17,654 research outputs found
The high latitude outer zone boundary for more than or equal to 40 keV electrons as observed by satellite Injun 3
High latitude outer zone boundary for greater than or equal to 40 keV electrons observed by Injun 3 satellit
Transition probabilities and measurement statistics of postselected ensembles
It is well-known that a quantum measurement can enhance the transition
probability between two quantum states. Such a measurement operates after
preparation of the initial state and before postselecting for the final state.
Here we analyze this kind of scenario in detail and determine which probability
distributions on a finite number of outcomes can occur for an intermediate
measurement with postselection, for given values of the following two
quantities: (i) the transition probability without measurement, (ii) the
transition probability with measurement. This is done for both the cases of
projective measurements and of generalized measurements. Among other
constraints, this quantifies a trade-off between high randomness in a
projective measurement and high measurement-modified transition probability. An
intermediate projective measurement can enhance a transition probability such
that the failure probability decreases by a factor of up to 2, but not by more.Comment: 23 pages, 5 figures, minor updat
Diurnal and latitude effects observed for 10 key electrons at low satellite altitudes
Observing diurnal and latitude effects for 10 keV electrons on low altitude, high latitude satellite Injun III using low energy electron detecto
Intra- and Interspecies Analyses of the Carcinoembryonic Antigen (CEA) Gene Family Reveal Independent Evolution in Primates and Rodents
Various rodent and primate DNAs exhibit a stronger intra- than interspecies cross-hybridization with probes derived from the N-terminal domain exons of human and rat carcinoembryonic antigen (CEA)-like genes. Southern analyses also reveal that the human and rat CEA gene families are of similar complexity. We counted at least 10 different genes per human haploid genome. In the rat, approximately seven to nine different N-terminal domain exons that presumably represent different genes appear to be present. We were able to assign the corresponding genomic restriction endonuclease fragments to already isolated CEA gene family members of both human and rat. Highly similar subgroups, as found within the human CEA gene family, seem to be absent from the rat genome. Hybridization with an intron probe from the human nonspecific cross-reacting antigen (NCA) gene and analysis of DNA sequence data indicate the conservation of noncoding regions among CEA-like genes within primates, implicating that whole gene units may have been duplicated. With the help of a computer program and by calculating the rate of synonymous substitutions, evolutionary trees have been derived. From this, we propose that an independent parallel evolution, leading to different CEA gene families, must have taken place in, at least, the primate and rodent orders
Essential closures and AC spectra for reflectionless CMV, Jacobi, and Schrödinger operators revisited
We provide a concise, yet fairly complete discussion of the concept of essential closures of subsets of the real axis and their intimate connection with the topological support of absolutely continuous measures. As an elementary application of the notion of the essential closure of subsets of R we revisit the fact that CMV, Jacobi, and Schrödinger operators, reflectionless on a set ∈ of positive Lebesgue measure, have absolutely continuous
spectrum on the essential closure ⋶^e of the set ∈ (with uniform multiplicity two on ∈). Though this result in the case of Schrödinger and Jacobi operators is known to experts, we feel it nicely illustrates the concept and usefulness of essential closures in the spectral theory of classes of reflectionless differential and difference operators
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