443 research outputs found

    An evaluation of the Hand-held Electronic Dictionaries Used by Chinese EFL Learners

    Get PDF
    PACLIC 20 / Wuhan, China / 1-3 November, 200

    Preparation of Mesoporous Yttria-Stabilized Zirconia (YSZ) and YSZ-NiO Using a Triblock Copolymer as Surfactant

    Get PDF
    Mesoporous yttria-stabilized zirconia (YSZ) and YSZ-NiO have been prepared for the first time using Pluronic P103 as a structure-directing agent and inorganic chlorides as precursors in a nonaqueous medium. After being fired at 500°C for 2 h, mesostructured YSZ has a BET surface area of about 146 m2 g-1, with an average pore size of 3.8 nm, while mesostructured YSZ-NiO has a BET surface area of about 108 m2 g-1, with an average pore size of 4.5 nm

    Preparation of Mesoporous Tin Oxide for Electrochemical Applications

    Get PDF
    Mesoporous tin oxide stable up to 500 °C has been prepared for the first time using both cationic and neutral surfactants

    Reduced-Temperature Solid Oxide Fuel Cells Fabricated by Screen Printing

    Get PDF
    Electrolyte films of samaria-doped ceria (SDC, Sm0.2Ce0.8O1.9) are fabricated onto porous NiO-SDC substrates by a screen printing technique. A cathode layer, consisting of Sm0.5Sr0.5CoO3 and 10 wt % SDC, is subsequently screen printed on the electrolyte to form a single cell, which is tested at temperatures from 400 to 600°C. When humidified (3% H2O) hydrogen or methane is used as fuel and stationary air as oxidant, the maximum power densities are 188 (or 78) and 397 (or 304) mW/cm2 at 500 and 600°C, respectively. Impedance analysis indicates that the performances of the solid oxide fuel cells (SOFCs) below 550°C are determined primarily by the interfacial resistance, implying that the development of catalytically active electrode materials is critical to the successful development of high-performance SOFCs to be operated at temperatures below 600°C

    Preparation of Mesoporous SnO\u3csub\u3e2\u3c/sub\u3e-SiO\u3csub\u3e2\u3c/sub\u3e Composite as Electrodes for Lithium Batteries

    Get PDF
    Mesoporous SnO2–SiO2 composite stable up to 600 °C with a BET surface area of 350 m2 g-1 and an average pore size of 3.4 nm is successfully prepared, which exhibits promising cycling properties as anodes for lithium batterie

    Study on Social Network for College Students\u27 Job Hunting

    Get PDF
    SNSs recruitment has caused the change of the traditional recruitment mode due to its advantages such as broad audience, quick information transmission, low recruitment cost and good interpersonal interaction. Through questionnaire survey, the paper implements on a study on the situation that the college students use social networks to find jobs. It is found that social network platforms are popular with college students, but it is not widely used in social job hunting platforms. What is more, the job hunting effect is not obvious. Meanwhile, the user information is prone to leakage, and the job hunting information provided is in poor quality. The paper proposes that the social network job hunting platforms should take measures to perfect the service content, strengthen the technical level and improve the information security for the college students. Additionally, the college students should also make reasonable choices and correctly utilize the social recruitment platform to protect the personal information security and improve the job hunting efficiency

    Distributions of Noble Metal Pd and Pt in Mesoporous Silica

    Get PDF
    Mesoporous silica nanostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalytic properties for CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors

    Distributions of Nobel Metal Pd and Pt in Mesoporous Silica

    Get PDF
    Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH4CO–CH4CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors

    Surface States in Template Synthesized Tin Oxide Nanoparticles

    Get PDF
    Tin–oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800 °C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease
    • …
    corecore