bluuebunny/crossref_metadata_2025 huggingface dataset:
Movement of arboviruses between Indonesia and Western Australia
Authors: Harapan Harapan , Imrie Allison
Published: November 2021

Dengue virus (DENV) and chikungunya virus (DENV) are arboviruses of major public health importance. Monitoring circulation of medically important mosquito-borne viruses in the Indo Pacific region allows countries to predict disease outbreaks and prepare mitigation and control strategies. We have monitored long-term molecular epidemiology of DENV and CHIKV in Indonesia and Western Australia (WA), with febrile Western Australian travellers returning from Indonesia as sentinels. Our findings provide insights into the transmission dynamics of CHIKV genotypes and DENV serotypes, genotypes and lineages in the region and virus importation to WA. Our ongoing studies provide valuable and timely information on transmission of emerging and re-emerging arboviruses in the Indo Pacific region and furthermore provide detailed genomic data that inform our understanding of viral and epidemic virulence.
Emergence of a compositional neural code for written words: Recycling of a convolutional neural network for reading
Authors: Hannagan T. , Agrawal A. , Cohen L. , Dehaene S.
Published: November 2021

Significance

Learning to read results in the formation of a specialized region in the human ventral visual cortex. This region, the visual word form area (VWFA), responds selectively to written words more than to other visual stimuli. However, how neural circuits at this site implement an invariant recognition of written words remains unknown. Here, we show how an artificial neural network initially designed for object recognition can be retrained to recognize words. Once literate, the network develops a sparse neuronal representation of words that replicates several known aspects of the cognitive neuroscience of reading and leads to precise predictions concerning how a small set of neurons implement the orthographic stage of reading acquisition using a compositional neural code.
Geometry and dynamics link form, function, and evolution of finch beaks
Authors: al-Mosleh Salem , Choi Gary P. T. , Abzhanov Arhat , Mahadevan L.
Published: November 2021

Significance

Understanding how development and evolution shape functional morphology is a basic question in biology. A paradigm of this is the finch’s beak that has adapted to different diets and behaviors over millions of years. We take a mathematical and physical perspective to quantify the nature of beak shape variations, how they emerge from changes to the development program of the birds, and their functional significance as a mechanical tool.
Plus in the French negative system
Authors: Amsili Pascal , Beyssade Claire
Published: November 2021

This contribution focuses on the place of plus (“no more”) in the system of negation in French. Is it merely the presuppositional counterpart of pas (“not”), or does it belong to the class of n-words, such as personne (“nobody”) and rien (“nothing”), which can combine with each other and give rise to negative concord readings? We show that when plus co-occurs with an n-word, it brings different semantic contributions depending on the place it occupies. This leads us to assume that two instances of plus have to be distinguished: one that incorporates a sentential negation and the other which has only a presuppositional contribution. These two instances differ in assertive content, but convey the same presuppositional content. The chapter shows how to derive the observed interpretations in each kind of configuration.
An experimental approach to parallelism in ellipsis
Authors: Bîlbîie Gabriela , De La Fuente Israel
Published: November 2021

The present study investigates parallelism constraints in Romance gapping with pro-drop. We provide empirical evidence from two acceptability judgment tasks in Romanian and Spanish, that syntactic parallelism in gapping is less strict than traditionally assumed. Parallelism constraints are stronger at the discourse and information structure levels than at the syntactic level. Our experimental findings show that gapping with pro-drop is as acceptable as without pro-drop, challenging the double foci analysis and supporting the topic-focus pattern for gapping constructions. At the semantic level, our data show that the contrast in gapping is not always established explicitly; more generally, they show that one cannot make a correlation between contrast and subject (null vs overt) expression in Romance.
On focal and wh-projections, indirect wh-questions, and quantificational chains
Authors: Bonan Caterina
Published: November 2021

In this chapter, I investigate the cartography of focus using novel data from non-standard Italian (non-StandIT) and Trevigiano, a Venetan dialect. I argue that focus is less constrained in indirect wh-questions in these varieties than in Standard Italian (StandIT). Indeed, in Trevigiano both focalised objects and adverbials are felicitous in constructions with a lower wh-phrase. Using Featural Relativized Minimality, I argue that in the case of direct objects, the problem of crossing chains is circumvented using an IP-internal clitic that absorbs the [+N] feature of the direct object. Then, I explain the behaviour of focalised adverbials in these varieties claiming that they are externally-merged directly in the Left Periphery, hence create a high focus-chain that does not interfere with the creation of the lower wh-chain.
The syntactic distribution of raddoppiamento fonosinttatico in Cosentino
Authors: Ledgeway Adam
Published: November 2021

