• 제목/요약/키워드: CD-E

검색결과 1,230건 처리시간 0.033초

HgCdTe 반도체 재료의 C-V 특성 계산 (A Calculation of C-V characteristics for HgCdTe Semiconductor material)

  • 이상돈;강형부;김봉흡;김동호;김재묵
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 B
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    • pp.813-815
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    • 1992
  • Accurate Capacitance-Voltage characteristics of Metal-Insulator-Semiconductor (MIS) devices in narrow band-gap semiconductors are presented. The unique band structure of narrow band-gap semiconductors is taken into account such as non-parabolicity and degeneracy. Compensated and partially ionized impurities either in the bulk or the space charge region are also considered. HgCdTe is a defect semiconductor, so this approach is very important for characterization and analysis of MIS devices.

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$Cd_4SnSe_6:Co^{2+}$ 단결정의 성장 (Crystal Growth of $Cd_4SnSe_6:Co^{2+}$ Single Crystals)

  • 김덕태;송민종;김형곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.607-608
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    • 2005
  • In this paper, author describe the undoped and $Co^{2+}$(0.5mole%) doped $Cd_4SnSe_6$ single crystals were grown by the chemical transport reaction(CTR) method. The grown single crystals crystallize in the monoclinic structure of space group Cc and have the direct band gap structure. The energy gaps of them are 1.68 eV for $Cd_4SnSe_6$ and 1.50 eV for $Cd_4SnSe_6:Co^{2+}$ at 300K respectively.

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Bridgman법에 의한 $Cdln_2Te_4$단결정의 성장과 가전자대 갈라짐에 대한 광전류 연구 (Photocurrent study on the splitting of the valence band and growth of $Cdln_2Te_4$ single crystal by Bridgman method)

  • 홍광준;이관교;이봉주;박진성;신동찬
    • 한국결정성장학회지
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    • 제13권3호
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    • pp.132-138
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    • 2003
  • 수평 전기로에서 $CdIn_2Te_4$ 다결정을 용응법으로 합성하고 Bridgman법으로 tetragonal structure의 $CdIn_2Te_4$ 단견정을 성장시켰다. c축에 수직한 시료의 광흡수와 광전류 spectra를 293k에서 10K까지 측정하였다. Hall효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293 K에서 각각 $8.61\times 10^{16}\textrm{cm}^3,\;242\textrm{cm}^$V .s였다. $CdIn_2Te_4$ 단결정의 광흡수와 광전류 spectra를 293k에서 10K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap $E_g$(T)는 Varshni 공식에 따라 계산한 결과 $1.4750ev - (7.69\times10^{-3})\; ev/k)\;T^2$/(T + 2147k)이었다. 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting Δcr값이 0.2704 eV이며 spin-orbit $\Delta$so값은 0.1465 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n : 1일때 $A_\;{1-} B_\;{1-}$$C_\;{1-}$-exciton봉우리임을 알았다

Expression and Characterization of catA1 (catechol 1,2-dioxygenase I1) of Acinetobacter lwoffii K24 in Escherichia coli

  • Kim, Seung-Il;Kweon, Soo-Mi;Kim, Soo-Hyun;Ha, Kwon-Soo
    • BMB Reports
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    • 제30권5호
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    • pp.342-345
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    • 1997
  • Catechol 1,2-dioxygenase $I_1$ (CD $I_1$) gene of Acinetobacter Iwoffii K24, $catA_1$ was expressed in Escherichia coli and was partially purified by using a MonoQ column. Expressed CD $I_1$ had the same molecular weight as purified CD $I_1$ from A. Iwoffii K24 on SDS-PAGE. Expressed CD $I_1$ was also identified by Western blotting and peptide sequencing of N-terminal and internal regions. When compared with purified CD $I_1$ of A. Iwoffii K24, expressed CD $I_1$ had similar substrate specificities and the effects of compounds on enzyme activity. N-terminal amino acid sequence of CD I expressed in E. coli was the same as that of purified CD $I_1$, suggesting that CD $I_1$ may be under the same posttranslational processing in E. coli and A. Iwoffii K24.

