bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Dy 4f electrons on magnetic coupling and reorientation in DyFeO3
Authors: Cui Rui , Jiang Hongping , Du Yixuan , Xu Yuanhui , Jia Yongchao , Sun Keju , Hao Xianfeng
Published: May 2024

Spin reorientation transition is an ubiquitous phenomenon observed in magnetic rare earth orthferrites RFeO3, which has garnered significant attention in recent years due to its potential applications in spintronics or magnetoelectric devices. Although a plenty of experimental works suggest that the magnetic interaction between R3+ and Fe3+ spins is at the heart of the spin reorientation, but a direct and conclusive theoretical support has been lacking thus far, primarily due to the challenging nature of handling R 4f electrons. In this paper, we explored DyFeO3 as an example by means of comprehensive first principles calculations, and compared two different approaches, where the Dy 4f electrons were treated separately as core or valence states, aiming to elucidate the role of Dy 4f electrons, particularly in the context of the spin reorientation transition. The comparison provides a solid piece of evidence for the experimental argument that the Dy3+−Fe3+ magnetic interactions play a vital role in triggering spin reorientation of Fe3+ moments at low temperatures. The findings revealed here not only extend our understanding on the underlying mechanism for spin reorientation transition in RFeO3, but also highlight the importance of explicit description of R 4f electrons in rationally reproducing their structural, electronic and magnetic properties.
Order-N calculations for thermoelectric power factor based on linear response theory
Authors: Ishii Hiroyuki , Kobayashi Nobuhiko , Hirose Kenji
Published: May 2024

We present an order-N quantum transport calculation methodology to evaluate thermoelectric transport coefficients, such as electric conductivity and Seebeck coefficient. Different from a conventional method using the electric conductivity spectrum, it obtains the coefficients directly from the correlation function between heat and electric current based on linear response theory. As an example, we apply the methodology to a two-dimensional square-lattice model with static disorder and confirm that the calculated results are consistent with those obtained by the conventional method. The proposed methodology provides an effective approach to evaluate the thermoelectric performance of micron-scale materials based on quantum mechanics from an atomistic viewpoint.
A method for determining the actual coordinate system of spiral bevel gears by the measured positions of eight tooth surfaces
Authors: Zhou Lihua , Fang Suping , Liu Yongsheng , Li Yuan , Taguchi Tetsuya , Takeda Ryohei
Published: May 2024

The coordinate system for the measurement of spiral bevel gear (SBG) by gear measuring center (GMC) is discussed and the misalignment between the actual coordinate system and the theoretical coordinate system of the SBG is analyzed. The misalignment can cause measurement errors and cannot be neglected in SBG precision measurements. To calculate the misalignment and accurately establish the actual coordinate system, a novel re-fitting method based on the measured positions of eight tooth surfaces is proposed. First, eight sets of gear axis direction vectors and original points can be obtained from the measurement of eight tooth surfaces, by the single tooth surface matching method. Second, the actual axis vector and the original point of the gear can be obtained, by re-fitting those eight sets of gear axis vectors and original points. Then, the actual coordinate system can be established by the actual gear axis direction vector and the original point. The least square method is used to calculate the original point, and a basis vector fitting method is proposed to solve the gear axis direction vector. Finally, two groups of preset coordinate system deviation tests are carried out to verify the accuracy and feasibility of the fitting algorithm. The results show that the fitting error of the original point is far less than

1
×

10

−
1

μ

m

and the fitting error of the angle is far less than

1
×

10

−
7

degree, which are superior to the design accuracy of the GMC. Therefore, the proposed algorithm can be applied to improve the measurement accuracy of current GMC.
A novel decoupling method of compound faults with incomplete dataset of rotating machinery
Authors: Hu Aijun , Yang Bowen , Xing Lei , Yu Tianxiao , Xiang Ling
Published: May 2024

The occurrence of fault in rotating machinery is random and complex, and the diagnosis of the compound faults has been a challenge in industrial production. Accurate diagnosis of the compound faults can be of significant help to practical maintenance and management. However, most existing intelligent diagnostic methods typically require abundant data for training, which is often difficult to collect for compound faults. In this paper, a novel method called impact feature-based decoupling capsule network (IFDCN) is proposed for diagnosing compound faults with incomplete datasets. In this model, an improved Laplace wavelet kernel capsule neural network is proposed to extract and enhance the impact features of vibration signal. A decoupling classifier is designed to decouple the compound faults in the diagnostic process so as to identify the sub-faults contained in the compound faults. In using this proposed model for incomplete datasets, the compound fault data is not trained and is not labeled. Through training on single-fault data, the proposed model is capable of classifying and decoupling the fault types. The feature extraction capability of the network is visualized by heat maps, and the physical significance of feature extraction is explained by deep learning network. The effectiveness of IFDCN is verified through different experimental of gear and bearing and the experiment results indicate that the proposed model has higher identifying precision and can accurately decouple the compound faults without compound fault samples.
Research on indoor and outdoor positioning switching algorithm based on improved PSO-BP
Authors: Zhao Yang , Wang Tianhu , Miao Qiannian , Yan Jin , Wang Rong
Published: May 2024

