The frequency-tunable light,which was produced by using YAG laser to pump the dye rhodamine 590/610,was used to measure the ions number in ionization of the benzene molecules Rydberg state 5Rg|10 as a function of the ...The frequency-tunable light,which was produced by using YAG laser to pump the dye rhodamine 590/610,was used to measure the ions number in ionization of the benzene molecules Rydberg state 5Rg|10 as a function of the light intensity.Fitting the measured data by using the deduced equation from the method of spatial integration,the ionization cross section of single photon of molecule benzene 5Rg|10 was obtained to be 2.1×10-19cm2 approximately.展开更多
The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radia...The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations are obtained with the spin-coupled valence-bond approach. Electronic and vibrational state-selective differential cross sections are presented for projectile energies of 0.1, 1.0 and 10.0eV/u in the H2 orientation angles of 45° and 89°. The electronic and the vibrational state-selective differential cross sections show similar behaviours： they decrease as the scattering angle increases, and beyond a specific angle the oscillating structures appear. Moreover, it is also found that the vibrational state-selective differential cross sections are strongly orientation-dependent, which provides a possibility to determine the orientations of molecule H2 by identifying the vibrational state-selective differential scattering processes.展开更多
Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser...Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum展开更多
As a crucial parameter in the design and analysis of laser performances, stimulated emission(SE) cross-section is currently considered to be dependent on several factors, such as temperatures and eigen-polarizations f...As a crucial parameter in the design and analysis of laser performances, stimulated emission(SE) cross-section is currently considered to be dependent on several factors, such as temperatures and eigen-polarizations for anisotropic crystals. In contrast with these factors, impact of propagating directions upon SE cross-section has garnered less attention.In this paper, to investigate the SE cross-section in arbitrary propagating directions, fluorescence spectra for the transition ~4F_(3/2)→~4I_(11/2) in Nd:YVO_4 are measured in different propagating directions. Based on Fuchtbauer–Ladenburg equation model, the propagating direction-dependent SE cross-section spectra in Nd:YVO_4 are obtained for the first time, to our best knowledge. A novel concept of anisotropic SE cross-section is proposed to interpret the propagating direction-dependent effect. The experiment results reveal that for an arbitrary propagating direction the SE cross-section of e light around 1064 nm can be expressed as a superposition from two principle axial propagating directions with a weight of plane projection.展开更多
In this paper by means of the exact analytic method [1], the general solution fordynamic response of nonhomogeneous beam with variable cross section is obtained un-der arbitrary resonant load and boundary conditions. ...In this paper by means of the exact analytic method [1], the general solution fordynamic response of nonhomogeneous beam with variable cross section is obtained un-der arbitrary resonant load and boundary conditions. The problem is reduced to solvea non-positive differential equation. Generally, it is not solved by variational method.By the present method, the general solution for this problem may be written as an ana-lytic form. Hence, it is convenient for structure optimizing problem. In this paper, itsconvergence is proved. Numerical examples are given at the end of the paper. which in-dicates satisfactory results can be obtained.展开更多
In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were ...In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.展开更多
Quantum state-to-state dynamics of the N(4S) + H-2(X1+Σ) → NH(X3Σ) + H(2S) reaction is reported in an accurate novel potential energy surface constructed by Zhai et al.(2011 J. Chem. Phys. 135 104314). The time-dep...Quantum state-to-state dynamics of the N(4S) + H-2(X1+Σ) → NH(X3Σ) + H(2S) reaction is reported in an accurate novel potential energy surface constructed by Zhai et al.(2011 J. Chem. Phys. 135 104314). The time-dependent wave packet method, which is implemented on graphics processing units, is used to calculate the differential cross sections. The influences of the collision energy on the product state-resolved integral cross sections and total differential cross sections are calculated and discussed. It is found that the products NH are predominated by the backward scattering due to the small impact parameter collisions, with only minor components being forward and sideways scattered, and have an inverted rotational distribution and no inversion in vibrational distributions; both rebound and stripping mechanisms exist in the case of high collision energies.展开更多
