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        검색결과 249

        161.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        동해 연안에 위치한 대진, 갈남, 포항, 울산 등 4개 지역의 연안역을 대상으로 1994년 7월부터 1995년 4월까지 계절별로 4회에 걸쳐서 영양염과 유기물질의 분포에 관련된 환경요인, 영양염류, 부유성 유기물질 및 엽록소 함량 등을 조사하였다. BOD는 울산 처용암이 모든 정점 중에서 가장 높게 나타났으며, 영양염류의 농도는 근처에 오염원이 많은 포항과 울산의 처용암에서 전 조사기간 동안에 걸쳐 전반적으로 높았다. 특히, 처용암은 조사된 모든 영양염
        4,000원
        162.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Photo-crosslinkable polyimide(PI) which contains CF3 moiety was synthesized. Polarized UV light transformed ketone group of PI to hydroxyl group, which was confirmed by IR and UV-visible spectroscopy. We investigated the dichroic UV-absorption before and after photo-reaction with linearly polarized light. In particular we have attempted to clarify the relationship between the anisotropy of surface region and surface azimuthal anchoring energy and knew that the anchoring energy of photo-alignment PI is comparable with that of mechanical rubbing.
        4,000원
        168.
        1998.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        분자들이 용액 내에서의 cluster나 박막 내에서의 cluster와 같이 다른 cluster로 뭉쳐졌을 때, 가시광선과 자외선부근의 영역에서 fullerene C60의 전자흡수 스펙트럼 변화가 관찰되었다. 2.73eV에서 흡수 피크들이 관찰되었는데, 이러한 피크들은 독립된 분자들로부터 온 것이 아니라 분자들의 직접적인 상호작용으로부터 온 것으로 생각된다. Grained fullerene 박막에서는 흡수피크들이 3.35eV에서도 관찰되었는데 이러한 피크들은 grain의 계면에서 분자들의 상호작용으로부터 온 것으로 생각된다. 이러한 흡수의 Dichroism은 비등방성 macrostructure를 갖는 시료에서도 관찰되었다.
        3,000원
        171.
        1997.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, MEH-PPV was synthesized and MEH-PPV and its mixtures with PMMA were deposited on substrates with Langmuir-Blodgett(LB) technique and their photoluminescent char acteristics were investigated using UV-Vis absorption spectroscopy, and photoluminescence(PL) measurements. The surface morphology of the LB films of MEH-PPV and its mixture with PMMA were investigated using Atomic Force Microscopy(AFM). Electroluminescent devices using LB films were fabricated with Al and ITO as a top and bottom electrode, respectively, and their I-V characteristics were investigated.
        4,000원
        176.
        1995.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Frozen storage of the oocytes has been used in a few mammalian species including mouse, hamster, human and cattle. However, frozen4hawed oocvtes show different sperm penetration on the levels of the zona pellucida and the plasma memhrane when compared with fresh oocytes. To elucidate biological changes occurring during freezing and thawing, we examined the kinetics of sperm penetration into frozen-thawed hamster oocytes. Oocytes obtained from superovulated female golden hamsters were frozen-thawed in an autofreezer according to an established method. Fresh and frozen4hawed oocytes were fertilized in vitro with capacitated hamster spermatozoa after removing the zona pellucida. The oocytes were examined at 1, 2, 3 and 6 h postinsemination. Sperm penetration found to be 1 h delayed in frozen-thawed oocytes. Other parameters such as degree of polyspermy and decondensing sperm heads were not affected by freezing and thawing. The results suggest that freezing and thawing may cause changes in the egg membrane surface and subsequently which leads to delay in the sperm-egg fusion.
        4,000원
        180.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultra thin films of Tetra-3-hexadecylsulphamoylcopperphthalocyanine(HDSM-CuPc) were formed on various substrates by Langmuir-Blodgett method, where HDSM-CuPc was synthesized by attaching long-chain alkylamine(hexa-decylamine) to CuPc. The reaction product was identified with FT-IR, UV-visible absorption spectroscopies, elemental analysis and thin layer chromatography. The formation of Ultrathin Langmuir-Blodgett(LB) films of HDSM-CuPc was confirmed by FT-IR and UV-visible spectroscopies. A quartz piezoelectric crystal coated with LB films of HDSM-CuPc was examined as a gas sensor for N02 gas. HDSM-CuPc LB films were transferred to a quartz crystal microbalance(QCM) in the form of Z-type multilayers. Response characteristics of film-coated QCM to NO2 gas concentrations over a range of 100~600ppm have been tested with a thickness of 5~20 layers of HDSM-CuPc. Changes in frequency by adsorption of NO2 were increased With the number of LB layers and NO2 concentration, but the response time was slow.
        4,000원