Tunable white light emission from single‐phased Li2SrSiO4:Dy3+ phosphors by co‐doping with Eu3+

A series of single‐phase full‐color emitting Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors were synthesized by solid‐state reaction and characterized by X‐ray diffraction and photoluminescence analyses. The samples showed emission peaks at 488 nm (blue), 572 nm (yellow), 592 nm (orange) and 617 nm (red) under 393 nm excitation. The photoluminescence excitation spectra, comprising the Eu–O charge transfer band and 4f–4f transition bands of Dy³⁺ and Eu³⁺, range from 200 to 500 nm. The Commission Internationale de I'Eclairage chromaticity coordinates for Li₂Sr_0.98−xSiO₄:0.02Dy³⁺,xEu³⁺ phosphors were simulated. By manipulating Eu³⁺ and Dy³⁺ concentrations, the color points of Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ were tuned from the greenish‐white region to white light and eventually to reddish‐white region, demonstrating that a tunable white light can be obtained by Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors. Li₂Sr_0.98−xSiO₄:0.02Dy³⁺, xEu³⁺ can serve as a white‐light‐emitting phosphor for phosphor‐converted light‐emitting diode. Copyright © 2014 John Wiley & Sons, Ltd.     

兽用疫苗管理与控制的国际标准

兽用疫苗是兽医医学产品,需接受像医学产品相同或相似的管理和控制标准,这意味着动物疫苗必须满足复杂的要求,保障产品在预期使用条件下的质量、安全性和免疫效力.在动物医药领域中,欧盟和美国的动物疫苗管理和控制体系发展早,制度完整,为其他国家和地区建立良好的动物疫苗管理与控制标准提供了有价值的参考信息.另外,统一各个国家和地区...     

Luminescence enhancement of (Sr1–xMx)2SiO4:Eu2+ phosphors with M (Ca2+/Zn2+) partial substitution for white light‐emitting diodes

Eu²⁺‐doped Sr₂SiO₄ phosphor with Ca²⁺/Zn²⁺ substitution, (Sr_1–xM_x)₂SiO₄:Eu²⁺ (M = Ca, Zn), was prepared using a high‐temperature solid‐state reaction method. The structure and luminescence properties of Ca²⁺/Zn²⁺ partially substituted Sr₂SiO₄:Eu²⁺ phosphors were investigated in detail. With Ca²⁺ or Zn²⁺ added to the silicate host, the crystal phase could be transformed between the α‐form and the β‐form of the Sr₂SiO₄ structure. Under UV excitation at 367 nm, all samples exhibit a broad band emission from 420 to 680 nm due to the 4f⁶5d¹ → 4f⁷ transition of Eu²⁺ ions. The broad emission band consists of two peaks at 482 and 547 nm, which correspond to Eu²⁺ ions occupying the ten‐fold oxygen‐coordinated Sr.(I) site and the nine‐fold oxygen‐coordinated Sr.(II) site, respectively. The luminescence properties, including the intensity and lifetime of Sr₂SiO₄:Eu²⁺ phosphors, improved remarkably on Ca²⁺/Zn²⁺ addition, and promote its application in white light‐emitting diodes. Copyright © 2016 John Wiley & Sons, Ltd.     

Mechanoluminescence of SrAl2O4:Eu,Dy nanophosphors induced by low impact velocity

The present paper reports the impulsive excitation of mechanoluminescence (ML) in Sr_0.97Al₂O₄:Eu_0.01,Dy_0.02 nanophosphors prepared using a combustion technique. The phosphors are characterized using X‐ray powder diffraction (XRD), high‐resolution transmission electron microscopy (HRTEM) and photoluminescence (PL). The XRD results show that the samples exhibit a monoclinic α‐phase in the crystal structure. The space group of SrAl₂O₄:Eu,Dy nanophosphors is monoclinic P2₁. The PL and ML spectra of SrAl₂O₄:Eu,Dy nanophosphors are excited using light with a wavelength of 365 nm and emission is found at 516 nm. The prepared nanophosphors exhibits an intense ML that can be seen in daylight with the naked eye. When a sample powder is deformed impulsively by the impact of a moving piston, the ML intensity initially increases linearly with time, attains a peak value, I_m, at time t_m, and then decreases with time. The peak ML intensity, I_m, and total ML intensity, I_T, increase linearly with applied pressure and impact velocity. The ML intensity decreases with successive impacts of load onto the phosphors, and the diminished ML intensity can be approximately recovered by UV irradiation. The activation energy using thermoluminescence is found to be 0.57 eV for SrAl₂O₄:Eu,Dy nanophosphors. Copyright © 2016 John Wiley & Sons, Ltd.     

Cathodic electrochemiluminescence of acetonitrile, acetonitrile-1,10-phenanthroline and acetonitrile-ternary Eu(III) complexes at a gold electrode.

