Emission Analysis of Pr3 +& Tm3 +: B2O3-BaO-LiF/AlF3 Glasses

We report here on the preparation and emission properties of Pr³⁺(4f²) and Tm³⁺ (4f¹²) ions doped in newly developed to transparent glassy matrices of BBLi (= B₂O₃-BaO-LiF) BBAl (= B₂O₃-BaO-AlF₃). Under an UV source (355 nm), both the Tm³⁺: BBLi and Tm^{3 +}: BBAl glasses have shown bright blue emission at 452 nm. With regard to both the Pr³⁺: BBL and Pr³⁺: BBAl glasses red emission have been noticed upon excitation with blue excitation wavelength (445 nm).These results have also been obtained from the measurement of their emission spectra. For such emission bands, decay curves have been recorded to obtain their lifetimes. We have prepared optical glasses with good transparency and stability. From the measurement of XRD spectra, amorphous nature of these glasses have been confirmed. Between the two glasses studied, glass containing Li has demonstrated an extended UV transmission and also it has revealed an improved NIR transmission ability compared to the other glass with LiF.     

电解氧化镨制取金属镨工艺的研究与工业实践

对电解氧化镨制取金属镨的小型试验３０００Ａ电解槽的生产作了简要介绍，探讨了电解质组成，电解温度，阴极电流密度，加料速度对工业生产效果的影响，生产结果表明：电解槽连续稳定自热运行，台日产金属镨６５～７０ｋｇ，金属收率达９０％，电流效率大于８０％。     

CeO2掺杂Pr6O11系氧化锌压敏电阻的研究

探讨了添加不同CeO2含量对Pr6O11系ZnO压敏电阻显微结构及电性能的影响,以期能满足特高压用高电位样度的应用需求.结果表明:随着CeO2掺杂量的增加,ZnO-Pr6O11系压敏电阻电位梯度和非线性系数有明显的提高,在掺杂量为1.0mol%时达到峰值,分别为548V/mm和42.XRD、SEM检测分析表明,CeO2并不与ZnO及其他氧化物生成新相,而是以CeO2的形式独立存在,抑制了ZnO的生成,致使填隙锌离子的传质能力下降,从而减小ZnO晶粒尺寸,并改善了压敏电阻的晶界结构和成分.     

Layered Y3Al5O12:Pr/Gd3(Ga,Al)5O12:Ce optical ceramics: Synthesis and photo-physical properties

We report a study of composite scintillating ceramics based on coupled layers of two different garnets, namely Ce-doped gadolinium gallium aluminium (GGAG:Ce) and Pr-doped yttrium aluminium (YAG:Pr), fabricated by hot isostatic pressing. Two samples were prepared, with different GGAG:Ce layer thickness, 120 µm and 690 µm respectively, but with a comparable overall thickness of 1.4 mm. The key finding is that the material architecture strongly determines the scintillation response. The radioluminescence is that expected from the irradiated material when a thick layer of ceramic is exposed to X-rays. Conversely, exposing a thin layer allows a non-null probability —about 0.3% for 120 µm of GGAG— of finding an X-ray photon in the underlying layer, and thus radioluminescence from both materials is recorded. We believe these results can extend the potential of layered optical ceramics for advanced devices, such as energy- and direction-sensitive X-ray detectors.     

Synthesis of flower-like La or Pr-doped mesoporous ceria microspheres and their catalytic activities for methane combustion

La or Pr-doped flower-like mesoporous ceria microspheres were prepared by a unique calcination of La or Pr-doped Ce(OH)CO₃ microspheres hydrothermally synthesized with the aid of glucose and acrylic acid. Prepared flower-like ceria-based materials have a novel hierarchical architecture with mesoporous structure and high surface area, which can obviously facilitate the catalytic combustion of methane, compared with general La or Pr-doped ceria. The presence of La or Pr can promote the production of oxygen vacancies and improve oxygen mobility, which result in enhancing the oxygen-storage capacity of the flower-like ceria and its catalytic performance for the methane combustion.     

镅(Ⅲ)、锔(Ⅲ)、镨(Ⅲ)和钕(Ⅲ)与2-羟基-2,4-二甲基戊酸络合物稳定常数

本文研究了三价镅、锔、镨和钕与2-羟基-2,4-二甲基戊酸的络合作用。在pH=4.00,μ=0.5(NaClO_4)和25℃条件下,用静态阳离子交换法得到了各级稳定常数。指出了2-羟基-2,4-二甲基戊酸(HDMVA)可望成为三价镅、锔分离的优良淋洗剂。     

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确定储油气层岩石的物性参数是油气田勘探与开发中的一个重要问题，而岩心分析是获得储层岩石资料的一种基本手段。对于低渗透致密岩石的物性参数，由于流体流动速率很小，采用常规的岩心分析方法难以测量和解释。为测定岩心物性参数，在瞬时脉冲技术基础上，通过测试岩石样品两端的压力变化，提出了自动拟合岩石样品两端实测压力的模型及其数值解法,研制了岩心物性参数解释软件，配合实验装置，实现了岩心分析实验数据的自动采集与解释。由于实验是通过测量岩样上、下流压力随时间的变化而不需要测量流量来测定岩心物性参数，从而避免了用常规方法测量致密岩石时的困难，同时在高压下测定的岩心物性参数更接近于矿场实际。最后，通过例子说明了实验简单易行，方法稳定可靠，结果准确，具有推广应用价值。     

Pr~(3 )/Yb~(3 )共掺ZBLAN玻璃吸收与发光特性的研究

制备了几种掺杂不同Ｐｒ３＋／Ｙｂ３＋浓度的ＺＢＬＡＮ玻璃，测定了玻璃的吸收光谱。由Ｊｕｄｄ－Ｏｆｅｌｔ理论研究了不同浓度的玻璃的发光性质，并研究了Ｐｒ３＋与Ｙｂ３＋的能量交换速率。结果表明，Ｙｂ３＋的引入增强了Ｐｒ３＋的泵浦，起到了很好的敏化作用。     

Pr对Pr-Mn共掺BaTiO3陶瓷的气相扩渗及其PTC特性

在制备Pr-Mn共掺BaTiO3系列陶瓷(x(Mn)为0.006;x(Pr)为0,0.001,0.002,0.003,0.004,0.006)的基础上,对其在气态下扩渗Pr。经Pr扩渗后,陶瓷的室温电阻率降低为0.21Ω.m。变温电阻率的测试结果表明,陶瓷呈明显的正温度系数(PTC)效应。通过X-射线衍射(XRD)测试,发现Pr-Mn共掺并没有改变物相结构,Pr气相扩渗后,有新化合物PrO2和BaPr2Ti4O12生成。扫描电镜(SEM)测试结果表明,Pr气相扩渗有细化晶粒,增大晶界比例的作用,有利于材料的PTC效应。     

Pr3+/Yb3+共掺碲酸盐玻璃发光特性的研究

根据Pr3 /Yb3 共掺碲酸盐玻璃在 980nm附近的吸收谱及 1.3 1μm处的发射谱 ,研究了玻璃样品光谱特性随稀土离子浓度变化的规律。结果表明 :在Yb3 离子浓度不变的情况下 ,1.3 1μm处的发光随着Pr3 离子浓度的增加 ,其强度先增后减 ,并在浓度为 0 .15mol%时达到最大值 ,同时根据Judd -Ofelt理论计算了稀土离子的光辐射特性