簡介：附錄1BEGINNINGASPNET20INCASPACTIVESERVERPAGESISARELATIVELYNEWTECHNOLOGYTHAT’SALREADYLEAPTTHROUGHSEVERALSTAGESOFEVOLUTIONITWASINTRODUCEDABOUTSEVENYEARSAGOASANEASYWAYTOADDDYNAMICCONTENTTOORDINARYWEBPAGESSINCETHEN,IT’SGROWNINTOSOMETHINGMUCHMOREAMBITIOUSAPLATFORMFORCREATINGADVANCEDWEBAPPLICATIONS,INCLUDINGECOMMERCESHOPS,DATADRIVENPORTALSITES,ANDJUSTABOUTANYTHINGELSEYOUCANFINDONTHEINTERNETASPNET20ISTHELATESTVERSIONOFASP,ANDITREPRESENTSTHEMOSTDRAMATICCHANGEYETWITHASPNET,DEVELOPERSNOLONGERNEEDTOPASTETOGETHERAJUMBLEOFHTMLANDSCRIPTCODEINORDERTOPROGRAMTHEWEBINSTEAD,YOUCANCREATEFULLSCALEWEBAPPLICATIONSUSINGNOTHINGBUTCODEANDADESIGNTOOLSUCHASVISUALSTUDIO2005THECOSTOFALLTHISINNOVATIONISTHELEARNINGCURVENOTONLYDOYOUNEEDTOLEARNHOWTOUSEANADVANCEDDESIGNTOOLVISUALSTUDIOANDATOOLKITOFOBJECTSTHENETFRAMEWORK,YOUALSONEEDTOMASTERAPROGRAMMINGLANGUAGESUCHASCTHEINTERNETBEGANINTHELATE1960SASANEXPERIMENTITSGOALWASTOCREATEATRULYRESILIENTINFORMATIONNETWORKONETHATCOULDWITHSTANDTHELOSSOFSEVERALCOMPUTERSWITHOUTPREVENTINGTHEOTHERSFROMCOMMUNICATINGDRIVENBYPOTENTIALDISASTERSCENARIOSSUCHASNUCLEARATTACK,THEUSDEPARTMENTOFDEFENSEPROVIDEDTHEINITIALFUNDINGTHEEARLYINTERNETWASMOSTLYLIMITEDTOEDUCATIONALINSTITUTIONSANDDEFENSECONTRACTORSITFLOURISHEDASATOOLFORACADEMICCOLLABORATION,ALLOWINGRESEARCHERSACROSSTHEGLOBETOSHAREINFORMATIONINTHEEARLY1990S,MODEMSWERECREATEDTHATCOULDWORKOVEREXISTINGPHONELINES,ANDTHEINTERNETBEGANTOOPENUPTOCOMMERCIALUSERSIN1993,THEFIRSTHTMLBROWSERWASCREATED,ANDTHEINTERNETREVOLUTIONBEGANITWOULDBEDIFFICULTTODESCRIBEEARLYWEBSITESASWEBAPPLICATIONSINSTEAD,THEFIRSTGENERATIONOFWEBSITESOFTENLOOKEDMORELIKEBROCHURES,CONSISTINGMOSTLYOFFIXEDHTMLPAGESTHATNEEDEDTOBEUPDATEDBYHANDBASICHTMLPAGEISALITTLELIKEAWORDPROCESSINGDOCUMENTITCONTAINSFORMATTEDCONTENTTHATCANBEDISPLAYEDONYOURCOMPUTER,BUTITDOESN’TACTUALLYDOANYTHINGTHEFOLLOWINGEXAMPLESHOWSHTMLATITSSIMPLEST,WITHADOCUMENTTHATCONTAINSAHEADINGANDSINGLELINEOFTEXTANHTMLDOCUMENTHASTWOTYPESOFCONTENTTHETEXTANDTHETAGSTHATTELLTHEBROWSERHOWTOFORMATITTHETAGSAREEASILYRECOGNIZABLE,BECAUSETHEYOCCURINSIDEANGLEDBRACKETSHTMLDEFINESTAGSFORDIFFERENTLEVELSOFHEADINGS,PARAGRAPHS,HYPERLINKS,ITALICANDBOLDFORMATTING,HORIZONTALLINES,ANDSOONFOREXAMPLE,SOMETEXTTELLSTHEBROWSERTODISPLAYSOMETEXTINTHEHEADING1STYLE,WHICHUSESALARGE,BOLDFONTFIGURE11SHOWSTHESIMPLEHTMLPAGEINABROWSERHTML20INTRODUCEDTHEFIRSTSEEDOFWEBPROGRAMMINGWITHATECHNOLOGYCALLEDHTMLFORMSHTMLFORMSEXPANDHTMLSOTHATITINCLUDESNOTONLYFORMATTINGTAGSBUTALSOTAGSFORGRAPHICALWIDGETS,ORCONTROLSTHESECONTROLSINCLUDECOMMONINGREDIENTSSUCHASDROPDOWNLISTS,TEXTBOXES,ANDBUTTONSHERE’SASAMPLEWEBPAGECREATEDWITHHTMLFORMCONTROLSHTMLFORMSALLOWWEBAPPLICATIONDEVELOPERSTODESIGNSTANDARDINPUTPAGESWHENTHEUSERCLICKSTHEERRORPRONEDEPLOYMENTSTEPSINSTEAD,AWEBAPPLICATIONCANBEUSEDONANYCOMPUTERTHATHASINTERNETACCESSBUTWHENDEVELOPERSUSECLIENTSIDETECHNOLOGIES,THEYENCOUNTERAFEWFAMILIARHEADACHESSUDDENLY,CROSSBROWSERCOMPATIBILITYBECOMESAPROBLEMDEVELOPERSAREFORCEDTOTESTTHEIRWEBSITESWITHDIFFERNETOPERATINGSYSTEMSANDBROWSERS,ANDTHEYMIGHTEVENNEEDTODISTRIBUTEBROWSERUPDATESTOTHEIRCLIENTSINOTHERWORDS,THECLIENTSIDEMODELSACRIFICESSOMEOFTHEMOSTIMPORTANTBENEFITSOFWEBDEVELOPMENTORTHATREASON,ASPNETISDESIGNEDASASERVERSIDETECHNOLOGYALLASPNETCODEEXECUTESONTHESERVERWHENTHECODEISFINISHEDEXECUTING,THEUSERRECEIVESANORDINARYHTMLPAGE,WHICHCANBEVIEWEDINANYBROWSERFIGURE13SHOWSTHEDIFFERENCEBETWEENTHESERVERSIDEANDCLIENTSIDEMODELTHESEARESOMEOTHERREASONSFORAVOIDINGCLIENTSIDEPROGRAMMINGISOLATIONCLIENTSIDECODECAN’TACCESSSERVERSIDERESOURCESFOREXAMPLE,ACLIENTSIDEAPPLICATIONHASNOEASYWAYTOREADAFILEORINTERACTWITHADATABASEONTHESERVERATLEASTNOTWITHOUTRUNNINGINTOPROBLEMSWITHSECURITYANDBROWSERCOMPATIBILITYSECURITYENDUSERSCANVIEWCLIENTSIDECODEANDONCEMALICIOUSUSERSUNDERSTANDHOWANAPPLICATIONWORKS,THEYCANOFTENTAMPERWITHITMECASES,ASPNETALLOWSYOUTOCOMBINETHEBESTOFCLIENTSIDEPROGRAMMINGWITHSERVERSIDEPROGRAMMINGFOREXAMPLE,THEBESTASPNETCONTROLSCANINTELLIGENTLYDETECTTHEFEATURESOFTHECLIENTBROWSERIFTHEBROWSERSUPPORTSJAVASCRIPT,THESECONTROLSWILLRETURNAWEBPAGETHATINCORPORATESJAVASCRIPTFORARICHER,MORERESPONSIVEUSERINTERFACEHOWEVER,NOMATTERWHATTHECAPABILITIESOFTHEBROWSER,YOURCODEISALWAYSEXECUTEDONTHESERVERSTATELIMITATIONSTOENSUREOPTIMUMPERFORMANCE,THEWEBISBUILTONSTATELESSPROTOCOLS,WHICHMEANSASSOONASAPAGEISSENTTOAUSER,THECONNECTIONISCLOSEDANDANYUSERSPECIFICINFORMATIONISDISCARDEDASPINCLUDESASESSIONSTATEFEATURETHATALLOWSPROGRAMMERSTOWORKAROUNDTHISPROBLEMUSINGSESSIONSTATE,AWEBAPPLICATIONCANRETAINTEMPORARYINFORMATIONABOUTEACHCLIENTINSERVERMEMORYHOWEVER,SESSIONSTATEISUSELESSINSCENARIOSWHEREAWEBSITEISHOSTEDBYSEVERALSEPARATEWEBSERVERSINTHISSCENARIO,ACLIENTMIGHTACCESSSERVERBWHILEITSSESSIONINFORMATIONISTRAPPEDONSERVERAANDESSENTIALLYABANDONEDASPNETCORRECTSTHISPROBLEMBYALLOWINGSTATETOBESTOREDINACENTRALREPOSITORY,SUCHASASEPARATEPROCESSORADATABASETHATALLSERVERSCANACCESSASPNETDEALSWITHTHESEPROBLEMSANDMANYMOREBYINTRODUCINGACOMPLETELYNEWMODELFORWEBPAGESTHISMODELISBASEDONAREMARKABLEPIECEOFTECHNOLOGYCALLEDTHENETFRAMEWORKYOUSHOULDUNDERSTANDTHATTHENETFRAMEWORKISREALLYACLUSTEROFSEVERALTECHNOLOGIESTHENETLANGUAGESTHESEINCLUDECANDVBNETVISUALBASICNET,THEOBJECTORIENTEDANDMODERNIZEDSUCCESSORTOVISUALBASIC60THESELANGUAGESALSOINCLUDESCRIPTNETASERVERSIDEVERSIONOFJAVASCRIPT,JAJAVACLONE,ANDCWITHMANAGEDEXTENSIONSHECLRCOMMONLANGUAGERUNTIMETHECLRISTHEENGINETHATEXECUTESALLNETPROGRAMSANDPROVIDESAUTOMATICSERVICESFORTHESEAPPLICATIONS,SUCHASSECURITYCHECKING,MEMORYMANAGEMENT,ANDOPTIMIZATIONTHENETFRAMEWORKCLASSLIBRARYTHECLASSLIBRARYCOLLECTSTHOUSANDSOFPIECESOFREBUILTFUNCTIONALITYTHATYOUCAN“SNAPIN”TOYOURAPPLICATIONSTHESEFEATURESARESOMETIMESORGANIZEDINTOTECHNOLOGYSETS,SUCHASADONETTHETECHNOLOGYFORCREATINGDATABASEAPPLICATIONSANDWINDOWSFORMSTHETECHNOLOGY