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만성 카드뮴 중독 흰쥐에서 카드뮴 축적과 배설에 미치는 Vitamin E의 영향 (Effect of Vitamin E on Cadmium Accumulation and Excretion in Chronic Cadmium Poisoned Rats)

  • 김미지;홍정희;이순재
    • Journal of Nutrition and Health
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    • 제36권7호
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    • pp.691-698
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    • 2003
  • The purpose of this study was to investigate the effect of vitamin E on the cadmium accumulation in body, cadmium excretion and detoxification functions in chronic cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal group and three cadmium poisoned groups. Cadmium poisoned groups were classified to vitamin E free diet (Cd-0E group), vitamin E 40 mg/kg diet (Cd-400E group) and 400 mg/kg diet (Cd-400E group) according to the levels of vitamin E supplement. Animals were maintained on 0, 40 mg and 400 mg vitamin E/kg diets for 20 weeks and simultaneously administered 50 ppm Cd$^{2+}$ dissolved in the drinking water. Body weight, food intakes and food efficiency ratio were significantly decreased in all cadmium groups, compared with those of normal group. The accumulation of cadmium in rat liver, kidney and blood was reduced by sufficient vitamin E supplementation. The metallothionein (MT) content in liver and kidney were increased in all cadmium groups compared with that of normal group. The ratio of cadmium absorption and retention were significantly decreased in vitamin E supplementation groups. Accordingly, vitamin E supplementation resulted in an excretion of cadmium in urine and feces and a lowered accumulation of cadmium in liver and kidney. It can be suggested that increased MT synthesis lead to the significant decrease in cadmium absorption and retention ratios.s.

Hot Wall Epitaxy 법에 의한 CdIn2S4 단결정 박막의 성장과 광전류 특성 (Growth and Photocurrent Properties of CdIn2S4/GaAs Single Crystal Thin Film by Hot Wall Epitaxy)

  • 이상열;홍광준;박진성
    • 센서학회지
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    • 제11권5호
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    • pp.309-318
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    • 2002
  • 수평 전기로에서 $CdIn_2S_4$ 다결정을 합성하여 HWE(Hot Wall Epitaxy)방법으로 $CdIn_2S_4$ 단결정 박막을 반절연성 GaAs (100)기판에 성장시켰다. $CdIn_2S_4$ 단결정 박막의 성장 조건은 증발원의 온도 $630^{\circ}C$, 기판의 온도 $420^{\circ}C$였고 성장 속도는 $0.5\;{\mu}m/hr$였다. $CdIn_2S_4$ 단결정 박막의 결정성의 조사에서 10 K에서 광발광(photoluminescence) 스펙트럼이 463.9 nm (2.6726 eV)에서 exciton emission 스펙트럼이 가장 강하게 나타났으며, 또한 이중 결정 X-선 요동 곡선(DCRC)의 반폭치(FWHM)도 127 arcsec로 가장 작아 최적 성장 조건임을 알 수 있었다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 $9.01{\times}10^{16}/cm^3$, $219\;cm^2/V{\cdot}s$였다. $CdIn_2S_4$/SI(Semi-Insulated) GaAs(100) 단결정 박막의 광흡수와 광전류 spectra를 293K에서 10K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap $E_g(T)$는 Varshni 공식에 따라 계산한 결과 $2.7116eV-(7.74{\times}10^{-4}eV/K)T^2$/(T+434K)이었으며 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting ${\Delta}cr$값이 0.1291 eV이며 spin-orbit ${\Delta}so$값은 0.0248 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n = 1일때 $A_1$-, $B_1$-와 $C_1$-exciton 봉우리임을 알았다.

광전류 측정으로부터 얻어진 $CdGa_2Se_4$ 에피레이어의 결정장 갈라짐에 대한 에너지 (Crystal field splitting energy for $CdGa_2Se_4$ epilayers obtained by photocurrent measurement)

  • 홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.144-145
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    • 2009
  • Single crystal $CdGa_2Se_4$ layers were grown on a thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with the hot wall epitaxy (HWE) system by evaporating the poly crystal source of $CdGa_2Se_4$ at $630\;^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $CdGa_2Se_4$ thin films measured with Hall effect by van der Pauw method are $8.27\;\times\;10^{17}\;cm^{-3}$, $345\;cm^2/V{\cdot}s$ at 293 K, respectively. The photocurrent and the absorption spectra of $CdGa_2Se_4$/SI(Semi-Insulated) GaAs(100) are measured ranging from 293 K to 10K. The temperature dependence of the energy band gap of the $CdGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) = 2.6400 eV - ($7.721\;{\times}\;10^{-4}\;eV/K)T^2$/(T + 399 K). Using the photocurrent spectra and the Hopfield quasi cubic model, the crystal field energy(${\Delta}cr$) and the spin-orbit splitting energy(${\Delta}so$) for the valence band of the $CdGa_2Se_4$ have been estimated to be 106.5 meV and 418.9 meV at 10 K, respectively. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-, and $C_{11}$-exciton peaks.

