Study on Effect of Flux on CeMgAl11O19：Tb^3＋ Phosphor

High calcination temperature is an important factor in the preparation process of CeMgAl11O19:Tb^3 . To decrease the temperature, different fluxes (H3BO3, MgF2 and AlF3) were tested in order to compare their influence on the luminescence property and particle size distribution of CeMgAl11O19: Tb^3 . The result shows that when the content of MgF2 is 0.1 mol/mol, the intensity of luminescence can attain a maximum. Furthermore, MgF2 can improve the particle size quality of the phosphor. So MgF2 can take the place of the conventional flux H3BO3 to prepare high quality CeMgAl11O19:Tb^3 phosphor. In addition, the relation between phosphor property and content of AlF3 was also studied. The crystal structure of the phosphor was analyzed by XRD method. The phase composition analysis shows that the reason of decrease of the brightness of CeMgAl11O19:Tb^3 phosphor is the emergence of TbAlO3 and α-Al2O3 during the preparation process.     

Influence of Flux on Structure and Luminescence of LaMgB_5O_(10)∶Ce~(3 ), Mn~(2 )

Recently ,manystudiesonthecompoundofLn MgB5O10 asanexcellentluminescenthosthavebeenreportedworldwidely .Variantluminescentmaterialssuchasluminescentpowders ,luminescentglasses ,lu minescentceramicandluminescentpigmentsetc ,canbeobtainedwhenLn3 ispartiallyorallreplacedbytherareearthionsofLa3 ,Ce3 ,Eu3 ,Tb3 ,Gd3 ,Pr3 ,Dy3 ionsetc ,andMg2 isreplacedbyCa2 ,Mn2 ,Zn2 ,Cd2 ions ,forexamples ,Ln1-x -yCexTbyMgB5O10 ,(CeGa) (MgCa )B5O10 ∶Mn2 and (La1-x -y GaxCey)MgB5O1…     

Study on Spectra of La_2CaB_(10)O_(19)∶Eu~(3 ) in VUV-VIS Range

Manyboratesareexcellenthostsforrareearthlu minescence ,forexample ,nowbestredphosphorinplasmadisplaypanel (PDP )is (Y1-xGdx)BO3∶Eu[1] .Boratephosphorsdopedwithrareearthionshavebeenrichlystudiedinthepastfewdecades[2 ,3] .RecentlyWuYichengetal .[4 ] synthesizedanewbo rateLa2 CaB10 O19,whichispotentialnonlinearopticalmaterials.InthisworkweselectedLa2 CaB10 O19ashostofluminescencematerialsbecauseitprobablyisabetterhostforrareearthluminescence .Duetotherequirementofplasmadisplaypenal(PDP)…     

Synthesis,fluorescence properties of Tb(Ⅲ) complexes with novel mono-substituted β-diketone ligands

Two novel pyridine-2,6-dicarboxylic acid derivatives of mono-β-diketone named methyl 6-biphenylacetyl-2-pyridinecarboxylate (MBP) and 6-biphenylacetyl-2-pyridinecarboxylic acid (BAA) and their corresponding binary complexes Tb(MBP)3.6H2O and Tb(BAA)3·6H2O were synthesized. The ligands were characterized by elemental analysis, FT-IR and 1H-NMR, and the complexes were characterized with elemental analysis, FT-IR, 1H-NMR and thermogravimetric and differential thermal analysis(TG-DTA). The investigation of fluorescence properties of the complexes Tb(MBP)3·6H2O and Tb(BAA)3·6H2O showed that the introduction of the biphenyl enlarged the π-conjugated system of the ligands and enhanced the luminescent intensity of the complexes. The Tb(Ⅲ) ion could be sensitized more efficiently by the ligands, in particular, the fluorescence intensity of the complex Tb(BAA)3·6H2O was about 20% higher than that of Tb(MBP)3·6H2O and 30% higher than that of Tb(Ⅲ) complexes with bis-β-diketone-type ligands that we have previously reported.     

