We report the first discovery of pure face-centered-cubic (fcc) Ru nanoparticles. Although the fcc structure does not exist in the bulk Ru phase diagram, fcc Ru was obtained at room temperature ...because of the nanosize effect. We succeeded in separately synthesizing uniformly sized nanoparticles of both fcc and hcp Ru having diameters of 2–5.5 nm by simple chemical reduction methods with different metal precursors. The prepared fcc and hcp nanoparticles were both supported on γ-Al2O3, and their catalytic activities in CO oxidation were investigated and found to depend on their structure and size.
Pd x Ru1–x solid solution alloy nanoparticles were successfully synthesized over the whole composition range through a chemical reduction method, although Ru and Pd are immiscible at the atomic level ...in the bulk state. From the XRD measurement, it was found that the dominant structure of Pd x Ru1–x changes from fcc to hcp with increasing Ru content. The structures of Pd x Ru1–x nanoparticles in the Pd composition range of 30–70% consisted of both solid solution fcc and hcp structures, and both phases coexist in a single particle. In addition, the reaction of hydrogen with the Pd x Ru1–x nanoparticles changed from exothermic to endothermic as the Ru content increased. Furthermore, the prepared Pd x Ru1–x nanoparticles demonstrated enhanced CO-oxidizing catalytic activity; Pd0.5Ru0.5 nanoparticles exhibit the highest catalytic activity. This activity is much higher than that of the practically used CO-oxidizing catalyst Ru and that of the neighboring Rh, between Ru and Pd.
Surface superconductors such as Si(111)-(√7 × √3)-In (referred to as (√7 × √3)-In, hereafter) can be sensitively doped by surface dopants to tune their transition temperature (T c) even via a weak ...interaction induced by molecular overlayers. Here, we examined the effect of Cu-phthalocyanine (CuPc) and Cu-hexadecafluorophthalocyanine (F16CuPc) overlayers on the electronic structure on (√7 × √3)-In. While both molecules formed well-ordered monolayers, molecular adsorption geometries were found to be different; CuPc formed an ordered monolayer of face-on molecules, while F16CuPc tended to adsorb in a slightly tilted geometry. The normal-state electronic structures of (√7 × √3)-In covered with these molecules were found to be similar. Photoelectron spectroscopy have suggested that the charge transfer to the molecules was negligible and that the interaction between the molecules and (√7 × √3)-In were weak. Nevertheless, CuPc enhanced the superconducting transition temperature (T c) of (√7 × √3)-In by approximately 0.2 K, while F16CuPc suppressed it by approximately 1.0 K. The density functional theory (DFT) calculations combined with work function measurements showed that the surface electrons were accumulated in the region between the surface In atoms and the molecules, while molecules remain nearly uncharged. The increase in T c in the case of CuPc overlayer is explained by a hole doping into (√7 × √3)-In due to the extraction of surface electrons. In contrast, the decrease in T c for F16CuPc overlayer is attributable to the tilting adsorption geometry, possibly inducing an enhanced exchange interaction between spin magnetic moments of the molecular orbitals of inclined F16CuPc and the conduction electrons of (√7 × √3)-In. The high sensitivity of T c to the small difference in the adsorption geometry of weakly interacting molecules suggests the possibilities of modifying the superconducting properties of various surface materials.
In this paper, we consider diffeomorphisms on a closed manifold
$M$
preserving a hyperbolic Sinaĭ–Ruelle–Bowen probability measure
$\unicodeSTIX{x1D707}$
having intersections for almost every pair of ...stable and unstable manifolds. In this context, we show the ergodicity of
$\unicodeSTIX{x1D707}$
when the dimension of
$M$
is at most three. If
$\unicodeSTIX{x1D707}$
is smooth, then it is ergodic when the dimension of
$M$
is at most four. As a byproduct of our arguments, we obtain sufficient (topological) conditions which guarantee that there exists at most one hyperbolic ergodic Sinaĭ–Ruelle–Bowen probability measure. Even in higher dimensional cases, we show that every transitive topological Anosov diffeomorphism admits at most one hyperbolic Sinaĭ–Ruelle–Bowen probability measure.
We consider the shadowing property from the measure theoretical view point. Let
f
be a homeomorphism of a compact metric space. Then
f
has the shadowing property on the chain recurrent set if and ...only if there exists a shadowable
f
-invariant measure having full support. Suppose that
f
does not have the shadowing property. Then, if there exists a
f
-invariant measure having full support, then, generically, every
f
-invariant measure is not shadowable.
Using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we directly determine the spatial and energetic distributions of superatom molecular orbitals (SAMOs) of an ...Li@C60 monolayer adsorbed on a Cu(111) surface. Utilizing a weakly bonded Li+@C60 NTf2 – (NTf2 –: bis(trifluoromethanesulfonyl)imide) salt makes it possible to produce a Li@C60 monolayer with high concentration of Li@C60 molecules. Because of the very uniform adsorption geometry of Li@C60 on Cu(111), the p z -SAMO, populated above the upper hemisphere of the molecule, exhibits an isotropic and delocalized nature, with an energy that is significantly lower compared to that of C60. The isotropic overlapping of p z -SAMOs in the condensed monolayer of Li@C60 results in a laterally homogeneous STM image contributing to the formation of a free-electron-like states. These findings make an important step toward further basic research and applicative utilization of Li@C60 SAMOs.
In this paper, it is proved that every diffeomorphism possessing the filtrated pseudo-orbit shadowing property admits an approximately shadowable Lebesgue measure. Furthermore, the C1-interior of the ...set of diffeomorphisms possessing the filtrated pseudo-orbit shadowing property is characterized as the set of diffeomorphisms satisfying both Axiom A and the no-cycle condition. As a corollary, it is proved that there exists a C1-open set of diffeomorphisms, any element of which does not have the shadowing property but admits an approximately shadowable Lebesgue measure.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Partial hyperbolicity and specification Sumi, Naoya; Varandas, Paulo; Yamamoto, Kenichiro
Proceedings of the American Mathematical Society,
03/2016, Letnik:
144, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We study the specification property for partially hyperbolic dynamical systems. In particular, we show that if a partially hyperbolic diffeomorphism has two saddles with different indices, and the ...stable manifold of one of these saddles coincides with the strongly stable leaf, then it does not satisfy the specification property.
In this paper we consider diffeomorphisms preserving hyperbolic Sinaĭ–Ruelle–Bowen (SRB) probability measures
${\it\mu}$
having intersections for almost every pair of the stable and unstable ...manifolds. In this context, when the dimension of the unstable manifold is constant almost everywhere, we show the ergodicity of
${\it\mu}$
. As an application we obtain another proof of the ergodicity of a hyperbolic SRB measure for transitive surface diffeomorphisms, which is shown by Rodriguez Hertz, Rodriguez Hertz, Tahzibi and Ures Uniqueness of SRB measures for transitive diffeomorphisms on surfaces. Comm. Math. Phys.
306(1) (2011), 35–49.
We prove that if a flow exhibits a partially hyperbolic attractor Λ with splitting
and two periodic saddles with different indices such that the stable index of one of them coincides with the ...dimension of E
s
then it does not satisfy the specification property. In particular, every sectional-hyperbolic attractor with the specification property is hyperbolic. As an application, we prove that no geometric Lorenz attractor satisfies the specification property.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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