bluuebunny/crossref_metadata_2025 huggingface dataset:
Virgilio nel Purgatorio di Dante: poesia, politica e morale
Authors: Ledda Giuseppe
Published: May 2022

La presenza di Virgilio nelPurgatoriodi Dante è complessa e problematica: si tratta di un regno proprio dell’aldilà cristiano, che il poeta latino non ha mai visitato prima e le cui dinamiche gli sono in gran parte ignote. Perciò la sua funzione di guida è messa ripetutamente in discussione, specie nei primi canti, e poi si esaurirà con la sua scomparsa e sostituzione con Beatrice. Al centro del percorso di ascesa c’è l’incontro drammatico e rivelatore con Stazio, che deve il proprio essere poeta ma anche la propria conversione e la propria salvezza a Virgilio, che invece da tale salvezza resta escluso. Ma la poesia di Virgilio è citata continuamente anche nella seconda cantica, e offre tra l’altro numerosi esempi morali del vizio punito nel sistema degli esempi delle cornici purgatoriali, oltre a essere, con il suo poema imperiale, un punto di riferimento per la poesia politica di Dante, riferimento ben presente nella parte centrale della cantica, ma invece trascurato nella parte iniziale e in quella conclusiva, in coincidenza con i momenti di maggiore difficoltà per la guida e di più severa correzione dei suoi testi. Il saggio passa in rassegna questi aspetti della presenza di Virgilio proponendo anche una chiave di lettura che cerca di tenere insieme i suoi aspetti positivi e quelli negativi.
Nonlinear aeroelastic analysis of a damped elastica-aerofoil system
Authors: Jayatilake Sanuja , Titurus Branislav
Published: May 2022

This work formulates a comprehensive model of a nonlinear aeroelastic system developed for the analysis of complex aeroelastic phenomena related to structural and aerodynamic nonlinearities. The system is formulated as a two-dimensional cantilevered elastica with a rigid airfoil section firmly attached at its tip undergoing large displacements in the crosswind conditions. The system can demonstrate a wide range of domain specific as well as coupled nonlinear phenomena. The structural model is developed by means of the Rayleigh–Ritz approach, with shape functions discretizing both vertical and horizontal displacements and Lagrangian multipliers enforcing inextensibility. Damping is modeled based on a non-local strain-based mechanism in the Kelvin–Voigt arrangement. The resulting structural model is examined through studying the behavior under a follower load and with a tip-attached tendon under tension to study the shape convergence properties and the alignment of the results with known characteristics in the literature. The ONERA dynamic stall model is used to model the aerodynamics of the problem to accurately capture post-stall behavior at large deformations. The LCO responses of the aeroelastic problem are evaluated through time-marched simulations, and the combined airspeed–damping interactions are studied in this manner.
Profile of individuals with low back pain and factors defining chronicity of pain: a population-based study in Ethiopia
Authors: Beyera Getahun Kebede , O’Brien Jane , Campbell Steven
Published: May 2022

Purpose

Low back pain (LBP) is the most prevalent public health problem globally, second only to headaches in the ranking of painful disorders that affect human beings. However, evidence about the profile of LBP patients is lacking in low-income countries for appropriate management approaches. This study examined the profile of individuals with LBP and factors defining chronicity of pain in Ethiopia.

Methods

A population-based cross-sectional study design was used to collect data from 1812 adults (≥ 18 years) with LBP at present. Data were collected by interviewing the study participants using an instrument developed and validated in the same study population. The instrument includes socio-demographic information, health behaviours/lifestyle habits, beliefs about pain, and pain and general health-related characteristics of the participants. Data analysis was performed using R version 3.5.1. Both unconditional and conditional logistic regression models were fitted and Odds Ratio (OR) with 95% confidence intervals (95% CIs) were computed to identify factors significantly associated with chronicity of pain at p ≤ 0.05 significance level.

Results

Negative beliefs about pain, a varying degree of pain interference with daily and social activities, complaining of pain in other anatomical sites other than the low back region, general health status rated as not excellent, depressive symptomology, and sleeping problems/insomnia were common within the profile of individuals with LBP. Age, educational level, residential setting, beliefs about pain, and depressive symptomology were found to have a statistically significant association with chronicity of pain.

Conclusions

This study provides an overview of the profile of individuals with LBP and factors defining chronicity of pain, assisting clinicians to design appropriate management strategies to improve patients' outcomes.
Adapted physical activity in subjects and athletes recovering from covid-19: a position statement of the Società Italiana Scienze Motorie e Sportive
Authors: Venturelli Massimo , Mancini Annamaria , Di Cagno Alessandra , Fiorilli Giovanni , Paneroni Mara , Roggio Federico , Musumeci Giuseppe , Buono Pasqualina , Schena Federico , Paoli Antonio
Published: May 2022

