• 제목/요약/키워드: Excitation Transfer Theory

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Excitation Hopping Behavior between Two Naphthy1 Moieties Spatially Fixed in Triptycene Structure

  • Lee, Bong
    • 한국재료학회지
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    • 제6권12호
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    • pp.1242-1247
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    • 1996
  • Spatially fixed bichromophoric systems with nonidentical chromophores have been extensively employed for studies of electron transfer and excitation transfer. Excitation hopping behavior between two naphthy1 moieties on 7,14-dihydro-7,14-ethanodibenz[a,h] anthracene(DEA)has been explored by the time-resolved fluorescence anisotropy measurements. The experimentally obtained value of the hopping rate in DEA agrees at least qualitatively with that calculated on the basis of the Dexter's theory, but disagrees with that calculated on the basis of the Forster's theory, indicates that for a pair of donor and acceptor with inter-chromophore separation as short as 4.5 $\AA$, excitation transfer via electron exchange is a predominant process.

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Integrated Thermochemical Approach to Collision-Induced Dissociation Process of Peptides

  • Shin, Seung Koo;Yoon, Hye-Joo
    • Mass Spectrometry Letters
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    • 제12권4호
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    • pp.131-136
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    • 2021
  • Collision-induced dissociation of peptides involves a series of proton-transfer reactions in the activated peptide. To describe the kinetics of energy-variable dissociation, we considered the heat capacity of the peptide and the Marcus-theory-type proton-transfer rate. The peptide ion was activated to the high internal energy states by collision with a target gas in the collision cell. The mobile proton in the activated peptide then migrated from the most stable site to the amide oxygen and subsequently to the amide nitrogen (N-protonated) of the peptide bond to be broken. The N-protonated intermediate proceeded to the product-like complex that dissociated to products. Previous studies have suggested that the proton-transfer equilibria in the activated peptide affect the dissociation kinetics. To take the extent of collisional activation into account, we assumed a soft-sphere collision model, where the relative collision energy was fully available to the internal excitation of a collision complex. In addition, we employed a Marcus-theory-type rate equation to account for the proton-transfer equilibria. Herein, we present results from the integrated thermochemical approach using a tryptic peptide of ubiquitin.

럭셔리 브랜드 소비가치가 컬트 의도에 미치는 영향 : 긍정적 정서와 적합성의 매개효과를 중심으로 (The Effect of Consumption Values in Luxury Brands on Cult Intention : Focusing on the Mediating Effects of Positive Affect and Compatibility)

  • 김기형;한상린;신윤창
    • 산업경영시스템학회지
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    • 제43권2호
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    • pp.98-109
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    • 2020
  • What is purchase motivation for luxury brands? and what kind of process through makes higher cult intention(i.e.,loyalty). How does consumption value affect loyalty? Theoretically, it was studied whether it could be explained. The luxury products and services were divided into categories and surveys were conducted at the national level. This research analyzed the influence of positive affect on cult intention by mediating luxury consumption value with S-O-R frame. The logic was developed with excitation transfer theory. Positive affect, compatibility mediating effect were investigated. Unlike the previous studies that have been recognized as important in terms of symbolic value in luxury brands, it was confirmed that experiential consumption value had the greatest impact. In addition, the influence of functional value and symbolic value had a significant effect. The effect of consumption value on cult intention was mediated by positive affect and compatibility. Therefore, emotional response can be seen as having an effect on cult intention through excitement transfer. These findings suggest that luxury brand marketers need to develop consumer values that can lead to arousal and positive emotional responses to suit consumer lifestyle. The research results are expected to contribute to the experience marketing and the hospitality service of luxury brands.

Influence of second order wave excitation loads on coupled response of an offshore floating wind turbine

  • Chuang, Zhenju;Liu, Shewen;Lu, Yu
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.367-375
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    • 2020
  • This paper presents an integrated analysis about dynamic performance of a Floating Offshore Wind Turbine (FOWT) OC4 DeepCwind with semi-submersible platform under real sea environment. The emphasis of this paper is to investigate how the wave mean drift force and slow-drift wave excitation load (Quadratic transfer function, namely QTF) influence the platform motions, mooring line tension and tower base bending moments. Second order potential theory is being used for computing linear and nonlinear wave effects, including first order wave force, mean drift force and slow-drift excitation loads. Morison model is utilized to account the viscous effect from fluid. This approach considers floating wind turbine as an integrated coupled system. Two time-domain solvers, SIMA (SIMO/RIFLEX/AERODYN) and FAST are being chosen to analyze the global response of the integrated coupled system under small, moderate and severe sea condition. Results show that second order mean drift force and slow-drift force will drift the floater away along wave propagation direction. At the same time, slow-drift force has larger effect than mean drift force. Also tension of the mooring line at fairlead and tower base loads are increased accordingly in all sea conditions under investigation.

