bluuebunny/crossref_metadata_2025 huggingface dataset:
A computationally efficient discrete pseudomodulation algorithm for real-time magnetic resonance measurements
Authors: Manning Brian R. , Sharov Fedor V. , Lenahan Patrick M.
Published: January 2022

Rapid-scan electron paramagnetic resonance (RSEPR) results in a significant improvement in signal-to-noise over magnetic field modulated continuous wave EPR (CWEPR). However, the RSEPR raw absorption spectra can make the real-time comparison of CWEPR spectra difficult, especially in systems where the total number of paramagnetic spins is low. In this paper, we illustrate a method of applying pseudomodulation within RSEPR data collection software in real-time. Pseudomodulation is generally carried out in post-processing to increase signal-to-noise and simulate the effects of modulation on the spectra observed in traditional magnetic field modulated CWEPR. By applying the pseudomodulation method on a discrete computational basis, the technique can be utilized in parallel with data collection due to the significantly reduced computational power of the discretized pseudomodulation calculation. This allows for the live alteration of modulation parameters, such as the modulation amplitude and modulation harmonic. This real-time simulation allows for the comparison of the accumulated non-adiabatic rapid-sweep EPR spectra with the known CWEPR spectra available in the literature and has the ability to view smaller and less sensitive resonance features for various harmonics during high-frequency experiments while retaining all signal-to-noise improvements.
Thermal conductivity prediction of C/CaO packing bed with molecular dynamics corrected effective medium model
Authors: Lin Zizhen , Dang Hao
Published: January 2022

High-temperature driven solid–solid reaction at coke (C)/calcium oxide (CaO) interfaces is attractive for industrial-scale production of calcium carbide (CaC2). However, the reaction rate limited by the low thermal conductivity (k) results from a high Kapitza thermal resistance (Rk) at C/CaO interfaces. Identifying various factors including temperature and absorbed moisture on the k of C/CaO pellets is significant for heat transfer enhancement. Here, we developed a modified effective medium assumption model considering the particle-packed configuration to predict the influence of temperature and moisture on the k of C/CaO pellets, in which the Rk is evaluated by the non-equilibrium molecular dynamics. The results show that the k of C/CaO pellets increases from 0.48 to 0.55 W/(m K) when the temperature increases from 300 to 900 K, which is attributed to a 19.7% decrease in the Rk of C/CaO interfaces caused by a rising temperature activated inelastic interfacial phonon scattering. Moreover, it is found that the k of C/CaO pellets decreases from 0.48 to 0.44 W/(m K) after inserting absorption water layers with a thickness of 0.5 nm at C/CaO interfaces. A further 38.4% degeneration in k is harvested when increasing the thickness of the absorption water layers from 0.5 to 1.3 nm. This work provides an overall insight into the interfacial effect on the k of C/CaO porous pellets and guides the heat transfer optimization for particle-packed systems.
Effect of varying frequency of a synthetic jet on flow separation over an airfoil
Authors: Kim M. , Essel E. E. , Sullivan P. E.
Published: January 2022

An experimental investigation on the effects of the synthetic jet actuator (SJA) was conducted on a National Advisory Committee for Aeronautics 0025 airfoil in a low-speed recirculating wind tunnel at a chord Reynolds number of 100 000 and at an angle of attack 12°. Particle image velocimetry was used to visualize the flow separation for the uncontrolled baseline flow, and the flow attachment for the SJA controlled flows. The location of the SJA was at −1.3% from the separation point, and a blowing ratio of 0.8 was chosen for this study. The blowing ratio proved to be effective in suppressing the separation of the flow. The reduced frequency (Ste) was varied between 1, 2, 14, and 58. The momentum bursts from the SJA based on the reduced frequency determined the effectiveness of the control method. The Reynolds stresses and turbulence production decreased dramatically with increasing frequency up to the shear layer frequency (Ste= 14), but further excitation (Ste= 58) resulted in a regain of turbulence levels. Proper orthogonal decomposition was performed which showed that the low frequency operations globally affect the modes in the shear layer while the high frequency operations are confined to the airfoil surface.
Dust dynamics in the lunar dusty plasmas: Effects of magnetic fields and dust charge variations
Authors: Popel S. I. , Golub' A. P. , Kassem A. I. , Zelenyi L. M.
Published: January 2022

The influence of the magnetic field of the Earth's magnetotail on dusty plasmas above the sunlit surface of the Moon is studied. For this purpose, a physical-mathematical model for a self-consistent description of dust grains and photoelectrons in the presence of the magnetic field is developed. Trajectories of motion of dust grains above the lunar surface are considered. It is shown that a distinguishing feature of the trajectory of a dust grain motion is the presence of oscillations. The process of damping of these oscillations is demonstrated to be related to variations of dust grain charges that is consistent with the concept of anomalous dissipation in dusty plasmas. We clarify whether dust grains in dusty plasmas above the sunlit lunar surface are “levitated” or “lofted.” The processes of dust grain charge variations are too fast in comparison with the day duration of the Moon. In this connection, for the majority of dust grains above the sunlit lunar surface, the oscillations are damped, and these grains can be considered as levitated. Only very fine grains do not go into “levitating” grain mode during the entire day on the Moon and can be treated as lofted those. A theory of dusty plasmas above the sunlit surface of the Moon, which takes into account the lunar gravity and the electrostatic processes but does not take into account the magnetic fields, explains the existence of dusty plasmas only for rather high lunar latitudes. The magnetic fields of the Earth's magnetotail are shown to provide a possibility of dust transport above the lunar surface, which can result in the existence of positively charged dust and correspondingly dusty plasmas at the sunlit side of the Moon for the whole range of the lunar latitudes.
Effect of Gd-doping in Ni/NiO core/shell magnetic nanoparticles (MNPs) on structural, magnetic, and hydrogen evolution reaction
Authors: Adanur İdris , Karazehir Tolga , Doğru Mert Başak , Akyol Mustafa , Ekicibil Ahmet
Published: January 2022

