bluuebunny/crossref_metadata_2025 huggingface dataset:
A new numerical approach for efficient modeling of positive corona discharge and its associated electric wind
Authors: Yanallah K , Chelih A , Bouazza M R , Pontiga F , Bouadi M , Vázquez P A , Bendaoudi Z
Published: July 2023

Research on corona wind generation has been increasing in recent years because of its potential technological applications, particularly those related to improving heat transfer in small-scale devices. Since numerical simulations play a key role in the design of these applications, computationally efficient modeling of corona discharge is imperative. This work presents a new approach that allows rapid computation of the electrohydrodynamic (EHD) force density responsible for the generation of electric wind. Arbitrary electrode configurations can easily be dealt with in the model, since only the Laplacian electric field lines have to be determined numerically. Then, using approximated analytical approximations of the electric field intensity along the field lines, the spatial distribution of the current density and the space charge density can be easily determined. The model has been satisfactorily tested against experimental measurements of the current–voltage characteristic and the current density distribution on the cathode. Furthermore, the electric wind computed from the EHD force agrees quite satisfactorily with measurements carried out in different electrode configurations. Finally, the model has been applied to a new electrode configuration that has greater potential for heat transfer applications.
Multifunctional metamaterial for realizing absorption and polarization conversion on the basis of vanadium dioxide
Authors: Qiu Yu , Yan Dexian , Feng Qinyin , Li Xiangjun , Zhang Le , Li Jining
Published: July 2023

In this paper, the phase change material vanadium dioxide (VO2) is introduced to propose a tunable multifunctional metamaterial device, which treats the phase change property of VO2 to realize the switching of absorption, linear to linear (LTL) polarization conversion, and linear to circular (LTC) polarization conversion functions. When VO2 is in metal state, the structure can be applied as an absorber to achieve the wide-band and narrow-band absorption. In the broad frequency area of 2.007–2.803 THz, the absorption is above 90%. And the narrow-band absorption near the center frequency 1.0126 THz reaches 95.04%. When VO2 is in the insulator state, the studied device can be treated as a polarization conversion device to achieve LTL and LTC polarization conversion. In the low frequency range, the device achieves LTL with polarization conversion efficiency (PCR) above 90% when the frequency is between 0.439 and 0.907 THz. In the high frequency range, the structure can be treated as the LTC polarization converter to achieve right-hand circular polarization, left-hand circular polarization (LHCP), and LHCP in the ranges of 2.317–2.329 THz, 2.356–2.531 THz and 2.582–2.633 THz, respectively. In addition, the ellipticity is above 0.9. Finally, the effects of geometric parameters, angle of incidence and polarization angle on the absorption and PCR are also discussed. The proposed structure has great potential for advanced technologies such as imaging, sensing, communication, and stealth.
Low-frequency electrical response related to oxygen vacancies in Al3+ substituted M-type hexaferrite
Authors: Singh Hodam Karnajit , Mohapatra Prajna P , Dobbidi Pamu , Chittari Bheema Lingam
Published: July 2023

The presence of oxygen vacancies is unavoidable in many complex metal oxide materials such as hexaferrites. This article investigates the role of crystal defects, such as oxygen vacancies, and different oxidation states of Fe ions, on the electrical conduction behaviors of Al3+ substituted Ba0.4La0.1Sr0.5Al
x
Fe12−x
O19 hexaferrites by analyzing the temperature dependent AC impedance and AC conductivity. The optimal substitution of La3+ ions and high-temperature sintering is responsible for forming oxygen vacancies while reducing Fe from Fe3+ to Fe2+ cations, as observed in structural and XPS analysis, which affects electrical conduction behaviors. The departure from ideal Debye-type relaxation behavior is also one of the effects of crystal defects. Temperature variation of relaxation time shows a sharp change at around 403 K. This may be due to different electrical entities influencing the mode of electron hopping with temperature. The activation energy calculated from the temperature dependent relaxation time confirmed the presence of electron hopping through the bridging effects of the first ionization of oxygen vacancies Fe2+–

V

o

⋅

–Fe3+ below a temperature of 403 K. Above 403 K, electron hopping through different oxidation states of Fe3+ + e− → Fe2+ and migration of oxygen vacancies toward the bulk surface are responsible for the conduction mechanism. The DC resistivity and AC conductivity show that the bridging effects of oxygen defects can also induce Coulomb interaction between the defect sites resulting in Efros–Shklovskii variable range hopping and correlation barrier hopping below 403 K. Above 403 K, polaron-assisted electron hopping is more desirable, as confirmed by the non-overlapping small polaron tunneling model.
Active topological defect absorption by a curvature singularity
Authors: Vafa Farzan , Nelson David R , Doostmohammadi Amin
Published: July 2023

We leverage the Born–Oppenheimer approximation to present a general description of topological defects dynamics inp-atic materials on curved surfaces. Focusing on the case of an active nematic, we find that activity induces a geometric contribution to the motility of the+1/2defect. Moreover, in the case of a cone, the simplest example of a geometry with curvature singularity, we find that the motility depends on the deficit angle of the cone and changes sign when the deficit angle is greater thanπ, leading to the change in active behavior from contractile (extensile) to extensile (contractile) behavior. Using our analytical framework, we then identify for positively charged defects the basin of attraction to the cone apex and present closed-form predictions for defect trajectories near the apex. The analytical results are quantitatively corroborated against full numerical simulations, with excellent agreement when the capture radius is small compared to the cone size.
Field-free spin-orbit torque switching in interlayer exchange coupled Co/Ta/CoTb
Authors: Wu Chuangwen , Zhou Xiangqing , Zeng Guang , Sun Chen , Li Peizhi , Li Jiaxu , Chen Shiwei , Yang Guang , Liang Shiheng
Published: July 2023

