SCIEI学术论文写作与发表攻略 课件 第二章 前言撰写

第二章

前言撰写目录CONTENTS一通用模板五本文工作模板句二研究重要性模板句六经典范文分析三文献综述模板句四存在问题模板句七实例练习学术论文写作与发表攻略由浅入深、由宽到窄将读者带到论文中讲清楚为什么要开展此项研究、撰写该论文包括背景介绍、文献综述、本文工作三个部分前言撰写学术论文写作与发表攻略背景介绍：研究重要性扫盲信息：研究相关基础知识、基本概念共性问题：当前业内研究热点文献综述：文献综述：建议写成总分结构存在问题：指出当前研究存在的具体问题或空白本文工作：告诉读者本文的主要研究内容让读者把思路集中到要讨论的问题上来通用模板学术论文写作与发表攻略备受关注：....hasgeneratedconsiderablerecentresearchinterest.....hasattracted(received)muchattention.是一个主题或问题：...hasbeenthesubjectofnumerousstudies......isabasicsubjectinregardto...时间表达：Inrecentyears,...重要作用或泛应用：...playanimportant(key)roleinthedevelopmentof......playamajorpartinthedevelopmentof...研究重要性模板句学术论文写作与发表攻略开展研究/试验：...carriedout(performed/undertook/conducted)theexperiment(research/analysis).研究表明：Theyclaimed(stated/reported/concluded/presented/found)that...研究...：...explored(investigated/studied)examined...经典例句：AnoverviewofworkinthisareacanbefoundinRefs.[1,2]....isreportedinLeon(1971).Itisevident,fromliteraturesurvey,Ref.[1],that...文献综述模板句学术论文写作与发表攻略提出一种新方法、新方向：However,littleinformation(littleresearch……)(orfewstudies)(orno)has(have)beendoneon(focusedon/studied(withrespectto))与别人研究类似：However,dataisstillscarce(rare),weneedto(aimto)providemoredocuments(data).Furtherstudiesarestillnecessary(essential)…经典例句：However,testresultsonthissubjectarescarce,andthisisespeciallytruefor

thecaseofelastic-plasticbuckling.ThereremainsaneedforanefficientmethodthatcanHowever,theexperimentalconfigurationwasfarfromoptimal.存在问题模板句学术论文写作与发表攻略第一句表达：hiscurrent(present)paper(work/study)reportson(concentrateon/examine/provide)...其它语句表达：Furthermore(Moreover,Inaddition),wewillalsodiscuss…...ispresentedindetail经典例句：Thecurrentpaperexaminestheloadcarryingcapacityof

bowedoutsteelshellssubjectedtostaticexternalpressure.Thepaperaimstodemonstratethat

