学科分类
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500 个结果
  • 简介:系统介绍了利用SilviScan-3TM测量细胞结构、术材密度、微纤丝角和划分年轮界线的方法,并以祁连山青海云杉为例,分析青海云杉6个术材性质参数(年轮细胞直径、年轮细胞壁厚、年轮宽度、年轮密度、年轮微纤丝角、年轮弹性模量)与气候因子的关系,以期为利用多个树轮参数研究气候提供参考.结果表明:6个木材性质参数与月平均气温和月降水量都有显著相关的月份,但显著相关的时间段不同,并且微纤丝角和细胞结构参数中包含的气候信息强于常用的年轮宽度和年轮密度.SilviScan-3TM测量木材性质参数的优越性体现在:测量精度高、速度快,能在同一个试样上测量多个参数并能精确定年.

  • 标签: SilviScan-3TM 木材性质参数 气温 降水 气候重建
  • 简介:Thesolutionreactionmechanisms,composition,donoratoms,propertiesofcoordinatelinkandstabilityofthecomplexesonthesystemsofadrenalinewithNa3+,Gd3+andTm3+havebeenstudiedbypH-potentiometrictitrationandelectronicspectroscopy.Adrenalineperturbsthef-felectronictransitionofNd3+andTm3+sothattheabsorptionspectraoftheircomplexesareshiftedtowardlongerwavelengths.Theabsorptionspectraofthecomplexesformedbythethreef-blockelementionswithadrenalineareshiftedtowardshorterwavelengthswiththeincreaseofPHinΔγ=350~650nm

  • 标签: ADRENALINE NEODYMIUM GADOLINIUM THULIUM Solution EQUILIBRIUM
  • 简介:GID3SIM^TM模拟探测器是英国ArgonElectronics公司专为训练而研发的一款模拟探测器。它能够监测诸如空军基地、车厢内外、指挥中心、集防设施乃至战士栖身的地洞上风环境空气的安全。

  • 标签: 探测器 Electronics公司 模拟 GID 空军基地 指挥中心
  • 简介:SpectralParameterStudyonTm+inNa5Tm(WO4)4CrystalYaoLianzeng(姚连增)(DepartmentofMaterialsScienceandEnginering,UniversityofScienc...

  • 标签: Rare earths NA 5Tm(WO 4) 4
  • 简介:摘要:采用共沉淀法制备了具有Yb3+/Tm3+稀土离子掺杂的YOF纳米前驱体材料,并对其吸光度、红外光谱及荧光性质进行分析。结果表明,共沉淀法可合成多壳层纳米前驱体;其在紫外光区具有较高的吸光度;红外光谱表明其在1081 cm-1处有明显的二氧化硅特征吸收峰;纳米前驱体颗粒的荧光发射能力随着壳层增加逐渐降低,双层包覆时红绿比可低至100左右。

  • 标签: 共沉淀 稀土 前驱体 荧光
  • 简介:(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+)phosphorwassynthesizedbysolid-statereactions.ThesamplewascharacterizedbyX-raydiffraction(XRD),scanningelectronicmicroscope(SEM),vacuumultraviolet(VUV)spectra,ultraviolet(UV)spectraandFT-IRspectrum.XRDpatternrevealsthatBSMA:Tm3+hasthesamestructureasBaAl12O19phase.SEMimageillustratesthatthephosphorhasthehexagonalshapeanddeepslicestructure.VUVandUVemissionspectraat20,50and100Kshowthatthelowtemperatureluminescenceintensitiesbecomeweakgraduallywiththeincreasingofthetemperatureunder147and254nmexcitation.Thestrongbroadbandpeaksataround357and397nmandthepeakat516nmunder147nmexcitationallcorrespondtothecharacteristictransitionsofTm3+ions.However,underUV(254nm)excitation,themainpeakbecomes530nmwhichhasveryhighlineintensity,andthepeaksatabout362and403nmareveryweak.Theexcitationspectrumat20Kshowsthattherearethreeabsorptionpeaksataround153,186and193nmwhen516nmemissionismonitored.Theabsorptionpeaksof[AlO4],[AlO6]andAl-OcanbeobservedinFT-IRspectrum.

