简介：Background:Athleteshavebeenshowntoexhibitbetterbalancecomparedtonon-athletes(NON).However,fewstudieshaveinvestigatedhowthesurfaceonwhichathletestrainaffectsthestrategiesadoptedtomaintainbalance.Twodistinctathletegroupswhoexperiencedifferenttypesofsport-specificbalancetrainingarestablesurfaceathletes(SSA)suchasbasketballplayersandthosewhotrainonunstablesurfaces(USA)suchassurfers.ThepurposeofthisstudywastoinvestigatetheeffectsoftrainingsurfaceondynamicbalanceinathletescomparedtoNON.Methods:EightNON,eightSSA,andeightUSAperformedfive20-strialsineachoffiveexperimentalconditionsincludingastaticconditionandfourdynamicconditionsinwhichthesupportsurfacetranslatedintheanteroposterior(AP)ormediolateral(ML)planesusingpositiveornegativefeedbackparadigms.Approximateentropy(ApEn)androotmeansquaredistance(RMS)ofthecenterofpressure(CoP)werecalculatedfortheAPandMLdirections.Four3×5(group×condition)repeatedmeasuresANOVAswereusedtodeterminesignificanteffectsofgroupandconditiononvariablesofinterest.Results:USAexhibitedsmallerApEnvaluesthanSSAintheAPsignalswhilenosignificantdifferenceswereobservedintheMLCoPsignals.Generally,thenegativefeedbackconditionswereassociatedwithsignificantlygreaterRMSvaluesthanthepositivefeedbackconditions.Conclusion:USAexhibituniqueposturalstrategiescomparedtoSSA.Theseuniquestrategiesseeminglyexhibitadirection-specificattributeandmaybeassociatedwithdivergentmotorcontrolstrategies.

简介：Fatiguecuttingisanewapproachforseparatingmaterial.Man-madefatiguecanberealizedbyapplyingarotatingbendingloadtoanotchedbar.Tobetterutilizethenewmethod,lasertreatmentisadoptedinthisstudy.Afterlaserradiationatthenotchroot,thefatiguecycleofthebardropsdramatically.Basedontheexperimentalresult,wedrawtheconclusionthatthefatigueofthebarisinfluencedbytheshapeofthehardenedarea.Ahardenedareathathasasmallaxialdimensionandarelativelylargeradialdimensionfacilitatesthefatigue.Thedesirablehardenedareacanbeobtainedbycontrollingthelasertreatmentparameters.

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简介：Microbe-inducedcalciteprecipitationisasustainableimprovementtechniqueforsandysoil,whichcanalterthepropertiesofsandviamicrobialactivity.Inthisstudy,weinvestigatedtheloose-sand-consolidationeffectbycontrollingtheinjectionvelocity,bacterialandcementingsolutionconcentrations,andholdtimes.Theresultsdemonstratethat,asthecyclicbatchincreases,theutilizationrateofthebacterialfluidincreasesandboththeopticaldensity(OD600)ofthebacteriaandureaseactivitydecrease.Moreover,itwasdeterminedthata3-hholdtimefora0.5mol/Lcementingsolutionwithacementingfluidvelocityof2mL/minhasthegreatestbondingeffect.Thefinalstrengthoftheloosesandwithanincreaseincalciumcarbonatecontentwasfurtherdiscussed.

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简介：Osteoarthritis(OA)isthemostcommonformofarthritis.ThekneeandhipjointsarethemostcommonsitesforOA,andkneeOAismoreprevalentthanhipOA.1KneeOApatientsoftensufferpain,functionaldisability,articularcartilagewearandrelatedjointspacenarrowing.AmongU.S.adults,46.4millionhavephysician-diagnosedarthritisrepresenting

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简介：摘要： 目前, 随着国内水轮发电机组单机容量的不断增加，轴电压成为大型发电机采用自并励不可忽视的问题。正常情况下，机组各轴承对地绝缘良好，产生的轴电流非常小；当绝缘下降后，机组大轴与接地系统构成一个回路，则在整个回路形成很大的轴电流。轴电流长时间作用下将使各导轴承与轴领之间的油膜发生劣化，从而使导轴瓦温度升高，甚至烧毁轴瓦，造成机组停运。长河坝水电站采用哈尔滨电机厂主机及监测设备，4台机组均存在不同程度的轴电流，其中1号机组轴电流最为突出，本文重点介绍长河坝1号机组轴电流超标的排查方法。为同类型机组轴电流分析排查提供参考。

简介：摘要：住宅项目地下停车库已成为拓展城市空间利用率的重要举措，地下车库作为车辆停、行主要场所，对地面使用功能、安全耐久的提出了更高的需求，金刚砂+固化剂一体化成型地面的技术逐渐普及。建设工程的前期的发展阶段，大量采用普通的混凝土地坪，项目实际的操作人员对金刚砂地坪工艺存在质量控制、技术要求的盲区，导致质量问题频发，主要体现在金刚砂完成面产生裂缝、工序安排不当造成成品破坏、多种颜色金刚砂混淆致使感观差、渗水处理不到位四方面的主要问题。实践表明，金刚砂施工采用凿毛、结浆工艺、不同颜色金刚砂施工时间流水搭接、定板取样、不同情况采取不同治理渗漏措施等一系列的技术措施，能够大幅度的提高金刚砂地面的成型质量和耐久性，满足感观和使用要求。