This chapter undertakes an overview of the structural conditions regulating the distribution of a phonological fortition process, raddoppiamento fonosintattico “phonosyntactic doubling”, in the Calabrian dialect of Cosenza, focusing on some particularly striking cases which also reveal the role of phases in constraining the application of RF. On the one hand, the data highlight the advantages of interpreting locality not just narrowly in terms of the three core structural configurations Spec-Head, Head-Head and Head-Comp, but also more broadly in terms of phasal domains, showing how different phonological realizations represent the spell-out of deep syntactic differences mapped at the interface between narrow syntax and PF (Phonological Form). On the other, the theoretical assumptions assumed here provide us with the key to understanding some intriguing empirical generalizations about the role of RF in signalling, among other things, informational structure content and binding relations, which, in turn, throw new light on current theoretical assumptions about clause structure and the nature of phases.
On another apparent violation of the subject-island constraint in French
Authors: Mensching Guido , Werner Franziska
Published: November 2021

This chapter addresses extractions of wh-marked complements of nouns out of French subject DPs into direct interrogatives – an apparent violation of the subject island constraint. We explain why some speakers of French can extract such constituents into interrogatives with complex inversion, whereas the grammaticality of other interrogative structures is clearly degraded. Our formal analysis is based on the Minimalist Program and assumes that material extracted from DPs has to pass through the DP phase-edge. In complex inversion, a structure in which the subject itself needs to move to the CP, the reordered subject DP (with the complement of N at the DP phase-edge) moves as a whole, thus giving a surface order that violates the subject island constraint only in appearance.
Moving towards an event
Authors: Soare Elena
Published: November 2021

This chapter addresses the status of the prepositional supine construction with the locative preposition la “at”, especially as complement of motion verbs. This construction encodes a goal of motion event, and it interestingly admits a continuation in which this event goal is not reached. In Romanian, locative prepositions have the following properties: (i) they select bare nouns; (ii) they can introduce dative arguments; (iii) in accomplishments, they undo the telos of the predicate when introducing an argument. The analysis proposed in this contribution provides a unified account for these three properties, in which the preposition selecting a bare noun introduces a non-achieved goal meaning in the shape of a [–bounded] Path.
Cyclicity without containment in Romanian perfects
Authors: Steriade Donca
Published: November 2021

The Romanian perfect exhibits a form of directional paradigm uniformity: verbal perfect forms adopt the stress and segmental characteristics of the perfect participle. An analysis of this pattern of paradigmatic identity is proposed, which has broader implications for the theory of the phonological cycle.
On the impact of the initial phrase length on the position of enclitics in Old Czech
Authors: Čech Radek , Kosek Pavel , Navrátilová Olga , Mačutek Jan
Published: November 2021

This paper presents an analysis of the relationship between the length of the initial phrase and the positions of pronominal enclitics in a clause. The hypothesis predicting the negative correlation between the length of the phrase and the proportion of enclitics in the post-initial position was set up and tested. For testing the hypothesis, selected books – Genesis (Gn), Isaiah (Is), Job (Jb), Sirach (Sir), Gospel of St. Matthew (Mt), Gospel of St. Luke (Lk), Acts (Act), and Revelation (Rev) – from the first edition of the Old Czech Bible translation were used. The hypothesis was not rejected; however, some differences among particular pronouns were revealed.
A method for the comparison of general sequences via type-token ratio
Authors: Matlach Vladimír , Krivochen Diego Gabriel , Milička Jiří
Published: November 2021

This article proposes a new method for analyzing and comparing general linear sequences with the minimum prior knowledge on the sequences needed. Sequence analysis is a broad problem studied by various fields from sociology and computer security to linguistics or biology. The method presented here applies the simplest quantitative linguistic tools in order to achieve methods transparency and easily interpretable results. The results form a vector describing the sequence and allow their clustering, machine learning and simple visualizations by line charts or multidimensional methods as MDS or tSNE. For completeness, artifacts and several formal models are derived to describe methods behavior in both common and extreme cases.
Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian
Authors: Rujević Biljana , Kaplar Marija , Kaplar Sebastijan , Stanković Ranka , Obradović Ivan , Mačutek Jan
Published: November 2021

Ten chapters from a Russian novel and its translations into Croatian, Serbian, and Ukrainian are automatically syllabified following the same approach in all four languages. Syllable frequencies and syllable length are modelled by probability distributions which are commonly used for frequency and length of words (the Zipf-Mandelbrot distribution and the Dacey-Poisson distribution, respectively). We show that Zipf’s law of brevity, according to which the more frequent words tend to be shorter, can be extended to syllables. We suggest a generalization of the Menzerath-Altmann law, a relation between word length and the mean syllable length. The generalized version of the law is valid for both word types and word tokens.
Linking the dependents
Authors: Steiner Petra
Published: November 2021

This chapter relates the syntactic and semantic aspects of case and valency to morphological properties and builds a model of these. Two linguistic hypotheses are derived and tested on corpus data and data of a lexicon which are built on the principles of Frame Semantics. My hypotheses are confirmed: (A) the larger the number of variables of a semantic predicate, the larger is the number of the syntactic dependents of the realized syntactic constructs, and (B) the larger the number of semantic roles, the larger is the tendency for shortening on the syntactic level.
Distribution and characteristics of commonly used words across different texts in Japanese
Authors: Yamazaki Makoto
Published: November 2021

