bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacy students’ conceptions of theory–practice relation in the analytical chemistry laboratory – a phenomenographic study
Authors: Finne Laura Teinholt , Gammelgaard Bente , Christiansen Frederik Voetmann
Published: October 2022

In the undergraduate student laboratory teaching, one of the most common goals is developing improved conceptual understanding linking theory and practice. This study presents a phenomenographic analysis of pharmacy students’ conceptions of the theory–practice relation in the laboratory. Through semi-structured interviews with pharmacy students about laboratory teaching and learning, we find that the students conceive the laboratory experience of the theory–practice relation in three qualitatively different ways. They perceive the laboratory experience as either (i) a visual representation of the theory, (ii) acting in a multimodal setting supporting theory, or (iii) as a complementary perspective in understanding theory. Furthermore, the conceptions were context-dependent and changed over time. We discuss how these three different perspectives may affect the students’ learning outcomes and suggest how teachers can accommodate the perspectives in their teaching.
Manipulation of oxygen evolution reaction kinetics of a free-standing CoSe2–NiSe2heterostructured electrode by interfacial engineering
Authors: Rauf Muhammad , Yang Ling , Wang Jingwen , Mi Hongwei , Zhang Qianling , Zhang Peixin , Ren Xiangzhong , Li Yongliang
Published: October 2022

3D cross-linked CoSe2–NiSe2nanosheets were grown on nickel foam by an electrodeposition route and demonstrated high OER activity.
Comment on “Bilayer aggregate microstructure determines viscoelasticity of lung surfactant suspensions” by C. O. Ciutara and J. A. Zasadzinski, Soft Matter, 2021, 17, 5170–5182
Authors: Berret Jean-François
Published: October 2022

This note discusses the possible causes of the discrepancy between two studies and suggests that for pulmonary surfactant substitutes, the microrheology technique known as rotational magnetic spectroscopy can provide valuable results.
Multiple strategies of porous tetrametallene for efficient ethanol electrooxidation
Authors: Xiong Juan , Li Hongdong , Pan Yue , Liu Jiao , Zhang Yan , Xu Jixiang , Li Bin , Lai Jianping , Wang Lei
Published: October 2022

The first synthesized porous Pd59W8Rh19Bi14 metallene combines OH adsorption effects, electronic effects and C–C bond cleavage site strategies to improve EOR performance. The metallene stable structure further accelerates the mass transfer rate.
A 3D-printed framework with a gradient distributed heterojunction and fast Li+conductivity interfaces for high-rate lithium metal anodes
Authors: Wang Shuo , Shi Haiting , Xia Yuanhua , Liu Dong , Min Chunying , Zeng Ming , Liang Sirui , Shao Ruiqi , Wu Xiaoqing , Xu Zhiwei
Published: October 2022

A 3D framework with a gradient-distributed heterojunction and fast Li+conductivity Li–Al–O interfaces promotes the rate performance in lithium metal anodes.
A humidity-resistant bio-inspired microfibrillar adhesive fabricated using a phenyl-rich polysiloxane elastomer for reliable skin patches
Authors: Xia Shuang , Chen Yukun , Fu Wenxin , Tian Jinfeng , Zhou Yilin , Sun Yini , Cao Ruoxuan , Zou Huawei , Liang Mei
Published: October 2022

We present a specific phenyl-rich microfibrillar adhesive with reliable humidity macroadhesion, which can be well applied to fix electrodes for long-time health-care when exposed to significantly varying humid conditions of skin surface.
Hierarchical pompon-like cobalt phosphide as a platinum-free electrocatalyst for dye-sensitized solar cells
Authors: Yeh Chia-Lin , Huang Yi-June , Chen Han-Ting , Tsai Hsin-An , Li Chun-Ting , Lee Chuan-Pei , Ho Kuo-Chuan
Published: October 2022

Hierarchical 3D CoP micro-pompon assembled by 1D-nano-needle-array decorated 2D-micro-sheets provided facile charge transfer and lots of electrocatalytic active sites to deliver decent DSSC performance (8.80% at 1 sun; 17.27% at 7 klux).
Emerging trends in 2D TMDs with a broken gap interface
Authors: Aftab Sikandar , Iqbal Muhammad Zahir
Published: October 2022

Several review articles have previously addressed the investigation of p–n junction design.
Stuttering Behavior in a National Age Cohort of Norwegian First-Graders With Down Syndrome
Authors: Hokstad Silje , Næss Kari-Anne B. , Yaruss J. Scott , Hoff Karoline , Melle Ane H. , Lervåg Arne Ola
Published: October 2022

Purpose:

The aims of this study were to investigate the occurrence of stuttering behavior across time and to evaluate the relationship between stuttering behavior and language ability in children with Down syndrome.

Method:

A national age cohort of Norwegian first graders with Down syndrome (
N
= 75) participated in the study. Speech samples from a story-retelling task and a picture book dialogue as well as standardized measures of vocabulary, grammar, and nonverbal mental ability were collected at two time points approximately 5 months apart. Stuttering behavior was evaluated through counting stuttering-like disfluencies and stuttering severity ratings. The relationship between stuttering behavior and language ability was investigated through hierarchical regression analysis.

