排序方式: 共有87条查询结果,搜索用时 15 毫秒
1.
A. I. Khil’ko A. G. Luchinin V. G. Burdukovskaya I. P. Smirnov 《Acoustical Physics》2007,53(3):381-392
Potentialities of observing spatially localized inhomogeneities by the low-frequency low-mode pulsed diffraction tomography in a shallow sea are analyzed. A numerically simulated model is used to study the procedure of reconstructing the parameters of inhomogeneities by coprocessing the signals of the tomographic projections formed at the multistatic excitation and reception of low-frequency low-mode acoustic pulses. 相似文献
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We have developed an algorithm for reconstructing the geoacoustic parameters of bottom layers using parametric models of the formation of signals reflected from a layered halfspace during coherent sounding of the bottom of a sea shelf. We propose a method for layer-by-layer reconstruction that makes it possible to efficiently search for a solution in the multiparameter space with limited a priori data. 相似文献
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Boris A. Trofimov Ludmila A. Oparina Lidiya N. Parshina Marina Ya. Khil’ko Anatolii P. Tantsyrev Galina P. Aleksandrova 《Cellulose (London, England)》2013,20(3):1201-1214
Diverse celluloses including non-mercerized and mercerized ones have been successfully vinylated with acetylene in the superbase catalytic systems MOH/DMSO and MOH/THF (M = Na, K) at 85–140 °C. Depending on the reaction conditions, degree of substitution of the hydroxyl groups by highly reactive polymerazable vinyloxy groups ranges 0.11–1.22, the yields of vinylated celluloses (insoluble in water, but soluble in DMSO) being 41–89 %. Vinylated celluloses are easily decomposed under the action of white rot fungi: Phanerochaete chrysosporium, Trametes versicolor and Trametes hirsutus, and can constitute a basis for the preparation of biodegradable polymer materials (due to polymerization or polyaddition at the vinyloxy group). 相似文献
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Kholupenko E. E. Krassilchtchikov A. M. Badmaev D. V. Bogdanov A. A. Tuboltsev Yu. V. Chichagov Yu. V. Antonov A. S. Kuleshov D. O. Khil’kevich E. M. 《Technical Physics》2020,65(6):886-895
Technical Physics - Source and noise signals in a new camera of the TAIGA-IACT Cherenkov γ-ray telescope based on silicon photomultipliers (SiPM) have been simulated. It is shown that... 相似文献
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M. Shamshi HassanYoung-Sic Kang Byoung-Suhk KimIck-Soo Kim Hak-Yong KimMyung-Seob Khil 《Superlattices and Microstructures》2011,50(2):139-144
Well-defined and uniform Pr6O11 nanofibers were synthesized by electrospinning of an aqueous sol-gel consisting of praseodymium nitrate hexa-hydrate and polyvinyl acetate. The synthesized Pr6O11 nanofibers mat was dried at 80 °C for 24 h under vacuum and finally annealed at 600 °C for 2 h in static air furnace. From crystalline properties, the synthesized Pr6O11 nanofibers XRD analysis revealed the typical cubic structure. The morphological observation showed that the synthesized Pr6O11 nanofibers composed of fibers length in several 100 nm and diameter of ∼20 nm. Similarly, transmission electron microscope (TEM) measurement revealed the good crystalline nature of the synthesized Pr6O11 nanofibers with the average diameter of ∼20 nm. Photoluminescence (PL) demonstrated a strong green-blue emission peak at 521 nm, suggesting that the Pr6O11 nanofiber exhibited good crystal quality with very less structural defects. 相似文献
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I. P. Smirnov J. V. Caruthers A. I. Khil’ko 《Radiophysics and Quantum Electronics》1999,42(10):864-872
We found conditions for the existence of weakly divergent bundles (WDB) of rays of different types in waveguides with a power-law
dependence of the square of the refractive index.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika Vol. 42, No. 10, pp. 982–991, October, 1999. 相似文献
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We formulate and solve certain problems of the optimal amplitude-phase tuning of antenna complexes that emit and receive acoustic
signals in inhomogeneous ocean-type waveguides. 相似文献
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P. K. Gaikovich A. I. Khil’ko K. P. Gaikovich 《Radiophysics and Quantum Electronics》2011,54(6):390-401
In this work, we propose a method of near-field acoustical multi-frequency coherent tomography of spatially localized inhomogeneities
of the shallow-sea bottom. In the framework of the developed method, two-dimensional spatial scanning of the radiating-receiving
system along the bottom over the region of location of the inhomogeneities is performed at multiple frequencies. Using the
Born approximation, the initial three-dimensional integral equation for the scattered field is reduced to one-dimensional
Fredholm equation of the first kind with respect to the depth profile of the transverse spatial spectrum of the inhomogeneities.
In the solution of this integral equation for each pair of spectral components, we use the method of generalized residual
and obtain the sought three-dimensinal distribution via the inverse Fourier transform of the reconstructed spectrum. Results
of numerical simulation of the tomography scheme and visualized inhomogeneities of shallow-sea bottom are presented. 相似文献
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Kyu-Oh Kim Yun-A Seo Byoung-Suhk Kim Kee-Jong Yoon Myung-Seob Khil Hak-Yong Kim Ick-Soo Kim 《Colloid and polymer science》2011,289(8):863-870
We report solution properties of the blend solutions of poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG)–POSS telechelic
and its corresponding hybrid nanofibers prepared by electrospinning. The morphologies, microstructures, and wettability of
the resulting PVA/PEG3.4k–POSS hybrid nanofibers are studied. The morphologies of the resultant PVA/PEG3.4k–POSS nanofibers
are regular with the fiber diameter ranging from 610 ± 110 to 810 ± 280 nm. When the content of PEG3.4k–POSS telechelic increases
above 20 wt.%, the beaded fiber morphologies are observed due to severe aggregations of the PEG3.4k–POSS telechelics as well
as increased viscosity at higher concentration. In addition, the solution properties of pure PEG3.4k–POSS telechelic solution
(ca. 3–5 wt.%) and PVA/PEG3.4k–POSS solutions blended with PVA are explored, and found to show the reversible turbid-to-transparent
transition behavior with respect to the solution temperature. Water contact angle measurement of the PVA/PEG3.4k–POSS nanofiber
membranes demonstrates an enhanced hydrophobic nature due to the incorporated POSS moieties. 相似文献