学科分类
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2 个结果
  • 简介:Unusualcarbonaceousmatter,termedherechiemite,composedofmorethan90%CfromtheAlpineForelandatLakeChiemseeinBavaria,southeasternGermanyhasbeeninvestigatedusingopticalandatomicforcemicroscopy,X-rayfluorescencespectroscopy,scanningandtransmissionelectronmicroscopy,high-resolutionRamanspectroscopy,X-raydiffractionanddifferentialthermalanalysis,aswellasbyδ13Cand14Cradiocarbonisotopicdataanalysis.Inthepumice-likefragments,poorlyorderedcarbonmatterco-existswithhigh-orderingmonocrystallineα-carbyne,andcontainssubmicrometer-sizedinclusionsofcomplexcomposition.Diamondandcarbyneaddtothepeculiarmixofmatter.TherequiredveryhightemperaturesandpressuresforcarbyneformationpointtoashockeventprobablyfromtherecentlyproposedHoloceneChiemgaumeteoriteimpact.Thecarbonmaterialissuggestedtohavelargelyformedfromheavilyshockedcoal,vegetationlikewood,andpeatfromtheimpacttargetarea.Thecarbonization/coalificationhighPTprocessmaybeattributedtoastrongshockthatinstantaneouslycausedthecompleteevaporationandlossofvolatilematterandwater,whichneverthelesspreservedtheoriginalcellularstructureseenfossilizedinmanyfragments.Relativelyfreshwoodencapsulatedinthepurportedstronglyshockedmatterpointtoquenchedcarbonmeltcomponentspossiblyimportantforthediscussionofsurvivaloforganicmatterinmeteoriteimpacts,implyinganastrobiologicalrelationship.

  • 标签: astrobiology diamond CARBYNE COALIFICATION CARBONIZATION METEORITE
  • 简介:<正>1IntroductionVirusesarethemostabundantbiologicalentitiesonEarth.Theycaninfluencethesuccessionofindividualmicrobialpopulations,biogeochemicalcyclesofC/Nand,ultimately,microbialcommunitystructurethroughkilling

  • 标签: T4-like BACTERIOPHAGES major CAPSID gene(g23) SALINE