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1.
The kinetics of sensitized fluorescence of O2 has been recorded for the first time in solutions at transition from the second singlet excited state b{su1}Σ{sk{su\s+}/{in{itg}}
to the first excited state \ga{su1}\gD{in{itg}} (b→a. We measured the quantum yield of the b→a-fluorescence at γ≈1.93 μm and
assessed its probability with respect to the a→ X-phosphorescence at 1.27 μm. We show that the lifetime of the b→a-fluorescence
(105 nsec for CCl4 and 140 nsec for CS2) becomes much shorter on addition of solvents with large frequencies of intramolecular vibrations. The measured radiative
velocity constant of the b→a-transition Kb→a is by three orders of magnitude larger than for the phosphorescence (≈1.27 μm) of the a→X-transition from the first singlet
to the ground triplet state. The method of recording IR fluorescence is promising for determining O2 in solutions and biosystems.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp 5–8, January–February, 1998. 相似文献
2.
E. K. Naumenko 《Journal of Applied Spectroscopy》1998,65(3):434-441
The spectral dependences of the optical characteristics governing radiation transfer in scattering media are analyzed within
the wavelength range of 0.4–14 μm for three types of aerosols. The wavelength ranges where approximate methods of calculation
of frequency-contrast characteristics are applicable are established; the corresponding limitting masses of aerosol particles
in a layer per unit of surface area are determined for which approximate methods provide acceptable accuracy.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 70 F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 419–425 May–June, 1998. 相似文献
3.
Spectral dependences of the coefficients of absorption by free carriers and of multiphoton absorption by a silicon lattice
in the region of the interstitial oxygen band at 5.8 μm are established. A procedure for measurement of the distribution of
oxygen and alloying impurities in silicon ingots is given. The effectiveness of the spectrometers developed for controlling
the segregation of impurities and nonstationary convection of the silicon melt in growing ingots by the Czochralski method
is shown.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220080, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 5, pp. 655–659, September–October, 1997. 相似文献
4.
V. A. Dlugunovich 《Journal of Applied Spectroscopy》1999,66(5):719-725
The degree and azimuth of polarization and the indicatrix of the intensity of radiation (λ=0.63 μm) reflected by the surface
of a monodirectional superhigh-modulus organoplastic material after structural transformations induced in it by CO2-laser radiation are measured. It is shown that the space-polarization characteristics of the radiation reflected by the organoplastic
material charred as a result of laser heating correspond to the parameters of radiation scattered by a nontransparent material
with an isotropic surface in the approximation of geometrical optics.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 635–639, September–October, 1999. 相似文献
5.
Regression relations between the first main component, slope of the SBC curve towards the wavelength axis, and the degree
of mineralization of peat soils are established from experimental data. Errors in determination of peat soil productivity
are estimated using different spectral indices. For practical use it is recommended to measure the spectral brightness coefficients
of peat soils in the 0.50–0.75 μm range.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 102–106, January–February, 1998. 相似文献
6.
S. A. Mikhnov 《Journal of Applied Spectroscopy》1999,66(6):994-998
It has been found that the F-band of optical absorption which is observed in ψ-irradiated NaF crystals consists of three overlapping
bands. The band at 345 nm of width 40 nm is independent of the impurity composition of the crystals; it disappears upon exposure
to radiation at 345 nm and appears again upon annealing at 460±15 K for 15 min. This band is correlatable in intensity with
the superfine structure of an EPR spectrum. The width (65–110 nm) and the spectral position (355–375 nm) of the second band
depend on the impurity composition of the crystal. The band of width 90–110 nm at 320–325 nm disappears upon annealing and
appears after exposure to light simultaneously with the disappearance of an EPR signal. It is established that the band at
345 nm is caused by quasimolecules based on fluorine atoms, that at 355–375 nm is triggered by F-centers with a different
impurity composition near the haloid vacancy, and the band at 320–325 nm owes its appearance to F-centers in a negatively
charged state (F′).
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70 F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 6, pp. 849–853, November–December, 1999. 相似文献
7.
V. I. Blynskii 《Journal of Applied Spectroscopy》1998,65(2):308-310
The spectral dependence of the coefficient of photoelectric coupling between photosensitive elements in rulers of silicon
bipolar transistors is investigated. It is shown that in the spectral range 0.5–1.0 μm with weak radiation power the coefficient
of photoelectric coupling in bipolar phototransistors with separate bases is lower than in photodiode rulers.
Institute of Electronics, National Academy of Sciences of Belarus, 22, Logoiskii Trakt, Minsk, 220090, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 293]2-295, March–April, 1998. 相似文献
8.
