2,577 research outputs found
Lifshitz Scaling Effects on Holographic Superconductors
Via numerical and analytical methods, the effects of the Lifshitz dynamical
exponent on holographic superconductors are studied in some detail,
including wave and wave models. Working in the probe limit, we find
that the behaviors of holographic models indeed depend on concrete value of
. We obtain the condensation and conductivity in both Lifshitz black hole
and soliton backgrounds with general . For both wave and wave models
in the black hole backgrounds, as increases, the phase transition becomes
more difficult and the growth of conductivity is suppressed. For the Lifshitz
soliton backgrounds, when increases (), the critical chemical
potential decreases in the wave cases but increases in the wave cases.
For wave models in both Lifshitz black hole and soliton backgrounds, the
anisotropy between the AC conductivity in different spatial directions is
suppressed when increases. The analytical results uphold the numerical
results.Comment: Typos corrected; Footnote added; References added; To be published in
Nuclear Physics
Tetraaquabis(3-carboxylatopyridine N-oxide-κO 3)cadmium(II)
In the title complex, [Cd(C6H4NO3)2(H2O)4], the CdII atom is situated on a crystallographic centre of inversion. The CdII atom shows a slightly distorted octahedral geometry and is coordinated by four O atoms from water molecules and two O atoms from deprotonated carboxyl groups of nicotinic acid N-oxide ligands. The mononuclear complex molecules are linked by O—H⋯O hydrogen bonds, forming a three-dimensional network structure
Tetra-μ-acetato-bis[(pyridine N-oxide)copper(II)](Cu—Cu)
The molecule of the title binuclear copper(II) complex, [Cu2(CH3COO)4(C5H5NO)2], occupies a special position on a crystallographic inversion centre; the coordination environment of the CuII atom is slightly distorted square-pyramidal and is made up of four O atoms belonging to four acetate groups in the basal plane with the O atom of pyridine N-oxide ligand in the apical position. The Cu—Cu distance is 2.6376 (6) Å
Two types of generalized integrable decompositions and new solitary-wave solutions for the modified Kadomtsev-Petviashvili equation with symbolic computation
The modified Kadomtsev-Petviashvili (mKP) equation is shown in this paper to
be decomposable into the first two soliton equations of the 2N-coupled
Chen-Lee-Liu and Kaup-Newell hierarchies by respectively nonlinearizing two
sets of symmetry Lax pairs. In these two cases, the decomposed
(1+1)-dimensional nonlinear systems both have a couple of different Lax
representations, which means that there are two linear systems associated with
the mKP equation under the same constraint between the potential and
eigenfunctions. For each Lax representation of the decomposed (1+1)-dimensional
nonlinear systems, the corresponding Darboux transformation is further
constructed such that a series of explicit solutions of the mKP equation can be
recursively generated with the assistance of symbolic computation. In
illustration, four new families of solitary-wave solutions are presented and
the relevant stability is analyzed.Comment: 23 page
catena-Poly[silver(I)-μ-pyrazolato-κ2 N:N′]
The title compound, [Ag(C3H3N2)]n, has an infinite helical chain structure in which each pyrazolate group bridges two AgI atoms related by a 21 axis with an intrachain Ag⋯Ag separation of 3.3718 (7) Å. Each AgI center is linearly coordinated by two N atoms [N—Ag—N angle = 169.98 (14)°]. The chains are held together by interchain Ag⋯Ag interactions [3.2547 (6) Å], forming a two-dimensional layer. The X-ray single-crystal diffraction result is consonant with that of the ab initio X-ray powder diffraction reported by Masciocchi, Moret, Cairati, Sironi, Ardizzoia & La Monica [J. Am. Chem. Soc. (1994). 116, 7668–7676], with only minor deviations of structural parameters
Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN 3)copper(II) pentahydrate
The title compound, [Cu(C9H4N2O4)(H2O)5]·5H2O, contains one crystallographically independent CuII atom and one 1H-benzimidazole-5,6-dicarboxylate (bdc) ligand, along with five coordinated and five uncoordinated water molecules. The CuII atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water molecules, giving an octahedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water molecules into a three-dimensional network
Ba-enhanced dwarf and subgiant stars in the LAMOST Galactic surveys
Ba-enhanced stars are interesting probes of stellar astrophysics and Galactic
formation history. In this work, we investigate the chemistry and kinematics
for a large sample of Ba-enhanced ([Ba/Fe]1.0) dwarf and subgiant stars with
\,K from LAMOST. We find that both stellar internal
evolution process and external mass exchange due to binary evolution are
responsible for the origins of the Ba-enhancement of our sample stars. About
one third of them exhibit C and N enhancement and ultraviolet brightness
excess, indicating they are products of binary evolution. The remaining
Ba-enhanced stars with normal C and N abundances are mostly warm stars with
\,K. They are likely consequences of stellar internal
elemental transport processes, but they show very different elemental patterns
to the hotter Am/Fm stars. Our results reveal a substantially lack of
high-[/Fe] Ba-enhanced stars in the [Fe/H]--[/Fe] plane, which
we dub as a {\em high- desert}. We suggest it is due to a lower
efficiency for producing Ba-enhanced stars by low-mass AGB progenitors in
binary systems. Our results call for detailed modellings for these Ba-enhanced
stellar peculiars, in the context of both stellar internal elemental transport
and external mass accretion.Comment: 20 pages, 17 figures. Accepted for publication in Ap
- …