共查询到20条相似文献,搜索用时 390 毫秒
1.
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
2.
The effect of rotational predissociation on the polarization response of an ensemble of photofragments is investigated within
the framework of the model with free scatter of fragments for the most general case when both original molecules and fragments
are asymmetric rotators. Photoinduced decomposition reactions with single- and two-photon excitation of fragment fluorescence
are analyzed. Second- and third-order orientational correlation functions determining the polarization degree of fragment
fluorescence are calculated. The behavior of these correlation functions depending on the shape of original molecules and
fragments, directions of dipole moments, and characteristic times of the process are analyzed.
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. 908–914, November–December, 1998. 相似文献
3.
Yu. I. Atrashevskii A. V. Sikorskii V. V. Sikorskii G. F. Stel’makh V. I. Shuplyak 《Journal of Applied Spectroscopy》1998,65(1):110-116
Angle distributions of the degree and azimuth of polarization of radiation scattered by individual leaves were measured. The
polarization characteristics of the reflected radiation were investigated at four radiation wavelengths (460, 550, 680, and
740 nm) and angles of exposure of leaves to light of 60–70°. The experiments were performed with leaves of maples (Acer platonoides)
at different stages of vegetation and withering. More than 1000 distributions of the spectral polarization characteristics
of the reflected radiation were obtained for maple leaves taken from regions with different ecological conditions during 1993–1995
It was established that the spectral polarization characteristics of the radiation scattered by a leaf markedly change with
the state of the leaf.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220080, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 65, No. 1, pp. 107–113, January–February, 1998. 相似文献
4.
Yu. I. Atrashevskii A. V. Sikorskii V. V. Sikorskii G. F. Stel’makh 《Journal of Applied Spectroscopy》1999,66(1):105-114
The spectral polarization characteristics of the visible radiation reflected and scattered by a plant leaf were investigated.
Measurements of the spectral brightness coefficient, the directed reflection coefficients, and the degree and azimuth of polarization
of radiation reflected from a leaf were performed at different angles of incidence of radiation on the leaf and different
angles of observation. More than 500 measurements were performed for 36 samples. Maple (Acer platanoides) leaves from different
trees were used as objects of investigation. Peculiarities of the mechanism of formation of the flux of radiation reflected
from a plant leaf have been revealed.
Belarussian State University, 4, F. Skorina Ave., Minsk, 220080, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 1, pp. 101–108, January–February, 1999. 相似文献
5.
The kinetics of fluorescence polarization in intense pulse excitation of solid disordered solutions of bichromophores that
consist of complex molecules of two types between which there can be inductiveresonance transfer of electron-excitation energy
is theoretically investigated. Variants of fluorescence excitation by single pulses and pulse trains are considered. The lifetime
of the fluorescence of a given solution increases with the intensity of the exciting pulses. The possibility of controlling
the duration of fluorescence attenuation for donor molecules incorporated into the bichromophores by the action of luminescence
radiation at the frequency of acceptor-molecule absorption on the solution is demonstrated.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii
Vol. 65, No. 4, pp. 546–550, July–August, 1998. 相似文献
6.
B. I. Belyaev Yu. V. Belyaev A. V. Chumakov V. P. Nekrasov V. I. Shuplyak 《Journal of Applied Spectroscopy》2000,67(4):723-730
The results of laboratory investigations of the spectral and spectral-polarization characteristics of radiation reflected
from the leaves of potato(Solanum tuberosum) of different varieties are discussed. During the vegetation season of 1997, the angular dependence of the degree and azimuth
of polarization of radiation reflected from potato leaves as well as the scattering indicatrices in the range 380–1080 nm
were determined by a specially developed method with the use of a laboratory goniometric setup. The relationship between the
spectral polarization characteristics of radiation and biological parameters of the potato has been obtained with the help
of different methods of statistical analysis and explained on the basis of the known physical mechanisms.
Translated from Zhurnal Prikladnoi Spektroskopii. Vol. 67, No. 4, pp. 524–529, July–August, 2000. 相似文献
7.
Using the methods of laser-induced fluorescence and emissive spectroscopy, we carried out investigations of the formation
of TiO molecules in a laser plasma produced by focusing the radiation of an AYG:Nd3+ laser on the surface of a titanium target in air. The radiation flux density varied within the range 108–1010 W/cm2. We investigated the distribution of molecules over internal states and the space-time distributions of Ti atoms in the ground,
metastable, and excited states, as well as of TiO molecules in the ground and excited states. We found that gas-phase reactions
with participation of Ti atoms in the ground state provide the most probable channel for the formation of TiO molecules; the
role of reagents in ionized, excited, and metastable states is of secondary importance.
