bluuebunny/crossref_metadata_2025 huggingface dataset:
Various solitons induced by relative phase in the nonlinear Schrödinger Maxwell–Bloch system
Authors: Ren Yang , Guo Liang , Cao Xin-Wei , Duan Liang
Published: January 2024

We study the effect of relative phase on the characteristics of rogue waves and solitons described by rational solutions in the nonlinear Schrödinger Maxwell–Bloch system. We derived the rational rogue wave and soliton solutions with adjustable relative phase and present the parameter range of different types of rogue waves and solitons. Our findings show that the relative phase can alter the distribution of rational solitons and even change the type of rational solitons, leading to a rich array of rational soliton types by adjusting the relative phase. However, the relative phase does not affect the structure of the rogue wave, because the relative phase of the rogue wave changes during evolution. In particular, we confirm that the rational solitons with varying relative phases and the rogue waves at corresponding different evolution positions share the same distribution mode. This relationship holds true for rogue waves or breathers and their stable counterparts solitons or periodic waves in different nonlinear systems. The implications of our study are significant for exploring fundamental excitation elements in nonlinear systems.
Mean sinc sums and scale invariant scattering
Authors: Curtright Thomas
Published: January 2024

Scattering from a scale invariant potential in two spatial dimensions leads to a class of novel identities involving the sinc function.
A novel experimental setup for axial–torsional coupled vibration impact-assisted PDC drill bit drilling
Authors: Ji Ran , Shi Huaizhong , Huang Zhongwei , He Wenhao , Wu Xiaoguang , Fu Xinkang , Sun Zhaowei , Xiong Chao
Published: January 2024

The geological conditions of hot dry rock (HDR) reservoirs are complex. The geothermal mining of HDR faces major challenges in the drilling and construction of wells, fracturing to create storage, and flowing to extract heat. Vibration impacts help improve the rock-breaking efficiency, where the axial–torsional coupled vibration impact technology can increase the bit penetration depth and reduce the stick–slip effect. To study the feasibility and efficiency of the axial–torsional-coupled vibration impact-assisted Polycrystalline Diamond Compact (PDC) bit to break high-temperature and high-pressure rocks, a new experimental setup was designed. The system includes a drilling fluid circulation system, an axial–torsional coupled impact drilling system, a formation simulation system, and a data acquisition and control system. This setup can produce a rock-breaking torque of 2000 N·m, a drilling speed of 200 rpm, a weight on bit of 100 kN, an axial vibration frequency of 100 Hz, and a torsional vibration frequency of 50 Hz. It can simulate the formation pressure of 70 MPa and the rock temperature of 400 °C. A series of rock-breaking drilling experiments were successfully conducted using this setup. The results show that the axial–torsional coupled vibration-impact assisted PDC bit has a good performance in breaking high-temperature and hard rocks, which can accelerate the application of this new technology in deep formation drilling.
An improved neural network for modeling airfoil's unsteady aerodynamics in transonic flow
Authors: Pan Yihua , An Xiaomin , Lei Yuqi , Ji Chen
Published: January 2024

Understanding the aerodynamic hysteresis loop phenomenon is essential when assessing aerodynamic performance and designing aircraft control systems. This phenomenon is a result of time delay effects in unsteady flow. Traditional methods of predicting unsteady aerodynamic forces using computational fluid dynamics have drawbacks, such as long cycles and low efficiency. In this paper, we focus on predicting the aerodynamic hysteresis loop of the NACA (National Advisory Committee for Aeronautics) 0012 airfoil in transonic flow using a new model called LIDNN (Latin hypercube sample input deep neural network). This model integrates input signals and optimization methods to improve upon traditional neural network models. Based on the example validation, the LIDNN model is authenticated as an accurate and efficient method in predicting the unsteady aerodynamic hysteresis loop of the NACA 0012 airfoil in transonic flow, and another significant advantage of the proposed model is its ability to solve multivariable problems effectively, even under varying Mach numbers.
Linear stability analysis on the thermocapillary flow of molten silicon in a liquid bridge between unequal disks under a rotating magnetic field
Authors: Li Hao , Zeng Zhong , Zhang Liangqi , Wang Yue , Liu Yong , Liu Hao
Published: January 2024

This paper explores the stability of thermocapillary flow in a molten silicon liquid bridge situated between two unequal disks and subjected to a rotating magnetic field. Two different heating strategies are examined, and the static deformation of the free surface is taken into account by solving the Young–Laplace equation. Using linear stability analysis based on the Legendre spectral element method, the critical conditions are determined, and the underlying instability mechanism is uncovered through energy analysis. When heated from the bottom disk, three transitions between axisymmetric steady flow and three-dimensional oscillatory flow are observed within a narrow range of 7000 ≤ Ta ≤ 9000. In contrast, when heated from the top disk, the rotating magnetic field significantly enhances the flow stability. Furthermore, based on the energy analysis, we identify two types of instability caused by purely hydrodynamic mechanisms.
Extending the depth-of-field of computational ghost imaging: Computational refocus via in situ point spread function estimation
Authors: Ma Mengchao , Liang Wenbo , Qin Fushun , Guan Qingtian , Zhong Xiang , Deng Huaxia , Wang Ziwei
Published: January 2024

