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Probability density and oscillating period of magnetopolaron in parabolic quantum dot in the presence of Rashba effect and temperature

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Chinese Physics B 2021年第11期30卷 207-213页

作者： Ying-Jie Chen Feng-lan shao School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China

We study the property of magnetopolaron in a parabolic quantum dot under the Rashba spin–orbit interaction(RSOI)by adopting an unitary transformation of Lee–Low–Pines type and the variational method of Pekar type with and without considering the *** temporal spatial distribution of the probability density and the relationships of the oscillating period with the RSOI constant,confinement constant,electron–phonon coupling strength,phonon wave vector and temperature are *** results show that the probability density of the magnetopolaron in the superposition of the ground and first excited state takes periodic oscillation(T0/period)in the presence or absence of *** of the RSOI,the oscillating period is divided into different ***,the results indicate that the oscillating period increases(decreases)when the RSOI constant,electron-phonon coupling strength and phonon wave vector(the confinement constant)increase in a proper temperature,and the temperature plays a significant role in determining the properties of the polaron.

关键词： Rashba spin-orbit interaction quantum dot polaron temperature

Modeling ε Eri and Asteroseismic Tests of Element Diffusion

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Chinese Journal of Astronomy and Astrophysics 2008年第5期8卷 591-602页

作者： Ning Gai shao-lan Bi Yan-Ke Tang National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Department of Astronomy Beijing Normal University Beijing 100875 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Taking into account the helium and metal diffusion, we explore the possible evolutionary status with a seismic analysis, of the MOST （Microvariability and Oscillations of STars） target： the star e Eri. We adopt different input parameters to construct models to fit the available observational constraints in, e.g., Teff, L, R and [Fe/H]. From the computation we obtain the average large spacings of e Eri to be about 194 ± 1μHz. The age of the diffused models was found to be about 1 Gyr, which is younger than the age determined previously by models without diffusion. We found that the effect of pure helium diffusion on the internal structure of the young low-mass star is slight, but that of metal diffusion is obvious. The metal diffusion leads the models to have much higher temperature in the radiative interior, and, correspondingly a higher sound speed there, hence a larger frequency and spacings.

关键词： stars evolution - stars interiors -stars individual ∈ Eridani

Corrections to Solar Thermal Structure when a Turbulent Magnetic Field is Included

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Chinese Journal of Astronomy and Astrophysics 2004年第5期4卷 490-498页

作者： YiLiao shao-lanBi NationalAstronomicalObservatories YunnanObservatoryKunming650011

Correction of non-ideal effect due to a magnetic fluctuating tensor is derived from the ideal MHD equations. The inclusion of a magnetic turbulent field leads to modifications of the hydrostatic equilibrium equation and thermodynamical variables such as the temperature T, the adiabatic exponent γ, the adiabatic temperature gradient ?ad and the temperature gradient ?. In particular, the modifications in the adiabatic and radiative temperature gradients will result in a change in the Schwarzchild criterion, hence in the location of the base of the convective zone. Incorporating the modifications, we construct a modified thermodynamical equilibrium structure of the Sun.

关键词： solar convection MHD: thermodynamics variables sun: hydrostatic equilibriumequation

On the Physical Processes in Contact Binary Systems

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Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 235-244页

作者： Run-Qian Huang Han-Feng Song shao-lan Bi National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 Graduate University of Chinese Academy of Sciences Beijing 100049