簡介：1外文原文外文原文THECDESIGNRATIONALECISDESIGNEDTOBEANEXTENSIBLEPLATFORMFORRAPIDLYDEVELOPINGPROGRAMANALYSISTOOLSSEVERALFEATURESOFCFACILITATETHISBYCONVENTION,CWRITTENINLOWERCASELETTERSREFERSJUSTTOTHEPROGRAMTHATABSTRACTSDATAFROMACPROGRAMCIAWRITTENINCAPITALLETTERSREFERSTOTHESYSTEMMADEOFTHATABSTRACTORANDALLOFTHETOOLSTHATUSETHEDATABASEITGENERATESENTITIESINCLUDELES,MACROS,TYPES,FUNCTIONSANDVARIABLESSEPARATIONOFINFORMATIONEXTRACTIONANDPRESENTATIONTHEPROCESSOFEXTRACTINGINFORMATIONFROMAPROGRAMANDTHEPROCESSOFPRESENTINGTHATINFORMATIONSHOULDBESEPARATETHISELIMINATESTHENEEDFOREACHCANALYSISTOOLTODUPLICATETHEPARSINGPROCESSANDALLOWSCTOOLSTOSHARETHEINFORMATIONANDPRESENTITINDIFFERENTWAYSASIMILARDOCTRINEWASDEVELOPEDINTHEINTERLISPPROJECTUNFORTUNATELY,MANYCANDCTOOLSTODAYSTILLVIOLATETHISBASICPRINCIPLEAWELLCONCEIVEDCONCEPTUALMODELACONCEPTUALMODELBASEDONTHEENTITYRELATIONSHIPMODELWASDESIGNEDTODESCRIBETHEENTITIES,ATTRIBUTES,ANDRELATIONSHIPSINCPROGRAMSTHEMODELSERVESASANACCURATEHIGHLEVELSPECIFICATIONFORTHECONTENTSOFTHEPROGRAMDATABASERELATIONALDATABASETOSUPPORTREUSE,CSTORESABSTRACTEDINFORMATIONINTHEFORMOFARELATIONALDATABASETHISMAKESITPOSSIBLEFORTHATINFORMATIONTOBEACCESSEDBYAWIDEVARIETYOFEXISTINGDATABASEQUERYSYSTEMSINCREMENTALDATABASECONSTRUCTIONCBUILDSANDMAINTAINSAPROGRAMDATABASEFORLARGESYSTEMSEFFICIENTLYBECAUSEITALLOWSINCREMENTALUPDATESOFADATABASEWHENASETOFCSOURCELESISUPDATED,ONLYTHATPORTIONHASTOBEREABSTRACTEDTOUPDATETHEDATABASETHESEBASICDESIGNPRINCIPLESGIVETOOLSBASEDONCANADVANTAGEOVERMANYTRADITIONALDEVELOPMENTTOOLS,WHICHUSUALLYMERGETHEINFORMATIONEXTRACTIONAND3OFTHESIGNALREFLECTEDBYTHETARGET,ISADIRECTMEASUREOFTHEDISTANCEDTOBEMEASUREDHOWEVER,THELASERSIGNALISTRANSMITTEDATTHESPEEDOFLIGHTTHEREFORE,APRECISERANGINGREQUIRES,ACHANGEINTHEDISTANCETOTARGETBYFIFTEENCENTIMETERCORRESPONDSTOACHANGEINTIMEDIFFERENCEOFONLYONENANOSECONDINTHEPRIORART，THEREARESOMEMETHODSTOTRANSFORMTHEMEASUREDVALUESINORDERTOOBTAINTHEREQUIREDTIMERESOLUTIONANDCALCULATETHETIMEOFFLIGHTTHESEMETHODS,EITHERSTRETCHORTRANSFORMITINTOANOTHERMEASURABLEVALUESUCHASAVOLTAGE,RELYONAGREATQUANTITYOFPRECISEELECTRONICCOMPONENTS,INCREASETHECOMPLEXITYOFTHECIRCUITTHEACCURACYOFTHESEMETHODSISEASILYDEGRADEDBYTEMPERATUREAFFECTSMETHODSOFCALCULATINGTHEPHASEDIFFERENTBETWEENTHEELECTRONICCIRCUITMORECOMPLICATEDANDTAKEALONGERTIMETOPERFORMGENERALLY,ASPECIFICRANGINGMETHODANDAPPARATUSLIMITSTHERANGEANDRESOLUTIONOBTAINABLETHEREWITHTHATMEANS,ITISALMOSTIMPOSSIBLETOCHANGETHEMBYJUSTMODIFYINGAPARTOFTHECIRCUITOBJECTORIENTATIONANDCCISJUSTONEOFMANYPROGRAMMINGLANGUAGESINUSETODAYWHYARETHERESOMANYLANGUAGESWHYDONEWONESAPPEAREVERYFEWYEARSPROGRAMMINGLANGUAGESHAVEEVOLVEDTOHELPPROGRAMMERSEASETHETRANSITIONFROMDESIGNTOIMPLEMENTATIONTHEFIRSTPROGRAMMINGLANGUAGESWEREVERYDEPENDENTONTHEUNDERLYINGMACHINEARCHITECTUREWRITINGPROGRAMSATTHISLEVELOFDETAILISVERYCUMBERSOMEJUSTASHARDWAREENGINEERSLEARNEDHOWTOBUILDCOMPUTERSYSTEMSOUTOFOTHERCOMPONENTS,LANGUAGEDESIGNERSALSOREALIZEDTHATPROGRAMSCOULDBEWRITTENATAMUCHHIGHERLEVEL,THEREBYSHIELDINGTHEPROGRAMMERFROMTHEDETAILSOFTHEUNDERLYINGMACHINEWHYARETHERESUCHALARGENUMBEROFHIGHLEVELPROGRAMMINGLANGUAGESTHEREARELANGUAGESFORACCESSINGLARGEINVENTORYDATABASES,FORMATTINGFINANCIALREPORTS,CONTROLLINGROBOTSONTHEFACTORYFLOOR,PROCESSINGLISTS,CONTROLLINGSATELLITESINREALTIME,SIMULATINGANUCLEARREACTOR,PREDICTINGCHANGINGATMOSPHERICCONDITIONS,PLAYINGCHESS,ANDDRAWINGCIRCUITBOARDSEACHOFTHESEPROBLEMSREQUIRESDIFFERENTSETSOFDATASTRUCTURESAND

簡介：內(nèi)蒙古科技大學本科生畢業(yè)設計說明書（畢業(yè)論文）題目基于AT89C51單片機的步進電機控制系統(tǒng)學生姓名學號專業(yè)自動化班級自動化063班指導教師內(nèi)蒙古科技大學畢業(yè)設計說明書（畢業(yè)論文）IIBASEDONAT89C51SINGLECHIPCOMPUTERSTEPPINGMOTORCONTROLSYSTEMABSTRACTSTEPPINGMOTORISAKINDOFDIGITALCONTROLSYSTEMCOMPONENTSITCANACHIEVEQUICKSTARTUP,POSITIVEINVERSION,STOPPINGANDSPEEDCONTROL,ACCORDINGTOTHECONTROLPULSEITHASHIGHPRECISIONSTEPANGLE,ANDCANBESELFLOCKINGWHENITKEEPSSTILLASTHESECHARACTERISTICS,STEPPINGMOTORINAUTOMATICCONTROLSYSTEM,ESPECIALLYINTHEOPENLOOPCONTROLSYSTEMHASBEENWIDELYAPPLIEDTHISARTICLEMAINLYFOCUSESONTAKINGSINGLECHIPCOMPUTERANDCYCLEPULSEDISTRIBUTORASTHECORE,ANDDESIGNINGTHESTEPPINGMOTORCONTROLSYSTEMTHROUGHTHEDESIGNOFTHESOFTWAREANDHARDWAREDEBUGGING,ITREALIZESCONTROLLINGTHESTEPMOTOR’SACCELERATIONANDDECELERATIONAUTOMATICALLY,ACCORDINGTOPARAMETERSETTINGMAKINGTHESYSTEMARRIVETHEENDPOINTWITHTHESHORTESTTIME,BUTNOTOCCUROUTINGOFSTEPBESIDESITCANACCURATELYACHIEVESTARTUP,POSITIVEINVERSIONANDSHUTDOWNHARDWARETAKESAT89C51ASTHECOREOFCONTROLCIRCUIT,MAINLYINCLUDINGCYCLEPULSEDISTRIBUTOR,KEYBOARDANDDISPLAYCIRCUIT,STEPPINGMOTORDRIVINGCIRCUIT,ETCSOFTWAREPARTADOPTSTHECLANGUAGEPROGRAMMING,MAINLYINCLUDINGKEYBOARDANDDISPLAYPROGRAM,STEPPINGMOTORSPEEDCONTROLPROGRAM,STOPJUDGINGPROGRAM,ETCKEYWORDSSTEPPINGMOTORCONTROLSYSTEMSPEEDCONTROLSINGLECHIPCOMPUTER

