bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical analysis and validation of the detonation wave interaction based on an overdriven detonation
Authors: Liu Moyan , Liu Yan , Bai Fan , Wang Hongfu , Chu Shanyong , Huang Fenglei
Published: September 2024

The oblique collision and reflection of a detonation wave can lead to extremely high pressure and considerable dynamic load mixing in the resulting product, which has been a focus of research in detonation and defense applications. In this paper, the relationships among wave velocity, mass velocity, pressure, and the specific volume of detonation products (DPs) under overdriven detonation (ODD) conditions are analyzed. Additionally, the equations of state (EOS) of the ODD are calibrated by using real-coded genetic algorithms combined with experimental Hugoniot strong detonation data, and the effects of different DPs on pressure accuracy are assessed. Accordingly, a dynamic evolution model of detonation wave interactions in a collision zone is established, and theoretical calculations of regular and Mach reflections occurring after the interactions of typical condensed explosive [such as PBX9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/F)] detonation waves are carried out. The results show that the overpressure Hugoniot data and the isentropic expansion line can be better fitted by using the JWL (Jones–Wilkins–Lee) + γ equation than other EOSs, and the deviation of the calculated pressure and the height of the Mach stem from the experimental value is within 5%. Additionally, a formula is derived for the slow-variable function k(ξ) by combining the improved Whitham method and the JWL + γ EOS, and a propagation law is obtained for the detonation wave interaction.
Pressure-induced structural transition and superconductivity in hard compound IrB4
Authors: Song Ting , Chen Meng-Ru , Peng Hai-Jun , Li Wei-Wei , Dou Xi-Long , Sun Xiao-Wei
Published: September 2024

The recent discovery of MoB2 with a superconducting transition temperature (Tc) of up to 32 K at 100 GPa provides new insights into the metallization and subsequently high-Tc superconductivity of diborides, highlighting the potential of transition metals in these compounds. We herein re-evaluated the structure, mechanical, and superconducting properties of IrB4 under pressure up to 300 GPa using first-principles. Our calculations reveal that a new P21/c phase exhibiting a hardness of 15.75 GPa surpasses the stability of the C2/m structure identified through the particle swarm optimization at ambient pressure. Upon compressing, the P21/c phase transforms into an MgB2-type structure with a space group of P63/mmc at 62.5 GPa and then into the orthorhombic Cmca phase above 109 GPa. Unlike semiconductor behavior of the atmospheric pressure phase, the two high-pressure structures are metallic and superconducting, with Tc values of 29.90 for P63/mmc at 62.5 GPa and 13.45 K for Cmca at 125 GPa. Analysis of the electronic structure and electron–phonon coupling (EPC) reveals that the high Tc, similar to MgB2-type MoB2, stems from the Van Hove Singularities (VHS) near the Fermi level donated by transition metal Ir. The effect further enhances the EPC based on the boron contribution. More interestingly, pressure has little impacts on the position of the VHS. These findings provide a new platform for designing advanced high-Tc superconductors.
Synthesis and optical properties of perovskite nanocrystals in glass with cationic substitution
Authors: Kuznetsova Maria S. , Kolobkova Elena V. , Bataev Matvey N. , Berdnikov Vladimir S. , Pankin Dmitrii V. , Smirnov Mikhail B. , Ubyivovk Evgenii V. , Ignatiev Ivan V.
Published: September 2024

The effect of cadmium ions introduced into fluorophosphate glass on the growth and photoluminescence (PL) of the CsPb1–xCdxBr3 perovskite nanocrystals (NCs) is systematically studied. The x-ray diffraction patterns have shown that cadmium ions are really incorporated into the NCs that results in a decrease in the lattice constant from 5.85 (x = 0) to 5.75 Å (x = 0.45). At the large cadmium content in the glass (x > 0.38), simultaneous formation of the perovskite CsPb1–xCdxBr3 NCs and the non-luminescent CsCdBr3 NCs in the hexagonal phase is found. It is also found that the lattice contraction leads to an increase in the bandgap energy and a noticeable shift of the PL band to the blue region of the spectrum (from 2.42 to 2.68 eV) with a drop in quantum yield from 85% for CsPbBr3 NCs down to 4% for CsPb0.55Cd0.45Br3 NCs. It is shown that the PL quantum yield decreases due to the formation of deep trap states, which manifest themselves as a PL band in the energy range of 1.6–2.5 eV at cryogenic temperatures. A simple model explaining the behavior of the PL band as a function of temperature in the range from 30 to 300 K is proposed.
Influence of interstitial cluster families on post-synthesis defect manipulation and purification of oxides using submerged surfaces
Authors: Jeong Heonjae , Seebauer Edmund G.
Published: September 2024

Injection of interstitial atoms by specially prepared surfaces submerged in liquid water near room temperature offers an attractive approach for post-synthesis defect manipulation and isotopic purification in device structures. However, this approach can be limited by trapping reactions that form small defect clusters. The compositions and dissociation barriers of such clusters remain mostly unknown. This communication seeks to address this gap by measuring the dissociation energies of oxygen interstitial traps in rutile TiO2 and wurtzite ZnO exposed to liquid water. Isotopic self-diffusion measurements using 18O, combined with progressive annealing protocols, suggest the traps are small interstitial clusters with dissociation energies ranging from 1.3 to 1.9 eV. These clusters may comprise a family incorporating various numbers, compositions, and configurations of O and H atoms; however, in TiO2, native interstitial clusters left over from initial synthesis may also play a role. Families of small clusters are probably common in semiconducting oxides and have several consequences for post-synthesis defect manipulation and purification of semiconductors using submerged surfaces.
Wearable self-powered motion sensor based on biomass carbon-dots/polyvinyl alcohol film
Authors: Cai Tingting , Yang Yun , Zhang Gaiqing , Zhao Yifan , Kong Lingyue
Published: September 2024

