Bimetallic au/ag metal superstructures from macromolecular metal complexes in solid-state

Indexación: Web of Science; Scielo.Novel bimetallic Au/Ag superstructures have been prepared from solid-state pyrolysis of the macromolecular complexes Chitosan(MLn/M'Ln)n y PSP-4-PVPx( MLn/M'Ln)n with MLn = AuCl3 and M'Ln = Ag(CF3SO3)The characterization was made from XRD (X-ray diffraction of powder), SEM and EDS analysis. Morphologies are influenced by both the nature of the polymer and the metal/polymer, molar ratio of the polymer precursor. EDS analysis suggests a core/shell Au/Ag structure for the materials. A probable mechanism of the formation of these superstructures is discussed. Although separated reports of metallic superstructures of Au or Ag have been recently described, the here reported are the first bimetallic Au/Ag. Key words: Superstructures, Macromolecular complexes, metallic Au and Ag, Pyrolysishttp://ref.scielo.org/y6jcg

Relative Morsification Theory

In this paper we develope a Morsification Theory for holomorphic functions defining a singularity of finite codimension with respect to an ideal, which recovers most previously known Morsification results for non-isolated singulatities and generalize them to a much wider context. We also show that deforming functions of finite codimension with respect to an ideal within the same ideal respects the Milnor fibration. Furthermore we present some applications of the theory: we introduce new numerical invariants for non-isolated singularities, which explain various aspects of the deformation of functions within an ideal; we define generalizations of the bifurcation variety in the versal unfolding of isolated singularities; applications of the theory to the topological study of the Milnor fibration of non-isolated singularities are presented. Using intersection theory in a generalized jet-space we show how to interprete the newly defined invariants as certain intersection multiplicities; finally, we characterize which invariants can be interpreted as intersection multiplicities in the above mentioned generalized jet space.Comment: 56 pages, some typos correcte

The L\^e numbers of the square of a function and their applications

L\^e numbers were introduced by Massey with the purpose of numerically controlling the topological properties of families of non-isolated hypersurface singularities and describing the topology associated with a function with non-isolated singularities. They are a generalization of the Milnor number for isolated hypersurface singularities. In this note the authors investigate the composite of an arbitrary square-free f and $z^2$. They get a formula for the L\^e numbers of the composite, and consider two applications of these numbers. The first application is concerned with the extent to which the L\^e numbers are invariant in a family of functions which satisfy some equisingularity condition, the second is a quick proof of a new formula for the Euler obstruction of a hypersurface singularity. Several examples are computed using this formula including any X defined by a function which only has transverse D(q,p) singularities off the origin.Comment: 14 page

“CONDICIONES DE PRODUCCIÓN Y COMERCIALIZACIÓN DE LOS MICROTALLERES TEXTILES PRODUCTORES DE REBOZO DEL MUNICIPIO DE TENANCINGO, ESTADO DE MÉXICO”

Para lograr el desarrollo es necesario impulsar y fortalecer la participación de las localidades y regiones, en el que los actores locales y/o regionales deben estar directamente involucrados en los procesos de desarrollo, ya que son estos los que están en las mejores condiciones para encontrar y proponer solución para los problemas. El sector textil en México ha constituido una rama importante en el ámbito económico a través del tiempo, por ello es importante fortalecer las localidades que desarrollan dicha actividad (Gómez, 2007). La presente investigación parte de un análisis de la industria textil en México, como rama importante del desarrollo económico nacional, enfatizando el caso particular de la industria textil artesanal, como referencia inmediata para conocer el comportamiento productivo y de comercialización de los microtalleres textiles productores de rebozo del Municipio de Tenancingo, Estado de México. Estos microtalleres textiles atraviesan por serios problemas, debido a diversos factores, entre ellos la obtención de materias primas, la falta de mano de obra, no existe innovación en su sistema productivo y la limitada capacidad para comercializar sus productos; lo cual limita significativamente el desarrollo de estas unidades de producción (Gómez, 2007). En este sentido, se plantea la siguiente pregunta: ¿Cuáles son las condiciones de producción y comercialización que afectan a los microtalleres textiles de rebozo del municipio de Tenancingo, Estado de México. En consecuencia, la presente investigación pretende analizar las condiciones de producción y comercialización que presentan los microtalleres textiles productores de rebozo del municipio de Tenancingo, Estado de México