~(133)Sm的(EC+β~+)衰变和~(133)Pr的1.1s同质异能态

通过96 Ru( 4 0 Ca ,ln2p)反应 ,采用氦喷嘴带传输系统和X γ与γ γ符合测量方法 ,首次建议了133Sm的简单的 (EC + β+)衰变纲图 .由于Ru靶中含有98— 10 2 Ru的成分 ,同时产生了133Pr,并首次测定了133Pr的 1 1 / 2 - 同质异能态的寿命为( 1 .1± 0 .2 )s.用单粒子模型提取了131,133,135 ,137Pr的 1 1 / 2 - 同质异能态的约化跃迁几率的实验值 ,并与Weisscopf近似估计进行了比较 .

在相对论平均场框架下Pr同位素链中滴线核的确定

在相对论平均场框架下研究了Pr同位素链中中子和质子滴线核的可能位置及相关性质 .对效应的处理采用了BCS方法 ,并使用了与同位素有关的对力常数 ,对不成对的核子采用了‘阻塞法’ ,考虑了核的轴对称形变 .计算结果表明 ,对不同物理量的研究都可得到185 Pr为同位素链中丰中子边最后一个稳定核 .而在丰质子边 ,采用本方法很难确定质子滴线核的位置 .原因是由于在丰质子边随着A的减少 ,费米面比丰中子边的费米面更快地趋于连续态 ,BCS方法不再成立 ,并须考虑束缚态和连续态的耦合 .

缺中子~(130)Pm和~(128)Pr核的EC/β~+衰变研究

171MeV 36Ar束轰击96Ru靶由熔合蒸发反应生成了130 Pm和12 8Pr核 .由氦喷嘴快速带传输系统将反应产物送到低本底区 .基于X γ t,γ γ t符合测量 ,首次建立了130 Pm的 (EC + β+)衰变纲图 .重新研究了12 8Pr核的衰变 ,订正和补充了γ射线 ,建立了新的 (EC + β+)衰变纲图

在相对论平均场框架下Pr同位素链的基态性质

在相对论平均场框架下研究了Pr同位素链的基态性质 .对关联的处理采用了BCS方法 ,并使用了与同位旋有关的对力常数 ,对不成对的核子采用了‘阻塞法’ ,并考虑了核的轴对称形变 .计算结果表明 ,包含非线性介子自相互作用的相对论平均场理论可以在很大的同位旋范围内很好地描述Pr同位素链的结合能、形变、中 (质 )子密度分布、同位素位移等 .理论计算的结果与有限力程小液滴模型的结果符合得很好 .特别检验了描述对关联的BCS近似在Pr链的适用范围和适用的程度

Pr掺杂对Ce_(0.87)Sm_(0.13)O_(2-δ)结构及电性能的影响

采用溶胶-凝胶法合成Ce0.87Sm0.13-xPrxO2-δ(x=0.00,0.01,0.02)氧化物,通过X射线衍射、拉曼光谱、场发射扫描电镜对氧化物进行结构表征,利用交流阻抗谱测试电性能,并讨论了掺杂Pr对Ce0.87Sm0.13O2-δ微观结构和电性能的影响.结果表明,掺入少量Pr3+可减少或消除晶粒表面和晶界处的坑痕或孔隙,增加材料的致密性,从而降低材料的晶界电阻和电极界面电阻以及晶界电阻在总电阻中所占的比例,提高了材料的电导率.

Syntheses, crystal structures and near-infrared luminescent properties of holmium (Ho) and praseodymium (Pr) ternary complexes

A series of near-infrared (NIR) luminescent complexes Ho(dbm)(3)L and Pr(dbm)(3)L [where dbm = dibenzoylmethane; L = 1,10-phenanthroline (phen), 2,2'-bipyridine (bipy), or triphenyl phosphate oxide (TPPO)] were synthesized. Their elemental analyses, crystal structures, fluorescence spectra and luminescent lifetimes were successfully investigated.

Synthesis and luminescent properties of Lu3Ga5O12 : RE3+ (RE = Eu, Tb, and Pr) nanocrystalline phosphors via sol-gel process

Lu3Ga5O12:Eu3+, Lu3Ga5O12:Tb3+, and Lu3Ga5O12:Pr3+ phosphors were prepared through a Pechini-type sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence, and cathodoluminescence spectra were utilized to characterize the synthesized phosphors. The XRD results reveal that the sample begins to crystallize at 800 degrees C and fully crystallined pure Lu3Ga5O12 phase can be obtained at 1000 degrees C. The FESEM image indicates that the phosphor sample is composed of aggregated rice grainlike particles with sizes around 80-120 nm.