簡介：外文翻譯1附錄附錄A英文原文英文原文DESIGNOFPWMCONTROLLERINAMCS51COMPATIBLEMCUAUTHORYUELIHU,WEIWANGMICROELECTRONICRESEARCHDEVELOPMENTCENTERCAMPUSPOB221,149YANCHANGRD,SHANGHAI200072,CHINAINTRODUCTIONPWMTECHNOLOGYISAKINDOFVOLTAGEREGULATIONMETHODBYCONTROLLINGTHESWITCHFREQUENCYOFDCPOWERWITHFIXEDVOLTAGETOMODIFYTHETWOENDVOLTAGEOFLOADTHISTECHNOLOGYCANBEUSEDFORAVARIETYOFAPPLICATIONSINCLUDINGMOTORCONTROL,TEMPERATURECONTROLANDPRESSURECONTROLANDSOONINTHEMOTORCONTROLSYSTEMSHOWNASFIG1,THROUGHADJUSTINGTHEDUTYCYCLEOFPOWERSWITCH,THESPEEDOFMOTORCANBECONTROLLEDASSHOWNINFIG2,UNDERTHECONTROLOFPWMSIGNAL,THEAVERAGEOFVOLTAGETHATCONTROLSTHESPEEDOFMOTORCHANGESWITHDUTYCYCLEDT1/TINTHISFIGURE,THUSTHEMOTORSPEEDCANBEINCREASEDWHENMOTORPOWERTURNON,DECREASEDWHENPOWERTURNOFFFIG1THERELATIONSHIPBETWEENVOLTAGEOFARMATUREANDFIG2ARCHITECTUREOFPWMMODULETHEREFORE,THEMOTORSPEEDCANBECONTROLLEDWITHREGULARLYADJUSTINGTHETIMEOFTURNONANDTURNOFFTHEREARETHREEMETHODSCOULDACHIEVETHEADJUSTMENTOFDUTYCYCLE1ADJUSTFREQUENCYWITHFIXEDPULSEWIDTH2ADJUSTBOTHFREQUENCYANDPULSEWIDTH3ADJUSTPULSEWIDTHWITHFIXEDFREQUENCYGENERALLY,THEREAREFOURMETHODSTOGENERATETHEPWMSIGNALSASTHEFOLLOWING1GENERATEDBYTHEDEVICECOMPOSEDOFSEPARATELOGICCOMPONENTSTHISMETHODISTHEORIGINALMETHODWHICHNOWHASBEENDISCARDED2GENERATEDBYSOFTWARETHISMETHODNEEDCPUTO外文翻譯3DUTYCYCLEUPDATESARECONFIGURABLETOBEIMMEDIATEDORSYNCHRONIZEDTOTHEPWMFIG3ARCHITECTUREOFPWMMODULEDETAILSOFTHEARCHITECTUREPMWGENERATORTHEARCHITECTUREOFTHE2OUTPUTPWMGENERATORSHOWNINFIG4ISBASEDONA16BITRESOLUTIONCOUNTERWHICHCREATESAPULSEWIDTHMODULATEDSIGNALTHESYSTEMISSYNTHESIZEDBYASYSTEMCLOCKSIGNALWHOSEFREQUENCYCANBEDIVIDEDBY4TIMESOR12TIMESTHROUGHSETTINGTHEVALUEOFT3MFORPWM0ORT4MFORPWM1INTHESPECIALREGISTERPWMCONASSHOWNINFIG4TOPWM0GENERATOR,THECLOCKTO16BITCOUNTERWILLBEPREDIVIDEDBY4TIMESBYDEFAULTWHENT3MISSETTOZEROANDTHECLOCKWILLBEDIVIDEDBY12TIMESWHENT3MISSETTO1THISISALSOTRUEFORPWM1THEOTHERBITSINPWMCONAREEXPLAINEDINDETAILINTABLE1FIG4BITMAPPINGOFPWMCON

簡介：武漢工業(yè)學院武漢工業(yè)學院畢業(yè)設計（論計（論文）文）設計（論文）題目設計（論文）題目基于基于DSPDSP的語音信號的去噪方法的語音信號的去噪方法姓名________李YI__________YI__________學號___090000000____________090000000_________院（系）院（系）_電氣與電子工程學院電氣與電子工程學院______專業(yè)______通信工程通信工程______________________指導教師指導教師_____00000_____________00000________20132013年5月5日2目錄摘要基于DSP的語音信號的去噪方法1目錄2第一章緒論31．1課題的研究背景及意義31．2語音去噪的基礎知識41．2．1語音信號的特點41．2．2噪聲特性41．3TIDSP介紹5131C54X芯片614CCS開發(fā)環(huán)境6141CCS集成開發(fā)環(huán)境715本文重點總結(jié)8第二章小波在語音消噪中的應用921經(jīng)典的小波算法9211模極大值去噪算法9212相關(guān)性去噪算法9213小波閾值去噪算法1022一種新的小波閾值去噪方法1123本章總結(jié)12第三章實驗設計原理及過程1331小波去噪原理分析13311小波去噪原理13312小波去噪步驟1432閾值的選取與量化14321軟閾值和硬閾值14322閾值的幾種形式15323閥值的選取1633實驗步驟16331小波去噪驗證仿真16332小波去噪與FFT去噪效果對比1734本章總結(jié)18第四章實驗仿真及圖1941實驗結(jié)論19結(jié)論21致謝22參考文獻23附錄24

簡介：中文中文4220字畢業(yè)論文外文資料翻畢業(yè)論文外文資料翻譯題目合成ΒMO2C薄膜和電子場發(fā)射13我們目的是用價格低廉的材料替代鉑族金屬來表面氫分離。這種材料合成的薄膜將有利于催化劑性能的基礎研究。許多技術(shù)已被用于沉積碳化鉬薄膜，包括化學氣相沉積（CVD），814，物理氣相沉積（PVD），9，11和電化學沉積。15MOC是相當復雜的，它有眾多的穩(wěn)定和亞穩(wěn)化合物和晶相。1416，相純度的控制一直是個難題，CVD和PVD兩種方法的制備中，薄膜通常包含混合富含碳的產(chǎn)物，它是一個復雜的依賴具體操作條件選測的過程。8，11，14與此相反，它的催化應用制備所需的粉末狀ΒMO2C相。14，后來BOUDART和他的同事12開發(fā)出一種方法，加入H2稀釋的碳氫化合物并采用程序升溫反應或TPR的混合物轉(zhuǎn)換成高表面積MO2C密集的氧化鉬粉。MOO3轉(zhuǎn)變?yōu)镸O2C方法涉及MOO3的晶格中的氧碳替代，在反應過程中有MO原子的微小位移。因為MO2C的摩爾體積比MOO3的摩爾體積小，微孔狀的氧化物轉(zhuǎn)換成碳化物。在適當條件下的氧化鉬被轉(zhuǎn)換成MO2C過程中沒有形成金屬鉬作為反應中間體。金屬燒結(jié)，避免使用這種方法，在物催化劑催化劑條件下，它可以準備具有很高的表面積（5090平方米/克）。REBROVETAL5采用這方法，形成催化劑通過預氧化的鉬片滲碳涂料把它們應用到水煤氣變換反應。本實驗是合成純相的ΒMO2C未來研究模型催化劑層薄膜。下面我們介紹一個兩步合成方法。首先，采用等離子體增強化學氣相沉積法（PECVD）在MOF6/H2/O2混合物中使密集的氧化鉬薄膜沉積在硅片上。MOF6在這種化學反應中是很獨特，以前的含鉬的化合物的反應是用MO（CO）的1718或MOCL514，19來化學氣相沉積。用PECVD參數(shù)來描述氧化物的增長速度和質(zhì)量。使用的PECVD形成氧化物將產(chǎn)生在更廣泛的承印物上。薄膜通過TPR的催化條件轉(zhuǎn)化為ΒMO2C相。使用一套分析技術(shù)可將整個過程中膜的組成和結(jié)構(gòu)的演變進行了量化。2試驗一氧化氮合成在MOF6/H2/O2混合在一個電容耦合的PECVD系統(tǒng)中使氧化鉬薄膜沉積。采用類似PECVD反應的化學的方法，用類似的氣體混合物（WF6/H2/O2）17，20已成功地應用于合成的電致變色WO3的薄膜。鉬六氟化硫ACROSORGANIC,995VOL的分解容易，但是反應過程中產(chǎn)生的氟自由基蝕刻膜是可逆的。為了解決這一問題，我們添加了氫的高頻電子流來除去氟原子形成。還提供氧氣過量，以形成充分的氧化膜。這里描述的所有方法是在常溫下進行的，并且電壓固定在200W。使用校準的針閥控制MOF6生成，而電子質(zhì)量流量控制器控制氧氣和氫氣流速。該反應的沉積壓力范圍為500?700毫托取決于機械泵（愛德華茲，E2M40）的控制。

簡介：中文中文43754375字出處出處SCHAFERRW,RABINERLRDESIGNOFDIGITALFILTERBANKSFORSPEECHANALYSISJBELLSYSTEMTECHNICALJOURNAL,1971,501030973115實現(xiàn)語音分析的數(shù)字濾波器組設計RWSCHAFERANDLRRABINERBELLTELEPHONELABORATORIES,INCORPERATEDMURRYAYHILL,NJ本文是關(guān)于數(shù)字濾波器組的設計和分析，這些濾波器組是由相同帶通特性的等間隔帶通濾波器組成。通過選擇合適的相關(guān)相位的帶通濾波器，合成濾波器的響應特性得到顯著提升。這個結(jié)果擴展了一般濾波器的功能。I引言許多語音處理系統(tǒng)是基于短時頻譜分析的概念。這些系統(tǒng)的頻譜分析儀通常是由一組具有合適頻率范圍的混合通帶的帶通濾波器組組成。連續(xù)時間濾波的濾波器組往往被用在語音分析上，現(xiàn)在基于數(shù)字硬件實現(xiàn)的數(shù)字濾波器組也是可用的。在數(shù)字濾波器組的設計方面，其提供了很多優(yōu)點，這些優(yōu)點包括單個帶通濾波器設計的靈活性，實現(xiàn)的精確性，數(shù)字硬件的穩(wěn)定性，通過數(shù)字硬件的復用實現(xiàn)濾波器組應用的高效性。此外，由數(shù)字帶通濾波器組成的濾波器組的設計技術(shù)也值得考慮。為了專注于濾波器組的設計的基礎概念，定義一個理想濾波器組的頻譜分析儀是很有用的。（圖1）描述了一個這樣的濾波器組，II均勻濾波器組的分析假定圖1的帶通濾波器有以下形式的脈沖響應（1）其中，這里的K1,HNT是原型低通濾波器的脈沖響應，（K01?W時濾波器被使用）這組帶通濾波器的功能是公式（2）中的Z用取代后，獲得這些濾波器的頻率響應E?JΩT如果原型低通濾波器的頻率響應急劇，從公式（3）中可以得到

簡介：中文中文3580字畢業(yè)設計（論計（論文）外文）外文參考資料及譯文譯文題目譯文題目基于語音識別的智能門控系統(tǒng)設計出處出處2009ISECSINTERNATIONALCOLLOQUIUMONCOMPUTING,COMMUNICATION,CONTROL,ANDMANAGEMENT3