Three important physical processes occurring in contact binary systems are studied. The first one is the effect of spin, orbital rotation and tide on the structure of the components, which includes also the effect of meridian circulation on the mixing of the chemical elements in the components. The second one is the mass and energy exchange between the components. To describe the energy exchange, a new approach is introduced based on the understanding that the exchange is due to the release of the potential, kinetic and thermal energy of the exchanged mass. The third is the loss of mass and angular momentum through the outer Lagrangian point. The rate of mass loss and the angular momentum carded away by the lost mass are discussed. To show the effects of these processes, we follow the evolution of a binary system consisting of a 12M⊙ and a 5M⊙ star with mass exchange between the components and mass loss via the outer Lagrangian point, both with and without considering the effects of rotation and tide. The result shows that the effect of rotation and tide advances the start of the semi-detached and the contact phases, and delays the end of the hydrogen-burning phase of the primary. Furthermore, it can change not only the occurrence of mass and angular momentum loss via the outer Lagrangian point, but also the contact or semi-contact status of the system. Thus, this effect can result in the special phenomenon of short-term variations occurring over a slow increase of the orbital period. The occurrence of mass and angular momentum loss via the outer Lagrangian point can affect the orbital period of the system significantly, but this process can be influenced, even suppressed out by the effect of rotation and tide. The mass and energy exchange occurs in the common envelope. The net result of the mass exchange process is a mass transfer from the primary to the secondary during the whole contact phase.

关键词： stars binaries general - stars mass-loss - stars evolution

A Model for Contact Binary Systems

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Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 539-550页

作者： Han-Feng Song Run-Qian Huang shao-lan Bi National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 Graduate School of Chinese Academy of Sciences Beijing 100049

A model for contact binary systems is presented, which incorporates the following special features： a） The energy exchange between the components is based on the understanding that the energy exchange is due to the release of potential, kinetic and thermal energies of the exchanged mass. b） A special form of mass and angular momentum loss occurring in contact binaries is losses via the outer Lagrangian point, c） The effects of spin, orbital rotation and tidal action on the stellar structure as well as the effect of meridian circulation on the mixing of the chemical elements are considered, d） The model is valid not only for low-mass contact binaries but also for high-mass contact binaries. For illustration, we used the model to trace the evolution of a massive binary system consisting of one 12M⊙ and one 5M⊙ star. The result shows that the start and end of the contact stage fall within the semi-detached phase during which the primary continually transfers mass to the secondary. The time span of the contact stage is short and the mass transfer rate is very large. Therefore, the contact stage can be regarded as a special part of the semi-detached phase with a large mass transfer rate. Both mass loss through the outer Lagrangian point and oscillation between contact and semi-contact states can occur during the contact phase, and the effective temperatures of the primary and the secondary are almost equal.

关键词： stars: binaries - stars: evolution

Grids of rotating stellar models with masses between 1.0 and 3.0 M_⊙

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Research in Astronomy and Astrophysics 2013年第5期13卷 579-592页

作者： Wu-Ming Yang shao-lan Bi Xiang-Cun Meng Department of Astronomy Beijing Normal University School of Physics and Chemistry Henan Polytechnic University

We calculated a grid of evolutionary tracks of rotating models with masses between 1.0 and 3.0 M⊙ and resolution δM 〈 0.02 M⊙, which can be used to study the effects of rotation on stellar evolution and on the characteristics of star clusters. The value of ～ 2.05 Me is a critical mass for the effects of rotation on stellar struc- ture and evolution. For stars with M 〉 2.05 Me, rotation leads to an increase in the convective core and prolongs their lifetime on the main sequence （MS）; rotating mod- els evolve more slowly than non-rotating ones; the effects of rotation on the evolution of these stars are similar to those of convective core overshooting. However for stars with 1.1 〈 M/M⊙ 〈 2.05, rotation results in a decrease in the convective core and shortens the duration of the MS stage; rotating models evolve faster than non-rotating ones. When the mass has values in the range ～ 1.7 - 2.0 M⊙, the mixing caused by rotationally induced instabilities is not efficient; the hydrostatic effects dominate pro- cesses associated with the evolution of these stars. For models with masses between about 1.6 and 2.0 M⊙, rotating models always exhibit lower effective temperatures than non-rotating ones at the same age during the MS stage. For a given age, the lower the mass, the smaller the change in the effective temperature. Thus rotations could lead to a color spread near the MS turnoff in the color-magnitude diagram for intermediate-age star clusters.

