Shen Wen-Qing

Isoscaling of projectile-like fragments

In this paper, the isotopic and isotonic distributions of projectile fragmentation products have been simulated by a modified statistical abrasion–ablation model and the isoscaling behaviour of projectile-like fragments has been discussed. The isoscaling parameters α and β have been extracted respectively, for hot fragments before evaporation and cold fragments after evaporation. It looks that the evaporation has stronger effect on α than β. For cold fragments, a monotonic increase of α and |β| with the increase of Z and N is observed. The relation between isoscaling parameter and the change of isospin content is discussed.

Isoscaling Behaviour in the Isospin-Dependent Quantum Molecular Dynamics Model

The isoscaling behaviour is investigated in a frame of isospin-dependent quantum molecular dynamics models. The isotopic yields ratio Y2/Y1 for reactions 48Ca+48Ca and 40Ca+40Ca at different entrance channels are simulated and presented, the relationship between the isoscaling parameter and the entrance channel is analysed, the results show that α and β reduce with the rise of incident energies and increase with the impact parameter b, which can be attributed to the temperature varying of the pre-fragments in different entrance channels. The relation of α and symmetry-term coefficient Csym reveals that the chemical potential difference Δμ is sensitive to the symmetry-term coefficient Csym, and raises with the increasing Csym.

Proton Halo or Skin in the Excited States of Light Nuclei

Properties of nuclei N-13,N-15 and B-9 are investigated in the relativistic mean-field theory with NLZ and NL3 force parameters. The calculated binding energies are very close to the experimental ones. The calculations show that the first excited state (1p(1/2)) in B-9, the first excited state (2s(1/2)) in N-13 and the second excited state (2s(1/2)) in N-15 are weakly bound. In particular, for N-13 and N-15, the proton density distributions in the two above excited states have a long tail and the rms radii of the last proton are greatly larger compared with their respective matter radii. It is predicted that a proton halo exists in the first excited state of N-13 and in the second excited state of N-15, respectively. It also indicates that the first excited state in B-9 is a proton skin state.

Transmutation of nuclear wastes using photonuclear reactions triggered by Compton backscattering photons at the Shanghai laser electron gamma source

Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS), the transmutation for nuclear wastes such as Cs-137 and I-129 is investigated. It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO2 laser photons and 3.5 GeV electrons. The nuclear activities of Cs-137 and I-129 are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser. Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons, the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method.

Scale-Free Download Network for Publications

The scale-free power-law behaviour of the statistics of the download frequency of publications has been reported, for the first time to our knowledge. The data of the download frequency of publications are taken from a well-constructed web page in the field of economic physics (http://www.unifr.ch/econophysics/). The Zipf-law analysis and the Tsallis entropy method were used to fit the download frequency. It was found that the power-law exponent of rank-ordered frequency distribution is ?~0.38?0.04, which is consistent with the power-law exponent ?~3.37?0.45 for the cumulated frequency distributions. The preferential attachment model of Barabasi and Albert network has been used to explain the download network.The scale-free power-law behavior of the statistics of the download frequency of publications has been, for the first time, reported. The data of the download frequency of publications are taken from a well-constructed web page in the field of economic physics (http://www.unifr.ch/econophysics/). The Zipf-law analysis and the Tsallis entropy method were used to fit the download frequency. It was found that the power-law exponent of rank-ordered frequency distribution is

Study on excitation function and isospin dependencies of total reaction cross section via the Boltzmann-Uehling-Uhlenbeck model

\gamma \sim 0.38 \pm 0.04

One-Proton Halo Structure in 23Al

which is consistent with the power-law exponent

Total reaction cross section in an isospin-dependent quantum molecular dynamics model

\alpha \sim 3.37 \pm 0.45

Possible 1d(5/2) and 2s(1/2) level inversion in the proton-rich nucleus Al-23

for the cumulated frequency distributions. Preferential attachment model of Barabasi and Albert network has been used to explain the download network.

Scaling of anisotropic flows and nuclear equation of state in intermediate energy heavy ion collisions

The excitation function and isospin dependencies of sigma(R) have been investigated by using the Boltzmann-Uehling-Uhlenbeck (BUU) model with a square-type density distribution. When the width parameter of the square distribution is obtained by fitting sigma(R) at relativistic energies, the BUU-model can reproduce the experimental data at intermediate energies better than Glauber model. The systematical underestimation of sigma(R) at intermediate energy by Glauber model was removed out now by BUU calculation framework. It is also found that sigma(R) is sensitive to nuclear equation of state and sigma(NN)(in-medium). The difference factor d defined in text is sensitive to the nuclear structure such as neutron halo and neutron skin, etc.