Effect of Tb(Ⅲ) on activity and stability of nattokinase

Nattokinase, is an effective fibrinolytic enzyme with the potential for fighting cardiovascular disease. The aim of study was to investigate the interaction of Tb(Ⅲ) with nattokinase and the impact of Tb(Ⅲ) on the enzyme activity and protein stability. The binding of Tb(Ⅲ) with nattokinase was studied by fluorescence spectrum in 100 mmol/L Tris-HCl(pH 8.0). It could be seen that the protein bound one Tb(Ⅲ) with low affinity, and the binding constants K were 2.90×10~4 L/mol at 288 K. Although the activity of nattokinase determined by tetra-peptide substrate method at proper pH and temperature was not influenced for the binding of Tb(Ⅲ), the transformation rate of substrate was increased to 113%. To better assess the stability of protease in the absence and presence of Tb(Ⅲ), nattokinase was unfolded through continuous concentrations urea. Based on the model of structural element, the results showed that Tb(Ⅲ) could not change the average structural element free energy ?G~0 element(H_2O) of nattokinase by the measurement of enzyme activity, but it could improve the stability of the global protein by the fluorescence spectral measurement.     

Tb(Ⅲ)对辣根若干生理生化指标的影响

以辣根为实验材料,研究不同浓度的Tb(Ⅲ)对辣根过氧化物酶(HRP)、辣根超氧化物岐化酶(SOD)、过氧化氢(H2O2)的影响,结果表明,低浓度Tb(Ⅲ)对辣根的生长有一定的刺激作用,高浓度Tb(Ⅲ)则对辣根生长有抑制作用.表现为,随着Tb(Ⅲ)浓度的增加,HRP和SOD酶活先增高,后减小;H2O2含量先减少后增加.最适浓度处HRP活性增加了5.3%,SOD活性增加了33.36%,H2O2含量减少了11.68%.低浓度Tb(Ⅲ)不能显著提高辣根抗逆性,Tb(Ⅲ)对辣根的作用主要表现为毒理效应.     

Luminescence Properties of (Y, Gd)Al_3(BO_3)_4∶Eu ~(3 ) under VUV excitation

Thephosphorsasanimportantpartofplasmadis playpanel (PDP)deviceemitvisiblelightundervac uumultraviolet (VUV)excitationof 14 7nmand/or172nmfromXe/Hegasplasma[1] .Untilrecently ,Y2 O3∶Eu3 and (Y ,Gd)BO3∶Eu3 havebeenusedascommercialred emittingphosphorsforPDP[2 - 3] .Butthesematerialsstillhaveshortcomingstobeim proved :lowlightoutputofY2 O3∶Eu3 uponVUVex citationandbadcolorpurityof (Y ,Gd )BO3∶Eu3 [4～ 5] .AluminoborateshavestrongabsorptionintheVUVregion ,andexhibitexcellentma…     

PDP用(Y,Gd)BO_3:Tb~(3+)绿色荧光粉的合成及性能研究

采用高温固相法合成了PDP用绿色荧光粉(Y,Gd)BO3:Tb3+。主要研究了原料配比、烧结温度、保温时间、还原气氛、助熔剂等对材料发光性能的影响。结果表明,当原料中Y3+∶Gd3+∶Tb3+∶BO33-的摩尔比为4∶5∶1∶12,烧结温度为1100℃,保温时间为4 h时,在氢气还原气氛下所制得材料的发光亮度最高,且XRD显示在H3BO3过量20%时没有其他杂相的形成。同时考察了(Y,Gd)BO3:Tb3+中离子间的能量传递,以及Tb3+离子的浓度猝灭机制。结果表明,适量Gd3+离子的加入既能提高基质的吸收,又能改善Tb3+离子的跃迁;Tb3+离子的浓度猝灭是由Tb3+离子间的交换相互作用引起的。最后研究表明碱金属碳酸盐的加入能够提高材料的发光亮度和猝灭浓度。     

