We report that the photoinduced dynamics of the phytochrome chromophore is strongly dependent on the protonation/deprotonation states of the pyrrole ring. The on-the-fly surface hopping dynamics simulations were perfo...We report that the photoinduced dynamics of the phytochrome chromophore is strongly dependent on the protonation/deprotonation states of the pyrrole ring. The on-the-fly surface hopping dynamics simulations were performed to study the photoisomerization of different protonation/deprotonation phytochrome chromophore models. The simulation results indicate that the deprotonations at the pyrrole rings significantly modify the photoinduced nonadiabatic dynamics, leading to distinctive population decay dynamics and different reaction channels. Such feature can be well explained by the formation of the different hydrogen bond network patterns. Therefore, the proper understanding of the photoisomerization mechanism of phytochrome chromophore must take the hydrogen bond network into account. This work provides the new insights into the photobiological functions of phytochrome chromophore and suggests the possible ideas to control of its photoconversion processes for further rational engineering in optical applications.展开更多
After the Big Bang,chemical reactions of hydrogen with LiH and its isotopic variants played an important role in the late stage of recombination.Moreover,these reactions have attracted the attention of experts in the ...After the Big Bang,chemical reactions of hydrogen with LiH and its isotopic variants played an important role in the late stage of recombination.Moreover,these reactions have attracted the attention of experts in the field of molecular dynamics because of its simple structure.Electronically non-adiabatic effects play a key role in many chemical reactions,while the related studies in LiH2 reactive system and its isotopic variants are not enough,so the microscopic mechanism of this system has not been fully explored.In this work,the microscopic mechanism of H+LiD reaction are performed by comparing both the adiabatic and non-adiabatic results to study the non-adiabatic effects.The reactivity of R1(H+LiD→Li+HD)channel is inhibited,while that of R2(H+LiD→D+LiH)channel is enhanced when the non-adiabatic couplings are considered.For R1 channel,a direct stripping process dominates this channel and the main reaction mechanism is not influenced by the non-adiabatic effects.For R2 channel,at relatively low collision energy,the dominance changes from a rebound process to the complex-forming mechanism when the non-adiabatic effects are considered,whereas the rebound collision approach still dominates the reaction at relatively high collision energy in both calculations.The presented results provide a basis for further detailed study on this importantly astrophysical reaction system.展开更多
We propose an identical geometrical representation scheme for both Landau-Zener （LZ） tunneling process in two-waveguide coupler with a cubically bent structure and stimulated Raman adiabatic passage （STIRAP） in th...We propose an identical geometrical representation scheme for both Landau-Zener （LZ） tunneling process in two-waveguide coupler with a cubically bent structure and stimulated Raman adiabatic passage （STIRAP） in three-waveguide coupler, similar to the geometrical representation of sum frequency process. The results show that although the two-waveguide coupler with a cubically bent axis has not aperiodic structure, it acts as a chirped quasi-phase-matching （QPM） grating and corrects the relative phase between the two supermodes in the curved coupler system. We present a scheme about how to choose the parameters to design the curved beam splitter.展开更多
This paper presents the fundamentals of thermal pyrolysis and discusses the modern ethylene furnace technology and its design trends. Technip’s proprietary SPYRO? program is discussed for prediction of hydrocarbon cr...This paper presents the fundamentals of thermal pyrolysis and discusses the modern ethylene furnace technology and its design trends. Technip’s proprietary SPYRO? program is discussed for prediction of hydrocarbon cracking.展开更多
The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magne...The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magnetic reconnection has the potential to preserve the ion-to-electron temperature ratio under certain conditions.If the charged particles are non-adiabatically accelerated no more than once in a single reconnection,the temperature ratio would be preserved;on the other hand,this ratio would not be preserved if they are accelerated multiple times.Consequently,under a northward interplanetary magnetic field(IMF)condition,the reconnection in the nonlinear phase of the Kelvin-Helmholtz instability is the dominant process for solar-originated plasma entering the Earth’s magnetosphere,and the ion-to-electron temperature ratio is preserved inside the plasma sheet.When the direction of the IMF is southward,the reflection of electrons from the magnetic mirror point,and subsequent multiple non-adiabatic accelerations at the reconnection site,are the primary reasons for the observed low ion-to-electron temperature ratio close to the Earth at midnight.While reconnections that occur in the night-side far tail might preserve the ratio,turbulence on the boundaries of the bursty bulk flows(BBFs)could change the ratio in the far tail through the violation of the frozen-in condition of the ions.The plateau in the contour of the calculated ion-to-electron temperature ratio in the down tail distance between 40 and 60 Earth radii may explain the strong correlation between the ion and electron temperatures in the outer central plasma sheet,which has not been clearly understood till date.展开更多