In this chapter, I survey the frequency distribution of commonly used words across different texts in Japanese. Using the Balanced Corpus of Contemporary Written Japanese, we examined the distribution. The results show the following. (1) The distribution draws a curve similar to Zipf’s law, but the curve always begins to increase shortly before the degree of commonality reaches its maximum, (2) neither the length nor the number of the texts affects the distribution trend, (3) as the text length increases, the number of commonly used words also increases linearly, but it reaches a maximum point due to the limited number of basic words.
A Modern Greek readability tool
Authors: Mikros George , Voskaki Rania
Published: November 2021

The aim of this paper is to develop an automatic readability analysis tool that focusses on Modern Greek as a foreign language. Based on previous work done in the Centre for the Greek Language (CGL), we offer an enhanced methodology in readability prediction for Modern Greek texts matching the adequacy level (A1 to C2) according to the Common European Framework of Languages. The proposed tool is based on several stylometric indices inspired by work done in the field of quantitative linguistics. The resulting feature vectors train a Random Forest, a robust and accurate machine learning algorithm that predicts readability in our testing dataset with 0.943 accuracy, surpassing all previous readability tools for Modern Greek. Further, analysis of the results with advanced visualization methods reveals the complex and fluid dynamics of the features used and their readability predictions.
Topological mapping for visualisation of high-dimensional historical linguistic data
Authors: Moisl Hermann
Published: November 2021

This paper addresses an issue in visualization of high-dimensional data abstracted from historical corpora whose importance in quantitative and corpus linguistics has thus far not been sufficiently appreciated: the possibility that the data is nonlinear. Most applications of data visualization in these fields use linear proximity measures which ignore nonlinearity, and, if the data is significantly nonlinear, can give misleading results. Topological mapping is a nonlinear visualization method, and its application via a particular topological mapping method, the Self-Organizing Map, is here exemplified with reference to a small historical text corpus.
Effects of constrained groove pressing on mechanical properties of a TWIP steel
Authors: Shirani Mahla , Anjabin Nozar , Kim Hyoung Seop
Published: November 2021

The evolution of mechanical properties and microstructure of a twinning induced plasticity (TWIP) steel sheet during constrained groove pressing (CGP) was investigated. It was found that by imposing CGP, the volume fraction of twins, hardness and yield strength increase significantly, while ductility decreases. The results of the pin-on-disk wear test showed that the CGP process improves the wear resistance of the TWIP steel, where oxidation is the main wear mechanism. The effect of annealing treatment at various temperatures on the hardness evolution of the CGP-treated samples was also investigated. Moreover, a modified work-hardening model was applied to predict the flow behaviour of TWIP steel during the severe plastic deformation. The model successfully predicts the flow curve and measured dislocation density and twin evolution.
Cultural political economy, crisis management, and COVID-19 in the United States
Authors: Mueller Jason C.
Published: November 2021

The Coronavirus Disease 2019 (COVID-19) has ravaged the world. The pace at which this pandemic spread left policy makers scrambling to understand the virus and craft ameliorative policy measures, while populations struggled to make sense of the pandemic’s impact on their lives. This opened up many opportunities for crisis learning. This article deploys the Cultural Political Economy (CPE) approach to analyse discursive and material ways in which the President of the United States engaged in crisis learning and crisis management during the early months of the pandemic. Although preexisting conditions structured the early response to COVID-19, contingent moments of (in)action by the President had significant, path-shaping impact on the scope and severity of the pandemic. A vignette on the functionality of the US healthcare system during the early days of the pandemic offers further clarity on the interplay between material and discursive factors impacting real-time crisis learning and management.
Upconversion lanthanide nanomaterials: basics introduction, synthesis approaches, mechanism and application in photodetector and photovoltaic devices
Authors: Mehrdel Baharak , Nikbakht Ali , Aziz Azlan Abdul , Jameel Mahmood S. , Dheyab Mohammed Ali , Khaniabadi Pegah Moradi
Published: November 2021

Upconversion (UC) of lanthanide-doped nanostructure has the unique ability to convert low energy infrared (IR) light to high energy photons, which has significant potential for energy conversion applications. This review concisely discusses the basic concepts and fundamental theories of lanthanide nanostructures, synthesis techniques, and enhancement methods of upconversion for photovoltaic and for near-infrared (NIR) photodetector (PD) application. In addition, a few examples of lanthanide-doped nanostructures with improved performance were discussed, with particular emphasis on upconversion emission enhancement using coupling plasmon. The use of UC materials has been shown to significantly improve the NIR light-harvesting properties of photovoltaic devices and photocatalytic materials. However, the inefficiency of UC emission also prompted the need for additional modification of the optical properties of UC material. This improvement entailed the proper selection of the host matrix and optimization of the sensitizer and activator concentrations, followed by subjecting the UC material to surface-passivation, plasmonic enhancement, or doping. As expected, improving the optical properties of UC materials can lead to enhanced efficiency of PDs and photovoltaic devices.
Development of a reduced model for energetic particle transport by sawteeth in tokamaks
Authors: Podestà M , Gorelenkova M , Gorelenkov N N , White R B , Bonofiglo P J , Poli F M , Teplukhina A , Yang J , Cecconello M , Vallar M
Published: November 2021

