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简介：桥梁监测序列是典型的非平稳时间序列,需要进行一些处理将非平稳序列平稳化后再拟合ARMA模型。将监测数据平稳化后将因变量仅对它的滞后值以及随机误差项的现值和滞后值进行回归所建立的模型即为ARIMA模型。以玉峰大桥为例,介绍了季节ARIMA模型的建模思路与总体流程,模拟了检测序列的变化趋势。以季节ARIMA模型为预测模型作为结构的退化模型,对测点进行退化趋势模拟与退化临界时刻预测。结果显示ARIMA模型对序列的拟合效果良好,可以用于桥梁监测序列的预测,其对退化临界时刻的预测可以从整体上掌握桥梁的整体退化趋势和极限使用寿命。

简介：AsimplecyclicelastoplasticconstitutivemodelforsandisproposedbasedontheUHmodelforoverconsolidatedclay.Theproposedmodelhasthefollowingfeatures.First,inordertodescribethestress-inducedanisotropyinsand,arotationalhardeningruleisintroducedfortheevolutionoftheyieldsurfaceaxiswithdevelopmentofplasticdeviatoricstrainintheprincipalstressspace.Second,therelationshipbetweentherotationalaxisandstress-inducedanisotropyismodeledbyintroducingtheslopeofrotationalaxisintotheyieldfunction.Theflatnessoftheyieldsurfacecanbedeterminedbytheslopeofrotationalaxis.Finally,arevisedunifiedhardeningparameterisproposedtoincorporatethestress-inducedanisotropy.Themodelcapabilityindescribingthecyclicresponseofsandisverifiedbycomparingthesimulationswithavailabletestresults.

简介：TheperformanceofalinearresuspensionmodeldevelopedintheBalticSeawasstudiedintheconditionsofaeutrophicLakeKirkkoj(a|¨)rvi(southernFinland).Themodelpredictssedimentresuspensionrateusingdataonvegetationcover,windandsedimentqualityasaninput.Whentheoriginalmodelcoefficientswereused,themodelresultedonaverage1.8foldoverestimationoftheresuspensionrateinKirkkoj(a|¨)rvi.Thiswasduetolowerfetchandwaterdepth,andlessconsolidatedsedimentofKirkkoj(a|¨)rvicomparedwiththeBalticSeastudysite.WhencoefficientswereadjustedforKirkkoj(a|¨)rvi,themodelpredictionswere1.1timesthemeasuredvalues.Duetothecontinuousresuspension,theeffectofthewindterminthemodelwassolowthatitcouldbeexcludedwithoutaffectingtheaccuracyofmodelpredictions.Thestudydemonstratedthatinashalloweutrophiclakeaccuratepredictionsonresuspensionratecanbemadeusingonlydataonsedimentqualityandonfactorsinhibitingresuspension(macrophytes).Themodelresidualsincreasedwithincreasingresuspensionrateandhighratesofresuspensionwereunderestimatedbythemodel.DuetothefluffysedimentinKirkkoj(a|¨)rvi,erosionofsedimentincreasesmorethanlinearwithincreasingshearstress.Thusinsuchconditions,evenbetterpredictionscouldbeachievedbyanon-linearresuspensionmodel.

简介：INMay2013,YunnanChihongZincandGermaniumCo.,Ltd.（Chi-hongZn＆Ge）bought51percentofthesharesoftwoBolivianminingcompaniesandundertookamonth-longevaluationofthemines＇localenviron-ments.LaRazonnewspaper,whichhasthebiggestcirculationinBolivia,reportedChihong＇sacquisitionwiththeheadline＂Chinaassessestheenviron-mentalimpactoftheirinvestments,＂claimingthattheminingprojectswerethefirsttopassthetestinBolivia.

简介：从哈萨克斯坦经济发展的实际情况出发,加强哈萨克斯坦经济发展水平的合理预测,对确定哈萨克斯坦经济发展目标和发展策略以及建设丝绸之路经济带有重要的意义。文章根据世界银行公布的数据,用EViews软件对1990-2012年的哈萨克斯坦经济发展水平建立ARIMA模型,并对2013-2020年哈萨克斯坦的经济发展水平作出预测,得出结论并以＂丝绸之路经济带＂为背景,立足新疆为提高与哈萨克斯坦经贸合作提出合理的政策建议。

简介：Thetransitiontoturbulenceinflowswherethelaminarprofileislinearlystablerequiresperturbationsoffiniteamplitude."Optimal"perturbationsaredistinguishedasextremaofcertainfunctionals,anddifferentfunctionalsgivedifferentoptima.Weherediscussthephasespacestructureofa2Dsimplifiedmodelofthetransitiontoturbulenceanddiscussoptimalperturbationswithrespecttothreecriteria:energyoftheinitialcondition,energydissipationoftheinitialcondition,andamplitudeofnoiseinastochastictransition.Wefindthatthestatestriggeringthetransitionaredifferentinthethreecases,butshowthesamescalingwithReynoldsnumber.

