• 제목/요약/키워드: CD spectrum

검색결과 193건 처리시간 0.025초

d-주석산이온과 라세미코발트(III) 착물과의 상호작용에 따른 유발원편광이색성 Spectra와 크로마토그래피 (Induced Circular Dichroism Spectra and Chromatography by Interaction of Some Racemic Cobalt (III) Complexes and d-Tartrate$^2$- in Aqueous Solution)

  • 오창언;강대호;신갑철
    • 대한화학회지
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    • 제25권5호
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    • pp.306-310
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    • 1981
  • 라세미코발트(III)착물인 $[Co(en)_3]^{3+},\;[Co(tn)_3]^{3+},\;cis-[Co(NH_3)(en)_2]^{3+},\;[Co({\beta}-ala)(en)_2]^{2+},\;[Co(gly)(en)_2]^{2+}$ 및 [Co(acac)(en)$_2]^{2+}$을 실온에서 d-주석산염의 수용액에 녹여 원편광이색성 spectra를 측정하였다. 측정된 모든 착물에 대해서 가시부영역 (400∼500nm)에 한개의 음의 CD spectrum이 관측되었다. 이것은 d-주석산이온과 ${\Lambda}$-및 ${\Delta}$-거울상이성질체의 상호작용에 대한 차에의한 것이라고 해석되었다. 즉 ${\Lambda}$-및 ${\Delta}$-거울상이성질체에 d-주석산이온을 각각 부가했을때 ${\Lambda}$-거울상이성질체는 크게 변하였고 ${\Delta}$-거울상이성질체는 약하게 변하여 그 결과 유발원편광이색성 spectrum으로 나타났다. 이온교환 관크로마토그래피에 있어서 용리제와 더 강하게 회합하는 거울상이성질체가 관으로부터 더 빨리 용출된다. 만일 chiral음이온과 착물과의 더 강한 상호작용이 착물의 원래 부호로부터 크로마토그래피의 용리순서를 예측할 수가 있고, 실험결과 용리순서는 측정된 모든 착물에 대하여 유발 원편광이색성 spectrum의 부포로부터 예측된 거울상이성질체의 절대구조와 완전히 일치하였다.

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CdTe/HgTe/CdTe구조 나노입자의 광전류 특성 (Photo current Characteristic of CdTe/HgTe/CdTe Structured Nanoparticles)

  • 김동원;조경아;김현석;박병준;김상식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.139-140
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    • 2005
  • The photocurrent characteristics of CdTe/HgTe/CdTe structured nanoparticles are studied. CdTe/HgTe/CdTe multilayer structured nanoparticles were synthesized by colloidal method. CdTe/HgTe/CdTe multilayer structured nanoparticles were characterized by x-ray diffraction, high-resolution transmission electron microscopy(HRTEM), absorbance and photoluminescence(PL). PL spectrum of CdTe/HgTe/CdTe multilayer structured nanoparticles exhibits a strong exciton bond in the near infrared range. The I-V curves and photoresponses revealed that CdTe/HgTe/CdTe multilayer structured nanoparticles are very prospective materials for the photodetectors.

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Cyclodextrin의 Inclusion Complex 형성능과 Fatty Acid와의 Complex 형성조건과 특성 (Comparison of Inclusion Complex Formation Capacity of Cyclodextrins with Various Molecules and Characterization of Cyclodextrin-fatty Acid Complex)

  • 이용현;정승환박동찬
    • KSBB Journal
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    • 제10권2호
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    • pp.149-158
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    • 1995
  • 각종 CD와 여러 종류의 화합물, pH indicator, biostain, 아미노산, 천연배당체, 그리고 fatty acid 간의 inclusion complex 형성능을 비교하였다. Fatty acid가 각종 CD에 대한 포접형성능과 선택성 이 높아 CD 분리용 ligand로 적합함을 알았다. Fatty acid의 포접능과 선택성은 탄소쇄의 길이와 밀접한 상관관계를 나타내어 capric acid는 ${\alpha}$- CD와 palmitic acid는 ${\beta}$-CD와 높은 선택성을 보였다. Complex형성에 미치는 반융조건인 흔합 농도비, pH, ionic strength, 그리고 온도의 영향을 검토하였다. 적정 혼합 농도비는 CD가 50mM 그리고 lig and 인 fatty acid가 50mM 일 때 였으며 , 온도가 중 요한 형성조건으로 작용하였다. 포접되지 않은 CD 와 fatty acid가 포접 된 CD의 분자구조를 X-ray diffraction과 IR spectrum을 사용하여 비교 검토하였으며, DSC로 inclusion complex 형성반응의 en­t thalpy의 변화값(${\gamma}H$)을 측정하여 발열반응임을 확인하였다.

