首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 806 毫秒
1.
Trivalent rare-earth ions (La3+,Pr3+,Nd3+,Sm3+,Gd3+,Tb3+,Dy3+,Ho3+,Er3+,Tm3+,and Yb3+) were investigated as the codoped auxiliary sensitizer for the electron trapping materials SrS:Eu2+ in order to enhance the fluorescence properties.It was found that Sm3+ and Tb3+ had the best photoluminescence stimulated luminescence (PSL) effect among the selected trivalent rare-earth ions.All the SrS:Eu2+ samples doped by different trivalent rare-earth ions could be stimulated by 980 nm laser after being exposed to the conventional sunlight,and they emitted PSL with the peak located at 615 nm.The result also indicated that some co-doped rare earth ions could increase fluorescence intensities of the traditional electron trapping materials SrS:Eu2+.  相似文献   

2.
以香豆素为主配体,邻菲罗啉、三苯基氧化磷、氨替吡啉、水这些中性配体作为第二配体,合成了不同稀土离子(Eu3+、Tb3+、Sm3、Dy3+)的配合物,通过元素分析、红外、紫外、荧光光谱等分析,表征了这些配合物的组成结构和发光性能.结果表明,在所合成的配合物中,香豆素与铕、邻菲罗啉形成的配合物发光强度最强,对其掺入不同比例的钆,发现可改变该配合物的发光强度.  相似文献   

3.
1 ,10 Phenanthrolinehasbeenextensivelyusedasanazaheterocyclicchelateligandinbothanalyticalandpreparativecoordinationchemistry[1] .Asanim portantligand ,1,10 phenanthrolineunitplaysanim portantroleforthedevelopmentofthesupramolecularchemistry .Manynovelsupramolecularcompoundsin clude 1,10 phenanthrolineunit[2~ 4 ] .Furthermore ,consideringtheuniquecombinationofchemicalstabil ities ,redoxproperties ,luminescenceemissionandex citedstatelifetime ,derivativesof 1,10 phenanthrolinehaveplayedama…  相似文献   

4.
Four new complexes RE(ABMF)2AA (RE=Sm, Eu, Tb, Dy) were synthesized by the reaction of RECl3·6H2O with acrylic acid (HAA) and 1-(2-furyl)-3-phenyl-1,3-propanedione (ABMF). The copolymerization of the rare earth complexes with methyl methacrylate was studied by using 2,2-azobis-isobutyronitrile as an initiator. The composition and structure of the four complexes were characterized by elemental analysis, UV-vis and FTIR. The glass transition temperature and molecular weight of the copolymers were determined. Photoluminescent measurement showed that ligand ABMF could efficiently transfer the energy to Sm3+ and Eu3+ ions in the complexes and sensitize the luminescence of the rare earth ions, but could not sensitize Tb3+ and Dy3+ ions. As a result, both Sm3+ and Eu3+ complexes emitted the characteristic fluorescence of Sm3+ and Eu3+ ions due to the f-f transitions. The four copolymers could emit strong fluorescence of the rare earth ions.  相似文献   

5.
The luminescence properties of CdSiO3:RE^3 phosphors doped with various rare earth ions are reported. The series of rare earth ions doped CdSiO3 phosphors are prepared by the conventional high-temperature solid-state method, and characterized by XRD and photoluminescence (PL) spectra. The results of XRD measurement indicate that the products fired under 1050 ~C for 3 h have a good crystallization without any detectable amount of impure phase. The PL spectra measurement results show that CdSiO3 is a novel self-activated luminescent matrix. When rare earth ions such as Y^3 ,La^3 , Gd^3 , Lu^3 , Ce^3 , Nd^3 , Ho^3 , Er^3 , Tm^3 and Yb^3 are introduced into the CdSiO3 host, one broadband centered at about 420 nm resulted from traps can be observed. In the case of other earth ions which show emissions at the visible spectrum region, such as Pr^3 , Sm^3 , Eu^3 , Tb^3 and Dy3 , the mixture of their characteristic line emissions with the ~420 nm strong broadband luminescence results in various emitting colors. As a consequence, different emitting colors can be attairied via introducing certain appropriate active ions into the CdSiO3 matrix. In additional, this kind of phosphors shows good long-lasting properties when excited by UV light. All the results show that CdSiO3 is a potential luminance matrix.  相似文献   

6.
SrGdGa3 O7belongstothelargefamilieswhosegeneralchemicalformulaisAMM′3 O7(A =Ca ,Sr ,Ba ;M =La ,Gd ,Y ;M′ =Al,Ga) .Thesecom poundshavemelilitestructure .Structuralinvestiga tionsindicatethatSrGdGa3 O7formstetragonalcrystalswithspacegroupP 4 2 1m .Theunit…  相似文献   

