Explicit summation of the constituent WKB series and new approximate wave functions

The independent solutions of the one-dimensional Schr\"odinger equation are approximated by means of the explicit summation of the leading constituent WKB series. The continuous matching of the particular solutions gives the uniformly valid analytical approximation to the wave functions. A detailed numerical verification of the proposed approximation is performed for some exactly solvable problems arising from different kinds of potentials.Comment: 8 pages, LaTeX, minor changes and stylistic improvements, final versio

About the personal approach in physical education of students

In recent scientific publications on improving the students’ physical education learning process, many authors point to the need for a personal approach to each student, but the technology of such an approach are not described. The research conducted at the Department of Physical Education and Health of Ryazan State Medical University has shown that the methodological basis of the personality-oriented educational process of physical education of students is a systematic approach. The approach offered by P. K. Anokhin, aims to get the final useful result in the process of any activity. The low level of motivation for regular physical exercises noted among students largely depends on the fact that students do not know what useful result they will receive from classes and when they will get it. Tested at the Department of Physical Education and Health of Ryazan State Medical University for many years, the methodology of individual planning to increase the level of physical fitness when passing the physical fitness standards is easy to apply, but the use of tables in each university should be different according to the local contingent of students

Plasma immersion ion implantation for surface treatment of complex branched structures

The paper presents experimental results demonstrating the capabilities of plasma immersion ion implantation of silicon (Si) for surface treatment of complex branched structures such are self-expanding intravascular nickel-titanium (NiTi) stents. Using NiTi stents of diameter 4 and 8 mm, it is shown that plasma immersion ion implantation can provide rather homogeneous doping of their outer and inner surfaces with Si atoms. Also presented are research data on the processes that determine the thickness, composition, and structure of surface layers subjected to this type of treatment

Conical refraction lasing in a Nd:YVO4 laser with a conerefringent KGW element

A conical refraction (CR) laser based on a separate gain medium (Nd:YVO4) and an intracavity CR element (KGW) was demonstrated. The decoupling of the gain and CR media enabled the laser to produce a well-behaved CR laser beam with excellent quality, while reducing the complexity of the pumping scheme. The proposed laser setup has the potential for power scaling using the efficient diode pumping approach and the properties of the generated CR beam are independent from the laser gain medium

Non-resonant operation of microcavity Brillouin lasers

We present theoretical framework to describe Brillouin lasing in microcavities in the case of a significant mismatch between the Brillouin shift and the cavity intermode spacing. We show that despite an increase of the lasing threshold a significant increase of the Brillouin power in comparison with the resonance case is achievable. A necessary condition for this effect is the optimal value of the pump frequency detuning from the cavity mode frequency. An increase of the Brillouin threshold is accompanied by narrowing of the spectrum range where the Brillouin signal could be generated in non-resonant case. Besides, with the optimal pump frequency detuning the Brillouin signal noise level is reduced. Analytical results are in quantitative agreement with the results of numerical simulations

Interpretation of the Spectral Inhomogeneity in the 10 TV Region in Terms of a Close Source

The description of the inhomogeneity of the cosmic ray spectrum in the region of 10 TV, which is observed in experimental data, in terms of isotropic diffusion from a single close source is considered. It is shown that such a description is possible, and the area of possible localization of the source in space and time and its energy are found. The method of penalty functions is used to account for the data on the spectrum of all particles

Plasma immersion ion implantation for surface treatment of complex branched structures

The paper presents experimental results demonstrating the capabilities of plasma immersion ion implantation of silicon (Si) for surface treatment of complex branched structures such are self-expanding intravascular nickel-titanium (NiTi) stents. Using NiTi stents of diameter 4 and 8 mm, it is shown that plasma immersion ion implantation can provide rather homogeneous doping of their outer and inner surfaces with Si atoms. Also presented are research data on the processes that determine the thickness, composition, and structure of surface layers subjected to this type of treatment

Ultra-high Q whispering-gallery-mode bottle microresonators: Properties and applications

Highly prolate-shaped whispering-gallery-mode "bottle microresonators" have recently attracted considerable attention due to their advantageous properties. We experimentally show that such resonators offer ultra-high quality factors, microscopic mode volumes, and near lossless in- and out-coupling of light using ultra-thin optical fibers. Additionally, bottle microresonators have a simple and customizable mode structure. This enables full tunability using mechanical strain and simultaneous coupling of two ultra-thin coupling fibers in an add-drop configuration. We present two applications based on these characteristics: In a cavity quantum electrodynamics experiment, we actively stabilize the frequency of the bottle microresonator to an atomic transition and operate it in an ultra-high vacuum environment in order to couple single laser-cooled atoms to the resonator mode. In a second experiment, we show that the bottle microresonator can be used as a low-loss, narrow-band add-drop filter. Using the Kerr effect of the silica resonator material, we furthermore demonstrate that this device can be used for single-wavelength all-optical signal processing