Results:

The participants had stuttering severity ratings ranging from no stuttering behavior to severe and displayed all types of stuttering-like disfluencies. There were significant relationships between stuttering behavior and language ability at the first time point, whereas the relationships were not significant at the second time point. The stuttering severity ratings were significantly predicted by language ability across time, whereas the frequency of stuttering-like disfluencies was not.

Conclusions:

The occurrence of stuttering behavior was high across the measures and time points; however, the relationship between stuttering behavior and language ability varied across these variables. Thus, the nature of the relationship does not seem to follow a strict pattern that can be generalized to all children across time.
Statistical Errors in “How Graduate Students With Vocal Fry Are Perceived by Speech-Language Pathologists”
Authors: Theodore Rachel M.
Published: October 2022

Purpose:

Perspectives of the ASHA Special Interest Groups
recently published a study (Gallena & Pinto, 2021) that investigated how graduate students with vocal fry are perceived by speech-language pathologists. The statistical analysis of the data presented in this study contains errors. The purpose of this letter is to describe these errors, outline practices that may facilitate error detection prior to publication, and position these errors in the broader context of vocal quality biases that may influence hiring and supervision decisions among speech-language pathologists.

Conclusions:

The statistical errors in Gallena and Pinto (2021) reflected a violation of the assumption of independence required by the employed statistical tests and inaccurate calculation of effect size measures. The severity of these errors makes it difficult to determine whether the reported results would hold if the correct statistical analyses were applied to the data and, thus, challenge an understanding of the degree to which vocal quality may influence perceived speaker traits and hiring or supervision decisions. Open science practices, including the Registered Report model of publication and open access to data and analysis pipelines during the review process, provide mechanisms to support error detection prior to publication.
State vulnerability assessment against false data injection attacks in AC state estimators
Authors: Khare Gaurav , Mohapatra Abheejeet , Singh Sri Niwas
Published: October 2022

The transformation of the conventional power grid into a smart grid has revolutionised the power industry. However, this has also made the power grid vulnerable to various cyberattacks. This study evaluates the vulnerability of system states, which act as crucial inputs to other essential grid monitoring and control functions, against credible false data injection attacks on nonlinear AC state estimators. Accordingly, two approaches are proposed. The first maximises the yield of the attack, and the second reduces the number of physical meters to be manipulated to launch an attack. This study also develops an attack feasibility index, which can assist in quantifying the feasibility of an false data injection attack while considering various characteristics of a cyberattack. The attack feasibility index also aids in simultaneously comparing the effects of both approaches and assessing the vulnerability of the estimated states. The effectiveness of the proposed methods and the index are established by calculating the state vulnerability of the IEEE 39 bus and IEEE 118 bus test systems.
Constraints on planetary tidal dissipation from a detailed study of Kepler 91b
Authors: Fellay L. , Pezzotti C. , Buldgen G. , Eggenberger P. , Bolmont E.
Published: October 2022

Context. With the detection of thousands of exoplanets, characterising their dynamical evolution in detail represents a key step in the understanding of their formation. Studying the dissipation of tides occurring both in the host star and in the planets is of great relevance in order to investigate the distribution of the angular momentum occurring among the objects populating the system and to studying the evolution of the orbital parameters. From a theoretical point of view, the dissipation of tides throughout a body may be studied by relying on the so-called phase or time-lag equilibrium tides model in which the reduced tidal quality factor Q′p, or equivalently the product between the love number and the time lag (k2,pΔtp), describe how efficiently tides are dissipated within the perturbed body. Constraining these factors by looking at the current configuration of the exoplanetary system is extremely challenging, and simulations accounting for the evolution of the system as a whole might help to shed some light on the mechanisms governing this process.

Aims. We aim to constrain the tidal dissipation factors of hot-Jupiter-like planets by studying the orbital evolution of Kepler-91b.

Methods. We firstly carried out a detailed asteroseismc characterisation of Kepler-91 and computed a dedicated stellar model using both classical and astereoseismic constraints. We then coupled the evolution of the star to the one of the planets by means of our orbital evolution code and studied the evolution of the system by accounting for tides dissipated both in the planet and in the host star.

Results. We found that the maximum value for k2,pΔtp (or equivalently the minimum value for Q′p) determining the efficiency of equilibrium tides dissipation occurring within Kepler-91b is 0.4 ± 0.25 s (4.5−1.5+5.8 × 105). We constrained these factors by computing the evolution of the planetary orbit and by reproducing the current properties of the Kepler-91 system.

