• 대한화학회지
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• 제67권6호
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• pp.407-414
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• 2023

The present study uses quasi-classical trajectory procedures to examine the vibrational relaxation and dissociation of the methyl and ring C-H bonds in excited methylpyrazine (MP) during collision with either N₂ or O₂. The energy-loss (-ΔE) of the excited MP is calculated as the total vibrational energy (E_T) of MP is increased in the range of 5,000 to 40,000cm^-1. The results indicate that the collision-induced vibrational relaxation of MP is not large, increasing gradually with increasing E_T between 5,000 and 30,000 cm^-1, but then decreasing with the further increase in E_T. In both N₂ and O₂ collisions, the vibrational relaxation of MP occurs mainly via the vibration-to-translation (V→T) and vibration-to-vibration (V→V) energy transfer pathways, while the vibration-to-rotation (V→R) energy transfer pathway is negligible. In both collision systems, the V→T transfer shows a similar pattern and amount of energy loss in the ET range of 5,000 to 40,000cm^-1, whereas the pattern and amount of energy transfer via the V→V pathway differs significantly between two collision systems. The collision-induced dissociation of the C-H_methyl or C-H_ring bond occurs when highly excited MP (65,000-72,000 cm^-1) interacts with the ground-state N₂ or O₂. Here, the dissociation probability is low (10^-4-10^-1), but increases exponentially with increasing vibrational excitation. This can be interpreted as the intermolecular interaction below E_T = 71,000 cm^-1. By contrast, the bond dissociation above E_T = 71,000 cm^-1 is due to the intramolecular energy flow between the excited C-H bonds. The probability of C-H_methyl dissociation is higher than that of C-H_ring dissociation.

• 대한화학회지
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• 제49권1호
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• pp.7-15
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• 2005

• 대한화학회지
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• 제49권1호
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• pp.16-28
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• 2005

• 대한화학회지
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• 제49권2호
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• pp.129-137
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• 2005

• 한국통신학회:학술대회논문집
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• 한국통신학회 1986년도 춘계학술발표회 논문집
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• pp.202-205
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• 1986

In this paper, real-time vibration measurement using system is described. Modes getting from different vibrational frequencies of come vibrational plates are rectified and filtered by digitizer and recorded 488 dots(abscissa) printer. PZT and mechanical chopper is placed in front of cw laser for better resolving power. Rayleigh`s mode theory and mode pattern are compared with experimental results.

• 대한화학회지
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• 제59권4호
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• pp.358-363
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• 2015

• 대한화학회지
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• 제57권6호
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• pp.869-873
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• 2013

• 대한화학회지
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• 제52권3호
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• pp.322-327
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• 2008

HOOCl-H2O cluster에 대하여 안정한 구조와 결합에너지를 MP2/6-311G(d,p), MP2/6-311G(2d,2p)의 방법으로 계산하였고 vibrational frequency계산을 하여 HOOCl의 vibrational frequency와 비교하였다. Skew HOOCl-H2O cluster가 가장 안정한 cluster로 나타났고 결합에너지는 46~48 kJ/mol 정도이며 trans HOOCl-H2O cluster의 경우도 이보다 불안정하나 비교적 큰 결합에너지를 갖는 것으로 나타났다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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• pp.583-595
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• 2018

Stiffened panels are widely used in naval architecture and ocean engineering, and knowledge about their dynamic behaviour represents important issue in the design procedure. Ordinary vibration analysis consists of natural frequencies and mode shapes determination and can be extended to forced response assessment, while the Structural Intensity (SI) analysis, assessing magnitude and direction of vibrational energy flow provides information on dominant transmission paths and energy distribution including sink positions. In this paper, vibrational energy flow in stiffened panels under harmonic loading is analyzed by the SI technique employing the finite element method. Structural intensity formulation for plate and beam element is outlined, and developed system combining in-house code and general finite element tool is described. As confirmed within numerical examples, the developed tool enables separation of SI components, enabling generation of novel SI patterns and providing deeper insight in the vibrational energy flow in stiffened panels, comparing to existing works.

• 대한화학회지
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• 제46권1호
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• pp.14-18
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• 2002

산화질소 분자(NO)가 전자 한 개를 받아 산화질소 음이온$(NO^-)$으로 환원되는 반응의 정도가 진동에너지에 따라 크게 달라질 수 있음을 제시하였다. NO와 $NO^-$의 포텐샬에너지 표면은 진동에너지가 많아짐에 따라 NO 분자가 전자를 받아 $NO^-$음이온으로 바뀔수 있는 에너지적 측면을 가짐을 보여준다. 또한, 진동 파동함수간의 Franck-Condon 인자를 계산하였다. 진동에너지가 많아지면 NO에서 $NO^-$로 바뀔 경로가 더 많이 증가함을 보인다. 이 결과는 NO 분자에게 적절한 빛을 조사시킴으로 $NO^-$이온으로의 환원반응속도를 조절할 수 있음을 의미한다.