The formulation of the problem of surface control of an electroactive unidirectional multicomponent elastic wave propagation in an infinite piezoelectric waveguide over a finite time interval is ...discussed. Based on the conditions for conjugation of electromechanical fields on the surface of piezoelectric media, as well as on the nature of possible surface electromechanical effects, a variety of surface dynamic effects is considered through the components of the elastic displacement vector, the mechanical stress tensor, the tangential component of the electric field strength and the normal component of the electric field displacement. The possibility of setting the control problem in the case of three-component electroacoustic waves depending on the anisotropy of the piezoelectric material of the waveguide is studied. The anisotropy of a piezoelectric medium leads to the formulation of an initial-boundary mathematical problem for controlling the motion of a multicomponent system. The variety of surface actions leads to the formulation of heterogeneous initial-boundary mathematical problems with surface actions of the first kind, with surface actions of the second kind, as well as for the case of mixed surface actions. An invariant record of heterogeneous initial-boundary mathematical problems is proposed in the form of a system of inhomogeneous quasi-static electro-elasticity equations, with homogeneous boundary conditions and inhomogeneous conditions of the initial and final states
.
Abstract
In the region of the first positive system (FPS) band of spectrum of nitrogen in acoustoplasma, under laboratory conditions, the generation of intense lines was experimentally obtained at ...forbidden transitions of a singly ionized nitrogen molecule at 654.81 and 658.36 nm. The intense lines obtained correspond to the stimulated emission mechanism. The intensity of the forbidden lines significantly (up to 17 times) exceeded the intensity of neighboring lines in the spectrum of the first positive system band of nitrogen. Spectroscopic studies did not allow resolution of the rotational spectrum. However, the spectral width for both lines at forbidden transitions is much smaller than the FPS bandwidth of nitrogen. The result obtained is explained by an analogue of Raman scattering and an acoustoplasmic medium, which remove the prohibitions characteristic of dipole radiation.
JLab E12-19-002 Experiment is planned to measure the Λ-binding energies of
3
Λ
H
J
π
= 1/2
+
or 3/2
+
(
T
= 0) and
4
Λ
H (1
+
) at JLab Hall C. The expected accuracy for the binding-energy ...measurement is |Δ
B
total
Λ
| ≃ 70 keV. The accurate spectroscopy for these light hypernuclei would shed light on the puzzle of the small binding energy and short lifetime of
3
Λ
H, and the chargesymmetry breaking in the ΛN interaction. We aim to perform the experiment in 2025.
We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to ...short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.
The results to increase the rated energy of the linear accelerator of electrons LUE-75 from 50 to 75 MeV are presented. The characteristics of the beam are investigated, and the measured energy ...spectra of the obtained beams are presented in the range of 50–75 MeV at the average intensity up to 10 μA. The modernization of the elements of magnetic optics for the parallel transfer path was performed, and the beam was tracked to the end of the transport channel.
Experimentally, under laboratory conditions in the nitrogen acoustic plasma in the region of the forbidden lines at 654.81 and 658.36 nm, a spectral emission line of high intensity was obtained (up ...to 17 stronger than the neighboring lines of the first positive system of nitrogen). The results were obtained both in pure low-pressure nitrogen acoustic plasma (several hundreds of Pa) and various mixtures containing nitrogen, including the CO
2
: N
2
: He = 1 : 1 : 8 mixture. The results obtained are explained by the acoustic plasma state of the discharge and an analog of Rahman scattering, which remove some of the quantum mechanical prohibitions. The possible influence of the Coriolis force is also considered.
The aim of this article is to represent the characterization of the clinical case of chemotherapy-related atrial fibrillation (AF) development in the young woman, elaborated as a result of multiple ...neoadjuvant and adjuvant modes of the intake of chemotherapy (both anthracycline based and non-anthracycline ones). In this case, the noted disturbances of heart rhythm should be recognized as a manifestation of cardiotoxicity. The latter implies the degree of detrimental effect of chemotherapeutical medication on the morphophynctional parameters of the cardiovascular system. Anthracycline drugs, being highly effective chemotherapytical agents, provide well-known toxic effects on the heart and vessels. Anthracycline mediated cardiotoxicity is a well- known veracity that dates back to the 60s of the last century, but up to now this medication sustains irreplaceable components of big volume of chemotherapy modes. Moreover, it should be noted that relatively newer drugs also posses certain cardiotoxicogenic potential.
The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we ...present the details of performed measurements and report on the status of the ongoing analysis.
For the production of a polarized antiproton beam, various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The ...polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization, a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.
We investigate the radiation from a bunch of relativistic electrons moving along the cylindrical waveguide axis, assuming that the waveguide is partially loaded by a medium with periodic dielectric ...permittivity and magnetic permeability. The spectral distribution of the radiation energy flux through the cross section of the waveguide is studied at large distances from the medium. The analysis is based on the corresponding exact solution of Maxwell equations for the case of a single electron moving along the waveguide axis. The results of numerical calculations are presented in the special case of layered medium consisting of a finite number of dielectric plates separated by vacuum gaps. We show that under certain conditions on the problem parameters the quasi-coherent Cherenkov radiation generated by the electron bunch inside the plates is self-amplified at certain waveguide modes. A visual explanation of this phenomenon is provided that reproduces the main features to rather good accuracy.
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