简介：Macroseismic紧张数据在可靠地震损失模型发展也在地震危险分析的过程起一个重要作用。这份报纸论述一个物理底的模型基于在时间时期1975-2013在伊朗获得的560紧张数据预言macroseismic紧张变细。几何传播和震波的精力吸收在建议模型被考虑了。求婚对工具关系容易简单地把紧张描述为时刻大小，到地点距离的来源和焦点的深度的功能。建议模型的预言能力借助于剩余分析被估计。预言结果与为意大利，土耳其，伊朗和中亚的另外的紧张预言模型的那些相比。结果在远处为学习区域显示更高的变细率不到70km。

简介：Inthepaperthewaveattenuationinatwolayerfluidsystemisstudied.ThefluidinthetoplayerisidealandthatinthelowerlayeristheVoigtmodeloftheviscoelasticmedium.Adispersionrelationisderivedandtherateofthewavedecayiscomputed.Theapproximateexplicitexpressionsofthedecayratefordifferentwaterdeptharegiven,wheretheviscoelasticityiseitherverylargeorverysmall.Comparedwiththenumericalresults,ourresultsareveryaccurate,whichcanbeusedbyanengineer.

简介：Ultrasonicattenuationinliquidhydrogenhasbeenmessuredwiththepulse-echotechniqueasafunctionoftemperaturefrom13.84Kto20.50K,at45MHz.Theresultsindicatethatthetemperaturedependenceofultrasonicattenuationinliquidhydrogenismainlydeterminedbyvolumeviscosityeffect.Ultrasonicattenuatinduetovolumeviscosityisgettingmoreandmorewithcooling.Theratiobetweenvolumeviscouscoefficientandshearviscouscoefficientisfrom1.4to4.2withinthemeasuredtempera-tureregion.

简介：Thispapercontributestoextractinginformationfromsignalsofbroadbandultrasonicattenuationspectrumforeffectiveutilizationinparticlesizecharacterization.Thesingleparticlescatteringmodelandthecoupled-phasemodelareformulatedsimultaneously,therelationshipbetweenparticlesizedistributionandultrasonicspectrumisestablished,andaconvergencecriterionforcalculationisquantified.Demonstrationinversionbytheoptimumregularizationfactormethodiscarriedouttoyieldtypicalnumericalresultsfordiscussion.Withtheexperimentalset-updevelopedbytheInstituteofParticleandTwo-PhaseFlowMeasurement(IPTFM)attheUniversityofShanghaiforScienceandTechnology,sandsedimentparticlesizeismeasuredbyattenuationspectrumandanalyzedusingtheaboveinversionalgorithmandtheoreticalmodels.Tovalidatetheproposedultrasonicspectrumparticlesizingmethod,resultsarecomparedwiththoseobtainedbymicroscopy.

简介：Byanalyzingandcomputing,accordingtothewavetheoryofplanaropticalwaveguideattenuation,anewopinionisputforward.Aseriesoftransmissionatteenuationwithwaveguidefilm-thicknessaregivenanditillustratesthatopticaltransmissionisnotcarryingoutefficientlywithinsomewaveguidefilm-thickness.

简介：我们由使用nonstationary多项式试穿(NPF)为地震噪音变细建议一个新奇方法，它能沿着事件与振幅变化估计协调部件。有变化时间的系数的NPF能适应地估计协调部件。多项式系数的光滑被塑造规则化控制。信号沿着在一个普通中点(CMP)的偏移量轴是协调的在正常moveout(NMO)以后的集合。我们使用NPF估计有效信号并且从而稀释随机的噪音。为象地面转动那样的光线的像事件的噪音，我们首先采用光线的踪迹(RT)转变数据到时间速度域的变换。然后，NPF被用来在RT领域估计协调噪音。最后，协调噪音适应地从吵闹的数据集被减去。建议方法能有效地沿着事件与振幅变化估计协调噪音，没有需要建议那个噪音振幅是不变的。结果合成并且域数据例子证明与象静止多项式适合和低切割过滤器那样的常规方法相比，建议方法能有效地压制地震噪音并且保存信号。

