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51.
The processes of heating a body in a high-enthalpy spatial flow with allowance for body rotation around its longitudinal axis and ablation of the thermal protection material are studied by means of mathematical simulation. The obtained solution of the problem in conjugate formulation allowed us to take into account the effect of nonisothermic characteristics of the shell on the heat and mass transfer in the boundary layer. 相似文献
52.
S. A. Novokreshchenov V. S. Shvydkii V. P. Zhukov Yu. N. Ovchinnikov D. D. Cheremisin 《Russian Journal of Non-Ferrous Metals》2013,54(6):489-492
The formation and motion of gas bubbles in the melt substantially affect the heat exchange and kinetics of chemical transformations when performing the fire refining of copper in the ladle furnace. The variation in the bubble velocity, as well as of the volume and surface of the moving gas bubble over the melt height, is considered in the presented mathematical model. 相似文献
53.
M. S. Smirnov O. V. Ovchinnikov A. N. Latyshev A. M. Smirnova P. V. Novikov M. A. Efimova 《Semiconductors》2009,43(7):852-857
In the AgCl microcrystals with adsorbed methylene blue dye molecules, sensitized anti-Stokes luminescence centers formed as a result of a photostimulated low-temperature (77 K) process are observed. The emission is recorded on excitation of the samples by radiation with the flux density 1014?1015 photon cm?2 s?1 in the spectral range 620–750 nm corresponding to optical absorption in the adsorbed dye molecules and adsorbed Ag1, Ag2, and Ag3 clusters. It is shown that the anti-Stokes luminescence centers formed by photo-stimulation present (adsorbed dye molecule)—(silver subnanocluster) hybrid nanostructures, in which the bonding between the components is weak but sufficient to provide the possibility for two-photon interband transitions that occur due to transfer of the electron’s excitation energy from the dye molecule to the silver cluster with subsequent photoionization of the cluster. 相似文献
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55.
V. I. Lukin E. N. Ioda E. A. Tkachenko L. V. Kotel'nikova A. V. Bazeskin V. V. Ovchinnikov 《Welding International》2013,27(7):535-538
The special features of electron beam welding of pressed strips of the V-1963-strength aluminium alloy of the Al–Zn–Mg–Cu system with a thickness of 40 mm are investigated. The results of tests of the welded joints in static tensile loading, bending, and impact toughness of the weld metal are presented. It is shown that the strength of the welded joints equals 0.7–0.8 of the strength of the parent material. The results of investigations of the macro- and microstructure of the welded joints are generalized and it is shown that the welded joints are characterized by the formation of an equiaxed fine-grained structure with the grain size of 5–10 μm. 相似文献
56.
B. M. Lapshin A. L. Ovchinnikov A. S. Chekalin 《Russian Journal of Nondestructive Testing》2011,47(10):710-717
An algorithm for filtering acoustic-emission signals and a technique for measuring the velocity of sound during searches for
leaks in pipelines of heat networks are considered. The results of experimental studies are presented. 相似文献
57.
58.
LP Ormerod A Charlett C Gilham JH Darbyshire JM Watson 《Canadian Metallurgical Quarterly》1998,53(3):176-181
Refractory hypotension with end-organ hypoperfusion is an ominous feature of inflammatory shock. In the past fifteen years, nitric oxide (a diffusible, short-lived product of arginine metabolism) has been found to be an important regulatory molecule in several areas of metabolism, including vascular tone control. Vascular endothelial cells constitutively produce low levels of nitric oxide that regulate blood pressure by mediating adjacent smooth-muscle relaxation. In an inflammatory shock state, cytokines, like interleukin-1 and tumor necrosis factor-alpha, induce a separate, high-output form of the enzyme that synthesizes nitric oxide in both endothelial and smooth-muscle cells. The ensuing high rates of nitric oxide formation result in extensive smooth-muscle relaxation, pressor refractory vasodilation, and--ultimately--shock. The concept of the pathogenesis of inflammatory shock explains many limitations of current therapies and may foster the development of new interventions to mitigate the effects of nitric oxide overproduction in this syndrome. 相似文献
59.
LP Nielsen T Bjerke MB Christensen M Skamling CG Peterson N Mygind R Dahl 《Canadian Metallurgical Quarterly》1998,53(8):778-785
BACKGROUND: The purpose was to study activation markers of the eosinophil granulocytes in seasonal allergic rhinitis, and the impact of topical steroid therapy thereupon. METHODS: Sixty-three rhinitis patients with monoallergy to grass were examined before and at peak pollen season. Blood eosinophil count, eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO) in serum and nasal lavage fluid were measured. During the season, patients were randomized to treatment with intranasal fluticasone propionate 0.1 mg o.d. (n=26), 0.2 mg o.d. (n=25), or placebo (n=12). Six healthy persons served as controls. RESULTS: During the season, all parameters, except nasal lavage ECP, increased in the placebo group (P<0.001-P<0.05). Significant differences were seen between the steroid groups and the placebo group for all parameters (P<0.001-P<0.05). Higher eosinophil count (P<0.05), serum EPO (P<0.02), and nasal lavage EPO (P<0.05) were found in patients before season than in controls. The following winter, 44 patients returned for repeated measurement. Lower levels of nasal lavage EPO were observed for patients than levels at the beginning of the season (P<0.0001). CONCLUSIONS: Intranasal fluticasone propionate reduced inflammation of the nasal mucosa, demonstrated locally by nasal lavage ECP and EPO, and systemically by blood eosinophils, serum ECP, and serum EPO. EPO seemed more sensitive than ECP as indicator of allergic inflammation. EPO demonstrated some perennial eosinophil activity in hay fever patients, increasing locally during spring. 相似文献
60.