bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tests of Solar X-ray Image Reconstruction: Study of X-ray Imaging Algorithms and Reconstruction Parameters
Authors: YU Wenhui , Su Yang , Li Zhentong , Chen Wei , Gan Weiqun 
Published: January 2025

Abstract
Abstract Imaging observations of solar X-ray bursts can reveal details of the energy release process and particle acceleration in flares. Most hard X-ray imagers make use of the modulation-based Fourier transform imaging method, an indirect imaging technique that requires algorithms to reconstruct and optimize images. During the last decade, a variety of algorithms have been developed and improved. However, it is difficult to quantitatively evaluate the image quality of different solutions without a true, reference image of observation. How to choose the values of imaging parameters for these algorithms to get the best performance is also an open question. In this study, we present a detailed test of the characteristics of these algorithms, imaging dynamic range and a crucial parameter for the CLEAN method, clean beam width factor (CBWF). We first used SDO/AIA EUV images to compute DEM maps and calculate thermal X-ray maps. Then these realistic sources and several types of simulated sources are used as the ground truth in the imaging simulations for both RHESSI and ASO-S/HXI. The different solutions are evaluated quantitatively by a number of means. The overall results suggest that EM, PIXON, and CLEAN are exceptional methods for sidelobe elimination, producing images with clear source details. Although MEM_GE, MEM_NJIT, VIS_WV and VIS_CS possess fast imaging processes and generate good images, they too possess associated imperfections unique to each method. The two forward fit algorithms, VF and FF perform differently, and VF appears to be more robust and useful. We also demonstrated the imaging capability of HXI and available HXI algorithms. Furthermore, the effect of CBWF on image quality was investigated, and optimal settings for both RHESSI and HXI were proposed.
Plug-and-play myoelectric control via a self-calibrating random forest common model
Authors: Jiang Xinyu , Ma Chenfei , Nazarpour Kianoush 
Published: January 2025

Abstract

Objective. Electromyographic (EMG) signals show large variabilities over time due to factors such as electrode shifting, user behavior variations, etc substantially degrading the performance of myoelectric control models in long-term use. Previously one-time model calibration was usually required each time before usage. However, the EMG characteristics could change even within a short period of time. Our objective is to develop a self-calibrating model, with an automatic and unsupervised self-calibration mechanism. Approach. We developed a computationally efficient random forest (RF) common model, which can (1) be pre-trained and easily adapt to a new user via one-shot calibration, and (2) keep calibrating itself once in a while by boosting the RF with new decision trees trained on pseudo-labels of testing samples in a data buffer. Main results. Our model has been validated in both offline and real-time, both open and closed-loop, both intra-day and long-term (up to 5 weeks) experiments. We tested this approach with data from 66 non-disabled participants. We also explored the effects of bidirectional user-model co-adaption in closed-loop experiments. We found that the self-calibrating model could gradually improve its performance in long-term use. With visual feedback, users will also adapt to the dynamic model meanwhile learn to perform hand gestures with significantly lower EMG amplitudes (less muscle effort). Significance. Our RF-approach provides a new alternative built on simple decision tree for myoelectric control, which is explainable, computationally efficient, and requires minimal data for model calibration. Source codes are avaiable at: https://github.com/MoveR-Digital-Health-and-Care-Hub/self-calibrating-rf.
Investigating the design characteristics and parameter laws of bird-like flapping-wing aerial vehicles from the perspective of scaling
Authors: Ma Dongfu , Song Bifeng , Cao Jianing , Wang Jiaxin , Xuan Jianlin , Liu Xia 
Published: January 2025

