简介:摘要目的探讨彩色多普勒血流显像对甲状腺疾病的诊断价值。方法选取2016年10月~2018年2月期间我院68例甲状腺疾病患者,常规二维超声诊断的基础上,应用彩色多普勒血流显像超声进一步明确诊断并分析图像特点。结果本研究中总超声诊断符合率为91.89%(68/74),其中恶性病变的诊断符合率为80.00%(8/10),良性病变的诊断符合率为93.75%(60/64)。甲状腺腺瘤的超声诊断符合率95.83%,甲状腺功能亢进的超声诊断符合率94.74%,结节性甲状腺肿的超声诊断符合率92.86%,甲状腺癌超声诊断符合率80.00%。亚急性甲状腺炎的超声诊断符合率80.00%,桥本氏甲状腺炎的超声诊断符合率100.00%。结论应用二维声像结合彩色多普勒血流显像,对病变的形态、边界和内部回声类型、血流特点及对甲状腺疾病的诊断具有重要意义。
简介:摘要目的研究彩色多普勒血流显像诊断糖尿病下肢动脉病变的价值。方法随机抽取该院自2018年2月—2019年4月收治的糖尿病下肢动脉病变患者50例,将其设为实验组,另随机选取该院非糖尿病下肢动脉病变的正常患者50例作为对照组。对100例患者均进行彩色多普勒血流显像诊断。而后对比两组患者的肢斑块、狭窄及闭塞检出率以及下肢动脉内径、血流速度。结果实验组的下肢斑块、狭窄及闭塞检出率(84%、32%、26%)均明显高于对照组的下肢斑块、狭窄及闭塞检出率(16%、8%、0%),差异有统计学意义(P<0.05);实验组的下肢动脉内径明显小于对照组的下肢动脉内径,差异有统计学意义(P<0.05);实验组的下肢动脉血流速度明显慢于对照组的下肢动脉血流速度,差异有统计学意义(P<0.05)。结论彩色多普勒血流显像对糖尿病下肢动脉病变的诊断具有重要价值,对于患者病情的评估、判定及临床治疗方案的制定提供了依据。
简介:摘要目的探究彩色多普勒血流显像(CDFI)诊断肝癌门静脉癌栓的价值评定。方法选取2016年10月—2018年10月到我院收治的疑似肝癌门静脉癌栓患者124例进行研究,对术前三种影像学诊断准确性情况进行分析。结果常规超声诊断肝癌门静脉癌栓灵敏度89.80%,特异度88.00%,准确率88.71%;增强CT检查诊断肝癌门静脉癌栓灵敏度93.88%,特异度94.67%,准确率94.35%;肝癌门静脉癌栓灵敏度97.96%,特异度98.67%,准确率98.39%。结论在肝癌门静脉癌栓诊断过程中应用彩色多普勒血流显像诊断技术可有效提高肝癌门静脉癌栓诊断的敏感性、特异性和准确性,值得临床推广应用。
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简介:近年来,蓬勃发展的自动驾驶技术为自动驾驶汽车的E/E架构设计提出了新的挑战。除了高带宽,高传输速率和其他基本功能元件外,考虑周全的E/E架构安全性是实现自动驾驶技术的重要因素。本文讨论了在功能安全性和预期功能安全性(SOTIF)方面系统故障后安全回退的设计步骤和解决方案。在安全性回退的基础上,本文提出了E/E架构的安全设计,提出了一种技术上可行的设计方法,同时也着重于车辆中安全网络拓扑和冗余系统的设计,并提出了一个可实现的解决方案。在安全性回退方面,本文结合了特定的自动驾驶场景,说明基于功能安全性和预期功能安全性(SOTIF)的安全回退设计方法。在车辆系统冗余方面,本文从主控制系统冗余、制动系统冗余、转向系统冗余、供电系统冗余、通信系统冗余和传感器冗余六个方面提出具体的设计方法。
简介:摘要目的探讨全身骨显像联合SPECT/CT显像在骨纤维异常增殖症中的临床应用价值。方法选取我院2014年1月-2018年6月共收治经病理确诊的26例骨纤维异常增殖症患者,综合其一般资料,分析所有患者全身骨平面显像及局部SPECT/CT显像的影像特点,继而探讨其临床应用价值。结果16例单骨型中,12例(75.0%)发生于四肢骨;10例(62.5%)位于下肢骨,多骨型10例患者中双侧受累2例(20.0%),一侧受累8例(80.0%),四肢骨受累5例(50.0%),颅骨及下肢骨均受累者2例(20.0%);26例患者中,累及四肢骨者占17例(65.3%)。全身骨显像联合SPECT/CT显像具有较高的灵敏度准确性。结论全身骨显像联合SPECT/CT显像分析具有较高的灵敏度,能够准确定位全身多处病灶组织,便于临床上确定疾病范畴,实现分子影像与解剖影像的融合,提升早期确诊率,值得进一步推广研究。
简介:摘要E-09地块地上办公、商业等(丽泽商务区E-08、E-09地块商业金融项目),建筑面积110185㎡,2016年3月1日开工,2019年5月1日竣工。该工程自施工伊始便建立了绿色施工管理体系,制定了相应的管理制度与目标。
简介:U-shapedmicro-nanochannelscangeneratesignificantflowdisturbanceaswellaslocallyamplifiedelectricfield,whichgivesitselfpotentialtobemicrofluidicmixers,electrokineticpumps,andevencelllysisprocess.NumericalsimulationisutilizedinthisworktostudythehiddencharacteristicsoftheU-shapedmicro-nanochannelsystem,andtheeffectsofkeycontrollingparameters(theexternalvoltageandpressure)onthedeviceoutputmetrics(current,maximumvaluesofelectricfield,shearstressandflowvelocity)wereevaluated.Alargeportionofcurrentflowingthroughthewholesystemgoesthroughthenanochannels,ratherthanthemiddlepartofthemicrochannel,withitsvalueincreasinglinearlywiththeincreaseofvoltage.Duetothelocaliondepletionnearmicro-nanofluidicjunction,significantlyenhancedelectricfield(asmuchas15foldatV=1VandP0=0)aswellasstrongshearstress(leadingtoelectrokineticflow)isgenerated.Withincreasingexternalpressure,bothelectricfieldandshearstresscanbeincreasedinitially(duetoshorteningofdepletionregionlength),butaresuppressedeventuallyathigherpressureduetothedestructionofiondepletionlayer.Insightsgainedfromthisstudycouldbeusefulfordesigningnonlinearelectrokineticpumpsandothersystems.
