简介：ThecharacteristicsofsuspendedsedimentimagecanbereflectedbythecoefficientsofbiorthogonalwavelettransformofCDF(2,2).Basedonthepowerdistributionindifferentscales,anadaptivealgorithmisproposedinthispaper,wherebythecoefficientsareadjustednon-linearly.Theparticleinformationcanbewellretainedwhiletheuselessbackgroundisremoved.Inthisway,satisfactorybinaryimagecanbeobtainedforfurtheranalysisofthesedimentparticle.

简介：提出了一种在带有反转平台的精密离心机上标定陀螺加速度计二次项系数丘的方法。阐述了其测试原理，指出这种带反转平台的测试原理改善了PIGA离心机测试的环境条件。所提出的测试方案和辨识方法解决了陀螺加速度计在精密离心机上进行高占测试时，受到离心机大臂旋转牵连运动影响的关键问题，并提出分离和精确标定陀螺加速度计二次非线性项系数届的数据处理方法，解决了反转平台引入后造成的正弦输入问题。

简介：针对平台式惯导系统海上动态启动时传统的罗经对准方法和传递对准方法的缺点,提出了一种双平台双位置海上启动方法。粗对准阶段以牵引惯导提供的姿态角作为水平和航向基准通过伺服回路完成粗水平调平和粗方位对准。精对准阶段建立了双位置下的卡尔曼滤波方程,实现了东向陀螺漂移的估计补偿,解决了海上启动时对舰船匀速直航的限定条件。仿真结果表明,相比传统的海上启动法,在0.01（°）/h的东向陀螺漂移的情况下方位失准角的估计误差由2′减小到0.5′左右。

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简介：TiO2@ZrO2@Y2O3:有coremultishell结构的Eu3+合成粒子通过layer-by-layer(LBL)的联合被综合自己组装方法和一个solgel过程。获得的样品与扫描电子被描绘显微镜学(SEM)，传播电子显微镜学(TEM)，X光检查光电子光谱学(XPS)，X光检查衍射(XRD)，和荧光spectrophotometry。结果证明合成粒子有coremultishell结构，球形的形态学，和狭窄的尺寸分布。TiO2核心上的ZrO2层的存在能有效地阻止在TiO2核心和Y2O3壳之间的反应；为在在TiO2@ZrO2@Y2O3的TiO2核心和Y2O3壳之间的反应的温度:Eucoremultishell黄磷能被300提高

简介：TheinfluenceofNa2SO4ontheformationofZnOwhiskerswasinvestigatedinthispaper.ZnOwhiskerswithaspectratiosofupto50weresynthesizedbydissolvingε-Zn（OH）2precursorinNaOH/Na2SO4solutionatroomtemperature,followedbyagingoftheresultingsolutionat140℃for6h.Fouriertransforminfraredspectroscopy,Ramanspectroscopy,andX-rayphotoelectronspectroscopyanalysesrevealedthatSO42-ionswereprimarilyadsorbedonthe（100）planeoftheZnOwhiskersviaanouter-spherecomplexconfiguration（O-H…O）,therebypromotingtheone-dimensionalgrowthofZnOwhiskersalongthec-axis.

简介：TiO2nanoparticlesweresynthesizedbyahomogeneouscontrolledprecipitationmethodusingindustrialtitaniumsulfate(Ti(SO4)2).TheobtainedpowderswerecharacterizedbyX-raydiffraction(XRD),transmissionelectronmicroscope(TEM),Fouriertransforminfraredspectroscopy(FTIR)andICPplasmaspectrometer.EDTAwasusedascomplexingagenttoimprovethepurityandtheformationofTiO2nanoparticles.Experimentalresultsindicatedthatthehigh-purityTiO2nanoparticleswere20nminmeansizeandnearlymonodispersed.

简介：PureAl2O3-2SiO2powderswerepreparedbysol-gelandcoprecipitationmethods,andtheiralkaliactivationreactivitieswerecompared.Thealkali-activationreactivityofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbythecoprecipitationmethod.Thepowderswereinvestigatedby27AIand29Simagic-anglespinningnuclearmagneticresonancespectroscopy（MASNMR）tounderstandtherelationshipbetweentheirstructureandalkali-activationreactivity.The27AlMASNMRdatashowedthatthefive-coordinateAIcontentofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbycoprecipitation.Thehighercontentoffive-coordinateAlcorrespondedtohigheralkali-activationreactivity.The29SiMASNMRdatashowedthatforthepowderpreparedbythesol-gelmethod,siliconwasreplacedbyaluminumatsecondarycoordinationsitesofthecentralSiatomsduringcalcination.However,forthepowderpreparedbysingle-batchcoprecipitation,themainchangewasfromalowdegreeofpolycondensationtoahighdegreeofpolycondensation.