The functionalized polymer with scalable properties presents a promising option for flexible triboelectric nanogenerators designed for detecting human motion. In this study, a novel method to fabricate tribopositive composite film was proposed by incorporating high permittivity N-doped orange peel-based carbon dots (O-CDs) into the highly cross-linked polyvinyl alcohol (PVA). The O-CDs/PVA sensor showed elevated electrical output with the raised content of O-CDs until 1.5 wt. % with a peak voltage of 3.5 V. The response characteristics under various external force conditions were tested, and the maximum peak voltage and current reached 3.92 V and 28.6 A under the force of 50 N. Moreover, O-CDs/PVA sensors present superior high-output stability, durability, and accurate distinction to different movement states, even the vocal cord vibration. By introducing the support vector machine learning algorithm, intelligent gesture recognition was achieved. This work paves a facile, feasible, and scalable pathway to the self-powered human motion sensor device.
Molecular dynamics simulation of slit rheometer for predicting shear thinning of short polyethylene chains
Authors: Chang Tzu-Chuan , Chang Rong-Yeu , Tseng Huan-Chang
Published: September 2024

Understanding the molecular basis of rheological properties is crucial from both experimental and theoretical perspectives. Slit rheometry is commonly employed to measure the viscosity of fluids. This study utilized molecular dynamics simulations to investigate isothermal contraction flow at the nanoscale. Short linear polyethylene chains were uniformly extruded by a constant-speed piston from a reservoir through an abrupt contraction slit into the surrounding vacuum. Overall, die swelling and die wetting phenomena were observed. Molecular chains were stretched within the slit, while those outside the slit shrunk. Notably, the velocity profile within the slit varied with wall slip at different extrusion velocities. The relationship between the apparent shear viscosity and shear rate exhibited two primary characteristics: the first-Newtonian plateau and the shear thinning slope. Therefore, this molecular simulation method effectively demonstrates the general non-Newtonian behavior of macroscopic polymer fluids.
Research on outburst gas pressure dynamics and water-injected coal damage
Authors: Wei Chengmin , Li Chengwu , Lu Shuhao , Li Zhenfei , Li Mingjie , Hao Min
Published: September 2024

Coal and gas outbursts are complex dynamic disasters closely associated with gas pressure dynamics and coal damage. An experimental system was established to investigate the effects of water injection on coal particles. The experiments utilized helium (He) and carbon dioxide (CO2) gases, at initial pressures ranging from 0.25 to 1.0 MPa and water injection periods ranging from 0 to 12 days, to measure gas pressure variation, particle size distribution, equivalent diameter, and newly generated surface area. The results indicated that outburst gas pressure follows a power-law decay, with He decaying more rapidly than CO2. Elevated gas pressure and adsorptivity intensified coal particle damage: each 0.25 MPa rise in pressure increased the new surface area by 1.02 times for He and 1.28 times for CO2, with the CO2's surface area being 5.03–5.20 times larger than that of He. Water injection mitigated the damage caused by adsorptive gases; as the injection time increased, the new surface area initially decreased and then increased, with the least damage at 6 days. For every 3 day increase in the water injection time, the average surface area of He-fractured coal increases by 0.69 times. A gas pressure decay model and a coal damage model considering pressure differential tension, gas adsorption expansion, and adsorption-induced strain were developed and validated against experimental results. These findings provide theoretical insights into coal and gas outbursts.
Oblique impingement of an ice particle on a water film
Authors: Yang Zhe , Jin Zheyan , Yang Zhigang
Published: September 2024

In the present study, we experimentally investigated the oblique impinging process of an ice particle on a water film. A parameter study of the impact velocity, impact angle, and water film thickness was carefully carried out. The results showed that three impact categories occurred, namely uprising liquid sheet, crown with a notch, and complete crown. The uprising liquid sheet only occurred in the case when the dimensionless water film thickness was 0.1, which appeared to be independent of the impact velocity and the impact angle. The crown with a notch only occurred in the case when the impact velocity was 23.0 m/s. The left tilt angles of uprising liquid sheet, crown with a notch, and complete crown all increased first and then decreased with the dimensionless time. Among the three experimental parameters investigated in the present study, the dimensionless water film thickness had the most significant effect on the evolutions of the left tilt angles. The dimensionless spreading lengths in x- and y-direction all increased with the increase in dimensionless water film thickness. In addition, the correlations of dimensionless spreading lengths in x- and y-direction were proposed. In addition, the lifetime of complete crown generally increased with the increase in the impact velocity and the dimensionless water film thickness. Within the scope of the present study, the dimensionless maximum height of uprising liquid sheet generally ranged from 3.0 to 3.5. When the impact angle was 30.0°, the dimensionless maximum height of the crown with a notch increased with the increasing dimensionless water film thickness. The present work not only provides a new insight into the study of the ice crystal icing but also offers effective support for the development of efficient anti/de-icing methods.
Proteomic and phosphoproteomic landscape of localized prostate cancer unveils distinct molecular subtypes and insights into precision therapeutics
Authors: Wang Zengming , Yu Haolan , Bao Wei , Qu Min , Wang Yan , Zhang Liandong , Liu Xubing , Liu Chen , He Miaoxia , Li Jing , Dong Zhenyang , Zhang Yun , Yang Bo , Hou Jianguo , Xu Chuanliang , Wang Linhui , Li Xin , Gao Xu , Yang Chenghua
Published: September 2024