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. 1, pp. 109–115, January–February, 1999. 相似文献
8.
A. V. Kukhto 《Journal of Applied Spectroscopy》1998,65(5):722-738
Pesults of investigation of the luminescence of complex organic compounds upon excitation with electrons of various energies
are reported. Data on spectra of energy losses of electrons, fluorescence excitation cross sections and functions, fluorescence
emission spectra, fluorescence kinetics, polarization, and energy yield, effects of impurity gases, and theoretical analysis
of the processes taking place in the system are presented. Results of investigation of the luminescence of complex molecules
in electric discharges (dc, pulsed, high-frequency, non-self-maintained, and plasma-beam) and in a condensed state (solutions,
molecular crystals, and thin solid films) are discussed.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk 220072, Belarus.
Transtated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 694–708, September–October, 1998. 相似文献
9.
V. Yu. Plavskii V. A. Mostovnikov G. R. Mostovnikova A. I. Tret’yakova 《Journal of Applied Spectroscopy》2007,74(1):120-132
We have studied the spectral fluorescence and polarization characteristics of Z,Z-bilirubin IXα, at room temperature in chloroform
and in aqueous buffer medium, within an equilibrium complex with human serum albumin (HSA), and also under low temperature
conditions (T = −100°C) in isobutyl alcohol. We have observed a bathochromic shift of the fluorescence spectra, which is most
pronounced for the bilirubin-albumin complex. The following are considered as possible reasons for the observed dependence
of the position of the fluorescence (fluorescence excitation) spectra on the excitation (detection) wavelength: structural
and spectral differences between the chromophores making up the bilirubin molecule; conformational heterogeneity of the pigment
in solution; a contribution to the fluorescence from molecules which have not completed the vibrational relaxation process;
inhomogeneous orientational broadening of the levels; heterogeneity of the microenvironment of the chromophores in the protein
matrix. We show that polarized fluorescence of bilirubin occurs at room temperature, due to the anomalously short fluorescence
lifetime τ (picosecond or subpicosecond ranges). Despite such a short τ, the absorption and emission polarization spectra
suggest the presence of intramolecular nonradiative singlet-singlet energy transfer when bilirubin is excited to high vibrational
sublevels of the S1 state (degree of polarization p = 0.11–0.12). When fluorescence is excited on the long-wavelength slope of the absorption
band, no transfer occurs: the degree of polarization (p = 0.46−0.47) is close to the limiting value (p = 0.50). We discuss
the question of the role played by exciton interactions between chromophores in the bilirubin molecule when it is excited.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 108–119, January–February, 2007. 相似文献
10.
V. A. Dlugunovich E. A. Kruplevich Yu. A. Kurochkin V. N. Snopko 《Journal of Applied Spectroscopy》1998,65(6):973-978
The effect of a smooth surface binder film and the orientation of filler fibers of unidirectional superhigh-modulus organoplastic
on space-polarization characteristics of He−Ne laser reflected radiation is investigated.
B. I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220078, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 926–931, November–December, 1998. 相似文献
11.
A. P. Blokhin M. F. Gelin I. I. Kalosha S. A. Polubisok V. A. Tolkachev 《Journal of Applied Spectroscopy》1999,66(1):55-61
The polarization of the fluorescence of radicals formed in laser-induced photodissociation of some disulfides in the gas phase
is measured. Experimental data obtained in the study are interpreted within the free recoil model. It is shown that polarization
experiments carried out to investigate photodecay in vapors allow researchers to uniquely the intramolecular direction of
the dipole moments of transitions with absorption and emission.
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. 66, No. 1, pp. 54–59, January–February, 1999. 相似文献
12.
We have studied the ratio of the intensities of radiation scattered by a layer of blood in a cuvet and by the cuvet walls
for normal incidence or incidence at the Brewster angle for probing radiation from a He-Ne laser, linearly polarized in the
plane of incidence (plane of observation) or orthogonal to that plane. We have compared it with the intensity of the radiation
reflected by the surface of the cuvet wall, as estimated based on the geometric approximation. We have found the optimal conditions
for probing and observing scattering for the layer in a cuvet, where such conditions are characterized by a minimal effect
from the cuvet walls and the maximum ratio of useful signal to background.
Report given at the Fifth International Scientific and Technical Conference on Quantum Electronics, 22–25 November 2004, Minsk,
Belarus.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 270–272, March–April, 2006. 相似文献
13.
A. S. Prishchepov 《Journal of Applied Spectroscopy》1998,65(1):97-103
In an “oriented gas” model expressions are obtained for the angle of nongyrotropic rotation of the polarization plane (NRPP)
of transmitted light by an ensemble of oriented associates consisting of nongyrotropic molecules. The cluster character of
the nongyrotropic rotation of the polarization plane and the dependence of its angle on the incident light polarization vector
azimuth are noted, which distinguish linear and circular polarization effects. Measurement of linear dichroism by the angle
of nongyrotropic rotation of the polarization plane with the use of commercial spectropolarimeters is theoretically justified.
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. 95–101, January–February, 1998. 相似文献
14.
V. A. Tolkachev 《Journal of Applied Spectroscopy》1998,65(5):643-658
A number of phenomena that determine the nature of the fluorescence of free complex molecules and the possibility of its analytical
application are considered. Attention is specially paid to the specific features of the energetics of radiationless transitions,
the role of statistical factors in the formation of spectral properties and the interrelationship among the luminescence-spectrum
characteristics of rarefied vapors of complicated molecules, and the processes of energy transfer in collisions. The properties
of polarized fluorescence of hot and jet-cooled vapors, the processes of relaxation of anisotropy in time and during collision
reorientation, and transfer of anisotropy in photodisintegration are analyzed.
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. 5, pp. 620–634, September–October, 1998. 相似文献
15.
We present the most important results of investigations of lasers based on vapors and solutions of complex organic compounds.
We investigated the effect of a foreign gas, the duration and intensity of the exciting pulse, the temperature of the active
medium, and the spectroscopic parameters of the material on the generation characteristics of complex molecules in the gas
phase. The special features of generation of radiation by a laser with distributed feedback in transition from a condensed
to the gas phase in heating the active medium are considered. It is suggested that the polarization characteristics of the
radiation generated by a vapor laser be used to investigate the laws that govern the relaxation of optically induced anisotropy
of excited molecules of the active medium.
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. 5, pp. 709–720, September–October, 1998. 相似文献
16.
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
17.
The present article is concerned with theoretical consideration of the effect of oxygen diffusion on the relaxation parameters
of paramagnetic centers (PC) located on a surface. Proceeding from a model of dipole-dipole interaction between paramagnetic
molecules of O2 and PC that is modulated by translational diffusion motion of O2 molecules in the volume and on surface of an adsorbent and in its pores, we give an explanation for the observed dependence
of the intensity of the EPR signal on the pressure of O2. In the present case, diffusion in the volume is the decisive factor. We also managed to explain the presence of an SHF field
power threshold for the indicated phenomenon to be observed. In the calculations we used correlation functions obtained earlier
for diffusion in a volume.
Institute of Physicoorganic Chemistry, National Academy of Sciences of Belarus, 13, Surganov St., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 230–235, March–April, 1998. 相似文献
18.
The study puts toward a theoretical model describing the fluorescence parameters for concentrated solid solutions consisting
of complex molecules of two types (donor-acceptor) with nonradiative transfer of electronic-excitation energy with intense
pulse excitation. Consideration is given to the dynamics of quenching of the luminescence of the donor molecules due to transfer
of electronic-excitation energy to the acceptor molecules. Numerical results are presented in the form of approximation formulas.
To whom correspondence should be addressed.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 5, pp. 652–656, September–October, 1999. 相似文献
19.
We have studied the degree of fluorescence polarization for 1,3,4-oxadiazole derivatives in the binary solvents hexane-ethanol,
toluene-ethanol, toluene-acetonitrile, 2-propanol-water, dioxane-water, 2-propanol-glycerol, glycerol-water vs. the composition
of the solvent. We have shown that in systems with predominant universal interactions, the characteristic changes in the degree
of polarization reflect the change in the viscosity of the mixture, while in systems with pronounced specific interactions
they reflect the characteristic structural features of the fluorescent centers.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 677–683, September–October, 2008. 相似文献
20.
A theoretical study was carried out to investigate concentration self-quenching which is nonlinear in intensity in a molecular
system caused by nonradiative electronic excitation energy transfer to relatively long-lived acceptors that are formed in
a solution and whose function is performed by molecules that have acquired the triplet state. It is shown that at ratios of
constants of radiative and nonradiative transitions typical of complex molecules at concentrations of ∼10−3–10−2 mole/liter substantial (2- to 10-fold) fluorescence takes place at intensities of excitation of ∼104–103 of the intensity of saturation for a singlet subsystem. Polarization characteristics of the system are analyzed.
Belarusian State University, 4, F. Skorina Ave., 220050, Minsk, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 6, pp. 729–733, November–December, 1997. 相似文献