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145 个结果
  • 简介:TheoptoelectronicandmagneticpropertiesofpureHoMnO3andHo0.67T0.33MnO3(T=La,Y)alloysinhexagonalphasearetheoreticallyinvestigatedbyusingthefirst-principlescalculations.TheinvestigationsareperformedbymeansofthedensityfunctionaltheorythroughusingthespinpolarizedgeneralizedgradientapproximationplustheHubbardpotential(SPGGA+U,Ueff=3eV).ThestudiedmaterialHoMnO3exhibitstwoindirectbandgaps:1.58eVforthespinupstateand0.72eVforthespin-downstatealongtheS–GdirectionwithintheSPGGA+Uapproximation.ItisfoundthatthebandgapofpureHoMnO3forthespin-upstateincreaseswithincreasingLaandYdopants.Theresultsshowthatallofthestudiedmaterialshavesemi-metallicbehaviorsforthespin-upstateandsemiconductingcharacterforthespin-downstate.ThesubstitutionsofLaandYforHoinHoMnO3causethestaticdielectricconstant(ε0)toincreaseinthexdirectionbuttodecreaseinthezdirection.ThecalculatedopticalconductivityspectrumofHoMnO3inalowenergyrangeisingoodagreementwiththerecentexperimentaldata.

  • 标签: 第一性原理计算 光电性能 过渡金属 III 磁性 B型
  • 简介:BackgroundThevideo-assistedthoracoscopicsurgicaltechniquesarewidelyusedinthetreatmentofpatientswithcongenitalheartdiseaseswithgoodoutcomes.However,thefeasibilityandsignificanceofnursebasedearlycardiacrehabilitationincardiacintensivecareunit(ICU)forpatientswithtotallythoracoscopiccardiacoperationhasbeenseldomstudied.MethodsThirty-sixpatientswithtotallythoracoscopiccardiacoperationundertheconditionofthecardiacICUinGuangdongGeneralHospitalwererandomallocatedtotheinterventiongroupandthecontrolgroupbetweenJanuary2012toDecember2014.Thecontrolgroupreceivedstandardnursingcare,andtheinterventiongroupreceivedearlycardiacrehabilitationnursingcareinadditiontostandardcare.Theoutcomemeasuresincludedtheoxygensaturation(SpO2%),vitalcapacity,forcedexpiratoryvolumein1second(FEV1),andpaininthethoracicwound(visualanaloguescale,VAS),whichweremeasuredatthebaselineandwithin2-dayafter4-weeknursingcare.Forsafetyreason,wealsomonitoredtherateofperceivedexertion(RPE),heartrate,systemicbloodpressure.ResultsTherewerenon-significantdifferencesbetweenthegroupsinage,sex,totalnumberofcomorbidconditions,totalnumberofmedications,surgicaltime,andanesthetictime(P>0.05).Following4weekstreatment,thecardiopulmonaryfunctionsandVASscorewereimproved(P<0.05)inallgroups.Inaddition,theimprovementsweremoreintheearlycardiacrehabilitationnursecaregroupthaninthecontrolgroup(P<0.05).ConclusionTheearlycardiacrehabilitationnursingcareincardiacICUissafe,feasibleandbeneficialforpatientswithtotallythoracoscopiccardiacoperation.

  • 标签: 心脏病患者 ICU 护理 康复 腔镜 手术
  • 简介:Purpose:ThepurposeofthisstudywastoinvestigatetheimpactofacuteexerciseonreactiontimeandresponsepreparationduringaGo/NoGoTaskinchildrenwithattentiondeficithyperactivitydisorder(ADHD).Methods:NineteenchildrenwithADHD(agedbetween8and12yearsold)undertooka30-mininterventionthatconsistedoftreadmillrunningorvideo-watchingpresentedinacounterbalancedorderondifferentdays.AGo/NoGoTaskwasadministratedafterexerciseorvideo-watching.Results:Theresultsindicatedashorterreactiontimeandsmallercontingentnegativevariation(CNV)2amplitudefollowingexerciserelativetothevideo-watching.Foreventrelatedpotential(ERP)analyses,greaterCNV1andCNV2amplitudesinresponsetoNoGostimuliincomparisontoGostimuliwasobservedinthevideo-watchingsessiononly.Conclusion:ThesefindingssuggestthatacuteexercisemaybenefitchildrenwithADHDbydevelopingappropriateresponsepreparation,particularlyinmaintainingastablemotorpreparatorysetpriortoperformingthegiventask.

