Ga2O3-La2O3-Yb2O3-Er2O3(HO2O3)体系光谱性质的研究

根据稀土离子能级的特点,对Ga2O3-La2O3-Yb2O3-Er2O3(HO2O3)体系的光谱性质进行了探讨,发现它们有二类发光性质:Stokes发光和反Stokes发光,研究了发光强度和发射波长与掺杂离子的依赖关系,观察到由能量的共振转移引起的荧光浓度猝灭现象,并取得了最大发光强度时的掺杂离子浓度和一些规律性结果.     

209Bi NQR in Mixed Oxides 2Bi2O3· B2O3, 3Bi2O3· 5B2O3, and Bi2O3· 3B2O3

It was earlier found from nuclear quadrupole resonance (NQR) measurements and computer modeling that -Bi₂O₃, Bi₃O₄Br and mixed oxides Bi₂O₃· 2Al₂O₃, Bi₂O₃· 2Ga₂O₃, Bi₂O₃· 3GeO₂, and 2Bi₂O₃· 3GeO₂exhibit local ordered magnetic fields from 30 to 200 G. It thus follows that these compounds are not diamagnets in a conventional sence of the word. With the aim of revealing previously unknown magnetic properties in bismuth(III) oxide-based Main Group element compounds, the mixed bismuth–boron oxides 2Bi₂O₃· B₂O₃, 3Bi₂O₃· 5B₂O₃, and Bi₂O₃· 3B₂O₃were prepared and studied using ²⁰⁹Bi NQR. The quadrupole interactions of the ²⁰⁹Bi nuclei and their electronic environment were studied, the crystallochemical features of the compounds were discussed, and the conformity of the ²⁰⁹Bi results to the X-ray structure data was verified. The preliminary tests in the field of a permanent magnet showed that the resonance intensities increase in external magnetic fields, indicating that a magnetism of unknown nature develops in the titled compounds. It was found reasonable to continue studies of the magnetic properties of these compounds using single-crystal ²⁰⁹Bi NQR in external magnetic fields.     

Al2O3-B2O3-Eu2O3体系的振动光谱和发光特性

采用高温固相反应法,合成了一系列不同组份的磷光体,测定了它们的振动光谱．结果表明,随着Al／B比的减小,在1100～1000cm－1的区域内的振动光谱没有明显变化,铕离子不可能进入Al18B4O33的晶格中;振动光谱的背底升高,非晶相逐渐增加．研究了Al2O3－B2O3-Eu2O3中Eu3＋离子的光谱特性,发现随着Al／B比的减少,Eu3＋离子的存在相由晶相逐渐向非晶相转化。在非晶相中,Eu3＋离子的声子伴带表明电子与声子的耦合强度随着Al／B比的减少而减小,Eu3＋离子的发射强度相应的增加,这与多声子弛豫的理论一致．     

Yb2O3对Bi2O3-MoO3催化剂性能的影响

在Bi2O3-MoO3复合氧化物催化剂中加入Yb2O3，可明显提高异丁烯转化率和生成甲基丙烯醛的选择性，用XRD、FT-Raman光谱和SEM技术研究了催化剂的组成和性质，Bi2O3—MoO3催化剂的成分主要是α-Bi2Mo3O12，添加镱后出现了Yb2Mo3O12的吸收峰；且Bi2O3-MoO3-Yb2O3催化剂的FT—Raman光谱图在363cm^-1处出现了Yb—O伸缩振动峰，同时既Bi2O3-MoO3催化剂的铝-氧振动发生红移，表明镱的加入使铝-氧键的振动减弱，使Bi2O3-MoO3-Yb2O3催化剂有较高传递晶格氧给予异丁烯的能力，导致异丁烯转化率和生成甲基丙烯醛的选择性均显著提高。     

ZrO2–Sc2O3 Solid Electrolytes Doped with Yb2O3 or Y2O3

Russian Journal of Electrochemistry - The effects of the Y2O3 and Yb2O3 co-doping impurities on the transport characteristics and stabilization of the cubic phase in solid solutions based on...     

化学气相传输法分离稀土混合氧化物Sm2O3-Eu2O3-Gd2O3

以ＡｌＣｌ３ 为络合物配体, 研究Ｓｍ２Ｏ３Ｅｕ２Ｏ３Ｇｄ２Ｏ３ 的分离特性。结果表明, 其传输能力为：Ｓｍ ≈Ｇｄ＞ Ｅｕ, 氯化物主要在９８０ ～１１００ Ｋ 沉积。不同温区的最大分离系数分别为： βＥｕ／Ｓｍ;１２００ Ｋ＝ １－７０ ,βＥｕ／Ｇｄ;１３００ Ｋ＝ １－８８ , βＳｍ／Ｇｄ;１３００ Ｋ ＝ １－２４ , β′Ｓｍ／Ｅｕ;８５０ ～８８０ Ｋ＝ ２－７６ , β′Ｇｄ／Ｅｕ;８８０～９００ Ｋ ＝ ２－８３ , β′Ｇｄ／Ｓｍ;８００ Ｋ＝１－１２ , 高于传统的湿法分离系数。     

