1,731 research outputs found
Matter-positronium interaction: An exact diagonalization study of the He atom - positronium system
The many-body system comprising a He nucleus, three electrons, and a positron
has been studied using the exact diagonalization technique. The purpose has
been to clarify to which extent the system can be considered as a
distinguishable positronium (Ps) atom interacting with a He atom and, thereby,
to pave the way to a practical atomistic modeling of Ps states and annihilation
in matter. The maximum value of the distance between the positron and the
nucleus is constrained and the Ps atom at different distances from the nucleus
is identified from the electron and positron densities, as well as from the
electron-positron distance and center-of-mass distributions. The polarization
of the Ps atom increases as its distance from the nucleus decreases. A
depletion of the He electron density, particularly large at low density values,
has been observed. The ortho-Ps pick-off annihilation rate calculated as the
overlap of the positron and the free He electron densities has to be corrected
for the observed depletion, specially at large pores/voids.Comment: 18 pages, 8 figure
Langmuir wave linear evolution in inhomogeneous nonstationary anisotropic plasma
Equations describing the linear evolution of a non-dissipative Langmuir wave
in inhomogeneous nonstationary anisotropic plasma without magnetic field are
derived in the geometrical optics approximation. A continuity equation is
obtained for the wave action density, and the conditions for the action
conservation are formulated. In homogeneous plasma, the wave field E
universally scales with the electron density N as E ~ N^{3/4}, whereas the
wavevector evolution varies depending on the wave geometry
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ Π½Π° ΡΠΈΠ·ΠΈΠΊΠΎ-Ρ ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° Π²ΠΎΠ΄Ρ ΠΈ Π²ΠΎΠ΄Π½ΡΡ ΡΠ°ΡΡΠ²ΠΎΡΠΎΠ²
Objectives. Changes to the properties of water caused by factors such as pressure or temperature, can only be explained by its structural changes. Scientists study changes to the properties of water due to various physical stimuli only without the addition of any substances. Examples of stimuli are acoustic exposure, thermal exposure, pressure variation, shaking, intensive vibration treatment followed by dilutions, vortexing, bubble generation, inter alia.The aim of the present review article is to summarize the available data on how the above processes affect the physicochemical and biological properties of water and aqueous solutions.Results. It has been shown that heating makes water less compressible and decreases air solubility in water, while cooling enhances its viscosity. Acoustic exposure makes the structure of water become coarse-grained, followed by an increase the number of large clusters, pH and temperature inside a cavitation bubble. High pressure enhances the viscosity, self-diffusion, and compressibility of water. For