An Asymmetric Grating Refractive Index Sensor Generating Quasi-Bound States in the Continuum with High Figure of Merit and Temperature Self-Compensation

A subwavelength asymmetric grating refractive index (RI) sensor based on quasi-bound states in the continuum (q-BIC) with temperature self-compensation was proposed. The sensor structure consisted of a Prism / Asymmetric grating / Analytes, where the grating layers were periodically arranged asymmetric silicon (Si) and polydimethylsiloxane (PDMS). The asymmetry of the structure led to the fact that the tangential field component and the radiative field component in the grating layer were no longer in a fully decoupled state at the resonance position, creating two extremely narrow q-BIC resonance peaks, which gave the sensor a high Figure of Merit (FOM) and a low detection limit (DL). In addition, the thermo-optical coefficient of the materials made one of the resonance peaks more sensitive to temperature changes, realizing the temperature self-compensation of RI detection and thus improving the detection accuracy. From the results, reducing the asymmetry of the structure by modifying the parameters could theoretically make FOM > 5.1*106 RIU-1 and DL < 9.8*10-9 RIU. For the RI sensor with temperature self-compensation, FOM = 3057.85 RIU-1 and DL = 1.64*10-5 RIU for the RI, FOM = 0.88 °C-1 and DL = 0.057 °C for the temperature. These findings could effectively improve the temperature interference resistance of the sensor and thus the accuracy of trace substance detection.

Studies of Magnetic Chemically Peculiar Stars Using the 6-m Telescope at SAO RAS

We present a survey of the most important results obtained in observations with the 6-m telescope in the studies of magnetic fields of chemically peculiar stars. It is shown that we have found more than 200 new magnetic chemically peculiar stars, which is more than 30% of their total known number. Observations of ultra-slow rotators (stars with rotation periods of years and decades) have shown that there are objects with strong fields among them, several kG in magnitude. In the association of young stars in Orion, it has been found that the occurrence and strength of magnetic fields of chemically peculiar stars decrease sharply with age in the interval from 2 to 10 Myr. These data indicate the fossil nature of magnetic fields of chemically peculiar stars. About 10 magnetic stars were found based on ultra-accurate photometry data obtained from the Kepler and TESS satellites. A new effective method of searching for magnetic stars was developed. In addition, the exact rotation periods make it possible to build reliable curves of the longitudinal field component variability with the phase of the star’s rotation period, and hence to create its magnetic model. The survey is dedicated to the memory of Prof. Yuri Nikolaevich Gnedin.

Inherent and Local Magnetic Field Structures in Jets from Active Galactic Nuclei

In theoretical models for the electromagnetic launching of astrophysical jets, a helical magnetic (B)-field component is generated through the winding up of an initial longitudinal field component by the rotation of the cental black hole and accretion disk. This helical field component travels outward with the jet plasma. There is now abundant evidence that the jets of active galactic nuclei carry helical B fields, and the presence of such fields has been invoked to explain a wide range of phenomena observed in these jets. However, distinguishing between features associated with this inherent jet B field and with B fields generated by local phenomena such as shocks and shear can be challenging. There is now evidence that the field that is accreted is dipolar like, giving rise to a current distribution with inward currents along both jet axes and outward currents in a more extended region around the jets. Striking limb brightening has been observed for several relatively nearby active galactic nuclei; it is argued that this must be due to some intrinsic property of the jet, which is independent of the viewing angle, such as its helical B field, or mass loading and/or particle acceleration at the jet edges. Circular-polarization observations may make it possible to reconstruct the full three-dimensional B field of jets carrying a helical B-field component, and to correctly infer the direction of rotation of the central black hole and its accretion disk.

The methods of studying emotive vocabulary

This article is dedicated to studying the lexical composition of language, namely lexical units that denote emotions. The choice of topic is substantiated by certain difficulties in creating the methodology for working with vocabulary, due to the amorphous nature of this language component, as well as the importance of studying the part of vocabulary that describes the emotional sphere of human existence. The subject of this research is the linguistic content of emotive lexical units. Emotive vocabulary is analyzed using several methods of linguistic analysis: method of semantic field, component analysis, transmission of meaning, analysis of significances, word formation, and method of inner form. The novelty of this research consists in application of comprehensive approach towards studying the linguistic content of lexical units denoting emotions. Special attention is given to the description of practical component of the used methods based on denominations of emotions in the English, Russian, German, and French languages. The author concludes on the need to develop a specific methodology for studying lexical material, and the cumulative application of these methods for the most comprehensive examination of the linguistic content of words denoting emotions in different languages.

Incorporating cumulative environmental effects of finfish mariculture into Canadian environmental assessment

A Traffic Light Decision Support System (DSS) used in marine finfish federal environmental assessments was expanded to include regional and cumulative environmental impacts. A retrospective review of 23 existing mariculture farms in southwestern New Brunswick indicated whether cumulative interactions would have justified site approvals. Six new criteria were added to the far-field component and other existing criteria were amended. Scores of A, B+, B⁻, C and pre-emptive C were based on acceptability criteria. Calculations of cumulative ecosystem indices and potential site indices revealed site acceptability, and the index combinations suggested potential site approvals predicted using Hargrave's (2002) three-colour Traffic Light scheme. Before mitigation was considered, 19 of 23 sites failed the amended set of criteria and after considering mitigation, 8 sites failed. Combining the site and ecosystem indices yielded varying site acceptability scores. The role of mitigation and other factors in hindering sustainable siting was discussed