  • 标签: VACUUM ULTRAVIOLET low temperature LUMINESCENCE Tm3+
  • 简介:Differentfluxeswereusedtosynthesizelongpersistencephosphors,calciumsulfidesactivatedbyEu2+andTm3+,byconvenientsolid-statemethod.ThephosphorusingNH4Fasafluxhasgoodcrystallinityandlargeparticlesize,itsstabilityagainstwaterandotheratmosphericcomponentsisenhanced,anditsafterglowislongerandfluorescentintensityismoreintensethanthoseofthephosphorusingNH4Clasflux.TheirPLintensitiesvariedwithtimeinmoistairweremeasured,noremarkablechangewasfoundforthosepreparedwithNH4FfluxincontrastwithNH4Clasflux.SousingNH4Fasfluxisagoodmethodtoenhancethestabilityofalkalineearthsulfides.

  • 标签: 磷光体 CaS:Eu^2+/Tm^3+ 化学稳定性 稀土 硫化钙 铕二价
  • 简介:3TM—213型伸缩臂装载机是具有饺接车架的自行式轮式机械,它由两个半车架组成。带液力机械传动系统的动力装置装在后半车架上。在前半车架上装有门架(用于固定两节伸缩动臂)、司机室和伸出支腿。由两个液压缸实现转向操纵,保证半车架相对垂直轴左右折

  • 标签: 装载机 伸缩臂 车架 液力机械传动系统 动力装置 司机室
  • 简介:Er3+-Tm3+-Yb3+tri-dopedBaMoO4phosphorsweresynthesizedbyco-precipitationtechniqueandcharacterizedbyX-raydiffractionanalysis,absorptionstudyandfieldemissionscanningelectronmicroscopyanalysis.Upconversionaswellasdownconversionluminescencestudieswereperformedbyusingnearinfrared(980nm)andultraviolet(380nm)excitations.Energyleveldiagram,pumppowerdependenceandcolourcoordinatestudywereutilizedtodescribethemulticolorupconversionemissionproperties.Undersingle980nmdiodelaserexcitationthedualmodesensingbehaviourisrealizedviaStarksublevelsandthermallycoupledenergylevelsoftheTm3+andEr3+ionsinthepreparedtri-dopedphosphors.AcomparativefluorescenceintensityratioanalysisforintegratedemissionintensitiesarisingfromtheStarksublevels{1G4(a)and1G4(b)}andthermallycoupledenergylevels{2H11/2and4S3/2}oftheTm3+andEr3+ions,respectivelywascarriedoutinthepreparedtri-dopedBaMoO4phosphors.ThemaximumsensitivityforthermallycoupledenergylevelsoftheEr3+andStarksublevelsoftheTm3+ionwasreported.Thedevelopedphosphorscouldbeusefulinthedisplaydevicesandopticalthermometricapplications.

  • 标签:
  • 简介:LanthanidedopedNaYF4microcrystalsweresynthesizedviaafacilehydrothermalmethod.MulticolorupconversionluminescencewasobservedinNaYF4microcrystalsdopedwithYb3+/Er3+,Yb3+/Tm3+,andYb3+/Er3+/Tm3+undertheexcitationof980nminfraredlight.Importantly,theexcitationpowerdensitydependenceofupconversionemissionintensityindicatedclearlytheenergytransferfromTm3+toEr3+ionsundertheexcitationoflowpowerdensity(5×102–9×102W/cm2).Meanwhile,theinverseenergytransferfromEr3+toTm3+ionsundertheexcitationofrelativelyhigherpowerdensity(4.1×104–4.9×104W/cm2)wasalsorevealed.ThiswasadirectevidenceforreversibleenergytransferbetweenEr3+andTm3+ions.Undertheexcitationofhighpowerdensity(4.1×104–4.9×104W/cm2),darksensitizerswerealsomotivatedsothatthebottleneckeffectofhighconcentrationYb3+iondopingwasbroken.ThiswasthemainreasonforrealizinghighupconversionefficiencyofthesampleswithheavydopingofYb3+ion.

