Analysis of the Scanning Tunneling Microscopy Images of the Charge Density Wave Phase in Quasi-one-dimensional Rb0.3MoO3

The experimental STM images for the CDW phase of the blue bronze RbMoO3 have been successfully explained on the basis of first-principles DFT calculations. Although the density of states near the Fermi level strongly concentrates in two of the three types of Mo atoms Mo-II and Mo-III, the STM measurement mostly probes the contribution of the uppermost O atoms of the surface, associated with the Mo-IO6 octahedra. In addition, it is found that the surface concentration of Rb atoms plays a key role in determining the surface nesting vector and hence the periodicity of the CDW modulation. Significant experimental inhomogeneities of the b* surface component of the wavevector of the modulation, probed by STM, are reported. The calculated changes in the surface nesting vector are consistent with the observed experimental inhomogeneities.Comment: 4 pages 5 Figure

A dataset of acoustic measurements from soundscapes collected worldwide during the COVID-19 pandemic

Political responses to the COVID-19 pandemic led to changes in city soundscapes around the globe. From March to October 2020, a consortium of 261 contributors from 35 countries brought together by the Silent Cities project built a unique soundscape recordings collection to report on local acoustic changes in urban areas. We present this collection here, along with metadata including observational descriptions of the local areas from the contributors, open-source environmental data, open-source confinement levels and calculation of acoustic descriptors. We performed a technical validation of the dataset using statistical models run on a subset of manually annotated soundscapes. Results confirmed the large-scale usability of ecoacoustic indices and automatic sound event recognition in the Silent Cities soundscape collection. We expect this dataset to be useful for research in the multidisciplinary field of environmental sciences

High-pressure electronic structure and phase transitions in monoclinic InSe: X-ray diffraction, Raman spectroscopy, and density functional theory

International audienceWe have studied the crystal and electronic structure of monoclini

Capturing Centimeter Scale Local Variations in Paper Pore Space via mu CT A Benchmark Study Using Calendered Paper

A two step framework to analyze local microstructure variations of paper sheets based on 3D image data is presented. First, a multi stage workflow efficiently acquires a large set of highly resolved tomographic image data, which enables in combination with statistical image analysis the quantification of local variations and pairwise correlations of morphological microstructure characteristics on length scales ranging from micrometers to centimeters. Secondly, the microstructure is analyzed in terms of the local behavior of porosity, thickness, and further descriptors related to transportation paths. The power of the presented framework is demonstrated, showing that it allows one i to quantitatively reveal the difference in terms of local structural variations between a model paper before and after unidirectional compression via hard nip calendering and that ii the field of view which is required to reliably compute the probability distributions of the considered local microstructure characteristics is at least 20mm2. The results elucidate structural differences related to local densification. In particular, it is shown how calendering transforms local variations in sheet thickness into marked local mass density variations. The obtained results are in line with experimental measurements of macroscopic properties basis weight, Bekk smoothness parameters, thickness, and Gurley retention time

Óptica de nanopartículas y nanocompuestos

IP 1101-05-036-99of the XV latinamerican symposium on solid state physics (SlafesXV), Cartagena de Indias, Colombia, November;1 to 5, 1999 / latinamerican simposium on solid state physics(slafes XV)(15: 1999 nov. 1-5 : Cartagena de;Indias, Colombia) Guest editors J. Giraldo, L. Quiroga, R.Merlin, J.R. Leite. -- En: Physica status solidi;(b) : Basic research Vol. 220, no. 1 (july 2000): p. 1-804. --ISSN 03701972.;Oaxaca: Sociedad Mexicana de ciencia de superficies y vacio A.C., 2000. --28 cm. -- REVISTA(S): Proceedings;ARTICULOS EN REVISTA: Funcion dielectrica de un medio quepercola / Adriana Gutierrez Rodriguez, Jairo;Giraldo Gallo. -- En: Revista colombiana de un medio que percola. -- Vol.32, no. 1 (2000). -- A statistical;model for flash thermal desorption of carbon dioxide frompolycrystallinemolybdenum / L.D Lopez Carreño, A.J.;Ramirez Cuesta, L.Viscido, J.M Heras. -- En: Journal of molecular catalysis a: chemical. -- Vol. 167 (june;2001); p. 157-163. -- Diffusive like minibands in finite superlattices ofdisordered quantum wells / R.R. Rey;Gonzalez, E. Machado -- En: Brazilian journal of physics.'-- Vol. 31 no. 4(dic. 2001). -- RF sputtered a Si:H;and aGe:H films: a comparative study / A.R. Zanatta, F. Fajardo,M. Mulato, M.M. Lima, F.C. Marques, I.;Chambouleyron. -- En: Asian journal of physics. -- Vol. 9(2000); p. 681.'-- PONENCIA(S) en Congreso: Atomic;ordering in Cd1-xZnxTe for low Zn concentration: optical,thermal and structural characterization / A.;Guterrez, M.E. Rodriguez, O. Zelaya, C. Vasquez, L. Baños,JairoGiraldo Gallo. -- En: Sociedad mexicana de;ciencia de superficies y vacio A.C. 20 congreso nacional.(20:2000 ago.28 - sep.1 :Oxaca, Mexico). -

Off-Lattice Kinetic Monte Carlo Methods

International audienceExact modeling of the dynamics of chemical and material systems over experimentally relevant time scales still eludes us even with modern computational resources. Fortunately, many systems can be described as rare event systems where atoms vibrate around equilibrium positions for a long time before a transition is made to a new atomic state. For those systems, the kinetic Monte Carlo (KMC) algorithm provides a powerful solution. In traditional KMC, mechanism and rates are computed beforehand, limiting moves to discretized positions and largely ignoring strain. Many systems of interest, however, are not well-represented by such lattice-based models. Moreover, materials often evolve with complex and concerted mechanisms that cannot be anticipated before the start of a simulation. In this chapter, we describe a class of algorithms, called offlattice or adaptive KMC, which relaxes both limitations of traditional KMC, with atomic configurations represented in the full configuration space and reaction events are calculated on-the-fly, with the possible use of catalogs to speed up calculations. We discuss a number of implementations of off-lattice KMC developed by different research groups, emphasizing the similarities between the approaches that open modeling to new classes of problems