简介：摘要进入21世纪以来，智能化已成为时下最热门的课题。智能小车在日常生活、交通、军事等领域中发挥了独有作用，不仅断提高了人们的生活品质，而且还能够提升人们的服务效率、工作效率，成为了智能化研究的热门课题。利用超声波传感器和SG90舵机组成超声波云台，以stm32单片机作为控制核心，对智能小车控制进行详细研究。

简介：摘要本设计用stm32单片机搭以其它硬件组成数字电子秒表，采用主程序设计，通过数码管显示计时结果。对硬件电路和软件进行设计，并进行仿真测试，结果表明，计时准确，结构简单，稳定性强。

简介：设计一种基于STC89C51单片机的无线收发系统,本设计采用频率合成技术、FM调制技术及超外差解调技术,单片机对锁相环本振频率(发射43MHZ、接收53.7MHZ)锁定并通过液晶显示,本振频率在一定的范围内可调。将音频信号、咪头信号和数字英文字母信号作为调制信号,最后实现了音频、数字、英文字母等信号的重现。

简介：TheRFsystemforTESLArequiresacomprehensiveinterlocksystem.Usuallyinterlocksystemsareorganizedinahierarchicalway,Inordertoreacttodifferentfaultconditionsinafastandflexiblemanneranonhierarchicalorganizationseemstobethebettersolution,AttheTESLATestFacility(TTF)atDESYwewillinstallanonhierarchicalinterlocksystemthatisbasedonuserdesgnedreprogrammablegate-arrays(FPGA's)whichincorporateanembeddedmicrocontrollersystem.ThissystemcouldbeusedlaterfortheTESLAlinearcolliderreplacingastrictlyhierarchicaldesign.

简介：IMPCSRRFGroupcooperatingwithBINPhasfulfilledthefollowingprojects.PCIbasedRFsignalgenerator;PLDcenteredRFstationinterlockandsurveillanceunit;Highfrequencyanalogsignalprocessingunits;CVIandWindowsplatformbasedmonitorandoperationinterface.

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简介：Siliconnitridenanoparticlesweresynthesizedbyradio-frequency(RF)plasmachemicalvapordeposition(PCVD)usingsilicontetrachlorideandammoniaasprecursors,andargonascarriergas.Byassumingchemicalthermodynamicequilibriuminthesystem,acomputerprogrambasedonchemicalthermodynamicswasusedtocalculatethecompositionsofthesystematdifferentinitialconcentrationsandfinaltemperatures.Atfirst,fiveelementsandthirty-fourspecieswereconsidered.Theeffectsoftemperatures,andconcentrationsofammonia,hydrogenandnitrogenontheequilibriumcompositionswereanalyzed.Itwasfoundthattheoptimalreactiontemperaturerangeshouldbe1200to1500KtoobtainthehighestconversionandyieldofSi3N4.Theinletpositionofammoniashouldbelowerthanthatofsilicontetrachloride,andbothshouldbelocatedatthetailoftheplasmatorch.Thebestmoleratioofammoniatosilicontetrachloridewasfoundtobeabout6.Later,theinfluencesofwater(andoxygen)wereconsidered,and17additionalspecieswereincludedinthecomputations.ItwasfoundthatoxygenorwatercontentintherawmaterialsshouldbeaslowaspossibleinordertohavehighnitridecontentintheproducedSi3N4.Nitrogenorhydrogenmightbeusedtoreplacesomeorevenalltheargontoimprovetheyieldofsiliconnitrideandreducethecost.Theratioofammoniatosilicontetrachlorideshouldbehighenoughtoobtainhighconversion,butnotexcessivelyhightoreducetheoxygencontentduetotheexistenceofwaterinammonia.Thesimulatedresultswereverifiedbyexperiments.

简介：RFpoweramplifiers(PAs)areusuallyconsideredasmemorylessdevicesinmostexistingpredistortiontechniques.Nevertheless,inwidebandcommunicationsystems,PAmemoryeffectscannolongerbeignoredandmemorylesspredistortioncannotlinearizePAseffectively.AfteranalyzingPAmemoryeffects,anovelpredistortionmethodbasedonwaveletnetworks(WNs)isproposedtolinearizewidebandRFpoweramplifiers.Acomplexwaveletnetworkwithtappeddelaylinesisappliedtoconstructthepredistorterandthenacomplexbackpropagationalgorithmisdevelopedtotrainthepredistorterparameters.Thesimulationresultsshowthatcomparedwiththepreviouslypublishedfeed-forwardneuralnetworkpredistortionmethod,theproposedmethodprovidesfasterconvergencerateandbetterperformanceinreducingout-of-bandspectralregrowth.

