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1.
采用ESR、CD谱和荧光光谱研究了pH=6.3时六次甲基四胺-HCl缓冲溶液中LaCl3和TbCl3与Cu(Zn)-SOD的配位作用和结构。Cu(Zn)-SOD可增强Tb^3+的荧光发射,Tb^3+与Cu(Zn)-SOD有多个配位位置,其中有2个强结合位点,La^3+可Tb^3+可竞争Cu(Zn)…SOD上相同结合位点,77K下La^3+与Tb^3+使Cu(Zn)-SOD的Cu^2+活性中心的配位  相似文献   

2.
应用荧光光度法研究了Tb^3+与牛胰脱氧核糖核酸酶(BPD),枯草杆菌α-淀粉酶(BSα-A)的络合发光现象,实验表明,BPD和BSα-A分别在PH=7-8和5-6范围内与Tb^3+络合,并发射Tb^3+的特征荧光,Tb^3+与BPD和BSα-A的络合比分别为2:1和4:1。并应用Forster理论测定了Tb^3+与BPD和BSα-A之间能量传递的距离R分别为1.39nm和1.48nm,其临界距离  相似文献   

3.
吡嗪-2,3-二羧酸体系导数荧光法同时测定铕、铽   总被引:2,自引:0,他引:2  
研究了以吡嗪-2,3-二羧酸(PYDA)为荧光试剂应用导数荧光技术同时测定Eu~(3+)、Tb~(3+)的最佳条件、共存离子的影响和Eu~(3+)、Tb~(3+)-PYDA配合物的配合比、稳定常数及发光机理。Eu~(3+)、Tb~(3+)的检测限分别达4.0和2.0ng/mL,利用本方法成功地测定了稀土试样中铕、铽的含量。  相似文献   

4.
植物细胞外钙调素的稀土发光探针研究   总被引:10,自引:1,他引:9  
从植物中提纯了细胞外钙调素(CaM),并利用NAD激酶激活作用及拮抗剂的抑制作用进行了CaM特性试验。利用稀土(Tb^3+)发光探针测得胞外CaM具有4个金属离子结合位点。敏化Tb^3+激发光谱结果证明其含有1个Tyr残基。胞外CaM(Yyr?能够向Tb3+传能并使Tb3+特征发光增强。根据Forster能量传递理论测得胞外CaM中Tyr→Ⅲ,Ⅳ位之间距离分别为1.104和1.056nm,它们均小  相似文献   

5.
研究了Gd_xY_(1-x)P_5O_(14):Ce_(0.01),Tb_(0.02)体系中Gd的子晶格在Ce→Gd→Tb能量传递中的中介作用规律及GdP_5O_(14),GdP_5O_(14):Ce,GdP_5O_(14):Tb和Gd_xY_(1-x)P_5O_(14):Ce,Tb的荧光光谱、激发光谱。结果表明,当x>0.7时,结构从单斜Ⅱ(C2/c)的层状结构变为单斜I(P2_1/c)的带状结构,Ce ̄(3+)的发射光谱和Gd ̄(3+)的吸收光谱交迭增加等是Ce ̄(3+)→Gd ̄(3+)→Tb ̄(3+)能量传递几率增加的主要原因。  相似文献   

6.
研究发现La^3+(Lu^3+,Y^3+)对Tb^3+均苯四甲酸(BTCA)体系具有强烈的共发荧光效应,在最佳条件下,共发光离子La^3+,Lu^3+,Y^3+可分别使Tb-BTCA体系的荧光增强312,133和100倍,介绍了Tb-La(Lu,Y)-BTCA共发荧光体系的荧光特点,形成条件和影响因素,利用La^3+(Lu^3+,Y^3+)的增敏效应,测定了合成稀土样品和包头稀土标准氧化物中的Tb  相似文献   

7.
用高温固相法合成了系列化合物RE0.06La0.94M2O6Br(M=Nb,Ta;RE=Eu,Tb,Pr,Sm),并测定了其激发和发射光谱。室温下Eu^3+,Tb^3+,Pr^3+,Sm^3+在稀土-铌(钽)复合溴氧化物中呈现特征激发谱线,但Nb和Ta的光谱特性稍有不同。  相似文献   