简介:Basedonthevolumeoffluid(VOF)method,weconductanumericalsimulationtostudythehydrodynamicbinarycoalescenceofdropletsunderairflowinahydrophobicrectangularmicrochannel.Twodistinctregimes,coalescencefollowedbyslidingmotionandthatfollowedbydetachingmotion,areidentifiedanddiscussed.Additionally,thedetailedhydrodynamicinformationbehindthebinarycoalescenceisprovided,basedonwhichadynamicmechanicalanalysisisconductedtorevealthehydrodynamicmechanismsunderlyingthesetworegimes.Thesimulationresultsindicatethattheslidingmotionofdropletsisdrivenbythedragforceandrestrainedbytheadhesionforceinducedbytheinterfacialtensionalongthemainflowdirection.Thedetachment(i.e.,upwardmotion)ofthedropletisdrivenbytheliftforceassociatedwithanaerodynamicliftingpressuredifferenceimposedonthecoalescentdroplet,andalsorestrainedbytheadhesionforceperpendiculartothemainflowdirection.Especially,theliftforceismainlyinducedbyanaerodynamicliftingpressuredifferenceimposedonthecoalescentdroplet.TwotypicalregimescanbequantitativelyrecognizedbyaregimediagramdependingonReandWe.ThehigherReandWerespectivelyleadtorelativelylargerliftforcesandsmalleradhesionforcesactingonthedroplet,bothofwhicharehelpfultodetachmentofthecoalesceddroplet.
简介:FlowstructuresofaMach6transitionalboundarylayerovera260mmlongflaredconeareinvestigatedbytheparticleimagevelocimetry(PIV).Particleimagesnearthecurvedwallareinitiallytransformedintosurface-fittedorthogonalcoordinatesandsplicedwiththeir180°-symmetricimagestosatisfyano-slipconditionatthewall.Theresultsarethenreverselytransformedtothephysicaldomain.Directnumericalsimulation(DNS)isalsoperformedtovalidatetheexperimentalresults.Theexperimentalandnumericalresultsareinagreement,indicatingastrongdilatationprocesswithinthesecond-modeinstability.
简介:Themassflowrateofagranularflowthroughanapertureundergravityisalong-standingchallengeissueinphysicalscience.Weshowthatforsteadyflowfieldclosetolaminarflow,thedynamicalequationstogetherwiththecontinueequationandMohr-circledescriptionofthestressareclosed,andhencesolvable.Inacaseofstreamlineguidedbythetwo-dimensionalhopper,weobtainaconsistentconditionanduseittodeterminethestressandthevelocitydistribution.Ourresultindicatesthat3/2powerscalingbehaviorisrecoveredwithacoefficientC(μ,α)beingafunctionoffrictionalcoefficientandthehopperangle.ItisfoundthatthepredictedcoefficientC(μ,α)iscompatiblewithpreviousstudies.
简介:Theeffectoffullysubmergedbouldersontheflowstructureinchannelshasbeenstudiedbysomeresearchers.However,manynaturalstreamshavebedmaterialwithbouldersthatarenotfullysubmergedunderwater.Inmanynaturalstreams,boulderscoverbetween1%and10%oftheareaofthestreamreach.Theeffectofnon-submergedbouldersonthevelocityprofileandflowcharacteristicsisveryimportantforassessingriverbeddeformation.Theobjectivesofthispaperaretofindthepatternofvelocitydistributionaroundanon-submergedboulderandtocompareitwiththeclassicalstudiesonflowresistanceandReynoldsstressdistributioninopenchannels.Also,byconsideringthevariationintheReynoldsstressdistributionatdifferentlocationsaroundanon-submergedboulder,theeffectofanon-submergedboulderontheestimationofshearvelocityandresistancetoflowhasbeeninvestigated.Resultsindicatesthatinsidethescourholecausedbyanon-submergedboulderinarivervelocitydistributionsareirregular.However,velocitydistributionsareregularoutsidethescourhole.ThepresenceofthebouldercausesaconsiderabledeviationoftheReynoldsshearstressfromtheclassicdistribution,showinganon-specificdistributionwithnegativevalues.TheclassicalmethodsforcalculatingshearvelocityarenotsuitablebecausethesemethodsdonotgivedetailedvelocityandReynoldsstressdistributionsinnaturalriverswithalotofboulders.Thus,theeffectofanon-submergedboulderontheestimationoftheresistancetoflowbyconsideringthevariationsinvelocityandReynoldsstressdistributionsatdifferentlocationsaroundanon-submergedboulderisimportantandneedstobestudiedinanaturalriverinsteadofjustinlaboratoryflumes.ThenegativevaluesinReynoldsstressdistributionaroundaboulderindicatethattheclassicalmethodsareunabletopredictresistancetoflow,andalsoshowstrongturbulenceinsidethescourholewherethecomplexflowconditionspresentambi