共查询到20条相似文献,搜索用时 31 毫秒
1.
I. V. Berezovskaya N. P. Efryushina A. S. Voloshinovskii G. B. Striganyuk P. V. Pir V. P. Dotsenko 《Journal of Applied Spectroscopy》2006,73(6):861-865
We have studied the luminescent properties of Eu2+/3+ and Yb2+ ions in strontium hexaborate SrB6O10 for excitation in the 120–400 nm region. The luminescence spectra of Ln2+ ions in SrB6O10 consist of overlapping bands in the 370–520 nm region, due to 5d → 4f transitions at several nonequivalent centers. In the
excitation spectra, besides the bands associated with 4f → 5d transitions in the Ln2+ ions, we also observe a band in the 135–160 nm region due to the transitions O(2p) → B(2s,2p) within the borate anions. The
luminescence of the Eu3+ ions is excited most efficiently in the region of the Eu3+ charge transfer band (λmax = 226 nm). The results obtained are compared with data for Ln in other strontium borates.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 770–774, November–December, 2006. 相似文献
2.
T.C. Brunold H.U. Güdel M.F. Hazenkamp G. Huber S. Kück 《Applied physics. B, Lasers and optics》1997,64(6):647-650
4+ doped Ca2GeO4 in the 450–2000 nm spectral region at room temperature are presented. Weak ESA bands due to the transition are observed between 1200 and 2000 nm and stronger ESA bands due to peak below 1200 nm. The overlap of the ESA band with the emission which extends from 1100 to about 1600 nm will significantly affect the laser performance of Cr4+ doped Ca2GeO4. The effective peak stimulated emission cross section at 1350 nm in E∥b polarization is only about 3×10-20 cm2. However, our results indicate that tunable laser action between 1300 and 1500 nm should, in principle, be possible.
Received: 28 October 1996 相似文献
3.
The radiation spectra of plasma in the region of 130–350 nm and the intensities of the 175-nm ArCl, 193-nm ArF, and 258-nm
Cl2 bands produced in the transverse volume discharge on a mixture of Ar/CF2Cl2 = (1–15)/(0.008–0.150) kPa are investigated. The discharge is shown to be a multiwave source of UV-VUV radiation on transitions
of ArCl, ArF, and Cl2 molecules. The optimum content of Freon-12 molecules is 0.008–0.010 kPa and that of argon atoms 10–15 kPa. The ratio of the
intensities of the ArCl (B-X) and ArF (B-X) bands is 10, which is approximately equal to the ratio of concentrations of [Cl−] and [F−] ions, which are formed in the reaction of dissociative electron attachment to CF2Cl2 molecules. The service life of a radiator with λ = 175 nm of ArCl on one mixture in a gas-static mode is not greater than
5·103 pulses.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 407–408, May–June, 2000. 相似文献
4.
We investigate the spectra of the x-ray radiation-induced absorption of SrCl2−Ce crystals over the spectral range 345–830 nm and their temperature transformations in the interval from 77 to 450 K. We
found that radiative color centers are characterized by a complex spectrum of induced absorption that contains wide bands
of photochromic PC (750, 519, 378 nm) and PC+ (620, 446, 340 nm) centers and quasi-linear bands of Ce2+ centers. The most significant thermal transformations of radiative color centers occur in the vicinity of the thermostimulated
luminescence peak of 394 K, at which the holes of the PC+ centers recombine with the electrons of the Ce2+ centers.
Ivan Franko L’vov State University, 8, Kirilla i Mefodiya St., L’vov 290005, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 4, pp. 545–547, July–August, 1997. 相似文献
5.
Yu. V. Zorenko R. M. Turchak T. I. Voznyak Yu. B. Mamai 《Journal of Applied Spectroscopy》2006,73(3):406-410
We have used the Bridgman method to grow CsBr:Eu2+ single crystals, adding an activator to the mix in the form of Eu2O3 in amounts of 0.0125, 0.0250, and 0.0500 mole %. At T = 300 K, we studied the absorption spectra, the photoluminescence (PL)
spectra, and the photostimulated luminescence (PSL) spectra of the grown crystals. We have established that the structure
of the photoluminescence and photostimulated luminescence centers in crystals grown from the CsBr:Eu2O3 mix includes isolated dipole centers Eu2+-VCs, emitting in bands with maxima at 432 nm and 455 nm respectively, and in crystals grown at activator concentrations of 0.025
and 0.050 mole % they also include aggregate centers (AC) based on CsEuBr3 nanocrystals with emission bands at 515 m and 523 nm. We have shown that the maximum concentration of aggregate centers of
the CsEuBr3 nanocrystal type in CsBr:Eu2+ crystals is achieved for an activator content in the mix within the range 0.01–0.05 mole %.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 359–362, May–June, 2006. 相似文献
6.