The sawtooth instability is known for inducing transport and loss of energetic particles (EPs), and for generating seed magnetic islands that can trigger tearing modes. Both effects degrade the overall plasma performance. Several theories and numerical models have been previously developed to quantify the expected EP transport caused by sawteeth, with various degrees of sophistication to differentiate the response of EPs at different energies and on different orbits (e.g. passing vs. trapped), although the analysis is frequently limited to a single time slice during a tokamak discharge. This work describes the development and initial benchmark of a framework that enables a reduced model for EP transport by sawteeth retaining the full EP phase-space information. The model, implemented in the ORBIT hamiltonian particle-following code, can be used either as a standalone post-processor taking input data from codes such as TRANSP, or as a pre-processor to compute transport coefficients that can be fed back to TRANSP for time-dependent simulations including the effects of sawteeth on EPs. The advantage of the latter approach is that the evolution of the EP distribution can be simulated quantitatively for sawtoothing discharges, thus enabling a more accurate modeling of sources, sinks and overall transport properties of EP and thermal plasma species for comprehensive physics studies that require detailed information of the fast-ion distribution function and its evolution over time.
Fuel retention and erosion-deposition on inner wall cladding tiles in JET-ILW
Authors: Dittrich Laura , Petersson Per , Rubel Marek , Tran Tuan Thien , Widdowson Anna , Jepu Ionut , Porosnicu Corneliu , Alves Eduardo , Catarino Norberto , Contributors JET
Published: November 2021

The morphology of beryllium coatings on the Inconel inner wall cladding tiles after JET-ILW campaigns was determined. The focus was on: (i) fuel retention and its share in the overall fuel inventory; (ii) the change of the layer structure and composition. The study is motivated in the view of planned D-T operation in JET. Four tiles were examined: the initial not exposed; one exposed to two campaigns (ILW1-2) and two facing the plasma during ILW1–3. As determined with ion beam and microscopy methods, the initial Be layer (9.0 μm thick) contained up to 4–5 at.% of impurities, mainly H, O, C, Ni. In the exposed tiles, the impurity content increases to 14–26 at.% (up to 20 at.% O, 1.7 at.% C, 1.0 at.% N, 1.3 at.% Ni and under 0.1 at.% W). The surface composition indicates gettering of O and a long-term retention of N. The Be thickness on the tile exposed to ILW1–2 was between 7.6 and 9.7 μm, thus indicating erosion in some areas, while the thickness after ILW1–3 increased to 10–12 μm. The D content was in the range 1.2–3.4×1017 cm−2 after ILW1–2 and 3.2–10×1017 cm−2 after ILW1–3 on most of the analyzed area, but in the limiter shadow values up to 58 ×1017 cm−2 were measured. Taking into account the total area of the Be-coated inner wall cladding tiles, the lower limit of D inventory amounts to 5.3×1022 atoms corresponding to about 176 mg, i.e. somewhat greater than the amount determined on Be limiters. The formation and spalling-off of Be-O particles was revealed.
A whole-process interpretable and multi-modal deep reinforcement learning for diagnosis and analysis of Alzheimer’s disease
∗
Authors: Zhang Quan , Du Qian , Liu Guohua
Published: November 2021

Objective. Alzheimer’s disease (AD), a common disease of the elderly with unknown etiology, has been adversely affecting many people, especially with the aging of the population and the younger trend of this disease. Current artificial intelligence (AI) methods based on individual information or magnetic resonance imaging (MRI) can solve the problem of diagnostic sensitivity and specificity, but still face the challenges of interpretability and clinical feasibility. In this study, we propose an interpretable multimodal deep reinforcement learning model for inferring pathological features and the diagnosis of AD. Approach. First, for better clinical feasibility, the compressed-sensing MRI image is reconstructed using an interpretable deep reinforcement learning model. Then, the reconstructed MRI is input into the full convolution neural network to generate a pixel-level disease probability risk map (DPM) of the whole brain for AD. The DPM of important brain regions and individual information are then input into the attention-based fully deep neural network to obtain the diagnosis results and analyze the biomarkers. We used 1349 multi-center samples to construct and test the model. Main results. Finally, the model obtained 99.6% ± 0.2%, 97.9% ± 0.2%, and 96.1% ± 0.3% area under curve in ADNI, AIBL and NACC, respectively. The model also provides an effective analysis of multimodal pathology, predicts the imaging biomarkers in MRI and the weight of each individual item of information. In this study, a deep reinforcement learning model was designed, which can not only accurately diagnose AD, but analyze potential biomarkers. Significance. In this study, a deep reinforcement learning model was designed. The model builds a bridge between clinical practice and AI diagnosis and provides a viewpoint for the interpretability of AI technology.
Soliton gas in integrable dispersive hydrodynamics
Authors: El Gennady A
Published: November 2021

