Key Laboratory at Universities of Education

Urunchi, China

Key Laboratory at Universities of Education

Urunchi, China
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Liu H.,Liaoning University of Technology | Castle R.-S.,Liaoning University of Technology | Li W.,CAS Dalian Institute of Chemical Physics | Li W.,Key Laboratory at Universities of Education | And 2 more authors.
Journal of Nonlinear Optical Physics and Materials | Year: 2016

Spatial distribution and quantum trajectory control of the molecular harmonic spectra from H2 + are theoretically investigated through the combination of a few-cycle 800nm pulse and a half-cycle pulse. Results show that by properly adding the half-cycle pulse, the harmonic cutoffs from the recombination process are extended, and the harmonic intensities from the positive-x direction are suppressed. Moreover, as the internuclear distance increased, the modulations on the harmonic spectra are reduced. The time-dependent wave function and the time-frequency analyses of the harmonic spectra are shown to explain the above physical mechanism. Further, by adding the laser pulse to the bowtie-shaped gold nanostructure separated by an air gap g = 18nm, much higher harmonic cutoff order can be obtained in the positive-x0 region. Finally, two isolated attosecond pulses with the full width at half maximum of 34as and 31as are obtained. © 2016 World Scientific Publishing Company.


Feng L.-Q.,Liaoning University of Technology | Feng L.-Q.,CAS Dalian Institute of Chemical Physics | Li W.-L.,Liaoning University of Technology | Li W.-L.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chinese Physics B | Year: 2017

The laser phase effect on the spatial distribution of the molecular high-order harmonic generation (MHHG) spectrum from H+ 2 is theoretically investigated through solving the Non-Bohn-Oppenheimer (NBO) time-dependent Schrödinger equation (TDSE). The results are shown as follows. (i) The generated harmonics from the two nuclei each present an asymmetric distribution. Particularly, when the laser phases are chosen from 0.0π to 0.6π and from 1.7π to 2.0π, the contribution from the negative-H plays a main role in harmonic generation. When the laser phases are chosen from 0.7π to 1.6π, the contribution from the positive-H to the harmonic generation is remarkably enhanced and becomes greater than that from the negative-H. The electron localization, the time-frequency analyses of the harmonic spectrum and the time-dependent wave function are shown to explain the asymmetric harmonic distribution in H+ 2 , which provides us with a method to control the electron motion in molecules. (ii) As the pulse duration increases, the asymmetric distributions of the MHHG in two H nuclei decrease. (iii) Isotope investigation shows that the asymmetric harmonic distribution can be reduced by introducing the heavy nucleus (i.e., D+ 2 ). © 2017 Chinese Physical Society and IOP Publishing Ltd.


Feng L.-Q.,Liaoning University of Technology | Feng L.-Q.,CAS Dalian Institute of Chemical Physics | Li W.-L.,Key Laboratory at Universities of Education | Liu H.,Liaoning University of Technology
Communications in Theoretical Physics | Year: 2017

Molecular harmonic spectra of H+ 2 driven by the linearly polarized laser pulses with different polarized angles have been theoretically investigated through solving the two-dimensional time-dependent Schrödinger equation. (i) Below-threshold harmonic spectra show a visible enhanced peak around the 7th harmonic (H7), which produces a red-shift phenomenon as the internuclear distance increased. Theoretical analyses show the red-shift enhanced peak is caused by the laser-induced electron transfer between the ground state and the 1st excited state of H+ 2 . (ii) Due to the two-centre interference phenomenon, the above-threshold harmonic spectra exhibit many maxima and minima. (iii) With the introduction of the polarized angle, the anomalous elliptically polarized harmonics can be found. But, with the introduction of the spatial inhomogeneous effect, not only the ellipticities of the harmonics are equal to a stable value of ϵ ∼ 0:1-0.3, but also the harmonic cutoffs are extended. As a result, four super-bandwidths of 407 eV, 310 eV, 389 eV, and 581 eV can be obtained. Time profiles of the harmonic generations have been shown to explain the harmonic characteristics. Finally, a series of elliptically polarized (ϵ ∼ 0:1-0.3) attosecond X-ray pulses with durations from 18as to 25as can be directly produced through Fourier transformation of the spectral continuum. © 2017 Chinese Physical Society and IOP Publishing Ltd.


