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1.
用高温固相法合成了Sr3B2O6:Tb^3+,Li^+绿色荧光粉,并研究粉体的发光性质。发射光谱由位于黄绿区的4个主要荧光发射峰组成,峰值分别位于495,548,598,625nm,对应了Tb^3+的^5D4→^7F6,^5D4→^7F5,^5D4→^7和^5D4→^7F3特征跃迁发射,548nm的发射最强。激发光谱表现从200—400nm的宽带,可以被近紫外光辐射二极管(near-ultraviolet light-emitting diodes,UVLED)管芯产生的350-410nm辐射有效激发。研究了Tb^3+掺杂和电荷补偿剂对样品发光亮度的影响。Sr3B2O6:Tb^3+,Li^+是一种适用于白光LED的绿色荧光粉。  相似文献   

2.
铽-丙烯酸聚合物薄膜的制备和谱学性质   总被引:1,自引:0,他引:1  
以键合方式制备了键合型稀土聚合物-铽-丙烯酸聚合物,通过三维荧光光谱确定了铽在丙烯酸聚合物中的最佳激发波长为306nm,最强发射波长为544nm,Tb-丙烯酸聚合物薄膜在306nm光激发下,产生Tb^3 的特征发射,归属于^5D4-^7FJ跃迁(J=6,5,4,3),其最大发射位于544nm,归属于Tb^3 的^5D4-^7F5跃迁,呈现强的绿色发射,说明丙烯酸的聚合没有影响Tb^3 的发光性质,而Tb^3 的参入也没有影响丙烯酸的透明性。通过发射光谱、激发光谱、中红外光谱、远红外光谱和拉曼光谱,研究了铽-丙烯酸聚合物薄膜的荧光性质和谱学性质。  相似文献   

3.
CaTiO3:Pr3+长余辉玻璃的制备与发光性能   总被引:3,自引:1,他引:2  
用二次熔融法制备了CaTiO3:Pr^3+红色长余辉玻璃。测量了样品的发射光谱,其发射光谱峰值为611.7,614.5nm,对应于Pr^3+的4f-4f(^1D2→^3H4)跃迁,与CaTiO3:Pr^3+晶态长余辉发光粉的发射光谱峰值相一致。玻璃粉与发光粉的质量配比在95:5~80:20时,都可以形成玻璃态并得到红色长余辉发光。研究了气氛和熔融温度对发光性能的影响,在空气环境下,800℃即可得到性能良好的样品。  相似文献   

4.
稀土掺杂长余辉发光玻璃的研究   总被引:8,自引:1,他引:7  
分别采用空气气氛和还原气氛,制备了稀土Eu2O3,Dy2O3掺杂的铝硅酸盐玻璃,利用荧光光谱仪对样品进行了测试。结果表明:空气气氛条件下制备的铝硅酸盐玻璃样品均不具备长余辉发光性能,其激发光谱和发光光谱均是Eu^3+的^5Di(i=0,1)→^7 F(j=0~4)跃迁的典型光谱。经还原气氛处理后,单掺和双掺的铝硅酸盐玻璃样品均具有长余辉发光现象,单掺Eu^2+的发光峰位于462nm,而双掺Eu^2+和Dy^3+的发光峰位于457nm,且双掺Eu^2+和Dy^3+的样品陷阱能级较深,样品的发光持续时间长达12h以上。  相似文献   

5.
Eu3+和Tb3+掺杂的Y2SiO5体系发光特性研究   总被引:10,自引:0,他引:10  
采用溶胶-凝胶法合成了Eu^3 和Tb^3掺杂的Y2SiO5基发光材料,通过测量它们的激发光谱和发射光谱,研究了它们的发光特性,探讨了材料中Tb^3和Eu^3 两种发光中心间的能量关系。结果表明,Eu^3+在其中的特征发射以^5D0→^7F2电偶极跃迁为,Eu^3处于非反演对称中心格位;Tb^3在其中的发射为^5D4→^7FJ(J=4-6)跃迁发射。当Eu^3和Tb^3共存于Y2SiO5基质中时Eu^3的发射增强,Tb^3的发射减弱,存在Tb^3→Eu^3能量传递,Tb^3对Eu^3具有敏化作用。  相似文献   

6.
(Y,Gd)BO3:Tb3+的真空紫外及紫外激发光谱特性   总被引:2,自引:0,他引:2  
采用传统的高温固相反应法合成出(Y,Gd)BO3:Tb荧光体,对所制得的荧光体进行了晶体结构分析,分析结果表明结晶良好。(Y,Gd)BO3:Tb在147nm真空紫外光激发下的发射主峰在544nm(Tb^3+的^5D4→^7F5跃迁),是一种绿色发光材料。样品的真空紫外激发光谱及紫外激发光谱表明,(Y,Gd)BO3:Tb的基质吸收带位于150nm附近。Gd^3+离子对真空紫外区的光吸收有增强作用,存在着Gd^3+→Tb^3+的能量传递。测量了荧光粉在室温下的荧光衰减特性,其余辉时间约为8ms,能够满足显示显像技术的要求。因此,(Y,Gd)-BO3:Tb是一种有前景的PDP用绿色发光材料。  相似文献   

