• 한국전기전자재료학회논문지
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• 제33권2호
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• pp.155-160
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• 2020

Ga₂O₃/n-type 4H-SiC heterojunction diodes were fabricated by RF magnetron sputtering. The optical properties of Ga₂O₃ and electrical properties of diodes were investigated. I-V characteristics were compared with simulation data from the Atlas software. The band gap of Ga₂O₃ was changed from 5.01 eV to 4.88 eV through oxygen annealing. The doping concentration of Ga₂O₃ was extracted from C-V characteristics. The annealed oxygen exhibited twice higher doping concentration. The annealed diodes showed improved turn-on voltage (0.99 V) and lower leakage current (3 pA). Furthermore, the oxygen-annealed diodes exhibited a temperature cross-point when temperature increased, and its ideality factor was lower than that of as-grown diodes.

• 대한화학회지
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• 제31권3호
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• pp.225-230
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• 1987

0.8mol%의 CdO가 도프된 $CdO-La_2O_3$계의 전기전도도를 및 $10^{-7}{\sim}10^{-1}atm$의 산소분압하에서 측정하였다. 일정한 산소분압하에서 log ${\sigma}$ vs. 1/T도시는 직선관계를 보여주었고 직선의 기울기에서 구한 활성화에너지는 0.97eV이다. $500{\sim}900^{\circ}C$영역에서 log ${\sigma}$vs. log $PO_2$의 도시결과는 직선 관계를 나타내었으며 전기전도도의 산소분압 의존성은 ${\sigma}\;{\alpha}\;PO_2^{1/4}$이다. $CdO-La_2O_3$계의 결함구조는 ${V_{La}}^{'''}$ 와V\"{o}$의 혼합형으로 사료되며, 전기전도도의 온도의존성과 산소분압의존성으로부터 혼합형의 결함구조 반응식을 유도하였으며, $CdO-La_2O_3$계의 전기전도 메카니즘을 결함구조반응식으로부터 규명하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.194-197
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• 2002

Applying dual layer insulator on plastic substrates improved electrical characteristics of organic thin film transistor(TFT). A high-quality silicon dioxide(SiO$_2$) suitable for a insulator was deposited on plastic substrates by e-beam evaporation at 110$^{\circ}C$. The insulator film which was treated by N$_2$ annealing at 150$^{\circ}C$ showed excellent I-V, C-V characteristics. The dual layer insulator structure of polyimide-SiO$_2$ improved the roughness of SiO$_2$ surface and showed very low leakage current. In addition, the flat band voltage has been reduced from -2.5V to about 0.5V.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 춘계학술대회 논문집
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• pp.8-13
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• 2007

2005년 남극의 해빙을 촬영한 Kompsat-1 EOC 영상을 이용하여 SSM/I와 AMSR-E 해빙 면적비를 비교， 분석하였다. EOC 영상은 남극의 봄철에 해당하는 9-11월 사이에 남극 대륙의 가장자리를 가로지르는 11 개 궤도로부터 총 676개 영상이 획득되었으며， 이 중 대기 및 광량 조건이 양호한 68개 의 영상을 선별하였다. EOC 영상에 감독분류 방볍 을 적 용하여 표면 유형 을 White ice(W), Grey ice(G), Dark-grey ice(D), Ocean(O)로 분류하였고 해빙 면적비를 산출하였으며, 이를 NASA Team Algorithm(NT)으로 계산된 SSM/I 해빙 면적비, NASA Team2 Algorithm(NT2)으로 계산된 AMSR-E 해빙 면적비와 비교하였다. 남극의 봄철에 SSM/I 해빙 면적비는 EOC W+G 면적비와 잘 일치하였고，AMSR-E 해빙 면적비는 EOC W+G+D 면적비와 좋은 상관성을 나타내었다. 따라서 이 시기의 남극 SSM/I NT 해빙 면적비는 W와 G만을 반영하며, AMSR-E NT2 해빙 면적비는 D도 포함하는 것을 알 수 있었다. 또한 AMSR-E가 SSM/I보다 높은 해빙 면적비를 나타내는 것을 확인하였으며，두 수동 마이크로파 해빙 면적비의 차이는 EOC D 면적비와 높은 상관성을 보였다. 이로부터 EOC 영상에서 분류된 D와 NT2에 서 고려되는 Ice type C가 서로 유사한 해빙 유형임을 추정할 수 있었다.