In this study, Gdx-doped Ni/NiO MNPs (x: 0.0%, 2.5%, 5.0%, and 10.0%) with a protective polyvinylpyrrolidone (PVP) layer have been synthesized via a polyol reduction process. The x-ray diffraction patterns revealed that samples have a cubic structure with Fm3̄m space group and no change in the crystallite structure was observed with doping Gd3+ ions. The crystallite size (Dc) decreases from 2.70 to 1.27 nm when Gd is doped into Ni/NiO MNPs. Transmission electron microscopy analysis revealed that the Ni/NiO MNPs with Gd(5%) concentration are formed as spherical multicore-like shape core/shell MNPs with a protective PVP layer. The magnetic hysteresis measurements taken at 10 and 300 K show that the saturation magnetization (Ms) decreases with increasing Gd3+ ions in the structure. The highest effective magnetic moment (μeff) was obtained as 10.34 μB in the NG-2 sample. We ascribe that the high μeff value in this sample is due to the increase in d–f exchange interaction between Ni(3d7) and Gd(4f7) and the contribution of the dipole moment of PVP molecules. The electrochemical measurements showed that the current density values were 0.294 and 0.319 mA/cm2 at-1.3 V in the absence of Gd (NG-0) and Gd(5%) doped (NG-2) samples, respectively. βc was 159 and 132 mV/dec for NG-0 and NG-2 samples, respectively. The diminishing of βc and the charge resistance (Rct) proved that the Gd doped catalyst enhanced the hydrogen evolution activity and the Gd(5%) doped sample exhibited the highest catalyst performance.
Aeroacoustic interaction between owl-inspired trailing-edge fringes and leading-edge serrations
Authors: Rong Jiaxin , Liu Hao
Published: January 2022

The silent flight achieved by owls is attributed to their unique wing morphologies, characterized by leading-edge (LE) serrations, trailing-edge (TE) fringes, and a velvet-like surface. The specific morphological effects of LE serrations and TE fringes on aeroacoustic performance have been widely studied, but the LE–TE aeroacoustic interaction remains poorly understood. This paper describes a simulation-based study of the aeroacoustic characteristics of owl-inspired TE fringes and their interplay with LE serrations by combining large-eddy simulations of unsteady near-field flow structures with the Ffowcs Williams–Hawkings equation for sound radiation. Using owl-inspired LE serrated and TE fringed wing models, it is verified that TE fringes enable a pronounced high-frequency sound reduction at angles of attack (AoAs) of 5–15° while achieving comparable aerodynamic performance to a clean model. The near-field vortex dynamics, pressure distributions, and velocity spectra reveal that TE fringes suppress flow separation and vortex shedding in the vicinity of the TE, consequently reducing local velocity fluctuations and far-field overall sound pressure levels. Furthermore, the combination of TE fringes and LE serrations enables a remarkable reduction in overall sound pressure levels at all AoAs, and their aeroacoustic interplay is responsible for stabilizing velocity fluctuations over the suction surface, which suppress both low- and high-frequency sound. Our results demonstrate that TE fringes are a robust sound reduction device in resolving the trade-off between aerodynamic force production and sound reduction, while LE serrations and TE fringes complement one another as an effective noise-reducing biomimetic design.
Self-consistent construction of grand potential functional with hierarchical integral equations and its application to solvation thermodynamics
Authors: Yagi Tomoaki , Sato Hirofumi
Published: January 2022

The construction of the density functional for grand potential is fundamental in understanding a broad range of interesting physical phenomena, such as phase equilibrium, interfacial thermodynamics, and solvation. However, the knowledge of a general functional accurately describing the many-body correlation of molecules is far from complete. Here, we propose a self-consistent construction of the grand potential functional based on the weighted density approximation (WDA) utilizing hierarchical integral equations. Different from our previous study [T. Yagi and H. Sato, J. Chem. Phys. 154, 124113, (2021)], we apply the WDA to the excess Helmholtz free energy functional rather than the bridge functional. To assess the performance of the present functional, we apply it to the solvation thermodynamics of Lennard-Jones fluids. Compared to the modified Benedict–Webb–Rubin equation of state, the present functional qualitatively predicts the liquid–vapor equilibrium. The solvation free energy obtained from the present functional provides a much better agreement with the Monte Carlo simulation result than the hypernetted chain functionals. It constitutes a general starting point for a systematic improvement in the accuracy of the grand potential functional.
Experimental study of the semi-active mass damper under impulse excitation
Authors: Wang Xi , Wang Dida , Xu Zhenyuan , Wang Tao , Fu Guoqiang , Lu Caijiang
Published: January 2022