Coronavirus disease 2019 (COVID-19) is a worldwide pandemic illness that is impacting the cardiovascular, pulmonary, musculoskeletal, and cognitive function of a large spectrum of the worldwide population. The available pharmacological countermeasures of these long-term effects of COVID-19 are minimal, while myriads of non-specific non-pharmacological treatments are emerging in the literature. In this complicated scenario, particular emphasis should be dedicated to specific exercise interventions tailored for subjects and athletes recovering from COVID-19. Specific guidelines on adapted physical activity in this critical population are unavailable so far, therefore, in this position statement of the Società Italiana di Scienze Motorie e Sportive (SISMeS) the members of the steering committee of the research group Attività Motoria Adattata, Alimentazione, Salute e Fitness have indicated the adapted physical activity approaches to counteract the long-term effects of the COVID-19, both in good health people and athletes.
Development of a maxillofacial virtual surgical system based on biomechanical parameters of facial soft tissue
Authors: Cheng Mengjia , Zhuang Yu , Zhao Hanjiang , Li Meng , Fan Lingfeng , Yu Hongbo
Published: May 2022

Purpose

Lack of biomechanical force model of soft tissue hinders the development of virtual surgical simulation in maxillofacial surgery. In this study, a physical model of facial soft tissue based on real biomechanical parameters was constructed, and a haptics-enabled virtual surgical system was developed to simulate incision-making process on facial soft tissue and to help maxillofacial surgery training.

Methods

CT data of a 25-year-old female patient were imported into Mimics software to reconstruct 3D models of maxillofacial soft and skeletal tissues. 3dMD stereo-photo of the patient was fused on facial surface to include texture information. Insertion and cutting parameters of facial soft tissue measured on fresh cadavers were integrated, and a maxillofacial biomechanical force model was established. Rapid deformation and force feedback were realized through localized deformation algorithm and axis aligned bounding box (AABB)-based collision detection. The virtual model was validated quantitatively and qualitatively.

Results

A patient-specific physical model composed of skeletal and facial soft tissue was constructed and embedded in the virtual surgical system. Insertion and cutting in different regions of facial soft tissue were simulated using omega 6, and real-time feedback force was recorded. The feedback force was consistent with acquired force data of experiments conducted on tissue specimen. Real-time graphic and haptic feedback were realized. The mean score of the system performance was 3.71 given by surgeons in evaluation questionnaires.

Conclusion

The maxillofacial physical model enabled operators to simulate insertion and cutting on facial soft tissue with realization of realistic deformation and haptic feedback. The combination of localized deformation algorithm and AABB-based collision detection improved computational efficiency. The proposed virtual surgical system demonstrated excellent performance in simulation and training of incision-making process.
In Situ Investigation of TCP Phase Formation, Stress Relaxation and γ/γ′ Lattice Misfit Evolution in Fourth Generation Single Crystal Ni-Base Superalloys by X-Ray High Temperature Diffraction
Authors: Bezold A. , Stone H. J. , Rae C. M. F. , Neumeier S.
Published: May 2022

In nickel-based superalloys, the lattice misfit between the γ and γ′ phases and the propensity to TCP phase formation at service temperatures critically influence the microstructural evolution that takes place and hence the resultant mechanical properties. In this work, the lattice misfits of a series of highly alloyed Ru-containing 4th generation Ni-base superalloys are investigated by in situ X-ray diffraction (XRD) at high temperature. While the lattice misfit values of all alloys range between − 0.3 and − 1.3 pct at room temperature, they show an atypical temperature dependence, becoming less negative above 900 °C. In situ XRD measurements at 1100 °C reveal that the majority of the internal coherency stresses are already relieved after two hours. This is particularly pronounced for the alloys that have both a lattice misfit larger than |0.6| pct at 1100 °C and are prone to TCP phase formation. However, throughout the relaxation of the internal coherency stresses the lattice misfit remains fairly constant. Due to the similar chemical compositions of the alloys studied, qualitative guidelines for an optimum lattice misfit magnitude are developed by comparing the lattice misfit values with previous creep experiments. Our results indicate that no universal optimal lattice misfit value exists for these alloys and the value strongly depends on the applied creep conditions.

Graphical Abstract
Study of the Crystallisation Reaction Behaviour to Obtain Struvite
Authors: Corona Francisco , Hidalgo Dolores , Martín-Marroquín Jesús María , Castro Juan , Sanz-Bedate Sergio , Antolín Gregorio
Published: May 2022

The potential of N and P recovering from digestate by means of its precipitation in the form of struvite is evident. However, it is necessary to optimise the process at a larger scale, to achieve results that can be extrapolated to evaluate the technical and economic feasibility of the process at an industrial scale. In this work, batch and pilot plant tests were carried out in order to consolidate, at a sufficiently relevant scale, the results obtained at lab scale. For this purpose, the parameters that have the greatest effect on the reaction yield in a fludised bed reactor were selected (Mg and P concentration, flow rate of the fluidising agent (air) and reaction time). Digestate produced in anaerobic digestion plant from pig manure was used as raw material. According to the results obtained, for the struvite crystallisation reaction, the great operational levels for the Mg/P, N/P, air flow rate and reaction time are 1.5, 4.0, 6.0 NL·min−1 and 0.5 h, respectively. Finally, a study was carried out to establish the agronomic potential of the salt (struvite) as a biofertiliser in the turf crop, obtaining a similar behaviour of the struvite used in this work to that of commercial struvite.

