Methods for the application of neural networks in searches for new physics in collider experiments are described. Mechanisms of selecting observables, optimizing hyperparameters, and constructing ...cascades of deep neural networks are considered. Methods for a statistical analysis of neural-network discriminants in theta and CombinedLimit packages with allowance for various uncertainties are presented.
Supramolecular polymerization, i.e., the self-assembly of polymer-like materials through the utilization of the noncovalent bond, is a developing area of research. In this paper, we report the ...synthesis and investigation of nucleobase-terminated (N 6-anisoyl-adenine and N 4-(4-tert-butylbenzoyl)cytosine) low molecular weight poly(THF) macromonomers (<2000 g mol-1). Even though the degree of interaction between the nucleobase derivatives is very low (<5 M-1) these macromonomers self-assemble in the solid state to yield materials with film and fiber-forming capability. While the mechanical properties of films of both materials show extreme temperature sensitivity, resulting in the formation of very low viscosity melts, they do behave differently, which is attributed to the nature of the self-assembly controlled by the nucleobase. A combination of FT-IR, WAXD, and rheological experiments was carried out to further investigate the nature of the self-assembly in these systems. The studies demonstrate that a combination of phase segregation between the hard nucleobase chain ends and the soft poly(THF) core combined with aromatic amide hydrogen bonding is utilized to yield the highly thermosensitive supramolecular polymeric materials. In addition, analysis of the data suggests that the rheological properties of these supramolecular materials is controlled by the disengagement rate of the nucleobase chain ends from the “hard” phase, which, if shown to be general, provides a design criteria in the development of more thermally responsive materials.
The determination of the potential characteristics of new thermoelectric materials from the results of measurements of the Seebeck coefficient is described. A device has been developed for measuring ...the Seebeck coefficient (thermoelectric motive force) of thermoelectric materials in the temperature range 300–800 K in argon, air, or vacuum. The design and technical characteristics of the created device are described in detail. The Seebeck coefficient of standard nickel samples in the temperature range of 300–800 K in an argon medium was measured in order to verify the applicability of the developed device by the differential method. Measurement error of the Seebeck coefficient is less than 5%. Negative values of the Seebeck coefficient of the nickel sample were obtained throughout the studied temperature range, which indicates the predominance of electrons as the main charge carriers in the sample material. At room temperature, the measured value of the Seebeck coefficient is −19.05 μV/K and decreases to a value of −25.71 μV/K as the temperature increases to 515 K. As the temperature increases further to 640 K, the Seebeck coefficient monotonically increases to a value of −19.60 μV/K. At temperatures above 640 K, the Seebeck coefficient decreases continuously, and at 824 k reaches the value −24.12 μV/K. The Curie point is 644 K. The values of the Seebeck coefficient for nickel that are obtained in the temperature range 300–800 K are comparable with the data given in the literature. In calculating the values of the Seebeck coefficient based on measured thermoelectric voltages, equations with known reference values of this coefficient for positive and negative branches of the thermocouple are used, which eliminates the need for additional measurement probes and contacts to measure the thermoelectric voltage of a sample. The installation can also be used to measure electrical resistance using the standard 4‑point method.
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This paper reports on structure and phase formation of a Ni–Al–Co based alloy prepared by self-propagating high-temperature synthesis. The maximum combustion temperature was 1020°C in argon and ...913°C in vacuum. The phase composition of the synthesized alloy includes a Ni
0.7
Co
0.3
solid solution with a cubic (
Pm
m
) crystal lattice. Its microstructural constituents based on γ- and β-phases are 10–20 μm in size, and γ + β interlayers located on the interface between the γ- and β-phases are up to 1–2 μm in thickness. The alloy offers high plasticity, and its compressive strength is 451 MPa. Its low remanence, low coercive force, and high saturation magnetization indicate that the alloy is a soft magnetic material. It has a coercive force
H
c
= 146 Oe, remanent magnetization σ
r
= 0.35 emu/g, and saturation magnetization σ
s
= 36.76 emu/g.
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