铽在硫氧化镧基质中的光致发光

采用高温固相反应法制备了La2O2S∶Tb3+、La2O2S∶Tb3+,RE3+(RE=Dy,Gd,Ce,Sm)荧光粉样品并进行了相关表征。结果表明,合成样品的晶体结构与La2O2S相同,为六方晶系;荧光粉颗粒的形貌多为长方形片状;发射光谱由494 nm、545 nm、587 nm、622 nm的一系列锐发射峰组成。研究发现Tb3+的掺杂浓度对样品主发射峰545 nm的发光强度影响很大,且在摩尔分数x(Tb3+)=0.02时达到最强。稀土离子Dy3+、Gd3+对La2O2S∶Tb3+荧光粉的发光有明显的敏化作用。     

Fluorescence enhancement of Tb(Ⅲ) complex with a new β-diketone ligand by 1,10-phenanthroline

A novel β-diketone, 1-(3,4,5-trisbenzyloxy)benzoyl-5-benzoyl acetylacetone (TBAA), and its corresponding binary Tb(Ⅲ) complex Tb(TBAA)3·2H2O and ternary complex Tb(TBAA)3Phen with 1,10-phenanthroline (Phen) were prepared. The ligand was characterized based on elemental analysis, FT-IR, and 1H NMR. The complexes were characterized with elemental analysis, FT-IR and thermogravimetry and derivative thermogravimetry (TG-DTG). Photoluminescence measurements indicated that the energy absorbed by the organic ligan...     

邻菲罗啉导向合成缆线状纳米结构CePO_4和Ce_(0.95)PO_4:Tb_(0.05)及其发光性能

采用水热法通过调节邻菲罗啉(phen)的加入量导向合成了六方相CePO_4及Ce0.95PO4∶Tb0.05纳米线。用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、透射电镜(TEM)分析产物的相结构、晶粒尺寸及微观形貌。实验结果表明,当反应体系中不加入导向剂phen时,获得分散不均匀的CePO_4纳米棒;加入phen使Ce~(3+)∶phen摩尔比为1.0∶0.5时,得到分散均匀的直径约20 nm、长约2μm~3μm的CePO_4缆线状纳米线,phen增加到Ce~(3+)∶phen摩尔比为1.0∶3.0时,又获得直径约20 nm~30 nm、长约200 nm CePO_4纳米棒。发现反应体系中phen加入量会影响产物形貌的控制合成,所以讨论了phen对产物微观形貌的影响。不同Ce~(3+)∶phen摩尔比下所得产物CePO_4的荧光性质表明,当Ce~(3+)∶phen摩尔比为1.0∶0.5时,所合成的纳米线的发射强度比无添加phen时所获产物的荧光强度增强,随着Ce~(3+)∶phen摩尔比的减少,所合成产物的发光强度反而降低。发现随着产物长径比的增加,荧光强度增强,Ce0.95PO4∶Tb0.05中Ce~(3+)将能量传递给Tb3+,敏化Tb3+的发光。     

[Nd(PW11O39)(H2O)3](H2bpy)2·4H2O的水热合成及晶体结构

采用水热法合成稀土无机有机杂化化合物[Nd(PW11O39)(H2O)3 ](H2bpy)2·4H2O.采用NdCl3·6H2O,(NH4)3PW12O40·3H2O, 4,4'-联吡啶(bpy),和去离子水(摩尔比为4∶1∶4∶3900, pH=6)在130℃下进行水热反应3天,得到标题化合物的紫红色块状晶体,并进行了红外光谱分析,元素分析.用单晶X射线衍射法测得晶体结构,属三斜晶系,空间群为P-1,晶胞参数为a=1.18824(9) nm,b =1.35707(10)nm,c=1.77691(13)nm,α=71.551(2)°,β=82.478(2)°,γ=80.568(2)°.该晶体由无机的共价链∞1[Nd(PW11O39)(H2O)3]4- 和有机的二质子化的4,4'-联吡啶(H2bpy)2 及结晶水分子堆积而成的, 是一个新的稀土磷钨酸盐无机有机杂化化合物.     

