bluuebunny/crossref_metadata_2025 huggingface dataset:
A new approach in classical Klein–Gordon cosmology: ‘Small Bangs’, inflation and Dark Energy
Authors: Kontou Eleni-Alexandra , Rothe Nicolai
Published: January 2025

In this work, we analyze the cosmological model in which the expansion is driven by a classical, free Klein–Gordon field on a flat, four-dimensional Friedmann–Lemaître—Robertson–Walker spacetime. The model allows for arbitrary mass, non-zero cosmological constant and coupling to curvature. We find that there are strong restrictions to the parameter space, due to the requirement for the reality of the field values. At early cosmological times, we observe Big Bang singularities, solutions where the scale factor asymptotically approaches zero, and Small Bangs. The latter are solutions for which the Hubble parameter diverges at a finite value of the scale factor. They appear generically in our model for certain curvature couplings. An early inflationary era is observed for a specific value of the curvature coupling without further assumptions (unlike in many other inflationary models). A late-time Dark Energy period is present for all solutions with positive cosmological constant, numerically suggesting that a ‘cosmic no-hair’ theorem holds under more general assumptions than the original Wald version which relies on classical energy conditions. The classical fields in consideration can be viewed as resembling one-point functions of a semiclassical model, in which the cosmological expansion is driven by a quantum field.
Bearing fault diagnosis method using CNN with denoising structure under strong noise background
Authors: Wang Junxiang , Li Hongkun , Liu Xuejun , Sun Bin , Liu Yefei
Published: January 2025

In the monitoring of rotating machinery area, intelligent fault diagnosis based on signal analysis has been widely applied. However, due to modulation of the hardware transmission path and interference from environmental noise, the quality of collected vibration signals is prone to degradation. Convolutional neural networks (CNNs) are currently the most widely used models for fault diagnosis. However, their lack of dedicated denoising structures makes them less robust against noise. Therefore, this paper proposes an end-to-end denoising CNN fault diagnosis model. Firstly, a discrete-wavelet attention layer (DAL) and convolutional layers are alternately employed to extract signal features in the wavelet domain. Secondly, according the periodic self-similarity of vibration signals, the Gramian noise reduction (GNR) method is utilized to enhance fault features in the signal. Subsequently, GNR and DAL are integrated into the model to simultaneously extract features from the original signal and the vibration signal enhanced by GNR, thereby enhancing the model fault diagnosis performance in noisy environments. Finally, various levels of noise are added to Case Western Reserve University and Dalian University of Technology data, and compared with other advanced methods, to verify the effectiveness and universality of the proposed method.
Continuous single-ended depth-of-interaction measurement using highly multiplexed signals and artificial neural networks
Authors: Shim Hyeong Seok , Cho Min Jeong , Lee Min Sun , Lee Jae Sung
Published: January 2025

Objective: This study aims to enhance positron emission tomography (PET) imaging systems by developing a continuous depth-of-interaction (DOI) measurement technique using a single-ended readout. Our primary focus is on reducing the number of readout channels in the scintillation detectors while maintaining accurate DOI estimations, using a high-pass filter-based signal multiplexing technique combined with artificial neural networks (ANNs).Approach: Instead of reading out all 64 signals from an 8×8 silicon photomultiplier array for DOI estimation, the proposed method technique reduces the signals into just four channels by applying high-pass filters with different time constants. To recover the original signal amplitudes, an ANN is used to demultiplex the multiplexed signals. Specifically, the ANN processes the sampled waveforms of these four multiplexed signals and estimates the energy information of the original 8×8 SiPM channels. In this study, two DOI estimation strategies were explored for a continuous DOI PET detector utilizing triangular teeth-shaped reflectors: a ‘single-step estimation’ method directly estimating DOI from multiplexed signals, and a ‘two-stage cascade estimation’ method that first demultiplexes the signals and then estimates DOI. The performances of proposed strategies were validated using data irradiated at five steps (2 mm, 6 mm, 10 mm, 14 mm, and 18 mm).Results: The signal amplitude of row/column summed signals, which were recovered using the proposed ANN-based demultiplexing, showed strong correlation with ground truth (e.g., R2=0.98 for 125 MHz digitizer sampling rate). Moreover, both the single-step and two-stage estimation methods achieved high accuracy in DOI estimation, with an average DOI estimation accuracy of 72.9% and 74.0% at 125 MHz sampling rate when considering an error range of ± 1 DOI position. Significance: This novel signal multiplexing technique significantly reduces the number of required readout channels, making continuous DOI PET more cost-effective. 
Predicting thermal stress and failure risk in monoblock divertors using 2D finite difference modeling and gradient boosting regression for fusion energy applications
Authors: Daramola Ayobami Daniel
Published: January 2025

