外文翻译--化工工业离心泵.doc外文翻译--化工工业离心泵.doc

收藏 分享

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

1CENTRIFUGALPUMPSINTHECHEMICALINDUSTRYABSTRACTACENTRIFUGALPUMPCONVERTSTHEINPUTPOWERTOKINETICENERGYINTHELIQUIDBYACCELERATINGTHELIQUIDBYAREVOLVINGDEVICEANIMPELLERTHEMOSTCOMMONTYPEISTHEVOLUTEPUMPFLUIDENTERSTHEPUMPTHROUGHTHEEYEOFTHEIMPELLERWHICHROTATESATHIGHSPEEDTHEFLUIDISACCELERATEDRADIALLYOUTWARDFROMTHEPUMPCHASINGAVACUUMISCREATEDATTHEIMPELLERSEYETHATCONTINUOUSLYDRAWSMOREFLUIDINTOTHEPUMPTHISARTICLESTRESSESONASERIESOFCENTRIFUGALPUMPS,FROMABRIEFINTRODUCTIONTOTHEPRINCIPLESKEYWORDSCENTRIFUGALPUMP,INTRODUCTION,WORKINGPRINCIPLE,CAVITATION,MECHANISMOFCAVITATION,SOLUTIONANDREMEDIES1INTRODUCTIONPUMP,DEVICEUSEDTORAISE,TRANSFER,ORCOMPRESSLIQUIDSANDGASESFOURGENERALCLASSESOFPUMPSFORLIQUIDSAREDESCRIBEDBELOWINALLOFTHEM,STEPSARETAKENTOPREVENTCAVITATIONTHEFORMATIONOFAVACUUM,WHICHWOULDREDUCETHEFLOWANDDAMAGETHESTRUCTUREOFTHEPUMPPUMPSUSEDFORGASESANDVAPORSAREUSUALLYKNOWNASCOMPRESSORSTHESTUDYOFFLUIDSINMOTIONISCALLEDFLUIDDYNAMICSWATERPUMP,DEVICEFORMOVINGWATERFROMONELOCATIONTOANOTHER,USINGTUBESOROTHERMACHINERYWATERPUMPSOPERATEUNDERPRESSURESRANGINGFROMAFRACTIONOFAPOUNDTOMORETHAN10,000POUNDSPERSQUAREINCHEVERYDAYEXAMPLESOFWATERPUMPSRANGEFROMSMALLELECTRICPUMPSTHATCIRCULATEANDAERATEWATERINAQUARIUMSANDFOUNTAINSTOSUMPPUMPSTHATREMOVEWATERFROMBENEATHTHEFOUNDATIONSOFHOMESONETYPEOFMODERNPUMPSUSEDTOMOVEWATERISTHECENTRIFUGALPUMPEARLYVERSIONOFTHECENTRIFUGALPUMP,THESCREWPUMP,CONSISTSOFACORKSCREWSHAPEDMECHANISMINAPIPETHAT,WHENROTATED,PULLSWATERUPWARDSCREWPUMPSAREOFTENUSEDINWASTEWATERTREATMENTPLANTSBECAUSETHEYCANMOVELARGEAMOUNTSOFWATERWITHOUTBECOMINGCLOGGEDWITHDEBRISINTHEANCIENTMIDDLEEASTTHENEEDFORIRRIGATIONOFFARMLANDWASASTRONGINDUCEMENTTODEVELOPAWATERPUMPEARLYPUMPSINTHISREGIONWERESIMPLEDEVICESFORLIFTINGBUCKETSOFWATERFROMASOURCETOACONTAINERORATRENCHGREEKMATHEMATICIANANDINVENTORARCHIMEDESISTHOUGHTTOHAVEDEVISEDTHEFIRSTSCREWPUMPINTHETHIRDCENTURYBCLATERGREEKINVENTORCTESIBIUSDEVELOPTHEFIRSTLIFTPUMPDURINGTHELATE17THANDEARLY18THCENTURIESAD,BRITISHENGINEERTHOMASSAVERY,FRENCHPHYSICISTDENISPAPIN,ANDBRITISHBLACKSMITHANDINVENTORTHOMASNEWCOMENCONTRIBUTEDTOTHEDEVELOPMENTOFAWATERPUMPTHATUSEDSTEAMTOPOWERTHEPUMP’PISTONTHESTEAMPOWEREDWATERPUMP’SFIRSTWIDEUSEWASINPUMPINGWATEROUTOFMINESMODERNDAYEXAMPLESOFCENTRIFUGALPUMPSARETHOSEUSEDATTHEGRANDCOULEEDAMONTHECOLUMBIARIVERTHISPUMPSYSTEMHASTHEPOTENTIALTOIRRIGATEOVERONEMILLIONACRESOFLANDALSOKNOWNASROTARYPUMPS,CENTRIFUGALPUMPSHAVEAROTATINGIMPELLER,ALSOKNOWNASABLADE,THATISIMMERSEDINTHELIQUIDLIQUIDENTERSTHEPUMPNEARTHEAXISOFTHEIMPELLER,ANDTHEROTATINGIMPELLERSWEEPSTHELIQUIDOUTTOWARDTHEENDSOFTHEIMPELLERBLADESATHIGHPRESSURETHEIMPELLERALSOGIVESTHELIQUIDARELATIVELYHIGHVELOCITYTHATCANBECONVERTEDINTOPRESSUREINASTATIONARYPARTOFTHEPUMP,KNOWNASTHEDIFFUSERINHIGHPRESSUREPUMPS,ANUMBEROFIMPELLERMAYBEUSEDINSERIES,ANDTHEDIFFUSERSFOLLOWINGEACHIMPELLERMAYCONTAINGUIDEVANESTOGRADUALLYREDUCETHELIQUIDVELOCITYFORLOWERPRESSUREPUMPS,THEDIFFUSERISGENERALLYASPIRALPASSAGE,KNOWNASAVOLUTE,WITHITSCROSSSECTIONALAREAINCREASINGGRADUALLYTOREDUCETHEVELOCITYEFFICIENTLYTHEIMPELLERMUSTBEPRIMEDBEFOREITCANBEGINOPERATION,THATIS,THEIMPELLERMUSTBESURROUNDEDBYLIQUIDWHENTHEPUMPISSTARTEDTHISCANBEDONEBYPLACINGACHECKVALVEINTHESUCTIONLINE,WHICHHOLDSTHELIQUIDINTHEPUMPWHENTHEIMPELLERISNOTROTATINGIFTHISVALVELEAKS,THEPUMPMAYNEEDTOBEPRIMEDBYTHEINTRODUCTIONOFLIQUIDFROMANOUTSIDESOURCESUCHASTHEDISCHARGERESERVOIRACENTRIFUGALPUMPGENERALLYHASAVALVEINTHEDISCHARGELINETOCONTROLTHEFLOWAND2PRESSUREFORLOWFLOWSANDHIGHPRESSURES,THEACTIONOFTHEIMPELLERISLARGELYRADIALFORHIGHERFLOWSANDLOWERDISCHARGEPRESSURE,THEDIRECTIONOFTHEFLOWWITHINTHEPUMPISMORENEARLYPARALLELTOTHEAXISOFTHESHAFT,ANDTHEPUMPISSAIDTOHAVEANAXIALFLOWTHEIMPELLERINTHISCASEACTSASAPROPELLERTHETRANSITIONFROMONESETOFFLOECONDITIONSTOTHEOTHERISGRADUAL,ANDFORINTERMEDIATECONDITION,THEDEVICEISCALLEDAMIXEDFLOWPUMP2THECENTRIFUGALPUMPTHECENTRIFUGALPUMPISBYFARTHEMOSTWIDELYUSEDTYPEINTHECHEMICALANDPETROLEUMINDUSTRIESITWILLPUMPLIQUIDSWITHVERYWIDERANGINGPROPERTIESANDSUSPENSIONSWITHAHIGHSOLIDSCONTENTINCLUDING,FOREXAMPLE,CEMENTSLURRIES,ANDMAYBECONSTRUCTEDFROMAVERYWIDERANGOFCORROSIONRESISTANTMATERIALSTHEWHOLEPUMPCASINGMAYBECONSTRUCTEDFROMPLASTICSUCHASPOLYPROPYLENEORITMAYBEFITTEDWITHACORROSIONRESISTANTLININGBECAUSEITOPERATESATHIGHSPEED,ITMAYBEDIRECTLYCOUPLEDTOANELECTRICMOTORANDITWILLGIVEAHIGHFLOWRATEFORITSSIZEINTHISTYPEOFPUMP,THEFLUIDISFEDTOTHECENTREOFAROTATINGIMPELLERANDISTHROWNOUTWARDBYCENTRIFUGALACTIONASARESULTOFTHEHIGHSPEEDOFROTATIONTHELIQUIDACQUIRESAHIGHKINETICENERGYANDTHEPRESSUREDIFFERENCEBETWEENTHESUCTIONANDDELIVERYSIDESARISESFROMTHECONVERSIONOFKINETICENERGYINTOPRESSUREENERGYTHEIMPELLERCONSISTSOFASERIESOFCURVEDVANESSOSHAPEDTHATTHEFLOWWITHINTHEPUMPISASSMOOTHASPOSSIBLETHEGREATERTHENUMBEROFVANESONTHEIMPELLER,THEGREATERISTHECONTROLOVERTHEDIRECTIONOFTHELIQUIDANDHENCETHESMALLERARETHELOSSESDUETOTURBULENCEANDCIRCULATIONBETWEENTHEVANESINTHEOPENIMPELLER,THEVANESAREFIXEDTOACENTRALHUB,WHEREASINTHECLOSEDTYPETHEVANESAREHELDBETWEENTWOSUPPORTINGPLATESANDLEAKAGEACROSSTHEIMPELLERISREDUCEDASWILLBESEENLATER,THEANGLEOFTHETIPSOFTHEBLADESVERYLARGELYDETERMINESTHEOPERATINGCHARACTERISTICSOFTHEPUMPTHELIQUIDENTERSTHECASINGOFTHEPUMP,NORMALLYINANAXIALDIRECTION,ANDISPICKEDUPBYTHEVANESOFTHEIMPELLER.INTHESIMPLETYPEOFCENTRIFUGALPUMP,THELIQUIDDISCHARGESINTOAVOLUTE,ACHAMBEROFGRADUALLYINCREASINGCROSSSECTIONWITHATANGENTIALOUTLET.AVOLUTETYPEOFPUMPISSHOWNINFIGA.INTHETURBINEPUMPFIG.BTHELIQUIDFLOWSFROMTHEMOVINGVANESOFTHEIMPELLERTHROUGHASERIESOFFIXEDVANESFORMINGADIFFUSIONRING.THISGIVESAMOREGRADUALCHANGEINDIRECTIONTOTHEFLUIDANDMOREEFFICIENTCONVERSIONOFKINETICENERGYINTOPRESSUREENERGYTHANISOBTAINEDWITHTHEVOLUTETYPE.THEANGLEOFTHELEADINGEDGEOFTHEFIXEDVANESSHOULDBESUCHTHATTHEFLUIDISRECEIVEDWITHOUTSHOCK.THELIQUIDSFLOWSALONGTHESURFACEOFTHEIMPELLERVANEWITHACERTAINVELOCITYWHILSTTHETIPOFTHEVANEISMOVINGRELATIVETOTHECASINGOFTHEPUMP.THEDIRECTIONOFMOTIONOFTHELIQUIDRELATIVETOTHEPUMPCASINGANDTHEREQUIREDANGLEOFTHEFIXEDVANESISFOUNDBYCOMPOUNDINGTHESETWOVELOCITIES.INFIG.C,3CVUISTHEVELOCITYOFTHELIQUIDRELATIVETOTHEVANEANDTUISTHETANGENTIALVELOCITYOFTHETIPOFTHEVANE;COMPOUNDINGTHESETWOVELOCITIESGIVESTHERESULTANTVELOCITY2UOFTHELIQUID.ITISAPPARENT,THEREFORE,THATTHEREQUIREDVANEANGLEINTHEDIFFUSERISDEPENDENTONTHETHROUGHPUT,THESPEEDOFROTATION,ANDTHEANGLEOFTHEIMPELLERBLADES.THEPUMPWILLTHEREFOREOPERATEATMAXIMUMEFFICIENCYONLYOVERANARROWRANGEOFCONDITIONS.VIRTUALHEADOFACENTRIFUGALPUMPTHEMAXIMUMPRESSUREISDEVELOPEDWHENTHEWHOLEOFTHEEXCESSKINETICENERGYOFTHEFLUIDISCONVERTEDINTOPRESSUREENERGYASINDICATEDBELOW.THEHEADISPROPORTIONALTOTHESQUAREOFTHERADIUSANDTOTHESPEED,ANDISOFTHEORDEROF60MFORASINGLESTAGECENTRIFUGALPUMP;FORHIGHERPRESSURES,MULTISTAGEPUMPSMUSTBEUSED.CONSIDERTHELIQUIDWHICHISROTATINGATADISTANCEOFBETWEENRANDRDRFROMTHECENTREOFTHEPUMPFIG.D.DTHEMASSOFTHISELEMENTOFFLUIDDMISGIVENBY2ΠRDRDΡ,WHEREΡISTHEDENSITYOFTHEFLUIDAND6ISTHEWIDTHOFTHEELEMENTOFFLUID。IFTHEFLUIDISTRAVELINGWITHAVELOCITYUANDATANANGLEΘTOTHETANGENTIALDIRECTION.THEANGULARMOMENTUMOFTHISMASSOFFLUIDDMURCOSΘTHETORQUEACTINGONTHEFLUIDDΤISEQUALTOTHERATEOFCHANGEOFANGULARMOMENTUMWITHTIME,ASITGOESTHROUGHTHEPUMPDΤDMΑ/ΑTURCOSΘ2ΠRBΡDRΑ/ΑTURCOSΘ21THEVOLUMETRICRATEOFFLOWOFLIQUIDTHROUGHTHEPUMPQ2ΠRBΑ/ΑT224DRQΡDURCOSΘ23THETOTALTORQUEACTINGONTHELIQUIDINTHEPUMPISTHEREFOREOBTAINEDINTEGRATINGDΤBETWEENTHELIMITSDENOTEDBYSUFFIX1ANDSUFFIX2,WHERESUFFIX1REFERSTOTHECONDITIONSATTHEINLETTOTHEPUMPANDSUFFIX2REFERSTOTHECONDITIONATTHEDISCHARGE.THUS,ΤQΡ2U2RCOS21U1RCOS1THEADVANTAGESANDDISADVANTAGESOFTHECENTRIFUGALPUMPTHEMAINADVANTAGESARE1ITISSIMPLEINCONSTRUCTIONANDCAN,THEREFORE,BEMADEINAWIDERANGEOFMATERIALS2THEREISACOMPLETEABSENCEOFVALVES.3ITOPERATESATHIGHSPEEDUPTO100HZAND,THEREFORE,CANBECOUPLEDDIRECTLYTOANELECTRICMOTORINGENERAL,THEHIGHERTHESPEEDTHESMALLERTHEPUMPANDMOTORFORAGIVENDUTY.4ITGIVESASTEADYDELIVERY.5MAINTENANCECOSTSARELOWERTHANFORANYOTHERTYPEOFPUMP.6NODAMAGEISDONETOTHEPUMPIFTHEDELIVERYLINEBECOMESBLOCKED,PROVIDEDITISNOTRUNINTHISCONDITIONFORAPROLONGEDPERIOD.7ITISMUCHSMALLERTHANOTHERPUMPSOFEQUALCAPACITY.ITCAN,THEREFORE,BEMADEINTOASEALEDUNITWITHTHEDRIVINGMOTORANDIMMERSEDINTHESUCTIONTANK.8LIQUIDSCONTAININGHIGHPROPORTIONSOFSUSPENDEDSOLIDSAREREADILYHANDLED.THEMAINDISADVANTAGESARE1THESINGLESTAGEPUMPWILLNOTDEVELOPAHIGHPRESSURE.MULTISTAGEPUMPSWILLDEVELOPGREATERHEADSBATTHEYAREVERYMUCHMOREEXPENSIVEANDCANNOTREADILYBEMADEINCORROSIONRESISTANTMATERIALBECAUSEOFTHEIRGREATERCOMPLEXITY.ITISGENERALLYBETTERTOUSEVERYHIGHSPEEDSINORDERTOREDUCETHENUMBEROFSTAGESREQUIRED.2ITOPERATESATAHIGHEFFICIENCYOVERONLYALIMITEDRANGEOFCONDITIONS;THISAPPLIESESPECIALLYTOTURBINEPUMPS.3ITISNOTUSUALLYSELFPRIMING4IFANONRETURNVALVEISNOTINCORPORATEDINTHEDELIVERYORSUCTIONLINE,THELIQUIDWILLRUNBACKINTOTHESUCTIONTANKASSOONASTHEPUMPSTOPS.5VERYVISCOUSLIQUIDSCANNOTHEHANDLEDEFFICIENTLY.3CAVITATIONINCENTRIFUGALPUMP(1)THETERM‘CAVITATION’COMESFROMTHELATINWORDCAVUS,WHICHMEANSAHOLLOWSPACEORACAVITYWEBSTER’SDICTIONARYDEFINESTHEWORD‘CAVITATION’ASTHERAPIDFORMATIONANDCOLLAPSEOFCAVITIESINAFLOWINGLIQUIDINREGIONSOFVERYLOWPRESSUREINANYDISCUSSIONONCENTRIFUGALPUMPSVARIOUSTERMSLIKEVAPORPOCKETS,GASPOCKETS,HOLES,BUBBLES,ETCAREUSEDINPLACEOFTHETERMCAVITIESTHESEAREONEANDTHESAMETHINGANDNEEDNOTBECONFUSEDTHETERMBUBBLESHALLBEUSEDHEREAFTERINTHEDISCUSSIONINTHECONTEXTOFCENTRIFUGALPUMPS,THETERMCAVITATIONIMPLIESADYNAMICPROCESSOFFORMATIONOFBUBBLESINSIDETHELIQUID,THEIRGROWTHANDSUBSEQUENTCOLLAPSEASTHELIQUIDFLOWSTHROUGHTHEPUMPGENERALLY,THEBUBBLESTHATFORMINSIDETHELIQUIDAREOFTWOTYPESVAPORBUBBLESORGASBUBBLES1VAPORBUBBLESAREFORMEDDUETOTHEVAPORISATIONOFAPROCESSLIQUIDTHATISBEINGPUMPEDTHECAVITATIONCONDITIONINDUCEDBYFORMATIONANDCOLLAPSEOFVAPORBUBBLESISCOMMONLYREFERREDTOASVAPOROUSCAVITATION2GASBUBBLESAREFORMEDDUETOTHEPRESENCEOFDISSOLVEDGASESINTHELIQUIDTHATISBEINGPUMPED
编号:201311171547576971    类型:共享资源    大小:230.50KB    格式:DOC    上传时间:2013-11-17
  
