bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perpendicular magnetic properties and field-free current-induced switching in W/CoFeB/MgO trilayers with a compensating oblique W underlayer
Authors: Li G S , Zhu Z Z , Wang Z , Ke J T , Wang P J , Bi L Z , Hu C Q , Zhang Y , Cai J W 
Published: April 2024

Abstract
Zero-field magnetization switching (ZFS) driven by current-induced spin–orbit torque (SOT) holds significant importance in spintronic applications. The introduction of a lateral asymmetric structure (LAS) through oblique deposition proves to be an effective strategy for breaking inversion symmetry, thereby enabling SOT-driven ZFS. However, the coexistence of wedge thickness structure and slanted columnar microstructure in the obliquely deposited films poses challenges in distinguishing their respective effects. In this study, we conducted a comparative investigation of the perpendicular magnetic properties and current-induced switching in W/Co40Fe40B20/MgO films by oblique sputtering of the W underlayer at a fixed tilting angle and at two opposite tilting angles with its wedge thickness compensated. We have found that the perpendicular magnetic properties of the Co40Fe40B20 layer are significantly altered at large tilting angles, irrespective of whether the W wedge thickness is compensated. Notably, at a tilting angle of 50°, ZFS is realized for both the conventional oblique sample and the compensating oblique sample, with the switching polarity contingent on the final tilting direction of the W layer. We have identified a gradient in perpendicular magnetic anisotropy in these samples, attributed to the laterally varying roughness associated with the slanted columnar microstructure of the W underlayer. This study underscores the dominant role of microscopic LAS in obliquely deposited films in breaking SOT symmetry. Our research sheds light on the impact of the slanted columnar microstructure on the magnetic and magneto-transport properties of films, offering valuable insights for advancing spintronic device research.
A metasurface for suppressing mode conversion and achieving directional reflection of shear horizontal wave
Authors: Fu Mingtao , Zhu Qingfeng , Miao Hongchen 
Published: April 2024

Abstract
The lowest-order shear horizontal (SH0) guided wave in a plate is crucial for nondestructive testing and structural health monitoring due to its nondispersive nature. However, mode conversion at the interface for the SH0 wave complicates the received information and increases the difficulty of signal analysis. In this work, an elastic metasurface is proposed to suppress mode conversion at the interface and to reflect the SH0 wave directionally. The metasurface comprises a series of rectangular elements with a specific phase gradient covering the 2π phase range. The effectiveness of the proposed metasurface is confirmed through finite element simulations and experimental validation. The results indicate that the metasurface can significantly reduce the amplitude of the reflected lowest-order symmetric Lamb wave when compared to the reflection without the metasurface, while simultaneously allowing the reflected SH0 wave to propagate at the designed angle. Furthermore, the metasurface maintains its functionality for SH0 wave with incident angles varying from 0° to 25°. This study provides a viable approach for suppressing mode conversion and modulating the reflection behavior of SH0 wave, which is expected to find applications in nondestructive testing and structural health monitoring.
Spray-lithography of hybrid graphene-perovskite paper-based photodetectors for sustainable electronics
Authors: Malik Sunaan , Zhao Yining , He Yutong , Zhao Xinyu , Li Hongyu , Yi Wentian , Occhipinti Luigi G , Wang Mingqing , Akhavan Shahab 
Published: April 2024

