Literatura académica sobre el tema "Composés aromatiques polycycliques – Propriétés optiques"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Composés aromatiques polycycliques – Propriétés optiques".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Artículos de revistas sobre el tema "Composés aromatiques polycycliques – Propriétés optiques":
Anthoine, G., J. Nasielski y B. Wilmet-Devos. "Propriétés physico-chimiques de composés caractère aromatique. potentiels de demi-onde de réduction polarographique d'aldéhydes polycycliques aromatiques". Bulletin des Sociétés Chimiques Belges 78, n.º 9-10 (2 de septiembre de 2010): 465–69. http://dx.doi.org/10.1002/bscb.19690780904.
Klopman, G. y J. Nasielski. "Propriétés Physico-Chimiques de Composés A Caractère Aromatique II. Application de la Méthode des Orbitales Moléculaires Aux Spectres électroniques et a la Réduction Polarographique D'Esters Dérivés D'Acides Aromatiques Polycycliques Alternants et non Alt". Bulletin des Sociétés Chimiques Belges 70, n.º 9-10 (1 de septiembre de 2010): 490–510. http://dx.doi.org/10.1002/bscb.19610700904.
Pelletier, Émilien y Peter G. C. Campbell. "L’écotoxicologie aquatique - comparaison entre les micropolluants organiques et les métaux : constats actuels et défis pour l’avenir". Revue des sciences de l'eau 21, n.º 2 (22 de julio de 2008): 173–97. http://dx.doi.org/10.7202/018465ar.
Tesis sobre el tema "Composés aromatiques polycycliques – Propriétés optiques":
Bejaoui, Salma. "Etude spectroscopique des suies et de leurs précurseurs par incandescence et fluorescence induite par laser". Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10145.
In this thesis, we used several techniques of analysis to determine the spectroscopic properties of soots and their precursors (the polycyclic aromatic hydrocarbons: PAH); two types of quite different atmospheric flames were investigated: a premixed flat flame of methane (equivalence ratio: 2.1) and a jet diffusion flame of liquid hydrocarbons (methyl ester of rapeseed oil or diesel fuel). We coupled optical methods in-situ (incandescence and fluorescence induced by laser, extinction, measurement of the thermal radiation by pyrometry) and of soots sampling for analysis by transmission electronic microscopy. Firstly, the premixed flame was characterized in term of soot volume fraction profiles, of temperature of soots before and during the laser excitation and distributions of monomers soot size. Confrontation between the temporal decreases of LII signals experimental and modelled (in the case of a collaboration with NRC, Canada) made it possible to better determine the evolution of the absorption function of soots during their formation. Secondly, by a non-intrusive method, the ratio of the absorption function based on our method using two excitation wavelengths (1064 nm taken as a reference) was obtained directly for 266, 355, 532 and 660nm. To finish, the fluorescence induced by laser was applied to various excitation wavelengths to probe the fluorescence of the PAH along the flames, as well for the intensity and the spectral response. We showed that the HAP absorb and fluoresce from UV to 680 nm. This fluorescence is emitted by various families of PAH (from the smaller to the larger) when the wavelength of excitation increases. With an excitation in UV, we showed that the spectra of fluorescence are shifted towards the red. For an excitation in the visible, the spectra become centered on the laser wavelength at 532 nm and then after comprise a majoritary component “anti-Stokes” when the excitation tends to 680nm
Bouvier, Yoann. "Caractérisation de suies et de précurseurs de suies dans des flammes par incandescence induite par laser". Lille 1, 2006. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2006/50376-2006-Bouvier.pdf.
Cette étude a été effectuée de manière originale en utilisant un profil de faisceau laser gaussien et en comparant la détection "classique" à angle droit à la détection dans le sens contraire à la propagation du faisceau (rétro-LII) Cette comparaison a permis de valider un dispositif de mesure de fraction volumique de suies par rétro-LII à l'échappement des moteurs. Une méthode expérimentale de détermination de révolution de la fonction d'indice de réfraction E(m) avec la longueur d'onde est proposée par comparaison des signaux LII obtenus en utilisant des longueurs d'onde d'excitation dc 532 nm et 1064 nm. Une validation de la méthode est effectuée par comparaison avec des mesures d'extinction obtenues par mesure du temps de déclin d'une cavité optique (CRDS) aux mêmes longueurs d'onde. La structure des flammes "jet" supports a été étudiée par couplage de l'Incandescence Induite par Laser des suies et de la Fluorescence Induite par Laser des HAP à 532 nm (LII / LIF). La calibration des fractions volumiques de suies est effectuée par mesure du temps de vie d'une cavité optique à 1064 nm. Des cartographies suies / HAP sont ainsi obtenues dans une flamme de diffusion de méthane et dans les deux flammes de prémélange. La sensibilité des techniques mises en œuvre permet de détecter de très faibles teneurs en suies (< 1 ppb). Une méthode novatrice de mesure de la vitesse des particules de suie dans les flammes est également proposée
Labarrière, Luc. "Spectroscopic properties of environmental relevant systems : 2’,3-dihydroxyflavone-ion complexes and polycyclic aromatic hydrocarbons : a joint experimental and theoretical study". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR069.