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简介：Propagationthroughstress-alignedfluid-filledcracksandotherinclusionshavebeenclaimedtobethecauseofazimuthalanisotropyobservedinthecrustanduppermantle.Thispaperexaminesthebehaviorofseismicwavesattenuationcausedbytheinternalstructureofrockmass,andinparticular,theinternalgeometryofthedistributionoffluid-filledopeningsSystematicresearchontheeffectofcrackparameters,suchascrackdensity,crackaspectratio(theratioofcrackthicknesstocrackdiameter),porefluidproperties(particularlyporefluidvelocity),VP/VSratioofthematrixmaterialandseismicwavefrequencyonattenuationanisotropyhasbeenconductedbasedonHudson'scracktheory.Theresultshowsthatthecrackdensity,aspectratio,materialfiller,seismicwavefrequency,andP-waveandshearwavevelocityinthebackgroundofrockmass,andespeciallyfrequencyhasgreateffectonattenuationcurves.Numericalresearchcanhelpusknowtheeffectofcrackparametersandisagoodsupplementforlaboratorymodeling.However,attenuationislesswellunderstoodbecauseofthegreatsensitivityofattenuationtodetailsoftheinternalgeometry.Somesmallchangesinthecharacteristicsofporefluidviscosity,porefluidscontaininggasandliquidphasesandporefluidscontainingclaycaneachalterattenuationcoefficientsbyordersofmagnitude.Someparameterscontrollingattenuationarethereforenecessarytomakereasonableestimations,andanisotropicattenuationisworthstudyingfurther.

简介：技术上导致的表面波浪的变细理论上并且试验性地被学习。在这篇论文，地面颤动的十九大小包括交通、振动、冲动的构造工作或堆积开车，爆炸，榔头推动和质量掉的道路和栏杆由八不同技术来源导致了被描述，并且技术上导致的地面颤动展出幂定律变细v锝?r，这被显示出?代表q在0.5～2.0的范围并且依靠消息提供者的q打字。执行的比较比理论上期望证明测量代表更加高。地面颤动变细上的一些潜在的效果理论上被分析。最重要的效果由于材料或散布抑制。每个频率部件作为exp指数地被稀释(?kr)，要不是宽带刺激，指数的法律的和也产出一条幂定律但是与一个高代表。另外的效果被讨论，例如瑞利的分散由于土壤layering飘动，它在冲动的装载的情况下产出0.5的一个另外的代表。关键词波浪变细-环境颤动-地测试-抑制的材料-散布抑制-瑞利波浪

简介：Inthispaperanewmethodofultrasonicquantitativediagnosisisdiscribed.Thismethodcanelminatetheeffectofsystemdeviationandlessenthetheeffectofbeamradiationdiffraction.Incanbespp1iedtogetherwithmanykinksofB-scanners.Toverifythemethod,thispaperhasshownanewmethodtomakeatissuephantomandaspecialapparatus.Theresultsshowthatthemethodisusefulinthediagnosisofdiffuseliverdiseases,tumorsandcanccrs.Itisalsousefulintheappraisalofthehealthandthestagesoffetus.

简介：Inthispaper,nonlinearobserversareincorporatedintotheadaptivecontroltosynthesizecontrollersforaclassofuncertainnonlinearsystemswithunknownsinusoidaldisturbanceswhicharepresentedinmatchedandunmatchedforms.Inadditiontomagnitudesandphases,frequenciesofthesinusoidaldisturbancesneednotbeknownaswell,solongastheoverallorderisknown.Nonlinearobserversareconstructedtoeliminatetheeffectofunknownsinusoidaldisturbancestoimprovethesteady-stateoutputtrackingperformance-asymptoticoutputtrackingisachieved.Theadaptationlawisusedtoobtaintheestimateofallunknownparameters.Thepresenteddisturbancedecouplingalgorithmscandealwithmatchedandunmatchedunknownsinusoidaldisturbances.

