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鸿发国际注册送58:中国科学家利用新技术破解2亿年前昆虫真实颜色

2018-04-12 20:23:48
来源:中国新闻网

金牛国际娱乐网址:Still,Brazil'sroadtoqualificationwasrockyinthebeginning.ThesurprisingappointmentofDungaasheadcoachafterBrazillostitshomeWorldCupdistancedmanyfans.Andfrustrationgrewafteragroup-stageeliminationinthe2015CopaAmerica,whichpopularizedanewsayingintheeverydayBrazilianlexicon:"Everydayisanew7-1."EliminationtoParaguayatCopaAmericaCentenariointheUnitedStatesin2016endedDunga'srunatthehelm.Brazil'ssoccerconfederationdidn'tneedmerelyasuccessorforDunga-itneededanationalhero.ThemostpopularchoicewasCorinthianscoachTite,whowasoverlookedafterthe2014WorldCupdebacle.TitewasnotinchargeoftheBrazilteamthatwongoldattheRiodeJaneiroOlympics,thankstoNeymar'sreturntoform,buthisadvicewassurelyheeded.Playerssaidthattitlehelpedrestoretheirconfidence.WhenWorldCupqualifiersresumedinSeptemberlastyear,Tite'steamwasreadytodominate.A3-0wininEcuadorwasfollowedbya2-1homevictoryoverColombiathatrestoredyetmoreoftheBrazilianpublic'sfaith.Withthe3-0victoryoverArgentinainthesamestadiumwhereBrazilhadbeenhumiliatedbyGermany,thecoach'sreputationwasenhanced.ResultsandstylehavebecomesoimpressivethatBrazilsecuredoneofthetopfourautomaticSouthAmericanqualifyingspotswithfourmatchestospare.Ithasbecomeateamtofearagain,asadversariessuchasUruguaycoachOscarTabarezacknowledged.WhenTitetookover,Brazilwassixthinthestandings.Now,thecoachwhomadethecontemporaryBrazilteammoreliketheBrazilofoldisreadytoquaffafewcocktailsincelebration."WhenIlookatmyfamily-theplayers-andwhenwetalktothefansandseehowhappytheyare,that'swhenyouthink'I'mpartofsomethingveryspecial,'"TitesaidafterBrazil'squalificationwasconfirmed."Thankyou,mygoodGod.Iwillhaveacaipirinhathisbig,"thecoachsaid,indicatinganextra-largeglasswithhishands.BrazilnolongerdependsentirelyonNeymar,whiletheinjuryabsenceofteenagetargetmanGabrielJesushasdriedupitsgoals.Itsstrongdefensehasconcededonlytwogoalsineightmatches.Therearestillweaknesses,includingalackofexperienceforthecoachagainstteamsfromoutsideSouthAmericaandthecorruptionscandalsthataffectitsfootballconfederation.ButthemomentumisclearlywiththeSambaBoysagain."Everythingchanged,"RealMadridwingerMarcelosaid."Youcanseetheatmosphere,howmuchtheplayersaregiving.Everyoneisworkinghardineachtraining,givingourlives."Underthenewmanagement,Brazilwoneightstraightmatchesandsecured24ofits33points.Second-placeColombiaisalongwaybehindtheleader,with24points.Neymarisalsoanoticeablymorematurecharacteronthepitch,aswitnessedbyonetellingtackleduringthe4-1thumpingofUruguaylastThursday.BeforescoringBrazil'sthird,theBarcelonastarcouldhavehitthedeckinachallengewithSebastianCoates,whohadalreadybeenbooked.However,Neymarstayedonhisfeettonetthebestgoalofthenight."Thereweremanyfoulsonme,"NeymarsaidoftheParaguaydefense."ButIdon'tcareanymore.Theycanhitmeasmuchastheywant.Itistheonlywaytheywillstopme."Someoftheveteransofthat7-1losstoGermanyarekeytoBrazil'ssuccesstoo-notably,wingersDaniAlvesandMarceloandmidfielderPaulinho."Wearejustgettingstarted,"saidPaulinho,ofGuangzhouEvergrande."AdversariesbetterwatchoutbecauseBraziliscomingwithitall."AssociatedPress

  中新社南京4月12日电 (杨颜慈)中国科学院南京地质古生物研究所12日发布消息,该所研究团队利用新的分析技术,从欧亚大陆中生代蛾类标本中发现了结构色的确切证据,破解了目前已知最早的昆虫真实颜色(约1.95亿年前),同时也提出蛾类翅膀鳞片结构最原始的类型。

  研究成果当天在线发表于美国《科学》(Science)杂志的子刊《科学进展》(ScienceAdvances)。

  专家介绍,昆虫是地球上物种数量最多的动物,展现了极其丰富的颜色。昆虫颜色分为色素色(化学色)和结构色;其中结构色是光照射在虫体表面的微观结构上产生折射、衍射及干扰而形成的。长期以来,学界对昆虫化石鳞片的光学结构知之甚少。

  近期,该所博士生张青青和博士后任笑吟在研究员王博和张海春指导下对英国、德国、哈萨克斯坦和中国的侏罗纪蛾类标本以及白垩纪缅甸琥珀中飘翅目昆虫进行了系统调查。团队成员利用光学显微镜、扫描电镜、透射电镜等技术,首次分析了这些化石中鳞片的微观结构和可能的结构色,为昆虫鳞片和颜色的演化提供了全新的观点。

  研究证据表明,侏罗纪早期(约1.95亿年前)的蛾类与现生小翅蛾非常类似,它们的翅膀鳞片已经具有较复杂的光学结构,可以产生银色或金黄色的结构色。这不仅是已知最早的昆虫真实颜色,也是最古老的昆虫结构色,并将该记录提前了至少1.3亿年。

  “先前经典的发育生物学理论认为,镂空型鳞片是最原始的状态,但本研究表明融合型鳞片才是最原始的类型,并且一型双层鳞片应为鳞翅目的基本构型特征。另外,昆虫的翅膀鳞片与羽毛的演化或许有一些共性。”王博称,先前的研究认为羽毛是鸟类的独有特征,但中国东北长毛恐龙化石表明羽毛也大量出现于非鸟类恐龙。与之类似,本研究表明具结构色的翅膀鳞片在鳞翅目出现之前就已经在一些原始类群广泛存在。

  本研究还证实了纳米级的光学结构可以保存在中生代的琥珀、压痕以及印模化石标本中,为复原远古动物和植物的结构色打开了新的窗口。(完)


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