Graphical Abstract
Plowing-Extrusion Processes and Performance of Functional Surface Structures of Copper Current Collectors for Lithium-Ion Batteries
Authors: Wang Chun , Yuan Wei , Chen Yu , Zhao Bote , Tang Yong , Zhang Shiwei , Ding Xinrui , He Jun , Chen Songmao , Pan Baoyou , Chen Mingyue
Published: May 2022

Most copper current collectors for commercial lithium-ion batteries (LIBs) are smooth copper foils, which cannot form a stable and effective combination with electrode slurry. They are likely to deform or fall off after long-term operation, resulting in a sharp decline in battery performance. What is worse is that this condition inevitably causes internal short circuits and thus brings about security risks. In this study, a process route of fabricating the functional surface structures on the surface of a copper collector for LIBs by twice-crisscross micro-plowing (TCMP) is proposed, which provides a new idea and an efficient method to solve the above problems from the perspective of manufacturing. The finite element simulation of TCMP combined with the cutting force test and morphological characterization is conducted to verify the forming mechanism of the surface structures on a copper sheet and its relationship with the processing parameters. The influence of several key processing parameters on the surface characteristics of the copper sheet is comprehensively explored. A series of functions is tested to obtain the optimal parameters for performance improvement of the current collector. Results show that the structured copper sheet with the cutting distance of 250 μm, cutting depth of 80 μm, and cutting crossing angle of 90° enables the best surface features of the current collector; the contact angle reaches 0°, the slurry retention rate is up to 89.2%, and the friction coefficient reaches 0.074. The battery using the as-prepared structured copper sheet as the current collector produces a specific capacity of 318.6 mAh/g after 50 cycles at a current density of 0.2 C, which is 132.7% higher than the one based on a smooth surface. The capacity reversibility of the sample with the new current collector is much better than that of the traditional samples, yielding a lower impedance.
Microscopic theory for nuclear fission dynamics
Authors: Sadhukhan Jhilam
Published: May 2022

Nuclear theory research is undergoing a renaissance owing to the recent advancements in the high-performance computing. As nucleus is a quantum many-body system with complicated interparticle interactions, initial theoretical developments were predominantly based on different phenomenological models derived with the help of numerous simplifying assumptions. Although appropriate nuclear many-body theories were formulated, these were hardly adopted in practical applications because of computational limitations. However, since the last decade, this scenario has changed as a result of rapid improvements in the computational power and the associated numerical techniques. Realistic microscopic theories with superior predictive power are now routinely used even for systems which are far beyond the laboratory reach. This review discusses recent achievements in the microscopic theories of large amplitude nuclear dynamics. Particularly, after a succinct historical introduction, emphasis is given to the discussions on the microscopic modelling of nuclear fission dynamics. Also, related future directions are mentioned in brief.
The North–South Asymmetry of Martian Ionosphere and Thermosphere
Authors: Le Huijun , Liu Libo , Chen Yiding , Zhang Hui
Published: May 2022

Based on Mars Atmospheric and Volatile EvolutioN's neutral composition and Langmuir probe electron density and temperature data, we statistically analyzed the climatic variations of the Martian thermosphere and ionosphere and found significant north–south asymmetry. In winter and summer, the asymmetry mainly originates from the north–south asymmetry of the solar zenith angle. However, the observed data still exhibit significant north–south asymmetry in equinox seasons. Under low solar extreme ultraviolet radiation, the thermospheric neutral density in the northern hemisphere is higher than that in the southern hemisphere. As solar radiation increases, the neutral density in the southern hemisphere gradually exceeds that in the northern hemisphere. In addition, the southern hemisphere density increases nonlinearly with the increase of solar radiation, whereas the northern hemisphere density increases linearly. The electron density and electron temperature in the Martian ionosphere also exhibit similar north–south asymmetry. The asymmetries in the ionosphere and thermosphere between the northern and southern hemispheres are likely related to significant differences in Mars' north–south topography or to north–south asymmetries in the residual magnetic field. After preliminary analysis, we found that the north–south asymmetry of Mars' remaining magnetic field would intensify the hemispheric asymmetry of the ionospheric electron density, but have no effect on the thermospheric neutral density. The hemispheric asymmetry may be primarily related to the significant difference in Mars' north–south topography.
The Effect of Large Wood Accumulations With Rootwads on Local Geomorphic Changes
Authors: Ravazzolo D. , Spreitzer G. , Tunnicliffe J. , Friedrich H.
Published: May 2022

Large wood (LW) can be transported along a river during floods, increasing flood‐associated hazards, particularly when it accumulates at river‐spanning infrastructures such as bridges and weirs. While most flume studies have explored LW movement with simple wooden elements (dowels), only a few studies have used elements with more complex LW geometries, such as rootwads, under unsteady flow conditions. Quantitative assessment of interactions amongst more complex wood elements and river flow has rarely been attempted the effect of this additional complication has even been ignored, in both field and laboratory studies. In this study, flume experiments were conducted to assess the effect of rootwads on local scour and deposition in a flume with a mobile gravel‐bed. The experiment was conducted under unsteady flow conditions, with a constricted segment of the reach, recreating conditions to wood accumulations and blockage. Results revealed that LW with rootwads tends to generate more stable accumulations than LW without rootwads, leading to the formation of more porous loosely packed accumulations. In this initial set of flume experiments, the patterns of scour were quite variable, but on average, the porous and stable LW accumulations with rootwads showed more spatially extensive disturbance of the bed. LW accumulations without rootwads led to the development of scour pits that reached the bottom of the flume more quickly than in the LW accumulations without rootwads. The mean accumulated bedload volumes were of similar magnitude overall, however, highlighting the many contingencies in the chain of processes between dam formation and resultant bed scour.
Transcription associated cyclin-dependent kinases as therapeutic targets for prostate cancer
Authors: Constantin Theodora A. , Greenland Kyle K. , Varela-Carver Anabel , Bevan Charlotte L.
Published: May 2022

