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2-Hydroxy-1-naphthaldehyde-4-pheny1-3-thiosemicarbazone을 사용하여 금(Ⅲ)의 용매추출 흡수광도법에 관한 연구
황교현 大田開放大學 1985 論文集 Vol.3 No.-
A solvent extraction-spectrophotometric method for the determination of gold using 2-hydroxy-1-naphthaIdehyde-4-phenyl-3-thiosemicarbazone (HNAPT) was studied. The method is based on the formation of an Insoluble gold(Ⅲ)-HHAPT complex, which Is extractable into ethylacetate from acidic solutions. The gold(Ⅲ)-HNAPT complex in ectylacetate exhibits a maximum absorption at 446 nm with apparent molar absorption coefficient of 2.08 × 10^4 1.mol^-1 cm^-1. Under the optimum conditions Beer's law is obeyed up to 100 ㎍ of gold(Ⅲ) In 10ml of ethylacetate. for 50 ㎍ of sold(Ⅲ), the coefficient of variation was 0.92% in 6 determinations. The recommended procedure is as follows: take an aliquot or sample solution containing up to 100 ㎍ of sold (Ⅲ) into a 50 ml-separately funnel. Add 7.5 ml of 3 mole/1 sulfuric acid solution, and dilute with water to about 30 ml (O.75 mole/1). Then add 10 ml of 2.5 × 10^-4 mole/l HNAPT ethylacetate solution and shake vigorously for 10 min. Filter the organic phase through a dry filter paper and measure the absorbance at 446 nm against reagent blank. By this method the gold (Ⅲ) in the presence of 500 ㎍ of silver (Ⅰ), cobalt (Ⅱ), Iron (Ⅲ), mercury (Ⅱ), Iridium (Ⅲ), nickel (Ⅱ),platinum (Ⅳ), titanium (Ⅳ) and vanadium (V) can be determined, although palladium (Ⅱ) seriously interfered. The method is simple, covenient and reproducible.
2, 2´ _dipyridylglyoxeal_bis(4,4_diphenylsemicarbazone)에 의한 닉켈(Ⅱ)의 용매추출 흡광광도법에 관한 연구
황교현 大田開放大學 1986 論文集 Vol.5 No.-
The use of 2,2'-dipyridylgIyoxal-bis (4,4-diphenylsemicarbazone) (PGPC), which was prepared by refluxing a 1:2 mixture of 2,2'-dipyridylgIyoxal and 4,4-diphenylsemicarbazone, was proposed for the spectrophotometric determination of nickel (Ⅱ) by solvent extraction. PGPC reacted with nickel (Ⅱ) to form a water-insoluble complex, which could be extracted with chloroform. The extracted solution showed an absorption maximum at 420nm. The calibration curve obeyed Beer's law over the concentration range 1㎍/10ml to 12㎍/10ml of nickel (Ⅱ) at 420 nm in the range of pH 4.5 to 10.6. The apparent molar absorption coefficient of the complex in chloroform was 5.42×10^4 d㎥ mol^(-1) cm^(-1). The combining ratio of nickel and PGPC was confirmed to be 1:2 by both the continuous variation method and elementary analysis on the isolated PGPC-nickel (Ⅱ) complex. Following procedures were recommended for the determination of nicdel (Ⅱ); The sample solution containing less than 12㎍ of nickel (Ⅱ) in a 100ml separatory funnel was adjusted to pH 4.5 to 10.6 with acetate or ammonia buffer solution, and then 5ml of 5×10^(-4)M PGPC methanol solution was added. The solution was diluted to about 60ml with water, and was shaken with 10ml chloroform for 3 min. After separation to two phases, the absorbance of the complex in chloroform phase was measured at 420 nm against the reagent blank.
흡광 광도법에 의한 미량 텅그스텐의 분석법에 관한 연구
황교현 大田工業專門大學 1982 論文集 Vol.31 No.-
Zephiramine reacts with complex tungsten thiocyanate in to form light-yellow precitate. The precipitate is extracted with chloroform. The extract is stable for at least 5days and has absorption miximun at 405 ㎛. The mole ratio of tungsten to zephirarmina in the extracted species is 1 : 1 Beer's law holds for the chloroform extract when tungste-thiocyanate-zephiramine is extracted into 10.0 ㎖ of chloroform from 25.0 ㎖ of the sample solution containing 2×10^-6M~2×10^-5 M tungsten. Many ions except vanadate and molybdate do not interfere with the determination.
(N-alkyl quinolinium)-TCNQ錯物의 合成
황교현 大田産業大學校 1993 한밭대학교 논문집 Vol.10 No.1
(N-alkyi quinolinium)-TCNQ comple'xes for fabrication of organic ultra thin films using Langmuir-Blogett technique were systhesized from N-alkyi bromides(n-docosylbromide, n-eicosylbromide), quinoline, and LiTCNQ. LiTCNQ was synthesized from Lif and 7,7,7,7- Tetracyanoquinodimethane(TCNQ) synthesized from 1,4-cyclohexadione. The new complexes of four specises (N-docosyi qumolium)-TCNQ(l : 1), (1 : 2), (N-eicosyl quinolinium)-TCNQ (1 : 1), (1 : 2)) were purified by column chromatography and their structures were determinded by its spectral (^1H-NMR, IR, and UV spectrum) and elemental analysis.
Methylmethacrylate와 n-butanol의 에스테르교환 반응에 관한 연구
정순욱,황교현 大田工業大學 1988 한밭대학교 논문집 Vol.5 No.1
The trans-esterification reaction between Methyl-methacrylate and n-Butanol was kinetically investigated in the presence of Lead-acetate at 100℃,110℃ and 120℃. The trans-esterification reaction was first-order kinetics with respect to the concentration of Methyl-methacrylate and n-Butanol. From the examination of the relationship between rate constant and reciprocal absolute temperature, the activation energy was calculated as 14.4 Kcal with Lead-acetate catalyst.
(N-alkyl pyridinium)-TCNQ(1:2)착물과 Arachidic Acid의 혼합 Langmuir-Blodgett 막의 물성에 관한 연구
손병청,황교현 大田工業大學 1990 한밭대학교 논문집 Vol.7 No.1
This paper takes aim at the reliability evaluation by application of Fault Tree Analysis and its computerization. Fault Tree Analysis is one of the methods for evaluation of system reliability and safety analysis. The characteristic of this paper is the computer program written in the package program (dBase 3+) by 16 Bit/AT personal computer. The program consists of three program segments. (1) The minimal cut sets of the system fault tree are obtained by means of “Fault Tree Reduction Algorithm”. (2) The minimal path sets are obtained by inversion of the minimal cut sets determined from fault tree. (3) The importance of the basic events which are presented in the minimal cut sets is obtained by means of structural importance analysis.