Behavior of Poisson Bracket Mapping Equation in Studying Excitation Energy Transfer Dynamics of Cryptophyte Phycocyanin 645 Complex

  • Lee, Weon-Gyu;Kelly, Aaron;Rhee, Young-Min
    • Bulletin of the Korean Chemical Society
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    • 제33권3호
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    • pp.933-940
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    • 2012
  • Recently, it has been shown that quantum coherence appears in energy transfers of various photosynthetic lightharvesting complexes at from cryogenic to even room temperatures. Because the photosynthetic systems are inherently complex, these findings have subsequently interested many researchers in the field of both experiment and theory. From the theoretical part, simplified dynamics or semiclassical approaches have been widely used. In these approaches, the quantum-classical Liouville equation (QCLE) is the fundamental starting point. Toward the semiclassical scheme, approximations are needed to simplify the equations of motion of various degrees of freedom. Here, we have adopted the Poisson bracket mapping equation (PBME) as an approximate form of QCLE and applied it to find the time evolution of the excitation in a photosynthetic complex from marine algae. The benefit of using PBME is its similarity to conventional Hamiltonian dynamics. Through this, we confirmed the coherent population transfer behaviors in short time domain as previously reported with a more accurate but more time-consuming iterative linearized density matrix approach. However, we find that the site populations do not behave according to the Boltzmann law in the long time limit. We also test the effect of adding spurious high frequency vibrations to the spectral density of the bath, and find that their existence does not alter the dynamics to any significant extent as long as the associated reorganization energy is changed not too drastically. This suggests that adopting classical trajectory based ensembles in semiclassical simulations should not influence the coherence dynamics in any practical manner, even though the classical trajectories often yield spurious high frequency vibrational features in the spectral density.

FLUORESCENCE DEPOLARIZATION IN DIFFERENT MOLECULAR SYSTEMS

  • Kim, Hack-Jin;Kang, Tai-Jong
    • Journal of Photoscience
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    • 제1권1호
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    • pp.75-82
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    • 1994
  • General features of the fluorescence depolarization are briefly reviewed. Molecular rotations and electronic excitation transports are considered to account for the fluorescence depolarization. Various molecular systems studied by the fluorescence depolarization are described. The FiSrster theory which forms a basis for the energy transfer is revisited. Several theoretical treatments for the fluorescence depolarization in liquid and solid phases such as classical hydrodynamics, probability distribution function, Green's function formalism, molecular dynamics simulation and Monte Carlo methods are introduced.

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반사계수를 고려한 광 결합기의 결합효율 (Coupling Efficiency of Optical Couplers considering Reflection Coefficient)

  • 호광춘;윤인국;박재서;김영권
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.966-969
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    • 1999
  • Using modal transmission-line theory (MTLT), we evaluate the power coupling of optical directional coupler composed by two parallel guiding slabs. The numerical results reveal that maximum power transfer occurs at a novel wavelength λ$_{opt}$, in which the excitation ratio of supermodes at input boundary is equal to each other, and it is generally different from minimum gap λ$_{min}$.in/.

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Effects of Light Pulse Intensity and Quencher Concentration on the Time-Dependent Fluorescence Quenching Kinetics

  • Yang Mino;Lee Sangyoub;Shin, Kook Joe;Choo Kwang Yul;Lee Duckhwan
    • Bulletin of the Korean Chemical Society
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    • 제13권3호
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    • pp.325-331
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    • 1992
  • By using the general theoretical framework proposed recently for treating the fluorescence quenching kinetics, we investigate the effect of light pulse intensity on the decay of fluorescence which follows excitation of fluorophors by the light pulse of very short but finite duration. It is seen that conventional theory breaks down when the exciting light pulse has a pulse width comparable to the fluorescent lifetime and its intensity is very high. We also find that even when the light intensity is not too high, conventional theory may fail in either of the following cases: (i) when the quencher concentration is high, (ii) when there is an attractive potential of mean force between the fluorophor and quencher, or (iii) when the energy transfer from the fluorophor to the quencher may also occur at a distance, e.g., via dipole-dipole interaction. The validity of the predictions of the present theory may thus be tested by fluorescence quenching experiments performed under such situations.

Luminescence Behavior of $YNbO_4$ and $YNbO_4:Bi$

  • Chang, Hyun-Ju;Lee, Seung-Kwon;Han, Cheong-Hwa;Park, Hee-Dong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.35-36
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    • 2000
  • The luminescence behaviors of Yttrium niobate and Bi doped Yttrium niobate were investigated under UV and low voltage electron excitations and interpreted with the first-principle calculations. In the UV excitation and emission spectra of $YNbO_4$ and $YNbO_4:Bi$, we were able to separate host contribution and Bi contribution and found that the shift in emission peak to longer wavelength is mainly due to Bi contribution. Using density functional theory, the cluster calculations were carried out for both $YNbO_4$ and $YNbO_4:Bi$. From the calculated density of states, we were also able to explain the charge transfer gap in the host and the effect of Bi in the excitation and emission spectra theoretically.

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강체 운동 해석 및 실험을 통한 엔진 내부 진동 예측에 관한 연구 (Estimation of Vibration Level Inside an Engine Based on Rigid Body Theory and Measurement Technology)

  • 김병현;박종호;김의열;이상권;김태정;허정기
    • 한국소음진동공학회논문집
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    • 제21권11호
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    • pp.1043-1050
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    • 2011
  • This paper presents practical results for the estimation of vibration level inside a powertrain based on the rigid body theory and measurement. The vibration level of inside powertrain has been used for the calculation of excitation force of an engine indirectly. However it was difficult to estimate or measure the vibration level inside of a powertrain when a powertrain works on the driving condition of a vehicle. To do this work, the rigid body theory is employed. At the first, the vibration on the surface of a powertrain is measured and its results are secondly used for the estimation the vibration level inside of powertrain together with rigid body theory. Also did research on how to decrease the error rate when the rigid body theory is applied. This method is successfully applied to the estimation of the vibration level on arbitrary point of powertrain on the driving condition at the road.