简介:SpectralandstructuralcharacteristicsofdistributedBraggreflector(DBR)invertical-cavitysurface-emittinglaserswerestudiedwithphotoluminescenceanddouble-crystalX-raydiffractionmeasurement.TheexpectedhighqualityepitaxialDBRstructurewasverified.IntheX-raydouble-crystalrockingcurvesofDBRthezeroth-orderpeak,thefirstandsecondordersatellitepeaksweremeasured.Splittingofdiffractionpeakappearedintherockingcurveswasanalyzed.Theeffectsofintroduceddeepenergylevelsonthestructuralperfectionandopticalpropertieswerediscussed.
简介:作为X光检查,计算断层摄影术(CT)广泛地在诊断和放射疗法被用作,减少象一样低的放射剂量是重要的相当可完成。为这个目的,一个人可以使用基于的TV方法或小浪框架基于方法重建从设计的减少的数字的高质量的图象。由使用仅仅照亮region-of-interest(ROI)的内部断层摄影术计划,而且,一个人能节省更多的放射剂量。在这份报纸,柔韧的小浪框架规则化基于模型为全球重建和内部断层摄影术被建议。模型能帮助减少巨大的稀少的设计矩阵的失配引起的错误。一个三系统的分解计划被使用把重建的图象分解成三不同部分:动画片,人工制品和噪音。由丢弃估计的人工制品和噪音部分,因此,重建的图象能与更少的噪音和人工制品被获得。类似于基于的图象恢复建模的另外的框架,模型能被裂口Bregman算法高效地解决。数字模拟证明建议模型以锋利的边,吝啬的结构的类似(SSIM),contrast-to-noise比率,相对错误和关联的保藏超过FBP和SART+TV方法。为真实绵羊肺重建,当FBP和SART+TV方法需要超过200设计时,例如,建议方法能到达用仅仅100设计象0.75一样高的吝啬的结构的类似。另外,建议柔韧的方法为有与FBP和SART+TV方法相比的更好的性能的内部、外面的断层摄影术是适用的。
简介:X光检查diffractometry被利用学习在3月18日在北京城市里在二灰尘暴风雨期间取样的inhalable粒子(PM10)和2008年5月21日的矿物学的特征。第一次,我们证实那稳定地在那里存在在空气的铵氯化物当温度是低的时。全部的硫酸盐粒子被相对湿度影响。硫酸盐的种类和集中首先减少了然后回来在每灰尘暴风雨底成长了。Koninckite,一种磷酸盐矿物质以前从来没作为微粒喷雾器报导,被识别。同时,我们的结果证明灰尘矿物质上的化学修正发生在长期的交通期间。在灰尘暴风雨的时期期间收集的PM10样品被象石英,illite/绿土,illite,绿泥石,长石和方解石那样的外壳的矿物质统治,并且在时间的正常时期比那在集中是尤其是更高的。在每灰尘改变的全部的硫酸盐,方解石和长石的数量下暴雨。它向后从24小时的isentropic被导出在春天2008的二个灰尘事件在不同来源发源的轨道。
简介:Inthefarfieldoftheintensitydistributionofthebeamdeliveredbyatwo-stagetransient–collisionalexcitationX-raylaser(XRL),anon-expectedinterferencepatternthatisstablefromshottoshothasbeendiscovered.Itisdemonstratedthattheinterferenceiscausedbytheemergenceofanimaginarysourceintheamplifyingplasma,whichisphasematchedtotheradiationofthegenerator.TheobservedphenomenoniscalledanX-raycoherentmirage.Toexplaintheobtainedresults,anewtheoreticalapproachisdeveloped.ThebasicessentialconditionsforformationoftheX-raymirageareformulated,andpossibleapplicationsarediscussed.Thispaperdetailstheexperiments,includingtheformulationofthenecessaryandsufficientconditionsforformationoftheX-raymirage,andpossibleapplicationsarediscussed.
简介:ThestatusoftheEuropeanX-rayFree-ElectronLaser(EuropeanXFEL),underconstructionnearHamburg,Germany,isdescribed.ThestartofoperationsoftheLCLSatSLACandofSACLAinJapanhasalreadyproducedimpressivescientificresults.TheEuropeanXFELfacilityispoweredbya17.5GeVsuperconductinglinearacceleratorthat,comparedtothesetwooperatingfacilities,willgeneratetwoordersofmagnitudemorepulsespersecond,upto27000.Itcanthereforesupportmodesofoperationswitchingthebeamupto30timespersecondamongthreedifferentexperiments,providingeachofthemwiththousandsofpulsespersecond.Thescientificpossibilitiesopenedupbythesecapabilitiesarebrieflydescribed,togetherwiththecurrentinstrumentaldevelopments(inoptics,detectors,lasers,etc.)thatarenecessarytoimplementthisprogram.