This manuscript reports the results of an experimental and theoretical study of two molecular systems of environmental interest: 2',3-dihydroxyflavone (2'3HF) and polycyclic aromatic hydrocarbons (PAH). These systems were studied by a combination of electronic spectroscopic techniques (absorption and fluorescence) and quantum chemical calculations (DFT and TD-DFT). In the first part of this thesis, it is shown that 2'3HF has singular acid-base properties compared to other flavonols. The decrease of the pKa by several units is attributed to the presence of a hydrogen-bond network. In the excited state, an intramolecular proton transfer causes a dual fluorescence. An additional emission band, seemingly originating from a tautomeric form perturbed by interaction with the solvent, was revealed. Finally, an exhaustive study of the Ca(II), Mn(II) and Zn(II) complexes showed the formation of chelates with the α-hydroxyketone function. In the second part, three structural hypotheses to explain the experimental observation of visible-range laser-induced fluorescence (LIF) were explored. A study of van der Waals (vdW) dimers of PAHs provided insights into the nature of the monomer interaction and highlighted the difficulty of modelling these systems. However, the calculated electronic transitions suggest that these species cannot be responsible for the LIF signals. Secondly, an identical study of aliphatically bridged PAHs showed very similar results to vdW dimers, ruling out their involvement in the observed fluorescence. Finally, the hypothesis of emission from PAH radicals was explored. The latter is very promising and opens the way for further experimental and theoretical studies
Dontot, Léo. "Propriétés structurales et spectroscopiques des agrégats d'hydrocarbures aromatiques polycycliques". Toulouse 3, 2014. http://thesesups.ups-tlse.fr/4526/.
Modeling of neutral or cationic molecular clusters remains a challenge in ab initio approaches as soon as the molecules involved are large or when their number exceed several units. We develop, in this thesis, a mixed method based on the combination of the DFTB method, an approximation of the Density Functional Theory (DFT), with a Configuration Interaction (CI). This method (DFTB-CI) provides an original and efficient approach to obtain a correct description of the charge resonance within cationic clusters. The application to polycyclic aromatic hydrocarbons clusters is of interest in various fields such as physics and chemistry of the interstellar medium, chemistry of the atmosphere and also combustion processes. This work has enabled the description of structural properties of the ground state of neutral and cationic clusters of pyrene and coronene containing up to ten molecules. A multi-method strategy has been implemented in order to efficient search for the most stable structures with the global exploration algorithm "Parallel Tempering Monte Carlo". In addition to the structural properties, we have determined the quantities characterizing the stability of these clusters (binding and dissociation energies) as well as their electronic properties such as the dependency of the ionization potentials on the size in good agreement with experimental results. Finally, we propose an extension to the DFTB-CI model in order to compute the excited states of molecular clusters. The results on dimers are found in good agreement with ab initio calculations. An application to small cationic clusters of benzene and pyrene presents the determination of their electronic absorption spectra
Dufitumukiza, Jean Pierre. "Développement des techniques optiques pour la caractérisation in-situ de la suie dans des foyers de combustion à haute pression". Electronic Thesis or Diss., Université de Lille (2022-....), 2023. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2023/2023ULILR010.pdf.
The growth of air traffic urges combustion research to get a detailed understanding of the physical and chemical processes occurring in the aircraft engine; the main objectives are 1) to improve the combustion process and 2) to lower gaseous and particulate emissions. A solution to the first issue lies in the combustion at higher pressure and temperature, but this can impact the second issue, particularly concerning the production of soot and NOx emissions. To find a solution, it is necessary to develop experimental tools applied in representative combustion conditions relative to those encountered in aircraft engines in order to capture complex phenomena occurring inside these engines. To do this, a semi-industrial aeronautical test rig equipped with suitable optical diagnostics implemented/available at ONERA Palaiseau offers a glimpse of information into these combustion processes. As a result, this research aims to develop and implement optical techniques for characterizing soot particles in aeronautical engine-relevant combustors. Laser-Induced Incandescence (LII) is the primary technique on which efforts are directed. This technique is based on Planck's law radiation model. LII technique is used due to its high sensitivity for detecting the soot volume fraction and flexibility for its implementation in various optical configurations. In addition, the coupling of LII with other optical techniques presents a high interest in understanding the mechanisms and parameters leading to soot formation. First, Laser-Induced Fluorescence (LIF) is added as a complementary technique to detect soot precursors known as Polycyclic-Aromatic Hydrocarbons (PAHs). Secondly, light scattering provides information on the distribution of unburnt liquid fuel droplets and possible soot particle localization inside the combustor. Thirdly, OH* chemiluminescence illustrates the reaction zone and heat release. Finally, the PAHs and soot transportation or interactions with the flow field are tackled via particle image velocimetry (PIV)
Michoulier, Eric. "Influence de la glace d’eau sur les propriétés spectroscopiques et énergétiques d’hydrocarbures aromatiques polycycliques". Electronic Thesis or Diss., Lille 1, 2017. http://www.theses.fr/2017LIL10122.
