He Liming

Experimental investigation of effects of airflows on plasma-assisted combustion actuator characteristics*

The effects of the airflow on plasma-assisted combustion actuator (PACA) characteristics are studied in detail. The plasma is characterized electrically, as well as optically with a spectrometer. Our results show that the airflow has an obvious influence on the PACA characteristics. The breakdown voltage and vibrational temperature decrease, while the discharge power increases compared with the stationary airflow. The memory effect of metastable state species and the transportation characteristics of charged particles in microdischarge channel are the dominant causes for the variations of the breakdown voltage and discharge power, respectively, and the vibrational temperature calculated in this work can describe the electron energy of the dielectric barrier discharge plasma in PACA. These results offer new perspectives for the use of PACA in plasma-assisted combustion.

Impacts of air pressure on the evolution of nanosecond pulse discharge products

Based on the nonequilibrium plasma dynamics of air discharge, a dynamic model of zero-dimensional plasma is established by combining the component density equation, the Boltzmann equation, and the energy transfer equation. The evolution properties of nanosecond pulse discharge (NPD) plasma under different air pressures are calculated. The results show that the air pressure has significant impacts on the NPD products and the peak values of particle number density for particles such as O atoms, O3 molecules, N2(A3) molecules in excited states, and NO molecules. It increases at first and then decreases with the increase of air pressure. On the other hand, the peak values of particle number density for N2(B3) and N2(C3) molecules in excited states are only slightly affected by the air pressure.

Density-functional investigation of 3d,4d,5d impurity doped Au6 clusters

The general features of the geometries and electronic properties for 3d, 4d, and 5d transition-metal atom doped Au6 clusters are systematically investigated by using relativistic all-electron density functional theory in the generalized gradient approximation (GGA). A number of structural isomers are considered to search the lowest-energy structures of M@Au6 clusters (M = 3d, 4d and 5d transition-metal atoms), and the transition metal atom locating in the centre of an Au6 ring is found to be in the ground state for all the M@Au6 clusters. All doped clusters, expect for PdAAu6, show large relative binding energies compared with a pure Au7 cluster, indicating that doping by 3d, 4d, 5d transition-metal atoms could stabilize the Au6 ring and promote the formation of a new binary alloy cluster.

The excitation energies and term energies of the excited states 1s2ns (n=3,4,5) and 1s2nf (n=4,5) of lithium-like systems of Z=11-20

In this paper, the full-core plus correlation (FCPC) and the Ritz method is extended to calculate the non-relativistic energies of 1s2ns (n=3,4,5) and 1s2nf (n=4,5) states and the wavefunctions of the lithium-like systems from Z=11-20. The mass-polarization and the relativistic correction including the kinetic-energy correction, the Darwin term, the electron-electron contact term and the orbit-orbit interaction are evaluated perturbatively as the first-order correction. The contribution from quantum electrodynamic is also included by using the effective nuclear charge formula. The excited energies, the term-energy and fine structure, are given and compared with the other theoretical calculation and experimental results. It is shown that the correlative wave in the FCPC method embodies well the strong correlation between the 1s2 core and the valence electron.