Analysis of a part of the meteorite which fell at Dergaon (India) on March 2, 16.40 local time (2001) is presented with the
help of FTIR, absorption and atomic spectra. The FTIR spectrum exhibits prominent absorption bands in the region 800–1100
cm−1, originating from the valence vibration of SiO4, a basic component of the silicate lattice. 相似文献
7.
A. K. Shuaibov L. L. Shimon A. I. Dashchenko A. I. Minya 《Journal of Applied Spectroscopy》1999,66(1):1-6
We present the results of investigation into radiation of a pulsed transverse discharge in neon at a pressure of 10–200 kPa.
Survey spectra of plasma radiation, time characteristics of radiation, and the effect of small impurities of water vapors
and air on the optical characteristics of a neon plasma were studied. We show that at a pressure of residual gases at a level
of 10 Pa intense OH*, NO*, and N
*
2
bands are observed in radiation of the plasma of a nanosecond transverse discharge in Ne against the background of continuous
plasma radiation, and in the spectral region with λ>400 nm radiation was observed on the Hβ 486.1 nm and NeI 585.3 nm lines, and (when P≥100 kPa) on the line at the 3s–3p-transitions of a Ne atom. The radiation intensity
of the third continuum of neon increases with pressure and with energy contribution to plasma, with its maximum being located
in the VUV spectral region (λ
max
<200 nm).
To whom correspondence should be adressed.
Uzhgorod State University, 46, Pidgirna St., Uzhgorod, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66,
No. 1, pp. 5–10, January–February, 1999. 相似文献
8.
Z.Y. Chen J.P. Zhao T. Yano T. Ooie 《Applied Physics A: Materials Science & Processing》2002,75(2):213-216
Raman characteristics of carbon nitride films synthesized by nitrogen-ion-beam-assisted pulsed laser deposition were investigated.
In addition to the D (disorder) band and G (graphitic) band commonly observed in carbon nitride films, two Raman bands located
at 1080–1100 and 1465–1480 cm-1 were found from our carbon nitride films. These two bands were well matched with the predicted Raman frequencies for βC3N4 and the observed Raman bands reported for carbon nitride films, indicating their relation to carbon-nitrogen stretching vibrations.
Furthermore, the relative intensity ratio of the two Raman bands to the D and G bands increased linearly with increasing nitrogen
content of the carbon nitride films.
Received: 30 October 2000 / Accepted: 5 February 2001 / Published online: 2 October 2001 相似文献
9.
N. M. Shishlov Sh. S. Akhmetzyanov S. L. Khursan 《Russian Journal of Physical Chemistry B, Focus on Physics》2010,4(5):846-859
IR spectroscopy measurements show that films of poly(diphenyl sulfophthalide) (PDSP), a cardo polymer, interact with atmospheric
moisture during storage at room conditions. A total of 15 absorption bands were isolated in spectra of PDSP hydrated during
storage, which belong to sorbed water and hydrolysis products. A number of absorption bands (within 1500–1800 cm−1 and 980–1100 cm−1) were obtained by subtracting the spectrum of the film after heating from that of the initial hydrated film. At least six
individual bands in the region of the O-H bond stretching vibration were isolated by decomposing a broad complex band (3700–2000
cm−1) into Gaussian components. The isolated bands were tentatively assigned based on the available literature data and quantum-chemical
calculations of the characteristics of a number of complexes of a diphenyl sulfophthalide model compound with water molecules.