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Hot Wall Epitaxy(HWE)법에 의해 성장된 $CdIn_2S_4$ 단결정 박막의 가전자대 갈라짐에 대한 광전류 연구 (Photocurrent Study on the Splitting of the Valence Band and Growth of $CdIn_2S_4$/GaAs Single Crystal Thin Film by Hot Wall Epitaxy)

  • 백승남;홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.79-80
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    • 2006
  • A stoichiometric mixture of evaporating materials for $CdIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CdIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-Insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The temperature dependence of the energy band gap of the $CdIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation. $E_g(T)=2.7116 eV-(7.74{\times}10^{-4} eV)T^2/(T+434)$. The crystal field and the spin-orbit splitting energies for the valence band of the $CdIn_2S_4$ have been estimated to be 0.1291 eV and 0.0248 eV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $AgInS_2$/GaAs epilayer. The three photocurrent peaks observed at 10K are ascribed to the $A_1-$, $B_1-$, and C1-exciton peaks for n = 1.

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상황(桑黃)버섯의 면역증진(免疫增進)에 관(關)한 연구(硏究) (A Study on the Immune activaty of Phellinus Linteus Extracts)

  • 임의수;최병렬;유화승;이용연;서상훈;조정효;이연월;손창규;조종관;이용구;송기철
    • 대한한방종양학회지
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    • 제8권1호
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    • pp.93-101
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    • 2002
  • Objectives This experimental study was carried out to evaluate the effects of Phellinus Linteus on immune activation. Methods In order to investigate the effect of Phellinus Linteus, the following was performed: The fraction of $CD4^+$, $CD8^+$, $CD19^+$ in splenic cell, gene expression of IL-12 (p35), IL-12 (p40) , $IFN-{\gamma}$, and splenic cell proliferation by PL-E. Results PL-E helped $CD4^+$, $CD8^+$, $CD19^+$ expression more effectively compared with control group. PL-E helped IL-12 (p35), IL-12 (p40), $IFN-{\gamma}$ gene expression in splenic cells more effectively compared with control group. PL-E proliferated splenic cells more effectively compared with control group. Conclusions: It is suggested that PL-E is able to activate immune response system.

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Effects of Mix-1 on Anti-CD40 Antibody and Recombinant IL4- Induced Cytokine Production and Immunoglobulin E in Highly Purified Mouse B Cells

  • Kim Jung Hwan;Choi Sun Mi;Lee Yong Gu;Namgoong Uk;Kim Dong Hee
    • 동의생리병리학회지
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    • 제18권6호
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    • pp.1869-1880
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    • 2004
  • In the oriental medicine, a mixture of herbs has been commonly used as important components to control allergic and inflammatory diseases. In the present study, we prepared a mixture of Dictamni Radicis Cortex(Baiksunpee), Houttuyniae Herba(Uhsungcho), and Aurantii Immaturus Fructus(Jisil) to examine its anti-allergic effects in activated mouse splenic cells and found that Mix-1 is involved in regulating levels of B cell activating factors (CD23 and CD11a), IL-1β, IL-6, IL-10, TNF-α, and 1gE as well as HRF expression. It was observed that Mix-1 did not have cytotoxic effects on mLFC. Mix-1 showed inhibition of CD23 and CD11 alpaha expression in mouse B cells, and also decreased the production of IL-6, TNF-α, and 1gE. Both RT-PCR and ELISA analyses indicated that IL-6 and TNF alpha production were regulated at the gene expression level. In contrast, IL-10 mRNA and protein levels were increased in activated B cells by Mix-1 treatment. We also found that Mix-1 inhibited B cell proliferation and inhibited histamine releasing factor(HRF) expression, suggesting its inhibitory effect on histamine secretion. These data indicated that Mix-1 has an anti-allergic effect in activated macrophages and further suggest the possible application of Mix-1 as a therapeutic agent for the treatment of allergy-related diseases.