35Cl nuclear quadrupole resonance spectra of etherates of trichloromethyl derivatives of mercury

Conclusions Complexes of trichloromethyl derivatives of mercury were investigated. In a series of cases, the intramolecular coordination C-Cl... Hg which exists in the initial compound is disturbed upon complex formation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 960–961, April, 1969.     

Symmetrizable spaces

Symmetrizable spaces are characterized and an example of a regular final compact symmetrizable space without a countable network is constructed (assuming the continuum hypothesis).Translated from Matematicheskie Zametki, Vol. 12, No. 5, pp. 577–582, November, 1972.     

Activation diffusion of oxygen under conditions of the metal-semiconductor phase transition in vanadium dioxide

Density functional theory is used to calculate the energies of formation of oxygen vacancies and migration of oxygen in the monoclinic and rutile phases of vanadium dioxide. The results are compared to estimates of the parameters of activation diffusion of oxygen using data from the electron-beam modification of thin film structures of vanadium dioxide and their subsequent reduction in the temperature range of 20–100°C. It is shown that diffusion in both phases of vanadium dioxide has a preferential direction of oxygen migration along axis а in the monoclinic phase and axis с in the rutile phase. The difference between the rate of oxygen vacancy generation upon electron-beam exposure above and below the temperature of metal–semiconductor phase transition is explained by the jump (~150%) in the activation energy of oxygen diffusion upon the structural transition of rutile–monoclinic phase. The mobility of oxygen (oxygen vacancies) correspondingly changes by more than an order of magnitude.     

Luminescence of Nanocrystalline Si in (Si + CaF2)/CaF2 Structures in the Visible Range of the Spectrum

Russian Physics Journal - Photoluminescence from Si nanocrystals embedded in a CaF2 dielectric matrix and formed on the surface of a Si(111) substrate is demonstrated. The photoluminescence was...     

Block Copolymer Based Molecular Motor

We propose a model of molecular motor based on diblock copolymer strongly adsorbed on a patterned surface. One of the blocks of the copolymer is modeled as field responsive. It is shown that time‐periodic collapse‐readsorption of the responsive block leads to the directed motion (reptation) of the molecule along the “track” provided by the surface pattern. Both the Langevin dynamics (LD) technique of computer simulation for the bead‐spring model and numerical solution of the Newton equations of a simplified (toy) model of the copolymer are used. The physical reason of directionality of the motion is shown to be an anisotropy of the friction of the molecule with the surface.

     

Novel techniques for improving NNetEn entropy calculation for short and noisy time series

Entropy is a fundamental concept in the field of information theory. During measurement, conventional entropy measures are susceptible to length and amplitude changes in time series. A new entropy metric, neural network entropy (NNetEn), has been developed to overcome these limitations. NNetEn entropy is computed using a modified LogNNet neural network classification model. The algorithm contains a reservoir matrix of N = 19,625 elements that must be filled with the given data. A substantial number of practical time series have fewer elements than 19,625. The contribution of this paper is threefold. Firstly, this work investigates different methods of filling the reservoir with time series (signal) elements. The reservoir filling method determines the accuracy of the entropy estimation by convolution of the study time series and LogNNet test data. The present study proposes 6 methods for filling the reservoir for time series of any length 5 ≤ N ≤ 19,625. Two of them (Method 3 and Method 6) employ the novel approach of stretching the time series to create intermediate elements that complement it, but do not change its dynamics. The most reliable methods for short-time series are Method 3 and Method 5. The second part of the study examines the influence of noise and constant bias on entropy values. In addition to external noise, the hyperparameter (bias) used in entropy calculation also plays a critical role. Our study examines three different time series data types (chaotic, periodic, and binary) with different dynamic properties, Signal-to-Noise Ratio (SNR), and offsets. The NNetEn entropy calculation errors are less than 10% when SNR is greater than 30 dB, and entropy decreases with an increase in the bias component. The third part of the article analyzes real-time biosignal EEG data collected from emotion recognition experiments. The NNetEn measures show robustness under low-amplitude noise using various filters. Thus, NNetEn measures entropy effectively when applied to real-world environments with ambient noise, white noise, and 1/f noise.