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Triplet harvesting in trifluoromethyl quinoxaline derivatives via TADF and RTP mechanisms
No full textInternational audienc
Colombia’s disappeared: changing features of a cultural motif
No full textInternational audienceThis article examines the evolving cultural representation of enforced disappearance in Colombia, tracing its transformation from an invisible crime to a central motif in national memory and artistic production. Initially overshadowed by paradigms drawn from Southern Cone dictatorships, enforced disappearance in Colombia has followed a distinct trajectory, shaped by a protracted armed conflict involving multiple non-state actors and a nominally democratic regime. The study maps four major periods—from the pre-1970s era of obliterative violence during La Violencia, to the conceptual emergence of disappearance in the late 1970s, its exponential rise and public acknowledgment in the 1990s–2000s, and its institutionalization through a post-conflict memorial culture since 2012. Drawing on literature, visual arts, cinema, popular music, and curatorial initiatives, the paper argues that the figure of the desaparecido has shifted from testimonial denunciation to a widely circulated cultural motif, which articulates loss, memory, social invisibility and marginality. The article emphasizes the role of artistic representation in rendering visible a crime defined by its erasure, highlighting how Colombian cultural production contributes to a continental redefinition of the disappeared—no longer confined to past authoritarian regimes but deeply embedded in current socio-political realities. By situating Colombia within a transnational memory framework, the article underscores the power of culture to contest impunity, shape historical consciousness, and transform public understanding of violence
Bac 2025, compétence « valider »
No full textCet article a été publié dans Le Bulletin de l’UdPPC, vol. 119, n°1079, p. 971-975. La version éditeur est disponible sur le site de l’UdPPC rubrique BupDoc à l’adresse https://bupdoc.udppc.asso.fr/consultation/une_fiche.php?ID_fiche=24496. Si l’article a moins de cinq ans, il faut être abonné au Bup de l’UdPPC : https://www.udppc.asso.fr/login pour y accéder. À défaut, vous accédez à la fiche descriptive de l’article.International audienceThis article examines a 2025 baccalaureate exercise in physics and chemistry. From the student’s perspective, answering it requires using flawed reasoning and disregarding contradictory data. Emphasizing the importance of didactic transposition, the article proposes simple adjustments to restore logical consistency and make the information usable. This critical analysis offers a possible starting point for developing students’ epistemic skills.Cet article analyse un exercice du baccalauréat 2025 en physique-chimie. Du point de vue de l’élève, y répondre impose un raisonnement inexact et l’élimination de données contradictoires. Soulignant l’importance de la transposition didactique, des ajustements simples sont proposés pour rétablir la validité logique et rendre les données exploitables. Cette analyse critique constitue en soi une amorce possible pour développer les compétences épistémiques des élèves
"A French Take on the Evolution of the British Idea of Democracy (1770–1920)" (review)
No full textInternational audienceHugo Bonin, “At the Sound of the New Word Spoken”: Le mot “démocratie” en Grande-Bretagne, 1770–1920 [“At the sound of the new word spoken”: The word “democracy” in Great Britain, 1770–1920] (Rennes: Presses Universitaires de Rennes, Collection Histoire, 2024), 256 pp
L'ancrage territorial de la culture face aux défis écologiques
No full textInternational audienceDans le cadre de la table ronde "L’ancrage territorial : les enjeux écologiques et sociaux de la culture" du colloque "Musique en transition : l’impératif écologique" organisé par le Conservatoire National Supérieur Musique et Danse de Lyon, cette communication avait pour objectif de présenter les résultats du projet de recherche ECOMUSIQ et d'éclairer les enjeux de l'ancrage territorial de la culture, en particulier dans le secteur musical, face aux bouleversements écologiques
Le numérique au prisme de l’atelier d’écriture. Repenser l’atelier comme dispositif de médiation et de transformation pédagogique dans le champ universitaire.
No full textInternational audienceThe digital transformation of higher education is profoundly changing writing practices, learning methods and the circulation of knowledge. In this context, writing workshops provide an ideal setting for observing the impact of technology on teaching dynamics. Historically conceived as a collective space for the creation and socialisation of skills, workshops are now undergoing a process of hybridisation with digital environments. The study presented here is based on three writing workshops conducted with undergraduate students at two French universities. It examines how digital tools – collaborative platforms, graphic tools, generative AI – are transforming writing practices and promoting access to literature through popular genres. The central question is: how does collaborative digital writing reconfigure writing practices and learning dynamics in a university workshop, while stimulating students' creativity?La transformation numérique de l’enseignement supérieur modifie profondément les pratiques d’écriture, les modes d’apprentissage et la circulation des savoirs. Dans ce contexte, l’atelier d’écriture constitue un terrain privilégié pour observer l’impact des technologies sur les dynamiques pédagogiques. Historiquement pensé comme un espace collectif de fabrication et de socialisation des savoir-faire, l’atelier connaît aujourd’hui une hybridation avec les environnements numériques. L’étude présentée ici s’appuie sur trois ateliers d’écriture menés auprès d’étudiants en Licence dans deux universités françaises. Elle interroge la façon dont les outils numériques – plateformes collaboratives, outils graphiques, IA génératives – transforment les pratiques d’écriture et favorisent l’entrée en littérature à travers des genres populaires. La problématique centrale est la suivante : comment l’écriture collaborative numérique reconfigure-t-elle les pratiques d’écriture et les dynamiques d’apprentissage dans un atelier universitaire, tout en stimulant la créativité des étudiants
Working with a Key Community Engaged in the Transformation of Work: Historical Analysis and Key Challenges