L. Y. Min'ko A. N. Chumakov A. N. Loparev G. I. Bakanovich V. B. Avramenko 《Journal of Applied Spectroscopy》1998,65(2):273-280
It is established that, in the case of laser action on materials in large illuminated spots in atmospheric-pressure air for
a laser radiation power density q≤2 MW/cm2 (λ=1.315 μm), an evaporative regime with plane scattering of the laser-produced erosion plasma is realized while, for q≈5–17
MW/cm2, the plasma front is transferred to the air, leading to plasma screening of the target and shaping of a subsonic radiation
wave in the air. As the duration of the laser pulses increases (τ∼160 μsec), in spite of the large illuminated spots (S∼150
cm2) the evaporative regime of the laser action with plane plasma scattering goes over into a regime with jet outlow and formation
of a quasistationary shock wave.
Deceased.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 261–268, March–April, 1998. 相似文献
9.
V. S. Pavlovich 《Journal of Applied Spectroscopy》1997,64(2):220-228
The paper sets out a statistical theory of the effect exerted by interactions of constant dipoles in solutions on the fluorescence
spectra of polar compounds. The theory is based on the concept of band structure of the electronic levels of a polar impurity
(dissolved) molecule in polar media.
Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 209–216, March–April, 1997. 相似文献
10.
By taking as an example a He−Ne laser that operates at the 3S2−3P4 transition (λ=3.39 μm), we studied the specific features of nonlinear interaction of the waves of linear orthogonal polarizations
in a transverse magnetic field. Using mutually orthogonal transverse magnetic fields on the neighboring portions of an active
medium, we implemented a regime of two-frequency generation, which was investigated theoretically and experimentally.
To whom correspondence should be addressed.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 568–573, July–August, 1999. 相似文献
11.
V. A. Gorobets V. O. Petukhov S. Ya. Tochitskii V. V. Churakov 《Journal of Applied Spectroscopy》1998,65(4):526-534
The possibility of remote detection of SO2 in the 9-μm region of the spectrum by means of a TEA CO2 laser was theoretically and experimentally investigated with regard to the real state of the atmosphere and the contribution
of background concentrations of H2O, CO2 and NH3 to absorption. For sounding along short paths (2L=2 km), the method of detection of small concentrations of SO2 (at the MPC level) with the use of the lines of the CO2-molecule regular transitions (00o1–02o0 band) has been devised and experimentally tested. It is shown that in sounding along longer paths (2L=6 km), a noticeable
increase in sensitivity can be achieved by the generation lines of the CO2-molecule sequential 00o2–02o1 band.
B. I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 508–515, July–August, 1998. 相似文献
12.
V. A. Dlugunovich V. A. Zhdanovskii V. N. Snopko 《Journal of Applied Spectroscopy》1998,65(4):634-637
An experimental system is described which is intended for measurements of reflection coefficients at wavelengths of 0.63;
1.15; 3.39, and 10.6 μm and of the thermodynamic temperature of the surface of materials heated in air or in an inert atmosphere
at pressures from 1.3·102 to 1.3·105 Pa. An analysis of the errors in reflection coefficient and temperature measurements is made.
B. I. Stepanov Institute of the Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 608–611, July–August, 1998. 相似文献
13.
Chalcogenide glasses are ideal materials for developing fiber lasers and amplifiers, remote sensors, high-speed switches,
and other devices that operate in the IR range of 1–10 μm. The nonlinear refractive index of chalcogenide glasses may exceed
that of quartz glass by a factor of 100–1200 or even more. The data on the dispersion properties of some chalcogenide glass
compositions in the IR range are presented. The possibility of forming waveguide structures with specified dispersion properties
(in particular with a fixed wavelength at which the group velocity dispersion is zero) from these glasses is numerically investigated.
It is shown by the example of completely glassy periodic waveguide structures with planar geometry that the use of photonic
band gap modes makes it possible the change the position of zero dispersion in a wide wavelength range. In the calculations
the contrast of waveguide structures was varied using parameters of glasses of different composition. 相似文献
14.
The dynamics of near-surface plasma formation and the formation of an erosion plasma flame was investigated for quasi-continuous
laser radiation (λ=1.06 μm, q=0.1–10 MW/cm2, τ∼1.5 msec) acting on bismuth targets in air. The absence of low-threshold plasma formation at q<2 MW/cm2 was established and explained. Instabilities in the plasma formation were revealed and the range of laser radiation power
densities (2≤q≤4 MW/cm2) at which these instabilities take place was determined. At q≥5.4 MW/cm2, brightening of the flame was noted. The dependence of the luminescence temperature of the flame on the laser radiation power
density q was determined.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 126–133, January–February, 1998. 相似文献
15.
M. Rahim A. Khiar F. Felder M. Fill H. Zogg M. W. Sigrist 《Applied physics. B, Lasers and optics》2010,100(2):261-264
Mid-IR tunable VECSELs (Vertical External-Cavity Surface-Emitting Lasers) emitting at 4–7 μm wavelengths and suitable for
spectroscopic sensing applications are described. They are realized with lead-chalcogenide (IV–VI) narrow band gap materials. 相似文献
16.
