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1.
应用燃烧法在空气中在较低的温度(600度)下成功地合成了铝酸盐荧光体BaMgAl10O17:E^2 ,RE0并研究了稀土离子对荧光体发光的影响和作用,第一次观察到荧光体的长余辉发光现象。  相似文献   

2.
据报道,日本芝浦电气公司井上泰一研制出一种红色发光荧光体。用紫外线、阴极射线、X光激发时发红色光,发光谱峰在6700A附近,发射光谱分布在6000A~7500A之间。 过去的灯用红色发光粉和电视用红色发光粉的发光总能量满足不了要求。该新型红色发光荧光体的发光总能量增加了。  相似文献   

3.
荧光体     
前言 早在17世纪初,人们就开始了对荧光体的研究。近年来,荧光体已在荧光灯和彩色电视等领域中得到了广泛应用。在改进和研制方面也取得了一些惊人的进展。本文不想逐一介绍荧光体材料的特性及其应用,只是重点讲一下荧光体的发光机理。  相似文献   

4.
纳米晶Y2O3:Eu3+红色荧光体的发光性质研究   总被引:8,自引:0,他引:8  
研究了纳米晶Y2 O3:Eu3 红色荧光体的发光性质。结果表明 :该荧光体最大激发峰位于 2 5 2 6nm ,最大发射峰位于 6 13 4nm ,随着团聚尺寸的增加、煅烧温度的提高和助熔剂的加入 ,Y2 O3:Eu3 红色荧光体的发光强度增大 ;包膜工艺消除了纳米晶Y2 O3:Eu3 红色荧光体的表面缺陷和悬挂键 ,改善了其发光特性。  相似文献   

5.
《发光学报》2021,42(9)
基于热活化延迟荧光的双发射有机材料,由于具有两种颜色的发光波长,且至少有一种发射的衰减寿命在微秒级以上,因此在白色有机发光二极管、多功能探针与传感、高质量生物成像、防伪等领域具有很大的应用前景。为了合理地设计基于热活化延迟荧光的双发射有机电子给体-受体型材料,最为关键的是研究分子结构与光物理性质之间的构效关系。本文将基于热活化延迟荧光的双发射有机电子给体-受体型分子,根据其发光属性分为三类:热活化延迟荧光-荧光双发射、热活化延迟荧光-磷光双发射和双热活化延迟荧光发射,进一步对其分子设计原则、发光机制和最新进展做出了简要综述,并展望了其发展前景。  相似文献   

6.
本文用固态反应合成了钙钛矿型的LaGaO3和LaGaO3:RE3+(RE3+=Eu3+,Ho3+)荧光体,并观察了物相随不同的激活离子浓度的变化。测量了化合物在室温下的反射光谱,激发光谱和荧光光谱。研究了Eu3+的D0→7F2和Ho3+的5S2→5I8的荧光强度与激活离子浓度的关系,发现了浓度猝灭,并得到了最大荧光强度的浓度值。  相似文献   

7.
O482.3 2005043092 锗酸锌锰荧光体发光学与荧光瞬态衰减研究=Lumines- cence and time-resolved fluorescence decay of Mn2+-activa- ted Zn2 GeO4 phosphors under ultraviolet excitation[刊, 中]/李映萓(台湾交通大学应用化学系.台湾,新竹 (300010)),骆力扬…//发光学报,-2005,26(2),-183- 188 制备一系列锗酸锌锰荧光体,并探讨其发光特性、瞬态荧光衰减与色度值与所掺杂锰离子含量之间的相互关系。本系列荧光体锰离子发射峰波长随Mn2+含量由0增  相似文献   

8.
2,3,7,8—四氯代—N—乙基吩噻嗪的荧光法研究   总被引:1,自引:1,他引:0  
本文研究了2,3,7,8-四氯代-N-乙基吩噻嗪在不同条件下的荧光强度变化规律,为荧光体确定了最佳发光体系,对提高有机光导体的灵敏度具有实际意义。  相似文献   

