1,902 research outputs found
Changes of some blood indices and myocardial electrolyte content during hypokinesia
Using special hypokinetic cages, the volume changes of circulating blood, its hematocrit and protein content, volume ratios between extra- and intracellular liquids in the body, as well as electrolyte content in the blood and myocardium during hypokinesia were investigated experimentally in rabbits
Kohn anomaly and interplay of electron-electron and electron-phonon interactions in epitaxial graphene
The interplay of electron-phonon (el-ph) and electron-electron (el-el)
interactions in epitaxial graphene is studied by directly probing its
electronic structure. We found a strong coupling of electrons to the soft part
of the A1g phonon evident by a kink at 150+/-15 meV, while the coupling of
electrons to another expected phonon E2g at 195 meV can only be barely
detected. The possible role of the el-el interaction to account for the
enhanced coupling of electrons to the A1g phonon, and the contribution of el-ph
interaction to the linear imaginary part of the self energy at high binding
energy are also discussed. Our results reveal the dominant role of the A1g
phonon in the el-ph interaction in graphene, and highlight the important
interplay of el-el and el-ph interactions in the self energy of graphene.Comment: accepted to Phys. Rev.
Weak Measurements of Light Chirality with a Plasmonic Slit
We examine, both experimentally and theoretically, an interaction of tightly
focused polarized light with a slit on a metal surface supporting
plasmon-polariton modes. Remarkably, this simple system can be highly sensitive
to the polarization of the incident light and offers a perfect
quantum-weak-measurement tool with a built-in post-selection in the
plasmon-polariton mode. We observe the plasmonic spin Hall effect in both
coordinate and momentum spaces which is interpreted as weak measurements of the
helicity of light with real and imaginary weak values determined by the input
polarization. Our experiment combines advantages of (i) quantum weak
measurements, (ii) near-field plasmonic systems, and (iii) high-numerical
aperture microscopy in employing spin-orbit interaction of light and probing
light chirality.Comment: 5 pages, 3 figure
On the Cartan Model of the Canonical Vector Bundles over Grassmannians
We give a representation of canonical vector bundles over Grassmannian
manifolds as non-compact affine symmetric spaces as well as their Cartan model
in the group of the Euclidean motions.Comment: 6 page
Effect of hypokinesia on blood microcirculation
Blood microcirculation in the region of the scleral bulbar conjunctiva and the nail folds on the fingers and toes was studied in 18 practically healthy men during 182 day antiorthostatic hypokinesia and 30 day rehabilitation period. Marked changes in microcirculation in the sclera and feet and less evident changes on the hands was revealed. A complex of special prophylactic physical exercises had a distinctly favorable effect on circulation in the hands
The Poisson equations in the nonholonomic Suslov problem: Integrability, meromorphic and hypergeometric solutions
We consider the problem of integrability of the Poisson equations describing
spatial motion of a rigid body in the classical nonholonomic Suslov problem. We
obtain necessary conditions for their solutions to be meromorphic and show that
under some further restrictions these conditions are also sufficient. The
latter lead to a family of explicit meromorphic solutions, which correspond to
rather special motions of the body in space. We also give explicit extra
polynomial integrals in this case.
In the more general case (but under one restriction), the Poisson equations
are transformed into a generalized third order hypergeometric equation. A study
of its monodromy group allows us also to calculate the "scattering" angle: the
angle between the axes of limit permanent rotations of the body in space
Quantum-secured blockchain
Blockchain is a distributed database which is cryptographically protected
against malicious modifications. While promising for a wide range of
applications, current blockchain platforms rely on digital signatures, which
are vulnerable to attacks by means of quantum computers. The same, albeit to a
lesser extent, applies to cryptographic hash functions that are used in
preparing new blocks, so parties with access to quantum computation would have
unfair advantage in procuring mining rewards. Here we propose a possible
solution to the quantum era blockchain challenge and report an experimental
realization of a quantum-safe blockchain platform that utilizes quantum key
distribution across an urban fiber network for information-theoretically secure
authentication. These results address important questions about realizability
and scalability of quantum-safe blockchains for commercial and governmental
applications.Comment: 7 pages, 2 figures; published versio
Hadron resonance gas and nonperturbative QCD vacuum at finite temperature
We study the nonperturbative QCD vacuum with two light quarks at finite
temperature in the framework of hadron resonance gas. Temperature dependence of
the quark and gluon condensates in the confined phase are obtained. We
demonstrate that the quark condensate and one half (chromo-electric component)
of gluon condensate evaporate at the same temperature, which corresponds to the
temperature of quark-hadron phase transition. Critical temperature is T_c~190
MeV when temperature shift of hadron masses is taken into account.Comment: 8 pages, 4 figures; to appear in JETP Lett.; v2: references adde
Quasiparticle-like peaks, kinks, and electron-phonon coupling at the (,0) regions in the CMR oxide LaSrMnO
Using Angle-Resolved Photoemission (ARPES), we present the first observation
of sharp quasiparticle-like peaks in a CMR manganite. We focus on the (,0)
regions of k-space and study their electronic scattering rates and dispersion
kinks, uncovering the critical energy scales, momentum scales, and strengths of
the interactions that renormalize the electrons. To identify these bosons we
measured phonon dispersions in the energy range of the kink by inelastic
neutron scattering (INS), finding a good match in both energy and momentum to
the oxygen bond-stretching phonons
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