简介：HomogeneousNi2+-dopedtitaniagelwassynthesizedbyasol-gelprocess,andthexerogelwasthenobtainedthroughaginganddrying,leadingtotheformationofNi/TiO2nanocompositeafterheattreatmentunderasuitablereducingatmosphere.TheresultingnanocompositewascharacterizedbyTGA-DSC,TEM,XRDandBETmethods.Theresultsshowthatthestructureandgrainsizeofthenanocompositescouldbemanipulatedbyalteringtheheat-treatmentconditions,andthatthenanocompositepossessesamesoporousstructurewithaporeradiusofca.28nmandaspecifictheanatase-rutilephasetransformation.

简介：DrivenbycuriosityaboutpossibleflightoptionsfortheChang’e-2spacecraftafteritremainsattheSun-EarthL2point,effectiveapproachesweredevelopedfordesigningpreliminaryfuel-optimalnear-Earthasteroidflybytrajectories.Theapproachesincludetheuseofmodifiedunstablemanifolds,gridsearchofthemanifolds’parameters,andatwo-impulsemaneuverfororbitalphasematchingandz-axisbiaschange,andaredemonstratedtobeeffectiveinasteroidtargetscreeningandtrajectoryoptimization.Asteroidflybysareexpectedtobewithinadistanceof2×107kmfromtheEarthowingtotheconstrainedEarth-spacecraftcommunicationrange.Inthiscase,thespacecraft’sorbitalmotionissignificantlyaffectedbythegravitiesofboththeSunandtheEarth,andtherefore,theconceptofthe"heliocentricoscillating-Keplerorbit"isproposed,becausetheclassicalorbitalelementsoftheflybytrajectoriesreferencedintheheliocentricinertialframeoscillatesignificantlywithrespecttotime.Theanalysisandresultspresentedinthisstudyshowthat,amongtheasteroidswhoseorbitsarethemostaccuratelypredicted,"Toutatis","2005NZ6",or"2010CL19"mightbeencounteredbyChang’e-2inlate2012or2013withtotalimpulseslessthan100m/s.

简介：Lithium-aluminum-cobalt-nickeloxideLiAlxCoyNi1xyO2particles,generallyusedascathodeoflithiumbattery,werepreparedbychemicalcoprecipitationfromanaqueoussolutionofLiOH,Al(NO3)3,Co(NO3)2andNi(NO3)2withNH4OH.XRD,SEMandFTIRwereusedtoexaminetheeffectofnickelcontentontheproduct.FTIRpatternsshowedthatincreaseinnickelcontentdecreasedtheabsorptionstrengthofthepeakofspinelstructureoftheproduct,attributedtotheoccupationbynickelinthealuminumsites.Particlesizeandelectricalpropertiesofthelithium-aluminum-cobalt-nickeloxide(abbreviatedasLACNO)particleswerealsodetermined.

简介：The(2+1)-dimensionalBKPequationintheHirotabilinearformisstudiedduringthiswork.WronskianandGrammiantechniquesareappliedtotheconstructionofWronskianandGrammiansolutionsofthisequation,respectively.ItisshownthatthesesolutionscanbeexpressedasnotonlyPfaffiansbutalsoWronskiansandGrammians.

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简介：针对无人运载器的快速定向需求,提出北斗双天线基线连续旋转整周和0°-180°两位置的两种快速定向方法。把一对北斗天线安装在一个旋转机构上,使双天线基线绕旋转机构中心轴转动,改变北斗双天线基线方向,运用卫星载波相位双差模型,计算出载波相位双差的整周模糊度,进而获得双天线基线航向角,通过旋转机构角度输出值,得到载体的真实航向。采用自行研制的旋转试验装置,验证了北斗短基线双天线两种旋转定向方法。对于0.3m北斗短基线双天线,载体定向精度优于1°。当北斗双天线接收机能够接收到4颗卫星时,上述两种方法都能够确定真实航向。与商业OEM定向板卡相比,所提出的定向方法定向速度快,定向精度高。

