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排序方式: 共有113条查询结果,搜索用时 15 毫秒
1.
《Advanced Powder Technology》2022,33(8):103685
In this study, the synthesis and luminescence characterization of Samarium (Sm3+) doped lithium metasilicate (Li2SiO3) phosphor ceramic were investigated. It was presented and discussed the results obtained on the luminescence and other optical studies such as X-ray diffraction (XRD), optical absorption and luminescence properties of Li2SiO3:Sm3+ phosphor ceramic. The Li2SiO3 compound was shown a characteristic phase in XRD. The doping in the lithium compound was not having a significant effect on the basic crystal structure of the material. The maximum photoluminescence (PL) emission for Sm3+ doped Li2SiO3 was observed at 554, 583, 641, 725 nm and bore resemblance to the visible region of the spectrum. The glow curves of all synthesized materials have a complex peak structure after being irradiated with a 90Sr–90Y beta source. In addition, the peak between 400 and 600 nm was seen in the radioluminescence (RL) spectrum because of a wide peak thought to be caused by silicate. 相似文献
2.
合成了系列钆钐双核稀土有机配合物GdxSm1-x(TTA)3phen(x=0~0.9).红外光谱(IR)、X射线衍射(XRD)、热重(TG)结果推测了配合物可能的分子结构;紫外可见光谱(UV/vis)结果表明,该系列稀土有机配合物能有效的吸收紫外光,吸收峰主要来自于有机配体TTA和phen(270nm和351nm处);荧光光谱(FS)结果表明,Gd3+对于Sm3+具有荧光增效,当Gd3+的摩尔分数为0.6时,Gd0.6Sm0.4(TTA)3phen类配合物的特征荧光(562nm,596nm和643nm处)强度均达到最大. 相似文献
3.
Tianmu Lv Jiang Li Xiao Dong Ji Yu Baolong Yu Ping Li Xueli Yao Yicheng Zhao Yongdan Li 《International Journal of Hydrogen Energy》2017,42(27):17528-17535
In this work, a solid oxide fuel cell with 60 μm samarium doped ceria film as the electrolyte is fabricated with a co-pressing technique. The performance of the cell is measured at 600, 650 and 700 °C. The corresponding maximum power outputs are 236, 331 and 401 mW cm?2, respectively. The measured current–voltage (I–V) curves are straight lines. A linear discharge model is derived based on the Gorelov and Liu modified electromotive force (EMF) equations. The model fits the measured I–V curves with the maximum errors less than 1.5%. The overall activation overpotential of the cell is therefore postulated to be proportional to the polarization current. 相似文献
4.
In recent year, new nanocomposite electrolytes materials have been developed for low-temperature ceramic fuel cells (CFCs). To further improve the performance of CFCs based on the nanocomposite electrolyte, compatible active anode with sufficient low polarizations is needed. To improve the performance of anode, i.e. to enlarge tripe phase boundaries (TPB), anode materials with both porous structure and phase homogeneity of metal and ceramic are preferred. In the present study, we developed a novel microwave-assisted template-, surfactant-free synthesis route for mesoporous CuO–Ce0.8Sm0.2O2−δ composite anode by homogeneous precipitation of microspherical precursor in aqueous solutions followed by calcination. The composite anode sample was characterized by thermogravimetry analysis, X-ray diffraction, SEM, EDX, etc. The characterization results indicated that CuO–SDC composite anode with mesoporous structure was prepared and both SDC and CuO phases were homogenously distributed. Fuel cells have been constructed using as-prepared composite as anodes and lithiated NiO as cathode based on the SDC–carbonate nanocomposite electrolyte. Fuel cell performance tests indicated that the cell with mesoporous Cu–SDC anode had better performance than conventional Cu–SDC anode prepared by solid-state method. 相似文献
5.