Aiming at the problems of poor positioning accuracy in the indoor and outdoor junction areas and the loss of positioning signals and discontinuous positioning results during the transition from the indoor area to the outdoor area, this paper proposes a machine learning method to solve the positioning problem in the indoor and outdoor junction areas and the switching problem of positioning methods. An indoor and outdoor positioning switching algorithm based on Particle Swarm Optimization-Back Propagation (PSO-BP) and BP neural network is designed. Through this algorithm, the position of the positioning tag can be judged independently and the coordinates of the positioning tag in the indoor and outdoor junction area can be predicted independently. The experimental results show that the accuracy of positioning area judgment based on PSO-BP neural network can reach 99.91%. The indoor and outdoor boundary area coordinates obtained by BP neural network prediction method are lower than the root mean square error of ultra wide band indoor positioning method and BDS positioning method. The algorithm model proposed in this paper effectively improves the positioning problem of the indoor and outdoor junction area and the positioning problem of the transition from the indoor area to the outdoor area, improves the positioning accuracy and positioning stability of the indoor and outdoor junction area, reduces the positioning cost, and has strong practicability.
Measurement insights and error analysis of electronic parameters for ultrasonic transducers
Authors: Zhou Yuhua , Fan Wei , Tang Hui , Meng Xiankai , Han Liling , Wu Jiang , Xu Xiaojing , Zhang Yanhu
Published: May 2024

Piezoelectric ultrasonic transducers with the function of energy conversation, as well as their numerous advantages in high-power density, quick response, flexible design, and service reliability, are involved in wide applications of industrial processing, precision driving, smart sensing, and medical services. The electromechanical equivalent circuit and Kirchhoff’s law indicate that mechatronics parameters are essential for performance evaluation, reliability analysis, and fault diagnosis of ultrasonic transducers. Importantly, the ultrasonic transducer is a time-variant system, data of one single parameter collected from a certain test cannot match with the data of another single parameter acquired from a different test. So, a synchronous and precise online measurement of electronic parameters is encouraged for performance evaluation and optimization design of ultrasonic transducers. With the combination of virtual instrument technology, an asynchronous measurement system of electrical excitation parameters for the ultrasonic transducers of linear driving motors was established in this study. Furthermore, the systematic measurement methods and error theory were illustrated, including the calculation methods and measuring circuits of electric signals. Experimental results proved that the proposed system and methods for measuring the input electronic power of ultrasonic transducer (e.g. effective value method for voltage and current, energy moment method for frequency, and spectrum analysis method for phase difference) are highly precise, quickly responsive, robust, and reliable for ultrasonic transducers. The findings of this study provide valuable references and suggestions for efficient, accurate, and online performance evaluation of ultrasonic transducers, particularly for piezoelectric transducers utilizing ultrasonic high-voltage exciting signals.
Cation-polymerized artificial SEI layer modified Li metal applied in soft-matter polymer electrolyte
Authors: Tang Siming , Mei Qingyang , Zhai Yutong , Liu Yulong
Published: May 2024

Li metal batteries with polymer electrolyte are of great interest for next-generation batteries for high safety and high energy density. However, uneven deposition on the lithium metal surface can greatly affect battery life. Therefore, surface modification on the Li metal become necessary to achieve good performance. Herein, an artificial solid electrolyte interface (SEI) modified lithium metal anode is prepared using cation-polymerization process, as triggered by PF5 generated from CsPF6. As a result, the polarization voltage of Li||Li symmetric battery assembled with artificial SEI-modified Li metal anode was stable with a small over-potential of 25 mV after 3000 h at current density of 1.5 mA cm−2. Electrochemical performance of Li||NCM 622 (LiNi0.6Co0.2Mn0.2O2) full cell with soft-matter polymer electrolyte is significantly improved than bare Li-metal, the capacity retention is 75% after 120 cycles with N/P = 3:1 at a cut-off voltage of 4.3 V. Our work has shed lights on the commercialization of Li metal battery with polymer electrolyte.
Prompt-gamma track-length estimator with time tagging from proton tracking
Authors: Létang Jean M , Allegrini Oreste , Testa Étienne
Published: May 2024

The design of prompt-gamma detectors necessitates numerous Monte Carlo simulations to precisely develop and optimize the detection stages in proton therapy. Alongside the advancement of MC simulations, various variance reduction methods have been explored to speed-up calculations. Among these techniques, track-length estimators are interesting scoring methods for achieving both speed and accuracy in Monte Carlo simulations of rare events. This paper introduces an extension of the GATE vpgTLE module that incorporates the prompt-gamma emission time, which is tagged from the proton tracking, enhancing its utility for studies focused on detector design and optimization that rely on time measurements. The results obtained from a clinical radiotherapy plan are presented. We demonstrate that the new vpgTLE tally with time tagging is accurate, except for certain prompt-gamma lines corresponding to long mean-life nuclei.
Prediction of ovarian cancer prognosis using statistical radiomic features of ultrasound images
Authors: Zuo Ruochen , Li Xiuru , Hu Jiaqi , Wang Wenqian , Lu Bingjian , Zhang Honghe , Cheng Xiaodong , Lu Weiguo , Qin Jiale , Liu Pengyuan , Lu Yan
Published: May 2024

