bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous description of wobbling and chiral properties in even-odd triaxial nuclei
Authors: Raduta C M , Raduta Apolodor A , Poenaru Robert , Raduta Alexandu Horia 
Published: November 2021

Abstract
A particle-triaxial rigid core Hamiltonian is semi-classically treated. The coupling term corresponds to a particle rigidly coupled to the triaxial core, along a direction that does not belong to any principal plane of the inertia ellipsoid.The equations of motion for the angular momentum components provide a sixth-order algebraic equation for one component and subsequently equations for the other two. Linearizing the equations of motion, a dispersion equation for the wobbling frequency is obtained. The equations of motion are also considered in the reduced space of generalized phase space coordinates. Choosing successively the three axes as quantization axis will lead to analytical solutions for the wobbling frequency, respectively. The same analysis is performed for the chirally transformed Hamiltonian. With an illustrative example one identiﬁed wobbling states whose frequencies are mirror image to one another. Changing the total angular momentum I, a pair of twin bands emerged. Note that the present formalism conciliates between the two signatures of triaxial nuclei, i.e., they could coexist for a single nucleus.
Reorganization of the topological surface mode of topological insulating α-Sn
Authors: Tan Rui , Qi Qi , Wang Peng , Cao Yanqiang , Si Rongrong , Wang Maoxiang , Wang Xiaoxiong 
Published: November 2021

Abstract
α-Sn is a topologically nontrivial semimetal in its natural structure. Upon compressively strained in plane, it transforms into a topological insulator. But, up to now, a clear and systematic understanding of the topological surface mode of topological insulating α-Sn is still lacking. In the present work, first-principle simulations are employed to investigate the electronic structure evolution of Ge1−x
Sn
x
alloys aiming at understanding the band reordering, topological phase transition and topological surface mode of α-Sn in detail. Progressing from Ge to Sn with increasing Sn content in Ge1−x
Sn
x
, the conduction band inverts with the first valence band (VB) and then with the second VB sequentially, rather than inverting with the latter directly. Correspondingly, a topologically nontrivial surface mode arises in the first inverted band gap. Meanwhile, a fragile Dirac cone appears in the second inverted band gap as a result of the reorganization of the topological surface mode caused by the first VB. The reorganization of the topological surface mode in α-Sn is very similar to the HgTe case. The findings of the present work are helpful for understanding and utilizing of the topological surface mode of α-Sn.
Stable and enhanced electrochemical performance based on hierarchical core–shell structure of CoMn2O4@Ni3S2 electrode for hybrid supercapacitor
Authors: Xu Qing , Wang Yintao , Meng Suci , Jiang Deli , Chen Min 
Published: November 2021

Abstract
Herein, accessible and low-cost CoMn2O4@Ni3S2 core–shell nanoneedle arrays have been prepared via a two-step approach comprised with hydrothermal-calcination and electrochemical deposition procedures, successfully. In the beginning, CoMn2O4 nanoneedle arrays took root on Ni foam to form the core skeleton and subsequently, hierarchical Ni3S2 nanosheets uniformly overlaid on the surface of CoMn2O4 nanoneedles shaping the shell structure. This CoMn2O4@Ni3S2 material was measured directly as supercapacitor electrode and presented high specific capacity of 192.2 mAh g−1 with current density of 1 A g−1. Besides, the electrode delivered outstanding cyclical stability as the capacity retention attained 90.2% after charge–discharge measurement at a large current density of 10 A g−1 for 10 000 cycles. Furthermore, a hybrid supercapacitor assembled by CoMn2O4@Ni3S2 cathode and activated carbon anode represented a high energy density of 51.2 Wh kg−1 with the power density of 1030.0 W kg−1. This work shows a facile and inexpensive procedure to design high-performance and strong-stability supercapacitor electrodes.
Electron beam analysis induces Cl vacancy defects in a NaCl thin film
Authors: Quertite Khalid , Enriquez Hanna , Trcera Nicolas , Bendounan Azzedine , Mayne Andrew J , Dujardin Gérald , El kenz Abdallah , Benyoussef Abdelilah , Dappe Yannick J , Kara Abdelkader , Oughaddou Hamid 
Published: November 2021