(Zn,Ca) Solid-Solution Behavior and Its Effect on Luminescence Properties in Ca_(1-x)Zn_xTiO_3∶0.002Pr~(3 ) Phosphors

Compared withthe classical sulfides MS∶Eu2 (M=Ca,Sr,Ba)red phosphor and ZnS∶Eu2 greenphosphor,the alkali-earth aluminate phosphors havesuperior blue-green long afterglowproperties,such asblue phosphors CaAl2O4∶(Eu2 ,Nd3 ),green phos-phor SrAl2O4∶(Eu2 …     

Synthesis, characterization and enhanced luminescence of terbium complexes with 2-pyrazinecarboxylic acid and butanedioic acid by inert-fluorescent lanthanide ions

Ten solid terbium complexes with 2-pyrazinecarboxylic acid (Hpyca) and butanedioic acid (BDAH) were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively coupled plasma (ICP), thermogravimetry-differential scanning calorimetry (TG-DSC) and infrared (IR) analyses. The results showed that the complexes had the compositions of Tb(pyca)(BDA)·2H2O, Tb0.5Y0.5(pyca)(BDA)·2H2O, Tb0.5La0.5(pyca)(BDA)·3H2O, Tb0.5Gd0.5(pyca)(BDA)·2H2O, Tb0.7Y0.3(pyca)(BDA)·3H2O, Tb0.7La0.3(pyca)(BDA)·0.5H2O, Tb0.7Gd0.3(pyca)(BDA)·H2O, Tb0.6Y0.4(pyca)(BDA)·2.5H2O, Tb0.6La0.4 (pyca)(BDA)·2.5H2O and Tb0.6Gd0.4(pyca)(BDA)·3H2O. IR spectra indicated that the rare earth ions coordinated with the carboxylic oxygen atoms of Hpyca and BDAH. Luminescence spectra showed that the doped La3+, Y3+ or Gd3+ ions did not affect the luminescence emission peak positions, but remarkably increased the luminescent intensities of terbium complexes. Furthermore, the doped lanthanide complexes showed longer luminescence lifetimes and higher quantum yields than pure terbium complex. The enhanced luminescence efficiencies of Tb3+ ions in the doped complexes might result from the antenna effect of the two carboxylate ligands as well as the decrease of the self-quench of the Tb3+ ions induced by the doped lanthanide ions.     

Synthesis of Phosphors(Ce0.67Tb0.33)MgAl11O19 and BaMgAl10O17:Eu2+ by Microwave Irradiation Technique and Their Luminescent Properties

The phosphors(Ce0.67Tb0.33)MgAl11O19(P-G) and BaMgAl10O17∶Eu2+(P-B) have been synthesized using the microwave irradiation technique. The data of X-ray powder diffraction(d-values and I/I0-values) are basically coincided with the data of JCPDF 36-73 and 26-163 cards. The calculated cell dimensions are a=0.5582 nm, c=2.1884 nm for P-G, and a=0.5616 nm, c=2.2614 nm for P-B. The excitation spectra and the emission spectra of the phosphors were measured. The chromatic coordinates are x=0.316, y=0.565 for P-G, and x=0.156, y=0.106 for P-B. The relative luminescent intensity is about 88%(P-G) and 80%(P-B), respectively, compared with the same commercial phosphors. The phosphors were also detected by scanning election microscope.     

