In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC), the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of variou...In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC), the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.展开更多
The dynamical correlation between quantum entanglement and intramolecular energy in realistic molecular vibrations is explored using the Lie algebraic approach. The explicit expression of entanglement measurement can ...The dynamical correlation between quantum entanglement and intramolecular energy in realistic molecular vibrations is explored using the Lie algebraic approach. The explicit expression of entanglement measurement can be achieved using algebraic operations. The common and different characteristics of dynamical entanglement in different molecular vibrations are also provided. The dynamical study of quantum entanglement and intramolecular energy in small molecular vibrations can be helpful for controlling the entanglement and further understanding the intramolecular dynamics.展开更多
Molecular dynamics method is applied to study the machining mechanisms of polishing based on coupling vibrations of liquid. The physical phenomena of abrasive particles bombarding on silicon monocrystal surface are si...Molecular dynamics method is applied to study the machining mechanisms of polishing based on coupling vibrations of liquid. The physical phenomena of abrasive particles bombarding on silicon monocrystal surface are simulated using Tersoff potentials. The effects of vibration parameters, particle size, incident angle and particle material are analyzed and discussed. Material removal mechanisms are studied. Deformation and embedment phenomena are found in the simulations, Bombardment will destroy the crystal structures near the impact point, and adhesion effect is responsible for final removal of material.展开更多
We describe high-level ab initio calculations on the BH_2, HBF, HBCl and HBBr radicals. Molecular structure,vibrational frequencies and potential energy curves of the ground state and the first excited state, which ar...We describe high-level ab initio calculations on the BH_2, HBF, HBCl and HBBr radicals. Molecular structure,vibrational frequencies and potential energy curves of the ground state and the first excited state, which are two Renner-Teller components for a^2Π state at linearity, are studied using the basis sets aug-cc-pVTZ and icMRCI+Q technique. On the basis of the potential energy curves, a reliable potential energy barrier to dissociation HB+X(X=F, Cl, Br) fragments and to linearity are given. The ab initio results will add some understanding on the spectrum and the photo-dissociation dynamics of the series of radicals.展开更多
Energy efficiency limits the application of atmospheric pressure dielectric barrier discharge(DBD),such as air purification,water treatment and material surface modification.This article focuses on the electrical and ...Energy efficiency limits the application of atmospheric pressure dielectric barrier discharge(DBD),such as air purification,water treatment and material surface modification.This article focuses on the electrical and optical effects of the DBD under three square wave pulses polarities-positive,negative and bipolar.The result shows that under the same voltage with the quartz glass medium,the discharge efficiency of bipolar polarity pulse is the highest due to the influence of deposited charge.With the increase of air gap distance from 0.5 to 1.5 mm,average power consumed by the discharge air gap and discharge efficiency decrease obviously under alumina,and increase,and then decrease under quartz glass and polymethyl methacrylate(PMMA).Through spectrum diagnosis,in the quartz glass medium,the vibration temperature is the highest under negative polarity pulse excitation.Under bipolar pulse,the vibration temperature does not change significantly with the change of air gap distance.For the three dielectric materials of quartz glass,alumina and PMMA,the molecular vibration temperature is the highest under the quartz glass medium with the same voltage.When the gap spacing,pulse polarity or dielectric material are changed,the rotational temperature does not change significantly.展开更多
Propagation of a few-cycle laser pulses in a dense V-type three-level atomic medium is investigated based on full-wave Maxwell-Bloch equations by taking the near dipole-dipole (NDD) interaction into account. We find...Propagation of a few-cycle laser pulses in a dense V-type three-level atomic medium is investigated based on full-wave Maxwell-Bloch equations by taking the near dipole-dipole (NDD) interaction into account. We find that the ratio, γ of the transition dipole moments has strong influence on the time evolution and split of the pulse: when γ≤ 1, the NDD interaction delays propagation and split of the pulse, and this phenomenon is more obvious when the value of γ is smaller; when γ =√2, the NDD interaction accelerates propagation and split of the pulse.展开更多
The photo-acoustic (PA) spectrum of nitrogen dioxide (NO2) in the range of 420 - 520 nm with a Nd:YAG pumped optical parametric generator and amplifier as radiation source is presented. The spectrum has a charact...The photo-acoustic (PA) spectrum of nitrogen dioxide (NO2) in the range of 420 - 520 nm with a Nd:YAG pumped optical parametric generator and amplifier as radiation source is presented. The spectrum has a characteristic of banded structure superimposed on continuum. The banded structure of the spectrum can be assigned to NO2 B2B1← X^2A1 transition. While the continual one comes from the chaos states of the first excited state A^2B2 and the high vibration levels of the ground state X^2A1. The relationship of PA signal with buffer gas pressure and NO2 concentration is measured. The PA signal intensity increases with buffer gas pressure and almost is invariable when the buffer gas pressure is more than 3.00 × 10^4 Pa. The PA signal intensity has linearity with NO2 concentration. The detection limit is about 2×10^-5 on the basis of SNR = 1, however lower value of the detection limit can be expected by improving the apparatus properties.展开更多
In this paper, we have suggested an iterative procedure of optimization of the linear parameters in an analytic potential energy function for a triatomic molecule, by combining both variational and second order pertur...In this paper, we have suggested an iterative procedure of optimization of the linear parameters in an analytic potential energy function for a triatomic molecule, by combining both variational and second order perturbation methods. The most important feature of this procedure is that the objective function is an analytical expression which can be optimized easily. The application to the water molecule is presented.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.60627003)the Foundation for Creative Team in Institution of Higher Education of Guangdong Province,China(Grant No.06CXTD009)
文摘In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC), the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.