The IR spectra and energies of the hydrogen bonds formed were calculated at the B3LYP/6-311G(d, p) level. In particular, the absorption bands at 1010 and 1079 cm−1 were assigned to the symmetric stretching vibrations of the S=O bonds in the −SO3− anion, the 1062-cm−1 absorption band, to ν(C-OH), and the absorption bands at 3646, 3586, and 3475 cm−1, to complexes of water with sulfophthalide cycles of the polymer. After a long storage, PDSP largely transforms into a polymeric
oxonium salt, and its spectrum becomes similar to that of a polymeric salt prepared by alkaline hydrolysis. A general mechanism
of the interaction of PDSP with water is proposed, according to which the hydrolysis of the sulfophthalide cycles (SPC) by
sorbed water yields new hydrophilic groups, sulfoacid, and hydroxyl groups. A further sorption of water by the sulfoacid results
in its ionization and the formation of various hydroxonium forms. Sorption and hydrolysis are reversible processes: water
is desorbed and the SPC is recovered when the polymer is heated to 100–150°C, as can be judged from an increase in the intensity
of the S=O bond vibrations of the sulfophthalide cycle at 1352 and 1192 cm−1. The possibility of using strongly hydrated PDSP for manufacturing proton-conducting membranes is discussed. 相似文献
10.
This paper reports the synthesis of high upconversion luminescent Gd2O3: Er3+, Yb3+ nanophosphor through optimized combustion route using urea as a reducing agent. The paper also reports the first observation
of upconversion emission bands extending upto the UV region (335, 366 and 380 nm) in Er3+–Yb3+ co-doped phosphor materials. The fuel to oxidizer ratio has been varied to obtain the maximum upconversion luminescence.
Three high intensity bands are found at 408, 523–548 and 667 nm due to the 4G11/2 → 4I15/2, 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively, along with the other bands. Input excitation power dependence has been studied for different transitions,
and the saturation effect and decrease in the slope of different transitions at higher input pump power has been explained.
Heat treatments of the samples show change in crystallite phase/size and relative upconversion luminescence intensities of
blue, green and red bands. The color of the phosphor emission has shown to be tunable with change in the crystal structure
as well as on excitation laser power and Er3+–Yb3+ concentration. The property of color tunability of the phosphor material has been used to record the fingerprint in different
colors. Also, the future prospect of the nanocrystalline phosphor material as a sensor for temperature, using FIR method,
has been explored. 相似文献
11.
A. K. Shuaibov 《Journal of Applied Spectroscopy》1999,66(2):256-262
Survey emission spectra in the region of 190–600 nm and time and service-life characteristics of a transverse nanosecond discharge
in He/Ar/CF2Cl2(CCl4) mixtures at a pressure of 10–100 kPa are investigated. In the emission spectra, excited products of the decomposition of
freons—C2(A−X), CN(B−X), Cl
2
*
, C*, Cl*, and Cl+*— and the emission of ArF at λ=193 nm are revealed. The emissions of Cl
2
*
at λ=258 nm and ArF at λ=193 nm were the most intense. The discharge in the He/Ar/CF2Cl2 mixture is a multiwave emission source with λ=258 nm Cl
2
*
193 nm ArF, and probably, 175 nm Arcl. It is of interest for applications in UV-VUV-range pulse photometry. The duration
of the emission on Cl
2
*
, ArF, ArI, ClI, and ClII transitions in the discharge in the Ar/CF2Cl2 mixture (P=10–20 kPa) was 200–300 nsec. With adding He and increasing pressure to 100 kPa the duration of the emission decreased
by a factor of 1.5–2. The basic mechanisms of the formation of Cl2, ArF, and CN(B) molecules in the transverse-discharge plasma are considered.
Uzhgorod State University, 46, Pidgirna Str., Uzhgorod, 294000, Ukraine. Translated from Zhurnal. Prikladnoi Spektroskopii,
Vol. 66, No. 2, pp. 241–246, March–April, 1999. 相似文献
12.
L. A. Khamidullina I. S. Puzyrev A. V. Pestov V. S. Moshkin Yu. G. Yatluk 《Journal of Applied Spectroscopy》2012,79(4):509-514
UV absorption spectra of substituted 2-hydroxy-2-trifluoromethylchroman-4-ones (chromanones) in aqueous ethyleneglycol were studied. Replacement of hydrogen in the aromatic ring of the chromanones by CH3 or CF3 groups was shown to cause the molar extinction coefficients of the K, B, and C=O bands to shift from 16,160 to 27,980 and 30,250 dm3/mol·cm; from 12,750 to 17,920 and 16,130 dm3/mol·cm; and from 3850 to 3630 and 2760 dm3/mol·cm, respectively. Increasing the solution pH from 1 to 10.5 affected weakly the aromatic ring bands yet impacted greatly the chromanone carbonyl bands, causing their λmax to shift from 311–326 nm to 342–346 nm and their extinction coefficients to increase from 2760–3850 dm3/mol·cm to 9940–10,160 dm3/mol·cm. A further rise in the pH resulted in hypochromia of the carbonyl band due to the destruction of the chromanones. The results were confirmed by NMR spectroscopy and GC methods. 相似文献
13.
