نتایج جستجو برای: fossil

تعداد نتایج: 25461  

Journal: :The Canadian Entomologist 1907

F. Nazari J. Raheb ME. Kefayati

    Combustion of sulfur components of fossil fuels such as oil causes the emission of SO2 in the atmosphere and lead to the formation of acidic rain in the environment. The conventional approach for desulfurization of fossil fuels is the chemical procedure of hydrodesulfurization (HDS). However, this method has low efficiency for desulfurization of ring components of sulfur such as dibenzothio...

2012
David Penney Jason A. Dunlop Yuri M. Marusik

Spiders (Araneae) are one of the most species-rich orders on Earth today, and also have one of the longest geological records of any terrestrial animal groups, as demonstrated by their extensive fossil record. There are currently around 1150 described fossil spider species, representing 2.6% of all described spiders (i.e. extinct and extant). Data for numbers of fossil and living spider taxa de...

2008
Yu Lin Jiang Yu-Sheng Liu

0146-6380/$ see front matter 2008 Elsevier Ltd doi:10.1016/j.orggeochem.2008.06.006 * Corresponding author. Tel.: +1 423 439 6917; fa E-mail address: [email protected] (Y.L. Jiang). A new and convenient fluorescence spectroscopic method has been developed for the separation and determination of perylene in fossil wood recovered from a late Miocene to early Pliocene Gray Fossil Site in Tennessee, ...

2015
Y.-L. Zhang R.-J. Huang I. El Haddad K.-F. Ho J.-J. Cao Y. Han P. Zotter C. Bozzetti K. R. Daellenbach F. Canonaco J. G. Slowik G. Salazar M. Schwikowski J. Schnelle-Kreis G. Abbaszade R. Zimmermann U. Baltensperger A. S. H. Prévôt S. Szidat

During winter 2013, extremely high concentrations (i.e., 4–20 times higher than the World Health Organization guideline) of PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm) mass concentrations (24 h samples) were found in four major cities in China including Xi’an, Beijing, Shanghai and Guangzhou. Statistical analysis of a combined data set from elemental carbon (EC), organic ca...

Journal: :Journal of human evolution 2005
Matt Sponheimer Darryl de Ruiter Julia Lee-Thorp Andreas Späth

A previous study of strontium/calcium (Sr/Ca) ratios in Paranthropus suggested that it consumed more animal foods than was previously believed. However, that study looked at Sr/Ca in fossil bone, which is known to be highly susceptible to diagenesis. Enamel, in contrast, is resistant to post-mortem alteration making it a more appropriate material for Sr/Ca analysis of Plio-Pleistocene fossils. ...

2017
Frederica P. Perera

BACKGROUND Approaches to estimating and addressing the risk to children from fossil fuel combustion have been fragmented, tending to focus either on the toxic air emissions or on climate change. Yet developing children, and especially poor children, now bear a disproportionate burden of disease from both environmental pollution and climate change due to fossil fuel combustion. OBJECTIVE This ...

Journal: :Proceedings of the United States National Museum 1915

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