共查询到20条相似文献,搜索用时 890 毫秒
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ExtendedXrayAbsorptionFineStructureStudyofEuDopedBaPbO3CaiWeimin(蔡伟民),FengYujie(冯玉杰),ZhouDing(周定)(DepartmentofApplicationCh... 相似文献
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铝镇静钢连铸保护渣对Al2O3夹杂物的吸收能力 总被引:1,自引:0,他引:1
釆用Al2Q3溶解速率测定仪测定了 CaO-SiO2-Na2O-CaF2-Al2O3-MgO连铸保护渣系的抱@溶解 速率。通过建立Al2O3溶解速率和渣成分关系的回归正交设计模型,精确预测铝镇静钢连铸保护渣的夹杂物 吸收能力,并通过建立的非线性规划模型对该保护渣进行优化设计。结果表明,在CaO/SiQ = 1.15,Na2CO30.0%,CaF2 20.0%,2.0%, MgO 8.0%时,连铸保护渣的溶解速率的最大值为1.73 x 10-3 kg·m-2 ·s-1 相似文献
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Lanthanidemetalsarethe 5 7thto 71thelementsintheperiodictable ,thetrivalentionsforlanthanideareofvalenceelectronshell 4f0~ 14 6s2 ,whicharefairlystablewhenthe 4felectronsub layerisemptyoral mostempty ,halffullorfull .Becauseofbigenergydifferencebetweenba… 相似文献
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采用CaO -SiO2 -Na2 O -CaF2 -Al2 O3-MgO渣系 ,通过测定熔渣的粘度和Al2 O3吸收速率 ,研究连铸保护渣的Al2 O3吸收速率与粘度及化学成分之间的关系。在一定条件下 ,当CaO SiO2 为1 .2左右时 ,粘度达到最小值 ,Al2 O3吸收速率达到最大值 ,分别为 0 .1 0Pa·s、8.4 0 3× 1 0 - 4 kg·m- 2 ·s- 1 。随着渣中Na2 CO3含量、CaF2 含量和MgO含量的增加 ,粘度减小 ,Al2 O3吸收速率增大。随着渣中Al2 O3含量的增加 ,粘度增大 ,Al2 O3吸收速率减小。粘度为Al2 O3吸收速率的主要控制因素。随着熔渣粘度的增加 ,连铸保护渣的Al2 O3吸收速率逐渐减小。 相似文献
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Dy^3+在(LaO)3BO3和(GdO)3BO3中的光致发光 总被引:1,自引:1,他引:0
研究了Dy^3+在(LaO)3BO3和(GdO)3BO3中的光致发光;探讨了基质晶体结构、稀土离子RE^3+的电荷半径比(Z/r)和Dy^3+含量对(Dy^3+)发光强度及发光颜色的影响;分析了(GdO)3BO3中Bi^3+对Dy^3+发光的敏化作用及Dy^3+4F9/2→^6H13/2超灵敏跃迁发射的自身浓度猝灭机理。 相似文献
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以碳酸盐为沉淀剂,采用共沉淀法合成Ni1/3Co1/3Mn1/3CO3前驱体,再按照一定的锂配比将其烧结合成层状Li(Ni1/3Co1/3Mn1/3)O2。通过SEM及电性能测试仪等方法,研究了碳酸盐前驱体的合成条件,考察了碳酸盐前驱体的振实密度与合成时pH值、溶液浓度以及反应时间的关系。经过实验分析,在pH=8、溶液浓度C=2mol.L^-1、反应时间t=12-13h时,合成的碳酸盐前驱体Ni1/3Co1/3Mn1/3CO3振实密度达到最高值0.98g.cm^-3。 相似文献
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Ca3La(BO3)3中Dy3+的光致发光 总被引:2,自引:0,他引:2
研究了Ca3La(BO3)3基质中Dy^3 的发射光谱和激发光谱。结果表明,强的激发峰值为351nm、367nm和386nm;Dy^3 的488nm和578nm发射的最佳浓度均为xDy=0.03;Dy^3 发射的黄光和蓝光强度比(用Y/B表示)随Dy^3 浓度的增加而逐渐增大;Dy^3 的^4F9/2→^6H15/2、^6H13/2跃迁发射的浓度猝灭机理均为电偶极-电偶极相互作用;同时还探讨了Ce^3 对Dy^3 发光的敏化作用。 相似文献
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Dy3 isanimportantactivator .Ithasbeenexten sivelyappliedinmanyluminescentmaterials .Inre centyears ,someresearchershavestudiedthespec trumcharacteristicsofluminescentmaterialsdopedDy3 [1~ 6 ] andhaveobtainedsomemeaningfulre sults .InordertodevelopnewfluorescentmaterialsanddiscussthephotoluminescentruleofDy3 inthecomplexborate ,thispaperstudiesthephotolumines centcharacteristicsofDy3 inBa3La(BO3) 3host ,anddiscussestheinfluenceofthecharge to radiusratio(z/r)ofrareearthionRE3 andthecon… 相似文献
