bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study on the trajectory characteristics of cylinders during asynchronous parallel high-speed vertical water entry
Authors: Wang Yulin , Wei Yingjie , Wang Cong
Published: December 2024

This study conducted asynchronous parallel high-speed vertical water entry experiments, acquiring trajectory for dual cylinders under varying lateral spacings and time intervals. The findings reveal that instability and tail slap phenomena are predominantly observed within the range of dimensionless time intervals less than 1 for the first cylinder. Instability manifests primarily as rotational instability. During the clockwise rotation of the first cylinder, the deflection angle exhibits an inverse relationship with the increasing time interval. When the first cylinder rotates anticlockwise, the deflection angle is proportional to the increase in the time interval. Regarding the second cylinder, the instability manifests primarily in three forms: collision instability, pressure difference instability, and puncture instability. As both lateral spacing and time interval increase, the second cylinder exhibits enhanced ballistic stability, concomitant with a diminished likelihood of tail slap occurrence. While the puncture process contributes to drag reduction for the second cylinder, it simultaneously introduces unpredictable forces acting upon the cylinder, potentially inducing instability. Furthermore, this study delineates the critical conditions of lateral spacings, and time intervals associated with the onset of puncture instability in the second cylinder. The research further revealed that the second cylinder consistently exhibits a lower drag coefficient than the first one, with a reduction of approximately 6.3%. Notably, during the puncture phenomenon of the second cylinder, the drag coefficient experiences its maximum reduction, decreasing by approximately 56.6%.
Particle flow simulation of fracture responses and anchoring mechanisms of cemented materials subjected to static-dynamic combined loads
Authors: Nie Xinxin , Yin Qian , Tao Zhigang , Wu Jiangyu , Meng Bo , Pu Hai , Jing Hongwen , Ren Yajun , Su Xiaoxiao
Published: December 2024

This study aims to reveal the evolution of energy, cracks, force chain, and ultimate failure modes of cemented gangue backfill materials subjected to static-dynamic combined loads, as well as the reinforcement mechanisms of pre-tightening bolts on mechanical performance and progressive damage. The particle flow models with various fractal dimensions (D) of particle size distribution were established, and irreversible damage accumulation during dynamic loading was achieved through a nonlinear parallel-bonded stress corrosion model. The simulation results show that, compared to uniaxial compression, the energy release lag at peak strength is eliminated under static-dynamic combined loading, and the brittle failure feature becomes more pronounced. The filling effect of fine aggregates optimizes the uniformity of internal stress distribution, with the peak parallel bond strain energy increasing by 9.60%, 8.42%, and 14.81% as D increases from 2.1 to 2.85. At initial dynamic loading, the instantaneous increase in axial stress reaches the crack initiation stress, significantly increasing the number of tensile cracks. As pre-static load increases, the model sample is subjected to a higher internal stress environment during dynamic loading, leading to more remarkable force chain breakage observed at peak strength. Shear failure, including oblique shear failure and tensile-shear mixed failure, is the primary failure mode under static-dynamic combined loading. The additional constraints provided by bolts increase strain energy stored in particles and contacts and reduce the crack number at peak strength, with the constraining effect exhibiting more pronounced as preload increases. For anchored samples, the end of pallets is the initiation point for shear cracks, which extend along the edge of the preload concentration area, while tensile cracks initiating from the sample ends propagate toward the preload concentration area.
New insights into methane storage through coal pore opening and closure mechanisms during transient supercritical CO2 fracturing
Authors: Li Yunzhuo , Ji Huaijun , Bai Bofeng , Sasmito Agus P. , Hu Shaobin
Published: December 2024

This study focuses on the often-overlooked closed pores in coal, which play a crucial role in isolating and storing significant amounts of methane, thereby directly impacting the efficiency of methane extraction. Using low-temperature nitrogen adsorption (LP-N2A) and small-angle x-ray scattering (SAXS) combined with multifractal theory, we examined the dynamics of pore opening and closure during supercritical CO2 (SC-CO2) fracturing at various pressures. Initially, chemical dissolution and the extraction of small organic molecules increased the surface area and volume of open pores. Stress-induced pore opening reduced closed pore volume, potentially increasing methane release. Enhanced fractal dimensions indicated greater pore heterogeneity. As fracturing progressed, pore interconnectivity improved, facilitating methane migration. Matrix contraction slightly expanded closed pores, increasing closed porosity. Fractal parameter decreases reflected changes in pore-scale correlation and reduced density. The isolation effect of closed pores delayed stress transmission, leading to asynchronous responses between total and open pores. Later, larger open pores collapsed, fragmenting the coal and increasing pore volume and surface area, while new closed pores raised closed porosity. These findings offer insights into how pore structure evolution during fracturing regulates methane at the micropore level.
Infinite ground-state degeneracy of a two-dimensional athermal lattice-gas
Authors: Sellitto Mauro
Published: December 2024