We review the spectral theory of soliton gases in integrable dispersive hydrodynamic systems. We first present a phenomenological approach based on the consideration of phase shifts in pairwise soliton collisions and leading to the kinetic equation for a non-equilibrium soliton gas. Then, a more detailed theory is presented in which soliton gas dynamics are modelled by a thermodynamic type limit of modulated finite-gap spectral solutions of the Korteweg–de Vries and the focusing nonlinear Schrödinger (NLS) equations. For the focusing NLS equation the notions of soliton condensate and breather gas are introduced that are related to the phenomena of spontaneous modulational instability and the rogue wave formation. The integrability properties of the kinetic equation for soliton gas are discussed and some physically relevant solutions are presented and compared with direct numerical simulations of dispersive hydrodynamic systems.
Metal hydride hydrogen storage and purification technologies
Authors: Blinov D V , Borzenko V I , Bezdudny A V , Kazakov A N
Published: November 2021

The results of the development of metal hydride (MH) reactors for the storage and purification of hydrogen of various types are presented. Two methods of metal hydride purification of hydrogen are presented. The use of the MH method of flow-through purification of hydrogen has high hydrogen recovery rates at high volume contents of hydrogen in the mixture (⩾10% vol.), while the method of periodic evacuation of accumulated impurities is most effective at low hydrogen contents in the mixture (<10% vol.).
Experimental investigations of the processes in gas generator of hydrogen-air energy storage
Authors: Chukhin N I , Schastlivtsev A I
Published: November 2021

This paper describes the results of experimental investigation of the sample of the hydrogen-air gas generator unit with the expected average power of 65 kW. In total 5 test runs were made. Two tests showed that the mass flow and outlet gas temperature was in an agreement with the designed parameters. Additional attention should be paid to the cooling system design for the combustion chamber. In future such a gas generator in couple with the suitable gas turbine unit could be a part of the renewable energy accumulation system e.g. of hydrogen-air energy storage.
Intensification of heat transfer during pool boiling of nitrogen on surfaces with capillary-porous coatings produced by 3D-printing
Authors: Kuznetsov D V , Pavlenko A N
Published: November 2021

The study of heat transfer, critical heat fluxes (CHF) and evaporation dynamics at pool boiling of nitrogen at atmospheric and low pressures in a stationary heat generation regimes was performed. The two flat cooper heaters with porous coatings of various structural parameters obtained by additive 3D-printing as well as smooth one were used as working surfaces. According to obtained results such coatings significantly effect on pool boiling increasing up to six times the heat transfer coefficients (HTC) in comparison with uncoated sample. For all investigated heaters and pressures, visualization of boiling was performed using a video camera from which data on the bubble departure diameters and estimates of the active nucleation site density were obtained.
The influence of anionic surfactant in water on the quenching process
Authors: Lexin M A , Zabirov A R , Molotova I A , Kaban’kov O N , Yagov V V
Published: November 2021

Understanding the patterns of heat transfer during quenching is important for many technical applications. Of particular interest is the boiling regime, which is characterized by high intensity and occurs at surface temperatures exceeding the temperature of attainable liquid superheat. This work is aimed at studying the effect of surfactants on the onset of intense heat transfer during quenching. For this, experiments were carried out on quenching spheres made of different metals (nickel, stainless steel and zirconium) in water with different concentrations of surfactants. The surfactant was alkylbenzene sulfonate, the concentration of which varied from 0.1 to 2%. The analysis of the obtained cooling thermograms revealed the influence of not only the surfactant concentration on the beginning of the intensive cooling mode, but also the state of the heat transfer surface.
Calculation of thermodynamic properties of mixtures in two-phase equilibrium
Authors: Luo Taiming , Chirkov A Yu
Published: November 2021

Thermodynamic properties of mixtures in vapor-liquid equilibrium (VLE) were studied. Thermodynamic properties of the methane-ethane mixtures in VLE were calculated with highly accurate Helmholtz free energy equation of state GERG-2008, simplified GERG-2008 and common cubic PR equation of state (EOS). Results show that GERG-2008 has high accuracy in VLE calculations. However, simplified GERG-2008 and PR-EOS both work unsatisfactorily in VLE calculations.
CCGT unit with a carbonation system for CO2 capture
Authors: Maslennikov G E , Nazarova V V , Lazebny I P , Ryzhkov A F
Published: November 2021

The paper considers the issues of creating energy-efficient and environmentally friendly resource-saving energy generation technologies based on fossil fuels, solid waste and materials. A natural gas CCGT with a MSW ash carbonation unit was chosen as the research object. The prototype of the CCGT unit is the CCGT “Akademicheskaya” with an installed capacity of 230 MW. For the carbonation of MSW ash, a direct semi-dry route is used. In the calculation of the CCGT, the power and efficiency of the cycle are determined, as well as the parameters of the flue gas, which are transferred to the calculation of carbonation. As a result of calculations, it was found that this specific CO2 emissions from the power plant using carbonation can be reduced by almost 20% from 403 to 329 g kWh-1, however, a large amount of required MSW (2.6-6.7 kg per kg of flue gases) causes certain difficulties for the implementation of the project.
Study of the heat flux fluctuations intensity during flow around a circular cylinder
Authors: Yu Mityakov V , Seroshtanov V V , Suchok V V , Zhidkov N A , Vlasov A S
Published: November 2021

