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1.
一类电子俘获型红外可激发材料光学性能研究   总被引:10,自引:0,他引:10  
测试了硫化助熔剂法制备的电子俘获型红外可激发材料Eu,Sm∶CaS和Ce,Sm∶CaS的激发光谱、红外激励光谱、荧光光谱及红外上转换发光光谱等,结果表明:这类材料不仅具有红外上转换及光存储功能,而且具有光谱响应范围广、可在室温下工作以及造价低等优点,是一类很有发展前途的光学功能材料。  相似文献   

2.
一类电子俘获型红外可激发料光学性能研究   总被引:7,自引:2,他引:5  
范文慧  杜力 《光学学报》1998,18(6):13-817
测试了硫化助熔剂法制务的电子俘获型红外可激发材料Eu,Sm:CaS和Ce,Sm:CaS的激发光谱、红外激励光谱、荧光谱及红外上转换发光光谱等,结果表明:这类不仅具有红外小转换及光学存储功能,而且具有光谱响应范围广,可在室浊罡工作以及造价低等优点,是一类很在发展前途的光学功能材料。  相似文献   

3.
王明昭  吕少哲 《发光学报》1995,16(2):165-170
合成了配合物Eu2(DBM)64,6`-BIPY,IR和Raman光谱都证实了配合物的生成,77K正派激发高分辨激光激发光谱和荧光光谱表明配合物存在^5D0能级能量差别为15cm^-1的两种Eu(Ⅲ)格位,两种Eu(Ⅲ)离子均不位于对称中心,由^5D0→^7D0.1,2跃迁荧光光谱峰数判断,两种Eu(Ⅲ)格位的区域对称性均为C1或C2或C,两种格位Eu(Ⅲ)离子的发光寿命分别为0.37ms和0.3  相似文献   

4.
合成了掺杂Y^3 和Gd^3 的Phen-Eu(Ⅲ)二元固体配合物,确定了它们的组成,测定了固体配合物的红外光谱和荧光光谱,并首次探讨了掺杂Y^3 和Gd^3 的Phen-Eu(Ⅲ)二元固体配合物荧光强度的影响。  相似文献   

5.
稀土硼酸盐玻璃中Ce3+的光谱性质和荧光衰减   总被引:2,自引:0,他引:2  
合成Ce^3+掺杂的稀土硼酸盐玻璃,测试了材料的激发和发射光谱及荧光衰减曲线。紫外光激发下,玻璃中的Ce^3+发射强的蓝紫光,光谱的荧光寿命的分析结果表明,Ce^3+在这种稀土硼酸盐玻璃中形成两种性质不同的发光中心。  相似文献   

6.
用漫反射红外光谱和光声红外光谱研究了金属羰基化合物(CpFe(CO)2)2Cp=η^5-C5H5与酸性,中性和碱性Al2O3及TiO2的相互作用,结果表明,在Al2O3表面生成的洗生物种类及浓度与Al2O3的酸碱度明显相关,在酸性Al2O3表面,主要存在衍生物(CpFe(CO)2Fe-H-Fe(CO2Cp)^+及少量的CpFe(CO)2(-O-);在中性Al2O3表面存在的CpFe(CO)2(-O  相似文献   

7.
苯甲酸稀土(Eu,La)配合物的红外和荧光光谱研究   总被引:27,自引:3,他引:27  
用氯化稀土与苯甲酸铵在水溶液中反应,合成了苯甲酸稀土(Eu,La)三元固体系列配合物,其化学组成式为(Eu1-xLax)L3(其中L为C6H5COO-,x=0.0~1.0)。研究了它们的红外光谱和荧光光谱。由红外光谱数据表明,配合物中羧基的对称和反对称伸缩振动吸收峰发生了分裂,而且羧基伸缩振动随着La3+离子含量的增加发生了规律性的变化。荧光光谱实验结果表明,用不发光的La3+离子取代苯甲酸铕中部分Eu3+离子可以提高Eu3+离子的特征荧光发射强度。  相似文献   

