Ammonia oxidization is a critical step in the soil N cycle and can be affected by the fertilization regimes. Chinese milk-vetch (Astragalus sinicus L., MV) is a major green manure of rice (Oryza sativa L.) fields in southern China, which is recommended as an important agronomic practice to improve soil fertility. Soil chemical properties, abundance and community structures of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in a MV-rice rotation field under different fertilization regimes were investigated. The field experiment included six treatments: control, without MV and chemical fertilizer (CK); 100% chemical fertilizer (NPK); 18 000 kg MV ha-1 plus 100% chemical fertilizer (NPKM1); 18 000 kg MV ha-1 plus 40% chemical fertilizer (NPKM2); 18 000 kg MV ha-1 alone (MV); and 18 000 kg MV ha-1 plus 40% chemical fertilizer plus straw (NPKMS). Results showed that NPKMS treatment could improve the soil fertility greatly although the application of 60% chemical fertilizer. The abundance of AOB only in the MV treatment had significant difference with the control; AOA were more abundant than AOB in all corresponding treatments. The NPKMS treatment had the highest AOA abundance (1.19 x 10(8) amoA gene copies g-1) and the lowest abundance was recorded in the CK treatment (3.21 x 10(7) amoA gene copies g-1). The abundance of AOA was significantly positively related to total N, available N, NH4+-N, and NO3--N. The community structure of AOA exhibited little variation among different fertilization regimes, whereas the community structure of AOB was highly responsive. Phylogenetic analysis showed that all AOB sequences were affiliated with Nitrosospira or Nitrosomonas and all AOA denaturing gradient gel electrophoresis (DGGE) bands belonged to the soil and sediment lineage. These findings could be fundamental to improve our understanding of AOB and AOA in the N cycle in the paddy soil.

ZnO particles were prepared from Zn nanoparticles by thermal oxidation in air, over a temperature range of 500 to 900 ºC. The microstructure of ZnO was investigated by SEM and XRD, showing that the thermal oxidation temperature affected the particle growth mechanism, morphology, and microstructure. Positron annihilation spectroscopy indicated that the thermal oxidation process has an important influence on the zinc-related vacancies and their clusters in the ZnO particles.

Crystalline, electric and fracture properties of Pb(Zr0.52Ti0.48)O3 (PZT) thin films are strongly affected by annealing temperatures in rapid treatment annealing (RTA) of metal organic decomposition (MOD). X-ray diffraction (XRD), RT66A standard ferroelectric analyzer and Vickers indentation method were used to investigate the crystalline, ferroelectric and mechanical properties, respectively. PZT thin film with complete perovskite structure and best ferroelectric property can be obtained at 750 °C, however the fracture toughness was weaker than the thin films annealed at 600 °C and 650 °C. With the increase of annealing temperature from 600 °C to 750 °C, the remanent polarization and coercive field increased in the ranges 13.8~25.2 (µC/cm²) and 7.2~8.3 (kV/cm) respectively, while the fracture toughness of PZT thin films decreased from 0.49 MPam½ to 0.47 MPam½.