Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

The Skyrme energy-density functional approach has been extended to study the massive heavy-ion fusion reactions. Based on the potential barrier obtained and the parameterized barrier distribution the fusion (capture) excitation functions of a lot of heavy-ion fusion reactions are studied systematically. The average deviations of fusion cross sections at energies near and above the barriers from experimental data are less than 0.05 for 92% of 76 fusion reactions with $Z_1Z_2<1200$. For the massive fusion reactions, for example, the $^{238}$U-induced reactions and $^{48}$Ca+$^{208}$Pb the capture excitation functions have been reproduced remarkable well. The influence of structure effects in the reaction partners on the capture cross sections are studied with our parameterized barrier distribution. Through comparing the reactions induced by double-magic nucleus $^{48}$Ca and by $^{32}$S and $^{35}$Cl, the 'threshold-like' behavior in the capture excitation function for $^{48}$Ca induced reactions is explored and an optimal balance between the capture cross section and the excitation energy of the compound nucleus is studied. Finally, the fusion reactions with $^{36}$S, $^{37}$Cl, $^{48}$Ca and $^{50}$Ti bombarding on $^{248}$Cm, $^{247,249}$Bk, $^{250,252,254}$Cf and $^{252,254}$Es, and as well as the reactions lead to the same compound nucleus with Z=120 and N=182 are studied further. The calculation results for these reactions are useful for searching for the optimal fusion configuration and suitable incident energy in the synthesis of superheavy nuclei.Comment: 24 pages, 10 figures, 3 tables, accepted by Phys.Rev.

China’s 40-year Road to Innovation

Purpose The purpose of this paper is to review the evolution of policies and practice of innovation in China for the past 40 years. Design/methodology/approach This is a review paper. It adopts a different multi-dimensional, qualitative methodology to examine China’s trajectory of innovation from the economic reform since 1978, highlighting ‘China’ experiences in the developing innovation-driven economy, also pointing the challenges that China faces in this transition process and future prospects. The analysis of China’s innovation performance was based mostly on secondary data from sources and institutions that use statistical data to build country rankings, such as Global Innovation Index (GII) and Global Competitiveness Index (GCI). Findings It is found that the institutional foundations of national innovation system in China are already being laid, and so far, China has made extraordinary progress regarding innovation performance from country to region and from business to individual. However, some critical challenges in its innovation-driven development still need urgent attention and effective efforts to reinforce them. Originality/value This paper aims to fill the gap in the literature by providing an overview of the evolution of the policies and practices of innovation development in China since the 1978 economic reforms, and explores the Chinese experiences in transforming into an innovation-driven economy

Further Development of the Improved QMD Model and its Applications to Fusion Reaction near Barrier

The Improved Quantum Molecular Dynamics model is further developed by introducing new parameters in interaction potential energy functional based on Skyrme interaction of SkM$^{*}$ and SLy series. The properties of ground states of selected nuclei can be reproduced very well. The Coulomb barriers for a series of reaction systems are studied and compared with the results of the proximity potential. The fusion excitation functions for a series of fusion reactions are calculated and the results are in good agreement with experimental data.Comment: 17 pages, 10 figures, PRC accepte