原料Al2O3与CMAT绿色荧光粉的晶体形貌及性能的关系

采用SEM、XRD、BET及发光光谱等手段研究了原料Al2O3形貌与高温固相反应合成的Ce0.67Tb0.33MgAl11O19(简称CMAT)绿色荧光粉粉体形貌与组成、结构及发光性质的关系.结果表明,Al2O3的形貌与CMAT荧光粉的形貌有一定的对应关系.不同形貌的CMAT的发光性能特别是初始光效和光衰有明显的差异.     

用溶胶-凝胶法制备Y2O3-SiO2∶Tb3+发光材料

采用溶胶-凝胶法制备了Y2O3-SiO2∶Tb3+发光材料.研究了Tb3+浓度、Y2O3和SiO2配比、烧结温度、烧结时间对发光强度的影响及其发光行为.     

用溶胶-凝胶法制备Y_2O_3-SiO_2:Tb~(3+)发光材料

采用溶胶-凝胶法制备了Y2O3-SiO2∶Tb3+发光材料。研究了Tb3+浓度、Y2O3和SiO2配比、烧结温度、烧结时间对发光强度的影响及其发光行为。     

BaAl12O19中Mn2+和Tb3+的发光及Tb3+对Mn2+的能量传递

采用溶胶-凝胶法合成了Mn2+、Tb3+单掺及共掺的BaAl12O19荧光粉,对其发光性质和Tb3+对Mn2+的能量传递机理进行了研究.研究结果表明,Tb3+单掺的BaAl12O19荧光粉,发射峰位于440nm、489nm、543nm、587nm和623nm,属于Tb3+的5D3→7FJ和5D4→7FJ (J=6,5,4,3)跃迁发射;Mn2+单掺的荧光粉,发射峰位于516nm,归属于Mn2+的4T1→6A1跃迁发射.Mn2+,Tb3+共掺后,Mn2+的发射强度明显提高,而Tb3+的发光强度降低,Tb3+对Mn2+有能量传递作用.初步证实Tb3+对Mn2+的能量传递机理为激子能量传递.     

Effect of Tb(Ⅲ) on the unfolding of ciliate Euplotes octocarinatus centrin induced by guanidine hydrochloride

To understand the unfolding of ciliate Euplotes octocarinatus centrin(EoCen), the glycine positioned at 115, the sixth residue of the loop of the protein's third EF-hand, was mutated into tryptophan(Trp).Intrinsic fluorescence and Tb(Ⅲ) binding properties of wild type EoCen and G115W mutant were monitored by fluorescence spectra in 10 mmol/L Hepes. The emission maximum of EoCen was 306 nm and mutation had no impact on the Tb(Ⅲ) binding properties. The properties of G115W were investigated by fluorescence, far-UV circular dichroism(CD) spectra and fluorescence decays in the absence or in the presence of 6 mol/L guanidine hydrochloride(GdnHCl). For the increase in polarity of microenvironment around Trp residue, the emission maximum of apoG115 W at 343 nm is shifted to 359 nm in 6 mol/L GdnHCI. Also the secondary structure is lost nearly and fluorescence lifetime decreases in 6 mol/L GdnHCI. The unfolding of G115W induced by GdnHCI was assessed by using the model of structural element The unfolding of proteins is a sequential reaction, namely two-transition. three-state process. The first transition belongs to the unfolding of the C-terminal domain, and the second transition is assigned to the unfolding of the N-terminal domain. The ⊿〈△G_(total)~0(H_2O)〉 was used to determine the effect of Tb(Ⅲ) on the stability of apoprotein. The 〈△G_(total)~0(H_2 O)〉for Tb_2-G115 W has a less increase of0.68 kJ/mol compared with apoG115W, proving Tb(Ⅲ) situated at C-terminal has negligible impact on the stability of protein. Whereas the △G_(total)~0(H_2 O) for Tb_4-G115W has a rise of 1.29 kJ/mol compared with Tb_2-G115W, manifesting Tb(Ⅲ) lcocated at low affinity sites has considerable influence on protein stability. mainly stabilizing the N-terminal domain.