I studied the ground state properties and phase behavior of a two-dimensional lattice gas in which hard-core particles can have at most one nearest neighboring occupied site on the square lattice. Monte Carlo simulations in the grand-canonical ensemble showed no apparent signature of singular thermodynamic behavior when the chemical potential was increased. The absence of an ordering phase transition is traced to the large number of ground state configurations the model is endowed, which is due to the impossibility of satisfying simultaneously closest packing around a vacancy and around a particle. Numerical simulations confirm that the ground state entropy is proportional to the square root of system size.
Mechanisms of mixed slurry flow of deep-sea hydrate exploitation
Authors: Tang Yang , Xu Jiaqing , Zhu Shudi , Fu Qiang , Wang Guorong
Published: December 2024

Marine gas hydrate test production faces several challenges, including low hydrate yield, severe sand sedimentation under jet-breaking conditions, and minimal or even absent fluid returns. To address these challenges and enhance gas hydrate production while maximizing the value of extraction equipment, a layered control engineering strategy is proposed. This strategy is based on the integrated vertical development approach encompassing natural gas hydrates, shallow gas, and natural gas reservoirs. Using a gas-liquid two-phase flow theory and considering both the self-dissociation behavior of hydrates and the effective transport conditions of solid-phase particles, a mathematical model for slurry lifting across different extraction stages was established. The model was solved and validated, ultimately producing a process flow diagram for natural-assisted lifting of hydrate slurry. During the horizontal drilling phase, effective transport of solid-phase particles can be achieved without additional gas injection when the drilling fluid flow rate exceeds 13 L/s. However, gas injection can be used to further accelerate solid particle transport, with an injection range of 0 to 67 L/s, depending on the drilling fluid input. During the hydrate fracturing and recovery stage, solid particle transport can be effectively maintained without additional gas injection when the fracturing flow rate is between 49 and 55 L/s. Within this range, gas injection can be adjusted from 0 to 129 L/s to meet the requirements of hydrate slurry flow. This research provides a reference for improving gas hydrate extraction yield, accelerating early commercialization of hydrate exploitation, and supporting China's “dual carbon” strategic goals.
Preferences for the delivery of early abortion services in Australia: a discrete choice experiment
Authors: Church Jody , Haas Marion , Street Deborah J. , Bateson Deborah , Mazza Danielle
Published: December 2024

Background Abortion is a common procedure in Australia; it is estimated that the rate is between 15 and 17 per 1000 women. Surgical and medical abortion options are available; however, the use of medical abortion is not as common as in other similar countries. The aim of this study is to understand preferences for the provision of early abortion services in Australia. Methods We conducted a survey of 821 members of an online panel representative of the Australian adult general population. The survey consisted of a discrete choice experiment including 16 choice tasks and a number of follow-up questions. A mixed logit model was used to analyse the responses to the discrete choice experiment. Results Respondents preferred services that provided surgical abortion compared with early medical abortion (EMA). They preferred consultations with a specialist gynaecologist compared with a general practitioner (GP); consultations with a GP were preferred to those with a nurse practitioner. Face-to-face consultations were preferred to telehealth. For EMA, respondents preferred to collect medication from the doctor’s surgery rather than from a pharmacy or to receive it by post. Overall, respondents preferred lower-cost services. There were no differences in preferences between respondents with or without experience of abortion or between genders. Conclusions Respondents prefer abortion services with low out-of-pocket costs. Their reluctance to use a nurse-led service may reflect the general public’s lack of understanding of and familiarity with the training and expertise of nurse practitioners. Similarly, the safety and benefits of EMA relative to surgery, including EMA delivered by telehealth, need to be emphasised.
Two distinct populations of dark comets delineated by orbits and sizes
Authors: Seligman Darryl Z. , Farnocchia Davide , Micheli Marco , Hainaut Olivier R. , Hsieh Henry H. , Feinstein Adina D. , Chesley Steven R. , Taylor Aster G. , Masiero Joseph , Meech Karen J.
Published: December 2024

Small bodies are capable of delivering essential prerequisites for the development of life, such as volatiles and organics, to the terrestrial planets. For example, empirical evidence suggests that water was delivered to the Earth by hydrated planetesimals from distant regions of the Solar System. Recently, several morphologically inactive near-Earth objects were reported to experience significant nongravitational accelerations inconsistent with radiation-based effects, and possibly explained by volatile-driven outgassing. However, these “dark comets” display no evidence of comae in archival images, which are the defining feature of cometary activity. Here, we report detections of nongravitational accelerations on seven additional objects classified as inactive (doubling the population) that could also be explainable by asymmetric mass loss. A detailed search of archival survey and targeted data rendered no detection of dust activity in any of these objects in individual or stacked images. We calculate dust production limits of

∼

10,

0.1

, and

0.1

kg s

−
1

for 1998 FR

11

, 2001 ME

1

, and 2003 RM with these data, indicating little or no dust surrounding the objects during the observations. This set of dark comets reveals the delineation between two distinct populations: larger, “outer” dark comets on eccentric orbits that are end members of a continuum in activity level of comets, and smaller, “inner” dark comets on near-circular orbits that could signify a different different population. These objects may trace various stages in the life cycle of a previously undetected, but potentially numerous, volatile-rich population that may have provided essential material to the Earth.
AI-boosted and motion-corrected, wireless near-infrared sensing system for continuously monitoring laryngeal muscles
Authors: Liu Yihan , Putcha Arjun , Lyda Gavin , Peng Nanqi , Pai Salil , Nguyen Tien , Xing Sicheng , Peng Shang , Fan Yiyang , Wu Yizhang , Xie Wanrong , Bai Wubin
Published: December 2024