Conclusions. We developed a new method to constrain the tidal dissipation factors using the observed eccentricity of a given planet. Our new approach showed that Kepler 91b has dissipation coefficients compatible with colder Jupiter-like planets. When applied to other targets, our new method could potentially give more precise boundary values to the tidal dissipation factors, and determine whether planetary tides dominate the dissipation during the stellar main sequence.
Removing biases on the density of sub-Neptunes characterised via transit timing variations
Authors: Leleu A. , Delisle J.-B. , Udry S. , Mardling R. , Turbet M. , Egger J. A. , Alibert Y. , Chatel G. , Eggenberger P. , Stalport M.
Published: October 2022

Transit timing variations (TTVs) can provide useful information on compact multi-planetary systems observed by transits by setting constraints on the masses and eccentricities of the observed planets. This is especially helpful when the host star is not bright enough for a radial velocity (RV) follow-up. However, in the past decade, a number of works have shown that TTV-characterised planets tend to have lower densities than planets characterised on the basis of RVs. Re-analysing 34 Kepler planets in the super-Earth to sub-Neptunes range using the RIVERS approach, we show that at least some of these discrepancies were due to the way transit timings were extracted from the light curve, as a result of their tendency to underestimate the TTV amplitudes. We recovered robust mass estimates (i.e. with low prior dependency) for 23 of the planets. We compared these planets the RV-characterised population and found that a large fraction of those that previously had unusually low density estimates were adjusted, allowing them to occupy a place on the mass-radius diagram much closer to the bulk of known planets. However, a slight shift toward lower densities remains, which could indicate that the compact multi-planetary systems characterised by TTVs are indeed composed of planets that are different from the bulk of the RV-characterised population. These results are especially important in the context of obtaining an unbiased view of the compact multi-planetary systems detected by Kepler, TESS, and the upcoming PLATO mission.
History of two mass loss processes in VY CMa
Authors: Quintana-Lacaci G. , Velilla-Prieto L. , Agúndez M. , Fonfría J. P. , Cernicharo J. , Decin L. , Castro-Carrizo A.
Published: October 2022

Context. Red supergiant stars (RSGs, Minit = 10 − 40 M⊙) are known to eject large amounts of material, as much as half of their initial mass during this evolutionary phase. However, the processes powering the mass ejection in low- and intermediate-mass stars do not work for RSGs and the mechanism that drives the ejection remains unknown. Different mechanisms have been proposed as responsible for this mass ejection including Alfvén waves, large convective cells, and magnetohydrodynamical (MHD) disturbances at the photosphere, but so far little is known about the actual processes taking place in these objects.

Aims. Here we present high angular resolution interferometric ALMA maps of VY CMa continuum and molecular emission, which resolve the structure of the ejecta with unprecedented detail. The study of the molecular emission from the ejecta around evolved stars has been shown to be an essential tool in determining the characteristics of the mass loss ejections. Our aim is thus to use the information provided by these observations to understand the ejections undergone by VY CMa and to determine their possible origins.

Methods. We inspected the kinematics of molecular emission observed. We obtained position-velocity diagrams and reconstructed the 3D structure of the gas traced by the different species. It allowed us to study the morphology and kinematics of the gas traced by the different species surrounding VY CMa.

Results. Two types of ejecta are clearly observed: extended, irregular, and vast ejecta surrounding the star that are carved by localized fast outflows. The structure of the outflows is found to be particularly flat. We present a 3D reconstruction of these outflows and proof of the carving. This indicates that two different mass loss processes take place in this massive star. We tentatively propose the physical cause for the formation of both types of structures. These results provide essential information on the mass loss processes of RSGs and thus of their further evolution.
Feasibility Analysis of Vacuum Pipeline Magnetic Levitation Energy Storage System Based on Existing Magnetic Levitation Transportation Technology
Authors: Fan Ziming , Yang Jun , Xun Hua
Published: October 2022

This paper is mainly summarized the research progress of maglev transportation technology. The vacuum pipeline magnetic levitation energy storage system is constructed based on the existing four types of magnetic levitation as technical prototypes, and the four schemes are formed: as followed: electromagnetic suspension (EMS) medium and low speed magnetic levitation type vacuum pipeline energy storage system, EMS high speed magnetic levitation type vacuum pipeline energy storage system, electric suspension (EDS) high speed magnetic levitation type vacuum pipeline energy storage system and super high-speed rail type vacuum pipeline energy storage system. The energy storage and energy storage cost of these four energy storage systems are analyzed to study their energy storage feasibility.
Research progress of tunnel air-tight concrete
Authors: An Junjie , Li Guang , Liu Gang , Xue Cheng , Hou Dingge , Wang Shaolong , Wang Zhendi , Li Bin
Published: October 2022

With the quick development of transportation network construction, the tunnel construction has been an important part. During the tunnel construction process, especially in the gas zone, gas leaking has been a common problem. For avoiding gas leakage, it is necessary to enhance the air-tightness of the tunnel concrete, air-tight concrete is a kind of concrete with excellent air tightness performance. In this paper, we introduced the research progress of tunnel air-tight concrete, including the effect of mix ratio, composition on the air-tight performance of tunnel concrete and corresponding characterization methods.
Retraction Note: Study and development of an optical waveguide cap for biomedical application
Authors: Ferreira Margarida , Monteiro Catarina S. , Henriques Patrícia C. , Gonçalves Inês C. , Frazão Orlando
Published: October 2022

This paper has been formally retracted because it has been accidentally published the volume. Request approved by the proceedings Editor and the Publisher on October 24, 2022.
An application of fuzzy logistic regression for predicting CVSS severity category of industrial control systems
Authors: Dere Ahmet Murat , Kabak Mehmet
Published: October 2022