A. Brockhinke A.T. Hartlieb K. Kohse-Höinghaus D.R. Crosley 《Applied physics. B, Lasers and optics》1998,67(5):659-665
2 in a flame, excited by a tunable KrF laser near 248 nm. The first comprises several P and R lines of the (1,0) band of the
e 3Πg-a 3Πu Fox–Herzberg system, with fluorescence bands extending past 350 nm. The second is the band head region of the (7,1) band
of the D 1Σu
+←B′ 1Σg
+ system, with fluorescence at 232 nm from D to the X 1Σg
+ ground state. Neither band has been previously observed in any environment. The flame in these experiments is highly sooting,
and the C2 seen here is likely produced by laser vaporization of the soot with subsequent laser photolysis of a C2 precursor. In a rich flame, this fluorescence could cause interferences in other studies such as KrF laser Raman scattering.
Moreover, signal level calculations suggest native C2 near 10 ppm could be readily observed using the Fox–Herzberg excitation. Raman measurements of major species (X≥0.01) in
the same flame, using the KrF laser, are in good agreement with a model prediction.
Received: 2 April 1998/Revised version: 8 June 1998 相似文献
14.
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
15.
Yu. V. Zorenko R. M. Turchak T. I. Voznyak A. P. Luchechko 《Journal of Applied Spectroscopy》2006,73(2):211-215
By liquid-phase epitaxy from an aqueous alcoholic solution, we have obtained films of the well-known storage phospor CsBr:Eu,
and we have studied their cathodoluminescence and photoluminescence (PL) spectra compared with the undoped CsBr films. We
have established that the structure of the photoluminescence centers of the CsBr:Eu films when excited by laser radiation
in the absorption band of the Eu2+ ions (λ = 337 nm) includes Eu2+-VCs isolated dipole centers and CsEuBr3 aggregate centers, and also luminescence centers based on inclusions of hydroxyl group OH− with the corresponding emission bands in the 440 nm, 520 nm, and 600 nm regions. We have studied the dependence of the spectra
and the intensity of the photoluminescence for CsBr:Eu films on annealing temperature in air at 423–483 K, compared with analogous
dependences for CsBr:Eu single crystals obtained from the melt. We have shown that annealing the films at T = 423–463 K leads
to rapid formation of CsEuBr3 aggregate luminescence centers, while for T > 473 K thermal degradation of these centers occurs.
We conclude that the observed differences between the photoluminescence spectra of CsBr:Eu films and CsBr:Eu single crystals
may be due to additional doping of the films with OH− ions.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 191–194, March–April, 2006. 相似文献
16.
Seung Kwon Hong Hye Young Koo You Na Ko Jung Hyun Kim Jang Heui Yi Yun Chan Kang 《Applied Physics A: Materials Science & Processing》2010,98(3):671-677
Eu-doped B2O3–ZnO–PbO glass phosphor powders with spherical shape and fine size were directly prepared by spray pyrolysis. The glass phosphor
powders prepared at a temperature of 1100°C had broad XRD peak at around 28°. One glass phosphor powder was formed from one
droplet at the preparation temperature range from 900 to 1100°C. The mean size of the glass phosphor powders was 0.75 μm.
The glass transition temperature (T
g
) of the glass phosphor powders prepared by spray pyrolysis was 378.5°C. The excitation spectrum of the glass phosphor powders
prepared at the optimum preparation temperature of 1100°C had bands at 362, 381, 392, 463, 525, and 532 nm. The glass phosphor
powders had emission spectra with bands at 579, 614, and 653 nm. The glass phosphor powders with doping concentration of Eu
of 7 wt% had the maximum photoluminescence intensity. The glass phosphor layer formed from the glass phosphor powders had
high transparencies above 90%. 相似文献
17.