8.
合成了配合物Eu2(DBM)64,4'-BIPY.IR和Raman光谱都证实了配合物的生成.77K下激光激发高分辨激发光谱和离光光谱表明配合物存在5D0能级能量差别为15cm-1的两种Eu(Ⅲ)格位,两种Eu(Ⅲ)离子均不位于对称中心.由5D0→7F0、1、2跃迁荧光光谱峰数判断,两种Eu(Ⅲ)格位的区域对称性均为C1或C2或C2.两种格位Eu(Ⅲ)离子的发光寿命分别为0.37ms和0.32ms.  相似文献   

9.
本文合成了氧心羧桥二种铁配合物:(Fe3O)(C6H5COO)6(H2O)3)Cl和(Fe4O2(C6H5COO)7(bipy)ClO4测定了它们的热失重及相应热效应峰值的红外光谱,根据不同温度下红外光谱基团的特征吸收峰的变化及热失重情况的分析,推测出该二种配合物可能的热解过程。  相似文献   

10.
用漫反射红外光谱和光声红外光谱法研究了金属羰基化合物[CpFe(CO)2]2Cp=η5—C5H5与酸性、中性和碱性Al2O3及TiO2的相互作用。结果表明,在Al2O3表面生成的衍生物种类及浓度与Al2O3的酸碱度明显相关。在酸性Al2O3表面,主要存在衍生物[CpFe(CO)2Fe—H—Fe(CO)2Cp]+及少量的CpFe(CO)2(—O—);在中性Al2O3表面存在CpFe(CO)2(—O—)及较少的[CpFe(CO)]4;而在碱性Al2O3表面主要衍生物为[CpFe(CO)]4及少量CpFe(CO)2(—O—)。衍生物的相对浓度以酸性Al2O3表面最高,碱性Al2O3表面最低。在TiO2表面,[CpFe(CO)2]2结构基本未变,在空气中比较稳定,没有观察到衍生物的生成。测定了[CpFe(CO)2]2及其在TiO2表面近红外漫反射光谱,指认了大部分观察到的光谱为羰基振动的合频和倍频,并尝试指认了少数光谱为高级(三级)倍频和多元组频(合频)。  相似文献   

11.

Objective

The purpose of this study was to evaluate the levels of evidence in the voice literature.

Study Design

Retrospective literature review.

Methods

Retrospective review of all original articles published between January 2004 and December 2009 from four general otolaryngology journals and one subspecialty voice journal. All abstracts related to voice were evaluated and rated as to evidence-based medicine rating, graded levels A–D and 1a–5. Articles were also stratified by time over two consecutive 3-year intervals to assess changes over the time period.

Results

Of the 6052 articles published, 950 (15.6%) were related to voice. Six hundred seventy-three articles (10.2%) were clinical articles, and 277 (4.6%) were basic science. Only 1% of the clinical articles were level A, 17% were level B, 73% were level C, and 9% were level D. No noticeable changes occurred in the levels of evidence over the interval of the first 3 years of the study in comparison to the last 3 years, although there was an increase in the number of basic science articles from 24.4% to 32.4%.

Conclusion

Despite strong recent interest in improving the quality of the evidence in the literature, the voice literature remains primarily level C and D with no appreciable change over the past 6 years.  相似文献   

12.
碱金属复合氟化物的红外光谱研究   总被引:3,自引:2,他引:1  
  相似文献   

13.
CH HCSB TBM�й�����մ���ֳ��΢���о���չ   总被引:3,自引:0,他引:3  
介绍了中国氦冷球床实验包层模块(CHHCSBTBM)设计中固体氚增殖剂陶瓷球的功能要求。考虑正硅酸锂(Li4SiO4)作为第一候选材料。对其陶瓷粉体的制作方法、微球成型方法和微球中氚的释放、辐射稳定性等进行了简要介绍,并概述了我国在固体氚增殖剂研究方面已经开展的工作。  相似文献   

