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        검색결과 2

        1.
        2012.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Two types of Pt nanoparticle electrocatalysts were composited on Pt nanowires by a combination of an electrospinning method and an impregnation method with NaBH4 as a reducing agent. The structural properties and electrocatalytic activities for methanol electro-oxidation in direct methanol fuel cells were investigated by means of scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry. In particular, SEM, HRTEM, XRD, and XPS results indicate that the metallic Pt nanoparticles with polycrystalline property are uniformly decorated on the electro-spun Pt nanowires. In order to investigate the catalytic activity of the Pt nanoparticles decorated on the electro-spun Pt nanowires, two types of 20 wt% Pt nanoparticles and 40 wt% Pt nanoparticles decorated on the electro-spun Pt nanowires were fabricated. In addition, for comparison, single Pt nanowires were fabricated via an electrospinning method without an impregnation method. As a result, the cyclic voltammetry and chronoamperometry results demonstrate that the electrode containing 40 wt% Pt nanoparticles exhibits the best catalytic activity for methanol electro-oxidation and the highest electrochemical stability among the single Pt nanowires, the 20 wt% Pt nanoparticles decorated with Pt nanowires, and the 40 wt% Pt nanoparticles decorated with Pt nanowires studied for use in direct methanol fuel cells.
        4,000원
        2.
        1993.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop nutrition education program that promotes eating behavior of preschool children. 118 parents of preschool children were surveyed to understand of children's food preferences and prejudices. The preference for vegetable showed the lowest score(2.345) and fruit was the favorite food(4.11). These results imply the consequence of teaching balanced diet with emphasizing vegetables for preschoolers. Thus, nutrition education program including teaching material were developed to provide the preschoolers with cognitive, affective, and psychomotor activities in order them to the familiar with vegetables. The program were consisted of following five parts: 1. Read-A-Story includes six stories with follow-up activities. 2. Grow-A-Plant gives instructions for growing vegetables. 3. Play-A-Game stimulates children's imagination and learning. 4. Take-A-Trip suggests places to visit that grow, sell, and prepare vegetables. 5. Eat-A-Treat presents easy ways to prepare and enjoy vegetables. Twenty one-Standardized recipes for vegetable dishes were also developed for preschooler's luncheon and snack in daycare center.
        4,500원