• 한국한의학연구원논문집
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• 제1권1호
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• pp.1-14
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• 1995

The clinical study was carried out on 1737 cases of inpatient and outpatient which have been diagnosed as C.V.A at hospital attached to 8 colleges of oriental medicine in Korea or National Medical Center from January 1st 1994 to December 31st 1994. The results were as follows; 1. In this study, the case of Occlusive C.V.D was 70.1%, Cerebral hemorrhage was 20.5%, Transient ischemic attack (T.I.A) was 5.3%, Subdural hemorrhage was 3.0%, Subarachnoid hemorrhage was 0.8% 2. It was confirmed by C.T (20%), E.K.G. (19%), X-ray (19%), Urinalysis (19%), Hematoscopy (20%). 3. The mean days of hospital treatment was 27.88 days, mean days of ambulation was 70.34 days. The mean days of hospital treatment of Occlusive C.V.D, Cerebral hemorrhage, T.I.A., Subdural hemorrhage, Subarachnoid hemorrhage were 25.79, 39.32, 12.49, 16.23, 23.40 days, respectively. The mean days of ambulation of Occlusive C.V.D, Cerbral hemorrhage, T.I.A., Subdural hemorrhage, Subarachnoid hemorrhage were 74.40, 93.68, 69.10, 29.75, 32.57 days, respectavely. 4. Oriental medical treatment of C.V.A was mainly Acupuncture (25%), Paper of Chinese herbs (22%), Chinese physiotherapy (14%), Extract of Chinese herbs (11%). 5. Oriental medical physiotherapy for C.V.A was mostly E.S.T., Kinesiatrics, electric negative therapy, others Aerohydrotherapy, interferential current therapy (I.C.T.), Carbon, Samhogi, T.E.N.S., Ultra-sound, Infra-red, Microwave, T.D.P., Ultraviolet, S.S.P., Chinese herbs beth, Prarffin bath, Magnetic treatment and tractions.

• 식물조직배양학회지
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• 제27권5호
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• pp.145-145
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• 2000

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.93-97
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• 1991

Rate constants have been measured spectrophotometrically for the reactions of alkali metal ethoxides with 4-nitrophenyl benzoate, S-4-nitrophenyl thiobenzoate and 4-nitrophenyl thionbenzoate in ethanol at 25$^{\circ}$C. Substitution of S for O in the leaving group has not affected reactivity significantly, while the effect of the similar replacement in the acyl group has led to rate decrease by a factor of 10, although pronounced rate enhancements have been expected for both systems. The replacement of O by a polarizable S has also influenced the reactivity of the esters toward alkali metal ethoxides, i.e. the reactivity decreases as the size of the metal ion decreases. The alkali metal ions have showed inhibition effect instead of catalytic effect which would have been expected for the present system. The effect of replaced sulfur atom on the reactivity for the present system is attributed to the nature of hard and soft acids and bases.

