The strain gap in a system of weakly and strongly interacting two-level systems

Many disordered lattices exhibit remarkable universality in their low temperature properties, similar to that found in amorphous solids. Recently a two-TLS (two-level system) model was derived based on the microscopic characteristics of disordered lattices. Within the two-TLS model the quantitative universality of phonon attenuation, and the energy scale of $1-3$ K below which universality is observed, are derived as a consequence of the existence of two types of TLSs, differing by their interaction with the phonon field. In this paper we calculate analytically and numerically the densities of states (DOS) of the weakly and strongly interacting TLSs. We find that the DOS of the former can be well described by a Gaussian function, whereas the DOS of the latter have a power law correlation gap at low energies, with an intriguing dependence of the power on the short distance cutoff of the interaction. Both behaviors are markedly different from the logarithmic gap exhibited by a single species of interacting TLSs. Our results support the notion that it is the weakly interacting $\tau$-TLSs that dictate the standard low temperature glassy physics. Yet, the power-law DOS we find for the $S$-TLSs enables the prediction of a number of deviations from the universal glassy behavior that can be tested experimentally. Our results carry through to the analogous system of electronic and nuclear spins, implying that electronic spin flip rate is significantly reduced at temperatures smaller than the magnitude of the hyperfine interaction.Comment: Version submitted to EPJ S

Цифровое определение параметров взаимодействия печатной бумаги с красками

Розроблено структуру системи для автоматизації вимірювання та визначення статичної обмінної ємності з використанням програмно-апаратних засобів з проблемною орієнтацією.Regardless of the type of printing on printing paper properties affect its opacity, whiteness, softness, uniformity and other indicators. Great importance is ability to perceive the paper ink. Ion exchange properties of fibrous materials are characterized by static exchange capacity, which is caused by the molecular nature of the fiber and defines interaction’s parameters of printed paper with inks. Actual solution to automate the definition of static exchange capacity is the use of tools with problem-oriented, which enable the description of measurement processes and parameters determination using software and hardware analog-to-digital conversion. Digital measurement and determination of the static exchange capacity with the use of software and hardware with problem orientation allows automated potentiometric titration method for the analysis of parameter exchange capacity of modified cellulose fibers, which makes it possible to predict with great authenticity of required printing properties of paper.Разработана структура системы для автоматизации измерения и определения статической обменной емкости с применением программно-аппаратных средств с проблемной ориентацией

Статистическое определение параметров увлажняющих растворов при печати гибридными красками

В статті розглянуто концепцію побудови структури системи для автоматизації процесів вимірювання та статистичного визначення параметрів зволожувальних розчинів при друкуванні гібридними фарбами із застосуванням програмно-апаратних засобів з проблемною орієнтацією.The article is devoted to the conception of construction of structure of the system for automation of processes of measuring and statistical determination of parameters of moistening solutions at printing by hybrid inks with the use of software and hardware with the problem orientation.Разработана структура системы для автоматизации измерения и статистического определения параметров увлажняющих растворов при печати гибридными красками с применением программно-аппаратных средств с проблемной ориентацией

Comparison of the hydrodynamic and Dirac models of the dispersion interaction between graphene and H, He∗{}^{\ast}, or Na atoms

The van der Waals and Casimir-Polder interaction of different atoms with graphene is investigated using the Dirac model which assumes that the energy of quasiparticles is linear with respect to the momentum. The obtained results for the van der Waals coefficients of hydrogen atoms and molecules and atoms of metastable He${}^{\ast}$ and Na as a function of separation are compared with respective results found using the hydrodynamic model of graphene. It is shown that, regardless of the value of the gap parameter, the Dirac model leads to much smaller values of the van der Waals coefficients than the hydrodynamic model. The experiment on quantum reflection of metastable He${}^{\ast}$ and Na atoms on graphene is proposed which is capable to discriminate between the two models of the electronic structure of graphene. In this respect the parameters of the phenomenological potential for both these atoms interacting with graphene described by different models are determined.Comment: 15 pages, 4 figure

Объективное определение электропроводности увлажняющего раствора

В статті розглянуто систему для об’єктивного вимірювання та статистичного визначення електропровідності зволожувального розчину із застосуванням програмно-апаратних засобів з проблемною орієнтацією.The paper considers a system for objective measurement and statistical determination of conductivity of moistening solution with application software and hardware with problem orientation. The process of measuring the electrical conductivity of moistening solution is based on the use of the voltage, which clearly reflects the value of conductivity. This value is measured by the analog-to-digital converter running computer and recorded in digital form in the computer for further processing and analysis. The use of problem-oriented software provides a unifying data structure and processing that allows you to create an information system for the objectivity and reliability of determining the quality of the solution and stabilization process of moistening. Automation of determining and processing of the experimental values of conductivity of moistening solution provides stabilization parameter in real time to ensure the quality of printed prints and their normalized values of deviations.Разработана структура системы для объективного измерения и определения электропроводности увлажняющих растворов с применением программно-аппаратных средств с проблемной ориентацией