The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
T E Bunch - One of the best experts on this subject based on the ideXlab platform.
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fullerenes fulleranes and polycyclic aromatic hydrocarbons in the allende meteorite
Meteoritics & Planetary Science, 1997Co-Authors: Luann Becker, T E BunchAbstract:In this paper, we confirm our earlier observations of fullerenes (C60 and C70) in the Allende meteorite (Becker et al., 1994a, 1995). Fullerene C60 was also detected in two separate C-rich (approximately 0.5-1.0%) dark inclusions (Heymann et al., 1987) that were hand picked from the Allende sample. The amounts of C60 detected were approximately 5 and approximately 10 ppb, respectively, which is considerably less than what was detected in the Allende 15/21 sample (approximately 100 ppb; Becker et al., 1994a, 1995). This suggests that fullerenes are heterogeneously distributed in the meteorite. In addition, we present evidence for fulleranes, (C60Hx), detected in separate samples by laser desorption (reflectron) time-of-flight (TOF) mass spectrometry (LDMS). The LDMS spectra for the Allende extracts were remarkably similar to the spectra generated for the synthetic fullerane mixtures. Several fullerane products were synthesized using a Rh catalyst (Becker et al., 1993a) and separated using high-performance liquid chromatography (HPLC). Polycyclic aromatic hydrocarbons (PAHs) were also observed ppm levels) that included benzofluoranthene and corannulene, a cup-shaped molecule that has been proposed as a precursor molecule to the formation of fullerenes in the gas phase (Pope et al., 1993).
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fullerenes in allende meteorite
Nature, 1994Co-Authors: Luann Becker, Randall E. Winans, Jeffrey L. Bada, T E BunchAbstract:The detection of fullerenes in deposits from meteor impacts has led to renewed interest in the possibility that fullerenes are present in meteorites. Although fullerenes have not previously been detected in the Murchison and Allende meteorites, the Allende meteorite is known to contain several well-ordered graphite particles which are remarkably similar in size and appearance to the fullerene-related structures carbon onions and nanotubes. We report that fullerenes are in fact present in trace amounts in the Allende meteorite. In addition to fullerenes, we detected many polycyclic aromatic hydrocarbons (PAHs) in the Allende meteorite, consistent with previous reports. In particular, we detected benzofluoranthene and corannulene (C20H10), five-membered ring structures which have been proposed as precursors to the formation of fullerene synthesis, perhaps within circumstellar envelopes or other sites in the interstellar medium.
Luann Becker - One of the best experts on this subject based on the ideXlab platform.
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fullerenes fulleranes and polycyclic aromatic hydrocarbons in the allende meteorite
Meteoritics & Planetary Science, 1997Co-Authors: Luann Becker, T E BunchAbstract:In this paper, we confirm our earlier observations of fullerenes (C60 and C70) in the Allende meteorite (Becker et al., 1994a, 1995). Fullerene C60 was also detected in two separate C-rich (approximately 0.5-1.0%) dark inclusions (Heymann et al., 1987) that were hand picked from the Allende sample. The amounts of C60 detected were approximately 5 and approximately 10 ppb, respectively, which is considerably less than what was detected in the Allende 15/21 sample (approximately 100 ppb; Becker et al., 1994a, 1995). This suggests that fullerenes are heterogeneously distributed in the meteorite. In addition, we present evidence for fulleranes, (C60Hx), detected in separate samples by laser desorption (reflectron) time-of-flight (TOF) mass spectrometry (LDMS). The LDMS spectra for the Allende extracts were remarkably similar to the spectra generated for the synthetic fullerane mixtures. Several fullerane products were synthesized using a Rh catalyst (Becker et al., 1993a) and separated using high-performance liquid chromatography (HPLC). Polycyclic aromatic hydrocarbons (PAHs) were also observed ppm levels) that included benzofluoranthene and corannulene, a cup-shaped molecule that has been proposed as a precursor molecule to the formation of fullerenes in the gas phase (Pope et al., 1993).
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fullerenes in allende meteorite
Nature, 1994Co-Authors: Luann Becker, Randall E. Winans, Jeffrey L. Bada, T E BunchAbstract:The detection of fullerenes in deposits from meteor impacts has led to renewed interest in the possibility that fullerenes are present in meteorites. Although fullerenes have not previously been detected in the Murchison and Allende meteorites, the Allende meteorite is known to contain several well-ordered graphite particles which are remarkably similar in size and appearance to the fullerene-related structures carbon onions and nanotubes. We report that fullerenes are in fact present in trace amounts in the Allende meteorite. In addition to fullerenes, we detected many polycyclic aromatic hydrocarbons (PAHs) in the Allende meteorite, consistent with previous reports. In particular, we detected benzofluoranthene and corannulene (C20H10), five-membered ring structures which have been proposed as precursors to the formation of fullerene synthesis, perhaps within circumstellar envelopes or other sites in the interstellar medium.
