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        검색결과 28

        1.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In the merger-driven galaxy evolution scenario, dust-obscured quasars are considered to be an intermediate population between merger-driven star-forming galaxies and unobscured quasars; however, this scenario is still controversial. To verify this, it is necessary to investigate whether dust-obscured quasars have higher Eddington ratio (λEdd) values than those of unobscured quasars, as expected in the merger-driven galaxy evolution scenario. In this study, we derive black hole (BH) masses of 10 dust-obscured quasars at z ∼ 2, during the peak period of star-formation and BH growth in the Universe, using a newly derived mid-infrared (MIR) continuum luminosity (LMIR)-based estimator that is highly resistant to dust extinction. Then, we compare the λEdd values of these dust-obscured quasars to those of unobscured type-1 quasars at similar redshifts. We find that the measured log (λEdd) values of the dust-obscured quasars, −0.06 ± 0.10, are significantly higher than those of the unobscured quasars, −0.86 ± 0.01. This result remains consistent across the redshift range from 1.5 to 2.5. Our results show that the dust-obscured quasars are at their maximal growth, consistent with the expectation from the merger-driven galaxy evolution scenario at the epoch quasar activities were most prominent in the cosmic history.
        4,000원
        7.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        톱다리개미허리노린재(Riptortus pedestris Fabricius)는 지역에 따라 사과에 심각한 경제적 피해를 야기하고 있지만, 사과에서 톱다리개미 허리노린재 친환경 방제에 대한 연구는 전무한 실정이다. 따라서, 이번 연구에서는 톱다리개미허리노린재의 집합페로몬 성분 중 (E)-2-hexenyl (Z)-3hexenoate (E2HZ3H)이 노린재검정알벌(Gryon japonicum Ashmead)과 노린재깡충좀벌(Ooencyrtus nezarae Ishii)에 미치는 영향을 조사하였다. 사과 과수원에서 E2HZ3H는 전체 과수원에 발생하는 2종의 포식기생자의 밀도에는 직접적으로 영향을 주지 않았고 이들 포식기생자의 공간분포도 변화시키지 않았다. 그러나, E2HZ3H 루어가 설치된 지역 주변에서는 2종의 포식기생자 모두 제한적으로 유인하는 것을 확인하였다. 따라서, E2HZ3H 루어는 사과 과수원 내에서 정밀방제를 목적으로 친환경 방제에 고려될 수 있을 것으로 생각된다.
        4,000원
        12.
        2017.10 구독 인증기관·개인회원 무료
        13.
        2017.04 구독 인증기관·개인회원 무료
        The female azuki bean beetle, Callosobruchus chinensis L., a worldwide notorious pest of azuki beans produces sex pheromone having two isomer compounds; (2Z,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2Z-homofarnesal) and (2E,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2E-homofarnesal). We synthesized and evaluated the attractiveness of different blends of the two isomeric compounds using Y-olfactometry in laboratory and rocket traps in the field. The attractiveness pattern of the tested blends in Y-olfactometry was found as 1:9≥6:4>9:1 of 2E-:2Z-homofarnesal. Under field condition also, the 6:4 blend was more attractive than 9:1 blend. The result ascertained the enhanced pheromonal activity of homofarnesal with the increased ratio of Z-component in the blend. This provides an opportunity to synthesize Z-rich homofarnresal with less sophisticated and economically feasible Z-selective method.
        14.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present physical properties of 24 μm galaxies detected by AKARI and Spitzer and their evolution between redshifts 0:4 < z < 2. Using multi-wavelength data from X-ray to radio observations in NEP Deep Field (for AKARI) and Subaru/XMM-Newton Deep Field (for Spitzer), we derive photometric redshift, stellar mass, star-formation rate (SFR), dust extinction magnitude and rest-frame luminosities/colors of the 24 μm galaxies from photometric SED fitting. We infer the SFRs from rest-frame ultraviolet luminosity and total infrared luminosity calibrated against Herschel photometric data. For both survey elds, we obtain complete samples with stellar mass of > 1010M⊙ and SFR of > 30M⊙=yr up to z = 2. We nd that specific SFRs evolves with redshift at all stellar masses in NON-power-law galaxies (non-PLGs) as star-formation dominant luminous infrared galaxies (LIRGs). The correlations between specific SFR and stellar mass in the Spitzer and AKARI galaxy samples are well consistent with trends of the main sequence galaxies. We also discuss nature of PLGs and their evolution.
        3,000원
        15.
        2016.10 구독 인증기관·개인회원 무료
        Ooencyrtus nezarae lshii (Hymenoptera: Encyrtidae) is a major egg parasitoid of Riptortus pedestris (F.) (Hemiptera: Alydidae). One of the components of the aggregation pheromone of R. pedestris, (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), is known to attract O. nezarae female. Response of O. nezarae females to E2HZ3H and its isomers was studied using electro-antennogram (EAG) and field tests. O. nezarae females showed higher antennal response to E2HZ3H and Z2HE3H isomers than E2HE3H and Z2HZ3H. In field tests, O. nezarae females were attracted to E2HZ3H traps, but not to Z2E3 traps. Interestingly, the blend of E2HZ3H and Z2HE3H showed significant antagonistic activities to the attraction of O. nezarae females in the field. We conclude from this study that Z2HE3H is a potent antagonist to the behavioral response of O. nezarae.
        16.
        2015.10 구독 인증기관·개인회원 무료
        18.
        2015.04 구독 인증기관·개인회원 무료
        20.
        2014.10 구독 인증기관·개인회원 무료
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