Bibliographies thématiques / Vibrational quenching / Articles de revues
Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Vibrational quenching.

Articles de revues sur le sujet « Vibrational quenching »

Auteur : Grafiati
Publié le 9 mars 2023
Mis à jour le 10 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « Vibrational quenching ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.

1

Richards, Caleb, Elijah Jans, Ilya Gulko, Keegan Orr et Igor V. Adamovich. « N2 vibrational excitation in atmospheric pressure ns pulse and RF plasma jets ». Plasma Sources Science and Technology 31, no 3 (1 mars 2022) : 034001. http://dx.doi.org/10.1088/1361-6595/ac4de0.

Texte intégral
Résumé :
Abstract Time-resolved N2 vibrational temperature and translational–rotational temperature in quasi-two-dimensional atmospheric pressure plasma jets sustained by ns pulse and RF discharges in nitrogen/noble gas mixtures are measured by the broadband vibrational Coherent Anti-Stokes Raman Scattering (CARS) . The results indicate a much stronger vibrational excitation in the RF plasma jet, due to the lower reduced electric field and higher discharge power. In a ns pulse discharge in N2/He, N2 vibrational temperature is significantly lower compared to that in N2/Ar, due to the more rapid vibration–translation (V–T) relaxation of nitrogen by helium atoms. In the RF plasma jets in N2/Ne and N2/Ar, the vibrational excitation increases considerably as the nitrogen fraction in the mixture is reduced. The experimental data in the RF plasma jet in N2/Ar jet are compared with the kinetic modeling predictions. The results indicate that nitrogen vibrational excitation in N2/Ar plasma jets with a small N2 fraction in the mixture (several percent) is controlled primarily by electron impact, anharmonic vibration–vibration (V–V) pumping, and V–T relaxation by N atoms. In comparison, V–V energy transfer from the vibrationally excited molecules in the first excited electronic state, N2(A3Σu +, v), which are generated primarily by the energy transfer from the metastable Ar atoms, has a minor effect on the vibrational populations of the ground electronic state, N2(X1Σg +, v). Although the discharge energy fraction going to electronic excitation is significant, the predicted quasi-steady-state N2(A3Σu +) number density, controlled by the energy pooling and quenching by N atoms, remains relatively low. Because of this, the net rate of N2(X1Σg +) vibrational excitation by the V–V energy transfer from N2(A3Σu +) is much lower compared to that by the direct electron impact. The results show that atmospheric pressure RF plasma jets can be used as sources of highly vibrationally excited N2 molecules and N atoms.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Morris, Robert A., A. A. Viggiano, F. Dale et John F. Paulson. « Collisional vibrational quenching of NO+(v) ions ». Journal of Chemical Physics 88, no 8 (15 avril 1988) : 4772–78. http://dx.doi.org/10.1063/1.454690.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Forrey, Robert C., B. H. Yang, P. C. Stancil et N. Balakrishnan. « Mutual vibrational quenching in CO + H2 collisions ». Chemical Physics 462 (novembre 2015) : 71–78. http://dx.doi.org/10.1016/j.chemphys.2015.07.001.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Feofilov, A. G., A. A. Kutepov, W. D. Pesnell, R. A. Goldberg, B. T. Marshall, L. L. Gordley, M. García-Comas et al. « Daytime SABER/TIMED observations of water vapor in the mesosphere : retrieval approach and first results ». Atmospheric Chemistry and Physics Discussions 9, no 3 (26 juin 2009) : 13943–97. http://dx.doi.org/10.5194/acpd-9-13943-2009.

Texte intégral
Résumé :
Abstract. This paper describes a methodology for water vapor retrieval using 6.6 μm daytime broadband emissions measured by SABER, the limb scanning infrared radiometer on board the TIMED satellite. Particular attention is given to accounting for the non-local thermodynamic equilibrium (non-LTE) nature of the H2O 6.6 μm emission in the mesosphere and lower thermosphere (MLT). The non-LTE H2O (ν2) vibrational level populations responsible for this emission depend on energy exchange processes within the H2O vibrational system as well as on interactions with vibrationally excited states of the O2, N2, and CO2 molecules. The paper analyzes current H2O non-LTE models and, based on comparisons with the ACE-FTS satellite solar occultation measurements, suggests an update to the rate coefficients of the three most important processes that affect the H2O(ν2) populations in the MLT: a) the vibrational-vibrational (V–V) exchange between the H2O and O2 molecules; b) the vibrational-translational (V–T) process of the O2(1) level quenching by collisions with atomic oxygen, and c) the V–T process of the H2O(010) level quenching by collisions with N2, O2, and O. We demonstrate that applying the updated H2O non-LTE model to the SABER radiances makes the retrieved H2O vertical profiles in 50–85 km region consistent with climatological data and model predictions.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Ackland, Graeme J. « Rapid Equilibration by algorithmic quenching the ringing mode in molecular dynamics ». MRS Advances 1, no 42 (2016) : 2857–65. http://dx.doi.org/10.1557/adv.2016.382.

