RESUMO
Here we present the first report of a carbon-γ-Fe2O3 nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739â Bq kg(-1) ((134)Cs and (137)Cs at 509â Bq kg(-1) and 1,230â Bq kg(-1), respectively) and 114,000â Bq kg(-1) ((134)Cs and (137)Cs at 38,700â Bq kg(-1) and 75,300â Bq kg(-1), respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used.
Assuntos
Adsorção/fisiologia , Descontaminação/instrumentação , Descontaminação/métodos , Acidente Nuclear de Fukushima , Resíduos Radioativos , Compostos Inorgânicos de Carbono , Radioisótopos de Césio/metabolismo , Meio Ambiente , Compostos Férricos/química , Japão , Fenômenos Magnéticos , Magnetismo , Nanopartículas Metálicas , Monitoramento de Radiação , Poluentes Radioativos do Solo/metabolismo , Propriedades de SuperfícieRESUMO
We report the unprecedented square-planar coordination of iridium in the iron iridium arsenide Ca(10)(Ir(4)As(8))(Fe(2)As(2))5. This material experiences superconductivity at 16 K. X-ray photoemission spectroscopy and first-principles band calculation suggest Ir(II) oxidation state, which yields electrically conductive Ir(4)As(8) layers. Such metallic spacer layers are thought to enhance the interlayer coupling of Fe(2)As(2), in which superconductivity emerges, thus offering a way to control the superconducting transition temperature.
RESUMO
Co-doping of lanthanum and phosphorus in CaFe2As2 induces superconductivity at 45 K. This superconducting transition temperature is higher than the 38 K transition in Ba1-xKxFe2As2, which is the maximum found thus far among the 122 phases. Superconductivity with a substantial shielding volume fraction was observed at 0.12 ≤ x ≤ 0.18 and y = 0.06 in Ca1-xLaxFe2(As1-yPy)2. The superconducting phase of the present system seems to be not adjacent to an antiferromagnetic phase.