Mass dampers usually aim to control the steady state vibration of harmonic excitation, but few efforts have focused on suppressing the transient vibration caused by impulse excitation. To obtain the optimum tuning parameters of the semi-active tuned mass damper (TMD) under impulse, optimization analysis of the transient vibration response is carried out. The analytical solutions of transient response are obtained. The transient response of the primary system is attenuated effectively by optimizing three parameters of the TMD, namely, the stiffness, initial displacement, and initial velocity. Three experimental setups are built to achieve different values of the parameters to verify the simulation results. The stiffness of the TMD is modeled analytically and experimentally, and the vibration magnitude denotes that there are several fluctuations when the stiffness of the TMD changes. The results also show that initial displacement and initial velocity of the TMD can lead to different transient vibration magnitudes for the primary system. The optimum parameters of the semi-active TMD can be obtained by the proposed method, and the transient response can be controlled by optimizing the stiffness, initial displacement, and initial velocity of the TMD.
Intermolecular rovibrational states of the H2O–CO2 and D2O–CO2 van der Waals complexes
Authors: Felker Peter M. , Bačić Zlatko
Published: January 2022

We present quantum five-dimensional bound-state calculations of the fully coupled intermolecular rovibrational states of H2O–CO2 and D2O–CO2 van der Waals (vdW) complexes in the rigid-monomer approximation for the total angular momentum J values of 0, 1, and 2. A rigid-monomer version of the recent ab initio full-dimensional (12D) potential energy surface of H2O–CO2 [Q. Wang and J. M. Bowman, J. Chem. Phys. 147, 161714 (2017)] is employed. This treatment provides for the first time a rigorous and comprehensive description of the intermolecular rovibrational level structure of the two isotopologues that includes the internal-rotation tunneling splittings and their considerable sensitivity to rotational and intermolecular vibrational excitations, as well as the rotational constants of the two vdW complexes. Two approaches are used in the calculations, which differ in the definition of the dimer-fixed (DF) frame and the coordinates associated with them. We demonstrate that with the approach introduced in this work, where the DF frame is fixed to the CO2 moiety, highly accurate results are obtained using significantly smaller basis sets in comparison to those for the alternative approach. In addition, the resulting wavefunctions tend to lend themselves better to physical interpretation and assignment. The H2O–CO2 ground-state internal-rotation tunneling splittings, the rotational transition frequencies, and the rotational constants of both vdW complexes are in excellent agreement with the experimental results. The calculated intermolecular vibrational fundamentals agree well with the scant terahertz spectroscopy data for these complexes in cryogenic neon matrices.
Mass fish kills catalyse improved water and fisheries management
Authors: Boys Craig A. , Rayner Thomas S. , Mitrovic Simon M. , Doyle Katherine E. , Baumgartner Lee. J. , Koehn John D.
Published: January 2022

Mass fish kills capture the world’s attention and their frequency is increasing worldwide. The sudden death of many millions of native fish in the Darling–Baaka River in Australia in 2018–19 was a catalyst for the 11 articles in this special issue. Collectively, they advance our understanding of how to manage these events, dealing with: ecological impacts and recovery; technologies and approaches for prediction, preparedness and response; and the role of the public in preparing and responding to these catastrophic events.
ISM1 protects lung homeostasis via cell-surface GRP78-mediated alveolar macrophage apoptosis
Authors: Lam Terence Y. W. , Nguyen Ngan , Peh Hong Yong , Shanmugasundaram Mahalakshmi , Chandna Ritu , Tee Jong Huat , Ong Chee Bing , Hossain Md. Zakir , Venugopal Shruthi , Zhang Tianyi , Xu Simin , Qiu Tao , Kong Wan Ting , Chakarov Svetoslav , Srivastava Supriya , Liao Wupeng , Kim Jin-Soo , Teh Ming , Ginhoux Florent , Fred Wong W. S. , Ge Ruowen
Published: January 2022

Significance

Inflammation regulation and homeostasis maintenance is of paramount importance for lung health. Using both genetic and pathological mouse models, this work reveals that the secreted proapoptotic isthmin 1 (ISM1) protects lung homeostasis by controlling alveolar macrophage (AM) population and functional phenotype via cell-surface GRP78 (csGRP78)-mediated apoptosis. In both mouse and human, AMs express varied amount of csGRP78, enabling ISM1 to selectively remove the proinflammatory csGRP78
high
AMs via apoptosis. In cigarette smoke–induced chronic obstructive pulmonary disease (COPD) mice, pulmonary delivery of recombinant ISM1 (rISM1) suppressed lung inflammation, blocked emphysema development, and preserved lung function. This work reveals molecular insights for lung homeostasis regulation and offers a rationale to target csGRP78 with pulmonary-delivered rISM1 as a potential therapeutic strategy for COPD.
COVID-19 increased censorship circumvention and access to sensitive topics in China
Authors: Chang Keng-Chi , Hobbs William R. , Roberts Margaret E. , Steinert-Threlkeld Zachary C.
Published: January 2022