Neuromuscular diseases pose significant health and economic challenges, necessitating innovative monitoring technologies for personalizable treatment. Existing devices detect muscular motions either indirectly from mechanoacoustic signatures on skin surface or via ultrasound waves that demand specialized skin adhesion. Here, we report a wireless wearable system, Laryngeal Health Monitor (LaHMo), designed to be conformally placed on the neck for continuously measuring movements of underlying muscles. The system uses near-infrared (NIR) light that features deep-tissue penetration and strong interaction with myoglobin to capture muscular locomotion. The incorporated inertial measurement unit sensor further decouples the superposition of signals from NIR recordings. Integrating a multimodal AI-boosted algorithm based on recurrent neural network, the system accurately classifies activities of physiological events. An adaptive model enables fast individualization without enormous data sources from the target user, facilitating its broad applicability. Long-term tests and simulations suggest the potential efficacy of the LaHMo platform for real-world applications, such as monitoring disease progression in neuromuscular disorders, evaluating treatment efficacy, and providing biofeedback for rehabilitation exercises. The LaHMo platform may serve as a general noninvasive, user-friendly solution for assessing neuromuscular function beyond the anterior neck, potentially improving diagnostics and treatment of various neuromuscular disorders.
A corpus-based analysis of ‘vernacular synonyms’
Authors: Guardamagna Caterina
Published: December 2024

Against the backdrop of the significant social changes taking place during the Renaissance, this paper
interrogates the lexical domain of citizenship, focusing on three words deemed near-synonymous in the historical literature:
citizens, burgesses, and freemen. The study takes a quantitative corpus-linguistic approach
to the data in the
Early English Books Online
corpus (1550–1699) and
consults lexicographical sources (the Oxford English Dictionary, the Historical Thesaurus of the Oxford
English Dictionary, and the Lexicons of Early Modern English 1550–1700) to offer an overview of the
organisation of the conceptual domain occupied by citizenship terms referring to “dwellers”. The relationships between
citizens, burgesses, and freemen over time are addressed through detailed quantitative
collocation analysis, considering their overall profile, stability and innovation, and areas of functional overlap and
distinctiveness. Overall, the results support historians’ intuitions that citizens, burgesses, and
freemen are “vernacular synonyms”.
Segmentation and analysis of the two English excerpts
Authors: Raso Tommaso , Barbosa Plínio A. , Cavalcante Frederico A. , Mittmann Maryualê M.
Published: December 2024

This paper has a tripartite focus: (1) to establish the best
segmentation for two American English texts according to inter-rater agreement measurements.
By doing this, we differentiate the behavior of experts and non-experts annotators. The
experts’ annotation constitute the basis for the analysis; (2) to capture, measure, and
analyze the phonetic features that correlate with boundaries, as they are marked by the
expert annotators; (3) to informationally annotate prosodic units according to the Language
into Act Theory, and analyze their corresponding information structure: in order to do this,
we make and justify decisions in marking the reference units and assigning informational
value to prosodic units; additionally we further discuss some cases of major
disagreements.
Astrocyte-dependent local neurite pruning in Beat-Va neurons
Authors: Lehmann Katherine S. , Hupp Madison T. , Abalde-Atristain Leire , Jefferson Amanda , Cheng Ya-Chen , Sheehan Amy E. , Kang Yunsik , Freeman Marc R.
Published: December 2024

Developmental neuronal remodeling is extensive and mechanistically diverse across the nervous system. We sought to identify Drosophila pupal neurons that underwent mechanistically new types of neuronal remodeling and describe remodeling Beat-VaM and Beat-VaL neurons. We show that Beat-VaM neurons produce highly branched neurites in the CNS during larval stages that undergo extensive local pruning. Surprisingly, although the ecdysone receptor (EcR) is essential for pruning in all other cell types studied, Beat-VaM neurons remodel their branches extensively despite cell autonomous blockade EcR or caspase signaling. Proper execution of local remodeling in Beat-VaM neurons instead depends on extrinsic signaling from astrocytes converging with intrinsic and less dominant EcR-regulated mechanisms. In contrast, Beat-VaL neurons undergo steroid hormone–dependent, apoptotic cell death, which we show relies on the segment-specific expression of the Hox gene Abd-B. Our work provides new cell types in which to study neuronal remodeling, highlights an important role for astrocytes in activating local pruning in Drosophila independent of steroid signaling, and defines a Hox gene-mediated mechanism for segment-specific cell elimination.
Parameters Optimization of Decoy-State Phase-Matching Quantum Key Distribution Based on the Nature-Inspired Algorithms
Authors: Liu 刘 Chang 畅 , Li 李 Yue 悦 , Wang 王 Haoyang 浩洋 , Shi 石 Kaiyi 开毅 , Ma 马 Duo 铎 , Zhang 张 Yujia 育嘉 , Ma 马 Haiqiang 海强
Published: December 2024

