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Research Areas
Nuclear Physics (Nucleonic system)
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We are interested in the following 5 aspects about heavy ion reaction theory
1. Isospin dynamics in heavy ion collisions.
We developed an isospin dependent quantum molecular dynamics model which can
successfully describe heavy ion collisions induced by radioactive ion beams
(see also Phys. Rev. C61, 2000, 067601, Phys. Rev. C60, 1999, 064604, Phys. Lett.
B459, 1999 ,21-26, Phys. Rev. C 58, 1998, 2283-2291, and Phys. Rev. C64, 2001, 064315).
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2. Dynamical nuclear multifargmentation. By using the Boltzmann-Langevin equation in which the dynamical fluctuations are properly
incorporated, we found that we can evaluate physical observables such as the ones developed by the ALADIN collaboration or the MSU group with a
reasonable degree of accuracy (see also Phys. Lett. B319, 1993, 35-40, and Phys. Rev. C51, 1995, 3201-3210). |
3. Importance of shell correction energy on synthesis of superheavy nuclei. We improve the isospin dependent molecular dynamics model from
various aspects for studying the dynamical process for synthesis of superheavy nuclei at low energies. The shell correction energy of the system is calculated
by using deformed two-center shell model. The surface energy of the system is improved by introducing a switch function that combines the surface energies of
projectile and target with the one of the compound nucleus. For reaction systems induced by of 16O and 40,48C at low energies near Coulomb barrier, it is found
that the calculated fusion cross sections show a strong enhancement for the neutron-rich combinations, which can regenerate the experimental data quantitatively.
For heavy systems such as 48Ca+208Pb and 48Ca+238U, preliminary calculations show that the experimental capture cross sections can be reproduced quanlitively.
This model could pave a way for realistic predication of cross sections for synthesis of superhavey nuclei for different projectile-target systems at low energies
near Coulomb barrier in future experiments. (see also Nucl. Phys. A750, 2005, 232-244 and High Energy Physics and Nuclear Physics, 29, 2005, 41-45). |
4. Phase transitions and equation of state of nuclear matter. It is shown that nuclear multifragmentation and intermittent patterns come mainly from the spinodal region of nuclear equation of state, critical behaviour comes mainly from the spinodal region while there is a small contribution from the super-heated liquid and liquid regions by a very simple schematic model(see Z. Phys. A356, 1996, 163-170). |
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5. Static properties of neutron stars. Within the framework of Hartree-Fock theory using Skyrme effective interaction, the composition fraction of beta-stable neutron stars and their radial distributions are investigated based on Tolman-Oppenheimer-Volkoff equation (see also Chinese Phys. Lett. 18, 2001, 142-145, IOP publishing Ltd, J. Phys. G27, 2001, 1799-1805, and Chinese Sci. Bull. 47, 2002, 632-635).
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Cluster physics and Nanotechnology(Ionic + Electronic system)
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1. Classical molecular dynamics: we developed a molecular
dynamics model based on three empirical model potentials. One
found the C_{20} and C_{36} were undergoing the transition from
solid-like phase to liquid-like phase at temperatures 1900 K and
3000 K, respectively. The mechanical stability of C_{20} and C_{36}
are also studied by using this model (see also Chem. Phys. Lett. 313,
1999, 40-44 and Phys. Lett. A255, 1999, 294-300). Connecting to the
experimental observation, the formation of a linear carbon-atom chain in
the core of nano-tubes, we demonstrated an extremely high thermal stability
and high mechanical strains based on the molecular dynamics simulations
see also Phys. Rev. B61, 2000, R2472-R2474).
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2. Simplification ab initio method. By using a distance-dependent tight-binding model for computing the potential energy surface, we have developed a model of tight-binding molecular dynamics to study thermodyamical and collisional properties of sidium clusters. We shown that the formation of a prolate dimer-like (Na_n)_2 in Na_n + Na_n collisions in analogy to heavy ion collisions by using this model (see also Phys. Lett. A193, 1994, 75-81 and Z. Phys. D35, 1995, 131-139). We also predicated the far infrared spectra of sodium micro-clusters (see also Chem. Phys. Lett. 300, 1999, 595-602). We first provided some evidence for the pseudorotation of Na_4 at temperature T>200 K with the barrier height for the pseudorotation being 0.23 eV (see also Chem. Phys. Lett. 326, 2000, 461-467).