7.
S100 beta is a member of a group of low-molecular weight acidic calcium binding proteins widely distributed in the vertebrate nervous system containing two helix-loop-helix calcium binding motifs (sites I and II). In addition, S100 beta also has auxiliary Zn2+ binding sites that are distinct from the Ca2+ binding sites. Luminescence spectroscopy using Eu3+ and Tb3+ as spectroscopic probes for Ca2+ is used to characterize the Ca2+ binding sites of this protein. Eu3+-bound S100 beta shows two distinct Eu3+ binding environments from both the excitation spectrum and Eu3+ excited state lifetimes. Eu3+ bound to the classical EF hand site II has a Kd of 660 +/- 20 nM, whereas the dissociation constant for the pseudo-EF hand site I is significantly weaker. Lifetimes in H2O and D2O lead to the finding that there are four water molecules coordinated to the Eu3+ in the weakly binding site I and two water molecules to the tightly binding site II. Site II in S100 beta expectedly is very similar to high-affinity Ln3+ binding domains I and II in calmodulin. Eu3+ luminescence experiments with Zn2+-loaded S100 beta show that the lifetime for Eu3+ in site I in Zn2+-loaded S100 beta is significantly different than that in the absence of Zn2+. Tyrosine-17-sensitized Tb3+ luminescence experiments indicate that the Tb3+ occupying the proximal weaker binding site I is sensitized, whereas Tb3+ in site II is not. The distance between sites I and II (15.0 +/- 0.4 A) in S100 beta was determined from Forster-type energy transfer in D2O solutions containing bound Eu3+ donor and Nd3+ acceptor ions. For Zn2+-S100 beta, the intersite distance is reduced to 13 +/- 0.3 A. Location of histidine-15 close to pseudo-EF site I suggests that Zn2+ binding likely changes the conformation of this site, causing a reduction of the intersite distance by approximately 2 A.  相似文献   

8.
Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen)L3·1/2H2O; Tb(phen)L3·H2O and Tb0.5RE0.5(Phen)L3·1/2H2O. (RE=Y3 , La3 and Gd3 ; L=biphenyl 4-carboxylic acid; phen=o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE(Ⅲ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 is raised by inert fluorescent rare earth ions (Y3 , Gd3 and La3 ), but in Tb3 hetero-nuclear rare earth complexes the intensity of Tb3 ions are quenched by the inert fluorescent rare earth ions.  相似文献   

9.
Three new rare earth ternary complexes,RE(PPP)3bpy(RE=Sm 3+ ,Eu 3+ ,Tb 3+ ),were synthesized by the reaction of 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione(HPPP)and 2,2′-bipyridine(bpy)with rare earth chloride RECl3,respectively,in alcohol solution. The compositions were characterized by means of infrared(IR)spectra,chemical analysis,elemental analysis,and thermodynamic analysis.Luminescent properties of the three complexes were studied.At room temperature,under UV light excitation,the Sm 3+ ,Eu 3+ and Tb 3+ complexes exhibited characteristic emission of the central ions.The fluorescence spectra showed that the fluorescence emission intensity of Eu 3+ complex was the strongest.The narrow strongest emission band of Eu 3+ complex was considered to be a valuable material with bright red fluorescence.  相似文献   

10.
Sinceaza crownethershowsspecialcoordinationpropertiestotransitionmetalandheavymetalions[1,2 ] ,therearemanyreportsofthecomplexesinhost guestchemistry ,molecularrecognition[3 ,4] andionophoreinmembranetransportation[5] ,butthereislittlereportontheirrareearthscomplexesandthefluorescenceaboutthecomplexes[6] ,andthefluorescenceintensityoftheircomplexesarenotverystrong .Weinsetbenzoylgroupintothemacrocycle ,expectingthatitsrareearthscomplexeshavebetterfluorescenceproperties .Inthispaperthesynthesis…  相似文献   

11.
稀土金属离子对5,-AMP和3',5'-cAMP的水解切断作用   总被引:2,自引:1,他引:1  
用HPLC法研究了稀土金属离子RE3+(如La3+,Ce3+,Nd3+,Sm3+,Eu3+,Tb3+)对5’-腺苷-磷酸(5’-AMP)和3’,5’-腺苷环磷酸(3’,5’-cAMP)的催化水解切断作用。结果表明在温和条件下,稀土金属离子对5,-AMP无明显的切断作用,而Ce3+对3’,5’-cAMP有很好的切断作用;另外,H2O2的加入能极大地促进稀土金属离子对5’-AMP和3’,5’-cAMP的水解切断作用。pH值对稀土金属离子水解切断5’-AMP是有影响的。  相似文献   

12.
A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La2O3, CeO2, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Dy2O3) and Nd2O3 doping content on the microstructure and dielectric properties of Y2Ti2O7 ceramics were investigated. The experimental results showed that the rare earth ions were considered to dissolve in Y-sites of the pyrochlore structure, different rare earth oxides and concentration had different influences on Y2Ti2O7 cerami...  相似文献   