Objective. Ovarian cancer is the deadliest gynecologic malignancy worldwide. Ultrasound is the most useful non-invasive test for preoperative diagnosis of ovarian cancer. In this study, by leveraging multiple ultrasound images from the same patient to generate personalized, informative statistical radiomic features, we aimed to develop improved ultrasound image-based prognostic models for ovarian cancer. Approach. A total of 2057 ultrasound images from 514 ovarian cancer patients, including 355 patients with epithelial ovarian cancer, from two hospitals in China were collected for this study. The models were constructed using our recently developed Frequency Appearance in Multiple Univariate pre-Screening feature selection algorithm and Cox proportional hazards model. Main results. The models showed high predictive performance for overall survival (OS) and recurrence-free survival (RFS) in both epithelial and nonepithelial ovarian cancer, with concordance indices ranging from 0.773 to 0.794. Radiomic scores predicted 2 year OS and RFS risk groups with significant survival differences (log-rank test, P < 1.0 × 10−4 for both validation cohorts). OS and RFS hazard ratios between low- and high-risk groups were 15.994 and 30.692 (internal cohort) and 19.339 and 19.760 (external cohort), respectively. The improved performance of these newly developed prognostic models was mainly attributed to the use of multiple preoperative ultrasound images from the same patient to generate statistical radiomic features, rather than simply using the largest tumor region of interest among them. The models also revealed that the roundness of tumor lesion shape was positively correlated with prognosis for ovarian cancer. Significance. The newly developed prognostic models based on statistical radiomic features from ultrasound images were highly predictive of the risk of cancer-related death and possible recurrence not only for patients with epithelial ovarian cancer but also for those with nonepithelial ovarian cancer. They thereby provide reliable, non-invasive markers for individualized prognosis evaluation and clinical decision-making for patients with ovarian cancer.
Unlocking the adaptive advantage: correlation and machine learning classification to identify optimal online adaptive stereotactic partial breast candidates
Authors: Pogue Joel A , Harms Joseph , Cardenas Carlos E , Ray Xenia , Viscariello Natalie , Popple Richard A , Stanley Dennis N , Boggs D Hunter
Published: May 2024

Objective. Online adaptive radiotherapy (OART) is a promising technique for delivering stereotactic accelerated partial breast irradiation (APBI), as lumpectomy cavities vary in location and size between simulation and treatment. However, OART is resource-intensive, increasing planning and treatment times and decreasing machine throughput compared to the standard of care (SOC). Thus, it is pertinent to identify high-yield OART candidates to best allocate resources. Approach. Reference plans (plans based on simulation anatomy), SOC plans (reference plans recalculated onto daily anatomy), and daily adaptive plans were analyzed for 31 sequential APBI targets, resulting in the analysis of 333 treatment plans. Spearman correlations between 22 reference plan metrics and 10 adaptive benefits, defined as the difference between mean SOC and delivered metrics, were analyzed to select a univariate predictor of OART benefit. A multivariate logistic regression model was then trained to stratify high- and low-benefit candidates. Main results. Adaptively delivered plans showed dosimetric benefit as compared to SOC plans for most plan metrics, although the degree of adaptive benefit varied per patient. The univariate model showed high likelihood for dosimetric adaptive benefit when the reference plan ipsilateral breast V15Gy exceeds 23.5%. Recursive feature elimination identified 5 metrics that predict high-dosimetric-benefit adaptive patients. Using leave-one-out cross validation, the univariate and multivariate models classified targets with 74.2% and 83.9% accuracy, resulting in improvement in per-fraction adaptive benefit between targets identified as high- and low-yield for 7/10 and 8/10 plan metrics, respectively. Significance. This retrospective, exploratory study demonstrated that dosimetric benefit can be predicted using only ipsilateral breast V15Gy on the reference treatment plan, allowing for a simple, interpretable model. Using multivariate logistic regression for adaptive benefit prediction led to increased accuracy at the cost of a more complicated model. This work presents a methodology for clinics wishing to triage OART resource allocation.
Non-uniformity of fluctuation characteristics inside an edge magnetic island in Heliotron J
Authors: Miyashita A , Ohshima S , Matoike R , Kin F , Kobayashi S , Kado S , Minami T , Mizuuchi T , Konoshima S , Okada H , Inagaki S , Nagasaki K
Published: May 2024

