共查询到20条相似文献,搜索用时 15 毫秒
1.
B. I. Turko V. B. Kapustyanyk V. P. Rudyk M. V. Partika M. V. Kvasnytsya A. P. Vas’kiv 《Journal of Applied Spectroscopy》2007,74(2):310-312
We have studied the behavior of the intrinsic absorption edge in zinc oxide thin films in the temperature range 80–300 K.
We have observed that the intrinsic absorption edge in films with crystal sizes of ≈45 nm or larger is described by the empirical
Urbach’s rule, while in films with crystallite sizes of ≈15 nm, it is described by a modified Urbach’s rule. We have calculated
the effective frequency of phonons taking part in formation of the absorption edge.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 275–277, March–April, 2007. 相似文献
2.
B. I. Turko V. B. Kapustianyk V. P. Rudyk G. A. Lubochkova B. A. Simkiv 《Journal of Applied Spectroscopy》2006,73(2):222-226
We have studied the temperature variation of the intrinsic absorption edge of thin polycrystalline films of zinc oxide, obtained
by high-frequency magnetron reactive sputtering. We ha ve observed that the intrinsic absorption edge in such films is described
by a modified Urbach’s rule. We have calculated the effective frequency of phonons taking part in formation of the absorption
edge.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 200–203, March–April, 2006. 相似文献
3.
Wai-Lun Chan Robert S. Averback D. G. Cahill 《Applied Physics A: Materials Science & Processing》2009,97(2):287-294
We use calorimetry to determine the energy absorption of femtosecond (fs) laser pulses as a function of incident fluence for
Ag, Ag alloys (Ag–Cu and Ag–Pt), and Pt. At low fluences, the measured absorption agrees well with reflectivity data derived
from ellipsometry measurements. For Ag and Ag–Cu, the absorbed energy increases nonlinearly with the incident fluence for
fluences larger than approximately half of the melting threshold. Near this threshold, the absorption increases by a factor
of 3–4. Similar nonlinear absorption is not observed in Pt or Ag–Pt. We propose that the nonlinear absorption is caused by
the excitation of d-band electrons below the Fermi surface. For pulse widths longer than 850 fs, the observed nonlinear absorption
in Ag diminishes, indicating that diffusive transport and not ballistic transport is the major mechanism of cooling at this
excitation level. 相似文献
4.
The fundamental absorption edge of glassy alloys of an As–Sb–S system was studied in the temperature range 77–300 K. The spectral and thermal behavior of the fundamental absorption edge of As40–x SbxS60 glasses was shown to be described by an exponential function of phonon energy. The temperature and concentration behavior of the optical band gap in the studied glasses was established. The well-known Varshni relationship was used to describe the temperature dependence of the optical band gap. 相似文献
5.
Alexey O. Levchenko Nikolay N. Ustinovskii Vladimir D. Zvorykin 《Journal of Russian Laser Research》2010,31(5):475-480
An original absorption probe technique using a laser plume as a probe source of UV–visible continuum radiation is proposed
and tested. To our knowledge, this is the first time that laser plume emission is used as a UV–VIS (190–510 nm) probe beam
in transient absorption spectroscopy. The technique allows virtually single-shot recording of continuous fluorescence and
absorption spectra and proved its applicability even when used at a high-voltage high-current e-beam gun facility with a high
level of electromagnetic interference. The developed technique is applied to record the transient absorption spectra of e-beam-excited
Ne, Ar, and Kr gases. 相似文献
6.
We describe a new technique to measure the UV/visible absorption spectrum of the ablated material during the laser pulse.
The technique utilizes the continuum emission from one laser produced plasma as a light source to measure the absorption properties
of a second laser produced plasma which is formed on a semi-transparent target with an array of 40 μm holes. A 6 ns, 1064
nm laser was used to ablate a Ag target and the plasma absorption was measured in the range 450–625 nm for a laser fluence
of 1 J cm−2. The total absorption cross-section is (0.5–1.5)×10−17 cm2 in the range 450–540 nm. By comparing the measured absorption with a calculation using the plasma spectroscopy code FLYCHK
it can be concluded that, in the wavelength region examined here, the absorption is mainly due to bound-bound transitions. 相似文献
7.