Cybersecurity is rapidly gaining significance due to growing use of computers in daily life and business sectors. Likewise, industrial sector has also become more vulnerable to cyber threats exclusively with the onset of Industry 4.0, which is a digital transformation evolved with industrial control systems (ICS). Nowadays industrial organizations aim to build capacity towards protection of ICS to be cybersafe. To assess the effects of vulnerabilities in ICS, organizations utilize Common Vulnerability Scoring System (CVSS), which calculates severity categories/scores. In this study, we implemented a prediction model for CVSS vulnerability categorization of ICS. Although there exist many applicable methods to use in data analysis paradigm such as statistical regression, cluster and classification analysis, the categorical form of CVSS data based on verbal statements and the failure to satisfy basic statistical assumptions for classical models motivated us to focus on implementation of fuzzy logistic regression (FLR) model, which is one possible alternative method. We chose the FLR method to explore that it is applicable to ICS vulnerability data. Furthermore, the model was improved by employing metaheuristic algorithms to optimize the spread of fuzzy numbers representing input variables. This study is expected to contribute to practical application of vulnerability categorization of ICS.
Cluster Preface: Development and Applications of Novel Ligands/Catalysts and Mechanistic Studies on Catalysis
Authors: Zhang Zhipeng , Zhao Baoguo
Published: October 2022

Zhipeng Zhang (left) received his B.S. degree from Shandong University (China) in 2004, and his Ph.D. degree from the Shanghai Institute of Organic Chemistry (SIOC) in 2010 under the supervision of Professor Kuiling Ding. In 2011, he began his postdoctoral studies with Professor Benjamin List at the Max Planck Institute for Coal Research in Mülheim an der Ruhr, Germany. After three years of research on asymmetric organocatalysis, he joined the group of Professor Jin-Quan Yu at The Scripps Research Institute in La Jolla, California as a postdoctoral research associate in 2014. He subsequently worked at the Genomics Institute of the Novartis Research Foundation (GNF) from 2016, before he began his independent career as a professor at the East China University of Science and Technology (ECUST) in 2017. His current research interests include asymmetric catalysis and synthetic methodology, focusing on the design and development of novel chiral ligands and catalysts.

Baoguo Zhao (right) received his B.S. degree from Wuhan University in 1996, his M.S. degree from Nanjing University under the supervision of Professor Jianhua Xu in 2002, and his Ph.D. degree from the Shanghai Institute of Organic Chemistry (SIOC) under the supervision of Professor Kuiling Ding in 2006. He subsequently worked with Professor Yian Shi for five years as a postdoctoral fellow at the Department of Chemistry of Colorado State University. In 2011, he joined Shanghai Normal University at the Department of Chemistry as a full professor. His current research interests are in the area of biomimetic asymmetric catalysis, including the development of bioinspired chiral catalysts and synthetic methodologies.
A distributional Gelfand–Levitan–Marchenko equation for the Helmholtz scattering problem on the line
Authors: Tataris Andreas , van Leeuwen Tristan
Published: October 2022

We study an inverse scattering problem for the Helmholtz equation on the whole line. The goal of this paper is to obtain a Gelfand–Levitan–Marchenko (GLM)-type equation for the Jost solution that corresponds to the 1D Helmholtz differential operator. We assume for simplicity that the refraction index is of compact support. Using the asymptotic behavior of the Jost solutions with respect to the wave-number, we derive a generalized Povzner–Levitan representation in the space of tempered distributions. Then, we apply the Fourier transform on the scattering relation that describes the solutions of the Helmholtz scattering problem and we derive a generalized GLM equation. Finally, we discuss the possible application of this new generalized GLM equation to the inverse medium problem.
Interplay of turbulence and proton-microinstability growth in space plasmas
Authors: Bandyopadhyay Riddhi , Qudsi Ramiz A. , Gary S. Peter , Matthaeus William H. , Parashar Tulasi N. , Maruca Bennett A. , Roytershteyn Vadim , Chasapis Alexandros , Giles Barbara L. , Gershman Daniel J. , Pollock Craig J. , Russell Christopher T. , Strangeway Robert J. , Torbert Roy B. , Moore Thomas E. , Burch James L.
Published: October 2022

Numerous prior studies have shown that as proton beta increases, a narrower range of proton temperature anisotropy values is observed. This effect has often been ascribed to the actions of kinetic microinstabilities because the distribution of observational data aligns with contours of constant instability growth rates in the beta-anisotropy plane. However, the linear Vlasov theory of instabilities assumes a uniform background in which perturbations grow. The established success of linear-microinstability theories suggests that the conditions in regions of extreme temperature anisotropy may remain uniform for a long enough time so that the instabilities have the chance to grow to sufficient amplitude. Turbulence, on the other hand, is intrinsically nonuniform and nonlinear. Thin current sheets and other coherent structures generated in a turbulent plasma may quickly destroy the uniformity. It is, therefore, not a-priori obvious whether the presence of intermittency and coherent structures favors or disfavors instabilities. To address this question, we examined the statistical distribution of growth rates associated with proton temperature-anisotropy driven microinstabilities and local nonlinear time scales in turbulent plasmas. Linear growth rates are, on average, substantially less than the local nonlinear rates. However, at the regions of extreme values of temperature anisotropy, near the “edges” of the populated part of the proton temperature anisotropy-parallel beta plane, the instability growth rates are comparable or faster than the turbulence time scales. These results provide a possible answer to the question as to why the linear theory appears to work in limiting plasma excursions in anisotropy and plasma beta.
Nematic electron and phonon dynamics in SnS crystals
Authors: Quyen Nguyen Nhat , Hong Tz-Ju , Hsu Chin En , Tzeng Wen-Yen , Tu Chien-Ming , Kuo Chia-Nung , Hsueh Hung-Chung , Lue Chin Shan , Luo Chih-Wei
Published: October 2022