9.
采用Czochralski方法生长了透明均匀的含Tm3 ,Er3 ,Yb3 稀土离子的YVO4晶体 ,室温下测量了各晶体试样在 32 6和 6 5 8nm泵浦光激发下的荧光光谱 ,分析了不同掺杂浓度和稀土离子的各晶体试样中的荧光光谱性质 ,并讨论了不同掺杂情况下对上转换发光的影响和激活离子之间的相互敏化作用  相似文献   

10.
皮肤的光学性质研究   总被引:2,自引:0,他引:2  
为了确认通过皮肤进行基于卟啉荧光的元创恶性肿瘤诊断的可行性,应用光谱法分析研究了人皮肤的光学特性。通过测量皮肤的反射光谱、透射光谱和荧光光谱分析确定皮肤中的发光物质及其光谱对卟啉荧光的影响。用280nm激发光对皮肤进行激发,测到皮肤在360nm发出的荧光。与牛血清白蛋白的荧光光谱比较,确定发光物质是某类蛋白质。选择350nm激发光对皮肤进行激发,测得了与离体类胡萝卜素荧光452nm相同的荧光,所以皮肤中的发光物质有类胡萝卜素。光谱分析还表明,皮肤的荧光中还有弹性蛋白和还原型烟酰胺腺嘌呤二核苷酸(NADH)的荧光发射,荧光峰分别在400,460nm。黑色素不发荧光,但皮肤中可能还存在氧化的黑色素,它的荧光波长是580nm,这些都与卟啉的荧光波长不同。由此可见皮肤中发光物质不会影响卟啉荧光的探测。由皮肤的透射光谱观察到,卟啉的荧光波长恰好在皮肤的透射窗口内,从而进一步确定了卟啉荧光的无创探测的可能性。  相似文献   

11.
12.
为了提高LED光源色温和亮度的调节精度和准确度,结合色温由低向高变化时光色所呈现的渐变特点,提出了一种低色温白光LED灯珠、高色温白光LED灯珠加红绿蓝光LED灯珠补偿式调光的方法.将色温分成三个部分进行调节,每个部分选用不同的LED灯珠组合来进行调光.实验结果表明:不同组合情况下的LED光源的初始输出色温相对于目标值的偏差范围在1%以内;亮度可以在保证色温不变的情况下独立进行调节,初始输出值与目标值的偏差范围在1%以内;经过微调之后可以达到目标值;达到了色温和亮度独立调节的要求;光源发光稳定,不会因为长时间工作而影响调节精度.  相似文献   

13.
A technique combining image processing and laser interferometry for visualizing and detecting the deformation of transparent cylindrical and spherical sample is proposed. This deformation includes geometric deformation such as volume transition in profilometry and physical deformation such as refractive index change in tomography. Phase contour lines are used for quantitative analysis and graphical representation of the deformation. This method allows us to visually detect the spatial variation of the deformation field and to evaluate the test quality such as misalignment of optical system. A theoretical analysis using phase contour map to characterize the deformation field is described in detail. A method using phase contour map to qualify the interferometric test is proposed. Analysis of test examples is carried out. Suggestions on using phase contour line method to ameliorate test system design are finally discussed.  相似文献   

14.
Discrepancies and accords between quantum (QM) and classical mechanics (CM) related to expectation values and periods are generally found for both the harmonic oscillator (SHO) and a free particle in a box (FPB), which may apply generally. These indicate non-locality is expected throughout QM. The FPB energy states violate the Correspondence Principle. Previously unexpected accords are found and proven that 〈x 2 CM =〈x 2 QM and τ CM =τ QMb (beat period i.e. beats between the phases for adjoining energy states) for the SHO for all quantum numbers, n. However, for the FPB the beat periods differ at small n. It is shown that a particle’s velocity in an infinite square well varies, no matter how wide the box, nor how far the particle is from the walls. The quantum free particle variances share an indirect commonality with the Aharonov-Bohm and Aharonov-Casher effects in that there is a quantum action in the absence of a force. The concept of an “Expectation Value over a Partial Well Width” is introduced. This paper raises the question as to whether these inconsistencies are undetectable, or can be empirically ascertained. These inherent variances may need to be fixed, or nature is manifestly more non-classical than expected.  相似文献   

