The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-w...The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.展开更多
This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on...This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on spatial correlation are synthesized.A two-scale modeling method of seismic random field is proposed.In large scale,the seismic ground motion field on bedrock surface is simplified to a two-dimensional spherical wave field based on the seismic point source and homogeneous isotropic media model.In small scale,the seismic ground motion field on the engineering site has a plane waveform.By introducing the physical models of seismic source,path and local site and considering the randomness of the basic physical parameters,the random model of seismic ground motion field is completed in a random functional form.This model is applied to simulation of the acceleration records at SMART-1 array by using the superposition method of wave group.展开更多
基金Li-hang Li thanks Dr. Yin Huang for assistance. The project is supported by the Specialized Research Fund for the Doctoral Program of Higher Education （No.20130041120053）, SRF for ROCS, SEM, the Sci- ence and Technology Research Funds of the Depart- ment of Education of Liaoning Province （L2013014）, the National Magnetic Confinement Fusion Science Pro- gram （No.2013GB109005）, the Fundamental Research Funds for the Central Universities （DUT12RC（3）60）, and the NationM Natural Science Foundation of China （No.21473018, No.10974024, and No.11274056）.
文摘The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.
基金supported by the Funds for Creative Research Groups of China (Grant No. 50621062)
文摘This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on spatial correlation are synthesized.A two-scale modeling method of seismic random field is proposed.In large scale,the seismic ground motion field on bedrock surface is simplified to a two-dimensional spherical wave field based on the seismic point source and homogeneous isotropic media model.In small scale,the seismic ground motion field on the engineering site has a plane waveform.By introducing the physical models of seismic source,path and local site and considering the randomness of the basic physical parameters,the random model of seismic ground motion field is completed in a random functional form.This model is applied to simulation of the acceleration records at SMART-1 array by using the superposition method of wave group.