State-to-state time-dependent quantum dynamics calculations are carried out to study F（2P） ＋ HO（2ЦП（→ O（3P） ＋ HF（1∑＋） reaction on 1^3A″ ground potential energy surface （PES）. The vibrationally resolv...State-to-state time-dependent quantum dynamics calculations are carried out to study F（2P） ＋ HO（2ЦП（→ O（3P） ＋ HF（1∑＋） reaction on 1^3A″ ground potential energy surface （PES）. The vibrationally resolved reaction probabilities and the total integral cross section agree well with the previous results. Due to the heavy-light-heavy （HLH） system and the large exoergicity, the obvious vibrational inversion is found in a state-resolved integral cross section. The total differential cross section is found to be forward-backward scattering biased with strong oscillations at energy lower than a threshold of 0.10 eV, which is the indication of the indirect complex-forming mechanism. When the collision energy increases to greater than 0.10 eV, the angular distribution of the product becomes a strong forward scattering, and almost all the products are distributed at θt = 0°. This forward-peaked distribution can be attributed to the larger J partial waves and the property of the F atom itself, which make this reaction a direct abstraction process. The state-resolved differential cross sections are basically forward-backward symmetric for v′ = 0, 1, and 2 at a collision energy of 0.07 eV; for a collision energy of 0.30 eV, it changes from backward/sideward scattering to forward peaked as v′ increasing from 0 to 3. These results indicate that the contribution of differential cross sections with more highly vibrational excited states to the total differential cross sections is principal, which further verifies the vibrational inversion in the products.展开更多
Ⅰ. INTRODUCTION The collision of ion beams with atomic or molecular target has attracted many physists, for it provides rich information, which, as shown by experiments, includes ion signals, electron signals, photon...Ⅰ. INTRODUCTION The collision of ion beams with atomic or molecular target has attracted many physists, for it provides rich information, which, as shown by experiments, includes ion signals, electron signals, photon Signals and cluster signals, etc. As for soft X-ray lasers, the information of photons and highly charged ions is spectacular.展开更多
A new technique for accurate determination of the electron and hole capture cross-sections of interface states at the insulator-semiconductor interface has been developed through measuring the initial time variation i...A new technique for accurate determination of the electron and hole capture cross-sections of interface states at the insulator-semiconductor interface has been developed through measuring the initial time variation in the carrier filling capacitance transient, and full consideration is given to the charge-potential feedback effect on carrier capture process. A simplified calculation of the effect is also given. The interface states have been investigated with this technique at the Si-SiO<sub>2</sub> interface in an n-type Si MOS diode. The results show that the electron capture cross-section strongly depends on both temperature and energy.展开更多
基金V. ACKNOWLEDGMENTS This work is supported by the National Natural Science Foundation of China （No.10674002 and No.20973001） and the Science Foundation of Anhui Education Committee （No.ZD2007001-1）.
文摘The frequency-tunable light,which was produced by using YAG laser to pump the dye rhodamine 590/610,was used to measure the ions number in ionization of the benzene molecules Rydberg state 5Rg|10 as a function of the light intensity.Fitting the measured data by using the deduced equation from the method of spatial integration,the ionization cross section of single photon of molecule benzene 5Rg|10 was obtained to be 2.1×10-19cm2 approximately.
基金supported by the National Natural Science Foundation of China (Grant Nos 10574018 and 10574020)
文摘The non-dissociative charge-transfer processes in collisions between O^3＋ and H2 are investigated by using the quantum-mechanical molecular-orbital coupled-channel （QMOCC） method. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations are obtained with the spin-coupled valence-bond approach. Electronic and vibrational state-selective differential cross sections are presented for projectile energies of 0.1, 1.0 and 10.0eV/u in the H2 orientation angles of 45° and 89°. The electronic and the vibrational state-selective differential cross sections show similar behaviours： they decrease as the scattering angle increases, and beyond a specific angle the oscillating structures appear. Moreover, it is also found that the vibrational state-selective differential cross sections are strongly orientation-dependent, which provides a possibility to determine the orientations of molecule H2 by identifying the vibrational state-selective differential scattering processes.
