scholarly journals Exploring the utility of coumarins-based luminescent spectra converters

2017 ◽  
Vol 30 (9) ◽  
pp. e3731 ◽  
Author(s):  
Viktoryia A. Lapina ◽  
Tatiyana A. Pavich ◽  
Piotr P. Pershukevich ◽  
Aleksei V. Trofimov ◽  
Natalia N. Trofimova ◽  
...  
Keyword(s):  
Luminescent Spectra

Fabrication of Bifunctional SiO2/Europium-Polyoxometalates/Ag Particles and their Luminescence and Catalysis Properties

2013 ◽  
Vol 575-576 ◽  
pp. 216-224
Author(s):  
Jun Wang ◽  
Shao Hua Fan ◽  
Wei Qian Zhao ◽  
Wu Ke Li ◽  
Xue Lian Lu
Keyword(s):  
Main Product ◽  
Catalytic Properties ◽  
Uv Light ◽  
Luminescent Properties ◽  
Silica Spheres ◽  
Hybrid Particles ◽  
Red Emission ◽  
Transmission Electron ◽  
Ag Particles ◽  
Luminescent Spectra

In this paper, Stöber silica particles were decorated with polyethyleneimine and silver nanoparticles and Eu-polyoxometalates were grafted on the surface of polyethyleneimine/silica spheres. The hybrid SiO2/Eu-polyoxometalates/Ag particles were characterized by IR, UVvis, luminescent spectra, scanning electron microscopy, transmission electron microscope, and cyclic voltammetry (CV), respectively. The hybrid particles show the bright red emission under UV light which can be observed by naked eyes. The luminescent properties of particles have been investigated which show that Ag nanoparticles have an influences on the luminescence of europium ions. The electrochemical activities of SiO2/Eu-polyoxometalates/Ag particles have been demonstrated by CV measurement. The catalytic results indicate that the hybrid particles show the catalytic properties in the oxidation of styrene and benzaldehyde is the main product of the reaction.

Conjugated polymer infiltrated silica opals and the effect of nano-confinement on the luminescent spectra

2005 ◽  
Author(s):  
Brandon Jarvis ◽  
Cody L. Gilleland ◽  
Jose Gutierrez ◽  
John W. Stadler ◽  
Jessica Gillespe ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Luminescent Spectra

Controlled Synthesis of Different Morphologies of SrWO4 Crystals via a Surfactant-Assisted Hydrothermal Precipitation Method

2013 ◽  
Vol 785-786 ◽  
pp. 449-454
Author(s):  
Yan Zhao ◽  
Chun Yan Wu ◽  
Dan Qin ◽  
Xin Lai ◽  
Si Wu ◽  
...  
Keyword(s):  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Infrared Spectrometer ◽  
Luminescent Spectra ◽  
Hydrothermal Precipitation ◽  
Surfactant Assisted

SrWO4 octahedrons, flowers, bundles, ellipsoids and dendrites had been successfully synthesized via surfactant-assisted method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photo-luminescent spectra techniques (PL) and fourier transrform infrared spectrometer (FTIR). By through various comparison experiments, it can be found that some related experimental parameters including the reagent concentration, [Sr2+]/[WO42-] molar ratio (R), aging temperature and the pH value had great influences on morphology of the products.

Assessment of the carotenoid pool using resonance Raman spectroscopy in pregnant women with preeclampsia

2021 ◽  
Vol 20 (1) ◽  
pp. 40-46
Author(s):  
R.Kh. Shavaeva ◽  
◽  
V.I. Kukushkin ◽  
D.N. Artemyev ◽  
A.V. Murashko ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Pregnant Women ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Good Method ◽  
Normal Pregnancy ◽  
Rapid Diagnostics ◽  
Diagnosis And Prognosis ◽  
Preclinical Diagnosis ◽  
Luminescent Spectra

Objective. To assess the performance of resonance Raman spectroscopy in the evaluation of the carotenoid pool (antioxidants) in plasma of pregnant women with preeclampsia (PE). Patients and methods. We examined 60 pregnant women aged between 21 and 41 years, including 30 women with moderate PE, 18 women with severe PE, and 12 women with normal pregnancy. We used Raman spectroscopy to analyze serum specimens. Results. We evaluated diagnostic accuracy of Raman spectroscopy (as a method of express diagnostics) and measured normalized integrated Raman scattering intensity for carotenoids in women with moderate preeclampsia (5.0 ± 0.2), severe preeclampsia (6.1 ± 0.3) and normal pregnancy (10.1 ± 0.6). We also separated Raman luminescent spectra of plasma specimens obtained from patients in different groups: the accuracy of distinguishing between normal pregnancy and PE was 96%, while the accuracy of distinguishing between moderate PE and severe PE was 72%. Conclusion. Raman spectroscopy is a relatively simple, but highly effective method for rapid estimation of carotenoid levels in plasma of pregnant women with various grades of PE. Our findings suggest that Raman spectroscopy is a good method of preclinical diagnosis and prognosis of PE, particularly in women at high risk. Key words: carotenoids, discriminant analysis, preeclampsia, Raman spectroscopy, rapid diagnostics

scholarly journals Change of silica luminescence due to fast hydrogen ion bombardment