Abstract
This work reports on the electron-induced modification of NaCl thin film grown on Ag(110). We show using low energy electron diffraction that electron beam bombardment leads to desorption and formation of Cl vacancy defects on NaCl surface. The topographic structure of these defects is studied using scanning tunneling microscopy (STM) showing the Cl defects as depressions on the NaCl surface. Most of the observed defects are mono-atomic vacancies and are located on flat NaCl terraces. Auger electron spectroscopy confirms the effect of electron exposure on NaCl thin films showing Cl atoms desorption from the surface. Using density functional theory taken into account the van der Waals dispersion interactions, we confirm the observed experimental STM measurements with STM simulation. Furthermore, comparing the adsorption of defect free NaCl and defective NaCl monolayer on Ag(110) surfaces, we found an increase of the adhesion energy and the charge transfer between the NaCl film and the substrate due to the Cl vacancy. In details, the adhesion energy increases between the NaCl film and the metallic Ag substrate from 30.4 meV Å−2 for the NaCl film without Cl vacancy and from 39.5 meV Å−2 for NaCl film with a single Cl vacancy. The charge transfer from the NaCl film to the Ag substrate is enhanced when the vacancy is created, from 0.63e− to 1.25e−.
Highlighting considerations in experimental design: the case of multimeters
Authors: Levy Smadar , Noga Adi , Kapach Zehorit , Yerushalmi Edit 
Published: November 2021

Abstract
The instructional lab setting has been found to be dominated by prescribed tasks and pre-prepared lab kits. This was explained by teachers’ need to guide students to simultaneously progress through a lab curriculum, which prompts them to standardize the lab experience. Nevertheless, prominent professional associations have persistently called to better represent experimental research practices in the lab, and to grant students more agency in the experimental process by orienting them towards more open-ended lab experiences. This paper reports a lab activity designed to advance students’ agency in the practice of experimental design, in a setting governed by a high-stakes national matriculation exam. Three hundred teachers of advanced level high-school physics experienced the lab activity in a national network of professional learning communities (PLCs). The activity was anchored in an experiment to determine the relationship between the current through a battery and its terminal voltage. It was designed to problematize students’ considerations underlying the choices of the location of the voltmeter and the measuring scale of the ammeter, and the possible implications for the validity of the experimental results; e.g. control of the variables, as well as the range and the accuracy of measurements. Teachers first performed the lab activity as learners, discussed it in the PLC meeting, and finally reflected on their experience. Individual responses to the lab worksheets and the reflections were analyzed. Initially, teachers’ considerations did not portray key aspects related to the validity of the experimental results, such as how design choices related to the location of the voltmeter and the ammeter measuring scale impacted the accuracy and range of the measurements and the control of variables. The teachers were highly engaged in the peer discussion in the PLC and found the lab activity valuable in raising students’ awareness of important considerations in experimental design.
Prostate and dominant intraprostatic lesion segmentation on PET/CT using cascaded regional-net
Authors: Matkovic Luke A , Wang Tonghe , Lei Yang , Akin-Akintayo Oladunni O , Abiodun Ojo Olayinka A , Akintayo Akinyemi A , Roper Justin , Bradley Jeffery D , Liu Tian , Schuster David M , Yang Xiaofeng 
Published: November 2021

Abstract
Focal boost to dominant intraprostatic lesions (DILs) has recently been proposed for prostate radiation therapy. Accurate and fast delineation of the prostate and DILs is thus required during treatment planning. In this paper, we develop a learning-based method using positron emission tomography (PET)/computed tomography (CT) images to automatically segment the prostate and its DILs. To enable end-to-end segmentation, a deep learning-based method, called cascaded regional-Net, is utilized. The first network, referred to as dual attention network, is used to segment the prostate via extracting comprehensive features from both PET and CT images. A second network, referred to as mask scoring regional convolutional neural network (MSR-CNN), is used to segment the DILs from the PET and CT within the prostate region. Scoring strategy is used to diminish the misclassification of the DILs. For DIL segmentation, the proposed cascaded regional-Net uses two steps to remove normal tissue regions, with the first step cropping images based on prostate segmentation and the second step using MSR-CNN to further locate the DILs. The binary masks of DILs and prostates of testing patients are generated on the PET/CT images by the trained model. For evaluation, we retrospectively investigated 49 prostate cancer patients with PET/CT images acquired. The prostate and DILs of each patient were contoured by radiation oncologists and set as the ground truths and targets. We used five-fold cross-validation and a hold-out test to train and evaluate our method. The mean surface distance and DSC values were 0.666 ± 0.696 mm and 0.932 ± 0.059 for the prostate and 0.814 ± 1.002 mm and 0.801 ± 0.178 for the DILs among all 49 patients. The proposed method has shown promise for facilitating prostate and DIL delineation for DIL focal boost prostate radiation therapy.
Impact identification on concrete panels using a surface-bonded smart piezoelectric module system
Authors: Manawadu Ayumi , Qiao Pizhong 
Published: November 2021

