Video Experimental Relacionado

Updated: Jun 24, 2026

$Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction$

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

Published on: April 1, 2017

El carbono grafítico en el meteorito de Allende: un estudio de microestructura

P P Smith¹, P R Buseck

¹Department of Geology, Arizona State University, Tempe 85251, USA.

Science (New York, N.Y.)

|April 17, 1981

Resumen

El carbono en el meteorito de Allende es principalmente grafito de baja cristalinidad. Este grafito es significativo ya que lleva gases nobles isotópicamente anómalos que se encuentran en las condritas carbonáceas.

Área de la Ciencia:

Cosmoquímica es la cosmoquímica.
Ciencia de los materiales Ciencia de los materiales.

Sus antecedentes:

Las condritas carbonáceas proporcionan información sobre los primeros materiales del sistema solar.
Comprender la forma y las propiedades del carbono es crucial para los estudios cosmoquímicos.

Objetivo del estudio:

Para caracterizar las propiedades microestructurales del carbono dentro de la condrita carbonácea de Allende.
Para identificar la forma de carbono que alberga gases nobles isotópicamente anómalos.

Principales métodos:

Se empleó microscopía electrónica de transmisión de alta resolución (HRTEM).
Análisis microestructural de materiales carbonosos.

Principales resultados:

El carbono en el meteorito de Allende es predominantemente grafito cristalino de baja calidad.
Este grafito poco cristalino es un portador significativo de gases nobles anómalos isotópicamente.

Conclusiones:

El estado microestructural del carbono influye en su papel en la preservación de los materiales presolares.
El grafito poco cristalino en las condritas carbonáceas es clave para comprender las anomalías de los gases nobles.

Más Videos Relacionados

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO₂ Reduction

Published on: April 10, 2018

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry

Published on: March 4, 2021

Videos de Conceptos Relacionados

Carbon Skeletons

Carbon Skeletons

Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side chains...

Network Covalent Solids

Network Covalent Solids

Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...