Tunable nonlinear graphene metasurfaces

We introduce the concept of nonlinear graphene metasurfaces employing the controllable interaction between a graphene layer and a planar metamaterial. Such hybrid metasurfaces support two types of subradiant resonant modes, asymmetric modes of structured metamaterial elements ("metamolecules") and graphene plasmons exhibiting strong mutual coupling and avoided dispersion crossing. High tunability of graphene plasmons facilitates strong interaction between the subradiant modes, modifying the spectral position and lifetime of the associated Fano resonances. We demonstrate that strong resonant interaction, combined with the subwavelength localization of plasmons, leads to the enhanced nonlinear response and high efficiency of the second-harmonic generation.Comment: 6 pages, 5 figure

Structure of coenopopulations and phytocoenotic confinement of Paeonia tenuifolia L. in floristic complexes of Oka-Don lowland

Paeonia tenuifolia L. is a rare and protected plant of Saratov region classified as 2 (V) vulnerable species. It has been established that in Kalininsky district, Saratov region, this plant is characterized by narrow environmental amplitude and is exerted to anthropogenic impacts, the coenopopulations are isolated from each other. Existence of the species in communities of the meadow–steppe floristic complexes of Kalininsky district has confirmed that peony is heliophyte, xeromesophyte, eutrophic plant and calcicole. Photophily of P. tenuifoliais confirmed first of all by its high abundance and occurrence in open steppe communities. In both coenopopulations of P.tenuifolia, the indices of recovery have been higher than 1 (CP 1 Irec = 3.38, CP 2 Irec = 1.67), that is, the coenopopulations are relatively steady, numerous seeds are generated giving birth to viable individuals. The index of replacement showing the ratio of the density of regrowth to total mature fraction of the population has been higher in CP 1 (Irepl = 0.80) and lower in CP 2 (Irepl = 0.67). Moderate index of maturing evidence long-term existence of the species in the generative state

Antiviral activity of lupane and oleanane A-seco-Triterpenoids

The work was supported by Federal program № AAAA-A20-120012090023-8

Phase and Intensity Distributions of Individual Pulses of PSR B0950+08

The distribution of the intensities of individual pulses of PSR B0950+08 as a function of the longitudes at which they appear is analyzed. The flux density of the pulsar at 111 MHz varies strongly from day to day (by up to a factor of 13) due to the passage of the radiation through the interstellar plasma (interstellar scintillation). The intensities of individual pulses can exceed the amplitude of the mean pulse profile, obtained by accumulating 770 pulses, by more than an order of magnitude. The intensity distribution along the mean profile is very different for weak and strong pulses. The differential distribution function for the intensities is a power law with index n = -1.1 +- 0.06 up to peak flux densities for individual pulses of the order of 160 Jy

Institutional analysis of the regulatory and legal framework for financial reporting control in Russia

The study contains the main approaches to the determination of various institutions affecting Russian accounting from the standpoint of their formal and informal types. In modern conditions, the economic actions of a subject must be matched to external factors that determine the correctness of economic decision-making, as well as consistency and the development of correct patterns and behavior algorithms that are most effective for each specific situation. Through the institutional analysis, the authors have identified several inconsistencies in the regulatory framework of related institutions and suggested ways to eliminate these disparities. Inter-institutional discrepancies have been found between law and accounting institutions, indicating non-compliance in the accounting practice of the substance over form principle, between recognition in the bookkeeping and tax accounting of the transfer of assets and liabilities ownership, as well as differences in the recording of investment real estate in the financial statements according to IFRS institutions and Russian national standards.peer-reviewe

Experimental Demonstration of Topological effects in Bianisotropic Metamaterials

Existence of robust edge states at interfaces of topologically dissimilar systems is one of the most fascinating manifestations of a novel nontrivial state of matter, a topological insulator. Such nontrivial states were originally predicted and discovered in condensed matter physics, but they find their counterparts in other fields of physics, including the physics of classical waves and electromagnetism. Here, we present the first experimental realization of a topological insulator for electromagnetic waves based on engineered bianisotropic metamaterials. By employing the near-field scanning technique, we demonstrate experimentally the topologically robust propagation of electromagnetic waves around sharp corners without backscattering effects

Image of Muslim women represented by means of modern English

The aim of the study is to show the image of Muslim women and to identify their position at the language leve