簡介：ANAT89C2051BASEDINTELLIGENTPROXIMITYWARNINGINDICATORFORAUTOMOBILEITINTRODUCESTHEFUNCTIONANDCHARACTERISTICSOFMICROCONTROLLERAT89C2051BASEDONITALOWCOSTHIGHACCURACYMICROMINIATURIZATIONANDDIGITALDISPLAYPROXIMITYWARNINGINDICATORFORAUTOMOBILEISDESIGNEDTHEINDICATORMEASURESTHEDISTANCEANDSPEEDOFTHEAUTOMOBILE,WITHULTRASONICWAVEANDINTEGRATEDHALLUNITANDCONTROLSTHESYSTEMBYTHEREALTIMECONTROLANDDATAPROCESSINGOFTHEMICROCONTROLLERMOREOVERITSCIRCUITRYPRINCIPLEISINTRODUCEDINDETAILASWELLASITSSOFTWAREDESIGNALONGWITHMODERNRHYTHMOFLIFESPEEDINGUP,THEFREQUENCYWHICHTHETRAFFICACCIDENTOCCURREDISINCREASING,FORENHANCESTHESECURITYOFAUTOMOBILEMOVEMENTTHISARTICLEINTRODUCEDONEKINDOFALARMSYSTEMBASEDONMONOLITHICINTEGRATEDCIRCUITCONTROLSTHEAUTOMOBILEGUARDSAGAINSTHITTINGTHISEQUIPMENTTHEMONOLITHICINTEGRATEDCIRCUITREALTIMECONTROLANDTHEDATAPROCESSINGFUNCTION,WITHTHEULTRASONICWAVERANGEFINDERTECHNOLOGY,THESENSORTECHNOLOGYUNIFIES,MAYEXAMINEINTHEAUTOMOBILEMOVEMENTREARAREATHEOBSTACLEANDTHEAUTOMOBILEDISTANCEANDTHEAUTOMOBILEVEHICLESPEED,REVEALSTHEINSTALLMENTDEMONSTRATIONDISTANCETHROUGHTHENUMBER,ANDISAWAYFROMFARANDNEARTHESITUATIONBYTHESOUNDPRODUCTIONELECTRICCIRCUITBASISTOSENDOUTTHEWARNINGSOUNDTHEULTRASONICRANGINGPRINCIPLEIS,AFTERUNCEASINGLYEXAMINESTHEULTRASONICWAVELAUNCHTOMEETTHEECHOWHICHTHEOBSTACLEREFLECTS,THUSDETERMINESTHELAUNCHULTRASONICWAVEANDRECEIVESTHEECHOTHETIMEDIFFERENCETHENEXTRACTSISAWAYFROMSCT/2,CISTHEULTRASONICWAVEWAVEVELOCITY,UNDERTHENORMALTEMPERATURETAKESIS344M/SAFTERSONICSPEEDDETERMINATION,SOLONGASOBTAINSTHEULTRASONICWAVEROUNDTRIPTHETIME,THENOBTAINSTHEDISTANCETHEAUTOMOBILEVEHICLESPEEDSURVEYISINTEGRATESTHESENSORTHROUGHHALLTOREALIZENAMELY,ISLOADEDWITHTHEPERMANENTMAGNETTHETURNTABLEINPUTAXISANDTHEWHEELREVOLUTIONAXISISCONNECTED,WHENTHEWHEELROTATES,THETURNTABLEALONGWITHITROTATION,THISTIME,ONTHETURNTABLEPERMANENTMAGNETCANINTEGRATETHESENSORAFTERHALL,THUSINTEGRATESTHESENSORINHALLTHEINPUTENDTOOBTAINAMAGNETISMSIGNAL,IFTHETURNTABLEDOESNOTSTOPTHEROTATION,HALLINTEGRATESTHESENSORTHENTOBEABLETOOUTPUTTHEROTATIONALSPEEDSIGNALITCANBESAIDTHAT,TOTHEAUTOMOBILEVEHICLESPEEDSURVEYESSENCEINTOTHEROTATIONALSPEEDSIGNALFREQUENCYSURVEYAT89C2051ISALOWPOWERLOSS,THEHIGHPERFORMANCE8CMOSMICROPROCESSOR,ISCOMPATIBLEWITHTHEMCS51SERIESINSTRUCTIONCOLLECTIONANDTHEPIN,HASFOLLOWINGCHARACTERISTIC128BYTESINTERNALRAM,2KBYTESEPROM,FIFTEENI/OLINE,TWOSIXTEENFIXEDTIMECOUNTERS,FIVETWOLEVELOFINTERRUPTSOURCES,ONEENTIREDUPLEXSERIALPORT,INTERNALPRECISELYSIMULATESTHECOMPARATORANDINTERNALSWINGMING,THELOWPOWERLOSSLEAVESUNUSEDANDFALLSTHEELECTRICITYPATTERNTHEWORKINGVOLTAGESCOPE42555V,THEOPERATINGFREQUENCYTAKES12MHZINAT89C2051,TWOSIXTEENFIXEDTIME/COUNTERSREGISTERSIST0ANDT1,MAKEFIXEDTIME/COUNTERS,MAYCOUNTTHEMACHINECYCLE,COUNTSTHEFREQUENCYFORTHEOSCILATIONFREQUENCY1/12WHENMAKESTHECOUNTER,MAYAPPEARSTOONEXTERIORINPUTPINP34/T0ANDP35/T1FROM1TO0CHANGESWHENINCREASE1,COUNTSTHEFREQUENCYFORWAY,WHENULTRASONICWAVELAUNCHSTARTSTOCOUNT,AFTERPINP32RECEIVESTHEECHO,STOPSCOUNTING,T0TIMESNAMELYFORTHEULTRASONICWAVEROUNDTRIPTRANSMISSIONTIME,THEMONOLITHICINTEGRATEDCIRCUITCARRIESONPROCESSINGTOTHISDATA,THENDETERMINESTHEDISTANCETHEINTERNALTIMERT1WORKISCOUNTINGTHEWAY,COUNTSBYP35PININPUTPULSESIGNALCONTROLT1,COUNTSTHEVALUEBYT1TODETERMINETHEAUTOMOBILETHEROTATIONALSPEEDTHEMONOLITHICINTEGRATEDCIRCUITBASISMEASUREDISAWAYFROMANDTHEVEHICLESPEEDCARRIESONTHECOMPARISON,JUDGESWHETHERACTUATESTHEALARMCIRCUITTOREPORTTOTHEPOLICE,LIKEHYPOTHESISWHENTHEVEHICLESPEEDISSMALLEROREQUALTO30KM/S,THESAFEDISTANCESHOULDBEBIGGERTHANISEQUALTO1MWHENTHEVEHICLESPEEDISSMALLEROREQUALTO80KM/S,THESAFEDISTANCESHOULDBEBIGGERTHANISEQUALTO2MWHENTHEVEHICLESPEEDISBIGGERTHAN80KM/S,THESAFEDISTANCESHOULDBEBIGGERTHANISEQUALTO5MTHISINSTALLMENTCONTROLSOFTWAREMUSTCOMPLETETHESYSTEMINITIALIZATION,THECONTROLTRIGGERPULSESIGNALLAUNCHANDTHERECEIVE,ACCORDINGTOFIXEDTIMETHECOUNTDOWNOBSTACLEDISTANCE,ACCORDINGTOCOUNTSTHEFREQUENCYCOMPUTATIONAUTOMOBILEVEHICLESPEED,JUDGESMEASUREDISAWAYFROMWHETHERINTHEMARGINFORSAFETYWHICHTHEVEHICLESPEEDCORRESPONDS,ANDACCORDINGTOCALCULATESHASTHEBCDCODEANDTHECORRESPONDINGFREQUENCYPULSESIGNALWITHTHEJUDGEMENTRESULT,ACTUATESTHEDISPLAYCIRCUITANDTHESOUNDPRODUCTIONELECTRICCIRCUIT

簡介：中文中文3487字出處出處WANGS,XUY,PANGYAFASTUNDERWATEROPTICALIMAGESEGMENTATIONALGORITHMBASEDONAHISTOGRAMWEIGHTEDFUZZYCMEANSIMPROVEDBYPSOJJOURNALOFMARINESCIENCEANDAPPLICATION,2011,1017075畢業(yè)論文（設計）外文翻譯水下強噪聲圖像目標分割方法研究學生姓名指導教師專業(yè)名稱電子信息工程所在學院信息工程學院2013年4月二、水下圖像分割傳統(tǒng)的二、水下圖像分割傳統(tǒng)的FCM算法算法FCM聚類分割算法的中心思想是根據(jù)加權(quán)相似性來衡量像素和聚類中心，迭代優(yōu)化目標函數(shù)已確定最佳的聚類。通過這個實現(xiàn)在LH圖像中（L和H待變相關(guān)圖像的寬度和高度），根據(jù)加權(quán)資格隸屬度N（NLH）屬于每個C聚類中心的圖像中的像素，當目標函數(shù)最小時，迭代地優(yōu)化目標函數(shù)來獲得模糊劃分矩陣U和類中心矩陣V。目標函數(shù)為通過拉格朗日乘數(shù)法，建立等式1的一個必要條件可以推導出這種典型的FCM圖像分割是為了通過迭代搜尋最優(yōu)聚類中心和隸屬度來獲得最小目標函數(shù)。三、直方圖加權(quán)三、直方圖加權(quán)FCM聚類算法（聚類算法（HWFCM）1、算法描述通過分析FCM算法，可以發(fā)現(xiàn)影響計算時間一個主要因素是聚類中心的更新頻率太低。在FCM算法中，每個聚類中心的更新必須等到所有輸入模式完成遍歷。當它用在圖像分割中，因為圖像的采樣數(shù)據(jù)數(shù)量非常大（每個圖像尺寸為768576，數(shù)量為442368），計算就十分耗時。因此，根據(jù)水下圖像的特性，我們提出了一種快速的FCM分割算法。在迭代處理中，通過采集圖像強度直方圖的統(tǒng)計特性作為隸屬度的權(quán)重，目標函數(shù)的最優(yōu)解可以得到。因此，它減少了FCM迭代過程大量的數(shù)據(jù)存儲而且加速了收斂速度。對于一個圖像（NLH），F(xiàn)（X,Y）是圖像在（X,Y）位置的灰度值，F(xiàn)∈{0,1,,I?1}，I是所有系列灰度圖像的數(shù)量。定義灰度圖像直方圖為HJ,因此一個加權(quán)直方圖修改的成員為相應的聚類中心新的目標函數(shù)為

