Incorporation of Si-Ninducing white light of SrAl_2Si_2O_8：Eu~（2＋）,Mn~（2＋） phosphor for white light emitting diodes

Photoluminescence (PL) and colorimetric properties of white-light emission SrAl2Si2O8:Eu2+,Mn2+ phosphor were tuned effectively through incorporating Si-N bond to the host in the form of Si3N4. A maximum solubility of Si-N bond in SrAl2-xSi2+xO8-xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2+ and an enhancement of yellow band emission peaked at ~565 nm for Mn2+ were observed with the increase of Si-N ...     

Investigation of the red-shift of the emission of microwave solvothermally-grown europium doped calcium sulphide crystals

A distinct red-shift to 660 nm-featured longer wavelength of europium doped calcium sulphide nanocrystals was observed in a microwave （MW）-assisted solvothermal synthesis procedure. This red-shift was probably due to a combined effect from Mg^2＋ codoping and strain accumulation at grain boundaries. The latter originated from the formation of small grains with an average size of around 200 nm in micrometer sized crystals upon Mg^2＋ codoping. In particular, MW electromagnetic field suppressed grain growth and enabled a reconstruction of atoms at the inner grain boundary at which the field strength was intensified around rare earth ions in host lattices. This MW synthesis route provided an option to prepare luminescent crystals with the desired blue-excitable longer wavelength emission.     

液态铝与陶瓷的润湿性改变机理

针对开展的液态铝合金制备铝基复合材料的工艺过程，分析界面润湿性改善的机理，氧化铝膜的形成和分解决定了附加压力和侵入功的大小，温度，液态合金成分，涂层等工艺参数对界面润湿性的改善起到重要作用。     

Multi-wavelength excitable europium-doped borosilicate glasses for orangered emission：composition-induced structure and valence variation

Europium-doped borosilicate glasses were prepared by melt-quenching procedure in the air.The mixed valence of Eu 2+ and Eu 3+ was identified by photoluminescence spectrum and electron paramagnetic resonance(EPR).The existence of mixed valence was observed owing to the unequivalent substitution and de-polymerization network of the as-prepared borosilicate glasses.The variation of the glass composition in B 2 O 3 /BaO ratios changed the stability of the Eu 3+ ions distinctly.In particular,as-prepared borosilicate glasses exhibited a tri-wavelength light excitable spectra centered at 397,466 and 534 nm to give the broadened orange-red emission at around 592 and 617 nm,due to supersensitive transitions of Eu 3+ ions.This simultaneous tri-wavelength excitation happened to correspond with the emitting wavelength from near ultraviolet,blue AlInGaN chips and that from YAG:Ce 3+.The total quantum yield(QY) of the Eu-doped glasses under 466 nm excitation was evaluated to be 10%,potentially providing a versatile combination with the europium-doped borosilicate glasses for red component addition to improve the quality of white light.     

纳米材料的合成与制备技术

综述了近年来纳米材料研究领域中合成和制备技术的进展，内容包括纳米颗粒、纳米块体材料和纳米薄膜材料的合成与制备。关键词     

铜电解液物理化学性质之二:电解液的粘度

在铜电解生产中，电解液的粘度是一个很重要的物理化学性质，它不仅影响电解槽中的热量和质量的传递，而且也影响电解过程中铜电沉积的表面状况。本文对铜电解液的粘度的各研究结果进行了比较和综述。     

纳米锌铈氧化物的紫外光屏与催化性能

研究同时具有紫外吸收、低光催化和氧化催化活性的纳米锌铈氧化物(ZCO).用无机聚合物凝胶燃烧法化学控制合成的纳米颗粒平均粒径约为10nm,原子比(Zn/(Zn+Ce))为0.2.实验评价了ZCO粉体的Uv-Vis光谱、紫外光光催化、氧化催化性能,并分别与TiO2、ZnO、CeO2进行了对比.UV-Vis光谱性能测试结果表明,ZCO在200～400nm范围强吸收,且峰值较宽且红移;用波长253.7nm紫外灯辐射,得出光催化活性顺序为ZnO＞R-TiO2＞ZCO＞CeO2;用氧化分解篦麻油电导率的测定,间接评价ZCO的氧化催化很低.     

Luminescence properties of a solid solution typed （Ba,Ca）3MgSI2O8： Eu2＋ , Mn 2＋ phosphor with a 660 nm- featured photosynthetic action spectrum

A solid-solution-phase Ba1.75Ca1.25MgSi2O8： Eu2＋, Mn2＋ phosphor in the photosynthetic action spectrum with dual band emissions at 438 nm and 660 nm is fabricated. X-ray diffraction （XRD） confirms the presence of the solid-solution phase. With the supporting information from the diffuse reflection spectrum, a feasible way to obtain higher energy-transfer （ET） efficiency is attained, and the ET efficiency of Eu2＋-Mn2＋ is enhanced to 76%. The mechanism of this enhancement is owing to variation of the solid solution composition of Ca3MgSi208 and Ba3MgSi2Os, which contributes to the extension of the critical distance. Temperature-dependent results show an en- hancement which is attributed to Ca. These enhancements show great promise for improving coo-lighting devices.     

Direct white-light from core-shell-like sphere with Sr3Mg-Si2O8: Eu2+, Mn2+ coated on Sr2SiO4:Eu2+

A method of color mixture for white light is presented with Sr3MgSi2O8:Eu2+, Mn2+ shell coated on Sr2SiO4:Eu2+ core by spray pyrolysis procedure. Upon near ultraviolet (NUV) excitation, a 550 nm band emission of Eu2+ from core host combines with the simultaneous emissions of Eu2+ at 457 nm and Mn2+ at 683 nm based on energy transfer in the shell lattice to generate warm white light with color rendering index (CRI) of 91. With such a core-shell-like structure, the re-absorption of blue light from shell layer can be effectively suppressed, and the chemical stability of the phosphor is verified experimentally to be superior to that of the Sr2SiO4:Eu2+. This new proposed phosphor provides great potential in the color mixture of blending-free phosphor converted white NUV light emitting diode (LED) devices.     

Ba^2＋离子对Sr2Al2SiO7∶Eu^2＋荧光体微结构及发光性能的影响

采用复合胶体喷雾工艺制备了Ba2＋离子掺杂的Sr2-xBaxAl2SiO7∶Eu2＋（x=0、0.1、0.2、0.4）荧光体。研究了Ba2＋离子在基质Sr2Al2SiO7中的取代位置和机理,分析了Ba2＋离子取代Sr2＋离子对基质微结构及Sr2Al2SiO7∶Eu2＋荧光体发光性能的影响。XRD结果表明Ba2＋离子取代Sr2＋格位进入Sr2Al2SiO7晶格,导致晶胞体积增大。进入Sr2Al2SiO7晶格的Ba2＋离子由于电负性较大,处在其周围的Eu2＋离子外层电子受Ba2＋离子影响,电子云膨胀,使发光波长发生红移。同时,掺入Ba2＋离子后Sr2-xBaxAl2SiO7晶场强度增强,晶体场对Eu2＋离子5d能级的劈裂程度增大,劈裂重心下降。Ba2＋离子掺杂的Sr2-xBaxAl2SiO7∶Eu2＋（x=0、0.1、0.2、0.4）荧光体发射主峰位于520nm,与未掺杂Sr2Al2SiO7∶Eu0.022＋荧光体的发射峰相比出现红移。