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1.
It has been found that on exposure of specimens of synthetic opal to UV radiation, luminescence is excited in them (337 nm)
that has spectral maxima at 400 and 500 nm. Its duration at half-height of a pulse is 9 nsec, and there is a weak slow component
with τ ∼ 1 μsec. The spectrum and intensity of the luminescence depend on the duration of irradiation and temperature. The
luminescence bands revealed relate to two individual luminescence centers, namely: the shortwave one, caused by the luminescence
centers formed in the bulk of the opal, and the longwave one, due to those formed on the opal surface.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 622–626, September–October, 2005. 相似文献
2.
E. M. Shishonok L. Trinkler S. V. Leonchik B. Berzinya 《Journal of Applied Spectroscopy》2008,75(4):567-575
Under high pressure and temperature conditions, we have obtained samples of thulium-activated cubic boron nitride in the form
of micropowders, ceramics, and polycrystals activated by thulium in the presence of aluminum. We studied the cathodoluminescence
(CL), photoluminescence (PL), and photoluminescence excitation spectra of the samples. In the luminescence spectra we observe
structured bands with maxima at ∼370, ∼475, ∼660, and ∼ 800 nm, assigned to electronic transitions in the triply charged thulium
ions. We have established that the most efficient method for excitation of “blue” luminescence at ∼475 nm for thulium ions
in cBN is excitation by an electron beam. The cBN samples synthesized in the presence of Al have photoluminescence spectra
with a more complex structure compared with samples not containing Al, with the band of dominant intensity at about 660 nm.
Hypothetically, this is a consequence of incorporation of thulium ions into the crystalline phases cBN and AlN, which are
equally likely to be formed during synthesis. The observed photoluminescence spectrum of the indicated samples is the superposition
of the photoluminescence spectra of the Tm3+ ions located in the crystal fields of cBN and AlN of different symmetries. The presence in the photoluminescence excitation
spectra (at 450, 490, and 660 nm) of structure, with features at wavelengths shorter than the excited photoluminescence, suggests
a nonresonant mechanism for its excitation. We have established that luminescence of Tm3+ ions is less intense than for other rare earth elements incorporated into cubic boron nitride.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 547–555, July–August, 2008. 相似文献
3.
I. M. Batyaev 《Journal of Applied Spectroscopy》1997,64(5):620-632
An attempt was made to describe and show the possibilities of new inorganic neodynium- and uranium-activated laser liquids:
SO2-GaCl3-NdCl4; SO2Cl2-GaCl3-NdCl3-UO2Cl2; POCl2-MCln-NdCl3-UO2Cl2 for development and synthesis of direct nuclear reaction-excited lasers. Luminescence data presented in the work were used
to calculate the luminescence parameters of the laser liquids such as oscillator strengths f, probability of spontaneous radiation
A, intermultiplet luminescence branching coefficient β, cross-section for induced radiation σ, luminescence decay time τ,
quantum yield η, and others. It is shown that the oscillator strengths of the normal absorption bands of Na3+, which play the main part in the pumping processes, exceed the oscillator strengths of Na3+ for aqueous and many other nonaqueous systems. In the luminescence excitation spectra of the Na3+ ion, bands are isolated in the range 400–1000 nm atλ
rec
=1.06 μm. With excitation, luminescence occurs through the4F3/2→4I9/2,11/2.13/2 channels. Luminescence spectral data are related to the lasing parameters. The threshold lasing energy is∼18 J/cm3. For a resonator with mirros h1=100% and h2=20, 40, 56, and 80%, the lasing energy is∼20–120 MJ/cm3 in the pumping energy range 18–180 J/cm3. The differential efficiency is ∼0.2% The substantial angular radiation divergence (θ∼4·10−2 rad) and strong thermostatic distortions that occur in the active element (dn/dT≈−1.9·10−4K−1) are a disadvantage of laser liquids. It is shown that operation of neodymium- and uranium-activated inorganic liquid lasers
is stable under the present conditions.
A. I. Gertsen Russian State Pedagogical University, Moika Embankment, 48, St. Petersburg, 191186, Russia. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 607–619, September–October, 1997. 相似文献
4.