AbstractTimely identification of collision damage, especially in aging bridges, is critical for the safety of commuters. However, there is no efficient, cost-effective,in-situtechnique to serve this purpose. Wave propagation-based structural health monitoring (SHM) using piezoelectric material is a promising alternative for remote sensing. To that end, this study aims to develop a wave propagation-based monitoring technique using surface-bonded smart piezoelectric modules (SPM) to determine the impact force, location, and projectile properties of low-velocity impacts on concrete panels. An impact source localization algorithm used in composite structures is adapted and simplified for concrete structures. This technique is validated using a combined experimental and numerical investigation, which shows good agreement with the actual impact source location. The impact force, projectile mass, and velocity are determined using a semi-theoretical-experimental technique based on Reed contact model. A special contact-SPM is fabricated and calibrated to determine the contact force at the impact location. The relationship between contact-SPM response and distributed-SPM response is determined using a drop-weight test with steel sphere. The peak contact force and contact duration are in good agreement with Reed contact model, although the latter overpredicts the given parameters. A simplified formula based on Reed contact model is used to inversely estimate the projectile velocity of a known mass and vice versa. Then, using the pre-calibrated data, the impact force, projectile properties, and impact force-time distribution are determined using the response of distributed-SPM system. The technique is validated using an arbitrary steel sphere mass. As demonstrated in the combined experimental, theoretical, and numerical study, the proposed surface-bonded SPM system is capable of effectively identifying low-velocity impact incidents on concrete structures, which could potentially facilitate inexpensive,in-situ, real-time condition assessment.
Metamaterials with enhanced mechanical properties and tuneable Poisson’s ratio
Authors: Alomarah Amer , Masood Syed H , Ruan Dong 
Published: November 2021

Abstract
This paper reports a structural modification of an auxetic metamaterial with a combination of representative re-entrant and chiral topologies, namely, a re-entrant chiral auxetic (RCA) metamaterial. The main driving force for the structural modification was to overcome the undesirable properties of the RCA metamaterial such as anisotropic mechanical response under uniaxial compression. Additively manufactured polyamide 12 specimens via Multi Jet Fusion were quasi-statically compressed along the two in-plane directions. The experimental results confirmed that the modified structure was less sensitive to the loading direction and the deformation was more uniform. Moreover, similar energy absorptions were obtained when the modified metamaterial was crushed along the two in-plane directions. The energy absorption per unit volume was improved from 390 to 950 kJ m−3 and from 500 to 1000 kJ m−3 compared with the RCA when they were crushed along the X and Y directions, respectively. The absorbed energy per unit mass (specific energy absorption) also improved from 1.4 to 2.9 J g−1 and from 1.78 to 3.1 J g−1 compared with that of the RCA under the axial compression along the X and Y directions. Furthermore, parametric studies were performed and the effects of geometric parameters of the modified metamaterial were numerically investigated. Tuneable auxetic feature was obtained. The energy absorption and Poisson’s ratio of the modified metamaterial offer it a good candidate for a wide range of potential applications in the areas such as aerospace, automotive, and human protective equipment.
Chaos in the Bose–Hubbard model and random two-body Hamiltonians
Authors: Pausch Lukas , Carnio Edoardo G , Buchleitner Andreas , Rodríguez Alberto 
Published: November 2021