Texte intégral
Résumé :
ABSTRACTLong wavelength acoustic phonons are normally weakly coupled to other vibrational modes in a crystalline system. This is particularly problematic in molecular dynamics calculations where vibrations at the system-size scale are typically excited at initiation. The equilibration time for these vibrations depends on the strength of coupling to other modes, so is typically very long. A very simple deterministic method is presented which removes this problem. Examples of equilibration in lithium and a martensitic phase transition in sodium are used to demonstrate the method.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Klemperer, W., C. C. Chuang, K. J. Higgins, A. Stevens Miller et H. C. Fu. « Spectroscopy of van der Waals molecules : Isomers and vibrational predissociation ». Canadian Journal of Physics 79, no 2-3 (1 février 2001) : 101–8. http://dx.doi.org/10.1139/p01-006.

Texte intégral
Résumé :
The inert-gas-halogen complexes have been studied for several decades by jet spectroscopy. Much of the seemingly bizarre behavior has become understandable in terms of two virtually isoenergetic isomer forms. The recently recognized linear isomer of Ar–I2 has a virtually continuous B ¬ X excitation spectrum. It also undergoes a very rapid vibrational predissociation, and suffers no electronic quenching from the B state. The well-known T-shaped isomer shows slow vibrational predissociation, which is competitive with electronic quenching. The quenching distorts the vibrational distribution of the I2 B state photofragments, consequently leading to a false estimation of the T-shaped Ar–I2 (B) state dissociation energy. The binding energies for the T-shaped Ar–I2 (X) and Ar–I2 (B) are unambiguously determined from the recent dispersed fluorescence study, which are also in good accord with the ab initio calculation. We discuss aspects of pure vibrational laser-induced fluorescence of hydrogen fluoride complexes. We contrast the behavior of Ar–HF with Ne–HF and present new results for the vHF = 3 level of Ne–HF. PACS Nos.: 33.80Gj, 34.30th
Styles APA, Harvard, Vancouver, ISO, etc.
7

Slanger, Tom G. « Vibrational excitation in ». Canadian Journal of Physics 64, no 12 (1 décembre 1986) : 1657–63. http://dx.doi.org/10.1139/p86-289.

Texte intégral
Résumé :
Excitation processes for [Formula: see text] in aurorae, in the nightglow, and in laboratory sources are discussed. It is shown that the observed vibrational distribution in aurorae is consistent with the [Formula: see text] + NO charge-transfer mechanism. Arguments are presented for the case that quenching of O2(b) in vibrational levels above ν′ = 1 is rapid, and that therefore the auroral source is much larger than previously supposed. It is suggested that oxygen atoms are an efficient quencher for O2(b) levels above ν′ = 1.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Giancarlo, Leanna C., et Marsha I. Lester. « Vibrational predissociation and electronic quenching dynamics of  (Σ) ». Chemical Physics Letters 240, no 1-3 (juin 1995) : 1–9. http://dx.doi.org/10.1016/0009-2614(95)00493-n.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Cheng, Rong, Wen-Cai Lu, K. M. Ho et C. Z. Wang. « Localized electronic and vibrational states in amorphous diamond ». Physical Chemistry Chemical Physics 23, no 8 (2021) : 4835–40. http://dx.doi.org/10.1039/d0cp06393b.