Abstract
Paper is an ideal substrate for the development of flexible and environmentally sustainable ubiquitous electronic systems. When combined with nanomaterial-based devices, it can be harnessed for various Internet-of-Things applications, ranging from wearable electronics to smart packaging. However, paper remains a challenging substrate for electronics due to its rough and porous nature. In addition, the absence of established fabrication methods is impeding its utilization in wearable applications. Unlike other paper-based electronics with added layers, in this study, we present a scalable spray-lithography on a commercial paper substrate. We present a non-vacuum spray-lithography of chemical vapor deposition (CVD) single-layer graphene (SLG), carbon nanotubes (CNTs) and perovskite quantum dots (QDs) on a paper substrate. This approach combines the advantages of two large-area techniques: CVD and spray-coating. The first technique allows for the growth of SLG, while the second enables the spray coating of a mask to pattern CVD SLG, electrodes (CNTs), and photoactive (QDs) layers. We harness the advantages of perovskite QDs in photodetection, leveraging their strong absorption coefficients. Integrating them with the graphene enhances the photoconductive gain mechanism, leading to high external responsivity. The presented device shows high external responsivity of ∼520 A W−1 at 405 nm at <1 V bias due to the photoconductive gain mechanism. The prepared paper-based photodetectors (PDs) achieve an external responsivity of 520 A W−1 under 405 nm illumination at <1 V operating voltage. To the best of our knowledge, our devices have the highest external responsivity among paper-based PDs. By fabricating arrays of PDs on a paper substrate in the air, this work highlights the potential of this scalable approach for enabling ubiquitous electronics on paper.
A Christmas story about quantum teleportation
Authors: Fitzgerald Barry W , Emonts Patrick , Tura Jordi 
Published: April 2024

Abstract
Quantum teleportation is a concept that fascinates and confuses many people, in particular, given that it combines quantum physics and the concept of teleportation. With quantum teleportation likely to play a key role in several communication technologies and the quantum internet in the future, it is imperative to create learning tools and approaches that can accurately and effectively communicate the concept. Recent research has indicated the importance of teachers enthusing students about the topic of quantum physics. Therefore, educators at both high school and early university level need to find engaging and perhaps unorthodox ways of teaching complex, yet interesting topics such as quantum teleportation. In this paper, we present a paradigm to teach the concept of quantum teleportation using the Christmas gift-bringer Santa Claus. Using the example of Santa Claus, we use an unusual context to explore the key aspects of quantum teleportation, and all without being overly abstract. In addition, we outline a worksheet designed for use in the classroom setting which is based on common naive conceptions from quantum physics. This worksheet will be evaluated as a classroom resource to teach quantum teleportation in a subsequent study.
A thermodynamic analysis of alternative cooling options for beverages
Authors: Costa Danielle C , Mata Angélica S , Nascimento Fábio S , Silva Saulo L L 
Published: April 2024

Abstract
The so-called artificial ices are easily found on the market nowadays. They are commercialized with the promise of freezing drinks in general. The advantage over traditional ice is that they do not dilute drinks during the cooling process. These artificial ices come in a variety of forms, including plastic, gel, stone, and metal. In this study, we investigate theoretically and experimentally the effectiveness of these objects in comparison to traditional water ice (ordinary ice). Our findings suggest that artificial ice produced without water provides a less significant cooling effect when compared to those made with water and traditional water ice. Additionally, we observed that the material used to coat the ice has a significant impact on the cooling process and can be selected based on its specific application. We also suggest an experimental parameter that can be used to verify the effectiveness of these objects. Finally, our results are supported by thermodynamic laws.
Study of an adiabatic and free rotation of a block around a fixed axis using videoanalysis
Authors: Falcari Derick , da Rocha Carlos Antônio , Manarelli Flávio Henrique , Bertuola Alberto Carlos 
Published: April 2024

Abstract
This work is a proposal for a basic physics class in which the statics and dynamics of a rigid body are approached simultaneously using a single experimental apparatus. A mechanical system was used to study the rotation of a rigid prismatic block around one of its edges. In the first part of this study (statics), the block is subjected to the action of a variable external force, the intensity of which decreases as the inclination of the block increases. The external force produces a slow rotation (adiabatic rotation) until it is in an unstable equilibrium configuration. The experiment allows data to be collected on the external force as a function of the block’s angle to the support surface. The graph of the theoretical force relative to the angle of the block with the surface is presented together with the experimental points. From the analytical expression of the force, the work is obtained and compared with the work of the weight force. In the graphical representation of work as a function of angle, a symmetry is identified in the curve drawings. In the second part (dynamics), the block is moved to rotate freely. The falling time is calculated considering two types of independent initial conditions. The first condition is a perturbation in angular velocity and the other in the initial angle. The graphs of the falling times as a function of the predicted perturbations are presented and the concordance between the experimental data and the respective theoretical curves can be checked. All equations obtained from the physical modelling are verified experimentally, through laboratory testing, image analysis and videoanalysis. The experimen-tal techniques and results are presented in detail throughout this paper. The practices described in this work are in harmony with active learning in physics teaching.
Sliding down an inclined plane: a new method for measuring gravitational acceleration and kinetic friction in upper-secondary school
Authors: Johansson Andreas , Kilde Löfgren Sebastian , Enger Jonas 
Published: April 2024