Non-uniform fluctuation characteristics are observed within an edge magnetic island in Heliotron J. The island possesses a long connection length comparable to the confined region. These fluctuations are measured using a Langmuir probe. The island’s presence is confirmed through the plasma response, observed in the modulation amplitude of electron temperature and its phase delay relative to the heat source in a heat modulation experiment. Within the island, the electron density is notably high, accompanied by distinct profiles of electron temperature and electric field, likely attributable to the magnetic island. Contrary to expectations, density fluctuations within the edge magnetic island are not locally minimized, despite the reduced gradient of the profile within the island. Statistical analysis shows a suppression of intermittent transport inside the island, while intermittent fluctuations increase towards the exterior. A further analysis to segregate turbulence-driving and spreading factors reveals that both turbulence-driven and spreading contributions are comparably significant inside the island. Additionally, the non-uniform turbulence results in a spatially structured fluctuation-driven particle flux. Overall, the experimental findings indicate that fluctuation characteristics exhibit notable non-uniformity both inside and near the island. This non-uniformity potentially complicates heat transport and may lead to three-dimensional, asymmetric transport within and at the periphery of the islands.
Thymus schimperi Ronniger plant flower extract dye-sensitized solar cells
Authors: Yitagesu Getye Behailu , Leku Dereje Tsegaye , Workneh Getachew Adam
Published: May 2024

The demand for energy is greatly increasing due to the world’s population growth and technological advancement. Natural dye-sensitized solar cells are attracting research as an alternative and renewable energy source due to their simple preparation technique, availability, cost effectiveness and environmental friendliness. In the present work, we have successfully fabricated dye-sensitized solar cells (DSSCs) from Thymus schimperi Ronniger plant flowers for the first time. The solvents used for extraction of the flower dye were deionized water and its mixture with ethanol. The T. schimperi Ronniger flower extract dye solutions and sensitized photoanodes were characterized by Fourier transform infrared and ultraviolet–visible techniques. The crystallinity of TiO2 films was analyzed by x-ray diffraction, and the films showed pure anatase phase behavior. The photoelectrochemical solar cell performance parameters, such as short circuit current density, open circuit voltage, fill factor and efficiency, were evaluated from current density–voltage measurements using a Keithley 2450 source meter. DSSCs sensitized with dye solution extracted by a mixture of water and ethanol showed better performance (1.37%) than those sensitized with dye solution extracted by deionized water alone (1.02%).
Resistor-to-Schottky barrier analytical model for ohmic contact test structures
Authors: Pham Thanh C , Tran Hiep N , Partridge James G , Holland Anthony S
Published: May 2024

Analytical models for investigating Metal–Semiconductor (M–S) ohmic contacts in test structures have conventionally included resistive-only contact interfaces. Given that M–S contacts are fundamentally governed by electron tunnelling across the potential energy barrier at the M–S interface, this simplified approach may result in misinterpretation. This paper describes, in detail, a novel Resistor-to-Schottky (RSB) barrier analytical model that enables a more in-depth exploration of the physics underlying ohmic contacts. The proposed model is analysed and compared with models constructed using the semiconductor device simulator tool TCAD. The study reveals significant differences in outcomes when employing the RSB model rather than the conventional Transmission Line model and contributes to a more comprehensive understanding of M–S ohmic contacts in test structures.
Hybrid optimization schemes for solving the piezoresistive inversion problem in self-sensing materials
Authors: Hassan Hashim , Crossley William A , Tallman Tyler N
Published: May 2024

Materials with electrically conductive nanofillers have the ability to ‘sense’ changes to their mechanical state. When these materials are deformed, the embedded nanofiller networks are disturbed causing a measurable change in the electrical conductivity of the material. This self-sensing property, known as piezoresistivity, has been leveraged in numerous engineering venues. Although this property has been thoroughly explored, prevailing self-sensing techniques provide little-to-no information about the underlying mechanical state of the material, such as the displacement and strain. This information must be indirectly obtained from the conductivity change. This limitation exists because obtaining mechanics from conductivity is an under-determined inverse problem with many possible mathematically feasible solutions. Previous work in this area used metaheuristic algorithms and imposed mechanics-based constraints to solve the piezoresistive inversion problem. Although this approach was successful, it was computationally inefficient due to the stochastic search process and the need to perform multiple searches to find a converged solution. To overcome this limitation, we herein propose a hybrid optimization scheme for solving the piezoresistive inversion problem. This scheme is implemented in two steps. In the first step, a metaheuristic algorithm performs a single search for a suitable solution to the inverse problem. In the second step, a gradient descent algorithm searches for the final solution using the solution from the previous step as the starting point. We explore different norms for the fitness function of the metaheuristic search and demonstrate using experimental data that the proposed hybrid optimization scheme can accurately and efficiently calculate displacements and strains from conductivity changes. This exploration significantly advances the state of the art by enabling computationally efficient and highly accurate predictions of full-field mechanical condition in self-sensing materials for the first time, thereby paving the way for greater use of these principles in practice.
Experimental and theoretical investigation on magnetorheological elastomers containing carbonyl iron particles coated with silane coupling agent
Authors: Tian Yun , Xu Zhao-Dong , Guo Ying-Qing , Zhu Li-Hua , Dong Yao-Rong , Li Qiang-Qiang , Hu Zhong-Wei , Wei Ya-Xin
Published: May 2024