Feng L.,Liaoning University of Technology | Li W.,Key Laboratory at Universities of Education | Liu H.,Liaoning University of Technology
International Journal of Modern Physics B | Year: 2017

Intensity enhancement of the attosecond pulse generation from the high-order harmonic spectra has been theoretically investigated through solving the three-dimensional time-dependent Schrödinger equation. It is found that with the introduction of the down-chirped pulse, the temporal frequency of the down-chirp region is decreased. As a result, the ionized electrons can receive much more energy during its acceleration in this region, showing the extension of the harmonic cutoff. Moreover, due to the multi-harmonic emission events contribute to the higher harmonics, the intensity of the harmonic cutoff from the down-chirped pulse is 1.5 orders of magnitude higher than those from the chirp-free pulse. Further, by properly introducing the asymmetric inhomogeneous effect, the plasmonic enhancement of the laser intensity in the negative direction is larger than that in the positive direction. As a consequence, the ionized electron from the down-chirp region with the negative amplitude can obtain the additional acceleration, thus leading to the further extension of the harmonic cutoff. Especially when the spatial position of the inhomogeneous field is chosen to be the negative value, due to the improved enhancement of the laser intensity, not only the harmonic cutoff is extended but also the harmonic yield is near-stable, showing a 175 eV supercontinuum with the single short quantum path contribution. Finally, by directly superposing the selected harmonics, three attosecond XUV pulses with the full widths at half maximum of 38, 35 and 36 as can be obtained, which are nearly 1.5 orders of magnitude enhancement compared with the chirp-free homogeneous field case. © 2017 World Scientific Publishing Company


Zhai H.,Henan Normal University | Li W.,Key Laboratory at Universities of Education | Liu Y.,Henan Normal University
Bulletin of the Korean Chemical Society | Year: 2014

We have reported the reaction probability, integral reaction cross section, and rate constant for the title system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Prudente et al. (Chem. Phys. Lett. 2009, 474, 18) is employed for the purpose. The calculations are carried out over the collision energy range of 0.05-1.4 eV for the two reaction channels of H + LiH → Li + H2 and Hb + LiHa → LiHb + Ha. The Coriolis coupling (CC) effect are taken into account. The importance of including the Coriolis coupling quantum scattering calculations are revealed by the comparison between the Coriolis coupling and the centrifugal sudden (CS) approximation calculations.


Li W.,Key Laboratory at Universities of Education | Zhai H.,Henan Normal University | Feng Y.,Key Laboratory at Universities of Education | Zhao J.,Key Laboratory at Universities of Education
International Journal of Quantum Chemistry | Year: 2013

In this theoretical work, we report quasiclassical dynamics predictions for the attack angle-dependence exchange processes for the H + HS (v = 0, 1; j = 0) reaction by using the new triplet 3A″ and 3A′ potential energy surfaces, respectively. The calculated quasiclassical reaction probabilities of exchange reaction channel of reaction H(D)′ + H(D)S for J = 0, 10, 20, 30, 40 are in good agreement with quantum wave packet results over the collision energy range from 0.1 to 2.0 eV on 3A″ surfaces. The attack angle dependence reaction probability of the title reactions at J = 0 are calculated, respectively, on the two surfaces. The reaction probability was found to be strongly dependent on the attack angle. It may be ascribe to the significant difference of the effective potential barrier height in the two reactions. Besides, the reaction probabilities of exchange reaction channel of reaction H(D)′ + H(D)S for J = 0, 10, 20, 30, 40 are also predicted on 3A′ surfaces. © 2013 Wiley Periodicals, Inc. Chemical reactions involving sulfur atoms and sulfur-containing species play an important role in combustion and atmospheric chemistry. Chemical stereo-dynamics can provide valuable information about relevant reactions. One stereo-dynamical effect of primary importance is the dependence of the reaction probability on the attack angle. This work analyzes barrier heights at different attack angles to obtain the influence of attack angles on the reaction probability, using new potential energy surfaces. © 2013 Wiley Periodicals, Inc.


Jiang X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Jiang X.,Key Laboratory at Universities of Education | Dong X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Dong X.,Key Laboratory at Universities of Education | And 5 more authors.
Journal of Alloys and Compounds | Year: 2015

A new vanadoborate, [Ni(en)2]6[(VO)12O6B18O39(OH)3]·5H2O, has been synthesized under a hydrothermal condition. It crystallizes into rhombohedral crystal system with centrosymmetric space group of R3¯ with a = 20.824(7) Å, c = 21.050(14) Å, Z = 3. The crystal contains a novel elliptical housing with V12B18O60 clusters. Around the housing, there is six nickel atoms coordinated with two ethylenediamine molecules. The oxidation states of vanadium in the compound are V(IV) and V(V). The characterizations by powder X-ray diffraction, infrared spectroscopy, UV-Vis diffuse reflectance spectrum, and TG curve are also described. © 2014 Elsevier B.V. All rights reserved.


