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Journal articles on the topic 'Spectroscopie par absorption laser'

Author: Grafiati

Published: 4 June 2021

Last updated: 10 February 2022

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1

Jardon, Pierre, Hans Dieter Brauer, and René Gautron. "Absorption triplet-triplet du mésodiphenylhélianthrène étude par spectroscopie laser." Journal de Chimie Physique 82 (1985): 1–7. http://dx.doi.org/10.1051/jcp/1985820001.

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2

Dunlea, E. J., S. C. Herndon, D. D. Nelson, et al. "Evaluation of nitrogen dioxide chemiluminescence monitors in a polluted urban environment." Atmospheric Chemistry and Physics 7, no. 10 (2007): 2691–704. http://dx.doi.org/10.5194/acp-7-2691-2007.

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Abstract. Data from a recent field campaign in Mexico City are used to evaluate the performance of the EPA Federal Reference Method for monitoring the ambient concentrations of NO2. Measurements of NO2 from standard chemiluminescence monitors equipped with molybdenum oxide converters are compared with those from Tunable Infrared Laser Differential Absorption Spectroscopy (TILDAS) and Differential Optical Absorption Spectroscopy (DOAS) instruments. A significant interference in the chemiluminescence measurement is shown to account for up to 50% of ambient NO2 concentration during afternoon hour

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3

Dunlea, E. J., S. C. Herndon, D. D. Nelson, et al. "Evaluation of nitrogen dioxide chemiluminescence monitors in a polluted urban environment." Atmospheric Chemistry and Physics Discussions 7, no. 1 (2007): 569–604. http://dx.doi.org/10.5194/acpd-7-569-2007.

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Abstract. Data from a recent field campaign in Mexico City are used to evaluate the performance of the EPA Federal Reference Method for monitoring ambient concentrations of NO2. Measurements of NO2 from standard chemiluminescence monitors equipped with molybdenum oxide converters are compared with those from Tunable Infrared Laser Differential Absorption Spectroscopy (TILDAS) and Differential Optical Absorption Spectroscopy (DOAS) instruments. A significant interference in the chemiluminescence measurement is shown to account for up to 50% of ambient NO2 concentration during afternoon hours. A

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4

Boukhlouf, Hamza, R. Benrabaa, S. Barama, and A. Barama. "Study of Unsupported and Al₂O₃ or SiO₂-Supported Nickel Molybdate for Oxireforming of Ethane." Materials Science Forum 609 (January 2009): 145–48. http://dx.doi.org/10.4028/www.scientific.net/msf.609.145.

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The nickel molybdate unsupported and supported on alumina or silica were prepared by co-precipitation and co-precipitation/impregnation methods and calcined in air at 550°C for 15h. The textural and structural properties of the solids have been studied using Brunner-Emmett-Teller surface analyze (BET), X-ray diffraction (XRD), Laser Raman Spectroscopy (LRS), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDX), temperature-programmed reduction (TPR) and Atomic absorption spectroscopy (AAS). The catalytic activity measurements were performed in a fixed bed qu

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5

Engel, A., T. Möbius, H. P. Haase, et al. "Observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003." Atmospheric Chemistry and Physics 6, no. 1 (2006): 267–82. http://dx.doi.org/10.5194/acp-6-267-2006.

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Abstract. During several balloon flights inside the Arctic polar vortex in early 2003, unusual trace gas distributions were observed, which indicate a strong influence of mesospheric air in the stratosphere. The tuneable diode laser (TDL) instrument SPIRALE (Spectroscopie Infra-Rouge par Absorption de Lasers Embarqués) measured unusually high CO values (up to 600 ppb) on 27 January at about 30 km altitude. The cryosampler BONBON sampled air masses with very high molecular Hydrogen, extremely low SF6 and enhanced CO values on 6 March at about 25 km altitude. Finally, the MIPAS (Michelson Interf

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Engel, A., T. Möbius, H. P. Haase, et al. "On the observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003." Atmospheric Chemistry and Physics Discussions 5, no. 4 (2005): 7457–96. http://dx.doi.org/10.5194/acpd-5-7457-2005.

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Abstract. During several balloon flights inside the Arctic polar vortex in early 2003, unusual trace gas distributions were observed, which indicate a strong influence of mesospheric air in the stratosphere. The tuneable diode laser (TDL) instrument SPIRALE (Spectroscopie InFrarouge par Absorption de Lasers Embarqués) measured unusually high CO values (up to 600 ppb) on 27 January at about 30 km altitude. The cryosampler BONBON sampled air masses with very high molecular Hydrogen, extremely low SF6 and enhanced CO values on 6 March at about 25 km altitude. Finally, the MIPAS (Michelson Interfe

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7

Poquerusse, A., and J. M. Boudenne. "Cristal trapézoïdal en spectroscopie X d'implosion par laser." Revue de Physique Appliquée 23, no. 3 (1988): 315–18. http://dx.doi.org/10.1051/rphysap:01988002303031500.

