• 전기화학회지
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• 제12권3호
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• pp.234-238
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• 2009

In the excitation spectra of $YNbO_4$ : $Eu^{3+}$, the charge transfer (CT) band around 270 nm due to $[NbO_4]^{3-}$$-Eu^{3+}$ interaction and sharp excitation peaks by f-f transition of $Eu^{3+}$ strongly appeared simultaneously. CT band depended on the structural properties of powders, showing the red-shift with increasing the crystallinity, while the f-f transition peaks were independent of the crystallinity. For $YNb_{1-x}Ta_xO_4$ : $Eu^{3+}$ (x = 0.05.0.2), $[TaO_4]^{3-}$. configuration was locally constructed, leading to the blue-shift in CT band and the decrease in the red emission intensity with increasing the Ta content.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.874-876
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• 2003

Blue light-emitting polyfluorene derivatives, poly[9,9-bis(4'-n-octyloxyphenyl) fluorene] (PBOPF), poly[9,9-bis(2'-ethylhexyl)]fluorene (PBEHF) and copolymers of PBOPF and PBEHF were synthesized through Ni(0) mediated polymerization and their light-emitting properties were investigated. The PBEHF thin film showed significant excimer band in PL spectra after thermal annealing at 100 $^{\circ}C$ for 2h. But no significant excimer emission was observed in the PL spectra of the PBOPF and the copolymers even after thermal annealing suggesting that BOPF unit effectively suppressed the excimer emission.

• 천문학회지
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• 제29권spc1호
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• pp.187-188
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• 1996

We have mapped $1 deg^2$ region toward a high latitude HII region S73 (l, b) = ($37^{\circ}.69$, $44^{\circ}.55$) and associated molecular cloud in $^{12}CO$ J = 1 - 0, and $^{13}CO$ J = 1 - 0, using the 3 mm SIS receiver on the 14 m telescope at Taeduk Radio Astronomy Observatory. A high resolution autocorrelator is used to resolve extremely narrow CO linewidths (FWHP < 1 km/s) of the molecular cloud. Though the linewidths are very narrow, it is found that there is systematic velocity gradient in the molecular gas associated with the H II region. Both of $^{12}CO$ and $^{13}CO$ averaged spectra are non-gaussian, and there are obvious blue wings in the spectra. It is remarkable that the linewidths at the blueshifted region are broader than those of the rest of the cloud. The CO emission does match well with the dust emission.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.241-241
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• 2014

$SnO_2-core/Zn-shell$ heteronanowires were fabricated by a two-step process: thermal evaporation of Sn powders and employing a sputtering technique with a Zn target. X-ray diffraction, high-resolution transmission electron microscopy, and EDX spectra coincidentally indicated that the shell layer comprised the Zn phase. From Gaussian deconvolution studies, we observed that photoluminescence (PL) spectra consisted of yellow, green, and ultraviolet (UV) emission bands, regardless of shell-coating. We speculated the possible mechanisms of these emission peaks.

• Fibers and Polymers
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• 제6권2호
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• pp.127-130
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• 2005

Intrinsic UV reflection and fluorescence behaviors of polycarbonate, polyurethane and poly(ethylene terephthalate) films were investigated in order to characterize the interaction of water in these films. During water sorption process, UV reflection spectra of polycarbonate and polyurethane films showed little peak position changes. Fluorescence emission spectra of polycarbonate films showed red spectral shifts from 332 nm with water immersion time. This red-shifted peak could be due to phenyl-2-phenoxybenzoate, which is one of the major thermal degradation products in polycarbonate. Fluorescence peaks of polyurethane films appeared at two different positions and the ratio of these peak intensities increased with increasing immersion time. In the case of PET films, the UV reflection spectrum showed the peak intensity around 340 nm to change in response to water sorption. The fluorescence near 388 nm probably due to ground state dimer exhibited sensitivity with water sorption, when excited at 340 nm.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.895-900
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• 2010

In order to find a relationship between firefly luciferases structure and bioluminescence spectra, we focus on excited substrate geometries which may be affected by rigid luciferases. Density functional theory (DFT) and time dependent DFT (TDDFT) were employed. Changes in only six bond lengths of the excited substrate are important in determining the emission spectra. Analysis of these bonds suggests the mechanism whereby luciferases restrict more or less the excited substrate geometries and to produce multicolor bioluminescence.

• 대한화학회지
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• 제37권4호
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• pp.371-377
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• 1993

불안정한 분자의 방출분광학에 상요이 가능하도록 Fourier Transform 분광기를 변형시켰다. 불안정한 분자 라디칼 $CH_3S$는 고전압 직류 방전에 의한 supersonic expansion 속에서 jet 형태의 흐름으로 생성되었다. Supersonic expansion에 의하여 냉각된 라디칼의 형광 스펙트럼은 Fourier Transform UV/VIS 분광기에 의해서 얻어졌다. 스펙트럼의 signal/noise 비율은 증가하였으며, 분자 라디칼 $CH_3S$의 회전구조도 명확하게 볼 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권11호
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• pp.609-615
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• 2000

A prototype electrodeless sulfur lamp was developed and investigated the spectroscopic characteristics. The emission spectra of $S_2$ in the microwave-discharged eletrodeless sulfur lamp (ESL) were studied at various input power. The emission spectra of the ESL shift to longer wavelength with increasing of the input power. We have shown that this is due to the self reversal effect in the high pressure gas discharge. We also show that the self reversal effect increases as the rotation of the discharged bulb. The spectral distribution of the ESL shifts about 45 nm toward visible region from UV region due to the rotation of the lamp bulb.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.72-78
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• 1993

The application of time-resolved laser induced fluorescence spectroscopy (TRLIF) to the complexation studies of Eu(III) and Cm(III) with humic substances is described. Using this method, three different spectroscopic characteristics(excitation spectra, emission spectra, and lifetimes) of these aquo ions and their complexes can be directly measured. By observing shifts in the wavelength and changes in the lifetime and intensities of the fluorescence emission, the information on the complexation behavior of humic substances with these trivalent metal cations in an aqueous solution, as well as energy transfer mechanisms, can be obtained. In addition, this method allows precise spectroscopic quantification of the complexation processes at very low concentrations of both components.

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.592-597
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• 2017

Three plastic scintillators of 4.5 cm diameter and 2.5-cm length were fabricated for comparison with commercial plastic scintillators using polymerization of the styrene monomer 2.5-diphenyloxazole (PPO) and 1,4-bis benzene (POPOP). Their maximum emission wavelengths were determined at 426.06 nm, 426.06 nm, and 425.00 nm with a standard error of 0.2% using a Varian spectrophotometer (Agilent, Santa Clara, CA, USA). Compton edge spectra were measured using three gamma ray sources [i.e., cesium 137 ($^{137}Cs$), sodium 22 ($^{22}Na$), and cobalt 60 ($^{60}Co$)]. Energy was calibrated by analyzing the Compton edge spectra. The fabricated scintillators possessed more than 99.7% energy linearity. Light output was comparable to that of the BC-408 scintillator (Saint-Gobain, Paris, France). The fabricated scintillators showed a light output of approximately 59-64% of that of the BC-408 scintillator.