Bi2O3—Y2O3系阻抗谱研究

本文用交流阻抗法研究了Bi_2O_3-Y_2O_3系的阻抗谱。呈现特有的Warburg阻抗及其相关阻抗。在高氧分压下,电极过程由氧原子在三相线发生反应后直接进入电解质步骤控制;低氧分压下,由上述步骤和界面浓差极化共同控制,或仅由浓差极化控制。在氧分压为1.01×10~(-10)～1.01×10~5Pa内时,Bi_2O_3-Y_2O_3系表现为纯氧离子导体。     

Al2O3·3H2O阻燃环氧树脂机理探讨

采用氧指数测定法与热重法研究了Al2O3·3H2O对环氧树脂固化物的阻燃效果与机理.结果表明,Al2O3·3H2O在热分解方面与树脂固化物有阻燃匹配性,并能以零级反应快速失去2个结晶水分子,失水后形成的活性氧化铝促进了树脂固化物热解时转化成难燃物的能力,具有较高的阻燃效果.     

HCl-NaCl-C3H8O3-H2O体系溶液热力学性质

在恒定丙三醇质量分数x=0．1的条件下，测定了无液接电池（A）和电池（B）的电动势根据电池（A）电动势确定了丙三醇和水混合溶剂中的Ag－AgCl电极的标准电极电势，讨论了HCl的迁移性质；由电池（B）测得的电动势计算了HCl在该体系中的活度系数γA，计算的结果表明，对于所讨论的体系，在溶液中总离子强度保持恒定，HCl的活度系数服从Harned规则．在溶液组成恒定时，IgγA是温度倒数1／T的线性函数，讨论了混合物中HCl的相对偏摩尔焓及介质效应．     

Ln2O3/Al2O3催化酯化合成邻苯二甲酸二辛酯

Ｌｎ_２Ｏ_３／Ａｌ_２Ｏ_３催化酯化合成邻苯二甲酸二辛酯陈其瑞，张凤美，罗明润，焦肇林（安徽师范大学化学系，芜湖２４１０００）关键词稀土氧化物，担载催化剂，催化酯化，邻苯二甲酸二辛酯邻苯二甲酸二（２－乙基己醇用酯（Ｄｉｏｃｔｙｌｐｈｔｈａｌａｔｅ）是一...     

17O excess transfer during the NO2 + O3 → NO3 + O2 reaction

The ozone molecule possesses a unique and distinctive (17)O excess (Δ(17)O), which can be transferred to some of the atmospheric molecules via oxidation. This isotopic signal can be used to trace oxidation reactions in the atmosphere. However, such an approach depends on a robust and quantitative understanding of the oxygen transfer mechanism, which is currently lacking for the gas-phase NO(2) + O(3) reaction, an important step in the nocturnal production of atmospheric nitrate. In the present study, the transfer of Δ(17)O from ozone to nitrate radical (NO(3)) during the gas-phase NO(2) + O(3) → NO(3) + O(2) reaction was investigated in a series of laboratory experiments. The isotopic composition (δ(17)O, δ(18)O) of the bulk ozone and the oxygen gas produced in the reaction was determined via isotope ratio mass spectrometry. The Δ(17)O transfer function for the NO(2) + O(3) reaction was determined to be: Δ(17)O(O(3)?) = (1.23 ± 0.19) × Δ(17)O(O(3))(bulk) + (9.02 ± 0.99). The intramolecular oxygen isotope distribution of ozone was evaluated and results suggest that the excess enrichment resides predominantly on the terminal oxygen atoms of ozone. The results obtained in this study will be useful in the interpretation of high Δ(17)O values measured for atmospheric nitrate, thus leading to a better understanding of the natural cycling of atmospheric reactive nitrogen.     

Y2O3, La2O3, Sm2O3对氧化铝瓷烧结及力学性能的影响

研究了3种稀土氧化物对氧化铝陶瓷烧结性能和力学性能的影响.结果表明 含Y2O3,La2O3,Sm2O3的添加剂促进了氧化铝瓷的烧结,提高了氧化铝瓷的力学性能.Y2O3和Sm2O3掺量为0.50%,La2O3掺量为0.75%时氧化铝瓷在1600或1620 ℃保温2 h烧结,相对密度达98.9%以上,强度超过439 MPa,断裂韧性达5.15 MPa·m1/2以上.微观结构分析表明,Y2O3,La2O3,Sm2O3抑止氧化铝晶粒生长,细化晶粒,使晶粒尺寸较均匀形成致密化结构.     

