RESUMO
Au/Pt nanoparticles show an optimized catalytic activity when compared with Pt nanoparticles because Pt activity is improved by the presence of Au on the surface. It was checked whether a controllable surface composition can be achieved by the simple strategy of varying the Au : Pt ratio. We present an in-depth kinetic simulation study on the influence of Au : Pt ratio on the formation of Au/Pt nanoparticles synthesized in microemulsions. This study is able to explain the resulting nanoarrangement as a function of kinetic parameters such as Au : Pt ratio and intermicellar exchange rate. The role of the micelles as a dosing pump of the Au precursor explains that a higher Au amount results in a Au reduction which takes place over a longer period of time. It implies that Au is deposited until longer stages of the synthesis, so Au is present at the nanoparticle surface. Micelles as reaction media produce a minor impact on Pt due to its slower reduction. These different kinetic behaviours of Au and Pt give rise to a surface composition which can be tailored by tuning the Au : Pt ratio. Numerical results on surface composition successfully reproduce experimental data and further support the outcomes of the degree of atomic mixing under different Au : Pt ratios.
RESUMO
El siguiente artículo, intenta explicar las preferencias electorales tomando en cuenta la influencia y la importancia de la imagen social y física como criterio de valoración y generación de actitudes y sentimientos favorables frente a un candidato u otros, es así que abordamos el tema, desde una explicación sobre el papel de la semejanza y su importancia, tomando algunos conceptos como la Congruencia cognitiva y el establecimiento de la realidad social. Así mismo pretendemos señalar las condiciones psicosociales que marcan una tendencia en la preferencia por algunos candidatos en la actualidad.
The following article, tries to explain the electoral preferences, taking the influence and the importance from the social and physical image, like criterion from valuation and generation from favorable attitudes and feelings of a candidate or others, so we approached the subject, from an explanation about the paper of the similarity and its importance, taking some concepts like the cognitive Congruence and the establishment from the social reality. Also we try to indicate the conditions psycho-social that they mark a tendency in the preference by some candidates actually.
