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  • 简介:Basedon3DBiot’sconsolidationtheoryandnonlinearDuncan-Chang’smodel,a3DFEM(finiteelementmethod)programisdevelopedconsideringthecouplingofgroundwaterseepageandsoilskeletondeformationduringexcavation.Thecomparisonbetweentheanalysisresultconsideringthevariationofwaterheaddifferenceandthatwithoutconsideringitshowsthattheporewaterpressuredistributionoftheformerisdistinctlydifferentfromthatofthelatterandthatthefoundationpitde-formationsoftheformerarelargerthanthoseofthelatter,sothattheresultwithoutconsideringthevariationofwaterheaddif-ferenceisunreliable.Thedistributionrulesofsoilhorizontalandverticaldisplacementsaroundthepitandexcessporewaterpressureareanalyzedindetailintimeandspace,whichisverysignificantforguidingundergroundengineeringconstructionandensuringenvironmentsafetyaroundthepit.

  • 标签: 环境作用 地基变形 孔隙压力 建筑工程
  • 简介:Anewtypeofelectrochemicaloscillationinducedbysurfactantwasobservedinexperiments.TheelectrochemicalsystemisaDaniellcellwithacopperrodinCuSO4aqueousandanaluminumrodinAl(NO3)3aqueousaselectrodes.ThesurfactantsareCTAB,TX-100,SLS.Theadditionoftracesurfactantsolutionbyamicro-syringemadetheoriginalmonotonouslychangingelectrochemicalsystemproduceobviousperiodicphenomena.Atthemeantime,thecopperionselectiveelectrodeandHg2SO4referenceelectrodewereusedtomonitorthecopperelectrodereactionanddetermineitsrateconstantkoffirstorderreaction.Accordingtotheexperimentalresultsofelectrodereactionkinetics,thepossiblemechanismwasfoundtobethepolarizationinducedfromthedirectionaladsorptionoftracesurfactantontheelectrodesurface.Thatistheelectrochemicaloscillations.

  • 标签: 丹聂尔电池 电化学反应 化学震荡器 表面活性剂 电极 硫酸铜
  • 简介:让Gn,d是有n顶点的一张随机的d常规的图,在此d=o(n)。给一张固定的图H,YH在Gn,d。在这篇论文,作者决定事件的阀值“YH>0',并且也在阀值间隔内获得劝诱的潜水艇图计数。

  • 标签: 子图 泊松分布 随机规则图 平衡性 阈值
  • 简介:K.J.,K.W. and K.R. Lees,we determined whether isoflurane preconditioning reduced glutamate receptor over-stimulation-induced neuronal death. Our results showed that isoflurane preconditioning reduced the neuronal death caused by over-stimulation of the major glutamate receptors [12]. Kapinya et al should be credited as the first group to show that isoflurane preconditioning induced a delayed phase of neuroprotection [13]. Our in vivo study showed that this protection was mediated by the activation of the mitogen-activated protein kinase p38 [14]. The isoflurane preconditioning-induced protection in human neuroblastoma SH-SY5Y cells involved the extracellular signal-regulated kinase-early growth response gene 1-Bcl-2 pathway activation [15]. Our in vivo study also showed that isoflurane preconditioning induced a delayed phase of protection in immature brains [16]. This protection was sustained even when animals were examined at one month after the brain ischemia [17]. In summary

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  • 简介:Asimulationiscarriedoutforthepressurefluctuationdrivenbythewaterhammer,basedonajointuseoftheonedimensionalmethodofcharacteristics(MOC)andthethree-dimensionalfinitevolumemethod(FVM).Thethree-dimensionalvisualizationofthecavitationinducedbythewaterhammerisimplemented,andthetemporalandspatialanalysesofextremeregionsaremade.Apracticalcaseofthewaterhammer,withtheminimumboundarypressurehigherthanthesaturatedvaporpressurecondition,issimulated.Thesimulationpredictionthatthecavitationwouldoccurinthefrontofthegasketcouldservesomeguidelinefortheoptimizationofindustrialdesigns.