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Bridgman법에 의해 $CdIn_2Te_4$ 단결정 성장과 광발광 특성 (Photoluminescience Properties and Growth of $CdIn_2Te_4$ Single crystal by Bridgman method)

  • 홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.278-281
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    • 2003
  • The p-CIn2Te4 single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The quality of the grown crystal has been investigated by the x-ray diffraction and the photoluminescence measurements. From the photoluminescence spectra of the as-grown CdIn2Te4 crystal and the various heat-treated crystals, the (Do, X) emission was found to be the dominant intensity in the photoluminescence spectrum of the CdIn2Te4:Cd, while the (Ao, X) emission completely disappeared in the CdIn2Te4:Cd. However, the (Ao, X) emission in the photoluminescence spectrum of the CdIn2Te4:Te was the dominant intensity like an as-grown CdIn2Te4 crystal. These results indicated that the (Do, X) is associated with VTe acted as donor and that the (Ao, X) emission is related to VCd acted as acceptor, respectively. The p-CdIn2Te4 crystal was found to be obviously converted into the n-type after annealing in the Cd atmosphere. The origin of (Do, Ao) emission and its TO phonon replicas is related to the interaction between donors such as VTe or Cdint, and accepters such as VCd or Teint. Also, the In in the CdIn2Te4 was confirmed not to form the native defects because it existed in the stable form of bonds.

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Enhanced Photocurrent from CdS Sensitized ZnO Nanorods

  • Nayak, Jhasaketan;Son, Min-Kyu;Kim, Jin-Kyoung;Kim, Soo-Kyoung;Lee, Jeong-Hoon;Kim, Hee-Je
    • Journal of Electrical Engineering and Technology
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    • 제7권6호
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    • pp.965-970
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    • 2012
  • Structure and optical properties of cadmium sulphide-zinc oxide composite nanorods have been evaluated by suitable characterization techniques. The X-ray diffraction spectrum contains a series of peaks corresponding to reflections from various sets of lattice planes of hexagonal ZnO as well as CdS. The above observation is supported by the Micro-Raman spectroscopy result. The optical reflectance spectra of CdS-ZnO is compared with that of ZnO where we observe an enhanced absorption and hence diminished reflection from CdS-ZnO compared to that from only ZnO. A very small intensity of the visible photoluminescence peak observed at 550 nm proves that the ZnO nanorods have very low concentrations of point defects such as oxygen vacancies and zinc interstitials. The photocurrent in the visible region has been significantly enhanced due to deposition of CdS on the surface of the ZnO nanorods. CdS acts as a visible sensitizer because of its lower band gap compared to ZnO.

Fabrication and characterization of CdS film, nanowires and nanobelts grown by VPE

  • Son, Moon-A;Lee, Dong-Jin;Kang, Tae-Won
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.69-69
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    • 2010
  • The research is the structural and optical characteristics of the Cadmium Sulfide(CdS) film, nanowires and nanobelts grown on the $Al_2O_3$ substrate using the vapor phase epitaxy method. The field-emission scanning electron microscopy(FE-SEM) were used to identify the shape of the surface of the nanostructures and x-ray diffraction(XRD) and transmission electron microscopy (TEM) were used to evaluate the structural characterisitcs. As a result, the XRD was confirmed the CdS peak and the substrate peak and TEM showed single crystals with wurtzite hexagonal structure on the nanostructures. As for the optical characteristic of the nanostructures, photoluminescence(PL) and micro-raman spectrum were measured. The PL measurements confirmed the emission peak related bound exciton to neutral donor($D^0X$) peak and free exciton(FX) peak. The micro-raman spectrum showed that the peak of the nanostructures were similar to the pure crystalline CdS peak and each peak were overtone of LO phonon of the hexagonal CdS of the longitudinal optical(LO) phonon mode. Therefore, it is confirmed that the CdS nanostructures grown in this research have superior crystallinity.

