简介：TravelingtoBeijingforthefirsttime?Don'tgetcaughtin,out,orupbyculturalshocks.Knowhowthingsshould-andshouldn't-hedonetoensureyourtripisamemorableoneforalltherightreasons.

简介：Chlorofluorocarbons(CFCs)orhydrochlorofluorocarbons(HCFCs)areasmainrefrigerantsusedintraditionalrefrigerationsystemsdrivenbyelectricityfromburningfossilfuels,whichisregardedasoneofthemajorreasonsforozonedepletion(man-maderefrigerantsemission)andglobalwarming(CO2emission).Sopeoplepaymoreandmoreattentiontonaturalrefrigerantsandenergysavingtechnologies.AninnovativesystemcombiningCO2transcriticalcyclewithejectorcycleisproposedinthispaper.TheCO2compressionsub-cycleispoweredbyelectricitywiththecharacteristicsofrelativelyhightemperatureinthegascooler(definedasanintercoolerbytheproposedsystem).Inordertorecoverthewasteheat,anejectorsub-cycleoperatingwiththenaturalrefrigerants(NH3,H2O)isemployed.Thetwosub-cyclesareconnectedbyanintercooler.Thiscombinedcyclejoinstheadvantagesofthetwocyclestogetherandeliminatesthedisadvantages.TheinfluencesoftheevaporationtemperatureinCO2compressionsub-cycle,theevaporationtemperatureintheejectorsub-cycle,thetemperatureintheintercoolerandthecondensationtemperatureintheproposedsystemperformancearediscussedtheoreticallyinthisstudy.Inaddition,someuniquefeaturesofthesystemarepresented.

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简介：ThedirectedmotionofaBrownianparticleinaflashingpotentialwithvarioustransitionprobabilitiesandwaitingtimesinoneoftwostatesisstudied.AnexpressionfortheaveragecycleperiodisproposedandthesteadycurrentJoftheparticleiscalculatedviaLangevinsimulation.Theresultsshowthattheoptimalcycleperiodrm,whichtakesthemaximumofJ,isshiftedtoasmallvaluewhenthetransitionprobabilityλfromthepotentialontothepotentialoffdecreases,themaximalcurrentappearsinthecaseoftheaveragewaitingtimeinthepotentialonbeinglongerthaninthepotentialoff,andthedirectionofcurrentdependsontheratiooftheaveragetimeswaitingintwostates.

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简介：Wepresentasufficientandnecessaryconditionforaso-calledCnkpatterntohavepositivesemidefnite(PSD)completion.SincethegraphoftheCnkpatterniscomposedbysomesimplecycles,ourresultsextendthosegivenin[1]forasimplecycle.WealsoderivesomeresultsforapartialToeplitzPSDmatrixspecifyingtheCnkpatterntohavePSDcompletionandToeplitzPSDcompletion.

简介：TheperformancesofnonlinearWDMsystemswithdifferentdutycyclearecomparedbymeansofnumericalsimulation.Thenumericalresultsshowthattheopticalpulsewithdutycycleof0.5issuperiortotheconventionalNRZmodulationschene.Theconclusionisdifferentfromthatofsomereferences.Thereasonisthatintersymbolinterferenceisnotincludedinsomereferences.Infact,intersymbolinterferenceplaysanimportantroleinmonlinearWDMsystem.Althoughthelargerthedutycycleis,thestrongertheeffectofthecross-phasemodulationandself-phasemodulationonnonlinearWDMishowever,thelargerthedutycycleis,thestrongertheintersymbolinterferenceis.

简介：Inordertoidentifythelocationsofirreversiblelosswithinthetranscriticalcarbondioxiderefrigerationcyclewithanexpansionturbine,amethodwithrespecttothesecondlawofthermodynamicsbasedonexergyanalysismodelisapplied.Theeffectsofheatrejectionpressures,outlettemperaturesofgascoolerandevaporatingtemperaturesontheexergyloss,exergyefficiencyandthecoefficientofperformance(COP)oftheexpansionturbinecycleareanalyzed.Itisfoundthatthegreatpercentagesofexergylossestakeplaceinthegascoolerandcompressor.Moreover,heatrejectionpressures,outlettemperaturesofgascoolerandevaporatingtemperatureshavestronginfluenceontheexergyefficiency,COPandtheexergylossofeachcomponent.TheanalysisshowsthatthereexistsanoptimalheatrejectionpressurecorrespondingtothemaximumexergyefficiencyandCOP,respectively.Theresultsareofsignificanceinprovidingtheoreticalbasisforoptimaldesignandthecontrolofthetranscriticalcarbondioxidesystemwithanexpansionturbine.

简介：Takingintoconsiderationthecharacteristicsofnowadayssociety,thispaperhasadvancedthesystemicthinkingonthebuildingofEnterprises'"ThreeCycle"IntegrationStructure.Afterpointingout,theprinciplesofoptimizationbetweentheoreticstructureandexecutivestructure,thispaperhasbroughtforwardtheEnterprises'"ThreeCycle"IntegrationStructureanditsinherentrelationshipamongeachcycle.

简介：ThecontentsofbiogenicelementsinChinamarginalseasedimentsarerelatedtotheirgrainsizes,rivertransport,etal.Ingeneral,thefinerthegrainsizeis,thehigherthecontentsoforganicmatterandOC,N,Pare,thelowerthecontentsofSandSiare.ThebiogeochemicalenvironmentsofsedimentsarerelatedtoEh,pH,temperaturecontentofOC,Fe3+/Fe2+radio,waterdynamicscondition,grainsizeofsediment,Ssysteminsedimentinterstitialwaters,etal.,andtheyinfluencetheearlydiagenesesandcycleofbiogenicelementsinsediments.InmostregionsofChinamarginalsea,thefluxdirectionsofS2-,HS-,3-NH4+H4SiO4,PO4,acrossthesediment-waterinterfacearefromsedimenttotheoverlyingseawater,thefluxdirectionsofSO42-,HCO3-,NO3-,NO2-acrossthesediment-waterinterfacearefromtheoverlyingseawatertosediment.Theirrigationoflivingthingsisimportantinthecycleofthebiogenicelementsacrosssediment-waterinterfaces.

