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Simultaneous Effects of External electric field and Conduction Band Nonparabolicity on Optical Properties of a GaAs Quantum Dot Embedded at the Center of a GaAlAs Nano-Wire

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Communications in Theoretical Physics 2014年第6期61卷 765-772页

作者： Gh.Safarpour M.A.Izadi M.Novzari E.Niknam M.M.Golshan Zarghan Branch Islamic Azad University Young Researchers and Elite Club Zarghan Branch Islamic Azad University Department of Physics College of Sciences Shiraz University

An investigation of the optical properties of a GaAs spherical quantum dot which is located at the center of a Ga1-xAlx As cylindrical nano-wire has been performed in the presence of an external electric field. The band nonparabolieity effect is also considered using the energy dependent effective mass approximation. The energy eigenvalues and corresponding wave functions are calculated by finite difference approximation and the reliability of calculated wave functions is checked by computing orthogonality. Using computed energy eigenvalues and wave functions, the linear, third-order nonlinear and total optical absorption coefficients and refractive index changes are examined in detail. It is found that （i） Presence of electric field causes both blue and red shifts in absorption spectrum; （ii） The absorption coefficients shift toward lower energies by taking into account the conduction band nonparabolicity; （iii） For large values of electric field the effect of conduction band nonparabolieity is less dominant and parabolic band is estimated correctly; （iv） In the presence of electric field and conduction band nonparabolicity the nonlinear term of absorption coefficient rapidly increases by increasing incident optical intensity. In other words, the saturation in optical spectrum occurs at lower incident optical intensities.

关键词： nonlinear optics conduction band nonparabolicity electric field spherical quantum dot

Shallow Donor Impurity Ground State in a GaAs/AlAs Spherical Quantum Dot within an electric field

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Communications in Theoretical Physics 2009年第10期52卷 710-714页

作者： YUAN Jian-Hui XIE Wen-Fang HE Li-Li Department of Physics College of Physics and Electronic Engineering Guangzhou University Guangzhou 510006 China

Using the configuration-integration methods （CI） [Phys. Rev. B 45 （1992） 19], we report the results of the Hydrogenie-impurity ground state in a GaAs/AIAs spherical quantum dot under an electric field. We discuss the variations of the binding energies of the Hydrogenic-impurity ground state as a function of the position of impurity D, the radius R of the quantum dot, and also as a function of electric field F. We find that the ground energy and binding energy of impurity placed anywhere depend strongly on the position of impurity. Also, electric field can largely change the Hydrogenic-impurity ground state only limiting to the big radius of quantum dot. And the differences in energy level and binding energy are observed from the center donor and off-center donor.

关键词： donor quantum dots binding energy electric field

EFFECT OF electric field ON THE AUSTENIZATION OF A LOW CARBON STEEL

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 689-693页

作者： X.T.Liu J.Z.Cui TheKeyLaboratoryofElectromagneticProcessingofMaterials MinistryofEducationNortheasternUniversityShenyang110004China

With an electric field during austenitizing, the martensite transformation of the low carbon steel was promoted, and more martensite were obtained. The electric field promotes the homogeneity of carbon, and reduces the free energy of austenite. The critical neuclus r* and the critical driving force G* responsible for the nucleation of proeutectoid ferrite were increased. As a result of which the diffusion controlled proeuctoid ferrite transformation was retarded and the hardenability was improved.

关键词： austenization electric field proeutectoid ferrite hardenability

Structural transformations of carboxyl acids networks induced by concentration and oriented external electric field

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Chinese Chemical Letters 2021年第1期32卷 480-484页

作者： Wei Li Shilin Xu Xiaoling Chen Chengyong Xu School of Science Nanchang Institute of TechnologyNanchang 330099China

The effects of concentration and an oriented external electric field on the transformations of hydrogenbonded structures of trimesic acid(TMA) and terephthalic acid(TPA) have been investigated at a liquidsolid interface by scanning tunneling microscopy(STM).The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in *** of TMA and TPA are porous at a negative substrate bias,but typically change to relatively compact forms when the polarity of the applied bias is *** change is reversible if the applied bias is *** effects have potentials to locally control the capture and release of analytes in host-guest systems and the 2D morphology in multicomponent layers.

关键词： Concentration electric field Structural transformation Scanning tunneling microscopy

Temperature Effects of electric field on the First Excited State of Strong Coupling Polaron in a CsI Quantum Pseudodot

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Communications in Theoretical Physics 2017年第3期67卷 337-340页

作者：孙勇丁朝华肖景林 Institute of Condensed Matter Physics Inner Mongolia University for Nationalities Tongliao 028043 China

Employing variational method of Pekar type(VMPT), this paper investigates the first-excited state energy(FESE), excitation energy and transition frequency of the strongly-coupled polaron in the Cs I quantum pseudodot(QPD)with electric field. The temperature effects on the strong-coupling polaron in electric field are calculated by using the quantum statistical theory(QST). The results from the present investigation show that the FESE, excitation energy and transition frequency increase(decrease) firstly and then at lower(higher) temperature regions. They are decreasing functions of the electric field strength.

