SrO-ZnO-B_2O_3-SiO_2-M_2O_3(M=Y,La,Gd)玻璃的制备和发光

采用传统熔体冷却技术制得了新型SrO-ZnO-B_2O_3-SiO_2-M_2O_3(M=Y La,Gd)发光玻璃.对玻璃密度、紫外-可见光区的透过性能以及荧光发射进行了检测.结果表明:SrO-ZnO-B_2O_3-SiO_2(SZBS)玻璃在可见光区具有高透过性能,稀土氧化物的引入增强了玻璃在可见光区的透过率.SZBS玻璃的激发主峰位于221 nm附近,发射光谱则是峰值位于410、475和502 nm附近的宽带,且蓝绿光强于紫外光发射,紫外光和蓝绿光发射分别归属于ZnO激子复合发光、Zn间隙原子的复合发光以及电子和深俘获的空穴复合发光.在SZBS玻璃组成中引入稀土氧化物造成激发峰红移并能增强玻璃的蓝绿光发射.     

闪烁玻璃原料的共沉淀法制备及其光学性能研究

采用共沉淀法制备了含0.2Pr3 :52PbO-13Bi2O3-23.33B2O3-11.67SiO2重金属氧化物玻璃组分的胶状物,作为重金属氧化物玻璃原料.该玻璃的密度为6.956 g/cm3,可见光透过率为62%,紫外吸收截止波长为410 nm,该玻璃系统能耐105r/min辐照损伤.用H2灯弱光源激发进行荧光寿命测试,0.2Pr3 :52PbO-13Bi2O3-23.33B2O3-11.67SiO2组分玻璃在H2灯激发下具有1.43 ns及5.83 ns的双指数荧光衰减时间.     

共沉淀法制备纳米铝酸锶长余辉发光粉体及其发光性能研究

用共沉淀法制备了发绿光的SrAl2O4:Eu2 ,Dy3 纳米长余辉发光粉体.用TG-DSC,XRD,SEM和荧光分光光度计等对发光粉体特性进行了表征.结果表明,在1150℃煅烧温度下合成了单相的SrAl2O4发光粉体,发光粉体的形貌为粒状,平均粒径为100 nm.在可见光(波长400 nm)激发下,SrAl2O4:Eu2 ,Dy3 纳米发光粉体的发射光谱为峰值位于512 nm的绿色宽带谱.与固相法合成的发光材料相比,发光粉体的激发光谱和发射光谱均发生了蓝移.并探讨了合成温度对发光粉体发光性能的影响.     

CHARACTERISTICS OF BaHfO3∶Ce NANO—POWDER

用湿化学共沉淀法制备了掺杂Ce的BaHfO3纳米粉体,采用XRD,TEM及TG-DTA等手段分析了粉体合成过程的物相变化及特性;用荧光光度计分析了样品的激发光谱和发射光谱.结果表明:先驱沉淀物经1000℃煅烧2 h,合成出多边形貌、分散性良好、粒径尺寸为30-50 nm的BaHfO3:Ce纳米粉体.掺杂Ce浓度(摩尔分数)为0.3%的BaHfO3的谱峰相对强度最高,其激发光谱在393和445 nm处出现2个激发峰. 393 nm波长激发的发射光谱主要由两个光谱带组成,其峰值分别位于485和530 nm波长处;用445 nm波长激发时,483 nm附近的峰已不明显,只在529 nm有一个较宽的发射峰. BaHfO3:Ce的发光特性由激活Ce3 的5d-2F5/2和5d-2F7/2宽带跃迁产生,其激发光谱和发射光谱均为宽带谱.     