Abstract
An essential goal of teaching experimental physics is to engage students in exploring the validity of models and refining them. To comprehend, test, and revise scientific models, students need well-designed learning activities that enable them to practice the necessary skills. In this paper, we critically review the prevalent assumption in contemporary literature that the coefficient of kinetic friction can be treated as a constant for a certain surface pair. Further, we introduce a novel approach for calculating gravitational acceleration by measuring accelerations on inclined planes. The study indicates that kinetic friction changes with different inclinations of the plane and cannot be assumed to be constant even with typical classroom laboratory equipment. Measuring the gravitational acceleration (g) via inclined planes can result in significant deviations if varying kinetic friction is not considered. This paper proposes a lab activity to investigate the validity of a naïve friction model, by measuring the well-defined gravitational acceleration (g) with controlled precision, in an upper secondary classroom setting.
Ultra-fast in vivo directional dark-field x-ray imaging for visualising magnetic control of particles for airway gene delivery
Authors: Smith Ronan , Morgan Kaye , McCarron Alexandra , Cmielewski Patricia , Reyne Nicole , Parsons David , Donnelley Martin 
Published: April 2024

Abstract

Objective. Magnetic nanoparticles can be used as a targeted delivery vehicle for genetic therapies. Understanding how they can be manipulated within the complex environment of live airways is key to their application to cystic fibrosis and other respiratory diseases. Approach. Dark-field x-ray imaging provides sensitivity to scattering information, and allows the presence of structures smaller than the detector pixel size to be detected. In this study, ultra-fast directional dark-field synchrotron x-ray imaging was utlilised to understand how magnetic nanoparticles move within a live, anaesthetised, rat airway under the influence of static and moving magnetic fields. Main results. Magnetic nanoparticles emerging from an indwelling tracheal cannula were detectable during delivery, with dark-field imaging increasing the signal-to-noise ratio of this event by 3.5 times compared to the x-ray transmission signal. Particle movement as well as particle retention was evident. Dynamic magnetic fields could manipulate the magnetic particles in situ. Significance. This is the first evidence of the effectiveness of in vivo dark-field imaging operating at these spatial and temporal resolutions, used to detect magnetic nanoparticles. These findings provide the basis for further development toward the effective use of magnetic nanoparticles, and advance their potential as an effective delivery vehicle for genetic agents in the airways of live organisms.
ReconU-Net: a direct PET image reconstruction using U-Net architecture with back projection-induced skip connection
Authors: Hashimoto Fumio , Ote Kibo 
Published: April 2024

Abstract

Objective. This study aims to introduce a novel back projection-induced U-Net-shaped architecture, called ReconU-Net, based on the original U-Net architecture for deep learning-based direct positron emission tomography (PET) image reconstruction. Additionally, our objective is to visualize the behavior of direct PET image reconstruction by comparing the proposed ReconU-Net architecture with the original U-Net architecture and existing DeepPET encoder–decoder architecture without skip connections. Approach. The proposed ReconU-Net architecture uniquely integrates the physical model of the back projection operation into the skip connection. This distinctive feature facilitates the effective transfer of intrinsic spatial information from the input sinogram to the reconstructed image via an embedded physical model. The proposed ReconU-Net was trained using Monte Carlo simulation data from the Brainweb phantom and tested on both simulated and real Hoffman brain phantom data. Main results. The proposed ReconU-Net method provided better reconstructed image in terms of the peak signal-to-noise ratio and contrast recovery coefficient than the original U-Net and DeepPET methods. Further analysis shows that the proposed ReconU-Net architecture has the ability to transfer features of multiple resolutions, especially non-abstract high-resolution information, through skip connections. Unlike the U-Net and DeepPET methods, the proposed ReconU-Net successfully reconstructed the real Hoffman brain phantom, despite limited training on simulated data. Significance. The proposed ReconU-Net can improve the fidelity of direct PET image reconstruction, even with small training datasets, by leveraging the synergistic relationship between data-driven modeling and the physics model of the imaging process.
X-ray source motion blur modeling and deblurring with generative diffusion for digital breast tomosynthesis
Authors: Gao Mingjie , Fessler Jeffrey A , Chan Heang-Ping 
Published: April 2024

