bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic crystal with half-wave vibrators sublattice
Authors: Fediy Alexander A , Anzulevich Anton P , Kalganov Dmitrii A , Bychkov Igor V 
Published: April 2020

Abstract
Volumetric metamaterials with a regular structure can have elemental structural cells that translation along coordinate axes simulates the entire structure of macroscopic sample. If there are elements in this metamaterial that are responsible for electrical and magnetic properties, then we can say that this is an electromagnetic crystal. Samples that electrical (effective permittivity) properties are determined by long conductors, and magnetic ones - by half-wave vibrators, were investigated. Measurements of transparency spectra and forbidden electromagnetic band gap were carried out in the frequency range of 8 - 12 GHz. Measurements of refractive index in the material were carried out on the angular deviation of microwave radiation passing through a prism. Measurements show that samples with the same structure (unit cell) can significantly change their characteristics even with a small change in one of the internal parameters of the cell.
Controllable antiphase domain density in dilute nitride GaPN/GaP heterostructures on silicon
Authors: Fedorov V.V. , Bolshakov A.D. , Koval O.Yu. , Sapunov G.A. , Sobolev M.S. , Pirogov E.V. , Kirilenko D.A. , Mozharov A.M. , Mukhin I.S. 
Published: April 2020

Abstract
Formation and propagation of the antiphase domains in dilute nitride GaPN/GaP epitaxial heterostructures grown on Si (001) by plasma assisted molecular beam epitaxy (PA-MBE) on silicon is studied. Role of the layer composition, substrate orientation and growth conditions are discussed. Composition of the dilute nitride film was studied by X-ray diffraction (XRD) while the effect of the antiphase disorder in GaP buffer layer on GaPN epilayer structural properties was studied by transmission electron (TEM) and scanning electron microscopy (SEM). Controllable transition between antiphase disordered and monodomain film depending on the concentration of incorporated nitrogen is demonstrated – transition to the monodomain film occurs in dilute nitride GaPN layers starting low with 0.4% of incorporated nitrogen. Control of the antiphase disorder allows to tune mean film polarity and second order nonlinear optical response of III-phosphide heterostructures.
Second harmonic generation driven by magnetic dipole moment in dielectric nanoparticles of different shapes.
Authors: Frizyuk Kristina , Petrov Mihail 
Published: April 2020

Abstract
In this work we suggest a technique helping to identify the selection rules in second harmonic generation from dielectric nanoparticles pumped at their magnetic dipole resonance. We present the identified mode content of the second harmonic field for nanostructures of cylindrical, cone, and prism shapes made of material with Td
and C
4v
symmetries. This method is applicable for finding the selection rules for arbitrary particle shapes and crystalline structures and can be expanded to other nonlinear processes.
Directing light with liquid crystal metasurfaces
Authors: Gorkunov M V , Kasyanova I V , Artemov V V , Mamonova A V , Ezhov A A , Palto S P 
Published: April 2020

Abstract
Liquid crystal metasurfaces self-assemble on polymer substrates regularly patterned by focused ion beam. Periodic deformations of nematic liquid crystal produce distinct colouring and strong diffraction. Applying AC voltage of 4 V across the liquid crystal layer straightens the nematic, suppresses diffraction and increases direct transmission within sub-millisecond switching times. Multi-parametric optimization of the metasurface design substantially enhances the efficiency of diffraction into a single particular channel.
Subwavelength vaterite spherulite scattering properties in optical region
Authors: Gurvitz Egor , Noskov Roman , Shalin Alexander 
Published: April 2020

Abstract
Vaterite is a very promising material for biological applications, but its electromagnetic properties have not been studied well enough. In this work we for the first time introduce multipole decompositions of subwavelength nanoparticles for dark field microscopy in optical range.
Volume metasolenoid-based coil for 23Na MRI at 7 Tesla
Authors: Solomakha G. , Hurshkainen A. , Glybovski S. , Andreychenko A. 
Published: April 2020