Transcriptional deregulation has emerged as a hallmark of several cancer types. In metastatic castration-resistant prostate cancer, a stage in which systemic androgen deprivation therapies fail to show clinical benefit, transcriptional addiction to the androgen receptor is maintained in most patients. This has led to increased efforts to find novel therapies that prevent oncogenic transactivation of the androgen receptor. In this context, a group of druggable protein kinases, known as transcription associated cyclin-dependent kinases (tCDKs), show great potential as therapeutic targets. Despite initial reservations about targeting tCDKs due to their ubiquitous and prerequisite nature, preclinical studies showed that selectively inhibiting such kinases could provide sufficient therapeutic window to exert antitumour effects in the absence of systemic toxicity. As a result, several highly specific inhibitors are currently being trialled in solid tumours, including prostate cancer. This article summarises the roles of tCDKs in regulating gene transcription and highlights rationales for their targeting in prostate cancer. It provides an overview of the most recent developments in this therapeutic area, including the most recent clinical advances, and discusses the utility of tCDK inhibitors in combination with established cancer agents.
Comparison of fludarabine–melphalan and fludarabine–treosulfan as conditioning prior to allogeneic hematopoietic cell transplantation—a registry study on behalf of the EBMT Acute Leukemia Working Party
Authors: Duque-Afonso Jesus , Finke Jürgen , Labopin Myriam , Craddock Charles , Protheroe Rachel , Kottaridis Panagiotis , Tholouli Eleni , Byrne Jenny L. , Orchard Kim , Salmenniemi Urpu , Hilgendorf Inken , Hunter Hannah , Nicholson Emma , Bloor Adrian , Snowden John A. , Verbeek Mareike , Clark Andrew , Savani Bipin N. , Spyridonidis Alexandros , Nagler Arnon , Mohty Mohamad
Published: May 2022

In recent years considerable variations in conditioning protocols for allogeneic hematopoietic cell transplantation (allo-HCT) protocols have been introduced for higher efficacy, lower toxicity, and better outcomes. To overcome the limitations of the classical definition of reduced intensity and myeloablative conditioning, a transplantation conditioning intensity (TCI) score had been developed. In this study, we compared outcome after two frequently used single alkylator-based conditioning protocols from the intermediate TCI score category, fludarabine/melphalan 140 mg/m2 (FluMel) and fludarabine/treosulfan 42 g/m2 (FluTreo) for patients with acute myeloid leukemia (AML) in complete remission (CR). This retrospective analysis from the registry of the Acute Leukemia Working Party (ALWP) of the European Society of Bone Marrow Transplantation (EBMT) database included 1427 adult patients (median age 58.2 years) receiving either Flu/Mel (n = 1005) or Flu/Treo (n = 422). Both groups showed similar 3-year overall survival (OS) (54% vs 51.2%, p value 0.49) for patients conditioned with FluMel and FluTreo, respectively. However, patients treated with FluMel showed a reduced 3-year relapse incidence (32.4% vs. 40.4%, p value < 0.001) and slightly increased non-relapse mortality (NRM) (25.7% vs. 20.2%, p value = 0.06) compared to patients treated with FluTreo. Our data may serve as a basis for further studies examining the role of additional agents/ intensifications in conditioning prior to allo-HCT.
Molecular insights into ligand recognition and activation of chemokine receptors CCR2 and CCR3
Authors: Shao Zhehua , Tan Yangxia , Shen Qingya , Hou Li , Yao Bingpeng , Qin Jiao , Xu Peiyu , Mao Chunyou , Chen Li-Nan , Zhang Huibing , Shen Dan-Dan , Zhang Chao , Li Weijie , Du Xufei , Li Fei , Chen Zhi-Hua , Jiang Yi , Xu H. Eric , Ying Songmin , Ma Honglei , Zhang Yan , Shen Huahao
Published: May 2022

Chemokine receptors are a family of G-protein-coupled receptors with key roles in leukocyte migration and inflammatory responses. Here, we present cryo-electron microscopy structures of two human CC chemokine receptor–G-protein complexes: CCR2 bound to its endogenous ligand CCL2, and CCR3 in the apo state. The structure of the CCL2–CCR2–G-protein complex reveals that CCL2 inserts deeply into the extracellular half of the transmembrane domain, and forms substantial interactions with the receptor through the most N-terminal glutamine. Extensive hydrophobic and polar interactions are present between both two chemokine receptors and the Gα-protein, contributing to the constitutive activity of these receptors. Notably, complemented with functional experiments, the interactions around intracellular loop 2 of the receptors are found to be conserved and play a more critical role in G-protein activation than those around intracellular loop 3. Together, our findings provide structural insights into chemokine recognition and receptor activation, shedding lights on drug design targeting chemokine receptors.
Nighttime smartphone use and changes in mental health and wellbeing among young adults: a longitudinal study based on high-resolution tracking data
Authors: Dissing Agnete Skovlund , Andersen Thea Otte , Jensen Andreas Kryger , Lund Rikke , Rod Naja Hulvej
Published: May 2022

