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简介：研究具有可选服务的M/M/1排队模型的主算子在左半实轴上的点谱.当顾客的到达率λ，必选服务的服务率μ1与可选服务的服务率μ2满足λ/μ1＋λμ2〈1时，证明区间（η，-λ）中的所有点都是该主算子的几何重数为1的特征值，其中η=max{-μ1，-μ2，-4/3λ，-2λμ2/μ1＋μ2-λ，-μ1μ2（μ1μ2-λμ1-λμ2）＋λ3μ1（1-r）/[μ12（μ2-λ）＋μ1μ2（μ1-λ）]（1-r）＋λ2μ1-λ}，r表示顾客选择可选服务的概率.

简介：为了解决M／M／c模型在实际运用中模拟精度不高及使用范围有限的问题，本文立足系统状态变化与输入率和服务率的关系，通过引入输入概率和服务度，构建依赖系统状态的递进式输入率和服务率。递进式输入率和服务率通过研究系统实际运行状况设定临界值，其中输入率分为两阶段，服务率分为三阶段。此外，结合递进式输入率和服务率及排队论状态转移过程构建了递进式M／M／c模型，并采用后确定法确定模型参数。递进式M／M／c模型是M／M／c模型的扩展形式，提高了M／M／e模型的模拟精度，在一定程度上拓展了模型的应用范围。最后，通过一个生活实例验证了递进式M／M／c模型的优化性和实用性。

简介：Wedesignafamilyof2DH~m-nonconformingfiniteelementsusingthefullP_(2m-3)degreepolynomialspace,forsolving2mthellipticpartialdifferentialequations.Theconsistenterrorisestimatedandtheoptimalorderofconvergenceisproved.Numericaltestsonthenewelementsforsolvingtri-harmonic,4-harmonic,5-harmonicand6-harmonicequationsarepresented,toverifythetheory.

简介：Inthiswork,weinvestigatethemethodstoimprovetheperformanceofthesweptsourceat1.0μmbasedonapolygonscanner,includingin-cavityparametersandboosterstructuresoutofthecavity.Thethreein-cavityparametersarethecavitylength,therotatingspeedofthepolygonscanner,andthein-cavityenergy.Withthedecreaseofcavitylength,thespectrumbandwidthbecomeswiderandthedutycyclebecomeshigher.Withtheincreaseoftherotatingspeedofthepolygon,thespectrumbandwidthbecomesnarrower,andthedutycyclebecomeslowerbuttherepetitionratebecomeshigher.Withmoreenergyin-cavity,thespectrumbandwidthbecomeswiderandthedutycyclebecomeshigher.Theboosterstructuresincludethebufferedstructure,secondaryamplifier,anddual-semiconductoropticalamplifierconfiguration,whichareusedtoincreasethesweepfrequencyto86kHz,theoutputpowerto18mW,andthetuningbandwidthto131nm,respectively.

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简介：针对物距像距法测量凹透镜焦距的实验现象进行了理论分析,加深了对成像规律的理解,并提出了减小视觉实验误差的方法：凹透镜尽量靠近虚物,减小清晰成像的范围.本文对凹透镜测焦距的实验有一定的指导意乂.

简介：Inthispaper,weconsideraLorentzspacewithamixednormofperiodicfunctionsofmanyvariables.WeobtaintheexactestimationofthebestM-termapproximationsofNikol'skii'sandBesov'sclassesintheLorentzspacewiththemixednorm.

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简介：利用TCAD仿真技术,研究了电离总剂量辐射陷阱电荷对0.18μmN沟道MOSFET转移特性的影响.构建了0.18μmN沟道MOSFET的三维仿真结构,获得了在电离总剂量（totalionizingdose,TID）效应影响下,负栅压偏置时器件中电流密度的分布情况.分析了器件浅槽隔离层（shallowtrenchisolation,STI）中氧化物陷阱电荷和界面态陷阱电荷对器件泄漏电流的影响.仿真计算了N-MOSFET的转移特性,仿真结果与辐照试验结果受辐照影响的趋势基本一致,为深亚微米MOS器件的总剂量辐射效应的损伤机制提供了一种分析手段.

简介：Atheoreticaldesignispresentedfora1×Mwavelength-selectiveswitch（WSS）thatroutesanyoneofNincomingwavelengthsignalstoanyoneofMoutputports.Thisplanaron-chipdevicecomprisesofa1×Ndemultiplexer,agroupofNswitching'trees'actuatedbyelectro-opticalorthermo-opticalmeans,andanM-foldsetofN×1multiplexers.Treesutilize1×2switches.TheWSSinsertionlossisproportionalto(log2（M+N+1）)Alongwithcrosstalkfromtrees,crosstalkispresentateachcross-illuminatedwaveguideintersectionwithintheWSS,andthereareatmostN-1suchcrossingsperpath.TheselossandcrosstalkpropertieswilllikelyplaceapracticallimitofN=M=16upontheWSSsize.Byconstrainingthe1×2switchingenergyto1fJ∕bit,wefindthatresonant,narrowband1×2switchesarerequired.The1×2devicesproposedherearenanobeamMach–Zehndersandasymmetriccontra-directionalcouplerswithgratingassistance.

简介：在b-距离空间中建立了含有四个映射的Ciric型公共不动点定理.这一结果统一和改进了Roshan等人的结果.进一步，利用Du的标量化方法，获得了TVS-锥b-距离空间中的一些公共不动点定理.