Abstract
In this work, we demonstrate a novel X-nuclei radiofrequency coil design aimed for ultra-high field magnetic resonance imaging. The proposed design is based on a set of coupled split-loop resonators, forming a so-called metasolenoid, fed via inductive coupling by a non-resonant loop. Due to the fundamental mode excitation in the metasolenoid the homogeneous RF magnetic field inside its inner volume is provided. 23Na RF coil for human wrist imaging at 7 Tesla based on the proposed approach is demonstrated and investigated numerically. The design is compared with a commercially available volume birdcage coil. The comparative study revealed 60% improvement of SAR efficiency of metasolenoid coil operating in the linearly-polarized mode over the birdcage coil driven in the circularly polarized mode.
Multifunctional Scaffolds Based on Piezoelectric Electrospun Fibers modified with Biocompatible Drug Carriers for Regenerative Medicine
Authors: Karpov Timofey E , Muslimov Albert R , Zyuzin Mikhail V , Peltek Oleksii O , Sergeev Igor S , Goncharenko Alexander A , Surmenev Roman A. , Timin Alexander S 
Published: April 2020

Abstract
The incorporation of bioactive compounds onto polymer fibrous scaffolds is essential to improve the functionality of scaffolds for personalized drug therapy and regenerative medicine. In this study, SiO2 microcapsules were prepared and used as drug carriers, which are further deposited onto polymer microfiber scaffolds [polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), and PHB doping with the conductive polyaniline (PANi) of 2 wt % (PHB-PANi)]. The number of immobilized microcapsules decreased with the increase of their ζ-potential due to the electrostatic repulsion forces between capsule wall and the negatively charged fiber surface, given the nature of the polymer used for the scaffold’s fabrication. Additionally, the immobilization of the capsules in dynamic mechanical conditions resulted in an increased number of the capsules attached on the fibers with the increasing of the scaffold piezoelectric response (PCL < PHB < PHB-PANi). Osteogenic factor dexamethasone (DEXA) is chosen for the microcapsules loading in order to demonstrate the osteogenesis of the developed scaffolds. The immobilization of microcapsules provides a simple and convenient way to incorporate bioactive compounds onto polymer scaffolds, which makes these multimodal materials suitable for the personalized drug therapy and bone tissue engineering.
Light interaction with nanoresonators: mode volume and quasinormal mode expansion
Authors: Lalanne P , Yan W 
Published: April 2020

Abstract
The most general motion of a system is a superposition of its normal modes, or eigenstates. For Hermitian system, classical normal mode theory applies. For non-Hermitian systems, presently a lot of progress is done to describe the response of optical micro and nanoresonators in their quasinormal mode basis. We have developed a rigorous modal analysis of nanoresonators with unprecedented generality and report numerical results for the general case of 3D resonators, made of dispersive materials on substrate with guiding layers.
1H MRS as a novel quantitative method for osteoporosis detection
Authors: Menshchikov P E , Ivantsova A S , Akhadov T A , Ublinskiy M V , Manzhurtsev A V , Semenova N A 
Published: April 2020

Abstract
Bone mineral density is an important parameter that determines strength of the bone. Decrease in bone mineral density (BMD) leads to dangerous skeletal diseases like osteopenia, osteoporosis and an increased risk of fractures, for instance compression vertebral fracture (CVF). Dual-energy x-ray absorptiometry (DXA) and quantitative CT (QCT) are commonly accepted methods for assessing of the BMD. Previously FF was shown to increase in adult patients with osteoporosis as compared to healthy volunteers. The aim of the study was to explore the relationship between FF and BMD in children. Correlation analysis revealed significant inverse correlation link (p<0.05) between FF and BMD for all vertebrae of all patients (Fig.1C). The correlation suggests that the processes of increasing FF in the bone marrow and lowering the BMD are parallel in children. Therefore, 1H MRS could be good alternative to QCT and DXA without radiation dose in osteoporosis detection. Revealed significant negative correlation between FF and BMD in children without osteoporosis suggests that the processes of increasing FF in the bone marrow and lowering the BMD are parallel. Therefore, 1H MRS could be good alternative to QCT and DXA without radiation dose in osteoporosis detection.
Glia-neuronal transitions in development: significance in medical research and treatment of pathologies
Authors: Kamenev D , Kotsyuba E , Kalachev A , Milichko V , Dyachuk V 
Published: April 2020

