bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase behavior and interfacial tension of ternary polymer mixtures with block copolymers
Authors: Liu Dongmei , Lin Ye , Gong Kai , Bo Huifeng , Li Deyang , Zhang Zhanxin , Chen Wenduo
Published: November 2021

The phase behavior and interfacial tension of ternary polymeric mixtures (polystyrene/polystyrene-b-poly(methyl methacrylate)/poly(methyl methacrylate), PS/PS-b-PMMA/PMMA) are investigated by dissipative particle dynamics (DPD) simulations.
Rxn Rover: automation of chemical reactions with user-friendly, modular software
Authors: Crandall Zachery , Basemann Kevin , Qi Long , Windus Theresa L.
Published: November 2021

Automation of chemical reactions through tools such as Rxn Rover in research and development is an enabling technology to reduce cost and waste management in technology transformations towards renewable feedstocks and energy in the chemical industry.
Modular synthesis of unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene molecular semiconductors for organic transistors
Authors: Tayu Masanori , Rahmanudin Aiman , Perry Gregory J. P. , Khan Raja U. , Tate Daniel J. , Marcial-Hernandez Raymundo , Shen Yuan , Dierking Ingo , Janpatompong Yurachat , Aphichatpanichakul Suphaluk , Zamhuri Adibah , Victoria-Yrezabal Inigo , Turner Michael L. , Procter David J.
Published: November 2021

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene (BTBT) scaffolds, combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction, delivers a library of BTBT materials.
Metal substrate catalysis in the confined space for platinum drug delivery
Authors: Velasco-Lozano Susana , Castro Silvia Alonso-de , Sanchez-Cano Carlos , Benítez-Mateos Ana I. , López-Gallego Fernando , Salassa Luca
Published: November 2021

Loading of a flavin catalyst and Pt prodrug onto a hydrogel affords biomaterials for the catalytic generation and delivery of cisplatin upon light irradiation or addition of electron donors. Confinement boosts the turnover frequency of the flavin.
Recent advances of cancer chemodynamic therapy based on Fenton/Fenton-like chemistry
Authors: Cao Changyu , Wang Xiaorui , Yang Nan , Song Xuejiao , Dong Xiaochen
Published: November 2021

Recent advances in cancer chemodynamic therapy based on Fenton chemistry are reviewed, including the working mechanism, characteristics, and strategies for optimizing treatment efficiency.
Controlled synthesis of Bi- and tri-nuclear Cu-oxo nanoclusters on metal–organic frameworks and the structure–reactivity correlations
Authors: Xue Qi , Ng Bryan Kit Yue , Man Ho Wing , Wu Tai-Sing , Soo Yun-Liang , Li Molly Mengjung , Kawaguchi Shogo , Wong Kwok Yin , Tsang Shik Chi Edman , Huang Bolong , Lo Tsz Woon Benedict
Published: November 2021

The controlled synthesis of novel bi- and trinuclear Cu-oxo nanoclusters supported on UiO-66-NH2 that show notably different catalytic properties in the photocatalytic formic acid decomposition reaction is reported.
Dynamics of microstructure anisotropy and rheology of soft jammed suspensions
Authors: Cuny Nicolas , Bertin Eric , Mari Romain
Published: November 2021

We explore the rheology predicted by a recently proposed constitutive model for jammed suspensions of soft elastic particles derived from particle-level dynamics [Cuny et al., Phys. Rev. Lett., 2021, 127, 218003].
Swift catalytic reduction of hazardous pollutants by new generation microgels
Authors: Singh Vinai Kumar , Kumar Krishna , Singh Nishant , Tiwari Rudramani , Krishnamoorthi S.
Published: November 2021

Swift catalytic reduction of toxic dyes and nitro compounds by new generation microgels.
Layered-perovskite oxides with in situ exsolved Co–Fe alloy nanoparticles as highly efficient electrodes for high-temperature carbon dioxide electrolysis
Authors: Sun Xiang , Ye Yongjian , Zhou Mengzhen , Chen Huijun , Li Ying , Chen Peirong , Dong Dehua , Ling Yihan , Khan Majid , Chen Yan
Published: November 2021

Ruddlesden–Popper phase oxide with exsolved Co–Fe alloy nanoparticles uniformly distributed on the surface (Co–Fe–STCF) exhibited outstanding activity towards CO2 electrolysis at elevated temperature.
Nutrient alloying elements in biodegradable metals: a review
Authors: Li Huafang , Lin Guicai , Wang Pengyu , Huang Jinyan , Wen Cuie
Published: November 2021

As a new generation of biomedical metallic materials, biodegradable metals have become a hot research topic in recent years because they can completely degrade in the human body, thus preventing secondary surgery, and reducing the pain and economic burden for patients.
Synergistic electronic coupling/cross-talk between the isolated metal halide units of zero dimensional heterometallic (Sb, Mn) halide hybrid with enhanced emission
Authors: Biswas Anupam , Bakthavatsalam Rangarajan , Das Deep K. , Sam Jisvin , Mali Bhupendra P. , Biswas Chinmoy , Maana Narugopal , Thomson Stuart , Raavi Sai Santosh Kumar , Kurungot Sreekumar , Gonnade Rajesh G. , Dutta Sudipta , Kundu Janardan
Published: November 2021

