共查询到20条相似文献,搜索用时 15 毫秒
1.
The absorption and fluorescence spectra and the lasing ability of aminocoumarin derivatives in thin polymer layers (0.5–0.8
μm) based on the copolymer methylmethacrylate with a methacrylic acid and the copolymer methylmethacrylate with glycidylmethacrylate
formed by coating of optically transparent glass substrates have been studied. It is found that the intensity of absorption
and luminescence as well as the lasing resource of coumarins are determined by the structure of the latter and by the nature
of the polymer medium. Compositions based on the copolymer methylmethacrylate with glycidylmethacrylate and aminocoumarin
derivatives with a fluorized methyl group at the 4th molecular position can be of interest in optical technologies (light
transformers, amplifiers).
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 464–467, July–August, 2005. 相似文献
2.
T. A. Pavich A. V. Vorobey S. M. Arabei K. N. Solovyov 《Journal of Applied Spectroscopy》2012,79(4):651-655
We have synthesized a folic acid–europium complex conjugate which shows promise for biomedical applications. We have studied the absorption spectra, the luminescence spectra, and the luminescence excitation spectra of folic acid–spacer–amino-substituted phenanthroline and folic acid–spacer–europium chelate conjugates, and also of the individual components of the synthesized triads. All the spectral luminescence data obtained confirm that a folic acid–europium complex conjugate is fogrmed. Binding of the synthesized conjugate to a folate receptor on HeLa tumor cells is demonstrated. 相似文献
3.
A. I. Nepomnyashchikh A. A. Shalaev A. K. Subanakov A. S. Paklin N. S. Bobina A. S. Myasnikova R. Yu. Shendrik 《Optics and Spectroscopy》2011,111(3):411-414
LiF single crystals with copper impurity (0.0004–0.002%) have been grown by the Czochralski method and investigated. The luminescence,
excitation, and optical absorption spectra have been recorded. The luminescence spectrum contains a band at 450 nm upon 250-nm
excitation. This band is attributed to Cu+ centers in the samples grown. The mechanisms of capture and recombination during thermoluminescence are considered. 相似文献
4.
V. S. Kortov I. A. Vainshtein A. S. Vokhmintsev N. V. Gavrilov 《Journal of Applied Spectroscopy》2008,75(3):452-455
We have studied the effect of bombardment by Cu+ and Ti+ ions with energy 30 keV on the optical absorption and luminescence of F centers in oxygen-deficient aluminum oxide. We have
shown that in the induced optical absorption spectra there are six components of gaussian shape, which can be assigned to
absorption bands of F+, F2, and F2+ centers. We have established that bombardment of the samples by ion beams has a weak effect on the thermoluminescence parameters
in the 3.0 eV and 2.4 eV bands, while in the 3.8 eV luminescence band for F+ centers, the thermoluminescent response increases considerably.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 422–424, May–June, 2008. 相似文献
5.
A. Ya. Khairullina T. V. Ol’shanskaya O. N. Kudanovich D. S. Filimonenko 《Journal of Applied Spectroscopy》2010,77(5):700-707
We have established a correlation between diffuse reflection of nickel oxide-based composites in the red region of the spectrum
and the nanostructural properties of the roughness profile of the composite. We present calculations of the absorption spectra
for samples of nanostructured nickel oxide of thickness 0.25–0.35 μm on aluminum oxide substrates from diffuse reflection
and transmission of the layers by multiple scattering methods, taking into account the luminescence of the samples in the
weak absorption region. Using a special optical system, we have determined the selective sensitivity to carbon monoxide exposure
of a nanostructured nickel oxide composite at room temperature. The result is of fundamental importance for development of
optical selective gas sensor technology in the visible region of the spectrum. 相似文献
6.
M. U. Belyi V. N. Bindyukevich A. S. Kolesnik B. A. Okhrimenko V. P. Yashchuk 《Journal of Applied Spectroscopy》2000,67(1):95-100
Comprehensive investigations of luminescence, excitation, and absorption spectra as well as of the luminescence kinetics of
a frozen LiCl-Tl+ solution are carried out. It is established that the luminescence spectrum consists of four components. One component is
caused by luminescence of the matrix and the remainder by luminescence of one luminescence center, namely, by the saturated
complex of thallium TlCl2(H2O)Cl4. The absorption spectrum consists of three components. Their parameters have been evaluated. Each component of the luminescence
spectrum is excited in several components of the absorption spectrum. It is found that the luminescence spectrum components
and their intrinsic absorption bands are located differently on the frequency axis. These data are similar to those obtained
for other activated solutions of electrolytes.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 75–78, January–February, 2000. 相似文献
7.
