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415 个结果
  • 简介:本期,我们将学习一些有关提前预约方面的语句,如预订餐厅座位,旅馆房间、机票、演唱会门票等。另外,还会学习到几个相关的俚语词汇。(更多说法请听光盘中的讲解!)

  • 标签: 俚语 词汇 大学英语 跨文化交际 礼仪知识 英汉对照
  • 简介:Inthispaperalumpedparametermodelofatwo-passgas-to-gascrossflowheatexchangerwithhighspeedairflowhasbeenpresentedfortheinvestigationofitstransientbehaviours.Theeffectsofboththechangesofinlettemperatureandflowrateonoutlettemperaturecanbepredictedwiththismodel.Thecalcuationresultsundertypicalconditionsarecomparedwithexperimentalresultsandgoodagreementsareobtained.

  • 标签: 热交换器 集中参数 瞬变现象
  • 简介:Amajorenergyconservationandretrofittingproject—ap-plicationofnaturalgasassupplementaryfuelforsteamcrackershasbeensuccessfullyputintooperationstartingApril30,2008attheSINOPECYangziPetrochemicalCompany.Foralongtimethesteamcrackersintheoldandnewplant-sitesattheYangziPetrochemicalCo.usedtoconsumemeth-

  • 标签: 石油化工产品 石油化工行业 公司 业务
  • 简介:Thebasinsbcaring0ilandgasinChinab1ongt0mu1titudinousmassifbasinswliichevo1vcdandformcdduringdiwaperiodf0llowingtheplatf0rmdisintegration.Nomatterint0whatstageintect0nicev0lutiondidabasindeve10p,thccrust0bodycharactcr0fthcbasinbasementhastliesamesignaturc.IntheBohaigulfbasinctc’whichhasc0met0diwasta8

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  • 简介:SystemofProvidingTEGas¥LiXuekuan;HeYusheng;ZhuLianfang;ChenXuebing;SuYouwuandJiaoDunpangThesystemofprovidingTEgasforcylinderf...

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  • 简介:Theplasma-neutralgasstructuregeneratedinamagnesiumcathodicarcoperatedwithoxygengasataconstantcurrentof50Ahasbeeninvestigatedbyemployingasimplifiedone-dimensionalfluidmodel.Themodelincludeselasticcollisionsandcharge-exchangereactionsbetweenmetallicparticlesandgasmolecules,andalsogenerationandrecombinationofgaseousionsbyelectronimpact.Thedistributionprofilesofdensityandvelocityofspeciesalongtheaxialdirectionwereobtainedatdiferentbackgroundgaspressures(intherangeof0.7~3.0Pa)bythismodel.Acomparisonwiththeexperimentswasmade.Atlowergaspressures,thedepositingparticlesweremainlythemetallicionswithalargerkineticenergy.Asthegaspressureincreased,themagnesiumatomswithsmallerkineticenergyactedasthedominantdepositingspecies.Determinedbytheminimizationofthesystem’stotalenergy,MgO(100)or/andMgO(110)orientationappearedeasilyintheMgOfilmsatlowergaspressures,andathighergaspressures,thefilmpreferredorientationwasMgO(111).

  • 标签: 电弧等离子体 气体压力 实验比较 阴极电弧 镁原子 体结构
  • 简介:Inthisarticletheemphasiswasgiventothediscussionoftheeffectsofdiameterratioandswirlingoninstabilitycharacterforthegas/liquidcoaxialjetusedbyLiao,etal.[1].Theresultsindicatethatthefinitediameterratiomarkedlyincreasesthemaximumgrowthrate,themostunstablewavenumber,aswellasthecutoffwavenumber.Itimpliesthatthefinitediameterratiowillleadtotheliquidjetbreakuplengthshorterandtheliquiddropsizesmaller.Theeffectoftheswirlingjetsismuchmorecomplex:fortheaxisymmetricperturbationmode,theswirlingenhancestheflowstability,forhelicalperturbation,thedominantinstabilitymodeoccursatn<0.Anditisfoundthatinlongwaveregionthereexistsanewkindofinstabilitymodesatn=1thatwasnotmentionedinLiaoetal.'sarticle.Forthisnewmode,thereappearsadominatedswirlingratioatwhichtheflowhasthemaximumgrowthrate.

