• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.216-217
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• 2008

Zinc-oxide films were deposited by pulsed laser deposition (PLD) technique using doped ZnO target (mixed $In_2O_3$ 0.1, 0.3, 0.6 at. % - atomic percentage) on the p-type Si(111) substrate. A little Indium has added at the n-ZnO films for the electron concentration control and enhanced the electrical properties. Also, post thermal annealed ZnO films are shown an enhanced structural and controled electron concentration by the annealing condition for the hetero junction diode of a better emitting characteristics. The electrical and the diode characteristics of the ZnO films were investigated by using Hall effect measurement and current-voltage measurement.

• 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.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2003-2008
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• 2007

The aminolysis of diphenyl thiophosphinic chloride (2) with substituted anilines in acetonitrile at 55.0 oC is investigated kinetically. Kinetic results yield large Hammett ρX (ρnuc = ?3.97) and Bronsted βX (βnuc = 1.40) values. A concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state is proposed on the basis of the primary normal kinetic isotope effects (kH/kD = 1.0-1.1) with deuterated aniline (XC6H4ND2) nucleophiles. The natural bond order charges on P and the degrees of distortion of 42 compounds: chlorophosphates [(R1O)(R2O)P(=O)Cl], chlorothiophosphates [(R1O)(R2O)P(=S)Cl], phosphonochloridates [(R1O)R2P(=O)Cl], phosphonochlorothioates [(R1O)R2P(=S)Cl], chlorophosphinates [R1R2P(=O)Cl], and chlorothiophosphinates [R1R2P(=S)Cl] are calculated at the B3LYP/ 6-311+G(d,p) level in the gas phase.

• 공업화학
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• 제29권2호
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• pp.196-200
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• 2018

본 연구에서는 복합 수소분리막 중간층의 pin hole, crack 및 defect를 최소화하기 위하여 powder type과 sol type의 금속산화물을 이용하여 복합화하였다. 중간층의 표면 형상과 투과 특성은 주사전자현미경(SEM) 분석과 $N_2$ 투과도 테스트를 통해 평가하였으며, 제조한 수소분리막의 성능평가를 위해 $N_2$와 $H_2$를 이용하여 단일가스 투과 테스트를 수행하였다. Powder type과 sol type의 금속산화물을 각각 이용하여 중간층을 적층한 결과 sol type 금속산화물을 이용하여 적층한 중간층의 표면 조도가 매우 낮았으며, 특히 $TiO_2$ sol로 형성된 중간층의 pin-hole, crack 및 defect가 현저히 감소하였다. Powder와 sol을 복합화하여 적층한 중간층은 sol로 형성된 중간층과 거의 유사한 특성을 보였으며, 이를 기반으로 제조한 수소분리막은 1 bar의 압력구배, 672 K의 온도에서 약 $0.32mol/m^2s$의 수소 투과도를 나타내었으며, 선택도는 약 10,890 이상으로 측정되었다.

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.634-641
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• 1998

Quasiclassical trajectory calculations were carried out for the reactions of $H+H_2$ (V=O, J=O) and its isotope variants on the Siegbahn-Liu-Truhlar-Horowitz potential energy surface for the relative energies E between 6 and 150 kcal/mol. The goal of the work was to understand the inter- and intramolecular isotope effects. We examine the relative motion of reactants during the collision using the method of analysis that monitors the intermolecular properties (internuclear distances, geometry of reactants, and final product). As in other works, we find that the heavier the incoming atom is, the greater the reaction cross section is at the same collision energy. Using the method of analysis we prove that the intermolecular isotope effect is contributed mainly by differences in reorientation due to the different reduced masses. We show that above E=30 kcal/mol recrossing also contributes to the intermolecular isotope effect. For the intramolecular isotope effect in the reactions of H+HD and T+HD, we reach the same conclusions as in the systems of $O(^3P)+HD$, F+HD, and Cl+HD. That is, the intramolecular isotope effect below E=150 kcal/mol is contributed by reorientation, recrossing, and knockout type reactions.

