简介：BytheaftershockfrequencyestimationmethodbasedonthecalculationofcoseismicstaticCoulombstresschangesandrate-andstate-dependentfaultconstitutivelaw,wecalculatethefrequencyof"direct"aftershocksoftheWenchuanearthquakerelatedtocoseismicstaticCoulombstresschangesinitsaftershockzoneandtheareasnearby.Itshowsthatthefrequencyissignificantlylowerthanthetruthinthemainrupturezone,especiallyinthesouthernrupturezone,duetothedecreaseofstresslevelontheruptureplaneofthemainshockresultingfromcoseismicCoulombstresschange.ThestudyalsoshowsthattheeffectoftheCoulombstresschangeonthedurationofaftershockactivityisassociatedwiththelowerlimitmagnitude.Thedurationisabout15-16monthsforaftershocksaboveML4.0,andcloseto60monthsforaftershocksaboveML3.5.Inthisperiod,theratioofthe"direct"aftershockscausedbycoseismicCoulombstresschangerangesbetween44.7%to48.6%,whichsuggeststhat,eveninthe"effective"periodofcoseismicCoulombstresschanges,abouthalfoftheaftershocksonthemainshockruptureplaneareindependentofcoseismicCoulombstresschanges.Itispointedoutthatthoseaftershocksmayberelatedtotheaftersliportheviscoelasticrelaxation,whicharetimedependentcases.

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简介：Inthispaper,aerodynamicactuationcharacteristicsofradio-frequency(RF)dischargeplasmaarestudiedandamethodisproposedforshockwavecontrolbasedonRFdischarge.Underthestaticcondition,aRFdiffuseglowdischargecanbeobserved;underthesupersonicinflow,theplasmaisblowndownstreambutremainscontinuousandstable.Time-resolvedschlierenisusedforflowfieldvisualization.ItisfoundthatRFdischargenotonlyleadstocontinuousenergydepositionontheelectrodesurfacebutalsoinducesacompressionwave.Underthesupersonicinflowcondition,aweakobliqueshockwaveisinducedbydischarge.Experimentalresultsoftheshockwavecontrolindicatethattheappliedactuationcandispersethebottomstructureoftheramp-inducedobliqueshockwave,whichisalsoobservedintheextractedshockwavestructureafterimageprocessing.Moreimportantly,thiscontroleffectcanbemaintainedsteadilyduetothecontinuoushigh-frequency(MHz)discharge.Finally,correlationsforschlierenimagesandnumericalsimulationsareemployedtofurtherexploretheflowcontrolmechanism.Itisobservedthatthevortexintheboundarylayerincreasesaftertheapplicationofactuation,meaningthattheboundarylayerinthedownstreamoftheactuationpositionisthickened.Thisisequivalenttocoveringalayeroflow-densitysmoothwallaroundthecompressioncornerandontherampsurface,therebyweakeningthecompressibilityatthecompressioncorner.OurresultsdemonstratetheabilityofRFplasmaaerodynamicactuationtocontrolthesupersonicairflow.

简介：Twomethodsforimprovingtheequidrivingpower-frequencycharacteristicsofbroad-bandhighpowerklystronsarepresented.Oneisthatacomb-linebandpassfilterwithsomeattenuationpropertiesisinsertedbetweentheTWTdriverandtheklystronforcompensatingthegain-frequencycharacteristicsoftheklystrontogettherequiredequidrivingpower-frequencycharacteristics.Theotheristhatareactiveelementisconnectedwiththeinputcavitytochangeitsresonancefrequenciesf0andQL,andthustoimprovethepower-frequencycharacteristicsoftheklystron.

简介：Forthemulti-frequencyacousticanalysis,aseriesexpansionmethodhasbeenintroducedtoreducethecomputationtimeofthefrequency-independentparts,buttheRungephenomenonwillarisewhenthismethodisemployedinhighfrequencyband.Therefore,thismethodisimprovedbyanalyzingtheapplicationconditionandproposingtheselectionprincipleoftheseriestruncationnumber.Theargumentintervalcanbeadjustedwiththewavenumberfactor.Therefore,theproblemofunstablenumerationandpoorprecisioncanbesolved,andtheapplicationscopeofthismethodisexpanded.Thenumericalexampleofacousticradiationshowsthattheimprovedmethodiscorrectforacousticanalysisinwiderfrequencybandwithlessseriestruncationnumberandcomputationamount.

