Физика список научных статей
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89Y nuclear spin-lattice relaxation in SrY2O4: Ho3+ single crystals
Measurements of 89Y nuclear spin-lattice relaxation in SrY2O4:Ho3+ crystals for the magnetic field B parallel to the crystal c axis show that 89Y at T < 20 K relaxes due to fluctuating magnetic field created only by Ho13+ transitions between the ground and the first excited Zeeman sublevels of the...
2017 / Dooglav A.V., Gilmutdinov I.F., Katkov V.I., Kiiamov A.G., Mukhamedshin I.R.WOSScopus -
Magnetic properties of DyF3 micro- and nanoparticles
The AC/DC magnetic susceptibility and heat capacity of microsized and nanosized DyF3 particles were measured. These measurements were used to estimate the influence of the size of DyF3 particles on their magnetic properties. Dipolar ferromagnetic transition was observed in susceptibility...
2017 / Alakshin E.M., Kondratyeva E.I., Nuzhina D.S., Iakovleva M.F., Gilmutdinov I.F., Kuzmin V.V., Safiullin K.R., Kiiamov A.G., Klochkov A.V., Tagirov M.S.WOSScopus -
Study of the crystal field and rare-earth magnetism in YF3: Yb3+
The electron paramagnetic resonance spectra (X-band,=~ 9.42 GHz) of Yb3+ ions have been measured at temperature 15=in YF3:Yb3+ single crystals. The principal values of the g-tensors, gb=g1=1.67, g2=2.42, g3=5.41, and directions=[0, 1,=? 0],=n=[±sin(54.8°), 0, cos(54.8°)], n3=[∓sin(35.2°), 0,...
2017 / Savinkov A.V., Gabbasov B.F., Morozov O.A., Kiiamov A.G., Tagirov M.S.WOSScopus -
Superhyperfine interactions in Ce3+ doped LiYF4 crystal: ENDOR measurements
The first observation of the resolved Mims electron-nuclear double resonance (ENDOR) spectra from the nearby and remote nuclei of 19F and 7Li nuclei on impurity Ce3+ ions in LiYF4 crystal is reported. It shows that LiYF4:Ce3+ system can be exploited as a convenient matrix for performing spin...
2017 / Gafurov M.R., Mamin G.V., Kurkin I.N., Rodionov A.A., Orlinskii S.B.WOSScopus -
Calculation of g-tensor of rare-earth ions with account of isotropic reduction of orbital momentum
g-tensor components for a Kramers doublet of an impurity ion doped into dielectric crystal are expressed through coefficients of expansion of the doublet wavefunctions in the basis of full momentum of the impurity ion taking into account isotropic reduction of orbital momentum in Zeeman energy due...
2017 / Dudalov A.S., Solovyev O.V.WOSScopus -
Disorder effect and the vortex phase transition in layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br
We report systematic detailed measurement of the superconducting properties on the layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br near 80 K and the effect of disorder on the superconducting transition temperature Tc. The reversible part of the magnetization (reversible magnetization) and...
2018 / El Ouaddi H., Tirbiyine A., Taoufik A., Ait Ahmed Y., Hafid A., Mamor M., Chaib H., Nafidi A., Snoussi S.WOSScopus -
Degenerated nuclear magnetostatic modes in ferromagnets
The detailed calculations of dependence of the frequency of oscillations on the external magnetic field and on the shape of ferromagnet sample with interacting electronic and nuclear subsystems were done. Such system possesses a discrete number of eigenfrequencies of precession of magnetization. It ...
2018 / M. A. Borich, S. P. Savchenko, A. P. TankeyevWOSScopus -
Calculation of the matrix elements of the long-range Coulomb interaction in low-symmetry crystals
The expressions for calculating the matrix elements of the Coulomb interaction between an electron and a low-symmetry infinite crystal lattice have been obtained. One-center matrix elements are considered. The Gaussian type of orbitals (GTO) is used in calculations. All expressions are absolutely...
2018 / O. A. AnikeenokWOSScopus -
Electrostatic interaction between two conducting spheres with equal radii and a point charge on their centerline
In this work we solve a particular case of the three body problem in the electrostatics. Let two conducting spheres of equal radii and arbitrary electric charges Q 1 and Q 2 and one point charge q lying on the line through the centers of the two spheres. We determinate the electrostatic force of...
