Detection of mechanical resonance of a single-electron transistor by direct current

We have suspended an Al based single-electron transistor whose island can resonate freely between the source and drain leads forming the clamps. In addition to the regular side gate, a bottom gate with a larger capacitance to the SET island is placed underneath to increase the SET coupling to mechanical motion. The device can be considered as a doubly clamped Al beam that can transduce mechanical vibrations into variations of the SET current. Our simulations based on the orthodox model, with the SET parameters estimated from the experiment, reproduce the observed transport characteristics in detail.Comment: 4 pages, 3 figure

Electronic structure, magnetic and optical properties of intermetallic compounds R2Fe17 (R=Pr,Gd)

In this paper we report comprehensive experimental and theoretical investigation of magnetic and electronic properties of the intermetallic compounds Pr2Fe17 and Gd2Fe17. For the first time electronic structure of these two systems was probed by optical measurements in the spectral range of 0.22-15 micrometers. On top of that charge carriers parameters (plasma frequency and relaxation frequency) and optical conductivity s(w) were determined. Self-consistent spin-resolved bandstructure calculations within the conventional LSDA+U method were performed. Theoretical interpetation of the experimental s(w) dispersions indicates transitions between 3d and 4p states of Fe ions to be the biggest ones. Qualitatively the line shape of the theoretical optical conductivity coincides well with our experimental data. Calculated by LSDA+U method magnetic moments per formula unit are found to be in good agreement with observed experimental values of saturation magnetization.Comment: 16 pages, 5 figures, 1 tabl

The influence of prenatal environmental conditions on the weight of newborn domestic pigs

The weight of newborn piglets in domestic pigs depends on the maternal environment. Using an original algorithm based on the comparison of the coefficients of correlation between the half-nests (the same average genotype and the same conditions of the embryonic environment) and the twin sockets (the same genotype, different conditions of the embryonic environment), it was possible to estimate the relative contribution of the various components to the weight of the newborn in the domestic pigs. Our investigation found that the relative contribution of environmental conditions during prenatal development into newborn weight variation is equal to 0.4717, the contribution of genotypic component is 0.4032; the contribution of interaction between environmental conditions and ambivalence of the “genotype–phenotype” relationships is 0.0846, indeterminacy of phenotypic realization of the littermate’s genotypes is 0.0405. Maternal resource plays the main role amongst factors forming the environmental conditions of prenatal development. The gene pool will remain unchanged in any number of generations, despite a change in the population parameters of the trait. In principle, it can be assumed that when a population reaches a certain level, when the mean value of the trait and the gene pool are optimal (the selection pressure vectors are mutually balanced), selection becomes less effective in transforming the average phenotype than changing environmental conditions. Obviously, therefore, livestock maintenance and feeding are paid as much attention as breeding, and breeds of farmed animals are zoned

Miniature directional coupler with different dielectric parameters

A study aimed at identifying the effect of substrate parameters such as dielectric permittivity and thickness on the characteristics of directional couplers, whose dimensions are reduced by means of compact structures. It was found that with the increase in the thickness of the substrate in a compact coupler increases the frequency band and the degree of miniaturization, and with increasing dielectric constant Vice versa. © 2019 IOP Publishing Ltd. All rights reserved

The first notes on taxonomic diversity of leaf-mining micromoths, Gracillariidae (Insecta, Lepidoptera) in Omskaya Oblast, Russia

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Spin-splitting in the quantum Hall effect of disordered GaAs layers with strong overlap of the spin subbands

With minima in the diagonal conductance G_{xx} and in the absolute value of the derivative |dG_{xy}/dB| at the Hall conductance value G_{xy}=e^{2}/h, spin-splitting is observed in the quantum Hall effect of heavily Si-doped GaAs layers with low electron mobility 2000 cm^2/Vs in spite of the fact that the spin-splitting is much smaller than the level broadening. Experimental results can be explained in the frame of the scaling theory of the quantum Hall effect, applied independently to each of the two spin subbands.Comment: 4 pages, 4 figure

Cross-frequency coupling of brain oscillations in studying motivation and emotion

Research has shown that brain functions are realized by simultaneous oscillations in various frequency bands. In addition to examining oscillations in pre-specified bands, interactions and relations between the different frequency bandwidths is another important aspect that needs to be considered in unraveling the workings of the human brain and its functions. In this review we provide evidence that studying interdependencies between brain oscillations may be a valuable approach to study the electrophysiological processes associated with motivation and emotional states. Studies will be presented showing that amplitude-amplitude coupling between delta-alpha and delta-beta oscillations varies as a function of state anxiety and approach-avoidance-related motivation, and that changes in the association between delta-beta oscillations can be observed following successful psychotherapy. Together these studies suggest that cross-frequency coupling of brain oscillations may contribute to expanding our understanding of the neural processes underlying motivation and emotion

A Miniature Study of Directional Couplers, Each with a Different Central Frequency

A study to determine how the operating frequency of the device during miniaturization depends on its efficiency and the safety of the original characteristics. It was found that the miniaturization efficiency decreases with increasing frequency. Thus, the design of compact couplers for Central frequencies from 1000 to 3000 MHz with a step of 500 MHz was studied. In this case, the dimensions in relation to the standard design were reduced by 78.8, 62.5, 46.7, 39 and 30%, respectively. © 2019 IOP Publishing Ltd. All rights reserved