Building upon our previous investigation of genomic, epigenomic, and transcriptomic profiles of prostate cancer in China, we conducted a comprehensive analysis of proteomic and phosphoproteomic profiles of 82 tumor tissues and matched adjacent normal tissues from 41 Chinese patients with localized prostate cancer. We identified three distinct proteomic subtypes with significant difference in both molecular features and clinical prognosis. Notably, these proteomic subtypes exhibited a parallel degree of heterogeneity in the phosphoproteome, featuring unique metabolism, proliferation, and immune infiltration characteristics. We further demonstrated that a combination of proteins and phosphosites serves as the most effective biomarkers in prostate cancer to predict biochemical recurrence. Through an integrated multiomics analysis, we revealed mechanistic differences underlying different proteomic subtypes and highlighted the potential significance of Serine/arginine-rich splicing factor 1 (SRSF1) phosphorylation in promoting the malignant characteristics of prostate cancer cells. Our multiomics data provide valuable resources for understanding the molecular mechanisms of prostate cancer within the Chinese population, which have the potential to inform the development of personalized treatment strategies and enhance prognostic analyses for prostate cancer patients.
Proteins required for stereocilia elongation during mammalian hair cell development ensure precise and steady heights during adult life
Authors: Hartig Elli I. , Day Matthew , Jarysta Amandine , Tarchini Basile
Published: September 2024

The hair bundle, or stereocilia bundle, is the mechanosensory compartment of hair cells (HCs) in the inner ear. To date, most mechanistic studies have focused on stereocilia bundle morphogenesis, and it remains unclear how this organelle critical for hearing preserves its precise dimensions during life in mammals. The GPSM2–GNAI complex occupies the distal tip of stereocilia in the tallest row and is required for their elongation during development. Here, we ablate GPSM2–GNAI in adult mouse HCs after normal stereocilia elongation is completed. We observe a progressive height reduction of the tallest row stereocilia totaling ~600 nm after 12 wk inGpsm2mutant inner HCs. To measure GPSM2 longevity at tips, we generated aHaloTag-Gpsm2mouse strain and performed pulse–chase experiments in vivo. Estimates using pulse–chase or tracking loss of GPSM2 immunolabeling followingGpsm2inactivation suggest that GPSM2 is relatively long-lived at stereocilia tips with a half-life of 9 to 10 d. Height reduction coincides with dampened auditory brainstem responses evoked by low-frequency stimuli in particular. Finally, GPSM2 is required for normal tip enrichment of elongation complex (EC) partners MYO15A, WHRN, and EPS8, mirroring their established codependence during development. Taken together, our results show that the EC is also essential in mature HCs to ensure precise and stable stereocilia height and for sensitive detection of a full range of sound frequencies.
When left dislocation meets epithets
Authors: Li Ningxian
Published: September 2024

In Spanish syntax, a clitic left-dislocated constituent may incorporate a coreferential epithet
within the sentence, along with a clitic as a resumptive element. In previous research, there exist three approaches
to the relationships among the dislocated constituent, the clitic, and the epithet. The first suggests the dislocated
constituent is originally generated in its surface position. The second argues it originates in a small clause with
the epithet, then moves to the left periphery. The third contends the constituent is part of a distinct clause,
truncated by ellipsis. This study examines ditransitive verb structures featuring epithets in Peninsular Spanish,
advocating that the left dislocation with an internal epithet results from syntactic movement, contributing new
insights to this ongoing debate.
The influence of temporal adverbials and lexical aspect on variable preterite and imperfect selection in native and
second language Spanish
Authors: Blaker Nicholas M.
Published: September 2024

This study adopts a variationist approach to SLA to investigate the influence of temporal
adverbials and lexical aspect on variable preterite and imperfect selection. A total of 110 L2 Spanish learners at
varying proficiency levels and 15 native speakers of Spanish completed a contextualized preference task that examined
the influence of both independent linguistic variables on the selection of preterite, imperfect and both. Results
for frequency of selection showed that learners overselected the imperfect and both in contexts where
NSs categorically selected the preterite. Mixed-effects logistic regressions indicated that both factors influenced
NSs’ selections, but not always for learners. NS variation with states and frequency adverbials is discussed and
avenues for additional research are presented.
A Corpus Stylistics Approach to Contemporary Present-tense
Narrative
Authors: Ikeo Reiko , Shigematsu Eri , Nakao Masayuki
Published: September 2024

