54,134 research outputs found
Superconducting properties of Gd-Ba-Cu-O single grains processed from a new, Ba-rich precursor compound
Gd-Ba-Cu-O (GdBCO) single grains have been previously melt-processed successfully in air using a generic Mg-Nd-Ba-Cu-O (Mg-NdBCO) seed crystal. Previous research has revealed that the addition of a small amount of BaO2 to the precursor powders prior to melt processing can suppress the formation of Gd/Ba solid solution, and lead to a significant improvement in superconducting properties of the single grains. Research into the effects of a higher Ba content on single grain growth, however, has been limited by the relatively small grain size in the earlier studies. This has been addressed by developing Ba-rich precursor compounds Gd-163 and Gd-143, fabricated specifically to enable the presence of greater concentrations of Ba during the melt process. In this study, we propose a new processing route for the fabrication of high performance GdBCO single grain bulk superconductors in air by enriching the precursor powder with these new Ba rich compounds. The influence of the addition of the new compounds on the microstructures and superconducting properties of GdBCO single grains is reported
Effect of depreciation of the public goods in spatial public goods games
In this work, depreciated effect of the public goods is considered in the
public goods games, which is realized by rescaling the multiplication factor r
of each group as r' = r(nc/G)^beta (beat>= 0). It is assumed that each
individual enjoys the full profit of the public goods if all the players of
this group are cooperators, otherwise, the value of the public goods is reduced
to r'. It is found that compared with the original version (beta = 0),
emergence of cooperation is remarkably promoted for beta > 0, and there exit
optimal values of beta inducing the best cooperation. Moreover, the optimal
plat of beta broadens as r increases. Furthermore, effect of noise on the
evolution of cooperation is studied, it is presented that variation of
cooperator density with the noise is dependent of the value of beta and r, and
cooperation dominates over most of the range of noise at an intermediate value
of beta = 1.0. We study the initial distribution of the multiplication factor
at beta = 1.0, and find that all the distributions can be described as Gauss
distribution
Mixed integer nonlinear programming for Joint Coordination of Plug-in Electrical Vehicles Charging and Smart Grid Operations
The problem of joint coordination of plug-in electric vehicles (PEVs)
charging and grid power control is to minimize both PEVs charging cost and
energy generation cost while meeting both residential and PEVs' power demands
and suppressing the potential impact of PEVs integration. A bang-bang PEV
charging strategy is adopted to exploit its simple online implementation, which
requires computation of a mixed integer nonlinear programming problem (MINP) in
binary variables of the PEV charging strategy and continuous variables of the
grid voltages. A new solver for this MINP is proposed. Its efficiency is shown
by numerical simulations.Comment: arXiv admin note: substantial text overlap with arXiv:1802.0445
Anti-lecture Hall Compositions and Overpartitions
We show that the number of anti-lecture hall compositions of n with the first
entry not exceeding k-2 equals the number of overpartitions of n with
non-overlined parts not congruent to modulo k. This identity can be
considered as a refined version of the anti-lecture hall theorem of Corteel and
Savage. To prove this result, we find two Rogers-Ramanujan type identities for
overpartition which are analogous to the Rogers-Ramanjan type identities due to
Andrews. When k is odd, we give an alternative proof by using a generalized
Rogers-Ramanujan identity due to Andrews, a bijection of Corteel and Savage and
a refined version of a bijection also due to Corteel and Savage.Comment: 16 page
The Rogers-Ramanujan-Gordon Theorem for Overpartitions
Let be the number of partitions of with certain difference
condition and let be the number of partitions of with certain
congruence condition. The Rogers-Ramanujan-Gordon theorem states that
. Lovejoy obtained an overpartition analogue of the
Rogers-Ramanujan-Gordon theorem for the cases and . We find an
overpartition analogue of the Rogers-Ramanujan-Gordon theorem in the general
case. Let be the number of overpartitions of satisfying
certain difference condition and be the number of overpartitions
of whose non-overlined parts satisfy certain congruences condition. We show
that . By using a function introduced by Andrews, we
obtain a recurrence relation which implies that the generating function of
equals the generating function of . We also find a
generating function formula of by using Gordon marking
representations of overpartitions, which can be considered as an overpartition
analogue of an identity of Andrews for ordinary partitions.Comment: 26 page
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