Magnetorheological (MR) elastomer composites, comprising soft silicone rubber, various additives, and different weight fractions of carbonyl iron particles (CIPs) coated with silane coupling agent, are produced via a novel manufacturing process in an anisotropic state. This study encompasses both experimental and modeling investigations into the dynamic viscoelastic properties of magnetorheological elastomer (MREs) in shear mode under varying magnetic fields, displacement amplitudes, and frequencies. Two MRE vibration mitigation devices are fabricated to experimentally assess the shear storage modulus and the loss factor of MREs. The experimental findings reveal a pronounced MR effect in the MRE devices, where both the shear storage modulus and the loss factor increase with rising magnetic fields, frequencies, and particle weight fractions, yet decrease with higher displacement amplitudes. A modified fractional-derivative equivalent parametric model, grounded in a magnetic field- and frequency-dependent shear modulus model along with internal variable theory, is proposed to describe the effects of these key influencing factors on the MREs’ dynamic viscoelastic properties. Comparative analysis of experimental and numerical data demonstrates that this refined mathematical model can accurately represent the dynamic viscoelastic properties of MREs.
A hybrid wave vibration energy harvester with electromagnetic double-speed and piezoelectric up-frequency driven by a rotating ball
Authors: Jia Shengyao , Zeng Chuanjun , Shi Ge , Xu Jubing , Xia Yinshui , Zeng Wentao , Wang Xiudeng , Xia Huakang
Published: May 2024

The energy crisis and environmental pollution have driven the development of ambient energy harvesting technologies, and ocean waves usually contain abundant vibration energy, making the study of wave energy harvesting technology of profound value. This paper proposes a hybrid wave vibration energy harvester with electromagnetic double-speed and piezoelectric up-frequency driven by a rotating ball. For the electromagnetic generator (EMG), the excitation magnet and coil move simultaneously, resulting in double the flux variation rate compared with traditional structures, enhancing the output voltage. For the piezoelectric transducer (PZT), four piezoelectric cantilever beams are magnetically coupled with the EMG, generating power through bistable motion and broadening the working frequency band of the cantilever beam structure. The harvester is modeled and simulated, and its performance is tested on a simulated vibration platform, with simulation and experimental results in good agreement. Under external excitation at 0.8 Hz, the optimal load and maximum power for each EMG are 8.2 Ω and 207.2 mW, respectively, and the optimal load and maximum power for each PZT are 100 kΩ and 1.52 mW, respectively. The harvester can produce a maximum output power of 420.48 mW, demonstrating high efficiency in energy capture under low-frequency and multidirectional wave excitation.
State-dependent misalignment and turbulence effects on high-dimensional quantum key distribution with orbital angular momentum
Authors: Li Jiahao , Wang Xingyu , Yu Huicun , Tang Jie , Liu Ying , Cao Yuexiang , Deng Zhifeng , Wu Dan , Hu Haoran , Wang Ya , Lun Huazhi , Zhang Bo , Wei Jiahua , Liu Bo , Shi Lei
Published: May 2024

High-dimensional quantum key distribution (HD-QKD) is a topic of growing interest in the quantum communication community, not only for its inherent properties but also for its possible applications. As the typical freedom in HD-QKD, orbital angular momentum (OAM) has made significant advancements in experiments recently. However, in the airborne scenario, different states suffer different amounts of misalignment and turbulence. A complete theoretical analysis model for the transmission characteristics of OAM in atmospheric channels is lacking. In this paper, we systematically analyze the extent to which degeneration including channel power loss and mode crosstalk are influenced by misalignment and turbulence effects. Furthermore, the performance of OAM-encoded HD-QKD system in different dimensions is evaluated while incorporating finite-key effects. We demonstrate that the performance of OAM-encoded HD-QKD will be better at short range, which provide a reference to implement QKD based on task requirements. Since OAM is desired to increase the capacity of QKD system and experiments have already been carried out, our work can not only bridge the gap between theory and practice, but also optimize experimental parameters and improve system performance.
Two-dimensional quantum droplets in binary quadrupolar condensates
Authors: Yang Aowei , Zhou Jiahao , Liang Xiaoqing , Li Guilong , Liu Bin , Luo Huan-Bo , Malomed Boris A , Li Yongyao
Published: May 2024

We study the stability and characteristics of two-dimensional (2D) quasi-isotropic quantum droplets (QDs) of fundamental and vortex types, formed by binary Bose–Einstein condensate with magnetic quadrupole–quadrupole interactions (MQQIs). The magnetic quadrupoles are built as pairs of dipoles and antidipoles polarized along the x-axis. The MQQIs are induced by applying an external magnetic field that varies along the x-axis. The system is modeled by the Gross–Pitaevskii equations including the MQQIs and Lee-Huang-Yang correction to the mean-field approximation. Stable 2D fundamental QDs and quasi-isotropic vortex QDs with topological charges

S
⩽
4

are produced by means of the imaginary-time-integration method for configurations with the quadrupoles polarized parallel to the system’s two-dimensional plane. Effects of the norm and MQQI strength on the QDs are studied in detail. Some results, including an accurate prediction of the effective area, chemical potential, and peak density of QDs, are obtained in an analytical form by means of the Thomas-Fermi approximation. Collisions between moving QDs are studied by means of systematic simulations.
Quantum sensing with tunable superconducting qubits: optimization and speed-up
Authors: Danilin S , Nugent N , Weides M
Published: May 2024