V. A. Ivantsov V. A. Sukhoveev V. I. Nikolaev I. P. Nikitina V. A. Dmitriev 《Physics of the Solid State》1997,39(5):763-765
A study has been performed of the crystalline structure and optical characteristics of single crystals of gallium nitride
(GaN). The crystals were grown from a gallium-based flux. X-ray structural analysis showed that the crystals have wurzite
structure 2H-GaN. From their luminescence characteristics and optical absorption spectra the crystals are similar to 2H-GaN epitaxial layers described in the literature.
Fiz. Tverd. Tela (St. Petersburg) 39, 858–860 (May 1977) 相似文献
8.
O. V. Ovchinnikov E. A. Kosyakova M. S. Smirnov A. B. Evlev V. G. Klyuev A. N. Latyshev A. N. Utekhin 《Journal of Applied Spectroscopy》2007,74(5):681-686
For microcrystals of Zn0.6Cd0.4S with adsorbed molecules of a number of organic dyes, we have observed sensitized anti-Stokes luminescence excited by radiation
with wavelengths in the range 610–750 nm and flux density 1014–1015 photons/cm2·sec. The positions of the bands in the excitation spectra for such luminescence match those of the absorption spectra for
the adsorbed dye molecules, which is evidence in favor of a cooperative mechanism for its appearance. We have shown that enhancement
of the anti-Stokes luminescence is possible when silver atoms and few-atom clusters appear on the Zn0.6Cd0.4S surface in addition to the dye molecules. We hypothesize that its excitation in the latter case occurs as a result of two-photon
optical transitions. These transitions occur sequentially, with transfer of an electron or the electronic excitation energy
from the dye molecules to silver atoms and few-atom clusters adsorbed on the surface of Zn0.6Cd0.4S, creating deep localized states in the bandgap with photoionization energies 1.80–2.00 eV.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 617–621, September–October, 2007. 相似文献
9.
E. I. Slobozhanina N. M. Kozlova L. P. Kas’ko M. V. Mamontova E. A. Chernitskii 《Journal of Applied Spectroscopy》1998,65(6):988-991
Absorption and luminescence excitation and emission spectra of the amniotic fluid from females with a normal course of pregnancy
and with fetation anomalies are investigated. It is shown that the amniotic fluid manifests, in addition to an intense UV
luminescence, a luminescence in the range of 380–650 nm. The first luminescence peak with λmax = 430–450 nm is most likely due to the presence of NADH2 and hormones in the amniotic fluid, whereas the peak located at longer wavelengths with λmax = 520–540 nm is due to pigments (bilirubin, etc.). Differences in absorption spectra of the amniotic fluid in the case of
the normal course of pregnancy and upon its pathologies are established. Luminescence emission and excitation spectra of the
amniotic fluid in cases of intrauterine fetation pathologies are shifted toward the longwave region compared to normal pregnancy
cases. It is concluded that the spectral-luminescent analysis of the amniotic fluid can be used as an additional rapid test
for monitoring of intrauterine fetal pathologies.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 939–942, November–December, 1998. 相似文献
10.
P. S. Parfenov A. P. Litvin A. V. Baranov A. V. Veniaminov E. V. Ushakova 《Journal of Applied Spectroscopy》2011,78(3):433-439
We present an analysis of methods for calibration of the spectral sensitivity of instruments in the near IR region of the
spectrum (0.90–2.05 μm), using as an example recording of the luminescence spectra of PbS semiconductor quantum dots using
a diffraction monochromator and an InGaAs photodiode as the detector. We show that when high-sensitivity detectors are employed
for calibration using the emission spectrum of an ideal black body, the problem of attenuation of the radiation flux is still
important. Instead of neutral density glass and mesh light filters for attenuation of the radiation, we propose using UFS
ultraviolet optical glasses (together with PS purple glasses), the maximum optical density of which is within the region of
maximum spectral sensitivity of InGaAs photodiodes. We give examples of spectral calibration, taking into account instrumental
characteristics and the effect of absorption by water vapor in the air, and also corrections of the luminescence spectra of
quantum dots. 相似文献
11.