7.
在254nm紫外光(UV)激发下,研究了(LaO)3BO3基质中Tb^3 的激发光谱、发射光谱、发光寿命与Tb^3 浓度的关系,并探讨了Tb^3 的^5D3→^7D3→F4。跃迁发射的自身浓度猝灭机理,在阴极射线(CD)激发下,研究了(LaO)3BO3:Tb^3 的发光强度与Tb^3 浓度、加速电压及电流密度的关系,发现在UV事CR两种激发条件下,试样均能发出明亮的绿色荧光,有望成为一种有发展前途的绿粉。  相似文献   

8.
硼酸掺量对SrAl2O4长余辉发光材料的发光性能影响   总被引:2,自引:0,他引:2  
用燃烧法制备了Eu2 ,Dy3 共掺杂SrAl2O4长余辉发光材料,研究了不同硼酸掺量对Eu2 ,Dy3 共掺杂SrAl2O4长余辉发光材料发光性能的影响。为了分析B2O3在材料制备中的作用,用XRD对所合成材料进行物相分析,用荧光光谱仪记录其发射光谱,并在暗室里拍摄紫外激发下的发光照片。结果表明:硼酸掺量为0.8的样品的发光光谱,其发射峰峰值位于518 nm,是典型的Eu2 的4f5d→4f的特征发射,为一宽谱带发光光谱。硼酸掺量为2的样品的发光光谱,其在518 nm位置的峰十分弱,而在487 nm处同时出现了一个弱峰,整个谱线呈一斜坡状。随着硼酸加入量的不同,Eu2 ,Dy3 共掺杂铝酸锶的发光效果、形貌特征均不同。在某一范围内,随着硼酸添加量的增加,合成了发光主晶相,烧结温度有所降低,材料的发光性能和发光亮度均有所提高。  相似文献   

9.
用二次熔融法制备了CaTiO3∶Pr3+红色长余辉玻璃。测量了样品的发射光谱,其发射光谱峰值为611.7,614.5 nm,对应于Pr3+的4 f-4 f(1D2→3H4)跃迁,与CaTiO3∶Pr3+晶态长余辉发光粉的发射光谱峰值相一致。玻璃粉与发光粉的质量配比在95∶5~80∶20时,都可以形成玻璃态并得到红色长余辉发光。研究了气氛和熔融温度对发光性能的影响,在空气环境下,800℃即可得到性能良好的样品。  相似文献   

10.
在本文中制作了CaAl4O7:Tb^3 ,Ce^3 新荧光材料。烧结温度为1300℃,烧结环境为N2+5%H2还原气。TEM实验结果表明样品的粒度小于1μm。X-射线和HRTEM实验证实,样品的晶格点阵十分规则,而且没有发现掺杂和助溶剂对基质结构的影响,表现出十分好的材料质量。光学实验观测到对应于Tb^3 离子的^5D4到^7FJ(J=6,5,4,3)的跃迁发射峰在485,545,590和630nm。CaAl4O7:Tb^3 ,Ce^3 降低了基质结构的不确定性,同时保持了Tb^3 发光中心的特性。  相似文献   

11.
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.  相似文献   

12.
A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.  相似文献   

13.
The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.  相似文献   

14.
A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.  相似文献   

15.
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.  相似文献   

16.
17.
A transient suppression method for piezoelectric ceramic transducer is presented. By adding some special pedestal pulses to the original transmitted signal, the transient effects in the output of the transducer can be just precisely transmission by use of a narrowband transducer. canceled, thereby achieving the broadband The experimental results show that the transient responses of the sinusoid pulses and coded signals are suppressed successfully and the acoustic waveforms radiated into the surrounding water are improved significantly.  相似文献   

18.
We experimentally demonstrate amplitude squeezed soliton utilizing intensity-dependent self-phase modulation in an asymmetric Sagnac interferometer.The system.whose components are connected via ferrule connector/physical connection(FC/PC)fiber connectors,constitutes all-fiber configuration to generate squeezed soliton.Soliton amplitude reduction measured by homodyne detection is near 4.0 dB below the shot-noise level.Optimal squeezing fields in both simple and compact all-fiber configuration are obtained.  相似文献   

19.
The(2 1)-dimensional nonlinear Schr(o)dinger(NLS)equation with spatially inhomogeneous nonlinearities is investigated,which describes propagation of light in(2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities.New types of optical modes and nonlinear effects in optical media are presented numerically.The results reveal that the regular split of beam can be obtained in (2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities,by adjusting the guiding parameter.Furthermore,the stability of beam regular split is discussed numerically,and the results reveal that the beam regular split is stable to the finite initial perturbations.  相似文献   

20.
In the real-world application of face recognition system, owing to the difficulties of collecting samples or storage space of systems, only one sample image per person is stored in the system, which is so-called one sample per person problem. Moreover, pose and illumination have impact on recognition performance. We propose a novel pose and illumination robust algorithm for face recognition with a single training image per person to solve the above limitations. Experimental results show that the proposed algorithm is an efficient and practical approach for face recognition.  相似文献   

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