中英文摘要格式

平頂山學(xué)院2010屆本科生畢業(yè)論文HPGe譜儀系統(tǒng)死時(shí)間校正方法的實(shí)驗(yàn)研究王某某注意標(biāo)題上邊有一空行四號(hào)黑體，加粗，居中，段前0行，段后1行。小二號(hào)黑體，加粗，居中，段前1.5行，段后注意標(biāo)題上邊有一空行四號(hào)黑體，加粗，居中，段前0行，段后1行。小二號(hào)黑體，加粗，居中，段前1.5行，段后1.5行。小五號(hào)宋體/TimesNewRoman摘要小四號(hào)宋體/TimesNewRoman，1.5倍行距。給出了HPGe小四號(hào)宋體/TimesNewRoman，1.5倍行距。關(guān)鍵詞：HPGe譜儀，死時(shí)間，校正因子小四號(hào)黑小四號(hào)黑體，加粗小四號(hào)宋體/TimesNewRomanExperimentalstudyonthemethodofdeadtime小三號(hào)字，ArialBlack，居中，段前1小三號(hào)字，ArialBlack，居中，段前1.5行，段后1.5行。標(biāo)題兩行間距30磅四號(hào)字，ArialBlack，居中，段前0行，段后1行。Abstract小四號(hào)字，TimesNewRoman，1.5倍行距（如果內(nèi)容較多可適當(dāng)減速小行距，以美觀為標(biāo)準(zhǔn)）ApracticalmethodofdeadtimecorrectionforHPGespectrometersystemwasgiven.TherelationbetweenthepercentdeadtimeandthecorrectionofcountingratelossesforHPGespectrometersystemwasfoundbyusingastrongsource.Therefore,小四號(hào)字，TimesNewRoman，1.5倍行距（如果內(nèi)容較多可適當(dāng)減速小行距，以美觀為標(biāo)準(zhǔn)）KeyWords：HPGespectrometer,Deadtime,Coefficientofcorrection英文狀態(tài)下的逗號(hào)，且后有一空格小四號(hào)字，TimesNewRoman英文狀態(tài)下的逗號(hào)，且后有一空格小四號(hào)字，TimesNewRoman小四號(hào)字，ArialBlack注意：如果摘要內(nèi)容較多，一頁(yè)排不下，則中文摘要（含關(guān)鍵詞）單獨(dú)占一頁(yè)，英文摘要（含關(guān)鍵詞）單獨(dú)占一頁(yè)。如下所示：

α-取代甲苯定向硝化的理論研究摘要運(yùn)用密度泛函理論(DFT),研究了吸電子氟基和供電子羥基在取代甲苯的α-H以后,其鄰、間、對(duì)各位次進(jìn)行硝化反應(yīng)的速控步驟,在B3LYP/6-311G**水平上,計(jì)算了該速控步驟基元反應(yīng)各反應(yīng)駐點(diǎn)(反應(yīng)物、過(guò)渡態(tài)和中間體)的優(yōu)化幾何、電子結(jié)構(gòu)和能量性質(zhì),并首次給出了目標(biāo)硝化反應(yīng)速控步驟的IR譜學(xué)的動(dòng)態(tài)特征及解析,從微觀層面上驗(yàn)證了反應(yīng)坐標(biāo)C—N的形成和C—H的斷裂是非協(xié)同的,從而無(wú)一級(jí)動(dòng)力學(xué)同位素效應(yīng)的實(shí)驗(yàn)事實(shí).通過(guò)對(duì)目標(biāo)硝化反應(yīng)速控步驟的微觀動(dòng)態(tài)計(jì)算,驗(yàn)證了氟基對(duì)甲基定位的影響.氟基的電負(fù)性大,吸電子能力強(qiáng),取代甲苯的α-H以后對(duì)硝酰陽(yáng)離子的進(jìn)攻有抑制作用,活化能較取代前高,但比較芐基氟各位次硝化活化能的相對(duì)大小得知,－CH2F仍為鄰、對(duì)位定向基團(tuán).而供電子羥基取代甲苯的α-H以后,則對(duì)硝酰陽(yáng)離子的進(jìn)攻有促進(jìn)作用,因而各反應(yīng)駐點(diǎn)絡(luò)合物的穩(wěn)定化能較α-H取代前甲苯的有所增大,且鄰、對(duì)位硝化的活化能較間位低,故－CH2OH為鄰、對(duì)位定位基.但對(duì)位因硝化活化能低,反應(yīng)放熱多,空間位阻小,為親電試劑NO＋最有利的進(jìn)攻位；而鄰位則因羥基取代甲苯α-H后多了2一個(gè)氧原子,增大了鄰位進(jìn)攻的空間位阻,使得其絡(luò)合物的能量比相應(yīng)對(duì)位的高.關(guān)鍵詞：芐基氟，芐醇，α-取代，取代基效應(yīng)，速控步驟

TheoreticalStudyonSelectivityforNitrationofα-SubstitutedToluenewithNitroniumAbstractTherate-determiningstepsofisomericortho,metaandparanitrationsofbenzylalcoholandbenzylfluoridehavebeentheoreticallyinvestigatedatB3LYP/6-311G**level.Stationarypointsofthestepinvolvingreactant,transitionstateandintermediatecomplexesweresuccessfullylocatedandcharacterizedwithoutanyrestrictionontheinternalcoordinates.Theirmoleculargeometries,electronicstructures,IRspectra,andtheFMOsymmetriesoftwoinitialaromaticcompoundsandthenitroniumionhavebeenstudied.ThevibrationalshiftsofC—NandC—HstretchesfromTStoINTattherate-determiningstepoftargetaromaticnitrationsshowupthattheformationofC—NandthecleavageofC—Harenotcon-cernedbutstepwisetoprovideanexplanation,onamicroscopicscale,fortheexperimentalfactoftheabsenceofkineticisotopiceffectinthenitrationprocessforthefirsttime.Also,theinfluenceofintroducedfluorineontheorientationeffectwasfiguredbycalculatingthemicroscopicandkineticpropertiesoftherate-determiningstepofconcernedaromaticnitrations.Theattacktothebenzylfluoridewasdeactivatedbecauseofhighelectronegativityandstrongelectronwithdrawaloffluorineatom.Theactivationenergyafterα-substitutionofmethylgroupbyafluorineatombecamehigher.YettheCH2Fgroupwasstillanortho-paradirective,sincetheactivationenergiesoforthoandparanitrationswererelativelylowerthanthatofmetanitration.Contrarily,theintroductionofelectron-donatingsubstituentOHontothemethylacceleratedtheattack.Consequentlythestabilizationenergiesofcomplexesweredropedevenlowerthanbeforetheα-substitutionoccurred.Theactivationenergiesoforthoandparanitrations,however,werealsoquitelowerthantheenergyofmetanitration.Therefore,theCH2OHisanortho-paradirectinggroup.Comparedtotheortho,theparapositionisthemostfavorableduetothetoapproach,foritslowsterichindranceeffectandhighexothermicity.Attackatortho,however,becameevenmorecrowdsinceonemoreOatomhasbeenintroducedaftertheα-substitutionontothemethylgroup.Hence,thee