By employing the NCEP/NCAR reanalysis data sets(1 000 to 10 hPa,2.5°× 2.5°),the thermal forcing impacts are analyzed of an easterly vortex(shortened as EV) over the tropical upper troposphere on the qua...By employing the NCEP/NCAR reanalysis data sets(1 000 to 10 hPa,2.5°× 2.5°),the thermal forcing impacts are analyzed of an easterly vortex(shortened as EV) over the tropical upper troposphere on the quasi-horizontal movement of the Western Pacific Subtropical Anticyclone(shortened as WPS A) during 22-25 June 2003.The relevant mechanisms are discussed as well.It is shown that the distribution and intensity of the non-adiabatic effect near the EV result in the anomalous eastward retreat of the WPSA.The WPSA prefers extending to the colder region,i.e.,it moves toward the region in which the non-adiabatic heating is weakening or the cooling is strengthening.During the WPSA retreat,the apparent changes of non-adiabatic heating illustrate the characteristics of enhanced cooling in the east side of the EV.Meanwhile,the cooling in the west side exhibits a weakened eastward trend,most prominently at 300 hPa in the troposphere.The evidence on the factors causing the change in thermal condition is found:the most important contribution to the heating-rate trend is the vertical transport term,followed in turn by the local change in the heating rate term and the horizontal advection term.As a result,the atmospheric non-adiabatic heating generated by the vertical transport and local change discussed above is mainly connected to the retreat of the WPSA.展开更多
This paper investigates the propagation of linear dust acoustic waves in inhomogeneous dusty plasmas due to spatial gradients of dust charge, plasma densities. A linear dispersion relation is obtained with the non-adi...This paper investigates the propagation of linear dust acoustic waves in inhomogeneous dusty plasmas due to spatial gradients of dust charge, plasma densities. A linear dispersion relation is obtained with the non-adiabatic dust charge iguctuation and the non-thermally distributed ions. The numerical results show that the inhomogeneity, nonthermal ions and non-adlabatic dust charge iguctuatlon have strong iniguence on the frequency and the damping rate of waves.展开更多
The second law of thermodynamics dictates that heat simultaneously flows from the hot to cold bath on average. To go beyond this picture, a range of works in the past decade show that, other than the average dynamical...The second law of thermodynamics dictates that heat simultaneously flows from the hot to cold bath on average. To go beyond this picture, a range of works in the past decade show that, other than the average dynamical heat flux determined by instantaneous thermal bias, a non-trivial flux contribution of intrinsic geometric origin is generally present in temporally driven systems. This additional heat flux provides a free lunch for the pumped heat and could even drive heat against the bias. We review here the emergence and development of this so called “geometric heat pump”, originating from the topological geometric phase effect, and cover various quantum and classical transport systems with different internal dynamics. The generalization from the adiabatic to the non-adiabatic regime and the application of control theory are also discussed. Then, we briefly discuss the symmetry restriction on the heat pump effect, such as duality, supersymmetry and time-reversal symmetry. Finally, we examine open problems concerning the geometric heat pump process and elucidate their prospective significance in devising thermal machines with high performance.展开更多
We perform an ab initio non-adiabatic molecular dynamics simulation to investigate the non-equilibrium spin and electron dynamics in a prototypical topological insulator(TI)Bi,Ses.Different from the ground state,we re...We perform an ab initio non-adiabatic molecular dynamics simulation to investigate the non-equilibrium spin and electron dynamics in a prototypical topological insulator(TI)Bi,Ses.Different from the ground state,we reveal that backscattering can happen in an oscillating manner between time-reversal pair topological surface states(TSSs)in the non-equilibrium dynamics.Analysis shows the phonon excitation induces orbital composition change by electron-phonon interaction,which further stimulates spin canting through spin-orbit coupling.The spin canting of time-reversal pair TSSs leads to the non-zero non-adiabatic coupling between them and then issues in backscattering.Both the spin canting and backscattering result in ultrafast spin relaxation with a timescale around 10o fs.This study provides critical insights into the non-equilibrium electron and spin dynamics in TI at the ab initio level and paves a way for the design of ultrafast spintronic materials.展开更多
