首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
形貌依赖的ZnO阴极射线发光性质研究   总被引:1,自引:0,他引:1  
采用溶剂热法,通过调节水和乙醇混合液的比例制备了多种形貌的ZnO微米结构。利用扫描电子显微镜(SEM)对ZnO微米结构的形貌及尺寸进行了观察。采用可以实现纳米级微观区域光谱采集的阴极射线发光(CL)技术,对不同形貌的单个粒子的光谱进行精细表征,获得了位置依赖的ZnO阴极射线发光数据。实验结果表明:ZnO材料的发光性质与形貌有关,由于形貌差异导致其局部结晶质量、界面缺陷、表面电荷分布、表面晶面等方面的差异,几种因素共同作用决定其最终的发光性质。  相似文献   

2.
铥、铽及铕离子掺杂的BaAl2O4膜的阴极射线发光特性   总被引:1,自引:0,他引:1       下载免费PDF全文
利用喷雾热解法合成了Tm、Tb及Eu离子掺杂的铝酸钡(BaAl2O4)发光膜,研究了合成条件对其结构和发光特性的影响.在退火温度达到700℃时,生成了BaAl2O4膜.Tm3+和Tb3+掺杂的BaAl2O4膜分别发蓝光和绿光,而Eu3+掺杂的BaAl2O4膜的发光既有Eu2+的特征发射——宽的蓝光发射带,也有Eu3+的特征发射——窄的红光发射峰.BaAl2O4:Tm3+的发射主峰位于462nm,在电压为5kV和电流密度为57μA/cm2的条件下,其阴极射线发光(CL)亮度可达25cd/m2,效率可达0.11lm/W.BaAl2O4:Tb3+的发射主峰位于549nm,在相同的条件下,其阴极射线发光亮度可达120cd/m2,效率可达0.55lm/W.BaAl2O4:Eu3+的发射主峰位于616nm,其阴极射线发光亮度为50cd/m2,效率为0.23lm/W.BaAl2O4:Eu2+发蓝光,峰值位于452nm,其阴极射线发光亮度为640cd/m2,效率为2.93lm/W.  相似文献   

3.
The mass spectra of 3,4-disubstituted-1,2,4-oxadiazole-5(4H)-thione and 3,4-disubstituted-1,2,4-thiadiazole-5(4H)-ones have been studied. The rearrangement of molecular ion of 1,2,4-oxadiazole-5-thiones to 1,2,4-thiadiazole-5-ones was proposed. Some major fragments observed in the spectra were interpreted and the fragmentation patterns involving McLafferty rearrangements were reported.  相似文献   

4.
Complexes of metal (II) halides with N-methyl-1,2,4-triazoles have been prepared, characterized, and studied by magnetism, and electronic and vibrational spectroscopies. The complex with 1:4 stoichiometry is monomeric; those of 1:1 or 1:2 stoichiometries are polymeric. It is seen from electronic studies that metal ions are trans-octahedrally coordinated and chromophores are MX4N2 or MX2N4. These structural results are in accordance with the magnitude of magnetic exchange between metallic ions. The effects of metal–ligand bond formation on the vibrational modes of the studied N-methyl-triazoles show the coordination mode of the ligand. In the low-frequency range, assignments of metal–nitrogen and metal-halide stretching vibrations confirm advanced structural proposals.  相似文献   

5.
有机分子的固态类阴极射线发光   总被引:5,自引:3,他引:2  
固态类阴极射线发光是我们提出的一种全新的激发发光方式,利用无机半导体作为电子加速层,加速电子使之获得高能量,然后碰撞激发有机分子(小分子和聚合物)发光。介绍和总结了固态类阴极射线发光方法提出的物理背景,已经取得的实验结果和目前尚存在的问题,并提出了解决这些问题的设想。  相似文献   

