排序方式： 共有34条查询结果，搜索用时 25 毫秒
1.
V. V. Kaminskiy N. N. Stepanov N. M. Volodin Yu. N. Mishin 《Solar System Research》2014,48(7):561-567
The paper describes the dependence of the piezoresistance of the hydrostatic compression of the SmS baroresistor on mechanical properties of the electrical part of the carrier. Isotropic and anisotropic materials are considered that can serve as a baroresistor carrier. 相似文献
2.
We examine a mechanism for breaking down solar wind (SW) speed shears within 1 astronomical unit (a.u.), initiated by the development of the Kelvin-Helmholtz (K-H) instability for typical parameters of the plasma and magnetic field in the interplanetary medium. A semi-empirical SW model has been invoked to derive a distribution of the plasma parameters β = 8πP/B2 and MA2 = (ρν2/2)/(B2/8π) between the Sun and 1 a.u. It is shown that in the vicinity of the Sun, up to heliocentric distances r ≈ 0.1 a.u., the parameters β ? 1, and M2A ? 1 and therefore the magnetic field here may be considered a very strong one. Because of the stabilizing effect of the magnetic field the K-H instability in this region does not develop and a presence of great shears in SW speed with large velocity gradients is possible here.At distances r > 0.1 a.u. the parameters β ? 1, and M2A > 1. Examination of a variety of SW speed profiles showed that the presence of plasma flow velocity shears in this region leads to an excitation of the K-H instability. Numerical analysis results indicate that a principal role in the excitation of this instability is played by oblique waves that propagate at an angle α ≈ 45° to the stream velocity vector.The question of the evolution of the leading front of a high speed SW streams within 1 a.u. is discussed, with a proper account of the influence of competing effects of kinematic steepening and turbulent viscosity, the latter being due to the development of the K-H instability. It is shown that the turbulent viscosity effect in this region is substantial and is capable of ensuring an expansion of the leading front of the high speed SW stream as this moves from 0.3 to 1 a.u., in agreement with experimental evidence reported by Rosenbauer et al. (1977). 相似文献
3.
V. M. Mishin A. D. Bazarzhapov U. Sukhbaatar M. Förster 《Geomagnetism and Aeronomy》2010,50(8):988-996
The simplest theory of electric circuits is applied to analysis of the observed large-scale electric field and currents in
a disturbed magnetosphere-ionosphere system. Maps of distribution of field-aligned currents (FACs) obtained from ground-based
magnetic measurements using the original magnetogram inversion method (MIT) and measurements by satellites were used. A method
for circuit determination according to the data of such maps based on the detection of spatial R.N inhomogeneities in each
of three Iijima and Potemra FAC zones is proposed. The results of the new method are used to describe some electric field
and current generators not known before, new types of current systems in tail lobes and plasma sheet, and the formation and
dynamics of new types of three-dimensional systems with auroral electrojets and meridional ionospheric Pedersen current, which
have not been paid due attention in the literature. 相似文献
4.
V. Mishin Z. Pu L. Sapronova A. Bazarzhapov Yu. Kuz’minykh X. Cao H. Zhang 《Geomagnetism and Aeronomy》2009,49(8):1193-1198
The maps of the field-aligned current (FAC) density distribution in the ionosphere obtained by the TIM-2 magnetogram inversion
technique are used to investigate the August 27, 2001 substorm. The open magnetic flux Ψ and intensity J of the substorm current wedge (SCW) have been determined with a step of 1–5 min. The substorm onsets are divided into two
types, PSR (plasma sheet reconnection) and TLR (tail lobe reconnection). The fast expansion tailward of the PSR region is
described as the transition from PSR to PSR+TLR. Assuming that the SCW FACs flow down into the ionosphere from the edges of
the disruption region of the cross-tail dawn-dusk current, several parameters of the disruption region have been estimated.
The disrupted magnetic field has been found to be ∼5% of the undisrupted one for PSR and ∼95% for PSR+TLR. The disturbance
power Q for PSR is an order of magnitude lower than that for PSR+TLR. The abrupt growth of Q during the transition from PSR to PSR+TLR is observed over the entire SCW area from its near-Earth part to the midtail and
distant tail. 相似文献
5.
L. F. Mishin 《Geochemistry International》2010,48(6):580-592
The example of eastern Russia is employed to analyze the influence of diverse factors on the development of negative Eu anomalies
in magmatic rocks at continental marginal volcanic belts. A strong correlation is identified between the relative value of
Eu minima and the degree of Fe oxidation, Fe/(Fe+Mg) of mafic minerals, and an increase in the Eu minimum from basic to acid
rocks. It is demonstrated that the value of the Eu minimum hardly depends on either the crystallization depth of the rocks
and/or their alkalinity. Within individual tectono-stratigraphic zones, the value of Eu anomalies is independent of the age
of the rocks, their affiliation with certain associations, and the basement structure of the volcanic zone. Rocks with clearly
pronounced negative Eu anomalies belong exclusively to the ilmenite series that are formed under reduced conditions. The rocks
of the magnetite series, which are formed under oxidized conditions, contain trivalent Eu, which behaves analogously to other
REE. 相似文献
6.
E. V. Mishin 《Astrophysics and Space Science》1974,27(2):367-382
Heat transport is considered both for quiet and disturbed solar winds. It is shown that heat may be transferred during solar flares by sharp fronted thermal wave pulses. Energy dissipation in the wave front arises from the firehose instability excitation. The effects of ionosonic turbulence on heat transport in a quiet solar wind are also investigated. A quasi-steady state, in which there is a balance between wave-particle interations and particle collisions is found. It is shown that the effect of wave-particle ‘collisions’ is to produce a significant decrease of the electron heat flow and electron temperature, and increase of the ion temperature relative to calculations which take into account particle particle collisions only. 相似文献
7.
8.
9.
We describe, for the first time, the following peculiarities of a substorm in the polar ionosphere and magnetotail including its distant lobe: (1) coherent variations in mesoscale vortices and in field-aligned currents of the magnetospheric-ionospheric (M-I) system; (2) instability of short—circuiting of currents in ionospheric part of the M-I system; (3) coexistence of Y- and X-currents as necessary elements of the M-I system. These new elements for the substorm scenario are principally relevant to understanding of basic processes in the mid-/near tail. 相似文献
10.
Mishin V. M. Saifudinova T. I. Karavaev Yu. A. Kurikalova M. A. Bazarzhapov A. D. 《Geomagnetism and Aeronomy》2009,49(7):975-982
The regular appearance of the chain of oppositely directed field-aligned current (FAC) pairs near the noon-midnight meridian
during three considered substorms has been described. The FAC pairs (FACs flowing into the ionosphere in the morning and flowing
out of this region in the evening and vice versa) are observed in each of three Iijima and Potemra zones. The FAC direction
in the fixed LT sector periodically varies along the chain. The scenario, according to which each FAC pair (seven pairs) is
identified with a hump or trough of one of the waves propagating from the Earth and toward the Earth in different magnetospheric
domains, has been described. The estimated wave velocities differ from ∼100 to >1000 km/s depending on the propagation region
but everywhere agree with the corresponding velocities of magnetosound waves (MSWs). The hypothesis is proposed, according
to which these MSWs are excited by plasma ejection during current disruption and reconnection near the dayside magnetopause
and in the near/middle regions of the nightside tail. 相似文献