In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examine...In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examined using a Lagrangian trajectory method.Evaporatively forced downdrafts in the outer rainbands can transport low-entropy air downward,resulting in the lowestθ_(e)in the downshear-left boundary layer.Quantitative estimations ofθ_(e)recovery indicate that air parcels,especially those originating from the downshear-left outer core,can gradually revive from a low entropy state through surface enthalpy fluxes as the parcels move cyclonically.As a result,the maximumθ_(e)is observed in the downshear-right quadrant of a highly sheared TC.The trajectory analyses also indicate that parcels that move upward in the outer rainbands and those that travel through the inner core due to shear make a dominant contribution to the midlevel enhancement ofθ_(e)in the downshear-left outer core.In particular,the former plays a leading role in suchθ_(e)enhancements,while the latter plays a secondary role.As a result,moist potential stability occurs in the middle-to-lower troposphere in the downshear-left outer core.展开更多
We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtain...We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtained results showed that under magnetic field effect,magnetopolaron quasiparticle was formed through the interaction of electrons and surrounding phonons.At the same time,magnetopolaron was influenced by phonon temperature statistical law and important energy level shifts down and binding energy increases.This revealed that lattice temperature and magnetic field could easily affect magnetopolaron and the above results could play key roles in exploring thermoelectric conversion and conductivity of crystal materials.展开更多
The pulsatile electroosmotic flow (PEOF) of a Maxwell fluid in a parallel flat plate microchannel with asymmetric wall zeta potentials is theoretically analyzed. By combining the linear Maxwell viscoelastic model, t...The pulsatile electroosmotic flow (PEOF) of a Maxwell fluid in a parallel flat plate microchannel with asymmetric wall zeta potentials is theoretically analyzed. By combining the linear Maxwell viscoelastic model, the Cauchy equation, and the electric field solution obtained from the linearized PoissomBoltzmann equation, a hyperbolic par- tial differential equation is obtained to derive the flow field. The PEOF is controlled by the angular Reynolds number, the ratio of the zeta potentials of the microchannel walls, the electrokinetic parameter, and the elasticity number. The main results obtained from this analysis show strong oscillations in the velocity profiles when the values of the elas- ticity number and the angular Reynolds number increase due to the competition among the elastic, viscous, inertial, and electric forces in the flow.展开更多
Based on a simple model, we theoretically show the transport behaviors of two harmonically coupled Brownian particles in an asymmetric saw-tooth potential with two slopes. The coupled particles are subject to stochast...Based on a simple model, we theoretically show the transport behaviors of two harmonically coupled Brownian particles in an asymmetric saw-tooth potential with two slopes. The coupled particles are subject to stochastic fluctuations. It is found that when the equilibrium distance of the coupled particles is between the two slopes of the potential, the transport direction of the coupled particles will be reversed with a certain harmonic coupling strength. This current reversal can be easily understood with the near rigid approximation, where the two coupled particles can be regarded as a single particle in an effective potential. Compared with the original saw-tooth potential, the asymmetry of the effective potential could be reversed when the equilibrium distance is between the two slopes of the original potential, which results in the current reversal.展开更多
Based on the perfect ohmic drop compensation by online electronic positive feedback, ultrafast cyclic voltammetry with asymmetrical potential scan is achieved for the first time, with the reduction of anthracene actin...Based on the perfect ohmic drop compensation by online electronic positive feedback, ultrafast cyclic voltammetry with asymmetrical potential scan is achieved for the first time, with the reduction of anthracene acting as the test system. Compared with the traditional cyclic voltammetry utilizing symmetrical triangular waveform as the excitation one, the new method allows a simpler approach to mechanistic analysis of ultrafast chemical reactions coupled with a charge transfer. And perhaps more important, it also provides a way to eliminate the interference of the adsorbed product in dynamic monitoring. 