外文翻译--叉车升降机构的创新设计 英文版.pdf外文翻译--叉车升降机构的创新设计 英文版.pdf

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

RAILWAYCONSISTSTHEfiELDTOINHERENTLYANDOTHERSCOMPUTERVISIONGUIDANCE5,6THESETRUCKSHAVEBETTERVISIBILITYFORDRIVERSBUTTHEYARENOTFUNDAMENTALSOLUTIONSTOOVERCOMEMECHANISMANDMACHINETHEORY4520101892–1896CONTENTSLISTSAVAILABLEATSCIENCEDIRECTMECHANISMANDMACHINETHEORYTHESHORTAGESOFTHEGENERALMASTSTRUCTURES,ANDTHEPROBLEMOFHIGHSELFWEIGHTHASNOTBEENCRACKEDCOMPLETELYEITHERINORDERTOIMPROVETHEDRIVINGCOMFORTANDSAFETYFORTHEDRIVERSANDTOREDUCEENERGYCONSUMPTION,THISPAPERFOCUSESONTHEINNOVATIVEDESIGNOFTHELIFTINGMECHANISMFORFORKLIFTTRUCKSASPATIALMULTILINKLIFTGUIDANCEMECHANISMISPROPOSED,ANDTHENANEWKINDOFLIFTINGMECHANISMBASEDONITISPRESENTEDTHISMECHANISMNOTONLYEXPANDSTHEVISIONfiELDOFTHEDRIVERBUTALSOREDUCESTHEWHOLEWEIGHTOFTHEVEHICLE2PROPOSITIONOFALIFTGUIDANCEMECHANISMEXPANDINGTHEDRIVERSVISIONHASALWAYSCHANGINGTHEFORMSOFTHEMAST2,3,WHILEASISWELLKNOWN,APLANARRRROPENCHASUPPOSETHATTWOSUCHPLANARRRRLINKAGESRRROPENCHAINLINKAGESARECONNECTEDWITH⁎CORRESPONDINGAUTHORFAX861062788308EMAILADDRESSJINGSHANZHAOMAILTSINGHUAEDUCN0094114X/–SEEFRONTMATTER2010ELSEVIERLTDDOI101016/JMECHMACHTHEORY201008002BEENANIMPORTANTRESEARCHPROJECTSOMEKINDSOFTRUCKSHAVEIMPROVEDVISIBILITYVIAUTILIZETHEVISUALGUIDANCEMETHODSOFMOBILECAMERASPACEMANIPULATION4ORCOMPONENTSWILLBADLYAFFECTTHEDRIVERSBETWEENPEDESTRIANSANDTRUCKSAREDUEANIMPORTANTROLEINSUPPORTINGTHELOADSENOUGHANDITSSELFWEIGHTHASTOBEINCREASEDTHEUNNECESSARYWASTEOFENERGYSTATIONS,WAREHOUSES,PORTSANDFACTORIESFORLOADING,UNLOADINGANDCONVEYINGAOFACHASSISANDAWORKDEVICEWHICHCANBETILTEDANDLIFTEDVERTICALLYFOLLOWINGMAJORDISADVANTAGESFIRST,THEMASTSYSTEMCOMPOSEDOFSEVERALLARGEOFVISIONBECAUSEITLOCATESINFRONTOFTHEDRIVERMANYACCIDENTSINVOLVINGCOLLISIONSBADVISIBILITIESOFTHEFORKLIFTTRUCKS1,2INADDITION,THEMASTSYSTEMPLAYSGUIDINGTHEFORKFRAMETOLIFTVERTICALLYSOITSSTRENGTHANDSTIFFNESSMUSTBEHIGHTHEWEIGHTOFTHEREAREQUILIBRATORISINCREASEDASARESULT,WHICHSURELYIMPROVES1INTRODUCTIONFORKLIFTTRUCKSAREUSUALLYUSEDATGENERALWEIGHTBALANCEDFORKLIFTTRUCKHOWEVER,THEGENERALFORKLIFTSHAVESHORTCOMMUNICATIONINNOVATIVEDESIGNOFTHELIFTINGMECHANISMSFORFORKLIFTTRUCKSJIANYIWANG,JINGSHANZHAO⁎,FULEICHU,ZHIJINGFENGDEPARTMENTOFPRECISIONINSTRUMENTSANDMECHANOLOGY,TSINGHUAUNIVERSITY,BEIJING100084,PRCHINAARTICLEINFOABSTRACTARTICLEHISTORYRECEIVED17JUNE2010RECEIVEDINREVISEDFORM3AUGUST2010ACCEPTED4AUGUST2010AVAILABLEONLINE1SEPTEMBER2010FORKLIFTTRUCKISONEOFTHEMOSTIMPORTANTTOOLSINLOGISTICSHOWEVER,THEGENERALMASTSYSTEMOFAFORKLIFTTRUCKNOTONLYRESTRAINSTHEDRIVERSVISION,BUTALSOINCREASESTHEWHOLEWEIGHTOFATRUCKANDDECREASESTHEFUELECONOMYTHEREFORE,THISPAPERFOCUSESONTHEINNOVATIVEDESIGNOFANEWLIFTINGMECHANISMFORFORKLIFTTRUCKFIRSTLY,ASPATIALMULTILINKLIFTGUIDANCEMECHANISMISPROPOSEDANDTHEN,UNDERTHECONSTRAINTSOFTHISMECHANISM,THEMOBILITYOFTHEFORKANDFORKFRAMEISINVESTIGATEDINTHEORYLASTLY,ANEWLIFTINGMECHANISMBASEDONITISPRESENTEDANDCOMPUTERSIMULATIONISUSEDTODEMONSTRATETHEFEASIBILITYOFMOTIONTHISMULTILINKLIFTINGMECHANISMTAKESADVANTAGEOFflEXIBLECABLEDRIVEANDRIGIDBODYGUIDANCE,WHICHNOTONLYPROVIDESTHEOPERATORWITHAWIDERfiELDOFVISIONBUTALSOREDUCESTHEEQUILIBRATEWEIGHTOFAVEHICLEANDTHEREFOREIMPROVESTHEFUELECONOMY2010ELSEVIERLTDALLRIGHTSRESERVEDKEYWORDSFORKLIFTTRUCKSPATIALMULTILINKMECHANISMRIGIDBODYGUIDANCEFLEXIBLEDRIVINGMETHODJOURNALHOMEPAGEWWWELSEVIERCOM/LOCATE/MECHMTINLINKAGETHATCONSISTSOFTHREEREVOLUTEPAIRSANDTWOLINKSGENERATESPLANARMOTIONSAREPLACEDINTWOPLANESWITHACERTAINNONZEROSUBTENDEDANGLETHEENDSOFTHETWOASAMERIGIDBODYTHROUGHREVOLUTEPAIRSSHOWNINFIG1LINK1ISTHEBASEANDRIGIDJSZHAOALLRIGHTSRESERVED1893JYWANGETAL/MECHANISMANDMACHINETHEORY4520101892–1896BODY4ISCONNECTEDWITHTHEBASETHROUGHTWOPARALLELRRRKINEMATICCHAINS,ABCANDDEFITISEASYTOfiNDTHAT,THESETWOKINEMATICCHAINSAREBOTHPLANARRRRKINEMATICLINKAGESTHEREFORETHETRACKOFRIGIDBODY4MUSTBEPARALLELTOBOTHOFPLANEΑANDPLANEΒTHATIS,RIGIDBODY4CANONLYMAKEAFREETRANSLATIONPARALLELTOTHEINTERSECTIONLINE,MN,OFTHETWOPLANESASARESULT,THETRACKOFRIGIDBODY4ISASTRAIGHTLINESLIDERCRANKMECHANISMISACOMMONMECHANISMTHATAPPLIESRRROPENCHAINSTRUCTUREITISWIDELYUSEDANDEXAMPLESOFITSFIG1SPATIALMULTILINKSTRUCTUREAPPLICATIONSAREEASILYFOUNDINGASOLINEANDDIESELENGINES7HOWEVER,INTHEAPPLICATIONSOFSLIDERCRANKMECHANISM,DEADPOINTSPOSSIBLYLEADTOACTUATINGFAILUREINORDERTOIMPROVETHESTABILITYANDAVOIDTHEDEADPOINTS,THISPAPERREPLACESTHERRRKINEMATICCHAINSWITHRPRKINEMATICCHAINS,WHICHARECOMPOSEDOFTWOREVOLUTEPAIRSANDONEPRISMATICPAIRANDCANALSOONLYGENERATEPLANARMOTIONSWITHOUTDEADPOINTSSUPPOSETHETWOVERTICALPLANESTHATTHESUPPORTBLOCKSANDTHEIRRPRKINEMATICCHAINSLOCATEDARESYMMETRICALWITHRESPECTTOTHELONGITUDINALSYMMETRICALPLANEOFTHEVEHICLEASISSHOWNINFIG2,THESUBTENDEDANGLEBETWEENTHETWOPLANESISDENOTEDBYΘ0∘BΘB180∘TWORPRKINEMATICCHAINSAREPLACEDINTHETWOPLANES,RESPECTIVELYEVERYRPRKINEMATICCHAININCLUDESTWOREVOLUTEPAIRSANDONEPRISMATICPAIR,ACONNECTINGRODANDASLIDEWAYTHECONNECTINGRODANDTHESLIDEWAYARECONNECTEDTHROUGHAPRISMATICPAIRTHEFORKFRAMEHASTWOEXTRUDEDREVOLUTEPAIRSCONNECTEDWITHTHEENDSOFTHETWORPRKINEMATICCHAINSASISDISCUSSEDABOVE,INSUCHASPATIALMULTILINKSTRUCTURE,THETRACKOFTHEFORKFRAMEISINASTRAIGHTLINEINADDITION,ONECANIMPROVETHESTRENGTHANDSTIFFNESSBYADDINGANOTHERSIMILARKINEMATICCHAININEACHVERTICALPLANE,INWHICHTHESUPPORTBLOCKSLOCATED,TOCONNECTTHEFORKFRAMEANDTHETRUCKCHASSISMEANWHILE,THEUPPERANDLOWERKINEMATICCHAINSARECONNECTEDBYCONSTRAINTRODSASTHETRACKOFTHEUPPERANDLOWERKINEMATICCHAINSAREPARALLEL,THECONSTRAINTRODSPROVIDEREDUNDANTRESTRAINTSANDIMPROVETHESTIFFNESSANDSTABILITYOFTHELIFTGUIDANCEMECHANISMANDTHELOADCARRYINGCAPACITY8NOWTHEKINEMATICPRINCIPLESOFTHESPATIALMULTILINKLIFTGUIDANCEMECHANISMCANBEANALYZEDINTHEORYINORDERTOINVESTIGATETHEDEGREEOFFREEDOMDOFOFTHEFORKFRAME,ONECANESTABLISHACARTESIANCOORDINATESYSTEM,WHEREXOYPLANEISTHEPLANEDETERMINEDBYTHEAXESOFREVOLUTEPAIRSAANDD,THEORIGINOFCOORDINATESYSTEMISTHEINTERSECTIONPOINTOFAXESOFAANDD,XAXISISTHEAXISOFREVOLUTEPAIRATHECOORDINATESYSTEMISSHOWNINFIG3ASSUMETHATTHESUBTENDEDANGLEOFTHEAXESOFREVOLUTEPAIRDANDREVOLUTEPAIRAISDENOTEDBYΦ0OBΦB180O,THEDISTANCEFROMREVOLUTEPAIRSAANDDTOTHEORIGINOFCOORDINATESYSTEMAREEQUALANDDENOTEDBYATHECOORDINATESOFAANDDAREA00ANDACOSΦASINΦ0,RESPECTIVELYINADDITION,THECOORDINATESOFCANDFCANBEEXPRESSEDASAYCZCANDXFYFZF,INDIVIDUALLYITISNOTDIFfiCULTTOfiNDTHAT,THEAXESOFREVOLUTEPAIRSAANDCAREPARALLEL,ANDSOARETHEAXESOFREVOLUTEPAIRSDANDFS1100TDENOTESTHEDIRECTIONVECTOROFTHEAXESOFREVOLUTEPAIRSAANDC,S2COSΦSINΦ0TDENOTESTHEUNITDIRECTIONVECTOROFTHEAXESOFREVOLUTEPAIRSDANDF,S30YCZCTDENOTESTHEDIRECTIONVECTOROFPRISMATICPAIRBANDS4XF−BCOSΦYF−BSINΦZFTDENOTESTHEDIRECTIONVECTOROFPRISMATICPAIREACCORDINGTOTHESCREWTHEORY9,THETERMINALCONSTRAINTSCREWMATRIXOFAKINEMATICCHAINCANBEOBTAINEDBYSOLVINGTHERECIPROCALSCREWEQUATIONTEΤ01WHEREΤTHETHETERMINALFIG2ANEWLIFTGUIDANCEMECHANISM1FORK;2FORKFRAME;3EXTRUDEDREVOLUTEPAIR;4CONNECTINGROD;5CONSTRAINTROD;6SLIDEWAY;7SUPPORTBLOCK1894JYWANGETAL/MECHANISMANDMACHINETHEORY4520101892–1896000001INACCORDANCEWITHEQ1,ONECANOBTAINTHETERMINALCONSTRAINTSCREWMATRIXCOMPOSEDOFASETOFBASESCREWSOFCONSTRAINTSCREWSYSTEMΤABC1000000000102435T31000ZC−YCTHEREFORE,ISAKINEMATICSCREWMATRIXANDISTHETERMINALCONSTRAINTSCREWKINEMATICSCREWMATRIXOFAKINEMATICCHAIN,ABC,CANBEEXPRESSEDASABCABCC1381000000000YCZC2435T2FIG3CARTESIANCOORDINATESYSTEMITPROVES1895JYWANGETAL/MECHANISMANDMACHINETHEORY4520101892–1896UNDERTHECONSTRAINTSOFTHELIFTGUIDANCEMECHANISM,THEFORKFRAMECANBELIFTEDUPANDDOWNPERPENDICULARTOTHEGROUND3IMPLEMENTTHISSIMULATEASWHILEISSHOWNOFTHEWORKS,INRAISEDMECHANISPERPENDICUTHISCABLEDRIVEWEIGHTREQUIREMMEANWHILTHISKINDTHEMBECOMESCF000001T6THATTHEFORKFRAMEHASONLYONEDOFALONGZDIRECTION,IE,THETRACKOFTHEFORKFRAMEISRESTRICTEDTOASTRAIGHTLINEACCORDINGTOEQ1,SOLONGAS0∘BΦB180∘,THEKINEMATICSCREWMATRIXOFTHEFRAMECFCANBESOLELYOBTAINEDΤCFΤABCΤDEFC2C35CONSEQUENTLY,THETERMINALCONSTRAINTSCREWMATRIXONCFCANBEEXPRESSEDASΤDEFCOSΦSINΦ0000000SINΦ−COSΦ0000001454SIMILARLY,THETERMINALCONSTRAINTSCREWMATRIXOFKINEMATICCHAINDEFISOBTAINED23TFIG4IMPLEMENTATIONOFTHENEWLIFTINGMECHANISMANDCOMPUTERSIMULATIONS1FORKFRAME;2FRONTPULLEY;3FRONTSUPPORTINGRODS;4BACKSUPPORTINGRODS;5CABLES;6BACKPULLEYATIONOFANEWLIFTINGMECHANISMSECTIONWILLPRESENTANEWLIFTINGMECHANISMFORFORKLIFTTRUCKBASEDONTHELIFTGUIDANCEMECHANISMPROPOSEDABOVEANDITSMOTIONINACOMPUTERISDISCUSSEDABOVE,THELIFTGUIDANCEMECHANISMRESTRAINSTHETRACKOFTHEFORKFRAMEINASTRAIGHTLINEINORDERTOLIFTGOODSNOTAFFECTINGTHEDRIVERSfiELDOFVISION,ONECANUSEWINDLASSANDSOFTSTEELCABLESTOLIFTTHEFORKANDFORKFRAMETHESTRUCTUREINFIG4AONECANSETAWINDLASSATTHEREAROFTHEFORKLIFTTRUCKANDPLACESSOMEPULLEYSANDSUPPORTINGRODSONTHETOPCABONEENDOFEACHCABLEISCONNECTEDWITHTHEFORKFRAMEANDTHEOTHERENDISfiXEDTOTHEWINDLASSWHENTHEWINDLASSTHECABLESWILLLIFTORDROPTHEFORKFRAMEORDERTOVERIFYWHETHERTHISKINDOFFORKLIFTTRUCKCANACHIEVETHEDESIREDMOVEMENTS,ESPECIALLYINSURETHEFORKFRAMETOBEVERTICALLY,PRO/ENGINEERSOFTWAREISUTILIZEDTOSIMULATEITSMOTIONFIG4A,BANDCSHOWDIFFERENTPOSITIONSWHENTHEMLIFTSTHEFORKANDFORKFRAMEUPFROMTHESIMULATIONONEfiNDSTHATTHETRACKOFTHEFORKANDFORKFRAMEISASTRAIGHTLINELARTOTHEGROUNDINADDITION,WITHOUTTHEMASTSYSTEM,THEDRIVERHASABETTERVISIONFORWARDSANDBACKWARDSKINDOFLIFTINGMECHANISMCONSISTSOFTHEflEXIBLECABLEDRIVEANDRIGIDBODYGUIDANCEWITHBETTERSTRUCTURALPERFORMANCESNMANIPULATORSHAVEBEENWIDELYINVESTIGATEDINAPPLICATIONSFORTHEIRUNIQUEADVANTAGESSUCHASLOWINERTIA,LIGHTANDSOON10ITISNOTDIFfiCULTTOfiNDTHATTHEWEIGHTOFGOODSISSUPPORTEDMOSTLYBYTHECABLESTHEREFORE,THEENTFORSTRENGTHANDSTIFFNESSOFTHELIFTGUIDANCEMECHANISMISLOWER,ANDTHEWEIGHTOFITCANBEDECREASEDASARESULTE,COMPAREDWITHCOMPONENTSOFTHEGENERALFORKLIFTTRUCKS,SUCHASCYLINDER,CHAINS,CHAINWHEELSANDTHEMASTSYSTEM,OFLIFTINGMECHANISMUTILIZESWINDLASS,CABLESANDSEVERALCONNECTINGRODSTHEIRWEIGHTISLOWERANDTHEGRAVITYCENTEROFMOVESBACKWARDSCONSEQUENTLY,THEWEIGHTOFREAREQUILIBRATORISGREATLYDECREASEDANDTHEWHOLEWEIGHTOFTHETRUCKMUCHLOWERSOTHEPROPOSEDFORKLIFTTRUCKREDUCESENERGYCONSUMPTIONANDIMPROVESTHEFUELECONOMYOFTHEVEHICLE
编号:201311171552196998    类型:共享资源    大小:460.98KB    格式:PDF    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--叉车升降机构的创新设计 英文版.pdf
链接地址:http://www.renrendoc.com/p-96998.html

当前资源信息

4.0
 
(2人评价)
浏览:153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