No full textInternational audienceErgonomic interventions aim to improve or adapt work situations, enhancing both health and performance. Ergonomists operate within evolving organizations and must adjust their methods to address emerging health risks. This proposal explores the learning challenges and historically rooted contradictions in ergonomic interventions. It draws on a workshop inspired by the change laboratory methodology, involving 75 consultant ergonomists and trainees. Key tools such as the history wall, activity system, contradictions, and "four fields models" are mobilized. The presentation highlights the importance of historical analysis, the future-oriented nature of the laboratories, and the potential for expanding the scope of ergonomic practice.</div
Quand la musique franchissait le rideau de fer
No full textNational audienceEn 1971, en pleine Guerre froide qui divise la planète entre les blocs occidental et communiste, le London Symphony Orchestra franchit le rideau de fer et se produit en URSS. En 1973, un autre orchestre britannique, le London Philharmonic Orchestra, se rend en République Populaire de Chine. Bien que ces orchestres soient privés, le gouvernement britannique y investit des sommes colossales pour financer leurs tournées. La musique apparaît alors comme un outil d’influence à une période où le dialogue entre Est et Ouest est rompu. Lauriane Simony, maîtresse de conférences en civilisation britannique à CY1 et spécialiste de la diplomatie culturelle britannique, questionnera le rôle politique de la musique. A-t-elle le pouvoir de faire passer des messages ? Peut-elle transgresser la censure des régimes communistes
Les matériaux piézoélectriques au service de l’électronique de puissance
No full textInternational audienceThis paper provides an introduction to power conversion using piezoelectric resonators as a means of temporary storage instead of inductors. This is a promising approach due to the high energy density per unit volume that can be stored in certain materials. A conversion power density of 5.7 kW/cm3 has been achieved in the state of the art with lithium niobate with an efficiency >97%Ce papier propose une introduction à la conversion de puissance utilisant des résonateurs piézoélectriques comme moyen de stockage temporaire au lieu des inductances. Il s’agit d’une voie prometteuse du fait de la densité élevée d’énergie stockable par unité de volume de certains matériaux. Une densité de puissance de conversion de 5.7 kW/cm3 a été atteinte dans l’état de l’art avec du Niobate de Lithium avec un rendement >97
Characterization of debris disks observed with SPHERE
No full textInternational audienceAims. This study aims to characterize debris disk targets observed with SPHERE across multiple programs, with the goal of identifying systematic trends in disk morphology, dust mass, and grain properties as a function of stellar parameters. By combining scattered-light imaging with photometric and parametric modeling, we seek to improve our understanding of the composition and evolution of circumstellar material in young debris systems and to place debris disks in the broader context of planetary system architectures. Methods . We analyzed a sample of 161 young main-sequence stars using archival SPHERE observations at optical and near-infrared (IR) wavelengths. Disk geometries were derived from ellipse fitting and model grids, while dust mass and properties were constrained by modified blackbody (MBB) and size distribution (SD) modeling of spectral energy distributions (SEDs). We also carried out dynamical modeling to assess whether the observed disk structures can be explained by the presence of unseen planets. Results . We resolve 51 debris disks, including four new detections where disks are resolved for the first time: HD 36968, BD-20 951, and the inner belts of HR 8799 and HD 36546. In addition, we find a second transiting giant planet in the HD 114082 system, with a radius of 1.29 ± 0.05 R Jup and an orbital distance of ~1 au, providing an important new benchmark for planet–disk interaction studies. Beyond these new detections, we identify nine multi-belt systems, with outer-to-inner belt radius ratios of 1.5–2, and find close agreement between scattered-light and millimeter continuum belt radii with a mean ratio R belt (near-IR)/ R belt (mm) of 1.05 ± 0.04. Belt radii scale weakly with stellar luminosity ( R belt ∝ L ⋆ 0.11±0.05 ), but show steeper dependencies when separated by CO and CO 2 freeze-out regimes, and also increase with age as R belt ∝ t age 0.37±0.11 . Uniform image modeling yields vertical disk aspect ratios of 0.02–0.06, consistent with collisionally stirred belts, while gas-rich systems show unusually small values. Inner density slopes steepen with stellar luminosity, indicating more efficient dust removal around luminous stars. Disk fractional luminosities follow collisional decay trends, declining as t age −1.18±0.14 for A-type and t age −0.81±0.12 for F-type stars. SD modeling yields minimum grain sizes consistently above the blowout limit, typically >0.8 μm, with a mean SD index of q = 3.6, assuming astrosilicate composition. The inferred dust masses span 10 −5 −1 M ⊕ from MBB modeling (and 0.01–1 M ⊕ from SD modeling for detected disks). These masses scale as R belt n with n > 2 in belt radius and super-linearly with stellar mass, consistent with trends seen in protoplanetary disks (PPDs). Our detailed analysis of disk scattered-light non-detections indicates that they are mainly caused by low dust masses, unfavorable viewing geometries, or suboptimal observing conditions. SD modeling combined with Mie theory further shows that bulk albedos are consistently above 0.5 with little variation, making albedo differences an unlikely explanation. To explore this further, we introduced a new parametric approach based on scattered-light and polarized-light images, which provides independent estimates of dust albedo and maximum polarization fraction. We find a correlation between measured disk polarized flux and IR excess, with a slope shallower than that of optical total-intensity fluxes measured with HST/STIS. The offset of ~1 dex between total-intensity and polarized fluxes arises because polarized flux represents only a fraction of the total scattered light which depends on both grain properties and disk inclination. Finally, a comparison of planetary architectures shows that most benchmark systems resemble the Solar System, with multiple planets located inside wide Kuiper-belt analogues. Dynamical modeling further indicates that many observed gaps and inner edges can be explained by unseen planets below current detection thresholds, typically with Neptune- to sub-Jovian masses, underscoring the likely ubiquity of such planets in shaping debris disk morphologies