简介:Phaeodactylumtricornutumisoneoftheimportantmarinediatomsforoceanicprimaryproduction.Itsreproductionhasprofoundsignificanceinthelifecycle;however,thenuclearbehaviorduringitssexualreproductionwasnotclear.Inthisstudy,weobservedthenucleartransitionanddetermineditscorrelationwithcellconjunction.Itwasfoundthattwocellsjointedattheirapicesfirstandswungandalignedeachotherimmediately,andnucleusfromonecellwasabletotransferintoanotheroneduringcellconjugation.Thecellpairsconjugatedfornucleartransitionweredifferentfromthoseformedinmitosisinhypovalvethicknessandcellulararrangement.OurfindingsprovedtheexistenceofsexualreproductioninP.tricornutum.
简介:OnthebasisofthesoundvelocitymeasurementsofthecoralreefcorefromNanyongNo.1wellofYongshuReefintheNanshaIslands,thepaperstudiestherelationsbetweentheverticalsoundvelocitytransitionfeaturesinthecoralreefcoreandthecorrespondingstratigraphicdepositionalfacieschangeaswellasstratigraphicgapoferosion,analysesthecauseofthesoundvelocitytransition,expoundstheconcreteprocessofthesealevelchangeresultinginthestratigraphicgapoferosionandfacieschangeinthecoralreefandexplainstherelationsbetweentheverticalsoundvelocitytransitioninthecoralreefcoreandthecorrespondingstratigraphicpaleoclimateandthesealevelchange.ThisstudyisofimportantpracticalvalueandtheoreticalsignificancetotheislandandreefengineeringconstructionandtheacousticloggingforoilexplorationinthereeflimestoneareaaswellasthepaleoceanographicstudyofthemarginalseainthewestermPacificOcean.