Frequent nighttime smartphone use can disturb healthy sleep patterns and may adversely affect mental health and wellbeing. This study aims at investigating whether nighttime smartphone use increases the risk of poor mental health, i.e. loneliness, depressive symptoms, perceived stress, and low life satisfaction among young adults. High-dimensional tracking data from the Copenhagen Network Study was used to objectively measure nighttime smartphone activity. We recorded more than 250,000 smartphone activities during self-reported sleep periods among 815 young adults (university students, mean age: 21.6 years, males: 77%) over 16 weekdays period. Mental health was measured at baseline using validated measures, and again at follow-up four months later. Associations between nighttime smartphone use and mental health were evaluated at baseline and at follow-up using multiple linear regression adjusting for potential confounding. Nighttime smartphone use was associated with a slightly higher level of perceived stress and depressive symptoms at baseline. For example, participants having 1–3 nights with smartphone use (out of 16 observed nights) had on average a 0.25 higher score (95%CI:0.08;0.41) on the Perceived stress scale ranging from 0 to 10. These differences were small and could not be replicated at follow-up. Contrary to the prevailing hypothesis, nighttime smartphone use is not strongly related to poor mental health, potentially because smartphone use is also a social phenomenon with associated benefits for mental health.
Climate-catchment-soil control on hydrological droughts in peninsular India
Authors: Ganguli Poulomi , Singh Bhupinderjeet , Reddy Nagarjuna N. , Raut Aparna , Mishra Debasish , Das Bhabani Sankar
Published: May 2022

Most land surface system models and observational assessments ignore detailed soil characteristics while describing the drought attributes such as growth, duration, recovery, and the termination rate of the event. With the national-scale digital soil maps available for India, we assessed the climate-catchment-soil nexus using daily observed streamflow records from 98 sites in tropical rain-dominated catchments of peninsular India (8–25° N, 72–86° E). Results indicated that climate-catchment-soil properties may control hydrological drought attributes to the tune of 14–70%. While terrain features are dominant drivers for drought growth, contributing around 50% variability, soil attributes contribute ~ 71.5% variability in drought duration. Finally, soil and climatic factors together control the resilience and termination rate. The most relevant climate characteristics are potential evapotranspiration, soil moisture, rainfall, and temperature; temperature and soil moisture are dominant controls for streamflow drought resilience. Among different soil properties, soil organic carbon (SOC) stock could resist drought propagation, despite low-carbon soils across the Indian subcontinent. The findings highlight the need for accounting feedback among climate, soil, and topographical properties in catchment-scale drought propagations.
Cubic-meter scale laboratory fault re-activation experiments to improve the understanding of induced seismicity risks
Authors: Oye Volker , Stanchits Sergey , Babarinde Oladipupo , Bauer Robert , Dichiarante Anna Maria , Langet Nadège , Goertz-Allmann Bettina , Frailey Scott
Published: May 2022

To understand fluid induced seismicity, we have designed a large-scale laboratory experiment consisting of a one-cubic-meter sandstone with an artificial fault cut and fluid-injection boreholes. The sandstone block is assembled in a true triaxial loading frame and equipped with 38 piezoelectric sensors to locate and characterise acoustic emission events. The differential stress on the artificial fault is increased in stages to bring it towards a critically stressed state. After each stage of differential stress increase, fluids are injected at low pressures through boreholes to test the potential of fault re-activation. In addition, a high-pressure injection was conducted that created a hydraulic fracture from the injection borehole towards the artificial fault. The newly generated fluid pathway resulted in an activation of the complete block through a stick–slip movement. We compare acoustic emission measurements from the laboratory experiment with seismicity observations from the field-scale CO2 injection at Decatur, Illinois, U.S., and conclude that the existence of fluid pathways plays a decisive role for the potential of induced seismicity.
Efficient improvement of the lithium ionic conductivity for a polymer electrolyte via introducing porous metal–organic frameworks
Authors: Tian Li , Tao Fencheng , Wang Xin , Liu Meiying , Kang Xiaomin , Liu Zhiliang
Published: May 2022

MOF-5 was synthesized and incorporated into PVDF–HFP to form PVDF–HFP/MOF-5 composites, significantly improving the porosity, mechanical properties and electrochemical performance.
A self-purifying electrolyte enables high energy Li ion batteries
Authors: Lu Di , Lei Xincheng , Weng Suting , Li Ruhong , Li Jiedong , Lv Ling , Zhang Haikuo , Huang Yiqiang , Zhang Junbo , Zhang Shuoqing , Fan Liwu , Wang Xuefeng , Chen Lixin , Cui Guanglei , Su Dong , Fan Xiulin
Published: May 2022

Self-purifying electrolyte effectively eliminates the reactive pernicious species and endows high energy Li ion batteries with stable long-term cycling.
Synergistically coupling P-doped Mo2C@N, P dual-doped carbon-nanoribbons as an efficient electrocatalyst for the hydrogen evolution reaction
Authors: Wang Baoli , Huang Yuhao , Ai Yijing , Yao Yucen , Shi Fan , Xu Shiguan , Zhang Zejun , Wang Xianghui , Sun Wei
Published: May 2022

The design and synthesis of a P-doped Mo2C and ultrathin N, P-doped carbon nanoribbon (P-Mo2C/NPC) composite as an excellent HER catalyst in both acidic and alkaline media.
Triaxiality in galaxy clusters: Mass versus potential reconstructions
Authors: Stapelberg S. , Tchernin C. , Hug D. , Lau E. T. , Bartelmann M.
Published: May 2022

Context. Accounting for the triaxial shapes of galaxy clusters will become important in the context of upcoming cosmological surveys. This will provide a challenge given that the density distribution of gas cannot be described by simple geometrical models without loss of information.

