简介:Ahigh-repetitionratemasteroscillatorpoweramplifierpumpedwithlaserdiodes(LDs)isreported.Aninjectionseedingsingle-frequencyelectro-opticalQ-switchedNd:YAGlaserisusedasanoscillator,andaconductivelycooledNd:YAGzigzagslabwithabounce-pumpedarchitectureisutilizedasapoweramplifier.Pulseenergiesofover800mJat1064nmand400mJat532nm,correspondingtoaveragepowersof200and100W,respectively,areachievedwitha12.6-nspulsewidthat250Hz.Outputfrequencyfluctuationsandsingle-frequencyoperationarefurthermonitored.Experimentalresultsrevealthattheproposedsystem,whichfeaturesasingle-passamplifiedconfiguration,isapromisingdesignforspace-basedapplications.
简介:Themasterdesignof300kt/avinylacetateunitattheSichuanVinylonPlanthaspassedreview,andconstructionofthisunitwillbekickedoffsoon.ThisprojectisakeyassociatedprojectenvisagedbytheprojectfortransmissionofSichuangastoEasternChina,anditsfeasibilitystudyreporthasbeenapprovedfollowingtheenvironmentassessmentconductedbytheStateBureau
简介:摘要:换热器芯体的检测[1]主要是检查其流通板与翅片叠放正确与否。将机器视觉识别技术应用于换热器芯体叠片的检测,基于vision master研发的换热器芯体的自动化检测的机器视觉识别方案能够高效的完成检测判断,由机器自主完成,适用于大规模工业生产,使换热器芯体的检测完全实现了自动化,极大地提高了检测效率和准确率。
简介:TheFe-Ti-Nmateralloywaspreparedthroughthein-situreactionofnitrogengaswiththeFe-Timelt.ScanningelectronmicroscoperesultsshowthattheparticlesuniformlydistributedintheironmatrixwereTiN.ThedeliberatelypreparedFe-Ti-Nmasteralloywasemployedforthe409Lferriticstainlesssteelinanattempttorefinetheas-castsolidificationstructure.ItwasfoundthattheeffectivenessofFe-Ti-Nmasteralloyonrefiningoftheas-cast409Lferriticstainlesssteelwasaffectedbyadditionlevel,holdingtimeandmeltstemperature.Itwasfoundthattheaverageequiaxedgrainsizedecreasedfrom1503μmto303μm,theproportionofequiaxedgrainzoneincreasedfrom14%to100%withincreasingtheFe-Ti-Nmasteralloyadditionlevelto2.5%.Theproportionofequiaxedgraindecreasedfrom85%to4%asthesolidificationtemperatureincreasedfrom1803Kto1883K.Whentheholdingtimereachedto8min,thesolidificationstructuresof409Lferriticstainlesssteelshowextremepointsintheproportionofequiaxedgrain.Itisclearthatthegrainrefiningefficiencygraduallyfadeawaywiththeincreasingoftheholdingtimeattheverybeginning.However,whentheholdingtimecontinuestoincreaseandexceedstheextremepoint,thegrainrefiningefficiencyoftheFe-Ti-Nmasteralloyrecoveredtoacertaindegree.Theexperimentalresultsmentionedabovehavebeenanalyzedintermsofthermodynamics.Underappropriateconditions,theFe-Ti-Nmasteralloyusedforgrainrefinementofthesolidificationstructureof409Lferriticstainlesssteelmayhavegoodprospectsforindustrialapplications.
简介:Theterm'physicalliteracy'isgainingtractioninmanycountriesandinstitutionsasagoalforphysicaleducation.Thispaperexplorestheconceptofphysicalliteracyandhighlightsthefoundationalworkinthisarea,particularlythatofMargaretWhitehead.Therelationshipofphysicalliteracytophysicaleducationisalsodiscussedwithpotentialramificationsforteachersandlearnerswhoadoptphysicalliteracyasthegoalofthesubjectarea.
