Eu~(3+)掺杂铌硅玻璃的微观局域环境特性

研究了Eu3+掺杂铌硅玻璃的5D0发射光谱,其激发谱中7F0 5D2声子边带,荧光窄化谱及5D0能级寿命。并由此计算了强度参数与晶场参数。结果显示5D0 7F2 5D0 7F1发光强度之比与强度参数Ω2随着Nb2O5浓度的增加而增大,表明材料对称性降低,Eu-O键强增加,共价性增强。晶场参数B20随着Nb2O5的浓度增加而减小,同样表明Eu-O键的距离减小,键强增加。随着Nb2O5的浓度增加,电 声子耦合增强,5D0能级的无辐射过程加快,寿命变短。     

Er^3＋掺杂硼硅酸盐玻璃的近红外发射特性研究

利用高温熔融法合成了掺Er^3 硼硅酸盐玻璃。测量了样品的吸收光谱，由J-0理论得到了强度参数Ωλ(λ＝2，4，6)及一些相关参数；用970nm光激发测量了10-300K之间的近红外发射光谱。利用McCumber理论拟合得到了1．53μm发射的受激发射截面，并与测量得到的发射光谱线形符合较好。由受激发射截面和发射光谱得到的半高全宽分别为59和56nm。利用能级简化模型讨论了样品的红外变温发射光谱，提出了增大1．53μm发射带宽的途径。     

Ga2S3：Eu^2＋和SrGa^2＋xS4＋y：Eu^2＋系列荧光粉的发光性能研究

采用高温固相法合成了Ga2S3：Eu^2 和SrGa2S4：Eu^2 系列荧光粉。发现Ga2S3：Eu^2 的发射峰位于570nm附近，SrGa2S4：Eu^2 的发射峰位于535nm附近。同时进一步探讨了SrGa2 xS4 y：Eu^2 体系中，过量的Ga对发光的影响，通过漫反射光谱和XRD谱确定过量的Ga是以Ga2S3的形式存在于SrGa2S4相中；通过荧光光谱发现过量的Ga并不引起SrGa2S4：Eu^2 发射峰的位移，而是增强其在400-520nm处激发峰的强度，从而增强Eu^2 在535nm处的发光强度。     

Eu3+掺杂的XFn-H3BO3玻璃材料的声子边带分析

制备了组分为５９．５Ｈ３ＢＯ３－４０ＸＦｎ－０．５Ｅｕ２Ｏ３（Ｘ＝Ｃａ,Ｍｇ,Ｙ,Ｐｂ：ｎ＝２或３）的玻璃材料,用Ｅｕ＾３＋对玻璃材料进行了声子边蛭 声子边带谱的高频模式进行了拟合,同时计算了与无辐射跃迁密切相关的不同模式的电声子耦合常数。结果表明电声子耦合常数ｇ由大到小随氟化物种类的变化顺序为ＣａＦ２、ＹＦ３、ＭｇＦ２、ＰｂＦ２,不同样品的声子边带谱与Ｒａｍａｎ散射谱的测定结果基本一致。     

溶胶—凝胶法制备掺Eu^3＋的SiO2玻璃的结构及发光性能

利用溶胶－凝胶技术制备了掺不同量Eu^3 和不同退火温度下的SiO2凝胶和玻璃,通过在不同退火温度下样品的激光发谱,发射光谱,红外光谱和差热－热重曲线,研究了掺Eu3 的SiO2玻璃材料的结构和发光性能,结果显示,当Eu3 的掺杂量大于1．86％（质量分数）,Eu^3 的发光强度趋于稳定,当样品的退火温度大于300度时,SiO2凝胶玻璃中吸附的水已基本除净,此时显示出Eu^3 的特征发射光谱,谱带位置分别是614,596,577nm,分别归属于^5Do-7F2,5D0-7F1,^5D0-^7F0跃迁,对应的激光发光谱显示6个峰,位置分别是318,362,380,393,412,462nm,说明300－500度是凝胶向玻璃转变的关键温度,而水对Eu^3 的发光有强烈的淬灭作用。     