This study investigates a T-type field-free spin-orbit torque device with an in-plane magnetic layer coupled to a perpendicular magnetic layer via a non-magnetic spacer. The device utilizes a Co/Ta/CoTb structure, in which the in-plane Co layer and the perpendicular CoTb layer are ferromagnetically (FM) coupled through the Ta spacer. ‘T-type’ refers to the magnetization arrangement in the FM/spacer/FIM structure, where the magnetization in FM is in-plane, while in FIM, it is out-of-plane. This configuration forms a T-shaped arrangement for the magnetization of the two magnetic layers. Additionally, ‘interlayer exchange coupling (IEC)’ denotes the interaction between the two magnetic layers, which is achieved by adjusting the material and thickness of the spacer. Our results show that an in-plane effective field from the IEC enables deterministic current-induced magnetization switching of the CoTb layer. The field-driven and the current-driven asymmetric domain wall motion are observed and characterized by magneto-optic Kerr effect measurements. The functionality of multistate synaptic plasticity is demonstrated by understanding the relationship between the anomalous Hall resistance and the applied current pulses, indicating the potential for the device in spintronic memory and neuromorphic computing.
GEMIMEG-II — How metrology can go digital
...
Authors: Engel Thomas
Published: July 2023

The GEMIMEG-II project is intended to pave the way for digitalization in metrology. The central element of this digitalization initiative is the digital calibration certificate (DCC). It contains all calibration information in full digital form. This means, that it is machine readable and machine understandable without human interaction. This enables its utilization by being securely machine interpretable and machine actionable in the entire chain of truly digital workflows and information technology (IT) environments in Industry 4.0. Therefore, the DCC is created automatically in the calibration process in a standardized form based on a digital document schema. This systematic schema enables to safely transfer, process, and interpret all data in the DCC automatically in all subsequent IT based processes. This paper reflects the project status of GEMIMEG-II in its final phase and shares some insights on the concepts developed and solutions implemented as the results will be demonstrated in five Realbeds. Furthermore, the concept of quality of sensing and quality of data will be introduced as it is implemented in the GEMIMEG-II project to convey supplementary information on the measurement, environmental and/or surrounding modalities, and data quality. Finally, a brief outlook will be given on next steps and actions planned in the project related to other digitalization initiatives for the fab of the future.
In situ fabrication of Cu–Mn–O nanostructure catalysts on Ti mesh and their catalytic property optimization for low-temperature and stable CO oxidation
Authors: Zhang Ruishi , Zhou Yang , Li Yunheng , Li Jing , Tang Xinyue , Liu Baodan
Published: July 2023

A series of interlaced ‘tripe-shaped’ nanoflake catalysts made of CuMn2O4 were in situ prepared on Ti mesh substrate through the associated methods of plasma electrolyte oxidation and hydrothermal technique. The surface morphology, elemental distribution and chemical state, phase composition and microstructure of CuMn2O4 nanostructures prepared under different conditions were systemically investigated. To evaluate the catalytic activity, the CO oxidation as a probe reaction was used, and the results showed that 12h-Cu1Mn2-300 (hydrothermal reaction at 150 °C for 12 h, Cu/Mn = 1/2 in initial precursor, heat treatment temperature at 300 °C) exhibited the best CO oxidation capability with T
100 = 150 °C owe to the formation of uniform CuMn2O4 nanosheet layers in situ grown on flexible Ti mesh and the synergistic effect of Cu and Mn species in spinel CuMn2O4, which makes it more active towards CO oxidation than pure copper/manganese oxides.
Colourful phase change material-incorporated flexible film for efficient passive radiative cooling
Authors: Zhang Yuruo , Liu Xianghui , Li Zhenyang , Xie Wei , Lou Xing , Fan Yile , Cao Kangli , Liu Gang , Kondo Hiroki , Zhou Han
Published: July 2023

Passive radiative cooling involves the emission of thermal radiation into cold space and the reflection of solar radiation, which aims to cool and lower the temperature of objects. However, currently most radiative coolers have a white appearance which restricts their potential applications. We develop a coloured bilayer radiative cooling membrane using polyvinylidene fluoride/tetraethoxysilane (PVDF/TEOS) fibres, with incorporation of phase change materials (PCMs) and active dyes through a simple and large-area electrospinning process. In comparison to traditional emitters, PCM-incorporated colourful coolers provide energy storage capacity and colourful appearances. Our phase-transition-based colourful flexible film (PCFF) achieves a total solar reflectance of 0.81 and a mid-infrared (8–13 μm) emissivity of 0.85 with superior mechanical strength and good hydrophobicity. We experimentally demonstrate that our PCFF can significantly reduce the temperature of objects exposed to direct sunlight, with a cooling effect of up to 9 °C compared to commercial fabrics of similar materials and colours. Our work provides a promising starting point for the design and manufacture of colourful and flexible thermal control films.
A simple stellar magnitude scale demonstration
Authors: Kaltcheva Nadia , Berry Peter
Published: July 2023

