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簡(jiǎn)介：北京化工大學(xué)北方學(xué)院畢業(yè)設(shè)計(jì)（論文）文獻(xiàn)綜述1文獻(xiàn)綜述文獻(xiàn)綜述前言本人畢業(yè)設(shè)計(jì)的題目為年產(chǎn)5萬噸丙酮生產(chǎn)工藝設(shè)計(jì)。本文主要介紹了丙酮產(chǎn)品的生產(chǎn)經(jīng)濟(jì)效益，產(chǎn)品國內(nèi)外的發(fā)展?fàn)詈蜕a(chǎn)工藝流程介紹。丙酮是一種用途十分廣泛的重要有機(jī)產(chǎn)品，主要用于生產(chǎn)醋酸纖維素膠片薄膜塑料和作為涂料的溶劑及制備甲基丙烯酸甲酯MMA的上游原料和制備環(huán)氧樹脂、聚碳酸酯中間體雙酚A的原料。目前世界上丙酮的生產(chǎn)方法有許多種，但主要方法是異丙苯法，其生產(chǎn)能力約占世界丙酮生產(chǎn)能力的90以上。本人根據(jù)國內(nèi)外學(xué)者對(duì)丙酮以及其生產(chǎn)工藝的研究成果，在本文中對(duì)丙酮做一個(gè)簡(jiǎn)單綜述。其中的一些國內(nèi)外文獻(xiàn)給了我很多參考價(jià)值。本文主要查閱近幾年有關(guān)丙酮研究以及生產(chǎn)工藝的一些文獻(xiàn)期刊。北京化工大學(xué)北方學(xué)院畢業(yè)設(shè)計(jì)（論文）文獻(xiàn)綜述32丙酮的安全及用途丙酮對(duì)吸入其蒸氣后可引起頭痛，支氣管炎等癥狀。如果大量吸入，還可能失去知覺。人體具有肝毒性，對(duì)于黏膜有一定的刺激性，日常生活中主要用于脫脂，脫水，固定等等。在血液和尿液中為重要檢測(cè)項(xiàng)目。有些癌癥患者尿樣丙酮水平會(huì)異常升高。采用低碳丙酮與氯仿不應(yīng)混合（特別是在堿性環(huán)境下），兩者會(huì)發(fā)生劇烈的放熱反應(yīng)，若混合可能導(dǎo)致強(qiáng)烈爆炸。最常見的用途是用作卸除指甲油的去光水，以及油漆的稀釋劑；同時(shí)可作為有機(jī)溶劑，應(yīng)用于醫(yī)藥、油漆、塑料、火藥、樹脂、橡膠、照相軟片等行業(yè)。在工業(yè)上應(yīng)用于制造雙酚A、甲基丙烯酸甲酯（MMA）、丙酮氰醇、甲基異丁基酮等產(chǎn)品，以及塑膠、纖維、藥物及其他化學(xué)物質(zhì)。自然界中亦存在天然的丙酮，人體內(nèi)也含有少量的丙酮。在建材方面，主要作為脂肪族減水劑的主要原料。二丙酮的國內(nèi)外發(fā)展情況二丙酮的國內(nèi)外發(fā)展情況1國內(nèi)發(fā)展情況國內(nèi)發(fā)展情況目前大多數(shù)丙酮是制備苯酚的副產(chǎn)品，是異丙苯氧化后的產(chǎn)物之一。從全球丙酮消費(fèi)市場(chǎng)看，未來幾年，除丙酮氰醇、溶劑等對(duì)丙酮的需求量有不同程度的增長(zhǎng)外，雙酚A仍是最主要的消費(fèi)領(lǐng)域尤其是亞洲地區(qū)，其他消費(fèi)增長(zhǎng)相對(duì)較為平穩(wěn)，雙酚A、MMA和溶劑仍將是丙酮的三大消費(fèi)領(lǐng)域。近年來，中國丙酮表觀需求量保持著高速增長(zhǎng)，平均增長(zhǎng)率達(dá)到15以上，2009年以后，隨著中國乃至全球經(jīng)濟(jì)進(jìn)入危機(jī)后的緩慢復(fù)蘇階段，終端下游需求不斷回升，加之下游雙酚A行業(yè)進(jìn)入擴(kuò)能高峰期，成為丙酮下游行業(yè)需

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簡(jiǎn)介：洗衣機(jī)洗衣機(jī)WASHINGMACHINESTHEWASHINGMACHINEFROMINVENTIONTONOWBASEXPERIENCEDMETHANACENTURYTHROUGHTHEFOLLOWINGSTAGESOFDEVELOPMENTTHEWLD’SFIRSTWASHINGMACHINEISTHEUNITEDSTATESIN1874BYBILLBLACKSTONESUCCESSFULLYDEVELOPEDAROUND1910AFIRSTHIZONTALSHAFTDRUMTYPEELECTRICWASHINGMACHINEMARKINGTHEHOUSEWKAUTOMATICSTARTNIEENTWENTIESTHEFIRSTVERTICALSHAFTSTIRRINGTYPEWASHINGMACHINETOTHEUNITEDSTATESOFAMERICATRIALPRODUCEISSUCCESSFULTHEWASHINGMACHINESTARTEDTHE“VERTICAL”“HIZONTAL”CENTTHE50SJAPAN’SSANYOCOMPANYLAUNCHEDDANTONGBOWHEELTYPEWASHINGMACHINESTARTSWITHTHEIDENTIFICATIONOFADRUMTYPEMIXINGTYPETHEWAVEWHEELTHREEWKINGMODESIN60THEJAPANESELAUNCHEDWITHFLINGSTHEDRYBARRELSEMIAUTOMATICWASHINGMACHINEALARGENUMBEROFAPPLICATIONSOFPLASTICSOTHATTHEWASHINGMACHINE’SDEVELOPMENTINTOANEWSTAGEIN70THEJAPANESELAUNCHEDAWAVEWHEELSETSOFBARRELSOFFULLYAUTOMATICWASHINGMACHINEBEGANWITH“AUTOMATIC”WASHINGMACHINECONCEPTINTHELATE70THEJAPANESELAUNCHEDAMICROCOMPUTERCONTROLLEDFULLAUTOMATICWASHINGMACHINECOMPLETEDBYTHEMECHANICALELECTRICPROGRAMCONTROLCOMPUTERCONTROLTRANSITIONSTARTEDTHECOMPUTERCONTROLERATHENTHEWASHINGMACHINEINTHEDEVELOPEDCOUNTRIESHAVEENTEREDTHEPERIODOFSATURATIONWHILEINASIAPACIFICDEVELOPINGCOUNTRIESBEGANTOENTERTHEPERIODOFPOPULARIZATIONTHELATE80S“FUZZYCONTROLWASHINGMACHINE”BEGANTOAPPEARTOACHIEVETHEHOMEELECTRICAPPLIANCECONTROLMETHODONTHEHIGHAUTOMATION“WHITEGOODS”CONCEPTIN90’SWITHTHEDEVELOPMENTOFINVERTERTECHNOLOGYJAPANLAUNCHEDTHEFIRSTOFUPMOTDIRECTDRIVENWASHINGMACHINEWASHINGMACHINEDRIVINGMODEREALIZEDTHEREVOLUTIONTHEWASHINGMACHINEWILLBEOFHIGHRELIABILITY，PERFECTFUNCTIONWATERSAVINGPOWERSAVINGTIMESAVINGNOISEREDUCTIONOFSPECIFICATIONSVARIETIESDIVERSIFICATIONFTHEDIRECTIONOFDEVELOPMENTTHEREASONWHYAWASHINGMACHINELIKETHISCANWASHGETTHEWATEROUTOFTHECLOTHESATTHESAMETIMEISBECAUSEITHASADOUBLELAYERDRUMWHENWASHINGRINSINGTHEPULSATSPINSMAKESTHEWATERSWIRLTOGETTHEWATEROUTOFTHECLOTHESTHEINNERWALLOFTHEDRUMSPINSTHEWATERGOESTHROUGHTHEHOLESTHESEDAYSTHE“CENTRIFUGALFCEWASHINGMACHINES”AREQUITEPOPULARTHISLOOKINGBACKNOWTHEREWASSOMETHINGSTRANGEFUNNYONSOMEOFTHEFIRSTVERSIONSOFTHEWASHINGMACHINETHEMACHINEHADTWOROLLERSTHATWEREUSEDTOSWICHEACHSHIRTOTHERCLOTHESTOSQUEEZETHEWATEROUTOFTHEMTHEROLLERSWERETURNEDBYHINFACTYOUNEEDEDALOTOFSTRENGTHTOTURNTHOSETHINGSSTILLPEOPLETHENTHOUGHTITWASAREALLYNEATINVENTIONTHISTYPEOFWATERSQUEEZERWASUSEDFALMOST30YEARSUNTILSOMETHINGNEWCAMEALONGTHESPINDRIERTHATUSED“CENTRIFUGALFCE”TOGETMOSTOFTHEWATERISOUTOFTHECLOTHESIN1953THENOZZLETYPEWASHINGMACHINEWASFIRSTSOLDINJAPANTHISWASHINGMACHINEISLIKETHEOLDERBROTHEROFTHESWIRLINGWASHINGMACHINETHATYOUSEETODAYTHEPRICEOFTHESEWASHINGMACHINESWASLOWERBECAUSEOFTHISMEPEOPLEBOUGHTTHEMTHEFIRSTFULLYAUTOMATICWASHINGMACHINEWASINTRODUCEDIN1968AFTERTHATWASHINGCLOTHESBECAMEALOTEASIERTODOTHEREAREALOTOFDIFFERENTTYPESOFWASHINGMACHINESWHATKINDOFWASHINGMACHINEDOYOUHAVEINYOURHOUSEFULLYAUTOMATICTHEFULLYAUTOMATICMACHINEHASTWODRUMLAYERSTHATWASHRINSEREMOVEWATERFROMCLOTHESTOGETHERALLYOUHAVETODOISADDDETERGENTPUTINDIRTYCLOTHESTHENWASHINGMACHINEWILLDOTHERESTTHEREISALSOANEWTYPEOFFULLYAUTOMATICWASHINGMACHINETHATCANDRYCLOTHESAFTERTHEYHAVEBEENWASHEDTWINTUBTHISWASHINGMACHINEHASONEPARTTHATDOSETHEWASHINGANOTHERPARTTHATDOESTHESQUEEZINGEVENTHOUGHIT’SAHASSLETOTAKETHECLOTHESOUTMOVETHEMTOOTHERTUBTHEGOODTHINGISTHATYOUCANWASHSQUEEZEATTHESAMETIMEWITHONEMACHINEFRONTLOADINGTHEMAINFEATUREOFFRONTLOADERSISTHATTHEYUSEALOTLESSWATERTHANOTHERTYPESTHISISTHETYPEOFWASHINGMACHINETHATDRYCLEANERSUSEBUTALOTOFPEOPLEINWESTERNCOUNTRIESHAVETHISTYPEOFWASHINGMACHINEINTHEIRHOMESTOOLET’STRYTOMAKETHEBESTWASHINGMACHINEINTHEWLDWESHOULDALREADYTHANKTHESCIENTISTSTHATINVENTEDTHEFULLYAUTOMATICWASHINGMACHINEBECAUSEITMAKESWASHINGCLOTHESAPIECEOFCAKESCIENTISTSARESTILLTRYINGREALLYHARDTOFINDWAYSTOMAKEWASHINGMACHINESALOTHIERTOUSEFEVERYONESOMEOFTHETHINGSTHATTHEYARETRYINGTODOARETOFINDBETTERWAYSOFMAKINGCLOTHESCLEANWAYSTOMAKEWASHINGMACHINESLASTLONGERTHEREAREWASHINGMACHINESWITHDRYINGFUNCTIONTODAYSOYOUDON’TEVENHAVETO

簡(jiǎn)介：日語專業(yè)畢業(yè)論文參考文獻(xiàn)的格式格式講解一，日文專著序號(hào)作者（出版年月）『書名』M、出版社例如1鶴田欣野（1998）『日本文學(xué)における「他者」』M、新曜社2木下是雄（1994）『レポートの組み立て方』、ちくま學(xué)蕓文庫3戸田山和久（2002）『論文の教室レポートから卒論まで』NHKブックス954、日本放送出版協(xié)會(huì)4中村廣治朗1997『イスラームと近代』（叢書現(xiàn)代の宗教13）、巖波書店5京都市編1994『甦る平安京平安遷都1200年記念図録』說明A文獻(xiàn)括號(hào)及數(shù)字要用半角輸入。正確的輸入方法1234515錯(cuò)誤的輸入方法【1】［１］［２］［３］B文獻(xiàn)中的年份也要用半角輸入。E序號(hào)，作者，年份，書名間要連續(xù)排列，中間不能空格。正確1鶴田欣野（1998）『日本文學(xué)における「他者」』錯(cuò)誤1鶴田欣野（1998）『日本文學(xué)における「他者」』F專著用M表示，M用半角輸入。錯(cuò)誤【M】［Ｍ］［M］G出版社后面需要加點(diǎn)“”正確新曜社錯(cuò)誤

簡(jiǎn)介：DIVIDENDDIVIDENDPOLICYPOLICY作者EUGENEFBRIGHAMJOELFHOUSTON刊物刊物FUNDAMENTALSFUNDAMENTALSOFOFFINANCIALFINANCIAL，2004，（8）2325ABSTRACTDIVIDENDPOLICYPLAYSANIMPTANTROLEINBUSINESSDECISIONMAKINGINTHESTOCKISTHECOMPANYSCEFINANCIALISSUESTHUSTHEDIVIDENDDISTRIBUTIONPOLICYHASBEENTHECOMPANYSSTAKEHOLDERSSHARESARECLOSELYWATCHEDONTHEBASISOFTHETEXTOFTHEINTRODUCTIONDIVIDENDPOLICYBASICTYPESOFTRADITIONALMODERNTHEIESOFDIVIDENDPOLICYELABATEONFOCUSINGONTHESTATUSOFTHEDIVIDENDDISTRIBUTIONPOLICYOFLISTEDCOMPANIESTHEDIVIDENDPOLICYCHOICESHOULDCONSIDERFACTSWEREANALYZEDDEALWITHTHEPROBLEMSRAISEDCRESPONDINGCONSTRUCTIVECOMMENTSKEYWDSDIVIDENDTHEYDIVIDENDDISTRIBUTIONPOLICYRECOMMENDATIONS1INTRODUCTIONPROFITABLECOMPANIESREGULARLYFACETHREEIMPTANTQUESTIONS1HOWMUCHOFITSFREECASHFLOWSHOULDITPASSONTOSHAREHOLDERS2SHOULDITPROVIDETHISCASHTOSHAREHOLDERSBYRAISINGTHEDIVIDENDBYREPURCHASINGSTOCK3SHOULDITMAINTAINASTABLECONSISTENTPAYMENTPOLICYSHOULDITLETTHEPAYMENTSVARYASCONDITIONSCHANGEWHENDECIDINGHOWMUCHCASHTODISTRIBUTETOSHAREHOLDERSFINANCEMANAGERMUSTKEEPINMINDTHATTHEFIRM’SOBJECTIVEISTOMAXIMIZESHAREHOLDERVALUECONSEQUENTLYTHETARGETPAYRATERATIODEFINEASTHEPERCENTAGEOFINCOMETOBEPAIDOUTASCASHDIVIDENDSSHOULDBEBASEDINLARGEPARTONINVESTS’PREFERENCEFDIVIDENDSVERSUSCAPITALGAINSDOINVESTSPREFER1TOHAVETHEFIRMDISTRIBUTEINCOMEASCASHDIVIDENDS2TOHAVEITEITHERREPURCHASESTOCKELSEPLOWTHEEARNINGSBACKINTOTHEBUSINESSBOTHOFWHICHSHOULDRESULTINCAPITALGAINSTHISPREFERENCECANBECONSIDEREDINTERMSOFTHECONSTANTGROWTHSTOCKVALUATIONMODELGDS1IFTHECOMPANYINCREASESTHEPAYOUTRATIONTHERAISESTHISINCREASEINTHE1DNUMERATTAKENALONEWOULDCAUSETHESTOCKPRICETORISEHOWEVERIFISRAISEDTHEN1DLESSMONEYWILLBEAVAILABLEFREINVESTMENTTHATWILLCAUSETHEEXPECTEDGROWTHRATETODECLINETHATWILLTENDTOLOWERTHESTOCK’SPRICETHUSANYCHANGEINPAYOUTPOLICYWILLHAVETWOOPPOSINGEFFECTSTHEREFETHEFIRM’SOPTIMALDIVIDENDPOLICYMUSTSTRIKEABALANCEBETWEENCURRENTDIVIDENDSFUTUREGROWTHSOTOMAXIMIZETHESTOCKPRICEIN2SAMESIMILARFIRMSINANYEVENTTHERISKINESSOFTHEFIRM’SCASHFLOWSTOINVESTSINTHELONGRUNISDETERMINEDBYTHERISKINESSOFOPERATINGCASHFLOWSNOTBYDIVIDENDPAYOUTPOLICYTAXPREFERENCETHEYTHEREARETHREETAXRELATEDREASONSFTHINKINGTHATINVESTSMIGHTPREFERALOWDIVIDENDPAYOUTTOAHIGHPAYOUT1RECALLFROMCHAPTERIITHATLONGTERMCAPITALGAINSARETAXEDATARATEOF20PERCENTWHEREASDIVIDENDINCOMEISTAXEDATEFFECTIVERATESWHICHGOUPTO396PERCENTTHEREFEWEALTHYINVESTSMIGHTPREFERTOHAVECOMPANIESRETAINPLOWEARNINGSBACKINTOTHEBUSINESSEARNINGSGROWTHWOULDPRESUMABLYLEADTOSTOCKPRICESINCREASESTHUSLOWTAXEDCAPITALGAINSWOULDBESUBSTITUTEDFHIGHERTAXEDDIVIDENDS2TAXESARENOTPAIDONTHEGAINSUNTILASTOCKISSOLDDUETOTIMEVALUEEFFECTSADOLLAROFTAXESPAIDINTHEFUTUREHASALOWEREFFECTIVECOSTTHANADOLLARPAIDTODAY3IFASTOCKISHELDBYSOMEONEUNTILHESHEDIESNOCAPITALGAINSTAXISDUEATALLTHEBENEFICIARIESWHORECEIVETHESTOCKCANUSETHESTOCK’SVALUEONTHEDEATHDAYASTHEIRCOSTBASISTHUSCOMPLETELYESCAPETHECAPITALGAINSTAXBECAUSEOFTHESETAXADVANTAGESINVESTSMAYPREFERTOHAVECOMPANIESRETAINMOSTOFTHEIREARNINGSIFSOINVESTSWOULDBEWILLINGTOPAYMEFLOWPAYOUTCOMPANIESTHANFOTHERWISESIMILARHIGHPAYOUTCOMPANIESTHERETHREETHEIESOFFERCONTRADICTYADVICETOCPATEMANAGERSSOWHICHIFANYSHOULDWEBELIEVETHEMOSTLOGICALWAYTOPROCEEDISTOTESTTHETHEIESEMPIRICALLYMANYSUCHTESTSHAVEBEENCONDUCTEDBUTTHEIRRESULTSHAVEBEENUNCLEARTHEREARETWOREASONSFTHIS1FAVALIDSTATISTICALTESTTHINGSOTHERTHANDIVIDENDPOLICYMUSTBEHELDCONSTANTTHATISTHESAMPLECOMPANIESMUSTDIFFERONLYINTHEIRDIVIDENDPOLICIES2WEMUSTBEABLETOMEASUREWITHAHIGHDEGREEOFACCURACYEACHFIRM’SCOSTOFEQUITYNEITHEROFTHESETWOCONDITIONSHOLDSWECANNOTFINDASETOFPUBLICLYOWNEDFIRMSTHATDIFFERONLYINTHEIRDIVIDENDPOLICIESNCANWEOBTAINPRECISEESTIMATESOFTHECOSTOFEQUITYTHEREFENOONECANESTABLISHACLEARRELATIONSHIPBETWEENDIVIDENDPOLICYTHECOSTOFEQUITYINVESTSINTHEAGGREGATECANNOTBESEENTOUNIFMLYPREFEREITHERHIGHERLOWERDIVIDENDSNEVERTHELESSINDIVIDUALINVESTSDOHAVESTRONGPREFERENCESSOMEPREFERHIGHDIVIDENDSWHILEOTHERSPREFERALLCAPITALGAINSTHESEDIFFERENCESAMONGINDIVIDENDSHELPEXPLAINWHYITISDIFFICULTTOREACHANYDEFINITIVECONCLUSIONSREGARDINGTHEOPTIMALDIVIDENDPAYOUTEVENSOBOTHEVIDENCELOGICSUGGESTTHATINVESTSPREFERFIRMSTHATFOLLOWASTABLEPREDICTABLEDIVIDENDPOLICY

