• 한국세라믹학회지
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• 제27권8호
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• pp.965-970
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• 1990

A nitrogenation of coal ash in the presence of carbon was carried out to examine the effects of reaction temperature, reaction time and carbon composition on the formation of AlN, SiC and Si3N4. Decreasing the particle size increased the formation of AlN and its maximum composition in the product was obtaiend under 1450~150$0^{\circ}C$, 2 hours of reaction time and about 30% of carbon addition(on the basis of sample weight). Compositions of SiC and Si3N4 were distributed to the opposite so that SiC showed a higher composition compared with Si3N4 at a lower temperature, a shorter reaction time and a greater carbon addition.

• Bulletin of the Korean Chemical Society
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• 제8권4호
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• pp.270-272
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• 1987

1,1-Dichloro-2,3,4,5-tetraphenyl-1-silacyclopenta- 2,4-diene was synthesized through the reaction of $SiCl_4$ with 1,4-dilithiotetraphenylbutadiene in 50% yield. From the reaction of this silole with metal, an air sensitive red-brownish solid was obtained. Treatment of this reaction product with $CH_3I\; and\; Me_3SiCl$ gave 1,1-dimethyl-2,3,4,5-tetraphenyl-1-silacyclopenta- 2,4-diene and 1,1-bis(trimethylsilyl)-2,3,4,5-tetraphenyl-1-silacyclopenta-2,4-diene, respectively. From these results, the formation of reactive 2,3,4,5-tetraphenyl-1-silacyclopenta-2,4-dienyl dianion was confirmed.

• 공업화학
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• 제10권5호
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• pp.772-777
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• 1999

$Y_2Ba_1Cu_1O_5(Y211)$ 분말은 출발물질로서 $Y_2O_3(99.9%)$, $BaCO_3(99.9%)$, and CuO(99.9%) 분말을 사용하여 고상반응법과 발화합성법을 이용하여 제조하였다. $Y_2Ba_1Cu_1O_5(Y211)$ 분말에 대한 상형성과 반응속도는 열처리 온도와 반응시간에 따른 시료들을 X-선 회절분석을 이용하여 연구하였다. X-선 회절선으로부터 측정된 전화율($X_{211}$)과 반응특성으로부터 상 형성속도가 분말의 입자크기에 의해 지배되는 것을 알 수 있었다. 그리고 발화합성법으로 제조된 Y211상의 활성화에너지(${\Delta}E_a$)는 고상반응법에 의해 제조된 것의 149.46 kJ/mol과 비교할 때 136.42 kJ/mol을 나타내었다. $Y_2Ba_1Cu_1O_5$계에서의 활성화에너지 값은 발화합성법이 고상반응법보다 더욱 효율적인 방법임을 보였다.

• 생약학회지
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• 제12권2호
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• pp.88-93
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• 1981

One hundred and forty-four extracts have been tested for the presence of saponins, using the method of froth formation, precipitate formation by acid hydrolysis, Liebermann-Buchard reaction on the acid hydrolysate, and hemolytic activity of the extracts. Among the samples tested, thirteen extracts showed positive saponin reaction in all the tests employed and one hundred and thirty-six showed positive in one or more tests of saponins. The results are tabulated.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
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• pp.104-104
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• 2009

• 분석과학
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• 제8권4호
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• pp.821-827
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• 1995

Polychlorodibenzo-p-dioxins(PCDDs) have been prepared by microsacale pyrolysis of trichlorophenates. During the pyrolysis reaction, dechlorinated dibenzo-p-dioxins were also formed by the thermolysis of PCDDs. The dechlorination pathways of PCDDs were suggested in this reaction. The identification of these products was performed using capillary column gas chromatography-mass spectrometry.

• 전자공학회논문지A
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• 제28A권5호
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• pp.375-379
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• 1991

Formation of TiAs precipitate through the reaction between TiSi2 with C54 structure and heavily doped arsenic ion in poly-silicon, and influence of TiSAs and silicon distribution resulted from the reaction TiSi2+As ->2Si on the morphology degradation have been studied.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1164-1166
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• 2009

Aromatic aldehydes are efficiently self-condensed into $\alpha$-hydroxy carbonyl compounds by polystyrene-supported ammonium cyanide as an excellent organocatalyst in C-C bond formation. The reaction proceeds in water under mild reaction conditions. The polymeric catalyst can be easily separated by filtration and reused several times without appreciable loss of activity.

• Bulletin of the Korean Chemical Society
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• 제5권6호
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• pp.211-215
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• 1984

Reaction of thianthrene cation radical perchlorate (1) with tert-butyl peroxide (TBP) in acetonitrile gave thianthrene (2), thianthrene 5-oxide (3), cis-thianthrene-5,10-dioxide (4), 5-acetonylthianthrenium perchlorate (9), along with small amount of thianthrene-5,5-dioxide (7) in some cases. Isolation of N-tert-butylacetamide indicated the formation of tert-butyl cation from TBP. The formation mechanisms of these products were proposed.

• Bulletin of the Korean Chemical Society
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• 제16권4호
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• pp.356-359
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• 1995

The reaction of 5-aryl-2-phenylisoxazolidine-3-thiones with more than 3 equivalents of anhydrous aluminum chloride in benzene at reflux gave N-(p-biphenylyl)-3-aryl-3-phenylpropanothioamides in good yields. It is conceived that the propanothioamides are formed via the formation of the corresponding N-phenyl-3-aryl-3-phenylpropanothiohydroxamic acids.