8.
张春梅  徐岩 《分析化学》1997,25(4):491-491
1引言作者等曾报道水杨酸苯酯-TritonX-100-Gd3+增敏体系荧光法测定Tb3+。为了进一步提高测定的灵敏度并探讨同时测定Dy3+的可能性,本文探讨了乙、丁、戊酯等烷基酯对测定的影响。结果表明,丁酯体系的灵敏皮最高,在该体系中Dy3+的特征荧光也明显加强,在Lu3+共存下Tb3+、Dy3+的检测限分别达到0.2和8.0μg/L,对Tb3+而言,灵敏度较苯酯-Gd3+增敏体系提高了10倍。2实验部分2.1试剂与仪器1g/LTb3+、Dy3+标准溶液;3.5×10-2mol/L水杨酸酯(乙、…  相似文献   

9.
合成了14种稀土元素与3吡啶甲酸(HL)及邻菲咯啉(Phen)的三元配合物,通过元素分析和化学分析确定其化学组成为REL3·Phen,并利用IR、UV、1HNMR、TGDTA和X射线粉末衍射等手段对配合物进行了表征.研究了Eu(Ⅲ)及Tb(Ⅲ)配合物的荧光性质.  相似文献   

10.
研究了稀土五磷酸盐Gdx1-XP5O14:Ce,Tb体系的制备,结构和光谱性质。当x>0.7时,该材料属单斜晶系I,P21/c结构,当≤0.7时,属单斜晶系Ⅱ,C2/c结构。研究了GdP5O14:Ce,Tb6 YP5O14:Ce,Tb的荧光光谱,确定了通过基质Gd离子中介的Ce^3+→Gd^3+→Tb^3+能量传递的现象。  相似文献   

11.
Three-dimensional (3D) nanostructured CaWO(4):Tb(3+)microspheres assembled by submicrospindles were synthesized via a mild sonochemical route from an aqueous solution of CaCl(2), TbCl(3) and Na(2)WO(4) with the aid of surfactant Polyglycol 600 (PEG-600). The crystal structure and morphology of the as-prepared products were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Rietveld refinement was carried out on the XRD data. The results showed that the CaWO(4):Tb(3+)nanoparticles can be formed without ultrasonic irradiation or addition of PEG-600. With continuously increasing irradiation time the submicrospindles and microspheres could be self-assembled. The central diameter and length of the submicrospindles are around 190 and 500 nm, respectively. The 3D CaWO(4):Tb(3+)nanostructured microspheres with diameter of 2-4 μm were assembled by the submicrospindles. A possible formation mechanism for the 3D-structured CaWO(4):Tb(3+)microspheres was proposed. The Photoluminescent (PL) properties of Tb(3+) ions in the nanostructured CaWO(4) microspheres were studied. The energy transfer processes in CaWO(4):Tb(3+)microspheres were analyzed. The electric dipole-dipole energy transfers related to (5)D(3) level were studied by inspecting the fluorescence decay of (5)D(3) level. The energy transfer critical distance was estimated.  相似文献   

12.
Xie M  Tao Y  Huang Y  Liang H  Su Q 《Inorganic chemistry》2010,49(24):11317-11324
The VUV-vis spectroscopic properties of Tb(3+) activated fluoro-apatite phosphors Ca(6)Ln(2-x)Tb(x)Na(2)(PO(4))(6)F(2) (Ln = Gd, La) were studied. The results show that phosphors Ca(6)Gd(2-x)Tb(x)Na(2)(PO(4))(6)F(2) with Gd(3+) ions as sensitizers have intense absorption in the VUV range. The emission color of both phosphors can be tuned from blue to green by changing the doping concentration of Tb(3+) under 172 nm excitation. The visible quantum cutting (QC) via cross relaxation between Tb(3+) ions was observed in cases with and without Gd(3+). Though QC can be realized in phosphors Ca(6)La(2-x)Tb(x)Na(2)(PO(4))(6)F(2), we found that Gd(3+)-containg phosphors have a higher QC efficiency, confirming that the Gd(3+) ion indeed plays an important role during the quantum cutting process. In addition, the energy transfer process from Gd(3+) to Tb(3+) as well as (5)D(3)-(5)D(4) cross relaxation was investigated and discussed in terms of luminescence spectra and decay curves.  相似文献   