Capturing details of objects beyond the focal plane is challenging due to the limited depth-of-field (DoF) of optical systems. Here, we report a computational refocusing ghost Imaging (CRGI) method to extend the DoF of computational ghost imaging (CGI) systems. An ultra-fast and in situ point spread function (PSF) estimation method is put forward utilizing the optical characterization of the system and compressive sensing modulation. The PSF distribution is measured with in situ compressive sensing algorithm according to reciprocity property using the same CGI system. The convolution of PSFs of various depths with modulation patterns is reshaped into measurement matrices to computationally refocus objects at different depths. From one measurement, CRGI can rebuild distinct and well-focused images of multiple objects at different depths. According to experiments, CRGI can nearly quadruple the DoF of typical CGI methods. CRGI represents a significant advancement in CGI domain by computationally surpassing the optical DoF limitations. This discovery enables recording object features beyond the focus plane using extended depth-of-field.
Rapid fluorescence lifetime imaging microscopy via few-photon imaging
Authors: Sun Ming-Jie , Zhang Yi-Cheng , Lin Fang-Rui , Wang Shuai , Liu Li-Wei , Qu Jun-Le
Published: January 2024

Conventional fluorescence lifetime imaging microscopy (FLIM) based on time-correlated single photon counting has great potential in various domains, notably in cellular biology, enabling comprehensive studies encompassing spatiotemporal dynamics and quantitative analysis of fluorescence lifetimes. However, it usually requires a long acquisition time, which limits its application in rapid imaging scenarios, such as investigation of rapidly evolving biological events and observation of living organisms. This work proposes a rapid fluorescence lifetime imaging scheme, which reduces the requirement of photon accumulating number and enables rapid fluorescence lifetime estimation under photon-limited conditions. Instead of relying on accumulated photons, the proposed scheme records the counts of emitted laser pulses upon photon counting events within different time gates to estimate the fluorescence intensity, and the fluorescence lifetime is then calculated using the rapid lifetime determination algorithm. Experimental results demonstrate that in order to reconstruct fluorescence lifetime images with similar quality, the proposed scheme requires only a fifth acquisition time that of the conventional time-correlated single photon counting FLIM. The proposed method offers a potential possible approach for rapid fluorescence lifetime determination in dynamic applications.
Ideal conductor/dielectric model (ICDM): A generalized technique to correct for finite-size effects in molecular simulations of hindered ion transport
Authors: Shoemaker Brian A. , Haji-Akbari Amir
Published: January 2024

Molecular simulations serve as indispensable tools for investigating the kinetics and elucidating the mechanism of hindered ion transport across nanoporous membranes. In particular, recent advancements in advanced sampling techniques have made it possible to access translocation timescales spanning several orders of magnitude. In our prior study [Shoemaker et al., J. Chem. Theory Comput. 18, 7142 (2022)], we identified significant finite size artifacts in simulations of pressure-driven hindered ion transport through nanoporous graphitic membranes. We introduced the ideal conductor model, which effectively corrects for such artifacts by assuming the feed to be an ideal conductor. In the present work, we introduce the ideal conductor dielectric model (Icdm), a generalization of our earlier model, which accounts for the dielectric properties of both the membrane and the filtrate. Using the Icdm model substantially enhances the agreement among corrected free energy profiles obtained from systems of varying sizes, with notable improvements observed in regions proximate to the pore exit. Moreover, the model has the capability to consider secondary ion passage events, including the transport of a co-ion subsequent to the traversal of a counter-ion, a feature that is absent in our original model. We also investigate the sensitivity of the new model to various implementation details. The Icdm model offers a universally applicable framework for addressing finite size artifacts in molecular simulations of ion transport. It stands as a significant advancement in our quest to use molecular simulations to comprehensively understand and manipulate ion transport processes through nanoporous membranes.
Efficient characterization of double-cross-linked networks in hydrogels using data-inspired coarse-grained molecular dynamics model
Authors: Zong Ting , Liu Xia , Zhang Xingyu , Yang Qingsheng
Published: January 2024

The network structure within polymers significantly influences their mechanical properties, including their strength, toughness, and fatigue resistance. All-atom molecular dynamics (AAMD) simulations offer a method to investigate the energy dissipation mechanism within polymers during deformation and fracture; Such an approach is, however, computationally inefficient when used to analyze polymers with complex network structures, such as the common chemically double-networked hydrogels. Alternatively, coarse-grained molecular dynamics (CGMD) models, which reduce the computational degrees of freedom by concentrating a set of adjacent atoms into a coarse-grained bead, can be employed. In CGMD simulations, a coarse-grained force field (CGFF) is a critical factor affecting the simulation accuracy. In this paper, we proposed a data-based method for predicting the CGFF parameters to improve the simulation efficiency of complex cross-linked network in polymers. Here, we utilized a typical chemically double-networked hydrogel as an example. An artificial neural network was selected, and it was trained with the tensile stress–strain data from the CGMD simulations using different CGFF parameters. The CGMD simulations using the predicted CGFF parameters show good agreement with the AAMD simulations and are almost fifty times faster. The data-inspired CGMD model presented here broadens the applicability of molecular dynamics simulations to cross-linked polymers and has the potential to provide insights that will aid the design of polymers with desirable mechanical properties.
Low-frequency directional wideband transducer based on lead-free piezoelectric ceramics
Authors: Zhang Xiuzhen , Wu Chaofeng , Gong Wen , Wang Ke , Mo Xiping , Chai Yong
Published: January 2024