Non-adiabatic dynamical calculations are carried out for the Na(3 p)+HD(ν = 1, j = 0)→NaH/NaD+D/H reaction on the diabatic potential energy surfaces of Wang et al.(Sci. Rep. 2018, 8, 17960) by using the time-depende...Non-adiabatic dynamical calculations are carried out for the Na(3 p)+HD(ν = 1, j = 0)→NaH/NaD+D/H reaction on the diabatic potential energy surfaces of Wang et al.(Sci. Rep. 2018, 8, 17960) by using the time-dependent wave packet method. The state-to-state integral cross sections and differential cross sections of two reaction channels(NaH/NaD+D/H)are calculated for collision energy up to 0.4 eV. The cross section branching ratio indicates that the dominant reaction channel changes from NaD+H to NaH+D when the collision energy is larger than 0.227 eV. The products from two reaction channels both prefer to form in vibrationally cold but rotationally hot states, and they both tend to forward scattering.展开更多
The flows in which thermal process plays an important role are discussed using the analytical method. An approximate expression for the variation of the stream-pipe cross-section with the temperature is obtained. Some...The flows in which thermal process plays an important role are discussed using the analytical method. An approximate expression for the variation of the stream-pipe cross-section with the temperature is obtained. Some basic properties of the thermofluid flow are dealt with, such as the phenomenon that the streamlines will "reject when heated and attract when cooled" or "attract when heated and reject when cooled" under different heat transfer conditions and the deviation of the sonic point from the point of the smallest cross-section area of the stream-pipe.展开更多
The latest results from the earth sciences indicated that the movement of the earth surface substances has a close relationship with the energy exchanges on large scale occurred in the margin between the core and mant...The latest results from the earth sciences indicated that the movement of the earth surface substances has a close relationship with the energy exchanges on large scale occurred in the margin between the core and mantle. There is a tendency towards the average temperature evolution of the earth dynamic system from higher to lower on the whole. And more and more evidence showed that the interior of the earth is in a non-adiabatic state, the cooling process occurred in the interior exerted a great influence on the surface environment. The development of the heat energy resources from the interior of the earth would result in the long term accelerating cooling though it may increase the surface temperature temporarily.展开更多
The H^++CO2 reaction at high energies is relevant in atmospheric chemistry,astrophysics,and proton cancer therapy research.Therefore,we present herein a complete investigation of H^++CO2 at ELab=30 eV with the simples...The H^++CO2 reaction at high energies is relevant in atmospheric chemistry,astrophysics,and proton cancer therapy research.Therefore,we present herein a complete investigation of H^++CO2 at ELab=30 eV with the simplest-level electron nuclear dynamics(SLEND)method.SLEND describes nuclei via classical mechanics and electrons with a singledeterminantal Thouless wavefunction.The 3402 SLEND conducted simulations from 42 independent CO2 target orientations provide a full description of all the reactive processes and their mechanisms in this system:non-charge-transfer scattering(NCTS),charge-transfer scattering(CTS),and single C=O bond dissociation;all this valuable information about reactivity is not accessible experimentally.Numerous details of the projectile scattering patterns are provided,including the appearance and coalescence of primary and secondary rainbow angles as a function of the target orientation.SLEND NCTS and CTS differential cross sections(DCSs)are evaluated in conjunction with advanced semi-classical techniques.SLEND NCTS DCS agrees well with its experimental counterpart at all the measured scattering angles,whereas SLEND CTS DCS agrees well at high scattering angles but less satisfactorily at lower ones.Remarkably,both NCTS and CTS SLEND DCSs predict the primary rainbow angle signatures in agreement with the experiment.展开更多
基金supported by National Natural Science Foundation of China (NSFC, Nos. 21903030, 21933011 and 21873112)。
文摘We report that the photoinduced dynamics of the phytochrome chromophore is strongly dependent on the protonation/deprotonation states of the pyrrole ring. The on-the-fly surface hopping dynamics simulations were performed to study the photoisomerization of different protonation/deprotonation phytochrome chromophore models. The simulation results indicate that the deprotonations at the pyrrole rings significantly modify the photoinduced nonadiabatic dynamics, leading to distinctive population decay dynamics and different reaction channels. Such feature can be well explained by the formation of the different hydrogen bond network patterns. Therefore, the proper understanding of the photoisomerization mechanism of phytochrome chromophore must take the hydrogen bond network into account. This work provides the new insights into the photobiological functions of phytochrome chromophore and suggests the possible ideas to control of its photoconversion processes for further rational engineering in optical applications.
