• Title/Summary/Keyword: O26

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Occurrence of Natural Hybrid between Oplegnathus fasciatus and Oplegnathus punctatus from the South Sea of Korea (한국 남해에서 출현한 돌돔 (Oplegnathus fasciatus)과 강담돔 (Oplegnathus punctatus) 사이의 자연교잡종)

  • Kwun, Hyuck-Joon;Kim, Jin-Koo
    • Korean Journal of Ichthyology
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    • v.22 no.3
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    • pp.201-205
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    • 2010

  • One specimen of a natural hybrid of an Oplegnathus (Oplegnathus fasciatus $\times$ Oplegnathus punctatus) was found in Tongyeong, Korea in August 2008. We, herein, describe its morphological and genetic characteristics and compare them with those of O. fasciatus and O. punctatus. In morphology, the hybrid showed many distinctive black rounded blotches on body sides and four faint vertical bars, being in those features similar to O. punctatus. Although the counts and measurements of the hybrid mostly overlapped between O. fasciatus and O. punctatus, the Oplegnathus hybrid resembled O. punctatus in the ratio of pelvic-fin length in standard length: Oplegnathus hybrid (26.7%) was closer to O. punctatus (26.4%) than to O. fasciatus (17.2~23.6%). In genetics, as a result of analysis of 510 base pair sequences of mitochondrial DNA 16S rRNA, the hybrid was closer to O. fasciatus (d=0.000~0.010) than to O. punctatus (d=0.020). Our results suggest that the natural hybridization represented by the subject specimen occurred between an O. fasciatus female and an O. punctatus male.

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Preparation and Luminescence of Europium-doped Yttrium Oxide Thin Films

  • Chung, Myun Hwa;Kim, Joo Han
    • Applied Science and Convergence Technology
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    • v.26 no.2
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    • pp.26-29
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    • 2017

  • Thin films of europium-doped yttrium oxide ($Y_2O_3$:Eu) were prepared on Si (100) substrates by using a radio frequency (RF) magnetron sputtering. After the deposition, the films were annealed at $1000^{\circ}C$ in an air ambient for 1 hour. X-ray diffraction analysis revealed that the $Y_2O_3$:Eu films had a polycrystalline cubic ${\alpha}-Y_2O_3$ structure. The as-deposited films showed no photoluminescence (PL), which was due to poor crystalline quality of the films. The crystallinity of the $Y_2O_3$:Eu films was significantly improved by annealing. The strong red PL emission was observed from the annealed $Y_2O_3$:Eu films and the highest intensity peak was centered at around 613 nm. This emission peak originated from the $^5D_0{\rightarrow}^7F_2$ transition of the trivalent Eu ions occupying the $C_2$ sites in the cubic ${\alpha}-Y_2O_3$ lattice. The broad PL excitation band was observed at wavelengths below 280 nm, which was attributed to the charge transfer transition of the trivalent Eu ion.

  • https://doi.org/10.5757/ASCT.2017.26.2.26 인용 PDF KSCI