Abstract
Bird-like flapping-wing aerial vehicles (BFAVs) represent a significant advancement in the application of bird biology to aircraft design, with scaling analysis serving as an effective tool for identifying this design process. From the perspective of aviation designers, this paper systematically organizes the scaling laws of birds that are closely related to the design of BFAVs. An intriguing topic further explored is the comparison between birds and BFAVs from the standpoint of scaling, along with an examination of the differences in relevant design parameters. This analysis aims to enhance communication between biologists and engineers, ultimately fostering the development of improved bionic systems. By introducing the concept of periodic average angular velocity, both frequency and amplitude are uniformly considered, providing a clearer explanation of the design characteristics of BFAVs. Finally, a method for establishing the initial parameters based on the scaling laws of BFAVs is proposed, and its effectiveness is validated through design cases, offering a novel approach for the development of new prototypes.
Resilience of hierarchical actuators highlighted by a myosin-to-muscle mock-up
Authors: Perrier Raphaël , Linares Jean-Marc , Tadrist Loïc 
Published: January 2025

Abstract
Skeletal muscle is the main actuator of various families of vertebrates (mammals, fish, reptiles). It displays remarkable robustness to micro-damage, that supposedly originates both from its redundant hierarchical structure and its nervous command. A bioinspired mock-up was designed and manufactured mimicking sarcomeres (micro-scale) and its series and parallel structure from fibre to muscle. First, the mechanical performances namely the force–velocity curve of the intact muscle mock-up were measured and modelled. Then, mimicking micro-damage by making some myosin heads inoperative, the mechanical performances were again measured to determine the resilience of the actuator. The mock-up is shown to be resilient: in the event of 10% damage of the mock-up, the mechanical performance of the mock-up was around 80% of the intact one. In this multi degrees of freedom actuator with hierarchical structure, the resilience is shown to be almost linear with the damage level for uniformly distributed damage (both maximal force and velocity decrease). Differently when micro-damage are clustered on a fibre, this decreases the maximal force with little effect on velocity.
Environmental features related to the decadal variation of South China Sea tropical cyclogenesis in the context of summer monsoon
Authors: Cai Yuhao , Yang Song , Wu Huan , Chen Weizhen , Xu Juying 
Published: January 2025

Abstract
This study investigates the changes in environmental conditions related to the decadal variation of genesis frequency of tropical cyclones (TCGF) over the South China Sea (SCS) during the summer. Corresponding to the decadal increase in TCGF, the seasonal mean anomalies of the genesis potential and environmental fields over the SCS are not favorable for tropical cyclogenesis, indicating their limited role in the decadal variation of the SCS TCGF. It is found instead that the decadal change in tropical cyclogenesis over the SCS is more attributed to the local environmental fields associated with atmospheric intraseasonal oscillation (ISO). The decadal change in SCS TCGF is closely linked to the northward extension of ISO-related convection from the central SCS, which is contributed by the horizontal advection by background monsoon flow and the vertical advection by ISO-related vertical motions. Further analyses indicate that the anomalous upper-level cyclonic circulation over East Asia and the lower-level anticyclonic circulation over the western Pacific produce unfavorable seasonal mean environmental fields in the SCS, whereas the resultant strong summer mean SCS monsoon flow facilitates the northward extension of ISO-related convection. This study highlights the importance of ISO activity for projections of long-term change in the SCS TC activity.
Intensification of Hurricane Idalia by a river plume in the eastern Gulf of Mexico
Authors: Shi Jing , Hu Chuanmin , Cannizzaro Jennifer , Barnes Brian , Zhang Yingjun , Lembke Chad , Henaff Matthieu Le 
Published: January 2025

