Search results for "funktion"
showing 10 items of 213 documents
Space partitioning of exchange-correlation functionals with the projector augmented-wave method
2018
We implement a Becke fuzzy cells type space partitioning scheme for the purposes of exchange-correlation within the GPAW projector augmented-wave method based density functional theory code. Space partitioning is needed in the situation where one needs to treat different parts of a combined system with different exchange-correlation functionals. For example, bulk and surface regions of a system could be treated with functionals that are specifically designed to capture the distinct physics of those regions. Here, we use the space partitioning scheme to implement the quasi-nonuniform exchange-correlation scheme, which is a useful practical approach for calculating metallic alloys on the gene…
Smooth surjections and surjective restrictions
2017
Given a surjective mapping $f : E \to F$ between Banach spaces, we investigate the existence of a subspace $G$ of $E$, with the same density character as $F$, such that the restriction of $f$ to $G$ remains surjective. We obtain a positive answer whenever $f$ is continuous and uniformly open. In the smooth case, we deduce a positive answer when $f$ is a $C^1$-smooth surjection whose set of critical values is countable. Finally we show that, when $f$ takes values in the Euclidean space $\mathbb R^n$, in order to obtain this result it is not sufficient to assume that the set of critical values of $f$ has zero-measure.
Trace and density results on regular trees
2019
We give characterizations for the existence of traces for first order Sobolev spaces defined on regular trees.
The Diccionario Inglés-Español de Contabilidad: Traducción and the Diccionario Inglés-Español de Contabilidad: Traducción de Frases y Expresiones: Tw…
2014
This paper focuses on the role dictionaries play in a translation situation. This role is analysed in terms of the tenets of the Function Theory of Lexicography, which proposes that users do not have needs in general but punctual needs in specific situations. For example, translators of accounting texts need insertable equivalents whose meanings and language behaviour are clearly described. Furthermore, translators also need contextual data on domain-specific consensual usage. The construction of the Accounting Dictionaries and Diccionarios de Contabilidad reveals that the Function Theory offers theoretical and practical solutions for constructing dictionaries that target user needs in a pr…
Grand-canonical approach to density functional theory of electrocatalytic systems: Thermodynamics of solid-liquid interfaces at constant ion and elec…
2018
Properties of solid-liquid interfaces are of immense importance for electrocatalytic and electrochemical systems, but modeling such interfaces at the atomic level presents a serious challenge and approaches beyond standard methodologies are needed. An atomistic computational scheme needs to treat at least part of the system quantum mechanically to describe adsorption and reactions, while the entire system is in thermal equilibrium. The experimentally relevant macroscopic control variables are temperature, electrode potential, and the choice of the solvent and ions, and these need to be explicitly included in the computational model as well; this calls for a thermodynamic ensemble with fixed…
Selective Acrolein Hydrogenation over Ligand-Protected Gold Clusters : A Venus Flytrap Mechanism
2022
The catalytic partial hydrogenation of α,β-unsaturated aldehydes is an ideal reaction to understand the selectivity between two different functional groups Here the two functional groups are C═C and C═O, and the hydrogenation of C═O is preferentially desired due to the importance of the issuing products, unsaturated alcohols, in fine-chemical industries. Using density functional theory calculations, we investigate the catalytic competency toward this reaction of a Au nanocluster in the presence of protecting ligands that offer higher stability and the possibility for the uniform distribution of size-selected clusters in the catalytic system. meta-Mercaptobenzoic-acid-protected-protected Au …
Modèle des voies réflexes et cérébelleuses, permettant le calcul de fonctions inverses et la commande d'un segment mécanique mobile
2004
14/07/2004; La commande et le contrôle des mouvements des membres par les voies cérébelleuses et réflexes sont modélisées au moyen d'un circuit dont la structure est déduite de contraintes fonctionnelles. 1/ La première contrainte est que les mouvements rapides des membres doivent être précis, quoiqu'ils ne puissent pas être commandés en boucle fermée au moyen de signaux sensoriels. Les voies qui préparent les ordres moteurs doivent donc contenir des fonctions inverses approximées des fonctions biomécaniques du membre et des muscles. Or une telle fonction peut être calculée au moyen de boucles de rétroaction parallèles, dont la structure est comparable à l'anatomie des voies cérébelleuses. …
Revisiting the role of embedding in Systemic Functional Linguistics : Construing depth in “big texts”
2021
This paper is concerned with exploring the role of embedded genres in expanding the meaning potential of long texts, focusing especially on complex tertiary assignments. A significant body of work has evolved in Systemic Functional Linguistics (SFL) on modelling “big texts” as macrogenres since Martin (1994: 29) posed the question how texts “get bigger than a page”. However, based on detailed genre analyses of high-scoring undergraduate business country reports, this paper illustrates that not all big texts are macrogenres made up of elemental genre complexes. Analogising from clause grammar, it will show that these texts unfold through multiple layers of embedded genres in their generic st…
Density functional/molecular dynamics simulations of phase-change materials
2013
Testing the Sobolev property with a single test plan
2020
We prove that in a vast class of metric measure spaces (namely, those whose associated Sobolev space is separable) the following property holds: a single test plan can be used to recover the minimal weak upper gradient of any Sobolev function. This means that, in order to identify which are the exceptional curves in the weak upper gradient inequality, it suffices to consider the negligible sets of a suitable Borel measure on curves, rather than the ones of the $p$-modulus. Moreover, on $\sf RCD$ spaces we can improve our result, showing that the test plan can be also chosen to be concentrated on an equi-Lipschitz family of curves.