The stellar magnitude scale is grounded in the human perception of starlight and is one of the basic concepts in astronomy. However, its introduction is not easy to incorporate in the classroom. We propose a simple demonstration related to the observational aspect of the stellar magnitude scale.
Pulmonary nodules segmentation based on domain adaptation
Authors: Sui Guozheng , Zhang Zaixian , Liu Shunli , Chen Shuang , Liu Xuefeng
Published: July 2023

With the development of deep learning, the methods based on transfer learning have promoted the progress of medical image segmentation. However, the domain shift and complex background information of medical images limit the further improvement of the segmentation accuracy. Domain adaptation can compensate for the sample shortage by learning important information from a similar source dataset. Therefore, a segmentation method based on adversarial domain adaptation with background mask (ADAB) is proposed in this paper. Firstly, two ADAB networks are built for the source and target data segmentation, respectively. Next, to extract the foreground features that are the input of the discriminators, the background masks are generated according to the region growth algorithm. Then, to update the parameters in the target network without being affected by the conflict between the distinguishing differences of the discriminator and the domain shift reduction of the adversarial domain adaptation, a gradient reversal layer propagation is embedded in the ADAB model for the target data. Finally, an enhanced boundaries loss is deduced to make the target network sensitive to the edge of the area to be segmented. The performance of the proposed method is evaluated in the segmentation of pulmonary nodules in computed tomography images. Experimental results show that the proposed approach has a potential prospect in medical image processing.
VAEs with structured image covariance applied to compressed sensing MRI
Authors: Duff M A G , Simpson I J A , Ehrhardt M J , Campbell N D F
Published: July 2023

Objective.This paper investigates how generative models, trained on ground-truth images, can be used as priors for inverse problems, penalizing reconstructions far from images the generator can produce. The aim is that learned regularization will provide complex data-driven priors to inverse problems while still retaining the control and insight of a variational regularization method. Moreover, unsupervised learning, without paired training data, allows the learned regularizer to remain flexible to changes in the forward problem such as noise level, sampling pattern or coil sensitivities in MRI. Approach. We utilize variational autoencoders that generate not only an image but also a covariance uncertainty matrix for each image. The covariance can model changing uncertainty dependencies caused by structure in the image, such as edges or objects, and provides a new distance metric from the manifold of learned images. Main results. We evaluate these novel generative regularizers on retrospectively sub-sampled real-valued MRI measurements from the fastMRI dataset. We compare our proposed learned regularization against other unlearned regularization approaches and unsupervised and supervised deep learning methods. Significance. Our results show that the proposed method is competitive with other state-of-the-art methods and behaves consistently with changing sampling patterns and noise levels.
The truth Hertz—synchronization of electroencephalogram signals with physiological waveforms recorded in an intensive care unit
Authors: Goodwin Andrew J , Dixon William , Mazwi Mjaye , Hahn Cecil D , Meir Tomer , Goodfellow Sebastian D , Kazazian Vanna , Greer Robert W , McEwan Alistair , Laussen Peter C , Eytan Danny
Published: July 2023

Objective. The ability to synchronize continuous electroencephalogram (cEEG) signals with physiological waveforms such as electrocardiogram (ECG), invasive pressures, photoplethysmography and other signals can provide meaningful insights regarding coupling between brain activity and other physiological subsystems. Aligning these datasets is a particularly challenging problem because device clocks handle time differently and synchronization protocols may be undocumented or proprietary. Approach. We used an ensemble-based model to detect the timestamps of heartbeat artefacts from ECG waveforms recorded from inpatient bedside monitors and from cEEG signals acquired using a different device. Vectors of inter-beat intervals were matched between both datasets and robust linear regression was applied to measure the relative time offset between the two datasets as a function of time. Main Results. The timing error between the two unsynchronized datasets ranged between −84 s and +33 s (mean 0.77 s, median 4.31 s, IQR25-4.79 s, IQR75 11.38s). Application of our method improved the relative alignment to within ± 5ms for more than 61% of the dataset. The mean clock drift between the two datasets was 418.3 parts per million (ppm) (median 414.6 ppm, IQR25 411.0 ppm, IQR75 425.6 ppm). A signal quality index was generated that described the quality of alignment for each cEEG study as a function of time. Significance. We developed and tested a method to retrospectively time-align two clinical waveform datasets acquired from different devices using a common signal. The method was applied to 33,911h of signals collected in a paediatric critical care unit over six years, demonstrating that the method can be applied to long-term recordings collected under clinical conditions. The method can account for unknown clock drift rates and the presence of discontinuities caused by clock resynchronization events.
Density limits as disruption forecasters for spherical tokamaks
Authors: Berkery J W , Sabbagh S A , Ham C J , Zamkovska V , Butt J , Riquezes J , Tobin M , Henderson S , Kogan L , Patel B S , Scannell R , Trier E , LeBlanc B
Published: July 2023