Focusing on the growing trend of employing the present tense in storytelling, this book explores present-tense narrative in contemporary fiction. Using a corpus approach, speech, writing, and thought presentation in 21st-century present-tense narrative is compared with 20th-century past-tense narrative. An in-depth comparative analysis reveals previously undiscovered innovative features specific to how character discourse is presented in modern narratives. Notably, narrative tenses have an impact on thought presentation; in present-tense narrative, Free Direct Thought (FDT) emerges as frequently as Free Indirect Thought (FIT), a departure from the dominance of FIT in modern past-tense narrative. This book will be of interest to stylisticians, narratologists, corpus linguists, and those who have found themselves absorbed in a 21st-century work of present-tense fiction.
Optical Mode Entanglement Generation from an Optomechanical Nanobeam
Authors: Cai 蔡 Qi-Zhi 淇智 , Fan 樊 Bo-Yu 博宇 , Fan 范 Yun-Ru 云茹 , Deng 邓 Guang-Wei 光伟 , Wang 王 You 浟 , Song 宋 Hai-Zhi 海智 , Guo 郭 Guang-Can 光灿 , Zhou 周 Qiang 强
Published: September 2024

Nano-optomechanical systems, capable of supporting enhanced light-matter interactions, have wide applications in studying quantum entanglement and quantum information processors. Yet, preparing optical telecom-band entanglement within a single optomechanical nanobeam remains blank. We propose and design a triply resonant optomechanical nanobeam to generate steady-state entangled propagating optical modes and present its quantum-enhanced performance for teleportation-based quantum state transfer under realistic conditions. Remarkably, the entanglement quantified by logarithmic negativity can obtain E
N = 1. Furthermore, with structural imperfections induced by realistic fabrication processes considered, the device still shows great robustness. Together with quantum interfaces between mechanical motion and solid-state qubit processors, the proposed device potentially paves the way for versatile nodes in long-distance quantum networks.
Pathfinding Pulsar Observations with the CVN Incorporating the FAST
Authors: Yan 闫 Zhen 振 , Shen 沈 Zhiqiang 志强 , Jiang 姜 Peng 鹏 , Zhang 张 Bo 波 , Zhang 张 Haiyan 海燕 , Cui 崔 Lang 朗 , Luo 罗 Jintao 近涛 , Chen 陈 Rurong 如荣 , Jiang 江 Wu 悟 , Zhang 张 Hua 华 , Wu 吴 De 徳 , Zhao 赵 Rongbing 融冰 , Yuan 袁 Jianping 建平 , Hu 胡 Yue 悦 , Wu 吴 Yajun 亚军 , Xia 夏 Bo 博 , Li 李 Guanghui 光辉 , Rao 饶 Yongnan 永南 , Chen 陈 Chenyu 晨雨 , Wang 王 Xiaowei 啸威 , Ding 丁 Hao 浩 , Liu 刘 Yongpeng 永朋 , Zhang 张 Fuchen 馥臣 , Jiang 蒋 Yongbin 甬斌
Published: September 2024

The importance of Very Long Baseline Interferometry (VLBI) for pulsar research is becoming increasingly prominent and receiving more and more attention. We present the pathfinding pulsar observation results with the Chinese VLBI Network (CVN) incorporating the Five-hundred-meter Aperture Spherical radio Telescope (FAST). On MJD 60045 (11th April 2023), PSRs B0919+06 and B1133+16 were observed with the phase-referencing mode in the L-band using four radio telescopes (FAST, TianMa, Haoping, and Nanshan) and correlated with the pulsar binning mode of the distributed FX-style software correlator in Shanghai. After further data processing with the NRAO Astronomical Image Processing System (AIPS), we detected these two pulsars and fitted their current positions with accuracy at the milliarcsecond level. By comparison, our results show significantly better agreement with predicted values based on historical VLBI observations than those with previous timing observations, as pulsar astrometry with the VLBI provides a more direct and model-independent method for accurately obtaining related parameters.
Graviton-photon oscillations as a probe of quantum gravity
Authors: Palessandro Andrea
Published: September 2024

The Gertsenshtein effect could in principle be used to detect a single graviton by firing it through a region filled with a constant magnetic field that enables its conversion to a photon, which can be efficiently detected via standard techniques. The quantization of the gravitational field could then be inferred indirectly. We show that for currently available single-photon detector technology, the Gertsenshtein detector is generically inefficient, meaning that the probability of detection is

≪
1

. The Gertsenshtein detector can become efficient on astrophysical scales for futuristic single-photon detectors sensitive to frequencies in the Hz to kHz range. It is not clear whether such devices are in principle possible.
AdaTL1: an adaptive non-convex sparse solver with applications to CT reconstruction and image denoising
Authors: Najiya K Z , Sastry C S
Published: September 2024

Sparsity-promoting optimization techniques have, in recent years, gained prominence due to the availability of efficient solvers and their capability to efficiently use inherent duplication present in underlying data. In clinical Tomography, a faithful reconstruction of the cross-section of an object or image from a reduced set of x-ray attenuation samples attains importance. Though sparsity methods in Computed Tomography (CT) have already been well attended to, there is still a need for newer ideas that accommodate the highly coherent nature of the sub-sampled Radon matrix and incorporate adaptive information into the recovery process. To this end, we propose an adaptive transformed L
1 minimization (referred to as AdaTL
1), which being a non-convex problem is a generalization of transformed L
1 minimization. We discuss the recovery guarantees of AdaTL
1 and propose its solver. Further, we compare and contrast its performance against the known methods in the reconstruction of CT as well as the denoising of images.
The effects of vacancy ordering on diffusion: a statistical study
Authors: Stotts J Carter , Tang Xiaochuan , Thompson Gregory B , Weinberger Christopher R
Published: September 2024