2007 Zhi Yong Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Under the influence of an applied magnetic field(MF), the eigenenergies and the eigenfunctions of the ground and the first excited states(GFES) are obtained by using a variational method of the Pekar type(VMPT) in a s...Under the influence of an applied magnetic field(MF), the eigenenergies and the eigenfunctions of the ground and the first excited states(GFES) are obtained by using a variational method of the Pekar type(VMPT) in a strong electron-LO-phonon coupling asymmetrical Gaussian potential quantum well(AGPQW). This AGPQW system may be employed as a two-level qubit. The numerical results have indicated(i) that when the electron situates in the superposition state of the GFES, we obtain the time evolution and the coordinate change of the electron probability density in the AGPQW,(ii) that due to the presence of the asymmetrical potential in the growth direction of the AGPQW, the probability density shows double-peak configuration, whereas there is only one peak if the confinement is a two dimensional symmetric one in the xy plane of the AGPQW,(iii) that the oscillatory period is a decreasing function of the cyclotron frequency of the MF, the height of the AGPQW and the polaron radius,(iv) and that as the range of the confinement potential(RCP) decreases the oscillatory period will decrease firstly and then increase and it will take a minimum when R =-0.234 nm.展开更多
: The effects of a magnetic field on the vibrational frequency, the ground state energy and the ground state binding energy of a weak-coupling polaron in asymmetrical Gaussian confinement potential quantum well (AGC...: The effects of a magnetic field on the vibrational frequency, the ground state energy and the ground state binding energy of a weak-coupling polaron in asymmetrical Gaussian confinement potential quantum well (AGCPQW) are investigated by using linear combination operator and unitary transformation methods. Our cal- culated results show that the vibrational frequency increases with increasing cyclotron frequency of the magnetic field; meanwhile, the absolute value of the ground state energy and the ground state binding energy decrease. The vibrational frequency, the absolute value of the ground state energy and the ground state binding energy are in- creasing functions of the barrier height of the AGCPQW. It is shown that the barrier height of the AGCPQW and the magnetic field are important factors that influence the properties of the magnetopolaron in AGCPQW.展开更多
By a combination method of Lee-Low-Pines unitary transformation method and Pekar-type variational method,the ground state energy(GSE)of the bound polaron is studied in the asymmetrical Gaussian potential quantum well ...By a combination method of Lee-Low-Pines unitary transformation method and Pekar-type variational method,the ground state energy(GSE)of the bound polaron is studied in the asymmetrical Gaussian potential quantum well considering the temperature and electromagneticfield.The impacts of the temperature and asymmetrical Gaussian potential,electromagnetic field and phonon-electron coupling upon the GSE are obtained.The results show that the GSE of the bound polaron not only oscillates as the temperature changes regardless of the electromagneticfield and asymmetrical Gaussian potential and Coulomb impurity potential(CIP)and electron-phonon coupling but also has different rules with the electromagnetic field and asymmetrical Gaussian potential and CIP and electron-phonon coupling at different temperature zones.展开更多
With the circumstance of the electron strongly coupled to LO-phonon and using the variational method of Pekar type(VMPT),we study the eigenenergies and the eigenfunctions(EE) of the ground and the first excited st...With the circumstance of the electron strongly coupled to LO-phonon and using the variational method of Pekar type(VMPT),we study the eigenenergies and the eigenfunctions(EE) of the ground and the first excited states(GFES) in a RbCl crystal asymmetric Gaussian potential quantum well(AGPQW).It concludes:(i) Twoenergy-level of the AGPQW may be seen as a qubit.(ii) When the electron located in the superposition state of the two-energy-level system,the time evolution and the coordinate changes of the electron probability density oscillated periodically in the AGPQW with every certain period T0=22.475 fs.(iii) Due to the confinement that is a two dimensional x-y plane symmetric structure in the AGPQW and the asymmetrical Gaussian potential(AGP) in the AGPQW growth direction,the electron probability density presents only one peak configuration located in the coordinate of z 〉 0,whereas it is zero in the range of z 〈 0.(iv) The oscillatory period is a decreasing function of the AGPQW height and the polaron radius,(v) The oscillating period is a decreasing one in the confinement potential R 〈 0.24 nm,whereas it is an increasing one in the confinement potential R 〉 0.24 nm and it takes a minimum value in R = 0.24 nm.展开更多
