简介:一个纤维节模型基于Timoshenko横梁元素在这研究被建议基于考虑轴的框架元素的非线性的分析,曲折,并且砍变丑。这个模型用砍弯曲被完成相互依赖的明确的表达(SBIF)。元素的形状功能从平衡方程的同类的形式的准确答案被导出因为Timoshenko变丑hypothesis.The建议元素从砍锁是免费的。部分纤维模型与一个多轴的粘性材料模型一起被组成,它被用来模仿每纤维的联合砍轴的非线性的行为。由在纤维之中强加变丑相容性条件,部分、元素的抵抗力量是计算的。因为SBIF形状功能与为节的不同形状的砍修正者因素是交互的,一个反复的过程在建议Timoshenko元素的非线性的州的决心被介绍。另外,建议模型由采用一条corotational坐标转变途径处理几何非线性的问题。为非线性的几何分析的SBIFTimoshenko元素的corotational算法的推导过程被介绍。数字例子证实与一个纤维节模型一起的SBIFTimoshenko元素有象基于灵活性的明确的表达的一样的精确性和坚韧性。最后,SBIFTimoshenko元素被扩大并且demonstratedin一个三维的数字例子。
简介:<正>所谓3S技术即GPS、GIS、RS技术。GPS(全球定位系统)是英文缩写词NAVSTAR/GPS(NAVigationSystemTimeAndRanging/GlobalPositioningSystem)的简称。全称应为“测时测距导航系统/全球定位系统”。GPS是由美国研制,并投入实际应用的最新卫星定位系统。其主要目的是为飞机和船舶导航定位。也可以用于其它多种目的。GPS技术已在航空、航天、航海、军事、地质、石油、勘探、交通、测绘等领域得到广泛的应用。美国于1993年6月26日已将GPS21颗卫星和3颗备用卫星全部发射入轨。
简介:OnJune2011,theBeijingResearchInstituteofUraniumGeology,anInstitutewithintheChinaNationalNuclearCorporation(CNNC),andtheDepartmentofGeology&MiningCNNCcarriedoutaprojectScientificDrillingforDeepMetallogenicResearchintheXiangshanLargeUraniumOreField.AyearlateronJune21,theproject,representingthefirstscientificdrillingofChina’suranium,wasofficiallylaunched,andsuccessfullycompletedonJune17,2013.A2818.88mofdrillingdepthhasbrokenthepreviousrecord1200mofexplorationdepth.TheXD-35DBdrillingmachinedevelopedbyChinaGeo-EquipmentCorporationistheChina’sfirstAC-VFDDirectDriveTopDriveCoreDrill.Ithasgreatlyimproved
简介:塑造耳朵的热前面(ESTF),由黄海温暖的水流(YSWC)和山东沿海的水流(SCC)的集中形成了,在冬季是在黄海(YS)的很重要的海洋的现象。在所有表明的situ大小和分析数据集,ESTF在1950s-1990s,和一个类似的变弱趋势期间一直在变弱,这是也在YS上在冬季季风发现。数字实验证明变弱冬季季风能沿着瓷器海岸和向南方的异常水流与向北方异常的水流在多十的timescale上在YS导致异常发行量在里面中央对季节的吝啬的循环YSgenerally相反。异常发行量引起YSWC和SCC的减速,并且因此削弱ESTF。因为ESTF在地区性的海洋动力学和由空至海的相互作用起重要作用,它变弱在冬季在YS为地区性的气候有重要含意。
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.
简介:Inordertotheoreticallystudythebucklepropagationofsubseapipelineswithslip-onbucklearrestors,atwo-dimensionalringmodelwassetuptorepresentthepipelineandanonlinearspringmodelwasadoptedtosimulatethecontactbetweenpipeline’sinnerwallsandbetweenpipeline’souterwallandslip-onbucklearrestor’sinnerwallduringbucklepropagation.Inaddition,somereversespringsareaddedtopreventthewallofleftandrightsidesseparatingfromtheinnerwallofslip-onbucklearrestors.Consideringlargedeformationkinematicsrelationsandtheelastic-plasticconstitutiverelationofmaterial,balanceequationswereestablishedwiththeprincipleofvirtualwork.Thevariationofexternalpressurewithrespecttothecross-sectionalareaofpipelineswasanalyzed,andthelowerboundofthecrossoverpressureofslip-onbucklearrestorswascalculatedbasedonMaxwell’senergybalancemethod.Bycomparingthetheoreticalresultswithexperimentandfiniteelementnumericalsimulation,thetheoreticalmethodisprovedtobecorrectandreliable.