In this paper we investigate the interconnection between vacancy-ordered phases and vacancy self-diffusion. Here, we investigate three ordered phases on a square lattice with energetics defined by two separate Hamiltonians. In the first case we used a classical antiferromagnetic Ising model Hamiltonian in order to generate a ‘checkerboard’ type ordered structure. In the second case, we used a modified Ising model with competing influence of second and third nearest-neighbors, which resulted in both ‘hatch’ and ‘labyrinthine’ structures, depending on concentration. To understand how vacancy-ordering affects diffusion, we determined the tracer diffusivity using rejection-free kinetic Monte Carlo and compared disordered and ordered structures. Finally, we developed an analytical model describing diffusion in the ordered ‘checkerboard’ structure and found that it was able to predict apparent activation energies in the ordered and disordered structures. Our results suggest that it is short-range order rather than long-range order that most significantly affects tracer diffusion.
Using ground state and excited state density functional theory to decipher 3d dopant defects in GaN
Authors: Schultz Peter A , Lutz Jesse J
Published: September 2024

Using ground state density functional theory (DFT) and implementing an occupation-constrained DFT (occ-DFT) for self-consistent excited state calculations, we decipher the electronic structure of the Mn dopant and other 3d defects in GaN across the band gap. Our analysis, validated with broad agreement with defect levels (ground-state calculations) and photoluminescence data (excited-state calculations), mandates reinterpretation and reassignment of 3d defect data in GaN. The MnGa defect is determined to span stable charge states from (1−) in n-type GaN through (2+) in p-type GaN. The Mn(2+) is predicted to be a d
2 ground state spin triplet defect with a singlet excited state, isoelectronic with the defect associated with the 1.19 eV photoluminescence in n-type GaN. The combined analysis of defect levels and excited states invites reassessment of all d
2-capable dopants in GaN. We demonstrate that the 1.19 eV defect, a candidate defect for optically controlled quantum applications, cannot be the Cr(1+) assumed in literature and instead must be the V(0). The combined ground-state/excited-state DFT analysis is shown to be able to chemically fingerprint defects.
The magnetization process of classical Heisenberg magnets with non-coplanar cuboc ground states
Authors: Richter Johannes , Schmidt Heinz-Jürgen , Schnack Jürgen
Published: September 2024

We consider a classical Heisenberg model on the kagomé and the square kagomé lattice, where at zero magnetic field non-coplanar cuboctahedral ground states with twelve sublattices exist if suitable exchange couplings are introduced between the other neighbors. Such ‘cuboc ground states’ are remarkable because they allow for chiral ordering. For these models, we discuss the magnetization process in an applied magnetic field H by both numerical and analytical methods. We find some universal properties that are present in all models. The magnetization curve M(H) usually contains only non-linear components and there is at least one magnetic field driven phase transition. Details of the M(H) curve such as the number and characteristics (continuous or discontinuous) of the phase transitions depend on the lattice and the details of the exchange between the further neighbors. Typical features of these magnetization processes can already be derived for a paradigmatic 12-spin model that we define in this work.
High-pressure synthesis and characterizations of a new ternary Ce-based compound Ce3TiAs5
Authors: Fu L C , Shi L C , Chen X M , Duan L , Peng Y , Zhang J , Song J , Deng Z , Zhang S J , Zhao J F , Liu Y , Zhang J F , Zhu J L , Wang X C , Jin C Q
Published: September 2024

We report the structure and properties of a new Ce-based compound Ce3TiAs5 synthesized under high-pressure and high-temperature conditions. It crystallizes in a hexagonal Hf5Sn3Cu-anti type structure with zig-zag like Ce chains along the c axis. This compound is metallic and undergoes a magnetic phase transition at T
N = 13 K. A metamagnetic transition occurs at ∼0.7 T. The Sommerfeld coefficient for the compound is determined to be about 215 mJ/(Ce-mol*K2), demonstrating a heavy Fermion behavior. The resistivity is featured with two humps, which arises from the synergistic effect of crystal electric field and magnetic scattering. The magnetic ordering temperature T
N gradually increases in the sequence of Ce3TiPn5 with Pn = Bi, Sb, and As, which implies that the Ruderman–Kittel–Kasuya–Yosida interaction should be still predominant in Ce3TiAs5.
Research on digital twin-assisted bearing fault diagnosis method based on virtual-real mapping
Authors: Shang Zhiwu , Wang Xunbo , Pan Cailu , Cheng Hongchuan , Wang Ziyu
Published: September 2024

The deployment of intelligent fault diagnosis for bearings within the industrial field is significantly challenged by the issue of limited sample sizes. Digital twin (DT) technology facilitates the replication of rotating machinery operations within a virtual environment, thereby enabling the acquisition of equivalent or superior information regarding physical entities at a reduced cost, introducing a novel method for fault diagnosis in scenarios characterized by limited sample sizes. Nevertheless, the disparity in data distribution across virtual and physical realms poses challenges to deploying DT-based fault diagnosis methods. In response to this challenge, this paper proposes a DT-assisted bearing fault diagnosis method based on virtual-real mapping. Firstly, a bearing dynamics model is constructed in the virtual space using finite element methods to reflect the bearing’s vibration response in physical space. Secondly, an efficient multi-scale attention cycle-consistent generative adversarial network with a perceptual loss function is proposed as a bridge between virtual and physical spaces, reducing the data distribution differences through data mapping. Finally, a multi-index evaluation framework was established to validate the effectiveness of the simulation data after mapping, and through two case studies, the proposed method’s ability to effectively address the small sample issue was confirmed.
Simple and efficient step detection algorithm for foot-mounted IMU
Authors: Shi Ling-Feng , Yan Xu , Zhou Wen , Shi Yifan
Published: September 2024