Tin sulfide (SnS) is one of the promising materials for the applications of optoelectronics and photovoltaics. This study determines the nematic dynamics of photoexcited electrons and phonons in SnS single crystals using polarization-dependent pump–probe spectroscopy at various temperatures. As well as the fast (0.21–1.38 ps) and slow (>5 ps) relaxation processes, a 36–41 GHz coherent acoustic phonon with a sound velocity of 4883 m/s that is generated by the thermoelastic effect is also observed in the transient reflectivity change (ΔR/R) spectra. Electrons and coherent acoustic phonons show significant in-plane anisotropy from 330 to 430 K due to strong electron–phonon coupling. However, this in-plane anisotropy weakens dramatically in the low-temperature (<330 K) and high-temperature (>430 K) phases. These results add to the knowledge about the anisotropy of electrons and coherent acoustic phonons that give SnS applications in photovoltaic or optoelectronic devices.
Integration of hydrogels into microfluidic devices with porous membranes as scaffolds enables their drying and reconstitution
Authors: Shahriari Shadi , Selvaganapathy P. Ravi
Published: October 2022

Hydrogels are a critical component of many microfluidic devices. They have been used in cell culture applications, biosensors, gradient generators, separation microdevices, micro-actuators, and microvalves. Various techniques have been utilized to integrate hydrogels into microfluidic devices such as flow confinement and gel photopolymerization. However, in these methods, hydrogels are typically introduced in post processing steps which add complexity, cost, and extensive fabrication steps to the integration process and can be prone to user induced variations. Here, we introduce an inexpensive method to locally integrate hydrogels into microfluidic devices during the fabrication process without the need for post-processing. In this method, porous and fibrous membranes such as electrospun membranes are used as scaffolds to hold gels and they are patterned using xurography. Hydrogels in various shapes as small as 200 μm can be patterned using this method in a scalable manner. The electrospun scaffold facilitates drying and reconstitution of these gels without loss of shape or leakage that is beneficial in a number of applications. Such reconstitution is not feasible using other hydrogel integration techniques. Therefore, this method is suitable for long time storage of hydrogels in devices which is useful in point-of-care (POC) devices. This hydrogel integration method was used to demonstrate gel electrophoretic concentration and quantification of short DNA (150 bp) with different concentrations in rehydrated agarose embedded in electrospun polycaprolactone (PCL) membrane. This can be developed further to create a POC device to quantify cell-free DNA, which is a prognostic biomarker for severe sepsis patients.
Deep level defects in low-pressure chemical vapor deposition grown (010) β-Ga2O3
Authors: Ghadi Hemant , McGlone Joe F. , Cornuelle Evan , Feng Zixuan , Zhang Yuxuan , Meng Lingyu , Zhao Hongping , Arehart Aaron R. , Ringel Steven A.
Published: October 2022

This study provides the full-bandgap evaluation of defect state distributions in beta phase gallium oxide (β-Ga2O3) grown by low-pressure chemical vapor deposition (LPCVD) on (010) β-Ga2O3 substrates at high growth of up to 20 µm/h. Deep-level optical spectroscopy and deep-level transient spectroscopy measurements applied to Ni/β-Ga2O3 Schottky diodes revealed the presence of a previously unreported defect state at EC-3.6 eV, which dominated the overall trap distribution in LPCVD grown material. However, states at EC-0.8 eV, EC-2.0 eV, and EC-4.4. eV were also detected, similar to prior studies on β-Ga2O3 grown by other methods, with similar or lower concentrations for the LPCVD samples. The EC-0.8 eV and EC-2.0 eV states were previously connected to residual Fe impurities and gallium vacancies, respectively. The total concentration of traps in the LPCVD material was on par with or lower than the state-of-the-art metal–organic chemical vapor deposition-grown materials despite the much higher growth rate, and the distribution of states showed negligible dependence on SiCl4 flow rate and doping concentration. These results demonstrate that the high growth rate of LPCVD-grown β-Ga2O3 is very promising for achieving thick, low defect density, and high-quality layers needed for multi-kV device applications.
Controlling species densities in structurally perturbed intransitive cycles with higher-order interactions
Authors: Chatterjee Sourin , Nag Chowdhury Sayantan , Ghosh Dibakar , Hens Chittaranjan
Published: October 2022

