Ca3Y2(Si3O9)2:Tb3+绿色荧光粉的光谱特性

采用高温固相法制备了Ca₃Y₂(Si₃O₉)₂: Tb³⁺绿色荧光粉,研究了材料的光学性能。X 射线衍射(XRD)结果显示,掺杂少量的Tb³⁺,并未影响Ca₃Y₂(Si₃O₉)₂材料 的晶相结构。Ca₃Y₂(Si₃O₉)₂:Tb³⁺ 荧光粉的激发光谱由较强的4f^75d1宽带吸收(200～300 nm )和较弱的4f-4f电子跃迁吸收 (300～500 nm)构成,主激发峰位于236nm。取波长分别为236、376和482nm的光 作为激发源时,发现样品的主发射峰均位于544 nm,对应Tb³⁺的⁵D 4→⁷F₅跃迁发射。以236nm 紫外光作为激发源,监测544nm主发射峰,随Tb³⁺浓度 的增大,Ca₃Y₂(Si ₃O₉)₂:Tb³⁺的荧光寿命逐渐减小,但在实验范围内并未出现浓度猝灭现象。     

Effect of Ce2O3 on the 1.53 μm spectroscopic properties in Er3+-doped tellurite glasses

Er3+/Ce3+co-doped tellurite-based glasses with composition of TeO 2-Zn O-Na2O are prepared by high-temperature melt-quenching technique.Effects of Ce2O3 content on the 1.53μm band fluorescence spectra and fluorescence lifetime of Er3+are measured and investigated.It is found that the tellurite glass containing Ce2O3 with molar concentration of 0.25%exhibits an increment of 13%in 1.53μm fluorescence intensity and an increment of 15%in the 4I13/2 level lifetime.The results indicate that the prepared tellurite-based glass with a suitable Er3+/Ce3+codoping concentration is an excellent gain medium applied for broadband Er3+-doped fiber amplifier(EDFA)pumped with a980 nm laser diode.     

Luminescent properties of blue emitting phosphor SrZn2(PO4)2:Eu2+ for white LEDs

Blue emitting phosphor SrZn2(PO4)2:Eu2+ is synthesized by a high temperature solid state method, and the luminescent properties are investigated. At the 330 nm radiation excitation, SrZn2(PO4)2:Eu2+ presents an emission band at 416 nm, which is assigned to the 4f65d1→4f7 transition of Eu2+ ion. The concentration quenching effect of Eu2+ in SrZn2(PO4)2 has been validated and proved to be a resonant type via a dipole-dipole interaction. The critical distance (Rc) of Eu2+ in SrZn2(PO4)2 is calculated to be 3.244 nm. The Commission International de I’Eclairage (CIE) chromaticity coordinates of SrZn2(PO4)2:Eu2+ locate at the blue region, such as (0.150, 0.072). The results indicate that the SrZn2(PO4)2:Eu2+ phosphor may have potential applications in white light emitting diodes (LEDs).     

Luminescent characteristics of Ba3Y2（BO3）4：Eu^3＋ phosphor for white LED

The Ba3Y2（BO3）4：Eu^3＋ phosphor was synthesized using a high temperature solid-state reaction method and the luminescent characteristics were investigated. The emission spectrum exhibited one strong red emission at 613 nm, corresponding to the electric dipole 5D0-TF2 transition of Eu^3＋, under 365 nm excitation. The excitation spectrum of 613 nm indicated that the Ba3Y2（BO3）n：Eu^3＋ phosphor was effectively excited by ultraviolet （UV） （254, 365 and 400 nm） and blue （470 nm） light. The effect of Eu^3＋ concentration on the 613 nm emission of the Ba3Y2（BO3）n：Eu^3＋ phosphor was measured. The results showed that the emission intensity increased with increasing Eu^3＋ concentration, and then decreased. The CIE color coordinates of Ba3Y2（BO3）4：Eu^3＋ phosphor were x=0.641 and y=0.359 at 15 mol.% Eu^3＋.     