含金属Bi和Bi_2S_3纳米晶玻璃的溶胶-凝胶法制备和微结构研究（英文）

用溶胶-凝胶法制备了含金属Bi和Bi_2S_3纳米晶的钠硼硅玻璃。利用差示扫描量热-失重法、X射线粉末衍射仪、透射电子显微镜详细表征了该玻璃的形成机制和微结构。结果显示,该玻璃的转变温度T_g大约为510 C,这意味着在600℃的热处理温度下可以形成玻璃。微结构分析揭示金属Bi和Bi_2S_5晶相结构已经在玻璃先驱体中形成,并且这些纳米晶的的尺寸通常在5~30 nm之间。     

PREPARATION AND CHAIACTERISTICS OF (Y,Gd)2O3:Eu3+ NANOPARTICLES

用湿化学共沉淀法制备了(Y, Gd)2O3:Eu3+纳米粒子. 用XRD, TEM, SEM及差示/热重分析 (DSC/TG)手段对粉体进行了表征. 用荧光光度计分析了样品的激发光谱和发射光谱. 结果表明： 在煅烧温度为800 ℃保温2 h时, 合成出近似球形、粒径均匀且分散性好的(Y, Gd)2O3:Eu3+纳米粒 子, 一次颗粒尺寸约为20 nm. 样品在波长为612.0 nm监控光下激发, 出现235和250 nm两个激发 峰, 分别为(Y, Gd)2O3基质吸收和Eu3+迁移态(CTS)吸收造成的. 两个波长激发下的发射光谱峰强 度前者高于后者. 当掺杂Eu3的摩尔浓度为3%时, 发射光谱对应5D07F2 能级跃迁的相对峰强度 最大, 当Eu3+掺杂的摩尔浓度为7%时, 相对峰强度反而降低, 这是由于Eu3+的浓度猝灭造成的.     

掺钨氧化钒薄膜的制备及研究

采用复合靶磁控溅射法在SiO2玻璃、普通玻璃和Si(100)上沉积氧化钒薄膜,然后对其进行真空退火.分别利用X射线衍射、原子力显微镜、紫外可见光分光光度计和红外光谱仪分析样品的物相、表面形貌和光透过率.结果表明:500 ℃下退火1 h,SiO2玻璃衬底上沉积40 min的薄膜主要物相为VO2和V2O5,退火时间延长到2 h,薄膜主要物相为VO2,薄膜晶粒尺寸均匀,晶粒大小约为100 nm;Si (100)上沉积40 min的薄膜在500 ℃下退火2 h后,物相为低于+4价的钒氧化物;掺钨后薄膜可见光和红外光的透过率都有提高.     

共沉淀法制备Sr4Al14O25:Eu2+,Dy3+长余辉发光材料

首先利用共沉淀法制备了发光材料前驱体,然后以石墨为还原剂、1280℃保温2 h烧结合成Sr4Al14O25Eu2+,Dy3+长余辉发光材料.通过XRD、荧光光谱分析方法,研究了助熔剂、稀土离子、烧结制度等对发光材料物相结构和发光性能的影响.结果表明发光粉体的主晶相为Sr4Al14O25,属斜方晶系,晶胞参数为a=2.480 nm,b=0.850nm,c=0.489nm;其激发光谱为一主峰波长在398 nm和356 nm的连续谱,包括紫外线和可见光;发射光谱为一主峰波长为491 nm的宽带谱,经自然光、紫外光照射后可发出明亮的蓝绿色光.     

Ca-α-SiAlON:Eu2 荧光发光材料的合成与发光性能

以α-Si3N4,AlN,CaCO3,Eu2O3为原料,采用固相烧结法获得了组成为CaxEuySi12-(3x 4.5y)Al3x 4.5yOx 1.5yN16-(x 1.5y)(x=0.220～1.525,y=0.02～0.15)的荧光发光材料.应用X射线衍射(XRD)仪,扫描电子显微镜(SEM),紫外-可见分光光度计和荧光分光光度计,研究了不同组成及烧结工艺对Ca-α-SiAlON:Eu2 的制备,Eu2 掺杂和荧光发射的影响.在所研究的组成范围,可以获得单相、Eu2 掺杂的Ca-a-SiAlON:Eu2 陶瓷粉体.提高烧结温度可以进一步改善Eu2 离子的分布均匀性.Ca-α-SiAlON:Eu2 在紫外-可见光部分具有强烈的吸收,其激发光谱的峰值波长为～270 nm、400 nm,发射光谱的峰值波长为～570 nm.采用氢气,氮气混合气氛烧结合成的Ca-α-SiAlON:Eu2 的发光强度要高于氮气气氛烧结合成的样品.     