基金supported by the National Natural Science Foundation of China(Grant No.11774043).
文摘After the Big Bang,chemical reactions of hydrogen with LiH and its isotopic variants played an important role in the late stage of recombination.Moreover,these reactions have attracted the attention of experts in the field of molecular dynamics because of its simple structure.Electronically non-adiabatic effects play a key role in many chemical reactions,while the related studies in LiH2 reactive system and its isotopic variants are not enough,so the microscopic mechanism of this system has not been fully explored.In this work,the microscopic mechanism of H+LiD reaction are performed by comparing both the adiabatic and non-adiabatic results to study the non-adiabatic effects.The reactivity of R1(H+LiD→Li+HD)channel is inhibited,while that of R2(H+LiD→D+LiH)channel is enhanced when the non-adiabatic couplings are considered.For R1 channel,a direct stripping process dominates this channel and the main reaction mechanism is not influenced by the non-adiabatic effects.For R2 channel,at relatively low collision energy,the dominance changes from a rebound process to the complex-forming mechanism when the non-adiabatic effects are considered,whereas the rebound collision approach still dominates the reaction at relatively high collision energy in both calculations.The presented results provide a basis for further detailed study on this importantly astrophysical reaction system.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304247 and 61505161)the Shaanxi Provincial Research Plan for Young Scientific and Technological New Stars,China(Grant No.2015KJXX-40)
文摘We propose an identical geometrical representation scheme for both Landau-Zener （LZ） tunneling process in two-waveguide coupler with a cubically bent structure and stimulated Raman adiabatic passage （STIRAP） in three-waveguide coupler, similar to the geometrical representation of sum frequency process. The results show that although the two-waveguide coupler with a cubically bent axis has not aperiodic structure, it acts as a chirped quasi-phase-matching （QPM） grating and corrects the relative phase between the two supermodes in the curved coupler system. We present a scheme about how to choose the parameters to design the curved beam splitter.
文摘This paper presents the fundamentals of thermal pyrolysis and discusses the modern ethylene furnace technology and its design trends. Technip’s proprietary SPYRO? program is discussed for prediction of hydrocarbon cracking.
文摘The ion-to-electron temperature ratio is a good indicator of the processes involved in solar wind plasma entering and being transported inside Earth’s plasma sheet.In this study,we have demonstrated that patchy magnetic reconnection has the potential to preserve the ion-to-electron temperature ratio under certain conditions.If the charged particles are non-adiabatically accelerated no more than once in a single reconnection,the temperature ratio would be preserved;on the other hand,this ratio would not be preserved if they are accelerated multiple times.Consequently,under a northward interplanetary magnetic field(IMF)condition,the reconnection in the nonlinear phase of the Kelvin-Helmholtz instability is the dominant process for solar-originated plasma entering the Earth’s magnetosphere,and the ion-to-electron temperature ratio is preserved inside the plasma sheet.When the direction of the IMF is southward,the reflection of electrons from the magnetic mirror point,and subsequent multiple non-adiabatic accelerations at the reconnection site,are the primary reasons for the observed low ion-to-electron temperature ratio close to the Earth at midnight.While reconnections that occur in the night-side far tail might preserve the ratio,turbulence on the boundaries of the bursty bulk flows(BBFs)could change the ratio in the far tail through the violation of the frozen-in condition of the ions.The plateau in the contour of the calculated ion-to-electron temperature ratio in the down tail distance between 40 and 60 Earth radii may explain the strong correlation between the ion and electron temperatures in the outer central plasma sheet,which has not been clearly understood till date.