Abstract
Hurricane Idalia formed on 26 August 2023 and three days later rapidly intensified from a Category 1 to Category 4 strength storm in less than 24 h over the west Florida shelf. On August 30, it made landfall along Florida’s Big Bend area as a Category 3 hurricane. Strikingly, despite Idalia’s moderate intensity and favorable vortex structure, neither upper ocean thermal energy nor environmental vertical wind shear conditions were as favorable during its intensification from Category 2 to Category 4 as earlier in its path, raising the question of what external factors contributed to its extreme intensification during this phase. Using satellite data, underwater glider observations, and numerical model outputs, this study reveals that, in addition to the 2023 marine heatwave, an extensive riverine plume in the eastern Gulf of Mexico, extending from the Mississippi-Alabama-Florida shelf to the Straits of Florida, produced a ∼20 m thick low-salinity layer (∼34–34.5 psu) and a corresponding warm upper ocean (>29 °C, ∼25–30 m thick). This defined a 10–20 m thick strongly stratified barrier layer below the surface layer with buoyancy frequencies exceeding 10−3 s−1 that suppresses vertical mixing and became a critical factor contributing to Idalia’s rapid intensification under the relatively less than favorable thermal and wind field environments. Therefore, incorporating the river plume in future forecast models appears to be essential to improve the accuracy of intensity predictions, especially in the areas affected by the plume, where stratification plays an important role in the intensification dynamics.
Impact of metakaolin to partially replace granulated blast furnace slag on the performance of alkali-activated slag grouting materials and evaluation of grouting effectiveness
Authors: Han Bo , Cai Lingjian , Chi Fengxia , Zhan Wei 
Published: January 2025

Abstract
In recent years, alkali-activated slag materials have garnered widespread attention in the construction field due to their environmental friendliness and excellent mechanical strength. However, optimizing their composition to reduce autogenous shrinkage remains a pressing issue. This study aims to explore the effects of partially replacing granulated blast furnace slag with metakaolin on the performance of alkali-activated slag grouting materials and evaluate its grouting effectiveness. By setting different replacement levels of metakaolin for granulated blast furnace slag, the study systematically investigates the fluidity, autogenous shrinkage, and mechanical properties of alkali-activated slag grouting materials. The experimental results show that as the amount of metakaolin increases, the fluidity of the grouting material significantly decreases, while the autogenous shrinkage rate reduces; however, the mechanical properties exhibit a complex variation trend. Specifically, when the metakaolin content is at 10%, the comprehensive performance is optimal with excellent grouting effect. This finding provides new insights and methods for optimizing alkali-activated slag grouting materials.
Quantum-enhanced clock synchronization using prior statistical information
Authors: Gosalia Ronakraj K , Malaney Robert 
Published: January 2025

Abstract
Optical frequency combs (OFCs) are paving the way for an unprecedented level of precision in synchronizing optical clocks over free-space. However, the conventional intensity-based strategy for estimating the timing offset between two OFCs is sub-optimal, whereas a strategy based on temporal modes can achieve the optimal precision bound under ideal conditions. In practice, the performance of both strategies depends on prior information about the relative intensity of the two OFCs, and the timing centroid between the OFCs. Here, for the first time, we quantify the amount of information required about these two parameters to guarantee that the temporal mode strategy is superior. Using tools from quantum estimation theory and numerical simulations, we ascertain the significance of the timing centroid in quantum-enhanced clock synchronization. Most notably, when the prior information on the timing centroid is at anticipated levels, we find the reductions in the timing deviation achieved by the temporal mode strategy, relative to the intensity-based strategy, to be in the range 2–10. Our new insights can also be one-to-one mapped to the problem of super-resolution imaging of incoherent point sources.
Proof-of-work consensus by quantum sampling
Authors: Singh Deepesh , Muraleedharan Gopikrishnan , Fu Boxiang , Cheng Chen-Mou , Roussy Newton Nicolas , Rohde Peter P , Brennen Gavin K 
Published: January 2025

