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排序方式: 共有1613条查询结果,搜索用时 15 毫秒
61.
K. A. Ten O. V. Evdokov I. L. Zhogin V. V. Zhulanov P. I. Zubkov G. N. Kulipanov L. A. Luk’yanchikov L. A. Merzhievskii B. Ya. Pirogov É. R. Pruuél V. M. Titov B. P. Tolochko M. A. Sheromov 《Combustion, Explosion, and Shock Waves》2007,43(2):204-211
A synchrotron radiation based technique is use to study the density distribution at the detonation front and its neighborhood
for condensed explosives. Particular data are obtained on the structure of the detonation front in TNT, RDX, and an alloy
of TNT with RDX; a comparison of the data with those obtained using different techniques confirms the correctness of the technique.
It is concluded that adequate information on the structure of the chemical-reaction zone can be obtained for charges of small
diameter. At the same time, it is shown that the Chapman-Jouguet parameters for such charges are far from their predicted
values for an infinite medium. The results of the work, including those on the curvature of the detonation front in charges
of small diameter, supplement the existing knowledge of the detonation transformation in condensed explosives.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 2, pp. 91–99, March–April, 2007. 相似文献
62.
63.
I.N. Andryushina L.A. Reznichenko V.A. Alyoshin L.A. Shilkina S.V. Titov V.V. Titov K.P. Andryushin S.I. Dudkina 《Ceramics International》2013,39(1):753-761
This work is concerned with the specific features of sintering of solid solutions of the PZT system (PbZr1?xTixO3, 0.0≤x≤1.0) depending on composition. The microstructure of the solid-solution ceramics has been found to be a fairly homogeneous, mosaic, sufficiently close packing of isometric crystallites with a range of section from 3 to 11 μm, but there exists a number of special features related to the component and phase composition of the objects. It has been found that the changes in multifractal parameters of grain structure of these ceramics reflect with high sensitivity the processes of phase transformations in the solid solutions. The obtained results are useful in developing piezoelectric materials based on the PZT system. 相似文献
64.
A. A. Titov 《Measurement Techniques》2011,54(7):790-793
A heterodyne instrument for the measurement of the vibration of wires is considered. A measurement circuit is presented and
its precision estimated. 相似文献
65.
66.
A. B. Arbuzov V. A. Drozdov M. V. Trenikhin A. T. Titov A. I. Nizovskii V. A. Likholobov 《Inorganic Materials》2009,45(12):1346-1350
The oxide layers on the surface of aluminum metal and the aluminum alloys AD-1 and A-5 have been studied by attenuated total reflection infrared spectroscopy. The Al-O and Al-OH surface vibrational modes and A-O modes of the AlO4 and AlO6 groups have been identified. The structural inhomogeneity of the surface oxide layers is shown to contribute to their disruption when the sample is brought into contact with the liquid In-Ga eutectic. In situ scanning electron microscopy and X-ray microanalysis have been used to follow the dynamics of oxide layer disruption and the morphological and compositional changes in the eutectic alloy and the surface layer of aluminum. 相似文献
67.
A. V. Kolomeychenko N. V. Titov V. V. Vinogradov A. M. Stolin P. M. Bazhin 《Welding International》2017,31(9):739-742
The results of investigation of the microstructure of composite coatings produced by carbo-vibroarc surfacing using cermet pastes are presented. It is shown that the composite cermet coating consists of two zones – the main and transition. The main zone of the coating contains the Fe2B hardening phase with nickel and chromium atoms implanted in the crystal lattice of the phase. The zone is situated in the matrix of the solid solution of iron and nickel Ni3Fe. The transition zone of the coating is formed by the mutual diffusion of the coating and the substrate and consists of the (Fe, Ni)2B hardening phase and the Ni3Fe matrix. It is also shown that the hardening phases form plate-shaped grains with thicknesses of 1–4 μm and more than 100 μm long, distributed in the form of colonies throughout the entire volume of the coating zone. In the direction to the transition zone, the shape of the structural components changes to circular with the diameter of up to 5 μm. 相似文献
68.
