Pr2O3,Sm2O3,Eu2O3及Dy2O3掺杂SrTiO3的发光光谱

SrTiO_3粉末分别用Pr_2O3、Sm_2O_3、Eu_2O_3以及Dy_2O_3掺杂处理后,以SrTiO_3能吸收的光波(≤387nm)激发后发出的荧光具有稀土离子的发光特征。     

Na2O＊B2O3＊V2O5玻璃的^51V核磁共振研究

本文应用~(51)V核磁共振研究了Na_2O·B_2O_3·V_2O_5玻璃的结构,结果表明: 1)R<0.5+K时,随着R的增加,依次形成NaV_3O_8、NaVO_3和NaVO_3-B结构。 2)R=0.5+K时,全部的V_2O_5转化为NaVO_3和NaVO_3-B结构。 3)R>0.5+K时,由于硼酸盐中非桥氧数的增加,NaVO_3-B结构逐步消失,并推测NaVO_3-B结构中的B原子为四配位结构。     

Al2O3-P2O5-H2O反应体系产物以及高温产物的光谱特征

以磷酸和氢氧化铝为原料,选取不同工艺合成了系列磷酸铝。用FTIR,XRD,Raman和SEM研究了相关产物阴离子基团的红外图谱变化和三聚磷酸二氢铝的热变化过程的光谱性质以及颗粒形貌的变化。当改变P2O5/Al2O3摩尔比或者缩合温度时,可以看到磷酸根形式H2PO4-,PO34-,H2P3O130-和PO3-的红外光谱特征的变化,P—O键的振动峰随着聚合程度的增加向短波长方向移动,而且峰宽增加。当三聚磷酸二氢铝经高温处理后,拉曼和红外光谱显示了聚合磷酸根中微结构间的相互作用引起P—O键伸缩振动频率增大以及结晶水的变化趋势,随着组成变化的同时,其颗粒的层状结构层厚度增加,层边界趋于模糊,直至呈现熔体状态。     

Quasi-classical rate constants for the inelastic process O2(υi≫ 1) + O2 → O2(υf) + O2

Rate constants have been calculated using quasi-classical trajectories (QCT) for the vibrational relaxation of highly excited O₂:O₂(X³Σ?,v_i) + O₂(X³Σ?,0) → O₂(X³Σ?,v_f) + O₂(X³Σ?) with 22 ≤v_i≤28. The present full-dimensional QCT results agree very well with recent quantum reduced dimensionality calculations, giving further support to the hypothesis that the observed experimental jump in depletion rates would be due partially to enhanced vibrational relaxation.     

水分子不是H2O

水分子的化学式其实不是H2 O .根据最新的实验 ,中子和电子与水碰撞的时间为几阿秒 (1 0 - 18s)时探测到的氢和氧的比例约为 1 .5— 1 .所以 ,水的更精确的分子式在这些情况下应该是H1.5O而不是H2 O .按照实验者 (德国柏林技术大学的Chatzidimitriou DreismannA)的说法 ,这个实验“打开了阿秒的时间窗口” ,可能揭示出奇迹般的量子效应 ,以前 ,这种量子效应由于持续的时间太短而没有捕捉到 .这类效应将修正传统的教科书中关于水和其他日常生活中接触到的分子的概念 .此外 ,这些实验能够提供 1 0 0— 5 0 0as时间尺度上的化学反应的新信…     

СПЕКТРАЛЬНОЕ РАСПРЕ ДЕЛЕНИЕ КВАНТОВОГО В ЫХОДА ИНФРАКРАСНОЙ ЛЮМИНЕ СЦЕНЦИИ Cu2O ПРИ НИЗКИХ ТЕМПЕРАТУРАХ

---

Spectral distribution of quantum yield of infra-red luminescence of Cu₂O at low temperatures

     

用Na2O2-DMSO体系产生O2·的ESR研究

提出了Na₂O₂的二甲基亚砜(DMsO)/H₂O溶液中产生超氧阴离子自由基(O₂^·)的新方法,用电子自旋共振仪(ESR)可直接检测到很强的O₂^·信号,研究了反应的条件及其O₂^·信号的特性,并用该法考察了茶多酚等清除剂对于超氧阴离子自由基的清除作用。结果表明本体系是产生O₂^·的有效方法,可用于超氧阴离子自由基清除剂的研究。     

Ga2O3组分对Tm 3+掺杂GeO2-Ga2O3-Li2O-BaO-La2O3玻璃的光谱性能影响

制备了Tm3 (8.0mol%)掺杂(77-x)GeO2-xGa2O3-8Li2O-10BaO-5La2O3(x=4,8,12,16)系列玻璃.系统地研究了Ga2O3从4mol%变化到16mol%时,玻璃的光谱性质与热学性质的变化规律.差热分析表明,随着Ga2O3含量的增加,锗酸盐玻璃的热稳定性增加.运用Judd-Ofelt(J-O)理论计算得到了Tm3 在不同Ga203含量的GeO2-Ga2O3-Li2O-BaO-La2O3玻璃中的J-O强度参数(Ω2,Ω4,Ω6)及Tm3 各激发能级的自发跃迁概率、荧光分支比以及辐射寿命等光谱参量.在808nm激光二极管的激发下,测试并分析了Ga2O3对Tm3 荧光光谱特性的影响.随着Ga2O3从4t001%增加到16mol%,Tm3 在1.8μm处的荧光强度呈现先减弱后增强的特性.当Ga2O3含量大约在12mol%时,Tm3 在1.8μm处的荧光强度最弱,受激发射截面达到最小.还初步讨论了Ga2O3对玻璃结构与光谱参数的影响规律.     