Aims. We investigate the effects of simple 3D models on cluster gravitational potentials and gas density distribution to determine which of these quantities is most suitable and appropriate for characterising galaxy clusters in cosmological studies.

Methods. We use a statistical sample of 85 galaxy clusters from a large cosmological N-body + hydrodynamical simulation to investigate cluster shapes as a function of radius for both gas density and potential. We examine how the resulting parameters are affected by the substructure removal (for the gas density) and by the definition of the computation volume (interior vs. shells).

Results. We find that the orientation and axis ratio of gas isodensity contours are degenerate with the presence of substructures and are unstable against fluctuations. Moreover, as the derived cluster shape depends on the method used for removing the substructures, thermodynamic properties extracted from the X-ray emissivity profile, for example, suffer from this additional and often underestimated bias. In contrast, the shapes of the smooth cluster potentials are less affected by fluctuations and converge towards simple geometrical models, both in the case of relaxed and dynamically active clusters.

Conclusions. The observation that cluster potentials can be represented better by simple geometrical models and reconstructed with a lower level of systematic error for both dynamically active and relaxed clusters suggests that characterising galaxy clusters by their potential is a promising alternative to using cluster masses in cluster cosmology. With this approach, dynamically active and relaxed clusters could be combined in cosmological studies, improving statistics and lowering scatter.
Chromospheric swirls
Authors: Dakanalis I. , Tsiropoula G. , Tziotziou K. , Kontogiannis I.
Published: May 2022

Context.Chromospheric swirls are related to convectively driven vortex flows and considered to play a significant role in the dynamics and heating of the upper solar atmosphere. It is important to automatically detect and track them in chromospheric observations and determine their properties.

Aims.We aim to detect and track chromospheric swirls both in space and time by applying a newly developed novel automated method on high quality time series of Hαobservations and to conduct a statistical analysis to determine their properties.

Methods.We applied a recently developed automated chromospheric swirl detection method to time-series observations of a quiet region of the solar chromosphere obtained in the Hα-0.2 Å wavelength of the Hαspectral line by the CRISP instrument at the Swedish 1-m Solar Telescope. The algorithm exploits the morphological characteristics of swirling events in high contrast chromospheric observations and results in the detection of these structures in each frame of the time series and their tracking over time. We conducted a statistical analysis to determine their various properties, including a survival analysis for deriving the mean lifetime.

Results.A mean number of 146 ± 9 swirls was detected within the Hα-0.2 Å field of view at any given time. The mean surface density is found equal to ∼0.08 swirls Mm−2and the occurrence rate is ∼10−2swirls Mm−2min−1. These values are much higher than those previously reported from chromospheric observations. The radii of the detected swirls range between 0.5 and 2.5 Mm, with a mean value equal to 1.3 ± 0.3 Mm, which is slightly higher than previous reports. The lifetimes range between 1.5 min and 33.7 min (equal to the duration of the observations) with an arithmetic mean value of ∼8.5 min. A survival analysis of the lifetimes, however, using the Kaplan-Meier estimator in combination with a parametric model results in a mean lifetime of 10.3 ± 0.6 min.

Conclusions.Swirls are ubiquitous in the solar chromosphere. An automated method sheds more light on their abundance than visual inspection, while higher cadence, higher resolution observations will most probably result in the detection of a higher number of such features on smaller scales and with shorter lifetimes.
One-Pot Synthesis of Glycosyl Chlorides from Thioglycosides Mediated by a Bromodiethylsulfonium Salt as a Mild Oxidant
Authors: Padungros Panuwat , Chooppawa Tianchai , Janprasert Penpicha
Published: May 2022

The conventional synthesis of glycosyl chlorides from thioglycosides relies on sequential oxidation and chlorination. A one-pot synthesis of glycosyl chlorides is warranted as an alternative method. Here, we report a one-pot synthesis of glycosyl chlorides from thioglycoside precursors. The transformation was mediated at low temperatures by bromodiethylsulfonium bromopentachloroantimonate (BDSB) as a mild oxidant with Bu4NCl as an additive. Armed thioglycosides afforded the corresponding α-glycosyl chlorides in moderate to good yields under the optimized conditions. Low conversions and yields were obtained when the less-reactive disarmed thioglycosides were used. Unexpectedly, BDSB-mediated oxidation of thioglycosides without the addition of Bu4NCl also afforded the α-glycosyl chlorides in moderate yields. We suggest a mechanism involving the transfer of chloride ions from the nonnucleophilic bromopentachloroantimonate (SbCl5Br) anion to the oxocarbenium ion.
Predicting waves in fluids with deep neural network
Authors: Deo Indu Kant , Jaiman Rajeev
Published: May 2022

