bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal dynamics of Odonata assemblages in an anthropogenically impacted lotic system
Authors: Maoduš Iva Vidaković , Pozojević Ivana , Vilenica Marina , Mihaljević Zlatko
Published: June 2022

European lowland rivers are extensively impacted by hydromorphological pressures, and the relationship between individual benthic macroinvertebrate groups and these degradations are insufficiently investigated. Therefore, we studied distribution and ecological traits of Odonata inhabiting a lotic system in the Pannonian lowland ecoregion (ER 11) in Croatia affected by degraded water quality and hydromorphological stressors. The study encompassed multihabitat sampling of 20 longitudinally distributed sampling sites, selected for their representativeness of disturbances. Only five species were recorded withPlatycnemis pennipes(Pallas, 1771) andOnychogomphus forcipatus(Linnaeus, 1758) dominating. We found woody debris samples contained a disproportionately higher number of Odonata, especially Zygoptera, compared to all other sampled microhabitats. The downstream longitudinal increase in Odonata abundance was not followed by an expected increase in species richness. Only five (oxygen saturation, pH, ammonium, water temperature and total nitrogen) of the sixteen tested water quality parameters were significant variables in determining the variation of Odonata assemblages.Calopteryx virgo(Linnaeus, 1758) and juvenileGomphidaewere associated with sites of somewhat higher ammonium and total nitrogen concentrations while all other taxa showed a negative association to ammonium. Odonata abundances were affected by modification of the river channel where significant decrease in abundance was observed with increased modification. Our results suggest that even species with a broad ecological tolerance are sensitive to hydromorphological pressures and represent an important background for further research and conservation practices of lotic European Odonata.
Parenchymsparende Operationen oder anatomische Resektionen bei
Lebermetastasen des kolorektalen Karzinoms?
Authors: Ghamarnejad Omid , Stavrou Gregor Alexander
Published: June 2022

Darmkrebs ist eine der häufigsten Todesursachen in der westlichen Welt. Die
Hälfte der Patienten entwickelt kolorektale Lebermetastasen (CRLM), dabei weisen
weniger als 30% der Patienten zum Zeitpunkt der Diagnose eine chirurgisch
resektable Metastasierung auf. Im Falle einer Resektabilität bietet die
klassische anatomische (Major-)Hepatektomie eine hohe R0-Resektionsrate,
allerdings bei gleichzeitig erhöhter Morbidität und Mortalität. In den letzten 2
Jahrzehnten wurden die potenziellen Vorteile der parenchymsparenden Hepatektomie
(PSH) in Bezug auf die onkologischen Gesamtergebnisse, das Überleben und die
Re-Resektion im Falle eines Rezidivs („Salvageability“) nachgewiesen. Der
Beitrag fasst die aktuellen Erkenntnisse zur PSH als chirurgische Therapieoption
zusammen und diskutiert den aktuellen „state of the art“ in verschiedenen
Szenarien.
Recent Advances in Thianthrenation/Phenoxathiination Enabled Site-Selective Functionalization of Arenes
Authors: Wang Peng , Chen Xiao-Yue , Wu Yichen
Published: June 2022

Site-selective functionalization of simple arenes remains a paramount challenge due to the similarity of multiple C–H bonds in the same molecule with similar steric environment and electronic properties. Recently, the site-selective thianthrenation/phenoxathiination of arenes has become an attractive solution to reach this challenging goal and it has been applied in the late-stage functionalization of various bioactive molecules. This short review aims to summarize recent advances in the site-selective C–H functionalization of arenes via aryl thianthrenium salts, as well as mechanistic insights in the remarkable site-selectivity obtained in thianthrenation step.

1 Introduction

2 Site-Selective Thianthrenation of Arenes and Mechanistic Insight

3 Thianthrenation-Enabled Site-Selective Functionalization of Arenes

3.1 Thianthrenation-Enabled C(sp
2)–C Bond Formation Reaction

3.2 Thianthrenation-Enabled C(sp
2)–X Bond Formation Reaction

4 Conclusion and Outlook
Design, Usability, and Acceptability of a Needs-Based, Automated Dashboard to Provide Individualized Patient-Care Data to Pediatric Residents
Authors: Yarahuan Julia K.W. , Lo Huay-Ying , Bass Lanessa , Wright Jeff , Hess Lauren M.
Published: June 2022

Background and Objectives Pediatric residency programs are required by the Accreditation Council for Graduate Medical Education to provide residents with patient-care and quality metrics to facilitate self-identification of knowledge gaps to prioritize improvement efforts. Trainees are interested in receiving this data, but this is a largely unmet need. Our objectives were to (1) design and implement an automated dashboard providing individualized data to residents, and (2) examine the usability and acceptability of the dashboard among pediatric residents.

Methods We developed a dashboard containing individualized patient-care data for pediatric residents with emphasis on needs identified by residents and residency leadership. To build the dashboard, we created a connection from a clinical data warehouse to data visualization software. We allocated patients to residents based on note authorship and created individualized reports with masked identities that preserved anonymity. After development, we conducted usability and acceptability testing with 11 resident users utilizing a mixed-methods approach. We conducted interviews and anonymous surveys which evaluated technical features of the application, ease of use, as well as users' attitudes toward using the dashboard. Categories and subcategories from usability interviews were identified using a content analysis approach.