  • 标签: 不稳定性特征 直径比例 旋涡比例 气液混合流 射流
  • 简介:数据熔化,新研究域,是现代信息技术和许多另外的题目的集成和扩展。数据熔化概念被介绍,Dempster-Shafer证据推理被描述并且适用于油和煤气的察觉。方法的一个例子用数字模拟数据被显示出。处理结果显示数据熔化方法能广泛地在烃察觉被使用。

  • 标签: 信息融合 综合推理 DEMPSTER-SHAFER理论 油气预测 数值模拟
  • 简介:Inordertoidentifyheavierelements,wehavedevelopedanewlongitudinalfieldgasionizationchamber(IC)withanangleof30°ofplate(asshowninFig.1).TheICisoperatedinflowingiso-butanegasatapressureof10kPa.Aftertestingbyusinga3-componentαparticlesourceandcomparingwiththeoldlongitudinalfield

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  • 简介:在前後一致的Hartree-Fock近似以内,一在为不同类的Bose气体的扎根的州的精力的这近似表情明确是被导出一Bose爱因斯坦冷凝物的不同类的密度功能。获得的结果与Bose爱因斯坦冷凝物为系统在单个粒子的密度矩阵基于离开斜的远程的顺序的存在。这使避免异常一般水准的使用可能。动能的明确的形式,在Gross-Pitaevski途径不同于一个,被发现。动能的获得的形式在Hartree-Fock近似以外是有效的并且能被申请任意的强壮的interparticle相互作用。

  • 标签: Hartree-Fock近似 非均匀 玻色-爱因斯坦凝聚体 基态能量 玻色气体 粒子间相互作用
  • 简介:Thispapergivesfourpairsofentropies(η_i,q_i)(i=1,2,3,4)totheisentropicgasdynamicsequationsρ_t+(ρu)_x=0(ρu)_t+(ρu~2+p(ρ))_x=0p(ρ)=k~2ρ~γ,1<γ<3。whenallthefunctionequationsaresatisfied

  • 标签: satisfied 君兰 下尸 鱼业 ENTROPY 十呼
  • 简介:TherearethreetypesofshalegasresourcesinChina.Theresourcesarepresentinlargeamountsandarewidelydistributed.Marinefacies,transitionalfaciesandcontinentalfaciesresourceseachaccountforathird.Basedonresourcedistributions,therearemanywellspenetratedintotheSinian,Cambrian,Ordovieian,Silurian,Devonian,CarboniferousandPermianstrataoftheYangtzeplateanditsperiphery,theNorthChinaCratonandtheTarimBasin.ManyyearsofexplorationhaveindicatedthatthemarineSilurianLongmaxishalegasiswidelydistributedinsouthChinaandhasbeenindustrializedinitsproductionintheSiehuanbasin.TheshalegasfromtheCambrianNiutitangFormationandtheSinianDoushantuoFormationareimportantdiscoveriesinYichang,HubeiandZhenba,Shanxi.TherearealsoshalegasresourcesfoundwithintransitionalfaciesandcontinentalfaciesindifferentareasinChina.The"twoelementenrichmenttheory"hasbeensummarizedduringtheexplorationprocessofSilurianmarineshalegasintheSichuanBasin.Inaddition,horizontaldrillingandfracturingtechnologiesupto3500mindepthhavebeendeveloped.BasedontheunderstandingofshalegasaccumulationinacomplextectoniczoneoutsidetheSichnanbasin,apreliminarysummaryoftheformationofthe"conversefaultsynelinecontrolreservoir"and"paleoupliftcontrolreservoir"modelhasbeenconstructed.Thedominanttheoryof"Trinity"shalegasenrichmentandthehighyieldofthe"deepwaterLuPengxiangsedimentaryfaciesbelt,structuralpreservationconditionsandoverpressure"issummarized.Guidedbytheabovetheories.AnyelwellinGuizhouandEyangyelwellinHubeiweredrilled."Fourstorey"oilandshale"gasisfoundinthePermianQixiagroup,theSilurianShiniulanFormation,theLongmaxiFormationandtheOrdovicianBaotaFormationinAnyelwell.GoodshalegashasbeengoundintheCambrianNiutitangformationinianDoushantuoformationinEyangyelwell.Thispaperaimstosummarizeandreviewthemainprogress,theoreticaltech

  • 标签: SHALE GAS EXPLORATION ENRICHMENT ACCUMULATION THEORETICAL
  • 简介:Basedonthelinearanalysisofstability,adispersionequationisdeducedwhichdelineatestheevolutionofageneral3-dimensionaldisturbanceonthefreesurfaceofanincompressibleviscousliquidjetinjectedintoagaswithswirl.Here,thedimensionlessparameterJ_eisagainintroduced,inthemeantime,anotherdimensionlessparameterEcalledascirculationisalsointroducedtorepresenttherelativeswirlingintensity.Withrespecttothespatialgrowingdisturbancemode,thenumericalresultsobtainedfromsolvingthedispersionequationrevealthefollowingfacts.First,atthesamevalueofE,inpacewiththechangingofJ_e,thevariationofdisturbanceandthecriticaldisturbancemodestillkeepthesamecharacters.Second,thepresentresultsarethesameasthatofS.P.LinwhenJ_e>1;butintherangeofJ_e<1,it’snomorethecase,theswirldecreasestheaxisymmetricdisturbance,yetincreasestheasymmetricdisturbance,furthermoretheswirlmaymakethecharacterofthemostunstabledisturbancemodechanged(axisymmetricorasymmetric);theaboveactionoftheswirlbecomesmuchstrongerwhenJ_e《1.

  • 标签: JET stability DISPERSION EQUATION swirling GAS