1,721,358 research outputs found
GPU-Enabled Multivariate Fox H-function Code
No full text<p>A GPU-enabled Matlab implementation of the multivariate Fox H-function. If you use this code of any (modified) part of it, please cite it as: H. Chergui, M. Benjillali and M.-S. Alouini, "Rician K-factor-based analysis of XLOS service probability in 5G outdoor ultra-dense networks," 2018. [Online]. Available: <a href="https://arxiv.org/abs/1804.08101">https://arxiv.org/abs/1804.08101</a></p>
Two dimensional ion-imaging of photofragments produced by photolysis of oriented molecules.
No full textLigand-Centred Fluorescence and Electronic Relaxation Cascade at Vibrational Time Scales in Transition-Metal Complexes
No full textUsing femtosecond-resolved photoluminescence up-conversion, we report the observation of the fluorescence of the high-lying ligand-centered (LC) electronic state upon 266 nm excitation of an iridium complex, Ir(ppy)3, with a lifetime of 70 ± 10 fs. It is accompanied by a simultaneous emission of all lower-lying electronic states, except the lowest triplet metal-to-ligand charge-transfer (3MLCT) state that shows a rise on the same time scale. Thus, we observe the departure, the intermediate steps, and the arrival of the relaxation cascade spanning ∼1.6 eV from the 1LC state to the lowest 3MLCT state, which then yields the long-lived luminescence of the molecule. This represents the first measurement of the total relaxation time over an entire cascade of electronic states in a polyatomic molecule. We find that the relaxation cascade proceeds in ≈10 fs, which is faster than some of the highest-frequency modes of the system. We invoke the participation of the latter modes in conical intersections and their overdamping to low-frequency intramolecular modes. On the basis of literature, we also conclude that this behavior is not specific to transition-metal complexes but also applies to organic molecules
The Role of Site-Specific Hydrogen Bonding Interactions in the Solvation Dynamics of N‐Acetyltryptophanamide
No full textMeasurements of the ultrafast broadband UV
fluorescence of N-acetyltryptophanamide (NATA) provide
detailed information on its relaxation patterns in three different
solvents: methanol (MeOH), water and acetonitrile (ACN).
Several processes leading to excited state solvation and cooling
are found to occur on different characteristic time scales and
are thoroughly analyzed. Comparison between protic MeOH
and aprotic ACN allows one to single out a 12 ps component
in the former, which is attributed to the rearrangement of H-bonds existing between the protic solvent and excited NATA. This
significantly stabilizes the excited state and provides the molecule with an efficient cooling mechanism. The corresponding
dynamics in water are much faster (<1.5 ps). Comparison with static spectroscopic properties stresses the role of site-specific Hbonding
in controlling the fluorescence quantum yield of NATA in protic solvents. These findings are consistent with existing
models that describe tryptophan quenching as a result of charge transfer from the indole to the amide assisted by H-bonding at
the carbonyl site
Deterministic control of subwavelength field localization in plasmonic nanoantennas
No full textAeschlimann M, Bauer M, Bayer D, et al. Deterministic control of subwavelength field localization in plasmonic nanoantennas. In: Chergui M, Jonas DM, Riedle E, Schoenlein RW, Taylor AJ, eds. Proc. 17th Int. Conference, Ultrafast Phenomena XVII. 2010: 667
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Nanolocalization of ultrashort time-reversed pulses in random nanoparticle assemblies
No full textDiffert D, Garcia de Abajo FJ, Pfeiffer W, Strüber C, Voronine D. Nanolocalization of ultrashort time-reversed pulses in random nanoparticle assemblies. In: Chergui M, Jonas DM, Riedle E, Schoenlein RW, Taylor AJ, eds. Proc. 17th Int. Conference, Ultrafast Phenomena XVII. OSA; 2010: 272
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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