简介: Introduction Withrapiddevelopmentandadvancementofeconomyandsociety,lotsofcitygroupsorcitybeltswithex-tra-largecitiesastheircentershavebeenformedinChina.Theregionsthesecitygroupslieinusuallyhavewell-developedeconomy,densepopulation,andareregionalpoliticsandculturecenters.Somegroupslieintheregionswithhighlevelofearthquakeactivity,suchastheSurroundingCapitalCityGroupwiththecentersofBei-jingandTianjin.Oncealargeearthquakeoccurs,itsinfluencewillspreadtoveryextensiveregionanditsdisasterwillbetremendoustoo.Soearthquakeresistanceanddisastermitigationofcitygroupwillbeverysignificantissue.Thecitiesinagrouphaveclosedistancewitheachother;theycancarryoutunifiedpreparationfordisasterasonewholeandreducetheheavyloadofsinglecitybeforeanearthquake,andhaveanadvantageofpromptmutual-aidafteranearthquakebecauseofclosedistance.Itisespeciallysignificanttomitigatetheloseoflives.Oneimportantpreconditionisthatallthecitiesinonegroupcannotbeexposedtothesamelevelofdestroyduringoneearth-quake.Sothedivisionofcitygroupintheregionwithdensecitiesdistributionshallbeverysignificanttotheemergentmutual-aidinearlytimeafteralargeearthquake.Forthisgoal,thecharacteristicsandcorrelativityofearthquake′simpactoncitiesinonegroupneedtoclearlybeconsidered.Thecitieswithsimilarfeaturesandstrongcorrelativityofhistoricalearthquakeinfluencehavelargechancetosuffersameleveldestroyduringthefuturestrongearthquakeandaredisadvantagetoprovidemutual-aidandshallnotbedividedintoonegroup. ……
简介:TheemergenceofZhangHeng’sseismoscopehasaprofoundhistoricalbackground.ThispaperintendstoexploretheformationandmaterialbasisofZhangHeng’sscientificthought.Itappearsthatthesimpleintentionof"observingvisionsanddistinguishinggoodfortuneormisfortune"washismotivationtodeveloptheseismoscope.Tracingitshistoricalbackground,theauthorsproposedinthispaperthatthedevelopmentofthisseismoscopestartedaround128A.D.,andbasedonperceptualknowledge,twoideasaboutearthquakescameintobeing,i.e.,earthquakelocationcouldbejudgedaccordingtotheinstrumentshakingdirection,andtheearthquakeandearthsplitwereessentiallydifferent.Intheinstrumentmanufacture,ZhangHengadvocatedaprincipleof"makingutensilstoimitatecosmos".Bythisprinciple,thefollowingthreeproblemswerereadilysolved:theseismoscopeimitatedtheresponseofthesuspensionsystemtoearthquakes(i.e.naturalseismoscope).Technically,thetriggermechanismofthelatchwasusedforreference,anditrecordedthephysicalevidenceofearthquakeoccurrencebyaningeniouswayofaballdroppingfromadragon’smouth.Thesolutionofthesethreekeyproblemsleadtotheemergenceoftheseismoscopein132A.D.andthesuccessfuldetectionofanearthquakein134A.D.Hisinventiondeepenedhumanity’sknowledgeofnaturallaws,andpromotedthedevelopmentofscienceandtechnologyinthattimeandlater.
简介:Long-termintegrationsareconductedusingtheSpectralAtmosphericModel(referredtoasSAMIL),whichwasdevelopedintheLaboratoryforNumericalModelingforAtmosphericSciencesandGeophysicalFluidDynamics(LASG)intheInstituteofAtmosphericPhysics(IAP),withdifferentresolutionstoinves-tigatesensitivityoftheMadden-JulianOscillation(MJO)simulationstothemodel'sresolution(horizontalandvertical).Threeresolutionsofthemodel,R15L9,R42L9andR42L26,withidenticalphysicalprocesses,allproducedthebasicobservedfeaturesoftheMJO,includingthespatiotemporalspace-timespectraandeastwardpropagation.Nofundamentaldifferencesamongthesesimulationswerefound.ThisindicatesthatthemodelresolutionisnotadeterminingfactorforsimulatingtheMJO.Detaileddifferencesamongthesemodelingresultssuggest,however,thatmodelresolutioncansubstantiallyaffectthesimulatedMJOincertainaspects.Forinstance,atalowerhorizontalresolution,highfrequencydisturbanceswereweakerandthestructuresofthesimulatedMJOwerebetterdefinedtoacertainextent.AhigherverticalresolutionledtoamorerealisticspatiotemporalspectrumandspatialdistributionofMJOprecipitation.Meanwhile,increasingthemodel'sresolutionimprovedsimulationoftheclimatology.However,increasingtheresolutionshouldbebasedonimprovingthecumulusparameterizationscheme.
简介:In2004,China’sdigitalseismicobservationnetworkprojectbegantodeploy40setsYRY-4four-componentboreholestrainmetersinordertomonitorearthquakepreparationprocess.Thepaperdescribesobservedsolidtidalstraindiscretenessandtidalfactoranisotropy,analyzesthereliabilityofobservationaldataanddiscussesthecauseforthisphenomenon.Aftergettingridofinterferences,thenetwork,intwoyearspractice,hasobservedseveralpre-seismicstrainanomaliesatstationsclosetoepicentersespeciallyintheWenchuanMS8.0megaquake.Itshowsthatthisboreholestrainmeternetworkiscapableofmonitoringseismogenicprocess.
简介:ThestudiesonthestructureandphysicalpropertiesoftheEarth'sinteriordonebyChinesegeophysicistsfrom1999to2002werereviewedinthispaper.Itincludesseveralresearchareas:thestructureoftheEarth'sinteriorsusingseismictomography,anisotropyoftheuppermantleinChinaanditsadjacentareas,qualityfactorQβforSwaves,subductionzone,mantlediscontinuities,physicalpropertiesofEarth'smaterialsandothers.Thereviewconcernsmainlythecontents,themethodsandtheresultsofthestudies.ItcanbeseenthatnewprogressinthestudyonthestructureandphysicalpropertiesoftheEarth'sinteriorhasbeenmadeinthelast4yearsinChina.Itisshownonthreeaspects:advancementmadeonsomepreexistentareas;pioneeringonsomenewfieldsandnewmethodsadopted.