The classical theory of the rate of unimolecular isomerization developed by Gray and Rice as extended by Zhao and Rice is applied to the calculation of the rate of isomerization in model systems which have linear asym...The classical theory of the rate of unimolecular isomerization developed by Gray and Rice as extended by Zhao and Rice is applied to the calculation of the rate of isomerization in model systems which have linear asymmetric double well potentials. We are interested in this system for two reasons. First, we are interested in the detailed dynamical processes for the mentioned system because it is widely related to practical chemical reactions. Second, the present model system has an asymmetric double well potential, which provides a different test of the accuracy of the approximations used in the Gray-Zhao-Rice theory than posed by previous applications. We have calculated relaxation rates and relaxation times for the model systems on different time scales. We find that for the systems under studies the Gray-Zhao-Rice version of the classical theory of isomerization rate yields values in good agreement with those generated from trajectory calculations and from the Reactive Island theory of De Leon et al.展开更多
Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obta...Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obtain the current average velocity.The current reversals and the absolute negative mobility are presented.The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear.When the static force is small,the increase of the potential deformation suppresses the absolute negative mobility.When the force is large,the absolute negative mobility disappears.In particular,when the potential deformation is equal to0.015,the two current reversals present with the increasing of the force.Remarkably,when the potential deformation is small,there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior.展开更多
The polaron phenomenon is commonly observed in low-dimensional semiconductor materials and is known to have unique effects on conductive material properties.Furthermore,the phonon dragging effect,which leads to the po...The polaron phenomenon is commonly observed in low-dimensional semiconductor materials and is known to have unique effects on conductive material properties.Furthermore,the phonon dragging effect,which leads to the polaron energy level,is less than the electron energy level.A decay magnetic field also affects the polaron effect,which causes polaron energy level changes.We demonstrate the unique electron-phonon coupling properties of this polaron using numerical calculations.Our findings have strong implications for theories of polaron properties and provide compelling evidence for a semiconductor device that industrial manufacturers use for new lowdimensional materials.展开更多
基金jointly supported by the National Key Research and Development Program of China under Grant No. 2017YFC1501601the National Natural Science Foundation of China under Grant Nos. 42175005 and 41875054
文摘In this study,the characteristics of azimuthally asymmetric equivalent potential temperature(θ_(e))distributions in the outer core of tropical cyclones(TCs)encountering weak and strong vertical wind shear are examined using a Lagrangian trajectory method.Evaporatively forced downdrafts in the outer rainbands can transport low-entropy air downward,resulting in the lowestθ_(e)in the downshear-left boundary layer.Quantitative estimations ofθ_(e)recovery indicate that air parcels,especially those originating from the downshear-left outer core,can gradually revive from a low entropy state through surface enthalpy fluxes as the parcels move cyclonically.As a result,the maximumθ_(e)is observed in the downshear-right quadrant of a highly sheared TC.The trajectory analyses also indicate that parcels that move upward in the outer rainbands and those that travel through the inner core due to shear make a dominant contribution to the midlevel enhancement ofθ_(e)in the downshear-left outer core.In particular,the former plays a leading role in suchθ_(e)enhancements,while the latter plays a secondary role.As a result,moist potential stability occurs in the middle-to-lower troposphere in the downshear-left outer core.
基金the National Natural Science Foundation of China(Grant Nos.12164032,11964026,and 12364010)the Natural Science Foundation of Inner Mongolia Autonomous Region,China(Grant Nos.2019MS01010,2022MS01014,and 2020BS01009)+1 种基金the Doctor Research Start-up Fund of Inner Mongolia Minzu University(Grant Nos.BS625 and BS439)the Basic Research Funds for Universities Directly under the Inner Mongolia Autonomous Region,China(Grant No.GXKY23Z029).
文摘We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtained results showed that under magnetic field effect,magnetopolaron quasiparticle was formed through the interaction of electrons and surrounding phonons.At the same time,magnetopolaron was influenced by phonon temperature statistical law and important energy level shifts down and binding energy increases.This revealed that lattice temperature and magnetic field could easily affect magnetopolaron and the above results could play key roles in exploring thermoelectric conversion and conductivity of crystal materials.