bubble processed water, there are changes in the spin-spin and spin-lattice relaxation times. Reactive oxygen species are formed, as well as increased solubility of gases in liquids and reduced friction. Vortex process technology causes an increase of electrical conductivity of water and reduced viscosity. Intensive vibration treatment and dilution processes result in changes in electrical conductivity of water, dissolved gas concentration, ultrasonic wave velocity, ΡΠ, surface tension, dielectric constant, and spectral response. There is also data to support the biological effects of different types of physical treatment of solutions.Conclusions. This review shows that physical treatment of water can induce changes both in physicochemical and biological properties of water and aqueous solutions.Π¦Π΅Π»ΠΈ. ΠΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠ²ΠΎΠΉΡΡΠ² Π²ΠΎΠ΄Ρ, Π²ΡΠ·Π²Π°Π½Π½ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌΠΈ ΡΠ°ΠΊΡΠΎΡΠ°ΠΌΠΈ, ΡΠ°ΠΊΠΈΠΌΠΈ ΠΊΠ°ΠΊ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ ΠΈΠ»ΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ°, ΠΌΠΎΠ³ΡΡ ΠΎΠ±ΡΡΡΠ½ΡΡΡΡΡ ΡΠΎΠ»ΡΠΊΠΎ ΡΡΡΡΠΊΡΡΡΠ½ΡΠΌΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡΠΌΠΈ Π²ΠΎΠ΄Ρ. Π£ΡΠ΅Π½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΡΡΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠ²ΠΎΠΉΡΡΠ² Π²ΠΎΠ΄Ρ, ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΡΡΠΈΠ΅ ΠΈΡΠΊΠ»ΡΡΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΈΠ·-Π·Π° ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ°Π·Π΄ΡΠ°ΠΆΠΈΡΠ΅Π»Π΅ΠΉ ΠΈ Π±Π΅Π· Π΄ΠΎΠ±Π°Π²Π»Π΅Π½ΠΈΡ ΠΊΠ°ΠΊΠΈΡ
-Π»ΠΈΠ±ΠΎ Π²Π΅ΡΠ΅ΡΡΠ². ΠΡΠΈΠΌΠ΅ΡΠ°ΠΌΠΈ ΡΠ°ΠΊΠΈΡ
ΡΠ°Π·Π΄ΡΠ°ΠΆΠΈΡΠ΅Π»Π΅ΠΉ ΡΠ²Π»ΡΡΡΡΡ Π°ΠΊΡΡΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΈ ΡΠ΅ΠΏΠ»ΠΎΠ²ΠΎΠ΅ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅, ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π΄Π°Π²Π»Π΅Π½ΠΈΡ, Π²ΡΡΡΡΡ
ΠΈΠ²Π°Π½ΠΈΠ΅, ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½Π°Ρ Π²ΠΈΠ±ΡΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° Ρ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠΈΠΌ ΡΠ°Π·Π²Π΅Π΄Π΅Π½ΠΈΠ΅ΠΌ, Π²ΠΈΡ
ΡΠ΅Π²ΠΎΠ΅ ΠΏΠ΅ΡΠ΅ΠΌΠ΅ΡΠΈΠ²Π°Π½ΠΈΠ΅, ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΡΠ·ΡΡΡΠΊΠΎΠ² ΠΈ Ρ.Π΄.Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΠ±Π·ΠΎΡΠ° ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠ±ΠΎΠ±ΡΠ΅Π½ΠΈΠ΅ ΠΈΠΌΠ΅ΡΡΠΈΡ
ΡΡ Π΄Π°Π½Π½ΡΡ
ΠΎ ΡΠΎΠΌ, ΠΊΠ°ΠΊ Π²ΡΡΠ΅ΡΠΊΠ°Π·Π°Π½Π½ΡΠ΅ ΠΏΡΠΎΡΠ΅ΡΡΡ Π²Π»ΠΈΡΡΡ Π½Π° ΡΠΈΠ·ΠΈΠΊΠΎ-Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° Π²ΠΎΠ΄Ρ ΠΈ Π²ΠΎΠ΄Π½ΡΡ
ΡΠ°ΡΡΠ²ΠΎΡΠΎΠ².Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π½Π°Π³ΡΠ΅Π² Π΄Π΅Π»Π°Π΅Ρ Π²ΠΎΠ΄Ρ ΠΌΠ΅Π½Π΅Π΅ ΡΠΆΠΈΠΌΠ°Π΅ΠΌΠΎΠΉ ΠΈ ΡΠ½ΠΈΠΆΠ°Π΅Ρ ΡΠ°ΡΡΠ²ΠΎΡΠΈΠΌΠΎΡΡΡ Π²ΠΎΠ·Π΄ΡΡ
Π° Π² Π²ΠΎΠ΄Π΅, Π° ΠΎΡ
Π»Π°ΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΏΠΎΠ²ΡΡΠ°Π΅Ρ Π΅Π΅ Π²ΡΠ·ΠΊΠΎΡΡΡ. ΠΠΊΡΡΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΡΠΎΠΌΡ, ΡΡΠΎ ΡΡΡΡΠΊΡΡΡΠ° Π²ΠΎΠ΄Ρ ΡΡΠ°Π½ΠΎΠ²ΠΈΡΡΡ ΠΊΡΡΠΏΠ½ΠΎΠ·Π΅ΡΠ½ΠΈΡΡΠΎΠΉ, ΡΡΠΎ ΡΠΎΠΏΡΠΎΠ²ΠΎΠΆΠ΄Π°Π΅ΡΡΡ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π° ΠΊΡΡΠΏΠ½ΡΡ