...Thispaperfocuseson...本文工作模板句学术论文写作与发表攻略深海球形耐压壳力学特性研究0引言根据《中国制造2025》文件，国家将大力推动海洋工程装备突破发展。深海潜水器是大洋勘查与深海科学研究的重要海洋工程装备。（研究重要性）在下潜过程中，潜水器的耐压壳起着保障内部设备正常工作和人员健康安全的作用，其重量占潜水器总重的1/4～1/2。（扫盲信息）现有的球形耐压壳的设计与分析基于薄壳理论，且已被各国船级社规范认同（主题句，承上启下）。潘彬彬等对现有深水球形耐压壳的设计规范进行了对比和分析，指出规范计算中存在的缺陷。然后通过原型试验和非线性有限元分析，建立了预测深海钛合金球形壳极限强度的经验公式。马永前等参考中厚板壳稳定性理论，研究厚球壳的屈曲问题，指出：由于厚度方向的剪切效应，厚球壳的实际临界屈曲载荷低于薄壳理论（Zolley公式）的结果。王自力、刘涛等的研究表明，随着水深增加，对于耐压壳经典范文分析学术论文写作与发表攻略的分析将从薄壳问题转化为中厚壳问题，然而现有的潜水器规范不适用于深海耐压壳分析，应直接根据有限元计算确定其极限强度。（文献综述）在有限元建模过程中，模型简化、单元类型、网格密度、网格划分形式、边界条件、求解方法等对球形壳计算结果的影响很大，不同人员对同一问题的计算结果存在差异，数值解的可信度有待商榷。（存在问题）本文从理论分析和数值计算这两方面研究球形耐压壳的强度、稳定性、储备浮力等性能。（本文工作，主题句）在1～6km水深条件下，分别按薄壳模型和厚壳模型，分析和对比壳体的强度和稳定性。建立球形耐压壳的壳单元和体单元数值模型，研究单元类型、网格密度对耐压壳强度和稳定性的影响。（本文工作，具体信息）经典范文分析学术论文写作与发表攻略Bucklingofsphericalshellssubjectedtoexternalpressure:Acomparisonofexperimentalandtheoreticaldata1.IntroductionFormorethan100years,researchhasbeenpublishedonsphericalshellssubjectedtouniformexternalpressure.（研究重要性）Knowledgeaboutthistypeofloadinghasbeenwidelyappliedinvariousengineeringfieldssuchasthoseinvolvingunderwaterpressurehulls,undergroundpressurevessels,andunderpressuretanks.Inparticular,thesphericalconfigurationisbroadlyconsideredanidealstructureforthepressurehullsofdeepsubmersibles.Thisisduetotheextremelyefficientstressandstraindistributionsinthematerial.（扫盲信息）Althoughthetheoreticalelasticbucklingloadsarehigh,thesphericalshellshavebeenfoundtobehighlyimperfectionsensitiveandbestronglyaffectedbyplasticmaterialproperties.Theexperimentalbucklingloadsareevenlowerthanthetheoreticalones.（共性问题）经典范文分析学术论文写作与发表攻略Thedifferencebetweentheoryandexperimenthaspromptednumerousstudiesregardingthebucklingofsphericalshellsloadedbyexternalpressure.（主题句，承上启下）Forexample,Blachutetal.presentedaseriesofexperimentalandnumericalstudiesconcerningelastic-plasticbucklingofspherical,torispherical,conicalorbarreledshellsunderexternalpressure.Inmostoftheirstudies,thematerialwasassumedtobeelastic-perfectlyplastic.Theeffectsofinitialgeometricimperfectionswerealsotakenintoaccount,whichincludedeigenmodeimperfectionsderivedfromlinearelasticbucklinganalysisoftheperfectgeometriesordeterministiconesderivedfromalimitednumberofmeasuringpoints.Moreover,Panetal.performedasetofexperimentalandnumericalstudiesontheultimatestrengthlevelsofsphericalpressurehullsusedindeepsubmersibles.Theirnumericalmodelswereelaboratedonthebasisofinitialequivalentgeometricimperfectionsintheshapeofthefirsteigenmodeandalocaldimple.Theirnumericalpredictions经典范文分析学术论文写作与发表攻略wereverifiedbypressurizingfourlaboratoryscalesphericalhullstocollapse.Morerecently,Quillietcarriedoutelasticitytheorycalculationstopredictthecollapsemodeofasphericalshell.Quillet’spredictionresembledpreviouslypublishedexperimentalresults.（文献综述）However,littleattentionhasbeenpaidtotruegeometry,includingdeterministicimperfections,derivedfromamoreprecisemeasurement.Andtheeffectsofplasticmaterialpropertiesincludingorexcludingyieldstrengthsandhardeningparametersonthebucklingofsphericalshellswererarelyinvestigatedaswell.Furtherstudyisstillnecessaryinthisbranchofmechanics.（存在问题）Forinvestigatingthebucklingofsphericalshellsloadedwithexternalpressure,（本文工作，主题句）sphericalshellsweremanufacturedfrom304stainlesssteelsheetsthroughstampingandbutt-weldingprocesses.Thegeometriesandthicknessesoftheseshellswereobtainedusingahighlyaccuratethree-dimensionalopticalscannerandanultrasonicprobe,respectively.Andtheir经典范文分析学术论文写作与发表攻略bucklingpropertieswerealsodemonstratedbyaseriesofhydrostatictests.Thebucklingandpostbucklingbehaviorsoftheseshellswerethendeterminednumericallyandverifiedexperimentally.Thenumericalanalysiswasbasedondeterministicimperfectionsobtainedfrommeasuredgeometricshapesandelastic-plasticmodelingoftruestress-straincurves.Furthermore,theeffectsofconstitutivemodels,suchaspurelyelasticandelastic-perfectlyplasticmodelingofmaterial,onthebucklingloadswerestudiednumerically.（本文工作，具体信息）Thispaperaimstoprovidearationalapproachtopredictingtherealload-carryingcapacitiesofsphericalshells.（论文主要发现、或研究意义）经典范文分析学术论文写作与发表攻略硬土-软土插桩过程数值分析及验证0引言当在硬土-软土结构的海底安装自升式钻井平台时，若某个桩靴突然发生无法控制的穿透，将导致桩腿屈曲、平台退役，甚至导致平台倾倒，这种灾难性的事故称为“刺穿”。为了避免发生“刺穿”事故，需要研究平台的插桩性能，包括插桩过程中桩靴周围土壤的流动特性、桩靴承载力（即插桩阻力）与插桩深度的关系、桩靴底部压力分布规律等。插桩过程中桩靴和土壤间的固定度决定了桩腿、固桩架和船体在作业和自存工况下的力学响应特性；插桩深度的大小决定了桩腿的设计总长；可靠的桩靴承载力设计是保证平台安全工作、避免发生“刺穿”事故的重要保障；桩靴底部压力分布规律不仅是桩靴强度校核的关键，也是对桩靴周围土壤剪切失效和“刺穿”失效进行分析的重要信息。实例练习学术论文写作与发表攻略

