简介:Thispaperpresentstheprincipleofphasemodulationoftheopticalwave,thatisusingadensefringefamilytomodulateanotherfringepattern,anditsapplicationinfringemultiplication.Itisofuniversalsignificanceinopticallyexperimentalmechanics.
简介:在液相的质传上的Marangoni传送对流和它的影响被调查。Marangoni传送对流用激光Schlieren技术被设想。有序的多角形的传送对流模式和随机的界面的骚乱被观察。质传率上的效果ofMarangoni传送对流被使放出学习从在掉落的电影的水溶液的乙醇。试验性的结果证明那Marangoni传送对流能加快表面更新并且在液相提高质传率。液体传质系数能被差不多3褶层提高。相应实验关联以质传改进因素被给。在考虑Marangonieffect,而且,常规质传关联被修改。关联和试验性的数据预言的价值之间的差别在±8.2%以内,平均差别是4.2%。
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简介:Itisbelievedthathumanancestorsevolvedtheabilitytorunbipedallyapproximately2millionyearsago.Thisformoflocomotionmayhavebeenimportanttooursurvivalandlikelyhasinfluencedtheevolutionofourbodyform.Asourbodieshaveadaptedtorun,itseemsunusualthatupto79%ofmoderndayrunnersareinjuredannually.Theetiologyoftheseinjuriesisclearlymultifactorial.However,1aspectofrunningthathassignificantlychangedoverthepast50yearsisthefootwearweuse.Modernrunningshoeshavebecomeincreasinglycushionedandsupportive,andhavechangedthewaywerun.Inparticular,theyhavealteredourfootstrikepatternfromapredominantlyforefootstrike(FFS)landingtoapredominantlyrearfootstrike(RFS)landing.Thischangealtersthewayinwhichthebodyisloadedandmaybecontributingtothehighrateofinjuriesrunnersexperiencewhileengagedinanactivityforwhichtheywereadapted.Inthispaper,wewillexaminethebenefitsofbarefootrunning(typicallyanFFSpattern),andcomparethelowerextremitymechanicsbetweenFFSandRFS.Theimplicationsofthesemechanicaldifferences,intermsofinjury,willbediscussed.WewillthenprovideevidencetosupportourcontentionthatFFSprovidesanoptimalmechanicalenvironmentforspecificfootandanklestructures,suchastheheelpad,theplantarfascia,andtheAchillestendon.Theimportanceoffootwearwillthenbeaddressed,highlightingitsinteractionwithstrikepatternonmechanics.Thisanalysiswillunderscorewhyfootwearmatterswhenassessingmechanics.Finally,properpreparationandsafetransitiontoanFFSpatterninminimalshoeswillbeemphasized.Throughthediscussionofthecurrentliterature,wewilldevelopajustificationforreturningtorunninginthewayforwhichwewereadaptedtoreducerunning-relatedinjuries.