Abstract

Objective. Digital breast tomosynthesis (DBT) has significantly improved the diagnosis of breast cancer due to its high sensitivity and specificity in detecting breast lesions compared to two-dimensional mammography. However, one of the primary challenges in DBT is the image blur resulting from x-ray source motion, particularly in DBT systems with a source in continuous-motion mode. This motion-induced blur can degrade the spatial resolution of DBT images, potentially affecting the visibility of subtle lesions such as microcalcifications. Approach. We addressed this issue by deriving an analytical in-plane source blur kernel for DBT images based on imaging geometry and proposing a post-processing image deblurring method with a generative diffusion model as an image prior. Main results. We showed that the source blur could be approximated by a shift-invariant kernel over the DBT slice at a given height above the detector, and we validated the accuracy of our blur kernel modeling through simulation. We also demonstrated the ability of the diffusion model to generate realistic DBT images. The proposed deblurring method successfully enhanced spatial resolution when applied to DBT images reconstructed with detector blur and correlated noise modeling. Significance. Our study demonstrated the advantages of modeling the imaging system components such as source motion blur for improving DBT image quality.
Finite element simulation and experimental investigation of in-situ laser-assisted diamond turning of monocrystalline silicon
Authors: Hu Wangjie , Zhao Xuesen , Sun Tao , Zhang Junjie 
Published: April 2024

Abstract
While the effectiveness of in-situ laser-assisted diamond turning (In-LAT) for promoting the ductile machinability of monocrystalline silicon has been demonstrated, the underlying cutting mechanisms remain inadequately understood. In this study, we investigate the fundamental mechanisms involved in the In-LAT of monocrystalline silicon by finite element (FE) simulations and experiments. Specifically, a FE model of In-LAT of monocrystalline silicon is developed, which incorporates a Drucker–Prager constitutive model to address the brittle fracture of the material, as well as temperature-dependent materials properties to address the thermal softening effect. Furthermore, experiments of In-LAT of monocrystalline silicon are conducted with the self-developed In-LAT device, including tapering cutting and end face cutting. Simulation results demonstrate that In-LAT significantly increases the critical depth of cut for the brittle-to-ductile transition of monocrystalline silicon in tapering cutting mode by 72.2% compared to conventional cutting, accompanied with significantly reduced cutting forces, continuous chip profile and reduced surface brittle damage. The promotion of ductile machinability of monocrystalline silicon under In-LAT is attributed to the reduction and dispersion of stress in the cutting zone, which is in contrast to the significant stress concentration at the rake face and cutting edge in conventional cutting. And simulation results also provide an optimal temperature field of 900 K for the In-LAT of monocrystalline silicon, above which the excessive plastic flow accompanied by thermal accumulation results into deteriorated surface roughness. These findings provide valuable insights for understanding the cutting mechanisms of In-LAT and the parameter optimization for In-LAT application.
The effect of TiSi2 healing improver in self-healing ability of ceramics
Authors: Tamagawa Yuki , Okayasu Kazuto , Nakao Wataru 
Published: April 2024