Reported here is a heterometallic 0D hybrid with constituent isolated metal halide units (Sb, Mn) that show strong synergistic interaction/coupling between the metal halide units (through Sb → Mn energy transfer) that results in enhanced emission.
A scintillating nanoplatform with upconversion function for the synergy of radiation and photodynamic therapies for deep tumors
Authors: Feng Yansong , Liu Xiaomeng , Li Qiqing , Mei Shilin , Wu Kefan , Yuan Jun , Tu Langping , Que Ivo , Tamburini Filippo , Baldazzi Fabio , Chan Alan , Cruz Luis J. , Zuo Jing , Yao Changjiang , Zhang Hong
Published: November 2021

Nanoplatforms consisting of an upconversion nanocore and an outermost X-ray active shell for PDT enable photoswitchable UCL imaging and RT&X-PDT.
A distributed adaptive protection scheme based on multi‐agent system for distribution networks in the presence of distributed generations
Authors: Ataei Mohammad Ali , Gitizadeh Mohsen
Published: November 2021

Distribution networks are operated in different conditions and the traditional protection systems might not be proper for all available operation conditions by using directional overcurrent relaying. Besides, the presence of distributed generations makes the protection setting and coordination more complex, and may even make it impossible to access a reliable protection system. Therefore, a fully distributed adaptive protection scheme based on the multi‐agent systems is proposed to improve the reliability, selectivity and sensitivity of relays. It uses only numerical directional overcurrent relays with instantaneous characteristics as agents, so that only need to pick‐up settings and react quickly. All agents dynamically update their pickup value to increase the fault detection sensitivity, and make reliable and selective on‐board decisions for fault location and isolation. In addition, in order to achieve high sensitivity and mitigate miscoordination, using setting groups of relays, a novel adaptive backup protection scheme, which does not need complex computational coordination, is proposed. The proposed system is performed in the distributed manner to enhance efficiency and robustness against cyber‐attacks and one‐point failures. The proposed system is tested on the meshed IEEE 14‐bus system and radial IEEE 13‐bus system with distributed generations to evaluate its performance.
Bild-basierte Patienten-individuelle Dosimetrie bei internen Radionuklidtherapien von neuroendokrinen Tumoren
Authors: Brosch-Lenz Julia , Gosewisch Astrid
Published: November 2021

Die Peptid-Radiorezeptor-Therapie (PRRT) mit Lutetium-177 (177Lu) hat sich als vielversprechende Therapieoption von metastasierten neuroendokrinen Tumoren (NETs) etabliert. Des Weiteren wird die Yttrium-90 (90Y) selektive interne Radio-Therapie (SIRT) als lokale Therapie von Lebermetastasen von NET Patienten durchgeführt. Beide Therapien werden von quantitativer Bildgebung begleitet und ermöglichen so Therapie-begleitende, Patienten-individuelle Dosimetrie. Die Abschätzung der Strahlendosis auf Risikoorgane und Tumore hat den großen Vorteil, dass weitere geplante Therapiezyklen möglicherweise angepasst werden können, um sowohl den Therapieerfolg zu verbessern, als auch die Nebenwirkung durch Toxizität von Risikoorganen zu minimieren. Die PRRT und SIRT unterscheiden sich sowohl in der Applikation, dem zugrundeliegenden therapeutischen Konzept, als auch den Radionukliden. Daraus resultieren verschiedene Anforderungen und Voraussetzungen für die Dosimetrie. Dieser Artikel beleuchtet detailliert die verschiedenen Herausforderungen für Bild-basierte Dosimetrie bei der PRRT und der SIRT von NET Patienten und unterstreicht die Notwendigkeit von routinemäßiger Dosimetrie.
Pädiatrische Nierendiagnostik
Authors: Vettermann Franziska , Sauerbeck Julia , Lange-Sperandio Bärbel , Pfluger Thomas
Published: November 2021

Die Nierenfunktionsszintigrafie stellt eine wichtige Säule in der Diagnostik von angeborenen oder erworbenen Niereninsuffizienzen und Nierenanomalien bei Kindern dar. Die nuklearmedizinischen Untersuchungsmodalitäten der Nieren sowie ableitenden Harnwege umfassen die MAG3-Szintigrafie, die DMSA-Szintigrafie sowie die direkte Radionuklid-Miktionszystografie. In dieser Übersichtsarbeit werden die wichtigsten Untersuchungsmethoden, deren Indikation, Nutzen und Risiko erläutert. Die MAG3-(Mercaptoacetyltriglycin)-Nierenfunktionsszintigrafie beurteilt die seitengetrennte Nierenfunktion und die Abflussverhältnisse, während die DMSA-Bildgebung hauptsächlich zur Beurteilung des funktionellen Nierenparenchyms und von Nierenparenchymdefekten verwendet wird. Zusätzlich kann die direkte Radionuklid-MCU (Urinzystografie) zur Refluxdiagnostik genutzt werden.
Profit bridges that disambiguate impacts of currency fluctuations from other marketing variables
Authors: Smith Tim J. , Westra Kyle T. , Phipps Nathan L.
Published: November 2021

