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简介：这份报纸试图为钢的静态的平衡配置介绍批评最高的紧张由使用有限元素方法的链状的起床人(SCR)。批评最高的紧张是能维持SCR的平衡的最小的最高的紧张。如果最高的紧张比批评价值小，SCR的平衡不存在。如果最高的紧张比批评价值大，有二种可能的平衡配置。这二种配置展出非线性的大排水量。有更小的排水量的配置是稳定的，当有更大的排水量的那种是不稳定的时。数字结果证明垂直距离，水平偏移量，起床人重量，内部流动速度，和当前的速度增加的起床人的增加SCR的批评最高的紧张。另外，参量的研究也被执行以便为SCR的分析和设计调查限制状态。

简介：压力关节(SJ)为深水工程在最高的Tensioned起床人(TTR)系统起一个关键作用。逐渐变细的SJ的一个初步的设计方法在纸被建议，它能帮助设计者获得精确设计数据。在进一步敏感的分析被执行以后，相关参数选择和控制方法在设计实践被推荐。由考虑极端环境条件，把压力减小和曲线控制弄弯的效果被分析，并且3-DFE模型被ABQOUS建立让数字评估验证设计结果的正确性。最后，基于实际工程，动态分析和疲劳分析与设计压力关节被执行。分析结果在实际工程应用证明这个方法的可行性和指导。

简介：Accordingtothecharacteristicsofdeepwatertoptensionedrisers,asimplifiedmodelispresentedtopredictthemulti-modalresponseofvortex-inducedvibration(VIV)innon-uniformflowbasedonenergyequilibriumtheoryandtheexperimentaldatafromVIVself-excitedandforcedoscillationsofrigidcylinders.Theresponseamplitudeofeachmodeisdeterminedbyabalancebetweentheenergyfedintotheriseroverthelock-inregionsandtheenergydissipatedbythefluiddampingovertheremainders.Comparedwiththepreviouspredictionmodels,thismethodcantakefullyaccountoftheintrinsicnatureofVIVforlowmassratiostructuresonlock-inregions,addedmassandnonlinearfluiddampingeffect,etc.Moreover,itisthefirsttimetoproposetheaccuratecalculatingprocedureforVIVamplitudecorrectionfactorbysolvingenergyequilibriumequationandaclosedformsolutionispresentedforthecaseofariserofuniformmassandcross-sectionoscillatinginauniformflow.ThepredictedvaluesshowareasonableagreementwithVIVexperimentsofrisermodelsinsteppedandshearedcurrents.

简介：ExperimentalstudiesonthefrictioncoefficientbetweenconcreteandthetopsurfaceofarubblemoundfoundationinChinaarereviewed.Throughcomparisonofdifferenttestresults,thedevelopmentofthisresearchiscomprehensivelyanalyzed.Anexperimentiscarriedoutintheconditionsimilartoprototype.Theprocesscurveoffrictioncoefficientwiththetestblockslidingisanalyzedandastandardfordeterminationofthefrictioncoefficientisdefined.ThevariationfeaturesofthefrictioncoefficientareanalyzedonthebasisofthepresentexperimentalresultsandotherstudiesinChina.Itisshownthatthefrictioncoefficientbetweenconcreteandthetopsurfaceofarubblemoundfoundationdecreaseswiththeincreaseofthefoundationpressure,andthefrictioncoefficientforaveryfinelevelingbedissmallerthanthatforafinelevelingbed.

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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：Parametricinstabilityofariseriscausedbyfluctuationofitstensionintimeduetotheheavemotionoffloatingplatform.Manystudieshavetackledtheproblemofparametricinstabilityofariserwithconstanttension.However,tensionintheriseractuallyvarieslinearlyfromthetoptothebottomduetotheeffectofgravity.Thispaperpresentstheparametricinstabilityanalysisofdeepwatertop-tensionedrisers(TTR)consideringthelinearlyvaryingtensionalongthelength.Firstly,thegoverningequationoftransversemotionofTTRunderparametricexcitationisestablished.ThisequationisreducedtoasystemofordinarydifferentialequationsbyusingtheGalerkinmethod.ThentheparametricinstabilityofTTRforthreecalculationmodelsareinvestigatedbyapplyingtheFloquettheory.TheresultsshowthatthenaturalfrequenciesofTTRwithvariabletensionareevidentlyreduced,theparametricinstabilityzonesaresignificantlyincreasedandthemaximumallowableamplitudeofplatformheaveismuchsmallerunderthesamedamping;Thenodesandantinodesofmodeshapearenolongeruniformlydistributedalongtheaxialdirectionandtheamplitudealsochangeswithdepth,whichleadstocouplingbetweenthemodes.Thecombinationresonancephenomenonoccursasaresultofmodecoupling,whichcausesmoreseriousdamage.