简介：Theadsorptionandelectronicpropertiesofisolatedcobaltphthalocyanine(CoPc)moleculeonanultrathinlayerofNaClhavebeeninvestigated.High-resolutionSTMimagesgiveadetailedpictureofthelowestunoccupiedmolecularorbital(LUMO)ofanisolatedCoPc.ItisshownthattheNaClultrathinlayerefficientlydecouplestheinteractionofthemoleculesfromtheunderneathmetalsubstrate,whichmakesitanidealsubstrateforstudyingthepropertiesofsinglemolecules.Moreover,strongdependenceoftheappearanceofthemoleculesonthesamplebiasintheregionofrelativelyhighbias(>3.1V)isascribedtotheimagepotentialstates(IPSs)ofNaCl/Cu(100),whichmayprovideuswithapossiblemethodtofabricatequantumstoragedevices.

简介：PitformationandsurfacemorphologicalevolutioninSi(001)homoepitaxyareinvestigatedbyusingscanningtunnelingmicroscopy.Anti-phaseboundaryisfoundtogiverisetoinitialgenerationofpitsboundbybunchedDBsteps.Theterracesbreakupandarereducedtoacriticalnucleussizewithpitformation.Duetoanisotropickinetics,adownhillbiasdiffusioncurrent,whichislargeralongthedimerrowsthroughthecentreareaoftheterracethanthroughtheareaclosetotheedge,leadstotheprevalenceofpitsboundby{101}facets.Subsequentannealingresultsinashapetransitionfrom{101}-facetedpitstomulti-facetedpits.

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简介：DGS（DefectedGroundStructure)结构是在金属地平面上蚀刻周期性或非周期性的各种栅格形状而形成的非理想地平面结构，它是光子带间隙结构(PBG)的一种发展形式，其效应可用LC谐振等效电路来表示。DGS结构可被广泛应用于谐振器、振荡器、滤波器、耦合器、分配／合成网络、天线、功率放大器等中，以实现常规技术无法得到的高性能。这种结构的等效电路是并联的电感和电容。

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简介：一个广泛地集成的40G-ROF和10-Gb/sWDM-PON多服务存取系统被建议并且试验性地示威了。这个计划由同时播送无线的独立2.5-Gb/s和10-Gb/s电线信号的40G-ROF和10-Gb/sWDM-PON的一个综合系统组成。在基础车站，它采用调整在DPSK下游的信号上策划在上游的OOK信号，它被remodulating完成，到减少基础车站的费用。传播实验在25-km-long单身者模式纤维(SMF-28)上被执行。下游的PON和ROF的敏感表明的结果表演是[?]14.5dBm并且[?]21.5dBm，分别地并且在上游的信号的敏感是[?]25.3dBm。[从作者抽象]

简介：ForquadraticnumberfieldsF=Q(√2pl…pt-1)withprimespj≡1mod8,theauthorsstudytheclassnumberandthenormofthefundamentalunitofF.TheresultsgeneralizenicelywhathasbeenfamiliarforthefieldsQ(√2p)withaprimep≡1mod8,includingdensitystatements.Andtheresultsarestatedintermsofthequadraticformx2+32y2andillustratedintermsofgraphs.

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简介：Continuoussiliconcarbidefiberreinforcedsiliconcarbide(SiCf/SiC)compositeshavebeenconsideredtobecandidatematerialsofhightemperaturestructuralapplicationinaerospace,energyconservationandpowergenerationduetotheexcellenthightemperaturemechanicalproperties,goodfractureresistance,corrosionresistanceandthermodynamicstability.Furthermore,duetothehighthermalstability,lowinducedradioactivity,quickdecayofactivityandlowafterheat,SiCf/SiCcompositeshavebeenrecognizedasthepromisingmaterialsoffissionandfuturefusionreactors.SiCf/SiCcompositesarecomposedofSiCfiberandSiCmarixmaterials.Radiationresistance,oxidationtolerance,fracturetoughnessandtensilestrengthofSiCfiberhaveadirectimpactontheSiCf/SiCcompositesperformance.

简介：摘要随着科学技术的发展，我国的频谱仪检测技术有了很大进展，本文设计了一种基于软件无线电的频谱检测平台，生成的数据格式完全自主可控，并且可以进一步地分析处理数据，为我国精细化、实时化、动态化的监测和频谱管控提供了平台和数据支撑，最后提出了该平台未来的研究方向。