简介：Cytoskeletonisanetworkoffilamentousproteins,suchasactinfilamentsandmicrotubules.Weproposeacontinuumcooperativehydrolysismodelwhichpossessesexactlyanalyticalsolutiontodescribethedynamicsoffilament.Theresultsshowthatthecooperativityleadstononnegative-exponentialdistributionofT(ATPorGTP)subunits.Asanapplication,weinvestigatethetreadmillingphenomenonusingourmodel.Itisshownthatthecooperativityremarkablyaffectsthelengthoffilament.

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简介：森林风景模型(FLM)是森林生态系统结构和功能的确定的表示的一个效率工具。根据识别FLM，根据开发的阶段，这篇论文总结模型的发展特征，它包括数学模型，的理论基础看台规模的FLM，空间风景模型，的主要开发生态系统过程模型的快速的开发作为优先级，并且开发多因素驾驶的结构和过程的时期。根据不同FLM的特征，这篇论文以机制，性质和应用程序分类存在FLM，并且详细描述模型的不同类型的鉴定，优点和劣势。它从是空间模式和生态的过程的变化的二个方面总结并且评估存在模型的主要应用程序领域。最后，这份报纸以后论述FLM挑战和开发的方向，包括：(1)森林管理目的实际策略上的更突出的服务；(2)多模块和多插件到的建设处于各种各样的条件满足风景研究需求；(3)高分辨率的采纳空间时间的数据；(4)多版本的结构的建设模块；(5)改进模型申请的空间适用性。

简介：这份报纸的目的是为Hormuz的海峡介绍一个适当单向性的波浪光谱模型。研究集中于在这个区域估计标准波浪光谱模型的性能。由基于最近出版的珍贵测量数据评估如此的模型，刻度过程在如此的标准模型上被进行了到达在一个修改标准之间的一个更好的词语索引光谱模型和观察领域系列。刻度开始关于与四个可得到的测量车站有关的四个不同方向被执行。那么，它为一个提名的模型导致系数的四个集合。下次，它继续被到达就对方向感觉迟钝的一个模型。结果清楚地证明国际拖引坦克会议(ITTC)模型在这个区域是比联合诺思海波浪工程(JONSWAP)和Pierson和Moskowitz(下午)模型更适当的，甚至没有任何刻度。然而，修正在改进模型的一致上是成功的。

简介：Thewave-seabedinteractionissueisofgreatimportanceforthedesignoffoundationaroundmarineinfrastructures.Mostpreviousinvestigationsforsuchaproblemhavebeenlimitedtouncoupledoronewaycoupledmethodsconnectingtwoseparatedwaveandseabedsubmodelswiththecontinuityofpressuresattheseabedsurface.Inthisstudy,astronglycoupledmodelwasproposedtorealizebothwaveandseabedprocessesinasameprogramandtocalculatethewavefieldsandseabedresponsesimultaneously.Theinformationbetweenwavefieldsandseabedfieldswerestronglysharedandthusresultsinamoreprofoundinvestigationofthemechanismofthewave-seabedinteraction.Inthisletter,thewaveandseabedmodelswerevalidatedwithpreviousexperimentaltests.Then,asetofapplicationofpresentmodelwerediscussedinpredictionofthewave-inducedseabedresponse.Numericalresultsshowthewave-inducedliquefactionareaofcoupledmodelissmallerthanthatofuncoupledmodel.

简介：Fourcategoriesofglobularproteins,includingall-α,all-β,α+β,andα/βtypes,aresimplifiedastheoff-latticeHNPmodelinvolvingthesecondary-structuralinformationofeachprotein.Thepropensityofthreetypesofresidues,i.e.,H,N,andPtoformasecondarystructureisinvestigatedbasedon146proteinsamples.WefindthatPresiduesareeasytoformα-helices,whereasHresidueshaveahighertendencytoconstructβ-sheets.ThestatisticalanalysisalsoindicatesthattheoccurrenceofPresiduesisinvariablyhigherthanthatofHresidues,whichisindependentofproteincategory.Changesinbond-andnon-bondedpotentialenergiesofallproteinsamplesunderawidetemperaturerangearepresentedbycoarse-grainedmoleculardynamics(MD)simulation.Thesimulationresultsclearlyshowalinearrelationshipbetweenthebond-stretching/bendingpotentialenergyandthereducedtemperature.Thebond-torsionalandnon-bondedpotentialenergiesshowdistincttransitionswithtemperature.Thebond-torsionalenergyincreasestothemaximumandthendecreaseswiththeincreaseoftemperature,whichisoppositetothechangeinnon-bondedpotentialenergy.Thetransitiontemperatureofnon-bondedpotentialenergyisindependentoftheproteincategory,whilethatofbond-torsionalenergyiscloselyrelatedtotheproteinsecondarystructure,i.e.,α-helixorβ-sheet.Thequantitativelybonded-andsemiquantitativelynon-bondedpotentialenergyof24α+βand23α/βproteinsamplesaresuccessfullypredictedaccordingtothestatisticalresultsobtainedfromMDsimulations.

