Advanced Materials Research Vols. 562-564

Abstract: To evaluate the influence of the ZnO buffer layer thickness on structural, electrical and optical properties of ZnO: Al (AZO)/ZnO bi-layer films, a series of AZO/ZnO films were deposited on the quartz substrates by electron beam evaporation. X-ray diffraction measurement shows that the crystal quality of the films is improved with the increase of the film thickness. The electrical properties results show that the resistivity decreases initial and then increases. However, optical transmittance of all the films is >80% regardless of the buffer layer thickness in the visible region. The results illustrate that the insertion of ZnO buffer layer can improve the film performance.

Abstract: The kinetics of ion exchange of taurine on D290 anion exchange resin was investigated. The uptake curves of taurine on D290 anion exchange resin were determined in batch stirred tanks, and the diffusion coefficient and the mass transfer coefficient were computed, and the effects of stirred velocity and experimental temperature on the rate of uptake of taurine on D290 resin were discussed. The results showed that with the experimental temperature and the stirred velocity increasing, the rate of uptake of taurine on D290 anion exchange resin increase. And with the increase of the experimental temperature, the diffusion coefficient and the mass transfer coefficient increase .With the increase of the stirred velocity, the diffusion coefficient increase and the mass transfer coefficient don’t be affected. Based on the Helfferich number of this system, the mass transfer process of taurine taken up on D290 resin is dominated by the film diffusion.

Abstract: In this study, the quality degradation of multi-crystalline silicon photovoltaic (PV) modules during the aging process was observed by using electroluminescence (EL) technology and IV curve measurements in order to find out the occurring timing of damages on solar cells. The influences of soldering materials and temperatures on the performance of the PV modules were also studied. Experimental data show that, high soldering temperatures which induce high thermal stress can easily lead to the power loss of the PV modules. On PV modules soldered with SnAgPb (SAP) solder, ca. 40% of module damages occurred after 25 cycles during the thermal cycling (TC) test. In contrast, there were 61.5% of damaged SnPb (SP) modules after the 25 TC. Most module damages which are attributed to the crack growth and the floating solder emerged during the soldering and encapsulation processes. In our experiment, the average power degradation of all modules was less than 10%.

Abstract: A simple preparation method of gold nanoparticle aggregates for highly active surface enhanced Raman scattering (SERS) substrates is developed by adding APS to gold sol under vigorous magnetic stirring. The optical and morphological properties of these aggregates are examined by UV-vis spectroscopy and atomic force microscopy. It is found that the SERS activity of the new synthesized gold nanoparticle aggregates is about 200 higher than that of single gold nanoparticles with Rhodamine 6G(R6G) probe.

Abstract: The conductive path formed by the interstitial Ag or substitutional Ag in HfO₂ was investigated by the Vienna ab initio. The calculated results indicated that the ordering of interstitial Ag increases the conductivity of HfO₂ by forming a conductive filament. The contribution to the electrical conductivity of Ag ions in the material of HfO₂ was investigated.

Abstract: Based on the principle of pore formation, geometric model to describe the closed-cell cellular materials is constructed. The model is tetrakaidecahedron shape with all thick edges. The dependence of relative density on microstructure of the model has been analyzed. By using finite elements method, the relative elastic modulus of the model is calculated. Wall-thickness and wall-face connective curvature radius are found to be the two independent factors affecting relative density. Nonlinearity which relative density produces on relative elastic modulus is obviously greater than one which wall thickness produces. For high and low porosity cellular materials, the materials added at the intersecting part of the wall-faces bring different influence on elastic modulus.

Abstract: The lamination defect makes the mechanical properties deterioration along the thickness of steel plate and therefore finding out the forming mechanism is of great significance for production of shipbuilding plate steel. The tensile fracture and microstructure characteristics on AH36 shipbuilding plate steel of lamination defect were studied with Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), etc. The results show that the strength-toughness properties vary widely at different thickness of the steel plate due to different ferrite grain size, and the center zone firstly yields and steps into plastic deformation stage due to coarse ferrite grain subjected to tensile stress, while the surface zone is still in elastic deformation stage due to relatively fine ferrite grain. The inconsistency of deformation and fracture leads to fracture separation, namely lamination. The continuous banded Widmanstätten structure, strip-shaped sulphide inclusions and mixed ferrite grain distributed at the center of shipbuilding plate steel create conditions for the lamination defect, which are important reasons for fracture separation. Widmanstätten structure at the center of steel plate has relationship with coarse austenite grain, and strip-shaped sulphide inclusions have relationship with centerline segregation of continuous casting slab during solidification process.

Abstract: Rare earth iodides are commonly used in ceramic metal halide (CMH) lamps, a kind of high intensity discharge (HID) lamp. Rare earth metals in the discharge plasma inside the arc tube contribute to the superb performance of CMH lamps. On the other hand, however, polycrystal alumina (PCA) arc tube corrosion due to its reaction with rare earth iodides causes the deterioration of parameter maintenance, and constrains lifetime of the lamps. In this study, PCA arc tubes with specific rare earth iodides are prepared. Aging tests up to 2000 hours are conducted to evaluate the effects of single rare earth iodides on lamp performance. Also X-ray analysis shows the corrosion content of PCA arc tube by different rare earth iodides. The result shows that PCA tubes with single rare earth iodides are more corrosive than the mixture of various rare earth iodides.

Abstract: 40Cr steel was grind-hardened on a surface grinder. The microstructure, wear resistance and wear mechanism of the grind-hardened layer were studied. The results indicate that the grind-hardened layer consists of the lath martensite and twin martensite, dislocation density is higher in the lath martensite. The microhardness is up to 670 HV0.5 and the compressive residual stresses exist in the grind-hardened layer. Compared with the matrix, the wear resistance of the grind-hardened layer is increased by 6-11 times. The wear mechanisms of the grind-hardened layer are characterized abrasive and oxidation under dry sliding conditions.

Abstract: In this paper, we present a design of a real-time computer vision system for polyurethane plate cutting line positioning and defects detection. The main defect of polyurethane plate is uneven texture which doesn’t meet the product requirements. We translate the original image to gray image and find the points with strongest gray as the cutting line, extract feathers and detect defects. The experimental results show that it is easy and effective to position cutting points and find defects of polyurethane plate, which can meet the requirements of production and has great practical value.