• 제목/요약/키워드: absorption spectrum

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마그네사이트의 적외선 흡수 스펙트럼 해석 (Analysis of the Infrared Absorption Spectrums of Magnesite)

  • 오기동
    • 한국세라믹학회지
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    • 제14권4호
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    • pp.226-229
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    • 1977
  • The infrared absorption spectrum of Synthesized magnesite is shown in the wve number region 2510 and 745cm-1. By using Wilson's GF matrices the force constants' of the Urey-Bradley force field were deterined from the infrared absorption frequencies. For magnesite the stretching force constant K=5.41, the bending force constant H=0.46, the repulsive force constant F=1.97, and the force constant for the out-of-plane vibration fθ=0.65md/Å. For calcite they are K=5.51, H=0.38, F=1.88 and fθ=0.64md/Å.

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543 nm 헬륨네온 레이저의 주파수 안정화를 위한 I2 포화흡수분광 (I2-Saturated Absorption Spectroscopy for Frequency-Stabilization of He-Ne Laser at 543 nm)

  • 김경찬;엄년식;홍주현;서호성
    • 한국산학기술학회논문지
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    • 제11권3호
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    • pp.859-865
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    • 2010
  • 본 연구는 543 nm 헬륨네온 레이저의 주파수 안정화를 위한 $^{127}I_2$ 포화흡수분광 장치의 설계와 제작에 관한 것이다. 온도와 PZT 변화에 의한 레이저관 길이 가변을 이용하여 543 nm 헬륨네온 레이저의 주파수를 주사시켰다. 3차 고조파 신호을 얻기 위해 PZT 변조 가능한 레이저 출력경을 이용하여 주파수 변조를 하였다. 그 결과, $^{127}I_2$용 B-X 시스템의 R(12) 26-0에서 R(106) 28-0의 천이를 가지는 초미세구조 분광은 포화흡수분광기를 사용한 3차 미분신호에서 관찰되었다. 또한, 전형적인 초미세구조 분광 신호의 신호대 잡음비는 약 30:1 로 얻어졌다.

Structure and Photoreaction of Photoactive Yellow Protein

  • Imamoto, Yasushi;Harigai, Miki;Shimizu, Nobutaka;Kamikubo, Hironari;Yamazaki, Yoichi;Kataoka, Mikio
    • Journal of Photoscience
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    • 제9권2호
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    • pp.126-129
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    • 2002
  • The chromophore/protein interactions in the photocycle intermediates of photoactive yel- low protein (PYP) were probed by site-directed mutagenesis. The absorption spectra of L- intermediates produced from E46Q, T50V, and R52Q mutants were calculated using the absorption spectra of dark states and difference absorption spectra between L-intermediates and dark states, and compared with that of PYP$\_$L/. The absorption spectrum of R52Q$\_$L/ agreed with that of PYP$\_$L/, but those of E46Q$\_$L/ and T50V$\_$L/ were red-shifted. The effect of these mutations on the absorption spectrum for L-intermediate was comparable to that for the dark state, suggesting that the interaction around the phe-nolic oxygen of the chromophore is conserved in PYP$\_$L/ unlike the crystal structure. On the other hand, we have reported that the absorption spectra of Y 42F$\_$M/, T50V $\_$M/, and R52Q$\_$M/ agreed with that of PYP$\_$M/, but that of E46Q$\_$M/ was red-shifted, suggesting that the hydrogen bond of the chromophore with Glu46 is conserved but that with Tyr42 is broken in PYP$\_$M/. These results suggest that the chromophore inter-acts with Glu46 throughout the photocycle, but never directly interacts with Arg52. This model con- flicts with some of the structural model of PYP intermediates proposed based on the high-resolution X -ray crystallography.

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Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex 99mTc-MDP

  • Qiu, Ling;Lin, Jian-Guo;Gong, Xue-Dong;Ju, Xue-Hai;Luo, Shi-Neng
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2358-2368
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    • 2011
  • Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

Outburst signatures of Class I source, IRAS 16316-1540

  • Yoon, Sung-Yong;Lee, Jeong-Eun;Lee, Seokho;Park, Sunkyung
    • 천문학회보
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    • 제41권2호
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    • pp.55.4-55.4
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    • 2016
  • We observed 10 Class I sources as part of the IGRINS (Immersion GRating INfrared Spectroscoph) Legacy Program, "IGRINS Survey of Protoplanetary Disks (PI: Jeong-Eun Lee)". Unlike other Class I sources, IRAS 16316-1540 shows broad absorption features in the near-infrared spectra (H and K bands). The broadened absorption features have been detected toward FU Orionis-type objects. Boxy or double-peaked absorption profiles can be produced by a Keplerian disk that has the hot mid-plane heated by a burst mass accretion. We could fit the broad absorption features of IRAS 16316-1540 with a K5 V template stellar spectrum convolved with a disk rotation profile of 45 km s-1. Therefore, rotationally broadened absorption features detected in this Class I source suggest that the episodic accretion process occurs from the early stage of star formation.

