Freon compounds are the most important material to deplete the ozone layer in thestratosphere. Under atmospheric conditions, the species which are produced bychemical and photolysis reactions of freon can directly res...Freon compounds are the most important material to deplete the ozone layer in thestratosphere. Under atmospheric conditions, the species which are produced bychemical and photolysis reactions of freon can directly result in the destruction of theozone layer. But the reaction channel and mechanism between ozone and freon arenot clear展开更多
In this paper a series of ab initio SCF and configuration calculations were reported for the ground state and excited states X^2E, A^2E,~2B_2 and ~2A_1 of allene.For ground state X^2E Jahn- Teller distorsion was discu...In this paper a series of ab initio SCF and configuration calculations were reported for the ground state and excited states X^2E, A^2E,~2B_2 and ~2A_1 of allene.For ground state X^2E Jahn- Teller distorsion was discussed and a twisted angle of 50° and a torsional barriers of 0.21—0.51 eV were derived.Based on calculated results,the experimental photoelectron spectrum of allene has been assigned.展开更多
The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the ...The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the simulation. The calculated results show that the changeof delay time will influence the shape of the photoelectron spectrum (PES), and the influence issubstantially due to the existence of the crossing between excited states and the strong laser fieldwhich will change the position of relevant curves.展开更多
This paper calculates quantum-mechanically the photoelectron energy spectra excited by attosecond x-rays in the presence of a few-cycle laser. A photoelectron laser phase determination method is used for precise measu...This paper calculates quantum-mechanically the photoelectron energy spectra excited by attosecond x-rays in the presence of a few-cycle laser. A photoelectron laser phase determination method is used for precise measurements of the pulse natural properties of x-ray intensity and the instantaneous frequency profiles. As a direct procedure without any previous pulse profile assumptions and time-resolved measurements as well as data fitting analysis, this method can be used to improve the time resolutions of attosecond timing and measurements with metrological precision. The measurement range is half of a laser optical cycle.展开更多
N-ethylpyrrole is one of ethylsubstituted derivatives of pyrrole and its excited-state decay dynamics has never been explored.In this work,we investigate ultrafast decay dynamics of N-ethylpyrrole excited to the S_(1)...N-ethylpyrrole is one of ethylsubstituted derivatives of pyrrole and its excited-state decay dynamics has never been explored.In this work,we investigate ultrafast decay dynamics of N-ethylpyrrole excited to the S_(1)electronic state using a femtosecond time-resolved photoelectron imaging method.Two pump wavelengths of 241.9 and 237.7 nm are employed.At 241.9 nm,three time constants,5.0±0.7 ps,66.4±15.6 ps and 1.3±0.1 ns,are derived.For 237.7 nm,two time constants of 2.1±0.1 ps and 13.1±1.2 ps are derived.We assign all these time constants to be associated with different vibrational states in the S_(1)state.The possible decay mechanisms of different S_(1)vibrational states are briefly discussed.展开更多
The ultrafast dynamics of water molecules excited to the two F states is studied by combining two-photon excitation and time-resolved photoelectron imaging techniques. The lifetimes of the F1A1 and F1B1 states of H2O ...The ultrafast dynamics of water molecules excited to the two F states is studied by combining two-photon excitation and time-resolved photoelectron imaging techniques. The lifetimes of the F1A1 and F1B1 states of H2O (D2O) were derived to be 1.0±0.3 (1.9±0.4) and 10±3 (30±10) ps, respectively. We propose that the F1A1 state mainly decays through the D state, due to the nonadiabatic coupling between them, while the F1B1 state decays through the F1A1 state via Coriolis interaction.展开更多
TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray ...TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray photoelectron spectrocopy studies provided that the Nls core-electron spectrum of TixAl1-xN thin film brodend with increasing Ti content, and the difference of the chemical shifts for Ti2p3/2 line between TiN and TixAl1-xN th77pj in film was 0.7 eV.展开更多
By solving the time-dependent Schr6dinger equation, the dependence of photoelectron energy spectra on the binding energy of targets, wavelength and the intensity of laser pulse is exhibited and a scaling law of kineti...By solving the time-dependent Schr6dinger equation, the dependence of photoelectron energy spectra on the binding energy of targets, wavelength and the intensity of laser pulse is exhibited and a scaling law of kinetic energy spectra of both the direct and the rescattered photoelectrons is concluded. The scaling law provides a convenient tool to determine the equivalent photoionization process of various atoms or molecules in various laser fields. The verification of the scaling law by independent methods provides incontestable support to the validity of the scaling law.展开更多
By developing a full quantum scattering theory of high-order above-threshold ionization,we study the energy spectra and the angular distributions of photoelectrons from atoms with intense laser fields shining on them....By developing a full quantum scattering theory of high-order above-threshold ionization,we study the energy spectra and the angular distributions of photoelectrons from atoms with intense laser fields shining on them.We find that real rescattering can occur many times,and even infinite times.The photoelectrons from the rescattering process form a broad plateau in the kinetic-energy spectrum.We further disclose a multiple-plateau structure formed by the high-energy photoelectrons,which absorb many photons during the rescattering process.Moreover,we find that both the angular distributions and the kinetic-energy spectra of photoelectrons obey the same scaling law as that for directly emitted photoelectrons.展开更多
In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the el...In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the electron loss caused by electron-hole recombination in latent image formation process. Through the hole-to-electron conversion, it can also release an extra electron or electron carrier, improving photosensitivity. In this paper the microwave absorption and dielectric spectrum detection technique is used to detect the time evolution behaviour of free photoelectrons generated by 35ps laser pulses in cubic AgCl emulsions doped with formate ions. The influence of different doping conditions of formate ions on the photoelectron decay kinetics of AgC1 is analysed. It is found that when the HCO2^- content is 10^-3mol/mol Ag and the doping position is 90% the electron decay time and lifetime reach their maxima due to the efficient trap of holes by formate ions.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘Freon compounds are the most important material to deplete the ozone layer in thestratosphere. Under atmospheric conditions, the species which are produced bychemical and photolysis reactions of freon can directly result in the destruction of theozone layer. But the reaction channel and mechanism between ozone and freon arenot clear
基金Project supported by the National Natural Science Foundation of China.