2017 / Doichev Dimitar, Bozhkov Stefan, Epitropov Yordan, Kolikov Kiril -
A noise model in transimpedance amplifiers realized by operational amplifier
The paper presents an analytical model of generated noise in the transimpedance amplifiers realized with operational amplifiers (op amp). The main goal is to determine the noise power spectral density (PSD) in respect to the amplifier input in order to give conclusions and recommendations for its...
2017 / Rachev Ivan -
Cnoidal waves in single-mode fibers
In the present paper analytically and numerically is investigated the evolution of cnoidal waves in silica single-mode fibers. A new exact analytical solution of the onedimensional nonlinear amplitude equation, describing the propagation of optical pulses innonlinear dispersive media, has been...
2017 / Dakova А, Dakova D, Slavchev V, Kovachev L, Kolev M -
Soliton solution of the nonlinear Schrödinger equation including third order of linear dispersion and dispersion of nonlinearity
In recent years actively are studied the effects resulting from the propagation of optical pulses in nonlinear dispersive media. One of the most commonly used equation, for describing the evolution of laser pulses, is the nonlinear Schrodinger equation (NSE). It works very well for nano and...
2016 / Staykov Petko, Bojikoliev Ivan, Dakova Diana, Dakova Anelia -
The circular velocities of stars in a galaxy are - result of its evolution
The present article considers the possibilities of recognising the real contribution of the theoretically-based determination of the masses of giant and supergiant stars and of the galaxy evolution in explaining astrophysical phenomena in galaxies and galaxy clusters via Newton's dynamics. A new...
2016 / Gemedjiev Georgy -
On homogeneous manifolds endowed withalmost product structure
The spaces admitting transitively acting Lie group of transformations arise in differential geometry, as well as differential equations and physics. Of a great importance are the invariant structures on these spaces. We consider almost product structures i.e. tensor fieldP of type (1,1), such that...
2016 / Georgieva Atanaska, Kostadinov Georgi, Melemow Hristo -
Heat-exchangers - pasteurizator
Heat-exchangers are thermal devices (appliances) which perform heat exchange between fluids, in order to create the heating or cooling of the fluid with one another. Often flow is realized as a combination where the two fluids move in different patterns combined by same-way, oppositeway and cross...
2013 / Ilijoska Meri, Jovanovska Vangelica -
Surface plasmon excitation assisted by thin cholestric liquid crystal film
In this work, we propose a structure based on an anisotropic thin film that convert the polarization and can trigger the forbidden polarization to excite surface plasmon resonance. We have simulated light propagation in three-layered structure: BK7 prism/cholesteric liquid crystal/ air for...
2013 / Zhelyazkova Katerina, Dyankov Georgi -
Spectral-interrogated Spr on low-cost grating
Due to its high applicability and commercial value, surface plasmon resonance (SPR) is one of the most actively researched phenomena in modern physics. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics. The...
2013 / Astašauskas Vytautas, Dyankov Georgi -
The non-local nature of quantum mechanics: a student laboratory experiment
Classical physics assumes that the world is real, in the sense that objects have certain properties and positions, independently from the observer. It is also assumed that identical causes always produce the same effect. In this sense nature is assumed to be deterministic, and everything is well...
2013 / Benhaim Edward, Lebedev Victor, Weis Antoine -
Measuring of the index of refraction and the thickness of thin plates by a Michelson interferometer in the student laboratory
The Michelson interferometer is an extremely versatile instrument that can be used to make an accurate comparison of wavelengths, to measure the refractive index of gases, liquids and transparent solids, as well to determine small changes in lengths quite precisely. The main purpose of the present...
2013 / Dimitrova Todorka, Bulota Simonas, Adliene Diana, Ivanov George -
Решение трехмерной обратной задачи по определению уровня шума на границе санитарно-защитной зоны промышленного предприятия
Традиционным методом снижения шума на селитебных территориях является разработка санитарно-защитных зон промышленных предприятий. При этом основой разработки является расчет шума на границе СЗЗ, основанный на прямых методах расчета, когда по известным характеристикам источников шума определяется...
2018 / Комарова Е.Г., Пименов И.К.