Search results for "MATTER"
showing 10 items of 16762 documents
Functional Extrapolations to Tame Unbound Anions in Density-Functional Theory Calculations
2019
Standard flavors of density-functional theory (DFT) calculations are known to fail in describing anions, due to large self-interaction errors. The problem may be circumvented using localized basis sets of reduced size, leaving no variational flexibility for the extra electron to delocalize. Alternatively, a recent approach exploiting DFT evaluations of total energies on electronic densities optimized at the Hartree-Fock (HF) level has been reported, showing that the self-interaction-free HF densities are able to lead to an improved description of the additional electron, returning affinities in close agreement with the experiments. Nonetheless, such an approach can fail when the HF densitie…
Visualization of Moiré Magnons in Monolayer Ferromagnet
2023
| openaire: EC/H2020/788185/EU//E-DESIGN Two-dimensional magnetic materials provide an ideal platform to explore collective many-body excitations associated with spin fluctuations. In particular, it should be feasible to explore, manipulate, and ultimately design magnonic excitations in two-dimensional van der Waals magnets in a controllable way. Here we demonstrate the emergence of moiré magnon excitations, stemming from the interplay of spin-excitations in monolayer CrBr3 and the moiré pattern arising from the lattice mismatch with the underlying substrate. The existence of moiré magnons is further confirmed via inelastic quasiparticle interference, showing the appearance of a dispersion …
Structures and energetic properties of 4-halobenzamides
2018
The amide bond represents one of the most fundamental functional groups in chemistry. The properties of amides are defined by amidic resonance (nN→π*C=O conjugation), which enforces planarity of the six atoms comprising the amide bond. Despite the importance of 4-halo-substituted benzamides in organic synthesis, molecular interactions and medicinal chemistry, the effect of 4-halo-substitution on the properties of the amide bond in N,N-disubstituted benzamides has not been studied. Herein, we report the crystal structures and energetic properties of a full series of 4-halobenzamides. The structures of four 4-halobenzamides (halo = iodo, bromo, chloro and fluoro) in the N-morpholinyl series h…
Durability of a 3D woven composite assisted by finite element multi-scale modelling
2012
International audience; The textile composite studied is a 3D woven composite. A unit cell is defined by using microscopic examinations of the microstructure. A multiscale approach assisted by the finite element method is performed in order to estimate the effective properties of the composite and then to access to local stress field. This approach allows the determination of the kind of load to which warp yarns are subjected. Moreover, detailed analysis of damaged model using different configurations of broken yarns are treated. The evolution of the stress concentration coefficient highlight the load transfers due to consecutive yarn breaks.
Excitation Transfer Engineering in Ce-Doped Oxide Crystalline Scintillators by Codoping with Alkali-Earth Ions
2018
This work has been supported by the European Social Fund Measure No. 09.3.3-LMT-K-712 activity Improvement of Researchers Qualification by Implementing the World-Class R&D Projects, and by grant #14.W03.31.0004 of the Russian Federation Government. Authors are grateful to CERN Crystal Clear Collaboration and COST Action TD1401 "Fast Advanced Scintillator Timing (FAST)" for support of collaboration.
Predicting mechanical behaviour and damage kinetics of a 3D interlock composite materials by using a multiscale approach
2012
International audience; The present work aims to investigate the mechanical behaviour and the damage kinetics of a3D interlock woven fabric composite, especially used for natural gas tanks dedicated to thetransportation industry. On the one hand, we aim at predicting the macroscopic coefficients ofthe stiffness matrix by homogenization multiscale approach. For this, we identified a basicunit cell which represents well the composite microstructure. On the other hand, damagemechanisms are analyzed: optical microscopy examinations on damaged specimens revealedseveral types of defects. We used the same multi-scale approach to assess the impact of thesedefects on the decrease of stiffness.
Synthesis, electron microscopy and X-ray characterization of oxymagnesite, MgO·2MgCO3, formed from amorphous magnesium carbonate
2014
At present, the peculiar compound called oxymagnesite, MgO·2MgCO3, an intermediate formed during thermal decomposition of hydrated magnesium carbonates, has only been described a handful of times without a distinct description of its formation or morphology. In the current work we present the first scanning and transmission electron microscopy images of an oxymagnesite crystal together with its crystallographic data. Oxymagnesite was synthesized in a controlled manner via decomposition of amorphous magnesium carbonates (AMCs) subjected to varying relative humidity. We show that oxymagnesite is formed only when AMC is hydrated above a certain level, which we attribute to structural inequival…
Lymphatic vessels of the dura mater: a new discovery?
2015
Aspelund et al. discover the presence of a lymphatic vessel network in the dura mater of the mouse brain and show that these dural lymphatic vessels are important for the clearance of macromolecules from the brain.
Fysiikan ja musiikin oppiaineintegrointi lukiotasolla
2014
Fysiikan ja musiikin oppiaineintegraatiosta on vähän tutkimusta, vaikka oppiaineet tarjoavat lukuisia mahdollisuuksia integroinnin toteuttamiseen. Integrointi auttaa tutkitusti muodostamaan opetettavista sisällöistä arjessa sovellettavia merkityksellisiä kokonaisuuksia. Tällöin opetus valmentaa opiskelijaa paremmin elämässä tarvittaviin taitoihin. Integrointi vaatii opettajilta käytännössä paljon, ja kahden aineen sisältöjen ja aikataulujen sovittaminen yhteen on haastavaa. Tämän tutkielman tarkoitus on kartoittaa lukion oppimäärän sisällä olevia integrointimahdollisuuksia ja antaa esimerkkejä integroituvista sisällöistä. Kartoitus perustuu voi-massa olevien opetussuunnitelmien, oppiaineide…
Purification of Nano-Porous Silicon for Biomedical Applications
2011
Recently, various bio-medical applications of nanoporous silicon (np-Si) have been suggested. This work investigates the biocompatibility of np-Si particles taking into account hazardous residua confined in the pores after preparation. The emphasis is on the potential application of such particles as oxygen photosensitizer for photodynamic therapy of cancer, which requires both negligible toxicity of np-Si particles in darkness and a high photo-cyto-toxic effect due to generation of singlet oxygen under illumination. Considerable amounts of water soluble toxic impurities are found to be present in the nanoporous shell of micrometer-sized np-Si particles immediately after their preparation b…