V. K. Goncharov K. V. Kozadaev V. I. Popechits M. V. Puzyrev 《Journal of Applied Spectroscopy》2008,75(6):892-897
We have used a combination of physical diagnostics methods (laser probe, absorption spectroscopy, transmission electron microscopy)
to study an aqueous suspension of silver nanoparticles, formed by laser ablation of a metal target in the atmosphere. We have
established that application of the methods described allows us to obtain the most complete information about the state of
nanosized metal particles in optically transparent media.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 896–901, November–December, 2008. 相似文献
8.
L. M. Bolot’ko A. N. Krasovskii A. M. Lyudchik V. I. Pokatashkin 《Journal of Applied Spectroscopy》2005,72(6):911-916
The conditions allowing one to measure the concentration of terrestrial ozone by the open-path DOAS method using a zero line
are considered. A technique based on measuring signals at two wavelengths, at least one of which belongs to the ozone absorption
UV band, is described. The error of measurements has been estimated. A block-diagram of the optical “open-path” meter for
measuring the terrestrial ozone concentration, TrIO-2, is presented.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 832–836, November–December, 2005. 相似文献
9.
Experimental absorption spectra of benzene, isooctane, and their mixtures are obtained in the wavelength range λ = 1620–1820
nm in which the first overtones of vibrational frequencies of CH, CH2, and CH3 hydrocarbon groups are located. Positions of fundamental absorption bands of benzene are refined. Absorption spectra of benzene-isooctane
mixtures are shown to intersect in a narrow area near λ ≈ 1695 nm. The main maximum of benzene absorption at λ = 1671.5 ±
0.5 nm, where the influence of isooctane absorption is practically absent, is proposed for determining the content of benzene
in benzene-isooctane mixtures. A linear calibration curve for λ = 1671.5 nm that encompasses the full range of benzene concentrations
(0–100%) is presented.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 631–634, September–October, 2008. 相似文献
10.
We show that when polystyrene is exposed (for 15–60 sec) to a UV laser light beam (λ = 248 nm), its absorption and luminescent
properties change significantly. In the irradiated polymer, optical centers are formed with absorption bands in the 280–460
nm region and fluorescence bands in the 330–520 nm region. We have established the chemical structure of the optical centers
for fluorescence of polystyrene.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 54–58, January–February, 2006. 相似文献
11.
M. G. Kisteneva A. S. Vishnev A. S. Akrestina A. A. Sergeev S. A. Smychkov S. M. Shandarov Yu. F. Kargin 《Russian Physics Journal》2008,51(6):562-567
Results of experimental investigations into the temperature dependences of the absorption of optical narrow-band quasi-monochromatic
radiation of semiconductor light-emitting diodes in the visible range of the spectrum in a bismuth titanium oxide crystal
doped by aluminum are presented. It is demonstrated that experimental dependences for temperatures 27–70 °C can be described
by the model of defects formed by donor-trap pairs that admit tunnel electron transitions between donor and trapping centers
in each pair.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 12–16, June, 2008. 相似文献
12.
Yi-Fan Liu Feng-Hua Wang Dong-Lai Guo Sheng-You Huang Jian-Ping Sang Xian-Wu Zou 《Applied Physics A: Materials Science & Processing》2009,97(3):677-681
Ni–P/AAO nano-array composite structure assemblies with Ni and P grown in the pores of anodic aluminum oxide (AAO) membranes
were prepared by electroless deposition. The results of SEM, TEM and SAED show that as-deposited Ni–P nanowires have an amorphous
structure and a few nanocrystallites form after annealing. The optical absorption spectra reveal that, as the annealing temperature
increases, the absorption band edge of the Ni–P/AAO composite structure is obviously blue shifted, which is attributed to
a decrease of the internal pressure after heat treatment. Meanwhile, the annealed Ni–P/AAO nano-array composite structure
exhibits the absorption behavior of a direct band gap semiconductor. Details of this behavior are discussed together with
the implications for potential device applications. 相似文献
13.
The anisotropy of the absorption of transverse elastic waves in uniaxial magnetic materials, connected with the deviations
of the vectors of spontaneous magnetization from the “easy” directions, is described.
Kursk State Technical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 55–59, March,
1998. 相似文献
14.
We have studied the optical absorption edge of solid solutions Cu6PS5I1 − x
Cl
x
at high absorption levels in the temperature range of 77–320 K. In a superionic state, we have revealed the Urbach behavior
of the absorption edge, determined its parameters, and studied their temperature and concentration variations. We consider
exciton-phonon interaction as a mechanism by which the Urbach bundle is formed and show that this bundle can be described
in terms of the Dow-Redfield model. 相似文献
15.
