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

  • 标签: 变张力 参数稳定性 长度 深水 FLOQUET理论 不稳定性
  • 简介:Thispaperconstructsa4-liercomputablegeneralequilibriummodelwhichincludessuchmodulesasmodelingcarbonemissionconstraintsandcarbontrading(CT),andincorporatesthecostofcarbonemissionsintoconstantelasticityofsubstituteproductionfunction.Underscenariosettingsunderdifferentcarbonabatementtargets,basedon2007nationalsocialaccountingmatrixandrelatedstatisticaldataaboutenergyconsumptionandcarbonemission,effectsoneconomicoutputs,energyconsumption,andcarbonabatementareestimatedandanalyzedatbothmacroandsectorlevel.Bycalculatingselectednovelindicatorsthatcompromisebetweenmacroeconomicopportunitycostandachievablecarbonabatement,reasonablecarbonpriceintervalsaregivenforenhancingtherobustnessandliquidityofcarbonmarket.Further,bydecompositionandshare-weightedmethods,expectedcarbonabatementandenergypricearemeasuredandanalyzedindetails.Someresultsaremeaningfulforfundamentaldesignofthefuturecarbonmarket.Givenconstantenergyutilizationandcarbonabatementtechnologiesatthemacrolevel,thehigherthecarbonpricethemoreactualcarbonabatement;themoregrossdomesticproductloss,thelessenergyconsumption.Accwdingtotheoverallsituationestimatedfor2007inChina,theadvicegivenistointroduceacarbonabatementtargetrate(R_c)of-10%,whichishelpfultomakecarbonmarketstableagainstunexpectedcarbonpriceshocksbetween[6.9,35]/tCwithlesseconomicloss.AccordingtoKayadecomposition,afterintroductionofcarbonpricing,carbonabatementismainlycontributedbytheeffectsofenergyintensity(EI)andtechnicalprogress.Further,CTmayhelpreduceenergyconsumptionandinducetransformationtoalow-carbonenergystructure.Atthesectorlevel,theintroductionofCTcouldinduceeconomicrecessioninallsectors,especiallyenergy.However,theoveralleconomicstructureremainsunchangedtosomeextent.CTwillhelpreduceenergyconsumptioninallsectors,especiallyenergy.Overallutilizationc

  • 标签: Computable general equilibrium model CARBON trading
  • 简介:在红外线的反射光谱学(NIRS)附近,一种非破坏性的测量技术,与部分最少的广场回归discrimiant分析(PLS-DA)被相结合区别转基因(TCTP和mi166)并且野类型(Zhonghua11)米饭。而且,米饭线与蛋白质基因(OsTCTP)转变了,规定基因(Osmi166)被NIRS方法也区别。PLS-DA在的表演光谱4000-8的范围000 ;cm-1和4000-10000 ;cm-1与相比获得最佳光谱范围。作为结果,转基因、野的类型米饭在4000-10的范围与对方被区分开来000 ;cm-1,和正确分类率在确认测试是100.0%。转基因的米饭TCTP和mi166也在4000-10的范围与对方被区分开来000 ;cm-1,和正确分类率也是100.0%。在结论,与PLS-DA相结合的NIRS能被用于转基因的米饭的辨别。