关键词： stars: evolution -- stars: rotation m stars: interiors

Asteroseismic study of the red giant ∈ Ophiuchi

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Research in Astronomy and Astrophysics 2010年第12期10卷 1265-1274页

作者： shao-lan Bi Ling-Huai Li Yan-Ke Tang Ning Gai Department of Astronomy Beijing Normal University Beijing 100875 China bisl@*** Department of Astronomy Yale University P.O. Box 208101 New Haven CT 06520-8101 USA Department of Physics Dezhou University Dezhou 253023 China

We test the possible evolutionary tracks of stars with various masses （1.8 M,1.9 M,2.0 M,2.1 M,2.2 M）and metallicities Z（0.008,0.010, 0.012）,including both models with and without convective core *** a given mass and metallicity,the models with a larger overshoot predict a larger radius and age of the *** on the observed frequency of oscillations and the position of Oph on the H-R diagram,we obtain two distinct better-fitting models：the solutions with mass M=1.9 M favor a radius in the range 10.55±0.03 R with an age of 1.01±0.08 Gyr;the solutions with mass M=2.0 M favor a radius in the range 10.74±0.03 R with an age of 0.95±0.11 ***,we investigate the influence of overshooting on the internal structure and the pulsation properties,and find that increasing the convective core overshoot significantly decreases non-radial mode inertia,while also increasing the mode ***,the estimation of stellar mass and age might be modified by convective core penetration.

关键词： stars: oscillations -- stars: individual: e Ophiuchi -- stars: interiors

Asteroseismic Analysis ofαCen B:Preliminary Tests of Effects of Rotation and Interior Magnetic Field in the Solar-like Star

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Chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 421-432页

作者： Yan-Ke Tang shao-lan Bi Ning Gai Hua-Yin XU National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming650011 China Department of Astronomy Beijing No rrnal University Beijing 100875 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Taking into consideration the effects of rotation and interior magnetic field during the lifetime of the star, we reconstruct the model of α Cen B to satisfy the latest nonasteroseismic and asteroseismic observational constraints. We find that the effects can induce a change of about 0.3 μHz in the large frequency spacings and can speed up the star＇s evolution. The model of a Cen B has thereby been improved.

关键词： stars oscillations - stars interiors - stars individual (α Cen B)

Production of light-flavor and single-charmed hadrons in pp collisions at√s=5.02 TeV in an equal-velocity quark combination model

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Chinese Physics C 2021年第11期45卷 60-71页

作者： Hai-hong Li Feng-lan shao Jun Song School of Physical Science and Intelligent Engineering Jining UniversityShandong 273155China School of Physics and Physical Engineering Qufu Normal UniversityShandong 273165China

We apply an equal-velocity quark combination model to study the production of light-flavor hadrons and single-charmed hadrons at midrapidity in the pp collisions at √s= 5.02 TeV. We find that the experimental data for the pT spectra of Ω and φ exhibit the quark number scaling property, which clearly indicates the quark combination mechanism at hadronization. Experimental data for the pT spectra of p,Λ,Ξ,Ω,φ and K^(+0) are systematically described by the model. The non-monotonic pT dependence of the Ω/φ ratio is naturally explained, and we find that it is closely related to the shape of the logarithm of the strange quark pT distribution. Using the pT spectra of light-flavor quarks obtained from light-flavor hadrons and the pT spectrum of charm quarks, which is consistent with perturbative QCD calculations, the experimental data for differential cross-sections of D^(0,+), D^(+)_s), and Λ^(+)_(c) as functions of p are systematically described. We predict the differential cross-sections of Ξ^(0,+)_(c) and Ω^(0)_(c) . The ratio Ξ^(0,+)_(c) /D^0) in our model is approximately 0.16, and Ω^(0)_(c) /D^(0) is approximately 0.012, owing to the cascade suppression of *** addition, the predicted Ξ^(0,+)_(c) /D^0) ratios exhibit the non-monotonic dependence on pT in the low pT range.

关键词： hadronization quark combination mechanism heavy-flavor