• 제목/요약/키워드: Overlap integral

검색결과 23건 처리시간 0.023초

분자의 사중극자모멘트의 계산 (제1보). 연산자법에 의한 사중극자모멘트행렬요소의 계산 (Calculation of the Molecular Quadrupole Moments (I). Calculation for the Quadrupole Moment Matrix Elements by Operator Technique)

  • 안상운;고정수
    • 대한화학회지
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    • 제23권5호
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    • pp.296-306
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    • 1979
  • 연산자법을 사중극자모멘트행렬요소를 계산하는데 응용하였다. Spherical harmonics의 전개방법과 사중극자모멘트행렬요소를 Mulliken의 overlap integral 로 전환시키는 방법을 사용하여 Slater 궤도함수쌍에 대한 사중극자모멘트행렬요소이 기본식을 유도하였다. 두 방법에 의하여 계산한 사중극자모멘트행렬요소의 값이 일치하였으며 바닥상태의 HCl 분자에 대하여 계산한 사중극자모멘트의 값이 Nesbet의 값과 일치하였다.

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음향을 이용한 복합 적층판의 층간분리 예측 (Prediction of Delamination for Composite Laminates Using Sound Radiation)

  • 김성준;채동철
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.800-804
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    • 2005
  • In this paper, the radiated sound pressure induced by low velocity impact is obtained by solving the Rayleigh integral equation. For structurally radiated noise, the sound field is directly coupled to the structural motion. Therefore the impact response should be analyzed. It is well known that the presence of the delamination in a composite laminate introduces a local flexibility which changes the dynamic characteristic of the structure. The 2-D simplified delamination model is used to analyze the impact response. And the 3-D non-linear finite element model is developed using gap element to avoid the overlap and penetration between the upper and lower sub-laminates at delamination region. Predicted impact response using 2-D equivalent delamination model are compared with the numerical ones from the 3-D non-linear finite element model.

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$1.48{\mu}m$ 레이저 다이오드로 여기된 $Er^{3+}$ 첨가 광섬유 광증폭기에 대한 이론적 분석 (Theoretical Analysis of a $1.48{\mu}m$ Diode Laser Pumped $Er^{3+}$ Doped Fiber Amplifier)

  • 김회종
    • 한국광학회지
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    • 제4권1호
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    • pp.101-107
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    • 1993
  • 3준위 레이저 rate equation 및 overlap integral로부터 파장 1.48 ${\mu}m$에서 여기된 E$r^{3+}$ 첨가 광섬유 광증폭기를 위한 광섬유 매개 변수의 최적 조건을 계산하였다. 이 계산으로부터 Er3+ 첨가 광섬유 광섬유 광증폭기의 소신호 이득(small signal gain) 특성을 개구수 (N.A.), V값, 광섬유 길이, 차단 파장(cutoff wavelength) 등의 함수로 알아 보았으며 또한, 최대 소신호 이득을 갖기 위한 광섬유 매개 변수를 결정하였다.

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몬테칼로 방법을 사용한 HgCdTe에서의 전자 전송 특성에 관한 연구 (A study on the electron transport properties in HgCdTe using monte carlo method)

  • 유상동;곽계달
    • 전자공학회논문지D
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    • 제35D권2호
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    • pp.40-51
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    • 1998
  • Electron transport properties are investigated by Monte Carlo simulation in n-HgCdTe. The material is easily degenerated at low temperature or being slightly doped, and is characterized by small band gap and large nonparabolic factor. The degeneracy is incorporated in the Monte Carlo simulation by taking into account the electron-electron scattering and the pauli exclusion principle. In the conventional method, however, the electron-electron scattering rate was developed under the assumption of parabolic conduction band. A new formulation of the electron-electron scattering rate is develop considering the band nonparabolicity and overlap integral. The electron-electron scattering effects on the electron distribution,impact ionization coefficienty, electron temperature, drift velocity and electron energy are presented.

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DNA Mediated Energy Transfer from 4',6-Diamidino-2-phenylindole to tetra- and bis-cationic Porphyrins at Low Binding Densities

  • Gong, Lindan;Ryu, Jae-Ki;Kim, Bok-Jo;Jang, Yoon-Jung
    • Bulletin of the Korean Chemical Society
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    • 제33권2호
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    • pp.529-534
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    • 2012
  • The fluorescence of 4',6-diamidino-2-phenylindole (DAPI) bound to DNA at a [DAPI]/[DNA base] ratio of 0.005 was quenched by meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) or cis-bis(N-methylpyridinium-4-yl)porphyrin (BMPyP) when both DAPI and either porphyrin spontaneously bound to the same DNA strand. The quenching was investigated using the "one-dimensional inner sphere" and the "F$\ddot{o}$rster resonance energy transfer" (FRET) models. Total quenching occurred when DAPI and TMPyP were up to 19.3 base pairs or $66\AA$ apart. BMPyP could quench the fluorescence up to 13.9 base pairs or $47\AA$. TMPyP, which intercalated between the DNA base-pairs, appeared to be a better acceptor than BMPyP, which stacked along the DNA stem. The higher quenching and higher resonance energy transfer efficiency of TMPyP was due to the larger overlap integral between its absorption spectrum and the emission spectrum of DNA-bound DAPI.