Polycyclic aromatic hydrocarbons (PAH) molecules are thought to be responsible for specific infrared emission bands in the interstellar medium (ISM). The cold and dense areas of the ISM, such as molecular clouds, contain dust particles whose mantle is predominantly composed of water ice. The interaction of PAH with ice tends, on the one hand, to modify its spectroscopic properties and, on the other hand, under UV irradiation, to induce a specific reactivity. Our theoretical work falls within this framework and aims to study the influence of ice on the energetic and spectroscopic properties of PAH, in connection with laboratory experiments. First, we have simulated the adsorption of PAH at the surface of amorphous and crystalline ice by classical molecular dynamics based on a force-field approach. A rigorous methodology has been developed to parameterize the charges of the different PAH. The adsorption energy of a various PAHs could thus be determined and a correlation was established between the adsorption sites and the presence of dangling bonds at the surface. Then, the generated configurations were used for SCC-DFTB calculations: the vibrational, harmonic and anharmonic spectra for the different PAHs and types of ice were determined. The shifts or emergences of bands identified on the calculated spectra were compared with the experimental data. The influence of the local organization of the surrounding water molecules on the vertical ionization potential has been characterized, as this process can impact precursor states to reactivity
Michoulier, Eric. "Influence de la glace d’eau sur les propriétés spectroscopiques et énergétiques d’hydrocarbures aromatiques polycycliques". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10122/document.
Polycyclic aromatic hydrocarbons (PAH) molecules are thought to be responsible for specific infrared emission bands in the interstellar medium (ISM). The cold and dense areas of the ISM, such as molecular clouds, contain dust particles whose mantle is predominantly composed of water ice. The interaction of PAH with ice tends, on the one hand, to modify its spectroscopic properties and, on the other hand, under UV irradiation, to induce a specific reactivity. Our theoretical work falls within this framework and aims to study the influence of ice on the energetic and spectroscopic properties of PAH, in connection with laboratory experiments. First, we have simulated the adsorption of PAH at the surface of amorphous and crystalline ice by classical molecular dynamics based on a force-field approach. A rigorous methodology has been developed to parameterize the charges of the different PAH. The adsorption energy of a various PAHs could thus be determined and a correlation was established between the adsorption sites and the presence of dangling bonds at the surface. Then, the generated configurations were used for SCC-DFTB calculations: the vibrational, harmonic and anharmonic spectra for the different PAHs and types of ice were determined. The shifts or emergences of bands identified on the calculated spectra were compared with the experimental data. The influence of the local organization of the surrounding water molecules on the vertical ionization potential has been characterized, as this process can impact precursor states to reactivity
Yang, Zhixin. "Préparation et propriétés des polycarbosilanes comportant des groupements acétyléniques et aromatiques dans le squelette". Montpellier 2, 1992. http://www.theses.fr/1992MON20177.
Catanéo, Clément. "Etude des mécanismes de production et de dépôt des composés de la fumée lors du fumage de la chair de poisson : contribution à l'obtention de produits sains possédant de bonnes propriétés organoleptiques". Nantes, 2011. http://www.theses.fr/2011NANT2062.
Quality of smoked fish is altered by several steps during the technological processing. This work aims at bringing out new control points of the final product through a better understanding of smoke production and deposit mechanisms. The studies focused on both volatile phenolic compounds (involved in aroma, colour and shelf life of smoked food) and polycyclic aromatic hydrocarbons (main toxic contaminants of smoke). To directly elucidate smoke composition and indirectly evaluate interactions between gaseous compounds and solid matrices, several analysis techniques were developed and validated. Potential improvement of smoke compounds quantification by means of comprehensive gas chromatography was also investigated. Smoke generation was studied by chemometric characterization of various smokes produced with an industrial friction generator and trapped by means of an electrostatic precipitator. The main importance of wood specie and moisture were confirmed, as well as the complexity of the operating conditions of that type of generator. Deposits and interactions of smoke compounds at the surface of the products were measured with artificial food matrices. Results obtained under both actual industrial smoking and model conditions (static headspaces with controlled composition) highlighted the major role of the oil fraction, particularly concerning phenolic compounds enrichment
Aoulmi, Aïssa. "Contribution à l'étude des propriétés thermodynamiques des hydrocarbures polycycliques, aromatiques et des alcanes à longue chaine". Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL140N.