In recent years, lead-free piezoelectric ceramic devices have been extensively researched and applied in the high-frequency range, specifically above 20 kHz, for airborne acoustics applications. However, few applications have been reported on low-frequency underwater acoustic transducers, which are crucial in the fields of underwater acoustic communication, ocean resource development, etc., because this imposes more stringent requirements for lead-free piezoelectric ceramics in terms of size, mechanical coupling coefficient, piezoelectric coefficients, and temperature stability. This paper explores the application of high-performance potassium sodium niobate based lead-free piezoelectric ceramics in a low-frequency directional wideband transducer. It covers design, fabrication, and performance testing of the transducer. The transducer measures Φ236 × 83 mm2 and weighs 4.45 kg, which achieves wideband emission (3500–8200 Hz) and directional sound emission with a front-to-back sound pressure ratio exceeding 6 dB across a significant frequency range. Both the theoretical analysis and the experimental results confirm the competitiveness application of the lead-free piezoelectric ceramics in the field of low-frequency underwater acoustic transducers applications.
Enhancing thermal mixing of supercritical water through a confined co-flowing planar jet
Authors: Pei Binbin , Lai Zitian , Zhao Kunpeng , Huang Ning , Bai Bofeng
Published: January 2024

Previous studies have reported that the thermal mixing of supercritical water (SCW) would be inhibited by the density gradient in jet flow. The confined co-flowing planar jet which has one central inlet and two outer inlets is expected to enhance thermal mixing through stronger turbulent entrainment induced by double mixing layers. Direct numerical simulations (DNS) of planar jet of supercritical water (653–843 K, 25 MPa) are performed. The effects of the density ratio ρr (1.1, 3, 6) between jet and ambient fluids, the Reynolds number based on the density, velocity, diameter, and viscosity of central inlet Rein=ρinUinDin/μin (1000–4000), and the buoyancy on thermal mixing properties are investigated. We find that increasing ρr results in the decay of turbulence near the double mixing layers and the attenuation of thermal mixing. The self-similar behavior for co-flowing planar jet of supercritical water can be more likely to achieve for the mean field than for the turbulence field. While increasing Rein results in the amplification of turbulence production in the far-field region due to the vortex stretching mechanism induced by larger velocity gradient, the enhancement of thermal mixing is insignificant. The gravity wave along the normal direction leads to density stratification and inhibition of turbulent mixing near the mixing layers when Rein less than 2000. The gravity effect can be neglected when Rein greater than 2000 due to the increasing turbulence production. Finally, we find that the enhancement of thermal mixing can be achieved by increasing the turbulent intensity of outer inlets.
Acoustic Bessel-like beam generation using phononic crystals
Authors: Dasila Santosh , Venkata Krishnamurthy Chitti , Subramanian Venkatachalam
Published: January 2024

Diffraction-free beams with large depth-of-field have a lot of potential in the field of acoustics, such as imaging, sensing, and particle manipulation. In this study, an acoustic Bessel-like beam is produced using an axicon-sonic crystal lens. The sonic crystal is created using cylindrical glass rods arranged in a triangular shape with a centered square lattice configuration. The numerical simulation between 4 and 8 kHz indicates that the axicon-sonic crystal converts the plane acoustic wave into a Bessel-like beam. The analysis of the beam indicates that the depth of field of this beam depends on the size and periodicity (lattice parameter) of the sonic crystal. The axicon lens also displays variable focal lengths at different frequencies. A graded index layer was implemented to mitigate the reflection caused by the significant impedance mismatch. Experimental validation of acoustic Bessel-like beam formation is also reported for the working frequencies. At 8 kHz, the measured range to the 50% on-axis intensity was 34λ, while the focus width at the same frequency was measured to be 2λ. The integration of three distinct design strategies—axicon shape, sonic crystal, and graded index—expands the possibilities for sound focusing applications.
Aerodynamic prediction and roughness implementation toward ice accretion simulation
Authors: Chen Jiawei , Yang Pu , Zhang YuFei , Fu Song
Published: January 2024

Ice accretion in aircraft leads to significant separation and surface roughness. Therefore, the simulation of icing is highly intricate and challenging. The aerodynamic prediction of an iced wing requires an accurate turbulence model. In this paper, a modified transition model for the Reynolds-averaged Navier–Stokes equation is developed. The model is implemented using a linear eddy viscosity transition model as a baseline. It is modified to accurately predict the flow separation and simulate the influence of roughness. Different cases are numerically tested based on the modified model, including two types of iced airfoils (glaze ice and rime ice) and two rough geometries. The results indicate that the model demonstrates engineering accuracy in terms of the flow separation and aerodynamic coefficient prediction. Moreover, this model could be adapted for a wide range of ice shapes. In addition, the present model is capable of accounting for the influence of surface roughness, leading to significant improvements in heat transfer coefficients that match the experimental data well.
Experimental simulation study on gas flow field in combined goaf during the transition period of coal pillar-free working face relocation
Authors: Fu Xiang , Liu Xuan , Wu Qixuan , Chang Teng , Wang Yifan , Sha Huihui
Published: January 2024

