简介:AnewcoexistingamphibolepairwasrecentlyfoundintheJianshanirondeposit,LoufanofShanxiProvince,China,ElectronmicroprobeanalysisshowsthatthecoexistingpairiscomposedofgrueneriteK0k.001(Na0.027Ca0.073Mn0.031Fe1.801^2+)1.932(Fe2.948^2+Mg1.964Ti0.002Al0.087)5Si8.069O22.10(OH)2andferropargasite(K0.135Na0.461)0.596(Na0.088Ca1.853Mn0.005Fe0.072^2+)2(Mn0.005Fe2.789^2+Mg0.875Ni0.021Fe0.499^3+Al0.812)5(Si6.103Al1.897)8O22.00(OH)2.Thetwokindsofamphibolesoccurinamphiboleschistnotonlyasseparatephenocrysts,butalsoarecombinedtoform"single-crystal"phenocrystsintheformoftopotacticintergrowthswiththecommonc-andb-axes.Theboundarybetweentopotacticgrueneriteandferropargasiteisopticallyandchemicallysharp.Incomparisonwiththecoexistingferromagnesianamphibloeandcalcicamphibolepairdiscoveredbypredecessors,thenewlydiscoveredpairhaslowerMg/Feratiosandwidermiscibilitygaps.
简介:Anumericalsimulationandanexperimentalstudyonvortex-inducedmotion(VIM)ofanewtypeofdeepdraftmulti-columnsfloatingdrillingproduction,storageandoffloading(FDPSO)arepresentedinthispaper.Themaindimension,thespecialvariablecross-sectioncolumnandthecabinarrangementoftheoctagonalpontoonareintroducedbasedontheresult.Thenumericalsimulationisadaptedtostudytheeffectsofcurrentincidenceanglesandreducedvelocitiesonthisplatform'sswaymotionresponse.The300mwaterdepthequivalenttruncatedmooringsystemisadoptedforthemodeltests.Themodeltestsarecarriedouttocheckthereliabilityofnumericalsimulation.Theresultsconsistofsurge,swayandyawmotions,aswellasmotiontrajectories.Themaximumswayamplitudesfordifferenttypesofoffshoreplatformisalsostudied.Themainresultsshowthatthepeakfrequenciesofswaymotionunderdifferentcurrentincidenceanglesandreducedvelocitiesvaryaroundthenaturalfrequency.TheanalysisresultofflowfieldindicatesthatthechangeofdistributionofvortexinverticalpresentssignificantinfluencesontheVIMofplatform.ThetrendofswayamplituderatiocurveofthisnewtypeFDPSOdiffersfromtheothertypesofplatform.Under45°currentincidenceangle,theswayamplitudeofthisnewtypeofFDPSOismuchsmallerthanthoseofothertypesofoffshoreplatformat4.4≤Vr≤8.9.Thetypical'8'shapetrajectorydoesnotappearintheplatform'smotiontrajectories.