Sensing and metrology are crucial in both fundamental science and practical applications. They meet the constant demand for precise data, enabling more dependable assessments of theoretical models’ validity. Sensors, now a common feature in many fields, play a vital role in applications like gravity imaging, geology, navigation, security, timekeeping, spectroscopy, chemistry, magnetometry, healthcare, and medicine. The advancements in quantum technologies have sparked interest in employing quantum systems as sensors, offering enhanced capabilities and new possibilities. This article describes the optimization of the quantum-enhanced sensing of magnetic fluxes with a Kitaev phase estimation algorithm based on frequency tunable transmon qubits. It provides the optimal flux biasing point for sensors with different qubit transition frequencies and gives an estimation of decoherence rates and achievable sensitivity. The use of 2- and 3-qubit entangled states are compared in simulation with the single-qubit case. The flux sensing accuracy reaches

10

−
8

⋅

Φ
0

and scales inversely with time, which proves the speed-up of sensing with high ultimate accuracy.
Amplification in parametrically-driven resonators near instability based on Floquet theory and Green’s functions
Authors: Batista Adriano A
Published: May 2024

Here we use Floquet theory to calculate the response of parametrically-driven time-periodic systems near the onset of parametric instability to an added external ac signal or white noise. We provide new estimates, based on the Green’s function method, for the response of the system in the frequency domain. Furthermore, we present novel expressions for the power and noise spectral densities. We validate our theoretical results by comparing our predictions for the specific cases of a single degree of freedom parametric amplifier and of the parametric amplifier coupled to a harmonic resonator with the numerical integration results and with analytical approximate results obtained via the averaging method up to second order.
A simple theory for training response of deep neural networks
Authors: Nakazato Kenichi
Published: May 2024

Deep neural networks give us a powerful method to model the training dataset’s relationship between input and output. We can regard that as a complex adaptive system consisting of many artificial neurons that work as an adaptive memory as a whole. The network’s behavior is training dynamics with a feedback loop from the evaluation of the loss function. We already know the training response can be constant or shows power law-like aging in some ideal situations. However, we still have gaps between those findings and other complex phenomena, like network fragility. To fill the gap, we introduce a very simple network and analyze it. We show the training response consists of some different factors based on training stages, activation functions, or training methods. In addition, we show feature space reduction as an effect of stochastic training dynamics, which can result in network fragility. Finally, we discuss some complex phenomena of deep networks.
Origin of regularity in different nuclei from the viewpoint of the effective quadrupole deformation and triaxiality
Authors: Hosseinnezhad Asgar , Sabri Hadi
Published: May 2024

This paper presents a theoretical investigation of the possible relation between the regularity of nuclei and the quadrupole deformation of different levels (and also triaxiality). The present paper aims to uncover the underlying physical reasons for this regularity. To this aim, we calculated the effective quadrupole deformation of different levels using the interacting boson model. Also, different ratios between the quadrupole deformations of the energy levels in the ground, beta, and gamma bands are defined. The results for the energy levels confirm the correctness of labeling these states by the quantum numbers of U(5) and SU(3) dynamical symmetry limits (and also the extraction processes). Also, we observed a repetition pattern for these ratios for regular nuclei. Of course, the regularity and sameness of repetition patterns for the levels of the rotational bands are more than the levels of the ground band. For further study, we analyzed the effective quadrupole deformation values of different levels of regular nuclei using random matrix theory. The results show a strong statistical correlation for these quantities and confirm the observed repetition pattern. Also, the results of our studies showed that regular nuclei have triaxial properties.
Exploring fission and quasi-fission in 31Al + 197Au: probing energies near and beyond Coulomb barrier
Authors: Jain Shivani , Jindal Chahat , Sharma Manoj K
Published: May 2024

An idea to understand the fragmentation of a formed nuclear entity (i.e. compound nucleus), induced via heavy-ion reactions, is an interesting task especially at incident energies near, above and far away from the Coulomb barrier. In the present work, we are studying the decay dynamics of a formed nuclear entity i.e. 228U* compound nucleus (CN), via the radioactive beam of Aluminium-31 (31Al) striking on the stable Gold-197 (197Au) target nucleus, for incident energies E
c.m. = 106.2–163.2 MeV. A comprehensive knowledge regarding the probable decaying fragments from 228U* has been accumulated using the collective clusterization approach of the Dynamical Cluster-decay Model (DCM) in terms of mass and charge dispersion, which built up on the Quantum Mechanical Fragmentation Theory (QMFT). Through both of these dispersion cases, we have identified the decaying fragments in the fission and heavy-mass regions, at different scale of incident energies. Further, the fission cross-sections (

σ

fis

Theo

) have been obtained for 31Al + 197Au → 228U* reaction at the above said E
c.m. (MeV) and compared with the experimental data. This study has been carried out using two different sets of Skyrme force parameters (SIII and SSk), which are employed within the semiclassical approach of Skyrme Energy Density Formalism. Unlike for energies below and near the barrier, a significant difference has been observed between calculated (