Regarding the gas disaster caused by the complex ventilation system and the changeable flow field in the combined goaf during the transition period of the coal pillar-free working face, the self-designed physical simulation test bench for the combined goaf of coal pillar-free mining was used to compare and analyze the distribution law of wind pressure, gas, and oxygen concentration field in the combined goaf during the moving period of the working face and the normal mining period. The results show that during the relocation period, the gas concentration in the stope will always be slightly higher than that in the normal mining period, and the existing air leakage channel will lead to complex air flow in the combined goaf, which is easy to cause gas explosion accidents. The formation conditions, judgment principles, and judgment methods of the dangerous area of gas explosion coupling disaster in goaf are analyzed. By changing the air distribution ratio of the main and auxiliary air intake roadways, it is concluded that the explosion area will form an “L”-shaped explosion zone in the goaf, and the area of gas explosion disaster area during the relocation period will be larger than that the normal mining period. According to the size of the gas explosion area, the optimal air distribution ratio of the main and auxiliary air intake roadway during the transition period of the working face relocation and the normal mining period is 2:1. Under this air distribution ratio, the gas explosion area is the smallest, which is 132 284 and 113 534 mm2, respectively. The research results are of great significance to reveal the mechanism of gas disaster induced by goaf during the transition period of coal pillar-free relocation.
Applications of regime-switching in the nonlinear double-diffusivity (D-D) model
Authors: Chattopadhyay Amit K. , Aifantis Elias C.
Published: January 2024

The linear double-diffusivity (D-D) model of Aifantis, comprising two coupled Fick-type partial differential equations and a mass exchange term connecting the diffusivities, is a paradigm in modeling mass transport in inhomogeneous media, e.g., fissures or fractures. Uncoupling of these equations led to a higher order partial differential equation that reproduced the non-classical transport terms, analyzed independently through Barenblatt’s pseudoparabolic equation and the Cahn–Hilliard spinodal decomposition equation. In the present article, we study transport in a nonlinearly coupled D-D model and determine the regime-switching of the associated diffusive processes using a revised formulation of the celebrated Lux method that combines forward Fourier transform with a Laplace transform followed by an Inverse Fourier transform of the governing reaction–diffusion (R–D) equations. This new formulation has key application possibilities in a wide range of non-equilibrium biological and financial systems by approximating closed-form analytical solutions of nonlinear models.
Neural heterogeneity controls computations in spiking neural networks
Authors: Gast Richard , Solla Sara A. , Kennedy Ann
Published: January 2024

The brain is composed of complex networks of interacting neurons that express considerable heterogeneity in their physiology and spiking characteristics. How does this neural heterogeneity influence macroscopic neural dynamics, and how might it contribute to neural computation? In this work, we use a mean-field model to investigate computation in heterogeneous neural networks, by studying how the heterogeneity of cell spiking thresholds affects three key computational functions of a neural population: the gating, encoding, and decoding of neural signals. Our results suggest that heterogeneity serves different computational functions in different cell types. In inhibitory interneurons, varying the degree of spike threshold heterogeneity allows them to gate the propagation of neural signals in a reciprocally coupled excitatory population. Whereas homogeneous interneurons impose synchronized dynamics that narrow the dynamic repertoire of the excitatory neurons, heterogeneous interneurons act as an inhibitory offset while preserving excitatory neuron function. Spike threshold heterogeneity also controls the entrainment properties of neural networks to periodic input, thus affecting the temporal gating of synaptic inputs. Among excitatory neurons, heterogeneity increases the dimensionality of neural dynamics, improving the network’s capacity to perform decoding tasks. Conversely, homogeneous networks suffer in their capacity for function generation, but excel at encoding signals via multistable dynamic regimes. Drawing from these findings, we propose intra-cell-type heterogeneity as a mechanism for sculpting the computational properties of local circuits of excitatory and inhibitory spiking neurons, permitting the same canonical microcircuit to be tuned for diverse computational tasks.
IκB kinase phosphorylates cytoplasmic TDP-43 and promotes its proteasome degradation
Authors: Iguchi Yohei , Takahashi Yuhei , Li Jiayi , Araki Kunihiko , Amakusa Yoshinobu , Kawakami Yu , Kobayashi Kenta , Yokoi Satoshi , Katsuno Masahisa
Published: January 2024