Phase-matching quantum-key distribution (PM-QKD) has achieved significant results in various practical applications. However, real-time communication requires dynamic adjustment and optimization of key parameters during communication. In this letter, we predict the PM-QKD parameters using nature-inspired algorithms (NIAs). The results are obtained from an exhaustive traversal algorithm (ETA), which serves as a benchmark. We mainly study the parameter optimization effects of the two NIAs: ant colony optimization (ACO) and the genetic algorithm (GA). The configuration of the inherent parameters of these algorithms in the decoy-state PM-QKD is also discussed. The simulation results indicate that the parameters obtained by the ACO exhibit superior convergence and stability, whereas the GA results are relatively scattered. Nevertheless, more than 97% of the key rates predicted by both algorithms are highly consistent with the optimal key rate. Moreover, the relative error of the key rates remained below 10%. Furthermore, NIAs maintain power consumption below 8 W and require three orders of magnitude less computing time than ETA.
Generation of Isolated Attosecond Pulses by the Harmonic Spectrum of MgO under a Three-Color Laser Pulse
Authors: Chen 陈 Jiaqi 家祺 , Jiang 蒋 Wenli 文丽 , Qiao 乔 Yue 月 , Yang 杨 Yujun 玉军 , Chen 陈 Jigen 基根
Published: December 2024

This study examines the high-order harmonic radiation behavior of MgO crystals driven by combined pulses based on the numerical solution of the semiconductor Bloch equation. We found that compared with the monochromatic pulse, the MgO crystal can radiate a continuous harmonic spectrum with two platforms driven by the three-color combined pulse. The reason is that under the three-color combined pulse, the electron ionization and recombination can be effectively controlled within a half-optical cycle of the laser pulse. Using this continuous spectrum, we synthesized an isolated attosecond pulse with a duration of approximately 370 as. This study provides a new perspective on all-solid-state compact optical devices.
AsterX: a new open-source GPU-accelerated GRMHD code for dynamical spacetimes
Authors: Kalinani Jay V , Ji Liwei , Ennoggi Lorenzo , Lopez Armengol Federico G , Timotheo Sanches Lucas , Tsao Bing-Jyun , Brandt Steven R , Campanelli Manuela , Ciolfi Riccardo , Giacomazzo Bruno , Haas Roland , Schnetter Erik , Zlochower Yosef
Published: December 2024

We present AsterX, a novel open-source, modular, GPU-accelerated, fully general relativistic magnetohydrodynamic (GRMHD) code designed for dynamic spacetimes in 3D Cartesian coordinates, and tailored for exascale computing. We utilize block-structured adaptive mesh refinement (AMR) through CarpetX, the new driver for the Einstein Toolkit, which is built on AMReX, a software framework for massively parallel applications. AsterX employs the Valencia formulation for GRMHD, coupled with the ‘Z4c’ formalism for spacetime evolution, while incorporating high resolution shock capturing schemes to accurately handle the hydrodynamics. AsterX has undergone rigorous testing in both static and dynamic spacetime, demonstrating remarkable accuracy and agreement with other codes in literature. Using subcycling in time, we find an overall performance gain of factor 2.5–4.5. Benchmarking the code through scaling tests on OLCF’s Frontier supercomputer, we demonstrate a weak scaling efficiency of about 67%–77% on 4096 nodes compared to an 8-node performance.
A new study of the Unruh effect
Authors: Dickinson Robert , Forshaw Jeff , Jenkinson Ross , Millington Peter
Published: December 2024

We revisit the Unruh effect within a general framework based on direct, probability-level calculations. We rederive the transition rate of a uniformly accelerating Unruh–DeWitt monopole detector coupled to a massive scalar field, from both the perspective of an inertial (Minkowski) observer and an accelerating (Rindler) observer. We show that, for a measurement at a finite time after the initial state is prepared, the two perspectives give the same transition rate. We confirm that an inertial detector in a thermal bath of Minkowski particles responds differently to the accelerated detector (which perceives a thermal bath of Rindler particles), except in the case of a massless field where there is agreement at all times. Finally, new numerical results for the transition rate are presented and explained, highlighting the transient effects caused by forcing the field to initially be in the Minkowski vacuum state.
Single ion effect on material and electrical properties of deposited and annealed Al2O3 film on 4H-SiC by atomic layer deposition
Authors: Miao Yuyang , Shen Zhanwei , Zhu Xiaogang , Hu Yinze , Yue Shizhong , Yu Huiyong , Wang Zhijie , Zhang Feng
Published: December 2024