15.
潘峰  戴连荣 《物理学进展》2004,24(2):216-258
本文总结了计算黑克、布劳、及伯曼 温采尔代数在各种工数链下诱导及分导系数的线性方程方法(LEM)。特别强调了关于A,B,C,D型李代数及其量子情形与其中心代数之间的舒尔 魏尔 布劳双关性关系。这一关系使我们能够利用相应中心代数的诱导及分导系数计算出经典李代数及其量子情形的耦合与重新耦合系数。讨论了从该方法得到B,C,D型李代数不可约表示克罗内克积分解的应用。基于LEM还得到了处理对应于置换群CG系列问题的黑克代数张量积的方法。  相似文献   

16.
We present a systematic study of the effect of methyl substitution on iso- and alloxazines in acetonitrile solutions. Substitution patterns have profound effects on both spectral and photophysical properties, with fluorescence quantum yields varying by more than an order of magnitude. TD-DFT calculation were used for the first time to correlate electronic structure changes with the substitution patterns, with good agreement between calculated and theoretical band positions and oscillator strengths. Both n-pi* and pi-pi* states in these compounds are predicted, with the oscillator strengths indicating that only the pi-pi* states should be observable in the absorption spectra. Substitution patterns are shown to be responsible for energy order inversion between these states.  相似文献   

17.
In this letter, we illustrate the importance of fluid dynamics research by considering two particular areas of study: nano- and micro-scale fluid and plasma dynamics. We show how improved scientific knowledge of nano- and micro-fluid dynamics can significantly enhance our future. Application is also discussed regarding environmental aspects.  相似文献   

18.
国外超导材料技术研究政策和方向   总被引:1,自引:1,他引:0  
超导材料技术是21世纪具有战略意义的高新技术,极具发展潜力和市场前景。世界各发达国家纷纷制定研发计划,给予高度重视和大力支持,加快超导材料技术的基础研究和产业化发展。主要从美国、日本、欧洲国家、韩国等国家的相关研发计划、政策以及主要科研机构的研发概况出发,阐明目前国外超导材料技术的研究政策和方向。  相似文献   

19.
We solve several problems that involve imposing metrics on surfaces. The problem of a strip with a linear metric gradient is formulated in terms of a Lagrangian similar to those used for spin systems. We are able to show that the low energy state of long strips is a twisted helical state like a telephone cord. We then extend the techniques used in this solution to two–dimensional sheets with more general metrics. We find evolution equations and show that when they are not singular, a surface is determined by knowledge of its metric, and the shape of the surface along one line. Finally, we provide numerical evidence by minimizing a suitable energy functional that once these evolution equations become singular, either the surface is not differentiable, or else the metric deviates from the target metric.  相似文献   

20.
基于OpenGL和大气传输光学分析的3维全数字仿真是激光跟瞄系统的重要研究手段。为提高跟踪和瞄准精度,从激光跟瞄仿真系统整体出发,研究了目标成像中的投影变换、成像与跟踪的关系、高精度跟踪现有算法的控制过程仿真等内容,并提出了基于大视口、目标大气传输图像序列的跟瞄仿真技术。说明了仿真系统中跟瞄精度分析的特点。就某仿真场景,设计了"头部顶点"和"两点提取"两种跟瞄方法,在不同大气湍流条件下得到了它们的跟瞄精度,说明应用该激光跟瞄仿真系统,能够预先设计、测试和验证一些跟瞄方法,帮助进行算法分析和改进,从而提高工作效率和节约成本。  相似文献   

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