Fusion power output from spherical tokamaks would benefit from increased confined plasma density, but there exists a limit on the density before confinement is lost and the plasma current is disrupted. This density limit has long been characterized by a simple, global Greenwald limit proportional to the plasma current and inversely proportional to the cross sectional area of the plasma. It is shown that in the database of discharges from the National Spherical Tokamak Experiment (NSTX) and Mega Ampere Spherical Tokamak (MAST) spherical tokamaks, the likelihood of disruption does increase above the Greenwald limit, and especially in the plasma current rampdown phase. The physics of the density limit has been recently theoretically explored through local criteria. Several of these are tested using the disruption event characterization and forecasting (DECAFTM) code for their potential effectiveness as disruption warning signals. For a limited set of NSTX discharges, a local island power balance criteria was found to be less reliable, presently, than the Greenwald limit. An empirical critical edge line density and a boundary turbulent transport limit were both tested for MAST-U, which has an electron density profile measurement with high spatial resolution in the outer part of the plasma. Both were found to have similar dependencies on key plasma parameters. In a limited set of MAST-U discharges that appear to disrupt due to rising density at values under the Greenwald limit, crossing of the boundary turbulent transport limit occurred close to the time of disruption. Finally, these limits were evaluated for their potential use in real-time, and it was found that with the necessary real-time inputs and with refinement through further testing, these limits could be implemented in a real-time disruption forecasting system.
Bioinspired design of stimuli-responsive artificial muscles with multiple actuation modes
Authors: Yang Huxiao , Zhang Chao , Chen Baihong , Wang Zhijian , Xu Yan , Xiao Rui
Published: July 2023

Artificial muscles that can reproduce the functions and biomimetic motions of natural muscles are widely used to construct soft robots with applications in various fields. However, it is still challenging to develop stimuli-responsive artificial muscles with multiple-mode actuation. Inspired by the forearm muscles, we propose a new type of stimuli-responsive artificial muscles with multiple-mode actuation using liquid crystal elastomers (LCEs), named FILAMs (forearm muscle-inspired LCE-based artificial muscles). The proposed FILAMs consist of active LCE driving units, a passive silicone rubber flexible skeleton and two quick connectors. By selectively actuating different types of LCE driving units, the FILAMs can achieve multiple-mode actuation, such as twisting, bending, combined twisting and bending. We introduce prototypical designs for the FILAMs and demonstrate that they can be used as ‘building blocks’ to reconfigure different soft robots. Three kinds of soft robots are constructed to show extensive applications through the cooperation of a combination FILAMs, i.e. a soft assembly robot, a soft crawling robot, and a soft flexible wrist.
Research on hierarchical cylindrical negative stiffness structures’ energy absorption characteristics
Authors: Liu Xin , Tan Xiaojun , Wang Bing , Chen Shuai , Wang Lianchao , Zhu Shaowei
Published: July 2023

Abstract

Negative stiffness (NS) structures possess distinctive mechanical properties and exhibit promising potential for diverse applications. In this paper, we presented an innovative hierarchical design to further enhance the capabilities of NS structures. The dynamic and static performance of the normal and hierarchical cylindrical NS structures were investigated and compared with experiments and numerical simulation. The results demonstrated that the hierarchical structures displayed superior cushioning performance relative to the traditional one. The presented approach offers a novel method to enhance cylindrical NS structures and serves as a valuable reference for future research in this field.
Mean-field dynamics of open quantum systems with collective operator-valued rates: validity and application
Authors: Fiorelli Eliana , Müller Markus , Lesanovsky Igor , Carollo Federico
Published: July 2023

We consider a class of open quantum many-body Lindblad dynamics characterized by an all-to-all coupling Hamiltonian and by dissipation featuring collective ‘state-dependent’ rates. The latter encodes local incoherent transitions that depend on average properties of the system. This type of open quantum dynamics can be seen as a generalization of classical (mean-field) stochastic Markov dynamics, in which transitions depend on the instantaneous configuration of the system, to the quantum domain. We study the time evolution in the limit of infinitely large systems, and we demonstrate the exactness of the mean-field equations for the dynamics of average operators. We further derive the effective dynamical generator governing the time evolution of (quasi-) local operators. Our results allow for a rigorous and systematic investigation of the impact of quantum effects on paradigmatic classical models, such as quantum generalized Hopfield associative memories or (mean-field) kinetically-constrained models.
Multi-mode resonance plasmonic solar absorber based on pyramid multiary-grating
Authors: Meng Qiqi , Chen Fang , Cheng Shubo , Yang Wenxing , Wang Boyun , Yi Zao
Published: July 2023

In the manuscript, a broad-band perfect absorber based on multilayer-grating and MDM film structure is proposed and numerically studied. Finite difference time domain (FDTD) simulations indicate the absorption performances are originated from Fabry–Perot (FP) resonance effect, localized, and propagating surface plasmons (LSPs and PSPs) effect. The designed absorber possesses over 95% absorption from 697 nm to 2906 nm, and an average absorption of 98.7% is achieved with TM-polarized. For TM-polarized, the designed absorber possesses over 95% between 534 nm and 2475 nm when the oblique-angle is up to 45°, while for a TE-polarized light, the corresponding average absorption remains 80.48% when the oblique-angle is up to 30°. The average absorption is larger than 94% in different environment refractive indexes (1 < RI < 1.5), which illustrates the designed absorber possesses excellent environment RI stability. Another absorber with triple layer grating of different sizes is also designed, and the absorber has more than 95% absorption between 400 nm and 2376 nm, based on the high absorption and waveband, the absorber can find potential applications in solar energy capture. It is believed the proposed work can be applied in plasmonic solar absorber design, thermal emitter, and plasmonic imaging.
The anapole state excited by an oblique incidence
Authors: Tian Shuo , Wang Junqiao , Sun Shuai , He Mengyue , Mao Yu , Ding Pei
Published: July 2023