Texte intégral
Résumé :
Amorphous diamond structures with more than 97% of sp3 bonding fraction are generated by quenching liquid carbon using tight-binding molecular-dynamics simulations. The electronic and vibrational properties of the amorphous sample are investigated.
Styles APA, Harvard, Vancouver, ISO, etc.
10

Ferguson, Eldon E. « Vibrational quenching of small molecular ions in neutral collisions ». Journal of Physical Chemistry 90, no 5 (février 1986) : 731–38. http://dx.doi.org/10.1021/j100277a008.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
11

Singer, W., A. Hansel, A. Wisthaler, W. Lindinger et E. E. Ferguson. « Vibrational quenching of NO+(v) ions by Ar collisions ». International Journal of Mass Spectrometry 223-224 (janvier 2003) : 757–62. http://dx.doi.org/10.1016/s1387-3806(02)00966-1.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
12

YOSHITAKE, Yutaka, Atsuo SUEOKA et Hideyuki TAMURA. « Analysis of vibrational systems with Coulomb's friction. (3rd report, Quenching of self-excited vibrations). » Transactions of the Japan Society of Mechanical Engineers Series C 56, no 523 (1990) : 568–73. http://dx.doi.org/10.1299/kikaic.56.568.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
13

Feofilov, A. G., A. A. Kutepov, W. D. Pesnell, R. A. Goldberg, B. T. Marshall, L. L. Gordley, M. García-Comas et al. « Daytime SABER/TIMED observations of water vapor in the mesosphere : retrieval approach and first results ». Atmospheric Chemistry and Physics 9, no 21 (2 novembre 2009) : 8139–58. http://dx.doi.org/10.5194/acp-9-8139-2009.

Texte intégral
Résumé :
Abstract. This paper describes a methodology for water vapor retrieval in the mesosphere-lower thermosphere (MLT) using 6.6 μm daytime broadband emissions measured by SABER, the limb scanning infrared radiometer on board the TIMED satellite. Particular attention is given to accounting for the non-local thermodynamic equilibrium (non-LTE) nature of the H2O 6.6 μm emission in the MLT. The non-LTE H2O(ν2) vibrational level populations responsible for this emission depend on energy exchange processes within the H2O vibrational system as well as on interactions with vibrationally excited states of the O2, N2, and CO2 molecules. The rate coefficients of these processes are known with large uncertainties that undermines the reliability of the H2O retrieval procedure. We developed a methodology of finding the optimal set of rate coefficients using the nearly coincidental solar occultation H2O density measurements by the ACE-FTS satellite and relying on the better signal-to-noise ratio of SABER daytime 6.6 μm measurements. From this comparison we derived an update to the rate coefficients of the three most important processes that affect the H2O(ν2) populations in the MLT: a) the vibrational-vibrational (V–V) exchange between the H2O and O2 molecules; b) the vibrational-translational (V–T) process of the O2(1) level quenching by collisions with atomic oxygen, and c) the V–T process of the H2O(010) level quenching by collisions with N2, O2, and O. Using the advantages of the daytime retrievals in the MLT, which are more stable and less susceptible to uncertainties of the radiance coming from below, we demonstrate that applying the updated H2O non-LTE model to the SABER daytime radiances makes the retrieved H2O vertical profiles in 50–85 km region consistent with climatological data and model predictions. The H2O retrieval uncertainties in this approach are about 10% at and below 70 km, 20% at 80 km, and 30% at 85 km altitude.
Styles APA, Harvard, Vancouver, ISO, etc.
14

Kirillov, A. S. « Electronic kinetics of molecular nitrogen and molecular oxygen in high-latitude lower thermosphere and mesosphere ». Annales Geophysicae 28, no 1 (20 janvier 2010) : 181–92. http://dx.doi.org/10.5194/angeo-28-181-2010.

Texte intégral
Résumé :
Abstract. Total quenching rate coefficients of Herzberg states of molecular oxygen and three triplet states of molecular nitrogen in the collisions with O2 and N2 molecules are calculated on the basis of quantum-chemical approximations. The calculated rate coefficients of electronic quenching of O2* and N2* molecules show a good agreement with available experimental data. An influence of collisional processes on vibrational populations of electronically excited N2 and O2 molecules is studied for the altitudes of high-latitude lower thermosphere and mesosphere during auroral electron precipitation. It is indicated that molecular collisions of metastable nitrogen N2(A3Σu*) with O2 molecules are principal mechanism in electronic excitation of both Herzberg states c1Σu&minus, A'3Δu, A3Σu+ and high vibrational levels of singlet states a1Δg and b1Σg+ of molecular oxygen O2 at these altitudes.
Styles APA, Harvard, Vancouver, ISO, etc.
15

Bahou, Mohammed, et Yuan-Pern Lee. « Photodissociation Dynamics of Vinyl Chloride Investigated with a Pulsed Slit-Jet and Time-Resolved Fourier-Transform Spectroscopy ». Australian Journal of Chemistry 57, no 12 (2004) : 1161. http://dx.doi.org/10.1071/ch04117.