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8

Poquérusse, A. "Cristal graduellement concave en spectroscopie X par laser." Optics Communications 58, no. 2 (1986): 108–12. http://dx.doi.org/10.1016/0030-4018(86)90401-3.

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9

Leprince, Marine, Lucie Sancey, Jean-Luc Coll, Vincent Motto-Ros, and Benoît Busser. "L’imagerie élémentaire par spectroscopie LIBS." médecine/sciences 35, no. 8-9 (2019): 682–88. http://dx.doi.org/10.1051/medsci/2019132.

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L’imagerie multi-élémentaire des tissus biologiques grâce à la spectroscopie LIBS (laser-induced breakdown spectroscopy) permet la visualisation directe de la distribution des éléments endogènes ou exogènes. Cette technologie est notamment utilisée pour mettre en image la cinétique des nanoparticules métalliques dans les organes d’élimination, mais également pour analyser la distribution physiologique des éléments biologiques in situ, et pour révéler la topographie des éléments chimiques, comme les métaux, dans des tissus humains qui ont été exposés à des agents extérieurs potentiellement toxi

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10

MOULIN, C., A. BRIAND, P. DECAMBOX, et al. "Techniques d'analyses d'actinides et de radioéléments d'intérêt par spectroscopie laser." Radioprotection 29, no. 4 (1994): 517–38. http://dx.doi.org/10.1051/radiopro/1994004.

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11

Yu, Jin, and Vincent Motto-Ros. "Spectroscopie du plasma induit par laser pour l'analyse de matière organique." Photoniques, no. 63 (January 2013): 38–43. http://dx.doi.org/10.1051/photon/20136338.

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12

Jardon, Pierre, Nellia Lazorchak, and René Gautron. "Propriétés du premier état triplet de l'hypericine. Étude par spectroscopie laser." Journal de Chimie Physique 83 (1986): 311–15. http://dx.doi.org/10.1051/jcp/1986830311.

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13

Jardon, Pierre, Nélia Lazortchak та René Gautron. "Formation d’oxygène singulet 1Δg photosensibilisée par l’hypericine caractérisation et étude du mécanisme par spectroscopie laser". Journal de Chimie Physique 84 (1987): 1141–45. http://dx.doi.org/10.1051/jcp/1987841141.

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14

Laroche, M., J. L. Doualan, S. Girard, J. Margerie, R. Moncorge, and M. Thuau. "Spectroscopie sur les niveaux d'énergie 4f5d du Pr3+par absorption dans l'état excité." Le Journal de Physique IV 10, PR8 (2000): Pr8–255. http://dx.doi.org/10.1051/jp4:2000879.

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15

Marécal, V., G. Krysztofiak, Y. Mébarki, et al. "Impact of deep convection on the tropical tropopause layer composition in Equatorial Brazil." Atmospheric Chemistry and Physics Discussions 11, no. 5 (2011): 16147–83. http://dx.doi.org/10.5194/acpd-11-16147-2011.

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Abstract. This paper documents measurements of carbon monoxide (CO), ozone (O3) and temperature in the tropical tropopause layer over Equatorial Brazil for the first time. These measurements were sampled by the balloon-borne instrument SPIRALE (Spectroscopie Infa-Rouge par Absorption de Lasers Embarqués) in June 2005 and in June 2008, both at the transition period from wet to dry season. The height of the Tropical Tropopause Layer (TTL) top and bottom determined from the chemical species profiles are similar for the two flights. Nevertheless the measured profiles of ozone and CO are different

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16

Lee, Jong-Won, Gyeongbo Kang, Minju Kim, et al. "Femtosecond soft X-ray absorption spectroscopy of warm dense matter at the PAL-XFEL." Journal of Synchrotron Radiation 27, no. 4 (2020): 953–58. http://dx.doi.org/10.1107/s160057752000524x.