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简介：高周波的地震变细通常被归因于有弹性的吸收。在这篇论文，我在场高周波的地震变细上的三研究并且建议物理机制源于有弹性的显微镜的多重散布波浪的干扰。首先，我在基于为波浪繁殖的基本单位是一个nano团点的概念的二阶段的媒介在波浪繁殖上建议一个新理论。由于毛孔液体和岩石框架的弹性变化，微多重散布波浪将在通过二阶段的媒介和他们的干扰的震波的波长出现，重叠将产生高周波的地震变细。第二，我在场由当模特儿的地震播送波浪的频率反应的研究与比毛孔直径没有大的厚度薄层。结果显示高周波的震波在一个近表面的水地区稍微稀释，但是在一个近表面的煤气的地区显著地腐烂。第三，我在Songliao盆用双井的射击在近表面的水和煤气的地区里分析地震变细特征，并且证明高周波的震波在水地区稍微稀释，但是在气体，宣传的1601600Hz挥动的地区显著地腐烂。来自观察与当模特儿的结果与一致的地的地震变细特征。理论上从这些研究得出的结论支持地震变细恢复。

简介：Thediffuseattenuationcoefficient(Kd)fordownwellingirradianceiscalculatedfromsolarirradiancedatameasuredintheArcticOceanduring3rdand4thChineseNationalArcticResearchExpedition(CHINARE),including18stationsandninestationsselectedforirradianceprofilesinseawaterrespectively.Inthisstudy,thevariationofattenuationcoefficientintheArcticOceanwasstudied,andthefollowingresultswereobtained.First,therelationshipbetweenattenuationcoefficientandchlorophyllconcentrationintheArcticOceanhastheformofapowerfunction.Thebestfitisat443nm,anditsdeterminationcoefficientismorethan0.7.Withincreasingwavelength,thedeterminationcoefficientdecreasesabruptly.At550nm,itevenreachesavaluelowerthan0.2.However,theexponentfittedisonlyhalfofthatadaptedinlow-latitudeoceanbecauseofthelowerchlorophyll-specificabsorptionintheArcticOcean.Theupshotwasthat,inthecaseofthesamechlorophyllconcentration,theattenuationcausedbyphytoplanktonchlorophyllintheArcticOceanislowerthaninlow-latitudeocean.Second,thespectralmodel,whichexhibitstherelationshipofattenuationcoefficientsbetween490nmandotherwavelength,wasbuiltandprovidedanewmethodtoestimatetheattenuationcoefficientatotherwavelength,iftheattenuationcoefficientat490nmwasknown.Third,theimpactfactorsonattenuationcoefficient,includingseaiceandseawatermass,werediscussed.Theinfluenceofseaiceonattenuationcoefficientisindirectandisdeterminedthroughthecontrolofenteringsolarradiation.Thelinearrelationshipbetweenaveragingseaiceconcentration(ASIC,from158Juliandaytoobservationday)andthedepthofmaximumchlorophyllisfittedbyasimplelinearequation.Inaddition,theseawatermass,suchastheACW(AlaskanCoastalWater),directlyaffectstheamountofchlorophyllthroughtakingmorenutrient,andresultsinthehigherattenuationcoefficientinthelayerof30–60m.Con

简介：ThegreatMs8.0Wenchuanearthquakehasbeenthemostdestructiveearthquakesince1949inChina.TheearthquakeoccurrednomorethanhalfayearaftertheestablishmentoftheNationalStrongMotionObservationNetworkSystem(NSMONS)ofChina;whatismore,theepicenterwaslocatedintheareawithdensestrongmotionobservationstationssothatalargenumberofstrongmotionrecordsofthemainshockwereobtained.Inthispaper,501strongmotionrecordsfrom167observationstationsareutilizedtoestablishthegroundmotionattenuationrelationsinthreedirectionsintherangeoffaultdistancelessthan600km.Theresultshowsthedifferenceofseismicmotionattenuationintwohorizontaldirectionsisinsignificant.Itisthefirsttimethatstrong-motionrecordsareusedtoestablishthegroundmotionattenuationrelationsoftheMS8.0earthquakeinChina.

