• Journal of the Korean Chemical Society
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• v.8 no.4
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• pp.158-163
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• 1964

Electronic spectra and quenching constants for ten N,N-dimethylanilines (DMA) have been determined. The $250m{\mu}$ absorption band (C band) of DMA was shown to be mainly responsible for the quenching. This band was confirmed as an $n{\to}{\pi}^{\ast}$ band through substituent and medium effects on the spectra shifts. The energy absorbed by this band then transfers to triplet and down to the lowest triplet state, $^{3}La$, where the energy is lost by non-radiative collisions.

• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.807-815
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• 2001

Two-dimensional (2D) correlation method, which generates the synchronous and the asynchronous 2D spectrum by complex cross correlation of the Fourier transformed spectra, is an analysis method for the changes of the sample spectrum induced by vari ous perturbations. In the present work, the 2D electronic correlation spectra have been simulated for the cases where the sample spectrum composed of two gaussian bands changes linearly. When only the band amplitudes of the sample spectrum change, the synchronous spectrum shows strong peaks at the band centers of the sample spectrum, but the asynchronous spectrum does not make peaks. When the sample spectrum shifts without changing intensity and width, the synchronous spectrum shows peaks around the initial and final positions of the band maximum and the asynchronous spectrum shows long peaks spanning the shifting range. The band width change produces the complex 2D correlation spectra. When the sample spectrum shifts with band broadening, the width change by 50% of full width at half maximum (FWHM) does not give so large an effect on the correlation spectrum as the spectral shift by one half of FWHM of the sample spectrum.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.384-388
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• 2003

The emission and excitation spectra of $cis-[Cr(cyclam)(NCS)_2]NCS$ (cyclam = 1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room temperature are also measured. The vibrational intervals due to the electronic ground state are extracted from the far-infrared and emission spectra. The ten pure electronic origins due to spin-allowed and spin-forbidden transitions are assigned by analyzing the absorption and excitation spectra. Using the observed transitions, a ligand field analysis has been performed to determine the bonding properties of the coordinated ligands in the title chromium(Ⅲ) complex. According to the results, it is found that nitrogen atoms of the cyclam ligand have a strong σ-donor character, while the NCS ligand has medium σ- and π-donor properties toward chromium(Ⅲ) ion.

• Transactions on Electrical and Electronic Materials
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• v.13 no.2
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• pp.102-105
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• 2012

The structural, electrical, and optical properties of layer-by-layer ZnO nanoparticles deposited using sol-gel spin coating technique were studied and now presented. Thicknesses of the thin films were varied by increasing the number of deposited layers. As part of our characterization process, XRD and FE-SEM were used to characterize the structural properties, current-voltage measurements for the electrical properties, and UV-Vis spectra and photoluminescence spectra for the optical properties of the ZnO thin films. ZnO thin films with thicknesses ranging from 14.2 nm to 62.7 nm were used in this work. Film with thickness of 42.7 nm gave the lowest resistivity among all, $1.39{\times}10^{-2}{\Omega}{\cdot}cm$. Photoluminescence spectra showed two peaks which were in the UV emission centered at 380 nm, and visible emission centered at 590 nm. Optical transmittance spectra of the samples indicated that all films were transparent (>88%) in the visible-NIR range. The optical band gap energy was estimated to be 3.21~3.26 eV, with band gap increased with the thin film thickness.

• Journal of Photoscience
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• v.9 no.3
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• pp.51-55
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• 2002

The 77 K emission and excitation spectra, and 298 K infrared and absorption spectra of [Cr(progly)(2,2-tri)]CIO$_4$[progly=prolylglycinate,2,2-tri=N-(2-aminoethyl)-1,2-ethanediamine] have been measured. The vibrational intervals of the electronic ground state are extracted from emission and infrared spectra. The twelve electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using the observed electronic transitions, a ligand field analysis was performed to determine the metaligand bonding properties for the coordinated atoms. It is found that the carboxylate oxygen of the progly is a strong $\sigma$-and $\pi$-donor while the peptide nitrogen has weak $\pi$-donor property toward chromium(III) ion.

• Journal of the Optical Society of Korea
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• v.5 no.4
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• pp.123-130
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• 2001

In this paper, we report measurement of absorption coefficient for various InGaAs MQW QCSE device structures. The absorption spectra over a range of QCSE were obtained from measured photocurrent spectra. The refractive index changes with applied electric field were calculated from the absorption spectra.

• Bulletin of the Korean Chemical Society
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• v.18 no.8
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• pp.819-823
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• 1997

The luminescence and photoexcitation spectra of cis-[Cr(cyclam)(NO3)2]NO3·½ H2O (cyclam=1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room-temperature are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. With observed transitions, a ligand field analysis has been performed to determine the bonding property of nitrate group in the chromium(Ⅲ) complex. According to the results, it is found that nitrate ligand has weak σ- and π-donor properties toward chromium(Ⅲ).

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1936-1938
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• 2000

In this paper, a frequency spectra of AE (acoustic emission) signals detected from the partial discharges of an epoxy resin void and a cast resin transformer in operating were analyzed to offer the proper frequency range of AE signals from the corona discharge for the purpose of AE sensor selection, From these results, a frequency spectra of AE signals emitted from the corona discharges in the void of an epoxy resin sample were about 190[kHz] to 220[kHz] by the FFT(fast fourier transform), A frequency spectra of AE signals emitted from a cast. resin transformer with non-load were appeared to be downward of about 140[kHz] by the FFT, and then a frequency spectra of AE signals emitted from the above of cast resin transformer with load were appeared to increase from about 190[kHz] to 220[kHz] by the FFT.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1875-1880
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• 2010

A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-($\alpha$-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffraction. Density function theory (DFT) calculations were performed by using B3LYP method with 6-$311G^{**}$ basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-$311G^{**}$ method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-$311G^{**}$ method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n $\rightarrow\pi^*$ and $\pi\rightarrow\pi^*$ transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been calculated, revealing the correlations between $C^0_{p,m}$, $S^0_m$, $H^0_m$ and temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.157-162
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• 2003

Piezoelectric ink jet offers a promising combination of productivity, reliability and uniformity that are appropriate for jetting organic electronic materials. Spectra is manufacturing a printhead specifically for display manufacturing. This printhead contains a robust material set and is intended to allow calibration of individual nozzles to meet uniformity requirements of+/-2% for display manufacture.