Anapole states supported by high-refractive-index dielectric nanoparticles have mostly been studied under normal incidence, but this work explores the oblique incidence excitation. For a single silicon nanodisk, as the incident angle (θ) increases, the anapole wavelength undergoes a gradual blueshift, while the wavelength of maximum near-field enhancement remains almost unchanged with increasing E-field enhancement factor (|E/E

0
|) due to phase retardation effect caused by oblique incidence, and some unique features in field distributions differed from normal excitation are exhibited. In the case of a silicon nanodisk array, the anapole state and near-field enhancement are affected by near-field coupling and the phase retardation effect is weakened. With increasing θ, the coupling between the units is enhanced, and the anapole wavelength and maximum field enhancement wavelength both blue shift. The field distributions in anapole wavelength and maximum enhancement wavelength have obvious near-field coupling characteristics. Oblique incident excitation gives us a deeper understanding of anapole state and may have potential applications in nanophotonics.
Random semi-horseshoe for partially hyperbolic systems driven by an external force
Authors: Huang Wen , Liu Xue , Ma Xiao
Published: July 2023

In this paper, we consider the symbolic representation of systems driven by an invertible measurable mapping on a measurable space. We prove that when such a system possesses an equicontinuous uniformly expanding subbundle, then it has a subsystem of its iterations randomly semi-conjugating to the full shift on two symbols. Examples such as random perturbation of partially hyperbolic systems, random composition of partially hyperbolic automorphisms on 3-d tori with a fixed central direction, and fiber partially hyperbolic maps on 3-d tori without stable subbundles are under consideration.
Evaluation of forming limit diagram and bending stiffness of SS316L/polyurethane/SS316L sandwich sheets
Authors: Kamali Andani Mehran , Manesh Habib Danesh , Jahromi Seyed Ahmad Jenabali
Published: July 2023

In this study, SS316L/polyurethane/SS316L was produced by warm roll bonding and direct adhesion without using any adhesive. By changing the polymer core thickness in the sandwich sheet, its mechanical properties, such as tensile behavior and flexural bending strength, were investigated. Also, by performing the Erichsen test and getting the experimental forming limit diagram, the forming behavior of the sandwich sheets in various thicknesses was investigated and compared with that of the monolithic steel sheet. The experimental results showed that by increasing the thickness of the sandwich sheets with polymeric core thickness of 2 mm to 2.5 and 3 mm, the bending stiffness was raised by 111% and 288%; also, the displacement in the second region of the bending test diagram, indicating the bending ability without delamination, was increased from 100% to 109%. Forming limit diagrams of the sandwich sheets were higher than those of the steel sheet, which indicates that the forming behavior of them are higher than that of the monolithic steel sheet.
Tunable topological states in antiferromagnetic MnSb4Se7 material
Authors: Huang Lu , Guo Wen-Ti , Ye Jiefeng , Liu Rui-Qi , Zhang Jian-Min
Published: July 2023

Magnetic topological insulators (MTIs) of the MnBi2xTe3x+1 family, discovered in recent years, have been successfully used to explore various emerging physical phenomena. In this work, the electronic structure and topological properties of the bulk structured antiferromagnetic (AFM) topological insulator (TI) MnSb4Se7 under spin–orbit coupling (SOC) are investigated based on the first-principle calculations. Our results show that the AFM MnSb4Se7 is a non-trivial TI. And applying strain to the AFM MnSb4Se7 can close the band gap. Furthermore, with increasing tensile and compressive strains, AFM MnSb4Se7 undergoes a topological phase transition from a non-trivial TI to a trivial insulator. With increasing strain further, the system undergoes an insulator-metal phase transition. These results suggest that the AFM MnSb4Se7 material has tunable topological properties and is a candidate for exploring interesting topological quantum states and that our work also provides effective help for experimental modulation.
Renormalization formalism for superconducting phase transition with inner-Cooper-pair dynamics
Authors: Su Yuehua , Wu Hongyun , Cao Kun , Zhang Chao
Published: July 2023

As charge carrier of the macroscopic superconductivity, the Cooper pair is a composite particle of two paired electrons, which has both center-of-mass and inner-pair degrees of freedom. In most cases, these two different degrees of freedom can be well described by the macroscopic Ginzburg-Landau theory and the microscopic Bardeen-Cooper-Schrieffer (BCS) theory, respectively. Near the superconducting phase transition where the Cooper pair is fragile and unstable because of the small binding energy, there are non-trivial couplings between these two different degrees of freedom due to such as finite energy and/or momentum transfer. The non-trivial couplings make the original derivation of the Ginzburg-Landau theory from the BCS theory fail in principle as where these two different degrees of freedom should not be decoupled. In this article, we will present a renormalization formalism for an extended Ginzburg-Landau action for the superconducting phase transition where there is finite energy transfer between the center-of-mass and the inner-pair degrees of freedom of Cooper pairs. This renormalization formalism will provide a theoretical tool to study the unusual dynamical effects of the inner-pair time-retarded physics on the superconducting phase transition.
Viable vector coherent oscillation dark matter
Authors: Kitajima Naoya , Nakayama Kazunori
Published: July 2023

