A systematic study of the adsorption of a methylthio on different sites of silver nanoparticles of 13, 55, 147, and 309 atoms with icosahedral symmetry as well as on the (111) surface is performed using density functional theory. Ab initio molecular dynamics were used to obtain the adsorption energies, atomic positions, and electronic properties of the lowest-energy configurations. Different adsorption sites and orientations of the molecule were tested. The electronic density of states also shows a size dependence, in which a transition from discrete to more band-like structure is found. Adsorption of a second methylthio is also studied. It was observed that final structures, adsorption energies, and electronic density of states strongly depended on the nanoparticle size and thus on the atomic coordination number, where bridge configurations had the lowest total energy and the highest adsorption energy for all sizes except Ag 13 .

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Honeycomb plasmonic lattices are characterized by a 2-particle unit cell. The difference between the intrasublattice and intersublattice coupling is distinctive of non-Bravais lattices. Although the two particles are identical the two types of coupling may be different.

A method to manipulate the multipolar plasmonic response of a nanostructure in the quasi-static limit is introduced. The theoretical method puts on the same footing geometry, dielectric properties, and incident field and proceeds in two steps: it optimizes the geometry of the nanostructure to maximize the intensity of the scattering crosssection spectrum. This is done by calculating the coupling strengths of the different modes of the system to the external field, which the method naturally provides. Then, it exploits the symmetry of the incident electromagnetic field to enhance or suppress specific orders, which, in turn, tunes the field enhancement. We demonstrate the method by using a plasmonic dimer of nanospheres.

El ecosistema antártico es una de las regiones del mundo más sensibles al cambio climático, y presenta amplia variabilidad ambiental que modifican los patrones espaciales y temporales de la estructura fitoplanctónica. Se estudió la comunidad del fitoplancton y su variabilidad espacial y temporal de la ensenada Mackellar-bahía Almirantazgo, Antártida, en los veranos australes de 2012 y 2013. Se hicieron muestreos de agua para fitoplancton y variables ambientales en 11 estaciones a tres profundidades (0, 10 y 20 m). La masa de Agua Superficial Antártica de la zona de estudio fue reconocida. La composición total del fitoplancton en la columna de agua incluyó 40 taxones de diatomeas, 6 taxones de dinoflagelados y varias especies de nanoflagelados (< 20 µm). Los nanoflagelados pertenecen a Prasinophyceae, Cryptophyta y Haptophyta. La alternancia entre diatomeas del microplancton (20-200 µm) y nanoflagelados (< 20 µm) fue evidente durante el período de estudio: en el verano 2012 el grupo de los nanoflagelados fue más abundante (86%), con especies de diatomeas del género Thalassiosira sp. (11%), y para el verano 2013 los nanoflagelados disminuyeron considerablemente (20%), la abundancia del fitoplancton estuvo dominada por diatomeas como Thalassiosira delicatula (36%), Pseudo-nitzschia grupo delicatissima (9%), Porosira glacialis (6%), y el dinoflagelado Gymnodinium sp. (19%). La densidad celular en el verano 2012 fue menor, en comparación con el verano 2013, donde ocurrió una floración de diatomeas. La diversidad del fitoplancton fue baja (< 1,97 bits⋅célula-1) en ambos veranos. Las principales diferencias fueron la dominancia de diatomeas del microplancton y nanoflagelados, las cuales probablemente fueron causadas por la disminución de la salinidad y el aumento de oxígeno superficial observado en la Antártida, producto del deshielo ocurrido durante los veranos 2012 y 2013.

We present a numerical calculation of the heat transport in a Bragg mirror configuration made of materials that do not obey Fourier’s law of heat conduction. The Bragg mirror is made of materials that are described by the Cattaneo-Vernotte equation. By analyzing the Cattaneo-Vernotte equation’s solutions, we define the thermal wave surface impedance to design highly reflective thermal Bragg mirrors. Even for mirrors with a few layers, very high reflectance is achieved (>90%). The Bragg mirror configuration is also a system that makes evident the wave-like nature of the solution of the Cattaneo-Vernotte equation by showing frequency pass-bands that are absent if the materials obey the usual Fourier’s law.

We analyze the time-harmonic heating of a non-Fourier medium by spherical nanoparticles via the photothermal effect. The nanoparticle is embedded in a medium with thermal properties similar to those reported for organic tissue that does not obey Fourier’s law of heat conduction but rather the Cattaneo–Vernotte equation. By assuming the nanoparticle is illuminated with an intensity-modulated laser, we show that the temperature profile outside the nanoparticle oscillates and, at specific separations, can have a temperature 16% lower than predicted using Fourier’s law of heat conduction.

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