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841.
J. Büchner 《Space Science Reviews》2006,124(1-4):345-360
Reconnection is a major commonality of solar and magnetospheric physics. It was conjectured by Giovanelli in 1946 to explain
particle acceleration in solar flares near magnetic neutral points. Since than it has been broadly applied in space physics
including magnetospheric physics. In a special way this is due to Harry Petschek, who in 1994 published his ground breaking
solution for a 2D magnetized plasma flow in regions containing singularities of vanishing magnetic field. Petschek’s reconnection
theory was questioned in endless disputes and arguments, but his work stimulated the further investigation of this phenomenon
like no other. However, there are questions left open. We consider two of them – “anomalous” resistivity in collisionless
space plasma and the nature of reconnection in three dimensions. The CLUSTER and SOHO missions address these two aspects of
reconnection in a complementary way -- the resistivity problem in situ in the magnetosphere and the 3D aspect by remote sensing of the Sun. We demonstrate that the search for answers to both questions
leads beyond the applicability of analytical theories and that appropriate numerical approaches are necessary to investigate
the essentially nonlinear and nonlocal processes involved. Necessary are both micro-physical, kinetic Vlasov-equation based
methods of investigation as well as large scale (MHD) simulations to obtain the geometry and topology of the acting fields
and flows. 相似文献
842.
Semkin N.D. Novikov L.S. Voronov K.E. Bobin D.G. Pomelnikov R.A. Rotov S.V. 《Space Debris》2000,2(4):273-293
The mathematical model of a space debris detector based on inflatable metal-dielectric-metal (MDM) film structure is presented. The efficiency of its implementation for detection of space debris particles at different altitudes is estimated, and the information obtained by the detector is investigated. 相似文献
843.
844.
SONG Falun CAO Jinxiang WANG Ge 《空间科学学报》2004,24(4):241-246
The numerical calculation of the transmission and absorption of microwaves at an arbitrarily incident angle to the inhomogeneous spherically symmetric plasma is presented.The nonuniform sphere is modeled by a series of concentric spherical shells, and the electron density is constant in each shell. The overall density profile follows any given distribution function. By using the geometrical optics approximation and considering the propagation coefficient is complex, as well as the attenuation and phase coefficients are vectors, the detailed evaluation shows that the transmission and absorption of microwaves in the inhomogeneous spherically symmetric plasma depend on the electron and neutral particle collision frequency, central density, incident angle of the microwaves and density distribution profiles. 相似文献
845.
846.
847.
E.E. Antonova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(10):1677-1681
High level of turbulence is one of the main peculiarities inherent to magnetospheric dynamics. Mechanisms for generation of magnetospheric turbulence are analyzed. The instabilities in the plasma pressure distribution are examined as source of large and medium scale modes in the turbulence spectra. Large-scale modes (which scales are comparable with scale of the magnetosphere) lead to convective transport of the magnetospheric particles. Excitation of such modes is analyzed being based on the suggestion of the existence of week instability in the distribution of plasma pressure. 相似文献
848.
在目标的雷达隐身方面,等离子体具有巨大的应用潜力。对隐身应用时产生等离子体的气压、放电气体种类以及放电方式进行了论述。指出在大气压下,适宜利用惰性气体放电来产生等离子体。而目前许多文献中所报道的隐身等离子体的产生方法离工程应用还有一定距离,还有许多问题亟待解决。 相似文献
849.
为了研究低温等离子体放电区长度,即放电区间隙不变,体积大小对脉冲爆震发动机点火起爆的影响,以丙烷为燃料,空气和纯氧为氧化剂,充分考虑其详细的化学反应动力学机理,将低温等离子体放电区等效为高温高压火核,对放电区长度为20,40,60mm三种结构,利用Fluent软件,对点火起爆过程进行数值模拟,并进行对比分析.结果表明:将低温等离子体放电区等效为高温高压火核是可行的,能够得到完整的点火起爆过程;不同放电区长度,对初始火焰形成、火焰传播速度和缓燃转爆震(DDT)时间有很大影响,对爆震波峰值压力影响不大. 相似文献
850.