We extend the normalized approach to constructing profit bridges proffered in a recent paper to examine the impact of currency exchange rate fluctuations within a multinational corporation. In doing so, we describe a profit bridge that would measure corporate performance distinct from that which would measure the performance of business units, including metrics for the impact of volume, price, variable cost, offering mix, and exchange rate changes.
Microstructuring of 2D perovskites via ion-exchange fabrication
Authors: Grimaldi G. , Antony L. S. D. , Helmbrecht L. , van der Weijden A. , van Dongen S. W. , Schuringa I. , Borchert J. , Alarcón-Lladó E. , Noorduin W. L. , Ehrler B.
Published: November 2021

In recent years, two dimensional (2D) perovskites have attracted growing interest as a material for optoelectronic applications, combining the defect tolerance and strong absorption of bulk perovskites with enhanced material stability. Moreover, the possibility to tune their bandgap via control of the thickness of the perovskite layers allows precise optimization of the energy levels in these materials, making them ideal candidates for rationally designed semiconductor heterojunctions. However, despite the advances in the synthesis of 2D perovskites, typical fabrication strategies produce either uniform thin-films or isolated single crystals, severely hindering the prospect of patterning these materials. We demonstrate an ion-exchange synthesis of 2D perovskites, starting from a lead carbonate host material and converting it to 2D perovskites via a solution-based treatment. The process allows for the fabrication of 2D perovskites spanning a range of halide compositions and 2D layer thicknesses and yields highly crystalline luminescent materials. We demonstrate the potential of this approach for 2D perovskite patterning, spatially localizing 2D perovskite structures via the conversion of pre-patterned lead carbonate structures. These results significantly expand the possibilities of 2D perovskite material design toward controllable integration of 2D perovskites in complex device architectures.
Numerical investigation on the flow characteristics of model dandelion seeds with angles of attitude
Authors: Qiu Fu-Sheng , Wang Bo-Wen , Du Yi-Ming , Qian Hui-Yuan
Published: November 2021

A stable and axisymmetric “separated vortex ring” formed above the pappus can greatly improve the aerodynamic efficiency of dandelion seeds and reduce the material requirement for flight. Since the dandelion seed is not always in a “regular” state (i.e., the pappus plane parallel to the horizontal plane) when flying, this paper uses a simplified rigid pappus model to simulate and analyze the influence of flight attitude on the flow patterns and the resulting changes in aerodynamic characteristics under different porosities. The numerical results are obtained by solving the three-dimensional incompressible steady RANS equations with the Spalart–Allmaras turbulence model in ANSYS Fluent software package. The results show that when there is an angle of attitude, the separated vortex ring will break with one of the vortices, losing its original recirculating structure, which leads to a considerable loss of the drag performance. In addition, the high-pressure region below the pappus plane shifting to one side will produce a horizontal force and a recovery moment against the rolling direction. The horizontal force component generated by a large-porosity pappus disk is much larger than that of a solid disk, which shows the good flight efficiency of dandelion seeds. At the same time, the inclined pappus will produce a recovery moment to keep the seed from rolling away from the horizontal plane. These conclusions show that the pappus structure has the potential to adjust the flight attitude and aerodynamic characteristics, which provides a preliminary understanding for further study on the flight dynamics of dandelion seeds.
Energy dissipation in turbulent reconnection
Authors: Bandyopadhyay R. , Chasapis A. , Matthaeus W. H. , Parashar T. N. , Haggerty C. C. , Shay M. A. , Gershman D. J. , Giles B. L. , Burch J. L.
Published: November 2021

We study the nature of pressure-strain interaction at reconnection sites detected by NASA's Magnetospheric Multiscale Mission. We employ data from a series of previously published case studies, including a large-scale reconnection event at the magnetopause, three small-scale reconnection events at the magnetosheath current sheets, and one example of the recently discovered electron-only reconnection. In all instances, we find that the pressure-strain shows a signature of conversion into (or from) internal energy at the reconnection site. The electron heating rate is larger than the ion heating rate and the compressive heating is dominant over the incompressive heating rate in all cases considered. The magnitude of thermal energy conversion rate is close to the electromagnetic energy conversion rate in the reconnection region. Although in most cases the pressure-strain interaction indicates that the particle internal energy is increasing, in one case, the internal energy is decreasing. These observations indicate that the pressure-strain interaction can be used as an independent measure of energy conversion and dynamics in reconnection regions, in particular, independent of measures based on the electromagnetic work. Finally, we explore a selected reconnection site in a turbulent Particle-in-Cell simulation which further supports the observational results.
An implicit split-operator algorithm for the nonlinear time-dependent Schrödinger equation
Authors: Roulet Julien , Vaníček Jiří
Published: November 2021

The explicit split-operator algorithm is often used for solving the linear and nonlinear time-dependent Schrödinger equations. However, when applied to certain nonlinear time-dependent Schrödinger equations, this algorithm loses time reversibility and second-order accuracy, which makes it very inefficient. Here, we propose to overcome the limitations of the explicit split-operator algorithm by abandoning its explicit nature. We describe a family of high-order implicit split-operator algorithms that are norm-conserving, time-reversible, and very efficient. The geometric properties of the integrators are proven analytically and demonstrated numerically on the local control of a two-dimensional model of retinal. Although they are only applicable to separable Hamiltonians, the implicit split-operator algorithms are, in this setting, more efficient than the recently proposed integrators based on the implicit midpoint method.
Interlayer magnetic interactions in π/3-twisted bilayer CrI3
Authors: Yu Haodong , Zhao Jize , Zheng Fawei
Published: November 2021

