A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the dimer structure.
ZHAO Qiang1,2, ZHANG FengShou1,2,3 & ZHOU HongYu1,2 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875, China
A semiempirical molecular dynamics model is developed to study the vibrational frequen cies of uracil at very low kinetic temperature by using the Fourier transform of velocity autocorrelation func tion of trajectories of molecular dynamics simulations The finite difference harmonic method is used to as sign the vibrational frequency of each mode. The calculated frequencies are found to be in good agreement with experimental measurements. More over, we make up for the lost vibrational modes in experiments self-consistently. A total of 30 vibrationa modes and their corresponding frequencies are re ported.
WANG ZhipingZHANG FengshouZENG XianghuaZHOU HongyuGU BinCHENG Wei
In this paper a scheme for quantum secure direct communication （QSDC） network is proposed with a sequence of polarized single photons. The single photons are prepared originally in the same state （0） by the servers on the network, which will reduce the difficulty for the legitimate users to check eavesdropping largely. The users code the information on the single photons with two unitary operations which do not change their measuring bases. Some decoy photons, which are produced by operating the sample photons with a Hadamard, are used for preventing a potentially dishonest server from eavesdropping the quantum lines freely. This scheme is an economical one as it is the easiest way for QSDC network communication securely.