Cytoplasmic aggregation of TDP-43 in neurons is a pathological feature common to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). We demonstrate that the IκB kinase (IKK) complex promotes the degradation of cytoplasmic TDP-43 through proteasomes. While IKKβ is a major factor in TDP-43 degradation, IKKα acts as a cofactor, and NEMO functions as a scaffold for the recruitment of TDP-43 to the IKK complex. Furthermore, we identified IKKβ-induced phosphorylation sites of TDP-43 and found that phosphorylation at Thr8 and Ser92 is important for the reduction of TDP-43 by IKK. TDP-43 phosphorylation at Ser92 was detected in a pattern different from that of C-terminal phosphorylation in the pathological inclusion of ALS. IKKβ was also found to significantly reduce the expression level and toxicity of the disease-causing TDP-43 mutation. Finally, the favorable effect of IKKβ on TDP-43 aggregation was confirmed in the hippocampus of mice. IKK and the N-terminal phosphorylation of TDP-43 are potential therapeutic targets for ALS and FTLD.
Pressure-induced phase transition of Lu2Ti2O7 and Lu1.5Ce0.5Ti2O7+x
pyrochlores
Authors: Xu Min , Niu Jingjing , Wu Guanfeng , Liao Qian , Tan Xi , Yang Dongyan , Liu Longcheng , Li Yuhong , Xia Yue
Published: January 2024

This study utilizes both experimental and computational approaches to investigate the performance of Lu2Ti2O7 (LTO) and Lu1.5Ce0.5Ti2O7+x
(LCTO) pyrochlores under high pressure. The structural changes of LTO and LCTO pyrochlores were characterized using in-situ synchrotron x-ray diffraction (SXRD) and in-situ Raman spectroscopy at pressures up to 44.6 GPa. The kinks in P–a and P–V curves at around 5 GPa are mainly attributed to the interaction between the pressure medium and the isostructural changes. The onset pressures for transitioning from the cubic pyrochlore phase (Fd-3 m) to the monoclinic phase (P2
1) are observed at 32.5 GPa and 38.1 GPa, respectively. It is important to note that at the highest measured pressures, the phase transition remains incomplete. This partial transition is likely the result of oriented disorder among cations and anions under high pressure. In addition, introducing Ce as a dopant significantly enhances structural stability. This can be explained by the larger ionic radius of Ce, which hinders the disordering process.
Improved protection level for the solution-separation ARAIM based on worst-case fault bias searching
Authors: Li Ruijie , Li Liang , Jiang Jiachang , Du Fengze , Na Zhibo , Xu Xin
Published: January 2024

The aviation community is actively pursuing advanced receiver autonomous integrity monitoring (ARAIM) to enhance the safety of aircraft navigation services. Protection level calculation is a crucial task in the solution separation-based ARAIM as it determines the availability of the ARAIM. Accurately determining the worst-case fault bias (WCFB) is beneficial in improving the bounding tightness of protection level on positioning error. Unfortunately, the WCFB determination is a challenging task that requires a time-consuming searching procedure, especially when dealing with the multi-satellite faults. The traditional ARAIM protection level is achieved by constructing a conservative worst-case positioning error bound to avoid the unacceptable time-consumption of the brute-force searching for multi-satellite WCFBs. However, this approach comes at the cost of losing the tightness of the protection level and the availability of the ARAIM. The ARAIM milestone reports have pointed out that the availability of the baseline ARAIM needs to be continuously improved in order to satisfy the worldwide localizer precision vertical 200 (LPV-200) requirements. In response, this paper proposes a novel multi-satellite WCFBs searching method for the ARAIM to improve the tightness of protection level. The method consists of determining the worst-case fault direction and constructing an efficient WCFBs searching procedure. GPS/Galileo dual-constellation simulation result demonstrates that the proposed method not only can improve the availability of ARAIM up to 9.33% when compared with the baseline ARAIM algorithm, but also achieves comparable computation efficiency.
Machine learning in legal metrology–detecting breathalyzers’ failures
Authors: Santos Ana Gleice da Silva , Carmo Luiz Fernando Rust , Bezerra do Prado Charles
Published: January 2024

Breathalyzers used at sobriety checkpoints undergo strict quality control by metrological institutes or police departments to ensure the accuracy of the results, thus avoiding measurement inaccuracies. This paper presents a new approach to instrument evaluation using machine learning algorithms that are capable of preemptively detecting failures. Our objective was to predict instrument failures before they occur. These faults may be errors or standard deviations that exceed the allowable limits defined by technical regulations. To predict these failures, we employed historical instrument measurement data and applied classification techniques to later label instruments as suitable or unsuitable. This was based on the instrument’s potential not to fail or fail during its operation or before subsequent checks. To increase the reliability of failure prediction, we conducted fuel cell experiments to identify which instruments have cells that could compromise measurement results. To this end, we used the K-means clustering model, which identified two clusters based on the response signals during the ethanol redox reaction. The study concluded with a wear simulation on low-performance electrochemical cells to understand whether an adjustment to the calibration curve on instruments with these cells would not compromise the instrument’s accuracy until the next check.
A soft sensor model based on an improved semi-supervised stacked autoencoder for just-in-time updating of cement clinker production process data f-CaO
Authors: Zheng Wei , Liu Hui , Zhou XiaoYu , Xue XiaoJun , Li Heng , Liu JianXun
Published: January 2024