The interlayer magnetic interaction in bilayer CrI3 plays a crucial role for its device applications. In this work, we studied the interlayer magnetic interaction in π/3-twisted bilayer CrI3 using first-principles calculations. Our calculations show that the interlayer coupling can be ferromagnetic or antiferromagnetic depending crucially on lateral shift. The strongest antiferromagnetic interlayer interaction appears in the A¯A-stacking. The magnetic force theory calculations demonstrate that such an antiferromagnetic interaction is dominated by the eg–eg channel. Particularly, the interlayer antiferromagnetic interaction is very sensitive to external pressure. This highly tunable interlayer interaction makes π/3-twisted bilayer CrI3 a potential building block for magnetic field effect transistors and pressure sensors.
Influence of Crystal Disorder in MoS
Authors: Strachan Jyah , Chen Lu , Ellis Thomas , Masters Anthony , Maschmeyer Thomas
Published: November 2021

The full extent to which the electrochemical properties of MoS2 electrodes are influenced by their morphological characteristics, such as crystalline disorder, remains unclear. Here, we report that disorder introduced by ball-milling decreases the Faradaic component of cell capacity and leads to increasingly pseudo-capacitive behaviour. After high temperature annealing, a more battery-like character of the cell is restored, consistent with a decrease in disorder. These findings aid the optimisation of MoS2 electrodes, which show promise in several battery technologies.
Fungicide sensitivity and resistance in the blackleg fungus,
Authors: Van de Wouw A. P. , Scanlan J. L. , Marcroft S. J. , Smith A. J. , Sheedy E. M. , Perndt N. W. , Harrison C. E. , Forsyth L. M. , Idnurm A.
Published: November 2021

Fungicide use has become a fundamental part of many crop protection systems around the world, including to control blackleg disease on canola (Brassica napus L.). In Australia, most canola growers routinely apply at least one fungicide, and potentially multiple fungicides with different modes of action, in a single growing season. There is evidence for the emergence of fungicide resistance in Leptosphaeria maculans, the causal agent of blackleg disease, to the demethylation inhibitor (DMI) class of fungicides in Australia. However, it is not known whether resistance exists towards other chemical classes such as the succinate dehydrogenase inhibitors (SDHI). In this work, 397 samples were screened for resistance towards seven fungicide treatments in stubble-borne L. maculans populations collected from eight canola-growing agro-ecological regions of Australia from 2018 to 2020, a time frame that bridges the introduction of new chemicals for blackleg control. We confirmed that DMI resistance in L. maculans is pervasive across all of the sampled canola-growing regions, with 15% of fungal populations displaying high levels (resistance scores >0.5) of resistance towards the DMI fungicides. Although resistance to newly introduced SDHI fungicides was low, we found evidence of positive cross-resistance between established DMI-only fungicides and a newly introduced combined DMI and quinone outside inhibitor fungicide, suggesting that the efficacy of the latter may be limited by widespread DMI resistance. Proactive surveillance, as performed here, may provide a means to avoid the rapid loss of fungicide efficacy in the field.
Plant biodiversity and the regeneration of soil fertility
Authors: Furey George N. , Tilman David
Published: November 2021

Significance

Both plant biodiversity and soil fertility are in decline. We find that restoration of plant biodiversity on a nutrient-poor, unfertilized soil led to greater increases in soil fertility than occurred when these same plant species grew in monocultures. The plant species in this biodiversity experiment fell along a trade-off surface in their nutrient content traits, precluding any one species, or any one type of species, from markedly increasing soil fertility. Our results have implications for degraded agroecosystems, suggesting that increasing plant functional biodiversity may help restore their soil fertility. Creative applications of our findings to pastures, cover crops, and intercropping systems may provide greenhouse gas benefits from soil carbon storage and reduce the amounts of fertilizers needed for optimal yields.
In vivo visualization of butterfly scale cell morphogenesis in
Vanessa cardui
Authors: McDougal Anthony D. , Kang Sungsam , Yaqoob Zahid , So Peter T. C. , Kolle Mathias
Published: November 2021

Significance

Many organisms exhibit functional micro- and nanoscale materials with structural definition and performance that challenge synthetic fabrication techniques, yet we know little about the processes that enable their formation. Using butterfly scales as a model system for functional biomaterials, we establish a timeline of scale formation and quantify relevant structural parameters for developing painted lady butterflies. We overcome challenges of previous efforts by imaging structure formation directly in living organisms, which allows us to continuously observe the evolving wing tissue and the fine details of individual scale cells. Visualization of scale structure formation in live butterflies forms the basis for modeling the underlying biomechanical processes and opens avenues for their translation into advanced fabrication strategies.
Effect of head impacts and chemical irritation on elite athletes’ olfaction
Authors: Manninen Iida‐Kaisa , Mäkinen Laura K. , Laukka Pippa , Klockars Tuomas , Blomgren Karin
Published: November 2021