Specific Features of the Local Structure and Transport Properties of ZrO2–Sc2O3–Y2O3 and ZrO2–Sc2O3–Yb2O3 Crystals

Optics and Spectroscopy - The specific features of the local structure of ZrO2–Sc2O3–Y2O3 and ZrO2–Sc2O3–Yb2O3 crystals are revealed by optical spectroscopy using the Eu3+...     

Activation energy and conductivity of glasses in the P2O5–V2O5–Li2O system

The conductivity of glasses in the 50\textP_\text2 \textO_\text5 - x\textV_\text2 \textO_\text5 - ( 50 - x )\textLi_\text2 \textO50{\text{P}}_{\text{2}} {\text{O}}_{\text{5}} - x{\text{V}}_{\text{2}} {\text{O}}_{\text{5}} - \left( {50 - x} \right){\text{Li}}_{\text{2}} {\text{O}} system was studied as a function of temperature and composition. For all compositions, the conductivity variation as a function of temperature followed an Arrhenius type relationship. Isothermal variation of conductivity as a function of composition showed a minimum for a molar ratio x near 20. Probable mechanisms for decrease of conductivity with decrease of vanadium oxide concentration were explained. The minimum in room temperature was attributed to increase of V⁴⁺/V⁵⁺ with decrease of vanadium oxide in specific concentrations of vanadium oxide. Activation energy increased with decrease of V₂O₅ content. This behavior was attributed to increase of average spacing between vanadium ions.     

Bi2O3—Sb2O3二元系的研究

本文用 X 射线衍射及差热-热重分析方法研究了 Bi_2O_3-Sb_2O_3二元系在 N_2和空气中的相关系.研究结果表明,在 N_2中发生自氧化-还原化学反应5Bi_2O_3+3Sb_2O_3→4Bi+6BiSbO4在空气中 Bi 和 Sb 分别主要以+3和+5价的形式存在.Sb 在 Bi_2O_3中的溶解度不超过3mol%.形成三种化合物:Bi3SbO_7、Bi_5Sb_2O_(12.5)和 BiSbO_4.前两者为包品反应产物,后者为固液同份化合物.BiSbO_4的熔点为1276℃.BiSbO_4与Sb_2O_4属共晶反应.并讨论了Sb 对 Bi-Sr-Ca-Cu-O 体系形成超导相的影响.     

O2/N2与O2/CO2条件下燃煤颗粒物的生成特性研究

将煤粉在O2/N2与O2/CO2条件下进行沉降炉燃烧实验,研究了燃煤颗粒物的质量粒径分布、生成浓度以及元素组成特性.研究结果表明,燃煤颗粒物均呈三模态粒径分布,气氛的改变不影响各模态的分布趋势.相同O2含量条件下,与O2/N2气氛相比,O2/CO2气氛中PM10和PM1的生成浓度均降低,PM1易挥发元素Na、K、S的含量升高,而难熔元素Si、Al、Mg、Ca、Fe的含量降低.随着O2浓度的增加,O2/N2燃烧气氛下PM10和PM1的生成浓度逐渐增加,O2/CO2燃烧气氛下PM10的生成浓度增加,而PM1的生成浓度先减小后增加.     

Crystallization and conductivity of 2CaO–La2O3–5P2O5 glass–ceramic with Al2O3 addition

Al₂O₃ was added to a 2CaO–La₂O₃–5P₂O₅ metaphosphate, to replace 10% of the Ca²⁺ ions by Al³⁺, forming a phosphate with the nominal composition 1.8CaO–0.1Al₂O₃–La₂O₃–5P₂O₅. The effect of Al₂O₃ addition and heat treatment on the microstructure and conductivity of the resulting glass–ceramics was investigated by XRD, SEM, TEM, and AC impedance spectroscopy. Upon transformation from glass to glass–ceramic, conductivities increased significantly. The glasses were isochronally transformed at 700 and at 800 °C for 1 h or 5 h, in air, following heating at 3 or 10 °C/min. With Al₂O₃ addition, after a heat treatment at 700 °C, 100–300 nm nano-domains of LaP₃O₉ crystallized from the glass matrix. Annealing at 800 °C produced a further order of magnitude conductivity increase for the Al-free glass, but less so for the Al-containing glass.     

E.P.R. study of γ-irradiated single crystals of K2C2O4.H2O and (NH4)2C2O4.H2O

The electron paramagnetic resonance of γ-irradiated single crystals of K₂C₂O₄.H₂O and (NH₄)₂C₂O₄.H₂O has been studied. The spectra show interesting microwave power saturation effects. The singlet spectrum is attributed to the C₂O₄ ^- radical derived from the C₂O₄ ^-- ion. The principal g-values are determined to be 1·998, 2·0028 and 2·0004. Certain weak lines are observed with different power saturation and interpreted as due to OH radicals derived from water molecules in the crystal lattice.