2,159 research outputs found
Comment on "Quantitative x-ray photoelectron spectroscopy: Quadrupole effects, shake up, Shirley background, and relative sensitivity factors from a database of true x-ray photoelectron spectra"
This Comment demonstrates that a comparison analysis by Seah and Gilmore
between experimental data on the X-ray photoelectron spectroscopy intensities
and theoretical data by Trzhaskovskaya et al. is misleading due to a number of
serious errors made by Seah and Gilmore (Phys. Rev. B, 73, 174113).Comment: 7 pages, 3 figures, submitted to Phys. Rev.
Pharmacological Correction of Neurological Disorders in Case of Multiple Sclerosis
The article analyzes the possibility of drug correction of common neurological disorders (pain, anxiety, depression, insomnia) using antidepressants under the conditions of experimental equivalent of multiple sclerosis on the background of basic drug therapy with methylprednisolone.Assessment of antidepressants antinociceptive potential identified “a range of activity” of the mentioned medicines (analgesic activity of classical amitriptyline antidepressant was accepted as conventional unit): paroxetine (0.9 c.u.), amitriptyline (1 c.u.), fluoxetine (1.11 c.u.) and trittico (1.16 c.u.).Comparative analysis of the duration of animals’ fading in the water at the forced swimming (Porsolt forced swimming test) found that the ability to weaken the level of anxiety and concern was the most significant for trittico and paroxetine groups. Immobilization time was 1.7 (p£0.05) and 1.6 (p£0.05), respectively, which was shorter than the corresponding figures of the active control group. The effect of antidepressants on latency, sleep duration when administered on a background of basic drug therapy with methylprednisolone was characterized by the following indicators: trittico (-66.5% and + 133.45%)³fluoxetine (-60.5% and + 117.79%)³paroxetine (-61.8% and + 93.59%)³amitriptyline (-52.75% and + 81.85%).Thus, trittico and paroxetine were reasonable to administer under the experimental equivalent of multiple sclerosis taking into account the basic hormonal therapy as a means of drug correction of pain, anxiety, depression and sleep disorders
Remote atomic clock synchronization via satellites and optical fibers
In the global network of institutions engaged with the realization of
International Atomic Time (TAI), atomic clocks and time scales are compared by
means of the Global Positioning System (GPS) and by employing telecommunication
satellites for two-way satellite time and frequency transfer (TWSTFT). The
frequencies of the state-of-the-art primary caesium fountain clocks can be
compared at the level of 10e-15 (relative, 1 day averaging) and time scales can
be synchronized with an uncertainty of one nanosecond. Future improvements of
worldwide clock comparisons will require also an improvement of the local
signal distribution systems. For example, the future ACES (atomic clock
ensemble in space) mission shall demonstrate remote time scale comparisons at
the uncertainty level of 100 ps. To ensure that the ACES ground instrument will
be synchronized to the local time scale at PTB without a significant
uncertainty contribution, we have developed a means for calibrated clock
comparisons through optical fibers. An uncertainty below 50 ps over a distance
of 2 km has been demonstrated on the campus of PTB. This technology is thus in
general a promising candidate for synchronization of enhanced time transfer
equipment with the local realizations of UTC . Based on these experiments we
estimate the uncertainty level for calibrated time transfer through optical
fibers over longer distances. These findings are compared with the current
status and developments of satellite based time transfer systems, with a focus
on the calibration techniques for operational systems
Mesoscopic cross-film cryotrons: Vortex trapping and dc-Josephson-like oscillations of the critical current
We investigate theoretically and experimentally the transport properties of a
plain Al superconducting strip in the presence of a single straight
current-carrying wire, oriented perpendicular to the superconducting strip. It
is well known that the critical current of the superconducting strip, Ic, in
such cryotron--like system can be tuned by changing the current in the control
wire, Iw. We demonstrated that the discrete change in the number of the pinned
vortices/antivortices inside the narrow and long strip nearby the
current-carrying wire results in a peculiar oscillatory dependence of Ic on Iw.Comment: 8 pages, 8 figure
Localization of superconductivity in superconductor-electromagnet hybrids
We investigate the nucleation of superconductivity in a superconducting Al
strip under the influence of the magnetic field generated by a current-carrying
Nb wire, perpendicularly oriented and located underneath the strip. The
inhomogeneous magnetic field, induced by the Nb wire, produces a spatial
modulation of the critical temperature T_c, leading to a controllable
localization of the superconducting order parameter (OP) wave function. We
demonstrate that close to the phase boundary T_c(B_ext) the localized OP
solution can be displaced reversibly by either applying an external
perpendicular magnetic field B_ext or by changing the amplitude of the
inhomogeneous field.Comment: 10 pages, 6 figure
Electromagnetic wave refraction at an interface of a double wire medium
Plane-wave reflection and refraction at an interface with a double wire
medium is considered. The problem of additional boundary conditions (ABC) in
application to wire media is discussed and an ABC-free approach, known in the
solid state physics, is used. Expressions for the fields and Poynting vectors
of the refracted waves are derived. Directions and values of the power density
flow of the refracted waves are found and the conservation of the power flow
through the interface is checked. The difference between the results, given by
the conventional model of wire media and the model, properly taking into
account spatial dispersion, is discussed.Comment: 17 pages, 11 figure
Hybridization and interference effects for localized superconducting states in strong magnetic field
Within the Ginzburg-Landau model we study the critical field and temperature
enhancement for crossing superconducting channels formed either along the
sample edges or domain walls in thin-film magnetically coupled superconducting
- ferromagnetic bilayers. The corresponding Cooper pair wave function can be
viewed as a hybridization of two order parameter (OP) modes propagating along
the boundaries and/or domain walls. Different momenta of hybridized OP modes
result in the formation of vortex chains outgoing from the crossing point of
these channels. Near this crossing point the wave functions of the modes merge
giving rise to the increase in the critical temperature for a localized
superconducting state. The origin of this critical temperature enhancement
caused by the wave function squeezing is illustrated for a limiting case of
approaching parallel boundaries and/or domain walls. Using both the variational
method and numerical simulations we have studied the critical temperature
dependence and OP structure vs the applied magnetic field and the angle between
the crossing channels.Comment: 12 pages, 13 figure
Effect of preparation conditions on physic-chemical properties of tin-doped nanocrystalline indium oxide
In this paper the results of investigation of phase formation and change of concentration of free electrons (Ne) in indium tin oxide system during heat treatment of coprecipitated hydroxides of indium and tin from nitric and hydrochloric solutions and also, for comparison melts of salts nitrates by an alkaline reactant (NH4OH) are considered.The performed investigation allowed to set the optimal condition of preparation of polycrystalline tin-doped indium oxide with maximal electron concentration
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