For an ensemble of different types of luminescence centers with overlapping absorption bands, with no restrictions on the
optical densities, we have obtained relations describing the luminescence excitation spectra for each type of center. We consider
transformations of the relations in some limiting cases. We suggest a procedure for using the equations obtained to determine
the characteristics of the luminescence centers. Some of these procedures have been experimentally implemented in study of
intrinsic radiation color centers in lithium fluoride crystals. We have determined the ratios of the luminescence quantum
yields for F2 and F3+ color centers, and we have observed that a major role is played by nonradiative transitions in deactivation of the first
excited singlet state of F3+ centers.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 365–371, May–June, 2008. 相似文献
12.
N. Rajeswari Yogamalar A. Chandra Bose 《Applied Physics A: Materials Science & Processing》2011,103(1):33-42
Nanopowders of pure and lithium-doped semiconducting ZnO (Zn1−x
Li
x
O, where x= 0, 0.01, 0.03, 0.06, 0.09 and 0.15 in atomic percent (at.%)) are prepared by PEG-assisted low-temperature hydrothermal method.
The average crystallite size is calculated using Debye–Scherrer formula and corrected for strain-induced broadening by Williamson–Hall
(W–H) plot. The peak shift in XRD and the lattice constant of ZnO as a function of unit cell composition are predicted by
Vegard’s law. The evolution of ZnO nanostructures from rod-shaped to particle nature is observed from TEM images and the influence
of dopant on the morphology is investigated. The optical absorption measurement marks an indication that the incorporation
of lithium ion into the lattice of ZnO widens the optical band gap energy from ∼2.60 to ∼3.20 eV. The near band edge (NBE)
emission peak centered at ∼3.10 eV is considered to be the dominant emission peak in the PL spectra. Blue emission peak is
not observed in doped ZnO, thus promoting defect-free nanoparticles. The Burstein–Moss shift serves as a qualitative tool
to analyze the widening of the optical band gap and to study the shape of the NBE luminescence in doped ZnO nanopowders. FT-IR
spectra are used to identify the strong metal–oxide (Zn–O) interaction. 相似文献
13.
L. I. Gurinovich V. S. Gurin V. A. Ivanov A. P. Molochko N. P. Solovei 《Journal of Applied Spectroscopy》1998,65(3):401-407
Glasses are obtained that contain CuInS2 nanoparticles dispersed in a silicate matrix. The absorption and luminescence spectra of the glasses containing CuInS2 nanocrystals with particle dimensions of 10–70 nm are studied. The possible reasons for the longwave shift of the fundamental
absorption edge and inconsistency of the crystal structure of the CuInS2 nanoparticles with a chalcopyrite lattice are discussed.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 387–393, May–June, 1998. 相似文献
14.
N. S. Eremina T. N. Kopylova G. V. Mayer L. G. Samsonova V. A. Svetlichnyi 《Russian Physics Journal》2005,48(10):1069-1072
Absorption and fluorescence spectra and lasing ability of pyran derivatives in thin polymeric layers (0.5–0.8 μm) based on
polymethylmethacrylate and copolymerized methylmethacrylate and methacrylic acid are investigated. It is revealed that the
absorption and luminescence intensities and the laser service lifetime of dicyanomethilene (DCM) pyran derivatives are determined
by their composition and nature of the polymeric medium. Compositions based on DCM and examined polymers are of interest for
preparation of thin-film active media lasing in the red range of the spectrum.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 63–66, October, 2005. 相似文献
15.
I. N. Ogorodnikov A. V. Kruzhalov E. A. Radzhabov L. I. Isaenko 《Physics of the Solid State》1999,41(2):197-201
A study of the luminescence characteristics of crystalline lithium triborate LiB3O5 (LBO) is reported. Investigation of the excitation and photoluminescence spectra of nominally pure, oriented LBO crystals
within broad spectral (1.2–10.5 eV) and temperature (8–500 K) regions, complemented by optical spectroscopy at the long-wavelength
fundamental-absorption edge, has revealed that the broad-band LBO luminescence in the 3.5–4.5-eV region is efficiently excited
by photons having energies above 7.5 eV in recombination processes and under corpuscular or x-ray irradiation. The totality
of the experimental data obtained permitted a conclusion that the LBO luminescence has an intrinsic nature and that it originates
from radiative decay of relaxed electronic excitations.
Fiz. Tverd. Tela (St. Petersburg) 41, 223–228 (February 1999) 相似文献
16.