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Free-electron laser pulse-based X-ray absorption spectroscopy measurements on warm dense copper are presented. The incident X-ray pulse energies were measured with a detector assembly consisting of a photocathode membrane and microchannel plates, and the transmitted energies were measured simultaneously with a photodiode detector. The precision of the absorption measurements was evaluated. For a warm dense copper foil irradiated by an intense femtosecond laser pulse, the enhanced X-ray absorption below the L 3-edge, followed by the rapid evolution of highly excited Fermi liquid within a picose

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17

Gibert, Fabien, Fabien Marnas, Dimitri Edouart, and Pierre H. Flamant. "An a Posteriori Method Based on Photo-Acoustic Cell Information to Correct for Lidar Transmitter Spectral Shift: Application to Atmospheric CO2 Differential Absorption Lidar Measurements." Applied Spectroscopy 61, no. 10 (2007): 1068–75. http://dx.doi.org/10.1366/000370207782217798.

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An a posteriori corrective method based on photo-acoustic cell (PAC) information is proposed to correct for laser transmitter spectral shift during atmospheric CO2 measurements by 2 μm heterodyne differential absorption lidar (HDIAL) technique. The method for using the PAC signal to retrieve the actual atmospheric CO2 absorption is presented in detail. This issue is tackled using a weighting function. The performance of the proposed corrective method is discussed and the various sources of error associated with the PAC signal are investigated. For 300 shots averaged and a frequency shift (from

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18

Vigne, Nathan, Baptiste Chomet, Alaeddine Abbes, et al. "États originaux de la lumière par structuration 3D de l’émission D’un laser à Métasurface." Photoniques, no. 109 (July 2021): 46–50. http://dx.doi.org/10.1051/photon/202110946.

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La génération d’états de photon cohérents puissants dans le proche-IR et THz, présentant une structuration 3D spatio-temporelle, représente un défi physique et technologique. Elle est d’intérêt pour les applications : pinces optiques, capteurs, microscopie, LIDAR, télécoms, spectroscopie… Ces états originaux sont ici générés en exploitant les nanotechnologies à semi-conducteur III-V et les lasers à cavité externe verticale intégrant une métasurface : lumière VORTEX, bi-fréquences pour le THz, ou sans mode.

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19

Gesuele, Felice. "Ultrafast Hyperspectral Transient Absorption Spectroscopy: Application to Single Layer Graphene." Photonics 6, no. 3 (2019): 95. http://dx.doi.org/10.3390/photonics6030095.

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We describe the basic principles and the experimental implementation of the hyperspectral transient absorption technique, based on femtosecond laser sources. In this technique the samples were optically “pumped” using the femtosecond tunable pulse delivered by an Optical Parametric Amplifier, and “probed” for changes in transmission in a broad spectral range with a “white light” laser-generated supercontinuum. The spectra were collected by a pair of multichannel detectors which allowed retrieval of the absorbance change in a wide spectral range in one time. The use of the supercontinuum probe

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20

Romanini, D. "Spectroscopie d'absorption quantitative à très haute sensiblité : "ring down" cavité et absorption intracavité laser." Annales de Physique 20, no. 5-6 (1995): 655–74. http://dx.doi.org/10.1051/anphys:199556059.

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21

Mialocq, J. C., and R. V. Bensasson. "Spectroscopie et photochimie des acides nucleiques, des protéines et de leurs composants par éclair laser." Annales de Physique 22 (February 1997): C1–169—C1–177. http://dx.doi.org/10.1051/anphys/1997036.

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22

Herm, Michel, Xavier Gaona, Thomas Rabung, et al. "Solubility and spectroscopic study of AnIII/LnIII in dilute to concentrated Na–Mg–Ca–Cl–NO3 solutions." Pure and Applied Chemistry 87, no. 5 (2015): 487–502. http://dx.doi.org/10.1515/pac-2014-1205.

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AbstractThe complexation of AnIII/LnIII with nitrate was investigated in dilute to concentrated Na–Mg–Ca–Cl–NO3 solutions at 2.94 ≤ pHm ≤ 13.2 and T = 22 ± 2 °C. Comprehensive solubility experiments with Nd(OH)3(s) were performed from undersaturation conditions and complemented by extensive spectroscopic studies using Cm(III)–TRLFS (time resolved laser fluorescence spectroscopy) and Nd–LIII EXAFS (extended X-ray absorption fine structure) under analogous pHm, Im and mNO3− conditions. Solid phases recovered from batch solubility experiments were characterized by XRD and SEM-EDS. A significant i

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23

Stein, H. J., P. S. Peercy, and C. R. Hills. "Metastable supersaturated solutions of nitrogen in rapidly-solidified silicon." Journal of Materials Research 4, no. 3 (1989): 616–22. http://dx.doi.org/10.1557/jmr.1989.0616.