The free calcium oxide (f-CaO) content in cement clinker serves as a critical quality indicator for cement production. However, many soft sensor models employed for predicting f-CaO content utilize a limited amount of labeled data, leading to the underutilization of a substantial volume of unlabeled data and its associated information. To tackle these challenges, this study introduces soft sensor methodology based on improved semi-supervised attention stacked autoencoders (ASS-SAE). We propose an enhanced confidence-generating pseudo-labeling technique to identify high-confidence pseudo-labeled samples from pseudo-labels within a subset of correlated samples, addressing the issue of inadequate labeled data. To fully utilize the information hidden in the unlabeled data, the proposed method incorporating the confidence attention mechanism then assigns weights to the high-confidence pseudo-labeled data and inputs them into the SAE along with labeled data from a subset of similar samples for re-fine-tuning. By conducting an illustrative analysis using authentic cement data proposed for this study, the effectiveness of the approaches employed in this research is substantiated.
A new model for bearing fault diagnosis based on mutual mapping of signals and images and sparse representation
Authors: Yang Jing , Bai Yanping , Tan Xiuhui , Cheng Rong , Hu Hongping , Wang Peng , Zhang Wendong
Published: January 2024

For the issue of significant noise in the collected bearing fault signals, a new bearing fault diagnosis model based on mutual mapping of signals and images (MMSI) and sparse representation (SR) denoising is proposed. Firstly, the fault signal is divided into several segments with the same number of sampling points, and then arrange these segments in ascending order of rows. Secondly, convert the arranged signals into grayscale image and use dictionary learning for block denoising. Then, the de-noised grayscale image is restored to a signal in line order. Finally, k-nearest neighbor (KNN) is used for fault classification. To verify the performance of the proposed model, experiments are tested on 12 single working conditions and 30 multi working conditions on the Case Western Reserve University dataset and the Paderborn dataset. The experimental results indicate that compared with some existing models, the MMSI–SR–KNN model can not only accurately diagnose bearing faults in artificial damage experiments, but also performs better in real damage faults. This indicates that the model has good generalization ability between different datasets and working conditions.
Vanadate-based Fe-MOFs as promising negative electrode for hybrid supercapacitor device
Authors: Wang Yuting , Lu Wenjie , Wang Lianchao , Li Yihao , Wu Hua , Zhu Xudong , Zhang Cheng , Wang Kuaibing
Published: January 2024

In the supercapacitor field, negative electrodes are mainly concentrated in carbon-based materials, such as activated carbon, carbon nanotubes, graphene, and so forth. However, materials based on metal–organic frameworks (MOFs) as negative active components are relatively rare. Herein, a series of composite materials based on graphene oxide (GO) and vanadate-based Fe-organic frameworks have been prepared by hydrothermal method namely GO/Fe-VO4-BIPY. The deposition amount of polyoxometalate-based metal–organic frameworks (POMOFs) on the surface of graphene is adjusted by changing the content of POMOFs. Through the deposition, it can effectively reduce the accumulation between graphene, and increase the dispersion of POMOFs. As a result, the charge storage performance of the as-obtained materials is greatly improved. Among these materials, GO/Fe-VO4-BIPY-1 has the most prominent performance, with a specific capacitance of 190 F g−1 at 0.5 A g−1, which is attributed to the excellent synergistic effect between the Faraday chemical reaction and electric double-layer capacitance. In comparison with pristine Fe-VO4-BIPY, GO/Fe-VO4-BIPY-1 delivers more excellent surface area and therefore exhibits abundant redox reaction sites, achieving better electrochemical performance the best. After assembly with the positive Ni(OH)2 electrode, the maximum energy density of 46.84 W h kg−1 at a power density of 850 W kg−1 is achieved.
BAG-Net: a boundary detection and multiple attention-guided network for liver ultrasound image automatic segmentation in ultrasound guided surgery
Authors: Ji Zihan , Che Hui , Yan Yibo , Wu Jian
Published: January 2024

Objective. Automated segmentation of targets in ultrasound (US) images during US-guided liver surgery holds the potential to assist physicians in fast locating critical areas such as blood vessels and lesions. However, this remains a challenging task primarily due to the image quality issues associated with US, including blurred edges and low contrast. In addition, studies specifically targeting liver segmentation are relatively scarce possibly since studying deep abdominal organs under US is difficult. In this paper, we proposed a network named BAG-Net to address these challenges and achieve accurate segmentation of liver targets with varying morphologies, including lesions and blood vessels. Approach. The BAG-Net was designed with a boundary detection module together with a position module to locate the target, and multiple attention-guided modules combined with the depth supervision strategy to enhance detailed segmentation of the target area. Main Results. Our method was compared to other approaches and demonstrated superior performance on two liver US datasets. Specifically, the method achieved 93.9% precision, 91.2% recall, 92.4% Dice coefficient, and 86.2% IoU to segment the liver tumor. Additionally, we evaluated the capability of our network to segment tumors on the breast US dataset (BUSI), where it also achieved excellent results. Significance. Our proposed method was validated to effectively segment liver targets with diverse morphologies, providing suspicious areas for clinicians to identify lesions or other characteristics. In the clinic, the method is anticipated to improve surgical efficiency during US-guided surgery.
Special features of the Weyl–Heisenberg Bell basis imply unusual entanglement structure of Bell-diagonal states
Authors: Popp Christopher , Hiesmayr Beatrix C
Published: January 2024