A. P. Voitovich V. S. Kalinov E. F. Martynovich A. N. Novikov A. P. Stupak 《Journal of Applied Spectroscopy》2011,78(5):725-732
We have developed a method for quantitative luminescent analysis of multicomponent media. To carry out this method, we need
to use a standard luminescent probe and have overlap between the luminescence excitation spectra of the probe and the analyte
substance. We have shown that the method is applicable for analysis of scattering media with different absorption optical
densities, including optically dense media. We have demonstrated that it is invariant relative to changes in the experimental
geometry and the parameters of the medium. A broad range of measurable values is characteristic of the method. Its sensitivity
is determined by the sensitivity of the luminescence intensity measurements. We have determined concentrations of organic
substances in the range ~10–10 to 10–11 g/cm3. 相似文献
17.
Xiong Wang Juanjuan Zhu Yan’ge Zhang Jinguo Jiang Subao Wei 《Applied Physics A: Materials Science & Processing》2010,99(3):651-656
Monodisperse ZnSe colloidal microspheres were fabricated by a green one-pot wet chemical strategy through aggregation of primary
nanoparticles without expensive organic additives or reductants involved. The as-prepared products were characterized by powder
X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectrum, X-ray photoelectron spectroscopy (XPS), UV–vis
absorption and room-temperature photoluminescence techniques. The size-dependent optical spectra of as-obtained microspheres
were blue-shifted in comparison with that of bulk ZnSe and exhibit near band edge luminescence, indicating the quantum confinement
effect. The strong and stable blue emission band from the ZnSe colloidal microspheres indicates their potential applications
as building blocks in photonic crystals. 相似文献
18.
Senoy Thomas D. Sakthikumar Yasuhiko Yoshida M. R. Anantharaman 《Journal of nanoparticle research》2008,10(1):203-206
Sol–gel glasses with Fe3O4 nanoparticles having particle sizes laying in the range 10–20 nm were encapsulated in the porous network of silica resulting
in nanocomposites having both optical and magnetic properties. Spectroscopic and photoluminescence studies indicated that
Fe3O4 nanocrystals are embedded in the silica matrix with no strong Si–O–Fe bonding. The composites exhibited a blue luminescence.
The optical absorption edge of the composites red shifted with increasing concentration of Fe3O4 in the silica matrix. There is no obvious shift in the position of the luminescence peak with the concentration of Fe3O4 except that the intensity of the peak is decreased. The unique combinations of magnetic and optical properties are appealing
for magneto–optical applications. 相似文献
19.
I. Kh. Abdukadyrova 《Journal of Applied Spectroscopy》2007,74(2):278-282
Features of the thermoradiative changes in the optical absorption and luminescence spectra of leucosapphire (colorless sapphire)
crystals irradiated by neutron fluences within the range 5·1015 to 5·1019 cm−2 have been studied in the visible region. The stepwise character of these processes was established as well as the basic steps
involved in bleaching the induced color of the wafers as a result of isochronal annealing. Some anomalies have been observed
in the temperature dependence of the optical density of the 460–620 nm bands, the activation energies for the color centers
as well as the color center concentrations have been calculated, and the nature of the radiation-induced centers has been
analyzed. An analytical expression is proposed to describe the accumulation kinetics for the centers during irradiation of
the crystals by reactor neutrons. It is concluded that there is an interconnection between, for example, the 460 nm color
centers and the 540 nm luminescence centers, and that there is a common mechanism for the process of radiation-induced defect
formation, initially responsible for their formation in the crystal. The possible effect of reabsorption of radiation on the
behavior of the Y(Φ) curve in the irradiated material is discussed.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 247–251, March–April, 2007. 相似文献
20.
Congji Zha Peter Osvath Gerry Wilson Anton Launikonis 《Applied Physics A: Materials Science & Processing》2009,94(2):427-430
Chalcogenide glasses are attractive for all-optical signal processing due to their outstanding optical properties, including
large optical nonlinearity, a high refractive index and high photosensitivity. In device fabrication, a challenge lies in
the difficulty of obtaining thin films with a high stability and good uniformity. In this paper, optical thin films containing
nano-sized chalcogenide clusters in polysiloxane matrices are fabricated by a modified plasma deposition process. The optical
absorption and luminescence emission properties of the hybrid thin films were characterized by UV-Vis-NIR and fluorescence
spectroscopy. Luminescent emission from Ag–As–Se nano-sized clusters was observed for the first time in these nano-hybrid
thin films, and the mechanism was discussed. 相似文献