Search results for "general [Radio continuum]"
showing 10 items of 56936 documents
Adjacency matrices of random digraphs: singularity and anti-concentration
2017
Let ${\mathcal D}_{n,d}$ be the set of all $d$-regular directed graphs on $n$ vertices. Let $G$ be a graph chosen uniformly at random from ${\mathcal D}_{n,d}$ and $M$ be its adjacency matrix. We show that $M$ is invertible with probability at least $1-C\ln^{3} d/\sqrt{d}$ for $C\leq d\leq cn/\ln^2 n$, where $c, C$ are positive absolute constants. To this end, we establish a few properties of $d$-regular directed graphs. One of them, a Littlewood-Offord type anti-concentration property, is of independent interest. Let $J$ be a subset of vertices of $G$ with $|J|\approx n/d$. Let $\delta_i$ be the indicator of the event that the vertex $i$ is connected to $J$ and define $\delta = (\delta_1, …
Statistics-preserving bijections between classical and cyclic permutations
2012
Recently, Elizalde (2011) [2] has presented a bijection between the set C"n"+"1 of cyclic permutations on {1,2,...,n+1} and the set of permutations on {1,2,...,n} that preserves the descent set of the first n entries and the set of weak excedances. In this paper, we construct a bijection from C"n"+"1 to S"n that preserves the weak excedance set and that transfers quasi-fixed points into fixed points and left-to-right maxima into themselves. This induces a bijection from the set D"n of derangements to the set C"n"+"1^q of cycles without quasi-fixed points that preserves the weak excedance set. Moreover, we exhibit a kind of discrete continuity between C"n"+"1 and S"n that preserves at each s…
Collisions moléculaires en phase gazeuse
2019
L’étude théorique des collisions entre atomes et molécules permet, grâce à la résolution d’état à état des simulations numériques basées sur la physique quantique, une description détaillée des mécanismes mis en jeu et contribue grandement à améliorer les modèles atmosphériques et astrophysiques. Dans cet article, après avoir présenté les méthodes de dynamique actuelles, nous donnons des exemples clés d’intérêt pour le milieu interstellaire, l’atmosphère terrestre et les milieux (ultra)froids, et présentons les défis majeurs à relever.
Analysis of the specific common competences of the Degree Courses in Speech Therapy and on the ability to apply in the didactic systems
2020
Law 11 January 2018 n. 3 places the attention of the Health Professions on the specific common skills, which must be evident in the didactic systems to protect the Profession. The purpose of this work is to identify which skills are always present among the training objectives of the Degree Courses in Speech Therapy, and which instead become "specific" for our profession. The data analysis was conducted on 27 Degree Courses in Speech Therapy present in Italy, using the portal "Universitaly" and evaluating the SUA cards of the various Degree Courses. The analysis of the data revealed that: basic skills were insufficient for the areas of labor law and corporate organization; transversal skill…
Migration kinetics of ion-implanted beryllium in glassy carbon
2008
Abstract Migration kinetics of low-concentration implanted 7 Be in glassy carbon has been studied by the modified radiotracer technique at temperatures 1285 °C and 1340 °C. The annealed sample concentration profiles show two distinctive components: (i) Main profile broadening assigned to beryllium trapping in defects during annealing. (ii) Tail parts on both sides of the profile maximum related to faster migration. Of the latter the profile representing bulk diffusion lies on the region free of defect influence and is well described by concentration-independent diffusivity. The features of the concentration profile broadening towards the sample surface indicate partial Be trapping in defect…
Evolution of the microstructure of sputter deposited TaAlON thin films with increasing oxygen partial pressure
2021
Abstract Recently, quaternary oxynitrides of transition metals and aluminum have attracted increasing interest due to their tunable properties. Within the present work, a series of TaAl(O)N films was sputter deposited using constant nitrogen and varying oxygen partial pressures. The films were grown from single element Ta and Al targets. The deposition parameters were adjusted to obtain a Ta/Al atomic ratio of ~50/50 for the oxygen-free film and were held constant for the following depositions, with the exception of the increasing oxygen partial pressure and compensatory decreasing argon partial pressure. Elastic recoil detection analysis revealed oxygen contents of up to ~26 at.%, while th…
Plastic yielding of glass in high-pressure torsion apparatus
2018
International audience; Hardness measurements performed at room temperature have demonstrated that glass can flow under elevated pressure, whereas the effect of high pressure on glass rheology remains poorly quantified. Here, we applied a high-pressure torsion (HPT) apparatus to deform SCHOTT SF6 â glass and attempted to quantify the effect of pressure and temperature on the shear deformation of glass subjected to pressures from 0.3 GPa to 7 GPa and temperatures from 25 ℃ to 496 ℃. Results show that the plastic yield deformation was occurring during the HPT experiments on the SF6 glass at elevated temperature from 350 ℃ to 496 ℃. The yield stress of SF6 glass decreases with increasing tempe…
Batch-to-Melt Conversion Kinetics in Sodium Aluminosilicate Batches Using Different Alumina Raw Materials
2016
The batch-to-melt conversion in batches of sand, soda ash and corundum (C), alumina spinel (A), boehmite (B), or gibbsite (G) as Al2O3 carrier are studied using thermal analysis, X-ray diffraction, and 27Al nuclear magnetic resonance spectroscopy. Laboratory-scaled batches are either heated continuously or quenched from 1600°C in a series of increasing dwell times. The results show that the conversion from the raw materials to the fresh melt proceeds in two kinetic stages. During the first stage (3–5 min), fast conversion of nearly 95% by mass occurs and the conversion coefficient increases in the order G < C ≈ A < B. The second stage is controlled by the slow dissolution of intermediate cr…
Elastic properties of the sigma W-Re phase: A first principles investigation
2017
Abstract We perform density functional theory (DFT) calculations to obtain the formation enthalpy and six independent elastic constants for the 32 possible occupations of the five non-equivalent sites of the σ -phase. The obtained results suggest linear correlation between bulk modulus and Re concentration and between shear modulus and formation enthalpy. The results are used to parameterize a sublattice model with ideal mixing on each sublattice for the free energy and elastic constants. The model allows one to predict the equilibrium composition on each sublattice and hence elastic constants as a function of global Re concentration and temperature of the W-Re alloy.
Irradiation effects in CaF2probed by Raman scattering
2016
The formation conditions and dynamics of Ca colloids and point defects that appear in irradiated single crystals of CaF2 were investigated by Raman spectroscopy. The intensity changes in the Raman spectra because of the presence of different concentrations of point defects and Ca colloids that emerged in CaF2 after irradiation with 2.2 GeV Au ions were used to study their distribution and stability under illumination with three laser wavelengths (473, 532 and 633 nm) at different output powers (2 to 200 mW). A damage saturation at a fluence of 6 × 1011 ion cm−2 was observed. The dependence of the spectral changes on the ion fluence can be described by a core/halo damage cross-section model.…