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简介：Inthisstudy,cloudbaseheight(CBH)andcloudtopheight(CTH)observedbytheKa-band(33.44GHz)cloudradarattheBoseongNationalCenterforIntensiveObservationofSevereWeatherduringfall2013(September-November)wereverifiedandcorrected.Forcomparativeverification,CBHandCTHwereobtainedusingaceilometer(CL51)andtheCommunication,OceanandMeteorologicalSatellite(COMS).Duringrainfall,theCBHandCTHobservedbythecloudradarwerelowerthanobservedbytheceilometerandCOMSbecauseofsignalattenuationduetoraindrops,andthisdifferenceincreasedwithrainfallintensity.Duringdryperiods,however,theCBHandCTHobservedbythecloudradar,ceilometer,andCOMSweresimilar.Thinandlow-densitycloudswereobservedmoreeffectivelybythecloudradarcomparedwiththeceilometerandCOMS.Incasesofrainfallormissingcloudradardata,theceilometerandCOMSdatawereproveneffectiveincorrectingorcompensatingthecloudradardata.Thesecorrectedclouddatawereusedtoclassifycloudtypes,whichrevealedthatlowcloudsoccurredmostfrequently.

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简介：分析了2005年5月5日下午福建中南部飑线天气过程。结果表明：飑线发生在高空槽和地面锋面过境前，福建处于中低空西南急流中。大气层结不稳定、上干下湿配置、逆温层以及地面上的高温、低压系统、露点锋是有利飑线天气发生的条件。飑线下游地区的负变压加大了变压梯度，使风速增大。较强的螺旋度、中尺度扰动低涡系统为飑线过程的动力触发机制。

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简介：1天气概况今年5月5日中午12时左右,我省河西走廊的酒泉、嘉峪关、张掖、金昌、武威及中部偏北地区的白银、定西等地市,自西北向东南出现了大风、沙尘暴天气,平均风力6—7级,最大风力9级。15时42分首先在金昌市附近生成黑风,天昏地暗,伸手不见五指,能见度降为0m,瞬间最大风速34m/s,达12

简介：Horizontalandverticaldistributionsofδ18Oandδ13Cwereinvestigatedinshellsoffourplanktonicforaminiferalspecies,Globigerinoidesruber,Globigerinoidessacculifer,PulleniatinaobliquiloculataandNeogloboquedrinadutertrei,fromatotalof62core-topsedimentsamplesfromtheIndonesianthroughflowregion.Resultswerecomparedtomodernhydrologicconditionsinordertoexplorepotentialofproxiesinreconstructingfluvialdischargeandupperoceanwatercolumncharacteristicsinthisregion.Ourresultsshowthat,intheMakassarStrait,bothofdepletedδ18Oandδ13Cofthesefourspecieswerelinkedtofreshwaterinput.IntheBaliSea,however,depletedδ18Oandδ13Cforthesespeciesmaybeduetodifferentreasons.Depletedδ18Owasaresultoffreshwaterinputandaswellinfluencedbyalong-shorecurrentswhiledepletedδ13CwasmorelikelyduetotheJava-Sumatraupwelling.Comparisonofshellδ18OrecordsandhydrographicdataofWorldOceanAtlas2005suggeststhatG.ruberandG.sacculifercalcifywithinthemixed-layer,respectivelyat0–50mand20–75mwaterdepth,andP.obliquiloculataandN.dutertreiwithintheupperthermocline,bothat75–125mwaterdepth.N.dutertreicalcifiesatslightlydeeperwaterdepththanP.obliquiloculatadoes.Ingeneral,δ13CvaluesofbothG.ruberandG.sacculiferarelargerthanthoseofP.obliquiloculataandN.dutertreiatallsites,possiblyrelatedtodepthhabitatsofthesespeciesandverticaldistributionofnutrientsintheIndonesianthroughflowregion.

简介：摘要： 本文介绍了无线通信技术的发展史,从第一代无线通信技术到现在的5G,无线通信技术得到了长足的发展,然后本文还介绍了5G网络的结构,最后介绍了5G的网络规划的方法.

简介：运用1小时间隔的GMS-4数字展宽红外资料和部分常规气象资料,分析了1993年5月5日下午至夜间发生在甘肃、宁夏等省(区)部分地区罕见特大沙尘暴的形成原因。结果指出,这场沙尘暴主要由冷锋前部的一次飑线活动造成的。飑线的形成,是冷锋强迫出的小对流单体群和冷锋云系分裂出的云区合并及与中纬度地区短波槽云系相互作用的结果,飑线的强烈发展,则是飑线云系、中纬度短波槽和孟加拉湾强热带风暴登陆后向北伸展云系三者之间的相互作用。以及局地性强烈增温共同造成的。飑线的移动大体与700—500hPa间的平均气流方向一致。最后对此飑线的可预报性问题作了讨论。

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简介：在第45届东方科技论坛上，与会专家认为中国能源发展方向可锁定5大目标。

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