Abstract
Since its advent in 2011, boson sampling has been a preferred candidate for demonstrating quantum advantage because of its simplicity and near-term requirements compared to other quantum algorithms. We propose to use a variant, called coarse-grained boson-sampling (CGBS), as a quantum proof-of-work (PoW) scheme for blockchain consensus. The miners perform boson sampling using input states that depend on the current block information and commit their samples to the network. Afterwards, CGBS strategies are determined which can be used to both validate samples and reward successful miners. By combining rewards for miners committing honest samples together with penalties for miners committing dishonest samples, a Nash equilibrium is found that incentivises honest miners. We provide numerical evidence that these validation tests are hard to spoof classically without knowing the binning scheme ahead of time and show the robustness of our protocol to small partial distinguishability of photons. The scheme works for both Fock state boson sampling and Gaussian boson sampling and provides dramatic speedup and energy savings relative to computation by classical hardware.
Quadrature-PT symmetry: classical-to-quantum transition in noise fluctuations
Authors: Wang Wencong , Zhai Yanhua , Liu Dongmei , Jiang Xiaoshun , Vashahri Ghamsari Saeid , Wen Jianming 
Published: January 2025

Abstract
While gain-loss-coupled photonic platforms have achieved significant success in studying classical parity-time (PT) symmetry, they encounter challenges in demonstrating pure quantum effects due to incompatible operator transformations and Langevin noise. Here, we present compelling evidence that a non-Hermitian (NH) twin-beam system, undergoing phase-sensitive amplification and balanced loss, not only enables observing the usual eigenvalue-associated PT phase transition but also exhibits distinctive features absent in classical NH or traditional Hermitian quantum scenarios, encompassing quadrature PT symmetry, anomalous loss-induced quadrature squeezing, and classical-to-quantum (C2Q) transitions in noise fluctuations. Furthermore, our proposed bipartite open system promises optimal sensing for various quantum observable measurements, showcasing an improved signal-to-noise ratio and sensitivity, constrained by quantum Cramér–Rao bound or Fisher information. These findings deepen the comprehension of authentic quantum optical PT symmetry involving both gain and loss, addressing contentious issues and illuminating new facets of the subject.
Enhancing environmental monitoring of harmful algal blooms with ConvLSTM image prediction
Authors: Kim Sung Jae , Cho Yongbok 
Published: January 2025

Abstract
This study advances environmental monitoring by predicting the spatial and temporal distribution of Harmful Algal Blooms (HABs) in the Republic of Korea through a hybrid approach that combines geostatistical and deep learning methods. Using 3D universal kriging, the study interpolates missing HAB concentration values, transforming geospatial point data into spatially continuous grid images that serve as the foundation for predictive modeling. These interpolated images are then used as input for a ConvLSTM (Convolutional Long Short-Term Memory) network, which integrates convolutional layers to capture spatial patterns and LSTM units to model temporal dependencies. By leveraging this spatiotemporal modeling framework, the ConvLSTM network effectively predicts future HAB concentrations with improved accuracy. This innovative methodology highlights the utility of combining 3D universal kriging for spatial interpolation with image-based ConvLSTM prediction, offering valuable insights into HAB dynamics and supporting sustainable strategies for environmental management and public health.
Electrochemical conversion of methane measured by anode out gas monitoring over Ce–Co–Cu anode electrocatalysts
Authors: Sarruf Bernardo Jordão Moreira , Steinberger-Wilckens Robert , Valadão de Miranda Paulo Emílio 
Published: January 2025

Abstract
Solid oxide fuel cells (SOFCs) enable the highly efficient conversion of fuels to electricity, offering notable fuel flexibility. However, conventional nickel-based SOFC anode materials currently available on the market are unable to effectively utilise low-carbon fuels without succumbing to carbon deposition, which degrades the anode rapidly. This study introduces a nickel-free SOFC anode electrocatalyst capable of achieving impressive power densities exceeding 400 mW cm−2 at 850 °C when operating directly with pure methane. Comparative analysis of three cell types, each with varying amounts of ceria, cobalt, and copper in their anode compositions, was conducted. Gas chromatography was employed to monitor anode effluent gases under electrochemical conditions, complemented by electrochemical impedance assessments using hydrogen as the fuel to identify polarisation sources within these innovative anode configurations. The findings reveal that tracking chemical and electrochemical reactions in SOFCs provides insights into efficiency and fuel conversion mechanisms, wherein the anode material transforms fuel into useful products while generating electricity and heat. Notably, copper additions influence these behaviours, although Cobalt-rich catalysts exhibit superior performance in facilitating fuel conversion through combined electrochemical and thermochemical reactions. Distribution of relaxation times analysis highlights the necessity of optimising microstructure and mitigating gas diffusion polarisation effects, corroborating the validity of equivalent circuit models aligned with electrochemical impedance spectroscopy data.
Micro-amplitude vibration-assisted scratching: a new method for one step and controllable fabrication of the microscale V-groove and nanoscale ripples
Authors: Wu Haoxiang , Huang Hu , Zhang Zhiyu , Yan Jiwang 
Published: January 2025