Er3+掺杂Li2O-CdO-Al2O3-SiO2玻璃的合成及光谱分析

合成了Er^3 掺杂Li2O—CdO—Al2O3-SiO2玻璃，对其吸收光谱、红外及上转换荧光光谱进行了测试和分析。根据吸收光谱和Judd—Ofelt理论计算了该玻璃中Er^3 离子在不同能级间的实验与理论振子强度、辐射跃迁几率、荧光分支比和寿命等光谱强度参数，在798和975nm激光激发下，观察到强的1．53μm红外发射及绿色上转换发光现象，对其形成机制进行了分析。探讨了这种玻璃作为新的激光材料及上转换实用功能材料的可能性。     

碱土金属离子（Mg^2＋，Ca^2＋，Ba^2＋）掺杂对长余辉荧光粉SrAl2O4：Eu^2＋，Dy^2＋发光性能的影响

采用高温固相法制备了碱土金属离子（Mg^2＋,Ca^2＋,Ba^2＋）掺杂的SrAl2O4：Eu^2＋,Dy^3＋长余辉荧光粉。XRD谱分析表明,随着基质中掺入的碱土金属离子（Mg^2＋,Ca^2＋,Ba^2＋）浓度增加,基质晶格常数也随之发生变化。Mg^2＋,Ca^2＋和Ba^2＋ 3种碱土离子在SrAl2O4中的固溶范围分别为40％,15％和30％。光谱分析则表明在固溶范围内随着掺杂Mg^2＋,Ca^2＋和Ba^2＋浓度的增大,样品的发射峰值会在480～530nm范围出现规律性移动。适当浓度的Mg^2＋,Ba^2＋掺杂会不同程度地提高样品的发光强度,而Ca^2＋的掺杂则会降低发光强度。但是碱土金属离子（Mg^2＋,Ca^2＋,Ba^2＋）的掺杂并不能延长SrAl2O4：Eu^2＋,Dy^3＋荧光粉的余辉时间。     

杂质的添加对SrAl2O：Eu^2＋,Dy^3＋余辉发光特性的改善

采用溶胶－凝胶法制备SrAl2O4:Eu^2 ,Dy^3 磷光体,并在合成过程中添加硼或硅以探讨光致发光及长余辉发光性质。发现硼、硅添加物不仅是助熔剂,且能改良SrAl2O4:Eu^2 ,Dy^3 之长余辉的持续时间及余辉发光强度。基于不同磷光体样品的实验结果比较,综合材料表面微结构观察、X射线衍射图谱、热释发光光谱与余辉衰减曲线的测量等实验结果分析,推断在SrAl2O4:Eu^2 ,Dy^3 中添加硼、硅可导致磷光体缺陷增加并稳定活化剂Eu^2 的价态。     

Er~(3+)掺杂硼硅酸盐玻璃的近红外发射特性研究

利用高温熔融法合成了掺Er3+硼硅酸盐玻璃。测量了样品的吸收光谱,由J-O理论得到了强度参数Ωλ(λ=2,4,6)及一些相关参数。用970nm光激发测量了10～300K之间的近红外发射光谱。利用McCumber理论拟合得到了1.53μm发射的受激发射截面,并与测量得到的发射光谱线形符合较好。由受激发射截面和发射光谱得到的半高全宽分别为59和56nm。利用能级简化模型讨论了样品的红外变温发射光谱,提出了增大1.53μm发射带宽的途径。     

Radiative lifetimes of the CO a′3Σ+, b3Σ+, c3Π, d3Δ and B1Σ+ states. Absolute emission cross sections for t

Radiative lifetimes have been measured for the CO a′³Σ⁺(ν′=4–9), b³Σ⁺(ν′= 0), c³Π(ν′=0), d³Δ(ν′=1–16) and B¹Σ⁺(ν′= 0) states. Our experimental values, arranged in the same order, are 7–10 μs, 56 ns, 16 ns, 3–7.5 μs, 34 ns. Some of these values disagree with the results of previous experiments. To our opinion this is due to an incomplete identification of the emission spectrum in regions where many bands may overlap, dependent on the applied spectral resolution. For the a′Σ⁺?a³Π and d³Δ?a³Π emissions effective cross sections for quenching by CO molecules are given. In connection with the identification of the spectrum, absolute emission cross sections for electrons incident on CO have been measured for the b³Σ⁺?a³Π and c³Π?a₃Π transitions. For an electron energy, corresponding to the maximum of the excitation function we find cross sections of 5.94 (?1.2) × 10^?18 cm² and 0.630 (? 0.13) × 10^?18 cm², respectively.     