This paper presents a concise, efficient, and adaptive step detection algorithm based on foot-mounted inertial measurement unit sensors. The proposed method maps the temporal values of pedestrian motion and gait diversity into two variables: the distance between peaks and valleys, and the slope. Compared to traditional sliding window methods, this approach amplifies the differences between normal and abnormal steps, allowing it to adapt to various indoor activities such as fast walking, slow walking, running, jogging, standing still, and turning. By incorporating adaptive factors, it addresses the challenge of detecting steps while going up and down stairs. The proposed algorithm overcomes the limitations of traditional adaptive threshold methods that require different temporal and peak thresholds for various gait conditions. By utilizing the significant differences in distance and slope, it effectively resolves the issue of detecting steps during stationary periods. Unlike neural network-based gait classifiers, this algorithm does not need to account for multiple gait conditions, thereby simplifying the training process. Experimental results demonstrate that the algorithm achieves an average accuracy of over 99% under mixed indoor walking conditions and over 98% accuracy in long-term outdoor walking conditions.
A robust factor graph optimization method of GNSS/INS/ODO integrated navigation system for autonomous vehicle
Authors: Huo Zhen , Jin Lisheng , Wang Huanhuan , Sun Xinyu , He Yang
Published: September 2024

The GNSS/INS/ODO integrated navigation system provides accurate positioning for autonomous vehicles. However, the observation quality of GNSS and ODO can decrease in complex environments and various driving conditions, leading to a decline in the accuracy and robustness of the integrated navigation system. An FGO-Robust method is proposed to resolve this challenge by fusing the INS/ODO-Slip factor and adaptive GNSS factor. The INS/ODO-Slip factor compensates for ODO measurement values by estimating the wheel slip ratio in real-time during optimization, thereby reducing ODO measurement errors’ impact on factor graph optimization. Additionally, the adaptive GNSS factor minimizes the impact of GNSS outliers in the optimization process by designing a dynamic observation weight function. The vehicle experiments are conducted to evaluate the performance of the proposed method in different simulated conditions with ODO and GNSS measurement failures. The experimental results demonstrate that the FGO-Robust method can effectively improve the positioning accuracy of the integrated navigation system under various measurement failure conditions, with improvements of 83.4%, 66.1%, and 68.1% relative to FGO. Moreover, the FGO-Robust method improves the robustness of the integrated navigation system in complex environments and various driving conditions.
Structural and excitonic properties of the polycrystalline FAPbI3 thin films, and their photovoltaic responses
Authors: Huang Yi-Chun , Yen I-Jane , Tseng Chih-Hsien , Wang Hui-Yu , Chandel Anjali , Chang Sheng Hsiung
Published: September 2024

Faormamadinium based perovskites have been proposed to replace the methylammonium lead tri-iodide (MAPbI3) perovskite as the light absorbing layer of photovoltaic cells owing to their photo-active and chemically stable properties. However, the crystal phase transition from the photo-active α-FAPbI3 to the non-perovksite δ-FAPbI3 still occurs in un-doped FAPbI3 films owing to the existence of crack defects, which degrads the photovoltaic responses. To investigate the crack ratio (CR)-dependent structure and excitonic characteristics of the polycrystalline FAPbI3 thin films deposited on the carboxylic acid functionalized ITO/glass substrates, various spectra and images were measured and analyzed, which can be utilized to make sense of the different devices responses of the resultant perovskite based photovoltaic cells. Our experimental results show that the there is a trade-off between the formations of surface defects and trapped iodide-mediated defects, thereby resulting in an optimal crack density or CR of the un-doped α-FAPbI3 active layer in the range from 4.86% to 9.27%. The decrease in the CR (tensile stress) results in the compressive lattice and thereby trapping the iodides near the PbI6 octahedra in the bottom region of the FAPbI3 perovskite films. When the CR of the FAPbI3 film is 8.47%, the open-circuit voltage (short-circuit current density) of the resultant photovoltaic cells significantly increased from 0.773 V (16.62 mA cm−2) to 0.945 V (18.20 mA cm−2) after 3 d. Our findings help understanding the photovoltaic responses of the FAPbI3 perovskite based photovoltaic cells on the different days.
Nanoheteroepitaxy of Ge and SiGe on Si: role of composition and capping on quantum dot photoluminescence
Authors: Ryzhak Diana , Aberl Johannes , Prado-Navarrete Enrique , Vukušić Lada , Corley-Wiciak Agnieszka Anna , Skibitzki Oliver , Zoellner Marvin Hartwig , Schubert Markus Andreas , Virgilio Michele , Brehm Moritz , Capellini Giovanni , Spirito Davide
Published: September 2024

