• Journal of Photoscience
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• 제10권1호
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• pp.149-155
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• 2003

The absorption, fluorescence and fluorescence-excitation spectra of concentrated toluene solutions of selected para substituted trans-stilbene derivatives provide strong evidence for aggregation. A red-shifted fluorescence spectrum peaking at 420 nm gains in intensity as the stilbene concentration is increased. The excitation spectrum of this new emission is well to the red of the normal stilbene absorption spectrum, consistent with the appearance of a red shifted shoulder in the UV spectrum. Formation of a fluorescent ground state dimer (or higher aggregate) is proposed to account for these observations. The presence of polar substituents is crucial to the formation of this ground state complex.

• Journal of Plant Biology
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• 제39권3호
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• pp.173-177
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• 1996

A novel calcium binding protein (CaBP) was purified to electrophoretic homogeneity from Dunaliella salina. In the course of purification experiment, this CaBP was identified as a monomer and its molecular weight was about 21 kDand isoelectric point (pI) value was about 4.1 using isoelectrofocusing. This CaBP was able to bind Ca2+ even in the pressence of an excess MgCl2 and KCI both in solution. In the SDS-PAGE, the Ca2+-bound form was slower than the Ca2+-free form in the nondenaturing PAGE. This means that the CaBP undergoes conformational change in the Ca2+-bound condition. Furthermore, UV absorption spectrum and fluorescence intensity of this CaBP was investigated. UV absorption peak was appeared at about 258 nm and decreased somewhat in Ca2+-bound condition. In the measurement of fluorescence, maximum intensity was appeared at 303 nm and decreased in Ca2+-bound state, similarly as UV absorption spectrum. These show distinct changes upon Ca2+-binding, which indicate of structural and/or dynamic changes largely reminiscent of other members of the EF-hand Ca2+-binding protein family.

• 한국인쇄학회지
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• 제13권2호
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• pp.47-53
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• 1995

Photosensitive resin of azide type is good for resolution and inner solvent, but it is really problem to development of practical use because fanctional groups of polymer has many hydrophilic radicals. By careful attention to this point, this study was investigated synthesis term, photo property and development property of composed photosensitive resin of azida type, it is to this effect. 1) H-NMR spectrum of compared DABCI showed amion redical by $\delta$6.0~6.1ppm to substitude for azide radical by amino radical by $\delta$8.9~9.45ppm, and FT-IR absorption spectra showed the absorption bends at 2100cm. 2)FT-IR absorption spectra of PHS1-DAB, PHS2-DAB, CMM-DAB and CHM-DAB showed azida radical pick to be lost at after irradiation by UV light. 3) According to exposuer change of PHS1-DAB, PHS2-DAB, CMM-DAB and CHM-DAB, absorption maximum value of UV spectrum change was 280nm. 4) to compared relative sensitivity of compared photosensitive resin, PHS2-DAB was the best and to compared insolubility rate of compared photosensitive resin, CMM-DAB was the lower. 5)Solubility if NaOH was the best by 1.0mol/$\ell$ and solubility of developing solution of ethanol to water was it in the ratio of 4 to 1.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.57-60
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• 2001

The characterization of organic Metal/Insulator/Metal(MIM) devices were investigated from LB films. The physicochemical properties of the LB films were by UV absorption spectrum and AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 2, 10, 30[mN/ml The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.11-14
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• 2001

We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 30[mN/m]. LB layers of Arac. acid deposited by LB method were deposited onto slide glass as Y-type film. The physicochemical properties of the LB films were examined by UV absorption spectrum, SEM and AFM. The structure of manufactured device is Au/arachidic acid/Al. the number of accumulated layers are 3~9. Also. we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Natural Product Sciences
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• 제1권1호
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• pp.66-69
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• 1995

Traditional Antheraea pernyi silkworm cocoon is tawny color. The white Antheraea pernyi silkworm cocoons studied here by IR and UV are new breeds of recent breeding. We discovered that the main body of the first grade structure of silk protein in the new white is as same as the one in the traditional tawny Antheraea pernyi silkworm cocoon, yet there are small quantities of cross-linked polymer of gentisic acid and silk protein in the white silkworm cocoons. In spite of the least surviving quantity of the polymer, the white silkworm cocoons are most white and its white color is similar to white Bombyx mori silkworm cocoon.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1729-1734
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• 2018

Organic-inorganic halide perovskite single crystals undergo phase transition of being cubic, tetragonal, or orthorhombic depending on the temperature. We investigated the $CH_3NH_3PbBr_{3-x}I_x$ single crystals grown by the inverse temperature crystallization method with temperature-dependent UV-Vis absorption and photoluminescence. From the temperature-dependent absorption measurement, the optical band gap is extracted by derivation of absorption spectrum fitting and Tauc plot. In our results, $CH_3NH_3PbBr_{3-x}I_x$ single crystals show that an abrupt change in optical band gap, PL peak position and intensity appears around 120 K - 170 K regions, indicating the phase transition temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 추계학술대회 논문집
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• pp.137-140
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• 1993

Electrical properties and thermal annealing effects of $C_{22}$-quinolium(TCNQ) Langmuir-Blodgett(LB) films were studied. Typical current-voltage(I-V) characteristics along the perpendicular direction chow an anomalous behavior of breakdown near the electric-field strength of $10^{6}$V/cm. To see the thermal influence of the specimen, current was measured as a function of temperature(20∼$180^{\circ}C$). It shows that the current increases about 4 orders of magnitude near 60∼$70^{\circ}C$ and remains constant far a while up to ∼$150^{\circ}C$ and then suddenly drops. Such increase of current near 60∼$70^{\circ}C$ seems tn be related to a softness of alkyl chains. Besides the electrical measurements, UV/visible absorption(300∼800 nm) of the thermally annealed sample was measured to see the internal-structure change. It is found that there are four characteristic peaks. At 494 nm, the optical absorption of the thermally annealed specimen at $60^{\circ}C$ starts increase and stays almost constant upto∼ $140^{\circ}C$. And eventually it disappears above $180^{\circ}C$. After heat treatment of the specimen up to $150^{\circ}C$, Uv/visible absorption was measured while cooling.

• 한국환경보건학회지
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• 제28권5호
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• pp.59-64
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• 2002

The photocatalytic decolorization of the Rhodamine B (RhB) was studied using a UV/TiO$_2$ reactor. Yakuri titanium dioxide(anatase) was used as the suspended photocatalyst and proved to be effective for decolorization irradiated with UV light (254 mm). The photocatalyzed dioxide concentrations, light intensity and air flow rates. In 0.01 mM RhB, color could be completely photodegraded after 3 hours. Absorption spectrum of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the solution bulk : concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the break up of the chromopore. The optimum loaded titanium dioxide for the decolorization was 0.75 g/(equation omitted). The light intensity showed exponential decay with distance. The decay of light intensity of RhB solution showed different tendency from TiO$_2$. These results suggested that the photocatalytic decolorization of dyes may be available method for decolorizing in wastewater.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2382-2388
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• 2007

A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.