We construct a viable model of the vector coherent oscillation dark matter. The vector boson is coupled to the inflaton through the kinetic function so that the effective Hubble mass term is cancelled out. In order to avoid strong constraints from isocurvature perturbation and statistically anisotropic curvature perturbation, the inflaton is arranged so that it does not contribute to the observed large scale curvature perturbation and we introduce a curvaton. We found viable vector coherent oscillation dark matter scenario for the wide vector mass range from 10-21 eV to 1 eV.
Self-interactions of ULDM to the rescue?
Authors: Dave Bihag , Goswami Gaurav
Published: July 2023

One of the most important unanswered questions in cosmology is concerning the fundamental nature of dark matter (DM). DM could consist of spinless particles of very small mass i.e.m∼ 10-22eV. This kind of ultralight dark matter (ULDM) would form cored density profiles (called “solitons”) at the centres of galaxies. In this context, recently it has been argued that (a) there exists a power law relation between the mass of the soliton and mass of the surrounding halo called the Soliton-Halo (SH) relation, and, (b) the requirement of satisfying observed galactic rotation curves as well as SH relations is so stringent that ULDM is disfavoured from comprising 100% of the total cosmological dark matter. In this work, we revisit these constraints for ULDM particles with non-negligible quartic self-interactions. Using a recently obtained soliton-halo relation which takes into account the effect of self-interactions, we present evidence which suggests that, form∼ 10-22eV, the requirement of satisfying both galactic rotation curves as well as SH relations can be fulfilled with repulsive self-couplingλ∼ 𝒪(10-90).
Photometric Observations of Flares on AD Leo from GWAC-F30 and TESS
Authors: Bai Jian-Ying , Wang J. , Li H. L. , Xin L. P. , Li G. W. , Yang Y. G. , Wei J. Y.
Published: July 2023

We observed active M dwarf star AD Leo for 146 hr in photometry by GWAC-F30 and also analyzed 528 hr of photometric data of the star from the Transiting Exoplanet Survey Satellite (TESS). A total of 9 and 70 flares are detected from GWAC-F30 and TESS, respectively. Flare durations, amplitudes and energies are calculated. The distributions of the three properties and flare frequency distributions (FFDs) are given. Within the same energy range of flares, the FFDs of AD Leo obtained in this research and the previous study are basically consistent, which suggests that the magnetic activity of this star has not significantly changed compared to decades ago. Comparing with the average FFD of M-type stars, AD Leo’s FFD is twice higher, indicating that its magnetic activity is more active than that of the average level of the M-type. Based on the TESS light curve, AD Leo’s rotation period is calculated as

2.21

−
0.01

+
0.01

days, supporting the result given in previous research. During the decay phase of the most energetic flare from TESS, we identified quasi-periodic pulsations and determined a 26.5 minute oscillation period, which is currently the longest period for AD Leo, suggesting that long periodic physical processes existed during the flare of this star.
Noise-like pulses in dispersion-controlled fiber lasers
Authors: K Komarov Andrey , M Kobtsev Sergey
Published: July 2023

Noise-like pulse generation in ring lasers in which the anomalous dispersion of the cavity fiber is partially compensated by using a normal-dispersion fiber has been studied by numerical simulation. Solitons moving in this cavity are periodically subjected to temporal compression in the anomalous-dispersion fiber and expansion in the normal-dispersion fiber. It has been found that in these lasers, stationary solitons become unstable and passive mode locking occurs through the emission of bunched noise-like pulses consisting of chaotically evolving solitons. The results are relevant to the development of noise-like pulse generation and methods for controlling lasing regimes.
High rejection stacked single-layer graphene membranes for water treatment
Authors: Laurenti Marco , Fontana Marco , Raffone Federico , Pellegrino Alberta , Bianco Stefano , Tresso Elena , Pirri Candido F , Cicero Giancarlo
Published: July 2023

Nowadays, the production of pure water from saltwater and wastewater is one of the most challenging issues. Polymeric materials represent, at the moment, the best solution for membranes technology but new materials with improved functionalities are desirable to overcome the typical limitations of polymers. In this work, graphene membranes with superior filtration properties are fabricated by stacking up to three graphene layers on a porous support and exploiting the intrinsic nanopores of graphene to filter diclofenac (drug), and methylene blue (dye). The rejection improves increasing the number of the stacked graphene layers, with the best results obtained with three graphene layers. Mass diffusion properties depend on the size of the probe molecule, consistently with the existence of intrinsic nanometer-sized pores within graphene. From the results of an in depth transmission electron microscopy analysis and molecular dynamics simulations it is inferred that graphene stacking results in a decrease of effective membrane pore sizes to about 13 Å diameter which corresponds to 97% rejection for diclofenac and methylene blue after one hour filtration.
Effects of Mn addition on mechanical properties, fracture surface, and electrochemical corrosion resistance of CoCrFeNiAl high-entropy alloys
Authors: Shi Shih-Chen , Liu Chi-Fan , Fang Tzu-Tung , Chen Tao-Hsing
Published: July 2023