Synthesis and luminescent properties of LaInO3: RE3+ (RE = Sm, Pr and Tb) nanocrystalline phosphors for field emission displays

LaInO3: Sm3+, LaInO3: Pr3+ and LaInO3: Tb3+ phosphors were prepared through a Pechini-type sol-gel process. X-ray diffraction, field emission scanning electron microscopy, photoluminescence, and cathodoluminescence (CL) spectra were utilized to characterize the synthesized phosphors. XRD results reveal that the pure LaInO3 phase can also be obtained at 700 degrees C. FE-SEM images indicate that the LaInO3: Sm3+, LaInO3: Pr3+ and LaInO3: Tb3+ phosphors are composed of aggregated spherical particles with sizes around 80-120 nm. Under the excitation of ultraviolet light and low voltage electron beams (1-5 kV), the LaInO3: Sm3+, LaInO3: Pr3+ and LaInO3: Tb3+ phosphors show the characteristic emissions of Sm3+ ((4)G(5/2)-H-6(5/2,7/2,9/2) transitions, yellow), Pr3+ (P-3(0)-H-3(4), P-3(1)-H-3(5), D-1(2)-H-3(4) and P-3(0)-F-3(2) transitions, blue-green) and Tb3+ (D-5(4)-F-7(6.5,4.3) transitions, green) respectively. The corresponding luminescence mechanisms are discussed. These phosphors have potential applications in field emission displays.

Self-assembled 3D flowerlike Lu2O3 and Lu2O3 : Ln(3+) (Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures: Ethylene glycol-mediated hydrothermal synthesis and luminescent properties

Three-dimensional flowerlike Lu2O3 and Lu2O3:Ln(3+) (Ln = Eu, Th, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures have been successfully synthesized via ethylene glycol (EG)-mediated hydrothermal method followed by a subsequent heat treatment process. X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectra, thermogravimetric and differential thermal analysis, elemental analysis, inductively coupled plasma atomic absorption spectrometric analysis, ion chromatogram analysis, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, photoluminescence spectra as well kinetic decays, and cathodoluminescence spectra were used to characterize the samples. Hydrothermal temperature, EG, and CH3COONa play critical roles in the formation of the lutetium oxide precursor microflowers. The reaction mechanism and the self-assembly evolution process have been proposed. The as-formed lutetium oxide precursor could transform to Lu2O3 With their original flowerlike morphology and slight shrinkage in the size after postannealing process.

3D 异金属Bi(III)-Pr(III)配位聚合物的合成、晶体结构和热稳定性

在水溶液中合成了双金属配位聚合物({[(NO3)(H2O)3Pr(μ4-Hedta)Bi-(NO3)2].2H2O}2)n,并通过元素分析、红外光谱和X射线单晶衍射等手段进行了表征.该配合物为单斜晶系,P2(1)/n空间群,a=1.26831(18)nm,b=0.82189(12)nm,c=2.3755(3)nm,β=105.055(2)°,R=0.0429,V=2.3913(6)nm3,Z=4.Bi(Ⅲ)-Pr(Ⅲ)间通过配阴离子Hedta3-中4个羧基的桥联作用构建配合物的3D结构.TG-DSC结果表明,该配合物热分解经历脱水、配体分解以及盐分解过程,残余物为Bi-Pr-O的三元复合氧化物.

Four New Lanthanide-Nitronyl Nitroxide (Ln(III)=Pr-III, Sm-III, Eu-III, Tm-III) Complexes and a Tb-III Complex Exhibiting Single-Molecule Magnet Behavior

Five new complexes based on rare-earth-radical [Ln(hfac)(3)(NIT-5-Br-3py)](2) (Ln=Pr (1), Sm (2), Eu (3), Tb (4), Tm (5); hfac = hexafluoroacetylacetonate; NIT-5-Br-3py = 2-(4,4,5,5-tetramethyl-3-oxylimidazoline-1-oxide)-5-bromo-3-pyridine) have been synthesized and characterized by X-ray crystal diffraction. The single-crystal structures show that these complexes have similar structures, in which a NIT-5-Br-3py molecule acts as a bridging ligand linking two Ln(III) ions through the oxygen atom of the N-O group and nitrogen atom from the pyridine ring to form a four-spin system. Both static and dynamic magnetic properties were measured for complex 4, which exhibits single-molecule magnetism behavior.

Near-infrared luminescent mesoporous materials covalently bonded with ternary lanthanide [Er(III), Nd(III), Yb(III), Sm(III), Pr(III)] complexes

New near-infrared-luminescent mesoporous materials were prepared by linking ternary lanthanide (Er3+, Nd3+, Yb3+, Sm3+, Pr3+) complexes to the ordered mesoporous MCM-41 through a functionalized 1,10-phenanthroline (phen) group 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline. The resulting materials (denoted as Ln(hfth)(3)phen-M41 and Pr(tfnb)(3)phen-M41; Ln=Er, Yb, Nd, Sm; hfth = 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dionate; tfnb = 4,4,4-trifluoro-1-(2-naphthyl)- 1, 3-butanedionate) were characterized by powder X-ray diffraction, N-2 adsorption/desorption, and elemental analysis. Luminescence spectra of these lanthanide-complex functionalized materials were recorded, and the luminescence decay times were measured. Upon excitation at the absorption of the organic ligands, all these materials show the characteristic NIR luminescence of the corresponding lanthanide (Er3+, Nd3+, Yb3+, Sm3+, Pr3+) ions by sensitization from the organic ligands moiety. The good luminescent performances enable these NIR-luminescent mesoporous materials to have possible applications in optical amplification (operating at 1300 or 1500 nm), laser systems, or medical diagnostics.