Abstract
We investigate the chaotic phase of the Bose–Hubbard model (Pausch et al 2021 Phys. Rev. Lett.
126 150601) in relation to the bosonic embedded random matrix ensemble, which mirrors the dominant few-body nature of many-particle interactions, and hence the Fock space sparsity of quantum many-body systems. The energy dependence of the chaotic regime is well described by the bosonic embedded ensemble, which also reproduces the Bose–Hubbard chaotic eigenvector features, quantified by the expectation value and eigenstate-to-eigenstate fluctuations of fractal dimensions. Despite this agreement, in terms of the fractal dimension distribution, these two models depart from each other and from the Gaussian orthogonal ensemble as Hilbert space grows. These results provide further evidence of a way to discriminate among different many-body Hamiltonians in the chaotic regime.
Multiple-relaxation-time lattice Boltzmann simulation of free convection and irreversibility of nanofluid with variable thermophysical properties
Authors: Islam Mashnoon , Abdul Hai Salma , Nag Preetom , Molla Md Mamun 
Published: November 2021

Abstract
This numerical study demonstrates heat transfer and irreversibility or entropy generation of non-Newtonian power-law Al2O3-H2O (aluminum oxide-water) nanofluids in a square enclosure using multiple-relaxation-time lattice Boltzmann method accelerated by graphics processing unit computing. In this investigation, the effective thermal conductivity and viscosity are variables, and they depend on the fluid temperature and rate of strain, respectively. The enclosure’s left and right walls are uniformly heated with different temperatures, and the upper and lower walls are thermally adiabatic. There is no valid study and results on non-Newtonian fluid using multiple-relaxation-time lattice Boltzmann method for this configuration and hence the novelty of the present results have been ensured. This paper has formulated and appropriately validated the Newtonian and non-Newtonian natural convection problem with the available numerical results. This study includes a set of comprehensive simulations, showing the effects of these fluids’ natural convection by varying three key parameters: the Rayleigh number, the volume fraction of nanoparticles, and the power-law index on the streamlines, isotherms, local and average Nusselt number as well as the local and total entropy generation. The results show that increasing the volume fraction of the nanoparticles from 0% to 2%, the average rate of heat transfer and the total entropy generation increase 6.5% and 7.4%, respectively, while the Rayleigh number, Ra = 105 and the power-law index n = 0.6.
Modeling of thermal studies on melt quenched Ge18Bi4Se78 chalcogenide
Authors: Hakeem A M Abdel , Abd El-Raheem M M , Wakkad M M , Mohamed H F , Ali H M , Mohamed SK , Diab A K 
Published: November 2021

Abstract
The crystallization characteristics for Ge18Bi4Se78 glass are studied in this work by means of differential thermal analysis (DTA) under non-isothermal conditions. One stage endothermic glass transition and one exothermic crystallization are observed in the DTA curves. The results of topological constraints for Ge18Bi4Se78 glass show that the calculated value of glass transition temperature (Tg) is very close to that of the experimental results. The as-prepared, as well as the annealed samples, are examined using x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), scan electron microscope (SEM) techniques. Avrami’s exponent (n) found to have an average value of 1.61

±
0.2

reveals a mixture of one dimensional and surface nucleation stages of growth. Many models are used to estimate the activation energies for glass transition (Eg) and crystallization (Ec). The crystallization process was found to be described by the Sestak- Berggren SB(M, N) model.
Measuring Microlensing Parallax via Simultaneous Observations from Chinese Space Station Telescope and Roman Telescope
Authors: Yan Shi , Zhu Wei 
Published: November 2021