简介:Wereportonthehigh-poweramplificationofa1064nmlinearlypolarizedlaserinanall-fiberpolarizationmaintainedmasteroscillatorpoweramplifier,whichcanoperateatanoutputpowerlevelof1.3kW.Thebeamquality(M~2)wasmeasuredtobe<1.2atfullpoweroperation.Thepolarizationextinctionrateofthefiberamplifierwasmeasuredtobeabove94%beforemodeinstabilities(MIs)setin,whichreducedtoabout90%aftertheonsetofMI.ThepowerscalingcapabilityofstrategiesforsuppressingMIisanalyzedbasedonasemianalyticalmodel,thetheoreticalresultsofwhichagreewiththeexperimentalresults.ItshowsthatmitigatingMIbycoilingthegainfiberisaneffectiveandpracticalmethodinstandarddouble-claddinglargemodeareafiber,and,bytightcoilingofthegainfibertotheradiusof5.5cm,theMIthresholdcanbeincreasedtothreetimeshigherthanthatwithoutcoilingorloosecoiling.Experimentalstudieshavebeencarriedouttoverifytheidea,whichhasprovedthatMIwassuppressedsuccessfullyintheamplifierbypropercoiling.
简介:AdditionofAl-5Ti-1Balloytomoltenaluminumalloyscanrefineα-Algrainseffectivelyandtherebyimprovetheirstrengthandtoughness.TiAl3andTiB2inAl-5Ti-1Balloyarethemainsecondary-phaseparticlesforrefinement,whiletheunderstandingontheeffectoftheirsizesonα-Algrainrefinementcontinuestobefragmented.Therefore,Al-5Ti-1Balloyswithvarioussizesandmorphologiesofthesecondary-phaseparticleswerepreparedbyequalchannelangularpressing(ECAP).Evolutionofthesecondary-phaseparticlesduringECAPprocessandtheirimpactonα-AlgrainrefinementwerestudiedbyX-raydiffractionandscanningelectronmicroscope(SEM).ResultsshowthatduringtheECAPprocess,micro-cracksfirstlyappearedinsideTiAl3particlesandthengraduallyexpanded,whichresultedincontinuousrefinementofTiAl3particles.Inaddition,micro-distributionuniformityofTiB2particleswasimprovedduetotheimpingementofTiAl3particlestoTiB2clustersduringdeformation.ExcessivelylargesizesofTiAl3particleswouldreducethenumberofeffectiveheterogeneousnucleusandthusresultedinpoorgrainrefinementeffectiveness.Moreover,excessivelysmallTiAl3particleswouldreduceinhibitoryfactorsforgraingrowthQandweakengrainrefinementeffectiveness.Therefore,anoptimalsizerangeof18-22μmforTiAl3particleswassuggested.
简介:【摘要】目的:探讨白内障患者术前的人工晶体度数测量方法,观察 IOL Master与 A超在其中的应用效果。方法:选取 2017年 4月 ~2018年 10月期间于我院接受手术治疗的 130例白内障患者作为研究对象,分为观察组( IOL Master)和对照组( A超)各 65例,观察两组患者在检测结果上的差异性。结果:与对照组相比,观察组患者在散光≤ 1.00D时的平均屈光误差 [( 0.39±0.13) D<( 0.51±0.27) D]、散光≤ 2.00D时的平均屈光误差 [( 0.37±0.15) D<( 0.93±0.33) D]以及散光≤ 3.00D时的平均屈光误差 [( 0.61±0.19) D<( 1.87±0.51) D]相对更低( P< 0.05)。结论:在白内障患者接受手术治疗前,应用 IOL Master进行人工晶体度数的测量,能够获得准确的测量结果,进而为手术治疗安全、顺利的进行提供保障,其应用效果明显优于 A超。
简介:[摘要] 目的:分析IOL Master700应用于白内障患者人工晶体屈光度测量的准确性。方法:2021年1月~2023年1月,选取本院诊治的105例白内障患者作为对象。围术期检查,分别使用眼科超声仪、角膜曲率计和IOL Master700系统,对比各项测量结果。结果:1)IOL法和常规法对术前眼部AL、ACD、Km、W-W参数的测定结果接近,无统计学差异(P>0.05)。2)不同轴长的患者中,IOL法和常规法对术前眼轴长度的测定结果接近,无统计学差异(P>0.05)。3)轴长L>26 mm的患者中,IOL法测量得到的术后绝对屈光误差值明显小于常规法,有统计学差异(P<0.05)。结论:白内障患者人工晶体屈光度测量时,使用IOL Master700具有较高的准确性,值得推广。