Advanced Materials Research Vols. 415-417

Abstract: Nanoscale ZnO has received considerable attention due to its remarkable properties like absorbing wave. Foam glass containing nano-ZnO can enhance the property of wave absorbing. Investigating the morphology of nano-ZnO and researching the moderate amount of Zn filler in the foam glass are important. In the work, Zn filler was added into the porous glass to grow the nano-ZnO with no catalyst by Vapor-Solid mechanism. Foam glasses were fabricated by sintering mixture of pure foam glass raw material and Zn powder. The patterns of nano-ZnO were investigated by scanning electron microscope (SEM). Meanwhile, the detail of the growth mechanism of ZnO in foam glass was analysed. The results indicate that with the content of Zn increased, the granular nano-crystals become more, and the crystal whiskers become less, shorter, and a little thicker in pores. The diameter of the whiskers is about 50 nm. What’s more, the size of pores become small as Zn mass ratio increasing.

Abstract: Citrate hydrolyzing method was used to prepare nano-LiAlO₂ powder, and the technological parameters were optimized by orthogonal experiment. The minimum size of LiAlO₂ powder was about 100nm, obtained when the green performs were sintered at 690°C for 2h, with the molar ratio of citric acid and metal-salt of 1:1 and concentration of Li⁺ of 0.5mol/L. XRD and SEM were used to examine the phase composition, particle size and microstructure. The LiAlO₂ powder had been agglomerated during the sintering process.

Abstract: Nanocrystalline porous Cu films were prepared on glass subtrates by sol-gel spin coating technique with copper(II) acetate as raw material and NH(C₂H₂OH)₂ as chelating agent. The characteristics of films were analyzed by IR, TG-DTG, XRD and SEM. The structure of Cu films was remarkable influenced by sol concentration and PEG content. The effects of calcining temperature and the way of the gelation on grain size were discussed. The results showed that the pore size and density are homogeneous when the sol concentration was 0.6 mol/L and the PEG content was 0.35 g.

Abstract: Laboratory-scale carbon anodes were produced by a new method of high-temperature mould pressing, and their physico-chemical properties were studied in laboratory. The results showed that the bulk density of carbon anodes produced by high-temperature mould pressing are 1.61-1.63g/cm³, they are higher than industrial carbon anode by 0.06 g/cm³, but the specific electrical resistance is higher and crushing strength is lower.

Abstract: Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Abstract: Analyze the dynamic characteristics of long tooth height gear transmission system by using transfer-matrix method. Firstly, set up a calculation model of level 2 transmission system for long tooth height gear and master gear and construct the transfer equation and transfer matrix of all components, then calculate the rigidity and rotational inertia of the system and know the natural frequency and dominant mode of the whole system through the computer, at last, analyze and compare two systems and prove the superiority of long tooth height gear for reducing vibration and lowering noise.

Abstract: La_1-xSr_xMnO₃ (x=0.2, 0.04)/Si PN heterostructures were prepared by RF magnetron sputtering method, which have evident rectifying properties. Furthermore, the excellent rectifying properties are presented in a relatively wide temperature range for La_0.8Sr_0.2MnO₃/Si heterostructures. The diffusion voltage decreases with increasing the temperatures, which is attributed to the modulation of the interfacial electronic structure of the heterostructures.

Abstract: Sodium hydroxymethyl lignosulfonate (NaHLS) was prepared by hydroxymethylation of sodium lignosulfonate (NaLS) and formaldehyde to enhance the performance as drilling fluids additive. The performances of the modified drilling fluid with NaLS and NaHLS, such as rheology behavior, filtration reducer and inhibitive ability were evaluated. The results indicate that the NaHLS can enhance the viscosity at low temperature, reduce the viscosity after ageing under 180 °C, which is more effective than that of NaLS. And NaHLS reduces the filtration, as the thickness of the modified fluid mud-cake is much thinner than that of NaLS. Besides, the inhibitive ability of NaHLS for clay hydrous disintegration is more effective than that of NaLS. The properties make NaHLS a potentially effective drilling mud additive.

Abstract: YVO ₄:Dy ³⁺ nanorods were synthesized via a solvothermal route at 150°C. The as-prepared products were investigated using the X-ray powder diffraction, transmission electron microscopy, and photoluminescence spectroscopy. The results showed that the average particle sizes of these nanorods are from 20 to 600 nm. The photoluminescence (PL) measurements showed that these nanorods exhibited improved photoluminescence compared with YVO ₄:Dy ³⁺ irregular nanoparticles. It is found that the appropriate calcinations temperature is helpful to improve the yellow emission.

Abstract: Under the natural ventilation conditions, two stage nitrogen oxides (NO_x), carbon monoxide (CO) and total suspended particles (TSP) in the air of GuanJiao tunnel were monitored. GuanJiao tunnel is located in plateau region and diesel traction trains run through it. Time and space distribution of NO_x, CO and TSP content in the tunnel were analyzed. The results show that the harmful gas concentration of freight train is higher than passenger train under the natural ventilation conditions. 15 min after the train run through the tunnel, NO_x concentrations were less than 2 mg/m3, CO concentrations were less than 3mg/m³, which meet the standard operating ventilation of the ‘operational railway tunnel ventilation design specifications’ (TB10068-2000).