Texte intégral
Résumé :
Following photodissociation of vinyl chloride seeded in a He supersonic jet at 193 nm, rotationally resolved infrared emission of HCl (v) are recorded to yield nascent rotational and vibrational distributions. Preliminary results show that the rotational distribution of HCl free from rotational quenching deviates slightly from Boltzmann-type distribution and agrees well with trajectory calculations; a portion of the low-J component observed previously in a flow system is attributed to quenching. The implications for photodissociation dynamics are discussed.
Styles APA, Harvard, Vancouver, ISO, etc.
16

Volchkov, Valery V., Mikhail N. Khimich, Mikhail V. Rusalov, Fedor E. Gostev, Ivan V. Shelaev, Viktor A. Nadtochenko, Artem I. Vedernikov et al. « Formation of a supramolecular charge-transfer complex. Ultrafast excited state dynamics and quantum-chemical calculations ». Photochemical & ; Photobiological Sciences 18, no 1 (2019) : 232–41. http://dx.doi.org/10.1039/c8pp00328a.

Texte intégral
Résumé :
The relaxation scheme of the 1·3 singlet state excited by a 25 fs laser pulse was proposed. It includes very fast vibrational relaxation, and direct and back electron transfer resulting in complete fluorescence quenching.
Styles APA, Harvard, Vancouver, ISO, etc.
17

Mant, Barry, Ersin Yurtsever, Lola González-Sánchez, Roland Wester et Franco A. Gianturco. « Vibrational quenching of CN− in collisions with He and Ar ». Journal of Chemical Physics 154, no 8 (28 février 2021) : 084305. http://dx.doi.org/10.1063/5.0039854.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
18

Wiesenfeld, Laurent. « Quantum nature of molecular vibrational quenching : Water–molecular hydrogen collisions ». Journal of Chemical Physics 155, no 7 (21 août 2021) : 071104. http://dx.doi.org/10.1063/5.0058755.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
19

Wang, Baoshan, Yueshu Gu et Fanao Kong. « Rapid Vibrational Quenching of CO(V) by H2O and C2H2 ». Journal of Physical Chemistry A 103, no 37 (septembre 1999) : 7395–400. http://dx.doi.org/10.1021/jp984616a.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
20

Monguzzi, Angelo, Alberto Milani, Lorenzo Lodi, Mario Italo Trioni, Riccardo Tubino et Chiara Castiglioni. « Vibrational overtones quenching of near infrared emission in Er3+ complexes ». New Journal of Chemistry 33, no 7 (2009) : 1542. http://dx.doi.org/10.1039/b901272a.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
21

Monguzzi, Angelo, Alberto Milani, Agniezka Mech, Luigi Brambilla, Riccardo Tubino, Carlo Castellano, Francesco Demartin, Francesco Meinardi et Chiara Castiglioni. « Predictive modeling of the vibrational quenching in emitting lanthanides complexes ». Synthetic Metals 161, no 23-24 (janvier 2012) : 2693–99. http://dx.doi.org/10.1016/j.synthmet.2011.10.002.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
22

Zobel, J. Patrick, Juan J. Nogueira et Leticia González. « Quenching of Charge Transfer in Nitrobenzene Induced by Vibrational Motion ». Journal of Physical Chemistry Letters 6, no 15 (20 juillet 2015) : 3006–11. http://dx.doi.org/10.1021/acs.jpclett.5b00990.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
23

Varandas, A. J. C. « Reactive and non-reactive vibrational quenching in O + OH collisions ». Chemical Physics Letters 396, no 1-3 (septembre 2004) : 182–90. http://dx.doi.org/10.1016/j.cplett.2004.08.023.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
24

Luque, Jorge, et David R. Crosley. « Vibrational and rotational dependence of NO B 2Π state quenching ». Journal of Chemical Physics 100, no 10 (15 mai 1994) : 7340–47. http://dx.doi.org/10.1063/1.466878.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
25

Koyama, Daisuke, et Andrew J. Orr-Ewing. « Triplet state formation and quenching dynamics of 2-mercaptobenzothiazole in solution ». Physical Chemistry Chemical Physics 18, no 37 (2016) : 26224–35. http://dx.doi.org/10.1039/c6cp05110c.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
26

Pradhan, G. B., J. C. Juanes-Marcos, N. Balakrishnan et Brian K. Kendrick. « Chemical reaction versus vibrational quenching in low energy collisions of vibrationally excited OH with O ». Journal of Chemical Physics 139, no 19 (21 novembre 2013) : 194305. http://dx.doi.org/10.1063/1.4830398.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
27

Humphries, Ben S., Dale Green et Garth A. Jones. « The influence of a Hamiltonian vibration vs a bath vibration on the 2D electronic spectra of a homodimer ». Journal of Chemical Physics 156, no 8 (28 février 2022) : 084103. http://dx.doi.org/10.1063/5.0077404.