• 한국재료학회지
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• 제11권10호
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• pp.889-894
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• 2001

2wt% $Al_2O_3-doped$ ZnO (AZO) thin films were deposited on sapphire (0001) single crystal substrate by parellel type rf magnetron sputtering at 55$0^{\circ}C$. The as-grown AZO thin films was polycrystalline and showed only broad deep defect-level photoluminescence (PL). In order to examine the change of PL property, AZO thin films were annealed in $N_2$ (N-AZO) and $H_2$ (H-AZO) at the temperature of $600^{\circ}C$~$1000^{\circ}C$ through rapid thermal annealing. After annealed at $800^{\circ}C$, N-AZO shows near band edge emission (NBE) with very small deep-level emission, and then N-AZO annealed at $900^{\circ}C$ shows only sharp NBE with 219 meV FWHM. In Comparison with N-AZO, H-AZO exhibits very interesting PL features. After $600^{\circ}C$ annealing, deep defect-level emission was quire quenched and NBE around 382 nm (3.2 eV) was observed, which can be explained by the $H_2$passivation effect. At elevated temperature, two interesting peaks corresponding to violet (406 nm, 3.05 eV) and blue (436 nm, 2.84 eV) emission was firstly observed in AZO thin films. Moreover, peculiar PL peak around 694 nm (1.78 eV) is also firstly observed in all the H-AZO thin films and this is believed good evidence of hydrogenation of AZO. Based on defect-level scheme calculated by using the full potential linear muffin-tin orbital (FP-LMTO), the emission 3.2 eV, 3.05 eV, 3.84 eV and 1.78 eV of H-AZO are substantially deginated as exciton emission, transition from conduction band maximum to $V_{ Zn},$ from $Zn_i$, to valence band maximum $(V_{BM})$ and from $V_{o} to V_BM}$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집
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• pp.47-52
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• 2004

$HgGa_2S_4$ single crystals were grown by the chemical transport reaction method. The $HgGa_2S_4$ single crystal crystallized into a defect chalcopyrite structure $(I\bar{4})$. The lattice constants of the single crystal were found to be a=5.635 ${\AA}$ and c=10.473 ${\AA}$. The direct and indirect optical energy gaps were found to be 2.84 eV and 2.78 eV, respectively. Photoluminescence peaks of $HgGa_2S_4$ single crystal were observed at 2.37 eV, 2.18 eV, and 1.81 eV. In the single crystal, the donor level of 0.25 eV, the acceptor levels of 0.97 eV and 0.41 eV were obtained by TSC, PICTS, and absorption measurements. The photoluminescence peaks were analyzed to relate to the indirect conduction band, the donor level, and the acceptor levels.

• Bulletin of the Korean Chemical Society
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• 제2권4호
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• pp.125-129
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• 1981

The addition reactions of cysteine without blocking amino and carboxyl groups to substituted and unsubstituted ${\beta}$-nitro-styrene derivatives were investigated. ${\beta}$-Nitrostyrene(1a), p-methyl-${\beta}$-nitrostyrene(1b), 3,4,5-trimethoxy-$[\beta}$ -nitrostyrene(1c), $[\varpi}$-3,4-methylenedioxy-${\beta}$ -nitrostyrene(1d), o-, m- and p-chloro-${\beta}$ -nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) easily undergo addition reactions with cysteine to form S-(2-nitro-1-phenylethyl)-L-cysteine(3a), S-[2-nitro-1-(p-methyl)phenyl-ethyl]-L-cysteine(3b), S-[2-nitro-1-(3',4',5'-trimethoxy) phenylethyl]-L-cysteine(3c), S-[2-nitro-1-($[\vatpi}$ -3',4'-methylenedioxy)phenylethyl]-L-cysteine(3d), S-[2-nitro-1-(o-chloro)phenylethyl]-L-cysteine(3e), S-[2-nitro-1-(m-chloro)-phenylethyl]-L-cysteine(3f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-cysteine(3g), S-[2-nitro-1-(o-methoxy)phenylethyl]-L-cysteine(3h), S-[2-nitro-1-(m-methoxy)phenylethyl]-L-cysteine(3i) and S-[2-nitro-1-(p-methoxy)phenylethyl]-L-cysteine(3j), respectively. The structure of adducts were confirmed by means of UV-spectrum, IR-spectrum, molecular weight measurement and elemental analysis. The various factors effecting the yield of cysteine adducts to ${\beta}$-nitrostyrene derivatives were also studied.