• Title/Summary/Keyword: 광반응

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Self-Sensitized Photooxygenation of Oxodipyrromethene (자체증감작용으로 인한 옥소디피로메텐의 광산소화반응)

  • Yong-Tae Park
    • Journal of the Korean Chemical Society
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    • v.24 no.2
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    • pp.146-149
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    • 1980

  • Oxodipyrromethene was degraded by a self-photosensitized reaction, similar to the degradation of bilirubin by other investigators. Photodegradation of oxodipyrromethene was faster in methanol-d4, in which the life time of singlet oxygen is longer, than in methanol. It was slower in a solvent which contained a singlet oxygen quencher. Moreover, the products from sensitized and unsensitized reactions are same.

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Enhanced photoelectrochemical property of Cu2O by controlling crystal structure and passivation with rGO (결정구조 제어 및 rGO 보호막형성으로 인한 전착된 Cu2O의 광특성 향상)

  • Kim, Mi-Seong;Yun, Sang-Hwa;Im, Dong-Chan;Yu, Bong-Yeong;Lee, Gyu-Hwan;Kim, In-Su;Im, Jae-Hong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2013.05a
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    • pp.183-183
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    • 2013

  • 본 연구는 전착법으로 형성된 $Cu_2O$ 박막의 광특성 변화를 고찰한 것이다. 0.3M $CuSO_4$과 4M Lactic acid에 4M NaOH로 전해액의 pH를 조절하여 $Cu_2O$ 박막의 결정성 및 극성을 조절하였다. $Cu_2O$ 박막의 결정성 및 극성에 따른 광특성을 고찰한 결과, 극성인 (111)면에서 광특성이 우수함을 확인하였다. 하지만, 측정시간의 증가에 따라 표면에 Cu 금속이 형성되어 광전류가 감소함을 확인 할 수 있었다. rGO는 페르미전위가 $Cu_2O$ 환원 전위보다 위쪽에 위치한다. 따라서 $Cu_2O$ 박막위에 rGO를 형성시켜 Cu 발생반응을 제한하고 광전류를 증가시키고자한다.

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Implementation and modeling of wavelength tunable all-optical clok recovery using a semiconductor-fiber ring laser (고리형 반도체-광섬유 레이저를 이용한 파장 가변형 전광 동기 신호 재생 구현과 모델링)

  • 유봉안;김동환;이병호
    • Korean Journal of Optics and Photonics
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    • v.11 no.3
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    • pp.166-170
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    • 2000

  • A wavelength tunable all-optical clock recovery using a semiconductor optical amplifier in a fiber ring cavity is proposed and demonstrated at the wavelength of 1530 nm to 1570 nm. A synchronized optical pulse train is recovered from 10 Gbps and 30 Gbps randomly generated optical pulse streams with injection locking technique. Also, the system responses to the perturbation and the input average power variation are analyzed by a large-signal model based on time-domain travelling wave equation. ation.

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A study on the amorphous s-i-n photodiode integrated with CMO IC (CMOS IC와 집적 가능한 비정질 p-i-n 광 수신기 제작에 관한 연구)

  • Kwak, Chol-Ho;Yoo, Hoi-Jun;Jang, Jin;Moon, Byoung-Yeon
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.500-505
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    • 1997

  • Experimental amorphous photodiode is fabricated on CMOS IC using a-Si:H p-i-n structure. Amorphous photodiode is scuccessfully integrated on CMOS IC using amorphous Si produced by PECVD system. The PECVD system can deposit a-Si:H at low temperature so that photodiode can be integrated with CMOS IC structure without any process incompatibility. The fabricated amorphous photodiode has a breakdown voltage of below -20 V, a leakage current of about 1 $\mu\textrm{A}$, and turn-on voltage of 0.6~0.8 V. It is demonstrated that the photocurrent of optical signal can be turned on and off by a small voltage and the fabricated amorphous p-i-n photodiode can be used as an optical switch.

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Effect of Light on the Formation of Non-Basidiocarpous Basidiospores of Ganoderma Lucidum (영지(靈芝)의 비자실체성(非子實體性) 담자포자(擔子胞子)의 형성(形成)에 미치는 광(光)의 영향)

  • Shin, Gwan-Chull;Seo, Geon-Sik
    • The Korean Journal of Mycology
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    • v.17 no.4
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    • pp.189-193
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    • 1989

  • Ganoderma lucidum formed uniquely non-basidiocarpous basidiospore (NBB) from the aerial mycelia on agar media without the normal basidiocarps. Light was necessary for NBB formation. Best sporulation was obtained at the periodic exposure of 16 hour light and 8 hour darkness for more than 8 days. Effective wave length was blue and yellow but non sporulation was induced by near U.V. light. Effective light intensity for NBB bearing appeared to be about 1,000 Lux as white light. Photomorphogenetic responses in Ganoderma lucidum were clearly different among strains of the fungus.

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Effects of Low Dose γ-Radiation on Photosynthesis of Red Pepper (Capsicum annuum L.) and the Reduction of Photoinhibition (저선량 γ선 조사가 고추의 광합성과 광 스트레스 경감에 미치는 효과)

  • Lee, Hae-Youn;Baek, Myung-Hwa;Park, Soon-Chul;Park, Youn-Il;Kim, Jae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.21 no.2
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    • pp.83-89
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    • 2002

  • The effect of low dose $\gamma$ radiation on photosynthesis and the reduction of photoinhibition in red pepper plant was investigated. The seedling height leaf width and leaf length of pepper were stimulated in plants grown from seeds irradiated with the low dose of 4 Gy. The $O_2$ evolution in the 4 Gy irradiation group was 1.5 times greater than in the control. To investigate the effect of low dose $\gamma$ radiation on response to high light stress, photoinhibition was induced in leaves of pepper by illumination of high light (900 $\mu mol/m^2/s$). Pmax was decreased with increasing illumination time by 20% in the control, while hardly decreased in the 4 Gy irradiation group. The photochemical yield of PSII, estimated as Fv/Fm, was decreased with increasing illumination time by 50% after 4 hours while Fo did not change. However, Fv/Fm in the 4 Gy irradiation group was decreased by 37% of inhibition, indicating that the photoinhibition was decreased by the low dose $\gamma$ radiation. Changes in the effective quantum yield of PSII, $\Phi_{PSII}$, and 1/Fo-1/Fm, a measure of the rate constant of excitation trapping by the PSII reaction center, showed similar pattern to Fv/Fm. And NPQ was decreased after photoinhibitory treatment showing no difference between the control and the 4 Gy irradiation group. These results showed the positive effect of low dose $\gamma$ radiation on the seedling growth and the reduction of photoinhibition.

  • https://doi.org/10.5338/KJEA.2002.21.2.083 인용 PDF KSCI