基金Project supported by the Fondo Sectorial de Investigación para la Educación from the Secretar a de Educación Pública-Consejo Nacional de Ciencia y Tecnología(No.CB-2013/220900)the Secretaría de Investigación y Posgrado from Instituto Politécnico Nacional of Mexico(No.20171181)
文摘The pulsatile electroosmotic flow (PEOF) of a Maxwell fluid in a parallel flat plate microchannel with asymmetric wall zeta potentials is theoretically analyzed. By combining the linear Maxwell viscoelastic model, the Cauchy equation, and the electric field solution obtained from the linearized PoissomBoltzmann equation, a hyperbolic par- tial differential equation is obtained to derive the flow field. The PEOF is controlled by the angular Reynolds number, the ratio of the zeta potentials of the microchannel walls, the electrokinetic parameter, and the elasticity number. The main results obtained from this analysis show strong oscillations in the velocity profiles when the values of the elas- ticity number and the angular Reynolds number increase due to the competition among the elastic, viscous, inertial, and electric forces in the flow.
基金Supported the National Natural Science Foundation of China under Grant Nos 11175230 and 11474299the Key Research Program of Chinese Academy of Sciences under Grant No KJZD-EW-M03
文摘Based on a simple model, we theoretically show the transport behaviors of two harmonically coupled Brownian particles in an asymmetric saw-tooth potential with two slopes. The coupled particles are subject to stochastic fluctuations. It is found that when the equilibrium distance of the coupled particles is between the two slopes of the potential, the transport direction of the coupled particles will be reversed with a certain harmonic coupling strength. This current reversal can be easily understood with the near rigid approximation, where the two coupled particles can be regarded as a single particle in an effective potential. Compared with the original saw-tooth potential, the asymmetry of the effective potential could be reversed when the equilibrium distance is between the two slopes of the original potential, which results in the current reversal.
基金We are grateful to the National Natural Science Foundation of China (No. 20173054);the Natural Science Foundation of Ningbo City (No. 2006A610044).
文摘Based on the perfect ohmic drop compensation by online electronic positive feedback, ultrafast cyclic voltammetry with asymmetrical potential scan is achieved for the first time, with the reduction of anthracene acting as the test system. Compared with the traditional cyclic voltammetry utilizing symmetrical triangular waveform as the excitation one, the new method allows a simpler approach to mechanistic analysis of ultrafast chemical reactions coupled with a charge transfer. And perhaps more important, it also provides a way to eliminate the interference of the adsorbed product in dynamic monitoring. 2007 Zhi Yong Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by the National Science Foundation of China under Grant No.11464034
文摘Under the influence of an applied magnetic field(MF), the eigenenergies and the eigenfunctions of the ground and the first excited states(GFES) are obtained by using a variational method of the Pekar type(VMPT) in a strong electron-LO-phonon coupling asymmetrical Gaussian potential quantum well(AGPQW). This AGPQW system may be employed as a two-level qubit. The numerical results have indicated(i) that when the electron situates in the superposition state of the GFES, we obtain the time evolution and the coordinate change of the electron probability density in the AGPQW,(ii) that due to the presence of the asymmetrical potential in the growth direction of the AGPQW, the probability density shows double-peak configuration, whereas there is only one peak if the confinement is a two dimensional symmetric one in the xy plane of the AGPQW,(iii) that the oscillatory period is a decreasing function of the cyclotron frequency of the MF, the height of the AGPQW and the polaron radius,(iv) and that as the range of the confinement potential(RCP) decreases the oscillatory period will decrease firstly and then increase and it will take a minimum when R =-0.234 nm.
基金Project supported by the National Natural Science Foundation of China(Nos.11464033,11464034)
文摘: The effects of a magnetic field on the vibrational frequency, the ground state energy and the ground state binding energy of a weak-coupling polaron in asymmetrical Gaussian confinement potential quantum well (AGCPQW) are investigated by using linear combination operator and unitary transformation methods. Our cal- culated results show that the vibrational frequency increases with increasing cyclotron frequency of the magnetic field; meanwhile, the absolute value of the ground state energy and the ground state binding energy decrease. The vibrational frequency, the absolute value of the ground state energy and the ground state binding energy are in- creasing functions of the barrier height of the AGCPQW. It is shown that the barrier height of the AGCPQW and the magnetic field are important factors that influence the properties of the magnetopolaron in AGCPQW.
