老婆往届转发杨中英文

附SchemedesignoflightningprotectionsystemofcampusnetworkincollegesanduniversitiesAlongwiththedevelopmentofnetworktechnologyisdevelorapidly,highereducationmeans,methodsandideashaveundergoneafundamentalchange.Inordertoadapttothedevelopmentofinformationera,universitieshaveinvestedahugesumofmoneytobuildaeducationinformationhighway-campusnetwork.Informationresourcessharing,onlineconference,academiccommunication,networkclassroom,remoteteachingapplicationlayerareemergingoneafteranother,greatlypromotethereformanddevelopmentofhighereducation,foreducationundertakingsbroughtgreatvitality.Atthesametime,networksecuritymanagement,namely,thecollegecampusnetworksecuritymanagementhasmoreandmore everyimportant,oneoftheveryimportantsecurityproblemsareoftenisignored,namelythecampusnetworklightningprotection.Lightningishappenedinbecauseoftherainandstrongconvectivecloudformationandbetweenstronginstantaneousdischargephenomenon,isaseriousnaturaldisasters,hasthehighvoltage,largecurrentandthecharacteristicsofthealmost.Lightninginvasionofthenetworksystemaccordingtoitswaytopoints,basicallyhavesingsremandinductionlightning.Lightninghitdirectlythewiringandtheelectricalequipmentintotheearthovercurrentdirectlightningforray;Andfromraypowerfulelectromagneticfieldgeneratedlightningflowchangesinducedovervoltageaconductorandovercurrentform,thelightningcalledinductionlightning.Theywillproducegreatofcampusnetworkdamage,themaincanbedividedintoasthefollowing:Thenetworkofpowersupplydestruction:lightningelectromagneticfieldgeneratedstrong,willproducethehighvoltageandcurrent,mightbeinnetworksystemofpowersupplytremendousdamageandburnedequipment,furthermaycausefire.ThedestructionoftheInternetconnection:ontheonehand,producedbylightningelectromagneticimpulsecoupledwithstrongwiretransmission,alongthelineinvasion,willleadtothenetworkequipmentdestroyed,andbecausethenetworkequipmentiselectronicequipment,cannotbeartoostrongpulseimpact;Ontheotherhand,lightningmayalsodirectlydestroyoutdoornetworkline,suchastwistedpairThegroundingbodydamage:intheroomwhenthedesignwillconsidertheproblemofgroundingbody,theequipmentinthegroundingbodywillproduceinstantwhenlightningstrikesandhighpotentialdamage.Thisisbecausethedevicewillbeprotectivesingsremlightningcurrenttooneselfbygroundingbodyintotheearthshunt,groundingbodyformedinthehighpotential,makeandgroundingsystemconnectednetworkequipmentduetogroundingbodypotentialriseanddamage.Generallyspeaking,thecampusnetwork,serverswitchesandroutersandothernetworkequipmentcementinthebuildingtobeoutsideofthebuildinglightningproofsystemprotection,singsremnetworkequipmentarelesslikelytodamage,buttheoutsideofthebuildinglinecouldbeinfluencedbyraysingsnetworkofthedamage,ifyouusefiberopticlines,greatlyreducingthedamagemaybedirectlyray;LANlightningeventsoccurmainlyinductionlightningdamage,solightningprotectionisthefocusoftheinductionlightning.Second,theuniversitycampusnetworkthemainproblemsofthelightningprotectionCampusnetworkisanopennetwork,hasthefollowingmainlightningprotectionweakness:1,bythedestructionofthelightningfromcampusnetworkofregionallook,inthenetworkhasbeenthearrivalofthebuilding,mostistheavailabilityofagroundingsystems,somebuildingnotorthodoxgroundingsystems,andsomeoftheendsofearthontothelinerustilyandserious,groundingsystemwaslargelyinvisible,andeachbuildinggroundingsystemconditionisdifferent,somearchitectureofgroundingtoolarge,makeitsdueprotectionbusting.2,moststoriedbuildingoncampusnetworkswitchoftheunitareinstalledinthebuildingwherethestairs,powercameneartothetotalswitchpowersupplyfromdormitorybuildingintheprotectionoftherelevantpartdoesnothavethepower,inductionlightningovervoltagecausedeasilyproduceswitchesdamage,anotheruseraccessthetwisted-paircablelengthdifferent,some40meterslong,andthemainpathalongthecorridortothewallforverticalfluctuation,easytoinductionlightningdamagecommunicationport.3,campusnetworksystemsusehavetheequipmentswitches,routers,server,computer,etc,mostofthemarecomposedofthemicroelectronicsdevices,thereisnosystemoflightningprotectionwavesintomeasures,theabilitytofightagainstovervoltageitselfisnotstrong.Lightningiseasytocausedamagetotheelectronicequipment.Generallyspeaking,ofthedeviceswitchportofover-voltageabilityisfarlowerthanthemachinespowerthedeviceused,somanyaccidentscausedbylightningdamageswitchport.Three,campusnetworkdesignandlightningprotectionDirectlightningprotectionandmechanicalAgoodgroundingsystemistoprotectal,equipmentsafetysystemisstable,theimportantguaranteeofthework,isalsotheimportantbasisofthelightningprotectionsystem.Especiallyinstrongmines,areasonablegroundingsystemfasterbleederlightningcurrent,reducethepressure,topreventpotentialcounttackaccident,effectivelyreducerayagainstthreats.ThepowersystemForcampusnetworkpowerprotection,firstofall,intothesystemtotaldistributionofpowersupplyintoline,shouldusemetalarmoredcableburiedinstallation,cablearmouredlayershouldbegoodatbothendsofthegrounding;Ifcablenolayer,itshouldbeburiedcablewearsteelpipe,steelpipeendsgrounding,thelengthoftheburiedshouldbenotlessthan15m.Thetotaldistributiontoeachbuildingdistributionboxandroomfloordistributionboxpowerlines,allshouldadoptmetalarmouredcablelaying.Thiscangreatlyreducethepowercordinductionofover-voltageofpossibility.Powersupplypreventsthunder'smainfunctionistopreventthelightningovervoltagefrompowerfortheendintotheequipment,toprotecttheequipment,datatransmissionclear.Commonsocketgroundingtotheground,thestandorfallofgroundnotonlyaffectthepowersupplypreventsthunderdeviceefficiencybutalsoaffectstheefficiencyoflightningprotectiondevicetosignal.SignalsystemAlthoughinthepowersupplyandcommunicationlinesandintroducinglineinstalledexternallightningprotectiondevice,duetolightningoccursnetworkline(suchastwistedpair)inductiontoovervoltage,itwillaffectthenormaloperationofthenetworkoreveneliminatenetworksystem.InthemoreexoticlineintotheDDNorISDNmustbeinimportantlinenetworkinterfaceontheprotectionofthecorresponding,suchasfirewallsinternalandexternalwebinterface.InstallationRJ45thelightningprotection,oncehavealightningcanavoidlightningstrikeseverelossesofnetworkequipment.Networktransmissionlineisusedmainlyopticalfiberandtwistedpair.Oneneednotspecialopticalfiberlightningprotectionmeasures,butiftheopticalfiberisofoutdoorarmouredofbuiltonstilts,soneedtothemetalpartsoftheopticalfibergrounding.Andtwistedpairshieldingeffectispoorer,thereforeinductionlightningthepossibilityofmore,shouldsuchsignallinesinshieldingwireslotoflaying,shieldingwireslotshouldbegoodgrounding;Alsocanwearmetalpipelaying,shouldkeeponallmetalelectricalconnectiontubeshouldbegoodatbothendsandgrounding.Shouldbetakenintoaccount,theworkingvoltagetransmissionrate,interfaceformetc.Allthelightningprotectionshallallbegoodgrounding.EquipotentialIntegratednetworksystembackboneswitchinthecentermachineroomshouldbeSettingsarepressureringintheroomallmetalobjects,includingcableshieldinglayer,metalpipe,metaldoorsandWindows,equipmentandallinandoutofthesbuildingmetalpipesetcmetalcomponentsforelectricalconnections,andconnectedtothepressureonthering,inabalancedpotential.TheselectionofspeciallightningprotectionFour,speciallightningprotectiondeviceselectionprinciplesThepowersupplypreventsthunderdevice1.1umcontinuousworkingvoltageofLightningprotectiondeviceumcontinuousoperationvoltagevalue,isrelatedtotheoperationstabilityofthelightningprotectionkeyparameters.Inthechoiceofthelightningprotectionumsustainedworkingvoltage,exceptinaccordancewiththerelevantstandardsoutside,stillshouldconsidertopowergridmayappearnormalfluctuationandthehighestpossibleforfaultvoltage.residualpressureOnlyconsiderthelightningprotectionresidualpressureislowerthebetter,arenotcomprehensive,andcanbemisleading.Thermistorsforlightningprotectiondevice,thepressureislower,usuallymeanstheumcontinuousworkingvoltagereduced.Sotoomuchemphasisonthepressure,istheneedtopaylowerumcontinuousworkingvoltageofthepriceforconsequences,maybeintheutilityisnotstableregion,thelightningprotectionforalongtimecontinuousovervoltagewithstandanddamage.thechoiceofalarmfunctioninordertomonitorthelightningprotectiontheoperationcondition,whenlightningprotectiondeviceappeareddamaged,theusershouldbeinstantknowandchangeintimetothedamageofthelightningprotectionmodules.Inordertotheapplicationofdifferentenvironment,canachievereal-timemonitoring,needtochoosearespectivelyaudibleandvisualalarmdeviceorremotealarmdeviceforlightningprotectionoftheletter.LightningprotectiondeviceoftheselectionofthethechoiceofvoltageThetopjoboflightningprotectionsignalvoltagechoice,shallbebasedontheworkingvoltageofdatatransmissionlinecanbedetermined.Itistochoosethesignalforlightningprotectiononeoftheimportantparameters,butinthepracticalapplicationofdifferent municationlineschoosenottohaveacommonstandard.Thehighestworkingvoltageoflightningprotectionmustbegreaterthanthelineoftheworkingvoltageof1.2times.ratethechoiceoftheDifferentcommunicationsystemdatatransferrateisdifferent,thesignalisinstalledinthelightningprotectionsignallines,whichsupportstransmissionrateshouldbenolessthanthecommunicationsystemitselftransmissionrate,otherwisewillleadtocommunicationinterruptortheincreaseofber,affectthenormalworkofthecommunicationsystem.Toinstallthesignalforlightningprotectioncommunicationsystem,ifappearcommunicationinterruptortheincreaseofber,itsreasonisrelativelycomplex,maynotbethecauseofthelightningprotection,userscanfromthefollowingpointstocheck:thelengthofthelineistoolong,ifitistoolong,canconsidertoshorten;Breakpointty;Connectionquality;Communicationjointistighten.insertionSignalisinstalledinthelightningprotectionsignallines,becauseofitsadditionalcapacitanceeffects,inthehighfrequency,canhavecertaininsertionloss.Intheselectionsignalwhenlightningprotectiondevice,erfacetypeofTheseriesisawayoflightningprotectionsignalinstallationw