  • 标签: 水路 模拟 成穴 压力变化 基于特征 联合使用
  • 简介:ThisarticlepresentstheresultsofanumericalsimulationonthevortexinducedvibrationofvariousfinnedcylindersatlowReynoldsnumber.Thenon-dimensional,incompressibleNavier-Stokesequationsandcontinuityequationwereadoptedtosimulatethefluidaroundthecylinder.Thecylinder(withorwithoutfins)influidflowwasapproximatedasamass-springsystem.Thefluid-bodyinteractionofthecylinderwithfinsanduniformflowwasnumericallysimulatedbyapplyingthedisplacementandstressiterativecomputationonthefluid-bodyinterfaces.Bothvortexstructuresandresponseamplitudesofcylinderswithvariousarrangementsoffinswereanalyzedanddiscussed.TheremarkabledecreaseofresponseamplitudefortheadditionsofTriangle60finsandQuadrangle45finswasfoundtobecomparablewiththatofbarecylinder.However,theadditionsofTriangle00finsandQuadrangle00finsenhancetheresponseamplitudegreatly.Despitetheassumptionoftwo-dimensionallaminarflow,thepresentstudycangiveagoodinsightintothephenomenaofcylinderswithvariousarrangementsoffins.

  • 标签: 涡流感应振动 圆柱钢片 液体流动性 汽缸
  • 简介:Weisolatedandpurifiedmitochondriafrommouseliversandspinachleaves.WhenaddedintoeggextractsofXenopuslaevis,theycausednucleiofmouselivertoundergoapoptoticchanges.Chromatincondensation,marginationandDNAladderwereobserved.Afterincubatingisolatedmitochondriainsomehypotonicsolutions,andcentrifugingthesemixturesatmghspeed,wegotmitochondrialsupernatants.Itwasfoundthatintheabsenceofcytosolicfactor,thesupernatantalonewasabletoinduceapoptoticchangesinnuclei.Theeffectivecomponentswerepartlyofprotein.DNAfragmentationwaspartlyinhibitedbycaspaseinhibitorsAC-DEVD-CHOandAC-YVAD-CHO.Meanwhile,caspaseinhibitorsfullyblockedchromatincondensation.Primarycharacterizationofthenuclearendonuclease(s)inducedbymitochondrialsupernatantswasalsoconducted.ItwasfoundthatthisendonucleaseisdifferentfromendonucleaseG,cytochromec-inducednuclease,orCa^2+-activatedendonuclease.

  • 标签: 分离线粒体 诱导 核凋亡 核酸内切酶
  • 简介:Westudyoptomechanicallyinducedtransparencyinaspinningmicroresonator.Wefindthatinthepresenceofrotation-inducedSagnacfrequencyshift,boththetransmissionrateandthegroupdelayofthesignalarestronglyaffected,leadingtoaFano-likespectrumoftransparency.Inparticular,tuningtherotaryspeedleadstotheemergenceofnonreciprocalopticalsidebands.Thisindicatesapromisingnewwaytocontrolhybridlight–sounddeviceswithspinningresonators.

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  • 简介:Alaboratoryexperimentwasconductedinsideawindwavetanktoinvestigatethewaveinducedturbulence.Inthisexperiment,thewavesurfaceelevationandvelocitybeneaththewatersurfaceweremeasuredsimultaneouslytoinvestigatetherelationbetweenthewavestatusandwaveinducedturbulence.TheprofileoftheturbulentdissipationrateandReynoldsstresswerecalculatedusingexperimentaldata.Theeffectofthewavestatusonturbulenceisinvestigatedwithregardtothewindwave,swell,andmixedwaveconditions.Itwasdepictedthattheturbulencedecreasedwithincreasingdepthfromthewatersurfaceandthattheturbulencethatwasinducedbyawavewithlargerwavelengthandwaveheightismuchstrongerforthesamewavestatus.Finally,weobservedthatthewindwaveismoreeffectiveinactivatingthewaveinducedturbulence.

  • 标签: WAVE induced TURBULENCE TURBULENT DISSIPATION RATE
  • 简介:Moleculardynamics(MD)simulationsoftheconsecutivecompression-decompressioncyclesofhexagonalzincsulfide(wurtzite)nanoparticlespredictanirreversiblephasetransformationtothecubicpolymorph.Thephasetransformationcommencesatthecontactareabetweentheparticleandtheindenterandproceedswiththenumberofcompressioncycles.Dislocationsarevisibleforaparticlesizeabove5nm.ResultsfromwetgrindinganddrypowdercompressionexperimentsonacommercialwurtzitepigmentagreequalitativelywithMDsimulationpredictions.X-raydiffractionpatternsrevealthattheamountofcubicpolymorphinthecompressedsamplesincreaseswithpressureappliedtothepowder.Incomparisonwithpowdercompression,wetmillingleadstoamorepronouncedphasetransformation.Thisoccursbecausetheparticlesareexposedtoalargenumberofstresseventsbycollisionwiththegrindingmedia,whichleadstotheformationofdefectsandnewsurfacecrystallitesbyparticlefracture.AccordingtotheMDsimulations,phasetransformationisexpectedtooccurpreferentiallyinsurfacecrystallitesbecausetheyexperiencethehighestmechanicalload.Becauseofthephasetransformation,thewetgroundandcompressedsamplesexhibitalowerphotoluminescenceintensitythanthefeedmaterial.Incomparisonwithpowdercompression,millingreducesthephotoluminescenceintensitymoresubstantially.Thisoccursbecauseahigherdefectconcentrationisformed.Thedefectscontributetothephasetransformationandphotoluminescencequenching.