镀膜方法对氧化硅介孔薄膜的微观结构和光学性能的影响（英文）

以CTAB为模板剂,采用溶胶-凝胶法制备SiO_2介孔薄膜,探究了浸渍-提拉法和旋涂法对其微观结构和光学性能的影响。用小角X射线散射(SAXS)和透射电镜(TEM)分析薄膜内部孔道排列方式,发现采用旋涂法镀膜更易得到较为有序的介孔阵列,其孔道周期参数a为3.76nm。用扫描电镜(SEM)观察样品发现通过两种镀膜方法制备得到的薄膜表面均平整无裂纹。紫外-可见光谱表明,采用两种镀膜方法均能得到可见光透过性良好的镀膜玻璃,其中通过旋涂法制得的薄膜厚度非常均一。     

Fe-15Ce合金在H2-CO2、H2-H2S及H2-H2S-CO2气氛下的腐蚀

研究了600℃时Fe-15Ce合金在H2-CO2、H2-H2S及H2-H2S-CO2 3种气氛中的腐蚀行为，Fe-15Ce合金腐蚀后发生了Ce的内氧化或形成了复杂的腐蚀产物膜，而未出现Ce的选择性氧化或硫化，这主要是合金中存在着两相及Ce在Fe中极低的溶解度的结果。Fe-15Ce合金在本实验条件下的氧化-硫化腐蚀速度低于相同温度、压力下的纯硫化。     

用氢-氧取代氧-乙炔作焊接切割的必要性及可行性

阐述了用氢代乙炔的必要性．通过时HGQU2000／315火焰电孤焊割机的考察和试用证实了用氢代乙炔的可行性，比较了两种气体的性质并提出了使用特性差异和注意事项．提出了进一步探索的问题。     

Thermodynamics and phase diagrams in the binary systems Na2O-SiO2, Na2O-GeO2, Na2O-B2O3, Li2O-B2O3, CaO-B2O3, SrO-B2O3, and BaO-B2O3

We applied our model to the enthalpy of mixing data of the binary systems Na₂O-SiO₂, Na₂O-GeO₂, Na₂O-B₂O₃, Li₂O-B₂O₃, CaO-B₂O₃, SrO-B₂O₃, and BaO-B₂O₃. The most stable composition in the liquid, that is where the enthalpy of mixing is most negative, is with a metal-oxygen ratio of 4 to 3, for monovalent metals (Na and Li) and 3 to 4 for divalent metals (Ba and Ca) in liquid silicates or borates. The same applies to the CaO-SiO₂, CaO-Al₂O₃, PbO-B₂O₃, PbO-SiO₂, ZnO-B₂O₃, and ZnO-SiO₂ systems. The oxygen to metal ratio, its constant value in various types of systems, reflects and describes the structure of the liquid. Using the analyzed enthalpies of mixing data and the available phase diagrams, we calculated the enthalpies of formation of the various binary compounds. The results are in excellent agreement with data in the literature that were obtained from direct solid-solid calorimetry.     

IrO2-MnO2中间层Ti/RuO2-TiO2-SnO2电极制备及性能

通过热分解法制备了含IrO2-MnO2中间层Ti/RuO2-TiO2-SnO2电极,采用SEM、EDX、XRD、CV等检测方法对中间层进行表征,同时采用强化加速寿命试验对电极电化学稳定性进行表征。结果表明:450℃时前躯体完全氧化并形成固溶体,制备的中间层晶粒细小,表面结构致密,电化学孔隙率小。添加中间层使Ti/RuO2-TiO2-SnO2电极强化寿命由未加中间层的7.5h提高到995.8h,远高于国家标准20h。     

ACTIVITY OF La_2O_3 IN LIQUID La_2O_3-CaF_2 AND La_2O_3-CaF_2-CaO-SiO_2 SLAGS

用石墨为还原剂,将渣中La_2O_3还原入液态Sn,以测定1500℃下La_2O_3-CaF_2和La_2O_3-CaF_2-CaO-SiO_2渣中La_2O_3的活度.对La_2O_3-CaF_2系,并用Gibbs-Duhem积分法求得CaF_2的活度. 根据液态渣的离子结构模型,对上述二渣系中La_2O_3的活度数据进行了简单的讨论.     