  • 标签: 偏最小二乘回归 近红外反射光谱 转基因水稻 线性判别分析 近红外光谱技术 近红外光谱法
  • 简介:Thisarticlemadeasystematicstatisticalanalysisontheduration,spatialdistribution,form,range,typeandreliabilityofprecursoryanomaliesbasedontheobservationsofprecursorsof24moderate-strongearthquakesoccurringalongtheTancheng-LujiangfaultzoneanditsbilateralareasinShandong,Liaoning,Hebei,JiangsuandJiangxiProvincesintheperiodfrom1966to2005.Resultsshowthat:(1)ForM7.0andM6.0earthquakes,med-termabnormitiesarethegreatestinnumber,short-termabnormitiescomesecond,andimminentanomaliesaretheleast.ForM5.0earthquakes,short-termabnormitiesareoftenthemostinnumber,imminentanomaliescomesecond,andthemed-termonesaretheleast.(2)Precursoryanomaliesareperiodical,partofthemedandshort-termanomaliesareshownasshort-termandimminentanomaliesduringtheirdevelopment.(3)Thedevelopmentofprecursorshowsquasi-synchronism;theclosertoearthquakeoccurrencetime,themoreturningchangesofanomalieswillappear.(4)Anomaliesmainlyoccurwithinanepicenterdistanceof100km,showingarelativeconcentrateddistributioninspace,andtheshorterthedistancetoepicenter,thehighertheanomalystation/itemrate.(5)Thespatialdistributionofanomaliesisrelativelycorrelatedtothestrikeofstructures,havingagoodconsistencywiththestructure.(6)Thereisnosignificantcorrelationbetweendurationofabnormitiesandtheepicenterdistance.(7)Thehigherthemagnitudeoftheearthquake,thegreatertheamplitudeoftheabnormitiesmeasuredwiththesameobservationapproach.(8)Intermsoftheitemsoftheobservations,fluidabnormitiesarethegreatestinnumber,followedbydeformationandelectromagnetismobservations.(9)Forallobservationitems,medandshort-termabnormitiesmakeupthemajorityandshort-termandimminentanomaliestheminority.(10)Influid,deformationandelectromagnetismobservations,fairlyreliableanomaliesareaboutdoublethenumberofreliableanomalies.

  • 标签: 郯城-庐江断裂带 异常特征 地震短期异常 空间分布特征 电磁观测 边带
  • 简介:有不同规模的很多海底的山崩在Liwan3-1气体地的海底的管道线路的峡谷区域被识别了。仍然有许多机会,海底的斜坡失败将发生,并且下列集体运动将介绍大风险给海底的管道。鉴于这,一个数字预言方法基于Eulerian-Eulerian二阶段的流动模型被介绍模仿潜在的海底的山崩的集体运动。滑动土壤和周围的水被Herschel-Bulkley流变学模型和牛顿的液体模型分别地模仿。骚乱用k-模型被模仿。与两个相比实验数据并且是结果,二阶段的流动模型显示出好精确性,并且它的结果是更多关门到实际状况;在土壤和周围的水之间的动态联合能有效地被模仿,hydroplaning和头分开的现象能被获得。最后,潜在的海底的山崩的土壤运动作为一个例子被模仿,根据在峡谷区域的地震侧面。结果证明hydroplaning发生在运动过程期间。二阶段的流动模型计算的刺杀距离是877m,它是27.1%比是大结果。然而,土壤的山峰前面速度是相对的小,与8.32m/s的最大的价值。是有一个简单、快速的过程的节目能被用于初步的评估,当二阶段的流动模型为一个精确评价是更适当的时。

  • 标签: 海底滑坡 动态特性分析 跳动 气田 两相流模型 模型模拟
  • 简介:TheunsteadycavitationevolutionaroundtheClark-Yhydrofoilisinvestigatedinthispaper,byusinganimprovedfilter-basemodel(FBM)withthedensitycorrectionmethod(DCM).Toimprovethepredictionaccuracy,thefilterscaleisadjustedbasedonthegridsize.Thenumericalresultsshowthatasmallfilterscaleiscrucialfortheunsteadysimulationsofthecavitysheddingflow.ThehybridmethodthatcombinestheFBMandtheDCMcouldhelptolimittheoverpredictionoftheturbulentviscosityinthecavitationregiononthewallofthehydrofoilandinthewake.Thelargevalueofthemaximumdensityratio?l/?v,clippromotesthemasstransferratebetweentheliquidphaseandthevaporphase,whichresultsinalargesheetcavitylengthandthevaporfractionriseinsidethecavity.Thecavitypatternspredictedbytheimprovedmethodareverifiedbytheexperimentalvisualizations.Thetime-averagelift,thedragcoefficientandtheprimaryoscillatingfrequencyStforthecavitationnumber?=0.8,theangleofattack,?=8o,ataReynoldsnumberRe=7?105are0.735,0.115and0.183,respectively,andthepredictederrorsare3.29%,3.36%and8.93%.Thetypicalthreestagesinonerevolutionarewell-captured,includingtheinitiationofthesheet/attachedcavity,thegrowthtowardthetrailingedge(TE)withthedevelopmentofthere-entrantjetflow,andthelargescalecloudcavityshedding.ItisobservedthatthecloudcavitysheddingflowinducesthevortexpairsoftheTEvorticesinthewakeandthesheddingvortices.Thepositivevorticityvortexofthere-entrantjetandtheTEvorticesinteractsandmergeswiththenegativevorticityvortexoftheleadingedge(LE)cavitytoproducethesheddingflow.