Abstract
The questions of how autonomic neurons and their fibers select the target organs and whether parasympathetic innervation affects the development and growth of diverse organs are still open. We hypothesize that glia-neuronal transitions in development is crucial for correct development and homeostasis of innervated tissues in mice. The result of this preliminary experiment using genetic tracing showed that the mice mutants with lack autonomic ganglia indeed have a problem with development of target organs and support idea that autonomic nervous system directly involved in innervated organs morphogenesis.
Staining protocols for whole-body and fast tissue clearance for marine invertebrates
Authors: Kotsyuba E , Yurchenko O , Kamenev D , Savelieva A , Kalachev A , Milichko V , Dyachuk V 
Published: April 2020

Abstract
Marine invertebrates are the most morphologically varied group of animals with tough and smooth covers, external and internal organ structures and different body designs in general. Very often researchers cannot see internal deep structures without mechanical damage of animals. Here, we focus on “not damage” protocols of immunostaining and clearance of whole-body of invertebrates.
Application of metasurface-based low-pass filters for improving THz-TDS characteristics
Authors: Nikolaev N A , Rybak A A , Kuznetsov S A 
Published: April 2020

Abstract
We propose an approach to improve the technical characteristics of terahertz time-domain spectrometers at low-frequency measurements. The approach is based on applying low-pass THz filters to narrow the frequency band of the THz signal that allows increasing the sampling interval in accordance with the Nyquist–Shannon theorem. This concept was verified by studying the transmission spectra of low-frequency band-pass THz filters centered at 156 and 376 GHz. We confirm that the high-quality low-pass filters can improve accuracy of THz measurements and significantly reduce data acquisition time. The reduction up to 12 times was experimentally demonstrated in our case.
Examination of metamaterial solid immersion lenses for subwavelength optical manipulation
Authors: Novitsky Andrey , Repän T. , Malureanu R. , Takayama O. , Shkondin E. , Lavrinenko A.V. 
Published: April 2020

Abstract
We theoretically inspect, whether a recently proposed metamaterial solid immersion lens (a cluster of closely packed nanospheres) possesses super-resolving properties that could be used for subwavelength optical manipulation. Harnessing the multiple scattering theory for assembly of electric dipoles, we investigate the evanescent-wave and point-source-radiation transmission through the slab of nanospheres to establish the mechanism of super-resolution. Our calculations do not confirm resolution of subwavelength details using the metamaterial solid immersion lens.
Metasurfaces based on Functional Materials in THz and Optical Regions
Authors: Erfani-azad A. , Shahmirzadi N.V. , Pakizeh T. , Kolodev V. , von Gratoswki S. 
Published: April 2020

Abstract
In this paper we present the properties of metamaterials and metasurfaces composed of resonant micro/nano-structures in which their tunable electromagnetic (EM) properties can be achieved by employing the substrate or resonant structures consisting of functional materials such as polydimethylsiloxane (PDMS), Vanadium-dioxide (VO2), shape memory alloys (SMAs) or in general smart materials. Using a mechanical stretching PDMS substrate for a metasurface, reflectance and transmission of electromagnetic (EM) wave can be remarkably altered. Moreover, by employing resonators consists of Nitinol (NiTi) split ring resonators (SRR) which transforms to complete ring resonator (CRR) thermally, the resonance wavelength and its modal behaviour are affected. Furthermore, the chiroptical activity of planar optical metasurfaces composed of L-shape heterogeneous (Ag-VO2) dimer is studied as well. It is shown that by increasing temperature from room temperature to 81°C, the observed optical activity (OA) at 690 nm has been raised ∼ 50%, because of the occurred phase transition.
Ultrafast all-optical switching in the presence of Bloch surface waves
Authors: Popkova Anna A , Chezhegov Aleksandr A , Soboleva Irina V , Rybin Maxim G , Obraztsova Elena D , Bessonov Vladimir O , Fedyanin Andrey A 
Published: April 2020