High-entropy alloys consisting of CoCrFeNiAl as the major elements and 2–5 at% Mn as the minor element were prepared using a vacuum arc melting method. The crystalline structures of the prepared alloys were identified by x-ray diffraction. Moreover, the mechanical properties of the alloys were examined under quasi-static (10−1, 10−2 and 10−3 s−1) and dynamic (3000, 4000, and 5000 s−1) loading conditions using a universal testing machine and split-Hopkinson pressure bar system, respectively. The experimental results showed that, for all of the HEA alloys, the flow stress and strain rate sensitivity coefficient increased with increasing strain rate. Among all the alloys, that with 3 at% Mn exhibited the best mechanical properties. A significant loss in plasticity was observed as the Mn content increased to 5 at%. The scanning electron microscope observations showed that the favorable mechanical properties of the alloy with 3 at% Mn were the result of a compact dimple structure, which enhanced the toughness. The HEA with 5 at% Mn showed the best electrochemical corrosion resistance among all the alloys due to the formation of dendritic structures at the grain boundaries.
Laser irradiation effects in FeRh thin film
Authors: Merkel D G , Sájerman K , Váczi T , Lenk S , Hegedűs G , Sajti S , Németh A , Gracheva M A , Petrik P , Mukherjee D , Horváth Z E , Nagy D L , Lengyel A
Published: July 2023

The effect of laser irradiation in the energy range from 20 mW to 200 mW was investigated in 109 nm thick Fe51Rh49 film deposited on an MgO (100) substrate. The initial, A1 structure with fully paramagnetic magnetic ordering was achieved after irradiating the samples with 120 keV Ne+ ions with a fluence of 1 × 1016 ion cm−2, as it was confirmed by conversion-electron Mössbauer spectroscopy. At higher powers physical damage of the layer was observed, while in the lowest power case, magnetic force microscopy revealed a well-defined magnetic structure reflecting the laser irradiation pattern. The presented results have the potential to be employed for laser ablation or allows the fabrication of arbitrary ferromagnetic pattern within a homogeneous paramagnetic FeRh thin films.
The Jones polynomial, Knots, diagrams, and categories
Authors: Kauffman Louis
Published: July 2023

This essay is a remembrance of Vaughan Jones and a diagrammatic exposition of the remarkable breakthroughs in knot theory and low-dimensional topology that were catalyzed by his work.
The legacy of Vaughan Jones in 𝐼𝐼₁ factors
Authors: Popa Sorin
Published: July 2023

We describe Vaughan Jones’s ground-breaking discovery that symmetries ofII1\mathrm {II}_1factors, as encoded by their subfactors, are quantized and have a natural index that can be non-integral. We then comment on the impact his revolutionary work had in the study ofII1\mathrm {II}_1factors.
Motion detection in diffraction tomography by common circle methods
Authors: Quellmalz Michael , Elbau Peter , Scherzer Otmar , Steidl Gabriele
Published: July 2023

The method of common lines is a well-established reconstruction technique in cryogenic electron microscopy (cryo-EM), which can be used to extract the relative orientations of an object given tomographic projection images from different directions.

In this paper, we deal with an analogous problem in optical diffraction tomography. Based on the Fourier diffraction theorem, we show that rigid motions of the object, i.e., rotations and translations, can be determined by detecting common circles in the Fourier-transformed data. We introduce two methods to identify common circles. The first one is motivated by the common line approach for projection images and detects the relative orientation by parameterizing the common circles in the two images. The second one assumes a smooth motion over time and calculates the angular velocity of the rotational motion via an infinitesimal version of the common circle method. Interestingly, using the stereographic projection, both methods can be reformulated as common line methods, but these lines are, in contrast to those used in cryo-EM, not confined to pass through the origin and allow for a full reconstruction of the relative orientations. Numerical proof-of-the-concept examples demonstrate the performance of our reconstruction methods.
Large-Scale Data Harmonization Across Prospective Studies
Authors: Pan Ke , Bazzano Lydia A , Betha Kalpana , Charlton Brittany M , Chavarro Jorge E , Cordero Christina , Gunderson Erica P , Haggerty Catherine L , Hart Jaime E , Jukic Anne Marie , Ley Sylvia H , Mishra Gita D , Mumford Sunni L , Schisterman Enrique F , Schliep Karen , Shaffer Jeffrey G , Sotres-Alvarez Daniela , Stanford Joseph B , Wilcox Allen J , Wise Lauren A , Yeung Edwina , Harville Emily W
Published: July 2023

The Preconception Period Analysis of Risks and Exposures Influencing Health and Development (PrePARED) Consortium creates a novel resource for addressing preconception health by merging data from numerous cohort studies. In this paper, we describe our data harmonization methods and results. Individual-level data from 12 prospective studies were pooled. The crosswalk-cataloging-harmonization procedure was used. The index pregnancy was defined as the first postbaseline pregnancy lasting more than 20 weeks. We assessed heterogeneity across studies by comparing preconception characteristics in different types of studies. The pooled data set included 114,762 women, and 25,531 (22%) reported at least 1 pregnancy of more than 20 weeks’ gestation during the study period. Babies from the index pregnancies were delivered between 1976 and 2021 (median, 2008), at a mean maternal age of 29.7 (standard deviation, 4.6) years. Before the index pregnancy, 60% of women were nulligravid, 58% had a college degree or more, and 37% were overweight or obese. Other harmonized variables included race/ethnicity, household income, substance use, chronic conditions, and perinatal outcomes. Participants from pregnancy-planning studies had more education and were healthier. The prevalence of preexisting medical conditions did not vary substantially based on whether studies relied on self-reported data. Use of harmonized data presents opportunities to study uncommon preconception risk factors and pregnancy-related events. This harmonization effort laid the groundwork for future analyses and additional data harmonization.
Catalytic and molecular properties of alkaliphilic and thermotolerant β-etherase from Altererythrobacter sp. B11
Authors: Kumagawa Eri , Katsumata Madoka , Ohta Yukari
Published: July 2023