V. N. Kuznetsov A. A. Lisachenko I. V. Ivanova V. A. Konnov 《Journal of Applied Spectroscopy》1997,64(5):678-682
Using the spectroscopic method of diffuse reflection in the region between 0.5 and 6 eV, we investigate the degradation of
reflectivity in thermal vacuum treatment of white anodic-oxide coatings on an Al alloy (Al–AOC) that are used as thermoregulating
coatings of space vehicles. It is established that at T≥350 K absorption bands at 4.05 and ∼4.7 eV resembling those induced
by UV irradiation in vacuum appear in the diffuse reflection spectra of Al–AOC. The kinetics of the increase of absorption
in heating Al–AOC with a constant rate correlates with the rate of gas liberation from specimens. We assume that a thermally
activated reaction with the formation of color centers identical to those produced by the photoeffect occur in Al–AOC in vacuum
at T≥350 K. This process is accompanied by desorption of molecular products.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 664–667, September–October, 1997. 相似文献
16.
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
17.
B. Denker B. Galagan V. Osiko I. Shulman S. Sverchkov E. Dianov 《Applied physics. B, Lasers and optics》2009,95(4):801-805
A new Bi-doped Mg–Al–silicate glass is suggested and investigated. It can be fabricated by moderate-temperature routine technology.
The characteristic relaxation time of 300–800 μs in combination with the high quantum yield (up to 85%) and wide excitation
spectrum makes this glass a promising laser material. The obtained quadratic dependence of the visible absorption intensity
is an argument in favor of the hypothesis that the absorption and infrared luminescence in Bi-doped glasses are caused by
Bi2 dimers. 相似文献
18.
Yu. S. Avlasevich O. G. Kulinkovich V. N. Knyukshto K. N. Solov'ev 《Journal of Applied Spectroscopy》1999,66(4):597-601
In a brief form, the authors provide their developed methods of synthesis and modification of the poly(N-isopropylacrylamide)
derivatives containing meso-tetraarylporphyrin substituents in the side chain. The specific features of absorption spectra
of the compounds obtained and their dependence on the method of introduction of porphyrin groups into the polymer are discussed.
The physical and chemical characteristics of the polymers described are given.
Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 538–541, July–August, 1999. 相似文献
19.
In this paper, we provide polynomial coefficients and a semi-empirical relation using which one can derive photon mass energy
absorption coefficient of any H-, C-, N-, O-based sample of biological interest containing any other elements in the atomic
number range 2–40 and energy range 200–1500 keV. More interestingly, it has been observed in the present work that in this
energy range, both the mass attenuation coefficients and the mass energy absorption coefficients for such samples vary only
with respect to energy. Hence it was possible to represent the photon interaction properties of such samples by a mean value
of these coefficients. By an independent study of the variation of the mean mass attenuation coefficient as well as mass energy
absorption coefficient with energy, two simple semi-empirical relations for the photon mass energy absorption coefficients
and one relation for the mass attenuation coefficient have been obtained in the energy range 200–1500 keV. It is felt that
these semi-empirical relations can be very handy and convenient in biomedical and other applications. One possible significant
conclusion based on the results of the present work is that in the energy region 200–1500 keV, the photon interaction characteristics
of any H-, C-, N-, O-based sample of biological interest which may or may not contain any other elements in the atomic number
range 2–40 can be represented by a sample-independent (single) but energy-dependent mass attenuation coefficient and mass
energy absorption coefficient.
相似文献
20.
The preparation of pyridine functionalized TbF3 nanoparticles are described in this report. Synthesized nanoparticles were characterized using the TEM, UV/Vis, FTIR and
photoluminescence spectroscopy. TEM micrograph reveals the nanorod shaped, uniform in size with a particles size in the range
of 20–30 nm. FTIR spectrum shown characteristic absorption bands of pyridine and a small intensity band at 411 cm−1 corresponding metal nitrogen ν(Tb–N) bonding. Uv-vis spectrum shown the characteristic absorption transitions of Tb3+ ion. A strong emission transition at 540 nm (5D4 → 7F5) was observed on excite by visible light at 414 nm. 相似文献