Significance

We study the impact of crisis on information seeking in authoritarian regimes. Using digital trace data from China during the COVID-19 crisis, we show that crisis motivates citizens to seek out crisis-related information, which subsequently exposes them to unrelated and potentially regime-damaging information. This gateway to both current and historically sensitive content is not found for individuals in countries without extensive online censorship. While information seeking increases during crisis under all forms of governance, the added gateway to previously unknown and sensitive content is disproportionate in authoritarian contexts.
Mechanistic differences between methanol and dimethyl ether in zeolite-catalyzed hydrocarbon synthesis
Authors: Kirchberger Felix M. , Liu Yue , Plessow Philipp N. , Tonigold Markus , Studt Felix , Sanchez-Sanchez Maricruz , Lercher Johannes A.
Published: January 2022

Significance

Methanol conversion to hydrocarbons has emerged as a key reaction for synthetic energy carriers and light alkenes. The autocatalytic nature and complex reaction network make a mechanistic understanding very challenging and widely debated. Water is not only part of the overall conversion, it is also frequently used as diluent, influencing, in turn, activity, selectivity, and stability of the catalysts. Water directly and indirectly influences the processes that initiate the C–C formation via adjusting the chemical potential of methanol and dimethyl ether, with the latter being more efficient to generate highly reactive C
1
species via hydride transfer. The insight shows paths to optimize the stability of catalysts and to tailor the product distribution for H-ZSM-5–based catalysts.
High-throughput selection of cells based on accumulated growth and division using PicoShell particles
Authors: van Zee Mark , de Rutte Joseph , Rumyan Rose , Williamson Cayden , Burnes Trevor , Radakovits Randor , Sonico Eugenio Andrew , Badih Sara , Lee Sohyung , Lee Dong-Hyun , Archang Maani , Di Carlo Dino
Published: January 2022

Production of high-energy lipids by microalgae may provide a sustainable energy source that can help tackle climate change. However, microalgae engineered to produce more lipids usually grow slowly, leading to reduced overall yields. Unfortunately, culture vessels used to select cells based on growth while maintaining high biomass production, such as well plates, water-in-oil droplet emulsions, and nanowell arrays, do not provide production-relevant environments that cells experience in scaled-up cultures (e.g., bioreactors or outdoor cultivation farms). As a result, strains that are developed in the laboratory may not exhibit the same beneficial phenotypic behavior when transferred to industrial production. Here, we introduce PicoShells, picoliter-scale porous hydrogel compartments, that enable >100,000 individual cells to be compartmentalized, cultured in production-relevant environments, and selected based on growth and bioproduct accumulation traits using standard flow cytometers. PicoShells consist of a hollow inner cavity where cells are encapsulated and a porous outer shell that allows for continuous solution exchange with the external environment. PicoShells allow for cell growth directly in culture environments, such as shaking flasks and bioreactors. We experimentally demonstrate that
Chlorella
sp.,
Saccharomyces cerevisiae
, and Chinese hamster ovary cells, used for bioproduction, grow to significantly larger colony sizes in PicoShells than in water-in-oil droplet emulsions (
P
< 0.05). We also demonstrate that PicoShells containing faster dividing and growing
Chlorella
clonal colonies can be selected using a fluorescence-activated cell sorter and regrown. Using the PicoShell process, we select a
Chlorella
population that accumulates chlorophyll 8% faster than does an unselected population after a single selection cycle.
Parkinson's disease protein PARK7 prevents metabolite and protein damage caused by a glycolytic metabolite
Authors: Heremans Isaac P. , Caligiore Francesco , Gerin Isabelle , Bury Marina , Lutz Marilena , Graff Julie , Stroobant Vincent , Vertommen Didier , Teleman Aurelio A. , Van Schaftingen Emile , Bommer Guido T.
Published: January 2022

Significance

Reactive compounds cause cellular damage that is suspected to contribute to aging and neurodegenerative diseases. Oxidative stress and environmental factors likely contribute to this. Here we report that an enzyme mutated in Parkinson’s disease can prevent damage of metabolites and proteins caused by a metabolite from the central pathway of sugar metabolism. Inactivation of this enzyme in model systems, ranging from flies to human cells, leads to the accumulation of a wide range of damaged metabolites and proteins. Thus, this enzyme represents a highly conserved strategy to prevent damage in cells that metabolize sugars. Overall, we discovered a fundamental link between carbohydrate metabolism and a type of cellular damage that might contribute to the development of Parkinson’s disease.
Multiple representations of the body schema for the same body part
Authors: Matsumiya Kazumichi
Published: January 2022

Significance

Accurate motor control depends on maps of the body in the brain, called the body schema. Disorders of the body schema cause motor deficits. Although we often execute actions with different motor systems such as the eye and hand, how the body schema operates during such actions is unknown. In this study, participants simultaneously directed eye and hand movements to the same body part. These two movements were found to be guided by different body maps. This finding demonstrates multiple motor system–specific representations of the body schema, suggesting that the choice of motor system toward one’s body can determine which of the brain’s body maps is observed. This may offer a new way to visualize patients’ body schema.
A multiscale biophysical model gives quantized metachronal waves in a lattice of beating cilia
Authors: Chakrabarti Brato , Fürthauer Sebastian , Shelley Michael J.
Published: January 2022