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Interaction of Cu(II)-meso-tetrakis(n-N-methylpyridiniumyl)porphyrin (n = 2,3,4) with Native and Synthetic Polynucleotides Probed by Polarized Spectroscopy

  • Lee, Mi-Jin;Lee, Gil-Jun;Lee, Dong-Jin;Kim, Seog-K.;Kim, Jong-Moon
    • Bulletin of the Korean Chemical Society
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    • 제26권11호
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    • pp.1728-1734
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    • 2005
  • The interactions of Cu(II)-meso-Tetrakis(n-N-methylpyridiniumyl)porphyrin (n = 2,3,4), respectively referred to as o-, m- and p-CuTMPyP, and DNA, poly$[d(A-T)_2]$ and poly$[d(G-C)_2]$ were investigated by circular and linear dichroism (CD and LD). In the o-CuTMPyP case, in which the rotation of the pyridinium ring is prevented, the shape of the CD spectrum when associated to DNA and poly$[d(A-T)_2]$ resembles and is characterized by a positive band at a low drug to DNA concentration ratio (R ratio) and is bisignate at a high R ratio. The former CD spectrum shape has been attributed to porphyrin that is bound monomerically outside of DNA while the latter can be attributed to those that are stacked. When o-CuTMPyP is bound to poly$[d(G-C)_2]$, the excitonic CD appeared at a relatively high R ratio. In contrast, a characteristic negative CD band in the Soret region was apparent for both m- and p-CuTMPyP when bound to DNA and poly$[d(G-C)_2]$ at the low R ratios, indicating that the porphyrin molecule intercalates. However, the DNA is bent near the intercalation site and the plane of the porphyrin molecule tilts relative to the DNA helix axis, as judged by the magnitude of the reduced LD. Various stacking patterns were identified by the shape of the CD spectrum for m- and p-CuTMPyP when bound to poly$[d(A-T)_2]$. Three species for the former complex and two for the latter complex were found which may reflect the extent of the stacking.

Effect of Heat Treatment and Platinum Loading on CdS Particles in the Photocatalytic Alanine Synthesis

  • Lee, Bu-Yong;Kim, Bong-Gon;Cho, Cheol-Rae;Sakada, Tadayoshi
    • Bulletin of the Korean Chemical Society
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    • 제14권6호
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    • pp.700-704
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    • 1993
  • The photocatalytic alanine and hydrogen production reaction were studied by using CdS as a semiconductor photocatalysts. The rate of alanine and hydrogen production depends strongly on the temperature in heat treatment of CdS powder. In particular, the rate of alanine production, which was observed using Pt/CdS(A)-(CdS from Mitsuwa), was increased about six times than that of using Pt/CdS(B)-(CdS from Furruchi) under the same heat treatment condition at 500$^{\circ}$C. And the photocatalytic activity for alanine production using bare CdS(A) or Pt/CdS(A) was almost same with increasing temperature in heat treatment in the range of 100-600$^{\circ}$C. From X-ray diffraction data and photoluminescence spectrum, we conclude that the crystal structure changes of CdS(A) or strong interaction at interface of Pt and CdS contribute to increasing the rate of alanine and hydrogen production reaction.

대전 지역의 공단 폐수에서 분리한 수은과 카드뮴 내성 세균의 분리 및 특성 (Lsolation and Characterization of Mercury- and Cadmium-resistant Bacteria isolated from Industrial complex Wastewater of Taejon Area)

  • 유경만;전희근
    • 한국환경과학회지
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    • 제6권3호
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    • pp.249-258
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    • 1997
  • Mercury- and cadmium-resistant bacteria were Isolated from an Industrial complex wastewater of Taejon area. All of them were motile, gram negative rods. In the results of physicochemical test and VITEK card test. HM1 was Identified with Achetobacter cd- coaceucus, CM3 was Identified 65 Commonas acidovorns, HM2, HM3, CMI , and CM4 were Pseudomonas sp., but HM4 and CM2 were unidenteed. They were tested for subceptlbility to 14 heavy metals. Mercury-resistant bacteria(HM1, HM2, HM3, and HM4) were sensitive to low concentration(100~400ppm) of $Cd^{2+}$, $Co^{2+}$. $Zn^{2+}$, and Ni2+, while cadmium-resistant bacteria(CM1, CM2, CM3, and CM4) showed resistance up to the high concentration(600~ 1, 200ppm) of these metal loons. As a result of resistance spectrum test of mercury-resistant bacteria, HM1 was broad-spectrum strain, HM2. HM3, and HM4 were narrow-spectrum stratas. Transmission electron microscopic examination of cell wall of HM1 culture grown with and without 100ppm of $HgCl_2$ showed remarkably merphological abnormalities. In the result of atomic absorption spectrometric analysis of cadmium-resistant bacteria grown at 200ppm of $CdCl_2$ for 6h, all of them accumulated cadrnium(14ppm~57ppm) In cell. In cadinium-resistant bacteria, CM1, CM2, and CM4 were spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$, CM4 were also spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$ as well as $Zn^{2+}$.

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