V. N. Knyukshto A. M. Shul’ga E. I. Sagun É. I. Zen’kevich 《Journal of Applied Spectroscopy》1998,65(6):943-951
It is established experimentally for the first time that Zn-octaethylporphyrin in a solution of dried methyl cyclohexane is
in unliganded form in the temperature interval of 293-77 K. This form is characterized by the shortest-wave position of absorption
and luminescence spectra, the independence of the degrees of fluorescence and phosphorescence polarizations from the excitation
wavelength, and high phosphorescence time (τT=126 μsec) and quantum yield (φp=0.085) at 77 K. Adding electrodonor components to the methyl cyclohexane or going over to
alcohol-containing polar media leads to the formation of a monoliganded form of ZnOEP, for which we observe a bathochromic
shift of ≈150–350 cm−1 for Q(0,0) absorption and luminescence bands, a splitting of ≈50–100 cm−2 for the Q(0, 0) absorption band, and phosphorescence quenching (τT=60 μsec, φp=0.05-0.03 at 77 K). The effects revealed are explained by a decrease in the symmetry of a ZnOEP molecule in extra
liganding and by an increase in the probability of nonradiative activation for a T1-state due to the extra ligand being involved in the exchange of electron-excitation energy and to the enhancement of a spin-orbital
coupling as a result of the disturbance of the planarity, of a macrocycle.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 900–907, November–December, 1998. 相似文献
17.
B. N. Gritsyuk T. S. Moshkova A. D. Ogorodnik I. M. Rarenko T. A. Volyanskaya 《Journal of Applied Spectroscopy》1999,66(4):651-653
We suggest using crystals of the In4(Se3)1−xTe3x solid solution for manufacturing absorption optical filters with the boundary wavelength regulated from 1.7 to 2.5 μm by
changing the composition of the solution. The refractive index is determined for different compositions, and the possibility
of making the filters antireflecting is shown. The advantages of the proposed filters are connected with the specific features
of the absorption edge of crystals and their structure.
To whom correspondence should be addressed.
Chernovtsy State University, 2, Kotsyubinskii Str., Chernovtsy, 274012, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 4, pp. 577–579, July–August, 1999. 相似文献
18.
Experimental performance parameters of Hg implanted Hg1−x
Cd
x
Te photovoltaic detectors are analyzed. At 77K, for 8–14 μm band, a comparison is made between performances and theoretical
ultimate diffusion limits in low frequency direct detection. Experimental features are well-explained by a model based on
the Auger band-to-band process for carrier recombination. Peak detectivities exceeding 1011 cm Hz1/2W−1, external quantum efficiencies as high as 90%, and zero-bias resistance-area products better than 1 Ω·cm2 have been achieved in devices with 12 μm cutoff wavelengths. In the 3–5 μm band performances are far from the diffusion limit.
Notwithstanding, at 77K zero-bias resistance-area products are better than 104Ω·cm2 and detectivities of the order of 1012 cm Hz1/2W−1 were observed at 5 μm.
Predominant generation-recombination contribution are present at room temperature in 1–1.3 μm photodiodes whose detectivities,
primarily limited by the Johnson noise, at 1.3 μm are higher than 1011 cm Hz1/2W−1 at 300 K.
The high frequency response of the photodiodes is also discussed. Response times as low as 0.5 ns are reached despite some
limitations arising from the implanted layer sheet resistance.
Work supported by CNR-CISE contract No. 73.01435. 相似文献
19.
D. I. Sagaidak G. G. Fedoruk B. G. Shulitskii V. V. Grigor’ev 《Journal of Applied Spectroscopy》1997,64(4):518-522
Visible and IR absorption spectra are studied for copper phthalocyanin (CuPc)-polyyimide composites. The composite films are
obtained by vacuum codeposition of CuPc, pyromellitedianhydride, and diaminodiphenyloxide followed by temperature-induced
imidization. On the basis of IR spectra it is shown that in the prepared composites imidization occurs over the whole CuPc
concentration range (10–90%). From the visible spectra it is found that CuPc is deposited mainly in the form of a-microcrystals,
which are destroyed during imidization to produce noncrystalline molecular aggregates. Subsequent heat treatment (320–350°C)
gives rise to CuPc β-microscrystals.
A. N. Sevchenko Research Institute of Applied Physical Problems, 7, Kurchatov St., 220064, Minsk, Belarus. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 4, pp. 502–506, July–August, 1997. 相似文献
20.
The infrared transmissivity of heavily dopedp-type contact layers on silicon was studied in the 3–5 μm and 8–14 μm wavelength range in order to optimise the layer thickness
and doping concentration for antireflection coating. The transmissivity of surface layers and buried layers was computed taking
into account the free carrier optical dispersion by the Drude theory and corrections due to intervalence band transitions
as well as multiple reflections and interferences in the layer. The computations are in quantitative agreement with measurements
on contact layers formed by multiple boron implantation. It was found that the free carrier absorption loss completely cancels
the gain due to the antireflection effect for a surface layer. Transmissivities of around 73% may be obtained by a buried
heavily doped layer. 相似文献