An experimental study performed in an air channel using gradient heatmetry is presented, for a configuration of three heated circular cylinders with different distance between them. Cylinders were installed one by one. The main objective is to analyze the heat flux fluctuations, employing gradient heat flux sensor. The behavior of the flow in the wake behind the first cylinder under various regimes, for the specified configuration, changes the fluctuations level at the surface of the second and third cylinders. By visualizing the flow using PIV, it was possible to see areas of stagnation, separation points and other features of flow around the model. The results showed that the fluctuations level for the second cylinder is an order of magnitude lower than for the first. We can say that the first cylinder stabilizes the flow. However, at the third cylinder, this level is comparable and even higher than on the first. Use of gradient heatmetry thus made it possible for the first time to estimate the fluctuating nature of the flow and heat transfer around cylinders.
Influence of microadditive of carbon dioxide on the kinetics of boiling-up of superheated n-pentane
Authors: Perminov S A , Lipnyagov E V , Parshakova M A
Published: November 2021

The effect of a low-boiling impurity (CO2 gas <1.5% mol) on the kinetics of boiling-up of superheated n-pentane in a vertical glass tube have been studied by high-speed video (2050 fps). The method of continuous pressure decrease from 2.00 to 0.10 MPa (in the temperature range of 100.2-145.1 °C), as well as the method of measuring the lifetimes of superheated liquids at 0.10 MPa (90.2-134.1 °C) have been used. The inner surface of the tube has two visible defects, one of which defines the boundary of the attainable superheat. After degassing the system, the defects of tube cease to play an appreciable role, the active centers are redistributed. The temperature of the attainable superheat increases from the initial value by 20 °C in tests with gas and by 10 °C in subsequent tests without it. The result obtained may be related to physical gas adsorption on the glass surface during the process of evacuation of the system.
Low-frequency fluorescence spectrum of a laser driven polar quantum emitter damped by squeezed vacuum with finite bandwidth
Authors: Bogolyubov N N , Soldatov A V
Published: November 2021

A two-level quantum emitter with broken inversion symmetry driven by external semiclassical monochromatic high-frequency electromagnetic (e.g., laser) field and damped by squeezed vacuum reservoir with finite bandwidth is presented. The squeezed vacuum source is assumed to be either degenerate parametric oscillator (DPO) or a non-degenerate parametric oscillator (NDPO). It is shown that the shape of low-frequency fluorescence spectrum of the emitter can be effectively alternated by controlling the degree of the squeezed vacuum source degeneration and phase of the squeezing.
Superconductivity of twisted double bi-layer graphene in chiral model
Authors: Rybakov Yu P , Umar M
Published: November 2021

Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very simple chiral model of graphene was suggested some years ago [1]. This model used as a special order parameter the unitary SU(2) -matrix U with the kink-like (or domain wall) structure for the description of electrons in a mono-atomic graphene sheet. However, later the new graphene physics began since studying twisted multilayer configurations revealing unconventional superconducting properties (twist-tronics) [2]. Within the scope of the chiral model these twisted configurations can be described by the so-called “product ansatz” U = U1U2
▪ ▪ ▪ Un
. As an example, the special case of twisted double bi-layer graphene (TDBG) configuration is studied and the corresponding twist angles, for which the superconductivity takes place, are found.
Direct stochastic molecular modelling of transport processes in gases
Authors: Ya Rudyak V , Lezhnev E V
Published: November 2021

The stochastic molecular modeling method (SMM) of transport processes in rarefied gases developed by the authors is systematically discussed in this paper. It is shown that, it is possible to simulate the transport coefficients of rarefied gas with high accuracy, using a relatively small number of molecules. The data of modeling the thermal conductivity coefficient are presented for the first time. The second part of the paper is devoted to the generalization of the SMM method for modeling transport processes in confined conditions. To describe the dynamics of molecules in this case, the splitting of their evolution by processes is used: first, the movement of molecules in the configuration space is simulated, and then their dynamics in the velocity space is imitated. Anisotropy of viscosity and thermal conductivity in nanochannels has been established. The interaction of gas molecules with walls is described by specular or specular-diffuse reflection laws. Gas viscosity can be either greater than in the bulk or less, depending on the law of gas interaction with the channel walls.
Study of the pressure distribution along a concentric annular channel
Authors: Germider O V , Popov V N
Published: November 2021

