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Stable carbon isotopic composition of biogenic carbonates
Geochimica et Cosmochimica Acta, 1965Abstract The geology and sulfur isotopic composition of epigenetic pyrite of the Gas Hills district, Wyoming, indicate a bacterial origin for these sandstone-type uranium deposits. The δC13 value of epigenetic calcite associated with organic materials, however, is heavier than the isotopic composition of calcite of biogenic native sulfur deposits ...
E.S Cheney, M.L Jensen
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The carbon-isotope signature of diagenetic carbonates
2020<p>Diagenetic carbonates often show large variations in their carbon isotope compositions. Variations are mainly the result of isotope fractionation effects during microbial metabolic processes, and these processes themselves may induce carbonate formation.
Patrick Meister, Carolina Reyes
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Carbon isotopic composition of individual Precambrian microfossils
Geology, 2000Ion microprobe measurements of carbon isotope ratios were made in 30 specimens representing six fossil genera of microorganisms petrified in stromatolitic chert from the approximately 850 Ma Bitter Springs Formation, Australia, and the approximately 2100 Ma Gunflint Formation, Canada. The delta 13C(PDB) values from individual microfossils of the Bitter
C H, House +5 more
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Laser-Based Analysis of Carbon Isotope Ratios
Science, 1994A laser technique for analysis of carbon-13:carbon-12 ratios with the specificity of laser resonance spectroscopy and the sensitivity and accuracy typical of isotope ratio mass spectrometers is reported. The technique is based on laser optogalvanic effect spectroscopy, in which an electrical (galvanic) signal is detected in response to the optical ...
D E, Murnick, B J, Peer
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Organic Carbon Isotope Systematics of Coastal Marshes
Estuarine, Coastal and Shelf Science, 1997Measurements of nitrogen, organic carbon and ...
Middelburg, J.J. +3 more
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Carbon dioxide gasification of carbon black: Isotope study of carbonate catalysis
Journal of Catalysis, 1984Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO/sub 2//90% He atmospheres. Catalytic gasification precursor complexes were observed.
John M. Saber +2 more
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Isomeres and isotopes of carbon
2020The nuclear geometry has been developed by analogy with the fullerene geometry. On the base of this geometric approach, the structure of carbon isomers and isotopes, which can be obtained by means of nuclear synthesis, has been designed. The mechanisms of possible nuclear reaction are discussed. Carbon is an unusual element.
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The Journal of Chemical Physics, 1977
The exchange reaction 12COCl2+13CO?13COCl2+ 12CO is theoretically expected to have a separation factor of 1.04 at 60°C, and of 1.07 at −35°C. Pure COCl2 and a series of COCl2–CO gaseous mixtures were irradiated either with the 253.7 nm mercury line or the light of a medium pressure mercury lamp (above 200 nm).
Zorka B. Vukmirović +1 more
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The exchange reaction 12COCl2+13CO?13COCl2+ 12CO is theoretically expected to have a separation factor of 1.04 at 60°C, and of 1.07 at −35°C. Pure COCl2 and a series of COCl2–CO gaseous mixtures were irradiated either with the 253.7 nm mercury line or the light of a medium pressure mercury lamp (above 200 nm).
Zorka B. Vukmirović +1 more
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Carbon isotopic composition of Mexican honey
Journal of Apicultural Research, 1997SUMMARYWe characterized Mexican honey from the main production regions, using the internal stable carbon isotope ratio (ISIRA) of the honey and its protein. We found the average δ13C given by White for American honey is very close to the corresponding value for Mexican honey even though clear evidence that C4 and CAM plants are visited by bees.
Edith Cienfuegos +2 more
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Carbon isotope discrimination of terrestrial ecosystems
2020Detailed knowledge of the interactions between the atmosphere, biosphere and pedosphere is essential for an understanding of global carbon dynamics in terrestrial ecosystems. This chapter addresses ecosystem level variation of Δe, possible impacts of seasonality, of characteristic features of the dominant plant species within an ecosystem (life form ...
Buchmann, N. +3 more
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