  • 标签: 机械负载 硫化锌 相变 诱导 模拟预测 粉末压缩
  • 简介:K.J.,K.W. and K.R. Lees,J.M.

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  • 简介:LetGbeasecondcountablelocallycompactgroupoidwithHaarsystem{λuH},HbeaclosedsubgroupoidcontainingG^0withHaarsystem{λuH}.T.MasudaintroducedtheC^*-Groupoiddynamicsystem(G,A,α)anditsreducedcrossedproductCrea(G,A)in[2]:whereAisC^*-algebraαisthekomomorphismG→Aut(A).InthispapertheauthorintroducestheC^*-groupoiddynamicsystems(H,A,α/H)and(H\G2,A,^-α)inducedby(G,A,α)andprovesthatC*red(H,A)andC^*red(H\G^2,A)arestronglyMoritaequivalentMoreovertheinducedrepresentationfromC^*red(H,A)toC^*red(G,A)isgot.

  • 标签: C^*-群力学系统 听觉系统 群代数 交叉乘积
  • 简介:YagerpresentedtheOrderedWeightedAveraging(OWA)operatortoprovideamethodforaggregatinginformationofdecision-making.YagerandFilevfurtherpresentedtheInducedOrderedWeightedAveraging(IOWA)operator.Inthispaper,weproposeaGeneralizedInducedOrderedWeightedGeometric(GIOWG)operatorandestablishasimpleobjective-programmingmodeltolearntheassociatedweightingvectorfromobservationaldata.EachobjectprocessedbytheGIOWGoperatorconsistsofthreecomponents,wherethefirstcomponentrepresentstheimportancedegreeorcharacterofthesecondcomponent,andthesecondcomponentisusedtoinduceanordering,throughthefirstcomponent,overthethirdcomponentswhicharethenaggregated.Thedesirableproperties,suchascommutativity,idempotencyandmonotonicity,etc.,associatedwlththeGIOWGoperatorarestudiedindetail,andsomenumericalexamplesaregiventoshowthepracticalityandeffectivenessofthedevelopedoperator.

  • 标签: 群集 有序加权平均值 几何算子 GIOWG
  • 简介:volatile anesthetics can induce acute and delayed phases of preconditioning effects in the brain. Since isoflurane is a relatively safe agent and has been frequently used in patients with potential brain ischemia,7]. We showed for the first time that preconditioning with the volatile anesthetic isoflurane induced an acute phase of neuroprotection [8]. Our subsequent study showed that this isoflurane preconditioning-induced acute phase of neuroprotection was dose-dependent with an EC50 1.17% and that preconditioning the brain with isoflurane for 15-30 min was needed for the preconditioning to be maximally protective. This effect was glutamate transporter-dependent [9]. Other volatile anesthetics,we determined whether isoflurane preconditioning reduced glutamate receptor over-stimulation-induced neuronal death. Our results showed that isoflurane preconditioning reduced the neuronal death caused by over-stimulation of the major glutamate receptors [12]. Kapinya et al should be credited as the first group to show that isoflurane preconditioning induced a delayed phase of neuroprotection [13]. Our in vivo study showed that this protection was mediated by the activation of the mitogen-activated protein kinase p38 [14]. The isoflurane preconditioning-induced protection in human neuroblastoma SH-SY5Y cells involved the extracellular signal-regulated kinase-early growth response gene 1-Bcl-2 pathway activation [15]. Our in vivo study also showed that isoflurane preconditioning induced a delayed phase of protection in immature brains [16]. This protection was sustained even when animals were examined at one month after the brain ischemia [17]. In summary

