검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 46

        41.
        2005.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present mm observations with the IRAM 30m radiotelescope of the HCN (J=1-0) and HCO+ (J=1-0) emission lines from Giant Moleculat Clouds (GMC) in the disk of the Andromeda Galaxy, The selected GMC targets have various morphology and environments, including locations within spiral arms or in interarm regions and with galactocentric radii ranging from 2.4 to 15.5 kpc over the disk. The radial distributions of the ratios HCN/CO and HCO+ /CO are discussed and their values are compared to other galaxies.
        3,000원
        43.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyvinylpyrrolidone을 포함하는 폴리이미드 전구체의 열분해 공정을 통해 탄소분자체막을 제조하였으며 열분해성 고분자를 포함하는 전구체를 통해 제조된 막의 구조 및 기체 투과 특성에 대해 연구 하였다. 열분해성 고분자를 포함하는 전구체의 열적 특성을 조사한 결과 열적으로 안정한 폴리이미드의 경우 550℃에서 분해되는 것을 확인할 수 있었으며 열분해성 고분자의 경우 400℃에서 분해가 시작되는 것을 TCA를 통해 확인하였다 제조된 탄소분자체막의 기체 투과 특성을 조사한 결과 최종 열분해 온도가 증가됨에 따라 기체 투과도는 감소하였으며 열분해성 고분자를 포함한 전구체로부터 제조된 탄소분자체막의 경우 기체 투과가 향상됨을 알 수 있었다. 열분해성 고분자를 함유하는 전구체로부터 550℃에서 열분해를 통해 제조된 탄소분자체막의 경우 O2 투과도 808 Barrer [10-10cm3 (STP)cm/cm2scmHg]과 O2/N2선택도 7을 나타내었다.
        4,000원
        45.
        1999.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have carried out high-resolution observations along one-dimensional cuts through the three Galactic super-shells GS 064-01-97, GS 090-28-17, and GS 174+02-64 in the HI 21 cm and CO J=l-0 lines. By comparing the HI data with IRAS data, we have derived the distributions of the I100 and T100 excesses, which are, respectively, the 100 μm intensity and 100 μm optical depth in excess of what would be expected from HI emission. We have found that both the I100 and T100 excesses have good correlations with the CO integrated intensity W co in all three supershells. But the I100 excess appears to underestimate H2 column density N(H2) by factors of 1.5-3.8. This factor is the ratio of atomic to molecular infrared emissivities, and we show that it can be roughly determined from the HI and IRAS data. By comparing the T100 excess with Wco, we derive the conversion factor X ≡ N (H2) /Wco ≃ 0.26 - 0.66 in the three supershells. In GS 090- 28-17, which is a very diffuse shell, our result suggests that the region with N(H2) ≾ 3 × 10 20 cm-2 does not have observable CO emission, which appears to be consistent with previous results indicating that diffuse molecular gas is not observable in CO. Our results show that the molecular gas has a 60/100 μm color temperature Td lower than the atomic gas. The low value of Td might be due either to the low equilibrium temperature or to the lower abundance of small grains, or a combination of both.
        4,500원
        46.
        1996.12 KCI 등재 SCOPUS 구독 인증기관·개인회원 무료
        Recent high resolution CO observations of normal and starburst galaxies at Owens Valley Millimeter Array are summarized. While normal disk galaxies generally show exponential distribution which follows the optical blue light, starburst galaxies are often characterized by a compact (~1 kpc) nuclear complex whose surface gas mass density is strongly correlated with the observed large infrared luminosity and thus the ongoing massive star formation.
        1 2 3