文摘In this paper a series of ab initio SCF and configuration calculations were reported for the ground state and excited states X^2E, A^2E,~2B_2 and ~2A_1 of allene.For ground state X^2E Jahn- Teller distorsion was discussed and a twisted angle of 50° and a torsional barriers of 0.21—0.51 eV were derived.Based on calculated results,the experimental photoelectron spectrum of allene has been assigned.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos.10474060 and 10574083) the Natural Science Foundation of Shandong Province of China (Grant No. Y2003A02).
文摘The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the simulation. The calculated results show that the changeof delay time will influence the shape of the photoelectron spectrum (PES), and the influence issubstantially due to the existence of the crossing between excited states and the strong laser fieldwhich will change the position of relevant curves.
文摘This paper calculates quantum-mechanically the photoelectron energy spectra excited by attosecond x-rays in the presence of a few-cycle laser. A photoelectron laser phase determination method is used for precise measurements of the pulse natural properties of x-ray intensity and the instantaneous frequency profiles. As a direct procedure without any previous pulse profile assumptions and time-resolved measurements as well as data fitting analysis, this method can be used to improve the time resolutions of attosecond timing and measurements with metrological precision. The measurement range is half of a laser optical cycle.
基金This work was supported by the National Natural Science Foundation of China(No.21833003 and No.21773213)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB17000000)Chinese Academy of Sciences(GJJSTD20190002).
文摘N-ethylpyrrole is one of ethylsubstituted derivatives of pyrrole and its excited-state decay dynamics has never been explored.In this work,we investigate ultrafast decay dynamics of N-ethylpyrrole excited to the S_(1)electronic state using a femtosecond time-resolved photoelectron imaging method.Two pump wavelengths of 241.9 and 237.7 nm are employed.At 241.9 nm,three time constants,5.0±0.7 ps,66.4±15.6 ps and 1.3±0.1 ns,are derived.For 237.7 nm,two time constants of 2.1±0.1 ps and 13.1±1.2 ps are derived.We assign all these time constants to be associated with different vibrational states in the S_(1)state.The possible decay mechanisms of different S_(1)vibrational states are briefly discussed.
基金supported by the National Natural Science Foundation of China (No.21573228, No.21833003, No.21673232, and No.21773236)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB17000000)
文摘The ultrafast dynamics of water molecules excited to the two F states is studied by combining two-photon excitation and time-resolved photoelectron imaging techniques. The lifetimes of the F1A1 and F1B1 states of H2O (D2O) were derived to be 1.0±0.3 (1.9±0.4) and 10±3 (30±10) ps, respectively. We propose that the F1A1 state mainly decays through the D state, due to the nonadiabatic coupling between them, while the F1B1 state decays through the F1A1 state via Coriolis interaction.
基金This work was supported by the National Natural Science Foundation of China under grant No.10474074the Hubei Natural Science Foundation under grant No.2001ABB060.
文摘TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray photoelectron spectrocopy studies provided that the Nls core-electron spectrum of TixAl1-xN thin film brodend with increasing Ti content, and the difference of the chemical shifts for Ti2p3/2 line between TiN and TixAl1-xN th77pj in film was 0.7 eV.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61078080 and 11174304)the National Basic Research Program of China (Grant Nos. 2010CB923203 and 2011CB808103)
文摘By solving the time-dependent Schr6dinger equation, the dependence of photoelectron energy spectra on the binding energy of targets, wavelength and the intensity of laser pulse is exhibited and a scaling law of kinetic energy spectra of both the direct and the rescattered photoelectrons is concluded. The scaling law provides a convenient tool to determine the equivalent photoionization process of various atoms or molecules in various laser fields. The verification of the scaling law by independent methods provides incontestable support to the validity of the scaling law.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10774513,61078080,11174304,and 11104167)the National Basic Research Program of China (Grant Nos. 2010CB923203 and 2011CB808103)
文摘By developing a full quantum scattering theory of high-order above-threshold ionization,we study the energy spectra and the angular distributions of photoelectrons from atoms with intense laser fields shining on them.We find that real rescattering can occur many times,and even infinite times.The photoelectrons from the rescattering process form a broad plateau in the kinetic-energy spectrum.We further disclose a multiple-plateau structure formed by the high-energy photoelectrons,which absorb many photons during the rescattering process.Moreover,we find that both the angular distributions and the kinetic-energy spectra of photoelectrons obey the same scaling law as that for directly emitted photoelectrons.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10354001, 60478033, and 10274017）, the Natural Science Foundation of Hebei Province of China （Grant No 603138） and the Doctorate Foundation of Hebei Province of China （Grant No B2003119）.
文摘In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the electron loss caused by electron-hole recombination in latent image formation process. Through the hole-to-electron conversion, it can also release an extra electron or electron carrier, improving photosensitivity. In this paper the microwave absorption and dielectric spectrum detection technique is used to detect the time evolution behaviour of free photoelectrons generated by 35ps laser pulses in cubic AgCl emulsions doped with formate ions. The influence of different doping conditions of formate ions on the photoelectron decay kinetics of AgC1 is analysed. It is found that when the HCO2^- content is 10^-3mol/mol Ag and the doping position is 90% the electron decay time and lifetime reach their maxima due to the efficient trap of holes by formate ions.