13.
Wang X  Wang Y  Liu Q  Li Y  Yu J  Xu R 《Inorganic chemistry》2012,51(8):4779-4783
A family of novel 2D-layered lanthanide germanates K(3)[Tb(x)Eu(1-x)Ge(3)O(8)(OH)(2)] (x = 1, 0.88, 0.67, 0; denoted as TbGeO-JU-87, Tb(0.88)Eu(0.12)GeO-JU-87, Tb(0.67)Eu(0.33)GeO-JU-87, and EuGeO-JU-87) were synthesized under mild hydrothermal conditions in a concentrated gel system. They are isostructural, as confirmed by the powder X-ray diffraction analysis. The single-crystal X-ray diffraction analysis of EuGeO-JU-87 reveals that it is a 2D-layered [EuGe(3)O(8)(OH)(2)](n)(3n-) anionic framework, which is built up from GeO(4)H/GeO(4) tetrahedra and EuO(6) octahedra by sharing vertex O atoms. Charge neutrality is achieved by K(+) ions located in the free void space. Interestingly, photoluminescence studies show that Tb(0.88)Eu(0.12)GeO-JU-87 and Tb(0.67)Eu(0.33)GeO-JU-87 exhibit a high Tb(3+)-to-Eu(3+) energy-transfer efficiency and the Tb(x)Eu(1-x)GeO-JU-87 system displays tunable photoluminescent properties.  相似文献   

14.
A series of Pr(1-x)Ca(x)CoO(3) samples were prepared using a novel molten salt reaction that is convenient to obtain single phases avoiding aggregates compared to conventional solid state reactions. The formation reaction was monitored by X-ray diffraction combined with thermal analysis, and all samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and alternating current impedance. It is demonstrated that all Pr(1-x)Ca(x)CoO(3) samples crystallized in a pure orthorhombic perovskite structure. By increasing the doping level, the symmetry of the orthorhombic structure was enhanced, and is followed by an increase in the population of Co(3+) in the intermediate spin state. All samples exhibited typical semiconducting behavior, showing conductivities highly dependent on the Ca(2+) doping. The conduction for x = 0 shows a simple thermal activated process, which changed into a Mott's variable range hopping mechanism for x > 0. By increasing the Ca(2+) doping level, the relevant activation energy is decreased, while the density of the localized electronic state is increased.  相似文献   

15.
The physical and chemical properties of bulk Ce(1-x)Tb(x)O(2) and Ce(1-x)Tb(x)O(y) nanoparticles (xTb exchange nor the introduction of oxygen vacancies in Ce(1-x)Tb(x)O(y) significantly affect the charge on the Ce cations. In contrast, the O K-edge and Tb L(III)-edge XANES spectra for Ce(1-x)Tb(x)O(y) nanoparticles show substantial changes with respect to the corresponding spectra of Ce and Tb single oxide references. The Ce(0.5)Tb(0.5)O(y) compounds exhibit a much larger Tb(3+)/Tb(4+) ratio than TbO(1.7). A comparison with the properties of Ce(1-x)Zr(x)O(y) and Ce(1-x)Ca(x)O(y) shows important differences in the charge distribution, the magnitude of the dopant induced strain in the oxide lattice, and a superior behavior in the case of the Ce(1-x)Tb(x)O(y) systems. The Tb-containing oxides combine stability at high temperature against phase segregation and a reasonable concentration of O vacancies, making them attractive for chemical and catalytic applications.  相似文献   

16.
Gd(2)(WO(4))(3) doped with Eu(3+) or Tb(3+) thin phosphor films with dot patterns have been prepared by a combinational method of sol-gel process and microcontact printing. This process utilizes a PDMS elastomeric mold as the stamp to create heterogeneous pattern on quartz substrates firstly and then combined with a Pechini-type sol-gel process to selectively deposit the luminescent phosphors on hydrophilic regions, in which a Gd(2)(WO(4))(3):Ln(3+) (Ln=Eu, Tb) precursor solutions were employed as ink. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectra, as well as low voltage cathodoluminescence (CL) spectra were carried out to characterize the obtained samples. Under ultraviolet excitation and low-voltage electron beams excitation, the Gd(2)(WO(4))(3):Eu(3+) samples exhibit a strong red emission arising from Eu(3+)(5)D(0,1,2)-(7)F(1,2) transitions, while the Gd(2)(WO(4))(3):Tb(3+) samples show the green emission coming from the characteristic emission of Tb(3+) corresponding to (5)D(4)-(7)F(6,5,4,3) transitions. The results show that the patterning of rare earth-doped phosphors through combining microcontact printing with a Pechini-type sol-gel route has potential for field emission displays (FEDs) applications.  相似文献   