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  • 作者: Zhang Hong Zhou Yu-Jie Zeng Yu-Jie
  • 学科: 医药卫生 >
  • 创建时间:2020-08-10
  • 出处:《中华医学杂志(英文版)》 2020年第13期
  • 机构:Emergency and Critical Care Center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China,Department of Cardiology, 12th Ward, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Key Laboratory of Precision Medicine of Coronary Atherosclerotic Disease, Clinical Center for Coronary Heart Disease, Capital Medical University, Beijing 100029, China
  • 简介:AbstractBackground:The detrimental outcomes of right ventricular pacing on left ventricular electromechanical function ultimately result in heart failure, a phenomenon termed pacing-induced cardiomyopathy (PICM) in clinical research. This study aimed to validate prognostic factors that can be used to identify patients with higher susceptibility to progress to the stage of cardiomyopathy before pacemaker implantation.Methods:This observational analysis enrolled 256 patients between January 2013 and June 2016, 23 (8.98%) of whom progressed to PICM after 1 year of follow-up. A Cox proportional hazard model was used to analyze the prognostic factors associated with PICM. Dose-response analysis was used to evaluate the relationship between significant indicators in multifactor analysis and PICM.Results:The mean values of left ventricular ejection fraction before and after pacemaker implantation in 23 patients diagnosed with PICM were 62.3% and 42.7%, respectively. Univariate analysis showed that sex, atrio-ventricular block, paced QRS duration, and ventricular pacing percentage were significantly associated with PICM. In the multivariate analysis, male sex (hazard ratio: 1.20, 95% confidence interval [CI]: 1.09-1.33, P < 0.005), paced QRS duration (hazard ratio: 1.95 per 1 ms increase, 95% CI: 1.80-2.12, P < 0.001), and ventricular pacing percentage (hazard ratio: 1.65 per 1% increase, 95% CI: 1.51-1.79, P < 0.001) were independent prognostic factors associated with the development of PICM. The ventricular pacing percentage and paced QRS duration level defined by the dose-response analysis were positively associated with PICM (P < 0.05).Conclusions:Our findings indicated that paced QRS duration and ventricular pacing percentage were the most sensitive prognostic factors for PICM.

  • 标签: Right ventricular pacing Pacing-induced cardiomyopathy Heart failure
  • 简介:Trimethyltin(TMT)isanoccupationalandenvironmentalhealthhazardbehavingasapotentneurotoxinknowntoaffectthecentralnervoussystemaswellastheperipheralauditorysystem.However,themechanismsunderlyingTMT-inducedototoxicityarepoorlyunderstood.ToelucidatetheeffectsofTMTonthecochlea,asingleinjectionof4or8mg/kgTMTwasadministeredintraperitoneallytoadultrats.Thecompoundactionpotential(CAP)thresholdwasusedtoassessthefunctionalstatusofthecochleaandhistologicaltechniqueswereusedtoassesstheconditionofthehaircellsandauditorynervefibers.TMTat4mg/kgproducedatemporaryCAPthresholdelevationof25-60dBthatrecoveredby28dpost-treatment.Althoughtherewasnohaircelllosswiththe4mg/kgdose,therewasanoticeablelossofauditorynervefibersparticularlybeneaththeinnerhaircells.TMTat8mg/kgproducedalargepermanentCAPthresholdshiftthatwasgreatestatthehighfrequencies.TheCAPthresholdshiftwasassociatedwiththelossofouterhaircellsandinnerhaircellsinthebasal,high-frequencyregionofthecochlea,considerablelossofauditorynervefibersandasignificantlossofspiralganglionneuronsinthebasalturn.Spiralganglionneuronsshowedevidenceofsomashrinkageandnuclearcondensationandfragmentation,morphologicalfeaturesofapoptoticcelldeath.TMT-induceddamagewasgreatestinthehigh-frequency,basalregionofthecochleaandthenervefibersbeneaththeinnerhaircellswerethemostvulnerablestructures.

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  • 简介:Basedontheself-excitedvibrationtheoryofice,thevibrationcontroltechnologyofjacketplatformisstudiedinthispaper.Themagnetorheologicalsuspensions(MR)unitischosenasthedamper,thecontrolobjectivefunctionforvibrationexcitedbyiceisdeterminedbyinstantaneousoptimalcontrol(IOC)method,andgeneticalgorithm(GA)isusedtoselecttheoptimalcontrolforce.Forthejacketplatformof40minheightanda3-floordeck,thevibrationresponsesinducedbyicehavebeencalculatedbeforeandaftercontrolconsideringthedifferentthicknessandspeedofice.Itisshownthatthecontrolmethodpresentedinthispapercanreducethevibrationresponseby30%,anditisfeasibletoadoptMRabsorberandGAinthecontrolofvibrationinducedbyice.

  • 标签: 振动控制 导管架平台 遗传算法 瞬间最优控制 IOC GA