简介:一座大楼城市的流动上的密度的效果与RNGκ用一个CFD模型被调查-ɛ骚乱闭合计划。有不同的造的27个案例是密度参数(例如,大楼和街峡谷纵横比)数字地被模仿。当大楼的密度参数变化,不同流动政体出现。当街峡谷相对狭窄、高时,在垂直方向的二个相反旋转的旋涡被产生。沿着街的风速被大楼的长度主要影响。然而,以一座单个大楼的密度参数发现或概括街峡谷流动的特征是很困难的。这是因为复杂流动模式由于旋涡结构和旋涡数字的变化出现。平均卷的涡度大小是很好的指示物尽管有流动的强壮的相关性,在大楼的密度参数的变化上反映流动特征。平均卷的涡度大小是大楼的长度和街峡谷宽度的强壮的功能的多线性的回归表演。大楼的长度的增加减少街峡谷的涡度流动,当时,在街上,峡谷宽度增加的增加涡度。
简介:TheanalysesoflighthydrocarbonsinoilsfromtheTarimBasinshowthattheMango'sparameterKisaboutunityexceptthoseoilstrappedintheeasternpartoftheTazhong(CentralTarim)FaultUplift,TheregularvarianceofKmayindicatestheaccumulationandadmixtureoftheoilpopulationsintheeasternpartoftheTazhongFaultUplift.
简介:2004台风Aere的降水的结构的特征从测量国家航空学空间管理(NASA)的使命(TRMM)的热带降雨用高分辨率的数据被分析。台风的特征在它的发展的不同阶段变化,这被发现。分析降水分发的不对称的引起,从环境预言(NCEP)分析的国家中心的数据被用来计算水蒸汽流动向量的垂直积分。因为这个过程,结果显示出那,与成双台风的循环的唯一的现象一起,在东方台风的北方面的空气电流和它的南部的方面的西南的空气水流在搬运水起一个联合作用蒸汽。而且,它的运输效果在开发的不同阶段极大地变化,显示出为这台风进程的水来源的怪癖。由重降水和水蒸汽流动的一个最大值的区域描绘区域的台风传送对流的分布,以及在台风的发展的不同阶段的强壮的上升运动区域不同。水蒸汽流动和垂直运动的不一致的分发引起台风降水的不均匀的分发。
简介:First,Wirsching'smodel,whichiswidelyemployedinfatiguereliabilityanlysisofmarineandoffshorestructures,isanalysedsystematically.Itisfoundthattheveryimportantrandomvariable△inWirsching'smodelcannotbedirectlydeterminedfromfatigueexperimentbecauseoftheirreversibilityoffatiguetest,andinfact,whatWirschingstudiedfromtestingresultsisnot△butαofthestatisticalMiner'srule.Second,byuseofthestatisticalMiner'srule,amodifiedWirsching'smodelisproposed.Thirdlyandmoreimportantly,basedonthetwo-dimensionalprobabilisticMiner'srule,anewmodelisestablishedforfatiguereliabilityanalysisofstructuralcomponentssubjectedtospecifiedcyclicloadingofvariableamplitudeorstochastictimehistory.Intheend,anexampleispresented,fromwhichitwillbeseenthatthisnewmodelisveryconvenienttouseandfeasibletoengineeringpractice.
简介:TheimpactsofclimatechangeonChina'sagriculturearemeasuredbasedonRicardianmodel.Byusingcounty-levelcross-sectionaldataonagriculturalnetrevenue,climate,andothereconomicandgeographicaldatafor1275agriculture-dominatedcountiesintheperiodof1985-1991,wefindthatbothhighertemperatureandmoreprecipitationwillhaveoverallpositiveimpactonChina'sagriculture.However,theimpactsvaryseasonallyandregionally.Highertemperatureinallseasonsexceptspringincreasesagriculturalnetrevenuewhilemoreprecipitationisbeneficialinwinterbutisharmfulinsummer.Applyingthemodeltofiveclimatescenariosinthe2020sand2050sshowsthattheNorth,theNortheast,theNorthwest,andtheQinghai-TibetPlateauwouldalwaysbenefitfromclimatechangewhiletheSouthandtheSouthwestmaybenegativelyaffected.FortheEastandtheCentralChina,mostscenariosshowthattheymaybenefitfromclimatechange.Inconclusion,climatechangewouldbebeneficialtothewholeChina.