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441.
Zh.?V.?Dashkevich "mailto:zhanna@pgia.ru " title= "zhanna@pgia.ru " itemprop= "email " data-track= "click " data-track-action= "Email author " data-track-label= " ">Email author V.?E.?Ivanov 《Cosmic Research》2017,55(5):318-322
Using numerical modeling, the influence of the NO concentration on the intensity of 557.7 nm emission in aurora caused by electron precipitation has been studied. It has been shown that the O2 + NO reaction, which reduces the contribution of the dissociative recombination of the O2 + ion into the formation of the 1S state of atomic oxygen, is the main channel of suppression of the intensity of the emission at 557.7 nm. A method of estimating the NO concentration in the aurora based on the data of photometric measurements of emissions at 391.4, 557.7, and 630.0 nm has been proposed. The method has been tested using the data of simultaneous rocket measurements of emissions at 391.4, 557.7, and 630.0 nm and the NO content in aurora. A good agreement of estimates of the NO concentrations performed by the method to the results of direct measurements has been obtained. 相似文献
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The results of a preliminary analysis of microperturbations on the International Space Station during physical exercises of the crew are presented. The goal of this paper is to identify the parameters of perturbations when physical exercises are performed. The results of measurements by sensors of microaccelerations of both Russian and American segments during physical exercises in the service module of the Russian segment are analyzed. 相似文献
444.
The methodology is proposed and the mathematical model is developed for the purpose of numerical simulation of the power circuit of the gas-hydraulic actuator with displacing power source for the gimbaled nozzle control. It provides the highest power efficiency factor of the actuator as a part of aircraft by means of pulling together the profiles of available and required power. 相似文献
445.
Using the method of characteristics, the problem of breaking or non-breaking of waves is studied in a plane cylindrically or spherically symmetric flow of an ideal dissociating gas. It is investigated as to how the effects of dissociation and that of the wave front curvature influence the breaking or non-breaking of waves. In a symmetrical converging gas motion a remarkable difference between the behaviours of cylindrical and spherical waves is discovered. 相似文献
446.
Energetic solar proton events within the energy interval 1–48 MeV at the stage of their decay are considered over the period of 1974–2001. The dependence of the characteristic decay time on the proton energy in the assumed power-law representation τ(E) =E ?n is analyzed for the events with an exponential decay form. The dependence of n on the heliolongitude of the flare (the particles source on the Sun) is studied. 相似文献
447.
The necessary first-order conditions of strong local optimality (conditions of maximum principle) are considered for the problems of optimal control over a set of dynamic systems. To derive them a method is suggested based on the Lagrange principle of removing constraints in the problems on a conditional extremum in a functional space. An algorithm of conversion from the problem of optimal control of an aggregate of dynamic systems to a multipoint boundary value problem is suggested for a set of systems of ordinary differential equations with the complete set of conditions necessary for its solution. An example of application of the methods and algorithm proposed is considered: the solution of the problem of constructing the trajectories of a spacecraft flight at a constant altitude above a preset area (or above a preset point) of a planet's surface in a vacuum (for a planet with atmosphere beyond the atmosphere). The spacecraft is launched from a certain circular orbit of a planet's satellite. This orbit is to be determined (optimized). Then the satellite is injected to the desired trajectory segment (or desired point) of a flyby above the planet's surface at a specified altitude. After the flyby the satellite is returned to the initial circular orbit. A method is proposed of correct accounting for constraints imposed on overload (mixed restrictions of inequality type) and on the distance from the planet center: extended (nonpointlike) intermediate (phase) restrictions of the equality type. 相似文献
448.
The separation of motions into slow (precession) and fast (nutation) components in the problem of the entry of a spacecraft (SC) with a small asymmetry into the atmosphere is considered. For the separation of the slow and fast motions the method of integral manifolds is used together with the asymptotic method for singularly perturbed systems. The separation of motions allows one to isolate the frequencies that are functions of the slow variables of a system, and further on, after determining the integer relations between them, to construct the resonant curves (surfaces). This method gives the possibility to analyze the conditions of the emergence of resonances for a SC at angles of attack that are not small and when aerodynamic characteristics are nonlinear. Examples of the construction of resonant curves for a SC with typical aerodynamic characteristics are considered. 相似文献
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Satellite systems continue to play an important role in the booming market for communication and broadcasting services, driving up demand for use of the orbit/spectrum resource. Studies are required to address the problem of orbit capacity and find ways of making more efficient use of it, to avoid a situation in which there is not enough orbit/spectrum resource to cater for the development of future satellite networks. It is argued that, as far as satellite networks are concerned, the current international regulatory regime governing the use of the spectrum has significant shortcomings, which have a cost, in terms of resources and time, and make investment in satellite projects less attractive. An approach is proposed for improving efficiency of the use of the orbit/spectrum through the introduction of economic methods, to supplement the existing technical and regulatory regime. A spectrum pricing method is proposed for satellite communication systems. 相似文献