Limited research exists on athletes’ olfaction. As diet is an elementary part of an athlete's lifestyle and training, it is important to know whether the sport discipline itself carries a risk for olfactory impairment. The aim of this study was to evaluate whether elite swimmers (chemical irritation), boxers (head impact) or soccer players (head impact) are at risk for impaired olfaction. Elite‐level male swimmers (n = 30), boxers (n = 35) and soccer players (n = 30) aged 18–40 years were recruited from Finnish sport clubs. Floorball players (n = 30) were recruited as a control group. All participants filled in a questionnaire about their training history, nasal and sinonasal diseases, asthma, nasal operations and traumas, smoking and self‐evaluation of olfaction and taste function. Sniffin’ Sticks odour identification test with 12 different odorants and anterior rhinoscopy were performed on all participants. The mean score from the smelling test did not differ between the sport groups. Sinonasal diseases and bronchial asthma were more common among swimmers than among the other athletes. Rhinitis symptoms were common among all athletes. Boxing, soccer or swimming does not seem to affect sense of smell. The majority of our participating elite athletes had normal olfaction, even if they had had a long history of active sports.

Highlights

Boxing, soccer or swimming does not seem to affect sense of smell.

Rhinitis symptoms were prevalent among all elite athlete groups in our study.

Athletes with hyposmia can perceive their own decreased olfaction.

Swimmers have more bronchial asthma and sinus diseases than other athlete groups.
μ-distortion around stupendously large primordial black holes
Authors: Deng Heling
Published: November 2021

In a variety of mechanisms generating primordial black holes, each
black hole is expected to form along with a surrounding underdense region that
roughly compensates the black hole mass. This region will propagate
outwards and expand as a shell at the speed of sound in the homogeneous background. Dissipation of the shell due to Silk damping could lead to
detectable μ-distortion in the CMB spectrum: if black holes are rare on the last scattering surface, the signal(s) would be pointlike; whereas if there are a sufficient number of them, we could have a uniform distortion in the CMB sky. While the current
bound on the average μ-distortion is |μ̅| ≲ 10-4,
the standard ΛCDM model predicts |μ̅| ∼ 10-8,
which could possibly be detected in future missions. It is shown in
this work that the non-observation of μ̅ beyond ΛCDM
can place a new upper bound on the density of supermassive primordial
black holes within the mass range 106
M
☉≲ M ≲ 1015
M
☉.
Furthermore, black holes with initial mass M ≳ 1012
M
☉
could leave a pointlike distortion with μ ≳10-8 at an
angular scale ∼ 1° in CMB, and its non-observation would
impose an even more stringent bound on the population of these stupendously large primordial
black holes.
Improved treatment of dark matter capture in neutron stars III: nucleon and exotic targets
Authors: Anzuini Filippo , Bell Nicole F. , Busoni Giorgio , Motta Theo F. , Robles Sandra , Thomas Anthony W. , Virgato Michael
Published: November 2021

We consider the capture of dark matter (DM) in neutron stars via scattering on hadronic targets, including neutrons, protons and hyperons. We extend previous analyses by including momentum dependent form factors, which account for hadronic structure, and incorporating the effect of baryon strong interactions in the dense neutron star interior, rather than modelling the baryons as a free Fermi gas. The combination of these effects suppresses the DM capture rate over a wide mass range, thus increasing the cross section for which the capture rate saturates the geometric limit. In addition, variation in the capture rate associated with the choice of neutron star equation of state is reduced.
For proton targets, the use of the interacting baryon approach to obtain the correct Fermi energy is essential for an accurate evaluation of the capture rate in the Pauli-blocked regime. For heavy neutron stars, which are expected to contain exotic matter, we identify cases where DM scattering on hyperons contributes significantly to the total capture rate. Despite smaller neutron star capture rates, compared to existing analyses, we find that the projected DM-nucleon scattering sensitivity greatly exceeds that of nuclear recoil experiments for a wide DM mass range.
P-wave Ω
b
states: masses and pole residues *
Authors: Xu Yong-Jiang , Liu Yong-Lu , Huang Ming-Qiu
Published: November 2021

In this study, we consider all P-wave

states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues using the QCD sum rule method. Because of the large uncertainties in our calculation compared with the small difference in the masses of the excited

states observed by the LHCb collaboration, it is necessary to study other properties of the P-wave

states represented by the interpolating currents investigated in the present work to gain a better understanding of the four excited

states observed by the LHCb collaboration.
Evaluating the Impact of Optical Axis Stability on Exoplanet Detection
Authors: Tan Dong-Jie , Liu Jia-Cheng , Zhu Zi , Liu Niu
Published: November 2021

For detecting exoplanets with high precision, using the angular distance between the two stars to detect the periodic motion of the star will be a better choice. This approach can avoid importing the position error of the reference catalog in the process that uses a traditional photographic plate to derive the star position suffers. At the precision level of microarcseconds, the error caused by optical axis deviation is not negligible. In this paper, we evaluate the impact of the stability of the optical axis on the relative angular distance measurement from the aspects of theoretical analysis and numerical simulation. When the angular distance error limit of 1 microarcsecond is given, the upper limit of optical axis deviation is estimated to be 68 milliarcsecond. In addition, when limiting the deviation of the optical axis, we give the corresponding error allowance of angular distance measurement. Moreover, we also discuss the way to resolve the problem of CCD distortion and focal length change on the measurement of angular distance. The work in this paper is of guiding significance to the design of a telescope.
Measuring space-time properties of baryon resonances around 1 GeV using intensity correlations
Authors: Qinghua HE
Published: November 2021