6.
多孔氧化硅薄膜阴极射线谱的研究   总被引:1,自引:0,他引:1  
采用近常压下等离子体增强化学气相沉积的方法制备得到多孔氧化硅薄膜,并在沉积区域加载偏压对薄膜形貌和性质进行调制。扫描电镜显示偏压条件下沉积的薄膜更加蓬松多孔,常温下阴极射线谱表明:增大偏压的占空比,CL谱中发光峰的位置并不改变,但谱线强度增大。发光峰的位置说明薄膜中的主要成分是Si-O-Si基团,且该种基团以非桥键的形式存在,薄膜中还存在少量的Si-H键,这与红外光谱测试结果一致。X射线衍射结果表明薄膜中的SiO2是非晶态的。  相似文献   

7.
We present the results of an investigation of the cathodoluminescence of the Eu2+ ion in gallium chalcogenides (Ga2S3) and europium thiogallate (EuGa2S4). We show that the intense wide-band radiation of these compounds is due to the 4f-5d transitions of the Eu2+ ions. With increase in the Eu2+ percent composition from 0.1 to 5.0 mol.% the luminescence brightness increases and then decreases. Translated from Zhurnal Prikladnoi Spektrskopii, Vol. 67, No. 2, pp. 268–270, March–April, 2000.  相似文献   

8.
In this article, ice-melting phenomena have been investigated experimentally. The geometrical shapes studied were cylindrical and right circular truncated cones. Ice blocks were left floating on a large water container in order to be melted. The rate of melting was measured experimentally. A relation was developed for the remaining mass of the ice in respect to time, considering the turbulent boundary layer around the ice block. Based on the experimental results, this assumption is confirmed, and a relation for a heat transfer coefficient between air and ice and water and ice has been developed in a dimensionless form. Using this relation, the ice-melting process can be presented by a single dimensionless number Kazeroon (Kz). This dimensionless parameter includes all of the effective parameters in ice-melting phenomena. A relation is presented between the mass of remaining ice and the Kz number. The mass of the remaining ice is calculated using this relation and is compared with the experimental results. Eighteen cylindrical and 15 right circular truncated cones have been experimentally examined. The results of the experimental studies have, with reasonable matching, been compared with those of the developed theoretical model.  相似文献   

9.
TDI CCD光子响应非均匀性噪音分析与测量   总被引:1,自引:0,他引:1  
探测器光子响应非均匀性噪音会降低低照度情况下遥感成像系统的成像质量.针对这一现象,本文首先结合探测器的物理性质,对各种噪音源进行了研究;建立了TDI CCD不同级数下的光子响应非均匀性噪音模型,随着曝光量的增加,光子响应非均匀性噪音也线性增加.其次根据曝光级数越多TDI CCD对非均匀性噪音的平滑效应越明显这一现象,提出一种光子响应非均匀性系数与曝光级数之间的关系式,并给出了利用TDI CCD输出图像提取光子响应非均匀性噪音的方法.最后建立了试验系统,通过试验对测试获得的光子响应非均匀性噪音与理论分析计算得出的结果进行了分析.  相似文献   

10.
The fluorescence properties of several pyrazoloquinoline derivatives were performed by stationary as well as by time-resolved spectrosopy. Non-donor-substituted compounds show a high quantum yield; transition dipole moments of absorption and fluorescence as well as experimental and calculated lifetimes are in excellent agreement. The donor-substituted compound DMA-DPPQ exhibits a charge transfer fluorescence in polar solvents. Additionally, dual fluorescence appears in polar protic solvents. The nature of the charge transfer state is discussed with respect to the the TICT model.  相似文献   

11.
采用密度泛函理论B3LYP方法,对1,3,4噁二唑衍生物和1,2,4三唑衍生物两类电子传输材料在中性、阴离子态和阳离子态下分别进行几何结构优化计算.结果表明,1,3,4噁二唑衍生物的电子传输过程主要是分子内噁二唑上的N→O电子转移,1,2,4三唑衍生物的电子传输过程主要是分子内三唑上N(双键)→N(单键)以及三唑环向与N相连的苯环电子转移.当其苯环上3位被拉电子基团取代后,其电子传输性能提高;而被给电子基团取代后,电子传输性能降低.  相似文献   