Thermodynamic properties of two zinc borates: 3ZnO·3B2O3·3.5H2O and 6ZnO·5B2O3·3H2O

Two pure zinc borates with microporous structure 3ZnO·3B₂O₃·3.5H₂O and 6ZnO·5B₂O₃·3H₂O have been synthesized and characterized by XRD, FT-IR, TG techniques and chemical analysis. The molar enthalpies of solution of 3ZnO·3B₂O₃·3.5H₂O(s) and 6ZnO·5B₂O₃·3H₂O(s) in 1 mol · dm⁻³ HCl(aq) were measured by microcalorimeter at T = 298.15 K, respectively. The molar enthalpies of solution of ZnO(s) in the mixture solvent of 2.00 cm³ of 1 mol · dm⁻³ HCl(aq) in which 5.30 mg of H₃BO₃ were added were also measured. With the incorporation of the previously determined enthalpy of solution of H₃BO₃(s) in 1 mol · dm⁻³ HCl(aq), together with the use of the standard molar enthalpies of formation for ZnO(s), H₃BO₃(s), and H₂O(l), the standard molar enthalpies of formation of −(6115.3 ± 5.0) kJ · mol⁻¹ for 3ZnO·3B₂O₃·3.5H₂O and −(9606.6 ± 8.5) kJ · mol⁻¹ for 6ZnO·5B₂O₃·3H₂O at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles.     

火焰热解喷涂Al2O3—Y2O3陶瓷涂层

采用火焰热解喷涂方法，以Ａｌ（ＮＯ３）３和Ｙ（ＮＯ３）３为源物质，在敞开的大气环境中，在不锈钢基板上获得了具有一定厚度的Ａｌ２Ｏ３Ｙ２Ｏ３复合氧化物陶瓷涂层。在１２７３Ｋ空气中的恒温氧化结果表明，涂层有效地促进了基体中铬元素的选择氧化，并提高了不锈钢的抗高温氧化性能。     

CaO-MgO-Fe2O3-Al2O3-SiO2玻璃晶化机理

玻璃晶化动力学对于理解玻璃的稳定性和制备微晶玻璃十分重要．目前，通过DTA或DSC等简单技术去研究非等温过程和等温过程的动力学已取得一定的进展[1]．这些方法虽然方便，但需要事先知道晶化机理或借助XRD等技术确定Avrami参数[2]才能得到活化能．根据动力学理论，晶体生长速度与晶体生长活化能尽有直接关系[3]，通过理论计算晶体生长速度（U）可以确定玻璃体系的活化能，再结合DTA技术和Kissinger修正方程就可能确定晶体生长机理，这方面研究还未见报导．CaO－MgO－Fe2O3－AI2O3－SiO2（CMFAS）是本文综合利用废渣和尾矿制…     

化学气相色传输法分离稀土混合氧化物Sm2O3—Eu2O3—Gd2O3

以ＡｌＣｌ３为络合物配体,研究Ｓｍ２Ｏ３－Ｅｕ２Ｏ３－Ｇｄ２Ｏ３的分离特性。结果表明,其传输能力为：Ｓｍ≈Ｇｄ〉Ｅｕ,氯化物主要在９８０￣１１００Ｋ沉积。没温区的最大分离系数分别为：βＥｕ／Ｓｍ：１２００Ｋ＝１．７０,βＥｕ／Ｇｄ;１３００Ｋ＝１．８８,βＳｍ／Ｇｄ;１３００Ｋ＝１．２４,βＳｍ／Ｅｕ;８５０￣８８０Ｋ＝２．７６,βＧｄ／Ｅｕ;８８０￣９００Ｋ＝２．８３,βＧｄ／Ｓｍ;８００Ｋ＝１     

Infrared,Raman and XPS spectroscopic studies of Bi2O3–B2O3–Ga2O3 glasses

Glasses with compositions 60Bi₂O₃–(40?x)B₂O₃–xGa₂O₃ (x = 5, 10, 15, 20 mol%) are prepared by conventional melting method. The thermal properties are investigated by differential thermal analysis (DTA) and the structures of the glasses were probed by Infrared, Raman and X-ray photoelectron spectroscopy (XPS). The results show that density, refractive index and optical basicity increase with the increase of Ga₂O₃. The glass transition temperature (T_g), the onset crystallization temperature (T_x), ΔT (T_x?T_g) decrease with the content of Ga₂O₃. The cut-off edges in ultraviolet and infrared shift to longer wavelength with the increase of Ga₂O₃. On the other hand, the addition of Ga₂O₃ causes a progressive coordination number change of the boron atom from 3 to 4. XPS result indicates both Bi⁵⁺ and Bi³⁺ exist in 5 mol% Ga₂O₃ content, while Bi⁵⁺ amounts decrease with the increase of Ga₂O₃ contents. The glass is mainly composed of [BiO₆], [BO₃], [BO₄] and [GaO₄] polyhedra. Glasses are supposed to have layer structure. [BO₃] triangle and [BO₄] tetrahedra may be located between the [GaO₄] tetrahedral and [BiO₆] octahedra to prevent crystallization and to compensate electric charge.     

负载型Fe2O3—La2O3—γ—Al2O3的XRD与MBS表征

对负载型Ｆｅ２Ｏ３－Ｌａ２Ｏ３－γ－Ａｌ２Ｏ３的ＸＲＤ，ＭＢＳ等方法的研究表明，Ｌａ２Ｏ３对γ－Ａｌ２Ｏ３的改性、提高了载体的热稳定性，增强了活性组份同载体的相互作用，提高了活性组份在载体表面的分散能力。