Abstract
A method to enhance the temperature range in which continuous self-healing fiber-reinforced ceramics (shFRCs) can self-heal is proposed to obtain a new high-temperature structural material. The effect of TiSi2 oxidation on self-healing was investigated using SiC, a typical self-healing agent, and TiSi2, which oxidizes at a lower temperature than SiC. Mixtures of SiC and TiSi2 powders were prepared by wet-mixing, and changes in their high-temperature oxidation behavior were investigated using thermogravimetry/differential thermal analysis. The oxidation of TiSi2 at 1000 °C enhanced the oxidation rate of SiC by 2–3 times. A shFRC consisting of an Al2O3 matrix, an interface layer of SiC and TiSi2, and Al2O3 fiber bundles was fabricated by slurrying and filament-winding. The strength recovery of the shFRC following three-point bending was investigated, and results indicated that the prepared material recovered 50 times faster than conventional shFRCs at 1000 °C. The self-healing improver described in this study can promote the oxidation of self-healing agents via its reaction heat. Thus, this improver may be applied as a practical component of self-healing materials.
Modeling and experimental evaluation of the stepping characteristic on a walking-type piezoelectric actuator
Authors: Yun Hao , Yuan Lusheng , Wei Shaoliang , Aoyagi Manabu 
Published: April 2024

Abstract
Aiming at the suppression of backward motion, a walking-type piezoelectric actuator was developed in this paper. Two walking modes of ellipse-shaped walking and rhombus-shaped walking were discussed. The dynamic models in the x and y direction were established to simulate the stepping characteristics of two walking modes. The simulated results depicted that the actuator was able to achieve stepping displacement free of backward motion. A prototype was fabricated, and a series of experiments were conducted. The experiments indicated that, under two walking modes, there was a backward displacement in each operating cycle due to assembly errors. To suppress backward motion, a solution to compensate for the assembly errors by varying the bias voltage difference between two stators was proposed. After correcting the assembly errors, the backward displacements were almost eliminated and reduced by 71.4% from 0.28 to 0.08 μm and 68.1% from 0.22 to 0.07 μm, respectively under the ellipse-shaped walking mode and rhombus-shaped walking mode, which proved the effectiveness of the proposed actuator.
Evaluation of strain-sensitive behavior in elastomeric conductive nanocomposites containing carbon nanotubes-a finite element-percolation model approach
Authors: Haghgoo Mojtaba , Alidoust Alireza , Ansari Reza , Hassanzadeh-Aghdam Mohammad Kazem 
Published: April 2024

Abstract
A finite element (FE)-percolation model approach is developed to predict the strain-sensitive response of the three-dimensional (3D) representative volume element (RVE) of carbon nanotube (CNT)-elastomeric nanocomposite. In the simulation model, CNTs are modeled as solid, impenetrable cylinders inside a cubic insulating matrix. FE simulation is performed to evaluate the structural response of the RVE under applied strain. The FE model updates the locations of the CNTs in the deformed RVE. The paths are found using a suitable 3D resistance network associated with different percolation paths involved in the critical distance criterion. The percolation model utilizes the paths found to identify the electrical circuit for predicting tunneling conductivity. The simulating algorithm is used to study the influence of tunneling barrier height, nanotube volume fraction, and geometrical aspects. The lowest critical distance criterion is achieved for higher volume fractions and the most heightened sensitivity is obtained for lower CNT aspect ratios.
Next-to-leading-order relativistic and QCD corrections to prompt
pair photoproduction at future
colliders*
Authors: He 何 Zhi-Guo 志国 , Jin 金 Xiao-Bo 小博 , Kniehl Bernd A. , Li 李 Rong 荣 
Published: April 2024

Abstract
Within the framework of nonrelativistic-QCD factorization, we calculate both the next-to-leading-order relativistic and QCD corrections to prompt

pair production, with feed-down from

mesons, via photon-photon collisions at future

colliders, including the Future Circular Lepton Collider (FCC-ee), the Circular Electron Positron Collider (CEPC), and the Compact Linear Collider (CLIC). We present total cross sections and distributions in single

transverse momentum and rapidity, as well as in

pair invariant mass. The relativistic and QCD corrections both turn out to be large and negative. However, the production rates are large enough for useful experimental studies.