  • 标签: 儿童多动症 有氧运动 ERP 急性 反应时间 事件相关电位
  • 简介:Rapidgrowthofmannedspaceflightresultsinmoreconcernabouthealthriskandanurgentneedofhealthassessmentinspacetravel.Sincetheimportanceofbrainfunctionstoastronauts,weexploredthelong-termeffectsandpotentialmechanismsof56Feionradiationonmicebrain.

  • 标签: COGNITIVE Function MOUSE BRAIN
  • 简介:Purpose:Thepurposeofthisstudywastodeterminetheeffectsofacuteexerciseonmotorresponseinhibitionusingbothbehavioralandelectrophysiologicalapproaches.Methods:TheP3andN1event-relatedpotential(ERP)componentswererecordedwhileperformingastop-signaltaskin21collegestudentsfollowingamoderatelyintenseacuteexerciseboutfor30minandasedentarycontrolsessionthatinvolvedreading.Results:Acuteexerciseinducedashorterstopsignalresponsetime(SSRT)ascomparedtocontrol;however,thegoresponsetime(GoRT)remainedunchanged.InexaminingtheERPdata,acuteexerciseincreasedbothP3amplitudeandlatencybutdidnotaffecttheN1component.Conclusion:Acuteexercisehasaselectiveandbeneficialeffectoncognitivefunction,specificallyaffectingthemotorresponseinhibitionaspectofexecutivefunction.Furthermore,acuteexercisepredominatelyimpactslaterstagesofinformationprocessingduringmotorresponseinhibition,whichmayleadtoanincreaseinattentionalresourceallocationandconfertheabilitytosuccessfullywithholdaresponsetoachievemotorresponseinhibition.

  • 标签: 运动反应 停止信号 ERP 急性 有氧运动 信号响应时间
  • 简介:Thefarmlandtoforestprojecthasasignificantpromotingroleonecologicalcivilization;thefollow-upindustrydevelopmentisthekeytoconsolidatingachievementsofthefarmlandtoforestproject.Usingthesurveydataoffarmlandfarmers,thisarticleanalyzesthestatusanddevelopmentofthefollowupindustryinGuizhouprovince.Theresultsshowthatthefollow-upindustrydevelopmentqualityislow,thefollow-upindustrydevelopmentwillingnessisweak,thefollow-upindustrydevelopmentabilityispoor,andthefollow-upindustrysustaineddevelopmentisinsufficient.Furtheranalysisindicatesthatthefollow-upindustrydevelopmentlackoffunds,technicalandsystemofpolicysupport.Policyimplicationsarediscussedfocusingonimprovingpolicysystem,thefollow-upindustrydevelopmentstrategy,thefollow-upindustrydevelopmentplanning,anddevelopmentwiththecombinationofdevelopmentstrategyofGuizhouprovince.