We investigate the nanoheteroepitaxy (NHE) of SiGe and Ge quantum dots (QDs) grown on nanotips (NTs) substrates realized in Si(001) wafers. Due to the lattice strain compliance, enabled by the nanometric size of the tip and the limited dot/substrate interface area, which helps to reduce dot/substrate interdiffusion, the strain and SiGe composition in the QDs could be decoupled. This demonstrates a key advantage of the NHE over the Stranski–Krastanow growth mechanism. Nearly semi-spherical, defect-free, ∼100 nm wide SiGe QDs with different Ge contents were successfully grown on the NTs with high selectivity and size uniformity. On the dots, thin dielectric capping layers were deposited, improving the optical properties by the passivation of surface states. Intense photoluminescence was measured from all samples investigated with emission energy, intensity, and spectral linewidth dependent on the SiGe composition of the QDs and the different capping layers. Radiative recombination occurs in the QDs, and its energy matches the results of band-structure calculations that consider strain compliance between the QD and the tip. The NTs arrangement and the selective growth of QDs allow to studying the PL emission from only 3–4 QDs, demonstrating a bright emission and the possibility of selective addressing. These findings will support the design of optoelectronic devices based on CMOS-compatible emitters.
Establishment of a Raman nanosphere based immunochromatographic system for the combined detection of influenza A and B viruses’ antigens on a single T-line
Authors: Li Ziyue , Zhu Aolin , Zhao Binbin , Zhang Yongwei , Zhang Qian , Zhou Hao , Liu Tingwei , Li Jiutong , Zhou Xuelei , Shi Qian , Li Yongxin , Liang Mengjie , Zhang Xin , Lu Dongmei , Li Xinxia
Published: September 2024

A simple and rapid system based on Raman nanosphere (R-Sphere) immunochromatography was developed in this study for the simultaneous detection of Influenza A, B virus antigens on a single test line (T-line). Two types of R-Sphere with different characteristic Raman spectrum were used as the signal source, which were labeled with monoclonal antibodies against FluA, FluB (tracer antibodies), respectively. A mixture of antibodies containing anti-FluA monoclonal antibody and anti-FluB monoclonal antibody (capture antibody) was sprayed on a single T-line and goat anti-chicken IgY antibody was coated as a C-line, and the antigen solution with known concentration was detected by the strip of lateral flow immunochromatography based on surface-enhanced Raman spectroscopy (SERS). The T-line was scanned with a Raman spectrometer and SERS signals were collected. Simultaneous specific recognition and detection of FluA and FluB were achieved on a single T-line by analyzing the SERS signals. The findings indicated that the test system could identify FluA and FluB in a qualitative manner in just 15 minutes, with a minimum detection threshold of 0.25 ng ml−1, excellent consistency, and specificity. There was no interference with the other four respiratory pathogens, and it exhibited 8 times greater sensitivity compared to the colloidal gold test strip method. The assay system is rapid, sensitive, and does not require repetitive sample pretreatment steps and two viruses can be detected simultaneously on a single T-line by titrating one sample, which improves detection efficiency, and provide a reference for developing multiplexed detection techniques for other respiratory viruses.
Isomonodromic and isospectral deformations of meromorphic connections: the

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case
Authors: Marchal Olivier , Alameddine Mohamad
Published: September 2024

We consider non-twisted meromorphic connections in

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and the associated symplectic Hamiltonian structure. In particular, we provide explicit expressions of the Lax pair in the geometric gauge supplementing results of Marchal et al (2022 arXiv:2212.04833) where explicit formulas have been obtained in the oper gauge. Expressing the geometric Lax matrices requires the introduction of specific Darboux coordinates for which we provide the explicit Hamiltonian evolutions. These expressions allow to build bridges between the isomonodromic deformations and the isospectral ones. More specifically, we propose an explicit change of Darboux coordinates to obtain isospectral coordinates for which Hamiltonians match the spectral invariants. This result solves the issue left opened in Bertola et al (2023 J. Math. Phys.
64 083502) in the case of

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.
Performance evaluation of image co-registration methods in photoacoustic mesoscopy of the vasculature
Authors: Lefebvre T L , Sweeney P W , Gröhl J , Hacker L , Brown E L , Else T R , Oraiopoulou M-E , Bloom A , Lewis D Y , Bohndiek S E
Published: September 2024

Objective. The formation of functional vasculature in solid tumours enables delivery of oxygen and nutrients, and is vital for effective treatment with chemotherapeutic agents. Longitudinal characterisation of vascular networks can be enabled using mesoscopic photoacoustic imaging, but requires accurate image co-registration to precisely assess local changes across disease development or in response to therapy. Co-registration in photoacoustic imaging is challenging due to the complex nature of the generated signal, including the sparsity of data, artefacts related to the illumination/detection geometry, scan-to-scan technical variability, and biological variability, such as transient changes in perfusion. To better inform the choice of co-registration algorithms, we compared five open-source methods, in physiological and pathological tissues, with the aim of aligning evolving vascular networks in tumours imaged over growth at different time-points. Approach. Co-registration techniques were applied to 3D vascular images acquired with photoacoustic mesoscopy from murine ears and breast cancer patient-derived xenografts, at a fixed time-point and longitudinally. Images were pre-processed and segmented using an unsupervised generative adversarial network. To compare co-registration quality in different settings, pairs of fixed and moving intensity images and/or segmentations were fed into five methods split into the following categories: affine intensity-based using (1) mutual information (MI) or (2) normalised cross-correlation (NCC) as optimisation metrics, affine shape-based using (3) NCC applied to distance-transformed segmentations or (4) iterative closest point algorithm, and deformable weakly supervised deep learning-based using (5) LocalNet co-registration. Percent-changes in Dice coefficients, surface distances, MI, structural similarity index measure and target registration errors were evaluated. Main results. Co-registration using MI or NCC provided similar alignment performance, better than shape-based methods. LocalNet provided accurate co-registration of substructures by optimising subfield deformation throughout the volumes, outperforming other methods, especially in the longitudinal breast cancer xenograft dataset by minimising target registration errors. Significance. We showed the feasibility of co-registering repeatedly or longitudinally imaged vascular networks in photoacoustic mesoscopy, taking a step towards longitudinal quantitative characterisation of these complex structures. These tools open new outlooks for monitoring tumour angiogenesis at the meso-scale and for quantifying treatment-induced co-localised alterations in the vasculature.
Fraction of reverse impedance change (FRIC): a quantitative electrical impedance tomography measure of intrapulmonary pendelluft
Authors: Adler Andy , Becher Tobias , Händel Claas , Frerichs Inéz
Published: September 2024