Significance

Understanding the emergence and properties of metachronal waves (MWs) in ciliary arrays is a multiscale problem central to developmental biology, transport phenomena, and nonequilibrium physics, and with potential biomedical applications. For 1D lattices of cilia, we report key mechanisms that lead to the robust emergence of MWs. Our modeling framework incorporates the full microscopic details of beating cilia. This helps us understand how ciliary bed morphology, beating patterns, and steric and hydrodynamic interactions work together to shape the emergent dynamics on 1D lattices. Due to the novelty of our modeling and computation, we have unraveled the spatiotemporal self-organization of nanometeric motor proteins in coordinating collective dynamics spanning millimeters: bridging length scales over six orders of magnitude.
Organic molecular dynamics and charge-carrier lifetime in lead iodide perovskite MAPbI
3
Authors: Koda Akihiro , Okabe Hirotaka , Hiraishi Masatoshi , Kadono Ryosuke , Dagnall Katelyn A. , Choi Joshua J. , Lee Seung-Hun
Published: January 2022

Significance

Hybrid organic–inorganic perovskites (HOIPs) are among the most promising materials for next-generation solar cells that combine high efficiency and low cost. The record efficiency of HOIP-based solar cells has reached above 25%, and they can be manufactured using simple solution-processing methods that can be drastically cheaper than the current commercial solar cell technologies. Despite the progress so far, the microscopic mechanism for the high solar cell efficiency in HOIPs is yet to be understood. In this study, we show that the ability of organic molecules to rotate on an appropriate time scale in HOIPs can extend the lifetime of photoexcited charge carriers and lead to higher efficiency. This insight can guide the progress toward improved solar cell performance.
Larger images are better remembered during naturalistic encoding
Authors: Masarwa Shaimaa , Kreichman Olga , Gilaie-Dotan Sharon
Published: January 2022

Significance

It is unclear what makes some of the numerous visual scenes we encounter every day memorable (while others are not) when we make no intentional effort to memorize them. Here, we reasoned that although visual perception is somewhat size invariant (e.g., we can recognize a person from multiple distances), visual memory would depend on image size. Across experiments, where participants freely viewed images without any memory- or nonmemory-related task (similar to naturalistic visual behavior), larger images were remembered better than smaller ones (about 1.5 times better), and this effect was proportional to image size. Our study indicates that physical stimulus dimensions (as the size of an image) influence memory, and this may have significant implications to learning, aging, development, etc.
Environmental factors affect the evolution of linguistic subgroups in Borneo
Authors: Smith Alexander D. , Rama Taraka
Published: January 2022

This study investigates the relatedness and history of the Austronesian languages of Borneo, which is the third largest island in the world and home to significant linguistic diversity. We apply Bayesian phylogenetic dating methods to lexical cognate data based on four historical calibration points to infer a dated phylogeny of 87 languages. The inferred tree topology agrees with the mid and lower-level subgrouping proposals based on the classical comparative method, but suggests a different higher-level organization. The root age of the dated tree is shallower than the archaeological estimates but agrees with a hypothesis of a past linguistic leveling event. The inferred homelands of the major linguistic subgroups from a Bayesian phylogeographic analysis agree with the homeland proposals from archaeology and linguistics. The inferred homelands for four of the eight subgroups support the riverine homeland hypothesis whereby the major linguistic subgroups developed initially in communities situated along Borneo’s major rivers.
Sous-titrage en B d’une série coréenne
Authors: Jeanmaire Guillaume , Kim Daeyoung
Published: January 2022

Cette étude a pour objectifs de montrer les mérites de la traduction télécollaborative en B en mode asynchrone.
Des apprenants français étudiant le coréen ont révisé les traductions de sous-titres, d’une série coréenne, réalisés par des
apprenants coréens de français. Les « réviseurs » français ont commenté en français et suggéré des modifications, partiellement
acceptées, sans pour autant travailler en mode TAV. Au-delà des compétences langagières et socioculturelles, cette collaboration
compétitive en ligne (deux équipes coréennes pour un même extrait) a permis à nos apprenants coréens d’expérimenter la plupart des
étapes afférentes à l’édition de sous-titres : traduction, révision, encodage, simulation, ajustements. Cette « collaboration »
franco-coréenne a procuré à chacun un sentiment d’accomplissement, partagé par l’enseignant. Pour que ce travail collaboratif
évolue vers une réelle « collaboration », il faudra désormais permettre l’implication des apprenants français jusqu’à l’édition
complète des sous-titres.
Weather expressions in Basque
Authors: Arteatx Iñigo , Artiagoitia Xabier
Published: January 2022

We make two claims regarding weather expressions in Basque: first, based onEriksen et al.’s (2010)typology, we show that Basque tends towards the argument type (and less frequently so to the predicate-argument type) when coding dynamic (precipitation or other) events and to both the argument and the predicate type when coding static events; Basque often has transitive structures (i.e. both transitive predicate and argument transitive types), apparently a rare typological feature. Second, with respect to two key issues in the study of weather predicates within Generative Grammar, we claim (a) that Basque supports the view that both lexicalizations of weather verbs (unaccusative and unergative/transitive) are possible across languages, as argued byBleotu (2015)andLevin & Krejci (2019); and (b) that the emptyprosubject of Basque transitive weather constructions is closer to a quasi-argument (Chomsky 1981;Levin & Krejci 2019) rather than to a true expletive.
Carleman estimates and the contraction principle for an inverse source problem for nonlinear hyperbolic equations
Authors: Nguyen Loc H , Klibanov Michael V
Published: January 2022