A new phenomenon — intense luminescence of noncolored lithium fluoride (LiF) crystals excited by an electrodeless pulsed microwave
discharge at the prebreakdown stage of development — is observed. This luminescence consists of the luminescence of short-lived
aggregate F2 and F
3
+
color centers at room temperature. It is shown that the density of short-lived color centers induced in the surface layer
of LiF crystals by a microsecond microwave discharge reaches values of ∼1019−1020 cm−3.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 3, 163–167 (10 August 1997) 相似文献
5.
The luminescence spectra are obtained in the visible region for the high-T
c superconductors La2CuO4, YBA2Cu3O7−δ
, Bi2Sr2CaCu2O8±δ
, and YBa2Cu3O8±δ
and for the secondary phases BaCuO2±γ and Y2Cu2O5. The presence of a luminescence band with energy E
lum∼2.4 eV in the spectra of all the investigated compounds is established. The nature of the observed luminescence bands is
discussed on the basis of a comparative analysis of the crystal structures and luminescence spectra and on the basis of notions
as to the presence of bands in the spectra accompanied by photoinduced diffusion of weakly bound oxygen and photoinduced charge
transfer in the CuO2 planes.
Fiz. Tverd. Tela (St. Petersburg) 39, 1739–1746 (October 1997) 相似文献
6.
I. R. Mardaleishvili P. P. Levin V. B. Ivanov 《Russian Journal of Physical Chemistry B, Focus on Physics》2009,3(4):560-566
The kinetics of luminescence and transformation of short-lived products of the photolysis of europium and lanthanum complexes
with thenoyltrifluoroacetone and 1,10-phenanthroline and their mixtures in polymethyl methacrylate films was studied by the
nanosecond laser photolysis method with recording both light emission and absorption. Fast (535 and 585 nm, 5
D
1 → 7
F
0, 7
F
3, decay time 0.7 μs) and slow (613 nm, 5
D
0 → 7
F
2, luminescence rise and decay times 0.7 μs and 0.5 ms, respectively) luminescence was studied. Induced absorption with a maximum
at 600 nm and decay time ∼3 ms was observed; this absorption was assigned to triplet states of the deprotonated form of thenoyltrifluoroacetone.
The dependences of luminescence intensity on the concentration of the components in a mixture of complexes were analyzed,
and synergistic effects of luminescence strengthening were estimated. The kinetics of a decrease in luminescence intensity
during photolysis was studied. Possible mechanisms of a decrease in the relative initial process rate and an increase in the
quasi-stationary value of relative luminescence intensity as the concentration of complexes in the polymer increased were
discussed. 相似文献
7.
The fluorescence system of the norfloxacin-Tb3+- sodium dodecylbenzene sulfonate (SDBS) was investigated in this paper. The experiments indicated that the fluorescence intensity
of the Tb3+-SDBS was greatly enhanced by the norfloxacin. On the basis of the above findings, a sensitive fluorimetric method for determining
the norfloxacin was established. The fluorescence intensity was measured by a 1-cm quartz cell with the excitation wavelength
of 290 nm and the emission wavelength of 545 nm. The enhanced fluorescence intensity of the system (Δ F) showed a good linear
relationship with the concentration of norfloxacin in the range of 5.0×10−9 mol L−1–2.0×10−6 mol L−1, its correlation coefficient was 0.9991 and the detection limit (S/N=3) was 1.2×10−9 mol L−1. The presented method was used to determine the norfloxacin in real pharmaceutical samples. The luminescence mechanism was
also discussed in detail. In the fluorescence system of the norfloxacin-Tb3+-SDBS, the SDBS not only acted as the surfactant, but also acted as the energy donor. 相似文献
8.
S. S. Novosad 《Technical Physics》1999,44(1):124-125
The effect of the conditions of preparation, temperature, and the action of x rays on the luminescence properties of calcium-iodide
scintillation crystals is investigated. On the basis of the results of a study of the spectral characteristics of CaI2 and CaI2:H2 crystals for optical and x-ray excitation in the temperature range 90–400 K, also taking into account the results of a study
of the luminescence properties of CaI2 crystals activated by Cl−, Br−, OH−, and Ca2+ impurities, it is suggested that the 236-nm band observed in the excitation spectra of crystals of calcium iodide may be
caused by an uncontrollable hydrogen impurity. The luminescence of these crystals with maximum at 395 nm is ascribed to radiative
recombination of excitons trapped at H− ions.