白光发光二极管用单基质全色荧光粉的研究进展

综述了单基质全色荧光粉的研究进展,重点评述了近年来新出现的单基质两基色或三基色白光发射体系,如Ce3+/Eu2+共激活的硼酸盐、氯铝酸盐等两基色体系,Eu2+/Mn2+共激活的氯硅酸盐、硼磷酸盐等三基色体系;同时分析该类材料及其应用的研究现状和发展方向。     

Improved luminescent properties of SrZn2(PO4)2:Sm3+ doped with Li+, Na+ and K+ ions

SrZn2(PO4)2:Sm3+ phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn2(PO4)2:Sm3+ phosphor is efficiently excited by ultraviolet (UV) and blue light, and the emission peaks are assigned to the transitions of 4G5/2-6H5/2 (563 nm), 4G5/2-6H7/2 (597 nm and 605 nm) and 4G5/2-6H9/2 (644 nm and 653 nm). The emission intensities of SrZn2(PO4)2:Sm3+ are influenced by Sm3+ concentration, and the concentration quenching effect of SrZn2(PO4)2:Sm3+ is also observed. When doping A+ (A=Li, Na and K) ions, the emission intensity of SrZn2(PO4)2:Sm3+ can be obviously enhanced. The Commission Internationale de l'Eclairage (CIE) color coordinates of SrZn2(PO4)2:Sm3+ locate in the orange-red region. The results indicate that the phosphor has a potential application in white light emitting diodes (LEDs).     

Improving the luminescence properties of Ba3Eu(PO4)3 by doping Sm3+ as sensitizer

For enhancing the emission intensity and broadening the excitation region of Ba3Eu(PO4)3 (BEP), Sm3+ is doped as sensitizer in this paper. BEP:Sm3+ can produce an obvious red emission at near ultraviolet (n-UV) radiation. An effective energy transfer from Sm3+ to Eu3+ is proved. The commission international de I’Eclairage (CIE) chromaticity coordinates of BEP:Sm3+ locate at red region. When the environment temperature is 150 °C, the emission intensity of BEP:0.10Sm3+ is decreased to 76% of the initial one at room temperature, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP:Sm3+. The results indicate that BEP:Sm3+ may have potential applications in white light emitting diodes (LEDs).     

Luminescence properties of tunable red-green emitting phosphor Ba2Ca(BO3)2:Eu3+, Tb3+

A series of Eu3+ or Tb3+ doped Ba2Ca(BO3)2 phosphors were synthesized by a high temperature solid state method, and the luminescence properties are investigated. Ba2Ca(BO3)2:Tb3+ can show an obvious green emission, and the peak locates at 551 nm, which corresponds to the 5D4→7F5 transition of Tb3+. Ba2Ca(BO3)2:Eu3+ can present the characteristic emission of Eu3+, and the peak locates at 600 nm, which is ascribed to the 5D0→7F2 transition of Eu3+. In order to achieve the emission-tunable phosphors, the Eu3+/Tb3+ co-doped Ba2Ca(BO3)2 are synthesized. When tuning the Eu3+ or Tb3+ concentration, Ba2Ca(BO3)2:Eu3+, Tb3+ can both show the tunable emission, which may be induced by the energy transfer from Tb3+ to Eu3+.     

A novel white-bluish emitting phosphor of (Ba0.49Sr0.49)2-B2P2O10:0.02Eu2+ for white LEDs

A novel white-bluish emitting phosphor of (Ba0.49Sr0.49)2B2P2O10:0.02Eu2+ is synthesized by the solid state reaction. (Ba0.49Sr0.49)2B2P2O10:0.02Eu2+ can be effectively excited by 370 nm ultraviolet (UV) light, and exhibits two emission bands at 430 nm and 522 nm which are attributed to the d-f transitions of the Eu2+ ions in two different cation sites in the host lattices. And the chromaticity coordinate of (Ba0.49Sr0.49)2B2P2O10:0.02Eu2+ phosphor is (0.29, 0.25).     

浅析GIS技术在消防通信指挥系统中的应用

社会经济的高速发展,加快了城市中各类基建设施的建设速度,越来越多建筑工程拔地而起,由此也极大地提升了消防安全隐患。近年来,随着现代化技术的高速发展,GIS 技术在各个行业中的应用更加广泛,对于消防工程而言,快速反应和及时决策是对消防通信指挥系统的基本要求,所以为了进一步提升消防通信指挥系统工作效率,GIS 技术快速融入就显得特别重要。基于此,本文将对 GIS 技术在消防通信系统中的应用进行探析,使消防救援的指挥方法更加现代化,各项决策更加科学、严谨。