排序方式: 共有26条查询结果,搜索用时 28 毫秒
1.
A. Greco G. Zimbardo P. Veltri A.L. Taktakishvili L.M. Zelenyi 《Astrophysics and Space Science》2001,277(1-2):35-38
We study the ion dynamics in a magnetic field reversal with a constant electric field and with a model of three dimensional
magnetic turbulence. By computing the mean square displacements in the plane of the current sheet we find superdiffusive and
superballistic transport regimes. Since velocity increases with the length of the free path, we have accelerated Lévyflights.
The possibility to generate power law velocity distribution functions is pointed out, as well as the long memory effects and
non local properties of ion transport.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
S. Savin A. Skalsky L. Zelenyi L. Avanov N. Borodkova S. Klimov V. Lutsenko E. Panov S. Romanov V. Smirnov YU. Yermolaev P. Song E. Amata G. Consolini T. A. Fritz J. Buechner B. Nikutowski J. Blecki C. Farrugia N. Maynard J. Pickett J. A. Sauvaud J. L. Rauch J. G. Trotignon Y. Khotyaintsev K. Stasiewicz 《Surveys in Geophysics》2005,26(1-3):95-133
We present both statistical and case studies of magnetosheath interaction with the high-latitude magnetopause on the basis of Interball-1 and other ISTP spacecraft data. We discuss those data along with recently published results on the topology of cusp-magnetosheath transition and the roles of nonlinear disturbances in mass and energy transfer across the high-latitude magnetopause. For sunward dipole tilts, a cusp throat is magnetically open for direct interaction with the incident flow that results in the creation of a turbulent boundary layer (TBL) over an indented magnetopause and downstream of the cusp. For antisunward tilts, the cusp throat is closed by a smooth magnetopause; demagnetized ‘plasma balls’ (with scale ∼ few RE, an occurrence rate of ∼25% and trapped energetic particles) present a major magnetosheath plasma channel just inside the cusp. The flow interacts with the ‘plasma balls’ via reflected waves, which trigger a chaotization of up to 40% of the upstream kinetic energy. These waves propagate upstream of the TBL and initiate amplification of the existing magnetosheath waves and their cascade-like decays during downstream passage throughout the TBL. The most striking feature of the nonlinear interaction is the appearance of magnetosonic jets, accelerated up to an Alfvenic Mach number of 3. The characteristic impulsive local momentum loss is followed by decelerated Alfvenic flows and modulated by the TBL waves; momentum balance is conserved only on time scales of the Alfvenic flows (1/fA
∼12 min). Wave trains at fA∼1.3 mHz are capable of synchronizing interactions throughout the outer and inner boundary layers. The sonic/Alfvenic flows, bounded by current sheets, control the TBL spectral shape and result in non-Gaussian statistical characteristics of the disturbances, indicating the fluctuation intermittency. We suggest that the multi-scale TBL processes play at least a comparable role to that of macro-reconnection (remote from or in the cusp) in solar wind energy transformation and population of the magnetosphere by the magnetosheath plasma. Secondary micro-reconnection constitutes a necessary chain at the small-scale (∼ion gyroradius) edge of the TBL cascades. The thick TBL transforms the flow energy, including deceleration and heating of the flow in the open throat, ‘plasma ball’ and the region downstream of the cusp. 相似文献
3.
4.
This article provides an overview of the scientific objectives of the project Phobos-Grunt. The set of scientific instruments installed on board the spacecraft is discussed and the main problems to be resolved using these devices. 相似文献
5.
The article gives a brief review of the scientific program of the unmanned studies of the Moon performed in the USSR in 1960s–1970s,
most notably by the “Luna” Spacecraft. The main results obtained during this period are considered, in particular photographing
of the far side of the Moon, mapping of the far side of the Moon, soft landing, remote (from the orbit of an artificial lunar
satellite) and in situ (on the surface) studies of the lunar surface composition and circumlunar space, automated soil sampling,
and delivery of surface samples to the Earth. Various institutes of the Russian Academy of Sciences played important role
in the studies, including the Vernadskii Institute of Geochemistry and Analytical Chemistry and the Space Research Institute,
established in 1965, where the Moon and Planets Department was established under the leadership of K.P. Florenskii. In the
conclusion, the article considers some further issues of lunar studies and possibilities for lunar exploration. The challenging
Moon exploration mission “Luna-Glob”, currently under development in Russia, is a potentially important step in the beginning
of the process. 相似文献
6.