A study of an isothermal rarefied gas flow through a long concentric annular channel is carried out. The solution is based on the linearized BGK model with diffuse boundary conditions and it is valid in the whole range of the rarefaction parameter. The pressure distribution along the channel is obtained and investigated depending on the values of the pressure maintained at the channel ends.
Semiclassical Qubits
Authors: Kamalov T F
Published: November 2021

The semiclassical approximation of quantum computing and quasi-qubits (s-bits) have been obtained by us as a result of our work over the past few years. This work can be conventionally divided into two parts. The first part, let’s call it the programming model, contains a computer model of quasi-qubits and quantum computing. The second part, let’s call it the microelectronic model, describes the microelectronic realization of qubits in the semiclassical approximation (quasi-qubits) and exists in the form of block diagrams, which are supposed to be easy to manufacture. How did we get the semiclassical approximation? The difficulty in solving such a problem was that microparticles in quantum mechanics are described in an infinite-dimensional Hilbert space. Classical models are much poorer in the number of variables; therefore, it is impossible to describe quantum mechanical objects by classical methods due to the small number of available parameters.
Physics of nonlinear oscillations with nonlocal variables
Authors: Volkova O A , Khamis Hassan M H , Kamalov T F
Published: November 2021

In cases where physical processes cannot be described by linear equations, and nonlinear equations are difficult to solve mathematically, we have to use approximate solutions to such problems. One such example is the description of the Kapitsa pendulum, which is a pendulum with a vibrating suspension point. In contrast to the previously known methods of describing such a problem, in this paper we propose to use additional variables in the form of higher derivatives, which allows us to obtain corrections that give a more detailed contribution to the description of this problem.
Based on kinetic theory computer models of a molecular beam in a collimator
Authors: Komarov E , Kloss Yu Yu , Tcheremissine F G , Govorun I V
Published: November 2021

The paper studies a molecular jet that is formed during a gas outflow through a circular tube from a vessel and determines geometric characteristics of the vessel that reduce the jet slope. Developed software is applicable for studying gas flow in various geometries and uses the GPU for computation.
Intermolecular interactions of layers octa-phenyl-2,3-naphthalocyaninato zinc
Authors: Chausov D N , Suleymanova S , Kazak A V , Savin A V , Vasilyeva I A , Kuznetsov M M
Published: November 2021

The orientation of octa-phenyl-2,3-naphthalocyaninato zinc molecules is modeled by the atom-atom potential method. The dependence of the interaction energy of octa-phenyl-2,3-naphthalocyaninato zinc molecules on the angles characterizing their orientation relative to each other is established. It is shown that the obtained values of the interaction energy allow us to qualitatively explain the formation of molecules in a columnar structure.
Molecular dynamics of DNA-binding protein and its 2D-crystals
Authors: Tereshkin E V , Tereshkina K B , Krupyanskii Y F
Published: November 2021

In this work the dodecamers and the two-dimensional crystals of DNA-binding protein from starved cells (DPS) of Escherichia coli bacteria were investigated. The DPS monomer contains 167 amino acids residues. It can form dimers, trimers, and dodecamers. The versatility of the DPS protein structure can be used to design nanomaterials with structures and functions not found in living nature. The ability of this protein to self-assemble into complex shapes and structures defined on the nanometer scale can make them highly demanded for various technological applications. It was used all-atom classical molecular dynamics simulation on 0.1 microsecond scale to obtain the spatial and energy characteristics of the proteins and the components of the simulation box. The fluctuation mobility of DPS protein at various temperatures was discussed. The diffusion of ions in the presence of dodecamers and 2D crystals was compared. It has been shown that this protein retains its ability to accumulate ions in a wide range of biological temperatures from 277 to 369K. It also retains the mobility of key amino acid residues involved in the formation of nanocrystals and the transport of ions into the cavity, even at low physiological temperatures.
The influence of Fermi surface anisotropy and the charge carrier surface scattering kinetics on the electrical conductivity of a thin metal film in the view of the quantum size effect
Authors: Kuznetsova I A , Savenko O V , Romanov D N
Published: November 2021

The electrical conductivity of a thin metal film in an alternating electric field is calculated considering the quantum size effect. The Fermi surface of the metal has the shape of an ellipsoid of rotation, the main axis of which is parallel to the plane of the film. The quantum kinetic equation obtained from the von Neumann equation (the Liouville quantum equation) is solved. The Soffer model is used as the boundary conditions for the distribution function. The dependence of the electrical conductivity on the film thickness is analyzed. A comparison is made with experimental data on the electrical conductivity of bismuth thin films.
Method of the electron distribution function calculation in a problem of the kinetic rarefied plasma plume modeling
Authors: Bishaev A M , Abgaryan M V
Published: November 2021

A problem related to the rarefied plasma plume of the stationary plasma thruster (SPT) is considered in the paper. The consideration is conducted fully in terms of kinetics, namely, distribution functions are introduced to describe motion of every plasma component. The system of kinetics equations for the distribution functions should be solved in combination with the Maxwell’s equations. The paper discusses methods for solving the stated problem.
Moving an atom by swapping places across a crystal lattice without vacancies
Authors: Askerova V I , Kalashnikov E V
Published: November 2021

