简介:Generalizingthenotionofstronglynilcleanrings,weintroducestronglyquasinilcleanrings.Somefundamentalpropertiesandequivalentcharacterizationsofthisclassofringsareprovided.Bymeansofg-Drazininverses,Cline'sformulaandJacobson'slemmaforstronglyquasi-nilcleanelementsareinvestigated.
简介:LadiesandGentlemen:Todiscussthedevelopmentorientationoftheoilindustryundernewcircumstances,JCCPhasdecidedthetopicofthisyear'sIntemationalSymposiumas"TheDevelopment&Har-monyoftheOilindustryontheGlobalView".Thistopicreflectsthecommonwishbytheglobaloilcommunitythatenvironmentimprovementandsocialresponsibilityshouldgohandinhandwiththedevelopmentofoilindustry.
简介:AccordingtoLorenz,chaoticdynamicsystemshavesensitivedependenceoninitialconditions(SDIC),i.e.,thebutterfly-effect:atinydifferenceoninitialconditionsmightleadtohugedifferenceofcomputer-generatedsimulationsafteralongtime.Thus,computer-generatedchaoticresultsgivenbytraditionalalgorithmsindoubleprecisionareakindofmixtureof'true'(convergent)solutionandnumericalnoisesatthesamelevel.Today,thisdefectcanbeovercomebymeansofthe'cleannumericalsimulation'(CNS)withnegligiblenumericalnoisesinalongenoughintervaloftime.TheCNSisbasedontheTaylorseriesmethodathighenoughorderanddatainthemultipleprecisionwithlargeenoughnumberofdigits,plusaconvergencecheckusinganadditionalsimulationwithevensmallernumericalnoises.Intheory,convergent(reliable)chaoticsolutionscanbeobtainedinanarbitrarylong(butfinite)intervaloftimebymeansoftheCNS.TheCNScanreducenumericalnoisestosuchalevelevenmuchsmallerthanmicro-leveluncertaintyofphysicalquantitiesthatpropagationofthesephysicalmicro-leveluncertaintiescanbepreciselyinvestigated.Inthispaper,webrieflyintroducethebasicideasoftheCNS,anditsapplicationsinlong-termreliablesimulationsofLorenzequation,three-bodyproblemandRayleigh-Bénardturbulentflows.UsingtheCNS,itisfoundthatachaoticthree-bodysystemwithsymmetrymightdisruptwithoutanyexternaldisturbance,say,itssymmetry-breakingandsystem-disruptionare'self-excited',i.e.,out-of-nothing.Inaddition,bymeansoftheCNS,wecanprovidearigoroustheoreticalevidencethatthemicro-levelthermalfluctuationistheoriginofmacroscopicrandomnessofturbulentflows.Naturally,muchmoreprecisethantraditionalalgorithmsindoubleprecision,theCNScanprovideusanewwaytomoreaccuratelyinvestigatechaoticdynamicsystems.
简介:TheelectricpowerindustryisafundamentalindustryinthenationaleconomyandtheChineseGovernmenthasalwaysputthepowerindustryonanimportantpriorityfordevelopment.Atpresent,keepingcontinuousrapidandstabledevelopmentofthepowerindustryfacestwochallengingissues—shortageofprimaryenergyresourcesandseriousenvironmentalpollution.Sothecleancoaltechnology(CCThereinafter)hasbeenplacedasoneofthemostpriorrealmfordevelopmentonthe
简介:重点词汇1.foldv.折叠;对折Foldthecard.折叠这张卡片。拓展unfoldv.展开2.messn.杂乱;不整洁Theroomwasinamess.这个房间杂乱不堪。'Whatamess.'shesaidaftertheparty.聚会后她说:'真是一片狼藉.'拓展inamess混乱;凌乱makeamess弄脏;搞成一团糟Thekidsmadeamessinthelivingroom.孩子们把客厅搞得一塌糊涂。3.throwv.(threw)扔;掷Throwmethecarkeys.=Throwthecarkeystome.把车钥匙扔给我。Shethrewhercoatonthebed.她把外套扔在了床上。
简介:Globalclimatechangehasbeenidentifiedasthefirstofthetoptenenvironmentalproblemsintheworld.Asclimatechangewillhaveseriouseffectsonthesocialandeconomicdevelopmentandeverydaylivingofpeopleintheworld,manyofthecountriesandgovernmentsaretakinguntiringeffortstocombatclimatechange.Asoneoftheimportantmechanismsofreducinggreenhousegas(GHG)emissionsintheKyotoProtocol,CleanDevelopmentMechanism(CDM)hasnotonlyprovidedchancefordevelopedcountriestofulfillgreenhouseemissionreductionobligations,butalsoprovidedanopportunityfordevelopingcountriestocombatclimatechangeunderthesustainabledevelopmentframe.Thedualobjectivesofdevelopedcountries'GHGemissions'reductionobligationachievementanddevelopingcountries'sustainabledevelopmentwillbeachievedundertheCDM.Asacountrywithresponsibility,ChinahasbeenpositivelydevelopingCDMprojectsandpromotingenergysavingandemissionsreductionduringthethreeyearsaftertheKyotoProtocolcameintoforce,andCDMprojectsdevelopmenthasalwaysbeeninthefronttankintheworld.However,asthevastclimewithinChina,notabledifferencesoccurindifferentregions.InordertopromotetheCDMdevelopmentinChina,itisnecessarytohaveregionalCDMcapabilityconstructioninaccordancewiththepracticalityindifferentregions.BasedontheSlatAnalysisofdevelopedCDMprojectsandcurrentCDMdevelopmentstatusinChina,problemsintheCDMdevelopmentofChina,includingtheinefficiencyinsmallandmedium-sizedCDMProjectsdevelopment,overcentralizationofCDMdevelopmentscopeandespeciallythedifferentiatedprovincialCDMprojectsdevelopingcapabilityarepointedoutinthepaper.What'smore,reasonsfortheproblemsareanalyzedfromtheleadingfactors,includingpolicyorient,informationasymmetryandweakCDMcapability.InordertopromoteCDMprojectsdevelopmentinChina,anewCDMcapabilityconstructionmodelisputforwardinthepaper
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简介:Thepaperdescribestheimportanceofcleanproductionofsteelandtherelationshipsamongstsustainingdevelopmentofsteelindustry,environmentprotectionandtheroleofrefractoriesinthecleanproductionofsteel.ThemainachievementsandmainshortcomingsinthecleanproductionofChina′ssteelindustryhavebeenreviewedtogetherwiththeintroductionofthepolicysupportingsystemandthefuturedevelopmentofcleanproductioninChina′ssteelindustry.