The persistence of biodiversity of species is a challenging proposition in ecological communities in the face of Darwinian selection. The present article investigates beyond the pairwise competitive interactions and provides a novel perspective for understanding the influence of higher-order interactions on the evolution of social phenotypes. Our simple model yields a prosperous outlook to demonstrate the impact of perturbations on intransitive competitive higher-order interactions. Using a mathematical technique, we show how alone the perturbed interaction network can quickly determine the coexistence equilibrium of competing species instead of solving a large system of ordinary differential equations. It is possible to split the system into multiple feasible cluster states depending on the number of perturbations. Our analysis also reveals that the ratio between the unperturbed and perturbed species is inversely proportional to the amount of employed perturbation. Our results suggest that nonlinear dynamical systems and interaction topologies can be interplayed to comprehend species’ coexistence under adverse conditions. Particularly, our findings signify that less competition between two species increases their abundance and outperforms others.
Two-dimensional vibrationally driven solid particle structures in non-uniformly heated fluid containers
Authors: Crewdson Georgie , Evans Matthew , Lappa Marcello
Published: October 2022

Building on a pre-existing line of inquiry where the presence of solid particle attractors in thermovibrationally driven flows was demonstrated in cavities subjected to a unidirectional temperature gradient, the present work considers cases where the direction of such a gradient is allowed to change inside the fluid. Moreover, the considered configurations differ with regard to the angle that vibrations form with respect to a reference axis. Variations in the orientation of the temperature gradient are made possible by setting a non-uniform temperature distribution along certain walls. The relationship between the multiplicity (N) of the loci of particle attraction and the inhomogeneities in the temperature field is studied. It is shown that N can exceed the limit N = 2 found in earlier studies and that a zoo of new particle accumulation structures show up, whose ranges of existence depend on the amplitude and frequency of vibrational acceleration, the particle Stokes number, the orientation of vibrations, and the number of inversions in the direction of the temperature gradient.
Influence of AC corona discharge on the hydrophobicity of silicone rubber surface in high-speed airflow environment
Authors: Chen Jigang , Liu Kai , Zhang Xiaoqing , Guo Yujun , Zhang Xueqin , Wu Guangning
Published: October 2022

Corona discharge is one of the key factors that lead to the hydrophobicity loss of silicone rubber insulators used on the roof of high-speed trains. Based on the artificial experimental wind-tunnel platform, influences of AC corona intensity and airflow velocity on the hydrophobicity distribution of the silicone rubber surface were studied. According to the corona discharge phenomena and measured discharge current, influences of airflow velocity and voltage on the characteristics of corona discharge in a high-speed airflow environment were discussed. Results reveal that the hydrophobicity distribution on the silicone rubber surface shifts along the airflow direction in the high-speed airflow environment when the voltage is relatively high. When ionization zone develops to the needle-plate gap, the discharge path is deflected to the direction of airflow, which is responsible for the change of the hydrophobicity distribution. It is notable that the deflection distance decreases with the increase of airflow velocity. This is attributed to the fact that the electrons with variable horizontal distance from the electron to the plate electrode center are subjected to different electric field forces, resulting in different influences of high-speed airflow on them. These results are of engineering and theoretical significance for insulators used in high-speed railways.
Effect of electropulsing and annealing treatment on microstructure and mechanical properties of 316L stainless steel
Authors: Ma Yunrui , Dong Manling , Geng Jinfeng , Xin Weifeng , Meng Lingxiao , Yang Huajie , Zhang Zhefeng
Published: October 2022

Considering the consumption of time and energy for the traditional heat treatment process, a new heat treatment method with high speed and low energy consumption has always been the direction of researchers. The microstructure and mechanical properties of engineering 316L stainless steel were measured under electropulsing treatment within 400 ns and annealing treatment for 2 h. Compared with the original cold-rolled state, it was found that the yield strength after 3.8 × 103 A/mm2 electropulsing treatment was reduced by 26.2% and that after 800 °C heat treatment was reduced by 27.7%. The nucleation after electropulsing treatment is mainly concentrated at one end of the lamellar grain and finally grows into the square or rhombic grain with an average grain size of 1.5 µm. After annealing, the nucleation is mainly concentrated at the grain boundaries of the lamellae and finally grows into equiaxed grains with an average grain size of 1.8 µm. Under the action of electronic wind, the recrystallization nucleation after electropulsing is mainly dominated by the mechanism of subgrain nucleation and growth. However, under the action of a uniform thermal field, the recrystallization nucleation after annealing is mainly based on the grain boundary bow-out mechanism.
Improvement of textured AlCu with Ta underlayer on LiNbO3 substrate
Authors: Achahbar H. , Bernard F. , Courjon E. , Martin N. , Baron T. , Ballandras S.
Published: October 2022

Improving the lifetime of surface acoustic wave filters requires reduction of electromigration effects. We report on the growth mechanism of AlCu2% films deposited by the e-beam physical vapor deposition technique. The state of the art shows that the introduction of an underlayer that alters the surface free energy can change a film’s growth mode or improve the earliest stages of film formation. In this work, this will be achieved by using an ultra-thin (<5 nm) Ta underlayer between the LiNbO3 substrate and the AlCu2% film. The effects of the Ta underlayer on the microstructure of AlCu2%/LiNbO3 films are investigated. An increase in the surface energy of the LiNbO3 substrate is observed with the addition of a 1.3 nm thick Ta underlayer. The crystalline quality of the AlCu2% thin film with a Ta underlayer is measured using XRD techniques. A post-deposition heat processing technique is also used to recrystallize the films. The AlCu2%/1.3Ta/LiNbO3 film annealed at 250 °C improved the electrode quality with the increase of 16% of the grain size.
Image enhancement for underwater range-gated image with multi-slice integration method
Authors: Lin Hongsheng , Han Hongwei , Ma Liheng , Zhang Xiaohui , Xiong Zhang
Published: October 2022

