简介:InallthearticlesinActaMechanicaSolidaSinica,Volume31,Issues1-4thecopyrightisincorrectlydisplayedas"TheChineseSocietyofTheoreticalandAppliedMechanicsandTechnology"whereitshouldbe"TheChineseSocietyofTheoreticalandAppliedMechanics".
简介:Wehavedesignedandrealizedanathermal4-channelwavelength(de-)multiplexerinsiliconnitride(SIN).Minimizedthermalsensitivityisachievedinawidewavelengthrangebyusingwideandnarrowwaveguideswithlowanddifferentthermal-opticcoefficientsinthetwoarmsofMach-Zehnderinterferometers(MZIs).TheSiNcorelayerandSiO2claddinglayersaredepositedbyalow-temperatureplasma-enhancedchemicalvapordep-ositionprocess.ThefabricatedMZIfilterexhibitsathermalsensitivitywithin4-2.0pm/℃inawavelengthrangeof55nmtonear1300nm.Then,anathermal(de-)multiplexerbasedoncascadedMZIshasbeendemonstratedwithacrosstalk〈-22dBandathermalsensitivity〈4.8pm/℃forallfourchannels,reducedby77%comparedtoaconventionalSiN(de-)multiplexer.OwingtothepassiveoperationandcompatibilitywiththeCMOSback-endprocess,ourdeviceshavepotentialapplicationsin3Dintegrationofphotonicsandelectronics.
简介:Inthiswork,SMAT(surfacemechanicalattritiontreatment)wasperformedonTi6Al4V.PlasmanitridingoftheSMATedsampleswasinvestigatedincomparisonwithcoarse-grainedsamples.Thesampleswerecharacterizedusingopticmicroscope,SEM,TEMandVickersmicrohardnesstester.TheresultsshowedthatasignificantlythickercompoundlayerwithhigherhardnesswasobtainedfortheSMATedsampleswhencomparedwithun-SMATedsamplesafternitriding.CorrosionresistanceofTi6Al4VinaRinger’ssolutionwasstudiedbyelectrochemicaltechniquesincludingopencircuitpotentialmeasurement,potentiodynamicpolarizationandEIS(electrochemicalimpedancespectroscopy).Overall,ourresultsidentifiedthebeneficialimpactsoftheduplexSMAT/nitridingtreatmentoncorrosionbehaviourofTi6Al4V.Weartestswerealsoperformedonaball-on-disctribometerwherethetreatedsampleswererubbedagainsta6mmdiameteraluminaballunderanormalloadof5NusingRinger’ssolutionaslubricantmedia.ThefrictioncoefficientoftheSMATedandnitridedsampleswasreducedcomparedtotheuntreatedsamples.WearratesdemonstratedthatSMATcombinedwithnitridingimprovedwearresistanceofTi6Al4Valloy.
简介:ThenovelverticallystandingPtSe2filmontransparentquartzwaspreparedbyselenizationofplatinumfilmdepositedbythemagnetronsputteringmethod,andanNd:LuVO4passivelymode-lockedsolid-statelaserwasrealizedbyusingthefabricatedPtSe2filmasasaturableabsorber.TheX-raydiffractionpatternandRamanspectrumofthefilmindicateitsgoodcrystallinitywithalayeredstructure.ThethicknessofPtSe2filmismeasuredtobe24nmaccordingtothecross-sectionheightprofileoftheatomicforcemicroscopeimage.High-resolutiontransmissionelectronmicroscopyimagesclearlydemonstrateitsverticallystandingstructurewithaninterlayerdistanceof0.54nmalongthec-axisdirection.Themodulationdepth(AT)andsaturationfluence(Фs)ofPtSe2filmaremeasuredtobe12.6%and17.1μJ/cm2,respectively.Theobtainedmode-lockedlaserspectrumhasacentralwavelengthof1066.573nm,witha3dBbandwidthof0.106nm.Thetransformlimitedpulsewidthofthemode-lockedlaserwascalculatedtobe15.8ps.Amaximumaverageoutputpowerof180mWwithaworkingrepetitionrateof61.3MHzisobtained.Tothebestofourknowledge,thisisthefirstreportofthegenerationofultrafastmode-lockedlaserpulsesbyusinglayeredPtSe2asasaturableabsorber.
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简介:为了实现GPS信号缺失下的移动机器人自主导航,解决传统粒子滤波中的粒子退化以及粒子贫乏引起的移动机器人定位和导航精度下降问题,提出了基于小生境理论的启发式蝙蝠优化粒子滤波的同时定位与地图构建算法。首先,在启发式蝙蝠优化算法的速度和位置更新过程中,引入惯性权重,加快了算法寻优精度,提高了收敛速度;然后,利用小生境理论进一步优化启发式蝙蝠算法,利用排挤机制和惩罚函数,有效地保证了种群的多样性,提高了算法的全局寻优能力;最后,将基于小生境理论的启发式蝙蝠优化算法用于传统粒子滤波采样中,使得粒子能够智能、快速地向高似然区域运动,同时提高了传统粒子滤波算法的全局寻优能力和寻优精度。实验结果表明:该算法显著提高了移动机器人导航和定位的精度和实时性。