E. E. Grigorenko S. D. Shuvalov H. V. Malova V. Yu. Popov V. N. Ermakov E. Dubinin L. M. Zelenyi 《Solar System Research》2017,51(5):347-361
During the last 15 years, the Current Sheets (CSs) have been intensively studied in the tail of the terrestrial magnetosphere, where protons are the dominated ion component. On the contrary, in the Martian magnetotail heavy ions (O+ and+ 0) usually dominate while the abundance of protons can be negligible. Hence it is interesting to study the spatial structure and plasma characteristics of such “oxygen” CSs. MAVEN spacecraft (s/c) currently operating on the Martian orbit with a unique set of scientific instruments allows observation of the magnetic field and three-dimensional distribution functions of various ion components and electrons with a high time resolution. In this paper, we analyse nine intervals of the CSs observed by MAVEN in the near-Mars tail at the distances from the planet ~1.5–1R M , where R M is the radius of Mars. We analyse the spatial structure of the CSs and estimate their thickness for different magnetic configurations and relative abundance of the heavy and light ions in the sheets. It is shown that, similarly to the CSs in the Earth’s magnetotail, the thickness and complexity of the spatial structure of the Maritan CSs (i.e. the presence of embedded and / or peripheral current structures) depend on the magnetic configuration of the sheets, which, in turn, affects the fraction of the quasi-adiabatic particles in the CSs. 相似文献
7.
M.?A.?IvanovEmail author L.?V.?Zasova M.?V.?Gerasimov O.?I.?Korablev M.?Ya.?Marov L.?M.?Zelenyi N.?I.?Ignat’ev A.?G.?Tuchin 《Solar System Research》2017,51(1):1-19
We discuss a change in the resurfacing regimes of Venus and probable ways of forming the terrain types that make up the surface of the planet. The interpretation of the nature of the terrain types and their morphologic features allows us to characterize their scientific priority and the risk of landing on their surface to be estimated. From the scientific point of view, two terrain types are of special interest and represent easily achievable targets: the lower unit of regional plains and the smooth plains associated with impact craters. Regional plains are probably a melting from the upper fertile mantle. The material of smooth plains of impact origin is a well-mixed and representative sample of the Venusian crust. The lower unit of regional plains is the most widespread one on the surface of Venus, and it occurs within the boundaries of all of the precalculated approach trajectories of the lander. Smooth plains of impact origin are crossed by the approach trajectories precalculated for 2018 and 2026. 相似文献
8.
Structural properties of the interplanetary magnetic field (IMF) are discussed. Our main interest is concentrated on the dynamical
structuring mechanisms associated with the dominant role of the wave processes in the solar wind. We argue that the IMF possibly
reveals the self-organized clustering driven by the low-frequency magnetosonic waves. It is shown that the self-organized
geometry of the IMF is a fractal, a specific object having a number of unusual topological features; this fractal geometry
is self-consistently generated by the allowed magnetosonic modes. To give an accurate treatment of waves on fractals, we propose
an unconventional approach based on the wave equation with the generalized, fractional time derivative. The allowed magnetosonic
modes are then defined as the generalized "resonance" solutions to the fractional wave equation and termed "fractons", vibrational
excitations of fractal objects. We found that the self-organized fractal geometry of the IMF as maintained by the fractons
could be described by the value of the Hausdorff fractal dimension D≈ 4/3. Convection of the IMF fractal structures by a spacecraft observer is shown to result in the power-law behavior of the
Fourier energy density spectrum of the in situobserved IMF turbulence, P(f) ∝ f
−α, with the characteristic slope α ≈ 5/3.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
V. A. Vorontsov M. G. Lokhmatova M. B. Martynov K. M. Pichkhadze A. V. Simonov V. V. Khartov L. V. Zasova L. M. Zelenyi O. I. Korablev 《Solar System Research》2011,45(7):710-714
A new phase of Venus research has started in Russia; the Federal Space Program includes the Venera-D design with the launch
of the spacecraft scheduled for 2016. The mission comprises an orbiter, a descent vehicle, and balloon probes. The balloon
probes will be placed at different altitudes in the cloud layer and under the clouds, where they are intended to last for
a long time in the atmosphere of Venus. The successful implementation of the design will allow solving of quite a number of
scientific tasks for comparative planetology. 相似文献
10.
Lunar Dust: Properties and Potential Hazards 总被引:1,自引:0,他引:1
Solar System Research - The surface of the Moon, like that of any airless body in the Solar System, constantly experiences micrometeorite bombardment as well as the influence of solar radiation,... 相似文献