Solid hydrogen at 342 GPa: no evidence for an alkali metal
Article Abstract:
Solid hydrogen is not yet an alkali metal at 300 K and at a pressure of at least 342 GPa, according to research using a diamond anvil cell. This pressure is much higher than those reached in earlier research at which hydrogen was found to be non-metallic. In the geometry used in this research, it was seen in one case that pressure dropped slowly from 203 GPa after additional turning of the loading screw. It was seen that the sample cavity had decreased in diameter, with a crack occurring at the centre of the diamond. The pressure continued to fall as the cavity diameter decreased and the crack in the diamond grew, with the gasket hole eventually closing.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Biological activation of hydrogen
Article Abstract:
The hydrogen activation site in Ni/Fe hydrogenases contain one carbon monoxide and two cyanide molecules in addition to the nickel and iron atoms. Based on bacteria growth on enriched media, one carbon monoxide and two cyanide groups have been found to be responsible for the three non-protein ligands of iron in the active site of Ni/Fe hydrogenases. The iron ion in Mossbauer spectra of 'Chromatium vinosum' hydrogenase comes from the iron atom in its active site.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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Single-molecule spectral fluctuations at room temperature
Article Abstract:
Spontaneous fluctuations occurring at hundreds of milliseconds and tens of seconds have been observed in the spectra of immobilized single dye molecules. This finding shows that spectral fluctuations have two different activation energies. Photoinduced spectral fluctuations were also found on single molecules subjected to repeated photoexcitation. These fluctuations could mean transitions between metastable minima in the potential-energy surface.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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