Silicon carbide (SiC) devices are highly preferred for space applications due to robust covalent bonding of the material, which imparts excellent radiation tolerance. However, metal–oxide–semiconductor (MOS) devices with silicon dioxide (SiO2) gate dielectrics continue to exhibit a high density of interface states. These defects create significant challenges in accounting for latent gate damage formed along the paths of heavy ion incidences. High-k materials, such as aluminum oxide (Al2O3), offer promising alternatives to the current SiO2 gate dielectrics. This study investigates the effects of heavy ion impact on the surface morphology and interfacial properties of Al2O3 gate dielectrics on 4 H-SiC, utilizing bismuth (Bi) ion radiation with a linear energy transfer of 99.8 MeV cm2 mg−1. It was observed that the uniformity of the refractive index in Al2O3 films annealed at 1100 °C was less affected by radiation compared to that in as-deposited films. The root mean square roughness (R
q) of the annealed films showed a minor variation from 0.28 nm to 0.34 nm before and after radiation exposure, whereas the roughness of the as-deposited films increased significantly from 0.24 nm to 0.54 nm. Furthermore, radiated amorphous Al2O3 exhibited swelling of approximately 3.10%, indicating the formation of bombarded pores, which were scarcely visible in annealed Al2O3 films. The radiation also led to the formation of oxygen vacancies or interstitial oxygen, contributing to a reduction in Al–O and Al–O–Si bonds. Nevertheless, poly-crystalline Al2O3 induced by annealing displayed more robust and stable bonding between aluminum and oxygen, with fewer damaged elemental components. This improvement led to a significant reduction in radiation-induced interfacial trap density from 6.00 × 1012 cm−2 in as-deposited films to 2.20 × 1012 cm−2 in annealed Al2O3/SiC MOS devices. These findings provide valuable insights into the mechanisms of heavy ion radiation effects and are crucial for developing radiation-hardened processes in SiC MOS field-effect transistors.
ASFormer: attentive semantic feature fusion transformer for pixel-level defect detection
Authors: Zhu Qinmiao , Hu Huan , Liu Teng , Yang Hua
Published: December 2024

Surface defect detection is pivotal for ensuring product quality in various industries. These defects typically manifest as low background contrast, substantial variations in shape, and a scarcity of balanced training samples. Traditional defect detection methods often encounter limitations in terms of low detection accuracy and insufficient detection granularity. This study introduces an innovative attentive semantic feature fusion transformer network (ASFormer) tailored for pixel-level defect detection tasks to overcome these challenges. Initially, the transformer architecture is employed to extract the multiscale features of defects. Subsequently, a multiscale semantic fusion module is integrated, complemented by a dynamic upsampling mechanism, to mitigate the loss of detailed information during feature fusion. Moreover, a scale-aware dual-attention module is developed, which effectively captures the intricacies of the fused features across both channel and spatial dimensions, ensuring pixel-level detection precision. Additionally, a contextual boundary loss function is proposed to augment the ability of the network to discern defect boundaries, different categories and defect scales. Experimental validation on the NEU-Seg and Crack500 surface defect datasets demonstrated that the proposed ASFormer achieved state-of-the-art performance, with mIoU scores of 85.24% and 78.20%, respectively.
Vehicle identification and analysis based on lightweight YOLOv5 on edge computing platform
Authors: Hong Tiansong , Ma Yongjie , Jiang Hui
Published: December 2024

With the accelerating process of urbanization, the role of intelligent transportation systems in urban traffic management has become more crucial. Nevertheless, traditional surveillance cameras only possess the ability to capture videos and lack the capacity for vehicle detection. Consequently, in order to enhance the intelligent capabilities of front-end surveillance cameras and achieve lightweight model deployment, this research has designed a lightweight detection model that can be deployed on embedded devices. Deploying detection models on embedded devices requires a high level of storage and system computing power, and there exist issues such as model speed, model accuracy, model size, and energy efficiency that are difficult to address in existing studies. Specifically, based on YOLOv5, we first use lightweight structures to replace the C3 module and introduce GSConv and Slim Neck structures to replace the Neck of YOLOv5 in order to reduce the model’s parameters and computational complexity. After replacing the model structure, we use global channel pruning to remove redundant information, and use asymmetric quantization to convert model parameters from floating point numbers to fixed point numbers, significantly reducing the model’s size and load time, and improving the inference speed. For the target tracking part, we combine the ByteTrack target tracking algorithm with the proposed model, effectively reducing the impact of target occlusion on detection and improving the correlation between video frames. In terms of data recording, detection information such as vehicle color, license plate number, and road blockage level can be uploaded to the database server, and the model’s detection results can be encoded using the H.264 video encoding format and uploaded to the streaming media server through streaming media protocols. In the experimental part, we selected the embedded Rk3399pro as the deployment object and achieved 97.8% accuracy in the vehicle counting task, meeting the real-time performance requirements of 31 FPS.
Remaining useful life prediction of pressure regulating shutoff valve based on feature fusion and bidirectional gated recurrent unit
Authors: Meng Ziran , Zhu Jun , Yang Lu , Yu Yang , Huo Yingdong , Zhao Zhibin
Published: December 2024

In the bleed air system of the ARJ21 aircraft, pressure regulating shutoff valve (PRSOV) failures are common, and their failures can lead to disasters and economic losses. Accordingly, prediction of the degradation performance of PRSOV is crucial. This work proposes a life prediction method based on principal component analysis (PCA) and bidirectional gated recurrent units (BiGRUs) to achieve accurate prediction. After obtaining pressure data throughout the entire life of PRSOV, considering that the pressure required for PRSOV during the takeoff and climb phases is the most critical, data from this phase are selected for focused monitoring. Classical statistical feature extraction methods are used to extract features from the raw pressure data during the takeoff and climb phases. An empirical feature extraction method with low-pressure weighting is also proposed based on engineering practical experience. Feature fusion is performed using PCA based on these two types of features. Finally, BiGRU is utilized to model the fused degradation feature indicators and estimate the remaining service life of PRSOV. The results of the analysis of the full life data of PRSOV in ARJ21 aircraft indicated that the proposed method can effectively predict its remaining service life. The proposed method demonstrated higher prediction accuracy compared with the related prediction methods.
An original feature retention deconvolution algorithm and its application to bearing fault diagnosis
Authors: Cheng Lei , Yang Gang
Published: December 2024

