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991.
The Galaxy Cluster Mass Scale and Its Impact on Cosmological Constraints from the Cluster Population
Pratt G. W. Arnaud M. Biviano A. Eckert D. Ettori S. Nagai D. Okabe N. Reiprich T. H. 《Space Science Reviews》2019,215(2):1-19
Space Science Reviews - The QB50 mission is a satellite constellation designed to carry out measurements at between 200–380 km altitude in the ionosphere. The multi-needle Langmuir probe... 相似文献
992.
This paper considers an air pressure probe, the head part of which is made in the form of a polyhedron inscribed into a sphere. Wind tunnel testing of the probe models is performed, a mathematical model and an algorithm are constructed to calculate all the altitude and airspeed parameters, and an error estimation is given. 相似文献
993.
Wafaa Kanaan David Farrelly Víctor Lanchares 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(8):2124-2134
A restricted 2?+?2 body problem is proposed as a possible mechanism to explain the capture of small bodies by a planet. In particular, we consider two primaries revolving in a circular mutual orbit and two small bodies of equal mass, neither of which affects the motion of the primaries. If the small bodies are temporarily captured in the Hill sphere of the smaller primary, they may get close enough to each other to exchange energy in such a way that one of them becomes permanently captured. Numerical simulations show that capture is possible for both prograde and retrograde orbits. 相似文献
994.
Cosmic Research - Using the Meteor M2 low-orbit satellite, the dynamics of the boundaries of the auroral oval on the nightside during the magnetic storm observed from May 27 to 29, 2017, was... 相似文献
995.
V. P. Okhlopkov 《Cosmic Research》2018,56(2):101-107
The quasi-biennial variations in the flux of galactic cosmic rays (GCRs) have been studied based on the data of stratospheric sensing and measurements by neutron monitors, as well as in various manifestations of solar activity and interplanetary medium parameters. It has been shown that quasi-biennial GCR variations are caused by variations with the same period in the mean magnetic field of the Sun that coincide with them over time and have been identified in the anti-phase, which respond to the sign of this field. The variations in the quasi-biennial cosmic ray are caused by quasi-biennial variations in the mean magnetic field of the Sun via the quasi-biennial variations in the interplanetary magnetic field. 相似文献
996.
Wen-jie Wang Ze-ping Wu Dong-hui Wang Wei-hua Zhang Kun Zhao Patrick N. Okolo Gareth J. Bennett 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(11):3706-3720
Hypersonic vehicles are receiving increased attention within the aerospace community due to their high cruise speed and long-range capabilities. In this paper, a modified Sequential Approximate Optimization method is proposed for an optimized aerodynamic design of a hypersonic vehicle. As part of this approach, a constrained experimental design method is developed to handle the constraints more efficiently. A radial basis function is used to surrogate time-consuming CFD analysis. An efficient and more robust numerical mesh morphing scheme for the hypersonic vehicle is developed for the generation of high-quality meshes. Within this paper, a novel adaptive infilling strategy is proposed which uses an inaccurate search technique coupled with an elite archive. This allows the location of a more promising sample region and hence improves the surrogate accuracy, thereby further enhancing the optimization efficiency. A hypersonic vehicle aerodynamic design problem is solved using the proposed approach and satisfactory results are obtained at much lower computational costs. The lift-to-drag ratio is increased by 23.8% when compared with the base configuration while also satisfying the volume and lift constraints. The pressure and Mach contours have been compared with those of the base configuration and the results demonstrate the strength of the optimized configuration. The modified sequential approximate optimization for designing an improved hypersonic vehicle is worth referencing in future work. 相似文献
997.
A. B. Agul’nik I. V. Kravchenko A. A. Gorbunov A. A. Novoselova A. P. Sklyarova 《Russian Aeronautics (Iz VUZ)》2018,61(3):441-444
This paper considers double bypass aircraft engine with controlled air bleed to the second bypass duct. Its performance is evaluated by mathematical modeling techniques. The second bypass air bleed amount is determined to provide the best engine efficiency at various operating modes. 相似文献
998.
The dynamics of a satellite-gyrostat moving in the central Newtonian force field along a circular orbit is studied. In the particular case when the vector of gyrostatic moment is parallel to one of the satellite’s principal central axes of inertia, all the equilibrium states are determined. For each equilibrium orientation, sufficient conditions of stability are obtained as a result of the analysis of the generalized energy integral, and necessary conditions of stability are determined as a result of analysis of the linearized equations of motion. The evolution of regions of validity for the conditions of stability of equilibrium positions are studied in detail depending on the parameters of the problem. All the bifurcation values of the parameters at which qualitative changes of the regions of stability take place are determined.__________Translated from Kosmicheskie Issledovaniya, Vol. 43, No. 4, 2005, pp. 283–294.Original Russian Text Copyright © 2005 by Sarychev, Mirer, Degtyarev. 相似文献
999.
Yu.A. Surkov V.L. Barsukov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(8):17-29
Physical and mechanical properties as well as chemical and mineral composition of Venus rocks are discussed on the basic of the data obtained by ground-based radar observations and the experiments in situ. 相似文献
1000.
S.J. Bauer L.M. Brace H.A. Taylor T.K. Breus A.J. Kliore W.C. Knudsen A.F. Nagy C.T. Russell N.A. Savich 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(11):233-267
Physical properties of the Venus ionosphere obtained by experiments on the US Pioneer Venus and the Soviet Venera missions are presented in the form of models suitable for inclusion in the Venus International Reference Atmosphere. The models comprise electron density (from 120 km), electron and ion temperatures, and relative ion abundance in the altitude range from 150 km to 1000 km for solar zenith angles from 0° to 180°. In addition, information on ion transport velocities, ionopause altitudes, and magnetic field characteristics of the Venus ionosphere, are presented in tabular or graphical form. Also discussed is the solar control of the physical properties of the Venus ionosphere. 相似文献