近年来，数值方法逐渐成为研究平台插桩性能的重要工具，小应变有限元法（SSFE）和大位移有限元法（LDFE）被广泛用于研究自升式平台插桩性能。但上述两种方法的运用需要丰富的工程经验，求解结果严重依赖网格划分和参数设置，且在研究深插桩过程时计算效率低、收敛困难。HossainMS利用土工欧拉-拉格朗日耦合法（CEL）非常适合求解经典有限元法不能求解的大变形土工问题，ThoKK等首次运用CEL法进行了插桩过程数值模拟，QiuG等通过试验法、数值分析LDFE法和解析法验证了CEL法的有效性。离心模型试验模拟了直径为6m的桩靴在硬土-软土中的插桩过程[10]，本文基于HossainMS的土工离心模型试验，采用CEL法建立插桩过程的数值模型，并利用HossainMS的试验结果对数值模型进行验证，然后根据数值计算结果分析插桩过程中土壤的流动特性以及插桩深度与插桩阻力的关系，并首次对桩靴底部压力分布规律进行研究。实例练习学术论文写作与发表攻略Bucklingofegg-shapedshellssubjectedtoexternalpressure1.IntroductionShellsofrevolutionhavereceivedconsiderableattentionforapplicationssuchasunderwaterpressurehulls,spacevehicles,pressurevessels,andpressuretanks.Themostfrequentlyinvestigatedstructuresarecylindrical,conical,andsphericalshellsandtheircombinations.Non-typicalshapessuchasellipsoidal,parabolical,andhyperboloidalshellshavealsobeenstudied.However,suchshellstendtolosestabilitywhensubjectedtoexternalpressure.AneffectivemeansforincreasingtheloadcarryingcapacityofshellsistheincorporationofashellofrevolutionthathasapositiveGaussiancurvature.Forexample,asphericalshelliswidelyacceptedtobeanidealsolutionbecauseoftheextremelyefficientstressandstraindistributionsinthematerial.However,ithasbeenfoundtobehighlyimperfectionsensitive;moreover,thesphericalconfigurationrendersthehousingofequipmentorhumanbeingsdifficult.

实例练习学术论文写作与发表攻略Asubstantialquantityofresearchhasfocusedonshellsofrevolutionwithnon-typicalmeridionalconfigurations.Thebarreledshellisanaptexamplethatcombinestheadvantagesofsphericalandcylindricalshells.Itisacylindricalshellthathasameridionalcurvature.Thebucklingofbarreledshellshasbeeninvestigatedinrecentyears.JasionandMagnucki,forinstance,proposedasetofbarreledshellswiththeCassinioval,clothoidalspherical,andcirculararcmeridians.Theyprovidedbucklingresultsfortheseshellsthatwereobtainedusinganalyticalornumericalmethods.Furthermore,Blachutdetailedtheresultsofthenumericalandexperimentalstudyintothebucklingbehaviorofbarreledshellsthathavemeridiansintheformofcirculararcsandgeneralizedellipses.Closeagreementbetweenthenumericalpredictionsandtheexperimentaldatawasobtained.Theeggshellisadesirableconfigurationforsupportinguniformpressurebymembraneaction.Ithasadvantagessuchasanexcellentloadcapacity,weight-to-实例练习学术论文写作与发表攻略strengthratio,span-to-thicknessratio,anda