Results Our dashboard provides individualized metrics including diagnosis exposure counts, procedure counts, efficiency metrics, and quality metrics. In content analysis of the usability testing interviews, the most frequently mentioned use of the dashboard was to aid a resident's self-directed learning. Residents had few concerns about the dashboard overall. Surveyed residents found the dashboard easy to use and expressed intention to use the dashboard in the future.

Conclusion Automated dashboards may be a solution to the current challenge of providing trainees with individualized patient-care data. Our usability testing revealed that residents found our dashboard to be useful and that they intended to use this tool to facilitate development of self-directed learning plans.
A modified modular multilevel converter topology trigger generator for a pseudospark switch
Authors: Petridi A. , Chatzipetrakis G. , Skoulakis A. , Fitilis I. , Tatarakis M. , Chatzakis J.
Published: June 2022

A novel trigger generator for operating a pseudospark switch has been developed based on a modified modular multilevel converter topology using insulated gate bipolar transistors. The trigger generator can be operated in either single- or high-repetition rate shot mode. It is characterized by a fast rise time and low temporal jitter between the output trigger pulses of less than 1 ns. It produces pulses of 4.5 kV and 1 µs duration into a 50 Ω load that can trigger a single pseudospark switch. By minimizing the high-voltage components, faster high-voltage switching takes place and the power density of the unit is increased. Furthermore, the overall volume of the trigger generator is reduced. Using this pseudospark trigger generator, it is possible to trigger single or multiple pseudospark gaps without the requirement to use a pulse shaping circuit.
High-performance IGZO/Ga2O3 dual-active-layer thin film transistor for deep UV detection
Authors: Han Zuyin , Song Shuang , Liang Huili , Shao Hang , Hu Sigui , Wang Yan , Wang Jiwei , Mei Zengxia
Published: June 2022

Owing to the intrinsically wide bandgap and high uniformity, amorphous Ga2O3 (a-Ga2O3) has been illustrating a great industrial potential for large-area deep ultraviolet (UV) photosensor arrays. However, a seemingly irreconcilable contradiction between high responsivity and long persistent photoconductivity has hampered the growing pace of such devices. In this work, three-terminal InGaZnO (IGZO)/a-Ga2O3 dual-active-layer (DAL) transistors were developed to realize the ability of a-Ga2O3 as the active layer both in switching and sensing. Benefitting from the introduction of ultrathin IGZO electron reservoir and defect control of a-Ga2O3, the DAL device demonstrates more stable and superior gate-control capability with promising performance including high on/off ratio and field-effect mobility of ∼108 and 8.3 cm2/V⋅s, respectively, as well as a small sub-threshold swing (SS) of 0.36 V/dec. Under 254 nm UV illumination, the DAL device manifests a light-to-dark ratio of ∼108, a responsivity of 4.8 × 103 A W−1, a detectivity of 8 × 1015 Jones, and a UV/visible rejection ratio (R254/R400) of 64. The simultaneous achievement of deep UV photo-detection and transistor's switching performance in a-Ga2O3 material offers excellent potential for the construction of large-area active-matrix UV photosensor arrays with the simple and low-cost fabrication process.
On the dose of plasma medicine: Plasma-activated medium (PAM) and its effect on cell viability
Authors: Cheng He , Luo Jingyi , Song Ke , Zhao Feng , Liu Dawei , Nie Lanlan , Lu Xinpei
Published: June 2022

Plasma-activated medium (PAM) has a broad prospect in the medical field. However, how to define the plasma dose of PAM and what is the dose–response relationship of PAM on cells are still open questions of plasma medicine. In this paper, the plasma dose of PAM based on equivalent total oxidation potential (ETOP) is introduced, and the S-logistic model is used to describe the relationship between PAM dose and the corresponding lethal effects of cells. Experiments of PAM on A875/HaCaT cell viabilities indicate that ETOP as a plasma dose is suitable for PAM. Evidence of dose discrepancies in 50% response intensity suggests that ETOP can be used to maximize the lethality difference between normal/cancer cells. Further validation by the published literature again indicates that ETOP may provide a well-defined strategy in evaluating the selectivity of PAM treatment on different cell types.
Shaping gels and gels mixture to create helices
Authors: D'Angelo M. V. , Pauchard L. , Auradou H. , Darbois Texier B.
Published: June 2022

In cooking, food gels, such as agar-agar or alginate, are often prepared and presented in the form of spheres or spaghetti. While experimenting in our kitchen, we realized that it is quite difficult to make more advanced shapes. In this study, we sought to develop new methods to obtain more complex shapes. Our first challenge was to obtain helices. The best method we selected was to deposit the solutions before their gelation in a thread. The robustness of the method is tested by systematically changing the thread pitch, diameter, and depth. From the deformation under its own weight, we propose to deduce the mechanical characteristics of the helix. These values are compared to those obtained in the laboratory using indentation testing. Finally, we experimented with mixed gels obtained by combining agar-agar and alginate.
Direct laser printing of high-resolution physically unclonable function anti-counterfeit labels
Authors: Lapidas V. , Zhizhchenko A. , Pustovalov E. , Storozhenko D. , Kuchmizhak A.
Published: June 2022

