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        검색결과 4

        1.
        2011.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        에멀션 기반의 계면활성제를 이용한 주형합성법을 이용하여 산촉매로서 염산과 실리카의 전구체인 테 트라에톡시실란을 사용함으로써 메조다공성 실리카 마이크로스피어를 합성하였다. 테트라에톡시실란의 농도 증가에 의해 구형의 입자 형태가 파괴되었고, 기공구조도 크게 변하였다. 산촉매 농도 증가에 의한 구형의 입자형태 파괴 현상은 적었지만 상대적으로 작은 크기의 구형의 마이크로입자가 더 많이 생성되 었다. 하지만, 산성조건에서 입자들 간의 강한 응집현상이 나타남에 따라 낱개의 분리되어 있는 단일입자 를 얻기 위해서는 초음파 등의 후처리 과정이 필요하였다.
        4,200원
        4.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        Male and female strobilus production was assessed annually over a five-year period for a clonal seed orchard of sugi (Cryptomeria japonica D. Don) in Korea. Clonal fertility and fertility variation, expressed by both sibling coefficient and coefficient of variation in strobilus production among 40 orchard clones, were reported. Fertility varied among clones and among years, producing five-year averages per ramet of 464.3 and 971.1 for female and male strobili, respectively. The correlation between female and male strobilus production was positive in each of the five years studied and statistically significant with the exception of one poor flowering year. The clonal status number (Ns), a measure of genetic diversity, was calculated based on the observed clonal fertility variation, varying from 27.6 (N = 40) in the poorest flowering year (2002) to 35.8 in the best year (2005). On average (pooled), the relative status number was 95% of the census number (N). Variation of female fertility was higher than that of male fertility for the five consecutive years, and the status numbers of female and male parents reflected this variation. The pooled Ns estimation from all five years was higher than any single year, implying that genetic diversity would increase when seeds collected from different years are pooled. Sexual asymmetry calculations showed that clonal contributions would be balanced between genders