  • 标签: 非定常特性 滤波器库 空化数 数值分析 模型 基础
  • 简介:ThepaperinvertsthefocalmechanismsolutionsoftheYutianM_S7.3mainshock,foreshocksandM_S≥3.5aftershocksbyusingtheCAPmethod,basedonthebroadbandwaveformsrecordedbytheXinjiangandTibetDigitalSeismicNetworks.TheresultsshowthattheM_S7.3strongearthquakeisofstrike-sliptypewithanormalfaultingcomponent,andcombinedwiththeanalysisoffocalstructureandtheaftershockdistribution,thenodalplaneIwithstrike241°,dip90°andrake-22°isconsideredtobetheseismogenicfaultplaneofthemainshock.ThedirectionofP-axisforthemainshockis194°,closetothenearNSdirectionoftheprincipalstressP-axisofhistoricalstrongearthquakesinthisregion.ThefocalmechanismsolutionoftheM_S5.4foreshockhasagoodconsistencywiththatofthemainshock.Amongthe18aftershocks,10areofstrike-sliptype,6areofnormalfaultingtypeand2areofthrusttype.70%oftheaftershocksinthesequencehaveafocalmechanismwithP-axisinthenear-NSdirection.ThefocaldepthsofthisM_S7.3earthquakesequencesaredistributedintherangeof5km-28km,withthemajorityinthedepthrangeof15km-20km,slightlydeeperthanthedepthof10kmofthemainshockascalculated.

  • 标签: 震源机制解 地震序列 特征 数字地震台网 余震分布 局部结构分析
  • 简介:Alinear4-nodequadrilateralquasi-conformingplaneelementwithinternalparametersisproposed.Theelementpreservesadvantagesofthequasi-conformingtechnique,includinganexplicitstiffnessmatrix,whichcanbeappliedtononlinearproblems.Theweakpatchtestguaranteestheconvergenceoftheelement.ThenthelinearelementisextendedtothegeometricallynonlinearanalysisintheframeworkofTotalLagrangian(TL)formulation.Thenumericaltestsindicatethatthepresentelementisaccurateandinsensitivetomeshdistortion.

  • 标签: 下线 服务 迁移
  • 简介:Betulin,oleanolic酸,和betulinic酸是自然地发生的pentacyclictriterpenoids重要药用的价值。这些triterpenoids的可观的数量是可得到的在外部白色吠叫桦树。在这研究,我们使用了帮助超声的抽取(UAE)从桦树提取triterpenoids很快并且与高效率吠叫。用高效液体层析(HPLC),triterpenoids的三种类型被分开并且检测。我们在提取从的triterpenoids之中检验了差别双对tetraploid白人桦树。然后,我们使用了因素分析外面与包括地优秀的性能屏蔽tetraploid白人桦树。结果显示为抽取的最佳条件作为抽取溶剂包括乙醇的使用,0.1的solid-to-liquid比率?g/10?ml,在100点的超声的力量集合?W,60的温度?

