The dynamics of the double-channel dissociation of the NaCs molecule is investigated by using the time-dependent wave packet （TDWP） method with the ＂split operator-Fourier transform＂ scheme. At a given wavelength ...The dynamics of the double-channel dissociation of the NaCs molecule is investigated by using the time-dependent wave packet （TDWP） method with the ＂split operator-Fourier transform＂ scheme. At a given wavelength and intensity of laser pulse, the population of each state changing with time is obtained. The photo-absorption spectra and kinetic- energy distribution of the dissociation fragments, which exhibit vibration-level structure and dispersion of the wave packet, respectively, are also obtained. The results show that by increasing the laser intensity, one can find not only the band center shift of the photo-absorption spectrum, but also the change of the fragment energy. The appearance of the diffusive band in the photo-absorption spectrum and the multiple peaks in the kinetic-energy spectrum can be attributed to the effects of the predissoeiation limit and the external field.展开更多
The photo-dissociation dynamics of LiF is investigated with newly constructed accurate ab initio potential energy curves （PECs） using the time-dependent quantum wave packet method. The oscillations and decay of the ...The photo-dissociation dynamics of LiF is investigated with newly constructed accurate ab initio potential energy curves （PECs） using the time-dependent quantum wave packet method. The oscillations and decay of the wave packet on the adiabats as a function of time are given, which can be compared with the femtosecond transition-state （FTS） spectroscopy. The photo-absorption spectra and the kinetic-energy distribution of the dissociation fragments, which can exhibit the vibration-level structure and the dispersion of the wave packet, respectively, are also obtained. The investigation shows a blue shift of the band center for the photo-absorption spectrum and multiple peaks in the kinetic-energy spectrum with increasing laser intensity, which can be attributed to external field effects. By analyzing the oscillations of the wave packet evolving on the upper adiabat, an approximate inversion scheme is devised to roughly deduce its shape.展开更多
The photo-absorption cross section of aluminum was obtained from the ratio of transmission of aluminum thin-films with different area densities from 50 to 250 eV with synchrotron radiation monochromatic beam. Two samp...The photo-absorption cross section of aluminum was obtained from the ratio of transmission of aluminum thin-films with different area densities from 50 to 250 eV with synchrotron radiation monochromatic beam. Two samples with different area densities were used to minimize the uncertainty caused by the sample surface oxidation and systematic factors of the X-ray source, beamline, and detector. The experimental results are in good agreement with the published data and FEFF program calculations in general.展开更多
根据甲烷气体的吸收光谱 ,研究了用 L ED作光源的差分吸收式光纤甲烷气体传感器。选择两个同型号 L ED光源作为差分吸收信号 ,光源驱动器自动实行交替斩波。建立了气体浓度差分吸收的数学模型 ,给出了甲烷气体浓度的测量结果。实验表明...根据甲烷气体的吸收光谱 ,研究了用 L ED作光源的差分吸收式光纤甲烷气体传感器。选择两个同型号 L ED光源作为差分吸收信号 ,光源驱动器自动实行交替斩波。建立了气体浓度差分吸收的数学模型 ,给出了甲烷气体浓度的测量结果。实验表明该仪器的测量灵敏度达到 2× 10 - 4。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11074151)the Doctoral Program Foundation of Institutions of Higher Education of China(Grant No.20123704110002)
文摘The dynamics of the double-channel dissociation of the NaCs molecule is investigated by using the time-dependent wave packet （TDWP） method with the ＂split operator-Fourier transform＂ scheme. At a given wavelength and intensity of laser pulse, the population of each state changing with time is obtained. The photo-absorption spectra and kinetic- energy distribution of the dissociation fragments, which exhibit vibration-level structure and dispersion of the wave packet, respectively, are also obtained. The results show that by increasing the laser intensity, one can find not only the band center shift of the photo-absorption spectrum, but also the change of the fragment energy. The appearance of the diffusive band in the photo-absorption spectrum and the multiple peaks in the kinetic-energy spectrum can be attributed to the effects of the predissoeiation limit and the external field.
基金the International Cooperation Program for Excellent Lectures of 2008 by Shandong Provincial Education Department,Chinathe National Natural Science Foundation of China(Grant No.11074151)Fundao para a Ciência e a Tecnologia,Portugal
文摘The photo-dissociation dynamics of LiF is investigated with newly constructed accurate ab initio potential energy curves （PECs） using the time-dependent quantum wave packet method. The oscillations and decay of the wave packet on the adiabats as a function of time are given, which can be compared with the femtosecond transition-state （FTS） spectroscopy. The photo-absorption spectra and the kinetic-energy distribution of the dissociation fragments, which can exhibit the vibration-level structure and the dispersion of the wave packet, respectively, are also obtained. The investigation shows a blue shift of the band center for the photo-absorption spectrum and multiple peaks in the kinetic-energy spectrum with increasing laser intensity, which can be attributed to external field effects. By analyzing the oscillations of the wave packet evolving on the upper adiabat, an approximate inversion scheme is devised to roughly deduce its shape.
基金NSFC (10374088)Innovation Foundation of University of Science and Technology of China
文摘The photo-absorption cross section of aluminum was obtained from the ratio of transmission of aluminum thin-films with different area densities from 50 to 250 eV with synchrotron radiation monochromatic beam. Two samples with different area densities were used to minimize the uncertainty caused by the sample surface oxidation and systematic factors of the X-ray source, beamline, and detector. The experimental results are in good agreement with the published data and FEFF program calculations in general.