简介：在双轴旋转式SINS中,惯性元件常值漂移误差对系统的影响可以得到调制,但安装误差和标度因数误差对系统的影响无法得到调制,同时这些误差会与旋转角速率耦合,引起速度锯齿波等误差从而降低了系统的各项性能指标。为了减少这种影响,分析了光学陀螺双轴旋转式SINS误差传播特性,利用奇异值分解法对系统的可观测程度进行了分析,经分析,与转动轴相关的安装误差和标度因数误差的可观测度较好,据此设计了系统的自主标定方案及滤波算法,进行了数字仿真和半实物仿真验证试验。试验结果表明,利用设计的自主标定方案,在1h内能估计出转轴上两个陀螺的标度因数误差及与转轴相关的四个安装误差,估计精度能达到95%以上。导航试验验证表明,利用自主标定的参数,相对于传统标定方法,使系统定位精度提高了20%。

简介：Thecoordinationpolymer,(Nd(H2O)5)2(2,6-AQDS)3·2H2Owhere2,6-AQDS=2,6-anthraquinonedisulfonate,hasbeensynthesisedviaahydrothermalroute.Structurally,itconsistsoflayersofmonomericNdpolyhedrawhicharelinkedby2,6-AQDSanionsformingapolymeric,three-dimensionalnetwork.EachNdatomisninecoordinate,bondingtofivewatermoleculesandtofouroxygenatomsfromfour2,6-AQDSanionswhichinturnpillarthelayersbybridgingtwoNdatomsinonelayer,andcoordinatingtoasingleNdintheother.

简介：NanocrystallineSnO2wassynthesizedbydirectmixingandgrindingofSnCI4-5H2OandNaOHatroomtemperature,followedbycalcinationatdifferenttemperaturesfordifferenttimesinair.ProductsampleswerecharacterizedbyX-raydiffractionandtransmissionelectronmicroscope,revealingthattheamorphousprecursorSnO2wastransformedtocrystalsat200℃for3h,andthattheaverageparticlesizeincreaseduponraisingthecalciningtemperatureorprolongingthecalciningtime.Themechanismofthephasetransformationoftheproductsisdiscussed.

简介：连贯的多角形的粒子的二维的分离元素模型(DEM)模拟被开发了估计点来源颤动的利益在楔形的hoppers导致流动。使用的particleparticle相互作用模型基于一个多接触原则。没有颤动，学习的第一部分在严肃下面调查了粒子分泌物决定批评的孔尺寸(Bc)就作为粒子形状的功能支撑流动。多角形形状的粒子比圆形的粒子需要一个更大的孔，这被显示出。当粒子顶点的数字增加，Bc减少，这也被显示出当粒子顶点的数字增加。圆形的粒子的增加以一种线性方式支持多角形的流动。学习的第二部分证明那颤动能提高流动，有效地减少Bc。模型表明了震荡器地点(高度)的重要性，与在提高的以前的连续统模型结果，和颤动振幅一致流动。

简介：Uniformlysizedα-Fe2O3hexagonalplateletsweresynthesizedbyahydrothermalprocessusingFe(OH)3suspensionandlargeamountofNaOH.ThereactionproductswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),selectedareaelectrondiffraction(SAED),andavibratingsamplemagnetometer(VSM).Theresultsshowthatthehexagonalplateletsarefine,monodisperseandconsistingofsingle-crystals.Themagnetichysteresis(M-H)curveofthesamplesmeasuredatroomtemperatureindicatesthattheα-Fe2O3micro-plateletsexhibitferromagneticbehaviorswithrelativelylowcoercivity.

简介：Commerciallyavailablelatticescontainvariouskindsofmorphologicalimperfectionswhichresultingreatdegradationinlattices’mechanicalproperties,therefore,toobtainimperfectioninsensitivelatticestructureisobviouslyapracticalresearchsubject.Hierarchicalstructurematerialswerefoundtobeaclassofpromisinganti-defectmaterials.Thispaperbuildshierarchicallatticebyaddingsoftadhesiontolattice’scelledgesandnumericalresultsshowthatitsimperfectionsensitivitytomissingbarsisminorcomparedwiththeclassiclattice.Softadhesionwithappropriatepropertiesreinforcecelledge’sbendingstiffnessandthusreducethebendingdeformationinlatticecausedbymissingbarsdefect,whichisconfirmedbystatisticalanalysisofnormalizednodedisplacementsofimperfectlatticesunderhydrostaticcompressionandshearloads.