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:Fifty-sevenstations(48gridstationsandninestratifiedstations)weresampledacrossthestudyregion(67.000°–88.394°N,152.500°–178.643°W)duringthe4thChineseNationalArcticResearchExpedition(CHINARE4)fromJulytoAugust2010bytheicebreakerR/VXuelong.Atotalof24speciesofHydromedusaewereidentifiedfrom130zooplanktonsamples,ofwhichsevenspeciesbelongedtoAutomedusa,eightspeciestoAnthomedusae,fourspeciestoLeptomedudae,andthreespeciestoSiphonophora.CatablemamulticirratumKishinouye,1910,BougainvilliabitentaculataUchida,1925,andEuphysajaponica(Maas,1909)wererecordedforthefirsttimeintheArcticsea.Inthepresentpaper,18speciesofHydromedusaeweredescribedandillustrated,ofwhichthreespeciesweredescribedforthefirsttimeintheArcticsea,and15speciesweredescribedforthefirsttimeinChina.
简介:HistoricaldataregardingZhangHeng'sseismoscopeisnotsingularproof.Actually,thefourearliesthistoricaldocuments,i.e.,ContinuationofHistoriographyofHanDynasty,HistoriographyoftheLaterHan,BookoftheLaterHanandDingRecordallhaverelevantrecordsofitsstructure,size,principle,responsetoearthquakeandactualapplications.Thesefiveaspectsaresupportedbyarchaeologicalresearch,unearthedculturalrelics,historicalearthquakesandmodernseismologicalstudy.Thesehistoricalmaterialscontainagreatdealofspecificinformationaboutthisancientseismoscope.Inconclusion,theauthenticityandreliabilityofZhangHeng'sseismoscopeareverified.
简介:EstimationofThomsen'sanisotropicparametersisveryimportantforaccuratetime-to-depthconversionanddepthmigrationdataprocessing.Comparedwithothermethods,itismucheasierandmorereliabletoestimateanisotropicparametersthatarerequiredforsurfaceseismicdepthimagingfromverticalseismicprofile(VSP)data,becausethefirstarrivalsofVSPdatacanbepickedwithmuchhigheraccuracy.Inthisstudy,wedevelopedamethodforestimatingThomsen'sP-waveanisotropicparametersinVTImediausingthefirstarrivalsfromwalkawayVSPdata.Modelfirst-arrivaltraveltimesarecalculatedonthebasisofthenear-offsetnormalmoveoutcorrectionvelocityinVTImediaandraytracingusingThomsen'sP-wavevelocityapproximation.Then,theanisotropicparameters0andearedeterminedbyminimizingthedifferencebetweenthecalculatedandobservedtraveltimesforthenearandfaroffsets.Numericalforwardmodeling,usingtheproposedmethodindicatesthaterrorsbetweentheestimatedandmeasuredanisotropicparametersaresmall.Usingfielddatafromaneight-azimuthwalkawayVSPinTarimBasin,weestimatedtheparameters0andeandbuiltananisotropicdepth-velocitymodelforprestackdepthmigrationprocessingofsurface3Dseismicdata.Theresultsshowimprovementinimagingthecarbonatereservoirsandminimizingthedeptherrorsofthegeologicaltargets.
简介:Thegrowth,biochemicalcontentandbioaccumulationquantityof2,2’,4,4’-tetrabromodiphenylether(BDE-47)inSkeletonemacostatumwerestudiedunderdifferentN:Pratios(1,4,16,64and128).AllcellularbiochemicalcontentsofS.costatumpresenteddecreasingtrendovercultivationtime.Atearlystageofcultivation,thecellularprotein,carbohydrateandlipidinS.costatumpresentedhighervaluesintreatmentsofN:P=4and16.However,theywerelowerinthesetreatmentsatthelatestage,buthigherintreatmentsN:P=1and128.Similarly,BDE-47levelspercellofS.costatumwerehigherintreatmentsofN:P=4and16atearlystageofcultivation,whichwere3.8and3.7ng(106cells)-1,respectively.Atthemiddlestageofcultivation,theBDE-47levelperS.costatumcelllowered;anditfurtherreducedinthetreatmentsofN:P=4and16atthelatestagewiththevalues0.6and0.5ng(106cells)-1,respectively.However,itroseinN:P=128,reachingupto2.3ng(106cells)-1.ComparedwithBDE-47percell,BDE-47peralgalvolumeunderdifferentN:Pratiosdidnotpresentobviousdifference.ThequantityBDE-47accumulatedpercellofS.costatumwaspositivelycorrelatedwithprotein,carbohydrateandlipidpercell;meanwhile,theBDE-47pervolumehadapositivecorrelationwithbiochemicalcontentpervolume.ThevariationofbioaccumulationabilityofBDE-47inS.costatumcanbeexplainedbybiochemicalchangesduetoN:Pratios.
