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991.
Problems of Information Transmission - A new problem of transmitting information over the adversarial insertion-deletion channel with feedback is introduced. Assume that the encoder transmits $$n$$...  相似文献   
992.
The field and temperature dependence of the transverse magnetoresistivity and the Hall coefficient for single-crystal tungsten with a resistivity ratio 293K/4.2K varying from 780 to 80800 are measured at temperatures between 4.2 K and 50 K in magnetic fields up to 150 kOe. The role of the static skin effect and the temperature breakdown in the galvanomagnetic properties of the compensated metals is evaluated through experiments with tungsten. The experimental data shows that the galvanomagnetic properties of the compensated metals in the high magnetic fields are not dependent only on the Fermi surface geometry. A substantial role in their formation is played by the processes of the electron-surface and the intersheet electron-phonon scatterings.  相似文献   
993.
Direct data have been obtained for the creep of high- and medium-strength aluminum alloys in the stress range of O.6–1.2 of the nominal yield strength 0.2 in laboratory air and in aqueous NaCl solution at room temperature. On this basis using known theories approximating functions have been determined for the creep curves. Stress 0.2 serves as a natural boundary for the macroelastic and macroplastic regions in the first of which creep is only transient, and in the second there are transient, quasisteady-state, and accelerated stages. Extrapolated estimates of creep strain in the macroelastic region from data measured in the macroplastic region are not physically competent. However, a tendency towards an increase in ductility with an increase in time to failure at stresses greater than o.2 makes it possible to estimate by extrapolation the time for onset of the accelerated creep stage with low test stresses from measured values at greater stresses in the macroplastic region. Fractographic and strain indices revealed the harmful effect of moist atmospheres on the deformation and failure resistance of alloys with prolonged loading.Translated from Problemy Prochnosti, No. 1, pp. 50–58, January, 1990.  相似文献   
994.
The article presents results of a study of the strengthening of threaded connections M6 and M8 of alloys ÉI698, VT16, and VTZ-1 by thermovibration treatment to raise their creep resistance. Treatment regimes and empirical formulas for determining the index of strengthening (for the ÉI698 alloy) are discussed. Data on long-term strength of threaded connections in initial and post-treatment states, and on the effect of aging on retention of the strengthening effect, are presented along with some mechanical and fatigue characteristics.Translated from Problemy Prochnosti, No. 9, pp. 98–103, September, 1990.  相似文献   
995.
The article presents the results of the investigation of the mechanical properties and microinhomogeneity of deformation of steel in dependence on its structure. A dependence of the characteristics of ductility and of impact toughness on the level of the microinhomogeneity of deformation is established. The change of ultimate (tensile) strength u corresponds to the change of microhardness which serves as indirect characteristic of the strength properties of microvolumes. It is shown that impact toughness is a characteristic sensitive to the manifestation of microinhomogeneity of deformation, and that it changes in dependence on its level more than the static characteristics. The obtained results make it possible to choose the optimal structure of the metal.Translated from Problemy Prochnosti, No. 1, pp. 120–122, January, 1990.  相似文献   
996.
1.  The algorithm for the integration of the reactor kinetics equations, based on Gear's numerical methods, provides an efficient means of calculating critical-assembly accidents, in which the assembly rapidly goes into prompt-neutron supercriticality and then slowly cools down.
2.  The maximum temperature in the assembly zones, and the energy released during the burst, are not appreciably affected by the positive reactivity insertion rate.
3.  Accident damage is significantly reduced (the assembly remains operational) only in cases of rapid scram-rod dumping (0.3 sec delay), provided the temperature coefficient of reactivity equals or exceeds the rated value.
Translated from Atomnaya énergiya, Vol. 69, No. 1, pp. 47–49, July, 1990.  相似文献   
997.
Translated from Poroshkovaya Metallurgiya, No. 8(332), pp. 6–9, August, 1990.  相似文献   
998.
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 32–35, February, 1990.  相似文献   
999.
1000.
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, pp. 17–20, May, 1990.  相似文献   
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