Due to the nonlinearity, time-varying and load disturbance in linear servo system, the conventional PID control is hard to get an ideal control effect, this paper deduces the mathematical model of the permanent magnet linear synchronous motor (PMLSM) direct drive system, designs a fuzzy PID controller by combining fuzzy control with conventional PID control, adjust the parameters of PID controller in real time by making use of fuzzy control's ability of adjusting online. Simulation and experimental results show that the fuzzy PID controller is superior to the conventional PID controller in responsiveness, steady performance and dynamic tracking, which can shorten the positioning time, improve the system positioning accuracy.

A study is reported on the growth mechanism of YBa2Cu307 with different growth speeds by high resolution transmission microscopy (HRTEM) and analysis of the interface and thin film microstructure. Two thin films were synthesized by pulse laser deposition on [ 1001, miscut 5", SrTi03 substrate at 820 "C, one with a pulse laser frequency of 1 Hz and one with 6 Hz. Crosssections were studied by an H-9000 NAR HRTEM along the [OlO] direction. The growth process of the sample made at 1 Hz was as follows. First, distorted step flow growth occurred on a step-mediated substrate surface of 3 4 cells thickness. Second, about a 15 nm thickness of island shape growth #becomes superimposed on the area of the step flow layer. Finally, thin f i l m growth occurred but with growth fluctuation. The sample made at 6Hz showed the characteristics of island growth; the growth area of island or ball shape was of small size and dense distribution, and seemed to be a confused mosaic stack. The influence of growth speed on YBCO epitaxial f i l m microstructure was studied explicitly by HRTEM.

Carbon encapsulated Ni nanoparticles (Ni(C)) were synthesized by modified arc-discharge reactor under methane atmosphere. The presence of carbon encapsulation is confirmed by HR-TEM imaging, and Nano-diffraction. The average particle radius is typically 10.5 nm with spherical shape. The intimate and contiguous carbon fringe around these Ni nanoparticles is good evidence for complete encapsulation by carbon shell layers.Superparamagnetic property studies were performed using SQUID magnetometer for the assemblies of Ni(C) nanoparticles. The blocking temperature (TB) is determined to around 115K at 1000Oe applied field. Above TB, the magnetization M (H, T) can be described by the classical Langevin function L using the relation, M/Ms(T=0) = coth(μH/kT)- kT/μH. The particle radius can be inferred from Langevin fit (particle moment μ) and blocking temperature theory (TB), which values are a little bigger than HR-TEM observations. It is suggested, these assemblies of carbon encapsulated Ni nanoparticles have been showed typical single-domain, field-dependent superparamagnetic relaxation properties.