Traditional blind deconvolution algorithms perform well in estimating the repetition rate of impulses within signals; however, they fall short in preserving the original features of the signal. In engineering applications, particularly for cyclic impulse signals, maintaining signal fidelity is as crucial as accurately estimating impulse counts, making pure impulse count estimation insufficient for practical needs. To address this limitation, we propose a novel deconvolution algorithm—maximum correlation Pearson fidelity coefficient deconvolution (MCPSFD). This method constructs an objective function based on two key metrics: the correlation Pearson coefficient (CPC), which quantifies the periodicity of impulses, and the signal fidelity coefficient (SFC), which measures the similarity between the original and recovered signals. By combining CPC and SFC, we introduce a new objective function, termed the correlated Pearson fidelity factor (CPSF), which simultaneously considers both the number of impulses and the original characteristics of the filtered signal without introducing redundant parameters. The MCPSFD algorithm is derived by maximizing the CPSF function. Extensive experiments on simulated and measured bearing signals demonstrate that the proposed method significantly outperforms existing deconvolution algorithms in recovering periodic impulses and minimizing signal distortion.
Improved performance in 0D/2D mixed dimensional homojunction MoS2 photodetectors by enhancing light absorption
Authors: Zhang Lin , Cheng Peiyu , Du Yongqiang , Wang Quan
Published: December 2024

Molybdenum disulfide (MoS2) possesses excellent potential for applications in the field of optoelectronic detection. However, the atomic-level thickness of the monolayer MoS2 leads to weak light absorption and a restricted absorption spectrum. The performance of monolayer MoS2 devices has reached a bottleneck. Fortunately, the above issues can be effectively solved by coupling with various types of photosensitivity nanostructures. In this work, we integrated MoS2 quantum dots (QDs) with high efficient light absorption with monolayer MoS2 to fabricate 0D/2D MoS2 QDs/MoS2 hybrid dimensional homojunction photodetectors. In this structure, MoS2 is used as an efficient carrier transport channel, while MoS2 QDs act as effective light absorbers to enhance the local electric field around MoS2. The synergistic effect of MoS2 QDs and MoS2 is utilized to accelerate the migration rate of photogenerated carriers in the structure, and in particular, the highest responsivity of the MoS2 QDs/MoS2 hybrid device is 27.6 A W−1 with the detectivity as high as 2.13 × 1011 Jones under 532 nm laser, which is an order of magnitude higher than that of the pristine MoS2 devices. The synergistic effect of MoS2 QDs with monolayer MoS2 is verified by finite-difference time-domain simulation. The results will pave the way for the future development of high-performance MoS2-based photodetectors.
Electronic, magnetic, and topological properties of ferromagnetic 2D perovskite-type oxides
Authors: Arokiasamy Susaiammal , Macam Gennevieve M , P C Sreeparvathy , Villaos Rovi Angelo B , Huang Zhi-Quan , Hsu Chia-Hsiu , Okada Yoshinori , Lin Hsin , Chuang Feng-Chuan
Published: December 2024

Two-dimensional (2D) materials within the hematene-type binary oxides and perovskites family have recently gathered huge research interest for nanoelectronic devices. However, the exploration of their fascinating topological properties remains limited. Herein, through first-principles calculations, we systematically examine the electronic, magnetic, and topological properties of substitutionally doped 2D ABO3 (A = As, Sb, or Bi, and B = V, Nb, or Ta) perovskite structures at the B site of a B2O3 system. Interestingly, the atomic substitution makes the 2D ABO3 structures dynamically stable. Our detailed calculations show the ferromagnetic (FM) and antiferromagnetic phases of these materials. The calculated Chern number (C) for the FM 2D ABO3 (A = As, Sb, or Bi, B = Nb or Ta) suggests their topologically non-trivial phases. Furthermore, the computed nontrivial Berry curvature highlights the topological properties in AsNbO3. These findings highlight opportunities in 2D-ABO3 materials, for applications in spintronics.
STIPS: The Nancy Grace Roman Space Telescope Imaging Product Simulator
Authors:   STIPS Development Team, Gomez Sebastian , Bellini Andrea , Al-Kowsi Hanna , Desjardins Tyler , Geda Robel , Han Eunkyu , Otor O. Justin , Riedel Adric , Ryan Russell , Spitzer Isaac , York Brian
Published: December 2024