부분 전하의 의미와 정의 (Meaning and Definition of Partial Charges)

  • 조승주
    • 통합자연과학논문집
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    • 제3권4호
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    • pp.231-236
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    • 2010
  • Partial charge is an important and fundamental concept which can explain many aspects of chemistry. Since a molecule can be regarded as neclei surrounded by electron cloud, there is no way to define a partial charge accurately. Nevertheless, there have been many attempts to define these seemingly impossible parameters, since they would facilitate the understanding of molecular properties such as molecular dipole moment, solvation, hydrogen bonding, molecular spectroscopy, chemical reaction, etc. Common methods are based on the charge equalization, orbital occupancy, charge density, and electric multipole moments, and electrostatic potential fitting. Methods based on the charge equalization using electronegativity are very fast, and therefore they have been used to study many compounds. Methods to subdivide orbital occupancy using basis set conversion, relies on the notion that molecular orbitals are composed of atomic orbitals. The main idea is to reduce overlap integral between two nuclei using converted orthogonal basis sets. Using some quantum mechanical observables like electrostatic potential or charge multipole moments. Using potential grids obtained from wavefunction, partial charges can be fitted. these charges are most useful to describe intermolecular electrostatic interactions. Methods to using dipole moment and its derivatives, seems to be sensitive the level of theory, Dividing electron density using density gradient being the most rigorous theoretically among various schemes, bears best potential to describe the charge the most adequately in the future.

Computational Study of 3-Aminophenol·(CO2)1 Cluster: CO2 Capture Ability of 3-Aminophenol

  • Sohn, Woon-Yong;Kim, Min-Ho;Kim, Sang-Su;Kang, Hyuk
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2806-2808
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    • 2010
  • The structure of 3-aminophenol $(CO_2)_1$ cluster was computationally studied both in the ground and the lowest singlet excited electronic states. The ground state structure and binding energy of the cluster was investigated using the second-order M$\ddoot{o}$ller-Plesset perturbation theory (MP2) at the complete basis set (CBS) limit. The excited state geometry of the cluster was obtained at the second-order approximate coupled cluster (CC2) level with cc-pVDZ basis set, and the $S_0-S_1$ absorption spectrum was simulated by calculating Franck-Condon overlap integral. The ground state geometry of the global minimum with a very high binding energy of 4.3 kcal/mol was found for the cluster, due to the interaction between amino group and $CO_2$ in addition to the strong $\pi-\pi$ interaction between the aromatic ring and $CO_2$. The excited state geometry shows a very big shift in the position of $CO_2$ compared to the ground state geometry, which results in low intensity and broad envelope in the Franck-Condon simulation.

시트-도막을 이용한 분리거동형 복합방수공법 개발 및 적용에 관한 연구 (Research on Separation Behavior Joint of Develop and Application in Sheet-Membrane Composite Waterproofing)

  • 허능회;김동범;오제곤;고건웅;고장렬
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.165-166
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    • 2014
  • The Composite waterproofing began to rise gradually 2000s in domestic. However, the sheet-membrane composite waterproofing method also acts as an abutment vulnerability that was a problem in a single method, and had the problem of damage to the formation of leakage paths. The existing non-overlap method, through vigorous research abutting sheet shall or could be developed to improve the seal performance of this method with the I-type joint coating material. Nevertheless, it has an integral top coat paint membrane and a sheet abutment limitation, damage to the upper membrane is damaged junction coating membranes has been generated. In this study, a method that has a layer of insulation on the joint bond breaker concept development, and to determine the physical properties with insulated joints to determine the breaking off of the upper joint is damaged coating membrane and tensile performance.

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유기재료의 이상분산을 이용한 파장변환 (Frequency conversion using anomalous dispersion of organic material)

  • 김응수;김민성;강신원
    • 한국광학회지
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    • 제16권1호
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    • pp.103-108
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    • 2005
  • Poled polymer를 사용하여 도파로구조를 제작하고 2차 비선형광학현상에 의해 제 2고조파(SHG)글 발생시켰다. 기본파와 제 2고조파 사이의 위상정합은 poled polymer의 이상분산 특성을 이용하여 기본파 도파모드(TM$_{0}$)로부터 제 2고조파 도파모드(TM$_{0}$)를 실현하였다. 이때 발생되는 제 2고조파의 power는 위상정합이 가능한 다른 모드의 기본파로부터 발생한 제 2고조파의 power보다 크게 됨을 이론적으로 확인하였고, 위상정합이 가능한 도파로를 제작하였다. 기본파로서 Ti-sapphire laser(740 nm)를 사용하여 근자외 영역의 제 2고조파(370 nm)를 관찰하였다.

Equilibrium Geometries of the Neutral and Ionic Clusters of $Ag_7$, $Ag_8$, and $Ag_9$ Studied by Intermediate Neglect of Differential Overlap Method

  • 유창현;선호성
    • Bulletin of the Korean Chemical Society
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    • 제21권10호
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    • pp.953-954
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    • 2000
  • The equilibrium geometrical structures of silver atom clusters at their electronic ground states have been theo-retically determined by using the nonrelativistic semiempirical INDO/1 method. The clusters investigated are Agn, Agn+, and Agn- (n = 7 , 8, 9). In order to find the most stable structure, i.e., the global minimum in energy hypersurface, geometry optimization and energy calculation processes have been repeatedly performed for all the possible graphical models by changing the bond parameters (resonance integral values). The heptamers are pentagonal bipyramidal-Ag7(D5h), Ag7+ (D5h), Ag7- (D5h); the octamers are pentagonal bipyramidal with one atom capped-Ag8(D2d), Ag8+ (Cs), Ag8- (D2d); the nonamers are pentagonal bipyramidal with two atoms capped -Ag9(C2v), Ag9+ (C2v), Ag9- (C2v). Our structures are in good agreement with those by ab initio calculations ex-cept for the anionic Ag9- cluster. And it is noted that the INDO/1 method can accurately predict the Ag cluster geometries when a proper set of bond parameters is used.