410012 Peoples R China

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关键词： stability microstructure liquid metal rapid cooling computer simulation

Diffusion behavior at void tip and its contributions to void shrinkage during solid-state bonding

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Journal of materials Science & Technology 2018年第8期34卷 1449-1454页

作者： C.Zhang m.q.Li H.Li School of materials Science and Engineering Northwestern Polytechnical University State Key Laboratory of Solidification Processing Northwestern Polytechnical University Department of mechanical Engineering University de Lyon

Solid-state diffusion bonding is an advanced joining technique, which has been widely used to join similar or dissimilar materials. Generally, it is easy to observe the diffusion behavior during dissimilar bonding, but for similar bonding the diffusion behavior has yet been observed via experiments. In this study, the diffusion behavior at void tip was firstly observed during similar bonding of stainless steel. Scanning electron microscopy with energy dispersive spectroscopy was used to examine the interface charac- teristic and diffusion behavior. The results showed that a diffusion region was discovered at void tip. Element concentrations of diffusion region were more than those of void region, but less than those of bonded region. This behavior indicated that the diffusion was ongoing at void tip, but the perfect bond has yet formed. The diffusion region was attributed to the interface diffusion from adjacent region to void tip due to the stress gradient along bonding interface. The mass accumulation at void tip transformed the sharp void tip into smooth one at the beginning of void shrinkage, and then resulted in shorter voids.

关键词： Stainless steel micro-void morphology Solid-state bonding Void tip Element diffusion