The Space Telescope Imaging Product Simulator (STIPS) is a Python-based package that can be used to simulate scenes from the upcoming Nancy Grace Roman Space Telescope (Roman). STIPS is able to generate post-pipeline astronomical images of any number of sensor chip assembly (SCA) detectors, up to the entire 18-SCA Wide-Field Instrument array on Roman. STIPS can inject either point spread functions generated with WebbPSF, or extended sources in any of the Roman filters. The output images can include flat field, dark current, and cosmic ray residuals. Additionally, STIPS includes an estimate of Poisson and readout noise, as well as an estimate of the zodiacal background and internal background from the telescope. However, STIPS does not include instrument saturation, nonlinearity, or distortion effects. STIPS is provided as an open source repository on GitHub ✎.
Combining machine learning algorithms with traditional methods for resolving the atomic-scale dynamic structure of monolayer MoS2 in high-resolution transmission electron microscopy
Authors: Meng 蒙 Yu 宇 , Wang 王 Shuya 淑雅 , Ren 任 Xibiao 锡标 , Xue 薛 Han 涵 , Yue 岳 Xuejun 学军 , Jin 金 Chuanhong 传洪 , Lin 林 Shanggang 上港 , Lin 林 Fang 芳
Published: December 2024

High-resolution transmission electron microscopy (HRTEM) promises rapid atomic-scale dynamic structure imaging. Yet, the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution. A machine learning algorithm is developed to determine the aberration parameters with higher precision from small, lattice-periodic crystal images. The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide (MoS2) monolayer with 25 variables (14 aberrations) resolved in wide ranges. Using these measured parameters, the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS2 monolayers. The images were acquired due to the unexpected movement of the specimen holder. Four-dimensional data extraction reveals time-varying atomic structures and ripple. In particular, the atomic evolution of the sulfur-vacancy point and line defects, as well as the edge structure near the amorphous, is visualized as the resolution has been improved from about 1.75 Å to 0.9 Å. This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.
EMC3-EIRENE simulations of edge plasma and impurity transport by toroidally localized argon seeding on CFETR X-divertor
Authors: Xie T. , Li H. , Zhang W. , Ding R. , Wang L. , Luo Y. , Wang D.Z.
Published: December 2024

The three-dimensional (3D) edge Monte Carlo transport code EMC3-EIRENE has been employed to study edge plasma and impurity transport with toroidally localized argon seeding using the Chinese fusion engineering testing reactor (CFETR) X-divertor configuration. The argon impurity seeded at different poloidal locations was investigated to evaluate the varied profile of the main plasma in the scrape-off layer (SOL) and on the divertor targets, which showed a strong dependence on the poloidal position of argon gas puffing. The argon impurity seeded in the upstream SOL regions can result in a toroidally asymmetric distribution of electron density and temperature, while a toroidally symmetric distribution was obtained for argon seeded in the strike point regions. The deposition pattern of electron density and temperature showed several lobe-like and island-like structures on the 3D divertor targets of CFETR with upstream argon injection, whereas a perturbed profile was achieved for argon seeding in the strike point regions. In order to verify the toroidal asymmetry of heat load distribution, the argon impurity seeded at different poloidal locations was investigated to estimate its influence on the toroidal heat load on divertor plates. The argon injected in the strike point regions gave rise to a toroidal asymmetry of heat load distribution on divertor targets, while a toroidal symmetry of heat load distribution was observed for argon injected in upstream SOL locations.
Study on the Performance of Secondary (Step) Curing Epoxy Resin Adhesive Layer
Authors: Zhang Xiaolin , Ding Runduo , Song Xiaoxiao , Zhang Yanjun , Han Zhenzhen , Zhou Haijun , Wang Wei
Published: December 2024

The waterproof bonding layer is between the bridge deck and the asphalt pavement, and its performance is very important to ensure the quality of the entire pavement system In this paper, the tension strength, elongation at break and thermosetting index are used to comprehensively judge the optimal ratio of A and B components of high temperature epoxy in the adhesive layer, and the characterization of secondary (step) current performance is explored The epoxy resin adhesive layer is analyzed and verified in the 60 ° C curing environment The best construction time corresponding to different application amounts is determined On this basis, the optimal amount of waterproof adhesive layer and adhesive layer is determined, and its performance is verified The results show that the optimal ratio of high temperature epoxy resin in adaptive layer A: B is 10: 9, the curing time at 60 ° C is 5 hours, and the validity period is about 3 hours The optimal amount of adhesive layer between mixture layers is about 0.60 kg/m2, and the optimal amount of adhesive layer between steel plate and mixture is about 0.42 kg/m2 The adaptive layer has good low temperature crack resistance and can be applied to low temperature areas in the north
The optimal shape of the nozzle for drying food grains
Authors: Akhunbaev A A , Khusanboev M A , Muminov J A , Sh Khasanova G , Khakimov A A , Ergashev N A
Published: December 2024

This article analyzes the optimal shape of a two-segment nozzle of a drum machine for drying food grains. The loading and unloading of the nozzle at any angle between the nozzle segments are investigated using a geometric model. Equations were proposed for the maximum volume carried by the nozzle, the maximum angle of incidence and the average height of the material drop.
Enhancing energy system efficiency through power flow redistribution and storage solutions
Authors: Sh Gaipov T , Xalilov A S , Murodov B X
Published: December 2024