J. Fachinger M. den Exter B. Grambow S. Holgersson C. Landesman M. Titov T. Podruhzina 《Nuclear Engineering and Design》2006,236(5-6):543-2004
One back-end option for spent HTR fuel elements proposed for future HTR fuel cycles in the EC is an open fuel cycle with direct disposal of conditioned or non-conditioned fuel elements. This option has already been chosen in Germany due to the political decision to terminate the use of HTR technology. First integral leaching investigations at Research Centre Juelich on the behaviour of spent HTR fuel in salt brines, typical of accident scenarios in a repository in salt, proved that the main part of the radionuclide inventory cannot be mobilised as long as the coated particles do not fail. However, such experiments will not lead to a useful model for performance assessment calculations, because a failure of the coatings by corrosion will not occur during experimental times of a few years. In order to get a robust and realistic model for the long-term behaviour in aqueous phases of host rock systems, it is necessary to understand the barrier function of the different parts of an HTR fuel element, i.e. the matrix graphite, the different coating materials, and the fuel kernel.Therefore, our attention is focused on understanding and modelling the barrier performance of the different parts of an HTR fuel element with respect to their barrier function, and on the development of an overall model for performance assessment. In order to understand this behaviour, it is necessary to start with investigations of unirradiated material, and to proceed with experiments with external gamma irradiation to determine the effects of oxidising radiolysis species. Further experiments with irradiated material have to be performed to investigate the influence of the irradiation damage, and finally an investigation has to be made of the irradiated material plus additional gamma irradiation. Experimental data are now available for the diffusive transport of radionuclides in the water-saturated graphite pore system, the corrosion rates of unirradiated graphite with and without external gamma irradiation and unirradiated and irradiated silicon carbide, and for the dissolution rates of UO2 and (Th,U)O2 fuel kernels with and without external gamma irradiation. All investigations were performed in aquatic phases from salt, granite, and clay host rock. 相似文献
69.
A modern fringe-pattern-analyzing interferometer with a resolution of 1 x 10(-9) and without exclusion of systematic uncertainties owing to optic effects of less than 1 nm was used to test a new method of interferometric length measurement based on a combination of the reproducible wringing and slave-block techniques. Measurements without excessive wringing film error are demonstrated for blocks with nominal lengths of 2-6 mm and with high surface flatness. The uncertainty achieved for these blocks is less than 1 nm. Deformations of steel gauge blocks and reference platens, caused by wringing forces, are investigated, and the necessary conditions for reproducible wringing are outlined. A subnanometer uncertainty level in phase-change-correction measurements has been achieved for gauge blocks as long as 100 mm. Limitations on the accuracy standard method of interferometric length measurements and shortcomings of the present definition of the length of the material artifact are emphasized. 相似文献
70.
Larionov PM Malov AN Maslov NA Orishich AM Titov AT Shchukin VS 《Applied optics》2000,39(22):4031-4036
Laser-induced fluorescence (LIF) spectra of calcified human heart-valve tissue and LIF spectra of macroscopic calcinosis fragments dissected from human heart valves were compared with LIF spectra of pig myocardium tissues. Excitation was provided by an excimer laser with wavelength lambda = 248 nm. Fluorescence bands that were due to mineral and organic tissue components were identified by measurement of LIF spectra of macroscopic fragments of calcified tissues that had been heat treated at 700 degrees C. The studies showed that LIF spectra of calcified tissues include fluorescence emission from tryptophan, collagen, elastin, and a mineral component of tissue, hydroxylapatite. The observed differences in LIF spectra of normal and calcified tissues with different pathologies may result not only from calcification-induced changes in relative collagen and elastin concentrations but also from additional (absent in normal heart tissue) fluorescence of hydroxylapatite. The calcification-induced changes in the LIF spectra of human heart-valve tissues, characterized by a 330/450 nm ratio, were found to be quite appreciable, which suggests that this ratio can be used with LIF measurements to evaluate the degree of heart-tissue calcification. 相似文献