基金supported by the National Natural Science Foundation of China under Grant No.11975011。
文摘By a combination method of Lee-Low-Pines unitary transformation method and Pekar-type variational method,the ground state energy(GSE)of the bound polaron is studied in the asymmetrical Gaussian potential quantum well considering the temperature and electromagneticfield.The impacts of the temperature and asymmetrical Gaussian potential,electromagnetic field and phonon-electron coupling upon the GSE are obtained.The results show that the GSE of the bound polaron not only oscillates as the temperature changes regardless of the electromagneticfield and asymmetrical Gaussian potential and Coulomb impurity potential(CIP)and electron-phonon coupling but also has different rules with the electromagnetic field and asymmetrical Gaussian potential and CIP and electron-phonon coupling at different temperature zones.
基金Project supported by the National Natural Science Foundation of China(No.11464033)the Mongolia University for Nationalities Fund(No.NMDYB1445)
文摘With the circumstance of the electron strongly coupled to LO-phonon and using the variational method of Pekar type(VMPT),we study the eigenenergies and the eigenfunctions(EE) of the ground and the first excited states(GFES) in a RbCl crystal asymmetric Gaussian potential quantum well(AGPQW).It concludes:(i) Twoenergy-level of the AGPQW may be seen as a qubit.(ii) When the electron located in the superposition state of the two-energy-level system,the time evolution and the coordinate changes of the electron probability density oscillated periodically in the AGPQW with every certain period T0=22.475 fs.(iii) Due to the confinement that is a two dimensional x-y plane symmetric structure in the AGPQW and the asymmetrical Gaussian potential(AGP) in the AGPQW growth direction,the electron probability density presents only one peak configuration located in the coordinate of z 〉 0,whereas it is zero in the range of z 〈 0.(iv) The oscillatory period is a decreasing function of the AGPQW height and the polaron radius,(v) The oscillating period is a decreasing one in the confinement potential R 〈 0.24 nm,whereas it is an increasing one in the confinement potential R 〉 0.24 nm and it takes a minimum value in R = 0.24 nm.
文摘The classical theory of the rate of unimolecular isomerization developed by Gray and Rice as extended by Zhao and Rice is applied to the calculation of the rate of isomerization in model systems which have linear asymmetric double well potentials. We are interested in this system for two reasons. First, we are interested in the detailed dynamical processes for the mentioned system because it is widely related to practical chemical reactions. Second, the present model system has an asymmetric double well potential, which provides a different test of the accuracy of the approximations used in the Gray-Zhao-Rice theory than posed by previous applications. We have calculated relaxation rates and relaxation times for the model systems on different time scales. We find that for the systems under studies the Gray-Zhao-Rice version of the classical theory of isomerization rate yields values in good agreement with those generated from trajectory calculations and from the Reactive Island theory of De Leon et al.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos.11575064 and 11175067the Natural Science Foundation of Guangdong Province under Grant No.2016A030313433
文摘Transport of an underdamped Brownian particle in a one-dimensional asymmetric deformable potential is investigated in the presence of both an ac force and a static force,respectively.From numerical simulations,we obtain the current average velocity.The current reversals and the absolute negative mobility are presented.The increasing of the deformation of the potential can cause the absolute negative mobility to be suppressed and even disappear.When the static force is small,the increase of the potential deformation suppresses the absolute negative mobility.When the force is large,the absolute negative mobility disappears.In particular,when the potential deformation is equal to0.015,the two current reversals present with the increasing of the force.Remarkably,when the potential deformation is small,there are three current reversals with the increasing of the friction coefficient and the average velocity presents a oscillation behavior.
基金supported by the National Natural Science Foundation of China(12164032 and 11964026)the Natural Science Foundation of Inner Mongolia(No.2019MS01010,2022MS01014)+1 种基金Doctor Research Start-up Fund of Inner Mongolia Minzu University(BS625)Scientific Research Projects in Colleges and Universities in Inner Mongolia(No.NJZZ19145)
文摘The polaron phenomenon is commonly observed in low-dimensional semiconductor materials and is known to have unique effects on conductive material properties.Furthermore,the phonon dragging effect,which leads to the polaron energy level,is less than the electron energy level.A decay magnetic field also affects the polaron effect,which causes polaron energy level changes.We demonstrate the unique electron-phonon coupling properties of this polaron using numerical calculations.Our findings have strong implications for theories of polaron properties and provide compelling evidence for a semiconductor device that industrial manufacturers use for new lowdimensional materials.