Zh. Tekh. Fiz. 69, 135–136 (January 1999) 相似文献
9.
The form of the stationary luminescence spectra of excitons, localized by composition fluctuations, in disordered solid solutions
under weak excitation is calculated. The tail states for which there are no nonradiative transition channels are distinguished
by means of continuum percolation theory. Such states are responsible for the “zero-phonon” luminescence band. The shape of
the short-wavelength luminescence band edge is determined mainly by the number of isolated localizing clusters and their smallest
complexes, which decreases rapidly near the mobility threshold. The real luminescence spectrum is due to the simultaneous
emission of phonons. The phonon emission determines the form of the long-wavelength wing of the emission band. The computed
shape of the emission spectrum is compared with the experimental luminescence spectra of the solid solution CdS(1−c)Sec.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 3, 274–279 (10 February 1997) 相似文献
10.
We have found that it is possible to enhance the luminescence of Pr(III) in solutions of complexes with β-diketones: acetylacetone
derivatives containing fluoroalkyl substituents of different lengths and structures. We have established that in the presence
of organic solvents, second (additional) ligands, and surfactants shielding the central ion from the quenching effect of the
water molecules (OH oscillators), the intensity of luminescence for Pr(III) increases by a factor of 65, 38, and 45 respectively.
In this case, cationic surfactants form ionic associates with Pr(III) β-diketonates, with incorporation of one more β-diketone
molecule (ratio Pr:β-diketonate:surfactant = 1:4:1). As a result of suppression of intramolecular energy losses in solutions
of Pr(III) β-diketonates, it is possible to observe its rather intense luminescence at 605 nm (the transition 1D2 → 3H4), 612 nm (3P0 → 3H6), and 646 nm (3P0 → 3F2).
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 746–750, November–December, 2006. 相似文献
11.
The charge neutral chiral optical sensors 1a∼d containing thiourea and amide groups were synthesized by simple steps in good yields and their structures were characterized
by IR, 1H NMR, 13C NMR, MS spectra and elemental analysis. The enantioselective recognition for α-phenylglycine and phenylglycinol was examined
by fluorescence emission and UV-vis spectra. The fluorescence and UV-vis spectra changes of 1a were obvious when the enantiomers of α-phenylglycine anion were added, which exhibited that 1a has good enantioselective recognition ability towards α-phenylglycine.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
O. M. Bordun 《Journal of Applied Spectroscopy》2002,69(3):430-433
Luminescence spectra of Y2O3 thin films annealed in air and in vacuum are investigated. It is established that the presence of oxygen vacancies leads to a decrease in the intensity of the luminescence band with a maximum at 3.4 eV (related to emission of selflocalized Frenkel excitons describing the excited state of a molecular ion (YO6)9–) and of the luminescence band with a maximum at 2.9 eV (related to the anion sublattice). It is revealed that the oxygen vacancies also lead to a decrease in the luminescence intensity in the 2.60, 2.35, 2.10. 1.90, and 1.70 eV bands that are related to radiative recombination in the donor–acceptor Y3+–O2– pairs. The donor–acceptor distances are calculated. 相似文献
13.
V. K. Rai 《Applied physics. B, Lasers and optics》2009,95(2):329-333
Upconversion luminescence in triply ionized praseodymium-doped TeO2–Li2O glass using excitation at ∼590 nm into the 1D2 level from a dye laser pumped with the second harmonic of a pulsed Nd:YAG laser has been reported. The mechanism involved
in the upconversion emission observed at ∼480 nm indicates that the most important contribution is energy transfer among praseodymium
ions in pairs followed by the dipole–dipole interaction. The rate-equation model for the emission at ∼480 nm that provides
direct information to determine the energy-transfer rates containing the pair of states involved in the upconversion process
has been explored. 相似文献
14.
