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1、江蘇高中英語【科技說明文】真題匯編江蘇高中英語【科技說明文】真題匯編AIfadiversurfacestooquicklyhemaysufferthebends.Nitrogen(氮)dissolved(溶解)inhisbloodissuddenlyliberatedbythereductionofpressure.Theconsequenceifthebubbles(氣泡)accumulateinajointissharppainab
2、entbody—thusthename.Ifthebubblesfminhislungshisbraintheconsequencecanbedeath.Otherairbreathinganimalsalsosufferthisdecompression(減壓)sicknessiftheysurfacetoofast:whalesfexample.solongagodidichthyosaurs.Thattheseancientsea
3、animalsgotthebendscanbeseenfromtheirbones.Ifbubblesofnitrogenfminsidethebonetheycancutoffitsbloodsupply.Thiskillsthecellsintheboneconsequentlyweakensitsometimestothepointofcollapse.Fossil(化石)bonesthathavecavedinonthemsel
4、vesarethusasignthattheanimaloncehadthebends.BruceRothschildoftheUniversityofKansasknewallthiswhenhebeganastudyofichthyosaurbonestofindouthowwidespreadtheproblemwasinthepast.Whatheparticularlywantedtoinvestigatewashowicht
5、hyosaursadaptedtotheproblemofdecompressionoverthe150millionyears.Tothisendhehiscolleaguestraveledthewld’snaturalhistymuseumslookingathundredsofichthyosaursfromtheTriassicperiodfromthelaterJurassicCretaceousperiods.Whenhe
6、startedheassumedthatsignsofthebendswouldberarerinyoungerfossilsreflectingtheirgradualevolutionofmeasurestodealwithdecompression.Insteadhewasastonishedtodiscovertheopposite.Methan15%ofJurassicCretaceousichthyosaurshadsuff
7、eredthebendsbefetheydiedbutnotasingleTriassicspecimen(標本)showedevidenceofthatstofinjury.Ifichthyosaursdidevolveanantidecompressionmeanstheyclearlydidsoquickly—moststrangelytheylostitafterwards.ButthatisnotwhatDrRothschil
8、dthinkshappened.Hesuspectsitwasevolutioninotheranimalsthatcausedthechange.Whalesthatsufferthebendsoftendosobecausetheyhavesurfacedtoescapeapredat(捕食動物)suchasalargeshark.OneofthefeaturesofJurassicoceanswasanabundanceoflar
9、gesharkscrocodilesbothofwhichwerefondofichthyosaurlunches.Triassicoceansbytodate:shiningnearinfraredlight(NIR近紅外線)onthedruginthecapsule.Theideaofusinglighttoliberatethedruginthecapsuleisn’tnew.Researchersaroundtheglobeha
10、vedevelopedpolymers(聚合物)othermaterialsthatbegintobreakdownwhentheyabsbeitherultraviolet(UV紫外線)visiblelight.ButtissuesalsoreadilyabsbUVvisiblelightwhichmeansthedrugreleasecanbetriggeredonlyneartheskinwherethelightcanreach
11、thecapsule.NIRlightlargelypassesthroughtissuessoresearchershavetriedtouseitasatrigger.Butfewcompounds(化合物)absbNIRwellgothroughchemicalchanges.ThatchangedlastyearwhenAdahAlmutairiachemistattheUniversityofCalifniaSiegorept
12、edthatshehercolleagueshaddesignedapolymerthatbreaksdownwhenitabsbsNIRlight.TheirpolymerusedacommerciallyavailableNIRabsbinggroupcalledonitrobenzyl(ONB).WhentheycatchthelightONBgroupsfalloffthepolymerleadingtoitsbreakdown
13、.ButONBisonlyasosoNIRabsberitcouldbepoisonoustocellswhenitseparatesfromthepolymer.SoAlmutairihercolleaguesreptedcreatinganewmaterialfcapsulesthat’sevenbetter.Thisoneconsistsofalongchainofcompoundscalledcresolgroupslinked
14、inapolymer.Cresolcontainsreactive(易反應的)componentsthatmakeithighlyunstableinitspolymericfmafeatureAlmutairihercolleaguesusetotheiradvantage.Afterpolymerizingthecresolstheycapeachreactivecomponentwithalightabsbingcompoundc
15、alledBhc.WhentheBhcsabsbNIRlightthereactivegroupsareexposedbreakthelongpolymerintotwoshtchains.Shiningadditionallightcontinuesthisbreakdownpotentiallyreleasinganydrugsinthecapsule.What’smeAlmutairisaysBhcis10timesbettera
16、tabsbingNIRthanisONBisnotpoisonoustocells.63.AccdingtothepassagewhichofthefollowingcouldbethebesttriggerA.Temperaturechange.B.NIRlight.C.Aciditychange.D.UVlight.64.WhyisONBunsatisfactyA.ItbreaksdownwhenitabsbsNIRlight.B.
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