Study of the parameters of a difference image in the presence of a linear phase shift

The spatial filtering in the localization range of the holographic lateral shearing interferograms of a solid object shows that the effect of the subtraction of the compared original data arrays is realized in the presence of a filtering aperture in the center of a dark fringe [1, 2]. Methods for the holographic subtraction of the images involving the detection and spatial filtering in the Fourier plane of the optical system are proposed and realized in [3–5]. Thus, the difference data can be reconstructed with a narrow (unexpanded) laser beam. However, a relatively high level of speckle noise in the difference image is caused by the spatial filtering with a small aperture (laser beam) in the minimum of the superposition field in the Fourier hologram plane. The detection of double-exposed Fourier holograms with a linear phase shift and the effect of the size of the filtering reconstructing beam on the resolution of the difference image are studied. In addition, the application of the multiple exposure for the broadening of the interference maxima is analyzed.     

The laser radiation action on the biological objects

The basic physical mechanisms of laser influence on living tissues are discussed. The role of radiation monochromaticity, self-organising and non-equilibrium of laser influence, intravenous blood photomodification of and others is considered. Laser anesthesia and antistress influence is discussed. It is experimentally confirmed biological substances solution manoclusterization under the influence of laser radiation.     

Kinetics of hologram recording on chromated gelatin using the diode-laser radiation

The hologram recording on the dichromated gelatin layers using the radiation of a diode laser and a diode-pumped solid-state laser is investigated. The recording on dry and self-developed dichromated gelatin layers is experimentally demonstrated. Various recording regimes are studied for wavelengths of 0.53 and 0.66 μm.     

Study of isotopes of carbon,thorium, and uranium in travertine and thermal spring samples: implications for effects of changes in geochemical environment and processes

Data on modern radiocarbon activity in the old travertine formations of the Pymvashor hydrothermal system were used, in combination with ²³⁰Th/U dating of the travertine, to estimate the ¹⁴C contents of the total dissolved inorganic carbon in the ancient thermal water at the time of precipitation of the travertine (¹⁴C_calc). With the known values of ¹⁴C_calc and average age of the thermal water, and under the assumption that the residence time of the water in aquifer was constant over the last 13.9?±?1.5 ka, the initial ¹⁴C contents (¹⁴C₀) in the ancient thermal water were estimated. The findings in this study are that (1) both ¹⁴C₀ and δ¹³С have decreased in young waters compared to the ancient waters; (2) although atmospheric ¹⁴C activity (¹⁴C_atm) has also decreased in the same time, the decrease in ¹⁴C₀ is faster than the decrease in ¹⁴C_atm. Under certain assumptions, one could link changes in ¹⁴C₀ and δ¹³C to climate change. Decrease in δ¹³С of soil CO₂ and decrease in ¹⁴C₀ was caused predominantly by warmer and wetter climate, decomposition of fossil organic matter, and decrease in ¹⁴C_atm. There could be also increased dissolution of solid carbonate and increased carbon exchange between DIC and soil CO₂, caused by thawing permafrost.     

Description of radiative strength functions in deformed nuclei

Radiative strength functions ofE1- andM1-transitions from ground states of doubly even deformed nuclei to states near the neutron binding energyB _n are calculated within the quasiparticle-phonon nuclear model. The wave functions of excited states include one- and two-phonon components. The calculations were made with the Pauli principle being or not included in the two-phonon components of the wave functions. It is shown that the radiativeE1- andM1-strength functions as well as the widths of giant dipole resonances in deformed nuclei are slightly influenced by the two-phonon components of the wave functions and they can be calculated in the RPA. Thek _E1- andk _M1-values are calculated for some deformed nuclei of the rare-earth and actinide region. The calculated values ofk _E1 are 1.5–2 times larger and the values ofk _M1 are somewhat less than the average values obtained in [14] from the analysis of available experimental data.     

Oxygen-phase-state changes in ZnS single crystals annealed in vapors of the constituents

Exciton reflection and emission spectra and edge emission have been investigated in ZnS sinle crystals grown from the melt and containing oxygen and then subjected to annealing in vapors of the constituents. The study of optical properties of the crystals cooled to 77°K were conducted in parallel with structural investigations of the crystals using proton and x-ray diffraction analyses. Based on the experimental data it was concluded that in the ZnS lattice, oxygen exists in a number of phase states: as part of a ZnS·O solid solution in the host lattice; as a precipitate from the saturated solid solutionβ=ZnS·O_sat; as an impurity atmosphere in the vicinity of packing faults; as ZnO precipitated on dislocations. The effect of oxygen in these various phase states on the exciton spectra and edge emission of ZnS was investigated. It was shown that oxygen is not very mobile in ZnS crystals annealed in sulfur vapor and it becomes concentrated mainly at packing defects. This leads to an increase in the concentration of packing defects and makes possible a transition from the cubic to the hexagonal modification of ZnS. The concentration of oxygen at packing defects leads to the appearance in reflection spectra and in the edge emission spectra ofα-ZnS of an additional hexagonal band located on the long wavelength side which is caused by the formation ofβ-ZnS·O solid solution. Oxygen diffuses quite rapidly through ZnS which has been annealed in zinc vapor and it precipitates from the crystals as the distinct phases ZnO orβ-ZnS · O_sat, and as a result the defect content of the hostα-ZnS lattice decreases. The concentration of the ZnO-phase is quite small and its exciton bands do not appear in the reflection spectra. The precipitation of the solid solution in the form of the phaseβ-ZnS · O_sat leads to the appearance of an additional long wavelength absorption edge in the 334 to 335 nm region (at 77°K). In addition, because single crystals of ZnS annealed in zinc vapor contain a large concentration of sulfur vacancies, there occurs a rather rapid formation of the solid solution on the layers ofα-ZnS close to the surface; this leads to a broadening and a shift toward longer wavelengths of the sphalerite exciton spectra. A similar shift is observed for the edge emission band ofα-ZnS. When the crystals are aged, theα-ZnS·O solid solution decomposes and the bands assume the standard sphalerite positions. Changes in the intensity of edge and exciton emission were investigated taking into account changes in the phase state of oxygen in the crystals.     

Application of nuclear magnetic double resonance method to a study of some aluminum borohydride complexes

Conclusions Employing the nuclear magnetic double resonance method, we determined the chemical shifts and the spin-spin coupling constants of a number of aluminum borohydride complexes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1143–1144, May, 1973.The authors are indebted to S. P. Shilkin for supplying the aluminum borohydride ammoniate samples, and to V. N. Fokin for supplying the chloroboralanes.