简介：本文根据在常见的物化教材中半衰期的通式和用半衰期确定反应级数的方法的知识,推导出其它反应时间的通式和用其它反应时间与浓度的关系确定反应级数的方法.

简介：Theextractivereactionprocessofoxygen-workingsolution-waterthree-phasesystemfortheproductionofhydrogenperoxidebytheanthraquinonemethodwasinvestigatedinasieveplatecolumnof50mmininternaldiameter.Theoxidationreactionofanthrahydroquinoneintheworkingsolutionwithoxygenandtheextractionofhydrogenperoxidefromtheworkingsolutionintoaqueousphaseoccurredsimultaneouslyinthecountercurrentmode.Theagitatingeffectcausedbygaseousphasemadethedropletsofthedispersedphasebecomesmaller,thus,increasingtheliquid-liquidinterfacialcontactareasandresultingintheimprovementofthemasstransfervelocity.Resultsshowedthatthegas-agitationhadabeneficialeffectontheextractionofhydrogenperoxidefromtheworkingsolutionintotheaqueousphase;theconcentrationofhydrogenperoxideintheraffinatedecreasedwiththeincreaseofthegaseoussuperficialvelocities;andtheconcentrationofH2O2intheraffinateincreasedwiththeincreaseofthedispersedphasesuperficialvelocityatthesamesuperficialvelocityofthegaseousphase.IntheG-L-Lextractivereactionprocess,withtheincreaseofthegaseoussuperficialvelocities,boththeconversionoftheanthrahydroquinoneoxidationandtheextractionefficiencyofhydrogenperoxidefirstincreasedsignificantly,thenincreasedgradually.

简介：Backgound:Barefoot(BF)runninghasrecentlyincreasedinpopularitywithclaimsthatitismorenaturalandmayresultinfewerinjuriesduetoareductioninimpactloading.However,noviceBFrunnersdonotnecessarilyimmediatelyswitchtoaforefootstrikepattern.Thismayincreasemechanicalparameterssuchasloadingrate,whichhasheenassociatedwithcertainrunning-relatedinjuries,specifically,tibialstressfractures.patellofemoralpain,andplantariasciitis.ThepurposeofthisstudywastoexaminechangesinloadingparametersbetweentypicalshodrunningandinstructedBFrunningwithreal-timeforcefeedback.Methods:Forty-ninepatientsseekingtreatmentforalowerextremityinjuryranonaforce-sensingtreadmillintheirtypicalshodconditionandthenBFatthesamespeed.WhileBFtheyreceivedverbalinstructionandreal-timefeedbackofverticalgroundreactionforces.Results:While92%ofsubjects(n=45)demonstratedarearfootstrikepatternwhenshod,only2%(n=1)didduringtheinstructedBFrun.Additionally,whileBF47%(n=23)eliminatedtheverticalimpacttransientinalleightstepsanalyzed.AllloadingvariablesofinterestweresignificantlyreducedfromtheshodtoinstructedBFcondition.Theseincludedmaximuminstantaneousandaverageverticalloadingratesofthegroundreactionforce(p<0.0001),stiffnessduringinitialloading(p<0.0001).andpeakmedial(p=0.001)andlateral(p<0.0001)groundreactionforcesandimpulsesinthevertical(p<0.0001).medial(p=0.047),andlateral(p<0.0001)directions.Conclusion:Asimpactloadinghasbeenassociatedwithcertainrunning-relatedinjuries,instructionandfeedbackontheproperforefootstrikepatternmayhelpreducetheinjuryriskassociatedwithtransitioningtoBFrunning.

简介：dichloro-methoxybenzenes的合成和动力学在353383K的一个温度范围从1,2,4-trichlorobenzene和钠甲氧化物被学习。反应物，溶剂和反应温度的臼齿的比率的效果被调查。反应产品包括三异构体。为三异构体的选择的顺序是1,4-dichloro-2-methoxybenzene>>2,4-dichloro-1-methoxybenzene>1,2-dichloro-4-methoxybenzene。为在1,2,4-trichlorobenzene和钠甲氧化物之间的平行液体固体接口反应的运动方程当催化剂不在时被建立。象pre指数的因素和激活精力那样的运动参数与Arrhenius方程被决定。

简介：ActiveFe-andMn-loadedMCM-41(Fe–Mn/MCM-41),whichwassynthesizedviaahydrothermalreactionfollowedbyimpregnation,isusedintheheterogeneousFentonreactiontodegrademethylorange(MO)inaqueoussolution.ThesynthesizedsampleswerecharacterizedbyX-raydiffraction,scanningelectronmicroscopy,transmissionelectronmicroscopy,N2adsorption–desorptionisothermanalysis,Fouriertransforminfraredspectroscopy,andX-rayphotoelectronspectroscopy.ComparedwithFe/MCM-41andMn/MCM-41,Fe–Mn/MCM-41showedhigheractivityforMOdegradationandmineralization.Effectsofvariousoperatingparameters,suchaspH,Mncontent,andH2O2dosage,onthedegradationprocessweresubsequentlyinvestigated.ResultsofexperimentsontheeffectofradicalscavengersrevealedthatthedegradationofMOcouldbeattributedtooxidationbyHO·.ThesynergyofFeandMnspeciesintheFentonoxidationprocesswasalsoexplained.

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