Bell states are of crucial importance for entanglement based methods in quantum information science. Typically, a standard construction of a complete orthonormal Bell-basis by Weyl–Heisenberg operators is considered. We show that the group structure of these operators has strong implication on error correction schemes and on the entanglement structure within Bell-diagonal states. In particular, it implies an equivalence between a Pauli channel and a twirl channel. Interestingly, other complete orthonormal Bell-bases do break the equivalence and lead to a completely different entanglement structure, for instance in the share of positive partial transposition (PPT)-entangled states. In detail, we find that the standard Bell basis has the highest observed share on PPT-states and PPT-entangled states compared to other Bell bases. In summary, our findings show that the standard Bell basis construction exploits a very special structure with strong implications to quantum information theoretic protocols if a deviation is considered.
Tunable and super-wide angle defocusing lens large phase modulator
Authors: Xu Qining , Zhu Jun , Qin Liuli
Published: January 2024

Traditional terahertz wavefront modulators exhibit significant limitations in controlling optical wavefronts. In order to address the adjustability issues of terahertz wavefront modulators, we have developed a novel optical device based on the tunability of Fermi energy levels. Structurally, we find the ability to modulate the Fermi energy levels of graphene by modulating the carrier concentration. We can also change the phase of the light, causing the transmission path of the light as it passes through the graphene array to change, affecting the position of the backfocusing focal point, thus realizing a dynamically adjustable backfocusing effect. Theoretically, employing Dirac notation and Matrix analyze, reveals the corresponding relationship between Fermi level and phase shift. Specifically, one group Fermi levels induces a set of modulated phase changes. Experimental results demonstrate that the proposed modulator offers a large phase modulation range, enabling

2
π

phase adjustments. Moreover, it accurately focuses on a predefined focal point located at 400 um, with a numerical aperture of 0.882, a resolution of 30.39, and a full-width at half-maximum of 38. The substantial numerical aperture and small full-width at half-maximum imply that the lens can focus more light while maintaining high resolution, enhanced optical efficiency, and concentrated light focusing. At the same time, by adjusting the position of the Fermi energy level, we have succeeded in realizing a wide-angle focusing effect up to 90°. This capability extends the terahertz wave’s focusing within a wide range, expanding the application scope of traditional focusing devices.
The growth mechanism of Co atoms on Cu substrates
Authors: Zhuangfei Xi , Xiongying Dai , Wangyu Hu
Published: January 2024

The growth mechanism of Co atoms on Cu atomic substrates was studied by molecular dynamics simulation with large scale atomic/polar massively parallel simulator (LAMMPS). The embedded atom method (EAM) potential was used to investigate the growth processes of Co atoms on different Cu atom configurations. The growth process of Co on Cu substrate was carefully observed. It was found that Co atoms preferentially grow on the (100) facet on the Wulff configuration. To find out under what conditions the core-shell structure is better formed, the number of Cu atoms adsorbed on the surface and the number of Co atoms entering the interior were calculated as a function of the number of deposited atoms. The Wulff configuration was found to be more favorable for the growth of Co atoms on the Cu substrates. And the effect of the size of the Cu substrate on the growth of the Co atoms was also investigated. The results show that the larger the size of the Cu substrate, the more unfavorable the core-shell structure formation. In addition, the effect of temperature on growth was also analyzed. It was found that the higher the temperature, the more unfavorable the growth.
The state of art on lubrication methods in space environment
Authors: Nautiyal Hemant , Singh Sudesh , Gautam Rohit Kumar Singh , Goswami Ramesh N , Khatri Om P , Verma Pooja , Tyagi Rajnesh
Published: January 2024

Space tribology is a very big aspect of space exploration, despite of this fact, there is a dearth of coherent and concise literature available in the field of space tribology. It becomes difficult to understand the tribological behaviour of mating bodies under the extreme environmental circumstances in space due to their potential chemical and physical interactions. The radiation, vacuum, environmental conditions and temperature, are the factors which affects the friction and wear behaviour of mating surfaces and may alter the chemical structure of solid or liquid lubricant. The combination of tribo-physical and tribo-chemical interactions makes the tribological analysis very difficult to understand. The lack of understanding and ignorance might be the reason for not addressing this issue in the past. This review contains the qualitative and quantitative information on the tribological behaviour of different types of liquid lubricants, greases, soft and hard coatings, combined lubrication systems, testing equipment, composites, solid lubricants and alloys developed for space applications.
A novel image encryption scheme based on ccnn
Authors: Zhang Xiangzi , Sun Lina , Geng Xicong , Yue Huaixiao , Zhao Xuan , Lei Junqiang , Liu Jizhao
Published: January 2024