  • 标签: 上转换发光 离子掺杂 能量转移 TM 微晶 证据
  • 简介:TM3/1机是广东糖机厂生产的TRANSOMATIC-3/1桶清洗一灌装机的简称。下面对该机在使用中常见的故障同各位同仁探讨一下。1开机故障,若机器不能开机可能由以下原因造成:1)检查机器有无电源,包括CPU电源、模板电源和控制变压器电源等;2)检查风压继电器是否闭合,若没有闭合,查明是风压不足还是风压继电器损坏;

  • 标签: 常见故障分析 糖机 风压继电器 开机故障 控制变压器 电源
  • 简介:Forenhancingthe2.0μmbandfluorescenceofHo3+,acertainamountofWO3oxidewasintroducedintoHo3+/Tm3+/Yb3+tri-dopedtelluriteglasspreparedusingmelt-quenchingtechnique.Thepreparedtri-dopedtelluriteglasswascharacterizedbytheabsorptionspectra,fluorescenceemissionandRamanscatteringspectra,togetherwiththestimulatedabsorption,emissioncross-sectionsandgaincoefficient.TheresearchresultsshowthattheintroductionofWO3oxidecanfurtherimprovethe2.0μmbandfluorescenceemissionthroughtheenhancedphonon-assistedenergytransfersbetweenHo3+/Tm3+/Yb3+ionsundertheexcitationof980nmlaserdiode(LD).Meanwhile,themaximumgaincoefficientofHo3+at2.0μmbandreachesabout2.36cm-1.Anintense2.0μmfluorescenceemissioncanberealized.

  • 标签: 碲酸盐玻璃 荧光发射 TM 掺杂 拉曼散射光谱
  • 简介:Enhanced2.7μmemissionisobtainedinEr3+/Tm3+andEr3+/Ho3+codopedZBYAglasses.Absorptionandemissionspectraaretestedtocharacterizethe2.7μmemissionpropertiesofEr3+/Tm3+andEr3+/Ho3+dopedZBYAglassesandareasonableenergytransfermechanismof2.7μmemissionbetweenEr3+andTm3+Ho3+)ionisproposed.CodopingofTm3+orHo3+significantlyreducesthelifetimeoftheEr3+:4I13/2levelduetotheenergytransferofEr3+:4I13/2→Tm3+:3F4orEr3+:4I13/2→Ho3+:5I7.Thus,the2.7μmemissionisstrengthenedandthe1.5μmemissionisdecreasedaccordinglyespeciallyintheEr3+/Tm3+sample.TheupconversioneffectsbetweentheEr3+/Tm3+andEr3+/Ho3+dopedZBYAglassesaredifferentattributetothedifferentenergytransferefficiencies.Bothofthetwocodopedsamplespossessnearlyequallargeemissioncrosssection(16.6×10-21cm-2)around2.7μm.TheresultsindicatethatthisEr3+/Tm3+orEr3+/Ho3+dopedZBYAglasshaspotentialapplicationsin2.7μmlaser.

  • 标签: 能量转移效率 能量传递机制 氟化物玻璃 发射光谱 共掺杂
  • 简介:瞄准:为了在steroidogenesis和机制上调查Cox7a2的规章的功能,在TM3老鼠Leydig房间包含了。方法:Cox7a2的cDNA从TM3老鼠Leydig房间被克隆。它是短暂基因transfection在表达式上为Cox7a2克隆到回来的pDsRed-Express-N1和transfected进TM3鼠标Leydig房间的潜水艇。Steroidogenesis影响了由在表示Cox7a2上被ELISA学习。得到这效果的机制,steroidogenic的表示尖锐规章(星)蛋白质和反应的氧种类(ROS)被西方的污点和氟量计分别地检验。结果:Cox7a2(249bp)的cDNA从Leydig房间被克隆并且由定序的DNA证实了。在构造pDsRed-Express-N1-Cox7a2是回来的transfected进TM3老鼠Leydig房间以后,Cox7a2禁止了导致的luteinizing(LH)不仅睾丸激素的分泌物而且星蛋白质的表示。同时,Cox7a2在TM3老鼠Leydig房间增加了ROS的活动。结论:Cox7a2禁止了导致LH的星蛋白质表示,和作为结果的睾丸激素生产,至少部分地,由在TM3鼠标Leydig房间增加ROS活动。