Texte intégral
Résumé :
We elucidate the influence of the system–bath boundary placement within an open quantum system, with emphasis on the two-dimensional electronic spectra, through the application of the hierarchical equations of motion formalism for an exciton system. We apply two different models, the Hamiltonian vibration model (HVM) and bath vibration model (BVM), to a monomer and a homodimer. In the HVM, we specifically include the vibronic states in the Hamiltonian capturing vibronic quenching, whereas in the BVM, all vibrational details are contained within the bath and described by an underdamped spectral density. The resultant spectra are analyzed in terms of energetic peak position and thermodynamic broadening precision in order to evaluate the efficacy of the two models. The HVM produces 2D spectra with accurate peak positional information, while the BVM is well suited to modeling dynamic peak broadening. For the monomer, both models produce equivalent spectra in the limit where additional damping associated with the underdamped vibration in the BVM approaches zero. This is supported by analytical results. However, for the homodimer, the BVM spectra are redshifted with respect to the HVM due to an absence of vibronic quenching in the BVM. The computational efficiency of the two models is also discussed in order to inform us of the most appropriate use of each method.
Styles APA, Harvard, Vancouver, ISO, etc.
28

Copeland, Richard A., Michael L. Wise et David R. Crosley. « Vibrational energy transfer and quenching of hydroxyl(A2.SIGMA.+, v' = 1) ». Journal of Physical Chemistry 92, no 20 (octobre 1988) : 5710–15. http://dx.doi.org/10.1021/j100331a033.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
29

Isakov, S. L., S. N. Ishmaev, V. K. Malinovsky, V. N. Novikov, P. P. Parshin, S. N. Popov, A. P. Sokolov et M. G. Zemlyanov. « Transformation of the vibrational spectrum and structure of glasses after quenching ». Solid State Communications 86, no 2 (avril 1993) : 123–27. http://dx.doi.org/10.1016/0038-1098(93)90934-f.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
30

Gao, Yide, Yang Chen, Qin Ran, Xingxiao Ma et Congxiang Chen. « Investigation of Collisional Quenching of CCl2(Ã1B1) in Different Vibrational States ». Journal of Physical Chemistry A 105, no 47 (novembre 2001) : 10651–56. http://dx.doi.org/10.1021/jp0124995.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
31

Cabrera-González, Lisán David, Otoniel Denis-Alpizar, Dayán Páez-Hernández et Thierry Stoecklin. « Quantum study of the bending relaxation of H2O by collision with H ». Monthly Notices of the Royal Astronomical Society 514, no 3 (30 juin 2022) : 4426–32. http://dx.doi.org/10.1093/mnras/stac1643.

Texte intégral
Résumé :
ABSTRACT Vibrationally excited levels of the H2O molecule are currently detected in various environments of the interstellar medium (ISM), and collisional data for H2O, including vibration with the main colliders of the ISM, are needed. The present study focuses on the bending relaxation of H2O by collision with H when taking bending–rotation coupling explicitly into account with the rigid-bender close-coupling (RB-CC) method. With this aim, a new four-dimensional potential energy surface including the H2O bending mode is developed from a large grid of ab initio energies computed using a high level of theory. For purely rotational transitions, our RB-CC rates show very good agreement with rigid-rotor calculations performed using our new potential energy surface (PES) and with those available in the literature. Calculations for pure rotational transitions inside the excited bending level ν2 = 1 of H2O are performed and compared with their equivalents inside ν2 = 0. Vibrational quenching of H2O is also calculated and found to be much more efficient through collision with H rather than with He.
Styles APA, Harvard, Vancouver, ISO, etc.
32

Bourja, L., B. Bakiz, A. Benlhachemi, M. Ezahri, J. C. Valmalette, S. Villain et J. R. Gavarri. « Structural and Raman Vibrational Studies ofCeO2-Bi2O3Oxide System ». Advances in Materials Science and Engineering 2009 (2009) : 1–4. http://dx.doi.org/10.1155/2009/502437.