简介:Thepost-earthquakerapidaccurateassessmentofmacroinfluenceofseismicgroundmotionisofsignificanceforearthquakeemergencyrelief,post-earthquakereconstructionandscientificresearch.TheseismicintensitydistributionmapreleasedbytheLushanearthquakefieldteamoftheChinaEarthquakeAdministration(CEA)fivedaysafterthestrongearthquake(M7.0)occurredinLushanCountyofSichuanYa’anCityat8:02onApril20,2013providesascientificbasisforemergencyrelief,economiclossassessmentandpost-earthquakereconstruction.Inthispaper,themeansforblindestimationofmacroscopicintensity,fieldestimationofmacrointensity,andreviewofintensity,aswellascorrespondingproblemsarediscussedindetail,andtheintensitydistributioncharacteristicsoftheLushan'4.20'M7.0earthquakeanditsinfluentialfactorsareanalyzed,providingareferenceforfutureseismicintensityassessments.
简介:Inthispaper,weadopttheobservationdataoftwo10HzYRY4-componentboreholestrainmetersandone100HzFBS-3BbroadbandseismometertostudytheresponsesoftheirobservationstotheApril11,2012MW8.6earthquakeoffthewestcoastofnorthernSumatra,andcomparetheresponsecharacteristicsduringthecoseismicstageafterpreprocessingofthedata.Weanalyzethespectrum’sdynamicprocessduringthecoseismicstagewiththeStransformationmethod,anddiscussthespectrum’sdetailsindifferentseismicphases.TheStransformationresultsofthedataofseismometerandboreholestrainmeteratthesamestationshowthatthecoseismicspectrumevolutionofthetwokindsofobservationaresimilartoeachotherandcanbecross-referencedinindentifyingthewavesignals,whichprovesthattheboreholestrainmetermeasurementsathighfrequenciesarereliable.
简介:Ingeneral,earthquakecyclerelatedtoearthquakefaultingcouldincludefourmajorprocesseswhichcouldbedescribedby(1)faultlocking,(2)self-accelerationornucleation(possibleforeshocks),(3)coseismicslip,and(4)post-stressrelaxationandafterslip.Asuddenstaticstresschange/perturbationinthesurroundingcrustcanadvance/delaythefaultinstabilityorfailuretimeandmodifyearthquakerates.Basedonasimpleone-dimensionalspring-sliderblockmodelwiththecombinationofrate-and-statedependentfrictionrelation,inthisstudy,wehaveapproximatelyderivedthesimpleanalyticalsolutionsofclockadvance/delayoffaultfailurescausedbyasuddenstaticCoulombstresschangeappliedinthedifferenttemporalevolutionperiodsduringanearthquakefaulting.Theresultshavebeenusedinthephysics-basedexplanationofdelayedcharacteristicearthquakeinParkfieldregion,California,inwhichthenextcharacteristicearthquakeofM6.0after1966occurredin2004insteadofaround1988accordingtoitscharacteristicreturnperiodof22years.Atthesametime,theanalyticalsolutionsalsoindicatethatthetimeadvance/delayinCoulombstresschangederivedbythedislocationmodelhasacertainlimitationandfundamentalflaw.Furthermore,wediscussedtheessentialdifferencebetweenrate-andstate-variableconstitutive(R–S)modelandCoulombstressmodelusedcommonlyincurrentearthquaketriggeringstudy,anddemonstratedthat,infact,theCoulombstressmodelcouldbeinvolvedintheR–Smodel.Theresults,wehaveobtainedinthisstudy,couldbeusedinthedevelopmentoftime-dependentfaultinteractionmodelandtheprobabilitycalculationrelatedtothetime-dependentandrenewalearthquakepredictionmodel.