基金supported by the National Natural Science Foundation of China(Grant Nos.11147019 and 91021009)
文摘The dynamical correlation between quantum entanglement and intramolecular energy in realistic molecular vibrations is explored using the Lie algebraic approach. The explicit expression of entanglement measurement can be achieved using algebraic operations. The common and different characteristics of dynamical entanglement in different molecular vibrations are also provided. The dynamical study of quantum entanglement and intramolecular energy in small molecular vibrations can be helpful for controlling the entanglement and further understanding the intramolecular dynamics.
基金This project is supported by National Natural Science Foundation of China (No.50375029)Provincial Natural Science Foundation of Guangdong,China(No.4009486).
文摘Molecular dynamics method is applied to study the machining mechanisms of polishing based on coupling vibrations of liquid. The physical phenomena of abrasive particles bombarding on silicon monocrystal surface are simulated using Tersoff potentials. The effects of vibration parameters, particle size, incident angle and particle material are analyzed and discussed. Material removal mechanisms are studied. Deformation and embedment phenomena are found in the simulations, Bombardment will destroy the crystal structures near the impact point, and adhesion effect is responsible for final removal of material.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11647011,11605105 and 11604181the Shandong Provincial Natural Science Foundation of China under Grant No 2016ZRB01A38
文摘We describe high-level ab initio calculations on the BH_2, HBF, HBCl and HBBr radicals. Molecular structure,vibrational frequencies and potential energy curves of the ground state and the first excited state, which are two Renner-Teller components for a^2Π state at linearity, are studied using the basis sets aug-cc-pVTZ and icMRCI+Q technique. On the basis of the potential energy curves, a reliable potential energy barrier to dissociation HB+X(X=F, Cl, Br) fragments and to linearity are given. The ab initio results will add some understanding on the spectrum and the photo-dissociation dynamics of the series of radicals.
基金supported by Shanghai Sailing Program(No.19YF1435000)National Natural Science Foundation of China(Nos.51707122 and 12005128)。
文摘Energy efficiency limits the application of atmospheric pressure dielectric barrier discharge(DBD),such as air purification,water treatment and material surface modification.This article focuses on the electrical and optical effects of the DBD under three square wave pulses polarities-positive,negative and bipolar.The result shows that under the same voltage with the quartz glass medium,the discharge efficiency of bipolar polarity pulse is the highest due to the influence of deposited charge.With the increase of air gap distance from 0.5 to 1.5 mm,average power consumed by the discharge air gap and discharge efficiency decrease obviously under alumina,and increase,and then decrease under quartz glass and polymethyl methacrylate(PMMA).Through spectrum diagnosis,in the quartz glass medium,the vibration temperature is the highest under negative polarity pulse excitation.Under bipolar pulse,the vibration temperature does not change significantly with the change of air gap distance.For the three dielectric materials of quartz glass,alumina and PMMA,the molecular vibration temperature is the highest under the quartz glass medium with the same voltage.When the gap spacing,pulse polarity or dielectric material are changed,the rotational temperature does not change significantly.
基金the National Basic Research Program of China (No.2006CB806003)the National Natural Science Foundation of China (No.10675076)+2 种基金the Natural Science Foundation of Shandong Province (No.Y2006A21)State Key Laboratory of High Field Laser Physics,Shanghai Institute of OpticsFine Mechanics,Chinese Academy of Sciences.
文摘Propagation of a few-cycle laser pulses in a dense V-type three-level atomic medium is investigated based on full-wave Maxwell-Bloch equations by taking the near dipole-dipole (NDD) interaction into account. We find that the ratio, γ of the transition dipole moments has strong influence on the time evolution and split of the pulse: when γ≤ 1, the NDD interaction delays propagation and split of the pulse, and this phenomenon is more obvious when the value of γ is smaller; when γ =√2, the NDD interaction accelerates propagation and split of the pulse.
基金This work was supported by the Natural Science Foundation of Hebei Province under Grant No. 102090
文摘The photo-acoustic (PA) spectrum of nitrogen dioxide (NO2) in the range of 420 - 520 nm with a Nd:YAG pumped optical parametric generator and amplifier as radiation source is presented. The spectrum has a characteristic of banded structure superimposed on continuum. The banded structure of the spectrum can be assigned to NO2 B2B1← X^2A1 transition. While the continual one comes from the chaos states of the first excited state A^2B2 and the high vibration levels of the ground state X^2A1. The relationship of PA signal with buffer gas pressure and NO2 concentration is measured. The PA signal intensity increases with buffer gas pressure and almost is invariable when the buffer gas pressure is more than 3.00 × 10^4 Pa. The PA signal intensity has linearity with NO2 concentration. The detection limit is about 2×10^-5 on the basis of SNR = 1, however lower value of the detection limit can be expected by improving the apparatus properties.
基金Project supported by the National Natural Science Foundation of China and the Special Doctoral Research Foundation of the State Education Commission of China.
文摘In this paper, we have suggested an iterative procedure of optimization of the linear parameters in an analytic potential energy function for a triatomic molecule, by combining both variational and second order perturbation methods. The most important feature of this procedure is that the objective function is an analytical expression which can be optimized easily. The application to the water molecule is presented.