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
关于本文
本文标题:外文翻译--化工工业离心泵.doc
链接地址:http://www.renrendoc.com/p-96971.html

当前资源信息

4.0
 
(2人评价)
浏览:52次
英文资料库上传于2013-11-17

官方联系方式

客服手机:17625900360   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

  • Thomas_Calculus_13th(托马斯微积分 13版)Thomas_Calculus_13th(托马斯微积分 13版)
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊2016】借助于电缆驱动系统改进工业机器人的静态性-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊2016】借助于电缆驱动系统改进工业机器人的静态性-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊2016】借助于电缆驱动系统改进工业机器人的静态性-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊2016】借助于电缆驱动系统改进工业机器人的静态性-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】最小化模式下料问题科林麦克迪尔米德-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】最小化模式下料问题科林麦克迪尔米德-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】组合机床行业现状与发展思考-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】组合机床行业现状与发展思考-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】自行航水器真正自治-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】自行航水器真正自治-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】自行航水器真正自治-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】自行航水器真正自治-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模具的设计与热分析-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模具的设计与热分析-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模的单浇口优化-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模的单浇口优化-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模的单浇口优化-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】注塑模的单浇口优化-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】主轴平衡力和曲轴弯曲应力的研究-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】主轴平衡力和曲轴弯曲应力的研究-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】轴对称降落伞形状的研究-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】轴对称降落伞形状的研究-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】轴对称降落伞形状的研究-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】轴对称降落伞形状的研究-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】中国乘用车燃料经济性标准的组成和影响-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】中国乘用车燃料经济性标准的组成和影响-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】指垫和平面之间的动态交互作用:实验和分析-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】指垫和平面之间的动态交互作用:实验和分析-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】指垫和平面之间的动态交互作用:实验和分析-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】指垫和平面之间的动态交互作用:实验和分析-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】直线电机高速数控切断机的发展-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】直线电机高速数控切断机的发展-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】直线电机高速数控切断机的发展-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】直线电机高速数控切断机的发展-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】支持机床系统的面向对象设计-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】支持机床系统的面向对象设计-中文翻译
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】支持机床系统的面向对象设计-外文文献[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】支持机床系统的面向对象设计-外文文献
  • [机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】振动镗孔与振动钻孔的研究-中文翻译[机械模具数控自动化专业毕业设计外文文献及翻译]【期刊】振动镗孔与振动钻孔的研究-中文翻译
  • 精品推荐

    相关阅读

    人人文库
    关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服客服 - 联系我们

    网站客服QQ:2846424093    人人文库上传用户QQ群:460291265   

    [email protected] 2016-2018  renrendoc.com 网站版权所有   南天在线技术支持

    经营许可证编号:苏ICP备12009002号-5