  • 标签: CONVERTING degraded FARMLAND into FOREST FOLLOW-UP
  • 简介:UsingvanderWaalscorrecteddensityfunctionaltheory(vdW-DF)methodwehaveinvestigatedtheadsorptionofacetonemoleculeonpristineandPt-dopedgraphene.Severalactivesitesforboththeinteractingsystemshavebeenconsideredintheadsorptionprocessincludingfullgeometryoptimization.Wehaveanalyzedthestructuralandelectricalpropertiesofenergeticallyfavorableconfigurations.TheresultsshowthatadsorptionofacetonemoleculeonthePt-dopedgrapheneisenergeticallypreferable.Thebindingenergyandbondingdistancearedeterminedtobe-5.277eVand2.206A,respectively,accompanyingwithchargetransferof1.11e.Furthermore,thePt-0bondisrathersignificantlyelongatedwhenacetoneisadsorbedonPt-dopedgraphene.Comparedtopristinegraphene,thePt-dopedgraphenehasstrongerinteractionwiththeacetoneandmayprovidemoresensitivesignaiforasingleacetonemolecule.Meanwhile,practically,thebandgapofPt-dopedgraphenewouldbecomereducedafteracetoneadsorption.Consequently,ourfirst-principlesstudypresentsevidenceforacoherentbenchmarkfortheapplicabilityofPt-dopedgrapheneforacetoneadsorptionanddetection.

  • 标签: Pt-doped GRAPHENE ACETONE ab INITIO calculations
  • 简介:BasedonarrivaltimedataofseismicphasesofML≥2.0earthquakesmeasuredatShanxiDigitalSeismicNetworkfortheperiodfromJanuary2001toOctober2014,V_P/V_SintheShanxiregioniscalculatedusingtheWadatisinglestationandmulti-earthquakemethod,andaninvestigationisconductedintothevariationbehaviorofV_P/V_SintheShanxiregionbeforeandafterthethreeearthquakesofMS≥4.5in2010.OurstudyfindsthatabnormalV_P/V_Sappearedearlieratdistantstationsbeforeallofthethreeearthquakes,whichisatthetimerangefrom6monthsto1yearbeforetheearthquakes,andlateratnearstations,atthetimerange10daysto2monthsbeforeearthquakes.Therefore,itspossibletonarrowdownthescopeofthelocationinearthquakepredictionfromthedistantandnearstationdata.ThecalculationsofDongshanseismicstationindicatethatthesizeoftheresidualoftheorigintimehasimpactonthedetailofV_P/V_Svariation,thus,appropriatethresholdsshouldfirstlybesetfortheresidualsoforigintimeateachseismicstationinpracticalapplication,toensurescientificandsteadyV_P/V_Scalculations.

  • 标签: 地震方法 山西地区 行为 单站 数字地震台网 起源时间
  • 简介:Background:Successionalpaludification,adynamicprocessthatleadstotheformationofpeatlands,isinfluencedbyclimaticfactorsandsitefeaturessuchassurficialdepositsandsoiltexture.Inborealregions,projectedclimatechangeandcorrespondingmodificationsinnaturalfireregimesareexpectedtoinfluencethepaludificationprocessandforestdevelopment.TheobjectiveofthisstudywastoforecastthedevelopmentofborealpaludifiedforestsinnortheasternNorthAmericainrelationtoclimatechangeandmodificationsinthenaturalfireregimefortheperiod2011–2100.Methods:Apaludificationindexwasbuiltusingstatic(e.g.surficialdepositsandsoiltexture)anddynamic(e.g.moistureregimeandsoilorganiclayerthickness)standscalefactorsavailablefromforestmaps.Theindexconsideredtheeffectsofthreetemperatureincreasescenarios(i.e.+1°C,+3°Cand+6°C)andprogressivelydecreasingfirecycle(from300yearsfor2011–2041,to200yearsfor2071–2100)onpeataccumulationrateandsoilorganiclayer(SOL)thicknessatthestandlevel,andpaludificationatthelandscapelevel.Results:Ourindexshowthatinthecontextwhereintheabsenceoffirethelandscapecontinuestopaludify,thenegativeeffectofclimatechangeonpeataccumulationresultedinlittlemodificationtoSOLthicknessatthestandlevel,andnochangeinthepaludificationlevelofthestudyareabetween2011and2100.However,includingdecreasingfirecycletotheindexresultedindeclinesinpaludifiedarea.Overall,theindexpredictsaslighttomoderatedecreaseintheareacoveredbypaludifiedforestsin2100,withslowerratesofpaludification.Conclusions:Slowerpaludificationratesimplygreaterforestproductivityandagreaterpotentialforforestharvest,butalsoagraduallossofopenpaludifiedstands,whichcouldimpactthecarbonbalanceinpaludifiedlandscapes.Nonetheless,asthethickSphagnumlayertypicalofpaludifiedforestsmayprotectsoilorganiclayerfromdroughtanddeepburns,asignificantprop