σ

fis

Theo

) and experimental (

σ

fis

Expt

) cross-sections for above barrier energies, with independent choice of Skyrme forces. Such discrepancy noticed has been addressed with the presence of quasi-fission (QF) event. Similar phenomena has also been seen for 19F-induced reaction forming the same CN (228U*).
Molecular strong coupling: evaluating dipole oscillator and cavity field parameters
Authors: Barnes William L
Published: May 2024

In this report we use material parameters to calculate the strength of the expected Rabi splitting for a molecular resonance. As an example we focus on the molecular resonance associated with the C=O bond in a polymer host, specifically the stretch resonance at ∼1730 cm−1. Two related approaches to modelling the anticipated extent of the coupling are examined, and the results compared with data from experiments available in the literature. The approaches adopted here indicate how material parameters may be used to assess the potential of a material to exhibit strong coupling, and also enable other useful parameters to be derived, including the molecular dipole moment and the vacuum cavity field strength.
Dielectric resonator antenna with graphene layer and NMP structure for THz applications
Authors: Miranda Igor R S , Santos Marcos G F , Souza Fiterlinge M , de Sousa Fabio B , Costa Marcos B C , Paschoal Waldomiro
Published: May 2024

Antennas with high performance and technological materials are relevant for several application on THz band. In this work, we investigate the cylindrical dielectric resonator antenna (CDRA) with non-resonant microstrip patch (NMP) feed combined with a thin layer of graphene on the top of the Dielectric Resonator (DR) designed for 3.30 THz. The NMP structure provides high order HEM12δ
mode with great advantages in gain values and radiation efficiency. The graphene layer associated with the NMP structure provided improvements in gain and return loss, as well as, tuning characteristics by changing the chemical potential. The antenna was simulated in Ansys HFSS, and the results obtained with NMP radius of 12.7 μm are

S
11
=
−
37.98

and

7.9

dB

gain. Besides, the bandwidth increased 6.6% to 20%. These results corroborate the effectiveness and enhancement of the antenna parameters providing a great alternative for Terahertz band applications.
Cosmologies in f(R, 
m
) theory with non-minimal coupling between geometry and matter
Authors: Bravo Medina Sergio , Nowakowski Marek , V Lobato Ronaldo , Batic Davide
Published: May 2024

Among the recent extensions to standard General Relativity,

f
(
R
,

L

m

)

gravity has risen an interest given the possibility of coupling between geometry and matter. We examine the simplest model with non-minimal coupling in the context of cosmology. We pay special attention to the question of how far this model could reproduce the observational fact of our universe.
Strain-induced giant enhancement and transformation of magnetocrystalline anisotropy in 1T-FeSe2 monolayer
Authors: Ruan Qianlian , Peng Ke , Chen Bowen , Ming Xing
Published: May 2024

The development of magnetic materials with large magnetic anisotropy energy (MAE) is crucial for magnetic storage and spintronics applications. The electronic structure and magnetic properties of 1T-FeSe2 monolayer have been systematically investigated by first-principles computational methods. The monolayer 1T-FeSe2 is confirmed to be a ferromagnetic semimetal with 100% spin polarization and exhibits pronounced magnetic anisotropy. It shows an easy magnetization plane in the two-dimensional plane and its MAE is as high as 8.134 meV. The MAE mainly originates from the contributions of transitions between Fe

d

yz

and

d

z

2

,

d

xy

and

d

x

2

−
y

2

orbitals, while the contributions of transitions between p
x and p
y, p
x and p
z orbitals of Se are also obvious. The biaxial strain significantly regulates the magnetic properties and electronic structures of the 1T-FeSe2 monolayer. Interestingly, the MAE increases significantly to 77.680 meV when the tensile strain increases to 3.5%, we can expect to achieve a reasonable value of MAE up to 98.951 meV by applying 5% tensile strain. In addition, the easy magnetization plane changes to perpendicular easy magnetization axis direction at −6% compressive strain or 7% tensile strain, which leads to a significant change in the band structure near the Fermi level. The 100% spin-polarized ferromagnetic semi-metallic behavior and the huge strain-induced magnetic anisotropy make the 1T-FeSe2 monolayer material promising for spintronics and magnetic data storage.
Finite and high-temperature series expansion via many-body perturbation theory: application to Heisenberg spin-1/2 XXZ chain
Authors: Tag M A , Boudiar A , Mansour M E H , Hafdallah A , Bendjeroudib C , Zaidi Beddiaf
Published: May 2024

We present a new algorithm to evaluate the grand potential at high and finite temperatures using many-body perturbation theory. This algorithm enables us to calculate the contribution of any Hugenholtz or Feynman vacuum diagrams and formulate the results as a sum of divided differences. Additionally, the proposed method is applicable to any interaction in any dimension, allowing us to calculate thermodynamic quantities efficiently at any given temperature, particularly at high temperatures.Furthermore, we apply this algorithm to the Heisenberg spin-1/2 XXZ chain. We obtain all coefficients of the high-temperature expansion of the free energy and susceptibility per site of this model up to the sixth order.
Isotactic-polypropylene (iPP) wettability modified by surface DBD plasma
Authors: Bedrouni F , Ouchabane M , Almabouada F , Saidi-Amroun N
Published: May 2024