簡介：USEOFVOICERECOGNITIONFORCONTROLOFAROBOTICWELDINGWORKCELLABSTRACTTHISPAPERDESCRIBESWORKUNDERWAYTOEVALUATETHEEFFECTIVENESSOFVOICERECOGNITIONSYSTEMSASANELEMENTINTHECONTROLOFAROBOTICWELDINGWORKCELLFACTORSBEINGCONSIDEREDFORCONTROLINCLUDEPROGRAMEDITORACCESSSECURITY,PREOPERATIONCHECKLISTREQUIREMENTS,WELDINGPROCESSVARIABLECONTROL,ANDROBOTMANIPULATORMOTIONOVERRIDESINTHELATTERTWOCATEGORIES,MANUALVOCALCONTROLISBEINGCOMPAREDAGAINSTMANUALTACTILECONTROLANDFULLYAUTOMATICCONTROLINTERMSOFSPEEDOFRESPONSE,ACCURACY,STABILITY,RELIABILITYANDSAFETYINTRODUCTIONVOICERECOGNITIONTECHNOLOGYISNOWRECOGNIZEDASAPOTENTIALMEANSFOREASINGTHEWORKLOADOFOPERATORSOFCOMPLEXSYSTEMSNUMEROUSAPPLICATIONSHAVEALREADYBEENIMPLEMENTED,AREINVARIOUSSTAGESOFDEVELOPMENT,ORAREUNDERCONSIDERATIONTHESEINCLUDEDATAENTRY,CONTROLOFAIRCRAFTSYSTEMS,ANDVOICEIDENTIFICATIONANDVERIFICATIONFORSECURITYPURPOSESVOICECONTROLHASALSOBEENPROPOSEDFORUSEABOARDTHESPACESTATIONONEPRIMEAREAFORAPPLICATIONWOULDBECONTROLOFSOMEFUNCTIONSOFROBOTSUSEDFORINTRAANDEXTRAVEHICULARINSPECTION,ASSEMBLY,REPAIR,SATELLITERETRIEVAL,ANDSATELLITEMAINTENANCEWHENACREWMEMBERISSERVINGINASUPERVISORYCAPACITYORTHESYSTEMISOPERATINGINATELEOPERATIONMODEVOICECONTROLOFSENSORSANDPROCESSVARIABLESWOULDFREETHECREWMEMBER’SHANDSFOROTHERTASKS,SUCHASDIRECTCONTROLOROVERRIDEOFTHEMANIPULATORMOTIONSIMILARLY,THEWORKLOADASSOCIATEDWITHCONTROLOFMANYONBOARDEXPERIMENTSCOULDBEEASEDTHROUGHTHEUSEOFTHISTECHNOLOGYTHISPAPERDESCRIBESTHEAPPLICATIONOFVOICERECOGNITIONFORCONTROLOFAROBOTICWELDINGWORKCELLTHISISACOMPLEXSYSTEMINVOLVINGINPUTSFROMMULTIPLESENSORSANDCONTROLOFAWIDEVARIETYOFROBOTMANIPULATORMOTIONSANDPROCESSVARIABLESWHILEMANYFUNCTIONSAREAUTOMATED,AHUMANOPERATORSERVESINASUPERVISORYCAPACITY,READYTOOVERRIDEFUNCTIONSWHENNECESSARYINTHEPRESENTINVESTIGATION,ACOMMERCIALLYAVAILABLEVOICERECOGNITIONSYSTEMISBEINGINTEGRATEDWITHAROBOTICWELDINGWORKCELLATNASAWIREFEEDGUIDETUBEORBYISSUINGTACTILECOMMANDSTOASERVOMECHANISMUSEOFAVOICERECOGNITIONSYSTEMCOULDELIMINATETHENEEDFORTHEOPERATORTOPLACEHISHANDWITHINTHEWORKINGENVELOPEOFTHEROBOTENDEFFECTOROR,IFSERVOMECHANISMSAREEMPLOYED,COULDIMPROVESPEEDOFRESPONSEANDSTABILITYANOTHERASPECTOFROBOTOPERATIONINANINDUSTRIALENVIRONMENTTHATISVERYIMPORTANTISTHESECURITYOFAPROGRAMEDITINGCAPABILITYOFTHESYSTEMUNDERNOCIRCUMSTANCESSHOULDANYUNAUTHORIZEDPERSONBEABLETOENTERTHISPROGRAMMINGMODEANDALTERTHEROBOT’SPROGRAMAVOICERECOGNITIONSYSTEMCANPROVIDETHENECESSARYSECURITYBYALLOWINGACCESSONLYFORINDIVIDUALSWHOAREAUTHORIZEDANDWHOSEVOICESCANBEIDENTIFIEDBYTHESYSTEMBACKGROUNDROBOTICWELDINGISUNDERDEVELOPMENTBYNASAANDROCKETDYNEFORTHEAUTOMATIONOFWELDSONTHESPACESHUTTLEMAINENGINETHATAREPRESENTLYMADEMANUALLYTHEPROGRAMMABILITYOFAROBOTCANREDUCETHEPERCENTAGEOFWELDINGDEFECTSTHROUGHACOMBINATIONOFCONSISTENCYANDREPEATABILITYUNATTAINABLEBYITSHUMANCOUNTERPARTSTODOTHIS,THEROBOTISPROGRAMMEDTOANOMINALWELDPATHANDLEVELOFWELDPROCESSPARAMETERSIE,CURRENT,TRAVELSPEEDVOLTAGE,WIREADDITIONRATESOMEADJUSTMENTOFTHESEVALUESISOFTENNECESSARYDUETOCONDITIONSCHANGINGDURINGTHEWELDAHUMANMAKINGAMANUALWELDACCOMPLISHESTHISADJUSTMENTREADILY,WHILEAROBOTMUSTRELYONTHELIMITEDTALENTSOFSENSORSANDTHEABILITYOFTHEOPERATORTOOVERRIDEFUNCTIONSWHENNECESSARYSYSTEMINTEGRATIONTHEBASICELEMENTSOFTHEWORKCELLSYSTEMARESHOWNDIAGRAMMATICALLYINTHEILLUSTRATIONTHEULTIMATEGOALOFTHESYSTEMDEVELOPMENTWORKINPROGRESSISTOGENERATEROBOTMANIPULATORPROGRAMSANDWELDPROCESSPROGRAMSOFFLINE,DOWNLOADTHEMTOTHEWORKCELLSUPERVISORYCOMPUTER,THENUSESENSORSUBSYSTEMSTOMAKECLOSEDLOOP

簡介：PUBLISHEDJANUARY20,2011R2011AMERICANCHEMICALSOCIETY517DXDOIORG/101021/AM101095H|ACSAPPLMATERINTERFACES2011,3,517–521RESEARCHARTICLEWWWACSAMIORGSYNTHESISOFΒMO2CTHINFILMSCOLINAWOLDEN,,?ANNAPICKERELL,?TRUPTIGAWAI,?STERLINGPARKS,?JESSEHENSLEY,?ANDJDOUGLASWAY??DEPARTMENTOFCHEMICALENGINEERING,COLORADOSCHOOLOFMINES,GOLDEN,COLORADO80401,UNITEDSTATES?NATIONALRENEWABLEENERGYLABORATORY,1617COLEBOULEVARD,GOLDEN,COLORADO80401,UNITEDSTATESABSTRACTTHINFILMSOFSTOICHIOMETRICΒMO2CWEREFABRICATEDUSINGATWOSTEPSYNTHESISPROCESSDENSEMOLYBDENUMOXIDEFILMSWEREFIRSTDEPOSITEDBYPLASMAENHANCEDCHEMICALVAPORDEPOSITIONUSINGMIXTURESOFMOF6,H2,ANDO2THEDEPENDENCEOFOPERATINGPARAMETERSWITHRESPECTTODEPOSITIONRATEANDQUALITYISREVIEWEDOXIDEFILMS100500NMINTHICKNESSWERETHENCONVERTEDINTOMOLYBDENUMCARBIDEUSINGTEMPERATUREPROGRAMMEDREACTIONUSINGMIXTURESOFH2ANDCH4XRAYDIFFRACTIONCONFIRMEDTHATMOLYBDENUMOXIDEISCOMPLETELYTRANSFORMEDINTOTHEΒMO2CPHASEWHENHEATEDTO700?CINMIXTURESOF20CH4INH2THEFILMSREMAINEDWELLADHEREDTOTHEUNDERLYINGSILICONSUBSTRATEAFTERCARBURIZATIONXRAYPHOTOELECTRONSPECTROSCOPYDETECTEDNOIMPURITIESINTHEFILMS,ANDMOWASFOUNDTOEXISTINASINGLEOXIDATIONSTATEMICROSCOPYREVEALEDTHATTHEASDEPOSITEDOXIDEFILMSWEREFEATURELESS,WHEREASTHECARBIDEFILMSDISPLAYACOMPLEXNANOSTRUCTUREKEYWORDSTHINFILM,CARBIDE,OXIDE,PLASMAENHANCEDCHEMICALVAPORDEPOSITION,CATALYST’INTRODUCTIONMOLYBDENUMCARBIDEISAVERSATILEMATERIALWITHPOTENTIALAPPLICATIONSINAVARIETYOFAREASMOLYBDENUMCARBIDEEXHIBITSCATALYTICPROPERTIESANALOGOUSTOPLATINUMGROUPMETALS,ANDINTHELASTFEWDECADES,EFFORTSHAVEBEENMADETOEXPLOITTHISTRAITINANUMBEROFCHEMICALPROCESSESINCLUDINGAMMONIASYNTHESIS,HYDROCARBONREFORMING,WATERGASSHIFT,H2PRODUCTION,ANDALCOHOLSYNTHESIS17ASATHINFILM,THEHIGHHARDNESSANDTHERMALSTABILITYOFTHETRANSITIONMETALCARBIDESMAKETHEMUSEFULASWEARRESISTANTMATERIALS8,9MORERECENTSTUDIESHAVEFOCUSEDONTHEOPTOELECTRONICPROPERTIESOFMOLYBDENUMCARBIDEFORARANGEOFAPPLICATIONSINCLUDINGMIRRORS,10DIFFUSIONBARRIERS,11INTERCONNECTS,12ANDELECTRONFIELDEMISSION13OURINTERESTISINTHECREATIONOFINEXPENSIVEALTERNATIVESTOPLATINUMGROUPMETALSFORSURFACEDISSOCIATIONOFH2FORMATIONOFTHISMATERIALASATHINFILMWOULDFACILITATEFUNDAMENTALSTUDIESOFCATALYSTPERFORMANCENUMEROUSTECHNIQUESHAVEBEENUSEDTODEPOSITMOLYBDENUMCARBIDEFILMSINCLUDINGCHEMICALVAPORDEPOSITIONCVD,8,14PHYSICALVAPORDEPOSITIONPVD,9,11ANDELECTRODEPOSITION15THEMOCSYSTEMISQUITECOMPLEX,WITHNUMEROUSSTABLEANDMETASTABLECOMPOUNDSANDCRYSTALPHASESTHATHAVEBEENOBSERVED14,16CONTROLOFPHASEPURITYHASBEENPROBLEMATICFORBOTHCVDANDPVDAPPROACHES,ANDFILMSOFTENCONTAINAMIXTUREOFCARBONRICHPRODUCTSTHATDISPLAYACOMPLEXDEPENDENCEONTHESPECIFICOPERATINGCONDITIONSEMPLOYED8,11,14INCONTRAST,FORCATALYSISAPPLICATIONSITISRELATIVELYSTRAIGHTFORWARDTOACHIEVETHEDESIREDΒMO2CPHASEINPOWDERFORM14THEKEYDEVELOPMENTCAMEFROMBOUDARTANDCOWORKERS1,2WHODEVELOPEDAMETHODTOCONVERTDENSEMOO3POWDERSINTOHIGHSURFACEAREAMO2CBYTEMPERATUREPROGRAMMEDREACTIONORTPR,USINGMIXTURESOFHYDROCARBONSDILUTEDINH2THEMECHANISMFORTHEMOO3TOMO2CTRANSFORMATIONINVOLVESTHESUBSTITUTIONOFCARBONFOROXYGENINTHEMOO3LATTICE,WITHLITTLEDISPLACEMENTOFTHEMOATOMSDURINGTHEREACTIONBECAUSETHEMOLARVOLUMEOFMO2CISSMALLERTHANTHEMOLARVOLUMEOFMOO3,MICROPORESFORMASTHEOXIDETRANSFORMSINTOTHECARBIDEUNDERPROPERCONDITIONSTHEMOO3ISCONVERTEDINTOMO2CWITHOUTFORMINGMETALLICMOASAREACTIONINTERMEDIATEMETALSINTERINGISAVOIDEDUSINGTHISMETHOD,ANDUNSUPPORTEDCATALYSTSCANBEPREPAREDWITHVERYHIGHSURFACEAREAS5090M2/GREBROVETAL5USEDTHISSTRATEGYTOFORMCATALYSTCOATINGSTHROUGHTHECARBURIZATIONOFPREOXIDIZEDMOLYBDENUMSHEETS,ANDAPPLIEDTHEMTOTHEWATERGASSHIFTREACTIONTHEGOALOFTHISWORKWASTOPRODUCEPHASEPUREΒMO2CFILMSFORFUTURESTUDYASMODELCATALYSTLAYERSBELOWWEDESCRIBEATWOSTEPSYNTHESISAPPROACHFIRST,DENSEMOLYBDENUMOXIDEFILMSAREDEPOSITEDONSILICONUSINGPLASMAENHANCEDCHEMICALVAPORDEPOSITIONPECVDUSINGMIXTURESOFMOF6/H2/O2THEUSEOFMOF6ANDTHISREACTIONCHEMISTRYISSOMEWHATUNIQUE,ASPREVIOUSCVDOFMOCONTAININGCOMPOUNDSHAVEEMPLOYEDEITHERMOCO617,18ORMOCL514,19ASTHEMOLYBDENUMPRECURSORTHEDEPENDENCEOFOXIDEGROWTHRATEANDQUALITYONPECVDPARAMETERSISDESCRIBEDTHEUSEOFPECVDTOFORMTHEOXIDEALLOWSTHESEFILMSTOBEPRODUCEDONABROADERSETOFSUBSTRATESTHEFILMSWERETHENTRANSFORMEDINTOTHEΒMO2CPHASEBYAPPLYINGTPRCONDITIONSDEVELOPEDBYTHECATALYSISCOMMUNITYTHEEVOLUTIONOFFILMCOMPOSITIONANDSTRUCTURETHROUGHOUTTHESEPROCESSESISQUANTIFIEDUSINGASUITEOFANALYTICALTECHNIQUES’EXPERIMENTALSECTIONOXIDESYNTHESISMOLYBDENUMOXIDEFILMSWEREDEPOSITEDUSINGMIXTURESOFMOF6/H2/O2INACAPACITIVELYCOUPLEDPECVDSYSTEMTHISPECVDCHEMISTRYADOPTSASIMILARAPPROACHTHATHASBEENRECEIVEDNOVEMBER11,2010ACCEPTEDDECEMBER31,2010519DXDOIORG/101021/AM101095H|ACSAPPLMATERINTERFACES2011,3,517–521ACSAPPLIEDMATERIALSINTERFACESRESEARCHARTICLETHEOBSERVEDPEAKPOSITIONOFTHEASDEPOSITEDFILMATABINDINGENERGYBEOF2328EVISINGOODAGREEMENTWITHTHEMOT6STATEOFFULLYOXIDIZEDMOO3THEDORBITALPEAKSARESEPARATEDBY31EVANDAPPEARINTHETHEORETICALLYEXPECTED32RATIO,24PROVIDINGFURTHERSUPPORTTHATTHEMOISPRESENTINASINGLEOXIDATIONSTATEOFCOURSEHYDROGENCANNOTBEDETECTEDBYXPS,BUTTHEPOSITIONOFMOSPECTRAINITSFULLYOXIDIZEDSTATESUPPORTSITSABSENCEXPSANALYSISOFMOLYBDENUMOXIDEFILMSINTERCALATEDWITHHDISPLAYTHEPRESENCEOFMOT5ANDMOT4OXIDATIONSTATES21MOREOVER,THETRANSPARENTNATUREOFTHEFILMPROVIDEFURTHERSUPPORTFORITSCHEMICALPURITY,SINCEMOO3HXHASAGREYCOLORTHATISEXPLOITEDINELECTROCHROMICAPPLICATIONS21,27CARBURIZATIONMOLYBDENUMOXIDEFILMSWITHTHICKNESSOF100500NMWEREDEPOSITEDONPIECESOF100SILICONWAFERSASDESCRIBEDABOVETHESESAMPLESWERETHENCARBURIZEDUSINGSTANDARDTPRCONDITIONSDESCRIBEDABOVEFILMSREMAINEDWELLADHEREDTOTHEUNDERLYINGSILICONSUBSTRATEAFTERCARBURIZATION,ANDWERECHARACTERIZEDUSINGTHETECHNIQUESDESCRIBEDBELOWTHECHANGESINCRYSTALSTRUCTURETHATWEREOBSERVEDINCONJUNCTIONWITHTPRARESUMMARIZEDINFIGURE4,WHICHCOMPARESRESULTSFROMBOTHPOWDERSAMPLESANDA200NMTHICKFILMWITHLITERATURESTANDARDSTHESTABLEPHASEOFMOLYBDENUMOXIDEHASANORTHORHOMBICSTRUCTURE,27ANDTHEASRECEIVEDPOWDERSWEREINGOODAGREEMENTWITHTHELITERATURESTANDARDSJCPDS761003THEASDEPOSITEDOXIDEFILMSAREXRDAMORPHOUS,HOWEVERTHEYCRYSTALLIZEWHENANNEALEDINAIRATTEMPERATURES150?CDURINGTHECARBURIZATIONPROCESS,THEOXIDEFILMSARETRANSFORMEDDURINGTHECALCININGSTEP,ANDANEXAMPLEOFAXRDPATTERNOBTAINEDFROMAFILMAFTERTHISTREATMENTISSHOWNINFIGURE4THEPATTERNOBTAINEDFROMTHETHINFILMSAMPLEISNOISYRELATIVETOTHEPOWDERSAMPLES,BUTNEVERTHELESSTHEFILMISCLEARLYIDENTIFIEDASPOLYCRYSTALLINEMOLYBDENUMOXIDEWITHAPREFERENTIALORIENTATIONINTHE110DIRECTIONLOCATEDAT2Θ2333?THESAMEMATERIALSWEREEXAMINEDAFTERTHECOMPLETIONOFTHECARBURIZATIONPROCESSAGAINITISOBSERVEDTHATTHEPOWDERSAMPLESAREINPERFECTAGREEMENTWITHLITERATUREEXPECTATIONSFORTHEΒMO2CPHASENOTETHATTHEΒMO2CPHASEHASANORTHORHOMBICCRYSTALSTRUCTUREJCPDS790744,THOUGHITSLATTICEPOSITIONSARENOMINALLYIDENTICALTOASLIGHTLYSTRAINEDHEXAGONALCLOSEDPACKEDSTRUCTUREJCPDS350787,ANDITHASOFTENBEENDESCRIBEDASSUCHINTHECATALYSTLITERATURE16,28BOTHCARBIDEPOWDERSANDFILMSDISPLAYTHETHREESIGNIFICANTPEAKSAT2ΘOF344,379,AND394WHICHAREINDEXEDASTHE100,002,AND101PLANESOFΒMO2C,RESPECTIVELYTHEREISNOEVIDENCEOFRESIDUALOXIDE,MOLYBDENUMMETAL,ORANYOTHERCRYSTALLINEPHASESOFMOLYBDENUMCARBIDETHEXRDPATTERNOBTAINEDFROMACARBURIZEDFILMISNOMINALLYIDENTICALTOBOTHTHELITERATUREVALUESANDTHEPOWDERSAMPLE,CONFIRMINGITSTRANSFORMATIONTOTHEΒMO2CPHASEXPSWASUSEDTOEXAMINETHECOMPOSITIONOFTHECARBURIZEDFILMSFIGURE3CONTAINSTHEHIGHRESOLUTIONSPECTRAOFMO3DREGIONTHEPOSITIONOFTHEMOPEAKSINTHECARBIDEWASSHIFTEDSIGNIFICANTLYTOLOWERBINDINGENERGYRELATIVETOTHEOXIDEFILM,ANDTHEPEAKPOSITIONATBE2282EVISINPERFECTAGREEMENTWITHLITERATUREVALUESFORMOT2TABLEITHECOMPOSITIONALPURITYOFTHISMATERIALISAGAINSUPPORTEDBYBOTHTHESPACING32EVANDRELATIVEINTENSITYOFTHETWOPEAKS,WHICHSUGGESTSTHATTHEMOISPREDOMINANTLYINASINGLEOXIDATIONSTATEFIGURE5COMPARESHIGHRESOLUTIONSPECTRAOFTHEO1SREGIONOBTAINEDFROMANOXIDEFILMANDAFTERCARBURIZATIONTHEOXIDEFILMDISPLAYSAPROMINENTPEAKATBE5308EV,WHICHISINGOODAGREEMENTWITHLITERATUREVALUES29THESURFACEOFTHECARBIDEISPARTIALLYOXIDIZEDDURINGTHEPASSIVATIONSTEPALTHOUGHTHESIGNALISATTENUATEDSUBSTANTIALLYRELATIVETOTHEOXIDEFILM,THEREARETWOFIGURE2HIGHRESOLUTIONXPSSPECTRAOFTHEF1SREGIONOBTAINEDFROMANASDEPOSITEDMOO3FILMSANDAFTERSPUTTERCLEANINGFIGURE3HIGHRESOLUTIONXPSSPECTRAOFTHEMO3DREGIONOBTAINEDFROMANASDEPOSITEDMOO3FILM,ANDAFTERCARBURIZATIONTABLEISUMMARYOFTHEBINDINGENERGYPOSITIONSREPORTEDINTHELITERATURE02EVFORTHEMO3D5/2ANDC1SCORELEVELSINOXIDATIONSTATESOFINTERESTTOMO2CFORMATIONSTATEBEEVMO6T2329MO5T2318MO4T2299MO3T2288MO2T2282MO02276CARBIDEC2830GRAPHITICC2845

