排序方式： 共有4条查询结果，搜索用时 15 毫秒
1
1.
We suggested a relatively simple model describing changes in the total balance of the ice sheet mass due to global climate
change. Taking into account the basic mechanisms behind change in the ice sheet mass and their relations with temperature,
we obtained a nonlinear analytical dependence of the ice sheet thickness on the global near-surface temperature. The behavior
of the ice sheet can be split into six regimes. Implementation of some regime or another depends essentially on the initial
(present-day) value of the mass balance and the sensitivity parameters of precipitation and ice melt to the temperature. Based
on this model, we obtained an analytical estimate of the critical level in global warming, in excess of which the regime of
the Antarctic ice sheet gain due to snow accumulation changes to sheet degradation due to more intense growth in ice melting. 相似文献
2.
V. S. Beskin & L. M. Malyshkin 《Monthly notices of the Royal Astronomical Society》1998,298(3):847-853
We consider a model of axisymmetric neutron star magnetospheres. In our approach, the current density in the region of open field lines is constant and the returning current flows in a narrow layer along the separatrix. In this case, the stream equation describing the magnetic field structure is linear both in the open and closed regions; the main problem is matching the solutions along the separatrix. We demonstrate that it is the stability condition on the separatrix that allows us to obtain a unique solution of the problem. In particular, the zero point of magnetic field is shown to be located near the light cylinder. Moreover, the hypothesis of the existence of the non-linear Ohm's Law, connecting the potential drop in the pair creation region and the longitudinal electric current flowing in the magnetosphere, is confirmed. 相似文献
3.
We consider the processes that might suppress the time variations in the solar neutrino flux produced by the radial motion of the Earth through the neutrino interference pattern. We calculate these time variations and the extent to which they are suppressed by Coulomb collisions of the neutrino-emitting nuclei. This is done for both the 0.862-MeV 7 Be neutrino line and the continuous neutrino spectrum, assuming a Gaussian energy response function of the neutrino detector. We find that the collisional decoherence averages out the time variations for neutrino masses A simple and clear physical picture of the time-dependent solar neutrino problem is presented and qualitative coherence criteria are discussed. 相似文献
4.
A magnetohydrodynamic model is constructed for a cylindrical jet embedded in an external uniform magnetic field. It is shown that, as in the force-free case, the total electric current within the jet can be zero. The particle energetics and the magnetic-field structure are determined in a self-consistent way; all jet parameters depend markedly on the physical conditions in the external medium. In particular, we show that a region with subsonic flow can exist in the central jet regions. In real relativistic jets, most of the energy is transferred by the electromagnetic field only at a sufficiently large magnetization parameter σ>106. We also show that, in general, the well-known solution with a central core B Z =B 0/(1+?2/? c 2 ) cannot be realized in the presence of an external medium. 相似文献
1