关键词： temperature effects electric field polaron CsI quantum pseudodot

EFFECT　OF　HOMOGENIZATION　TREATMENT　UNDER　AN　electric　field　ON　T_1　DISTRIBUTION　AND　MECHANICAL　PROPERTIES　OF　2091　Al－Li　ALLOY

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Acta Metallurgica Sinica(English Letters) 1995年第2期8卷 126-129页

作者： LIU Wei CUI Jianzhong(Northeastern University,Shenyang,China) Northeastern Univ Shenyang China

Homogenization treatment under an electric field increases the distributive homogeneity of the T1 precipitation and improves the yield strength of 2091 Al-Li alloy.

关键词： homogenization treatment 2091 Al-Li alloy electric field T_1 precipitation

Low-energy electronic states of carbon nanocones in an electric field

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Nano-Micro Letters 2010年第2期2卷 121-125页

作者： Jun-Liang Chen Ming-Horng Su Chi-Chuan Hwang Jian-Ming Lu Chia-Chang Tsai Department of Mechanical Engineering Wu Feng Institute of Technology Department of Fire Science Wu Feng Institute of Technology Department of Engineering Science National Cheng Kung University Advanced Networking Business Unit National Center for High-Performance Computing National Applied Research Laboratories Institute of Atomic and Molecular Sciences Academia Sinica

The low-energy electronic states and energy gaps of carbon nanocones in an electric field are studied using a single-?-band tight-binding model. The analysis considers five perfect carbon nanocones with disclination angles of 60°, 120°, 180°, 240° and 300°, respectively. The numerical results reveal that the low-energy electronic states and energy gaps of a carbon nanocones are highly sensitive to its geometric shape(i.e. the disclination angle and height), and to the direction and magnitude of an electric field. The electric field causes a strong modulation of the state energies and energy gaps of the nanocones, changes their Fermi levels, and induces zero-gap transitions. The energy-gap modulation effect becomes particularly pronounced at higher strength of the applied electric field, and is strongly related to the geometric structure of the nanocone.

关键词： Low-energy electronic states Carbon Nanocones electric field

Optimization of DC Resistance Divider Up to 1200 kV Using Thermal and electric field Analysis

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Energy Engineering 2023年第11期120卷 2611-2628页

作者： Dengyun Li Baiwen Du Kai Zhu Jicheng Yu Siyuan Liang Changxi Yue Department of Metrology China Electric Power Research InstituteWuhan430074China

Self-heating and electric field distribution are the primary factors affecting the accuracy of the Ultra High Voltage Direct Current(UHVDC)resistive *** the internal temperature rise of the voltage divider caused by self-heating,reducing the maximum electric field strength of the voltage divider,and uniform electric field distribution can effectively improve the UHVDC resistive divider’s *** this paper,thermal analysis and electric field distribution optimization design of 1200 kV UHVDC resistive divider are carried out:(1)Using the proposed iterative algorithm,the heat dissipation and temperature distribution of the high voltage DC resistive divider are studied,and the influence of the ambient temperature and the power of the divider on the temperature of the insulating medium of the divider is analyzed;(2)Established the finite element models of 1200 kV and 2×600 kV DC resistive dividers,analyzed the influence of the size of the grading ring and the installation position on the maximum electric field strength of the voltage divider,and calculated the impact of the shielding resistor layer on the vicinity of the measuring resistor *** research indicates that:(1)The temperature of the insulating medium is linearly related to the horsepower of the voltage divider and the ambient temperature;(2)After the optimized design of the electric field,the maximum electric field strength of the 1200 kV DC resistive divider is reduced to 1471 V/mm,which is about 24% lower than that of the unoptimized design;(3)Installing the shielding resistor layer can significantly improve the electric field near the measuring resistor *** paper has an important reference function for improving the accuracy of the UHVDC resistive divider.

关键词： DC voltage divider heat transfer electric field grading ring shielding resistor layer optimized design

The effect of an electric field on the thermomechanical damage of nodular defects in dielectric multilayer coatings irradiated by nanosecond laser pulses

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Light(Science & Applications) 2013年第1期2卷 135-142页

作者： Xinbin Cheng Jinlong Zhang Tao Ding Zeyong Wei Hongqiang Li Zhanshan Wang Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China Institute of Precision Optical Engineering School of Physics Science and EngineeringTongji UniversityShanghai 200092China

Thermomechanical damage of nodules in dielectric multilayer coatings that are irradiated by nanosecond laser pulses has been interpreted with respect to mechanical properties and electric-field ***,the effect of electric-field enhancement in nodular damage,especially the influence of electric-field distributions,has never been directly demonstrated through experimental results,which prevents the achievement of a clear understanding of the damage process of nodular ***,a systematic and comparative study was designed to reveal how electric-field distributions affect the damage behavior of *** obtain reliable results,two series of artificial nodules with different geometries and film absorption characteristics were prepared from monodisperse silica *** establishing simplified geometrical models of the nodules,the electric-field enhancement was simulated using a three-dimensional finite-difference time-domain ***,the damage morphologies of the artificial nodules were directly compared with the simulated electric-field intensity *** both series of nodules,the damage morphologies reproduced our simulated electric-field intensity distributions very *** results indicated that the electric-field distribution was actually a bridge that connected the nodular mechanical properties to the final thermomechanical *** of the damage mechanism of nodules was deepened by obtaining data on the influence of electric-field distributions on the damage behavior of nodules.

关键词： electric field nanosecond-pulse-laser damage nodular defects thin films