简介:Weestablishseveralfundamentalidentities,includingrecurrencerelations,degreeelevationformulas,partitionofunityandMarsdenidentity,forquantumBernsteinbasesandquantumBeziercurves.WealsodeveloptwotermrecurrencerelationsforquantumBernsteinbasesandrecursiveevaluationalgorithmsforquantumBeziercurves.Ourproofsusestandardmathematicalinductionandotherelementarytechniques.
简介:WedemonstrateaQ-switchedRamanfiberlaserusingmolybdenumdisulfide(MoS_2)asasaturableabsorber(SA).TheSAisassembledbydepositingamechanicallyexfoliatedMoS_2ontoafiberferrulefacetbeforeitismatchedwithanothercleanferruleviaaconnector.ItisinsertedinaRamanfiberlasercavitywithatotalcavitylengthofabout8kmtogenerateaQ-switchingpulsetrainoperatingat1560.2nm.A7.7-km-longdispersioncompensatingfiberwith584ps·nm~(-1)km~(-1)ofdispersionisusedasanonlineargainmedium.Asthepumppowerisincreasedfrom395mWto422mW,therepetitionrateoftheQ-switchingpulsescanbeincreasedfrom132.7to137.4kHzwhilethepulsewidthisconcurrentlydecreasedfrom3.35μsto3.03μs.Themaximumpulseenergyof54.3nJisobtainedatthemaximumpumppowerof422mW.TheseresultsshowthatthemechanicallyexfoliatedMoS_2SAhasagreatpotentialtobeusedforpuisegenerationinRamanfiberlasersystems.
简介:Wereportonthedesign,realization,andoutputperformanceofadiode-pumpedhigh-peak-powerpassivelyQ-switchedNd:YAG∕Cr4+:YAGcompositemediummonolithiclaserwithfour-beamoutput.Theenergyofalaserpulsewashigherthan3mJwithdurationof0.9ns.Theproposedsystemhastheabilitytochooseindependentlythefocusofeachbeam.Suchalaserdevicecanbeusedformultipointignitionofanautomobilegasolineengine,butcouldalsobeofinterestforignitioninspacepropulsionorinturbulentconditionsspecifictoaeronautics.
简介:用电感耦合等离子体原子发射光谱(ICP-AES)法研究了钢中硼的测定。实验发现,分析线在硼182.64nm处无硼铁基体空白值低于纯试剂(无铁)空白值。样品分析时,应进行无硼铁基空白实验,结果计算只能用此空白值。对普通玻璃烧杯和聚四氟乙烯烧杯的酸溶样品测定结果进行了比较,结果表明,测定结果和空白值相近且都很低,无硼普通玻璃烧杯也能满足钢中低含量硼的测定需要。通过对实验与报道结果比较分析表明,硝酸或王水加热溶解样品得到的溶液中硼没有损失,此溶液可测定钢中酸溶硼;用高氯酸发烟处理后,样品中酸不溶硼可能会溶解,但硼会挥发损失。因此,高氯酸发烟处理不能测定硼。