简介：Aphysiologicalmodelwithdelayisconsidered.Thetimedelaybeingregardedasaparameter,agroupofconditionsthatguaranteethemodelhavemultipleperiodicsolutionsisobtainedbytheglobalHopfbifurcationtheoremforFDEandBendixson’scriterionforhigh-dimensionalODE.Theresultsareillustratedbysomenumericalsimulations.

简介：Aquasi-steadymodeldescribingaerodynamicsofhoveringRuby-throatedhummingbirdsispresentedtostudyextentofthelow-ordermodelinrepresentingtheflowphysicsofthebirdandalsotoseparatelyquantifytheforcesfromthetranslational,rotational,andaccelerationeffects.Realisticwingkinematicsareadoptedandthemodeliscalibratedagainstcomputationalfluiddynamics(CFD)simulationsofacorrespondingrevolving-wingmodel.Theresultsshowthatthequasi-steadymodelisabletopredictoverallliftproductionreasonablywellbutfailstocapturedetailedforceoscillations.Thedownstroke-upstrokeasymmetryisconsistentwiththatinthepreviousCFDstudy.Furtheranalysisshowsthatsignificantrotationalforceisproducedduringmid-strokeratherthanwingreversal.

简介：骨胶原纤维提供成为强壮的一个好例子微--或从nanoscaletropocollagen分子通过的mesoscale纤维一蹒跚并且以一种自底向上的方式的cross-linked组织。骨胶原纤维的建筑上的特征被显示出是一条有希望的途径开发高效的碳nanotube(CNT)纤维的Mimicking。在现在的工作，一个有弹性的模型被开发在bioinspiredCNT捆以内描述负担转移和失败繁殖，并且与象CNT方面比率和纵的差距那样的很多个几何、物理的参数建立捆的机械性质的关系，接口交叉结合密度，和在CNT的导致functionalization的降级，等等。与模型一起，沿着CNTCNT接口以及在每单个CNT的压力分布是捕获的井，和沿着CNT捆的机械性质上的接口和它的效果的失败繁殖被预言。工作可以在实践为新奇CNT纤维的设计提供有用指南。

简介：Inthispaper,wepayattentiontothetime-decayrateoftheviscousbipolarquantumhydrodynamic(QHD)modelsforsemiconductors.Byapplyingtheentropymethod,weprovethatthesolutionoftheviscousbipolarQHDmodelstendstotheequilibriumstateatanexponentialdecayrateforthemulti-dimensionalcases.Theargumentsisbasedonaseriesofaprioriestimates.

简介：Thispaperpresentsamodifiedhalf-sine-squaredloadmodelofthejumpingimpulsesforasingleperson.Themodelisbasedonadatabaseof22,921experimentallymeasuredsinglejumpingloadcyclesfrom100testsubjects.Threedimensionalmotioncapturetechnologyinconjunctionwithforceplateswasemployedintheexperimenttorecordjumpingloads.Thevariationrangeandprobabilitydistributionofthecontrollingparametersfortheloadmodelsuchastheimpactfactor,jumpingfrequencyandcontactratio,arediscussedusingtheexperimentaldata.Correlationrelationshipsbetweenthethreeparametersareinvestigated.Thecontactratioandjumpingfrequencyareidentifiedasindependentmodelparameters,andanempiricalfrequency-dependentfunctionisderivedfortheimpactfactor.Thefeasibilityoftheproposedloadmodelisestablishedbycomparingthesimulatedloadcurveswithmeasuredones,andbycomparingtheaccelerationresponsesofasingle-degree-of-freedomsystemtothesimulatedandmeasuredjumpingloads.Theresultsshowthatarealisticindividualjumpingloadcanbegeneratedbytheproposedmethod.Thiscanthenbeusedtoassessthedynamicresponseofassemblystructures.

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