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研究了转速,球磨时间等球磨工艺对3Y2O3-5Al2O3机械合金化过程的影响。结果表明:在较低的转速下(250r/min),提供的球磨能量很低,只会细化粉体颗粒;提高转速(400r/min),会促使Y2O3发生晶型转变,由稳定的立方晶转变成非稳态的单斜晶;继续提高转速(500r/min),还会使混合粉体发生合成反应,生成YAlO3(YAP)。在转速为500r/min,球料比为20∶1的球磨条件下,3Y2O3-5Al2O3粉体发生固相反应的过程可分为两个阶段:第一阶段,Al2O3颗粒晶格畸变,快速细化;同时,高能球磨促使Y2O3发生了晶型转变。第二阶段,Y2O3晶型转变基本完成,并呈无定形化,Y2O3和Al2O3发生合成反应,生成YAlO3(YAP)。但在球磨条件下,难以合成Y3Al5O12(YAG)、Y4Al2O9(YAM)。 相似文献
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Luminescent material Ba3Gd(BO3)3 doped with Eu3+ ion was prepared by high temperature solid-state method. The preparing conditions, luminescent properties, and particle morphology of Ba3Gd(BO3)3:Eu3 + phosphor were studied with X-ray diffraction (XRD), fluorescence spectroscopy, and scanning electron microscopy (SEM). The results obtained by XRD showed that pure phase of Ba3Gd(BO3)3 was obtained at 1000℃. Images from SEM displayed that the particles of Ba3Gd(BO3)3:Eu3+ phosphor had a spherical shape with an average diameter of about 200-400 nm. The luminescence spectra showed that Ba3Gd(BO3)3:Eu3+ phosphor was effectively excited by the near ultraviolet (UV) light (396 nm) and blue light (466 nm). The main emission peaks of Ba3Gd(BO3)3:Eu3+ phosphor were assigned to the supersensitive transition 5D0-7F2 (611 and 616 nm) of Eu3+ ion when samples were excited at 255 and 396 nm, respectively, and the luminescent intensity of Ba3Gd(BO3)3:Eu3+ at 611 and 616 nm reached to the maximum when the doped content of Eu3+ ion was 10mol.%. Therefore, this phosphor could be a promising red component for possible applications in the field of white LED. 相似文献
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CaTiO_3∶Pr~(3 )的合成及发光性质 总被引:3,自引:0,他引:3
报道了稀土离子Pr3+激活的CaTiO3发光材料的合成方法,CaTiO3∶Pr3+位于613nm发射与Pr3+离子1D23H4光谱发射相一致。讨论了不同合成条件对CaTiO3∶Pr3+发光性质的影响 相似文献
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田莲花 《中国稀土学报(英文版)》2010,28(1):37-39
The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(BO3)3:Bi3+,Dy3+,energy transfer occurred from Bi3+ to Dy3+ somewhat.In Ca4YO(BO3)3:Bi3+,Dy3+,Pr3+,the excitation band at 367 nm was enhanced obviously due to the energy migration from Bi3+ to Pr3+,which converted efficiently the emission of semiconductor InGaN based light-emitting diode(LED).Therefore,the emission of Dy3+ ions was enhanced due to the energy migration from the process of Bi3+→Pr3+→Dy3+.It resulted in the good color rendering. 相似文献
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