• 천문학회지
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• 제29권spc1호
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• pp.345-346
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• 1996

The contrasting values of the oscillator strengths for the (0,0) band of SiH+ molecules for the $A\;^1II-X\;^1{\sum}+$ transition reported in literature, motivated us to reinvestigate the same with the help of a new set of well accepted solar photospheric models, elemental abundances and dissociation energy.

• Journal of Electrical Engineering and information Science
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• 제3권3호
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• pp.385-390
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• 1998

In this paper, the oscillator strengths of both the heavy-hole and the light-hole excitons in GaAs-A\ulcornerGa\ulcornerAs and In\ulcornerGa\ulcornerAs-InP quantum wells with the effect of a magnetic field applied along the growth axis are studied. The calculation is carried out usig a variational approach, based on a simple trial exction wave function. The exciton oscillator strengths are found to decrease with increasing well width and to increase with the applied magnetic fields which lead to additional quantum confinement for moderately wide well sizes. Also, the oscillator strengths for the heavy-hole exciton are found to be large than those of the light-hole exciton in these quantum well structures.

• 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.

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.232-237
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• 1995

The absorption spectra of holmium nitrate and erbium nitrate and the difference absorption spectra of their complexes with crown ethers were measured in acetonitrile. The crown ethers used in this study are 12-crown-4 and 15-crown-5. The oscillator strengths for the 4f→4f multiplet-to-multiplet transitions are empirically determined from the absorption spectra in combination with the difference spectra. The intensity parameters Ωλ (λ=2, 4, 6) for the systems are also evaluated by applying the Judd-Ofelt theorem to the observed oscillator strengths. The values of the intensity parameters are compared and discussed to investigate the sensitivity of the intensity parameters to the ligand environment.

• 대한화학회지
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• 제26권3호
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• pp.148-154
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• 1982

수용액중에서 Nd(III)와 Ho(III) 이온의 hypersensitive 전이대의 oscillator strength에 미치는 몇가지 리간드의 효과를 연구하였다. 이때에 사용한 리간드는 furoate, anthranilate와 squarate이다. 각 착화합물에 있어서 금속-리간드 결합간에 존재하는 공유결합성을 리간드의 $pK_a$와 착화합물의 hypersensitive 전이대의 oscillator strength 사이에 정립된 관계에 근거를 두고 논하였다.

• Bulletin of the Korean Chemical Society
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• 제13권1호
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• pp.54-59
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• 1992

Spectroscopic measurements and theoretical calculations are performed for the four 1 : 3 Sm(III) : ligand solutions. The ligands included in this study are oxidiacetate, iminodiacetate, methyliminodiacetate and dipicolinate. The oscillator strengths for the $4f{\to}4f$ multiplet-to-multiplet transitions are empirically determined from the absorption spectra. The intensity parameters ${\Omega}_{\lambda}\;({\lambda}=2,\;4,\;6)$ of $Sm^{3+}$(aquo) and ${SmL_3}^{3-}$ complexes are also evaluated by applying the Judd-Ofelt theorem to the observed oscillator strengths. The values of the intensity parameters are compared and discussed in term of structural properties of the complexes. In addition, the fluorescence spectra are reported for the Sm(III) complex systems under mild alkaline condition. The excitation from the $^6H_{5/2}$ ground state to any excited states lying above the emitting energy level $(^4G_{5/2})$ produces four fluorescence bands, following nonradiative transitions from a certain excited state to the $^4G_{5/2}$ state. The ratios of oscillator strengths of ${SmL_3}^{3-}$ complexes to that of $Sm^{3+}$(aquo) are also evaluated from the fluorescence spectra and compared to the results obtained from the absorption bands.

• Bulletin of the Korean Chemical Society
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• 제17권9호
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• pp.854-857
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• 1996

Absorption and luminescence spectra of Eu3+ (aquo) and the two different 1: 3 Eu3+: ligand systems in aqueous solutions are measured under mild acidic pH condition. The oxydiacetate (ODA) and dipicolinate (DPA) ligands, forming the similar geometric complexes, are used in this work. The three intensity parameters, Ωλ (λ=2, 4, and 6) are empirically determined by applying the Judd-Ofelt theorem to the oscillator strengths of the six absorption bands arising from the ground 7F0 state. Among the three intensity parameters, the Ω2 is found to response markedly to a miner change in the ligand environment via the 7F0→5D0 transition. In addition, the relative oscillator strengths of the four luminescence bands in the visible region, assigned to the 5D0→7FJ (J=1, 2, 3 and 4) transitions are obtained to investigate their sensitivity to the ligand environment. Among the four bands, the 610 nm band, attributed to the 5D0→7F2 transition, shows hypersensitivity in the luminescence.

• 대한전자공학회논문지
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• 제25권9호
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• pp.1108-1114
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• 1988

Usng the P.Yeh's analytic method, we derive the condition for oscillation of a linear phase conjugate oscillator which consists of photorefractive medium and two conventional mirrors. From this general oscillation condition, we obtain the threshold oscillation conditon of a single phase conjugate resonator and the self-oscillation condition of photorefractive medium, then in special case (phase shift =90\ulcorner: no external dc electric field), oscillation conditions of the linear phase conjugate oscillator for any cavity length are derived. The results indicate that, unlike in a phase conjugate oscillator with Kerr-like medium, oscillation cannot occur at special cavity length for given couplinyg strengths.

• 천문학회지
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• 제29권spc1호
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• pp.341-342
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• 1996

We present here the solar LOG GF values obtained using the Liege solar at las and the standard solar photospheric models for the spectral lines in the wavelength range ${\lambda}{\lambda}$ 6209 - 6273 ${\AA}$. These log gf values shall be used to interpret a high resolution spectra of the star $\gamma$ Draconics.

• 한국광학회지
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• 제6권1호
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• pp.33-38
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• 1995

$Ce:YAlO_{3}$ 단결정 재료에 대한 5d 준위로부터 전도대로의 여기상태 흡수스펙트럼을 최초로 측정하였다. 이를 위해 XeCl레이저의 308nm와 색소레이저의 400-650nm의 빔을 사용하였고 555nm와 465nm에서 최대치를 갖는 흡수띠를 얻었으며 이로부터 여기상태 흡수 cross section과 oscillator strength를 계산하였다. 또한 5d 준위로 부터 비발광 천이과정 연구를 위해 300-700K의 온도영역에서 형광수명시간을 측정하였고, 5d 준위로부터의 ESA와 천이를 배위좌표를 사용하여 설명하였다.