We measured the Δ(1232) radius using Bose-Einstein correlations (BEC) between two neutral pions from photo-production off a hydrogen/deuterium target at the incident photon energies around 1 GeV. The experiment was carried out at Research Center for Electron Photon Science (ELPH) in Tohoku University with a 4π electromagnetic calorimeter complex, named FOREST. For low-multiplicity BEC measurements, we developed an event mixing technique by introducing additional mixing constraints to delicately reduce the effect of other non-BEC correlations arising from global conservation law and resonance decays. In addition, a new BEC observing model was established to extract radius information from BEC effects in the presence of resonance decays.
Beam Asymmetries from Light Scalar Meson Production on the Proton at GlueX
Authors: Fegan Stuart
Published: November 2021

The GlueX facility, featuring a linearly polarised 9 GeV real photon beam delivered to a large-acceptance detector system, has recently completed its first phase of running, and analysis efforts of this dataset are well underway. It has been suggested that at GlueX energies, quark systems beyond the three quark and quark-antiquark systems of baryons and mesons, such as hybrid mesons, tetraquarks and glueballs, should exist, and studies of these systems could shed new light on how quarks combine under the strong force, particularly the role played by gluons.

Meticulous study of the spectrum of hadronic states is required to understand the strong force in the non-perturbative energy regime, and the light scalar meson sector is an area that remains poorly understood. GlueX data encompasses final states at energies where photoproduction of the a0
(980) and f
0 (980) mesons can provide discriminatory evidence between various models, manifested in experimental observables such as the cross section and beam asymmetry, and performing detailed measurements of these quantities is considered a priority of the ongoing research program.

The work presented showcases efforts to measure the beam asymmetry of the reaction γp→pηπ whose mass spectrum encompasses several mesons, including the a
0(980) light scalar, and the a
2(1320) tensor. Future prospects for related analyses in the light scalar meson sector, informed by this measurement, will also be discussed.
Timelike Compton Scattering with CLAS12 at Jefferson Lab
Authors: Chatagnon Pierre
Published: November 2021

Generalized Parton Distributions (GPDs) describe the correlations between the longitudinal momentum and the transverse position of the partons inside the nucleon. They are nowadays the subject of an intense effort of research, in the perspective of understanding nucleon structure. GPDs have been studied mainly using Deeply Virtual Compton Scattering (DVCS, ep → e’p’γ). Here we highlight the measurement of the time-reversal conjugate process of DVCS, Timelike Compton Scattering (TCS) using data taken by CLAS12. The experimental measurement of the TCS angular asymmetry will provide new information on the real part of GPDs. This proceeding assesses the current status of the TCS analysis and presents preliminary results based on CLAS12 data.
The hierarchical fuzzy model of hydro acoustic activity for underwater vehicles
Authors: Bolnokin V E , Sorokin S A , Storozhev V I , Hai Duong Minh , Shcheka A A
Published: November 2021

The description of the basic equations and numerical-analytical methods of analysis of the theoretical model of functioning and structural-parametric optimization of hydro acoustic screens of underwater vehicles. The technique is based on a hierarchical fuzzy model of hydro acoustic activity underwater vehicles.
Sub-band detection of small-sized objects during airspace sensing with ultra-short radio pulses
Authors: Zhukov A O , Zhilyakov E G , Oleynik I I , Orishchuk S G , Fedorov P A , Kartsan I N
Published: November 2021

The possibility of ensuring the safety of flights of aircraft, such as helicopters, at low altitudes, where there is a high probability of unauthorized appearance of small-sized objects such as unmanned aerial vehicles, is being considered. The possibility of solving the problem of detecting such objects on the basis of radar soundings in the resonant frequency range of the UHF radio wave range is considered. Sub-band processing of the received signals is proposed, based on the division of the spectral definition area into sub-bands, for adaptation to the frequency response band and noise filtering. The mathematical apparatus of sub-band signal analysis using sub-band matrices has been developed. An optimal solution to the problem of filtering responses in given sub-bands is obtained. A procedure for processing the received signals is given when making decisions about the presence of a response in a given sub-band. Estimates of the probabilities of erroneous decisions are given for a given probability of errors of the first kind.
Modeling of the stress-strain state at the Shtokman gas condensate field accounting its block structure
Authors: Kalashnik A I , Kalashnik N A
Published: November 2021

The stress-strain state of the Shtokman gas condensate field has been studied using mathematical modeling and accounting its block structure. It is assumed that the rock mass’s structure has a vertical block structure, which is under the influence of gravity and tectonic force fields. It has been revealed that the stress-strain state of the rocks depends essentially on relationships of initial operating efforts and in-situ gas pressure, which magnitude varies with its production; direction of the maximum forces and dip of angles of fault zones; and elastic characteristics of the main rock mass and fault zones. It has been established that the change in the dip of angle of fault zones and reducing the rocks’ stiffness increases tensile stress in the roof of a horizontal seam and near the sea bottom. A forecast assessment has been performed of the vertical displacement of a rock block contoured with faults relatively to the main rock mass.
Automation of the development of electrodynamic objects based on the dual approach
Authors: Lvovich I Ya , Lvovich Ya E , Preobrazhenskiy A P , Preobrazhenskiy Yu P , Choporov O N
Published: November 2021