Abstract
It is commonly known that Bloch surface waves (BSW) can be excited at the photonic crystal/dielectric boundary that leads to many features attractive for application these states as the basis of sensors and nanophotonic devices. The narrow spectral-angular resonance of BSW is very sensitive to properties of top layer and surrounding medium. There are few ways to enhance nonlinear optical response of a top layer without violation of BSW excitation conditions. In this work we choose graphene monolayer as a source of strong nonlinearity with tiny thickness. We study temporal nonlinear optical response of graphene in the case of Bloch surface waves excitation revealing subpicosecond switching time of probe dynamics.
Controlling Energy Spectra and Whispering Gallery Modes of Electrons in a Few Electrons Lateral QD
Authors: Ramezanpour S. , Mintairov A. M. , Bogdanov A. 
Published: April 2020

Abstract
In this work, we study energy spectra and Whispering Gallery Modes (WGMs) of electrons in Quantum Dot (QD). It is shown that the WGMs can exist between two lowest energy levels of a QD, s- and p-states by taking into account the Coulomb interaction between the electrons in the QD, since in a few electron QD, Coulomb Interaction plays a crucial role in its energy spectrum. In literature, lateral QDs are usually modeled by a 2D harmonic oscillator. However, our calculations reveal that some degenerate energy levels would be created due to the height of the QD. The effect of the dimension of the QD, and magnetic field are also investigated on the energy spectra.
Development of methods for safe MR-scanning of patients with implantable medical devices. Metal structures heating
Authors: Semenov D S , Vasilev Yu A , Akhmad E S 
Published: April 2020

Abstract
The paper presents the experience of experimental determination of implanted medical devices heating value during an MR-study. This work is a part of the development of a comprehensive methodology for ensuring the safety of patients with metal structures. Objects of various shapes and materials were placed in a gel phantom, scanning was performed on an MR scanner with a static magnetic field of 1.5 T. It is shown that the temperature change in close proximity to the surface of a metal object can be within the permissible normative documentation limits or be negligible. The existing in Russia indications for magnetic resonance imaging (MRI) for patients with various metal objects should be reviewed.
Simultaneous suppression of forward and backward light scattering by high-index nanoparticles based on Kerker-like effects
Authors: Shamkhi H. K. , Baryshnikova K. V. , Sayanskiy A. , Kapitanova P. , Terekhov P. D. , Belov P. , Karabchevsky A. , Evlyukhin A. B. , Kivshar Y. , Shalin A. S. 
Published: April 2020

Abstract
The ability of all-dielectric nanostructures to perform exotic photonics effects is with superior efficiency compared to their metallic counterparts. Free from joules losses, high-index dielectrics support comparable excitation of electric and magnetic resonances and pave a way to advanced technologies of light energy manipulation. One of the most important effects is directive light scattering provided by the Kerker and anti-Kerker effects giving the potential to realize Huygens source of light, transparent metasurfaces, router nanoantennas etc. Here we study an effect where most of the scattered power is redirected to the side directions rather than to the forward and/or backward directions. This kind of scattering on isotropic scatterer requires at least the presence of the first two orders of multipoles to enable simultaneous forward and back-scattering suppressions. Electric dipole Fano resonance profile and quadrupoles off-resonance characteristics provide the required phase and amplitude conditions to obtain such an optical signature. We find the individual scatterers sustain the transverse scattering conditions when assembled into a metasurface so exhibit invisibility effect. We investigate this phenomenon analytically and numerically in the visible and microwave domains and provide the proof-of-the-concept experiment in the gigahertz frequency and showing very good agreement with the theoretical predictions.
Formation of submicron- and micron-sized SiGe and Ge particles on Si substrates using dewetting
Authors: Shklyaev A. A. 
Published: April 2020

