Papers by Author: X.L. Chen

Abstract: PLZT9/65/35 thick films were prepared from the solution containing PVP360 (polyvinylpyrrolidone, with average molecular weight of 360000). With the solutions, the critical thickness of a single PLZT layer could increase to ~624nm compared with 77nm-thick films prepared without PVP360. Furthermore, by adding 20~35% excess of Pb to the precursor solutions, the nano-porous rosette-like structures and a small amount of pyrochlore remnant, which were found very common in the PVP-modified films, could be eliminated. 35% Pb excess was also found to initiate liquid-phase sintering, leading to dense and crack-free films. The effect of Pb excess on the rosette removal and densification behavior of the films was discussed. Moreover, the optical and electrical properties of the PLZT films with 35% Pb excess were also studied.

Abstract: Chemical components of the soil take an important role in the structure stability. It controls the soil structure under the normal water environment such as ordinary temperature, atmospheric pressure, and slowly changing hydro-chemical environment etc. It also has an important influence on the ground subsidence and the formation of soil caves as well as the collapse of dispersive soil. Scanning Electron Microscopy(SEM), CT technology and X diffraction were used to measure the chemical damage of water to the soil structure in the laboratory. Results indicate that under normal water environment, the change of the environmental parameters is not sufficient to cause damage to the internal crystal force of mineral intergranulars and to activate atoms in crystal lattice, which leads some defects and displacement of the crystal lattice. However, it can activate linking substance of clay grains be defined as “soil mini-structure”. As the greatest contributor of soil stability, the mini-structure is the "platform" and main place in which soil stability and instability will develop.