简介:摘要富源信德矿区上部地层结构松散、破碎、钻孔坍塌严重。而且存在少量石灰岩,灰岩裂隙大,漏水严重。而设计的钻孔深度大。给施工带来很大困难,通过采取多级钻孔结构,并在钻进参数,冲洗液、钻头扩孔器上的合理应用,解决了施工难题,顺利完成了1204米深ZK502#钻孔。
简介:利用NCEP再分析资料和常规观测资料,对比分析了陕西省4次台风远距离暴雨过程期间的水汽输送、水汽收支和水汽含量特征。结果表明:远距离台风用直接和间接2种方式影响热带低纬地区水汽向陕西方向的输送,中高纬度地区西风槽与高压系统直接参与暴雨区附近水汽的输送与再分配过程。远距离台风出现时,暴雨区南边界始终存在水汽的输入,占净输入的68%,西边界多为水汽的输出方,东边界上水汽收支变化趋势与台风移动路径密切相关。川东地区西南涡维持、发展并向东北向移动时,陕西水汽总收支成倍增大。台风远距离暴雨出现前12h左右,暴雨中心低层比湿出现极大值,对应的风场辐合中心一般出现在比湿增加之后。
简介:TheresistivityexperimentalmeasurementsofcoresamplesdrilledfromlowpermeabilityreservoirsofOrdosBasin,NorthwestChina,illustratethatthecementationfactorsarenotagminate,butvaryfrom1.335to1.749.Thisleadstoachallengefortheestimationofwaterandhydrocarbonsaturation.BasedontheanalysisofPurcellequationandassumptionthatrockresistivityisdeterminedbytheparallelconnectionofnumerouscapillaryresistances,atheoreticalexpressionofcementationfactorintermsofporosityandpermeabilityisestablished.Then,cementationfactorcanbecalculatediftheparametersofporosityandpermeabilityaredetermined.Inthefieldapplication,porositycanbeeasilyobtainedbyconventionallogs.However,itisatoughchallengetoestimatepermeabilityduetothestrongheterogeneityoflowpermeabilityreservoirs.Thus,theSchlumbergerDollResearch(SDR)modelderivedfromNMRlogshasbeenproposedtoestimatepermeability.BasedontheanalysisofthetheoreticalexpressionsofcementationfactorandSDRmodel,anovelcementationfactorpredictionmodel,whichisrelevanttoporosityandlogarithmicmeanofNMRT2spectrum(T2lm),isderived.TheadvantageofthismodelisthatalltheinputinformationcanbeacquiredfromNMRlogsaccurately.Inordertoconfirmthecredibilityofthenovelmodel,theresistivityandcorrespondinglaboratoryNMRmeasurementsof27coresamplesareconducted.Thecredibilityofthemodelisconfirmedbycomparingthepredictedcementationfactorswiththecoreanalyzedresults.Theabsoluteerrorsforallcoresamplesarelowerthan0.071.Oncethismodelisextendedtofieldapplication,theaccuracyofwaterandhydrocarbonsaturationestimationwillbesignificantlyimproved.
简介:选取福建省三明市米槠次生林内的4种植物,即米槠(CAC),木荷(SCS),山杜英(ELS),芒萁(DID)为研究对象,对其叶片进行了室内淋溶处理,并分析了淋溶液中的可溶性有机碳(DOC)和可溶性有机氮(DON)含量及pH值,芳香性指标(AI)和荧光效率指数(Fef)等,以揭示其淋溶液中可溶性有机质(DOM)的数量和质量特征。结果表明:4种植物叶片DOM含量总体随淋溶次数的增加逐渐减小,其中首次淋溶后淋溶液中的DOC和DON含量最大,分别占总淋溶量的平均值为67.90%和44.51%;淋溶液中前3次DOC和DON淋溶量总和分别占10次淋溶总量的87.40%~94.77%和68.46%~72.49%;且前3次淋溶次数间呈极显著差异(P<0.01),其后差异性不显著。DOM的pH值和光谱指标随着淋溶次数的增加逐渐上升.总体上乔木树种DOM的数量和质量比林下植被要高,这是由于乔木树种的DOM含有更多的养分和芳香类和腐殖化的高分子量化合物,而林下植被的DOM含有较多低分子量化合物和易分解组分。
简介:摘要BT(Build-Transfer,建设-移交)作为一种新型融资建设模式,近年来在我国一些工程建设项目中正逐步得到发展应用。设计管理作为BT模式下管理的重要组成部分,直接影响BT项目的投资控制及项目实施效果。本文以成都地铁4号线二期BT项目为依托,对设计管理在BT项目实施中的重要性、管理的目标、组织架构、实施等方面进行了分析和思考。