基金LASW State Key Laboratory Special Fund(2014LASW-A03)National Science Foundation of China(41475041)
文摘By employing the NCEP/NCAR reanalysis data sets(1 000 to 10 hPa,2.5°× 2.5°),the thermal forcing impacts are analyzed of an easterly vortex(shortened as EV) over the tropical upper troposphere on the quasi-horizontal movement of the Western Pacific Subtropical Anticyclone(shortened as WPS A) during 22-25 June 2003.The relevant mechanisms are discussed as well.It is shown that the distribution and intensity of the non-adiabatic effect near the EV result in the anomalous eastward retreat of the WPSA.The WPSA prefers extending to the colder region,i.e.,it moves toward the region in which the non-adiabatic heating is weakening or the cooling is strengthening.During the WPSA retreat,the apparent changes of non-adiabatic heating illustrate the characteristics of enhanced cooling in the east side of the EV.Meanwhile,the cooling in the west side exhibits a weakened eastward trend,most prominently at 300 hPa in the troposphere.The evidence on the factors causing the change in thermal condition is found:the most important contribution to the heating-rate trend is the vertical transport term,followed in turn by the local change in the heating rate term and the horizontal advection term.As a result,the atmospheric non-adiabatic heating generated by the vertical transport and local change discussed above is mainly connected to the retreat of the WPSA.
基金supported by the National Natural Foundation of China (Grant Nos 10475066 and 10347006)
文摘This paper investigates the propagation of linear dust acoustic waves in inhomogeneous dusty plasmas due to spatial gradients of dust charge, plasma densities. A linear dispersion relation is obtained with the non-adiabatic dust charge iguctuation and the non-thermally distributed ions. The numerical results show that the inhomogeneity, nonthermal ions and non-adlabatic dust charge iguctuatlon have strong iniguence on the frequency and the damping rate of waves.
基金Z.W.,L.W.,J.C.,and J.R.acknowledge the support by the National Natural Science Foundation of China(Grant Nos.11935010 and 11775159)the Natural Science Foundation of Shanghai(Grant Nos.18ZR1442800 and 18JC1410900)+1 种基金C.W.acknowledges support from the National Natural Science Foundation of China(Grant No.11704093)the Opening Project of Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology.
文摘The second law of thermodynamics dictates that heat simultaneously flows from the hot to cold bath on average. To go beyond this picture, a range of works in the past decade show that, other than the average dynamical heat flux determined by instantaneous thermal bias, a non-trivial flux contribution of intrinsic geometric origin is generally present in temporally driven systems. This additional heat flux provides a free lunch for the pumped heat and could even drive heat against the bias. We review here the emergence and development of this so called “geometric heat pump”, originating from the topological geometric phase effect, and cover various quantum and classical transport systems with different internal dynamics. The generalization from the adiabatic to the non-adiabatic regime and the application of control theory are also discussed. Then, we briefly discuss the symmetry restriction on the heat pump effect, such as duality, supersymmetry and time-reversal symmetry. Finally, we examine open problems concerning the geometric heat pump process and elucidate their prospective significance in devising thermal machines with high performance.
基金supported by National Key R&D Program of China(Grant No.2017YFA0204904)National Natural Science Foundation of China(Grants No.11620101003 and 11974322)Anhui Initiative in Quantum Information Technologies(Grant No.AHY090300).Calculations were performed at Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory,a user facility sponsored by the Us Department of Energy Office of Biological and Environmental Research.