Security labels combining facile structural color readout and physically unclonable one-way function (PUF) approach provide promising strategy for fighting against forgery of marketable products. Here, we justify direct femtosecond-laser printing, a simple and scalable technology, for fabrication of high-resolution (12 500 dots per inch) and durable PUF labels with a substantially large encoding capacity of 10895 and a simple spectroscopy-free optical signal readout. The proposed tags are comprised of laser-printed plasmonic nanostructures exhibiting unique light scattering behavior and unclonable 3D geometry. Uncontrollable stochastic variation of the nanostructure geometry in the process of their spot-by-spot printing results in random and broadband variation of the scattering color of each laser printed “pixel,” making laser-printed patterns unique and suitable for PUF labeling.
Equation of state for confined fluids
Authors: Bråten Vilde , Zhang Daniel Tianhou , Hammer Morten , Aasen Ailo , Schnell Sondre Kvalvåg , Wilhelmsen Øivind
Published: June 2022

Fluids confined in small volumes behave differently than fluids in bulk systems. For bulk systems, a compact summary of the system’s thermodynamic properties is provided by equations of state. However, there is currently a lack of successful methods to predict the thermodynamic properties of confined fluids by use of equations of state, since their thermodynamic state depends on additional parameters introduced by the enclosing surface. In this work, we present a consistent thermodynamic framework that represents an equation of state for pure, confined fluids. The total system is decomposed into a bulk phase in equilibrium with a surface phase. The equation of state is based on an existing, accurate description of the bulk fluid and uses Gibbs’ framework for surface excess properties to consistently incorporate contributions from the surface. We apply the equation of state to a Lennard-Jones spline fluid confined by a spherical surface with a Weeks–Chandler–Andersen wall-potential. The pressure and internal energy predicted from the equation of state are in good agreement with the properties obtained directly from molecular dynamics simulations. We find that when the location of the dividing surface is chosen appropriately, the properties of highly curved surfaces can be predicted from those of a planar surface. The choice of the dividing surface affects the magnitude of the surface excess properties and its curvature dependence, but the properties of the total system remain unchanged. The framework can predict the properties of confined systems with a wide range of geometries, sizes, interparticle interactions, and wall–particle interactions, and it is independent of ensemble. A targeted area of use is the prediction of thermodynamic properties in porous media, for which a possible application of the framework is elaborated.
Cavitation bubble collapse in a vicinity of a rigid wall with a gas entrapping hole
Authors: Sun Yurong , Yao Zhifeng , Wen Haigang , Zhong Qiang , Wang Fujun
Published: June 2022

This paper aims to reveal the influence of a rigid wall with a gas entrapping hole on the characteristics of the dynamic behavior of a laser-induced bubble collapse. A high-speed camera system was used to record the oscillation process of the laser-induced bubble on a rigid wall with a gas entrapping hole. When a bubble is generated by a laser above the wall with a gas entrapping hole, the entire bubble collapse stays away from the wall or splits into two bubbles because of a radial jet induced by bubble contraction. These two distinctive collapse modes are dependent on the distance between the wall and the bubble. The focus of this study is the quantitative analysis of the jet formation, bubble migration, and oscillation period, and compared with the behavior of the bubble near a rigid wall. The results show that unlike the generation of the bubble near a rigid wall, a rigid wall with a gas entrapping hole affects the morphology of the jet and changes the direction of migration of the bubble and decreases the oscillation period. Thus, the rigid wall with a gas entrapping hole could be effective for reducing cavitation erosion on the wall surface, which is supported by our experiment results.
Counter-flow phenomena studied by nuclear magnetic resonance (NMR) velocimetry and flow simulations
Authors: Kohn Benjamin , Walinda Erik , Sugase Kenji , Morimoto Daichi , Scheler Ulrich
Published: June 2022

Flow patterns including counter-flow and flow reversal effects have been studied by a combination of nuclear magnetic resonance flow imaging and numerical modeling using the finite volume method in the open-source computational fluid mechanics package OpenFOAM. Two cylindrical geometries have been used: In a concentric double-cylinder system the flow reversal under oscillatory rotation of the inner cylinder has been followed, and the time evolution of the flow reversal has been studied. We find extended periods of counter-rotating flow in the gap where fluid in the inner part of the gap follows the new direction of the rotor, while the outer part takes a longer time until the viscous forces transmit the reverted flow direction outwards. The radial position of the reversal of flow direction has been monitored as a function of the oscillation angle after the turning point. In the second cylindrical geometry, the rotating bob is placed off the center and a counter-rotating vortex is detected in the wider part of the gap. At constant viscosity and eccentricity, the position of the center of the vortex was found to depend on the rotation frequency of the bob. Qualitative and quantitative agreement between experiment and laminar (nonturbulent) flow simulations has been obtained for both steady-state flow using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE) algorithm and time-dependent flow using the Pressure Implicit with Splitting of Operators (PISO) algorithm.
Characteristics of boundary-layer transition driven by diverse streamwise vortices
Authors: Villodi Navaneet , K. V. Manu
Published: June 2022