Mechanoluminescence in BaSi2O2N2:Eu

Mechanoluminescence (ML), a general term for the phenomenon in which light emission occurs during any mechanical action on a solid, can be divided roughly into two classes: destructive ML and non-destructive ML. For practical use in high-end applications (e.g. pressure sensors), materials with non-destructive ML properties are preferred. This paper reports on the strong non-destructive ML in BaSi₂O₂N₂:Eu. When irradiated in advance with ultraviolet or blue light, this phosphor shows intense blue-green light emission upon mechanical stimulation such as friction or pressure. The ML has an emission band peaking at 498 nm, which is ～4 nm red-shifted compared to the steady-state photoluminescence. The origin of the ML is discussed and related to the persistent luminescence of BaSi₂O₂N₂:Eu. The same traps are responsible for both phenomena. Based on the occurrence of ML in this phosphor, we were able to show that the predominant crystallographic structure of BaSi₂O₂N₂:Eu belongs to space group Cmc2₁.     

氢分子在贮氢材料Li2MgN2H2表面的吸附与解离

采用第一性原理计算方法研究了Li-Mg-N-H体系贮氢材料的放氢产物Li2MgN2H2的吸氢反应过程中的过渡态、表面电子态密度和表面能。结果表明:氢分子在Li2MgN2H2低指数表面中最低能量(100)表面的Mg-Mg-Li穴位吸附位置能够形成最稳定的吸附结构并发生解离,氢分子吸附能为-0.1898eV,解离能约为0.84eV(81kJ/mol),表明该反应所需的反应活化能仍较高,吸氢反应速度缓慢。     

Thermodynamic evaluation of phase equilibria in the CaCl2-MgCl2-CaF2-MgF2 system

The phase diagram of the CaCl₂-CaF₂-MgCl₂-MgF₂ reciprocal ternary system was calculated thermodynamically from available data on the common-ion binary subsystems and from available data on the CaCl₂-MgF₂ join. This join is very nearly quasibinary and divides the system into two quasiternary systems: the CaCl₂-MgF₂-CaF₂ system with a ternary eutectic calculated at 724 +-5 °C and the CaC₂-MgF₂-MgCl₂ system with a ternary eutectic calculated at 561 +-5 °C.     

High temperature corrosion of Fe-Cr-Mn-alloys in H2-H2S and H2-H2O-H2S gas mixtures

The sulfidation of Fe-20% Cr-30% Mn, Fe-25%Cr-20%Mn and Fe-25% Cr was studied at 700°C in H₂-H₂S and the oxidation and sulfidation in H₂-H₂O-H₂S after preoxidation in H₂-H₂O. The sulfidation rate is strongly increased for the Mn-containing alloys, layers of (Mn,Cr)S and (Mn,Fe)Cr₂S₄ are formed. Also the oxidation rate is enhanced compared to Fe-25% Cr by formation of MnCr₂O₄ instead of Cr₂O₃. The sulfidation after preoxidation leads to internal and external sulfidation of the Mn-containing alloys. With increasing oxygen pressure p(O₂) = 10^?26…10^?22 atm. of the H₂-H₂O-H₂S mixtures the sulfidation is suppressed, for the higher oxygen pressure 10^?23 and 10^?22 atm. fast oxidation prevails under formation of MnCr₂O₄. Manganese cannot increase the sulfidation resistance of alloys, in spite of the stability and low degree of disorder of its sulfide, since the mixed sulfide (Mn,Cr)S is formed which has a high degree of disorder, high diffusivities and high growth rate according to the doping effect of trivalent Cr³⁺.     

The Quasi-Ternary System Cu2Se-Ga2Se3-GeSe2

The quasi-ternary system Cu₂Se-Ga₂Se₃-GeSe₂ was investigated using the methods of differential thermal and x-ray analysis. An isothermal section at 770 K and a liquidus surface projection of the phase diagram were constructed. The existence of the quaternary phase CuGaGeSe₄, the boundaries of solid solutions ranges of the system compounds were established.