643 research outputs found
A New Auction for Substitutes: Central-Bank Liquidity Auctions, 'Toxic Asset' Auctions, and Variable Product-Mix Auctions
Multiphoton radiative recombination of electron assisted by laser field
In the presence of an intensive laser field the radiative recombination of
the continuum electron into an atomic bound state generally is accompanied by
absorption or emission of several laser quanta. The spectrum of emitted photons
represents an equidistant pattern with the spacing equal to the laser
frequency. The distribution of intensities in this spectrum is studied
employing the Keldysh-type approximation, i.e. neglecting interaction of the
impact electron with the atomic core in the initial continuum state. Within the
adiabatic approximation the scale of emitted photon frequencies is subdivided
into classically allowed and classically forbidden domains. The highest
intensities correspond to emission frequencies close to the edges of
classically allowed domain. The total cross section of electron recombination
summed over all emitted photon channels exhibits negligible dependence on the
laser field intensity.Comment: 14 pages, 5 figures (Figs.2-5 have "a" and "b" parts), Phys.Rev.A
accepted for publication. Fig.2b is presented correctl
Three Wide-Separation L dwarf Companions from the Two Micron All Sky Survey: Gl 337C, Gl 618.1B, and HD 89744B
We present two confirmed wide separation L-dwarf common proper motion
companions to nearby stars and one candidate identified from the Two Micron All
Sky Survey. Spectral types from optical spectroscopy are L0 V, L2.5 V, and L8
V. Near-infrared low resolution spectra of the companions are provided as well
as a grid of known objects spanning M6 V -- T dwarfs to support spectral type
assignment for these and future L-dwarfs in the z'JHK bands. Using published
measurements, we estimate ages of the companions from physical properties of
the primaries. These crude ages allow us to estimate companion masses using
theoretical low-mass star and brown dwarf evolutionary models. The new L-dwarfs
in this paper bring the number of known wide-binary (Separation >= 100 AU)
L-dwarf companions of nearby stars to nine. One of the L-dwarfs is a wide
separation companion to the F7 IV-V + extrasolar planet system HD89744Ab.Comment: 20 pages including 6 tables and 4 figures, AJ, in pres
Internally Electrodynamic Particle Model: Its Experimental Basis and Its Predictions
The internally electrodynamic (IED) particle model was derived based on
overall experimental observations, with the IED process itself being built
directly on three experimental facts, a) electric charges present with all
material particles, b) an accelerated charge generates electromagnetic waves
according to Maxwell's equations and Planck energy equation and c) source
motion produces Doppler effect. A set of well-known basic particle equations
and properties become predictable based on first principles solutions for the
IED process; several key solutions achieved are outlined, including the de
Broglie phase wave, de Broglie relations, Schr\"odinger equation, mass,
Einstein mass-energy relation, Newton's law of gravity, single particle self
interference, and electromagnetic radiation and absorption; these equations and
properties have long been broadly experimentally validated or demonstrated. A
specific solution also predicts the Doebner-Goldin equation which emerges to
represent a form of long-sought quantum wave equation including gravity. A
critical review of the key experiments is given which suggests that the IED
process underlies the basic particle equations and properties not just
sufficiently but also necessarily.Comment: Presentation at the 27th Int Colloq on Group Theo Meth in Phys, 200
Effects of schistosomes on host anti-viral immune response and the acquisition, virulence, and prevention of viral infections: A systematic review.
Although a growing number of studies suggest interactions between Schistosoma parasites and viral infections, the effects of schistosome infections on the host response to viruses have not been evaluated comprehensively. In this systematic review, we investigated how schistosomes impact incidence, virulence, and prevention of viral infections in humans and animals. We also evaluated immune effects of schistosomes in those coinfected with viruses. We screened 4,730 studies and included 103. Schistosomes may increase susceptibility to some viruses, including HIV and Kaposi's sarcoma-associated herpesvirus, and virulence of hepatitis B and C viruses. In contrast, schistosome infection may be protective in chronic HIV, Human T-cell Lymphotropic Virus-Type 1, and respiratory viruses, though further research is needed. Schistosome infections were consistently reported to impair immune responses to hepatitis B and possibly measles vaccines. Understanding the interplay between schistosomes and viruses has ramifications for anti-viral vaccination strategies and global control of viral infections
Images of crustal and mantle structure across the northern margin of the Tibet-Pamir plateau
Abstract HKT-ISTP 2013
A
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