ΠΊΠ»Π°ΡΡΠ΅ΡΠΎΠ², ΡΠ ΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π²Π½ΡΡΡΠΈ ΠΊΠ°Π²ΠΈΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΏΡΠ·ΡΡΡ. ΠΡΡΠΎΠΊΠΎΠ΅ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ ΡΠ°ΠΊΠΈΡ
ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΠΎΠΉΡΡΠ² Π²ΠΎΠ΄Ρ, ΠΊΠ°ΠΊ Π²ΡΠ·ΠΊΠΎΡΡΡ, ΡΠ°ΠΌΠΎΠ΄ΠΈΡΡΡΠ·ΠΈΡ ΠΈ ΡΠΆΠΈΠΌΠ°Π΅ΠΌΠΎΡΡΡ. ΠΠ»Ρ Π²ΠΎΠ΄Ρ, ΠΎΠ±ΡΠ°Π±ΠΎΡΠ°Π½Π½ΠΎΠΉ ΠΏΡΠ·ΡΡΡΠΊΠ°ΠΌΠΈ, ΠΏΡΠΎΠΈΡΡ
ΠΎΠ΄ΡΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ Π²ΡΠ΅ΠΌΠ΅Π½ ΡΠΏΠΈΠ½-ΡΠΏΠΈΠ½ΠΎΠ²ΠΎΠΉ ΠΈ ΡΠΏΠΈΠ½-ΡΠ΅ΡΠ΅ΡΠΎΡΠ½ΠΎΠΉ ΡΠ΅Π»Π°ΠΊΡΠ°ΡΠΈΠΈ, ΠΎΠ±ΡΠ°Π·ΡΡΡΡΡ Π°ΠΊΡΠΈΠ²Π½ΡΠ΅ ΡΠΎΡΠΌΡ ΠΊΠΈΡΠ»ΠΎΡΠΎΠ΄Π°, Π° ΡΠ°ΠΊΠΆΠ΅ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ ΠΏΠΎΠ²ΡΡΠ΅Π½Π½Π°Ρ ΡΠ°ΡΡΠ²ΠΎΡΠΈΠΌΠΎΡΡΡ Π³Π°Π·ΠΎΠ² Π² ΠΆΠΈΠ΄ΠΊΠΎΡΡΡΡ
Π½Π°ΡΡΠ΄Ρ ΡΠΎ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ Π²ΡΠ·ΠΊΠΎΡΡΠΈ. ΠΠΈΡ
ΡΠ΅Π²ΠΎΠΉ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠΉ ΠΏΡΠΎΡΠ΅ΡΡ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄Π½ΠΎΡΡΠΈ Π²ΠΎΠ΄Ρ ΠΈ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ Π²ΡΠ·ΠΊΠΎΡΡΠΈ. ΠΠ½ΡΠ΅Π½ΡΠΈΠ²Π½Π°Ρ Π²ΠΈΠ±ΡΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° ΠΈ ΠΏΡΠΎΡΠ΅ΡΡΡ ΡΠ°Π·Π±Π°Π²Π»Π΅Π½ΠΈΡ ΠΏΡΠΈΠ²ΠΎΠ΄ΡΡ ΠΊ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ Π½Π΅ΠΊΠΎΡΠΎΡΡΡ
Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ Π²ΠΎΠ΄Ρ, ΡΠ°ΠΊΠΈΡ
ΠΊΠ°ΠΊ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄Π½ΠΎΡΡΡ, ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡ ΡΠ°ΡΡΠ²ΠΎΡΠ΅Π½Π½ΠΎΠ³ΠΎ Π³Π°Π·Π°, ΡΠΊΠΎΡΠΎΡΡΡ ΡΠ»ΡΡΡΠ°Π·Π²ΡΠΊΠΎΠ²ΠΎΠΉ Π²ΠΎΠ»Π½Ρ, ΡΠ, ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ½ΠΎΠ΅ Π½Π°ΡΡΠΆΠ΅Π½ΠΈΠ΅, Π΄ΠΈΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΏΡΠΎΠ½ΠΈΡΠ°Π΅ΠΌΠΎΡΡΡ ΠΈ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΠΉ ΠΎΡΠΊΠ»ΠΈΠΊ. Π ΡΠ°Π±ΠΎΡΠ΅ ΡΠ°ΠΊΠΆΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ Π΄Π°Π½Π½ΡΠ΅, ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°ΡΡΠΈΠ΅ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΡΡΠ΅ΠΊΡΡ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΡΠΈΠΏΠΎΠ² ΡΠΏΠΎΠΌΡΠ½ΡΡΠΎΠΉ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ ΡΠ°ΡΡΠ²ΠΎΡΠΎΠ².ΠΡΠ²ΠΎΠ΄Ρ. ΠΠ°Π½Π½ΡΠΉ ΠΎΠ±Π·ΠΎΡ ΠΏΠΎΠΊΠ°Π·ΡΠ²Π°Π΅Ρ, ΡΡΠΎ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° Π²ΠΎΠ΄Ρ ΠΌΠΎΠΆΠ΅Ρ Π²ΡΠ·ΡΠ²Π°ΡΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΊΠ°ΠΊ ΡΠΈΠ·ΠΈΠΊΠΎ-Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
, ΡΠ°ΠΊ ΠΈ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΠΎΠΉΡΡΠ² Π²ΠΎΠ΄Ρ ΠΈ Π²ΠΎΠ΄Π½ΡΡ
ΡΠ°ΡΡΠ²ΠΎΡΠΎΠ²
Macro- and micro-strain in GaN nanowires on Si(111)
We analyze the strain state of GaN nanowire ensembles by x-ray diffraction.
The nanowires are grown by molecular beam epitaxy on a Si(111) substrate in a
self-organized manner. On a macroscopic scale, the nanowires are found to be
free of strain. However, coalescence of the nanowires results in micro-strain
with a magnitude from +-0.015% to +-0.03%.This micro-strain contributes to the