Active illumination underwater brings the backscatter problem. The traditional pulsed laser range-gated imaging (PLRGI) system uses a small gate width to suppress most of the backscattered light. As a result, the depth of field (DOF) of the PLRGI system is small. In addition, the DOF has to be extended when the system is used for searching the target. There are several methods to extend the DOF. However, every method has its shortcoming. To overcome these problems, a multi-slice integration (MSI) method is proposed. In turbid water, the image captured by the MSI method also has the backscatter problem. The rolling ball and intensity transformation are proposed as an image enhancement method to remove the backscattered light and improve the brightness of the image. Experiments carried out in a towing boat tank and Mulan Lake show that the proposed method is better than lower-upper-threshold correlation, dark channel priors, and unsharp filtering for backscattered light removal.
An enhanced galloping-based piezoelectric energy harvester with non-rotational bluff body
Authors: Sun Wan , Zhang Yue , Cheng Guanggui , He Shangwen , Yang Zhaorui , Ding Jianning
Published: October 2022

This study proposes a bluff body non-rotational galloping-based piezoelectric wind energy harvester (BNRGH) for overall output performance enhancement. The bluff body used in this structure is designed to be available to rotate with respect to the free end of two cantilever beams by the connection of rotatable hinges. A series of performance comparisons are conducted experimentally in a wind tunnel between the proposed structure and the conventional galloping-based piezoelectric energy harvester, which commonly configured with a single beam. The results show that the proposed structure is capable of preventing the variation of the attack angle due to the self-rotation of the bluff body caused by the deflection of a common single beam, thus avoiding the amplitude saturation of the bluff body at a higher wind velocity range. It shows that the output voltage remains a continuous linear increase within elastic deformation range of the cantilever beam even in higher wind velocity range, which is helpful in accomplishing a broad wind range for a significant improvement of the overall performance. Overall, the proposed BNRGH provides a design guidance for a small size galloping-based energy harvester to achieve an excellent output performance, which holds great potential to promote its application in wireless node networks for self-power supply.
Dynamic electrical response of vortex polarization in (Pb0.9Sr0.1)TiO3/SrTiO3 artificial superlattice thin films
Authors: Song Jundong , Iguchi Yusuke , Okamoto Kazuki , Sakata Osami , Yoshino Masahito , Nagasaki Takanori , Yamada Tomoaki
Published: October 2022

Artificial superlattice thin films with alternative Pb0.9Sr0.1TiO3 (PST) and SrTiO3 layers were fabricated via pulsed laser deposition. The vortex domains were formed by adjusting the unit cell number of the PST layer to be 20. The electrical response measured by time-resolved synchrotron x-ray diffraction with the repeated pulse voltages of a time interval of 1000 μs indicates that the reorientation of dipole moments in the vortex domains is susceptible to the applied electric field and is a reversible process. Although the centrosymmetric vortex domain structure is not considered to exhibit piezoelectricity, an evident change in the out-of-plane lattice constant with the applied electric field was confirmed. The magnitude of the electromechanical response at 600 kV/cm was estimated to be 19 pm/V, which is nearly comparable to the piezoelectric constant d33 of bulk PbTiO3.
Surface discharge pattern of C4F7N/CO2 mixture under negative impulse voltages
Authors: Chen Junhong , Sun Peng , Li Jinshu , Li Wendong , Li Yuan , Deng Junbo , Ji Shengchang , Zhang Guan-Jun
Published: October 2022

Due to the excellent properties, C4F7N/CO2 mixture is the most concerned eco-friendly SF6 alternative gas. For a better understanding of the surface discharge characteristics, the surface discharge pattern of C4F7N/CO2 mixture under negative impulse voltages is investigated in this work. The morphology of the surface discharge is obtained by an optical method and a dust figure method. The structure of the surface discharge is established, which from the outside to the inside consists of electron cloud, streamer, streamer stem, and leader. The propagation pattern of the surface discharge in C4F7N/CO2 mixture under negative impulse follows the stepwise expansion pattern. The structure of the surface discharge in C4F7N/CO2 mixtures with different ratios and SF6 has no obvious difference, and the propagation pattern is also the same. The results of this work can help to better understand the surface discharge phenomenon and the insulation characteristics of C4F7N/CO2 mixture.
Self-filtering narrowband perovskite photodetector with ultra-narrowband and high spectral rejection ratio
Authors: Liao Yuhan , Wang Xin , Pan Yuzhu , Xu Yubing , Li Qing , Zhang Xiaobing , Chen Jing , Zhu Zhuoya , Zhao Zhiwei , Ertugrul Mehmet , Furuta Mamoru , Elemike Elias Emeka , Abbasian Mojtaba , Zhou Jianming , Lei Wei
Published: October 2022