簡介：1INTRODUCTIONVITAMINCOCCURSINDIFFERENTCONCENTRATIONSINAVARIETYOFNATURALSAMPLESITISADDEDTOSEVERALPHARMACEUTICALPRODUCTSASANESSENTIALINGREDIENT,ASTABILIZERFORVITAMINBCOMPLEX,ANDASANANTIOXIDANTCONSEQUENTUPONITSDESIRABLEEFFECTS,ITISWIDELYUSEDINTHETREATMENTOFCERTAINDISEASESSUCHASSCURVY,COMMONCOLD,ANEMIA,HAEMORRHAGICDISORDERS,WOUNDHEALING,ANDEVENINFERTILITY,TOMENTIONSOMESTARKCASESITISCONSIDEREDESSENTIALFORTHEDEVELOPMENTANDREGENERATIONOFMUSCLES,BONES,TEETHANDSKINTHEINCREASINGUSEOFPHARMACEUTICALSANDOTHERNATURALSAMPLESCONTAININGVITAMINCHASMEANTTHATTHEPRACTICISINGCHEMISTSSHOULDDEVELOPANALYTICALPROCEDURESFORITSDETERMINATIONWHICHARESIMPLETOOPERATE,RAPID,ACCURATE,SENSITIVEANDSELECTIVETHEDESIRETODEVELOPMETHODSWITHIDEALCHARACTERISTICSHASRESULTEDALARGENUMBEROFPROCEDURESWITHVARYINGAPPLICABILITYMANYINSTRUMENTBASEDANALYSESINCLUDINGFLUOROMETRY1–4,HPLC5–10,POLAROGRAPHY11–13ANDENZYMATIC14,15METHODSAREREPORTEDINTHELITERATUREBUTDUETOTHEIRINHERENTLIMITATIONS,THESETECHNIQUESARENOTCOMMONLYUSEDFORROUTINEANALYSESHOWEVER,PHOTOMETRICMETHODSAREPARTICULARLYATTRACTIVEBECAUSEOFTHEIRSPEEDANDSIMPLICITYCONSEQUENTLY,ALARGENUMBEROFSUCHPROCEDURESHAVEBEENDEVELOPEDFORTHEDETERMINATIONOFASCORBICACIDAATHOUGHSOMESHORTREVIEWS16–18HAVEBEENREPORTED,ACRITICALASSESSMENTOFTHESEMETHODSISDESIRABLETOEXAMINETHEIRSALIENTFEATURESANDUTILITYTHISREVIEWISANATTEMPTTOASSESSEXCLUSIVELYTHEEXISTINGSPECTROPHOTOMETRICMETHODSFORTHEDETERMINATIONOFVITAMINCASREGARDSTHEIRSIMPLICITY,RAPIDITY,BEER’SLAWRANGE,SENSITIVITY,SELECTIVITYANDAPPLICABILITYITISPRIMARILYBASEDONTHEINFORMATIONCOLLECTEDTHROUGHTHECHEMICALABSTRACTSFORTHEPERIOD1970TOMID19972RESULTSANDDISCUSSIONSEVERALDYESSUCHAS2,6DICHLOROPHENOLINDOPHENOLDCIP,DIMETHOXYDIQUINONEDMDQ,NINHYDRIN,FASTREDALSALTAND2′,7′DICHLOROFLUORESCEINETCHAVEBEENUSEDFORTHEDETERMINATIONOFVITAMINCAMONGTHESEDYES,DCIPHASBEENMOSTEXTENSIVELYSTUDIEDITISINCLUDEDINTHEOFFICIALTITRIMETRICMETHODSASREPORTEDINDIFFERENTPHARMACOPOEIAS19–21ANDITALSOFORMSTHEBASISOFMANYCOLORIMETRICMETHODSTHEBLUEDYEDCIPISREDUCEDTOTHECOLORLESSFORMONADDITIONOFASCORBICACIDASSHOWNINFIG1,BUTITGIVESAPINKCOLORTOTHEACIDICSOLUTIONSUSINGTHEDYE,ASCORBICACIDPRESENTINHUMANURINE22ANDPROCESSEDPOTATOES23HASBEENDETERMINEDTHEEXCESSDYECANBEEXTRACTEDWITHXYLENEORBUTANOL24MANYSUBSTANCESWHICHARECAPABLEOFREDUCINGTHEDYERESULTINGFROMTHEPREPARATIONANDPROCESSINGOFFOODSAMPLESINTERFEREFLOWDIALYSISPROPOSEDBYGARYETAL25ANDCONTINUOUSFLOWSYSTEMSHAVEBEENUSEDTOMONITORTHEDECREASEINABSORBANCEOFDCIPSUCHAUTOMATEDSYSTEMSAPPEARTOBEJUSTIFIEDONLYWHENROUTINEANALYSISOFALARGEANALYTICALSCIENCESOCTOBER1998,VOL14PHOTOMETRICMETHODSFORTHEDETERMINATIONOFVITAMINCSATYAPARYA?,MEENAKSHIMAHAJANANDPREETIJAINDEPARTMENTOFCHEMISTRY,KURUKSHETRAUNIVERSITY,KURUKSHETRA–136119,HARYANASTATE,INDIATHEIMPORTANCEOFVITAMINCTOTHEHUMANBODYISWIDELYACKNOWLEDGEDTHROUGHOUTTHEGLOBETHEDEFICIENCYOFTHISVITAMINLEADSTOVARIOUSDISEASESINVIEWOFITSIMPORTANCE,NUMEROUSMETHODSINCLUDINGSPECTROPHOTOMETRICONESHAVEBEENDEVELOPEDFORITSDETERMINATIONINPHARMACEUTICALS,FOODSANDBIOLOGICALSAMPLESACOMPREHENSIVEREVIEWOFTHEAVAILABLESPECTOPHOTOMETRICMETHODSFORTHEDETERMINATIONOFASCORBICACIDISPRESENTEDKEYWORDSVITAMINCDETERMINATION,SPECTROPHOTOMETRICMETHOD?TOWHOMCORRESPONDENCESHOULDBEADDRESSEDFIG1THEREDUCTIONOFDCIPWITHASCORBICACIDASCORBICACIDDCIPOXIDIZED,BLUEPINKDEHYDROASCORBICACIDDCIPREDUCED,COLORLESSANDTRINITROBENZENE47INTARTRATEBUFFERWHENSTUDIEDFORITSDETERMINATIONOVERTHECONCENTRATIONRANGES2–50AND0–125ΜGML–1OFASCORBICACIDRESPECTIVELYMETHANOLICSOLUTIONOFRESORCINOL48GIVESAPALEYELLOWCOLORΛMAX425NMWITHASCORBICACIDINHYDROCHLORICACIDMEDIUM,OBEYINGBEER’SLAWFOR80–400ΜGML–14CHLORO7NITROBENZOFURAZANE49FORMSABLUISHGREENCOLOREDSPECIESWITHASCORBICACIDINPRESENCEOF02MSODIUMHYDROXIDETHEABSORBANCEISMEASUREDAT582NMAFTERDILUTINGTHEREACTIONCONTENTSWITH50V/VAQUEOUSACETONESOLUTIONBEER’SLAWISOBEYEDINTHECONCENTRATIONRANGE5–20ΜGML–1THECOLOREDPRODUCTISSTABLEFOR30MINONLYWHENKEPTAWAYFROMDIRECTSUNLIGHTORARTIFICIALDAYLIGHTTHEMETHODISREPORTEDFREEFROMTHEINTERFERENCEOFALLOTHERVITAMINSANDMINERALSPRESENTINMULTIVITAMINPREPARATIONSANDCANBEAPPLIEDTOTHEANALYSISOFPHARMACEUTICALS,FRESHFRUITJUICESANDVEGETABLESHASHMIETAL50PROPOSEDAMETHODBASEDONTHEREACTIONOF2,3,5TRIPHENYLTETRAZOLIUMCHLORIDEWITHASCORBICACIDINALKALINEMEDIUMTHEPINKSOLUTIONISALLOWEDTOSTANDINTHEDARKFOR30MINAT25?CITOBEYSBEER’SLAWOVERTHERANGE5–25ΜGML–1SUGARS15ΜGML–1EXCEPTSUCROSEINTERFEREBYFORMINGASIMILARCOLORTOTHATOFTHEREAGENTRIBOFLAVIN,CYANOCOBALAMINANDFOLICACIDINTERFEREDUETOTHEIROWNCOLORBEUTLERETAL51,52INVESTIGATEDTHEUSEOFMETHYLTHIAZOLYLTETRAZOLIUMSALTINPRESENCEOFASCORBATEOXIDASEENZYMEAND34,5DIMETHYLTHIAZOLYL2YL2,5DIPHENYLTETRAZOLIUMCHLORIDEORBROMIDEINTHEPRESENCEOF5METHYLPHENAZINIUMMETHYLSULFATEELECTRONCARRIERATPH35FORTHEDETERMINATIONOFASCORBICACIDINFOODS,FRUITJUICESANDVEGETABLESJUICESTHESEREACTIONSINVOLVETHEFORMATIONOFFORMAZONΛMAX578NMTHEINTERFERENCEOFSULFURDIOXIDEREQUIRESTREATMENTWITHFORMALDEHYDE,ANDCOLORINTERFERENCEFROMDARKJUICESISREMOVEDBYDECOLORIZATIONWITH1POLYVINYLPOLYPYRROLIDONEBEFOREFILTRATIONSORBITOL,ALCOHOLANDOXALATEINTERFEREWITHTHEASCORBICACIDOXIDASEHOWEVER,THEEFFECTOFOXALATECANBECHECKEDBYADDINGASLIGHTEXCESSOFCAIIIONSOTHERDERIVATIVESSUCHAS2,5DIPHENYL3THIAZOLYLTETRAZOLIUMCHLORIDE53ATPH122,2PIODOPHENYL3PNITROPHENYL5PHENYLTETRAZOLIUMCHLORIDEATPH105ΛMAX540NMAND2,2′,5,5′TETRA4NITROPHENYL3,3′3,3′DIMETHOXY4,4′BIPHENYLDITETRAZOLIUMCHLORIDE54HAVEALSOBEENEMPLOYEDFORTHEASSAYOFASCORBICACIDTHECOUPLINGOF2,4DINITROPHENYLHYDRAZINEDNPHWITHKETONICGROUPSOFDHAAANDDIKETOGULONICACIDDKGAHASBEENTHEBASISOFMANYMETHODSFORTHEDETERMINATIONOFTOTALVITAMINCCONTENTSPROTEINSPRESENTINTHESAMPLESAREPRECIPITATEDBYADDINGTRICHLOROACETICACIDTCAANDALIQUOTSOFFILTRATEARESHAKENWITHACID–WASHEDCHARCOALNORITORACTIVATEDCHARCOAL55TOCLARIFYTHESOLUTIONSANDTOOXIDIZEAATODHAAAREDUCINGMEDIUMISPRODUCEDBYADDINGTHIOUREAPRIORTODNPHADDITION,OTHERWISEUNSPECIFICCOLORATIONISGIVENBYOXIDANTSTHEOSAZONESΛMAX545NMTHUSFORMEDDURINGTHE3HINCUBATIONAT37?CBYTHEREACTIONOFDNPHANDDHAAAREDISSOLVEDBYADDING85H2SO4VITAMINCCANBEEXTRACTEDWITHMETAPHOSPHORICACID–STANNOUSCHLORIDESOLUTIONWITHOUTCHARCOALTREATMENTFORDIFFERENTIALDETERMINATIONOFDKGA,DHAAANDAAINTHESAMETISSUEEXTRACTSTHEINTERFERENCEOFSUGARSCANBEMINIMIZEDBYCARRYINGOUTINCUBATIONAT15?CANDMEASURINGTHEABSORBANCEONLYAFTERADDINGSULFURICACIDFOR75MIN56THEUSEOFSEVERALACIDMIXTURESHASBEENPROPOSEDFORREPLACINGTHETEDIOUSDROPWISEADDITIONOFSULFURICACIDLACKOFSPECIFICITYISFOUNDWITHMANYOFTHESEMETHODSINTERFERINGOSAZONESCANBESEPARATEDBYCHROMATOGRAPHICMETHODSSUCHASTLC57ANDHPLC58,BUTATTHECOSTOFMAKINGTHESEPROCEDURESTEDIOUSANDCUMBERSOMETHENATUREOFDNPHMETHODSFORTOTALVITAMINCALSOMAKESITAMENABLETOAUTOMATICFLOWTHROUGHANALYSES59–61PHENYLHYDRAZINIUMCHLORIDE62PRODUCESAYELLOWCOLORΛMAX395NMWHENTREATEDWITHASCORBICACIDIN01MHCLMEDIUMTHEREACTIONCONTENTSAREKEPTFOR1HINANINCUBATORORWATERBATHAT50±2?C,THUSMAKINGTHEMETHODTIMECONSUMINGBEER’SLAWISOBEYEDINTHERANGE25–100ΜGOFASCORBICACIDNOINTERFERENCEISOBSERVEDFROMOTHERVITAMINS,MINERALS,GLUCOSE,SUCROSE,EXCIPIENTSANDREDUCINGAGENTSHOWEVER,THEPRESENCEOFEXCESSIVEAMOUNTSOFRIBOFLAVINREQUIRESTHEADDITIONOF05GTALC,WHICHIMPARTSAYELLOWCOLORTOTHESOLUTION3METHYL2BENZOTHIAZOLONEHYDRAZONE63REACTSINTHEPRESENCEOFSODIUMMETAPERIODATETOFORMABLUECOLOREDSOLUTIONΛMAX630NMWHICHHELPSINTHEDETERMINATIONOFASCORBICACIDOVERTHERANGE6–14MEQML–1WANG64SUGGESTEDTHEUSEOFPOTASSIUMIODATEFORTHEDETERMINATIONOFVITAMINCINPHARMACEUTICALSTHEABSORBANCEISMEASUREDEITHERINTHEUVREGION288NMORINTHEVISIBLEREGION445NMBESIDESAQUEOUSPHASEMEASUREMENTS,THEYELLOWPRECIPITATECANBEEXTRACTEDINTOCHLOROFORM65ΛMAX514NMTHEICL2–GENERATEDINTHEOXIDATIONOFAABYIODATE66INACIDMEDIUMINTHEPRESENCEOFCL–IONSHASBEENUSEDTOIODINATE2′,7′DICHLOROFLUORESCEINDYETHEIODINATEDDYEΛMAX525NMOBEYSBEER’SLAWUPTO300ΜGΕ881103SOFTDRINKS67HAVEBEENANALYZEDUSINGTHEREACTIONOFIODINEINANACETICACIDMEDIUMΛMAX350NMSIRIVIDYAANDBALASUBRAMANIAN68REPORTEDANINDIRECTPROCEDUREBASEDONTHEOXIDATIONOFASCORBICACIDBYAKNOWNEXCESSOFIODATEINTHEPRESENCEOFACIDFORTHEANALYSISOFPHARMACEUTICALSANDFRESHFRUITJUICESTHEUNREACTEDIODATEISUSEDFORHYDROXYLAMINEOXIDATIONTOGENERATENITRITE,WHICHISTHENDIAZOTIZEDWITHSULFANILICACIDTHERESULTINGDIAZONIUMSALTISCOUPLEDWITHN1NAPHTHYLETHYLENEDIAMINEDIHYDROCHLORIDETOFORMANAZODYEΛMAX540NMTHEPROCEDUREISACOMPLICATEDONEASITINVOLVESMANYSTEPSTHEREACTIONOFHEXACYANOFERRATEIII695WASUSEDFORTHEDETERMINATIONOFMICROQUANTITIESOFVITAMINCBYMEASURINGTHEDECREASEINCOLORINTENSITYOFTHEREAGENT5ΛMAX420NMINMCILVAINEBUFFERPH52891ANALYTICALSCIENCESOCTOBER1998,VOL14

簡介：開題報告表開題報告表課題名稱基于C的網(wǎng)上書店的設計與實現(xiàn)課題來源課題類型AX指導教師學生姓名學號專業(yè)一、設計的目的當今的社會是一個信息化的社會，互聯(lián)網(wǎng)的出現(xiàn)加速了這個社會信息的傳播。隨著INTERNET的普及，互聯(lián)網(wǎng)以一股巨大變革力量的面貌出現(xiàn)在商務關(guān)系領域。其強大的功能已為人們深刻認識,它已進入人類社會的各個領域并發(fā)揮著越來越重要的作用。因為網(wǎng)絡本身就是信息的載體，它與普通的書店等書籍出售場所相比，具有速度快、容量大、費用少、使用方便等優(yōu)勢。比如，從網(wǎng)上購書你可以快速分類瀏覽到全國各地的書籍報價。通過網(wǎng)絡進行購書，可以彌補實體書店購買的不足，網(wǎng)上購書不受時間的限制，并且可以買到全國各地的書籍，較少出現(xiàn)斷貨的情況，另外，網(wǎng)上書店節(jié)約了成本，相比之下價格要比實體書店的更實惠。對購書者來說，不僅節(jié)約了時間也買到了物美價廉的圖書。二、設計的要求21總體要求1建立對圖書提供全面管理的信息系統(tǒng)；2對所有的圖書、客戶提供全面管理；3對圖書詳細信息提供管理。22功能要求1在INTERNET,客戶可通過IE或其他瀏覽器瀏覽書目信息；2通過互聯(lián)網(wǎng)，可提交訂單；3具有購物車功能；4客戶能通過書名來檢索書籍；5客戶可在進行注冊，成為會員；6客戶能查看當前訂單和以往訂單；7書店管理員能查找客戶信息；8書店管理員在發(fā)貨后能改寫訂單中的發(fā)貨日期；23性能要求1系統(tǒng)可以對圖書的庫存進行統(tǒng)計；2系統(tǒng)界面設計友好，操作方便、靈活；3具有高可靠性和冗錯能力，不允許系統(tǒng)在工作時間停機，不允許系統(tǒng)丟失圖書信息。4具有安全檢查機制，非法用戶不能隨便修改網(wǎng)站會員信息等。三、思路1、前臺設計思路開題報告內(nèi)容（調(diào)研資料的準備，設計的目的、要求、思路與預期成果；任務完成的階段內(nèi)容及時間安排；完成設計（論文）所具備的條件因素等。）指導教師簽名日期（可加頁）課題類型（1）A工程設計；B技術(shù)開發(fā)；C軟件工程；D理論研究；（2）X真實課題；Y模擬課題；Z虛擬課題

簡介：1424412536/07/2500?2007IEEEPROCEEDINGSOFHDP’07DESIGNOFPWMCONTROLLERINAMCS51COMPATIBLEMCUYUELIHU,WEIWANGMICROELECTRONICRESEARCHSANDERS,SR,“ARCHITECTUREANDICIMPLEMENTATIONOFADIGITALVRMCONTROLLER,”POWERELECTRONICS,IEEETRANSACTIONSONVOLUME18,ISSUE1,PART2,JAN2003PAGES356–3647SMITH,KM,JRLAI,ZSMEDLEY,KM“ANEWPWMCONTROLLERWITHONECYCLERESPONSE,”POWERELECTRONICS,IEEETRANSACTIONSONVOLUME14,ISSUE1,JAN1999PAGES142150