177 research outputs found
Theory of fast field-cycling NMR relaxometry of liquid systems undergoing chemical exchange
This work was supported by the European Union Horizon 2020 research and innovation programme under grant agreement no. 668119 (project âIDentIFYâ), and was performed under the auspices of the COST Action AC15209, EURELAX.Peer reviewedPublisher PD
On some expansions for the Euler Gamma function and the Riemann Zeta function
In the present paper we introduce some expansions, based on the falling
factorials, for the Euler Gamma function and the Riemann Zeta function. In the
proofs we use the Fa\'a di Bruno formula, Bell polynomials, potential
polynomials, Mittag-Leffler polynomials, derivative polynomials and special
numbers (Eulerian numbers and Stirling numbers of both kinds). We investigate
the rate of convergence of the series and give some numerical examples.Comment: Published articl
Theoretical study of electronic relaxation processes in hydrated Gd<sup>3+</sup> complexes in solutions
The EPR line widths of [Gd(H2O)(8)](3+) measured in water at various magnetic fields by Merbach's group have been reinterpreted. A theoretical model of the transverse electronic relaxation is proposed, All the terms of the static zero-field splitting (ZFS) allowed by the symmetry of the complex are included and shown to have a significant contribution. The influence of a transient distortion ZFS is also studied
Prehistory of Transit Searches
Nowadays the more powerful method to detect extrasolar planets is the transit
method. We review the planet transits which were anticipated, searched, and the
first ones which were observed all through history. Indeed transits of planets
in front of their star were first investigated and studied in the solar system.
The first observations of sunspots were sometimes mistaken for transits of
unknown planets. The first scientific observation and study of a transit in the
solar system was the observation of Mercury transit by Pierre Gassendi in 1631.
Because observations of Venus transits could give a way to determine the
distance Sun-Earth, transits of Venus were overwhelmingly observed. Some
objects which actually do not exist were searched by their hypothetical
transits on the Sun, as some examples a Venus satellite and an infra-mercurial
planet. We evoke the possibly first use of the hypothesis of an exoplanet
transit to explain some periodic variations of the luminosity of a star, namely
the star Algol, during the eighteen century. Then we review the predictions of
detection of exoplanets by their transits, those predictions being sometimes
ancient, and made by astronomers as well as popular science writers. However,
these very interesting predictions were never published in peer-reviewed
journals specialized in astronomical discoveries and results. A possible
transit of the planet beta Pic b was observed in 1981. Shall we see another
transit expected for the same planet during 2018? Today, some studies of
transits which are connected to hypothetical extraterrestrial civilisations are
published in astronomical refereed journals. Some studies which would be
classified not long ago as science fiction are now considered as scientific
ones.Comment: Submiited to Handbook of Exoplanets (Springer
The magnetization process in free single-crystalline particles of rare-earth-transition-metal compounds
Prediction of low-field nuclear singlet lifetimes with molecular dynamics and quantum-chemical property surface
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