12.
本文比较了一系列对羟基苯衍生物的紫外可见吸收光谱和荧光光谱的差异,以及荧光试剂与其衍生后所得衍生物荧光光谱性质的区别,研究了产生这些差异的可能原因,提出了一些可行的分析此类物质的方法,便于肿瘤患者体液的分析,以期能为确定特征性癌变标志物及早期癌症的检测提供依据。  相似文献   

13.
Internal gear mechanism is widely used in micro-nano satellites due to its compact structure and high precision transmission. However, the vibration coupling caused by the small clearance coupling is more obvious and cannot be ignored under low speed, light load and zero gravity conditions. Based on the geometric relationship between radial clearance and backlash, a coupled model between dynamic backlash and radial clearance of internal meshing gear is established. Based on the conformal contact theory, the radial collision force model of the gear shaft and shaft sleeve considering the small clearances is established. Additionally, a multi-clearance gear rotor system test device is built to measure the vibration acceleration of the internal gear rotor system by an acceleration sensor and transmitted to the industrial computer through a signal collector for data processing. Through the comparison of simulation and experiment, the accuracy of the gear dynamics model is verified. The analysis results show that, compared with the traditional model, the calculation results of the gear mechanism model considering the small clearance coupling is closer to the experimental data.  相似文献   

14.
含有亚胺基芴类衍生物的合成及光物理过程   总被引:1,自引:0,他引:1  
通过2,7-二溴芴酮与相应的苯胺衍生物反应,合成了一系列新型的含有亚胺基的芴类衍生物:2,7-二溴-9-亚苯胺基芴(NBFA),2,7-二溴-9-亚(4-氯-苯胺)基芴(CNBFA),2,7-二溴-9-亚(4-甲基-苯胺)基芴(MN-BFA),其结构经氢核磁共振谱、红外光谱和质谱表征,并且采用紫外光谱法和荧光光谱法研究了这些化合物的光物理过程.  相似文献   

15.
The absorption and photoluminescence spectra of a number of derivatives of 3,3,6,6-tetramethyl-N-phenyl-decahydroacridine-1,8-dione with a regular change in the structure of molecules are investigated. Their electronic structure is calculated. The nature of some of the spectral bands is established. Significant differences in the efficiency of the processes of photochemical transformations of dyes exposed to UV irradiation have been revealed; these changes are attributable to the different donor-acceptor properties of the substituents introduced. A mechanism of phototransformations that agrees with both calculations of the electronic structure of molecules and the spectral-luminescent characteristics of the initial and irradiated compounds is suggested. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 454–459, July–August, 2005.  相似文献   

16.
利用Suzuki偶合反应合成了两种新的蒽衍生物9,10-二(2-联苯基)蒽(BBPA)和9,10-二[2-(α-萘基)苯基]蒽(BNPA),化合物结构通过核磁、质谱及元素分析进行了表征。量子化学计算结果显示,这两种化合物都具有非共面的分子结构,光物理性能主要决定于分子中的蒽结构单元。这两种化合物在二氯甲烷溶液中均可发射高效率的蓝光。BBPA在固态薄膜状态下的发射光谱相对其二氯甲烷溶液的发射光谱明显变宽,而BNPA的固态薄膜并未发生光谱变宽现象。分别利用化合物BBPA和BNPA作为发光层材料,制备出了非掺杂的深蓝光电致发光器件。发光层为BBPA的电致发光器件的最大外量子效率和CIE色坐标分别为2.48%和(0.16,0.09);基于BNPA的电致发光器件的最大外量子效率为2.68%,CIE色坐标为(0.15,0.07)。所制备的这两种器件均表现出了较低的开启电压和良好的稳定性。  相似文献   