17.
Hexagonal monodisperse NaCeF(4) and NaCeF(4):Tb(3+) nanorods have been successfully synthesized by a polyol-mediated solvothermal route with ethylene glycol (EG) as solvent. The crystalline phase, size, morphology, and luminescence properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectra as well as dynamic decays. The experimental results indicate that the content of NH(4)F and NaNO(3) are crucial in controlling product morphology and size. Nanorods with different aspect ratios could be controllably obtained under settled conditions. Shape-dependent luminescence and energy transfer routes from Ce(3+) to Tb(3+) in NaCeF(4):Tb(3+) nanorods were observed by the modified local crystal field environment around rare earth ions. The 4f-5d transitions of Ce(3+) ions have much higher sensitivity to the anisotropic shape of samples than that of Tb(3+) ions.  相似文献   

18.
C Liu  H Liang  X Kuang  J Zhong  S Sun  Y Tao 《Inorganic chemistry》2012,51(16):8802-8809
A series of Ca(3)La(3(1-x))Ce(3x)(BO(3))(5) phosphors were prepared by a high-temperature solid-state reaction technique. Rietveld refinement was performed using the powder X-ray diffraction (XRD) data, which shows occupation of Ce(3+) on both Ca(2+) and La(3+) sites with a preferred location on the La(3+) site over the Ca(2+) site. The prepared samples contain minor second phase LaBO(3) with contents of ~0.64-3.27 wt % from the Rietveld analysis. LaBO(3):1%Ce(3+) was prepared as a single phase material and its excitation and emission bands were determined for identifying the influence of impurity LaBO(3):Ce(3+) luminescence on the spectra of the Ca(3)La(3(1-x))Ce(3x)(BO(3))(5) samples. The luminescence properties of Ca(3)La(3(1-x))Ce(3x)(BO(3))(5) samples under vacuum ultraviolet (VUV) and UV excitation were investigated, which exhibited two-center luminescence of Ce(3+), assigned to the Ce(1)(3+) center in the La(3+) site and Ce(2)(3+) center in the Ca(2+) site, taking into account the spectroscopic properties and the Rietveld refinement results. The influences of the doping concentration and the excitation wavelength on the luminescence of Ce(3+) in Ca(3)La(3(1-x))Ce(3x)(BO(3))(5) are discussed together with the decay characteristics.  相似文献   

19.
刘胜利  苏锵 《中国化学》2004,22(5):437-440
The luminescence properties of aluminate sodalite Ca8[Al12024](WO4)2 (CAW) undoped and doped with Th^3 are reported and discussed. At room temperature the emission of tetrahedral WO4^2- in CAW showed an abnormally small Stokes shift (9060 cm^-1), which is related to the crystal structure of CAW. A strong absorption band in the excitation spectrum of the Th^3 -activated CAW is ascribed to the absorption of the charge transfer state Th^4 -W^5 , into which the excitation resulted in the efficient emission from the ^5D4 level of Tb^3 , but not from the ^5D3 level.  相似文献   

20.
《结构化学》2020,39(8):1515-1521
Rare earth phosphates have been used extensively in luminescent phosphors. Hexagonal Ce_(1-x)Gd_xPO_4 with crystal field manipulation was successfully synthesized using a hydrothermal method. The photoluminescence emission intensity of hexagonal CePO_4 was obviously enhanced by the crystal structure manipulation with gadolinium ions codoping. Compared to pure CePO_4, the intensity photoluminescence was enhanced about 15 folds with x = 0.05. The effect of gadolinium doping was systematically investigated by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and photoluminescence spectroscopy. Crystal field asymmetry can be effectively tuned by different amount of Gd~(3+) codoping, and the crystal field asymmetry is conductive to electron population of high energy level of Ce~(3+) ions. This material has potential applications in optics, electronics fields, and so on. Meanwhile, the method can be extended to another kind of high performance photoluminescence materials preparation.  相似文献   

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