Cathodic electrochemiluminescence (ECL) behaviours of the acetonitrile, acetonitrile-1,10-phenanthroline (phen) and acetonitrile-ternary Eu(III) complex systems at a gold electrode were studied. One very weak cathodic ECL-2 at -3.5 V was observed in 0.1 mol/L tetrabutylammonium tetrafluoroborate (TBABF(4)) acetonitrile solution. When 10 mmol/L tetrabutylammonium peroxydisulphate [(TBA)(2)S(2)O(8)] was added to 0.1 mol/L TBABF(4) acetonitrile solution, another cathodic ECL-1 at -2.7 V appeared and the potential for ECL-2 was shifted from -3.5 to -3.1 V. Furthermore, ECL-2 intensity was enhanced about 20-fold. When 1 x 10(-4) mol/L phen was added to 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution, the ECL intensities of ECL-1 and ECL-2 were enhanced about 20-fold compared with those of 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution. The maximum emission peaks of ECL-1 and ECL-2 in the three systems mentioned above appeared at about 530 nm. The products obtained by electrolysing 0.1 mol/L TBABF(4) acetonitrile solution at -3.5 V for 20 min were analysed by Fourier Transform Infrared (FTIR) spectra and gas chromatography-mass spectrometry (GC-MS) and the emitter of ECL-1 and ECL-2 was identified as excited state polyacetonitrile. When ternary Eu(III) complexes were presented in 0.1 mol/L TBABF(4) + 10 mmol/L (TBA)(2)S(2)O(8) acetonitrile solution, another maximum emission peak with a narrow band centred at about 610 nm appeared in ECL-1 in addition to the maximum emission peaks at about 530 nm for ECL-1 and ECL-2. The emitter of ECL emission at 610 nm was identified as the excited states Eu(III)*. The mechanisms for cathodic ECL behaviours of the acetonitrile, acetonitrile-phen and acetonitrile-ternary Eu(III) complex systems at a gold electrode have been proposed. The extremely sharp emission bands for ternary Eu(III) complexes may have analytical potential.     

Synthesis and study of the labeling of pregnenolone and progesterone specifically tritiated at the 17 position

The action of tritiated acetic acid on 17-bromopreg-[3_H] nenolone acetate treated with zinc metal dust produces 17 pregnenolone acetate which is then hydrolyzed to form 17 [3_H] pregnenolone.The flavobacterium dehydrogenans transforms the 17-bromopregnenolone into 17-bromoprogesterone which can also be tritiated by tritiated acetic acid to obtain 17 [3_H] progesterone. The study of the label distribution by different analytic techniques (I.R., nuclear magnetic resonance, mass spectrometry) as well as the. chemical and selective biochemical reactions indicate a specific labeling higher than 85% on the 17 position.     

White light emission and energy transfer of LaMgAl11O19:Eu3+, Tb3+ phosphors

White-light-tunable LaMgAl₁₁O₁₉:x%Tb³⁺, y%Eu³⁺ series phosphors were prepared using the gel-combustion method. The structure and luminescence properties were studied, and the energy transfer of Eu³⁺ and Tb³⁺ in the LaMgAl₁₁O₁₉ system was also discussed. The results showed that the LaMgAl₁₁O₁₉ matrix exhibited strong emission in the blue-light region under the excitation of ultraviolet light, which resulted in conditions suitable for the preparation of white-light-tunable phosphors. The emission spectra of LaMgAl₁₁O₁₉:2%Tb³⁺, y%Eu³⁺ (y = 2%–9%) series phosphors were obtained through optimization experiments. It could be seen from the CIE diagram that by adjusting the doping quantities of Eu³⁺ and Tb³⁺ in the LaMgAl₁₁O₁₉ host, multicolor luminescence and white light emission in a single host could be achieved. By calculating the energy transfer efficiency and critical distance between Eu³⁺ and Tb³⁺ series phosphors, the mechanism of energy transfer between Tb³⁺ and Eu³⁺ was found to be the interaction between electric quadruples.     

Imaging and spatial distribution of beta-amyloid peptide and metal ions in Alzheimer's plaques by laser ablation-inductively coupled plasma-mass spectrometry

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) has been developed as a new strategy for detection and imaging of β-amyloid protein in immunohistochemical sections from the brains of a transgenic mouse model of Alzheimer’s disease. The distribution of β-amyloid deposits in tissue was based on measurement of Eu- and Ni-coupled antibodies. The laser-based methodologies (spot ablation, single line raster, and two-dimensional imaging) were also used to detect and map trace element distributions and thus provide a novel probe for both elemental and protein data. We also report the combination of laser capture microdissection with LA-ICP-MS as an alternative strategy for microanalysis of immunohistochemical sections.     

Synthesis and luminescence properties of cubic‐shaped Ca1‐xTiO3:Eu3+ particles

In this article Ca_1‐xTiO₃:xEu³⁺ single crystalline particles with a cubic morphology and average size of 248 to 815 nm were synthesized by a solvothermal method. The structural and optical properties of the Ca_1‐xTiO₃:xEu³⁺ cubes were investigated, the formation mechanism of the cubes were analyzed and discussed, and the influence of Eu doping content and cubic size on the photoluminescence were examined. The differences in the photoluminescence between Ca_1‐xTiO₃:xEu³⁺ cubic crystals and nanoparticles was analyzed. It was found that an addition of a small amount of water can substantially reduce the size of the cubes. An obvious red emission band centered at 615 nm was observed under the excitation at 395 nm for the cubes. Our results demonstrate CaTiO₃ cubes are good host materials for designing red phosphors.     

铕螯合剂DTTAEuNa标记流行性出血热单克隆抗体的实验研究

用Ｎ′（对异硫氰基苄基）二乙三胺Ｎ１,Ｎ２,Ｎ３四乙酸铕钠（ＤＴＴＡＥｕＮａ）作为螯合剂,标记不同蛋白浓度的流行性出血热单克隆抗体（ＥＨＦＭｃＡｂ）,经ＳｅｐｈａｋｅｘＧ５０凝胶柱分离标记的单抗分子,通过对层析液的紫外吸收峰处的蛋白光密度,时间分辨荧光强度以及免疫活性测定表明：二批Ｅｕ标记单抗的比活性分别为７８和１４７个Ｅｕ３＋／ＥＨＦＭｃＡｂ,标记回收率分别为４１％和４２％,标记物的免疫活性良好,可用于流行性出血热的抗原及抗体检测