簡(jiǎn)介：我國老年人主觀幸福感研究現(xiàn)狀的綜述我國老年人主觀幸福感研究現(xiàn)狀的綜述教育學(xué)院心理健康教育專業(yè)摘要隨著社會(huì)的發(fā)展，中國老齡化程度日益加深，老年人的健康和主觀幸福感也備受關(guān)注。為了深入了解我國老年人主觀幸福感研究的現(xiàn)狀，運(yùn)用文獻(xiàn)計(jì)量法和內(nèi)容分析法對(duì)20032013年間的文獻(xiàn)進(jìn)行分析研究。從而對(duì)老年人主觀幸福感今后的進(jìn)一步研究提出建議。關(guān)鍵詞老年人主觀幸福感文獻(xiàn)計(jì)量法內(nèi)容分析法一、研究背景一、研究背景隨著社會(huì)的發(fā)展，中國人口老齡化的問題日益突出。老年人的年齡不斷增加、體質(zhì)卻不斷下降，他們逐漸從社會(huì)和工作中崗位中退出，甚至有些老人的子女、配偶也不在身邊。因此，老年人的生理、生活和心理問題受到社會(huì)越來越多的關(guān)注。主觀幸福感是個(gè)體對(duì)于自己是否幸福的主觀感受是個(gè)體按照自定的標(biāo)準(zhǔn)對(duì)其生活質(zhì)量所作的總體性評(píng)價(jià)具有主觀性、整體性、相對(duì)穩(wěn)定性等基本特點(diǎn)。1對(duì)老年人主觀幸福感的研究可以用來衡量老年人的身心健康狀況。我國近些年來對(duì)老年人主觀幸福感的研究越來越多，了解了老年人主觀幸福感的現(xiàn)狀，分析出了影響其主觀幸福感的因素，并提出了一些相應(yīng)的建議、措施。但是，從文獻(xiàn)的數(shù)量上來看，我國對(duì)于老年人主觀幸福感的研究還處于起步階段。為了更好地開展相關(guān)問題的研究，需要進(jìn)一步對(duì)研究現(xiàn)狀進(jìn)行反思。實(shí)現(xiàn)學(xué)科發(fā)展的理性反思的重要途徑之一就是歸納和總結(jié)，而對(duì)現(xiàn)有的研究成果進(jìn)行研究是主要手段。用科學(xué)的方法和工具研究現(xiàn)有的關(guān)于老年人主觀幸福感的研究成果，從質(zhì)和量?jī)煞矫嫣接懷芯楷F(xiàn)狀，為今后的相關(guān)研究提出合理化建議。二、研究方法與研究設(shè)計(jì)二、研究方法與研究設(shè)計(jì)（一）研究方法根據(jù)研究需要，參考借鑒陳麗（2011）等所采用的類目體系，分別制定了研究主題、研究性質(zhì)、研究方法等三個(gè)類目體系。如表24所示。表2研究主題類目體系名稱釋義現(xiàn)狀研究老年人主觀幸福感的基本狀況影響因素研究影響老年人主觀幸福感的影響因素促進(jìn)方法研究如何提升老年人的主觀幸福感研究發(fā)展?fàn)顩r研究目前國內(nèi)外對(duì)老年人主觀幸福感的研究現(xiàn)狀及相關(guān)研究的發(fā)展其他無法歸于上述任何一類的文章表3研究性質(zhì)體系類目研究性質(zhì)釋義基礎(chǔ)性研究指向普遍性、規(guī)律性的內(nèi)容，目的是豐富學(xué)科的知識(shí)性體系應(yīng)用型研究指向當(dāng)下的、實(shí)際的問題，目的是解決現(xiàn)實(shí)的問題綜合型研究指向上述兩種內(nèi)容，目的是既認(rèn)知規(guī)律、又解決現(xiàn)實(shí)問題表4研究方法類目體系方法類別特征定量與實(shí)證利用觀察法、實(shí)驗(yàn)法、問卷法等來收集數(shù)據(jù)并進(jìn)行分析，以此來進(jìn)行研究定性與思辨從經(jīng)驗(yàn)，歷史，資料，事實(shí)出發(fā)，通過比較分析、總結(jié)歸納來研究問題3、外部特征計(jì)量要素表5外部特征計(jì)量要素要素名稱備注說明作者文獻(xiàn)的第一作者作者來源指文獻(xiàn)作者所屬行政單位，反應(yīng)研究者地區(qū)

簡(jiǎn)介：外文翻譯外文翻譯英文原文英文原文ABSTRACTTHEWKINGPRINCIPLESTHEBASICFEATURESOFAIRCONDITIONINGWATERHEATERACWHSYSTEMAREINTRODUCEDINTHISPAPERTHEAIRCONDITIONINGWATERHEATERSYSTEMCANOPERATEINFIVEMODESWATERHEATINGONLYSPACECOOLINGWATERHEATINGSPACEHEATINGWATERHEATINGSPACECOOLINGSPACEHEATINGCOMPARATIVELYTHESYSTEMCANPROVIDEMUCHBETTERENERGYPERFMANCEHIGHEREQUIPMENTUTILIZATIONTHROUGHOUTAYEARCAUSELESSTHERMALPOLLUTIONTHANHEATPUMPWATERHEATERCOMMONAIRCONDITIONERAPROTOTYPEWITHFIVEMODESWASASSEMBLEDTESTEDATTHEAMBIENTTEMPERATUREFROM7℃TO43℃ESPECIALLYWHENFROSTINGWHENITWKSINTHEWATERHEATINGMODEITCANSUPPLY55℃HOTWATERWITHINTWOMINUTESTHECONDENSINGPRESSUREISJUSTSAMEWITHCOMMONAIRCONDITIONERWHENSOMEMODESSWITCHTHETEMPERATUREOFTHEOUTLETHOTWATERISCONSTANTTHEETICALANALYSISEXPERIMENTALSTUDYWEREDONETOTHEACWHINTHISTHESIS1THEPROTOTYPEWASTESTEDINTHEAIRCONDITIONERLABATYOFGREETHETESTINGDATAINDICATETHATTHEPROTOTYPEACCDSWELLWITHTHENATIONALSTARDSOFAIRCONDITIONERHEATPUMPWATERHEATER2BASEDONTHEEXPERIMENTALRESULTSANALYSISWASDONEONTHEACWHINMAINOPERATINGMODESSOMEIMPTANTCONCLUSIONSWEREGIVEN，THERESULTSINDICATETHATTHENEWSYSTEMCANSAVEENERGYTHROUGHMULTIDUTIESITCANWKSTABLYINFIVEWKMODESWITHHIGHEFFICIENCYCOMPAREDWITHOTHERMODELSTHENEWSYSTEMALSOINCLUDESAIRCONDITIONINGUNITWATERHEATERUNITBUTWITHFEWERCOMPONENTSHIGHERRELIABILITYBASEDONCOMMONAIRCONDITIONERTHISSYSTEMCANOFFERAPRACTICABLESOLUTIONCOUPLINGAIRCONDITIONERWATERHEATERITMUSTBECHANGINGTHEMARKETSOFBOTHAIRCONDITIONERWATERHEATER1INTRODUCTIONTHEHEATPUMPWATERHEATERHPWHHASBEENUSEDSINCE1950SMAINLYFHOUSEHOLDAPPLICATIONSITABSBSHEATENERGYFROMTHEAMBIENTAIRTOACQUIREHOTWATERINTHELAST20YEARSTHESTUDYINTENDSTODESIGNHEATPUMPWATERHEATERWITHHIGHRELIABILITYPRACTICABILITYMANYMANUFACTURERSTURNTOOFFERTHISPRODUCTIONBASEDONENVIRONMENTALPROTECTIONENERGYSAVINGINSOUTHAFRICAHPWHHASPERATED16PERCENTOFTHEMARKETSHAREFCOMMERCIALWATERHEATERSBECAUSEOFTHEHIGHLYPRIMARYCOSTITISDIFFICULTTOBECOMETHEALTERNATIVETOTHECOMMONWATERHEATERHOWEVERIFWECANOFFERANAIRCONDITIONERCOUPLEDWITHHPWHSYSTEMWHICHCANACTASAIRCONDITIONERWATERHEATERWITHTHEMAINCOMPONENTSSUCHASHEATEXCHANGERSCOMPRESSFOURWAYVALVETHEOTHERISHEATINGWATERWITHWATERRECYCLEINTHEADIABATICWATERTANKTHECONTROLLERCANADJUSTTHEOPERATINGMODEACCDINGTOTHEWATERLEVELSENSSINTHETANKAWATERVALVEISPLACEDATTHEHOTWATEROUTLETWHICHCANBEADJUSTEDTOCONTROLTHEWATERFLOWKEEPTHECONDENSINGPRESSURECONSTANTWHENTHETAPWATERGOESINTOTHEWATERREFRIGERANTHEATEXCHANGERWRHEITWILLBEHEATEDTO5055DIRECTLYWITHINTWOMINUTESIFNEEDED℃THEOUTLETWATERTEMPERATURECANBESETBYADJUSTINGTHEWATERVALVEASSHOWNINFIGURE1WHENTHEPOWERISONTHECOMPRESSSUCKSLOWPRESSUREREFRIGERANTGASTHENDISGESHIGHPRESSUREGASINTOWATERREFRIGERANTHEATEXCHANGERWRHEWHEREREFRIGERANTISCONDENSEDWATERISHEATEDDIRECTLYAFTERHEATEXCHANGESTHELIQUIDREFRIGERANTFLOWSACROSSFOURWAYVALVETHENITISTHROTTLEDTOLOWTEMPERATURELOWPRESSURELIQUIDGASBYANELECTRONICEXPANSIONVALVEREFRIGERANTFLOWSINTOOUTDOAIRCOOLEDCONDENSERWHEREITISEVAPATEDBECOMESLOWPRESSUREGASWHENTHELOWPRESSUREGASRETURNSTOTHECOMPRESSTHECIRCLEBEGINSAGAININTHISMODEVALVE1ISCLOSEDVALVE2ISOPENWHENHEATINGWATERTHEOUTDOAIRCOOLEDUNITACTSASEVAPATTHEINDOFANDOESN’TRUNTHECOPWISPRESENTEDASAFUNCTIONOFPOWERQWTHEELECTRICPOWERWASSHOWNINEQUATION1COPWQWWMC△T1WHEREMISTHEMASSFLOWOFWATERCISTHESPECIFICHEATOFWATER△TISTHEWATERTEMPERATUREDIFFERENCEBETWEENOUTLETINLETOFTHEWATERREFRIGERANTHEATEXCHANGERWRHE12SPACECOOLINGWATERHEATINGSCWHMODEINSUMMERWITHTHERECOVERYOFCONDENSINGHEATTHEINDOAIRISCOOLEDDOWNATTHESAMETIMECOMPAREDWITHWATERHEATINGMODETHEHIGHTEMPERATUREREFRIGERANTISALSOCONDENSEDINTHEWRHEDIRECTLYTHENGOESTHROUGHTHEAIRCOOLEDCONDENSERTOBESUPERCOOLEDWHERETHEOUTDOFANDOESN’TRUNITISTHROTTLEDBYCAPILLARY1TOLOWTEMPERATURELIQUIDGASTHEINDOAIREXCHANGESHEATWITHRETURNEDREFRIGERANTINTHISMODEVALVE1ISOPENVALVE2ISCLOSEDTHISMODECANACTASSPACECOOLINGWATERHEATINGATTHESAMETIMEHOWEVERITISNOTNECESSARYTORECOVERTHEENTIRECONDENSINGHEATWHICHCANBERELEASEDINTHEAIRCOOLEDCONDENSERTHETOTALCAPACITYISTHESUMOFCOOLINGCAPACITYQCHEATINGCAPACITYQWTHENTOTALCOPCWCANBESHOWNASTHEEQUATION2COPCWQC＋QWW223SPACEHEATINGWATERHEATINGMODEREFRIGERANTFLOWSACROSSWRHEEVAPATCAPILLARY2CAPILLARY1AIRCOOLEDCONDENSERINTURNSPACEHEATINGWATERHEATINGCANREALIZEINTHEYTHISMODESOMETIMESMAYNOTMEETCUSTOMERS’EXPECTATIONSSOTHATITMUSTOPERATE

簡(jiǎn)介：第1頁共50頁本科畢業(yè)論文（設(shè)計(jì)）本科畢業(yè)論文（設(shè)計(jì)）天然氣汽車研究綜述天然氣汽車研究綜述目錄摘要IIIABSTRACTIV第1章緒論111研究背景及意義1111研究背景1112研究意義2第2章天然氣及天然氣汽車的發(fā)展現(xiàn)狀、問題、對(duì)策321天然氣的特性3211天然氣的特性3212車用天然氣技術(shù)5213天然氣用作汽車能源的優(yōu)點(diǎn)722天然氣汽車8221天然氣汽車分類8222天然氣汽車的特性1023天然氣汽車的發(fā)展?fàn)顩r11231國外發(fā)展?fàn)顩r11232我國天然氣汽車發(fā)展?fàn)顩r1324我國天然氣汽車發(fā)展面臨的挑戰(zhàn)1425我國天然氣汽車發(fā)展的對(duì)策1526本章小結(jié)16第3章天然氣汽車性能及特性17第3頁共50頁摘要隨著世界經(jīng)濟(jì)的快速發(fā)展，汽車保有量的迅速增加，全球能源緊缺以及能源的消耗所帶來的環(huán)境問題，已經(jīng)日趨嚴(yán)峻。為了解決這個(gè)問題，實(shí)現(xiàn)可持續(xù)發(fā)展，開發(fā)新能源汽車低排放汽車，已經(jīng)成為汽車工業(yè)發(fā)展方向之一，尋求可代替能源成為當(dāng)務(wù)之急。天然氣作為一種“清潔能源”，用作汽車燃料，不僅可以節(jié)約石油資源、降低燃料費(fèi)用，而且還大大降低環(huán)境污染。所以發(fā)展天然氣汽車是解決傳統(tǒng)能源危機(jī)和環(huán)境污染的有效方法。本文闡述了天然氣汽車的現(xiàn)狀。并對(duì)其燃燒過程的計(jì)算分析、排放物生成機(jī)理以及影響因素進(jìn)行分析總結(jié)得出影響天然氣汽車性能下降的原因。最后闡述了天然氣汽車現(xiàn)狀的技術(shù)情況，就其性能下降的原因，提出解決和提高改善性能的方法、結(jié)論。關(guān)鍵詞天然氣汽車燃燒性能燃燒