The present direct numerical simulations investigate the dynamics of diverse streamwise vortices in a zero-pressure gradient incompressible laminar boundary layer and the onset of turbulence. Due to the critical role of streamwise vortices in bypass transitions, we compare the transition mechanisms induced by a single vortex and vortex pairs. We initially examine the evolution of a single vortex by employing streamwise vortex profiles at two wall-normal locations. The single streamwise vortex will prompt a more rapid eruption from the bottom part of the boundary layer if moved nearer to the wall, as observed in the experimental study by Manu et al. [“Evolution of isolated streamwise vortices in the late stages of boundary-layer transition,” Exp. Fluids 48, 431–440 (2010)]. In the late stages of boundary-layer transition, the vortex–wall interaction emerges to be particularly pronounced. The second set of simulations triggers flow transition by imposing counter-rotating vortex pairs at the inlet of the computational domain. Streamwise vortex pairs with net upward flows cause intense, sporadic ejections of near-wall fluids into the boundary-layer edge, providing the first signs of inflectional instability in all considered cases. Instead of vortex–wall interactions, flow structures created by vortex pairs penetrate deeply into the inviscid region, resulting in substantial unsteady viscous-inviscid interactions. When counter-rotating vortices accompany to form a net downward flow, the initial formation of each vortex is analogous to that of a single vortex. The instability frequency and wavelength of the transitional flow produced by a vortex introduced in the middle of the boundary layer are lower than those imposed near the wall. The transitional flow generated by the vortex pair exhibits longer-wavelength instability than the single vortex cases.
Modeling and observation of fine gas compression in a confined narrow tube by electrowetting-on-dielectric
Authors: Tan Jie , Zhang Haiqing , Li Mulin , Jiang Dongyue , Sun Shulan
Published: June 2022

Capillarity describes liquid flowing against gravity in an open narrow tube with certain wettability and is well described by the Young–Laplace equation. However, the modeling of the gas compression in a confined narrow tube due to capillary action with variable wettability is yet to be established. Thus, this study observes and models the relation between the gas pressure increment in a confined narrow tube and water contact angle (CA) variation induced by electrowetting-on-dielectric (EWOD). An increment of 1.64 Pa/°CA was obtained for a confined tube with a 3 mm diameter, which well matched the measured result (1.48 Pa/°CA). Fine gas compression can be achieved by varying the voltage input. The gas compression process was determined to be an adiabatic process with a ∼10% conversion efficiency (CA varying from 110° to 65°). The concept and modeling of this EWOD-based gas compression process will pave the way for fine gas compressors in microfluidic applications.
HIV-1 mutants expressing B cell clonogenic matrix protein p17 variants are increasing their prevalence worldwide
Authors: Caccuri Francesca , Messali Serena , Zani Alberto , Campisi Giovanni , Giovanetti Marta , Zanussi Stefania , Vaccher Emanuela , Fabris Silvia , Bugatti Antonella , Focà Emanuele , Castelli Francesco , Ciccozzi Massimo , Dolcetti Riccardo , Gallo Robert C. , Caruso Arnaldo
Published: June 2022

AIDS-defining cancers declined after combined antiretroviral therapy (cART) introduction, but lymphomas are still elevated in HIV type 1 (HIV-1)–infected patients. In particular, non-Hodgkin’s lymphomas (NHLs) represent the majority of all AIDS-defining cancers and are the most frequent cause of death in these patients. We have recently demonstrated that amino acid (aa) insertions at the HIV-1 matrix protein p17 COOH-terminal region cause protein destabilization, leading to conformational changes. Misfolded p17 variants (vp17s) strongly impact clonogenic B cell growth properties that may contribute to B cell lymphomagenesis as suggested by the significantly higher frequency of detection of vp17s with COOH-terminal aa insertions in plasma of HIV-1–infected patients with NHL. Here, we expand our previous observations by assessing the prevalence of vp17s in large retrospective cohorts of patients with and without lymphoma. We confirm the significantly higher prevalence of vp17s in lymphoma patients than in HIV-1–infected individuals without lymphoma. Analysis of 3,990 sequences deposited between 1985 and 2017 allowed us to highlight a worldwide increasing prevalence of HIV-1 mutants expressing vp17s over time. Since genomic surveillance uncovered a cluster of HIV-1 expressing a B cell clonogenic vp17 dated from 2011 to 2019, we conclude that aa insertions can be fixed in HIV-1 and that mutant viruses displaying B cell clonogenic vp17s are actively spreading.
The dynamics of SARS-CoV-2 infectivity with changes in aerosol microenvironment
Authors: Oswin Henry P. , Haddrell Allen E. , Otero-Fernandez Mara , Mann Jamie F. S. , Cogan Tristan A. , Hilditch Thomas G. , Tian Jianghan , Hardy Daniel A. , Hill Darryl J. , Finn Adam , Davidson Andrew D. , Reid Jonathan P.
Published: June 2022

