简介:为了解决M/M/c模型在实际运用中模拟精度不高及使用范围有限的问题,本文立足系统状态变化与输入率和服务率的关系,通过引入输入概率和服务度,构建依赖系统状态的递进式输入率和服务率。递进式输入率和服务率通过研究系统实际运行状况设定临界值,其中输入率分为两阶段,服务率分为三阶段。此外,结合递进式输入率和服务率及排队论状态转移过程构建了递进式M/M/c模型,并采用后确定法确定模型参数。递进式M/M/c模型是M/M/c模型的扩展形式,提高了M/M/e模型的模拟精度,在一定程度上拓展了模型的应用范围。最后,通过一个生活实例验证了递进式M/M/c模型的优化性和实用性。
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简介:BackgroundTaxifolin(Tax)isanessentialnaturalantioxidant.MultiplestudieshaveshownthatTaxcanprotectcardiomyocytesfromischemia-reperfusioninjury.However,theunderlyingmechanismisstillunclear.MethodsH9C2cellswererandomlydividedintocontrol,H_2O_2group,Taxpretreatmentgroup(Tax+H_2O_2);Taxeffectgroup.CellactivitywasdetectedbyCCK-8andtheintracellularstructurewasobservedbytransmissionelectronmicroscopy.AutophagywasdeterminebyWesternblottinganalysisofBeclin-1,Bcl-2andPKC.ResultsTaxpretreatmentsignificantlyincreasedanti-apoptoticproteinBcl-2andautophagyproteinBeclin-1.ExpressionofPKCwasinhibitedbyTax.ConclusionsTaxpretreatmentcouldprotectH9C2cellsagainstH_2O_2-induceddamagethroughtheBcl-2andautophagypathways.
简介:Asanodematerialsforlithium-ionbatteries,SiO_2isofgreatinterestbecauseofitshighcapacity,lowcostandenvironmentalaffinity.AfacileapproachhasbeendevelopedtofabricateSiO_2@Chollowspheresbyhydrolysisoftetraethylorthosilicate(TEOS)toformSiO_2shellsonorganicspheretemplatesfollowedbycalcinationsinairtoremovethetemplates,andthentheSiO_2shellsarecoveredbycarbonlayers.ElectronmicroscopyinvestigationsconfirmhollowstructureoftheSiO_2@C.TheSiO_2@ChollowsphereswithdifferentSiO_2contentsdisplaygradualincreaseinspecificcapacitywithdischarge/chargecycling,amongwhichtheSiO_2@CwithSiO_2contentof67wt%exhibitsdischarge/chargecapacitiesof653.4/649.6mAhg~(-1)over160cyclesatcurrentdensityof0.11mAcm~(-2).TheimpedancefittingoftheelectrochemicalimpedancespectroscopyshowsthattheSiO_2@CwithSiO_2contentof67wt%hasthelowestchargetransferresistance,whichindicatesthattheSiO_2@Chollowspheresispromisinganodecandidateforlithium-ionbatteries.
简介:Two-dimensional(2D)graphitecarbonnitride(g-C3N4)nanosheetshavebeensuccessfullyusedasasaturableabsorber(SA)inapassivelyQ-switchedNd:LLFlaserat1.3μmforthefirsttime,tothebestofourknowledge.Underanincidentpumppowerof9.97W,theshortestpulsedurationof275nswasacquiredwithoutputpowerof0.96Wandpulserepetitionrateof154kHz,resultinginapulseenergyof6.2μJ.Inaddition,thesaturableabsorptionbehaviorsofzero-dimensional12nmg-C3N4nanoparticles(g-C3N4-NPs)andthree-dimensionalorderedmesoporousg-C3N4(mpg-C3N4)werealsoobserved,althoughtheirmorphologyandstructurewerequitedifferentfrom2Dg-C3N4.Theexperimentalresultsintroducethepotentialapplicationofg-C3N4nanomaterialsasSAsinQ-switchedlasers.