Texte intégral
Résumé :
A series of ceramics samples belonging to theCeO2-Bi2O3phase system have been prepared via a coprecipitation route. The crystallized phases were obtained by heating the solid precursors at600∘Cfor 6 hours, then quenching the samples. X-ray diffraction analyses show that forx<0.20a solid solutionCe1−xBixO2−x/2with fluorine structure is formed. For x ranging between 0.25 and 0.7, a tetragonalβ′phase coexisting with the FCC solid solution is observed. For x ranging between 0.8 and 0.9, a new tetragonalβphase appears. Theβ′phase is postulated to be a superstructure of theβphase. Finally, close tox=1, the classical monoclinicα Bi2O3structure is observed. Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.
Styles APA, Harvard, Vancouver, ISO, etc.
33

Goldfield, Evelyn M. « Wave packet dynamics of vibrational quenching in collisions of Kr and O2+ ». Journal of Chemical Physics 97, no 3 (août 1992) : 1773–86. http://dx.doi.org/10.1063/1.463164.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
34

Higgins, Jacob S., Lawson T. Lloyd, Sara H. Sohail, Marco A. Allodi, John P. Otto, Rafael G. Saer, Ryan E. Wood et al. « Photosynthesis tunes quantum-mechanical mixing of electronic and vibrational states to steer exciton energy transfer ». Proceedings of the National Academy of Sciences 118, no 11 (9 mars 2021) : e2018240118. http://dx.doi.org/10.1073/pnas.2018240118.

Texte intégral
Résumé :
Photosynthetic species evolved to protect their light-harvesting apparatus from photoxidative damage driven by intracellular redox conditions or environmental conditions. The Fenna–Matthews–Olson (FMO) pigment–protein complex from green sulfur bacteria exhibits redox-dependent quenching behavior partially due to two internal cysteine residues. Here, we show evidence that a photosynthetic complex exploits the quantum mechanics of vibronic mixing to activate an oxidative photoprotective mechanism. We use two-dimensional electronic spectroscopy (2DES) to capture energy transfer dynamics in wild-type and cysteine-deficient FMO mutant proteins under both reducing and oxidizing conditions. Under reducing conditions, we find equal energy transfer through the exciton 4–1 and 4–2-1 pathways because the exciton 4–1 energy gap is vibronically coupled with a bacteriochlorophyll-a vibrational mode. Under oxidizing conditions, however, the resonance of the exciton 4–1 energy gap is detuned from the vibrational mode, causing excitons to preferentially steer through the indirect 4–2-1 pathway to increase the likelihood of exciton quenching. We use a Redfield model to show that the complex achieves this effect by tuning the site III energy via the redox state of its internal cysteine residues. This result shows how pigment–protein complexes exploit the quantum mechanics of vibronic coupling to steer energy transfer.
Styles APA, Harvard, Vancouver, ISO, etc.
35

Jachymski, Krzysztof, et Florian Meinert. « Vibrational Quenching of Weakly Bound Cold Molecular Ions Immersed in Their Parent Gas ». Applied Sciences 10, no 7 (30 mars 2020) : 2371. http://dx.doi.org/10.3390/app10072371.

Texte intégral
Résumé :
Hybrid ion–atom systems provide an excellent platform for studies of state-resolved quantum chemistry at low temperatures, where quantum effects may be prevalent. Here we study theoretically the process of vibrational relaxation of an initially weakly bound molecular ion due to collisions with the background gas atoms. We show that this inelastic process is governed by the universal long-range part of the interaction potential, which allows for using simplified model potentials applicable to multiple atomic species. The product distribution after the collision can be estimated by making use of the distorted wave Born approximation. We find that the inelastic collisions lead predominantly to small changes in the binding energy of the molecular ion.
Styles APA, Harvard, Vancouver, ISO, etc.
36

Helvajian, H., J. S. Holloway et J. B. Koffend. « Vibrational relaxation and electronic quenching rate coefficients for BiF(A0+,v’) by SF6 ». Journal of Chemical Physics 89, no 7 (octobre 1988) : 4450–51. http://dx.doi.org/10.1063/1.455701.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
37

Viggiano, A. A., R. A. Morris, F. Dale, J. F. Paulson et E. E. Ferguson. « Vibrational quenching of NO+(v) ions in collision with H2, D2, and O2 ». Journal of Chemical Physics 90, no 3 (février 1989) : 1648–51. http://dx.doi.org/10.1063/1.456057.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
38

Wysong, Ingrid J., Jay B. Jeffries et David R. Crosley. « Quenching and vibrational energy transfer in theB 2Π state of the NS molecule ». Journal of Chemical Physics 91, no 9 (novembre 1989) : 5343–51. http://dx.doi.org/10.1063/1.457665.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
39