Wen-Xian Li Yu-Shan Zheng Xiao-Jun Sun Xiao-Yan Shi Wen-Juan Chai Tie Ren 《Journal of fluorescence》2010,20(1):235-241
A ligand with double sulfinyl groups, naphthyl-naphthalinesulphonylpropyl sulfoxide(dinaphthyl disulfoxide, L), was synthesized
by a new method and its several lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity,
coordination titration analysis, IR, TG-DTA, 1HNMR and UV spectra. The composition of these complexes, were RE2(ClO4)6·(L)5·nH2O (RE = La, Nd, Eu, Tb, Yb, n = 2 ∼ 6, L = C10H7SOC3H6SOC10H7). The fluorescent spectra illustrated that the Eu (III) complex had an excellent luminescence. It was supposed that the ligand
was benefited for transferring the energy from ligand to the excitation state energy level (5D0) of Eu (III). The Tb (III) complex displayed weak luminescence, which attributed to low energy transferring efficiency between
the average triplet state energy level of ligand and the excited state (5D4) of Tb (III). So the Eu (III) complex displayed a good antenna effect for luminescence. The phosphorescence spectra and the
relationship between fluorescence lifetime and fluorescence intensity were also discussed. 相似文献
15.
Hongfei Jiang Guilan Wang Wenzhu Zhang Xiaoyu Liu Zhiqiang Ye Dayong Jin Jingli Yuan Zhiguang Liu 《Journal of fluorescence》2010,20(1):321-328
Because highly luminescent lanthanide compounds are limited to Eu3+ and Tb3+ compounds with red (Eu, ~615 nm) and green (Tb, ~545 nm) emission colors, the development and application of time-resolved
luminescence bioassay technique using lanthanide-based multicolor luminescent biolabels have rarely been investigated. In
this work, a series of lanthanide complexes covalently bound silica nanoparticles with an excitation maximum wavelength at
335 nm and red, orange, yellow and green emission colors has been prepared by co-binding different molar ratios of luminescent
Eu3+–Tb3+ complexes with a ligand N,N,N1,N1-(4′-phenyl-2,2′:6′,2′′-terpyridine-6,6′′-diyl)bis(methylenenitrilo) tetrakis (acetic acid) inside the silica nanoparticles.
The nanoparticles characterized by transmission electron microscopy and luminescence spectroscopy methods were used for streptavidin
labeling, and time-resolved fluoroimmunoassay (TR-FIA) of human prostate-specific antigen (PSA) as well as time-resolved luminescence
imaging detection of an environmental pathogen, Giardia lamblia. The results demonstrated the utility of the new multicolor luminescent lanthanide nanoparticles for time-resolved luminescence
bioassays. 相似文献
16.
V. S. Vavilov M. V. Chukichev R. R. Rezvanov A. A. Klyukanov K. D. Sushkevich E. K. Sushkevich 《Physics of the Solid State》1997,39(9):1358-1363
The cathodoluminescence (CL) in ZnSe crystals annealed at T=1200 K in a Bi melt containing an aluminum impurity is investigated. The spectra are recorded for different excitation levels,
temperatures, and detection delay times t
0. As t
0 is increased, the intensity of the orange band at λ
max=630 nm (1.968 eV) in the CL spectrum decreases in comparison to the intensity of the dominant yellow-green band at λ
max=550 nm (2.254 eV), whose half-width increases in the temperature range 6–120 K and then decreases as the temperature increases
further. It is shown that such behavior of the yellow-green band is caused by the competition between two processes: recombination
of donor-acceptor pairs and of free electrons with holes trapped on acceptors. The former mechanism is dominant at low temperatures,
and the latter mechanism is dominant at high temperatures. At T∼120 mK the contributions of the two mechanisms to the luminescence are comparable. The resultant structureless band then
achieves its greatest half-width, which is dictated by the interaction of the recombining charge carriers with longitudinal-optical
and longitudinal-acoustic phonons and with the free-electron plasma. The mean number of longitudinal-optical phonons emitted
per photon is determined mainly by their interaction with holes trapped on deep acceptors in the form of Al atoms replacing
Se. The donor in the pair under consideration is an interstitial Al atom.
Fiz. Tverd. Tela (St. Petersburg) 39, 1526–1531 (September 1997) 相似文献
17.