Randall E. Winans - One of the best experts on this subject based on the ideXlab platform.
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fullerenes in allende meteorite
Nature, 1994Co-Authors: Luann Becker, Randall E. Winans, Jeffrey L. Bada, T E BunchAbstract:The detection of fullerenes in deposits from meteor impacts has led to renewed interest in the possibility that fullerenes are present in meteorites. Although fullerenes have not previously been detected in the Murchison and Allende meteorites, the Allende meteorite is known to contain several well-ordered graphite particles which are remarkably similar in size and appearance to the fullerene-related structures carbon onions and nanotubes. We report that fullerenes are in fact present in trace amounts in the Allende meteorite. In addition to fullerenes, we detected many polycyclic aromatic hydrocarbons (PAHs) in the Allende meteorite, consistent with previous reports. In particular, we detected benzofluoranthene and corannulene (C20H10), five-membered ring structures which have been proposed as precursors to the formation of fullerene synthesis, perhaps within circumstellar envelopes or other sites in the interstellar medium.
Jeffrey L. Bada - One of the best experts on this subject based on the ideXlab platform.
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fullerenes in allende meteorite
Nature, 1994Co-Authors: Luann Becker, Randall E. Winans, Jeffrey L. Bada, T E BunchAbstract:The detection of fullerenes in deposits from meteor impacts has led to renewed interest in the possibility that fullerenes are present in meteorites. Although fullerenes have not previously been detected in the Murchison and Allende meteorites, the Allende meteorite is known to contain several well-ordered graphite particles which are remarkably similar in size and appearance to the fullerene-related structures carbon onions and nanotubes. We report that fullerenes are in fact present in trace amounts in the Allende meteorite. In addition to fullerenes, we detected many polycyclic aromatic hydrocarbons (PAHs) in the Allende meteorite, consistent with previous reports. In particular, we detected benzofluoranthene and corannulene (C20H10), five-membered ring structures which have been proposed as precursors to the formation of fullerene synthesis, perhaps within circumstellar envelopes or other sites in the interstellar medium.
Zhang Zhi-huan - One of the best experts on this subject based on the ideXlab platform.
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Geochemical Significance and Distribution Characterisitics of Polycyclic Aromatic Hydrocarbons from the Jurassic Source Rocks in the Heshituoluogai Basin,Northwest Junggar
Natural Gas Geoscience, 2012Co-Authors: Zhang Zhi-huanAbstract:According to the GC-MS analysis and identification of aromatic hydrocarbon,the distribution of aromatic hydrocarbons is investigated.The results indicate that the distribution of aromatic hydrocarbons is extensive from dinuclear aromatics to heptacyclic aromatics.The relative abundance of tetracyclic and pentacyclic aromatics is apparently higher than that of dinuclear and tricyclic aromatics in Jurassic source rocks.The distribution of PAH in mudstone and coal is easily affected by the sedimentary facies.The relative content of phenanthrene,fluoranthene,pyrene,chrysene,benzofluoranthene and benzo[e]pyrene is higher than other compounds in the mudstone from Badaowan Formation,but in Xishanyao Formation,the content of perylene is predominantly higher.In Sangonghe Formation,the content is high.However,in the coal from Badaowan Formation,the content of them is high,but in the coal from Xishanyao Formation,the content of benzofluoranthene,benzo[e]pyrene and benzo[a]pyrene is high and other compounds is low.Additionally,retene exits in Jurassic rock and its content is moderate.The parameters of alkyl naphthalene and dibenzothiophene reflecting maturity changes greatly,indicating that the indexes of coal is higher than mudstones′,which is positively correlated with the ratios of Pr/Ph and δ13Caro.But the parameters of tetracyclic and pentacyclic aromatics are negatively correlated with them.However,the parameters of alkylated phenanthrene of mudstones change less,which has shown that Rc ratios are close to the measured Ro.Therefore,organic facies affect PAHs′ parameters obviously.The correlatographs of dibenzothiophene/phenanthrene and Pr/Ph or OF/(OF+F) and SF/(SF+F) reflect that Jurassic source rock is deposited from weak oxidizing shore-shallow lacustrine to oxidative fluvial facies or delta facies.