简介:ThermalcharacteristicsarenumericallyinvestigatedforthehybridAlGaInAs/InPonsiliconmicroringlaserswithdifferentringradiiandwidths.Lowthresholdcurrentandlowactiveregiontemperatureriseareexpectedforamicroringlaserwithanarrowringwidth.Basedonthethermalanalysisandthe3Dsimulationformodecharacteristics,ahybridAlGaInAs/InPonsiliconmicroringlaserswithaninnern-electrodelaterallyconfinedbythep-electrodemetalliclayerisfabricatedusinganadhesivebondingtechnique.Athresholdcurrentof4mAisachievedforahybridmicroringlaserwitharadiusof20μmandaringwidthof3.5μmat12°C,andthecorrespondingthresholdcurrentdensityisaslowas1kA∕cm~2.Theinfluenceofthelocationofsiliconwaveguideonoutputperformanceisstudiedexperimentallyforimprovingtheoutputcouplingefficiency.Furthermore,continuous-waveelectricallyinjectedlasingupto55°Cisrealizedforahybridmicroringlaserwitharadiusof30μmandaringwidthof3μm.
简介:Thecapabilityofembeddedpiezoelectricwaferactivesensors(PWAS)toperformin-situnondestructiveevaluation(NDE)forstructuralhealthmonitoring(SHM)ofreinforcedconcrete(RC)structuresstrengthenedwithfiberreinforcedpolymer(FRP)compositeoverlaysisexplored.First,thedisbonddetectionmethodweredevelopedoncouponspecimensconsistingofconcreteblockscoveredwithanFRPcompositelayer.Itwasfoundthattheprescnceofadisbondcrackdrasticallychangestheelectromecbanical(E/M)impedancespectrummeasuredatthePWASterminals.ThespectralchangesdependonthedistancebetweenthePWASandthecracktip.Second,largescaleexperimentswereconductedonaRCbeamstrengthenedwithcarbonfiberreinforcedpolymer(CFRP)compositeoverlay.Thebeamwassubjecttoanacccleratcdfatigueloadregimeinathree-pointbendingconfigurationuptoatotalof807,415cycles.Duringthesefatiguetests,theCFRPoverlayexperienceddisbondingbeginningatabout500,000cycles.ThePWASwereabletodetectthedisbondingbeforeitcouldbereliablyseenbyvisualinspection.GoodcorrelationbetweenthePWASreadingsandthepositionandextentofdisbonddamagewasobserved.ThesepreliminaryresultsdemonstratethepotentialofPWAStechnologyforSHMofRCstructuresstrengthenedwithFRPcompositeovcrlays.
简介:摘要目的比较腕关节镜辅助尺骨头Wafer切除术与尺骨短缩截骨术治疗尺骨撞击综合征的疗效。方法回顾性分析2012年3月至2017年2月宁波市第六医院手外科收治的45例尺骨撞击综合征患者资料。男26例,女19例;年龄28~48岁,平均38岁;右侧31例,左侧14例。根据手术方式不同分为2组:22例患者关节镜下行尺骨头Wafer切除(切除术组),23例患者行开放尺骨截骨短缩钢板内固定手术(截骨术组)。术前行X线检查评估尺骨正变异的高度及MRI初步评估三角纤维软骨复合体(TFCC)、月骨和三角骨的损伤情况。术中采用腕关节镜检查关节内情况,清理增生滑膜并修复损伤的TFCC,术后所有患者腕关节内均注入富血小板血浆(PRP),定期随访并拍X线片观察尺骨愈合情况,采用改良Mayo评分评估腕关节功能。结果切除术组与截骨术组术前一般资料比较差异均无统计学意义(P>0.05),具有可比性。切除术组有20例患者获平均13.7个月随访,改良Mayo腕关节评分(80.3±6.2)分,其中优7例,良11例,可2例,优良率为90.0%(18/20);截骨术组有22例患者获平均14.3个月随访,均达到骨性愈合,有3例患者随访半年内仍有轻度疼痛;改良Mayo腕关节评分(85.1±5.9)分,其中优6例,良13例,可3例,优良率为86.4%(19/22)。两组改良Mayo腕关节评分比较差异均有统计学意义(P<0.05)。结论尺骨正变异高度≤3 mm时,采用腕关节镜下尺骨头Wafer切除术较尺骨短缩截骨术治疗尺骨撞击综合征可取得更好的临床效果。