A. A. Klochikhin 《Physics of the Solid State》1998,40(5):819-820
A unified method is developed for describing the steady-state luminescence of exciton fluctuation states for weak excitation
in different disordered systems. The phononless luminescence band is found to be formed by “radiative” states of the fluctuation
tail in the density of states, i.e., by states for which nonradiative states are either nonexistent or have a low probability.
The shape of the emission spectra calculated including the phonon interaction is in good agreement with experimental luminescence
spectra of α Si:H and of solid solutions of ZnSe(1−c)Tec and CdS(1−c)Sec.
Fiz. Tverd. Tela (St. Petersburg) 40, 890–891 (May 1998) 相似文献
18.
A. Ya. Khairullina T. V. Ol’shanskaya D. S. Filimonenko N. M. Kozlova Yu. M. Garmaza E. I. Slobozhanina 《Optics and Spectroscopy》2011,110(4):534-540
We studied changes in the surface of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range
of 0.1–2.0 mM/l using methods of light scattering, spectrofluorimetry, and atomic force microscopy. Using the spectrofluorimetry
method, we revealed a dose-dependent increase in the fluorescence intensity of a fluorescamine probe incorporated into erythrocyte
membranes modified by zinc ions, which is indicative of an increase in the level of NH2 groups on the cell surface. Using atomic force microscopy, we revealed changes in the surface topography of erythrocyte membranes
exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l. By performing a correlation analysis, we
revealed that the correlation length of the autocorrelation function of the erythrocyte surface irregularity profile directly
related to the fluorescence intensity of fluorescamine incorporated into erythrocyte membranes (r = 0.9, p < 0.05) modified by zinc ions. We showed that, in the zinc sulfate concentration range of 0.1–2.0 mM/l, zinc oxides form
in erythrocyte membranes, which is confirmed by the appearance of an absorption band at 330–340 nm and by an increase in the
light scattering. At more considerable concentrations, we identified absorption bands characteristic of zinc protein complexes
in erythrocyte membranes. A considerable decrease in the elongation of the scattering indicatrix of erythrocyte membranes
caused by luminescence correlates with the content of zinc proteins. Polarization measurements confirm the enhancement of
the aggregation of protein complexes observed by the atomic force microscopy method. The proposed complex approach can be
used in studies on the action of various abiotic factors on biological cells. 相似文献
19.
Spectral-luminescence properties of a norbornene-substituted tetraazachlorin and its metal complexes
M. V. Belkov A. A. Grishchuk S. V. Dudkin E. A. Makarova P. P. Pershukevich K. N. Solovyova 《Journal of Applied Spectroscopy》2010,77(2):213-222
The spectral-luminescence properties of a tetraazachlorin derivative with a norbornene fragment annelated to a reduced pyrrole
ring and its complexes with zinc and palladium have been studied at 293 and 77 K. For the norbornene-substituted free base,
differences in fluorescence from unsubstituted tetraazachlroin and its dibenzobarrelene-substituted analog are found. The
fluorescence lifetime is observed to rise by ∼7 times for the free base and by ∼1.6 ties for the Zn complex on going from
293 to 77 K. An essential dependence of the photophysical parameters on the nature of the solvent is noted. The fluorescence
polarization spectrum of the norbornene-substituted tetraazachlorin reveals in the Soret band region at least four electronic
transitions. For the Pd complex, weak phosphorescence in the near IR region has been detected; the 0–0 band maximum is at
990 nm and the singlet–triplet interval amounts to 5800 cm–1, which is larger by 400 cm–1 than for Pd tetraazaporphine. The quantum yields of the photosensitized formation of singlet oxygen have been determined
using a relative luminescence method. 相似文献
20.
Yoshihiro Hayashiuchi Takeshi Hagihara Yusuke Kojima Takayoshi Yamamoto Sigehiro Owaki Toichi Okada 《辐射效应与固体损伤》2013,168(2):645-650
Abstract Deformation Luminescence(DL) is studied on KCl crystal colored by γ-irradiation. The spectra analysis of DL and thermoluminescence reveals that F-center plays a role as electron donor through the interaction with moving dislocation and V2-center is a probable luminescence center. A theory is presented for understanding the deformation rate and temperature dependences of DL intensity. 相似文献