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简介：Two-dimensional（2D）graphitecarbonnitride（g-C3N4）nanosheetshavebeensuccessfullyusedasasaturableabsorber（SA）inapassivelyQ-switchedNd:LLFlaserat1.3μmforthefirsttime,tothebestofourknowledge.Underanincidentpumppowerof9.97W,theshortestpulsedurationof275nswasacquiredwithoutputpowerof0.96Wandpulserepetitionrateof154kHz,resultinginapulseenergyof6.2μJ.Inaddition,thesaturableabsorptionbehaviorsofzero-dimensional12nmg-C3N4nanoparticles（g-C3N4-NPs）andthree-dimensionalorderedmesoporousg-C3N4（mpg-C3N4）werealsoobserved,althoughtheirmorphologyandstructurewerequitedifferentfrom2Dg-C3N4.Theexperimentalresultsintroducethepotentialapplicationofg-C3N4nanomaterialsasSAsinQ-switchedlasers.

简介：Wereportonbroadlywavelength-tunablepassivemode-lockingwithhighpoweroperatingatthe2μmwaterabsorptionbandinaTm:CYAcrystallaser.Withasimplequartzplate,stablemode-lockingwavelengthscanbetunedfrom1874to1973nm,withatunablewavelengthrangeupto~100nmandmaximumoutputpowerupto1.35W.Thebandwidthisnarrowas~6GHz,correspondingtoahighcoherence.Toourknowledge,thisisthefirstdemonstrationofwavelength-tunablemode-lockingwithwatt-levelinthe2μmwaterabsorptionband.Thehightemporalcoherentlasercanbefurtherappliedinspectroscopy,theefficientexcitationofmolecules,sensing,andquantumoptics.

简介：Byusingtheultrasound-assistedliquidphaseexfoliationmethod,Bi2Te3nanosheetsaresynthesizedanddepositedontoaquartzplatetoformakindofsaturableabsorber（SA）,inwhichnonlinearabsorptionpropertiesaround2μmareanalyzedwithahome-mademode-lockedlaser.Withtheas-preparedBi2Te3SAemployed,astablepassivelyQ-switchedall-solid-state2μmlaserissuccessfullyrealized.Q-switchedpulseswithamaximumaverageoutputpowerof2.03Waregeneratedunderanoutputcouplingof5%,correspondingtothemaximumsingle-pulseenergyof18.4μJandpeakpowerof23W.Thedeliveredshortestpulsedurationandmaximumrepetitionrateare620nsand118kHzunderanoutputcouplingof2%,respectively.ItisthefirstpresentationofsuchBi2Te3SAemployedinasolid-stateQ-switchedcrystallinelaserat2μm,tothebestofourknowledge.Incomparisonwithother2Dmaterialssuitableforpulsed2μmlasers,thesaturableabsorptionperformanceofBi2Te3SAisprovedtobepromisingingeneratinghighpowerandhigh-repetition-rate2μmlaserpulses.

简介：Wehavedemonstratedahigh-average-power,high-repetition-rateopticalterahertz（THz）sourcebasedondifferencefrequencygeneration（DFG）intheGaSecrystalbyusinganear-degenerate2μmintracavityKTPopticalparametricoscillatorasthepumpsource.Thepowerofthe2μmdual-wavelengthlaserwasupto12.33Wwithcontinuoustuningrangesof1988.0–2196.2nm/2278.4–2065.6nmfortwowaves.DifferentGaSecystallengthshavebeenexperimentallyinvestigatedfortheDFGTHzsourceinordertooptimizetheTHzoutputpower,whichwasingoodagreementwiththetheoreticalanalysis.Basedonan8mmlongGaSecrystal,theTHzwavewascontinuouslytunedfrom0.21to3THz.ThemaximumTHzaveragepowerof1.66μWwasobtainedatrepetitionrateof10kHzunder1.48THz.Thesinglepulseenergyamountedto166pJandtheconversionefficiencyfrom2μmlasertoTHzoutputwas1.68×10-6.Thesignal-to-noiseratioofthedetectedTHzvoltagewas23dB.TheacceptanceangleofDFGintheGaSecrystalwasmeasuredtobe0.16°.

简介：ZnOfilmscontainingErandGenanocrystals（nc-Ge）weresynthesizedandtheirphotoluminescence（PL）propertieswerestudied.Visibleandnear-infraredPLintensitiesarefoundtobegreatlyincreasedinnc-Ge-containingfilm.Er-related1.54μmemissionhasbeeninvestigatedunderseveralexcitationconditionsupondifferentkindsofGe,ErcodopedZnOthinfilms.1.54μmPLenhancementaccompaniedbytheappearanceofnc-Geimpliesasignificantcorrelationbetweennc-GeandPLemissionofEr3+.Theincreasedintensityof1.54μminGe:Er:ZnOfilmisconsideredtocomefromthejointeffectofthelocalpotentialdistortionaroundEr3+andthepossibleenergytransferfromnc-GetoEr3+.

简介：2017年7月14日,以＂工业应用数学在中国及其他亚太地区：回顾与展望＂为主题的为期一天的研讨会在上海交通大学陈瑞球楼204室成功举办。作为＂第十四届国际自由边界问题理论及应用＂会议的嵌入会议,本次研讨会旨在探讨如何深化中国学术界与工业界在数学领域的合作,同时也特别回顾了中国工业应用数学工作坊（math-for-industry）的创始人谭永基教授为中国工业应用数学的发展所做出的突出贡献。

简介：理解和掌握物理规律的本质是物理学习的中心任务,又是物理思维能力培养的重要途径。所以教师在物理教学过程中,要避免简单粗暴地给出结论,而是要想方设法使学生掌握物理规律的本质,就要引导学生从形形色色的联系中,排除各种非本质的联系,把规律的本质暴露出来,透过表面现象,掌握它的本质。