Schottky diodes of rare-earth, praseodymium (Pr)-doped and samarium (Sm)-doped furazano [3,4-b] piperazine (FP), sandwiched between Al and indium-tin oxide (ITO) were made by a spin-coating technique. The diodes, in which doped FP behaves as a p-type organic semiconductor, exhibit rectification behaviour. The p-type semiconductivity and rectification properties of the devices improve with rare-earth doping. The electrical effects observed in these devices are explained in terms of the p-type semiconducting behaviour of the doped FP thin films and the formation of a blocking contact (Schottky barrier) with the Al electrode and ohmic contact with the ITO electrode. Various electrical parameters such as carrier mobility, position of Fermi level, free carrier concentration, trap density, trap level and conductivity of doped FP are calculated and discussed. It is found that the position of the Fermi level shifts toward the valence band on rare-earth doping; concentration of free carriers and carrier mobility increase on doping. From the capacitance-voltage (C-V measurements, various electrical parameters such as barrier height, density of ionized acceptor atoms and depletion layer width are calculated and discussed. From the action spectra and absorption spectra it is confirmed that the Al-doped FP interface forms a Schottky barrier and the ITO-doped FP interface shows ohmic contact. The photovoltaic measurement on the two devices reveals that the short circuit current, open circuit voltage, fill factor and power conversion efficiency increase on rare-earth doping. 相似文献
6.
7.
StudyonMonoxideEmisionSpectrometryofRareEarthElementsⅠ.DeterminationofSminRareEarthConcentratebyDualWavelengthMethodZhangZaiz... 相似文献
8.
J. Marcazzó M. Santiago C. D’Angelo C. Furetta 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(2):183-186
The photoluminescence (PL), radioluminescence (RL) and thermoluminescence (TL) of KMgF3 doped at several Sm concentrations have been investigated. The maximum TL and RL yield under beta irradiation has been observed in KMgF3:Sm 0.02 mol%. The glow curve of this doped perovskite is made up of at least five peaks located at 95, 120, 160, 270, and 330 °C. The third peak appears to be the most convenient for personal or environmental dosimetry, since it shows no fading and good linearity within the investigated dose range (0.020-200 Gy). From the RL and PL spectra it has been found that most of KMgF3:Sm emission is located at wavelengths higher than 650 nm. This emission, which is characteristic of Sm2+, makes this doped compound attractive for fiber-optic dosimetry. 相似文献
9.
同位素稀释质谱法测定动力堆辐照元件中^149Sm的含量 总被引:1,自引:0,他引:1
一、引言 核燃料经反应堆辐照后,产生一系列裂变产物。~(149)Sm是裂变产物中的一个核素,它具有较大的中子反应截面。当它大量存在时,严重影响中子的利用率。因此,~(149)Sm含量的测定,对反应堆的运行、设计和核燃料的后处理等工作,具有重要意义。 本工作采用同位素稀释质谱法,对反应堆辐照元件中~(149)Sm的累积量进行了测定。为了降低元件样品用量和减少误差来源,采取相应的措施,获得满意结果。 相似文献
10.
《Ceramics International》2023,49(10):15266-15275
In the present work, a series of Sm3+-doped MO-ZnO-B2O3–P2O5 (M = Mg, Ca, Sr, Ba) glasses were prepared. The glass structure and luminescence properties were investigated by XRD, DSC, IR, absorption spectroscopy, Judd-Ofelt theory and photoluminescence spectra. The J-O parameters of Sm3+-doped glasses follow the trend of Ω4>Ω6>Ω2. Under the excitation of 401 nm Xenon lamp, Sm3+-doped glasses exhibited four emissions from the transitions of 4G5/2→6HJ/2 (J = 5, 7, 9, 11) in the visible spectra. The luminous intensity of Sm3+ increases with the asymmetry in local environments and decreases with the increasing radius of the alkaline-earth cation. Among the as-prepared glass, the Sm3+-doped glass containing magnesium oxide exhibits higher values of stimulated emission cross-section (2.18 × 10−21 cm2), gain bandwidth (1.40 × 10−27 cm3), and optical gain (3.83 × 10−24 cm2). All the Sm3+-doped glasses show intense orange light in the CIE 1931 chromaticity diagram with a high color purity exceeding 99%. In addition, the time-resolved emission spectra reveal the decay process of the Sm3+ ions for the transitions 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 in the glass containing magnesium oxide. It suggests that Sm3+-doped alkaline-earth zinc borophosphate glasses could be a potential candidate for reddish-orange light-conversion fluorescent materials based on the ultraviolet light-emitting diode. 相似文献