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91.
We consider the stability of stationary motions of a model of a spacecraft as a system of coaxial bodies with small asymmetry caused by the shift of the axes of dynamic symmetry of bodies relative to the axis of rotation. We determine the stationary motions of the system; their stability is studied with respect to both the projections of angular velocity and the position of the axis of rotation. The sufficient conditions for the stability of these stationary motions are obtained by constructing a Lyapunov function, and the necessary conditions are obtained by analyzing the corresponding linearized equations of perturbed motion. 相似文献
92.
This paper presents the results of analyzing the shaping of thin-walled conical parts with the uniform thickness along generatrix. 相似文献
93.
V. G. Dmitriev V. I. Biryukov O. V. Egorova S. I. Zhavoronok L. N. Rabinskii 《Russian Aeronautics (Iz VUZ)》2017,60(2):169-176
The discretization of the boundary value problem for laminated composite shells is based on the finite difference approach using the regular mesh with the constant grid step and the difference operators of the second order of accuracy. The dynamic relaxation method is proposed for the solution of the nonlinear problem. The evolutionary equations of the dynamic relaxation are constructed, and the optimum parameters of the converging linear iterative process are estimated. 相似文献
94.
Systems for the indication and display of secondary information in avionics and autobasing complexes
A. A. Bagdasarov R. V. Anitropov O. V. Bagdasarova I. L. Livshits 《Russian Aeronautics (Iz VUZ)》2011,54(2):185-191
We consider the peculiarities of application for the cabin indicating systems of secondary information display, formulate
and systematize the compositional and technical requirements for display systems and their elements. The tendencies and lines
in the development of head-up displays for avionics and autobasing complexes were determined. The technique of calculating
optics of such display systems with the use of electronic distortion compensation is presented. 相似文献
95.
Concept of monitoring for thermostressed state and service life of aircraft gas turbine engine blades 总被引:1,自引:0,他引:1
G. G. Kulikov V. A. Trushin A. I. Abdulnagimov A. A. Ganeev 《Russian Aeronautics (Iz VUZ)》2016,59(1):77-83
A concept of monitoring for material properties with residual life estimation of rotor blades for gas turbine engines is proposed. The structure of on-board control and conditionmonitoring system based on the intelligent pyrometer module with the algorithm for calculating the residual life of turbine rotor blades is described. 相似文献
96.
R.?A.?KayumovEmail author I.?Z.?Mukhamedova E.?B.?Tuisina 《Russian Aeronautics (Iz VUZ)》2016,59(4):452-459
This paper considers a beam with a technological longitudinal section on the level of the gravity center of the cross section that is loaded by a vertical concentrated force. We study the structure durability depending on the load amplitude and the initial crack length. 相似文献
97.
Ueno K. Itanami T. Kumazawa H. Ohtomo I. 《IEEE transactions on aerospace and electronic systems》1995,31(2):600-607
Feasibility studies on a multiband communication satellite antenna system and the key technologies involved in devising this system are described. The proposed multiband communication satellite utilizes four frequency bands: Ka (30/20 GHz), Ku (14/12 GHz), C (6/4 GHz), and S (2.6/2.5 GHz). It has six beam configurations, three multibeam and three shaped-beam. The following key technologies are presented: (1) a low-loss frequency selective subreflector (FSR) for compact feeds, (2) a low-loss and broadband frequency selective surface (FSS), and (3) a highly accurate and reliable mesh reflector 相似文献
98.
Lazarus A. J. Belcher J. W. Paularena K. I. Richardson J. D. 《Space Science Reviews》1998,83(1-2):87-92
We discuss the solar wind parameters measured in the distant heliosphere from the Voyager 2 spacecraft. Periodic variations in the speed of the wind observed at roughly the solar rotation period may correspond to interaction regions between slower and faster streams of wind. Since the interplanetary magnetic field is enhanced in such regions, they are important for the study of modulation of cosmic rays. Unfortunately, direct observation of the enhanced magnetic field from Voyager 2 has been made difficult by spacecraft-associated noise since 1989. 相似文献
99.
G. Schubert C. C. Counselman III J. Hansen S. S. Limaye G. Pettengill A. Seiff I. I. Shapiro V. E. Suomi F. Taylor L. Travis R. Woo R. E. Young 《Space Science Reviews》1977,20(4):357-387
With the possible exception of the lowest one or two scale heights, the dominant mode of circulation of Venus' atmosphere is a rapid, zonal, retrograde motion. Global albedo variations in the ultraviolet may reflect planetary scale waves propagating relative to the zonal winds. Other special phenomena such as cellular convection in the subsolar region and internal gravity waves generated in the interaction of the zonal circulation with the subsolar disturbance may also be revealed in ultraviolet imagery of the atmosphere. We discuss the contributions of experiments on the Orbiter and Entry Probes of Pioneer Venus toward unravelling the mystery of the planet's global circulation and the role played by waves, instabilities and convection therein. 相似文献
100.
A. G. Yahnin I. V. Despirak A. A. Lubchich B. V. Kozelov N. P. Dmitrieva M. A. Shukhtina H. K Biernat 《Space Science Reviews》2006,122(1-4):97-106
Although the auroral substorm has been long regarded as a manifestation of the magnetospheric substorm, a direct relation
of active auroras to certain magnetospheric processes is still debatable. To investigate the relationship, we combine the
data of the UV imager onboard the Polar satellite with plasma and magnetic field measurements by the Geotail spacecraft. The
poleward edge of the auroral bulge, as determined from the images obtained at the LHBL passband, is found to be conjugated
with the region where the oppositely directed fast plasma flows observed in the near-Earth plasma sheet during substorms are
generated. We conclude that the auroras forming the bulge are due to the near-Earth reconnection process. This implies that
the magnetic flux through the auroral bulge is equal to the flux dissipated in the magnetotail during the substorm. Comparison
of the magnetic flux through the auroral bulge with the magnetic flux accumulated in the tail lobe during the growth phase
shows that these parameters have the comparable values. This is a clear evidence of the loading–unloading scheme of substorm
development. It is shown that the area of the auroral bulge developing during substorm is proportional to the total (magnetic
plus plasma) pressure decrease in the magnetotail. These findings stress the importance of auroral bulge observations for
monitoring of substorm intensity in terms of the magnetic flux and energy dissipation. 相似文献