13.
Nd3+,Eu3+ and Tb3+ ions doped transparent chlorophosphate glass ceramics were prepared and their frequency-conversion properties were studied. X-ray diffraction (XRD) patterns evidenced the formation of expected halide nanocrystals. The absorption,excitation and emission spectra investigation indicated that some of rare earth (RE) ions were trapped in low phonon energy halide nanocrystals,and therefore an efficient down frequency-conversion was observed. The comparative spectroscopic studies of RE doped samples suggested that the glass ceramics systems are potentially applicable as efficient ultraviolet to visible frequency-conversion photonics materials.  相似文献   

14.
Themetalcomplexesofhydrazideshaveattractedconsiderableinterestowingtotheirantifungalandantibacterialactivities[1 ,2 ] .Theycanalsobeusedasanalyticalreagents[3 ]andextractingagentsformetalsalts[4 ] .Manycomplexesofhydrazideshavebeensynthesizedandcharacterized[5]…  相似文献   

15.
A series of Sc,Y,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Ho,Er,Tm and Yb complexes with oxybenzoquinoline ligands(BQ) was synthesized by the reactions of 10-hydroxybenzo[h]quinoline with cyclopentadienides or tris(trimethylsilyl)amides of rare earth metals.The structure,as well as the photo-and electroluminescent(PL,EL) properties of these complexes in solutions and solid state were studied.In solutions,complexes of sodium and lanthanides exhibit double peaked ligand-centered PL of enol and keto forms of BQ with a...  相似文献   

16.
用硝酸和氢氟酸溶解试样,高氯酸冒烟除氟,在硝酸介质中用电感耦合等离子体原子发射光谱法(ICP-AES)测定了镝铁电解粉尘中La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y 15种稀土元素。为了提高高含量元素的测定准确度,在测定基体元素Dy时,采用铟作内标;为了消除基体效应对稀土杂质元素测定的影响,采用基体匹配的校准曲线。镝铁电解粉尘中铁含量很低(铁的质量分数不超过1%),对测定没有影响。实验方法测定了一镝铁电解粉尘样品,结果表明,La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Ho、Er、Tm、Yb、Lu和Y 14个稀土杂质元素测定值与ICP-MS的测定值基本一致,镝和14个稀土元素的合量与重量法测得的稀土总量吻合。  相似文献   

17.
Raman spectra of a series of cubic rare earth sesquioxides RE2O3 (RE=Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y) were investigated by Raman spectroscopy with both 532 and 785 nm laser lines. Abundant additional bands due to laser-excited lumines-cence were observed. For Eu2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3 and Yb2O3, the luminescence mainly came from the intrinsic trivalent lanthanide ions, while for Gd2O3, Lu2O3, Sc2O3 and Y2O3, their luminescence were attributed to the trace impurities of other lumines-cent lanthanide ions such as Eu3+, Nd3+and Er3+. This investigation confirmed Raman spectroscopy as a useful tool for detecting trace luminescent lanthanide impurities.  相似文献   

18.
研究了各种有机溶剂对Eu^3 ,Tb^3 -吡嗪-2,3-羧酸荧光体系的增敏效应。结果发现:乙醇不仅能使Eu^3 ,Pb^3 的特征荧光增敏,而且也使Sm^3 ,Dy^3 的荧光增敏,在PH6.0,99.6%乙醇浓度体系中,Eu^3 ,Pb^3 的荧光强度分别提高44和16倍,实现了同时测定Sm^3 ,Eu^3 ,.Pb^3 ,Dy^3 四种离子,本方法已成功地应用于混合稀土氧化物中四者含量的测定。  相似文献   

19.
RE(NO_3)_3-HNO_3-P507-kerosene extraction system(RE=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)was studied by the response surface technique.14 models for extracting single rare earth ele-ment in a broad range of acidity and initial rare earth concentration were obtained by using the stepwiseregression method.Three-dimensional display of the response surface of the model of extracting Er~(3 )wasshowed as an example,which reveals clearly the dependence of distribution ratio upon both initial acidity and ini-tial rare earth concentration.  相似文献   

20.
Deep eutectic solvents(DESs) were used for luminescence measurements in quantitative analysis of trivalent lanthanide ions and as solvents for light rare earth elements(LREE) in solid-liquid separation.The spectroscopic characteristics of lanthanide chlorides LnCl_3(Ln=Eu,Tb),respectively their aquo complexes,are described in a comprehensive study that demonstrates the significant enhancement of the phosphorescence emission intensity in DESs as polar and weakly coordinating solvent.Several DESs stabilize the lanthanide ion luminescence against changes in temperature and moisture,which is advantageous compared with the use of ionic liquids.Small amounts of water lead in certain eutectic systems even to a further increase in phosphorescence emission intensity.By investigating the solubility of lanthanide sesquioxides Ln_2 O_3(Ln=La,Nd,Sm,Eu,Gd,Tb,Dy) in DESs,selectivities are identified that may be of use for the separation of LREE.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号