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简介：我们由把一种适应传播技术与直角的频率部门multiplexing相结合建议并且试验性地示威一个简单可见轻通讯系统。在适应传播计划，力量分配以如此的一个方法被执行至于在电力限制，和适应调整下面最大化隧道能力然后被介绍完成给目标小点错误率的最大的数据率。试验性的结果证明光谱效率能极大地通过这种适应传播技术被改进。

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简介：Theresultsofasimplecomputationalmodelfordifferentialsettlingarepresentedillustratingthesignificantrolethatparticlesizedistributionplaysincollisionfrequencyandsedimentationrateofparticlesinaquiescentenvironment.Themodeltracksalargenumberofparticles(order10~5)withlog-normallydistributeddiameters,astheysettleattheirStokessettlingvelocities.Particlecollisionsaredetectedandresultinlargerparticlesthatfallmorerapidly.Anumberofsimplifyingassumptionsaremadeinthemodelinordertoavoidempiricalcorrelationsforphenomenasuchascollisionefficiencyandparticleshape.Thesesimplifyingassumptionswereneededtoisolateandquantifytheroleoftheparticlesizedistribution.Simulatedconcentrationprofilesindicatethat,evenintheabsenceofcollisions,thestandarddeviation(σ_D)oftheparticlesizestronglyinfluencesthebulkmasssettlingrateas,forlargerσ_D,moremassisconcentratedinlarger,fasterfallingparticles.Thecollisionfrequencyisalsoastrongfunctionofσ_D.Foragivenmassconcentrationthecollisionfrequencyfirstincreaseslinearlywithincreasingσ_Dasgreatervariationinparticlesizeleadstogreatervariationinparticlevelocity,andshortertimesforparticlestocatcheachother.Forlargerσ_Dmoremassisconcentratedinlargerparticles,so,foragivenmassconcentration,therearefewerparticlesperunitvolume,increasingthemeandistancebetweentheparticlesandreducingthecollisionfrequency.Theimplicationsoftheseresultsforsedimentationmeasurementusingopticalattenuationtechniquesarediscussed.

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简介：Themobilechannelisslowfadingandtimeselective,thusthemultiplicativeandadditivenoiseofthechannelwillsmearthespectralline,orarouseDopplerspread.Thisspreadwillmaketheparametersestimationaccuracydegrade.ThegoalofthispaperistoanalyticallyassessthisdegradationwhenCarrierFrequencyOffset(CFO)andDopplershiftexistjointly.Thenthefinite-sampleCramer-RaoLowerBound(CRLB)isderivedandclose-formasymptoticalexpressionisgivenforlarge-sampleCRLB.Theseexpressionsgiveinsightsintotheperformanceroomforfrequencyestimation.AlsothevarianceofDopplershiftestimatorissimulatedtoillustratethetheoreticalresults.

简介：我们执行驾驶的限制顺序的数字模拟SergiMalsov(SM)为probality分发和投标问传播和引号更改频率U的自相关功能建模并且调查。为probality分发，模型sucessfully复制传播的幂定律延期和引号更改频率的exponenetial腐烂。为自相关功能，传播和模型的引号更改频率由一条幂定律腐烂，它与实验学习一致。我们获得幂定律为传播的代表0.54，它在对真实金融市场的好同意。

简介：我们表明电的敲击笔记分析和一个连续波浪(cw)锁在3THz(100m)附近射出的兆兆赫量串联激光(QCL)的收音机频率(RF)注射。在免费的跑，QCL的敲击笔记频率与增加开车电流显示出180MHz的移动。敲击笔记，调整反应，拉的注射，和兆兆赫排放光谱在不同当前的政体的特征我，II，和III被调查。结果证明在我关上到激光阀值的当前的政体，我们在洞双程票频率获得RF调整的更狭窄的敲击笔记和扁平的反应。拉的效果并且光谱调整大小在当前的政体验证那我锁住的RF注射是有效的更多和一个柔韧的工具调制模式数字和兆兆赫QCL的模式频率。

简介：Severevibrationofundergroundstructuresmaybeinducedunderblastloads.Accordingtothecharacteristicsoftheexplosion-inducedgroundshockwave,anew-typedamper,inversecontrolmagneto-rheological(MR)damperwasdesignedtocontrolthevibration.Thehigh-frequencyperformancetestoftheMRdamperwascarriedoutonthesmallshakingtable.ItisshownthattheperformancecanbemodeledbyuseofthemodifiedBouc-Wenmodel,andtheparametersofthemodelkeepstableintheranqeof15-50Hz.