Veis, P., G. Cernogora et L. Magne. « Quenching rates of N2(a1Pig) vibrational levels from v'=3 to v'=6 ». Journal of Physics D : Applied Physics 26, no 5 (14 mai 1993) : 753–59. http://dx.doi.org/10.1088/0022-3727/26/5/006.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
40

Bohn, B., et F. Stuhl. « Quenching and relaxation of vibrational levels of imidogen (NH/ND)(a1.DELTA.,v) ». Journal of Physical Chemistry 97, no 28 (juillet 1993) : 7234–38. http://dx.doi.org/10.1021/j100130a018.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
41

Wight, A. C., et R. E. Miller. « Vibrational quenching of acetylene scattered from LiF(001) : Trapping desorption versus direct scattering ». Journal of Chemical Physics 109, no 19 (15 novembre 1998) : 8626–34. http://dx.doi.org/10.1063/1.477529.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
42

Yang, Benhui, P. Zhang, C. Qu, P. C. Stancil, J. M. Bowman, N. Balakrishnan et R. C. Forrey. « Inelastic vibrational dynamics of CS in collision with H2 using a full-dimensional potential energy surface ». Physical Chemistry Chemical Physics 20, no 45 (2018) : 28425–34. http://dx.doi.org/10.1039/c8cp05819a.

Texte intégral
Résumé :
A six-dimensional potential energy surface for the CS–H2 system was computed using high-level ab initio theory and fitted using a hybrid invariant polynomial method. Quantum close-coupling scattering calculations have been carried out for rovibrational quenching transitions of CS induced by H2.
Styles APA, Harvard, Vancouver, ISO, etc.
43

Zhao, Yao, et D. W. Setser. « Radiative Lifetime and Quenching Rate Constants of PF(b1.SIGMA.+) and Tests for an Electronic to Vibrational Energy Transfer Quenching Mechanism ». Journal of Physical Chemistry 98, no 39 (septembre 1994) : 9723–34. http://dx.doi.org/10.1021/j100090a004.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
44

Pavlov, A. V. « Subauroral red arcs as a conjugate phenomenon : comparison of OV1-10 satellite data with numerical calculations ». Annales Geophysicae 15, no 8 (31 août 1997) : 984–98. http://dx.doi.org/10.1007/s00585-997-0984-3.

Texte intégral
Résumé :
Abstract. This study compares the OV1-10 satellite measurements of the integral airglow intensities at 630 nm in the SAR arc regions observed in the northern and southern hemisphere as a conjugate phenomenon, with the model results obtained using the time-dependent one-dimensional mathematical model of the Earth ionosphere and plasmasphere (the IZMIRAN model) during the geomagnetic storm of the period 15–17 February 1967. The major enhancements to the IZMIRAN model developed in this study are the inclusion of He+ ions (three major ions: O+, H+, and He+, and three ion temperatures), the updated photochemistry and energy balance equations for ions and electrons, the diffusion of NO+ and O2+ ions and O(1D) and the revised electron cooling rates arising from their collisions with unexcited N2, O2 molecules and N2 molecules at the first vibrational level. The updated model includes the option to use the models of the Boltzmann or non-Boltzmann distributions of vibrationally excited molecular nitrogen. Deviations from the Boltzmann distribution for the first five vibrational levels of N2 were calculated. The calculated distribution is highly non-Boltzmann at vibrational levels v > 2 and leads to a decrease in the calculated electron density and integral intensity at 630 nm in the northern and southern hemispheres in comparison with the electron density and integral intensity calculated using the Boltzmann vibrational distribution of N2. It is found that the intensity at 630 nm is very sensitive to the oxygen number densities. Good agreement between the modelled and measured intensities is obtained provided that at all altitudes of the southern hemisphere a reduction of about factor 1.35 in MSIS-86 atomic oxygen densities is included in the IZMIRAN model with the non-Boltzmann vibrational distribution of N2. The effect of using of the O(1D) diffusion results in the decrease of 4–6% in the calculated integral intensity of the northern hemisphere and 7–13% in the calculated integral intensity of the southern hemisphere. It is found that the modelled intensities of the southern hemisphere are more sensitive to the assumed values of the rate coefficients of O+(4S) ions with the vibrationally excited nitrogen molecules and quenching of O+(2D) by atomic oxygen than the modelled intensities of the northern hemisphere.
Styles APA, Harvard, Vancouver, ISO, etc.
45

Ивашин, Н. В., et С. Н. Терехов. « Спектры РКР и механизмы тушения флуоресценции beta-нитро-тетрафенилпорфирина ». Журнал технической физики 126, no 3 (2019) : 285. http://dx.doi.org/10.21883/os.2019.03.47368.288-18.

