Advanced Materials Research Vol. 507

Abstract: (Sr₂FeMoO₆)_1-x/(CeO₂)_x composites with nanosized crystallite were prepared by Sr₂FeMoO₆ obtained from the sol-gel method and nanosized CeO₂ powders. The magnetoresistance of composites increase with the CeO₂ increasing. And the MR ratio at 10 K is 1.23%, and 2.48% for the x = 0.05 and 0.2 samples with H = 1 kOe, which are 1.25 times and 2.53 times as large as that for pure Sr₂FeMoO₆, respectively. The enhanced magnetoresistance was attributed to the spin-dependent tunneling at the interface of grain boundaries.

Abstract: The Ni/Carbon nanotubes (CNTs) composites for supercapacitor electrode have been synthesized by electroless deposition method. The morphology and structure of Ni/CNTs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The nano-size Ni particles coated the surface of carbon nanotubes. Electrochemical performances of the synthesized composites were investigated by cyclic voltammetry and galvanostatic charge/discharge measurement. The specific capacitance of prepared electrode is up to 281 F/g, which is much higher than acetylene black electrode and pure carbon nanotubes electrode, indicating an effective path for increasing specific capacitance of carbon materials for the appplication of supercapacitors.

Abstract: The study on the photonic crystal fibers becomes a new research field of fiber optics in recent years, and the bandgap properties of the photonic crystal fibers are the main different points different from those of the general optical fibers. This paper performs the analysis on the bandgap properties of the photonic crystal fibers with the triangular nonair-silica structures by use of the full-vector plane-wave expansion method, focusing on the effect of the dielectric materials filled in the holes on the existence of photonic bandgaps.

Abstract: This article used thiosemicarbazide and para-pyridinecarboxylic acid to carry out reaction and synthesized 5-(4-pyridyl)-2-amino-1,3,4-thiadiazole, and then reacted with benzoyl isocyanate to synthesize a new type of urea biological active meterial. The structure of the target compound was confirmed by IR, 1H NMR and elemental analysis. The preliminarily biological activity tests show that the target compound has an activity as plant growth regulator, it’s activity as auxin is 19.3% and it’s activity as cytokinin is 27.4%.

Abstract: The adsorption hydrogen molecule on intrinsic and Al-doped graphene was studied by density functional theory calculations. The results show that the intrinsic graphene is not an ideal hydrogen storage material. Compared with the intrinsic, H2 molecules are stongly adsorbed onto the Al-doped graphene with higher adsorbed energy and shorter distance between H2 and surface. The band structure and density of states results show that between hydrogen and other atoms, the charge transfers are apparent increased. All are help for hydrogen adsorption. Therefore, Al-doped graphene is a promising candidate for hydrogen storage material.

Abstract: In this paper, the ceramic samples of La₂Mo₂O₉ and La₂Mo_2-xGa_xO _9-δ(x=0.1,0.2)were prepared by conventional solid-state reaction method. The reducibility of pure La2Mo2O9 and La₂Mo_2-xGa_xO _9-δ(x=0.1,0.2) samples were studied in the reducing atmosphere of 5%H2+Ar by means of impedance spectroscopy measurement. For the La₂Mo_2-xGa_xO_9-δ(x=0.1,0.2) the difference between the conductivity in the reducing atmosphere and the one in air is small, indicating that partial substitution of Ga for Mo is effective to improve the reducibility of La₂Mo_2-xGa_xO_9-δ(x=0.1,0.2).

Abstract: Nickel oxide/yttrium stabilized zirconia (NiO/8YSZ) anodes with different amounts of pore formers for anode used for solid oxide fuel cell have been prepared by aqueous tape casting technique. The zeta potential of NiO/8YSZ aqueous suspensions with and without dispersants was characterized. Moreover, the viscosity of NiO/8YSZ aqueous suspensions with different amount of dispersants and pore formers were studied by the concentric cylindrical rotational viscometer. The microstructures of the anode with different amounts of pore formers were also studied by SEM. The electrochemical performance of the single cell with different amounts of pore formers( modified by 0.8 wt% of polyvinyl pyrrolidone (PVP) over graphite) was evaluated between 700 and 800 °C with hydrogen as the fuel and air as the oxidant. It was observed that the maximum power density of the single cell with the optimum amount of graphite content (20wt%) measured was over 0.8 Wcm-2 at 800 °C and the area specific resistance value was as low as 0.79Ωcm2. The study allowed identifying optimum amount of graphite modified by PVP as the most promising pore formers for the production of supporting anodes prepared by aqueous tape casting for intermediate temperature solid oxide fuel cell application.

Abstract: Research the application of nano materials in tennis rackets. This paper reviews the material development for tennis rackets and analyzes the differences of performance and price of various materials. It then summarizes the current application of nano material in tennis rackets and its pros and cons, and finally proposes reasonable usages of nano material, providing reference for the scientific development of nano tennis rackets. We can draw the conclusion that the application of nano materials in tennis has improves the performance of tennis rackets and promotes the scientific, personalized and humanized development of tennis, but the trend is to develop safer and more desirable nano tennis rackets with appropriate nano materials.

Abstract: Using density functional theory, the equilibrium geometries of TinO2n and TinO2n-1 clusters (n=1-4) have been obtained. It suggests that the structures of these two corresponding clusters are changed slightly, except for the number of terminal oxygen atoms. The electronic properties have also been investigated. The bond between Ti and terminal oxygen atom is found to be more covalent than other Ti-O bonds. It also indicates that by deleting one terminal oxygen atom, HOMO is mainly derived from titanium atoms with least coordination, but not from singly-coordination oxygen atoms as that in the stoichiometric clusters. Highest energy levels of least-coordination Ti atoms shift highly and they become more reactive. In addition, HOMO-LUMO energy gaps and binding energies were observed. The calculated results show that the energy gaps decrease quickly, except for Ti4O7 clusters and all the binding energies are relatively large.

Abstract: This paper briefly introduces the use of sound-absorbing materials and sound-proof materials in the buildings, concisely summarizes the factors taken into account in the acoustic design, and then introduces the requirements of architectural acoustics materials in sports venues. It ultimately introduces the general requirements for acoustic measurement. Therefore, we can draw some conclusions. On the one hand, it is necessary to strengthen basic research, technical measures and organizational management practices in acoustic materials. On the other hand, we should pay more attention to transmission channels and reception conditions. At last, it is necessary to establish cooperation with various professions for comprehensive study, with a view to obtaining the best technical performance and economic benefits.