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41.
D. D. Zaitsev E. A. Gravchikova P. E. Kazin A. V. Garshev Yu. D. Tret’yakov M. Jansen 《Inorganic Materials》2006,42(3):326-330
Glasses with the nominal compositions SrFe12O19 + nNa2Sr2B4O9 (n = 4, 6, 8, 10) and SrFe12O19 + 6Na2Sr3B4O10 were prepared via rapid quenching of oxide melts and were then heat-treated between 500 and 800°C in order to produce glass-ceramics containing fine SrFe12O19 particles. The materials were characterized by x-ray diffraction, differential thermal analysis, electron microscopy, and magnetic measurements. The crystallization behavior of the glasses was investigated. The coercivity of the glass-ceramics was shown to increase with heat-treatment temperature, up to 486 kA/m. By dissolving the nonmagnetic matrix of the glass-ceramics with the nominal compositions SrFe12O19 + 6Na2Sr3B4O10 and SrFe12O19 + 4Na2Sr2B4O9, submicron-sized strontium hexaferrite particles were obtained. 相似文献
42.
D. D. Zaitsev P. E. Kazin A. V. Garshev Yu. D. Tret'yakov M. Jansen 《Inorganic Materials》2004,40(8):881-885
Glasses with nominal compositions of SrFe12O19 + 8SrB2O4 (I) and SrFe12O19 + 12Sr2B2O5 (II) are prepared by rapid quenching from the liquid state and are converted to glass-ceramics containing fine magnetic particles of SrFe12O19 by heat treatment between 600 and 950°C. The materials are characterized by x-ray diffraction, differential thermal analysis, electron microscopy, and magnetic measurements. The phase transformations accompanying glass crystallization are identified. The glass composition and heat-treatment conditions are shown to influence the aspect ratio of the forming submicron-sized strontium hexaferrite particles. The strongest coercive fields reached in glass-ceramics I and II are 504 and 456 kA/m, respectively. 相似文献
43.
The transmittance spectra of thin “pure” GaAs bulk wafers upon optical pumping corresponding to the band of the ground state of the exciton series are recorded at a temperature of T = 1.7 K. The wafers were grown by molecular-beam epitaxy and vapor-phase epitaxy. An increase in the line amplitude and width upon pumping is observed, with no noticeable changes in the spectral position of the line peak. The increase is similar to that observed upon pumping in the continuum of states, but occurs at a somewhat lower rate. Estimation of the concentration of excitons created by pumping provides a means for determining the exciton-exciton interaction constant and comparing the result with known data. The integrated absorption method makes it possible to refine the exciton polariton-free charge carrier and exciton polariton-impurity interaction constants. The differential photoabsorption of the samples at the pumping modulation frequency is measured. The resultant modulated absorption spectra demonstrate the connection between induced absorption and the formation of differential spectra. 相似文献
44.
The growth of vertically oriented carbon nanotubes on nickel clusters formed by nanoimprint lithography is studied. It is shown that the nanotubes only grow at those places where the catalyst clusters are situated and the diameter of the nanotubes exactly corresponds to the dimensions of the nickel islands. 相似文献
45.
K. A. Balygin V. I. Zaitsev A. I. Klimov K. N. Kozlov E. A. Meleshko M. D. Karetnikov S. A. Korotkov T. O. Khasaev 《Instruments and Experimental Techniques》2014,57(6):680-683
A versatile spectrometer has been developed for measuring the nuclear radiation spectrum in discrete time intervals. The design and operating principle of the spectrometer are described. Since the main logical part is based on a field programmable gate array, time intervals may be tuned in a wide range without changing the spectrometer hardware. The test experiments have demonstrated the spectrometer applicability for measuring the amplitude and timing parameters of the γ response when an analyzed sample is irradiated with a pulsed neutron flux. This device can be used to solve many problems of nondestructive testing, e.g., spectrometric neutron logging, detection of explosives, identification and characterization of fissile materials. 相似文献
46.
47.
I. A. Treninkov A. A. Alekseev D. V. Zaitsev 《The Physics of Metals and Metallography》2012,113(10):938-946
Volume fractions of the ?? phase are calculated in the form of various geometrical figures depending on the ratio of the volume fraction of the ?? and ?á? phases. The ?? phase in the form of plates prevails at a 70% content of the ?á? phase, which is the most characteristic of the VZhM4 alloy after the complete heat treatment. The qualitative analysis is carried out for the arrangement of satellites in the reciprocal space of the VZhM4 single-crystal Ni-based superalloy. The lattice of the reciprocal space with the satellites caused by the stress state of ?? phase interlayers is constructed in the form of various geometrical figures. The set of experimental sections of the 3D structure of (222), (313), and (202) reciprocal lattice sites is obtained. 相似文献
48.
49.
V. I. Zaitsev I. A. Barykov A. V. Kartashov O. V. Terent’ev N. B. Rodionov 《Technical Physics Letters》2016,42(11):1134-1136
The effect observed upon interaction between the electromagnetic radiation with quantum energy of 25–1000 eV and a dielectric with metal coating is investigated. The radiation source was a megampere Z-pinch. Measurements performed on optical glass samples showed that radiation with a power of ~106 W/cm2 in the electric circuit switching on the metalized dielectric induces the current. It is shown that the observed galvanic effect originates from the generation of hot electrons in the dielectric. 相似文献
50.
The kinetics of interfacial energy transfer have been studied with colloidal TiO2 and AgBr particles, which form transparent aqueous dispersions. The fluorescence spectra and decay for both systems have been determined and discussed. The quenching of fluorescence emission of a sensitizing dye by a supersensitizer has been observed. The super-sensitizer shortens the fluorescence lifetime of the supersensitizing system, which has been determined by nanosecond time-resolved fluo-rescence spectroscopy. It is concluded that the Dye-Dye interaction plays an important role in the photographic process. Some rigidized cyanine dyes nave also been studied. 相似文献