  • 标签: 三萜类化合物 优树选择 白桦树 四倍体 高效液相色谱法 因子分析法
  • 简介:由于它在集成地区性的协调开发并且提高华中的上升的大战略意义,在Changjiang(Yangtze)河的中间的活动范围的城市的凝块从理论、实际的方面吸引了许多注意。对区域经济网络结构的如此的研究为城市发展、地区性发展的策略的形成是有益的。这篇论文基于一个修改引力模型构造一个经济领带模型。随后,指社会网络分析,论文以经验为主地学习网络密度,网络中心性,亚群和Changjiang河城市的凝块的中间的活动范围的结构的洞经济网络。调查结果是四折的:(1)在Changjiang河的中间的活动范围的城市的凝块的一个经济网络被形成了,并且在在这个网络的城市之间的经济关系是比较地稠密的;(2)在Changjiang河的中间的活动范围的城市的凝块能被划分成四重要亚群,与有它的自己的明显的经济通讯的每亚群,当在亚群之中有不太经济行为的异质时,这为在波伊昂·莱克存在的二亚群是特别真的生态的经济地区;(3)由武汉,长沙和南昌的中央城市驾驶的一个经济模式出现在Changjiang河的中间的活动范围的城市的凝块,当这三个首都的城市施加了大放射能力到他们的包围城市时,后者不太能从前者吸收资源;(4)武汉大城市的区域和波伊昂·莱克生态的经济地区比长沙,Zhuzhou和Xiangtan城市簇的戒指有更结构的洞,意味着在这二个区域的圆周的城市是容易由中央城市抑制了。长沙,Zhuzhou和Xiangtan城市的戒指聚类有更少结构的洞;因此,在这个区域的城市不在另外的二个区域与那些比面对同样多限制。

  • 标签: 网络结构分析 长江中游 经济网络 城市群 SNA 生态经济区
  • 简介:BackgroundPrematureventricularcontractions(PVCs)arefrequentlyseeninchildren.However,therearelesssystematicandlongerfollowing-upstudiesexaminingtheprognosisofPVCsinchildren.TheaimofthisstudywastoevaluatethemediumtolongtermprognosisofPVCsinchildhoodandwhetherthereisadifferentialprognosisindifferentprimarydiseasesofPVCs.MethodsThisstudyreviewedthedataof106pediatricpatients(49F/57M,7.5±3.8years)seenattheAffiliatedHospitalofQingdaoUniversitywiththediagnosisofPVCsbetween1999and2005.Dataondemographics,clinicalpresentation,laboratorytests,andechocardiogramsofpatientswereextractedfromtheavailableclinicalrecords.ResultsAtotalof35(33.0%)childrenpresentedwithPVCsduetomyocarditis,7(6.6%)duetocardiomyopathies,7(6.6%)duetomitralvalveprolapse(MVP),10(9.4%)duetooperationforcongenitalheartdisease(O-CHD),16(15.2%)duetoleftventricularfalsetendons(LVFT),and31(29.2%)duetounknowncause.HolterdidnotshowPVCsduringfollow-upperiodin100%ofmyocarditispatients,57%ofcardiomyopathypatients,71%ofMVPpatients,60%ofO-CHDpatients,88%ofLVFTpatients,87%ofunknowncausepatients.ThePVCsdisappearedin93%ofpatientswhodidnotuseanti-arrhythmicdrugsandin76%ofpatientswhousedantiarrhythmicdrugs.Therewasnoasignificantdifferenceinprognosisbetweenmyocardialnutritioncombinedwithintravenousinjectionofimmunoglobulin(IVIG)groupandpropafenonegroup.ConclusionsPVCscausedbydifferentprimarydiseaseshasafavorableprognosisinchildren.Usually,thePVCswillreduceevendisappearduringfollow-up.ThepatientswithPVCsduetomyocarditisshouldbepreferredusemyocardialnutrientcombinedwithIVIG.