In this paper, we present a deep learning technique for data-driven predictions of wave propagation in a fluid medium. The technique relies on an attention-based convolutional recurrent autoencoder network (AB-CRAN). To construct a low-dimensional representation of wave propagation data, we employ a denoising-based convolutional autoencoder. The AB-CRAN architecture with attention-based long short-term memory cells forms our deep neural network model for the time marching of the low-dimensional features. We assess the proposed AB-CRAN framework against the standard recurrent neural network for the low-dimensional learning of wave propagation. To demonstrate the effectiveness of the AB-CRAN model, we consider three benchmark problems, namely, one-dimensional linear convection, the nonlinear viscous Burgers equation, and the two-dimensional Saint-Venant shallow water system. Using the spatial-temporal datasets from the benchmark problems, our novel AB-CRAN architecture accurately captures the wave amplitude and preserves the wave characteristics of the solution for long time horizons. The attention-based sequence-to-sequence network increases the time-horizon of prediction compared to the standard recurrent neural network with long short-term memory cells. The denoising autoencoder further reduces the mean squared error of prediction and improves the generalization capability in the parameter space.
Aerodynamic performances and wake topology past a square cylinder in the interface of two different-velocity streams
Authors: El Mansy Reda , Bergadà Josep Maria , Sarwar Wasim , Mellibovsky Fernando
Published: May 2022

We analyze the incompressible flow past a square cylinder immersed in the wake of an upstream splitter plate, which separates two streams of different velocities, UT (top) and UB (bottom). The Reynolds number associated with the flow below the plate is kept constant at ReB=DUB/ν=56, based on the square cylinder side D as characteristic length. The top-to-bottom flow dissymmetry is measured by the ratio R≡ReT/ReB∈[1,5.3] between the Reynolds numbers above and below the plate. The equivalent bulk Reynolds taken as the mean between top and bottom changes with R in the range Re≡(ReT+ReB)/2∈[56,178]. A Hopf bifurcation occurs at R=2.1±0.1 (Re=86.8±2.8), which results in an asymmetric Kármán vortex street with vortices only showing on the high-velocity side of the wake. A spanwise modulational instability is responsible for the three-dimensionalization of the flow at R≃3.1 (Re≃115) with the associated wavelength of λz≃2.4. For velocity ratios R≥4, the flow becomes spatiotemporally chaotic. The migration of the mean stagnation and base pressure points on the front and rear surfaces of the cylinder as R is increased determine the boundary layer properties on the top and bottom surfaces and, with them, the shear layers that roll up into the formation of Kármán vortices, which in turn help to clarify the evolution of the lift and drag coefficients. The symmetries of the different solutions across the flow transition regime are imprinted on the top and bottom boundary layers and can, therefore, be analyzed from the time evolution and spanwise distribution of trailing edge boundary layer displacement thickness at the top and bottom rear corners.
A multiscale approach to predict the effective conductivity of a suspension using the asymptotic homogenization method
Authors: M. K. Easwar , Arockiarajan A. , Roy Anubhab
Published: May 2022

This work aims to implement the asymptotic homogenization method (AHM) to predict the effective thermal/electrical conductivity for suspensions with aligned inclusions. Exploiting the substantial separation of length scales between the macroscopic and microscopic structures, multiscale modeling using the AHM capitalizes on the perturbations of the potential field caused due to the presence of an inclusion under a macroscopic loading used to predict the effective property. The analytical formulation for the thermal/electrical conductivity problem is derived, and subsequently, the finite element formulation required to solve the unit cell problem is described. The results obtained for a cylindrical inclusion are validated against known analytical solutions for both the dilute [Mori–Tanaka (MT)] and concentrated volume fractions (ϕ) of the inclusion. This study revealed that MT estimate and AHM agree well at ϕ less than 0.4. However, in near-maximum packing fractions, the AHM results fared significantly better than MT when compared with known asymptotic forms [J. Keller, “Conductivity of a medium containing a dense array of perfectly conducting spheres or cylinders or nonconducting cylinders,” J. Appl. Phys. 34, 991 (1963)]. The proposed AHM method is then implemented in structures with aligned spheroidal inclusions of various aspect ratios and conductivity ratios, thus providing a more generalized approach to predict the effective thermal/electrical conductivity. The results obtained are systematically benchmarked and validated against known analytical expressions.
Influence of vibration on Marangoni flows in a floating droplet
Authors: Nepomnyashchy Alexander , Simanovskii Ilya
Published: May 2022

The action of vibration on Marangoni flows in a droplet on the liquid substrate is investigated. The problem is studied numerically in the framework of longwave amplitude equations. It is shown that vibration can lead to the change of the droplet's shape. Specifically, rhombic droplets have been obtained. The droplet's shape influences significantly the droplet oscillations.
Acoustic change complex using short duration stimuli in normal hearing children
Authors: El-Kholy Wafaa Abdel-Hay , Mohammed Hassan Dalia , El-Toukhy Yasmine El-Sayed , Shafik Noha Ali
Published: May 2022

Objective

Acoustic Change Complex (ACC) is a cortical auditory evoked potential elicited in response to a change in an ongoing sound. Since it is supposed to reflect auditory discrimination at the cortical level, recording of this potential has recently gained much attention. From a technical standpoint, the stimulus used should be long enough to accommodate the needed change. This research addresses the development and standardization of short duration tonal stimuli which can be implemented in most of the Evoked Potential (EP) equipment used in regular Audiology clinics.

