Chemical vapour deposition and atomic layer deposition of amorphous and nanocrystalline metallic coatings: towards deposition of multimetallic films

This paper provides a prospective insight on chemical vapour deposition (CVD) and atomic layer deposition (ALD) as dry techniques for the processing of amorphous and nanocrystalline metallic thin films. These techniques are part of major technologies in application fields such as microelectronics, energy, or protective coatings. From thermodynamic analysis, areas of investigation to generate a set of materials with the strongest propensity for amorphization as well as useful guidelines for the target phase material deposition are provided. Prospective to develop MOCVD (metalorganic chemical vapour deposition) and ALD of intermetallic films, in view of fabrication of metallic glass thin films is proposed. Examples from selected ALD and MOCVD single element metallic deposition processes will be described to illustrate the effect of deposition parameters on the physico-chemical properties of the films. This processing approach is particularly promising for metallic glass thin films

Interactive mixture of inhomogeneous dark fluids driven by dark energy: a dynamical systems analysis

We examine the evolution of an inhomogeneous mixture of non-relativistic pressureless cold dark matter (CDM), coupled to dark energy (DE) characterised by the equation of state parameter $w<-1/3$, with the interaction term proportional to the DE density. This coupled mixture is the source of a spherically symmetric Lema\^\ itre-Tolman-Bondi (LTB) metric admitting an asymptotic Friedman-Lema\^\ itre-Robertson-Walker (FLRW) background. Einstein's equations reduce to a 5-dimensional autonomous dynamical system involving quasi--local variables related to suitable averages of covariant scalars and their fluctuations. The phase space evolution around the critical points (past/future attractors and five saddles) is examined in detail. For all parameter values and both directions of energy flow (CDM to DE and DE to CDM) the phase space trajectories are compatible with a physically plausible early cosmic times behaviour near the past attractor. This result compares favourably with mixtures with the interaction driven by the CDM density in which conditions for a physically plausible past evolution are more restrictive. Numerical examples are provided describing the evolution of an initial profile that can be associated with idealised structure formation scenariosComment: 23 pages, IOP format, 8 figure

Myrrhido-Adenostyletum, endemična asocijacija jugozapadnih Alpa

Autor opisuje novu endemičnu asocijaciju Myrrhido-Adenostyletum iz sveze Adenostylion alliariae. To je zajednica visokih zeleni rasprostranjena u jugozapadnim Alpama u dolini rijeke Ubaye u subalpskom pojasu između 1800 i 2000 m na staništima gdje se nakuplja mnogo snijega. Zajednica je izgrađena gotovo isključivo od hemikriptofitskih biljaka. Floristički sastav vidi se na priloženoj fitosociološkoj tabeli

Online French Physical Society questionnaire: A way to identify students’ difficulties at the entrance at University

FRENCH CONTEXT In France, entry to university is determined by a national examination taken by all students in their final year at high school, the Baccalauréat (K12). Yet, its success rate (over 90%) no longer guarantees a satisfactory level of the laureates. French universities, where enrolment is (almost) free, are nevertheless legally obliged to accept all passed students. On leaving high school, other choices for students wishing to train in physics are to join either a preparatory school for engineering schools (CPGE), which is free for the most part, but is selective and includes intensive training, or a free and selective three-year professional course, or to enter university. The latest statistics show that only a small fraction of students who have followed a scientific course in high school choose to go to university (Inspection Générale - Ministry of National Education, 2022); scientific university tracks thus deal with students who are often already in difficulty and have to adapt their courses to help them succeed. Even if some universities have set up placement tests to organise support courses, there is no national system to monitor the evolution of students' levels and provide an overview. ONLINE PHYSICAL SOCIETY OF FRANCE QUESTIONNAIRE In this context, the French Physical Society has designed a one-hour online questionnaire (MCQ; Questionnaire de la Société Française de Physique, 2014) to help university teachers identify their students' difficulties. With four parts (basic mathematics, mechanics, waves and scientific culture) and around 100 questions, it can be completed in one hour and provides immediate feedback to students and their teachers on the answers provided. It also allows for the collection of data from all over the country. This MCQ, the content of which was chosen to comply with the high school curriculum (Ministry of National Education, 2019), consists primarily of questions on concepts, based on situations identified as likely to induce reasoning difficulties (Viennot, 1996) and is inspired by existing questionnaires (FCI, 1985 for example; Hestenes et al., 1992). Launched in 2014, this questionnaire was taken by more than 3000 students. It provides an admittedly partial view (but the only one available to our best knowledge) on the evolution of French students' understanding of concepts by the end of high school. We will present the results obtained by both CPGE classes and university students, and their evolution following the reform of the high school curriculum and the effects of COVID-19. While first analyses confirm the expected difference in level between the two populations, they also document, for both tracks, a significant decrease over time in the understanding of several concepts. REFERENCES Hestenes, D., Wells, M., &amp; Swackhammer, G. (1992). Force Concept Inventory. The Physics Teacher, 30, 141. https://doi.org/10.1119/1.2343497 Inspection Générale - Ministry of National Education (2022). Presentation at the "Adaptation of higher education pathways to baccalaureate graduates resulting from the new reform of the physics curriculum" days. Nice, 2022. Ministry of National Education (2019). Programmes de Terminale en physique-chimie. Bulletin official n° 8, 2019 https://eduscol.education.fr/1648/programmes-et-ressources-en-physique-chimie-voie-gt [in French] Questionnaire de la Société Française de Physique (2014). http://qcm.sfpnet.fr/ Viennot, L. (1996). Reasoning in Physics: The Part of Common Sense. Springer

Profil épistémologique des enseignants français du primaire au regard de la science

International audienceLa notion de profil épistémologique, développée par Bachelard, est appliquée à la notion de science elle-même. Une étude des représentations de la science de 777 enseignants et futurs enseignants a permis de montrer que 66% apparaissent majoritairement empiristes et que 91% n'expriment aucun rationalisme