• 대한화학회지
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• 제39권7호
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• pp.530-537
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• 1995

$MCl_z(M=Mo;\;z=5,\;M=V;\;z=3)$과 N, P 주개 리간드를 acetonitrile 용매에서 반응시켜 중성 착물 $MCl_3(phda)(MeCN)]과 \; [MCl_3(PPh_3)_2(MeCN)](M=Mo,\;V)$을 합성하였다. Acetone 용액에서 이들 중성 착물과 AgClO_4$를 반응시켜 양이온 착물 $MCl_{3-n}L_2(MeCN)(S)_n](ClO_4)_n$(n=1,2:s=solvent)을 얻었다. 염소가 연결된 $[(MeCN)(phda)ClM({\mu}-Cl)_2M'Cl(PPh_3)_2(MeCN)](ClO_4)_2$ 및 pyrazine이 연결된 $[(MeCN)(phda)Cl_2M({\mu}-pyz)M'Cl_2(PPh_3)_2(MeCN)](ClO_4)_2$형의 호모(M=M'), 헤테로 $(M{\neq}M')$ 이핵 착물을 합성하였다. 합성한 착물들은 원소분석과 적외선, $^1H,\;^13C$ 핵자기 공명 및 전자 흡수스펙트럼을 이용하여 그 특성을 조사하였다.

• 설비공학논문집
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• 제14권10호
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• pp.775-780
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• 2002

An experimental study on the characteristics of several kinds of packing materials was carried out in order to get the optimum design data for the packed-type rectification system of an NH$_3$/$H_2O$ GAX absorption heat pump. Several suitable packing materials were examined and the bulk of steel wire was shown as the most effective packing material in rectifier. The optimum volumetric ratio of packed steel wire in rectifier was obtained as around 36%. The performance results can be adapted in rectifier design of absorption heat pump.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.118-122
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• 1996

1wt% Pt/MoO$_3$ gas sensors for detecting H$_2$ gas were fabricated by the pressed pellet method and surface structures of Pt/MoO$_2$ were investigated by TEM and XRD. It was observed that as the calcination temperature is increased, the overlayers of MoO$_3$ on Pt are produced, but the Cl content in PtCl$\_$x/ are decreased. H$_2$ gas sensing properties in N$_2$ ambient and in air ambient were investigated, respectively, and Pt/MoO$_3$ had high sensitivity at low working temp ; 7.8% at 50$^{\circ}C$, 97.7% at 100$^{\circ}C$, 97.1% at 150$^{\circ}C$ when the specimens are treated at 400$^{\circ}C$, and 99.6% at 150$^{\circ}C$ when they are treated at 200$^{\circ}C$. It shows the development of a low-power type sensor is possible by using Pt/MoO$_3$.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2707-2710
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• 2012

The nucleophilic substitution reactions of O-ethyl phenyl phosphonochloridothioate with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from a secondary inverse DKIE ($k_H/k_D$ = 0.93) to a primary normal DKIE ($k_H/k_D$ = 1.28) as the substituent of nucleophile (X) changes from electron-donating to electron-withdrawing. These can be rationalized by the gradual transition state (TS) variation from a backside to frontside attack. A concerted $S_N2$ mechanism is proposed. A trigonal bipyramidal TS is proposed for a backside attack while a hydrogen-bonded, four-center-type TS is proposed for a frontside attack.

• 한국표면공학회지
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• 제25권5호
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• pp.215-221
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• 1992

This research is aimed at developing(110) preferred TiS2 cathode films and glass typed solid electro-lytes which have high ionic migrations and low electron conductivities for thin secondary solid batteries. To obtain preferred oriented TiS2 thin films on a substrate by CVD method using TiCl4 and H2S gases three factors of heating temperature, inner pressure of furnace and TiCl4/H2S gas mole fraction were ex-amined systematically. To obtain solid films of Li2O-B2O3-SiO2 electrolytes by r.f. sputtering for thin proto-type batteries of Li/Li2O-B2O3-SiO2TiS2, sputtering conditions were examined. TiS2 cathode films showed columnar structure, namely c axis oriented parallely. At low pressure of reaction chamber and low heating temperature, surface of smooth TiS2 films couldd be obtained. Ionic conductivity of Li2O-B2O3-SiO2 films manufactured by r.f. magnetron sputtering were 3$\times$10-7$\Omega$-1cm-1 and electron conductivities were 10-11$\Omega$-1cm-1. Open cell voltage of thin lithium batteries were 2.32V with a designed prototype cell.