14.
The spectrum of five-time ionized krypton, Kr VI, was recorded in the 240-2600 Å wavelength range, resulting in 61 new classified lines as transitions between levels of configurations 4p3, 4s25p, 4s4p4d, 4s4p5s and 4s4p5p. All the 18 energy levels belonging to 4s4p5p configuration except one were determined. Eight new energy level values corresponding to configurations 4s4p4f and 4p24d, supported by 26 new classified lines were also determined and used in the interpretation of the observed 4s4p5p configuration. The experimental data were obtained from a capillary-discharge tube and theta pinch light sources. Multiconfiguration Hartree-Fock calculations with relativistic corrections and a least-squares fitted parametric calculation has been carried out.  相似文献   

15.

Purpose

The goals of this study were to determine if there were significant differences between singers and nonsingers in the morphology of vocal nodules and the associated impact on vocal function.

Method

Participants were 10 professionally trained singers with nodules, eight nonsingers with nodules, and 10 individuals with healthy normal voice (controls). Surface electromyography (sEMG) from three anterior neck locations and acoustic rise times for vowels /a/ and /i/ were measured in all the participants. In individuals with nodules, dB SPL/cm H2O, glottal airflow, and nodule location and size were also measured.

Results

There were no significant differences between singers and nonsingers with nodules in terms of airflow, dB SPL/cm H2O, nodule size, or nodule location. In nonsingers with nodules, airflow and nodule size were significantly correlated, but were not significantly correlated in singers. Vowel rise times and sEMG during vocal tasks did not differentiate among nodule and control groups. Sternocleidomastoid sEMG during initiation of the vowel /a/ was statistically significantly stronger in nonsingers with nodules relative to singers with nodules and controls.

Conclusions

Nodule morphology did not differ between singers and nonsingers, although some behavioral aspects of phonation differed between the groups.  相似文献   

16.
Six new compounds were synthesized that have no alkyl chains in their structure: 4-nitrocinnonates of 4-hydroxyazobenzene, 4-nitro-4’-hydroxyazobenzene, 4-fluoro-4’-hydroxyazobenzene, 4-chloro-4’-hydroxyazobenzene, 4-bromo-4’-hydroxyazobenzene and 4-iodo-4’-hydroxyazobenzene. Using the polarizing microscopy and differential scanning calorimetry, enthalpies and temperatures of phase transitions were determined. All investigated compounds have an enantiotropic nematic phase. These compounds proved to be extremely thermally stable. Thermal decomposition was observed in temperatures above 300°C. Investigated compounds contain two different chromophore groups (i.e. azo and ethene moieties), which influenced the complex trans–cis isomerization processes of both groups (three time-separated processes were observed). It was shown that the presence of the ethene group significantly shifts the π-π* band towards higher energies. The substituent polarity in the azo group also affected the energy of this absorption band. A weak luminescence effect was observed in the 4-nitrocinnonates of 4-hydroxyazobenzene compound.  相似文献   

17.
The cross-linked microspheres 4VP/St made of 4-vinylpyridine (4VP) and styrene(St) were prepared with suspension copolymerization method using ethyl glycol dimethacylate (EGDMA) as cross-linker and polyvinyl alcohol (PVA) as disperser. The cobalt tetraphenylporphyrins (CoPs) were immobilized on 4VP/St microspheres via the axial coordination reaction between CoPs and the pyridine groups of 4VP/St microspheres, resulting in the functional microspheres CoP-4VP/St. The chemical structure of 4VP/St and CoP-4VP/St were characterized with infrared spectrum and their morphologies were observed with the scanning electron microscope. The experimental results show that via controlling the various reaction conditions of the suspension copolymerization, the 4VP/St microspheres with excellent sphericity and narrow particle diameter distribution can be gained. In addition, CoPs are successfully immobilized on 4VP/St microspheres by means of Co-N bonds, on which the immobilized content of CoPs goes up to 10.7-17.5 μmol/g.  相似文献   

18.

