• 한국분말재료학회지
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• 제12권6호
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• pp.441-446
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• 2005

The copper oxide nano powders were synthesized by levitational gas condensation (LGC) method, and were applied to catalyst to fabricate 3,4-dihydropyrimidin-2-(1H)-one. Processes of adsorption of Biginelli reaction reagents on the copper nanooxide surface $Cu_2O{\circ}CuO$ were studied by IR-spectroscopy. It was shown that benzaldehyde coordination, acetoacetic ether on the oxide surface is carried out with participation of carbonyl fragments, urea by N-H bonds which affects positively on the reagents reactivity.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.114-115
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• 2006

We investigated the effects of annealing on the rearrangement of H-bonding structure and its influence on the thermal and rheological properties of $2^{nd}\;and\;4^{th}$ pseudo-generation aliphatic hyperbranched (HB) polyesters based on 2,2-bis(methylol)propionic acid. During annealing of amorphous HB polyesters, the structure becomes more ordered as a consequence of multiple H-bonds formation between linear sequences. Structure ordering is more pronounced for the lower pseudo-generation HB polyester with low molar mass, low degree of branching and incompletely reacted core hydroxyl groups which greatly increases the possibility for multiple H-bond interactions.

• 대한화학회지
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• 제39권10호
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• pp.783-788
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• 1995

Silyltriflate는 phenyl기가 포함된 규소화합물을 $CF/_3/SO/_3/H$와 반응시켜 얻어진다. Silyltriflate와 allylmagnesium bromide와의 반응에서는 allyl기가 포함된 실란 유도체 $R/_2/SiHCH/_2/CH\;=\;CH/_2/(R\;=\;Me,Ph)$이 형성되었다. 이 화합물은 백금 촉매하에서 polycarbosilane을 형성하였으며 polycarbosilane의 Si-Ph 결합은 다시 트리플산에 의해 polycarbosilane의 triflat 유도체를 형성하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.487-488
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• 2008

SiOC films containing alkyl groups have a low dielectric constant because of the interaction between the C-H hydrogen bonds and the oxygen of high electro-negative atom. The Si-$CH_3$ in a void is broken by the $O_2$, therefore the strength of CH bond in Si-O-O-$CH_3$ bond increases. The Si-O-O-$CH_3$ bond is broken by nucleophilic attack due to Si atom, again. The elongation of C-H bond causes the red shift, and the compression of C-H bond causes the blue shift. Among these chemical shifts, the blue shift from $1000\;cm^{-1}$ to $1250\;cm^{-1}$ was related with the formation of pores. If the oxygen is deficient condition, the methylradicals of the electron-rich substitution group terminate easily the Si-O-Si cross-link, and the pore is originated from the cross-link breakdown due to much methyl radicals of Si-$CH_3$. The dielectric constant of the films decreases due to pore generation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.336-338
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• 1997

The anneal behavior of ArF excimer Laser CVD SiON films has been studied using FT-IR absorption spectroscopy. The anneal temperature range was $400{\sim}800^{\circ}C$ Abundant hydrogen effusion from thes layers was observed as anneal temperature increased. The coexistence of both Si-H am N-H bonds offers the possibility for cross linking am evidence for the occurrence of cross lingking was found in the IR spectrum. The electrical properties were also obtained that tire films have low leakage currents am good TZDB properties.

• 동력기계공학회지
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• 제9권4호
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• pp.110-117
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• 2005

Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.153-158
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• 2012

The hydrogenation of $AlB_2$-type BaGaGe exhibits a metal to insulator (MI) transition, inducing a puckering distortion of the original hexagonal [GaGe] layers. We investigate the electronic structure changes associated with the hydrogen-induced MI transition, using extended H$\ddot{u}$ckel tight-binding band calculations. The results indicate that hydrogen incorporation in the precursor BaGaGe is characterized by an antibonding interaction of $\pi$ on GaGe with hydrogen 1s and the second-order mixing of the singly occupied antibonding $\pi^*$ orbital into it, through Ga-H bond formation. As a result, the fully occupied bonding $\pi$ band in BaGaGe changes to a weakly dispersive band with Ge pz (lone pair) character in the hydride, which becomes located just below the Fermi level. The Ga-Ge bonds within a layered polyanion are slightly weakened by hydrogen incorporation. A rationale for this is given.

• 대한화학회지
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• 제57권3호
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• pp.352-356
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• 2013

In this work, a new cadmium complex $[Cd(L)(CH_3COO)_2].2H_2O$ (1) with the ligand L, N,N'-bis(2-pyridinecarboxalidene)-1,2-cyclohexanediamine was prepared and identified by elemental analysis, FT-IR, Raman, $^1H$ NMR spectroscopy and single-crystal X-ray diffraction. The cadmium atom in the crystal structure of 1 has distorted triangular dodecahedral geometry by coordination of the four nitrogen atoms of L and four oxygen atoms of the two acetate ions. Two water molecules are also incorporated in the crystal network. The $O-H{\cdots}O$ hydrogen bonds present in the crystal structure of 1. In this work, three structural surveys including coordination numbers of the cadmium atom, coordination modes of L and resonance in pyridine-2-ylmethanimine-based compounds are presented.

• 대한전기학회논문지
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• 제41권5호
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• pp.483-491
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• 1992

Plasma silicon oxynitride film has been applied as a final passivation layer for semiconductor devices, because it has high resistance to humidity and prevents from alkali ion's penetration, and has low film stress. Structure properties of plasma silicon oxynitride film have been studied experimentally by the use of FT-IR, AES, stress gauge and ellipsometry. In this experiment,Si-N bonds increase as NS12TO/(NS12TO+NHS13T) gas ratio increases. Peaks of Si-N bond, Si-H bond and N-H bond were shifted to high wavenumber according to NS12TO/(NS12TO+NHS13T) gas ratio increase. Absorption peaks of Si-H bond were decreased by furnace anneal at 90$0^{\circ}C$. The atomic composition of film represents that oxygen atoms increase as NS12TO/(NS12TO+NHS13T) gas ratio increases, to the contrary, nitrogen atoms decrease.

• 동력기계공학회지
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• 제10권4호
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• pp.111-118
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• 2006

Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.