Abstract
Simultaneous observations from two spatially well-separated telescopes can lead to measurements of the microlensing parallax parameter, an important quantity toward the determinations of the lens mass. The separation between Earth and Sun–Earth L2 point, ∼0.01 au, is ideal for parallax measurements of short and ultra-short (∼1 hr to 10 days) microlensing events, which are candidates of free-floating planet (FFP) events. In this work, we study the potential of doing so in the context of two proposed space-based missions, the Chinese Space Station Telescope (CSST) in a low-Earth orbit (LEO) and the Nancy Grace Roman Space Telescope (Roman) at L2. We show that joint observations of the two can directly measure the microlensing parallax of nearly all FFP events with timescales t
E ≲ 10 days as well as planetary (and stellar binary) events that show caustic crossing features. The potential of using CSST alone in measuring microlensing parallax is also discussed.
Progress of HL-2A experiments and HL-2M program
Authors: Duan X.R. , Xu M. , Zhong W.L. , Liu Y. , Song X.M. , Liu D.Q. , Wang Y.Q. , Lu B. , Shi Z.B. , Zheng G.Y. , Liu Yong , Yang Q.W. , Mao W.C. , Li Q. , Cai L.J. , Ji X.Q. , Liu X.L. , Li L.C. , Li B. , Dong J.Q. , Ding X.T. , Yan L.W. , Artaud J.F. , Bai X.Y. , Cao J.Y. , Cao Z. , Chen L. , Chen W. , Delpech L. , Du H.L. , Ekedahl A. , Gao Z. , Garcia J. , Han M.K. , Hao G.Z. , He H.M. , Hoang G.T. , Huang M. , Isobe M. , Jiang M. , Liang A.S. , Liu Y.Q. , Li D. , Li H.J. , Li J.Q. , Li J.X. , Li Qing , Li Yongge , Long T. , Mazon D. , Mckee G.R. , Qiu Z.Y. , Peng J.F. , Peysson Y. , Rao J. , Song X. , Sun T.F. , Wang Z.X. , Wei H.L. , Wen J. , Wu N. , Xu Y.H. , Xiao G.L. , Xiao X.P. , Xue L. , Yan Z. , Yang Z.Y. , Yu D.L. , Yu L.M. , Yu Y. , Zang L.G. , Zhang J.H. , Zhang N. , Zhang Y.P. , Zonca F. , Zou X.L. 
Published: November 2021

Abstract
Since the last IAEA Fusion Energy Conference in 2018, significant progress of the experimental program of HL-2A has been achieved on developing advanced plasma physics, edge localized mode (ELM) control physics and technology. Optimization of plasma confinement has been performed. In particular, high-β
N H-mode plasmas exhibiting an internal transport barrier have been obtained (normalized plasma pressure β
N reached up to 3). Injection of impurity improved the plasma confinement. ELM control using resonance magnetic perturbation or impurity injection has been achieved in a wide parameter regime, including types I and III. In addition, impurity seeding with supersonic molecular beam injection or laser blow-off techniques has been successfully applied to actively control the plasma confinement and instabilities, as well as plasma disruption with the aid of disruption prediction. Disruption prediction algorithms based on deep learning are developed. A prediction accuracy of 96.8% can be reached by assembling a convolutional neural network. Furthermore, transport resulting from a wide variety of phenomena such as energetic particles and magnetic islands has been investigated. In parallel with the HL-2A experiments, the HL-2M mega-ampere class tokamak was commissioned in 2020 with its first plasma. Key features and capabilities of HL-2M are briefly presented.
Simulation of Crane Trolley Motion Control to Reduce Load Sway
Authors: Reutov A A 
Published: November 2021

Abstract
the work aims to develop a method for controlling a crane trolley, providing a decrease in the swinging of the load on the rope at a given positioning accuracy and minimum time for moving the load.
Computer simulation of the trolley controlled movement with a load on a rope was carried out within the "Universal Mechanism" software.
The 2D computer model includes a trolley with a pulley, a rope with a hook, and a load. T-force represents the wind force effect.
The control system (CS) contains three blocks that ensure the movement of the trolley with limited speed and acceleration, the positioning accuracy of the trolley, limiting the deviation and acceleration of a load. List of requirements for the crane CS comprises six issues.
The simulation results illustrate the satisfactory performance of the proposed method. The swing angle and trolley positioning accuracy can be controlled within the acceptable range and the external wind disturbance on the load can be successfully suppressed. The optimal parameters of the proportional-differential corrective control, which ensure the minimum travel time of the trolley with limited oscillation of the load, have been determined. The optimal values of the control parameters depend on the inertial characteristics of the load. The maximum permissible values of speed, acceleration, and positioning errors of the trolley limit from above the optimal values of the control parameters.
Active Patch Antenna for Wi-Fi 5, 6 and Wi-Fi 6E Applications
Authors: Ischenko E A , Pasternak Yu G , Pendyurin V A , Fedorov S M 
Published: November 2021

Abstract
The article discusses a planar patch antenna with a metamaterial integrated into the structure, which allows the antenna to function in the upper Wi-Fi 5, 6 frequency range and the Wi-Fi 6E range. For the study, we built graphs of S-parameters, radiation patterns; on the basis of the resulting structure, we formed a MIMO antenna array for which we determined the main characteristics - the envelope correlation coefficient and the multiplexing efficiency