Understanding the factors that influence the airborne survival of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosols is important for identifying routes of transmission and the value of various mitigation strategies for preventing transmission. We present measurements of the stability of SARS-CoV-2 in aerosol droplets (∼5 to 10 µm equilibrated radius) over timescales spanning 5 s to 20 min using an instrument to probe survival in a small population of droplets (typically 5 to 10) containing ∼1 virus/droplet. Measurements of airborne infectivity change are coupled with a detailed physicochemical analysis of the airborne droplets containing the virus. A decrease in infectivity to ∼10% of the starting value was observable for SARS-CoV-2 over 20 min, with a large proportion of the loss occurring within the first 5 min after aerosolization. The initial rate of infectivity loss was found to correlate with physical transformation of the equilibrating droplet; salts within the droplets crystallize at relative humidities (RHs) below 50%, leading to a near-instant loss of infectivity in 50 to 60% of the virus. However, at 90% RH, the droplet remains homogenous and aqueous, and the viral stability is sustained for the first 2 min, beyond which it decays to only 10% remaining infectious after 10 min. The loss of infectivity at high RH is consistent with an elevation in the pH of the droplets, caused by volatilization of CO
2
from bicarbonate buffer within the droplet. Four different variants of SARS-CoV-2 were compared and found to have a similar degree of airborne stability at both high and low RH.
Mental health, financial, and social outcomes among older adults with probable COVID-19 infection: A longitudinal cohort study
Authors: Iob Eleonora , Steptoe Andrew , Zaninotto Paola
Published: June 2022

We investigated the immediate and longer-term impact (over 4-6 months) of probable COVID-19 infection on mental health, wellbeing, financial hardship, and social interactions among older people living in England. Data were analysed from 5146 older adults participating in the English Longitudinal Study of Ageing who provided data before the pandemic (2018-19) and at two COVID-19 assessments in 2020 (June-July and November-December). The associations of probable COVID-19 infection (first COVID-19 assessment) with depression, anxiety, poor quality of life (QoL), loneliness, financial hardship, and social contact with family/friends at the first and second COVID-19 assessments were tested using linear/logistic regression and were adjusted for pre-pandemic outcome measures. Participants with probable infection had higher levels of depression and anxiety, poorer QoL, and greater loneliness scores compared with those without probable infection at both the first (ORdepression= 1.62,P-value = 0.005; ORanxiety= 1.59,P-value = 0.049; bpoorQoL= 1.34,P< 0.001; bloneliness= 0.49,P< 0.001) and second (ORdepression= 1.56,P-value = 0.003; ORanxiety= 1.55,P-value = 0.041; bpoorQoL= 1.38,P-value < 0.001; bloneliness= 0.31,P-value = 0.024) COVID-19 assessments. Participants with probable infection also experienced greater financial difficulties than those without infection at the first assessment (OR = 1.50,P-value = 0.011). Probable COVID-19 infection is associated with longer-term deterioration of mental health and wellbeing and short-term increases in financial hardship among older adults. It is important to monitor the mental health of older people affected by COVID-19 and provide additional support to those in need.
A non-invasive and high precision sensor for in-situ temperature monitoring of cells
Authors: Zhang Fangzhou , Wang Fangxu , Gu Ning
Published: June 2022

Energy transformation, which can be described as temperature variations, is present in all activities of cellular metabolism. Detecting the temperature of numerous cells over the course of their lives is useful for studying the cellular physiological function and investigating the pathophysiology of illnesses. Current cell thermometric technologies, such as luminous temperature sensors, infrared thermometers, and thermocouple thermometers, have their own limitations, such as complicated operation, low repeatability, and inability to measure cell temperature in normal situations. Here, we have developed a high-precision platinum temperature sensor with small heat capacity, good heat conduction, excellent stability and biological compatibility, which made it possible to sense cells heat signal. The platinum resistance sensor’s temperature coefficient of resistance was around 2800 ppm °C−1, with a good linear correlation (R
2 > 0.999) between resistance and temperature from 35 °C to 43 °C. The noise of the sensor system was below 0.02 °C, giving a small and stability noise in detection. The detecting cells were CHO-K1 cells. They caused a temperature increase of about 0.075 °C, which is higher than the sensor without cells. This platinum sensor has been found to be useful for in situ temperature measurement of cells, which is important for investigating cell informatics and pathology.
Efficient annular aperture array (AAA) filter for thermophotovoltaic by sidewall lithography
Authors: Cai Maoqi , Chen Zhiwen , Qiu Keqiang , Wang Yanan , Chen Huoyao , Liu Zhengkun , Liu Ying , Hong Yilin , Qiu Jiawen
Published: June 2022

Thermophotovoltaic (TPV) systems consume near infrared (NIR) filters, which are key components for high conversion efficiency. Bandpass filters employing annular aperture array (AAA) on a fused silica substrate are one of candidates for matching GaSb cells in high-temperature TPV. It is often placed independently between the emitter and cell, and thus spectral control and heat insulation are simultaneously realized. For high efficiency, the smaller the characteristic size and the larger the size is beneficial for the filter. Novel sidewall lithography based on conventional interference lithography and ion-beam etching is first proposed and used for cost-effective fabrication. An AAA filter with a 80 nm critical dimension in a 100 mm × 160 mm area has been fabricated successfully. After the annealing process at 500 °C, the peak transmittance is increased to 70% from 65%, and no deformation is observed in the structural parameters of the filter before and after annealing, and calculated results demonstrate that the spectral efficiency is about 61%.
Phase diagram of chiral magnets via Green’s function method
Authors: Li Xi-Bin , Cao Yongjun , Bai Narsu
Published: June 2022