R. Mosimann D. Haertle M. Jazbinsek G. Montemezzani P. Günter 《Applied physics. B, Lasers and optics》2006,83(1):115-119
We determined high absorption constants of crystals from photocurrent measurements within the interband absorption region
(10–104 cm-1). The method has been demonstrated in the interband absorption regime near 530 nm in Sn2P2S6, a novel infrared sensitive photorefractive material, and in the interband absorption regime near 257 nm of near stoichiometric
LiTaO3. Besides the verification of older measurements with our new technique, precise absorption data for Sn2P2S6 in the wavelength range 488–514 nm are presented.
PACS 42.70.Nq; 72.41.+w; 78.20.Ci 相似文献
18.
V. L. Dubovskii A. L. Mikhal’chuk T. F. Raichenok A. N. Sobchuk A. A. Sukhodola G. B. Tolstorozhev 《Journal of Applied Spectroscopy》2006,73(3):347-352
We have used steady-state fluorescence spectroscopy and pulsed kinetic fluorimetry with high time resolution to experimentally
study the spectral and temporal characteristics of luminescence of immunoactive 8-aza-D-homogona-1,3,5(10), 13-tetraene-12,17a-dione
(8-aza-D-homogonane) molecules in the gas phase. We have established the existence of several centers emitting long-wavelength
and short-wavelength fluorescence. The fluorescence of high-temperature 8-aza-D-homogonane vapor (T = 550 K) when excited
by radiation with λex = 266 nm is represented by two spectrally separated emission bands with maxima λ
max
fl
= 465 nm and λ
max
fl
= 365 nm. Analysis of the distribution of fluorescence decay times for 8-aza-D-homogonane showed that in the spectral range
of the emission wavelengths 360–590 nm, the fluorescence decay kinetics contains three components with average lifetimes <200
psec, 2.8 nsec and 13.5 nsec. The multicenter nature of luminescence of 8-aza-D-homogonane was confirmed by direct measurements
of instantaneous fluorescence spectra in different stages of luminescence decay.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 309–314, May–June, 2006. 相似文献
19.
J. del-Castillo J. Méndez-Ramos A. C. Yanes V. D. Rodríguez 《Journal of nanoparticle research》2009,11(4):879-884
The generation of a wide colour gamut, based on up-conversion of cheap near-infrared photons into the visible range, is of
great importance for general lighting appliances and integrated optical devices. Here, we report for the first time on up-conversion
luminescence under infrared excitation at 980 nm in Yb3+–Er3+–Tm3+ triply doped sol–gel derived SiO2–LaF3 based nano-glass–ceramics (SOL-YET), containing LaF3 nanocrystals with a size about 13 nm. Efficient simultaneous up-conversion emission of the three primary colours (blue, green
and red) gives rise to a balanced white overall emission. The ratio between up-conversion emission bands can be varied by
changing pump power intensity resulting in colour tuneable up-conversion phosphor. 相似文献
20.
S. S. Novosad I. M. Matviishin I. S. Novosad O. S. Novosad 《Journal of Applied Spectroscopy》2008,75(6):826-831
We have studied the effect of lead dopant on the optical absorption, photoluminescence, and x-ray luminescence spectra, and
the scintillation characteristics of CdI2 at room temperature. The crystals for the study were grown by the Stockbarger-Bridgman method. Activation of CdI2 from the melt by the compound PbI2 leads to the appearance in the absorption spectra in the near-edge region of an activator band at 395–405 nm, which is interpreted
as an A band connected with electronic transitions from the 1S0 state to the 3P1 levels in the Pb2+ ion. For x-ray excitation, CdI2:Pb2+ crystals with optimal dopant concentration (∼1.0 mol%) are characterized by a light yield with maximum in the 570–580 nm
region that is an order of magnitude higher than for CdI2 crystals in the 490–500 nm band. For α excitation, the radioluminescence kinetics for cadmium iodide is characterized by
a very short (∼0.3 nsec) rise time and fast decay of luminescence, with τ1 ≈ 4 nsec and τ2 = 10–76 nsec. Depending on the conditions under which the crystals were obtained, the fast component fraction is 95%–99%.
The crystal is characterized by a similar scintillation pulse in the case of excitation by x-ray pulses. The radioluminescence
pulse shape for CdI2:Pb in the decay stage is predominantly exponential, with luminescence decay time constants τ1 ≈ 10 nsec and τ2 = 200–250 nsec. This system is characterized by low afterglow, at the level for the Bi4G3O12 scintillator. We have demonstrated the feasibility of using CdI2:Pb as a scintillator for detecting α particles.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 825–830, November–December, 2008. 相似文献