17.
We present a method for the fabrication of PVTri-BaFe12O19 nanocomposites by in-situ polymerization of PVTri in the presence of synthesized BaFe12O19 nanoparticles. Nanoparticles, polymer and nanocomposite were analyzed by XRD, FTIR, TGA, TEM, NMR, GPC and conductivity techniques for structural and physicochemical characteristics. Crystallographic analysis revealed the phase as hexaferrite and X-ray line profile fitting yielded a crystallite size of 17±5 nm. Conjugation of PVTri to nanoparticle surface was assessed to be via carbonyl groups on the polymer. TG analysis revealed that 45 wt% of nanocomposite is inorganic phase (BaFe12O19). It was found out that the ac conductivity of nanocomposite under a certain frequency increases with temperature.  相似文献   

18.
采用紫外-可见光谱法(UV-Vis)研究三种二茂铁衍生物[Fc(COOH)2(λmax=286 nm), Fc(OBt)2(λmax=305 nm), Fc(Cys)(λmax=289 nm)]与血红素(heme, λmax=386 nm)的相互作用。实验结果表明:当固定heme浓度时,heme的吸光度随着Fc(COOH)2和Fc(Cys)浓度的增加而增大,而heme的吸光度随着Fc(OBt)2的浓度的增加几乎没有增大;当分别固定Fc(COOH)2, Fc(Cys)和Fc(OBt)2的浓度时,Fc(COOH)2和Fc(Cys)的吸光度随着heme浓度的增加而增大,而Fc(OBt)2的吸光度随着heme浓度的增加没有变化,说明Fc(COOH)2和Fc(Cys)与heme存在分子间的相互作用,主要是由于Fc(COOH)2和 Fc(Cys)与heme能形成氢键,分子链增长,吸收的能量增加,导致吸光度增大;而Fc(OBt)2与heme没有分子间的相互作用,是由于Fc(OBt)2没有自由的氢,不能与heme形成分子间的氢键。同时考察了三种二茂铁衍生物与heme 的吸光度随时间的变化,Fc(COOH)2和 Fc(Cys)与heme的吸光度随着时间的增加而减少,而Fc(OBt)2与heme的吸光度随时间的变化几乎没有变化。Fc(COOH)2与Fc(Cys)和heme的反应时间为0.5,18和48 h,当固定Fc(COOH)2浓度时,在λmax=384 nm处的吸光度由2.64分别变为2.53和2.51;当固定heme的浓度时,在λmax=384 nm处的吸光度由1.76分别变为1.72和1.68;当固定Fc(Cys)浓度时,在λmax=397 nm处的吸光度由2.74分别变为2.63和2.55;当固定heme的浓度时,在λmax=397 nm处的吸光度由1.82分别变为1.58和1.49。  相似文献   

19.
Spectral properties of fluorene and its amino, hydroxyl and phenyl derivatives have been investigated in polar and non-polar solvents at 293 and 77 K as well as in binary mixtures, e.g. McH/EtOH. The hipsochromic shift of the fluorescence spectrum of the two amino derivatives of fluorene observed in polar solvents has been explained on the basis of its zwitterionic form appearing in the ground state only. The radiative k F and non-radiativer k NR and k ISC rate constants for the compounds under study have been calculated using experimentally determined quantum yields, fluorescence and phosphorescence decay times.  相似文献   

20.
刘瑞姣  曾竟  王慧 《发光学报》2017,38(7):862-873
将四苯乙烯基与取代水杨醛通过碳氮双键连接起来,合成了基于四苯乙烯基的水杨醛缩芳胺希夫碱TPE-SA1、TPE-SA2、TPE-SA3、TPE-SA4、TPE-SA5。利用IR、NMR、MS和元素分析等对其分子结构进行表征,通过紫外-可见光谱、分子荧光光谱、循环伏安分析法和热重测试分别考察了该类化合物的光学、电化学和热稳定性质。实验结果表明:该类化合物在纯THF溶液中,分别在260 nm和370 nm左右处出现B带和R带紫外吸收峰;在四氢呋喃/水的混合溶液中,表现出典型的聚集诱导发光(AIE)性能。目标化合物的热分解温度分别为262,283,295,278,299℃,具有较好的热稳定性。它们的电离势分别为5.31,5.43,5.41,5.30,5.15eV,电子亲合势均大于4.3 eV。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号