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The depth distribution, chemical bonding, and electrical behavior of N quenched into Si by pulsed laser-induced melting have been investigated by secondary ion mass spectroscopy, infrared (ir) absorption, transmission electron microscopy (TEM), and electrical conductivity. The results demonstrate that laser-induced melting of N-implanted layers provides access to a useful range of otherwise inaccessible conditions for the study of N in Si. Nitrogen concentrations four orders of magnitude above equilibrium solid solubility are retained in implanted layers with limited diffusion during laser-ind

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24

Verger, Louisiane, Olivier Dargaud, and Laurent Cormier. "Couleurs et émaux. Des décors de la Manufacture de Sèvres à la réactivité des pigments." Reflets de la physique, no. 63 (October 2019): 26–29. http://dx.doi.org/10.1051/refdp/201963026.

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Un décor de porcelaine est obtenu à l’aide de mélanges de pigments et de composants incolores qui, en se vitrifiant, fixent l’émail à la surface de l’objet et révèlent ainsi la couleu. Cet article s’intéresse à la stabilité d’un pigment de type spinelle au cours de la cuisson du décor. La caractérisation d’un grain de ce pigment par microscopie électronique, spectroscopie optique et absorption des rayons X, a permis de montrer que le changement de couleur parfois observé après cuisson résulte d’un enrichissement en chrome de la périphérie des grains de spinelle.

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25

Hermann, Jörg, Chao Shen, Antonio Hermann, Olivier Aleixo da Luz, Aya Taleb, and Frédéric Pelascini. "Analyse élémentaire : Des matériaux sans étalonnage." Photoniques, no. 103 (July 2020): 46–49. http://dx.doi.org/10.1051/photon/202010346.

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La mesure de la composition élémentaire d’un matériau nécessite habituellement un étalonnage à l’aide de références de composition proche du matériau à analyser. Cela implique de connaître la composition du matériau et d’avoir à disposition des étalons adéquats. La spectroscopie du plasma induit par laser permet de s’affranchir de cette étape d’étalonnage et de réaliser une analyse basée sur la comparaison d’un spectre mesuré avec le spectre calculé à l’aide d’un modèle : c’est l’approche « calibration-free ».

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26

Wolf, Thomas J. A., and Markus Gühr. "Photochemical pathways in nucleobases measured with an X-ray FEL." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377, no. 2145 (2019): 20170473. http://dx.doi.org/10.1098/rsta.2017.0473.

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The conversion of light energy into other molecular energetic degrees of freedom is often dominated by ultrafast, non-adiabatic processes. Femtosecond spectroscopy with optical pulses has helped in shaping our understanding of crucial processes in molecular energy-conversion. The advent of new, ultrashort and bright X-ray free electron laser sources opens the possibility to use X-ray-typical element and site sensitivity for ultrafast molecular research. We present two types of spectroscopy, ultrafast Auger and ultrafast X-ray absorption spectroscopy, and discuss their sensitivity to molecular

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27

Park, Sang Han, Jungbum Yoon, Changsoo Kim, et al. "Scientific instruments for soft X-ray photon-in/photon-out spectroscopy on the PAL-XFEL." Journal of Synchrotron Radiation 26, no. 4 (2019): 1031–36. http://dx.doi.org/10.1107/s1600577519004272.

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An overview is given of the soft X-ray photon-in/photon-out instruments on the free-electron laser (FEL) beamline at the Pohang Accelerator Laboratory, and selected commissioning results are presented. The FEL beamline provides a photon energy of 270 to 1200 eV, with an energy bandwidth of 0.44%, an energy of 200 µJ per pulse and a pulse width of <50 fs (full width at half-maximum). The estimated total time resolution between optical laser and X-ray pulses is <100 fs. Instruments for X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) have been set up. X-ra

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28

Scherman, Michael, Joanna Barros, Rosa Santagata, Alexandre Bresson, and Brigitte Attal-Tretout. "Thermométrie Raman cohérente pour l'étude de la combustion." Photoniques, no. 96 (May 2019): 23–29. http://dx.doi.org/10.1051/photon/20199623.

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La combustion est un sujet d’intérêt pour une large variété de domaines d’applications civils ou militaires. Comprendre les phénomènes physico-chimiques à l’oeuvre dans ces milieux complexes, et les décrire à l’aide de modèles éprouvés, sont des enjeux majeurs qui requièrent des mesures fiables et quantitatives. La spectroscopie par diffusion Raman anti-Stokes cohérente (DRASC ou CARS en anglais) a démontré des performances inégalées pour la mesure de température. Cette technique a été implémentée avec de nombreuses architectures laser, et appliquée avec succès à un large éventail de milieux.