文摘Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum
文摘As a crucial parameter in the design and analysis of laser performances, stimulated emission(SE) cross-section is currently considered to be dependent on several factors, such as temperatures and eigen-polarizations for anisotropic crystals. In contrast with these factors, impact of propagating directions upon SE cross-section has garnered less attention.In this paper, to investigate the SE cross-section in arbitrary propagating directions, fluorescence spectra for the transition ~4F_(3/2)→~4I_(11/2) in Nd:YVO_4 are measured in different propagating directions. Based on Fuchtbauer–Ladenburg equation model, the propagating direction-dependent SE cross-section spectra in Nd:YVO_4 are obtained for the first time, to our best knowledge. A novel concept of anisotropic SE cross-section is proposed to interpret the propagating direction-dependent effect. The experiment results reveal that for an arbitrary propagating direction the SE cross-section of e light around 1064 nm can be expressed as a superposition from two principle axial propagating directions with a weight of plane projection.
文摘In this paper by means of the exact analytic method [1], the general solution fordynamic response of nonhomogeneous beam with variable cross section is obtained un-der arbitrary resonant load and boundary conditions. The problem is reduced to solvea non-positive differential equation. Generally, it is not solved by variational method.By the present method, the general solution for this problem may be written as an ana-lytic form. Hence, it is convenient for structure optimizing problem. In this paper, itsconvergence is proved. Numerical examples are given at the end of the paper. which in-dicates satisfactory results can be obtained.
文摘In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.
基金supported by the National Natural Science Foundation of China(Grant No.11074151)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM022)
文摘Quantum state-to-state dynamics of the N(4S) + H-2(X1+Σ) → NH(X3Σ) + H(2S) reaction is reported in an accurate novel potential energy surface constructed by Zhai et al.(2011 J. Chem. Phys. 135 104314). The time-dependent wave packet method, which is implemented on graphics processing units, is used to calculate the differential cross sections. The influences of the collision energy on the product state-resolved integral cross sections and total differential cross sections are calculated and discussed. It is found that the products NH are predominated by the backward scattering due to the small impact parameter collisions, with only minor components being forward and sideways scattered, and have an inverted rotational distribution and no inversion in vibrational distributions; both rebound and stripping mechanisms exist in the case of high collision energies.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504206 and 11404049)the China Postdoctoral Science Foundation(CPSF)(Grant No.2014M561259)the Ph.D.Research Start-up Fund of Shandong Jiaotong University
文摘State-to-state time-dependent quantum dynamics calculations are carried out to study F（2P） ＋ HO（2ЦП（→ O（3P） ＋ HF（1∑＋） reaction on 1^3A″ ground potential energy surface （PES）. The vibrationally resolved reaction probabilities and the total integral cross section agree well with the previous results. Due to the heavy-light-heavy （HLH） system and the large exoergicity, the obvious vibrational inversion is found in a state-resolved integral cross section. The total differential cross section is found to be forward-backward scattering biased with strong oscillations at energy lower than a threshold of 0.10 eV, which is the indication of the indirect complex-forming mechanism. When the collision energy increases to greater than 0.10 eV, the angular distribution of the product becomes a strong forward scattering, and almost all the products are distributed at θt = 0°. This forward-peaked distribution can be attributed to the larger J partial waves and the property of the F atom itself, which make this reaction a direct abstraction process. The state-resolved differential cross sections are basically forward-backward symmetric for v′ = 0, 1, and 2 at a collision energy of 0.07 eV; for a collision energy of 0.30 eV, it changes from backward/sideward scattering to forward peaked as v′ increasing from 0 to 3. These results indicate that the contribution of differential cross sections with more highly vibrational excited states to the total differential cross sections is principal, which further verifies the vibrational inversion in the products.
基金Project supported by the National Natural Science Foundation of China and the Chinese Research Association for Atomic and Molecular Data
文摘Ⅰ. INTRODUCTION The collision of ion beams with atomic or molecular target has attracted many physists, for it provides rich information, which, as shown by experiments, includes ion signals, electron signals, photon Signals and cluster signals, etc. As for soft X-ray lasers, the information of photons and highly charged ions is spectacular.
文摘A new technique for accurate determination of the electron and hole capture cross-sections of interface states at the insulator-semiconductor interface has been developed through measuring the initial time variation in the carrier filling capacitance transient, and full consideration is given to the charge-potential feedback effect on carrier capture process. A simplified calculation of the effect is also given. The interface states have been investigated with this technique at the Si-SiO<sub>2</sub> interface in an n-type Si MOS diode. The results show that the electron capture cross-section strongly depends on both temperature and energy.