With the advancement of computational capacity, the key space will become one of the crucial factors influencing the security of digital cryptographic systems. Despite chaotic-based digital cryptographic systems possessing large key spaces, the post-Moore’s era rapid growth in computational capacity continues to pose challenges to the security of chaotic-based cryptographic systems. To address this issue, a novel image encryption scheme based on non-autonomous chaotic system is presented in this paper. In particular, a brain inspired neuron called continuous-coupled neural network (CCNN) is utilized to design image encryption scheme. To achieve the efficient image encryption scheme, firstly, the CCNN model is simplified to uncoupled-linking neuron model. The dynamic behavior under various driving signals is studied. The analysis showed that uncoupled-linking CCNN neuron exhibit various dynamic behavior under sine waves, triangular waves, sawtooth, superimposed sine waves, etc. Secondly, the decorrelation operation method is utilized to enhance the pseudo-randomness of the sequence. On this basis, thirdly, the image encryption scheme is proposed. It uses bit-level pixel scrambling, row scrambling, column scrambling and diffusion to modify the pixel value and the pixel position of the image. Security analysis shows that the proposed scheme is able to resist differential attack, statistics attack, known-plaintext attack and brute force attack. Moreover, the key space of the proposed scheme can be extended by the combination of drive signals. This unique feature makes the key space of the proposed scheme to be infinite, leading this kind of chaos-based cryptographic system to be a competitive candidate in post-Moore’s era.
Quantum teleportation of a two-qubit arbitrary entangled state with four-qubit cluster state
Authors: Yuan Hao , Kong Min , Pan Guo-Zhu , Zhang Gang
Published: January 2024

Based on the four-qubit cluster state as quantum channel, we put forward a novel scheme for teleporting a two-qubit arbitrary entangled state. The necessary quantum operations for accomplishing the task are two controlled-not gate operations, one controlled-phase gate operation, four single-qubit measurements and two single-qubit transformed operations. They are easily achievable with current experimental techniques. Besides, the present scheme is deterministic because its probability of success is

100
%

.
Tunable Yb:GdCOB self-frequency-doubling cyan laser
Authors: Du Zhenhua , Hu Zonghua , Li Yuzhao , Anh Nguyen Tuan , Fu Xinhua , Li Baozeng , Bai Junwen
Published: January 2024

We report a solid-state laser-pumped Yb:GdO(BO3)3 (Yb:GdCOB) tunable self-frequency-doubling continuous wave (CW) cyan laser. By adjusting the pump power, a CW cyan laser emission was obtained with wavelengths shifting from 502 nm to 506 nm. The highest output power of 835 mW was achieved at an emission wavelength with an optical conversion efficiency of 5.8%. To the best of our knowledge, there have been no studies of the self-frequency-doubled Yb:GdCOB lasers at the cyan wavelength. This work provides a novel method to generate tunable solid-state lasers with a compact and simple structure.
Effect of burst mode modulation ultrashort pulse laser on the laser processing transparent dielectrics
Authors: Murzakov M A , Evtikhiev N N , Grezev N V , Kataev D M , Shchekin A S
Published: January 2024

The effect of ultrashort pulse modulation on the formation of a modified zone of a transparent dielectric was investigated. The use of a femtosecond fiber laser in burst mode made it possible to control the energy that enters the processed material and thereby influence the geometry of the modification zone. In the course of the study, various types of pulses were tested—linear, sinusoidal, exponential, etc. It was noted that pulse modulation significantly affects the shape of the modified zone. Energy thresholds have been determined that lead to internal defects in the form of cracks.
Simulating gamma-ray production from cosmic rays interacting with the solar atmosphere in the presence of coronal magnetic fields*
Authors: Li 李 Zhe 哲 , Ng Kenny C. Y. , Chen 陈 Songzhan 松战 , Nan 南 Yuncheng 云程 , He 何 Huihai 会海
Published: January 2024

Cosmic rays can interact with the solar atmosphere and produce a slew of secondary messengers, making the Sun a bright gamma-ray source in the sky. Detailed observations with Fermi-LAT have shown that these interactions must be strongly affected by solar magnetic fields in order to produce a wide range of observational features, such as a high flux and hard spectrum. However, the detailed mechanisms behind these features are still a mystery. In this study, we tackle this problem by performing particle-interaction simulations in the solar atmosphere in the presence of coronal magnetic fields using the potential field source surface (PFSS) model. We find that low-energy (~ GeV) gamma-ray production is significantly enhanced by the coronal magnetic fields, but the enhancement decreases rapidly with energy. The enhancement directly correlates with the production of gamma rays with large deviation angles relative to the input cosmic-ray direction. We conclude that coronal magnetic fields are essential for correctly modeling solar disk gamma rays below 10 GeV, but above that, the effect of coronal magnetic fields diminishes. Other magnetic field structures are needed to explain the high-energy disk emission.
Nonlinear corrections for the nuclear gluon distribution in eA processes
Authors: Boroun G.R. , Rezaei B. , Abdi F.
Published: January 2024

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small x is presented. We consider the nonlinear corrections to the nuclear gluon distribution functions at low values of x and

using the parametrization

and the nuclear modification factors obtained from the Khanpour-Soleymaninia-Atashbar-Spiesberger-Guzey model. The CT18 gluon distribution is used for the baseline proton gluon density at

. We discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale

, as well as the modifications due to the nonlinear corrections. We find that the QCD nonlinear corrections are more significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy nuclei. The results of the nonlinear GLR-MQ evolution equation are similar to those obtained with the Rausch-Guzey-Klasen gluon upward and downward evolutions within the uncertainties. The magnitude of the gluon distribution with the nonlinear corrections increases with a decrease in x and an increase in atomic number A.