Triple-isotope composition of atmospheric oxygen as a tracer of biosphere productivity
Article Abstract:
The naturally occurring isotopes of oxygen are of mass numbers 16,17 and 18, and their ratio in atmospheric O(sub2) relies mainly on the isotopic composition of O(sub2) produced from terrestrial and aquatic plants. An experiment based on estimates of the size of the (super17)O/(super16)O anomaly in tropospheric O(sub2) was undertaken. It is argued that it mainly reflects the influences of biospheric cycling and stratospheric photochemical processes. It is proposed that the magnitude of the tropospheric (super17)O anomaly is useful as a tracer of global biosphere production.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
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Origin of luminescence from porous silicon deduced by synchrotron-light-induced optical luminescence
Article Abstract:
Soft X-rays with energies near the silicon K-edge induce optical luminescence in porous silicon and siloxene. X-ray absorption fine structure (XAFS) spectra for the luminescent sites can be obtained in both materials by the use of luminescence along with the total electrol yield. This explanation is given by the quantum-confinement model, the only model to explain this phenomenon.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
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Origins of sulphate in Antarctic dry-valley soils as deduced from anomolous (17)O compositions
Article Abstract:
A new study of Antarctica's dry-valley soils deduces that some of the sulphate they contain comes not only from sea salt but from atmospheric oxidation of gaseous sulphur compounds.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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