  • 标签: 森林采伐 气候变化 寒带地区 预测 生态园 安大略
  • 简介:Mostpublishedstudiesoninelasticearthquakeresponseofnon-symmetricbuildingsarebasedonsimplifiedinelastic,highlyidealizedmodels,whilegeneralconclusionsregardingtheinelastictorsionalresponseofmultistorybuildingarestilllacking.Thispaperaimstoprovideausefulcontributioninthestudyofthetorsionalresponseofrealirregularbuildings.Tothisaim,themanuscriptreportsthecomprehensivestudyontheseismicvulnerabilityofanirregularRCbuilding:thehospitalbuildingofAvezzano(L’AquilaItaly).Forthismulti-storybuilding,whichisirregularinbothplanandelevation,theapplicationofnonlinearstaticevaluationproceduresisbynomeansstraightforward.Thestudyproposesanonlinearstaticprocedurebasedonpushoveranalysisunderthemultimodaldistributionoflateralloadsandacapacityspectrummethod.Thispushoverprocedureaccountsformassdistribution,highermodescontributionandmode-shapescorrelation.Furthermore,duetoitsnon-iterativefeature,itavoidsproblemsofnon-convergenceandmultiplesolutionsoftheconventionalcapacityspectrummethod.Appliedtoarealcasestudy,theprocedureisusedtoinvestigate,ina3Dplanirregularbuilding,thesensitivityoftorsionalinelasticresponsetolateralforcedistribution,highermodescontribution,accidentaleccentricityandcontrolledpointformonitoringthetargetdisplacement.

  • 标签: 混凝土建筑物 医院建筑 抗震性能评估 意大利 案例 钢筋
  • 简介:Appearanceandexhaustionoftheresourcecityisaninevitableobjectivephenomenonintheprocessofindustrialization.Transformationoftheresourcecitybecamethefocusofattentionwithhighlightingproblemsandcontradictionsinthecity.Thepaperplacesemphasisonpathselectionandtransformationstrategiesofresource-exhaustedcitytransformationtakingthecoalcityPingxiangasanexample.FromtheperspectiveofprofileandeffectivenessoftransformationinPingxiangcity,thepaperanalyzesthemainproblemsinthecitytransformation,pointsoutitsmainpathdirectionfromeconomictransformation,socialtransformationandecologicaltransformation,andfinallypresentstransitionstrategyandpolicyrecommendationstothecity.

  • 标签: resource-exhausted CITY TRANSFORMATION path coal CITY
  • 简介:Weinvestigatetheinteractionbetweenapositivemassandanegativeeffectivemassthroughathreemasschainconnectedwithelasticsprings,apairofmassesisdesignedtohaveaneffectivenegativemass,anditinteractswiththethirdpositiveoneasifanequivalenttwo-masschain.Thedynamicsoftheequivalenttwo-masschainshowsthatthetwobodiesmaybeself-acceleratedinsamedirectionwhentheeffectivemassbecomesnegative,theexperimentisalsoconductedtodemonstratethistypeofmotion.Wefurthershowthattheenergyprinciple(Hamilton’sprinciple)isapplicableiftheenergyofthenegativemassunitisproperlycharacterized.Theresultmayberelevanttocompositewithcellsofeffectivenegativemass,theirinteractionwithmatrixmayleadtomorericherunexpectedmacroscopicresponses.

  • 标签: 负有效质量 质量弹簧系统 相互作用 实验 能量原理 哈密顿原理