  • 标签: COX7A2 甾酮 溶解蛋白 TM3 小鼠 动物实验
  • 简介:Glasseswiththecompositionof65GeO212Ga2O3-10BaO-8Li2O-5La2O3(molarratio)dopedwith1.526wt.%,3.006wt.%,5.836wt.%,11.028wt.%,and15.678wt.%Tm2O3,respectively,werefabricatedbyconventionalmeltingmethod.AccordingtotheabsorptionspectraandtheJudd-Ofelttheory,theJ-Ostrengthparameters(Ω2,Ω4,Ω6)werecalculated,withwhichtheradiativetransitionprobabilities,branchingratiosandradiativelifetimeswereobtained.Theinfraredemissionspectra(with808nmLDexcitation)at~1.47and~1.8μmofvariousconcentrationsofTm3+-dopedglasseswerestudied.Theemissionintensityat~1.8μmreachedtothemaximumwhentheTm2O3-dopingconcentrationwasneartobe~3.006wt.%(1.0mol.%),andthendecreasedasdopingconcentrationincreasedfurther.Themechanismofthefluorescenceintensitychangewasexplainedwiththecross-relaxationeffectandtheconcentrationquenchingeffectofTm3+.Meanwhile,accordingtoMcCumbertheory,theabsorptionandemissioncross-sectionscorrespondingtothe3F4→3H6transitionsofTm3+at1.8μmwasobtained.ForTm3+-dopedgermanateglasses,themaximumemissioncross-sectionreachedavaluehigherthanthatre-portedforfluorozircoaluminateglasses.Itisexpectedtobeafavorablecandidatehostfor~2.0μmmid-inflatedlaserbecausetheglassshowsfavorableopticalspectra.

  • 标签: Tm3+-doped germanium-gallate GLASSES spectral properties cross
  • 简介:酷毕^TM,化学名:5-氨基-1-(2,6-二氯-α.α,α-三氟-对甲基苯基)-4-乙基亚磺酰基吡唑-3-腈,通用名乙虫腈,是由德国拜耳作物科学公司开发生产的一种新型高效、长持效的苯吡唑类杀虫剂,在中国申请了行政保护。

  • 标签: 拜耳作物科学公司 行政保护 杀虫剂
  • 简介:决策管理层01负责协调各部门之间的合作。硬件生产部02负责人工智能的“身体”。除了电脑计算系统,人工智能还需要一些额外的硬件来完成各自的任务,例如自动驾驶汽车需要能控制汽车方向盘、刹车、油门的硬件控制系统,需要语音和显示屏告知乘客自动驾驶的状态;智能音响则需要稳定连接Wi-Fi和家里需要操控的智能设备,需要麦克风来识别人类的语音,需要扬声器来“说话”;灵活的机器人机械臂需要精密牢固的机械设计。为了让人工智能更好更快地运行,本部门还需要研发适用于人工智能计算的芯片。

  • 标签: 公司架构 人工智能 TM 机械设计 决策管理层 WI-FI
  • 简介:AdetailedstudyofthefluorescenceemissionpropertiesandenergytransfermechanisminEr3+/Tm3+co-dopedleadsilicateglasseswasreported.Enhancednearinfrared1.8μmandvisibleup-conversionemissionswereinvestigatedunder808and980nmexcitations,respectively.TheenergytransfermechanismbetweenEr3+andTm3+wasanalyzedaccordingtotheabsorptionspectra,theemissionspectraandthelevelstructuresofEr3+andTm3+.TheenergytransferefficiencybetweenEr3+andTm3+reached68.1%intheEr3+/Tm3+co-dopedleadsilicateglasseswhenpumpedby808nmlaserdiode.Basedontheabsorptionspectra,theJudd-Ofeltparameters,spontaneousemissionprobability,absorptionandemissioncrosssections,gaincoefficientswerecalculatedandanalyzed.Itwasfoundthatthecalculatedemissioncrosssectionandthemaximumgaincoefficientaround1.8μmwere4.9×10–21cm2and1.12cm–1,respectively.TheseresultsindicatedthattheEr3+/Tm3+co-dopedlead-silicateglasseshadpotentialapplicationinnearinfraredlasers.

  • 标签: 硅酸铅玻璃 近红外激光 发射特性 激发条件 共掺杂 TM