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简介：Nitrogenisoneofthemostimportantelementsthatcanlimitplantgrowthinforestecosystems.Studiesofnitrogenmineralization,nitrogensaturationandnitrogencycleinforestecosystemsisverynecessaryforunderstandingtheproductivityofstand,nutrientcycleandturnoverofnitrogenofforestecosystems.Basedoncomparisonandanalysisofdomesticandinternationalacademicreferencesrelatedtostudiesonnitrogenmineralization,nitrogensaturationandnitrogencycleinrecent10years,thecurrentsituationanddevelopmentofthestudyontheseaspects,andtheproblemsexistedincurrentresearcheswerereviewed.Atlast,someadvicesweregivenforfutureresearches.

简介：Inthecontextof1980—1992JMA(JapanMeteorologicalAgency)GMSTBBgriddeddataset,studyisundertakenofannualcyclefeaturesofFFT-derivedwindowpowerspectrumaveragedovertherecordlength,withlocalizedspace/timecharacteristicsoflow-frequencyoscillation(LFO)inthetropicalatmosphereinvestigatedalongsidepossiblecauses.ItturnsoutthattheLFOtakesonsurprisinglynoticeableannualcyclefeaturesmarkedbyawidervariablerangeoftheLFOperiodsovernortherntropicsthanthesoutherncounterpartandequatorialvicinity.Inaddition,onthewhole,thesignalsaremoreintenseintheNorthernHemisphereduringsummer/autumnandatequatorial/southernlatitudeswhennorthernwinter/springoccuraswell.Also,notallthesefeaturesareidenticalfordifferentsegmentsatthesamelatitudes,displayingsignaturesonalocalbasis,andthespatial/temporallocalitycanbequalitativelyinterpretedintermsofnonlinearinteractionbetweentropicalwaves,andmodulationofdiabaticheatingontheLFOperiods.

简介：ＴＨＥ　ＳＵＰＰＯＲＴＥＤ　ＧＯＬＤ　ＣＡＴＡＬＹＳＴＳ　ＦＯＲ　ＣＬＯＳＥＤ　ＣＹＣＬＥ　ＣＯ２　ＬＡＳＥＲＴＨＥＳＵＰＰＯＲＴＥＤＧＯＬＤＣＡＴＡＬＹＳＴＳＦＯＲＣＬＯＳＥＤＣＹＣＬＥＣＯ２ＬＡＳＥＲ￥ＺｈｅｎｇＰｉｎｇＨＡＯ；ＬｉＤｕｎＡＮ；...

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简介：During1985～1987,theconcentrationofnitratenitrogenwashigherintheLaizhouBayandtheBohaiBaywhilethatofnitritenitrogenwashigherintheLiaodongBayandtheBohaiBay,Theconcentrationofnitratenitrogenwashighestinwinterandlowestinsummerwhilethatofnitritenitrogenwashighestinautumnandlowestinspring.theseasonalvariationoftheconcentrationofnitratenitrogenwasmaximumintheLaizhouBayandtheBohaiBaywhilethatoftheconcentrationofnitritenitrogenwasmaximumintheLiaodongBay.Therewasagreatdifferenceintheconcentrationofnitratenitrogenbetweenthesurfaceandthebottominautumnandintheconcentrationofnitritenitrogenbetweenthesurfaceandthebottominsummer.Themainreasonfortheseasonalvariationsoftheconcentrationofnitratenitrogenandnitritenitrogenwasthemarinebiochemicalprocess.ThenitratenitrogenandnitritenitrogenintheBohaiSeabasicallymaintainedaquasi-equilibriumstateseasonalcycle,Thequesi-equilibriumstateseasonalcycleofnitratenitrogenandnitritenitrogenatthebottomwasstablewhilethatatthesurfacewasliabletovariationscausedbyotherfactors.

简介：MeasuresynchronizationisanewphenomenonfoundincoupledHamiltoniansystemsrecentlyanditisinterestingtounderstanditspropertiescomprehensively.Wediscussthemeasuresynchronizationofacoupledpairofstandardmapsinhighperiodquasi-periodorbits,andthemeasuresynchronizationtransitionisassociatedwiththetransitionofcoupledsystemsfromquasi-periodicitytochaos.ThisbehaviourisverydifferentfromthatfoundbyHamptonandZanette[Phys.Rev.Lett.83(1999)2179].

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简介：Acoupledmodel,whichisemployedtostudythedominatingfactorandkeyareaofElNinocycleformation,consistsofadynamicaloceanmodelandastatisticalatmosphericmodel.ThecoupledmodelwithseasonalforcingsuccessfullyreproducestheElNinoeventcyclewhichexhibitsquasi-regularoscillationswithapreferredperiodofabout4years.Theresultsshowthattheheatcontent(HC)istransportedbetweentheeasternandthewesterntropicalPacificareas.ThespatialdistributionofHCanomaliesforfourphasesofthewholecycleclearlyshowsapossibleformationmechanismofElNino.ExperimentsfurthersuggestthatseasurfacetemperatureinthetropicalPacificandHCinthecentraltropicalPacificarethemostimportantfactorsandthecentraltropicalPacificisthemostimportantareafordeterminingformationofElNinocycle.