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Infrared Detector Using Pyroelectrics

  • Hur, Chang-Wu
    • Journal of information and communication convergence engineering
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    • 제4권4호
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    • pp.147-150
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    • 2006
  • The thin film of PbTiO3 is fabricated at substrate temperature of 100-150$^{\circ}C$. The infrared spectrum of the ferroelectric thin film is measured as temperature of thermal treatment, 400 - 550$^{\circ}C$. According to infrared spectrum analysis, there are absorption bands at a nearby wave number of 1000 $\sim$ 400 cm-l and the thin film treated by temperature of 550$^{\circ}C$ has absorption bands of wave number 500 cm-l similar to infrared response property of PbTiO3 powder. The pyroelectric infrared detector is fabricated after deposition of Pt and PbTiO3 thin film on Si wafer by sputtering machine. The measured remnant polarization are 11.5-12.5$\muC/cm2$, breakdown electric field Ec is 100-120KV/cm, and voltage responsivity and detectivity is -280V/W, -108cm Hz/W.

폴리이미드 LB막의 광이성화 현상에 관한 연구 (A Study on the Photoisomerization of LB Films of Polyimide)

  • 박근호;변용진;송경호;박태곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1882-1884
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    • 1999
  • The photoisomerization of functional polyimide was investigated in the various temperatures and UV(360nm) & visible(450nm) light irradiation. The absorption spectrum of azobenzene containing polyamic acid in a mixture of N,N-dimethylacetamide and benzene(1:1 by volume) solution was induced photoisomerization by UV and visible light irradiation. The absorption spectrum of LB films are also induced photoisomerization by UV and visible light irradiation.

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나노구조 덴드리머의 변위특성 (Displacement Properties of Nano Structure Dendrimer)

  • 송진원;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1724-1726
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    • 2004
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. Until now, many methodologies have been developed in order to gain a better understand. Photoisomerization in monolayers of a novel azobenzene compound, azobenzene dendrimer, was investigated for the first time by means of the absorption spectrum and Maxwell displacement current (MDC) technique. Dendrimers are well-defined macromolecules exhibiting a tree-like structure, first derived by the cascade molecule approach. According to the absorption spectrum, trans-to-cis conversion ratio was estimated to the third generation of azobenzene dendrimer deposited onto a glass substrate. Temperature-dependent induced charge with trans-cis isomerization was also measured by means of MDC technique.

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Identification of MgII Absorbers in the Quasar Lines of Sight

  • Shim, Hyunjin
    • 천문학회보
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    • 제40권1호
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    • pp.75.3-75.3
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    • 2015
  • Large area infrared surveys are often accompanied with follow-up optical spectroscopic surveys that has a significant legacy value even for other areas of research. Using these spectral database, we have performed a search for MgII absorption lines in the optical spectrum of background quasar. Over the ~4deg2 of AKARI North Ecliptic Pole survey field and Spitzer First Look Survey field, 18 and 16 MgII absorber systems are identified respectively. The redshift range for the background quasars was 1.0<$z_{qso}$<3.4, while the redshift range for the absorber was 0.6<$z_{abs}$<1.6. Galaxies responsible for MgII absorptions are identified in the deep optical images (CFHT r-band), yet the identification still remains ambiguous for 60% of the systems due to the limited image depth and the source crowdedness. The impact parameter ranges 20-60kpc, and the rest-frame equivalent width of MgII absorption ranges $0.7-4{\AA}$. The most critical part in the identification of MgII absorber galaxies is the existence of deep optical images in addition to the high S/N quasar spectrum with R>3000.

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유기박막(Arac.acid)의 누적전이상태에 관한 연구 (A Study on the Deposition Transfer state of Organic Thin Films(Arac.acid))

  • 정헌상;송진원;이경섭;전연수;이우기
    • 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.

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