In this paper, Green’s function method is applied to study the ferromagnetic system with Dzyaloshinkii–Moriya (DM) interaction in both two-dimension (2D) and three-dimension chiral magnets. Relevant properties in 2D magnets are calculated, such as the susceptibility, correlation function and analytical expressions of phase boundary. Based on the theoretical results, a new phase is predicted in the window of strong DM interaction characterized by a negative winding number. In addition, helical state in pure 2D material only appears at zero temperature. The analysis on correlation function shows a special symmetry of transverse spin correlation, which corresponds to the skyrmion phase. The results also prove the instability of helical state and its lifetime is numerically computed. Different from 2D magnets, helical state in 3D exists in the window of a lower Zeeman energy and has a long lifetime. DM interaction also reduces Curie temperature because of the spatial symmetry breaking.
Comparison of mortality patterns after the Fukushima Daiichi Nuclear Power Plant radiation disaster and during the COVID-19 pandemic
Authors: Tsuboi Motohiro , Sawano Toyoaki , Ozaki Akihiko , Nonaka Saori , Kohayakawa Yoshitaka , Kondo Hisayoshi , Tsubokura Masaharu
Published: June 2022

The initial health impact caused by radiation disasters can be broadly classified into direct and indirect effects. Though no direct health hazards caused by radiation, such as acute radiation injury, were observed following the Fukushima Daiichi nuclear power plant accident, indirect deaths have been reported, including those caused by initial emergency evacuation and relocation, medical disruption, and psychological and social health effects. However, these indirect health effects have not been prioritised for addressal. We evaluated the radiation disaster experience with that of the coronavirus disease (COVID-19) pandemic that emerged while facing the challenges from the radiation disaster. Most of the health effects of COVID-19 are directly associated with infection, but indirect health effects of various scales and entities have been reported. The two disasters have similarities in terms of the strain on community healthcare and the large number of deaths. Adapting the measures implemented in the acute to subacute phases of the COVID-19 disaster to radiation disasters may help improve management following future radiation disasters. Based on the experience and findings during the COVID-19 pandemic, the pattern of deaths in radiation disasters can be divided into five major groups: direct deaths, and four indirect patterns of deaths due to a deteriorating supply-demand balance (a hospital-level problem), collapse of the healthcare system (a community-level problem), death due to neglect alongside underlying disease, and diseases other than direct invasion. From the similarities between the two disasters, three main issues should be prioritised as initial emergency evacuation measures in a radiation disaster: emergency exposure medicine, the establishment of a medical system, and protection of death with dignity. The validity of these priority issues needs to be verified in future research.
Time-resolved multi-parameter flow diagnostics by filtered Rayleigh scattering: system design through multi-objective optimisation
Authors: Doll Ulrich , Röhle Ingo , Dues Michael , Kapulla Ralf
Published: June 2022

The measurement of the time-resolved three-component (3C) velocity field together with scalar flow quantities such as temperature or pressure by laser-optical diagnostics is a challenging task. Current approaches usually employ combinations of different methods relying on tracer particles or molecules. This typically requires usage of at least two laser systems and detection units as well as elaborate calibration of the luminous properties of the applied tracer species with regard to the specific thermodynamic conditions anticipated for the flow case at hand. In contrast to this, the tracer-free filtered Rayleigh scattering (FRS) technique has been proven to obtain combined time-averaged velocity and scalar fields and might offer a viable alternative for unsteady flow diagnostics. By applying multiple perspective views, two detection system variants are presented, combining (1) six observation branches with one camera/molecular filter and (2) three camera views with two cameras and molecular filters of differing vapour densities. Both configurations in principle allow for the simultaneous measurement of instantaneous 3C velocity, temperature and pressure fields. Multi-objective optimisation is used to enhance the detection setups for different sets of experimental configurations. It is shown that a higher number of observation positions and the associated dynamics of the FRS signal prove to be advantageous compared to the use of less views in combination with two acquisition channels equipped with different molecular filters. It is also shown that the use of circularly polarised laser light offers no advantage over linear polarisation. By demonstrating a moderate sensitivity of the optimised observation arrangement to alignment errors, the presented FRS concept provides a practical solution for the simultaneous measurement of time-resolved 3C flow velocity and scalar fields.
Time-scale investigation with the modified phase field crystal method
Authors: Burns Duncan , Provatas Nikolas , Grant Martin
Published: June 2022

This paper extends the two time-scale modified phase-field crystal model to examine crystal plasticity. Two non-linear density dependent functions are constructed to effectively represent hydrostatic strain and dislocation density. The functions are then used to develop a new modified phase field crystal model, which accounts for strain and strain-rate couplings on density dynamics. The non-linear additions provide tunable parameters for controlling dislocation climb versus glide, as well as phonon softening mechanisms. A short-wavelength dampening is also introduced to account for phonon scattering and thermoelastic dissipation processes. Finally, a novel semi-implicit numeric scheme for efficient simulations of this model is presented, which also serves as a generalization of the commonly used Fourier pseudo-spectral method. The technique gives rise to unconditionally stable dynamics with simple numeric implementation requirements.
Variations of tunnelling resistance between CNTs with strain in composites: non-monotonicty and influencing factors
Authors: Wang Tengrui , Liu Yongzhi , Liu Hu , Liu Chuntai
Published: June 2022