文摘We perform an ab initio non-adiabatic molecular dynamics simulation to investigate the non-equilibrium spin and electron dynamics in a prototypical topological insulator(TI)Bi,Ses.Different from the ground state,we reveal that backscattering can happen in an oscillating manner between time-reversal pair topological surface states(TSSs)in the non-equilibrium dynamics.Analysis shows the phonon excitation induces orbital composition change by electron-phonon interaction,which further stimulates spin canting through spin-orbit coupling.The spin canting of time-reversal pair TSSs leads to the non-zero non-adiabatic coupling between them and then issues in backscattering.Both the spin canting and backscattering result in ultrafast spin relaxation with a timescale around 10o fs.This study provides critical insights into the non-equilibrium electron and spin dynamics in TI at the ab initio level and paves a way for the design of ultrafast spintronic materials.
基金Project supported by the National Natural Science Foundation of China(Grant No.11774043)
文摘Non-adiabatic dynamical calculations are carried out for the Na(3 p)+HD(ν = 1, j = 0)→NaH/NaD+D/H reaction on the diabatic potential energy surfaces of Wang et al.(Sci. Rep. 2018, 8, 17960) by using the time-dependent wave packet method. The state-to-state integral cross sections and differential cross sections of two reaction channels(NaH/NaD+D/H)are calculated for collision energy up to 0.4 eV. The cross section branching ratio indicates that the dominant reaction channel changes from NaD+H to NaH+D when the collision energy is larger than 0.227 eV. The products from two reaction channels both prefer to form in vibrationally cold but rotationally hot states, and they both tend to forward scattering.
基金Project supported by the National Natural Science Foundation of China.
文摘The flows in which thermal process plays an important role are discussed using the analytical method. An approximate expression for the variation of the stream-pipe cross-section with the temperature is obtained. Some basic properties of the thermofluid flow are dealt with, such as the phenomenon that the streamlines will "reject when heated and attract when cooled" or "attract when heated and reject when cooled" under different heat transfer conditions and the deviation of the sonic point from the point of the smallest cross-section area of the stream-pipe.
基金ThepartoftheresearchfruitoftheprojectfundedbyNationalNaturalScienceFoundationofChina . (No .497742 2 8)
文摘The latest results from the earth sciences indicated that the movement of the earth surface substances has a close relationship with the energy exchanges on large scale occurred in the margin between the core and mantle. There is a tendency towards the average temperature evolution of the earth dynamic system from higher to lower on the whole. And more and more evidence showed that the interior of the earth is in a non-adiabatic state, the cooling process occurred in the interior exerted a great influence on the surface environment. The development of the heat energy resources from the interior of the earth would result in the long term accelerating cooling though it may increase the surface temperature temporarily.
基金Present calculations were performed at the Texas Tech University High Performance Computer Center and the Texas Advanced Computing Center at the University of Texas at Austin.Prof.Morales acknowledges financial support from the Cancer Prevention and Research Institute of Texas(CPRIT)grant RP140478.Prof.Yan acknowledges the financial support from the National Natural Science Foundation of China(No.21373064)and the Program for Innovative Research Team of Guizhou Province(No.QKTD[2014]4021).
文摘The H^++CO2 reaction at high energies is relevant in atmospheric chemistry,astrophysics,and proton cancer therapy research.Therefore,we present herein a complete investigation of H^++CO2 at ELab=30 eV with the simplest-level electron nuclear dynamics(SLEND)method.SLEND describes nuclei via classical mechanics and electrons with a singledeterminantal Thouless wavefunction.The 3402 SLEND conducted simulations from 42 independent CO2 target orientations provide a full description of all the reactive processes and their mechanisms in this system:non-charge-transfer scattering(NCTS),charge-transfer scattering(CTS),and single C=O bond dissociation;all this valuable information about reactivity is not accessible experimentally.Numerous details of the projectile scattering patterns are provided,including the appearance and coalescence of primary and secondary rainbow angles as a function of the target orientation.SLEND NCTS and CTS differential cross sections(DCSs)are evaluated in conjunction with advanced semi-classical techniques.SLEND NCTS DCS agrees well with its experimental counterpart at all the measured scattering angles,whereas SLEND CTS DCS agrees well at high scattering angles but less satisfactorily at lower ones.Remarkably,both NCTS and CTS SLEND DCSs predict the primary rainbow angle signatures in agreement with the experiment.