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Siddiq, Muhammad, Khush Bakhat, and Muhammad Ajmal. "Stimuli responsive microgel containing silver nanoparticles with tunable optical and catalytic properties." Pure and Applied Chemistry 92, no. 3 (2020): 445–59. http://dx.doi.org/10.1515/pac-2018-1203.

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AbstractIn this work, poly (vinylcaprolactam-co-itaconic acid) microgel was prepared by free radical polymerization. Silver nanoparticles were prepared in synthesized microgel networks by in situ reduction of Ag+ ions, loaded in microgel from aqueous solution of AgNO3. The prepared microgel was characterized by Fourier transformation infra-red spectroscopy, UV-Visible spectroscopy, fluorescence spectroscopy, X-ray diffraction, laser light scattering, thermal gravimetric analysis, differential scanning calorimetry and transmission electron microscopy. Swelling behavior of microgel was studied a

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30

Lin, Haoyang, Zhao Huang, Ruifeng Kan, et al. "Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy." Sensors 19, no. 23 (2019): 5240. http://dx.doi.org/10.3390/s19235240.

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A novel quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a micro quartz tuning fork (QTF) is reported. As a photoacoustic transducer, a novel micro QTF was 3.7 times smaller than the usually used standard QTF, resulting in a gas sampling volume of ~0.1 mm3. As a proof of concept, water vapor in the air was detected by using 1.39 μm distributed feedback (DFB) laser. A detailed analysis of the performance of a QEPAS sensor based on the micro QTF was performed by detecting atmosphere H2O. The laser focus position and the laser modulation depth were optimized to improve the QEPAS

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31

Waskoenig, Jochen, Kari Niemi, Nikolas Knake, et al. "Diagnostic-based modeling on a micro-scale atmospheric-pressure plasma jet." Pure and Applied Chemistry 82, no. 6 (2010): 1209–22. http://dx.doi.org/10.1351/pac-con-09-11-05.

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Diagnostic-based modeling (DBM) actively combines complementary advantages of numerical plasma simulations and relatively simple optical emission spectroscopy (OES). DBM is applied to determine spatial absolute atomic oxygen ground-state density profiles in a micro atmospheric-pressure plasma jet operated in He–O2. A 1D fluid model with semi-kinetic treatment of the electrons yields detailed information on the electron dynamics and the corresponding spatio-temporal electron energy distribution function. Benchmarking this time- and space-resolved simulation with phase-resolved OES (PROES) allow

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32

Rosenzweig, Zeev, and Edward S. Yeung. "Laser-Based Double-Beam Circular Dichroism Detector for Liquid Chromatography." Applied Spectroscopy 47, no. 12 (1993): 2017–21. http://dx.doi.org/10.1366/0003702934066442.

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A highly sensitive and selective double-beam laser-based circular dichroism (CD) detector for high-performance liquid chromatography (HPLC) is presented. An all-electronic noise canceller circuit was used to subtract the intensity of the right circularly polarized light from the intensity of the left circularly polarized light. Both of these beams were derived from the same Ar-ion laser operated at 488 nm. The chiral inorganic complexes of tris(ethylenediamine)cobalt(III), Co(en)33+, which are CD active at this wavelength [Δɛ(488 nm) = 1.9 cm2 mol−1], were chosen as test compounds. The two ena

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33

Jordan, Nick, Connie Z. Ye, Satyaki Ghosh, Rebecca A. Washenfelder, Steven S. Brown, and Hans D. Osthoff. "A broadband cavity-enhanced spectrometer for atmospheric trace gas measurements and Rayleigh scattering cross sections in the cyan region (470–540 nm)." Atmospheric Measurement Techniques 12, no. 2 (2019): 1277–93. http://dx.doi.org/10.5194/amt-12-1277-2019.

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Abstract. An incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for quantification of atmospheric trace gases that absorb in the cyan region of the electromagnetic spectrum (470 to 540 nm), including NO2 and I2, is described. The instrument uses a light-emitting diode coupled to a 1 m optical cavity consisting of a pair of mirrors in stable resonator configuration. Transmitted light is monitored using a grating spectrometer and charge-coupled device array detector. The average mirror reflectivity was determined from the N2∕He and Ar∕He ratios of scattering coeffi

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34

Pépin, C., D. Houde, H. Remita, T. Goulet, and JP Jay-Gerin. "Génération de l'électron hydraté par absorption multiphotonique d'impulsions laser femtoseconde de 2 eV." Journal de Chimie Physique 90 (1993): 745–53. http://dx.doi.org/10.1051/jcp/1993900745.