The electro-mechanical response of conductive carbon-nanotube(CNT)-polymer composites is vital when they are used as smart-sensing materials. Clarifying the variation trend of resistance with strain is the key to design and regulate the piezoresistive property of such material. Here, we present some finite element simulations to predict the electro-mechanical response using a geometrical model comprising two hollow cylindrical CNTs and a cuboid matrix. The electrical contact between CNTs is represented by some elements which account for quantum tunnelling effects and capture the sensitivity of conductivity to separation. Different from classical simulations using solid model or one-dimensional beam model, in which the tunnelling resistance between two CNTs changes monotonously with strain, the results in this work show that the trend is non-monotonic in some cases, i.e. it increases at first and then decreases with the uniaxial compressive strain when the elastic modulus of the matrix is high. In addition, factors affecting the different variation trends are discussed in details, which include geometric model, elastic modulus and Poisson’s ratio of the matrix, and orientation angle.
Klein–Gordon equation with mean field interaction. Orbital and asymptotic stability of solitary waves
*
Authors: Kopylova Elena
Published: June 2022

We investigate orbital and asymptotic stability of solitary wave solutions to the U(1)-invariant nonlinear Klein–Gordon equation with mean field interaction.
The Cox–Voinov law for traveling waves in the partial wetting regime*
Authors: Gnann Manuel V , Wisse Anouk C
Published: June 2022

We consider the thin-film equation

∂

t

h
+

∂

y

m

(

h

)

∂

y

3

h

=
0

in {h > 0} with partial-wetting boundary conditions and inhomogeneous mobility of the form m(h) = h
3 + λ
3−n

h

n
, where h ⩾ 0 is the film height, λ > 0 is the slip length, y > 0 denotes the lateral variable, and n ∈ (0, 3) is the mobility exponent parameterizing the nonlinear slip condition. The partial-wetting regime implies the boundary condition ∂
y

h = const. > 0 at the triple junction ∂{h > 0} (nonzero microscopic contact angle). Existence and uniqueness of traveling-wave solutions to this problem under the constraint

∂

y

2

h
→
0

as h → ∞ have been proved in previous work by Chiricotto and Giacomelli (2011 Commun. Appl. Ind. Math.
2 e-388, 16). We are interested in the asymptotics as h ↓ 0 and h → ∞. By reformulating the problem as h ↓ 0 as a dynamical system for the difference between the solution and the microscopic contact angle, values for n are found for which linear as well as nonlinear resonances occur. These resonances lead to a different asymptotic behavior of the solution as h ↓ 0 depending on n. Together with the asymptotics as h → ∞ characterizing the Cox–Voinov law for the velocity-dependent macroscopic contact angle as found by Giacomelli, the first author of this work, and Otto (2016 Nonlinearity
29 2497–536), the rigorous asymptotics of traveling-wave solutions to the thin-film equation in partial wetting can be characterized. Furthermore, our approach enables us to analyze the relation between the microscopic and macroscopic contact angle. It is found that the Cox–Voinov law for the macroscopic contact angle depends continuously differentiably on the microscopic contact angle.
Physics of defects in metal halide perovskites
Authors: Bao Chunxiong , Gao Feng
Published: June 2022

Metal halide perovskites are widely used in optoelectronic devices, including solar cells, photodetectors, and light-emitting diodes. Defects in this class of low-temperature solution-processed semiconductors play significant roles in the optoelectronic properties and performance of devices based on these semiconductors. Investigating the defect properties provides not only insight into the origin of the outstanding performance of perovskite optoelectronic devices but also guidance for further improvement of performance. Defects in perovskites have been intensely studied. Here, we review the progress in defect-related physics and techniques for perovskites. We survey the theoretical and computational results of the origin and properties of defects in perovskites. The underlying mechanisms, functions, advantages, and limitations of trap state characterization techniques are discussed. We introduce the effect of defects on the performance of perovskite optoelectronic devices, followed by a discussion of the mechanism of defect treatment. Finally, we summarize and present key challenges and opportunities of defects and their role in the further development of perovskite optoelectronic devices.
Spin dynamics, critical scattering and magnetoelectric coupling mechanism of Mn4Nb2O9
Authors: Deng Guochu , Zhao Gang , Zhu Shuang , Feng Zhenjie , Ren Wei , Cao Shixun , Studer Andrew , McIntyre Garry J
Published: June 2022

The spin dynamics of Mn4Nb2O9 were studied using inelastic neutron scattering. A dynamic model is proposed to explain the observed spin-wave excitation spectrum from Mn4Nb2O9. The model indicates that the exchange interactions along the chain direction are weakly ferromagnetic while the exchange interactions between the neighbour chains are strongly antiferromagnetic. The antiferromagnetic interactions on the two MnO6 octahedron networks are dominant in the spin dynamics of this compound. A spin gap of about 1.4 meV was observed at the zone centre, which is attributed to the weak easy-axis magnetic anisotropy of Mn2+ ions. Magnetic critical scattering from Mn4Nb2O9 was studied in the vicinity of its Néel temperature T
N as well, indicating homogeneous development of magnetic correlations. According to the symmetry analysis and its magnetic structure, the weak magnetoelectric coupling effect in Mn4Nb2O9 is ascribed to the uncancelled exchange striction on the two non-equivalent Mn2+ sites.
Jet Formation Mechanism of the Gamma-Ray-emitting Narrow-line Seyfert 1 Galaxies
Authors: Chen Yongyun , Gu Qiusheng , Fan Junhui , Yu Xiaoling , Xiong Dingrong , Ding Nan , Guo Xiaotong , Ge Xue
Published: June 2022