Sm3+掺杂CaO-SiO2-B2O3发光玻璃的制备、表征及性质

用高温固相法合制备了以CaO-SiO₂-B₂O₃为基质，Sm³⁺为激活离子的发光玻璃。对Sm³⁺的淬灭浓度、基质中的硼硅比例、其他稀土离子的敏化作用以及基质组成等因素对玻璃发光特性的影响进行了探讨，并用红外和X-衍射分析对样品的结构进行了表征。结果表明：当Sm^3＋掺杂的物质的量分数为1.2%,激发波长λ ＝ 404 nm时,玻璃体60CaO-20SiO₂-20B₂O₃∶1.2Sm^3＋的发光强度为4 838 A.U.( λ ＝ 606 nm );这种发光玻璃具有将紫外及近紫外光转换为橙红色光的特点。少量的Eu^3＋的掺入，对玻璃体的发光起敏化作用；玻璃体中的组分CaO可被ZnO替代。     

A low energy ICR study of the symmetric charge transfer reaction 3He+ + 4He → 4He+ + 3He

The kinetic energy dependence of the charge reactions ³He⁺ + ⁴He ? ³He + ⁴He⁺ was investigated using a modified ion cyclotron double resonance technique. The rate constant increases monotonically from (5.0 ± 0.5) × 10^?10 cm³ molecule^?1 sec^?1 at 0.1 eV to 55 × 10^?10 cm³ molecule^?1 sec^?1 at a relative kinetic energy of 25 eV. The results compare favorably with theoretical predications for symmetric resonance charge transfer.     

Synthesis and Efficiency of Poly(Acryl- p-Nitrophenylamidrazone- p-Nitrophenylhydrazide) Chelating Fibre for Pre-Concentration and Separation of Trace Concentrations of Bi 3+, In 3+, Sn 4+, Ga 3+ and Ti 4+

A new poly(acryl-p-nitrophenylamidrazone-p-nitrophenylhydrazide) chelating fibre was synthesized from polyacrylnitrile fibre, and the structure of the chelating fibre was determined with the help of the FT-IR spectrum. The parameters influencing the efficiency of the fibre for concentrating trace amounts of Bi³⁺, In³⁺, Sn⁴⁺, Ga³⁺ and Ti⁴⁺, including sample acidity during enrichment, flow rate, adsorptive capacity, re-usability, interfering ions and desorption conditions were investigated. Trace Bi³⁺, In³⁺, Sn⁴⁺, Ga³⁺ and Ti⁴⁺ were enriched and separated from real sample solutions and detected using inductively coupled plasma optical emission spectrometry (ICP-OES) with satisfactory results. The experiments show that the method is rapid, precise, simple and convenient to use.     

Ce3+掺杂La2O3的17O固体核磁共振研究

本文用水热共沉淀法制备Ce³⁺掺杂La₂O₃的前驱体,随后在H₂/N₂气氛下用高温煅烧法合成了不同Ce³⁺浓度的掺杂La₂O₃。由于Ce³⁺的掺杂,¹⁷O固体核磁共振谱图中在698、650和558处出现了新的共振峰;随着Ce³⁺掺杂浓度的增加,这些峰的强度也随之增强。根据谱峰位置和强度,对谱图进行了归属:698、650处的共振峰应源自与Ce³⁺相连的四配位O(OCeLa₃),558处的信号则来自于与Ce³⁺相连的六配位O(OCeLa₅)。通过¹⁷O固体核磁共振能够直接观测与Ce³⁺直接相连的O显示该方法将可能用于研究稀土掺杂氧化物功能材料。     

Potential energy curve of 1Σ+ Li+/He

The potential energy curve of the system Li⁺/He has been determined with moderately large basis sets for 0.5 ? r ? 10.0 a₀ both at the SCF level and including correlation. The present SCF results predict a deeper well (?0.00248 au) at a smaller r(3.66 a₀) compared with earlier calculations. Correlation deepens the well further (?0.00274 au), but pulls it inward slightly (3.63 a₀). In the repulsive part the calculated curve lies above the experimental one, especially at shorter distances. A similar behavior has been noted in the systems Li⁺/H₂, Li⁺/CO and Li⁺/N₂, suggesting that the experimental determinations may underestimate the interaction in this region by 10–20%.