K-shell photoionization (PI) of Li, Be[Formula: see text] and B[Formula: see text] from ground state [Formula: see text] have been studied by using the [Formula: see text]-matrix method with pseudostates. The K-shell PI process is featured with the contributions from the core-excited metastable states or dominated by the Auger states 2Po. The resonant parameters of the Auger states 2Po and the PI cross-sections have been calculated and compared with the available experimental and theoretical works. Our results agree very well with that of the published works. It is worth noting that compared with previous theoretical calculations, our results of B[Formula: see text] show better agreements with the latest high-resolution advanced light source measurements [A. Müller et al., J. Phys. B 43 (2010) 135602].

Low-energy electron elastic scattering and impact ionization with hydrogenlike helium in Debye plasmas have been investigated by employing the exterior complex scaling method. The interactions between charged particles in the plasmas have been represented by Debye-Hückel potentials. The 1s-1s elastic collision strengths below the n = 2 excitation threshold of He + dominated by resonance structures are calculated for different screening lengths. As the screening strength increases, the resonance peaks studied [ 2 (1,0) 2

Slow positron beam are used to study defect structures in Co doped and undoped ZnO films prepared by Pulsed Laser Deposition (PLD) at 400°C, 600°C, 700°C on c-plane sapphire. Comparing with ZnO samples, Co doped ZnO samples have larger positron effective diffusion length (Leff), which change in different tendencies depending on the growth temperature. Crystal structures of the samples are investigated by X-ray diffraction (XRD) and wurtzite ZnO could be observed in Co doped samples.

Superposed-neutral-atom model and the finite-difference method (SNA-FD) are used to calculate the positron lifetime of different sizes and types of vacancy clusters in Ni3Al alloy. The calculated positron bulk lifetime in Ni3Al agrees well with the experimental results mentioned in literatures. The positron lifetimes of vacancy clusters with the same amount of vacancy but different components are also calculated. The results show that the positron lifetime is different when its components are different. The positron lifetimes of vacancy clusters with a single element but different sizes are also calculated. The result shows that the positron lifetime is almost a constant when its component is only Al vacancy, but the positron lifetime will increase at first and trend to be a constant when its component is only Ni vacancy.

The effect of microstructure on transport properties of nano-polycrystalline La0.7Sr0.3MnO3-δ films, which were prepared by DC magnetron sputtering at various working pressures and followed by air annealing at 973K for 1h, has been investigated. The result indicates that the change of working pressure can change the microstructure, metal-insulator transition temperature (TIM) and peak resistance but does not change the transport mechanism for the films. The vacancy defects have an important effect on the transport properties of the films. Higher working pressure tends to decrease the density of vacancy defects. Low vacancy defects account for the high TIM and low resistance of the films. In the region of T > TIM, the charge carriers are moving in variable range hopping mode. The behavior of resistance decreasing with the increasing of temperature at low temperature (T<23K) can be explained on the basis of thermal excitation tunneling effect. The minimum resistance results from the combined effect of the tunneling effect and intrinsic metallic transport characteristic of the films.