Phenylpropanone monomers, including guaiacyl hydroxypropanone, are important precursors for the synthesis of various chemicals. The monomers are obtained in a three-step cascade reaction catalyzed by a group of enzymes in the β-etherase system that cleaves the β-O-4 bond, the major bond in lignin. In this study, one of the β-etherase of the glutathione-S-transferase superfamily, AbLigF2, was discovered in genus Altererythrobacter, and the recombinant etherase was characterized. The enzyme showed maximal activity at 45 °C, maintained 30% of its activity after 2 h at 50 °C, and was the most thermostable among the previously reported enzymes. Moreover, N13, S14, and S115, located near the thiol group of glutathione, had a significant effect on the maximum reaction rate of enzyme activity. This study suggests that AbLigF2 has the potential to serve as a thermostable enzyme for lignin utilization and provides insights into its catalytic mechanism.
Common cuckoos do not mimic the size and shape of host eggs
Authors: Akkaynak Derya , Stoddard Mary Caswell
Published: July 2023

Often considered a textbook example of coevolution, common cuckoo (Cuculus canorus) eggs are among the best-studied eggs in the world. Female cuckoos belong to genetically distinct host-races, each laying a specific egg type. When host species evolved to reject cuckoo eggs from their nests, cuckoos evolved better egg color and pattern mimicry. In this study, we asked: have cuckoos also evolved eggs that are well matched to host eggs in size and shape, and is the match better for highly discriminating hosts? We used digital image analysis to quantify the sizes and shapes of ~1230 eggs laid by ten European host species and their respective cuckoo host-races. We found that there is some variation in egg size and shape among host species. By contrast, different cuckoo host-races lay eggs that are—on average—similar in size and shape. This generic “one size and shape fits all” cuckoo egg morph is a poor match to most host egg sizes but a good match to most host egg shapes. Overall, we showed that host discrimination behavior was not correlated with the degree of egg size or shape similarity. We concluded that cuckoo females have not evolved egg size or shape mimicry. Alternative explanations for egg shape similarity include biophysical constraints associated with egg formation and selection for incubation efficiency. Finally, to place our results in a broader context, we compared the egg shapes of the common cuckoo and its hosts to those of three Australian parasitic cuckoo species and their hosts.
DNA barcodes of the Greater Antillean butterflies (Lepidoptera: Papilionoidea) suggest a richer, more isolated fauna and higher endemism
Authors: Núñez Rayner , Genaro Julio A , Miller Jacqueline Y , Barro-Cañamero Alejandro , Álvarez Yosiel , Fernández Douglas M , Minno Marc C , Turner Thomas , Turlan Vaughan , Wahlberg Niklas , Pérez-Asso Antonio R , Hausmann Axel
Published: July 2023

We provide the first comprehensive assessment of the Greater Antilles butterfly fauna from a molecular perspective. We gathered COI barcodes for 82% of the archipelago’s 367 species. Barcodes perform relatively well for species identification. A barcode gap separates 83% of the 270 species (represented by at least two sequences) from its nearest neighbour (NN). Of the 31 species represented by single barcodes, 26 have minimum distances from their NN above 2%. Maximum intraspecific distances are higher than 2% for 57 species (21%); however, values are lower within single islands suggesting that a part of these species has evolved into endemic lineages overlooked or unrecognized until today. Barcodes are diagnostic for only 80 of the currently accepted 180 subspecies represented by at least two sequences suggesting numerous conflicts with the infraspecific classification and highlighting its subjectivity. For 20 species, and several subspecies within them, we propose a split into two or more species and elevating several subspecies to the species category. Other data sources including novel or previously ignored morphological characters of adults and immature stages, natural history and/or additional nuclear sequences support these taxonomic changes.
Flip a coin: cell senescence at the maternal–fetal interface
Authors: Gong Guang-Shun , Muyayalo Kahindo P , Zhang Yu-Jing , Lin Xin-Xiu , Liao Ai-Hua
Published: July 2023

During pregnancy, cell senescence at the maternal–fetal interface is required for maternal well-being, placental development, and fetal growth. However, recent reports have shown that aberrant cell senescence is associated with multiple pregnancy-associated abnormalities, such as preeclampsia, fetal growth restrictions, recurrent pregnancy loss, and preterm birth. Therefore, the role and impact of cell senescence during pregnancy requires further comprehension. In this review, we discuss the principal role of cell senescence at the maternal–fetal interface, emphasizing its “bright side” during decidualization, placentation, and parturition. In addition, we highlight the impact of its deregulation and how this “dark side” promotes pregnancy-associated abnormalities. Furthermore, we discuss novel and less invasive therapeutic practices associated with the modulation of cell senescence during pregnancy.