검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 3

        1.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The XYZ 3-dimensional thermal conductivities of the C/C up to 2000 °C were measured by a laser flash method. Carbon fiberreinforced carbon composites (C/C) were generally developed for aerospace missions due to their excellent thermal resistivity at ultrahigh temperature. C/C must endure harsh environments such as thousands of degrees Celsius without degradation of its mechanical properties. To solve this problem, among the passive thermal protection system, we suggest a method of conducting more heat through the mono-axial direction, which resulted in ease of the thermal rise in the heat receiving part. For example, the X-43A flight applied unbalanced C/C (UCC) with different carbon fiber orientation ratios according to the XY direction in the leading edge part. To investigate the difference in thermal conductivity between unbalanced C/C (UCC) and balanced C/C (BCC), unbalanced and balanced preforms were prepared by a needle punching process, and then they were densified by pitch infiltration and a carbonization process. We compared and analyzed the effects of unbalanced C/C(UCC) and balanced C/C (BCC) structures on the thermal conductivity. We also designed the “rule of mixtures” equation for calculating thermal conductivities of each C/C using reported data of carbon fiber and graphite matrix. Our calculations of thermal conductivity ratio match the ratio of real data.
        4,000원
        3.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        MADS-box genes encode a family of transcription factors which involve in diverse developmental processes in flowering plants. Because flowering time determines the timing of transition from vegetative to reproductive stage and time to harvest, it would be a significant trait not only to plant it-self but also to breeders. The sequences and gene structures of Arabidopsis MADS-box genes are conserved in model legumes. However, complex genome structure, in soybean, makes it difficult to identify actual genes related to flowering and maturity, although QTL researches have been generally conducted. Therefore, we hypothesized that putative MADS-box genes around the flowering time and maturity QTLs would be candidate genes for those loci. In this study, after surveying 84 QTLs highly associated with maturity and flowering, the QTLs were selected if they were located near 473 putative MADS-box genes. Finally, we found the highly associated 16 SNPs at non-coding region of the putative MADS-box gene around the QTL in 28 late maturity cultivars and 28 early maturity cultivars. Furthermore, by comparing genetic diversity in the cultivated soybeans of late and early maturity groups as well as 20 wild soybeans, selection pattern during domestication was predicted.