Objective. Pendelluft is the movement of air between lung regions, and electrical impedance tomography (EIT) has shown an ability to detect and monitor it. Approach. In this note, we propose a functional EIT measure which quantifies the reverse airflow seen in pendelluft: the Fraction of Reverse Impedance Change (FRIC). Main
Results. FRIC measures the fraction of reverse flow in each pixel waveform (as an image) or globally (as a single parameter). Significance. Such a measure is designed to be a more specific measure than previous approaches, to enable comparative studies of the pendelluft, and to help clarify the effect of ventilation strategies.
Detection of sleep arousal from STFT-based instantaneous features of single channel EEG signal
Authors: Ali Md Hussain , Uddin Md Bashir
Published: September 2024

Objective. Sleep arousal, a frequent interruption in sleep with complete or partial wakefulness from sleep, may indicate a breathing disorder, neurological disorder, or sleep-related disorders. These phenomena necessitate the detection of sleep arousals. Uses of deep learning methods to detect features inhibits the scope to understand the specific distinctive nature of the signals and reduces the interpretability of the model. To evade these inconsistencies and to improve the classification performance of the sleep arousal detection model, a model has been proposed in this study on the prospect of understandable features that are useful in detecting sleep arousals. Approach. Time–frequency analysis of the electroencephalogram signals was performed using short-time Fourier transform (STFT). From the STFT coefficients, the spectrogram and instantaneous properties (frequency, bandwidth, power spectrum, band energy, local maxima, and band energy ratios) were investigated. From these properties, instantaneous features were generated by statistical analysis. Additive feature sets and reduced feature sets, formed by adding features successively and reducing features using the analysis of variance test respectively, were subjected to a tri-layered neural network classifier to evaluate the capability of the features to detect sleep arousal and normal sleep segments. Main results. The reduced feature set (Set 6) has proved to be efficacious in facilitating superior classification performance metrics (accuracy, sensitivity, specificity, and AUC of 89.14%, 83.52%, 89.49%, and 93.84% respectively). Significance. This efficient model can be incorporated with an automatic sleep apnea detection system where the estimation of hypopnea requires the detection of sleep arousal.
Examination of sex differences in fatigability and neuromuscular responses during continuous, maximal, isometric leg extension
Authors: Benitez Brian , Kwak Minyoung , Succi Pasquale J , Mitchinson Clara J , Weir Joseph P , Bergstrom Haley C
Published: September 2024

Objective. This study examined sex-related differences in fatigability and neuromuscular responses using surface electromyographic (sEMG) and mechanomyographic (sMMG) amplitude (AMP) and frequency (MPF) during fatiguing, maximal, bilateral isometric leg extensions. Approach. Twenty recreationally active males and females with resistance training experience performed continuous, maximal effort, bilateral isometric leg extensions until their force reduced by 50%. Linear mixed effect models analyzed patterns of force, sEMG, and sMMG AMP and MPF responses in the dominant limb. An independent samples t-test compared time-to-task failure (TTF) between sexes. Main Results. There were no significant differences in TTF between males and females. However, males experienced a greater rate of force loss compared to females. Furthermore, sEMG AMP and MPF and sMMG AMP responses followed similar linear trends for both sexes, while sMMG MPF showed non-linear responses with sex-dependent differences. Significance. These data suggest that although TTF was similar, males had a higher rate of force reduction, likely due to greater absolute strength. Furthermore, despite parallel changes in sEMG AMP and MPF, as well as sMMG AMP, the divergent responses observed in sMMG MPF highlight sex-dependent differences in how males and females experience changes in the firing rates of active motor units during sustained maximal contractions.
A comprehensive review of quantum machine learning: from NISQ to fault tolerance
Authors: Wang Yunfei , Liu Junyu
Published: September 2024

Quantum machine learning, which involves running machine learning algorithms on quantum devices, has garnered significant attention in both academic and business circles. In this paper, we offer a comprehensive and unbiased review of the various concepts that have emerged in the field of quantum machine learning. This includes techniques used in Noisy Intermediate-Scale Quantum (NISQ) technologies and approaches for algorithms compatible with fault-tolerant quantum computing hardware. Our review covers fundamental concepts, algorithms, and the statistical learning theory pertinent to quantum machine learning.