This paper considers an approach that demonstrates the features of creating complex electrodynamic systems. In practice, the creation of such objects is associated with a decrease in the levels of electromagnetic radiation, control of the direction of propagation of electromagnetic waves. The main properties of the generated automated system for assessing the quality of the electrodynamic characteristics of objects are considered. Suggestions are given on its structural diagram, the contours of the operation control and control of the restructuring of electrodynamic objects are shown. The created system for assessing the quality of electrodynamic characteristics can be useful in the design of a wide class of technical systems.
Modelling of voltage changes in the n-p junction in the pulse mode
Authors: Bogatov N M , Grigoryan L R , Klenevsky A V , Kovalenko M S , Volodin V S
Published: November 2021

The article presents the results of modeling the effect of the effective lifetime in the space charge region (SCR) of the n+-p junction on the impulse characteristics of silicon structures. The model is based on solving the fundamental system of differential equations for the transport of charge carriers in inhomogeneous semiconductors. The calculated time dependences of the voltage change in the SCR for a pulse voltage change on the n+-p-p+structure correspond to the experimental data.
Investigation of heat transfer in metal nanofilms irradiated with ultrashort laser pulses: two-temperature model
Authors: Mikheeva G V , Pashin A V
Published: November 2021

A numerical study of heat transfer between an electron gas and a crystal lattice in a metal nanofilm under irradiation with an ultrashort laser pulse was carried out on the basis of a parabolic two-temperature model of thermal conductivity presented in a dimensionless form. For the numerical solution, the finite difference method was used using the explicit-implicit Crank-Nicholson scheme. As a result of the numerical study, it was found that with an increase in the thickness of the plate, the equilibrium temperature decreases, and the time for the onset of thermal equilibrium between the electrons and the crystal lattice increases.
Plasmon resonance at the interface dielectric - nanocomposite material with superconducting inclusions
Authors: Golovkina M V
Published: November 2021

This article theoretically considers surface plasmon resonance in composite structures. The features of the surface plasmon resonance arising at the interface with media containing nanoparticles from a high-temperature superconductor are investigated. The dielectric constant of spherical superconducting inclusions is considered taking into account Gorter-Casimir two-fluid model. The temperature dependence of the electrodynamic parameters of the superconductor is taken into account. The two-fluid model, the dependence of the concentration of non-superconducting electrons in a superconductor is often used as the fourth power of temperature nn~T4. In this work, a phenomenological model is used, according to which the electron concentration of non-superconducting electrons in a superconductor is determined by the formula nn~Tγ with γ=1.3÷2. This model is in good agreement with experimental data for high-temperature ceramic superconductors. The dispersion characteristics of surface plasmons arising in a planar structure with a thin nanocomposite superconductor layer are investigated. It is shown that the dispersion characteristics depend significantly on temperature.
Spherical model and quantum phase transitions
Authors: Udodov V N
Published: November 2021

The spherical Berlin-Katz model is considered in the framework of the epsilon expansion in one-dimensional and two-dimensional space. For the two-dimensional and threedimensional cases in this model, an exact solution was previously obtained in the presence of a field, and for the two-dimensional case the critical temperature is zero, that is, a “quantum” phase transition is observed. On the other hand, the epsilon expansion of critical exponents with an arbitrary number of order parameter components is known. This approach is consistent with the scaling paradigm. Some critical exponents are found for the spherical model in one-and twodimensional space in accordance with the generalized scaling paradigm and the ideas of quantum phase transitions. A new formula is proposed for the critical heat capacity exponent, which depends on the dynamic index z, at a critical temperature equal to zero. An expression is proposed for the order of phase transition with a change in temperature (developing the approach of R. Baxter), which also depends on the z index. An interpolation formula is presented for the effective dimension of space, which is valid for both a positive critical temperature and a critical temperature equal to zero. This formula is general. Transitions with a change in the field in a spherical model at absolute zero are also considered.
Intelligent control systems using algorithms of the entropie potential method
Authors: Jumaev O A , Nazarov J T , Makhmudov G B , Ismoilov M T , Shermuradova M F
Published: November 2021

As part of neural network systems, an artificial neural network can perform various functions like diagnostics of technological equipment, control of moving objects and technological processes, forecasting situations, as well as assessing the state and monitoring of technological processes.
Propagation conditions of 10 MHz signals along the paths between Rostov and Moscow
Authors: Ivanov I , Maltseva O , Nikitenko T
Published: November 2021

To determine the conditions for the propagation of HF signals through the ionosphere along various paths, there are several possibilities: (1) ionograms of vertical sounding, (2) ionograms of oblique sounding between transmission and receiver points, (3) receiving signals from transmitters of exact time at fixed frequencies (here ~10 MHz), (4) using ionospheric models. This paper presents the results of a comprehensive study that implements all these possibilities. They refer to the propagation of HF signals on reciprocal paths between Rostov and Moscow during the period of the lowest solar activity of cycle 24 (April-May 2020). It is shown that the maximum usable frequency (MUF) of propagation through the F2 layer of the ionosphere in the overwhelming majority of cases did not exceed 10 MHz both in the experiment and according to model calculations. The signals were propagated through the Es layer. If earlier it was shown that such a joint experiment allows revealing the presence of traveling ionospheric disturbances, the results of this work emphasize the role of the Es layer.
Toroidal free oscillations of a viscous liquid spherical shell with mixed boundary conditions
Authors: Vodinchar Gleb
Published: November 2021