简介:在计算机化的断层摄影术(CT)的高变细的导致目标的streaking和阴影人工制品有点被连接到X光检查设计数据的不合身的衣服到氡变换的范围空间。这件不合身的衣服主要由于变硬的横梁是为多色的来源不可避免的设计数据的因素。在处理横梁变硬导致streaking和阴影人工制品的主要困难来自它取决于高变细目标的几何学的高度非线性的性质。在这个工作,我们从设计数据的结构调查那些streaking和阴影人工制品的数学特征。我们也建议了金属由合并非线性的变硬横梁的修正者的最近的技术的人工制品减小方法。数字模拟证明没有改变背景图象,建议方法有效地减轻streaking人工制品。
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简介:Photoconductivityspectrameasurementofpolymersatx-rayenergiesaroundtheZnandCoKedges,showsobviousx-rayabsorptionfinestructureoscillations.Thephotoconductivityspectraobtainedforgappedandsandwichedelectrodegeometricsamples,indicatethattheshapeofphotoconductivityspectrumdependsontheelectrodeconfigurationofthesamples.Thethicknessoftheconductionlayercanbeestimatedfromthephotoconductivityspectrum.
简介:Undisturbedsoilcorewithmanymacroporesanddisturbedsoilcorewithonlyonemacropore(diameteris10mm)wereprobedbyx-raycomputedtomography(CT).Thesize,number,shapeandcontinuityofmacroporesinthetransverseandverticalsectionsofsoilwerecharacterizedusingCTscanningimages.TheprobabilitydensitiesofmacroporesinthetransversesectionofsoilcoreexhibitedalogarithmicΓdistribution.ResultsindicatedthatCTscanningwasapromisingnondestructivemethodforcharacterizingmacroporesinsoils.
简介:InordertoexplorethefeasibilityofusingX-raytomeasuremoisturecontentinthedryingprocessandhaveafurtherstudyontheeffectofprecisionofmoisturecontentwhenscanningthroughdifferentgraindirections,X-rayscanningmethodandweightingmethodwereusedtomeasureaveragemoisturecontentofCunninghamialanceolataduringhotairdrying.Theresultsshowthatthemoisturecontentvaluesoftwomethodswereveryclosetooneanother,thedeterminationcoefficientsofbothwerehighlycorrelatedwithavalueover0.99,andtheabsolutedeviationwasbelow2%;whenscanningalongradialdirectionandlongitudinaldirection,theprecisionsofaveragemoisturecontentwerehigherthanthatofthetangentialdirection,butthedeviationcanbenegligibleintheactualmeasurement;inthepracticalapplication,theeffectofgraindirectiononprecisionofmoisturecontentmeasurementcouldnotbetakenintoaccountwhenusingX-raytomeasurethemoisturedistributionofwood.
简介:Energylevels,radiativerates,oscillatorstrengthsandlinestrengthsarereportedfortransitionsamongthelowest97levelsofthe(1s22s22p6)3s23p2,3s23p3d,3s3p3,3p4,3s3p23d,and3s23d2configurationsofRbXXIV.AmulticonfigurationDirac–Fock(MCDF)methodisadoptedforthecalculations.Radiativerates,oscillatorstrengths,andlinestrengthsareprovidedforallelectricdipole(E1),magneticdipole(M1),electricquadrupole(E2),andmagneticquadrupole(M2)transitionsfromthegroundleveltoall97levels,althoughcalculationsareperformedforamuchlargernumberoflevels.Toachievetheaccuracyofthedata,comparisonsareprovidedwithsimilardataobtainedfromtheFlexibleAtomicCode(FAC)andalsowiththeavailabletheoreticalandexperimentalresults.Ourenergylevelsarefoundtobeaccuratetobetterthan1.2%.WavelengthscalculatedarefoundtolieinEUV(extremeultraviolet)andx-rayregions.Additionally,lifetimesforall97levelsareobtainedforthefirsttime.
简介:Wehavedevelopedanewradiographysetupwithashort-pulselaser-drivenx-raysource.Usingaradiographyaxisperpendiculartobothlong-andshort-pulselasersallowedoptimizingtheincidentangleoftheshort-pulselaseronthex-raysourcetarget.Thesetuphasbeentestedwithvariousx-raysourcetargetmaterialsanddifferentlaserwavelengths.Signaltonoiseratiosarepresentedaswellasachievedspatialresolutions.ThehighqualityofourtechniqueisillustratedonaplasmaflowradiographobtainedduringalaboratoryastrophysicsexperimentonPOLARs.
简介:一个高速度的X光检查非破坏性的察觉者在这份报纸被设计。X光检查非破坏性的察觉的原则被分析,并且高速度的X光检查非破坏性的察觉者的一个一般系统计划被建议。Virtex-4系列Fx12FPGA芯片被用来设计它的硬件电路,PowerPC405嵌入系统被开发,处理算法的高速度的图象被使用编译它的处理软件,并且TCP/IP协议被采用编译通讯软件,认识到高速度的X光检查信号聚会,处理并且传播。试验性的结果显示察觉者能在关联词工业地里与钢电线绳被用于生产线的长途、联机的非破坏性的察觉,例如矿,港口和码头。当察觉者的调查宽度是1.6m时,conveyer带的跑的率能完成6m/s。