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3. Ab initio method: we are developing a nonadiabatic ab initio molecular dynamics model, which can self-consistently describe the dynamics coupled electronic and ionic degrees of freedom beyond the Car-Parrinello method and a standard Fhi96md. We studied the dipole response of the valence electrons of Na_2 which can regenerate the experimental data (see also Chinese Physics, 12, 2003, 164-168, IOP publishing Ltd). The investigations of the excitation of sodium clusters by short and intense laser pulses and highly charged particles are in progress.
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Condensed matter physics (Ionic + Electronic system) |
1. A molecular dynamics model is developed to investigated the temperature and solvent dependence of the vibrational energy relaxation and pure dephasing rates of triiodide ion. We found the triiodide loses its symmetry in water, ethanol and methanol due to formatoion of hydrogen bonds with the ion. This kind of solvent-induced symmetry breaking has analogies with mean field model of second-order phase transitions (see also Phys. Rev. Lett. 90, 2003, 185505).
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2. The depahsing and energy relaxation rates of the triiodide stretching modes were measured from a flexible model of ion. Results from perturbation theory are applied to rigid simulations to interpret the experimental and simulation data (see also Mod. Phys. Lett. A18, 2003, 406-409, Mol. Phys. 101, 2003, 1641-1649, and J. Chem. Phys. 119, 2003, 6119-6131).
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Biophysics (DNA damage induced by heavy ion irradiation) |
A multi-scale microscopic dynamic model of heavy ion interacts with biomolecule is being developed.
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Current and Recent
Projects
| 1997-1999 |
National Natural Science Foundation of China :(Grant No.19600933) |
| Properties of fermonic system in far from equilibrium states |
| 1999-2001 |
National Natural Science Foundation of China:(Grant No.19875068) |
| Structure and reaction dynamics of exotic nuclei |
| 1999-2001 |
Special Funding of National Natural Science Foundation of China for Theoretical Physics:
(Grant No.19847002) |
| Theoretical studies on nuclear physics at RIBLL |
| 2000-2005 |
Major State Basic Research Development Program of China(973 Project) :
(Grant No.G2000077407) |
| Radioactive nuclear physics and nuclear astrophysics |
| 2006-2008 |
National Natural Science Foundation of China: (Grant No.10575012) |
| Interactions of heavy ion with DNA£º a theoretical study |
2009-2011 |
PHD Program Foundation of Ministry of Education: (Grant No.200800270017) |
| Interactions of heavy ion with biomolecules£º a theoretical study |
2010-2014 |
Major State Basic Research Development Program of China(973 Project):(Grant No.2010CB832903)
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| Irradiation damage in materials at
nano/micro-meter scale |
| 2011-2014 |
National
Science Foundation for Distinguished Young Scholars:(Grant
No.11025524) |
| Heavy ion nuclear
physics |
| 2011-2012 |
Science
and Technology Cooperation Project of China and Ukraine:(Grant
No.CU08-04) |
| Atomistic simulation
of the phase transtion of nuclear matter and properties
of ionic liquids in the irradiation with heavy ions |
| 2012-2015 |
Funds
for International Cooperation and Exchange supported
by the National Natural Science Foundation of China
(NSFC) and Agence National de la Recherch (ANR) of France:(Grant
No.11161130520) |
| Time dependent
electronic dynamics in molecules and nanosystems |
| 2013-2016 |
European Commission's 7th Framework Programme (FP7-PEOPLE-2010-IRSES) (Grant No. 269131) |
| CUTE— Crystalline Undulator: Theory and Experiment (Teoretical and experimental studies of the radiation formed in crystalline undulators) |
| 2017-2021 |
key project of National Natural Science Foundation of China (Grant No.11635003) |
| Production of super-heavy and neutron-rich nuclei |
| 2022-2026 |
Key project of National Natural Science Foundation of China (Grant No.12135004) |
| Production and decay properties of new heavy mass nuclei |
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