Methods

Short duration tonal stimuli (500 msec.) were generated and edited using Audacity software. Temporal change was done using gap-in-tones stimuli (6, 10, 30 and 50 msec. in 1000 Hz tone). Frequency change was represented by frequency pairs (2%, 4%, 10% and 25% change from 1000 Hz base frequency). The developed stimuli were then used to generate ACC potential in 41 normal hearing children ranging in age from 2 to 10 years. A comparison was held between ACC response recorded using the different stimuli in reference to percent identifiability, morphology, latency and amplitude measures.

Results

Gap-in-tones at 10 msec. and 4% frequency change could elicit ACC response in 100% of subjects. ACC had the same morphology of the onset response in the majority of subjects, with longer latency and smaller amplitude. ACC amplitude was consistently affected by magnitude of change.

Conclusion

ACC was successfully recorded in 100% of normal hearing children using the developed short duration tonal stimuli for temporal change (10 msec.) and frequency change (4%). These stimuli can be uploaded in clinical EP equipment. ACC amplitude could be a better indicator of cortical discrimination compared to latency.
State Classification via a Random-Walk-Based Quantum Neural Network
Authors: Wang Lu-Ji , Lin Jia-Yi , Wu Shengjun
Published: May 2022

In quantum information technology, crucial information is regularly encoded in different quantum states. To extract information, the identification of one state from the others is inevitable. However, if the states are non-orthogonal and unknown, this task will become awesomely tricky, especially when our resources are also limited. Here, we introduce the quantum stochastic neural network (QSNN), and show its capability to accomplish the binary discrimination of quantum states. After a handful of optimizing iterations, the QSNN achieves a success probability close to the theoretical optimum, no matter whether the states are pure or mixed. Other than binary discrimination, the QSNN is also applied to classify an unknown set of states into two types: entangled ones and separable ones. After training with four samples, it can classify a number of states with acceptable accuracy. Our results suggest that the QSNN has the great potential to process unknown quantum states in quantum information.
Noise-Induced Entanglement Transition in One-Dimensional Random Quantum Circuits
Authors: Zhang Qi , Zhang Guang-Ming
Published: May 2022

A random quantum circuit is a minimally structured model to study entanglement dynamics of many-body quantum systems. We consider a one-dimensional quantum circuit with noisy Haar-random unitary gates using density matrix operator and tensor contraction methods. It is shown that the entanglement evolution of the random quantum circuits is properly characterized by the logarithmic entanglement negativity. By performing exact numerical calculations, we find that, as the physical error rate is decreased below a critical value p
c ≈ 0.056, the logarithmic entanglement negativity changes from the area law to the volume law, giving rise to an entanglement transition. The critical exponent of the correlation length can be determined from the finite-size scaling analysis, revealing the universal dynamic property of the noisy intermediate-scale quantum devices.
Network-Initialized Monte Carlo Based on Generative Neural Networks
Authors: Lu Hongyu , Li Chuhao , Chen Bin-Bin , Li Wei , Qi Yang , Meng Zi Yang
Published: May 2022

We design generative neural networks that generate Monte Carlo configurations with complete absence of autocorrelation from which only short Markov chains are needed before making measurements for physical observables, irrespective of the system locating at the classical critical point, fermionic Mott insulator, Dirac semimetal, or quantum critical point. We further propose a network-initialized Monte Carlo scheme based on such neural networks, which provides independent samplings and can accelerate the Monte Carlo simulations by significantly reducing the thermalization process. We demonstrate the performance of our approach on the two-dimensional Ising and fermion Hubbard models, expect that it can systematically speed up the Monte Carlo simulations especially for the very challenging many-electron problems.
QCD Axial Anomaly Enhances the ηη′ Decay of the Hybrid Candidate η1(1855)
Authors: Chen Hua-Xing , Su Niu , Zhu Shi-Lin
Published: May 2022

We study the hybrid mesons with the exotic quantum numberIGJPC= 0+1−+and investigate their decays into theη η′,a1(1260)π,f1(1285)η,f1(1420)η,K*(892)K¯,K1(1270)K¯, andK1(1400)K¯channels. It is found that the QCD axial anomaly enhances the decay width of theη η′ channel although this mode is strongly suppressed by the small p-wave phase space. Our results support the interpretation of theη1(1855) recently observed by BESIII as thes¯sghybrid meson ofIGJPC= 0+1−+. The QCD axial anomaly ensures theη η′ decay mode to be a characteristic signal of the hybrid nature of theη1(1855).
Decoherence Effects of Terahertz Generation in Solids under Two-Color Femtosecond Laser Fields
Authors: Peng Qifang , Peng Zhaoyang , Lang Yue , Zhu Yalei , Zhang Dongwen , Lü Zhihui , Zhao Zengxiu
Published: May 2022

We theoretically investigate terahertz emission from solid materials pumped by intense two-color femtosecond laser field in the presence of decoherence effects. Quantum-mechanical simulations are based on the length gauge semiconductor Bloch equations describing the optical excitation and decoherence with phenomenological dephasing and depopulation times. Contributions of interband and intraband mechanisms are identified in time domain, and the latter has dominated THz generation in solid-state systems. It is found that dephasing is crucial for enhancing asymmetric intraband current and deduced that solid-state materials with short dephasing time and long depopulation time would be optimal selection for strong-field terahertz generation experiments.