中英文摘要格式

1、HPGe 丫谱仪系统死时间校正方法的实验研究四号黑体，加粗，居中，段前0、行，段后1行。摘要给出了HPGe谱仪系统死时间校正的一种实用方法。用强源干扰找到了HPGe飞谱仪系统百分死时间与计数率丢失校正因子的关系，使该系统允许计数率大大提高,ExperimentalstudyonthemethodofdeadtimecorrectionForHPGespectrometersystem小三号字，ArialBlack,居中，段前1.5行，段后1.5行。标题两行间距30磅ApracticalmethodofdeadtimecorrectionforHPGespectrometersystemwasg

2、iven.TherelationbetweenthepercentdeadtimeandthecorrectionofcountingratelossesforHPGespectrometersystemwasfoundbyusingastrongsource.Therefore,theactivitymeasurementcanbefinishedatveryhighcount注意：如果摘要内容较多，一页排不下，则中文摘要（含关键词）单独占一页，英文摘要（含关键词）单独占一页。如下所示：平顶从而解决了放射性定量测量中的一些困难。关键词：HPGe珊仪，死时间，校正因子小四号黑体，加粗小四方木体

3、/TimesNewRoman小四号宋体/TimesNewRoman,1.5倍行品巨。小二号黑体，加粗，居中，I段前1.5行,段后1.5行JAbstractrate,withthisspectrometer.TimesNewRoman,1.5KeyWords:HPGespectrometer,Deadtime,小四号字，ArialBlack小四号字，Times、NewRoman四号字，ArialBlack，居中,段前0行，段后1行。小四方子,英文状态下的逗号，且后有一空格倍行距（如果内容较多可适当减速小行距，以美观为标准）oefficientofcorrectiona-取代甲苯定向硝化的理论研究

4、摘要运用密度泛函理论(DFT),研究了吸电子氟基和供电子羟基在取代甲苯的a-H以后，其邻、间、对各位次进行硝化反应的速控步骤,在B3LYP/6-311G*水平上，计算了该速控步骤基元反应各反应驻点(反应物、过渡态和中间体)的优化几何、电子结构和能量性质，并首次给出了目标硝化反应速控步骤的IR谱学的动态特征及解析，从微观层面上验证了反应坐标CN的形成和CH的断裂是非协同的，从而无一级动力学同位素效应的实验事实.通过对目标硝化反应速控步骤的微观动态计算，验证了氟基对甲基定位的影响.氟基的电负性大，吸电子能力强，取代甲苯的为H以后对硝酰阳离子的进攻有抑制作用，活化能较取代前高，但比较甲基氟各位次硝化

5、活化能的相对大小得知，一CH2F仍为邻、对位定向基团.而供电子羟基取代甲苯的a-H以后，则对硝酰阳离子的进攻有促进作用，因而各反应驻点络合物的稳定化能较a-H取代前甲苯的有所增大，且邻、对位硝化的活化能较间位低，故CH20H为邻、对位定位基.但对位因硝化活化能低，反应放热多，空间位阻小，为亲电试剂NO+最有利的进攻位；而邻位则因羟基取代甲苯mH后多了2一个氧原子，增大了邻位进攻的空间位阻，使得其络合物的能量比相应对位的高.关键词：苇基氟，甲醇，e 取代，取代基效应，速控步骤TheoreticalStudyonSelectivityforNitrationofa-SubstitutedTolue

6、newithNitroniumAbstractTherate-determiningstepsofisomericortho,metaandparanitrationsofbenzylalcoholandbenzylfluoridehavebeentheoreticallyinvestigatedatB3LYP/6-311G*level.Stationarypointsofthestepinvolvingreactant,transitionstateandintermediatecomplexesweresuccessfullylocatedandcharacterizedwithoutan

7、yrestrictionontheinternalcoordinates.Theirmoleculargeometries,electronicstructures,IRspectra,andtheFMOsymmetriesoftwoinitialaromaticcompoundsandthenitroniumionNO2havebeenstudied.ThevibrationalshiftsofCNandCHstretchesfromTStoINTattherate-determiningstepoftargetaromaticnitrationsshowupthattheformation

8、ofC-NandthecleavageofCHarenotcon-cernedbutstepwisetoprovideanexplanation,onamicroscopicscale,fortheexperimentalfactoftheabsenceofkineticisotopiceffectinthenitrationprocessforthefirsttime.Also,theinfluenceofintroducedfluorineontheorientationeffectwasfiguredbycalculatingthemicroscopicandkineticpropert

9、iesoftherate-determiningstepofconcernedaromaticnitrations.TheNO2attacktothebenzylfluoridewasdeactivatedbecauseofhighelectronegativityandstrongelectronwithdrawaloffluorineatom.Theactivationenergyafter-substitutionofmethylgroupbyafluorineatombecamehigher.YettheCH2Fgroupwasstillanortho-paradirective,si

10、ncetheactivationenergiesoforthoandparanitrationswererelativelylowerthanthatofmetanitration.Contrarily,theintroductionofelectron-donatingsubstituentOHontothemethylacceleratedtheNO2attack.Consequentlythestabilizationenergiesofcomplexesweredropedevenlowerthanbeforetheo-substitutionoccurred.Theactivatio

11、nenergiesoforthoandparanitrations,however,werealsoquitelowerthantheenergyofmetanitration.Therefore,theCH20Hisanortho-paradirectinggroup.Comparedtotheortho,theparapositionisthemostfavorableduetotheNO2toapproach,foritslowsterichindranceeffectandhighexothermicity.Attackatortho,however,becameevenmorecrowdsinceonemoreOatomhasbeenintroducedaftertheo-substitutionontothemeth