Abstract
The arrays formation of submicron- and micron-sized SiGe and Ge dielectric particles on the Si and SiO2 surfaces, which occur due to solid-state dewetting, is investigated. The shape of the particles and their spatial distribution turned out to be strongly dependent on the crystallographic Si surface orientation, the amount of deposited Ge and the Ge deposition rate, as well as on the presence of a SiO2 film on the Si surface. Possible applications of various surface morphologies with metasurface properties are discussed.
A new RF-coil for UHF MRI based on a slotted microstrip line
Authors: Solomakha G. , Svejda J. T. , Rennings A. , Erni D. , Glybovski S. 
Published: April 2020

Abstract
We propose to use an antenna based on a microstrip line with a slotted ground plane, as a transcieve RF-coil for ultra-high field (UHF) human body MRI at 7 Tesla. In this work we show by numerical simulations, that while being loaded with a homogeneous dielectric phantom, this slotted line supports fast-wave propagation and radiation of power into the phantom. As a result, it produces high RF magnetic field at a deeply located region of interest, which is the same as one produced by the well-known fractionated dipole.
A review of exact solutions for conversion of a surface wave into a propagating wave
Authors: Tcvetkova Svetlana N , Maci Stefano , Tretyakov Sergei A 
Published: April 2020

Abstract
In this paper, we summarize our recent theoretical and numerical studies of conversion of a surface wave to a propagating wave (and vice versa) with maximized conversion efficiency. We show that the exact solution for the homogeneous plane wave to surface wave conversion in a homogeneous medium by a point-wise lossless metasurface is restricted by Maxwell’s equations. Such performance is possible only with approximations and implies some limitations, including impossibility to fully avoid unwanted scatterings. Nevertheless, an inhomogeneous plane wave can be converted into a surface wave perfectly, and it is described by an exact solution formed by a superposition of only two modes of the Floquet expansion. The results of the studies are expected to be of fundamental importance for leaky-wave antennas efficiency improvement. Besides, they can lead to novel applications in various research areas.
Multipole analysis of periodic array of rotated silicon cubes
Authors: Terekhov P. D. , Evlyukhin A. B. , Karabchevsky A. , Shalin A. S. 
Published: April 2020

Abstract
Dielectric nanophotonics is the modern and very relevant field of optics. In this work we use the recently reported Cartesian multipole decomposition approach for all-dielectric metasurfaces [1] to study optical properties of the silicon metasurface at the nanoscale. This metasurface consists of crystalline silicon cubes rotated by 45° around the axis perpendicular to the surface plane. We use numerical modeling and semi-analytical approach to find origins of the scatering by the considered metasurface. Results obtained with the multipole approach are in the good agreement with the direct calculations of transmission and reflection spectra. Insights from our study can be widely used to design novel metasurfaces and metadevices and tune their optical properties to achieve a needed functionality.
Purcell effect control in active silicon dielectric nanoantenna for the near-IR wavelength range
Authors: Yaroshenko Vitaly , Larin Artem , Ageev Eduard , Zuev Dmitriy 
Published: April 2020

Abstract
Nowadays active light-emitting dielectric nanophotonics is one of the most rapidly developing research field. These nanosystems make possible to direct emission of a light source placed inside nanoantenna in the specific direction with low-losses. Here we study the application of silicon for the creation of active all-dielectric nanoantenna emitting at the telecommunication wavelength (1540 nm). We numerically calculate Purcell factor in silicon nanoparticles (spherical and cylindrical) and demonstrate that in these nanostructures Purcell factor value can be enhanced by two orders of magnitude for this wavelength. The obtained data can be applied for the creation of active silicon nanoantenna doped with erbium for perspective light emitting metasurfaces.
All-Dielectric Optically Tunable Metasurface for Terahertz Phase and Amplitude Modulation
Authors: Lepeshov S , Gorodetsky A 
Published: April 2020

Abstract
The novel concept of an all-dielectric terahertz metasurface for amplitude and phase modulation is proposed. The results of numerical simulation of transmittance and phase shift of a broadband input THz signal are presented. The change of the amplitude and phase characteristics of the metasurface under the laser irradiation of the metasurface is shown. The phase modulation from 0 to π/2 is numerically observed. Our results pave the way for experimental realization of metasurface-based THz tunable modulators for cutting edge THz devices.