简介：AbstractBackground:The combination of high-frequency oscillations (HFOs) with single-mode imaging methods has been proved useful in identifying epileptogenic zones, whereas few studies have examined HFOs combined with multimodal imaging methods. The aim of this study was to evaluate the prognostic value of ripples, an HFO subtype with a frequency of 80 to 200 Hz is combined with multimodal imaging methods in predicting epilepsy surgery outcome.Methods:HFOs were analyzed in 21 consecutive medically refractory epilepsy patients who underwent epilepsy surgery. All patients underwent positron emission tomography (PET) and deep electrode implantation for stereo-electroencephalography (SEEG); 11 patients underwent magnetoencephalography (MEG). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting surgical outcome were calculated for ripples combined with PET, MEG, both PET and MEG, and PET combined with MEG. Kaplan-Meier survival analyses were conducted in each group to estimate prognostic value.Results:The study included 13 men and 8 women. Accuracy for ripples, PET, and MEG alone in predicting surgical outcome was 42.9%, 42.9%, and 81.8%, respectively. Accuracy for ripples combined with PET and MEG was the highest. Resection of regions identified by ripples, MEG dipoles, and combined PET findings was significantly associated with better surgical outcome (P < 0.05).Conclusions:Intracranial electrodes are essential to detect regions which generate ripples and to remove these areas which indicate good surgical outcome for medically intractable epilepsy. With the assistance of presurgical noninvasive imaging examinations, PET and MEG, for example, the SEEG electrodes would identify epileptogenic regions more effectively.

简介：Theprocessofionheatingbyamonochromaticobliquelypropagatinglow-frequencyAlfvenwaveisinvestigated.Thisprocesscanberoughlydividedintothreestages:atfirst,theionsarepickedupbytheAlfvenwaveinseveralgyro-periodsandabulkvelocityinthetransversedirectionisachieved;then,theionsarescatteredinthetransversedirectionbythewave,whichproducesphasedifferencesbetweentheionsandleadstoionheating,especiallyintheperpendiculardirection;andfinally,theionsarestochasticallyheatedduetothesubcyclotronresonance.Inthispaper,withatestparticlemethod,theefficiencyandtimescaleoftheionstochasticheatingbyamonochromaticobliquelypropagatinglow-frequencyAlfvenwavearestudied.Theresultsshowthatwiththeincreaseoftheamplitude,frequency,andpropagationangleoftheAlfvenwave,theefficiencyoftheionstochasticheatingincreases,whilethetimescaleoftheionstochasticheatingdecreases.Withtheincreaseoftheplasmabetaβ,theionsarestochasticallyheatedwithlessefficiency,andthetimescaleincreases.Wealsoinvestigatetheheatingofheavyionspecies(He2+andO5+),whichcanbeheatedwithahigherefficiencybytheobliqueAlfvenwave.

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简介：TheproblemofcheckingrobustD-stabilityofmulti-inandmulti-out(MIMO)systemswasstudied.Threesystemmodelswereintroduced,i.e.multilinearpolynomialmatrix,polytopicpolynomialmatrixandfeedbacksystemmodel.Furthermore,theconvexpropertyofeachmodelwithrespecttotheparametricuncertaintieswasestablishedrespectively.Basedonthis,sufficientconditionsforD-stabilitywereexpressedintermsoflinearmatrixinequalities(LMIs)involvingonlytheconvexvertices.Therefore,therobustD-stabilitywastestedbysolvinganLMIoptimalproblem.

简介：当一个使变形的目标有时，2蟺阶段歧义问题在阶段测量是很重要的一从飞机大排水量。双频率的设计栅栏阶段--变的profilometry(PSP)能被用来解决如此的一个问题。在测量，二合适--选择频率栅栏被利用综合在一个主要阶段范围保证计算阶段的一个相等的波长栅栏。因此，错误与常规阶段由阶段unwrapping过程引起了重建算法能被消除。最后，有大塑料变丑的一个标本的试验性的结果被给证明建议方法是有效的处理阶段断绝。

简介：Alocalizedparametrictime-shearedGaboratomisderivedbyconvolvingalinearfrequencymodulatedfactor,modulatinginfrequencyandtranslatingintimetoadilatedGaussianfunction,whichisthegeneralizationofGaboratomandismoredelicateformatchingmostofthesignalsencounteredinpractice,especiallyforthosehavingfrequencydispersioncharacteristics.Thetime-frequencydistributionofthisatomconcentratesinitstimecenterandfrequencycenteralongenergycurve,withthecurvebeingobliquetoacertainextentalongthetimeaxis.Anovelparametricadaptivetime-frequencydistributionbasedonasetofthederivedatomsisthenproposedusingaadaptivesignalsubspacedecompositionmethodinfrequencydomain,whichisnon-negativetime-frequencyenergydistributionandfreeofcross-terminterferenceformulticomponentsignals.Theresultsofnumericalsimulationmanifesttheeffectivenessoftheapproachintime-frequencyrepresentationandsignalde-noisingprocessing.