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NaF intermediate is introduced to simultaneously optimize back contact and passivate detrimental defects. Over 8% efficient flexible Sb2Se3thin-film solar cell can be achieved, accompanied with superior flexibility and weak light photo-response.

Chalcogenide glasses in the Na2S–GeS2–Ga2S3pseudoternary system were synthesized using a combination route of melt-quenching and mechanical-milling methods. First, a glass rich in germanium (90GeS2–10Ga2S3) is synthesized by melt-quenching synthesis in a silica tube sealed under vacuum. This glass is used as a precursor for the second step of mechanochemistry to explore the Na2S–GeS2–Ga2S3pseudoternary system. By using this synthesis route, the glass-forming ability is improved as the vitreous domain is enlarged, especially for Na- and Ga-rich compositions. The as-obtained amorphous powders are characterized by Raman spectroscopy, differential scanning calorimetry, X-ray total scattering, and pair distribution function (PDF) analysis. The evolution of the Raman features observed is reproduced using density functional theory calculations. Impedance spectroscopy was performed to determine the conductivity of the new glasses. The addition of germanium sulfide to the Na2S–Ga2S3pseudobinary system enables one to increase the conductivity by 1 order of magnitude. The highest room-temperature ionic conductivity, as measured by impedance spectroscopy, is 1.8 × 10–5S·cm–1.

The ever-growing complexity of radiating systems asks for always more challenging radiation pattern characterizations requiring time consuming field acquisitions and high-cost facilities. Consequently phaseless, or magnitude-only, measurements have recently regained of interest as they prevent the tedious and difficult task of phase acquisition. Consequently, it allows the use of cheaper or more versatile measurement setups like drone measurements or easier high-frequency measurements. However, the difficulty is shifted to the notoriously difficult resolution of the phase retrieval (PR) problem, the instability of which is commonly mitigated by the acquisition of a large number of phaseless field samples. A procedure enabling a reliable and accurate phaseless antenna measurement from a reduced number of spherical near-field (NF) samples based on the two scan technique is proposed. Its efficiency and stability, that relies on the systematic determination of a good starting point, is validated by representative simulations and experimental cases performed on various antenna structures.

Nearly 25 years ago, Optical Frequency Combs (OFCs) have revolutionized practically from one day to the next the metrology of optical frequencies. Before that, only a few labs in the world could connect the optical (~1015Hz) and the microwave (~1010Hz) domains, at the price of the complex operation of a chain of multiple non-linear frequency conversions. In contrast, OFCs provided a tabletop instrument, compact, reliable and operable by a single scientist. Unmistakeable sign: only a few years had passed before pioneering inventors of OFCs Theodor Hänsch and John Hall were awarded the 2005 Nobel prize in Physics, together with Roy Glauber.

L’augmentation croissante du nombre de plongeurs dans le monde implique pour tout médecin d’en connaître les risques potentiels. Après des rappels de physique, à l’aide d’une revue extensive de la littérature récente, nous résumons les principaux accidents en lien avec la pratique de la plongée à l’air en circuit ouvert ainsi que les thérapeutiques à mettre en œuvre pour les différents types d’accidents.

The phaseless characterization of antennas enables configurations with reduced measurement efforts as the phase acquisition is highly sensitive to numerous error sources. However, both the magnitude and phase information are necessary to reconstruct the 3-D radiation pattern of the tested radiating system. The two scans technique allows for accurate phase retrievals from magnitude-only measurements. In this communication, the two concentric spheres setup is considered with a Gerchberg–Saxton (GS) algorithm as a phase retrieval procedure. These methods are known for their convergence problems, the price to pay for the easier, magnitude-only, measurements. A filtering approach is studied to mitigate these effects and a new, more efficient, filter is proposed. A loop of GS runs coupled with filters is shown to improve the radiation pattern reconstruction without much considerations. Validations are led by simulations and experimental data acquired using a commercial system.

NaGaS2is a newly discovered compound that has already shown great promise for a variety of applications because of its layered structure and ion exchange properties. In this work, crystalline NaGaS2has been synthesized by an alternative method to what has been previously published, namely, by mechanochemistry, either by a direct one-step process or by a two-step process. In the one-step process, crystalline NaGaS2is directly formed by milling sodium sulfide Na2S and gallium(III) sulfide Ga2S3. However, an amorphous material is present in majority together with the crystalline phase. In the two-step process, amorphous NaGaS2is first obtained by mechanical milling and then heated above its glass transition temperature to obtain a glass–ceramic mainly composed of crystalline NaGaS2. For the two-step process, changes of the local atomic-level structure in amorphous NaGaS2and after crystallization were analyzed by high-field solid-state nuclear magnetic resonance (NMR) spectroscopy as well as by X-ray total scattering and pair distribution function (PDF) analysis. Based on quantitative analysis on the 23Na NMR spectra, modifying the annealing treatment can promote the formation of the crystalline phase up to a molar fraction of 83.8%.

AbstractThe selection of a geotextile to prevent the soil suffusion in a civil engineering work is a classical problem. The internal erosion is a key factor as the migration of fine particles damages the integrity of the soil structure. This work deals with the problem of using a draining system consisting of a layer of soil and a geotextile sheet in order to prevent soil suffusion. It proposes a methodology which allows ordering the performance of nonwoven geotextiles. A range of experimental approaches were implemented including seepage flow tests under controlled flow rates. A detailed analysis of the data shows that intrinsic properties of geotextiles are not sufficient to predict their behaviour in a draining system. Moreover, the classical flow tests of the draining systems are not sufficient to adequately discriminate the three geotextile specimen used here. On the other hand, it seems important to use the history of the hydraulic gradient with respect to the flow rate variation. Thus, the present data of normalised relative pressure drop and normalised relative variation of flow rate are arranged in terms of a dimensionless criterion. This methodology enables evaluating and discriminating the performances of the geotextiles used here in terms of filtration and drainage functions.