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35

Briot, Danielle, Luc Arnold, Stéphane Jacquemoud, and Jean Schneider. "Present and Future Detection of Terrestrial Biomarkers on Earthshine." Proceedings of the International Astronomical Union 8, S293 (2012): 65–67. http://dx.doi.org/10.1017/s1743921313012544.

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AbstractIn the context of life detection on terrestrial exoplanets, new methods of search for spectral signatures of chlorophyll and other biomarkers in the Earthshine have been developed in the last few decades. Astronomical observations made at OHP and ESO (NTT) showed a significant signal when continents are facing the Moon. This signal, called the Vegetation Red Edge (VRE), is undoubtedly due to chlorophyll absorption properties. In order to strengthen these results, the LUCAS (LUmière Cendrée en Antarctique par Spectroscopie) project dedicated to the measurement of the Earthshine from the

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36

Renger, G., HJ Eckert, A. Bergmann, et al. "Fluorescence and Spectroscopic Studies of Exciton Trapping and Electron Transfer in Photosystem II of Higher Plants." Functional Plant Biology 22, no. 2 (1995): 167. http://dx.doi.org/10.1071/pp9950167.

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Measurements of time-resolved fluorescence decay, laser-flash-induced absorption changes in the UV and at 820 nm and of the relative fluorescence quantum yield in different preparations (thylakoids, photosystem II (PSII) membrane fragments and PSII core complexes) from spinach led to a number of conclusions. (1) Light is transformed into Gibbs energy with trapping times of 250 ps and 130 ps in open reaction centres of PSII membrane fragments and PSII core complexes, respectively. Assuming rapid Boltzmann distribution of excitation energy and taking into account the antenna properties (size and

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37

Lemmens, A. K., D. B. Rap, J. M. M. Thunnissen, et al. "Anharmonicity in the mid-infrared spectra of polycyclic aromatic hydrocarbons: molecular beam spectroscopy and calculations." Astronomy & Astrophysics 628 (August 2019): A130. http://dx.doi.org/10.1051/0004-6361/201935631.

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Aims. In this work we determine the effects of anharmonicity on the mid-infrared spectra of the linear polycyclic aromatic hydrocarbons (PAHs) naphthalene, anthracene, tetracene and pentacene recorded using the free electron laser FELIX. Methods. Comparison of experimental spectra obtained under supersonic jet conditions with theoretically predicted spectra was used to show if anharmonicity explicitly needs to be taken into account. Results. Anharmonic spectra obtained using second-order vibrational perturbation theory agree on average within 0.5% of the experimental frequencies. Importantly,

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38

Chalvet, Odilon, Jean-François Gourvest, Hélène Strapelias, and Maurice Duquesne. "Identification, par spectroscopie optique, des dihydrodiols formés lors de la métabolisation des hydrocarbures polybenzéniques. Application dans le cas de la métabolisation in vitro du dibenzo[a,e]pyrène." Canadian Journal of Chemistry 63, no. 2 (1985): 500–502. http://dx.doi.org/10.1139/v85-081.

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The first step in the metabolization of a polycyclic hydrocarbon molecule is the saturation of a double bond, the formation of an epoxide, then of a dihydrodiol. Once separation has been achieved by chromatography, the absorption spectra of these dihydrodiols can be established and directly compared with theoretical predictions which are reasonably easy to elaborate in the case of plane molecules. The initial site of enzyme attack can then be identified without using model molecules.

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Sadat, M. E., David B. Mast, Jason Sookoor, Hong Xu, Andrew W. Dunn, and Donglu Shi. "Effects of Nanoscale Structures on Photothermal Heating Behaviors of Surface-Modified Fe3O4 Nanoparticles." Nano LIFE 09, no. 01n02 (2019): 1950001. http://dx.doi.org/10.1142/s1793984419500016.

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In this investigation, the photothermal heating of superparamagnetic Fe3O4 nanoparticles was carried out by irradiating with either 785[Formula: see text]nm or 808[Formula: see text]nm near infrared (NIR) lasers. The effects of nanoparticle configuration, arrangement, and surface coating on the photothermal heating behavior were investigated for different Fe3O4 nanoparticle systems. Depending on the preparation method, Fe3O4 nanoparticles with mean hydrodynamic diameter ranging from 30[Formula: see text]nm to 250[Formula: see text]nm were synthesized. Photothermal transduction efficiency is a

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Schuster, David I., Jie-Min Yang, Jan Woning, Timothy A. Rhodes, and Anton W. Jensen. "Mechanism of acid-catalyzed photoaddition of methanol to 3-alkyl2-cyclohexenones." Canadian Journal of Chemistry 73, no. 11 (1995): 2004–10. http://dx.doi.org/10.1139/v95-247.