The main aim of this paper is to solve an inverse source problem for a general nonlinear hyperbolic equation. Combining the quasi-reversibility method and a suitable Carleman weight function, we define a map of which fixed point is the solution to the inverse problem. To find this fixed point, we define a recursive sequence with an arbitrary initial term by the same manner as in the classical proof of the contraction principle. Applying a Carleman estimate, we show that the sequence above converges to the desired solution with the exponential rate. Therefore, our new method can be considered as an analog of the contraction principle. We rigorously study the stability of our method with respect to noise. Numerical examples are presented.
Self-biased Metglas/PVDF/Ni magnetoelectric laminate for AC magnetic sensors with a wide frequency range
Authors: Yang Shuya , Xu Jie , Zhang Xuanning , Fan Shaoxiong , Zhang Chenyan , Huang Yicong , Li Qiang , Wang Xia , Cao Derang , Xu Jie , Li Shandong
Published: January 2022

In this work, an arc-shaped Metglas/polyvinylidene fluoride (PVDF)/Ni laminate is proposed, which exhibits a large self-biased magnetoelectric (ME) effect due to the internal magnetization gradient field between the two magnetic layers and the built-in stress formed from the arc-shaped structure. The ME coefficients reach 38.24 and 15.0 V cm−1 Oe−1 without a DC bias magnetic field at resonance and nonresonant frequencies, respectively. The sample shows a high sensitivity, resolution and linearity with values of 210.07 mV Oe−1, 1 nT and 0.9999 at the resonance frequency, respectively. The sample was then used to detect AC magnetic fields with different nonresonant frequencies (ranging from 1 to 25 kHz), resulting in the measured data being in good agreement with the actual data. Under a zero bias magnetic field and at frequencies of 40 and 1 Hz, the limit of detection can reach 2 and 8 nT, and the resolution can reach 1 and 4 nT, respectively. The results indicate that the arc-shaped Metglas/PVDF/Ni laminate shows a large self-biased ME effect and good AC magnetic sensing performance in the bending state, which provides a new way to develop a wide frequency range AC magnetic sensor.
Berry curvature induced anisotropic magnetotransport in a quadratic triple-component fermionic system
Authors: Pal Ojasvi , Dey Bashab , Ghosh Tarun Kanti
Published: January 2022

Triple-component fermions (TCFs) are pseudospin-1 quasiparticles hosted by certain three-band semimetals in the vicinity of their band-touching nodes (2019 Phys. Rev. B 100 235201). The excitations comprise of a flat band and two dispersive bands. The energies of the dispersive bands are

E

±

=
±

α

n

2

k

⊥

2
n

+

v

z

2

k

z

2

with

k

⊥

=

k

x

2

+

k

y

2

and n = 1, 2, 3. In this work, we obtain the exact expression of Berry curvature, approximate form of density of states and Fermi energy as a function of carrier density for any value of n. In particular, we study the Berry curvature induced electrical and thermal magnetotransport properties of quadratic (n = 2) TCFs using semiclassical Boltzmann transport formalism. Since the energy spectrum is anisotropic, we consider two orientations of magnetic field (B): (i) B applied in the x–y plane and (ii) B applied in the x–z plane. For both the orientations, the longitudinal and planar magnetoelectric/magnetothermal conductivities show the usual quadratic-B dependence and oscillatory behavior with respect to the angle between the applied electric field/temperature gradient and magnetic field as observed in other topological semimetals. However, the out-of-plane magnetoconductivity has an oscillatory dependence on angle between the applied fields for the second orientation but is angle-independent for the first one. We observe large differences in the magnitudes of transport coefficients for the two orientations at a given Fermi energy. A noteworthy feature of quadratic TCFs which is typically absent in conventional systems is that certain transport coefficients and their ratios are independent of Fermi energy within the low-energy model.
A simple and precise calibration method for binocular vision
Authors: Zimiao Zhang , Kai Xu , Yanan Wu , Shihai Zhang , Yang Qi
Published: January 2022

Binocular vision is an important part of machine vision measurement. Calibration accuracy is crucial for binocular vision. As for the determination of the structure parameters of the two cameras, the existing approaches usually obtain the initial values and optimize them according to the image-space errors, object-space errors or a combination of these. In the optimization process, constructing the objective function only through the image-space errors or object-space errors is not enough. Moreover, the image-space and object-space errors can form a variety of combinations to construct the objective function. Therefore, it is hard to choose the error criterion. An inadequate error criterion may lead to over-optimized or local minima (ambiguity solution). To solve this problem, this paper proposes a simple and precise calibration method for binocular vision based on the points distance constraints and image-space errors. The process of determining the structure parameters was divided into noniterative and iterative parts. We calculated the structure parameters of the two cameras according to the distance constraints of every two feature points noniteratively. The results obtained in this step were set as the initial value and refined through minimizing the reprojection errors using the Levenberg–Marquardt method. Because the results obtained in the noniterative step are accurate enough, only one iteration is needed. In this way, we finish the calibration avoiding the need to choose the error criterion. Furthermore, our method reduces the number of iterations to improve the calibration efficiency on the premise of guaranteeing the calibration accuracy. The experimental results show the superiority of this calibration method compared with other calibration methods. Using the calibration results of our method, in the measurement range of −45°∼ 45°, the rotation angle measurement error was less than ±0.032°. In the measurement range of 0 ∼ 39 mm, the displacement measurement error was less than ±0.047 mm. As for the length measurement of a 300 × 225 mm target, the length measurement error was less than ±0.039 mm.
Grouping sparse filtering: a novel down-sampling approach toward rotating machine intelligent diagnosis in 1D-convolutional neural networks
Authors: Wang Pengxin , Song Liuyang , Wang Huaqing , Han Changkun , Guo Xudong , Cui Lingli
Published: January 2022