Li W.-L.,Key Laboratory at Universities of Education | Bian J.-C.,Key Laboratory at Universities of Education | Yang L.,Key Laboratory at Universities of Education
Chinese Journal of Chemical Physics | Year: 2014

Based on spin-unrestricted hartree fock theory, we present the spin unrestricted multi-configuration time dependent hartree fock theory (UMCTDHF) to describe the electron correlation dynamics of systems interacting with laser field. The positive spin orbitals and the negative spin orbitals are propagated in their own subspace respectively. The spin orbital in the spin-down subspace acts with that in the spin-up subspace by the reduced density matrix and mean field operator. The ground energy is acquired by propagating the trial wave function in the imaginary time by using spin-restricted MCTDHF (RMCTDHF) and UMCTDHF respectively. Then the ionization probabilities and the electrons energies are calculated by using RMCTDHF and UMCTDHF when the laser field is present. The ionization probability calculated with UMCTDHF agrees with the previous theoretical reports very well. The UMCTDHF method is accurate and applicable for open shell system beyond the capability of the RMCTDHF method. © 2014 Chinese Physical Society.


Sun G.L.,Xinjiang Agricultural University | Sun G.L.,Key Laboratory at Universities of Education | Xu M.,Xinjiang Agricultural University | Li J.,Xinjiang Agricultural University | Mei C.,Xinjiang Agricultural University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

The objective of this study was to investigate the diurnal variation curves of the net photosynthetic rate (Pn) and relationship between diurnal changes of Pn and the impact factors in open center shape and delayed-open central leader system in Korla fragrant pear. Diurnal changes of Pn and effect of environmental factors (i,e. photosynthetic available radiation, temperature and relative humidity) and physiology factors (i,e. stomatal conductance, transpiration rate and intercellular CO2 concentration) on Pn in leaves of Korla fragrant pear were measured using LI-6400 portable photosynthesis system. The relationship between Pn and environmental factors were analyzed by regression analysis and correlative analysis. In order to investigate the effects of tree shape on net photosynthetic rate, we analyzed the relationship between chlorophyll content, specific leaf weight, other photosynthetic parameters and Pn between delayed-open central leader system and open center shape in this study. The results showed that the Pn under two different tree shapes indicated a bimodal curve of the asymmetry, and the midday depression of photosynthesis phenomenon appeared at 14:00. During the full fruit period, the delayed-open central leader system tree had obviously higher net photosynthetic rate than the open center shape tree in each stage. This phenomenon maight be double impacted by stomatal and non-stomatal factors. Diurnally, photosynthesis increased gradually with increasing light intensity and then decreased at noon. The peak of delayed-open central leader system tree leaves occurred at 11:00 and 15:30. The peak of open center shape tree leaves occurred at 11:00 and 17:00. The seasonal variation on Pn indicated the Pn is least in June in two shapes of Korla fragrant pear. The Pn increased with leaf chlorophyll (chl) content and specific leaf weight (SLW) increasing. There are positive relations, the correlation index of leaf chlorophyll (chl) content and Pn were 0.9438 and 0.8952 in two shapes of Korla fragrant pear. The photosynthetic pigment index of different kinds of tree shapes also had great differences. There were significant correlations between Pn and SLW in delayed-open central leader system and open center shape, but the later is higher than the former. Stomatal conductance (Gs), transpiration rate (Tr) and relative humidity (RH) increased in response to increasing Pn in all the treatments. Sample CO2 concentration (Cs) and intercellular CO2 concentration (Ci) decreased in response to decreasing Pn in all the treatments. Besides, the Cs, stomatal conductance (Gs), Tr, and Pn have reached highly significant at P≤ 0.01 in delayed-open central leader system. There were significant at P ≤0. 05 between Ci, air tempreture (Ta), photosynthetically active radiation (PAR), RH and Pn in delayed-open central leader system. However, the relativity of photosynthetic parameters and Pn were unconspicuous in the open center shape tree, The findings demonstrate that delayed- open central leader system tree had obviously higher sensitivity to the influence factors of net photosynthetic rate than the open center shape tree in this study.


Li W.,Key Laboratory at Universities of Education | Jiang X.,Key Laboratory at Universities of Education | Bian J.,Key Laboratory at Universities of Education | Feng Y.,Key Laboratory at Universities of Education
Computational and Theoretical Chemistry | Year: 2013

Theoretical studies of the dynamics of the title reactions have been performed with quasi-classical trajectory (QCT) method on MB3 potential energy surface. The calculated quasi-classical reaction probabilities of two reaction channels of reaction H'. +. HBr for J=0, 10, 20, 30, 40 are in good agreement with quantum wave packet results over the collision energy range from 0.1 to 2.0. eV. The agreement between quasi-classical and quantum wave packet results is remarkably good for the integral cross section of the two reaction channels of reaction H'. +. HBr. The attack angle dependent reaction probabilities of the title reactions at J=0 have also been calculated. The distribution of the reaction probabilities was found to be strongly dependent on the attack angle. Besides, the integral cross sections of two channels of reaction D'. +. DBr are predicted in this work. Validity of the QCT calculation has been examined and proved in the comparison with the quantum wave packet calculation. © 2013 Elsevier B.V.

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