Texte intégral
Résumé :
AbstractThe study of the excited states and photophysical characteristics of β-nitro-tetraphenylporphyrin (TPP–NO_2) has been carried out using resonance Raman scattering (RRS) spectroscopy and methods of the density functional theory. The appearance of new lines, the intensity of which depends on the composition of the matrix and excitation wavelength, has been found in the TPP–NO_2 RRS spectra in the low-temperature matrix. The calculation of the vibrational states of TPP–NO_2 allowed the linking of the additional lines with the asymmetric vibrations of the nitro group and valence C–C vibrations of the phenyl ring (Ph1) that was nearest to it. The activation of these modes is related to the specific features of the TPP–NO_2 geometry in the charge transfer (CT) state from Ph1 to the porphyrin macrocycle. It has been concluded on the basis of the analysis of the data of the study of the RRS spectra and the results of calculations that use the СAM-B3LYP and wB97XD functionals that the CT states do not play a significant role in the TPP–NO_2 fluorescence quenching, as previously assumed. The fluorescence quenching owes to strengthening channels of internal and inter-conversion by reducing the energy gaps Δ E ( S _1 – T _1) and Δ E ( S _1 – S _0) as well as increasing the spin-orbit coupling between the S _1 and T _1 states. It has been shown that TPP–NO_2 is characterized by conformational heterogeneity both in the ground and in the excited states, which explains the absence of the monoexponentiality of fluorescence decay kinetics.
Styles APA, Harvard, Vancouver, ISO, etc.
46

Feofilov, A. G., A. A. Kutepov, C. Y. She, A. K. Smith, W. D. Pesnell et R. A. Goldberg. « CO<sub>2</sub>(<i>ν</i><sub>2</sub>)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere ». Atmospheric Chemistry and Physics Discussions 11, no 12 (9 décembre 2011) : 32583–600. http://dx.doi.org/10.5194/acpd-11-32583-2011.

Texte intégral
Résumé :
Abstract. Among the processes governing the energy balance in the mesosphere and lower thermosphere (MLT), the quenching of CO2(ν2)-O vibrational levels by collisions with O atoms plays an important role. However, there is a factor of 3–4 discrepancy between various measurements of the CO2-O quenching rate coefficient, kVT. We retrieve kVT in the altitude region 80–110 km from coincident SABER/TIMED and Fort Collins sodium lidar observations by minimizing the difference between measured and simulated broadband limb 15 μm radiances. The retrieved kVT varies from about 5 × 10−12 cm3 s−1 at 87 km to about 7 × 10−12 cm3 s−1 at 104 km. A detailed consideration of retrieval errors and uncertainties indicates deficiency in current understanding the non-LTE formation mechanism of atmospheric 15 μm radiances. An updated mechanism of CO2-O collisional interactions is suggested.
Styles APA, Harvard, Vancouver, ISO, etc.
47

Nizamov, Boris, et Paul J. Dagdigian. « Collisional Quenching and Vibrational Energy Transfer in theA2Σ+Electronic State of the CF Radical ». Journal of Physical Chemistry A 105, no 1 (janvier 2001) : 29–33. http://dx.doi.org/10.1021/jp0026989.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
48

Richter, R., W. Lindinger et E. E. Ferguson. « Vibrational quenching of NO+(v) in collisions with CH4 from 0.04 to 1.2 eV ». Journal of Chemical Physics 89, no 9 (novembre 1988) : 5692–94. http://dx.doi.org/10.1063/1.455578.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
49

Jund, P., D. Caprion et R. Jullien. « Structural and vibrational properties of a soft-sphere glass : Influence of the quenching rate ». Philosophical Magazine B 77, no 2 (février 1998) : 313–20. http://dx.doi.org/10.1080/13642819808204957.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
50

Grätz, Fabian, Daniel P. Engelhart, Roman J. V. Wagner, Henrik Haak, Gerard Meijer, Alec M. Wodtke et Tim Schäfer. « Vibrational enhancement of electron emission in CO (a3Π) quenching at a clean metal surface ». Physical Chemistry Chemical Physics 15, no 36 (2013) : 14951. http://dx.doi.org/10.1039/c3cp52468j.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie