5,101 research outputs found
A critical Mach number for electron injection in collisionless shocks
Electron acceleration in collisionless shocks with arbitrary magnetic field
orientations is discussed. It is shown that the injection of thermal electrons
into diffusive shock acceleration process is achieved by an electron beam with
a loss-cone in velocity space that is reflected back upstream from the shock
through shock drift acceleration mechanism. The electron beam is able to excite
whistler waves which can scatter the energetic electrons themselves when the
Alfven Mach number of the shock is sufficiently high. A critical Mach number
for the electron injection is obtained as a function of upstream parameters.
The application to supernova remnant shocks is discussed.Comment: 4 pages, 2 figure, accepted for publication in Physical Review
Letter
Comparison of thread-cutting behaviour in three specialist predatory mites to cope with complex webs of Tetranychus spider mites
Anti-predator defenses provided by complex webs of Tetranychus mites can severely impede the performance of generalist predatory mites, whereas this may not be true for specialist predatory mites. Although some specialist predatory mites have developed morphological protection to reduce the adverse effects of complex webs, little is known about their behavioral abilities to cope with the webs. In this study, we compared thread-cutting behavior of three specialist predatory mites, Phytoseiulus persimilis, Neoseiulus womersleyi and N. californicus, exhibited inside the complex web of T. urticae. No major difference was observed among them in the basic pattern of this behavior, using chelicerae and palps, and in the number of silken threads severed while moving inside the web. These results and observations suggest that each predator species cut many sticky silken threads to move inside the complex web without suffering from serious obstructio
Momentum Analyticity and Finiteness of the 1-Loop Superstring Amplitude
The Type II Superstring amplitude to 1-loop order is given by an integral of
-functions over the moduli space of tori, which diverges for real
momenta. We construct the analytic continuation which renders this amplitude
well defined and finite, and we find the expected poles and cuts in the complex
momentum plane.Comment: 10pp, /UCLA/93/TEP/
Fusion cross section and total kinetic energy of fission fragments by the dynamical dissipative surface-friction model
The capture cross section, the fusion cross section, and the quasi-fission
yield producing symmetric fragments () in the
Ca+U reaction are analyzed by the multidimensional Langevin
equation taking account of the surface friction effect. From the experimental
data, the strength of the tangential friction has been determined. It is
presented that tangential friction increases in proportional to the power of
the relative velocity of the projectile and the target.Comment: 12 pages, 8 figure
Cardiac rupture after catheter ablation procedure
ArticleAnnals of Thoracic Surgery. 80(1): 326-328 (2005)journal articl
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