Convolutional neural networks (CNNs) have weight-sharing and feature-learning abilities, and can efficiently and effectively be used for the health monitoring of industrial equipment. However, the pooling operation in a typical CNN can cause the loss of valuable impulse features during data down-sampling. We propose grouping sparse filtering (GSF) to overcome this problem. Instead of using a pooling operation, the GSF splits the channels of features obtained after convolution into equal-length groups. A feature selector with a feature aggregation function based on the channel importance factors and a lasso constraint is used to filter the groups to perform down-sampling. The GSF method preserves the impulse features due to the block sparsity of the vibration signal. Theoretical analysis demonstrates that the GSF has a similar computational complexity to using a pooling layer in a CNN for the same number of layers. Two experimental studies were conducted using data from a laboratory test and industrial environments. The experimental results show that the 1D-CNN with GSF provides better performance for retaining the impulse features of the rotating machinery signals and higher fault identification accuracy than a CNN with a pooling layer.
Nanostructured transition-metal phthalocyanine complexes for catalytic oxygen reduction reaction
Authors: Chen Siyu , Xu Zhanwei , Li Jiayin , Yang Jun , Shen Xuetao , Zhang Ziwei , Li Hongkui , Li Wenyang , Li Zhi
Published: January 2022

Oxygen reduction reaction (ORR) plays a key role in the field of fuel cells. Efficient electrocatalysts for the ORR are important for fuel cells commercialization. Pt and its alloys are main active materials for ORR. However, their high cost and susceptibility to time-dependent drift hinders their applicability. Satisfactory catalytic activity of nanostructured transition metal phthalocyanine complexes (MPc) in ORR through the occurrence of molecular catalysis on the surface of MPc indicates their potential as a replacement material for precious-metal catalysts. Problems of MPc are analyzed on the basis of chemical structure and microstructure characteristics used in oxygen reduction catalysis, and the strategy for controlling the structure of MPc is proposed to improve the catalytic performance of ORR in this review.
Advanced three-dimensional hierarchical porous α-MnO2 nanowires network toward enhanced supercapacitive performance
Authors: Su Xiaohui , Liang Zicong , He Qingqing , Guo Yanxin , Luo Gaodan , Han Shengbo , Yu Lin
Published: January 2022

Hierarchical α-MnO2 nanowires with oxygen vacancies grown on carbon fiber have been synthesized by a simple hydrothermal method with the assistance of Ti4+ ions. Ti4+ ions play an important role in controlling the morphology and crystalline structure of MnO2. The morphology and structure of the as-synthesized MnO2 could be tuned from δ-MnO2 nanosheets to hierarchical α-MnO2 nanowires with the help of Ti4+ ions. Based on its fascinating properties, such as many oxygen vacancies, high specific surface area and the interconnected porous structure, the α-MnO2 electrode delivers a high specific capacitance of 472 F g−1 at a current density of 1 A g−1 and the rate capability of 57.6% (from 1 to 16 A g−1). The assembled symmetric supercapacitor based on α-MnO2 electrode exhibits remarkable performance with a high energy density of 44.5 Wh kg−1 at a power density of 2.0 kW kg−1 and good cyclic stability (92.6% after 10 000 cycles). This work will provide a reference for exploring and designing high-performance MnO2 materials.
A mathematical model of cavitation behaviour in a single-ended magnetorheological damper: experimental validation
Authors: Kang Byung-Hyuk , Kim Bo-Gyu , Jung Dongsoo , Choi Seung-Bok
Published: January 2022

This paper proposes a mathematical model of the cavitation behavior to occur in a single-ended magnetorheological (MR) damper (MRD), and the effectiveness of the model is validated through the comparison with experimental results. Several causes of the cavitation behavior of MRD are discussed with different conditions of the initial pressure of the gas chamber and the piston stroke speed. The model to capture the cavitation behavior is then formulated considering differential equations for gas volume, internal pressure, ideal gas law, and bulk modulus of MR fluid. To calculate the flow rate, which is difficult to solve from the differential equations, the model is approximated as a nondimensional equation the parameters of the yield stress and pole length. Subsequently, the field-dependent damping force of MRD is computed using the gaseous cavitation model and nondimensional equation. To validate the proposed cavitation model, a single-ended MRD is designed, manufactured, and tested. It is observed that the damping force characteristics under cavitation are revealed to be much different from those under regular operation without cavitation. More specifically, it is hard to calculate the dissipation energy and hysteretic damping due to highly nonlinear characteristics with respect to the stroke and velocity. However, the proposed model can fairly capture the cavitation behavior showing an excellent agreement between simulation and experiment. In this work, to confirm the internal influence of MRD by cavitation, which is difficult to confirm experimentally, the changes of the pressure distribution and the gas-to-liquid volume ratio are analyzed through the simulation of the nondimensional equation. In addition, the bubbles representing the cavitation behavior are visually observed from the lower chamber of MRD.
Hypercritical Accretion for Black Hole High Spin in Cygnus X-1
Authors: Qin Ying , Shu Xinwen , Yi Shuangxi , Wang Yuan-Zhu
Published: January 2022