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Contrary to a previous report, it is concluded that formation of methanol adducts to 3-methyl-2-cyclohexenones and of deconjugated enones on irradiation of the enones in acidified solutions proceeds via protonation of the intermediate enone π,π* triplet excited state and not by protonation of a relatively long-lived ground state trans-cyclohexenone. A rate constant for protonation of the triplet state of 3-methyl-2-cyclohexenone by sulfuric acid of 1.7 × 109 M−1 s−1 was determined by laser flash photolysis in ethyl acetate. Based on quantum efficiencies of product formation, a rate constant of

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Reghioua, Imène, Mattia Fanetti, Sylvain Girard, et al. "Study of silica-based intrinsically emitting nanoparticles produced by an excimer laser." Beilstein Journal of Nanotechnology 10 (January 16, 2019): 211–21. http://dx.doi.org/10.3762/bjnano.10.19.

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We report an experimental study demonstrating the feasibility to produce both pure and Ge-doped silica nanoparticles (size ranging from tens up to hundreds of nanometers) using nanosecond pulsed KrF laser ablation of bulk glass. In particular, pure silica nanoparticles were produced using a laser pulse energy of 400 mJ on pure silica, whereas Ge-doped nanoparticles were obtained using 33 and 165 mJ per pulse on germanosilicate glass. The difference in the required energy is attributed to the Ge doping, which modifies the optical properties of the silica by facilitating energy absorption proces

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Briot, Danielle, Luc Arnold, and Stéphane Jacquemoud. "Present and Future Observations of the Earthshine from Antarctica." Proceedings of the International Astronomical Union 8, S288 (2012): 214–17. http://dx.doi.org/10.1017/s1743921312016900.

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AbstractIt is likely that images of Earth-like planets will be obtained in the next years. The first images will actually come down to single dots, in which biomarkers can be searched. Taking the Earth as a example of planet providing life, Earthshine observations showed that the spectral signature of photosynthetic pigments and atmospheric biogenic molecules was detectable, suggesting that, in principle, life on other planets could be detected on a global scale, if it is widely spread and distinguishable from known abiotic spectral signatures. As for the Earth, we already showed that the Vege

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Vandevelde, Ségolène, Jean-Luc Lacour, Céline Quéré, Lionel Marie, Christophe Petit, and Ludovic Slimak. "Identification du rythme annuel de précipitation des carbonates pariétaux pour un calage micro-chronologique des occupations archéologiques pyrogéniques : cas de la Grotte Mandrin (Malataverne, Drôme, France)." BSGF - Earth Sciences Bulletin 192 (2021): 9. http://dx.doi.org/10.1051/bsgf/2021002.

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Dans les abris-sous-roche et grottes, la lecture géoarchéologique des sédiments peut permettre, dans des cas favorables, une étude micro-chronologique des traces d’activités anthropiques et en particulier de l’usage du feu. Si la récurrence dans l’utilisation des foyers peut parfois être identifiée par une étude micromorphologique de ces structures au sol, il n’est pas évident que l’ensemble des différents épisodes de combustion puisse y être identifié. Il se trouve que les événements de paléo-feux peuvent être enregistrés ailleurs que dans les foyers, par exemple sous la forme d’imprégnations

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Adeyemi, D. K., A. O. Adeluola, M. J. Akinbile, O. O. Johnson, and G. A. Ayoola. "Green synthesis of Ag, Zn and Cu nanoparticles from aqueous extract of Spondias mombin leaves and evaluation of their antibacterial activity." African Journal of Clinical and Experimental Microbiology 21, no. 2 (2020): 106–13. http://dx.doi.org/10.4314/ajcem.v21i2.4.

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Background: Nanotechnology offers an advantage as a green route for synthesis of metal nanoparticles (NPs) with plant extracts as capping agent. Spondias mombin is a fruit-bearing tree and its leaf extracts have been reported to possess anxiolytic, hypoglycaemic, antiepileptic, antipsychotic, sedative, antioxidant, and antimicrobial properties. The objective of the study is to determine the antibacterial potential of a simple non-toxic product of green synthesis of metallic (Ag, Zn and Cu) nanoparticles using the leaf of Spondias mombin aqueous extracts (SMAE) as a reducing and capping agents

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Smolin, Andrey, Juan Li, Yuxiang Mo, and Oleg Vasyutinskii. "Investigation of superexcited states in molecular deuterium." Open Physics 11, no. 3 (2013). http://dx.doi.org/10.2478/s11534-012-0163-3.