The problem of toroidal eigenmodes of free oscillations of a viscous fluid spherical shell is solved under mixed boundary conditions. These conditions are a combination of free surface conditions and solid boundary conditions. Such an artificial combination is used sometimes in the numerical simulation of geodynamo problem. The scheme for calculating the eigenmodes is described. It is shown that the use of mixed conditions leads to the disappearance of the first eigenmode with the smallest eigenvalue. A possible reason for this is the physical incorrectness of the mixed boundary conditions.
Determination of the limiting state of bodies during separation in the case of the general plane problem
Authors: Matveeva A N , Matveev S V , Andreeva A A
Published: November 2021

The paper considers the general plane problem of determining the limiting state of bodies during separation. The conditions for reaching the limiting state are considered to depend on the average pressure and the direction of separation. The paper defines the characteristic equations for two cases of separation: equality of two principal stresses to the limiting value of separation and equality of one principal stress to the limiting value of separation. Equations of characteristics’ lines and relations along them are determined.
Nanoparticles in marine antifouling coatings: a case study
Authors: Mosunov A A , Evstigneev V P
Published: November 2021

The problem of fouling of hydraulic structures, marine structures, ships and vessels has been acute since the beginning of the era of navigation. The formation of a biofilm of fouling reduces the speed of the vessel, worsens its controllability, increases fuel consumption, shortens the service life of hydraulic structures and increases the load on them. Many methods have been proposed to control fouling. One of the most promising coatings is considered to be based on the use of nanoparticles of biologically active metals and their oxides. The paper discusses various strategies for using nanoparticles to combat biofouling. The paper also presents preliminary results of a study of the antifouling efficiency of coatings modified with nanoparticles of metal oxides Fe-ZnO, ZnO, CuO. The study was carried out by exposing plates with experimental compositions at the sea test site in the Sevastopol Bay for a year, starting from August 2020. The species composition of a separate group of microperiphyton - microalgae - on plates with experimental coatings in the first two months of exposure, as well as the result of photographic fixation of the state of the surface of the plates from the point of view of macro-fouling, was investigated.
Applied spectroscopy methods application in the defluorinated phosphate production technological process control problem
Authors: Vaganov M A , Kazakov V I , Lebedev V F , Bestugin A R , Kitaev V V
Published: November 2021

The paper considers the applied optical spectroscopy methods application in the defluorinated phosphate production, controlling the technological process task. The emission spectral analysis using the method possibilities to control the charge hydrothermal acid processing process, which takes place in special furnaces with natural gas burning and a temperature of 1340 – 1400°C, have been studied. Experiments have been carried out in production conditions, and the radiation spectral characteristics study results from the furnace during the defluorination technological process are presented. It is shown that, by measuring individual spectral lines, it is possible to provide an automatic control mode for the defluorination technological process in the furnace burner controlling the combustion mode terms without the need for visual observation by the operator to ensure a better product yield. The work second part is devoted to the defluorinated phosphate chemical composition study by the laser-spark emission spectrometry method (LIBS). The LIBS method application for the defluorinated phosphate chemical composition analysis is proposed, which allows the production process parameters real-time control. The plasma spectra measurement and interpretation results from the ready-made defluorinated phosphate sample, obtained using the LIBS method, are presented.
Ab initio calculation of the electronic structure of a solid solution of strontium-bismuth molybdat
Authors: Sokolenko E V , Buyanova E S , Mikhaylovskaya Z A , Slusarev G V
Published: November 2021

Scheelite-like compounds based on SrMoO4 have been studied. Based on X–ray structural data, models of Sr1-3xBi2xMoO4 structures (x=0.2125) are constructed, at x≧0.175, a superstructural ordering is observed associated with the location of cationic vacancies. From the first principles, calculations of the density of states in the vicinity of the forbidden zone are performed. The calculated values of the band gap width were compared with the values obtained from the reflection spectra.
Digital demodulators for analog signals: comparative analysis and simulation
Authors: Kudinova T V , Osipov G A , Nanay F A
Published: November 2021

The paper examines digital demodulators for two commonly used techniques of modulating analog signals: amplitude modulation (AM) and frequency modulation (FM). The described demodulators can be used to perform the radio monitoring of narrowband signal ranges including FM broadcasting stations as well as license-free CB, LPD, PMR bands. The demodulators considered in this work are intended for programmable devices with limited memory and computing resources, for example, for STM32F407 microcontrollers and similar ones. The paper presents the analysis and simulation of demodulators for AM signals, FM signals with low modulation indices and for FM signals without restriction on the modulation indices. In addition, the authors demonstrate how to demodulate the phase-modulation signal using a quadrature demodulator. The number of operations that are available for demodulation is limited by IF multiplication and filtering. The simulation of the analyzed demodulation algorithms was carried out in the Scilab environment which is a free analogue of the Matlab environment. To explain the principle of operation of demodulators, block diagrams and graphs of signals in time and frequency domains are shown.