A zero-dimensional model is used for studying the behavior of main particle species in atmosphere plasmas with different ionization degrees. The electron lifetimes are obtained for different initial density in an afterglow plasma, and the temporal evolutions of the main charged and neutral species are presented. The results show that the electron number density decays fast, and the lifetimes decrease with ionization degree increasing. Some important neutral species such as O, N, O3 and NO are also analyzed with ionization degree increasing.

A zero-dimensional model is used for studying the behaviors of NOx in atmosphere plasmas with different ionization degrees. The temporal evolutions of NOx (including NO, NO+, NO2, NO2+, N2O, N2O+, NO3 and N2O5), N and O3, the main important reactants which influence the producing and the consuming of NOx, are obtained in different initial densities for afterglow plasmas. The results show that the removal rates of NO and NO2 are higher when ne0=109 cm-3, and the total nitrogen oxide density is lower, so it is suited for the removal of the pollution of NOx. Some important reactants such as N and O3 varying with the increase of ionization degree are also analyzed.

Structural stability,electronic and optical properties of Ni-doped silicon nanowires are investigated by first-principles calculations based on the density functional theory. The results show that Ni can preferentially occupy substitutional sites near the surface of silicon nanowire. The doping of Ni atom in silicon nanowire introduces the impurity levels. The impurity level is mainly contributed by Ni 3d orbital. The decrease of the band gap results from the coupling of Ni 3d and Si 3p states. A strong absorption peak occurs in the low energy region of Ni-doped silicon nanowire,accompanied by the widening of the absorption band.

A zero-dimensional model which includes 56 species of reactants and 427 reactions is used to study the behavior of charged particles in atmospheric plasmas with different ionization degrees at low altitude (near 0 km). The constant coefficient nonlinear equations are solved by using the Quasi-steady-state approximation method. The electron lifetimes are obtained for afterglow plasma with different initial values, and the temporal evolutions of the main charged species are presented, which are dominant in reaction processes. The results show that the electron number density decays quickly. The lifetimes of electrons are shortened by about two orders with increasing ionization degree. Electrons then attach to neutral particles and produce negative ions. When the initial electron densities are in the range of 10 10 ∼ 10 14 cm −3 , the negative ions have sufficiently high densities and long lifetimes for air purification, disinfection and sterilization. Electrons, O − 2 , O − 4 , CO − 4 and CO − 3 are the dominant negative species when the initial electron density ne0 ≤ 10 13 cm −3 , and only electrons and CO − 3 are left when ne0 ≥ 10 15 cm −3. N + 2 , N + 4 and O + 2 are dominant in the positive charges for any ionization degree. Other positive species, such as O + 4 , N + 3 , NO + , NO + 2 , Ar + 2 and H3O + • H2O, are dominant only for a certain ionization degree and in a certain period.

A zero-dimensional model is used to study the processes of physical and chemical reactions in atmospheric plasma with different ionization degrees near the ground (0 km). The temporal evolutions of CO, CO2 and other main reactants (namely OH and O2), which affect the conversion of CO and CO2, are obtained for afterglow plasma with different initial values. The results show that the consumption rate of CO is largest when the initial electron number density ne0=10 12 cm −3 , i.e. the ionization degree is 0.000004%. The number density of CO2 is relatively small when ne0=10 16 cm −3 , i.e. the ionization degree is 0.04%, whereas they are very close under the condition of other ionization degrees. Considering the total number densities of CO and CO2 and the consumption rate of CO comprehensively, the best condition is ne0=10 13 cm −3 , i.e. the ionization degree is 0.00004% for reducing the densities of CO and CO2 in the atmospheric plasma. The temporal evolutions of N + , Ar + , CO + and CO + 2 are also shown, and the influences on the temporal evolutions of CO and CO2 are analyzed with increasing ionization degree.