linewidth observed in low-temperature photoluminescence spectra
Logarithmic perturbation theory for radial Klein-Gordon equation with screened Coulomb potentials via expansions
The explicit semiclassical treatment of logarithmic perturbation theory for
the bound-state problem within the framework of the radial Klein-Gordon
equation with attractive real-analytic screened Coulomb potentials, contained
time-component of a Lorentz four-vector and a Lorentz-scalar term, is
developed. Based upon -expansions and suitable quantization conditions a
new procedure for deriving perturbation expansions is offered. Avoiding
disadvantages of the standard approach, new handy recursion formulae with the
same simple form both for ground and excited states have been obtained. As an
example, the perturbation expansions for the energy eigenvalues for the
Hulth\'en potential containing the vector part as well as the scalar component
are considered.Comment: 14 pages, to be submitted to Journal of Physics
Foam Metals High-Temperature Electrical Characteristicsβ Investigation
In the work presented we have carried out experimental investigations of high- temperature electrophysical
properties of foam metals. We have obtained data of foam nickel and foam copper resistivity
and temperature coefficients of resistance (TCR) versus their plane deformation degree within the
temperature range from 100 to 950 ΒΊΠ‘
Structure and hardness of B2 ordered refractory AlNbTiVZr0.5 high entropy alloy after high-pressure torsion
High-pressure torsion (HPT) at room temperature was applied to an AlNbTiVZr0.5 refractory high entropy alloy. In the initial as-cast condition the alloy was composed of a coarse-grained B2 matrix phase and a continuous network of C14 Laves phase particles with the volume fraction of 19%. HPT resulted in the formation of a nanocrystalline structure in the B2 matrix with an average size of grains/subgrains of 25 nm after 5 revolution
The "Horizon-T" Experiment: Extensive Air Showers Detection
Horizon-T is an innovative detector system constructed to study Extensive Air
Showers (EAS) in the energy range above 10^16 eV coming from a wide range of
zenith angles (0 - 85 degrees). The system is located at Tien Shan
high-altitude Science Station of Lebedev Physical Institute of the Russian
Academy of Sciences at approximately 3340 meters above the sea level. It
consists of eight charged particle detection points separated by the distance
up to one kilometer as well as optical detector subsystem to view the
Vavilov-Cerenkov light from the EAS. The time resolution of charged particles
and Vavilov-Cerenkov light photons passage of the detector system is a few ns.
This level of resolution allows conducting research of atmospheric development
of individual EAS.Comment: Initial technical note for Horizon-T experiment, updated with recent
detector upgrades, 11/2016. Updated 12/2017 with minor edits. Large upgrade
will be in another articl
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