Objective

Assessment of the voice-change progress of 20 girls (12–13 years) over 1 year by observing changes in speaking fundamental frequency (SFo), voice range, and register pitch breaks in the context of weight, height, voice training, and self-perception.

Study Design

One-year longitudinal collective case study.

Method

Twenty girls were recorded at the beginning and end of a year; nine girls were recorded another three times. SFo, vocal range, and characteristics were analyzed and interactions between these data assessed against weight and height to indicate pubertal development, and to test the hypothesis that changes in weight, height, SFo, and pitch breaks were related. Effects of training and the girls' self-perception of their voice use were also assessed.

Results

Vocal characteristics changed as the girls passed through different weight ranges. During 47.5–52.4 kg (called band 2) and 52.4–57.5 kg (band 3), there was progressive contraction of vocal range and in some girls a slight rise in SFo between recording times 1 and 5. Both high- and low-pitch breaks were present in 45% of girls' voices. Girls in band 4 (<57.5 kg) had an increased vocal range, and pitch breaks in vocal-range areas that indicated the development of adult vocal registers. In this study, voice-trained girls were heavier, had higher SFo, used wider speech-range inflection, had a higher vocal range, and greater voice-use confidence; all girls lost confidence in their voice use over the year.

Conclusions

In this longitudinal study of twenty 13-year-old girls, voice changes in SFo, vocal range, and pitch-break frequency were synchronous with certain weight ranges. Girls with training registered higher maximum phonational frequency and were more confident in their voice use than girls without training.  相似文献   

19.
Silver thiolate is a layered compound with a Raman spectrum that is known to change with time, becoming the same as the surface‐enhanced Raman scattering (SERS) spectrum of the parent thiol molecule adsorbed on Ag nanoparticles. On this basis, the Raman scattering characteristics of silver 4‐aminobenzenethiolate (Ag‐4ABT) compounds were investigated to determine whether certain peaks that are identifiable in the SERS spectrum of 4‐aminobenzenethiol (4‐ABT) but absent in its normal Raman spectrum were also apparent in the Ag salt spectrum. For comparative purposes, the Raman scattering characteristics of silver 4‐dimethylaminobenzenethiolate (Ag‐4MABT) were also examined. Raman spectra acquired while spinning the sample were typified by only a1‐type vibrational bands of Ag‐4ABT and Ag‐4MABT, whereas in the static condition, several non‐a1‐type bands were identified. The spectral patterns acquired in the static condition were similar to the intrinsic SERS spectra of 4‐ABT or 4‐dimethylaminobenzenethiol (4‐MABT) adsorbed on pure Ag nanoparticles. Notably, the CH3 group vibrational bands were observable for Ag‐4MABT irrespective of the sample rotation. In addition, no decrease in intensity during irradiation with a visible laser was observed for any of the bands, suggesting that no chemical conversion actually took place in either 4‐ABT or 4‐MABT. The preponderance of evidence led to the conclusion that the non‐a1‐type bands observable in the SERS spectra must be associated with the chemical enhancement mechanism acting on the Ag nanoparticles. The chemical enhancement effect was more profound at 514.5 nm than at 632.8 nm, and was more favorable for 4‐ABT than 4‐MABT at both wavelengths. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

20.
The experimental and theoretical vibrational spectra of 4‐chloro‐ and 4‐bromophenylboronic acids (abbreviated as 4Clpba and 4Brpba) were studied. The Fourier transform Raman and Fourier transform infrared (FTIR) spectra of 4Clpba and 4Brpba molecules were recorded in the solid phase. The structural and spectroscopic analyses of the molecules were made by using Hartree–Fock and density functional harmonic calculations. In both 4Clpba and 4Brpba only one form was most stable using B3LYP level with the 6–311 + + G(d,p) basis set. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution (TED). Finally, geometric parameters as well as infrared (IR) and Raman bands were compared with the experimental data of the molecules. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

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