Narrowband photodetectors have broad application prospects in many fields where only a range of specific wavelengths of light needs to be detected. However, the current narrowband detectors have some disadvantages, such as the integration is difficult, the full width at half-maximum is not narrow enough, and the spectral rejection ratio is not ideal (≤20). Here, we present a self-filtering photodetector based on MAPbX3 single crystals with a very narrow spectral response and a full width of 15 nm at half maximum. It also shows a high responsivity (∼100 mA/W) and a high spectral rejection ratio (∼300). What is more, the response spectrum can be tuned within a certain range (from 440 to 560 nm) by varying the halide composition and thus its bandgap. This provides a new design paradigm for self-filtering narrowband photodetectors.
Deformation dynamics of spherical red blood cells in viscous fluid driven by ultrasound
Authors: Liu Yifan , Xin Fengxian
Published: October 2022

In this paper, the deformation dynamics of spherical red blood cells in viscous fluid driven by ultrasound are theoretically and numerically studied. Red blood cells are considered to be composed of a homogenous cytoplasm enclosed by a biological membrane. The developed theoretical framework consists of two sets of equations, which describe the acoustic wave propagation and the time-averaged mean dynamics of the fluid-cell system, respectively. Specifically, the separated acoustics and mean responses of viscous fluid are formulated based on the acoustic perturbation method in a generalized Lagrangian framework. Considering the viscoelasticity of the membrane, the cell deformation is coupled to the fluid mean motion through the time-averaged fluid–membrane coupling boundary conditions. A computational model is established by deriving weak form formulations of the final governing equations and implementing them by the finite element method. The computational model is verified by comparing the steady-state deformation of the numerical results with previous experimental results. This model can accurately characterize the deformation of cells over time, which helps to extract the viscoelastic properties of cells.
Dynamic flow characteristics influenced by impinging shear layer mode in a rectangular tube with a closed side branch
Authors: Wang Xi , Shuai Zhi-Jun , Liu Shuai , Yu Tao , Jian Jie , Yin Wen-Hui , He Jia-Xuan , Meng Chang-Lin , Li Wan-You , Jiang Chen-Xing
Published: October 2022

The pipeline with a closed side branch is a typical structure in nuclear systems; the shear layer flow and deep cavity in this structure can lead to a complex flow-acoustic coupling, which may result in severe vibration and noise. To clarify the shear layer flow characteristics in this typical structure filled with water, the numerical strategy is established by employing the localized dynamic k-equation large eddy simulation model. Then, the statistical and instantaneous characteristics of the fluid field are analyzed, respectively. The dynamic vortex evolution process is presented by time–frequency domain analysis. Also, the phase relationship of pressure in shear layer is adopted to investigate the formation process of the shear layer mode. The results verify that the pressure fluctuation near the downstream corner is the sound source as the vortex impacts the wall periodically. The convection effect and disturbance intensity effect are separated for the first time through the control of the kinematic viscosity. The results show that the convection velocity influences the vortex shedding frequency (VSF) by changing the vortex moving speed. Also, changes in the disturbance intensity and branch length rectify the VSF by changing the phase relationship of impinging shear layer mode. Finally, a suppressing method of shifting the VSF is put forward by modifying the disturbance only.
Research on the hydrodynamic performance of double manta ray gliding in groups with variable attack angles
Authors: Gao Pengcheng , Huang Qiaogao , Pan Guang , Ma Yunlong , Song Dong
Published: October 2022

To investigate the effect of arrangement and attack angle on the hydrodynamic performance of double manta rays in group gliding, a manta ray model was first established based on the actual shape of manta rays, and then, numerical simulations were carried out with Fluent software to simulate the group gliding of double manta rays in three arrangements of tandem, parallel, and vertical with variable attack angle and variable spacing. Then, the average lift/drag of the group system and the lift/drag of each individual in the group were analyzed by combining with the flow field pressure cloud. From the drag performance, a systematic drag reduction was observed for the double manta rays in tandem and parallel group gliding; in vertical cluster gliding, with the change of attack angle, the individual in the group alternately gained drag reduction, but no systematic drag reduction was found. In terms of lift performance, the average system lift is basically the same as that received by the single body when gliding, regardless of the arrangement, and the difference in lift received by each individual in the group decreases with the increase in the arrangement spacing. This study provides useful results for the formation arrangement of group gliding with twin underwater vehicles.
Relativistic effects on electronic pair densities: A perspective from the radial intracule and extracule probability densities
Authors: Rodríguez-Mayorga M. , Keizer D. , Giesbertz K. J. H. , Visscher L.
Published: October 2022

While the effect of relativity in the electronic density has been widely studied, the effect on the pair probability, intracule, and extracule densities has not been studied before. Thus, in this work, we unveil new insights related to changes in the electronic structure caused by relativistic effects. Our numerical results suggest that the mean inter-electronic distance is reduced (mostly) due to scalar-relativistic effects. As a consequence, an increase in the electron–electron repulsion energy is observed. Preliminary results suggest that this observation is also valid when electronic correlation effects are considered.