In this paper, atmospheric pressure plasma of ambient air was generated by a surface dielectric barrier discharge (SDBD) device for the purpose of modifying the surface of isotactic-polypropylene (iPP). The effect of SDBD treatment time on the chemical and physical properties of iPP was studied using various analytical techniques including, water contact angle (WCA), attenuated total reflection (ATR), Raman spectroscopy, x-ray diffraction (XRD), and atomic force microscopy (AFM). The results indicate that the hydrophilicity and the C=O bonds of the treated iPP were improved as observed, respectively, through WCA and ATR analysis. The crystal structure was evaluated by Raman spectroscopy and XRD. It was found that the iPP chain was under microscopic stress, which affected its crystallinity degree depending on the duration of the treatment. Furthermore, the AFM analysis revealed that the surface roughness was substantially modified.
Development of pulsed plasma operation scenario and required conditions in JA DEMO
Authors: Sugiyama S. , Aiba N. , Asakura N. , Hayashi N. , Sakamoto Y.
Published: May 2024

We have developed the pulsed plasma operation scenarios for JA DEMO, a design concept of the steady-state tokamak demonstration reactor, to clarify controls of the current profile and power required for the operation. We compare the scenarios when injecting electron cyclotron waves only and both neutral beam and electron cyclotron waves for external heating and current drive. We demonstrate current profile control that maintains the minimum value of the safety factor above one and avoids creating the local minima in the safety factor profile and power control by argon seeding that maintains the fusion power constant at the desired value and reduces the heat load on the divertor, performing long-time integrated modeling simulations. We clarify the conditions of the heating and current drive system and impurity injection system required for such control. The dependence of power control on argon anomalous transport coefficients is investigated. We have the prospect of maintaining the fusion power of 1 GW for more than two hours, i.e. obtaining the required plasma performance determined using a systems code.
The use of supramolecular systems in biomedical applications for antimicrobial properties, biocompatibility, and drug delivery
Authors: Li Yijie , Vrana Nihal Engin , Letellier Baptiste , Lavalle Philippe , Guilbaud-Chéreau Chloé
Published: May 2024

Supramolecular chemistry is versatile for developing stimuli-responsive, dynamic and multifunctional structures. In the context of biomedical engineering applications, supramolecular assemblies are particularly useful as coatings for they can closely mimic the natural structure and organisation of the extracellular matrix (ECM), they can also fabricate other complex systems like drug delivery systems and bioinks. In the current context of growing medical device-associated complications and the developments in the controlled drug delivery and regenerative medicine fields, supramolecular assemblies are becoming an indispensable part of the biomedical engineering arsenal. This review covers the different supramolecular assemblies in different biomedical applications with a specific focus on antimicrobial coatings, coatings that enhance biocompatibility, surface modifications on implantable medical devices, systems that promote therapeutic efficiency in cancer therapy, and the development of bioinks. The introduced supramolecular systems include multilayer coating by polyelectrolytes, polymers incorporated with nanoparticles, coating simulation of ECM, and drug delivery systems. A perspective on the application of supramolecular systems is also included.
High-speed spinning of collagen microfibers comprising aligned fibrils for creating artificial tendons
Authors: Yunoki Shunji , Kishimoto Masanori , Mandai Yoshinobu , Hiraoka Yosuke , Kondo Eiji
Published: May 2024

Bundles of engineered collagen microfibers are promising synthetic tendons as substitutes for autogenous grafts. The purpose of this study was to develop high-speed and continuous spinning of collagen microfibers that involves stretching of collagen stream. Our study revealed the ‘critical fibrillogenesis concentration (CFC)’ of neutralized collagen solutions, which is defined as the upper limit of the collagen concentration at which neutralized collagen molecules remain stable as long as they are cooled (

⩽

10 °C). Neutralized collagen solutions at collagen concentrations slightly below the CFC formed cord-like collagen gels comprising longitudinally aligned fibrils when extruded from nozzles into an ethanol bath. Dry collagen microfibers with a controlled diameter ranging from 122 ± 2–31.2 ± 1.7 μm can be spun from the cord-like gels using nozzles of various sizes. The spinning process was improved by including stretching of collagen stream to further reduce diameter and increase linear velocity. We extruded a collagen solution through a 182 μm diameter nozzle while simultaneously stretching it in an ethanol bath during gelation and fiber formation. This process resembles the stretching of a melted thermoplastic resin because it solidifies during melt spinning. The mechanical properties of the stretched collagen microfibers were comparable to the highest literature values obtained using microfluidic wet spinning, as they exhibited longitudinally aligned fibrils both on their surface and in their core. Previous wet spinning methods were unable to generate collagen microfibers with a consistent tendon-like fibrillar arrangement throughout the samples. Although the tangent modulus (137 ± 7 MPa) and stress at break of the swollen bundles of stretched microfibers (13.8 ± 1.9 MPa) were lower than those of human anterior cruciate ligament, they were within the same order of magnitude. We developed a spinning technique that produces narrow collagen microfibers with a tendon-like arrangement that can serve as artificial fiber units for collagen-based synthetic tendons.