簡(jiǎn)介：1電磁閥外文翻譯3OFSTRESSPRELOADSUCHINHOMOGENEITIESMAYBEINHERENTTOANATTACHMENTMETHODITSELFMAYSUBSEQUENTLYBECAUSEDBYSYSTEMICALLYRENDEREDMALFMATIONSTHERMALSPRAYTHEPROCESSWHEREMETALPARTICLESAREDEPOSITEDONTOASUBSTRATETOFMACOATINGWASUSEDTOADDRESSTHEISSUEOFSECURELYAFFIXINGMAGICMATERIALTOATQUEBEARINGMEMBERINADDITIONTOACHIEVINGTHEPREREQUISITEOFANINTIMATESECUREBONDTHETHERMALSPRAYPROCESSCANBEREGULATEDSUCHTHATTHEDEPOSITEDMAGICMATERIALISPRELOADEDWITHTHEINTERNALSTRESSESNEEDEDTOINVOKETHEINVERSEMAGOSTRICTIONEFFECTSUMMARIZINGTHEPASSIVENATUREOFTHEMAGICSENSEELEMENTPROVIDESANINTRINSICALLYSIMPLEKERNELFTHESIEMENSVDOTQUESENSTHATMAKESFAHIGHLYRELIABLESTABLEDESIGNTHETHERMALSPRAYPROCESSADDSROBUSTNESSTOTHEMECHANICALASPECTBYPERMITTINGTQUEEXCURSIONSTOANUNPRECEDENTED2000OFFULLSCALEPERPROTOTYPEVALIDATIONTESTINGOFCERTAINCONSTRUCTSWITHOUTTHENEEDFANCILLARYTQUELIMITINGPROTECTIONDEVICESFURTHERMEACCURACYREPEATABILITYSTABILITYLOWHYSTERESISROTATIONALPOSITIONINDIFFERENCELOWCOSTAMENABILITYTOTHEHIGHVOLUMEMANUFACTURINGNEEDSOFTHEAUTOMOTIVEMARKETPLACEAREALLATTRIBUTESOFTHISTQUESENSINGTECHNIQUEWHENCOUPLEDWITHAMAGOMETERTHATISGROUNDEDINWELLESTABLISHEDFLUXGATETECHNOLOGYTHERESULTANTSENSISINHERENTLYDEPENDABLECANPOTENTIALLYESTABLISHANEWSTARDFTQUEMEASURINGSENSSINTRODUCTIONASISWELLKNOWNAUTOMOTIVETRANSMISSIONSAREDESIGNEDTOALTERTHEPOWERTRANSFERRATIOBETWEENTHEENGINETHEDRIVEWHEELSEFFECTIVELYOPTIMIZINGENGINELOADINGTHEENGINETHEREBYRUNSINANARROWEFFICIENTOPERATINGBEVENTHOUGHTHEVEHICLETRAVELSOVERAWIDERANGEOFSPEEDSFAUTOMATICTRANSMISSIONSSHIFTVALVESTHEGEARRATIOBASEDGENERALLYONTHETHROTTLEPOSITIONENGINEVACUUMTHEOUTPUTSHAFTGOVERNVALVESTATEWITHTHEADVENTOFELECTRONICSENSSCOMPUTERIZEDENGINECONTROLLERSTRANSMISSIONSHIFTFUNCTIONSHAVEBEENMIGRATINGTOWARDSCLOSEDLOOPOPERATIONUNDERSOFTWAREPROCESSINGCONTROLALONGWITHTHISPROGRESSIONCAMETHEREALIZATIONTHATTHETRANSMISSIONOUTPUTTQUEWOULDPROVIDEAVALUABLEFEEDBACKPARAMETERFSHIFTTRACTIONCONTROLALGITHMSTHEMEASUREMENTOFOUTPUTTQUEHOWEVERPROVEDELUSIVEDUETOTHEEXTREMELYHARSHOPERATINGCONDITIONSONEPARTICULARSUVAPPLICATIONUNDERCONSIDERATIONREQUIRED1?CURACYINMEASUREMENTSOFROUGHLY2700NMWITHPOSSIBLETQUEEXCURSIONOF4700NMALLWHILEEXPOSEDTOTEMPERATUREEXTREMES45TO160OCONEMETHODFMEASURINGTQUEISTOEXAMINETHEPHYSICALSTRESSESTHATDEVELOPINASHAFTWHENITISSUBJECTEDTOANENDTOENDTWISTINGFCETHEPRINCIPLESTRESSESARECOMPRESSIVETENSILEINNATUREDEVELOPALONGTHETWOCOUNTERSPIRALINGMUTUALLYTHOGONAL45OHELICESTHEYAREDEFINEDBYTHEEQUATIONTTRJ

簡(jiǎn)介：外文文獻(xiàn)譯文設(shè)計(jì)論文題目S7200系列PLC實(shí)現(xiàn)電梯模型控制專業(yè)與班級(jí)學(xué)生姓名指導(dǎo)教師年月日2LISTIL1THETECHNIQUEOFPLCUSINGPROGRAMMABLELANGUAGETOCONTROLLARGESCALEINTEGRATEDCIRCUITHASBEENWIDELYUSEDININDUSTRY2BECAUSEOFSAFETYCRITICALSOFTWARECANCAUSESERIOUSDAMAGETOLIFEPROPERTYVERIFICATIONOFSAFETYCRITICALSOFTWAREHASBECOMEANINDISPENSABLESTEPREQUIREDTOASSURESOFTWAREQUALITYTHEPRESENTVERIFYINGMETHODFTHEPLCISSTILLSTUCKBYSIMULATIONTESTINGHOWEVERTHEYCANNOTCOVERALLPOSSIBLECASESESPECIALWHETHERTHEDESIGNMODELOFPLCTOMEETTHEDEMTHEREFETHEMODELCHECKINGTECHNOLOGYISINTRODUCEDINTOTHEFIELDOFPLCTOGIVETHEETICALANALYSISOFPLCDESIGNBECOMESIMPTANTTHEPRIMARYSTEPOFPLCMODELCHECKINGISTOTHEESTABLISHMENTOFPLCMODELSUCHASESTABLISHAMODELFROMFUNCTIONTS3THEPLCMODELFOCUSESONTHEESTABLISHMENTOFTHETIMEATTRIBUTES4ITCANBEMODELEDBYTHEMETHODOFTIMEDAUTOMATA5TIMEPERIODMODELINGMETHOD6THUSSTATESPACEOFTHEMODELWILLBEDECREASEDCOMPAREDTOTIMEDAUTOMATAEITHERWAYONECHOOSEEVENTUALLYANABSTRACTMODELCANBEGIVEN7HOWTOBUILDAGOODPLCABSTRACTMODELISTHEMOSTIMPTANTISSUETOTHECHECKINGASTHEMANUALLYMODELINGISEASYTOINTRODUCEMANYERRSSOTHEESTABLISHMENTOFANINTEGRATEDMODELINGTESTINGTOOLISVERYIMPTANTTHISISONEOFTHEISSUESOFCONCERNTOTHISPAPERPLCCONTROLPROGRAMRUNSINREALTIMEOPERATINGSYSTEMMULTITASKSINGLETASKTHISPAPERISMAINLYBASEDONMULTITASKSCHEDULINGPLCSYSTEMSECTION2OFTHEARTICLEHASANINTRODUCTIONTOTHEMODELINGMETHODOFPLCSYSTEMSECTION3GIVESTHEANALYSISIMPROVEMENTOFTHISMODELASWENEEDTOREDUCETHEPROBABILITYOFPSEUDOERRSSECTIONIVDESIGNSAMODELCHECKINGTOOLPLCCHECKERTOCHECKTHEESTABLISHEDMODELINCLUDINGINTRODUCETHEWAYOFCONVERTINGPLCPROGRAMINTOSPINSINPUTLANGUAGEPROMELACODEFINALLYACLASSICALPLCEXAMPLEISAPPLIEDTOCHECKACRITICALCOUNTEREXAMPLEISFOUNDBYTHEPLCCHECKER2PLCMODELINGTHEREARETHREESTEPSOFMODELCHECKINGMODELINGPROPERTYDEIONVERIFICATIONTHEMOSTIMPTANTISHOWTOBUILDTHESYSTEMMODELINTHESYSTEMPLCCONTROLLERISNOTISOLATEDBUTHASINTERACTIONWITHITSWKINGENVIRONMENTDRIVERHUMAN8THEREFETHESEFACTSSHOULDALSOBEMODELINGTHEENVIRONMENTHUMANTHEPLCCONTROLLERISINDEPENDENTCONCURRENTWITHEACHOTHERINLOGICALSOTHEMODELCHECKERSPIN’SINPUTLANGUAGEPROMELAISFOCUSEDONDESCRIBINGTHECONCURRENTSOSTARTINGFROMTHISIDEAWEBUILDTHESEFACTSINTOSEVERALCONCURRENTPROCESSESTOFITTHECHECKINGFROMSPINITWILLALSOACCURATELYDESCRIBETHESYSTEMTODESCRIBECONVENIENTLYTHEYWILLBECALLEDCONCURRENTENTITIESPLCCONTROLLERINTERACTSWITHTHECONCURRENTENTITIESTHROUGHTHESYMBOLSINIMAGETABLETHESYMBOLSOFPLCSYSTEMINCLUDEI

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簡(jiǎn)介：附錄附錄ELEMENTARYTALKONMANAGEMENTOFTHEGASFROMWKFACEOFINTEGRATEDRELEASETOPCOALINHIGHGASTHICKCOALBEDLILICHENZHIPINGCOLLEGEOFRESOURCESENVIRONMENTALENGINEERINGLIAONINGTECHNICALUNIVERSITYABSTRACTCOMBINATIONSTOPINGTECHNIQUESONINTEGRATIONRELEASETOPCOALANALYSISOFTHESOURCESOFGASCARRYINGOUTTHE12ACTERGUIDELINEOFGASMANAGEMENTCLASSIFICATIONSUBSOURCESMANAGEMENTOFTHEGASCHOOSETHESPECIALMEASURESTOCONTROLTOACHIEVEASAFEENVIRONMENTHIGHYIELDEFFICIENTFMINESKEYWDSGASSOURCESGASMANAGEMENTHIGHGASINTEGRATEDRELEASETOPCOAL1INTRODUCTIONMINEGASISONEOFTHEFIVEMAJDISASTERSBUTALSOWITHTHEMINEFROMTHEABONEDBUILDINGTOTHEWHOLEPROCESSOFCOEXISTENCECHINASGASACCIDENTSFREQUENTLYOCCURITISIMPERATIVEGASCONTROLTHELINETOBEEFFECTIVEATPRESENTLARGESCALECOALMININGINTHESHAFTTHEMECHANIZEDPRODUCTIONEFFICIENTDECENTRALIZEDPRODUCTIONDIRECTIONTHETHICKATHICKSEAMFULLYCAVINGMETHODOFMININGTHEFULLREALIZATIONOFAWELLSIDEOFTHEHIGHCONCENTRATIONOFHIGHYIELDHIGHEFFICIENCYMODEOFPRODUCTIONASCOMPREHENSIVECAVINGFACEAHIGHDEGREEOFMECHANIZATIONTHEINTENSITYOFMININGPRODUCTIONCONCENTRATEDINHIGHGASCOALMINEPRODUCTIONPROCESSTHEFACEOFASINGLEINDUSTRYWILLFOCUSONALOTOFGASEMISSIONWILLAPPEARREGULARLYONTHECNERBACKTOTHEGASSUPERMERRYRESTRICTIONSWHICHBECAMETHEFACEOFAMAJOBSTACLETOPRODUCTIONINDERTOENSUREPRODUCTIONSAFETYGASISSUESMUSTTAKEMEASURESTOBEADDRESSED2INTEGRATEDCAVINGMININGTECHNOLOGYFEATURESSHEARERTOUSEACERTAINHIGHLEVELOFCOALCUTTINGHIGHLYDEPENDENTONCOALMININGTHANTHERESTINTHEUPPERPARTOFTHECOALMINEUNDERPRESSUREBROKENITSOWNUSINGINTEGRATEDCAVINGCOALPOWEREDSUPPTTHERELEASEWINDOWTHEFACELENGTHMININGGEDMEIKUAISMALLERMEPULVERIZEDCOALCOALTRANSPTATIONFEXPLOITATIONOFINTENSITYFOCUSONPRODUCTIONRESULTINGINMININGOFCOALGASEMISSIONINTHECOURSEOFRAPIDINCREASEINCOALDUSTPRODUCEDALARGEQUANTITYGASEASYTOINCREASECUTINPROMOTINGEARLYSTAGEFACETHEGASCOMESMAINLYFROMTHECOALMININGGASEMISSIONWITHTHEFACEOFADVANCINGTHETOPCOALMINEUNDERPRESSURESELFLOADINGBROKENGASEMISSIONINTHEFACEDRAMATICALLYTHEINCREASEBASICSTABILITYINAVALUE44MINEDOUTAREAOFTHEGASEMISSIONACTERISTICSGOAFGASCOMESMAINLYFROMDILAPIDATEDCOALCOALEXPOSEDROCKFACEINTHEFMOFANATTENUATIONCURVETHEMEGRADUALDEPLETIONCUMULATIVEGASMINEDOUTAREAOFTHEDEPTHCONCENTRATIONWITHTHEINCREASEMOSTOFTHEWINDGATHEREDINTHEALLEYNEARTHEBACKOFTHEROOFDEPARTMENTINTHEINITIALPRESSURETOTHEFMERNOTTHEBASICLAYERADJACENTTOTHEMINEDOUTAREAOFTHEEXPLOITATIONOFTHEINFLUXOFGASCANBECONSIDEREDOUTOFTHEMAINGASBASEDLAYEROFGASEMISSIONWHENTHEROOFFIRSTRUNBACKWARDRELIEVEDONLYINTHEVICINITYOFTHEMINEDOUTAREATOTHEINFLUXOFGASTHEINFLUXOFGASISCONSTANTLYINCREASINGACHIEVEASTABLEVALUEWHENTHEWKINGFACECLOSETOTHESTOPLINEGASEMISSIONINGRADUALLYDECREASEDFFULLYCAVINGMININGCOALINTHEFACEATTHETOPOFPROMOTINGACERTAINDISTANCEBEFEBEGINNINGTOTAKEOFFBROKENGASEMISSIONINCREASESINCETHERELEASEOFTHECOMPREHENSIVEEFFICIENCYISNOTHIGHTHECOALRECOVERYRATEISLOWLEFTOVERFROMCOALMINEDOUTAREADEEPMINEDOUTAREAOFHIGHGASCONCENTRATIONINGENERALOUTOFTHEMINEVENTILATIONMINEDOUTAREAISNOTCLOSEDTIGHTAIRLEAKAGESERIOUSVERYEASYFTHEGASGAUGE5IMPACTONTHEVOLUMEOFGASEMISSIONFACTS1MINEPRESSUREGENERALTOTHEINITIALPRESSUREOFGASEMISSIONBEFETHESMALLERTOTHEINITIALPRESSURETHEROOFBEHINDTHEFIRSTTIMETHEVOLUMEOFGASEMISSIONINCREASESPARTICULARLYDURINGTHEEARLYRELEASETHEGASEMISSIONINTHEREASONSFTHESURGEISINITIALCAVINGAGOJUSTINTHEFACEOFRECOVERYTHISTIMEAFTERWKBEFETHEMINEPRESSUREWITHOUTMAJCHANGESCOALROCKARENOTMOBILEFIXEDBEARINGPRESSUREDESTRUCTIONTHATISNOTANEWFISSURESITSSURROUNDINGGASWILLBENORELIEFWASOUTWITHALLEYESINTHECONSTRUCTIONPROCESSINTHEDISGEOFGASHASTHEREFEASMALLERVOLUMEOFGASEMISSIONAFTERTHEINITIALCAVINGNEARTHECOALFACEINCLUDINGTHEUPPERLOWERSEAMROCKTOBEFIXEDMOBILEBEARINGTHEIMPACTOFPRESSUREGENERATEDALOTOFNEWFISSURESTHENASHARPPRESSURERELIEFSOTHATNEARBYCOALFACEROCKALARGENUMBEROFGASFROMTHESEFISSURESINTHEEMISSIONTHATISOUTOFTHECHANNELASUBSTANTIALINCREASEINGASFALLINGATTHESAMETIMEALSOACCOMPANIEDBYTHEWASTEGASEMISSIONSINCETHEINITIALCAVINGTHEROOFINITIALMINEPRESSUREGREATERIMPACTONTHEWIDERSCOPETHEWASTEISFALLINGMETHUSTHEVOLUMEOFGASEMISSIONWILLINCREASEMERAPIDLYF

簡(jiǎn)介：文獻(xiàn)出處作者M(jìn)ARIANMOFFETTMICHAELWFAZIO期刊或書名AWLDHISTYOFARCHITECTURE出版社NEWYKHARPERIFSOMEONEINTHEFAMILYISINTERESTEDINPLANTMAINTENANCEMANAGEMENTTHEYCANPLANTSOMESEASONALHERBACEOUSFLOWERSTHUSBUILDAPERFECTNAMENTALGARDENINSHTCOURTYARDSTYLECULTIVATIONOFPLANTSPECIESSHOULDBEBASEDONCOMPOSITIONAGESTRUCTUREOFTHEFAMILYTHEREAREVARIOUSGARDENSTYLESWHOSEBASICFMSAREGENERALLYBASEDONTHEOWNERS

簡(jiǎn)介：壓控振蕩器（VCO）技術(shù)綜述1前言壓控振蕩器VOLTAGECONTROLLEDOSCILLATVCO是一種以電壓輸入來用來控制振蕩頻率的電子振蕩電路是現(xiàn)代無線電通信系統(tǒng)的重要組成部分課題。在當(dāng)今集成電路向尺寸更小、頻率更高、功耗更少、價(jià)格更低發(fā)展的趨勢(shì)下，應(yīng)用標(biāo)準(zhǔn)工藝設(shè)計(jì)生產(chǎn)高性能的壓控振蕩器已是射頻集成電路中的一個(gè)重要課題。環(huán)形振蕩器易于集成，可調(diào)頻率范圍大，但相位噪聲不如性能不如LC振蕩器。LC壓控振蕩器要求高品質(zhì)因素的無源器件，需要片上電感和變?nèi)莨芷骷拍芗杉伞Ｕ袷幤髯云湔Q生以來就一直在通信、電子、航海航空航天及醫(yī)學(xué)等領(lǐng)域扮演重要的角色，具有廣泛的用途。在無線電技術(shù)發(fā)展的初期，它就在發(fā)射機(jī)中用來產(chǎn)生高頻載波電壓，在超外差接收機(jī)中用作本機(jī)振蕩器，成為發(fā)射和接收設(shè)備的基本部件。隨著電子技術(shù)的迅速發(fā)展，振蕩器的用途也越來越廣泛，例如在無線電測(cè)量?jī)x器中，它產(chǎn)生各種頻段的正弦信號(hào)電壓在熱加工、熱處理、超聲波加工和某些醫(yī)療設(shè)備中，它產(chǎn)生大功率的高頻電能對(duì)負(fù)載加熱某些電氣設(shè)備用振蕩器做成的無觸點(diǎn)開關(guān)進(jìn)行控制電子鐘和電子手表中采用頻率穩(wěn)定度很高的振蕩電路作為定時(shí)部件等。尤其在通信系統(tǒng)電路中，壓控振蕩器VCO是其關(guān)鍵部件，特別是在鎖相環(huán)電路、時(shí)鐘恢復(fù)電路和頻率綜合器電路等更是重中之重，可以毫不夸張地說在電子通信技術(shù)領(lǐng)域，VCO幾乎與電流源和運(yùn)放具有同等重要地位。圖1各種VCO技術(shù)壽命期變?nèi)荻O管、電容器、電感器等元器件的小型化為制造VCO組件創(chuàng)造了條件。VCO組件是一種混合集成電路器件，具有封裝和外引線。雖然分立元件的晶體管VCO具有按用戶要求設(shè)計(jì)工作頻率和調(diào)諧范圍的靈活性，但一般在生產(chǎn)中都需要耗費(fèi)大量的人工對(duì)確定頻率的元件進(jìn)行調(diào)試，以消除元件誤差對(duì)頻率的影響。此外，分立元件VCO需要良好的屏蔽，其尺寸也比較大。分立元件的VCO已不能完全滿足現(xiàn)代無線電子系統(tǒng)發(fā)展的要求。20世紀(jì)80年代末、90年代初，移動(dòng)電話迅速發(fā)展，對(duì)帶封裝的振蕩器組件的需求也日益增長(zhǎng)。這為VCO組件的發(fā)展提供了難得的市場(chǎng)機(jī)遇。隨著新型無線應(yīng)用領(lǐng)域的不斷發(fā)展，各VCO組件廠商開發(fā)了適合不同應(yīng)用領(lǐng)域所需頻率的產(chǎn)品。由于表面安裝元件的不斷小型化1206，0805，0603，0402和0201，新開發(fā)的VCO組件的尺寸也越來越小，成本也越來越低。圖2說明了現(xiàn)代商用VCO組件尺寸隨時(shí)間減小的變化情況。目前，VCO組件達(dá)到了新的水平，其體積已減小到4MM5MM2MM，大批量供貨VCO的銷售單價(jià)已降至1美元左右。VCO組件在15年中其尺寸急劇減小，滿足了蜂窩電話等新型無線移動(dòng)裝置對(duì)小型化的要求。