Advanced Materials Research Vols. 197-198

Abstract: An industrial Ethernet based motion control system is presented in the paper. The first slave node in the line topology is responsible for the precise cyclic communication, and it will reduce the real-time requirement on the main controller. The communication protocol is implemented as Windows NDIS protocol driver, and provides higher priority than normal user mode application. In addition, the development environment and process are also discussed, through which the developer can debug the system software at a single computer in both simulated mode and real mode.

Abstract: HfTaO-based MOS capacitors with different top electrode (Ag、Au、Pt) were successfully fabricated by dual ion beam sputtering deposition (DIBSD). We presented the effect of different metal gate on the capacity, flat band voltage shift, leakage current and conduction mechanism. It has been found that the Pt-electrode capacitor exhibited the highest accumulation capacitance. In addition, the largest hysteresis loop in Pt/HfTaO/Si capacitor during the forward-and-reverse voltage sweeping from +2.5V to -2.5V was observed. The result indicates the presence of a large amount of fixed charges or oxygen vacancies exist in interface Pt/HfTaO, which is consistent with the prediction from Qf results. It is proved that even though E_ot of the Pt-electrode capacitor is lower than that of the Ag, Au-electroded, and that of leakage current still has the smallest value at a high electric field due to Pt with a high enough work function Φ_ms(Pt)=5.65eV.

Abstract: ZnO thin films were prepared by DC reactive magnetron sputtering at room temperature. Two of them were annealed with different modes under vacuum condition. One was annealed with constant temperature of 300°C ; the other was annealed with temperature rising step by step from room temperature to 300°C . By comparing the microstructure and optical properties of the as-grown and annealed samples, the effects of different annealing modes on ZnO films performances were revealed. The experiment results investigated that the sample annealed with constant temperature of 300°C has the high grain size and surface roughness. Both of the two annealing modes could release the intrinsic stresses to some degree. The optical band gap of the samples narrowed after annealing, and the two annealed samples have almost the same band gap. Strong green emissions are observed for all the samples, but the emission intensity decreased of the sample annealed with the temperature rising step by step compared with that of other samples.

Abstract: The leaching tests of heavy metals in sewage sludge were carried out under different extraction time by the solid waste extraction procedure for leaching toxicity(GB5086.2-1997) of China on the base of the contents of Zn, Cu, Pb, Cr, Mn and Ni elements. The results showed that the sludge was with higher levels of Mn and Zn, followed by Cu and Ni, while the higher toxicity of Pb and Cr was lower, in which the order from the high to low was 1152mg/kg, 987mg/kg, 274mg/kg, 132mg/kg, 104 mg/kg and 87mg/kg, respectively. The extraction time had an important effects on the leaching of heavy metals in sewage sludge, in which the Zn, Ni, Cu leaching contents of the largest in range of 0-8h and Fe, Mn were increasing all through 0-24h. Different extraction time of the leaching amount of metals was very different, which may be related to the process of adsorption/desorption, complexation/dissociation, dissolution-precipitation/co-precipitation and other reactions.

Abstract: This paper presents a theoretical study concerning the static and dynamic characteristics of high speed journal floating ring hybrid bearing compensated by interior restrictor under laminar flow and turbulent flow respectively. The turbulent flow fluid film control equations and the pressure boundary conditions of this floating ring bearing together with the restrictor flow equation are solved by using the Finite Element Method. The variation regularity of static and dynamic characteristics such as load capacity, friction power loss, stiffness, damping etc. is analyzed. By comparing the laminar flow results and turbulent flow results, it is found that the characteristics coefficients are adjacent under small Reynolds number (laminar flow is dominant). But the characteristics coefficients are discrepant under big Reynolds number (turbulent flow is dominant). So turbulence lubrication theory is more accurate to high speed floating ring bearing.

Abstract: Intergrowth-superlattice-structured SrBi₄Ti₄O₁₅–Bi₄Ti₃O₁₂ (SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization P_r of SBT–BIT films increases, while the coercive electric field E_c decreases. SBT–BIT films annealed at 700°C have a P_r value of 18.9µC/cm² which is higher than that of SBT (16.8µC/cm²) and BIT (14.6µC/cm²), and have the lowest E_c of 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.

Abstract: The failure analysis of a thermocouple thimble used in hydrogen pipeline of hydroforming cracking system is presented. In order to analyze the failure reason, detail checks and tests such as macroscopic check, chemical compositions analysis, residual stress test, mechanical property test, metallurgical structure and fracture analysis were carried out. Based on the results of investigation, the main causes of the failures are presented.