Today, new innovative technologies are widely used in all fields. The energy sector is certainly not an exception, especially in matters of efficient storage and use of electricity. There are many scientific developments in this field. Some of them are at the stage of theoretical development, while others are already in the form of working prototypes. Energy storage technologies store the excess power that occurs in the system when the consumption of electricity is at a minimum, and transmits the stored electricity to the system in the modes of maximum consumption. These technologies not only ensure the continuity of electricity, but also guarantee the energy security of the system. It can quickly provide the system with the necessary power even in various emergency situations that may occur at power stations. It also allows to adjust generation schedules of electricity produced by renewable energy sources that change dramatically due to weather. Energy storage systems are also useful for consumers - through them it will be possible to maintain stable electricity prices within the general network or to ensure individual flexibility and independence of consumption in households.
Justification of parameters and operating modes of a screw feed chopper for livestock farms
Authors: Jumatov Y , Savutov R
Published: December 2024

The focus of the research is on developing a new grinder design that uses less energy and metal, starting from a theoretical perspective. The study looks into how the screw cutter system’s quantitative and qualitative indicators relate to geometric factors and speed modes of operation. Only by decreasing the average cut length, or by speeding up the screw knife’s spin, can the degree of stem chopping be increased. According to the knife’s rotation speed, the experiment displays the average slice lengths and the associated productivity of the screw cutting pair. In order to comply with zootechnical criteria, the following modes should be used: n = 400-450 rpm (lav = 5,5-4 cm) with an inclined feed angle of β = 450, and n = 550-650 rpm (lav = 8-4,5 cm) with vertical loading. The productivity of the cutting pair sharply decreases as the knife’s rotation frequency increases. The aforementioned numerical examples demonstrate good agreement with the experimental results and were chosen in accordance with the characteristics of the experimental setup.
Improving the method of calculating the water balance of the Khan canal
Authors: Akhmedkhodjaeva I , Yuldasheva H , Apakhodjaeva T , Sattorov A , Melikuziyev S
Published: December 2024

In this article, the Morgunenkov (Khan) canal in the Chirchik-Ohangaron Basin Management for Irrigation Systems area was selected. This canal is one of the more important canal in Tashkent region because it supplies water to irrigation fields in the Urta Chirchik, Buka and Akkurgan districts of the region. In this paper the technical condition of the canal and its hydrotechnical facilities was studied. The received data was entered into the database of the processed program and the efficiency of the canal was determined. The program helps to quickly and easily identify defects that cause water wastage. This is the reason for increasing the hydraulic efficiency of the canal. In addition, the developed computer program allows for the correct distribution of water resources of the Morgunenkov (Khan) canal, taking into account the demand for water in the entire system, to prevent water shortages in the downstream areas of the canal. The benefit from the practical application of the program will be at the expense of improving the efficiency of water resources management.
Intelligent system for measuring and monitoring water levels
Authors: Djalilov A , Tasheva U , Allenova I , Umarov Sh , Yuldashev M
Published: December 2024

Measuring and controlling water levels at water management facilities is one of the important tasks. In this research work, we, the authors, have studied the available means of measuring water level. Some of their drawbacks were brought to light throughout the investigation. For instance, if you take a water level control gauge, you have to keep an eye on it all the time, and automation is challenging. These water level measurement devices are not up to date with modern standards. At present, there is a need for systems for continuous monitoring of water resources, collection of necessary information and, if necessary, delivery of processed information to the user or decision-making in complex situations. Taking this into account, it was aimed to develop an intelligent system for measuring and controlling the water level that meets the requirements of the time. As the basis of the intelligent system, the JSN SR-04T ultrasound sensor, which is resistant to various aggressive conditions and has high measurement accuracy, and the Arduino Nano board were taken. This intelligent system was tested at the facility and the developed system performed all tasks reliably and qualitatively.
Bedrock characterization and geochemical evolution of whole-rock weathering profile at GAG Ni laterite deposit, Southwest Papua, Indonesia
Authors: Sari D V , Wibowo G S , Nurdiyansyah A
Published: December 2024

A series of laboratory analyses were conducted to investigate the correlation of petrography analyses of a bedrock coupled with microscope observation and X-Ray Diffraction (XRD) then compared with distribution of geochemical elements of whole-rock weathering profile by X-Ray Fluorescence (XRF). The microscope identification revealed that the bedrock was marked by the appearance of pyroxene predominantly surrounding olivine and serpentine, then magnetite, while XRD clarified that the bedrock was predominantly contained by a number of serpentine (lizardite), then pyroxene (enstatite), and magnetite. The geochemical evolution by bulk major-minor elements geochemistry as well as gain and losses of elements (τ) and compared with the equation from the ultramafic index alteration (UMIA) revealed that Fe2O3, NiO, Al2O3, CoO, Cr2O3 and MnO contents in the bedrock were 7.18wt%, 0.23 wt%, 1.23wt%, 0.01wt%, 0.35wt%, and 0.11wt%, respectively, then strongly increased towards the transition zone to 35.89wt%, 2.04wt%, 9.01wt%, 0.10wt%, 1.87wt%, and 0.51wt%, respectively. SiO2 and MgO revealed an inverted trend where it enriched in the bedrock then extremely decreased limonite layer with SiO2 (τ = ~ -0.92) and MgO (τ = ~ -0.99). The highest value of UMIA as well as consequently the highest degree of chemical weathering in this study was located in the upper limonite with a value of 63.87.