简介:目的:探索1T-MoS2(多型结构的二硫化钼)的除汞机制。方法:1.采用密度泛函理论(DFT)分析Hg~0在1T-MoS_2单层上的吸附机理。2.考察1T-MoS_2的不同吸附位置。3.对不同的吸附构型,研究电子吸附前后的变化,从而进一步了解吸附过程。结论:1.化学吸附是Hg原子与1T-MoS_2单层吸附的主导因素。同时,在所有可能的吸附位置中,T_(Mo)(在钼原子上方)的位置是最强烈的吸附构型。2.汞(Hg)原子在1T-MoS_2单层上的吸附受邻近的硫(S)和钼(Mo)原子的影响。3.吸附的汞(Hg)原子在1T-MoS_2的Tmo位置上会被氧化,其吸附能为-1.091eV。4.从局部态密度(PDOS)分析来看,Hg原子和1T-MoS_2表面之间的相互作用是由汞(Hg)原子的d轨道与硫(S)原子的s轨道及钼(Mo)原子的p轨道和d轨道重叠所致。
简介:Thesingle-shotspiralmagneticresonanceimaging(MRI)techniquewasimplementedandoptimizedonaBrukerBiospec47/30scanner.Thetechniqueincludesthepulsesequenceforgenerationanddetectionofthek-spaceMRIsignal(freeinductiondecay(FID)),andPC-basedprogramsforthedatagridandimagereconstruction.Thetemporalresolutionis70ms(14imagespersecond),whichconsistsofadataacquisitiontimeasshortas13.7ms,aspin-echotimeof13.6msandamagnetizationrecoverytimeof43ms.Thismakesitpossibletotakereal-timeimagesofmovingobjects.Thetechniqueisdemonstratedusingapendulum(tube)filledwithwater.
简介:Ultrafastfiberlasersareingreatdemandforvariousapplications,suchasopticalcommunication,spectroscopy,biomedicaldiagnosis,andindustrialfabrication.Here,wereportthehighlystablefemtosecondpulsegenerationfromaMXenemode-lockedfiberlaser.Wehavepreparedthehigh-qualityTi3C2Txnanosheetsviatheetchingmethod,andcharacterizedtheirultrafastdynamicsandbroadbandnonlinearopticalresponses.Theobviousintensity-andwavelength-dependentnonlinearresponseshavebeenobservedandinvestigated.Inaddition,ahighlystablefemtosecondfiberlaserwithsignal-to-noiseratioupto70.7dBandcentralwavelengthof1567.3nmhasbeendelivered.Thestudymayprovidesomevaluabledesignguidelinesforthedevelopmentofultrafast,broadbandnonlinearopticalmodulators,andopennewavenuestowardadvancedphotonicdevicesbasedonMXenes.