• 천문학논총
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• 제29권3호
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• pp.35-44
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• 2014

In ground-based astronomical spectroscopic observations, there are many telluric absorption lines that are laid on the spectra of celestial objects. To study the physical properties of the celestial objects with these contaminated spectra, the telluric lines should be removed. A conventional method for removing the telluric lines is using the standard stellar spectrum as telluric line. In this paper, we introduce a technique to calculate synthetic telluric spectra and use them to remove telluric lines from a spectrum of a celestial object. We used Line-by-Line Radiative Transfer Model (LBLRTM) for calculating a synthetic spectrum and selected Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) model as atmospheric model. We apply our method to some spectra obtained by Bohyunsan Observatory Echelle Spectrograph (BOES) to show that the telluric lines are well removed from the observed spectra by our model within an accuracy of 2% which is close to the 1-sigma rms of the original spectra.

• Journal of the Optical Society of Korea
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• 제5권4호
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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.

• 대한화학회지
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• 제13권1호
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• pp.25-28
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• 1969

몇가지 monoazo 一金屬錯鹽들의 UV吸收 spectra를 測定하여 이것을 基礎로 하여 그 金屬錯鹽들의 構造를 論하였다. 옆으로 찌그러진 八面體모양의 幾何學的構造를 提案하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1398-1400
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• 1998

The physical properties of the LB films with merocyanine dyes have been published and attract attention due to the possibility of molecular structure control. The evaluation of the thin films was focused for the purpose of molecular structure control. The molecular structure in the case of the thin films with dyes can be examine by optical absorption spectra measurements. In the case of optical absorption spectra of the LB films by the heat treatment at $70^{\circ}C$ in the air, both of the shifted absorption bands decay and a monomer absorption peak of about 530 nm appears instead. And, the formation and dissociation of J-aggregates, anisotropic behavior was no longer observed in the heat treated merocyanine dyes LB films. In the results, study of the merocyanine dyes LB films using optical absorption spectra would an interesting problem of absorption peak shifts and mixed components.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.118-122
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• 1993

The 77 K luminescence and excitation spectra, room-temperature FT-infrared and visible absorption spectra of a newly prepared complex cis-[Cr(cyclam)(pn)]$(ClO_4)_3$, where cyclam and pn represent 1,4,8,11-tetraazacyclotetradecane and 1,2-propanediamine respectively, have been measured. Absorption maximum of the first spin-allowed transition in the electronic absorption spectra of cis-[Cr(cyclam)(pn)]$^{3+}$ and cis-[Cr(cyclam)(en)]$^{3+}$ appears at nearly the same position. The two spin-allowed and six spin-forbidden electronic transitions are assigned from the visible absorption and excitation spectra. It is also shown that the zero phonon line in the excitation spectrum splits into two components by 50 cm$^{-1}$.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.650-654
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• 1992

Absorption and fluorescence spectra are reported for four different 1 : 3 $Dy^{3+}$ : ligand systems in aqueous solution under mild alkaline pH conditions. The ligands included in this study are oxidiacetate, dipicolinate, iminodiacetate and methyliminodiacetate. The oscillator strengths for the 4f→4f multiplet-to-multiplet transitions are empirically determined from the absorption spectra and the intensity parameters ${\Omega}_{\lambda}$}(${\lambda}$ = 2, 4, 6) for the systems are also obtained by applying the Judd-Ofelt theorem to the observed oscillator strengths. The values of the intensity parameters for the systems are compared and discussed in terms of ligand structural properties to investigate how the intensity parameters can response to the minor changes in the ligand environment. In addition, the relative oscillator strengths for fluorescence are evaluated and compared to the results obtained from absorption spectra.

• Journal of Magnetics
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• 제13권3호
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• pp.85-87
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• 2008

I report a simple method to correct the saturation effect in absorption spectra measured in total electron yield (TEY) mode. It does not require additional measurements of the X-ray penetration depth. In order to check the reliability of the method, X-ray magnetic circular dichroism (XMCD) spectra for polycrystalline Fe were measured at two different incident angles, and then processed with the method. The two resultant XMCD spectra were identical, and their sum rule analysis produced the ratios of orbital magnetic moment to spin magnetic moment, which were very close to the well-known value.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.127-131
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• 1993

Laser optoacoustic technique has been employed to obtain the gas phase absorption spectra of 1-chloronaphthalene, 3-chlorobiphenyl, and 2,5,2'-trichlorobiphenyl in conjunction with a gas chromatograph and a Helmholtz resonator at the various $CO_2$ laser wavelengths. Raman spectra of 1-chloronaphthalene, 4-chlorobiphenyl, and 4,4'-dichlorobiphenyl in condensed phase have been also obtained. The optoacoustic measurement of the infrared absorption in gas phase has been shown to be of value in monitoring the environmental pollutants.

• 광물과 암석
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• 제34권2호
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• pp.121-131
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• 2021

마그네슘(magnesium; Mg)은 탄산염 광물이 침전된 과거의 환경 조건을 유추하기 위한 지화학 지시자로 활용되어오고 있다. Mg를 신뢰도 높은 지화학 지시자로 활용하기 위해서는 Mg의 화학종을 근거로 한 Mg의 광물 함유 기작이 반드시 규명되어야만 하며, 관련 실험 연구들은 주로 고해상도(high resolution)의 방사광가속기(synchrotron) X-선 흡수 분광(X-ray absorption spectroscopy; XAS) 기법을 통해 Mg의 화학종을 유추한다. 그러나, Mg가 미량 함유된 광물의 XAS 스펙트럼 해석의 높은 불확실성 때문에 화학종 유추가 어려운 경우가 많다. 양자역학 밀도범함수이론(density functional theory; DFT)은 결정구조에 대한 흡수 스펙트럼을 예측할 수 있기 때문에, XAS 스펙트럼 해석의 불확실성을 줄일 수 있다. 이번 논문에서는 DFT 기반의 제일원리 내각 준위 분광법(ab initio core-level spectroscopy method)을 통해 Mg 규산염 및 (수)산화광물에 대한 Mg K-edge 흡수 스펙트럼을 계산하여 Mg의 배위 결합 환경을 나타내는 구조 인자와의 상관관계를 분석하였다. 계산 결과, DFT 계산으로 얻은 Mg 규산염 및 (수)산화물의 이론 Mg K-edge 흡수 스펙트럼은 기존 XAS 실험으로 얻어진 스펙트럼의 주요 형태를 상당 부분 재현해낼 수 있었다. 계산으로 얻은 광물의 제일원리 Mg K-edge 흡수 스펙트럼의 흡수-끝(absorption edge)과 평균 Mg-O 결합거리 및 Mg 유효배위수를 비교 분석한 결과, 약한 양의 상관관계를 보여주었다. 이번 연구 결과는 DFT 계산이 다양한 광물 내 Mg의 화학종에 대한 표준 스펙트럼 세트를 제공할 수 있는 강력한 도구임을 보여주며, 추후 탄산염 광물에 함유된 정확한 Mg의 화학종을 동정하는데 DFT 계산이 큰 역할을 할 수 있음을 제시한다.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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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.