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 289-292 ◽  
Author(s):  
Vitaliy P. Zhurenko ◽  
Oganes V. Kalantaryan ◽  
Sergiy I. Kononenko
Keyword(s):  
Extended Period ◽  
Implantation Dose ◽  
Visible Range ◽  
Blue Band ◽  
Dose Accumulation ◽  
Oxygen Hole ◽  
Mathematical Processing ◽  
Luminescent Radiation ◽  
Luminescent Spectra ◽  
Hole Centers

AbstractThis paper deals with the luminescence of silica (KV-type) induced by beam of hydrogen ions with the energy of 210 keV per nucleon. An average implantation dose of up to 3.5 × 1021cm−3(5 × 1010Gy) was accumulated during irradiation over an extended period. The luminescent spectra consisted of the blue band (maximum at 456 nm) and the red band (650 nm) in the visible range. It was shown that increase in the absorption dose had an effect on the silica luminescence. It was found that the most significant changes in the spectrum occurred during the dose accumulation in the region of 550–700 nm. The shape of the spectrum of the luminescent radiation in this wavelength range was affected both by the oxygen deficient centres (blue band) and non-bridging oxygen hole centers (red band). Mathematical processing of the experimental spectra permitted to identify contributions to the luminescent radiation coming from both types of defects.

Study on the Optical Properties of PbWO4 Crystal in Material Engineering

2012 ◽  
Vol 583 ◽  
pp. 399-402
Author(s):  
Dong Mei Zhao ◽  
Xue Peng Liu
Keyword(s):  
Optical Properties ◽  
Raman Spectra ◽  
Scattering Method ◽  
Regular Lattice ◽  
Luminescent Center ◽  
Laser Scattering ◽  
Material Engineering ◽  
Luminescent Spectra

On the basis of measuring its Raman spectra in material engineering with four kinds of geometrical configurations laser scattering method is utilized. Compared with other scheelite scintillators crystals， the blue luminescent center is the regular lattice ，green luminescent center is (WO3+F). Finally the crystal’s luminescent spectra is measured

Vibronic Sideband of Er3+ in CaF2

1974 ◽  
Vol 52 (13) ◽  
pp. 1185-1188 ◽  
Author(s):  
R. W. Ward ◽  
P. W. Whippey
Keyword(s):  
Low Temperature ◽  
Density Of States ◽  
Electronic Transition ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Luminescent Spectra ◽  
Vibronic Sideband

Measurements of the low temperature luminescent spectra of CaF2:Er3+ have revealed a vibronic sideband associated with the Er3+ electronic transition at 5512 Å. The phonon frequencies observed are shown to be related to the single phonon density of states of CaF2.

Uniform Cerium-Based Coordination Polymer Microspheres: Preparation and Upconversion Emission

2016 ◽  
Vol 16 (4) ◽  
pp. 3705-3709 ◽  
Author(s):  
Zhi-Wen Nie ◽  
Cheng-Hui Zeng ◽  
Gang Xie ◽  
Sheng-Liang Zhong
Keyword(s):  
Electron Microscopy ◽  
Coordination Polymer ◽  
Large Scale ◽  
Upconversion Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Band Emission ◽  
Transmission Electron ◽  
Light Excitation ◽  
Luminescent Spectra

Homogeneously doped Yb3+ and Er3+ cerium-based coordination polymer (CP) microspheres have been successfully synthesized on a large scale through a simple solvothermal route with 2, 5-pyridinedicarboxylic acid (2, 5-H2PDC) as the organic linker. CeO2:Yb3+, Er3+ porous microspheres were obtained by annealing the corresponding CP microspheres at 600 °C for 4 h under atmospheric pressure. These as-prepared products were characterized by Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersion X-ray (EDX) spectroscopy, Thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis. The room temperature upconversion luminescent spectra of the as-prepared microspheres were carried out by 980 nm NIR light excitation. Interestingly, Yb3+ and Er3+ codoped CP microspheres give a single-band emission centered at 673 nm, while the CeO2:Yb3+, Er3+ microspheres give emission in green and red region, with red being the dominant emission. The emission intensity of the CeO2:Yb3+, Er3+ microspheres were much stronger than that of the Yb3+ and Er3+ codoped CP microspheres.

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