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AbstractA high-resolution VUV laser absorption spectroscopy is used to investigate the photon-induced ion-pair formation in D2 in the spectral region from 140117.4 to 140732.0 cm−1. We report determination of photoionization efficiency in ortho-para D2 in supersonic molecular beam with energy resolution of 0.1 cm−1. The assignment of the superexcited D2 Rydberg states is done based on the quantum defect theory.

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Qian, F., R. K. Singh, S. Dutta, P. P. Pronko, and W. H. Weber. "Femtosecond Laser Deposition of Diamond-Like Carbon Films." MRS Proceedings 397 (1995). http://dx.doi.org/10.1557/proc-397-297.

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ABSTRACTWe have deposited unhydrogenated diamond-like carbon (DLC) films with 100 femtosecond laser pulses, at intensities in the 3x1014 - 6.5x1015 W/cm2 range. Film surface topography, optical property, and bonding structure were examined, respectively, with atomic force microscopy (AFM), spectroscopie ellipsometry (SE) and Raman spectrometry. The femtosecond pulse generated plasma was studied through time-of-flight (TOF) experiment. The most probable kinetic energy of carbon ions was estimated to be in the 300 – 2000 eV range, increasing with laser intensity. In addition, a unique ‘suprather

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Furstenberg, Robert, Christopher A. Kendziora, Michael R. Papantonakis, Viet Nguyen, and R. A. McGill. "Photo-Thermal Spectroscopic Imaging of MEMS Structures with Sub-Micron Spatial Resolution." MRS Proceedings 1415 (2012). http://dx.doi.org/10.1557/opl.2012.71.

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ABSTRACTWe are developing a new non-contact and non-destructive imaging technique which requires no sample preparation and provides similar content information as FTIR or Raman spectroscopy while being immune to fluorescence and offers a potentially faster scan rate and/or higher spatial resolution. It utilizes photo-thermal heating of the sample with a quantum cascade laser (or other suitable infrared laser) and measuring the resulting increase in thermal emissions by either an infrared (IR) detector or a laser probe consisting of a visible laser reflected from the sample. The latter case all

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Wang, Jin, Natalia V. Lebedeva, Matthew S. Platz, and Malcolm D. E. Forbes. "Carbene Spin Multiplicity in Solution Probed Using Time-Resolved EPR Spectroscopy." Journal of the Mexican Chemical Society 53, no. 3 (2019). http://dx.doi.org/10.29356/jmcs.v53i3.999.

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Time-resolved (CW) EPR spectroscopy at X-band has been used to detect free radicals created by H-atom abstraction reactions of photochemically generated carbenes in n-hexadecane solutions at room temperature. Three different carbenes were studied, formed via loss of nitrogen after photo-excitation of a substituted biphenyl diazo precursor. The TREPR signals from two different alkyl radicals and the benzylic-type radical from the carbene are detected for two of the three diazo substrates. The radicals were unambiguously identified by spectral simulation using literature parameters (g-factors an

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Bejaoui, Salma, Farid Salama, and Ella Sciamma-O'Brien. "Absorption and Laser Induced Fluorescence Spectroscopy of Neutral Polycyclic Aromatic Hydrocarbons in Argon matrices." Proceedings of the International Astronomical Union 11, A29A (2015). http://dx.doi.org/10.1017/s1743921317005075.

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Polycyclic aromatic hydrocarbons (PAHs) are considered as plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments, as well as for broad emission band features seen in cometary spectra. We report the absorption spectra of phenanthrene, anthracene, fluoranthene, pentacene, pyrene, chrysene and triphenylene isolated at 10 K in solid argon matrices together with laser induced fluorescence (LIF) spectra at 355 nm of matrix-isolated anthracene and fluoranthene. LIF spectra are compared with the UV/blue fluorescenc

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Ratajczak, Jakub M. "Measurement of the dependence of ultra diluted gas transmittance on the size of the detector." Scientific Reports 11, no. 1 (2021). http://dx.doi.org/10.1038/s41598-021-85568-w.

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AbstractWe show that measured optical transmittance of an ultra thin gas depends on the detector size. To this end we conducted an experiment that compares transmittances measured in parallel with a pair of detectors with different diameters ranging from 2 to 200 $$\upmu$$ μ m. A Tunable Diode Laser Absorption Spectroscopy type system was used. Transmittance of $$\sim$$ ∼ 10$$^{-2}$$ - 2 mbar water vapor on NIR absorption line $$\lambda =1368.60$$ λ = 1368.60 nm was measured using a 61.6 m long multi-pass cell placed inside the $$\sim$$ ∼ 300 l vacuum chamber. The result of the experiment show

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