Recent observations of AdLIGO and Virgo have shown that the spin measurements in binary black hole (BH) systems are typically small, which is consistent with the predictions by the classical isolated binary evolution channel. In this standard formation channel, the progenitor of the first-born BH is assumed to have efficient angular momentum transport. The BH spins in high-mass X-ray binaries (HMXBs), however, have consistently been found to be extremely high. In order to explain the high BH spins, the inefficient angular momentum transport inside the BH progenitor is required. This requirement, however, is incompatible with the current understanding of conventional efficient angular momentum transport mechanism. We find that this tension can be highly alleviated as long as the hypercritical accretion is allowed. We show that, for a case study of Cygnus X-1, the hypercritical accretion cannot only be a good solution for the inconsistent assumption upon the angular momentum transport within massive stars, but match its other properties reported recently.
Estimation of rotor and main bearing loads using artificial neural networks
Authors: Loriemi A. , Jacobs G. , Bosse D.
Published: January 2022

Wind energy is one of the most important technologies for a climate-neutral energy supply. However, the premature failure of wind turbines due to unknown loads leads to a reduction in competitiveness compared to other energy sources. Here, load monitoring systems can make a significant contribution to the prevention of such failures. Most load monitoring systems for wind turbines focus on strain signals of structural components as the tower, main shaft or the rotor blade root. Based on these signals, axial forces, torsion or bending moments, which are acting on these components, are calculated. But this provides only partial information about the complete load situation, as transverse forces are not considered. Other methods use simulation or measurement data to train artificial neural networks (ANN) to estimate damage-equivalent loads acting on a wind turbine. However, this approach is accompanied by a loss of information, because the individual load components are condensed to an equivalent. In this work a method is presented that enables a measurement of rotor and main bearing loads considering all their individual load components. For this purpose, an ANN is trained with elastic multibody simulation (eMBS) data. Based on displacement signals, acting rotor and main bearing loads are estimated. The results show that even with consideration of nonlinearities, including nonlinear stiffness curves and bearing clearances, an appropriate accuracy can be achieved using the method presented.
The influence of atmospheric stability on wind turbine performance: a quantitative study using measurement from SCADA system and mast
Authors: Do Minh-Thang , Li Ru , Jiang Zixiao
Published: January 2022

In the wind resource assessment, to estimate the energy potential of a site, engineers use the manufacturer power curve. This power curve is an ideal relationship between the wind speed of an ideal wind flow and the output power of the designed turbine. The industry standard IEC 61400-12-1 establishes some requirements to measure such power curves. In the real condition, with the same value of wind speed, a large range of output power could be obtained. This difference may be caused by atmospheric stability, which affects wind profiles across the turbine blades. This study focuses on the influence of atmospheric stability on wind turbine performance in real condition. It is shown that the atmospheric stability calculated using the standard wind measurements from a conventional weather mast could be applied for every turbine in a medium size wind farm (33 wind turbines). This influence is very sensitive to the shape factor k of the wind speed distribution. The loss of AEP between neutral/stable conditions could be neglected while the loss of AEP between unstable/stable conditions is significant and depends on the average wind speed. In practice, it is possible to consider this influence during the wind resource assessment study while knowing the percentage of each atmospheric stability condition and the distribution of wind speed on the site.
Dynamic load balancing algorithm for continuum mechanics problems with essential redistribution of workloads among the processes
Authors: Karpeev Artem
Published: January 2022

A number of important applications have computational requirements that vary over time inan unpredictable way. For the effcient usage of distributed-memory parallel systems when solving such problems a new dynamic load balancing algorithm is suggested and explored. It allows to raise the load efficiency for model task up to 70% with balancing frequency v
bal ≈cnbv0:1.
Evaluation Method of Partial Discharge Evolution Degree of Cable Intermediate Joint
Authors: Ou Xiaomei , Li Guowei , Chen Jiayang , Liu Yijun , Zhang Yin , Liang Nianbai
Published: January 2022

The evolution process of partial discharges generated under typical air gap defects of 10kV XLPE cable intermediate joints was experimentally studied by the built experimental model. In the experimental process, five characteristic parameters representing the severity of partial discharge are extracted, and their change trends with time are analyzed, and the value ranges of various characteristic parameters are divided. Using BP neural network algorithm, the nonlinear relationship network between PD severity and multiple characteristic parameters is established, and the evaluation system of partial discharge severity of cable intermediate joint is constructed. Finally, the correctness and effectiveness of the method is verified by the example testing.