Abstract
Micro/nano hierarchical structures could endow materials with various surface functions. However, the multilayer and multiscale characteristics of micro/nano hierarchical structures bring difficulties for their one step and controllable fabrication. Accordingly, based on tip-based fabrication techniques, this study proposed a micro-amplitude vibration-assisted scratching method by introducing a periodic backward displacement into the conventional scratching process, which enabled the synchronous creation of the microscale V-groove and nanoscale ripples, i.e. a typical micro/nano hierarchical structure. The experiments and finite element modeling were employed to explore the formation process and mechanism of the micro/nano hierarchical structures. Being different from conventional cutting, this method was mainly based on the plow mechanism, and it could accurately replicate the shape of the indenter on the material surface. The microscale V-groove was formed due to the scratching action, and the nanoscale ripple was formed due to the extrusion action of the indenter on the microscale V-groove’s surface. Furthermore, the relationships between the processing parameters and the dimensions of the micro/nano hierarchical structures were established through experiments, and optimized processing parameters were determined to achieve regular micro/nano hierarchical structures. By this method, complex patterns constructed by various micro/nano hierarchical structures were fabricated on both flat and curved surfaces, achieving diverse surface structural colors.
Power quality enhancement in grid-connected PV systems with battery backup: A filterless control strategy
Authors: Tiwari Anurag 
Published: January 2025

Abstract
The present research paper presents a novel control strategy developed to maximize the utilization of grid-connected photovoltaic (PV) systems incorporated with battery backup. It is intended to provide enhanced power quality across a range of operating modes. The designed controller coordinates uninterrupted power transfer from PV modules to the grid, maintaining unity power factor (UPF) at the point of common coupling (PCC), and compensates for reactive power and current harmonics in the presence of PV generation. It also significantly improves the efficiency of using batteries in electric vehicle solutions, leading to system simplification. An MPPT (maximum power point tracking) controller is used to secure the optimal output from PV modules, which has been optimized with the P&O algorithm-based strategy. These approaches were extensively simulated in different operational modes to meet the IEEE standard requirement for THD of grid currents and load current under a wide range of nonlinear loads. In fixed-load conditions, total harmonic distortion (THD) values of 15.46%, 7.96%, and 3.84% were observed for load, inverter, and grid currents, respectively. In varying load conditions, THD values for inverter and grid currents were 10.88% and 7.41%, respectively, with a grid THD of 3.71%. In order to secure robust and efficient control, the proposed converter is used, and sinusoidal grid currents are achieved, indicating that this strategy works well in hybrid PV system-connected battery storage segments.
Britain’s World
Authors: Gurney Peter , Grant Matthew , Morley Joel 
Published: January 2025

Abstract
Our participants reflected on the relationship between British power, national service as an institution, and their own part in it. Although they had differing views on whether their service contributed anything to the nation, they were united by a lack of questioning of the state’s basic right to demand military service, suggesting a degree of deference to the political system. Their sense of Britain’s world role was often vague, with a firm commitment to a notion of British power but lacking an explicit awareness of the Cold War context of their service. In same way, the nature of empire was equally unquestioned by the majority.