The mechanism of moving an atom through a crystal lattice without vacancies is considered. This situation can be observed when all sites of the lattice are occupied by atoms of the same type, or when some of them are occupied by isotopes of the same atoms. It is shown that in a three-dimensional crystal lattice constructed from identical atoms without vacancies, one-dimensional motion of the own atom along the lattice chain is possible. This movement is realized as a Frenkel-Kontorova soliton.
MATLAB Wavelet analysis of electron energy spectrum in one-dimensional quantum well with infinitely high walls for Al-Ga-As system (0 < x < 1)
Authors: Kozhanova E R , Tkachenko I M , Belyaev V V , Maignan S
Published: November 2021

This paper presents calculations of electronic states in AlxGa1-x As semiconductor nanostructures and simulates the envelope wave functions of quantum energy levels in a one-dimensional quantum well with infinitely high walls of a given width at various values of x. For the analysis of results the authors choose the function wtmm from the Matlab library that fixes the extremums and which is a characteristic of the fractality of the envelope wave functions of quantum energy levels.
Structural transformations in the system lanthanum bromide – water – electrical field
Authors: Vinokurov S A , Klassen N V , Orlov A D
Published: November 2021

We found several manifestations of severe influence of relatively week direct electrical fields on interactions of water with lanthanum bromide. The rate of dissolution of these crystals in water at the negative electrode exceeds this value at the positive electrode by several times. Pulse-like growth of solid micro-rods at the negative electrode from the solution of lanthanum bromide subjected to direct electrical field was observed. Auto-oscillations between the contents of water bound in hydrated lanthanum bromide and free water were found. These oscillations are attributed to severe difference of the electrical polarizabilities of free and bound water.
Spatial and spectral features of the luminescence of liquid nitrogen stimulated by infrared lasers
Authors: Klassen N V , Provotorov P V
Published: November 2021

Spectral features of cryogenic liquids, especially nitrogen, seem to be clearly investigated due to the wide application in science. On the other hand, material properties can really be different under intensive laser irradiation. During irradiation of liquid nitrogen with pulsed (pulse duration 20 ns) YaG: Nd 1064 nm laser with average power of 0.3 W we have found bright luminescence in the visible region with five narrow spectral lines. This phenomenon can be explained by the multiphoton excitation of nitrogen molecules and ions with infrared photons. Its spatial and spectral characteristics are attributed to Amplified Spontaneous Emission. The main features include super-linear dependence of the emission intensity on the intensity of the excitation radiation, limited amount of narrow spectral bands and conical geometry of the emission with the clear separation of the cones in correspondence with the spectral lines of the emission. This phenomenon manifests liquid nitrogen as the convenient substance of Kerr type for studies of various non-linear optical processes by means of nanosecond lasers instead of femtosecond lasers applied usually for these purposes.
Self- concentrated mass-transfer during deformation treatments of organic-inorganic compositions
Authors: Tsebruk I S , Pokidov A P , Kedrov V V , Klassen N V
Published: November 2021

This paper prolongs the series of our previous papers where we found super-fast and super-deep introduction of foreign substances in crystalline materials by means of the ball rolling. A set of new experimental results was used to justify the new version of the mechanism of this introduction with the record speed and depth. The main process which determines this phenomena is connected with the sequence of openings and closings of nanocracks at the surface subjected to the rolling and the capture of the substance introduced from the surface by these cracks. The process of this introduction with the record parameters is supported by the intense chemical interactions between the matrix and the substance being introduced. This chemical interaction is intensified by several times with the deformation treatments. The analogous super-fast mass transfer is observed in the situation of the pulling out of the polystyrene fibers from the solution of polystyrene in benzene when the interaction of the organic components with cesium iodide nanoparticles was activated by the deformation treatment of the solution during its pulling out resulting in the formation of big amounts of nano-channels promising for effective utilization of hazardous radioactive wastes.
Effect of aluminum alloying on the structure and properties of rapidly quenched TiNiCu alloy
Authors: Shelyakov A V , Sitnikov N N , Zaletova I A , Eroshenkov S A , Sevryukov O N
Published: November 2021

The efficiency of shape memory alloys for the MEMS technology has been recently demonstrated. Quasibinary intermetallic TiNi-TiCu alloys produced by rapid quenching from liquid phase in the form of thin (about 40 um) ribbons are an attractive material for the fabrication of micro-actuators due to their narrow temperature hysteresis of the shape memory effect (SME) and relatively large recoverable strain. In order to broaden the functionality of SME microdevices, in this work we have alloyed TiNiCu containing 25 at.% copper with aluminum. The results have shown that alloying with 0.6 at.% Al increases the cast characteristics of the composition and favors its amorphization. Upon crystallization by isothermal annealing or electropulse treatment the resultant microstructure and SME properties of the Al containing alloy change but slightly in comparison with the original alloy however there is a significant shift (by more than 15°C) of the SME temperature range toward lower temperatures.