1,541 research outputs found
Asymptotics for the number of n-quasigroups of order 4
The asymptotic form of the number of n-quasigroups of order 4 is . Keywords: n-quasigroups, MDS codes, decomposability,
reducibility.Comment: 15 p., 3 fi
A New High Energy Photon Tagger for the H1 - Detector at HERA
The H1 detector at HERA has been upgraded by the addition of a new
electromagnetic calorimeter. This is installed in the HERA tunnel close to the
electron beam line at a position 8m from the interaction point in the electron
beam direction. The new calorimeter extends the acceptance for tagged
photoproduction events to the high y range, 0.85 < y < 0.95, and thus
significantly improves the capability of H1 to study high energy gamma-p
processes. The calorimeter design, performance and first results obtained
during the 1996-1999 HERA running are described.Comment: 17 pages, 16 figure
Representations of -semigroups by multiplace functions
We describe the representations of -semigroups, i.e. groupoids with
binary associative operations, by partial -place functions and prove
that any such representation is a union of some family of representations
induced by Schein's determining pairs.Comment: 17 page
Holy Synod and Political Crisis of Interregnum
The features of the development of the dynastic crisis of the interregnum of 1825 through the prism of the functioning of one of the key public authorities - the Holy Synod is discussed in the article. An analysis of the literature allows us to conclude that in modern historiography, the events of the oath to Grand Duke Konstantin received conflicting estimates. It is noted that as a result there were several interpretative schemes of what happened in the capital on November 27. An appeal to the workflow of the Synod makes it possible to assert that from the point of view of the logic of the functioning of the state apparatus, a coup d’etat took place. An analysis of everyday activities, the key bureaucratic formulas in the protocols leads to the conclusion that the bureaucratic reaction to the oath to Konstantin did not correspond to the established traditions and was distinguished by haste and internal contradictions. This was reflected primarily in the decisions of November 27: the Synod decides on the oath, relying on oral reports from the synodal members, but the next day duplicates its own decision, referring to the jurisdiction of the Senate. Moreover, a comparison with the events of December 12-14 shows that the accession to the throne of Nikolai Pavlovich was carried out in accordance with the order established in the previous century and was distinguished by deliberate legal accuracy and consistency
Tagging High Energy Photons in the H1 Detector at HERA
Measures taken to extend the acceptance of the H1 detector at HERA for
photoproduction events are described. These will enable the measurement of
electrons scattered in events in the high y range 0.85 < y < 0.95 in the 1998
and 1999 HERA run period. The improvement is achieved by the installation of an
electromagnetic calorimeter, the ET8, in the HERA tunnel close to the electron
beam line 8 m downstream of the H1 interaction point in the electron direction.
The ET8 will allow the study of tagged gamma p interactions at centre-of-mass
energies significantly higher than those previously attainable. The calorimeter
design and expected performance are discussed, as are results obtained using a
prototype placed as close as possible to the position of the ET8 during the
1996 and 1997 HERA running.Comment: 13 pages, 13 figure
Josephson array of mesoscopic objects. Modulation of system properties through the chemical potential
The phase diagram of a two-dimensional Josephson array of mesoscopic objects
is examined. Quantum fluctuations in both the modulus and phase of the
superconducting order parameter are taken into account within a lattice boson
Hubbard model. Modulating the average occupation number of the sites in
the system leads to changes in the state of the array, and the character of
these changes depends significantly on the region of the phase diagram being
examined. In the region where there are large quantum fluctuations in the phase
of the superconducting order parameter, variation of the chemical potential
causes oscillations with alternating superconducting (superfluid) and normal
states of the array. On the other hand, in the region where the bosons interact
weakly, the properties of the system depend monotonically on . Lowering
the temperature and increasing the particle interaction force lead to a
reduction in the width of the region of variation in within which the
system properties depend weakly on the average occupation number. The phase
diagram of the array is obtained by mapping this quantum system onto a
classical two-dimensional XY model with a renormalized Josephson coupling
constant and is consistent with our quantum Path-Integral Monte Carlo
calculations.Comment: 12 pages, 8 Postscript figure
New model for system of mesoscopic Josephson contacts
Quantum fluctuations of the phases of the order parameter in 2D arrays of
mesoscopic Josephson junctions and their effect on the destruction of
superconductivity in the system are investigated by means of a quantum-cosine
model that is free of the incorrect application of the phase operator. The
proposed model employs trigonometric phase operators and makes it possible to
study arrays of small superconducting granules, pores filled with superfluid
helium, or Josephson junctions in which the average number of particles
(effective bosons, He atoms, and so on) is small, and the standard approach
employing the phase operator and the particle number operator as conjugate ones
is inapplicable. There is a large difference in the phase diagrams between
arrays of macroscopic and mesoscopic objects for and ( is
the characteristic interaction energy of the particle per granule and is
the Josephson coupling constant). Reentrant superconductivity phenomena are
discussed.Comment: 4 pages, 3 Postscript figure
Representations of Menger -semigroups by multiplace functions
Investigation of partial multiplace functions by algebraic methods plays an
important role in modern mathematics were we consider various operations on
sets of functions, which are naturally defined. The basic operation for
-place functions is an -ary superposition , but there are some
other naturally defined operations, which are also worth of consideration. In
this paper we consider binary Mann's compositions \op{1},...,\op{n} for
partial -place functions, which have many important applications for the
study of binary and -ary operations. We present methods of representations
of such algebras by -place functions and find an abstract characterization
of the set of -place functions closed with respect to the set-theoretic
inclusion
Copper-Containing Magnesioferrite in Vesicular Trachyandesite in a Lava Tube from the 2012-2013 Eruption of the Tolbachik Volcano, Kamchatka, Russia
Cu-rich magnesioferrite was found in vesicular basaltic trachyandesite in one of lava tubes (Duplex) that formed during the 2012-2013 eruption of the Tolbachik volcano, Kamchatka. This mineral is commonly associated with hematite, tenorite, halite, sylvite, and Ca-rich silicates (mainly, esseneite and Na-rich melilite) in high-temperature (800-1000 degrees C) reactionary zones (up to 100 mu m) covering vesicular rocks and lava stalactites in the Duplex tube. The mineral relationships of this assemblage indicate the following crystallization sequence: Ca-rich silicates + hematite -> Cu-rich magnesioferrite -> tenorite -> chlorides. This formed due to the reaction of hot gases containing Cu, alkalis, and Cl with solidified lava rock. The composition of magnesioferrite varies strongly in CuO (5.8-17.3 wt %; cuprospinel end-member-15-47 mol %), whereas the contents of other oxides are minor, indicating the main isomorphic substitution is Mg2+ Cu2+. Compositions with maximal CuO content nominally belong to Mg-rich cuprospinel: (Cu0.48Mg0.41Mn0.09Zn0.02Ca0.02) (Fe1.943+Al0.03Ti0.02)O-4. Increasing CuO content of the Duplex Cu-rich magnesioferrite is reflected in Raman spectra by moderate right shifting bands at approximate to 700-710 and 200-210 cm(-1) and the appearance of an additional band at 596 cm(-1). This supports the main isomorphic scheme and may indicate a degree of inversion in the spinel structure.Peer reviewe
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