We use a large sample of gamma-ray narrow-line Seyfert 1 galaxies (γ-NLS1s) to study the jet formation mechanisms. We find that the jet power of γ-NLS1s is lower than the maximum jet power of the Blandford–Payne (BP) mechanism. At the same time, we find that there is a significant correlation between jet power and accretion disk luminosity. Moreover, the contribution rates of the accretion to the jet power are larger than that of black hole mass to jet power. These results further suggest that the jet of γ NLS1s is mainly produced by the BP mechanism.
Experimental research of magnetic circuits of current converters taking into account the nonlinearity of magnetic characteristics
Authors: Safarov A M , Sattarov Kh A , Mustafoqulov A M , Shoyimov Yu Yu
Published: June 2022

The article is devoted to the development of methods for calculating magnetic circuits of current converters taking into account the nonlinearity of magnetic characteristics. At the same time, magnetic systems of current converters are of great interest, which, according to the principle of their operation, are magnetized simultaneously by constant and alternating magnetic fields (magnetomodulation converters). Analytical expressions of the magnetization curves of magnetic materials are proposed, experimental schemes are presented, and the feasibility of using a combination of oscillographic and wattmeter methods, the convergence of the calculated and experimental data are shown.
Using capillary pressure curves when searching for analog objects
Authors: Akhmetov R T , Mukhametshin V V , Kuleshova L S , Grezina O A
Published: June 2022

In this work, the capillary pressure curves were approximated using fractions of various types for the conditions of individual oil deposits of the West Siberian oil and gas province. A mathematical model of capillary curves in the coordinate axes of dimensionless time from the normalized water saturation has been created. The obtained models make it possible to search for analog objects and effectively solve the problems of increasing the efficiency of developing low-profitable deposits with hard-to-recover reserves based on comparing the regression equations of generalized models with models of the required deposits.
Developing “friend or foe” protocol in residue number system code for satellite authentication
Authors: Kalmykov I A , Mukhametshin V Sh , Tyncherov K T , Selivanova M V
Published: June 2022

Low-earth orbit (LEO) satellite communication systems are successfully used in control and monitoring systems for the production and transportation of hydrocarbons from fields located beyond the Arctic Circle. As the number of countries engaged in the development of such fields expands, the number of groupings of LEO satellite communication systems grows as well. To prevent the possibility of intercepting and imposing a delayed command to control the intruder satellite, it is necessary to use the “friend or foe” identification system for the LEO satellite communication systems. At the same time, it is proposed to use authentication protocols with zero knowledge to ensure high imitation resistance in such systems. To increase their efficiency, the article proposes to use the codes of the residual number system (RNS). The novelty of this idea lies in the fact that the use of parallel RNS codes will reduce the time spent on performing arithmetic operations implemented in authentication protocols. This will reduce the likelihood of an intruder satellite picking up the correct response signal. Therefore, the development of an authentication protocol for LEO satellite communication systems based on RNS codes, the use of which will reduce the time for satellite identification, is an urgent task.
Analysis and calculation of energy efficiency of radio beacons Internet of Things (IoT)
Authors: Daudov I M
Published: June 2022

The paper examines one of the most relevant trends in the development of information technology Internet of Things (IoT). The analysis and calculation of the energy efficiency of the IOT solutions sensors are carried out. The key characteristics of assessing the durability of the sensors are investigated.
IoT as a high degree of autonomy system
Authors: Zyukin D A , Khasambiev I V
Published: June 2022

The article describes the need for IoT technology in the study of biologists, for the influence of genomes and microclimate on the degree of yield, for a possible increase in the quality and productivity of products. There is a description of questions regarding environmental problems. It also discusses the issues related to the use of the latest IoT technology in agriculture, shows the main role of the Internet of Things in agriculture, which is to control all important information thanks to the equipment equipped with the latest advanced technologies. And also analyzed the possibilities of introducing IoT technology in the agricultural industry, thanks to which you can easily track the necessary data, such as moisture, soil quality, air temperature, and also shows the possibilities that arise due to the use of remote sensors
Influence of shock-vibration loads of drilling equipment on the drilling indicators of oil and gas wells
Authors: Minnivaleev T N , Kuleshova L S , Arslanov I G , Gizzatullina A A , Minnivaleev A N
Published: June 2022

When drilling oil and gas wells, downhole and drilling wellhead equipment is subject to the influence of significant vibration processes of different directions with different amplitude-frequency characteristics. The paper describes the main sources of vibration of drilling equipment, which have a downhole origin. In this paper an amplitude-frequency characteristic of oscillatory processes of a drill string and their influence on drilling performance are given. In addition to the sources of fluctuations of the bottomhole nature of origin, sources of the wellhead nature can also be distinguished. Thus drilling mud pump is a generator of pulsations and beats of the pressure of drilling fluid, which in turn leads to the increase in the dynamics of the drilling tool, the appearance of torsional vibrations of downhole motors and bits. We established the negative influence of vibrations of the bottomhole assembly and drilling mud on the stability of the operation of hydraulic downhole motors, penetration on the bit, durability of the elements of the string and energy indicators of drilling. The proposed device allows reducing the amplitude of pressure fluctuations of the drilling fluid and drilling tool.