简介:回顾了Arrhenius理论的发展历程并简介了理论的基本内容。从食品品质损失的基本反应动力学出发,介绍Arrhenius理论在预测食品货架期、研究食品流变学特性及预测食品微生物学等方面的应用。
简介:TheresponsetosingleheattreatmentandStep-downheat(SDH)treatmentinvitroofV79andLcellswasstudied.Colony-formingabilitywasassayedinmediumaftertreatmentinvitro.Time-responsecurveswereestablishedandsubjectedtoArrheniusanalysis.TheArrheniuscurvesshowedinflectionpointsat43℃forV79cellsandat42℃forLcells.Theactivationenergieswere145kcal/moleand400kcal/moleaboveandbelow43℃(P<0.05),respectively,forV79cells,while160kcal/moleand300kcal/moleaboveandbelow42℃(P<0.05),respectively,forLcells.ThermosensitivityofLcellsaremarkedlyhigherthanV79cells.BothV79andLcellsweresensitizedbySDH.TheSDHeffectwascharacterizedbyareductioninshoulder(anadditioneffecttosublethaldamage),anincreaseinslope(thermosensitization),andthedelayanddisappearanceofthermotolerant"tail"forV79andLcellsat45℃to40℃and44℃to42℃SDHtreatmentrespectively.Particularly,42℃to39℃or42℃to40℃SDHforLc
简介:Thermalmaturationandpetroleumgenerationmodelingofshalesisessentialforsuccessfulexplorationandexploitationofconventionalandunconventionaloilandgasplays.Forbasinwideunconventionalresourceplayssuchmodeling,whenwellcalibratedwithdirectmaturitymeasurementsfromwells,cancharacterizeandlocateproductionsweetspotsforoil,wetgasanddrygas.Thetransformationofkerogentopetroleumisassociatedwithmanychemicalreactions,butmodelstypicallyfocusonfirst-orderreactionswithratesdeterminedbytheArrheniusEquation.AmisconceptionhasbeenperpetuatedformanyyearsthataccuratethermalmaturitymodelingofvitrinitereflectanceusingtheArrheniusEquationandasingleactivationenergy,toderiveatime-temperatureindex(∑TTIARR),asproposedbyWood(1988),isflawed.ThisclaimwasinitiallymadebySweeneyandBurnham(1990)inpromotingtheir'EasyRo'method,andrepeatedbyothers.Thispaperdemonstratesthroughdetailedmulti-dimensionalburialandthermalmodelinganddirectcomparisonofthe∑TTIARRand'EasyRo'methodsthatthisisnotthecase.The∑TTIARRmethodnotonlyprovidesaveryusefulandsensitivematurityindex,itcanreproducethecalculatedvitrinitereflectancevaluesderivedfrommodelsbasedonmultipleactivationenergies(e.g.,'EasyRo').Throughsimpleexpressionsthe∑TTIARRmethodcanalsoprovideoilandgastransformationfactorsthatcanbeflexiblyscaledandcalibratedtomatchtheoil,wetgasanddrygasgenerationwindows.Thisisachievedinamore-computationally-efficient,flexibleandtransparentwaybythe∑TTIARRmethodthanthe'EasyRo'method.Analysisindicatesthatthe'EasyRo'method,usingtwentyactivationenergiesandaconstantfrequencyfactor,generatesreactionratesandtransformationfactorsthatdonotrealisticallymodelobservedkerogenbehaviourandtransformationfactorsovergeologictimescales.
简介:在小学数学中,列方程解应用题与用算术方法解应用题是有密切联系的。它们都是以四则运算和常见的数量关系为基础,通过分析题里的数量关系,根据四则运算的意义列式解答的。但是,两种解答方法的解题思路却不同。由于数量关系的多样性和叙述方式的不同,用算术方法解答应用题,时常要用逆向思考,列式比较困难,解法的变化也比较多。用列方程的方法解答应用题,由于引进了字母表示未知数,可以使未知数直接参与运算,使题目中的数量关系更加清楚,把未知数当成已知数来用,使我们很容易理
简介:摘要:自古至今,人们对于宇宙的探索,前仆后继,不停脚步,不知耗费了多少人的心血,陨损了多少人的躯体?至今仍然迷途奔波、孜孜不倦。为了益于芸芸,此处对宇宙作一数学描述,建立一方程,以期有所依也、有所范也。虽是贻笑天下,愚亦乐乎。何以自诮自娱?——凡人之心、莫不如是,螃蟹首食、以为责也。
简介:摘 要 : 《极坐标与参数方程》是全国卷高考选考的重要内容,大部分学校都选这部分内容,而且《极坐标与参数方程》对必修中的圆锥曲线解题有很大的帮助。 极坐标方程和参数方程的综合问题一直是高考命题的热点,主要考查等价转换思想,代数式变形能力,逻辑思维推理能力,本文主要介绍的是将参数方程转化普通方程的高考常用的四种方法。