简介：——PhaseBehavioroftheAqueousSolutionofPoly(vinylmethylether)SensitivetoTemperatureandtheModificationoftheBehaviorbyUsingPoly(acrylicacid)Thephasebehavioroftheaqueoussolutionofpoly(vinylmethylether)(PVME)sensitivetotemperatureandthemodificationofthebehaviorbyusingpoly(acrylicacid)(PAA)havebeenstudiedbyultrasonicattenuationmeasurementsandfluorescenceprobetechniques.IthasbeenobservedthatPVMEsolutionistransparentatroomtemperatureandbecomesturbiduponheating.Thesolutionturnsclearagainassoonasthetemperatureisdecreasedtoroomtemperature.Theheatingandcoolingprocesscanberepeatedformanytimes.Thephasebehaviorofthesolutionsensitivetotemperatureisattributedtotheconformationalchangesofthepolymer.PVMEmayadoptanopencoilconformationatroomtemperature.Withthisconformation,thepolymeriswellmisciblewiththesolvent,water,andtherebythesystemisarealsolution.Thepolymermayadoptacompactcoilconformationwhenthetemperatureishigherthanaspecificvalue,whichiscalledtheLCST(thelowercriticalsolutiontemperature)ofPVME.Inthiscase,thepolymertanglestoeachotherandformsvariousaggregates,whichcanscatterincidentlightandultrasonicwavesgreatly,resultinginthephaseseparation.IntroductionofPAAdecreasesthetemperaturesensitivityofthephasebehaviorofthepolymer.ThenatureoftheinhibitionisattributedtothecomplexationofPAAwithPVMEandthestronghydrophilicityofPAA.Resultsfromfluorescenceprobestudiesareinaccordancewiththosefromultrasonicattenuationmeasurements,indicatingagainthattheultrasonicattenuationmethodcanbesuccessfullyusedforthequalitativestudiesofpolymerconformationsandcomplexationbetweenpolymers.

简介：Background:Theforefootrunningfootfallpatternhasbeensuggestedtoreducetheriskofdevelopingrunningrelatedoveruseinjuriesduetoareductionofimpactrelatedvariablescomparedwiththerearfootrunningfootfallpattern.However,onlytime-domainimpactvariableshavebeencomparedbetweenfootfallpatterns.Thefrequencycontentoftheimpactshockandthedegreetowhichitisattenuatedmaybeofgreaterimportanceforinjuryriskandpreventionthantime-domainvariables.Therefore,thepurposeofthisstudywastodeterminethedifferencesinheadandtibialaccelerationsignalpowerandshockattenuationbetweenrearfootandforefootrunning.Methods:Nineteenhabitualrearfootrunnersand19habitualforefootrunnersranonatreadmillat3.5m/susingtheirpreferredfootfallpatternswhiletibialandheadaccelerationdatawerecollected.Themagnitudeofthefirstandsecondheadaccelerationpeaks,andpeakpositivetibialaccelerationwerecalculated.Thepowerspectraldensityofeachsignalwascalculatedtotransformtheheadandtibialaccelerationsinthefrequencydomain.Shockattenuationwascalculatedbyatransferfunctionoftheheadsignalrelativetothetibia.Results:Peakpositivetibialaccelerationandsignalpowerinthelowerandhigherrangesweresignificantlygreaterduringrearfootthanforefootrunning(/><0.05).Thefirstandsecondheadaccelerationpeaksandheadsignalpowerwerenotstatisticallydifferentbetweenpatterns(p>0.05).Rearfootrunningresultedinsignificantlygreatershockattenuationforthelowerandhigherfrequencyrangesasaresultofgreatertibialacceleration(p<0.05).Conclusion:Thedifferenceinimpactshockfrequencycontentbetweenfootfallpatternssuggeststhattheprimarymechanismsforattenuationmaydiffer.Therelationshipbetweenshockattenuationmechanismsandinjuryisnotclearbutgiventhedifferencesinimpactfrequencycontent,neitherfootfallpatternmaybemorebeneficialforinjury,ratherthetypeofinjurysustainedmayvary

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简介：TwomethodsformeasuringtheattenuationQvalue,frequency-amplituderatiomethodandwaveforminversionmethod,wereanalyzed.Thesizeandshapeofmostrocksamplesinthelaboratorycanhardlyfulfilltherigorousrequirementsoftheabovemethods.AnewtestmethodofusingthewaveenergytocalculatetheQvaluewasproposed.Theprinciple,calculationformulaeandsomepointsforattentionwereexpounded;therelationshipbetweenQ_PandQ_Ewasdiscussed;andmanysamplesweremeasuredbythismethod.Theresultwascomparedwiththosebyothermethods,anditwasconsideredthattheQvaluebythismethodliesbetweenQ_PandQ_E·

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