  • 标签: 预后 室性 随访 PVCs 抗心律失常 先天性心脏病
  • 简介:Theelasto-plasticpostbucklingoffibermetallaminatedbeamswithdelaminationandtheenergyreleaseratealongthedelaminationfrontarediscussedinthispaper.Consideringgeometricalnonlinearity,thermalenvironmentandgeometricalinitialimperfection,theincrementalnonlinearequilibriumequationsofdelaminatedfibermetallaminatedbeamsareestablished,whicharesolvedusingthedifferentialquadraturemethodanditerativemethod.Basedonthese,accordingtotheJ-integraltheory,theelasto-plasticenergyreleaserateisstudied.Theeffectsofsomeimportantparametersontheelasto-plasticpostbucklingbehaviorandenergyreleaserateofthearamidreinforcedaluminumlaminatedbeamsarediscussedindetails.

  • 标签: 下线 服务 迁移
  • 简介:Thepseudoexcitationmethod(PEM)hasbeenimprovedintoamorepracticalform,onwhichtheanalyticformulaeofseismicresponsepowerspectraldensity(PSD)ofsimplifiedlarge-spanstructuralmodelshavebeenderived.TheanalyticformulaeandnumericalcomputingresultsofseismicresponsePSDhavebeenderivedtostudythemechanismofmulti-supportexcitationeffects,suchasthewave-passageeffectandincoherenceeffect,fortheseismicresponseofmultiandlarge-spanstructures.Byusingamulti-spantrussasanexample,theinfluenceofmulti-supportexcitationeffectsontheseismicresponseofsuchstructuresisstudied.

  • 标签: RANDOM SEISMIC RESPONSE multi-support EXCITATIONS
  • 简介:TheKarhunen-Loeve(KL)expansionandprobabilisticcollocationmethod(PCM)arecombinedandappliedtoanuncertaintyanalysisofrockfailurebehaviorbyintegratingaselfdevelopednumericalmethod(i.e.,theelastic-plasticcellularautomaton(EPCA)).TheresultsfromthemethoddevelopedarecomparedusingtheMonteCarloSimulation(MCS)method.ItisconcludedthatthemethoddevelopedrequiresfewercollocationsthanMCSmethodtoobtainveryhighaccuracyandgreatlyreducesthecomputationalcost.Basedonthemethod,theelastoplasticandelasto-brittle-plasticanalysesofrocksundermechanicalloadingsareconductedtostudytheuncertaintyinheterogeneousrockfailurebehaviour.

  • 标签: 不确定性分析 破坏行为 弹塑性 元胞自动机 岩石 概率
  • 简介:Adual-stageservosystemconsistsofaprimarycoarseactuatorforfacilitatinglargemotionandasecondarymicro-actuatorforsmallbutprecisemotiontoimprovetrackingperformance.Piezoelectricmicro-actuatormadefromleadzirconatetitanate(PZT)hasbeenapopularchoiceforthesecondarystage.However,theadvantagegainedbytheresolutionofthesecondaryPZTactuatorisreducedbyitsinherenthysteresisnonlinearity.Modelbasedhysteresiscompensationtechniquesarepreferredduetotheirsimplicityandfastresponse.Identificationandmodelingaretwosubstantialpartsinsuchmodel-basedtechniques.ThispaperpresentsarigorousanalysisandmodelingofthehysteresisofPZTmicro-actuator.ModifiedGeneralizedPrandtl-IshlinskiiandColeman-Hodgdonmodelsarestudied.Identificationofthemodelthroughnonlinearleastsquareandparticleswarmoptimizationareexaminedandcompared.Severalanalysesaredonethroughtuningofthemodelparametersandidentificationtechniques.Experimentalanalysisandsimulationresultsunderscoretheeffectivenessofthismodelingapproach.Finallyasadesignexample,adual-stagesimulationanalysisisdonetoshowtheeffectivenessofsystematicmodelingonhysteresiscompensation.

  • 标签: HYSTERESIS particle SWARM optimization(PSO) modified generalized