Advanced Materials Research Vols. 532-533

Abstract: This paper experimentally investigates the dynamic response of a single fuel cell under various dynamic loadings with different operating conditions. Three kinds of loadings are applied to the PEM fuel cell and they are simulated NEDC mode, simulated 10/15 mode, and modified mode. The operating conditions are set at different cell temperatures, humidification temperatures, and stoichiometric rates during each test to study the effects of these parameters on the cell performance of a PEM fuel cell. The cell performance is found increased with increasing cell temperature in the range of 45-65°C. On the other hand, there exist optimal conditions for the humidification temperature and the stoichiometric rate at 70°C/60°C and 1.5/2.0 on the anode and cathode sides, respectively.

Abstract: The zinc-based aerogel was synthesized via a sol-gel route that it was processed using Zinc chloride as precursor, polyacrylic acid as the template and propylene oxide as the gelation agent. The Zn-based aerogel is formed the length and cross-link of the zinc chloride hydroxide chain, owing to a dominant influence of PAA on the nucleation and growth position of sol nucleus. Nevertheless, ZnO aerogel was prepared with the method that the zinc-based aerogel was calcined at 400°C. Consequently, the R_WP value was in reasonable 7.35% according to X-ray diffraction pattern (XRD) refinement. The crystal system of the ZnO aerogel was monoclinic.

Abstract: A light porous unsintered building material was prepared with red mud, fly ash, silica fume as the main raw materials, mixed with a certain amount of foam and curing agent, by the technology of casting and curing at ambient conditions. The influence of different ratio of red mud to fly ash on compressive strength was studied. The microstructure properties of light porous unsintered building material were characterized by scanning electron microscopy (SEM) and then the strength mechanism was studied. The results showed that the optimum ratio of red mud to fly ash was 2:1, and for the best sample, its bulk density was 891kg•m^-3, 7d and 28d compressive strength were 8.4MPa and 14.7MPa, thermal conductivity coefficient was 0.235W•(m•K)^-1, which may have a broad application prospect in the building materials field.

Abstract: The pure barium is used as target to deposit Ba films on p-Si(111) substrates by magnetron sputtering system, then the films as-deposited are subsequently annealed by annealing furnace with various temperature. The crystal structure, surface morphology and electricity property of the films annealed are characterized by X-ray diffraction, scanning electron microscope and Hall-effect instrument, respectively. The results show the annealing temperature favoring orthorhombic BaSi₂ film growth is about 800°C.

Abstract: Ag surface doped TiO₂-SiO₂ composite films had been synthesized by the sol-gel method and doping processes, in which tetrabutyl titanate (Ti(OC₄H₉)₄) and tetraethylorthosilicate (TEOS) were chosen as the precursors and silver nitrate (AgNO₃) was chosen as silver source. The experimental results revealed that the Ag surface doped TiO₂-SiO₂ composite film was composed of uniform round-like nano-particles or aggregates with the size range of 4–10 nm. Compared with pure TiO₂ film, Ag surface doped TiO₂-SiO₂ composite film exhibited excellent photocatalytic activity. It is believed that the microstructure of the composite film is responsible for improving the photocatalytic activity.

Abstract: An organic-medium screen printing technique was applied to fabricate dye-sensitized nanocrystalline microporous TiO₂ electrodes. The TiO₂ colloid was prepared by hydrothermal method, then the colloid was mixed with anhydrous terpineol, polyacrylate, TX-100 and ethanolic solution of ethylene cellulose to prepare TiO₂ film electrodes. The cells based on these TiO₂ film electrodes exhibited good photoelectrochemical properties under 100mW/cm² illumination intensity. The overall energy conversion efficiency of 6.49% has been achieved for the resulting cells in this paper.

Abstract: It analysises the performance advantages of the green packaging materials made by synthetic paper and the feasibility that it replaces the materials made by paper and plastic, it elaborate the raw material ratio of synthetic paper material and production process, and a study on the mechanical properties of synthetic paper honeycomb paperboard was been done, it provides a theoretical basis to drive the developmental application of green packaging materials made by synthesis paper.

Abstract: The micro-displacement worktable is the main part of precise mechanical scanning systems. In the study the worktable is used for single-axis precise positioning and combines a piezoelectric driving element and monolithic flexure hinge mechanism to achieve a compact, vacuum compatible device with the resolution of 0.1nm over the range of 10um.The worktable is designed and optimized on the basis of comparing two types of parallel four-bar flexure hinge mechanism. Additionally, stiffness radio is defined for evaluating the guide performance, and good optimization result is achieved through simulation.

Abstract: The research described the status of bar code in the timber production and circulation in timber yards of forestry zone, main characteristics and some existing problems, and then proposed some technologies required by using bar code and problems that must be considered when choosing the bar code. The result in this paper laid the foundation for the application, identification and management of bar code in timber circulation.

Abstract: Air-coupled ultrasonic non-destructive testing technology, possessing the characters of complete non-contact and non-destruction, can be used in some situations in which traditional testing is hardly applicable. This article summarized the development of air-coupled ultrasonic non-destructive testing technology briefly, the main existing problems that restrict its progress are analyzed respectively from three processes, concluded and summarized the development and progress of the current solutions to these problems. People can promote the development of this technology more efficiently and directly by the research of its present development.