This study presents a combined approach using a 2D finite difference method and gradient boosting regressor (GBR) to analyze thermal stress and identify potential failure points in monoblock divertors made of tungsten, copper, and CuCrZr alloy. The model simulates temperature and heat flux distributions under typical fusion reactor conditions, highlighting regions of high thermal gradients and stress accumulation. These stress concentrations, particularly at the interfaces between materials, are key areas for potential failure, such as thermal fatigue and microcracking. Using the GBR model, a predictive maintenance framework is developed to assess failure risk based on thermal stress data, allowing for early intervention. This approach provides insights into the thermomechanical behavior of divertors, contributing to the design and maintenance of more resilient fusion reactor components.
Study of the influence of dry air on the plasma parameters in a cascaded arc Ar plasma using laser Thomson scattering approach
Authors: Wang Yong , Zhou Lina , Shi Jielin , Li Yu , Li Cong , Feng Chunlei , Ding Hongbin
Published: January 2025

In this work, the influence of dry air on the electron density (n
e) and electron temperature (T
e) in a cascaded arc Ar plasma is firstly studied by the state-of-the-art laser Thomson scattering approach. The results reveal that a small amount of dry air can induce a sharp drop in n
e, which is ascribed by the dissociative recombination reactions between electron and molecular ions formed in charge transfer reactions. With the increase in dry air ratio, T
e exhibits a non-monotonic trend which initially increases and then decreases. This should be caused by the cooperation between super-elastic collision with highly vibrationally excited molecules and electron impact vibrational excitation to molecules. Additionally, the calculated electron density (n
e
cal) and electron temperature (T
e
cal) are derived using n
e and T
e obtained from the separate additions of N2 and O2, along with the respective proportions of N2 and O2 in dry air. It is found that both n
e
cal and T
e
cal closely match the experimentally measured values in dry air, which indicates that the impact on n
e and T
e are mainly dominated by N2 and O2 molecules and the interplay between nitrogen and oxygen, has minimal effect on the plasma parameters.
Multi-stage infrared detectors
Authors: Shen Zhijian , Yang Zezheng , Dai Zhecheng , Chen Baile
Published: January 2025

This paper provides a comprehensive review of multi-stage infrared detectors, including interband cascade infrared photodetectors (ICIPs) and quantum cascade detectors (QCDs). These detectors exhibit low dark current, high detectivity, and high 3 dB bandwidth positioning them as promising candidates in infrared (IR) detector technology. The review covers the history of multi-stage IR detectors, the corresponding device physics, materials systems, DC and RF performance, and recent advancements. Additionally, a comparative analysis of ICIPs and QCDs is provided, along with discussions on optimization strategies. This review is intended to be a valuable resource for researchers and engineers in the field of IR detector technology, offering a detailed insight into the most advanced multi-stage IR detector technology and providing guidance for future development.
Bi-Josephson effect in a driven-dissipative supersolid
Authors: Qin Jieli , Li Shijie , Tu Yijia , Gu Maokun , Guan Lin , Xu Weimin , Zhou Lu
Published: January 2025

The Josephson effect is a macroscopic quantum tunneling phenomenon in a system with superfluid property, when it is split into two parts by a barrier. Here, we examine the Josephson effect in a driven-dissipative supersolid realized by coupling Bose–Einstein condensates to an optical ring cavity. We show that the spontaneous breaking of spatial translation symmetry in supersolid makes the location of the splitting barrier have a significant influence on the Josephson effect. Remarkably, for the same splitting barrier, depending on its location, two different types of DC Josephson currents are found in the supersolid phase (compared to only one type found in the superfluid phase). Thus, we term it a bi-Josephson effect. We examine the Josephson relationships and critical Josephson currents in detail, revealing that the emergence of supersolid order affects these two types of DC Josephson currents differently—one is enhanced, while the other is suppressed. The findings of this work unveil unique Josephson physics in the supersolid phase, and show new opportunities to build novel Josephson devices with supersolids.
(t, m) Threshold quantum secret sharing with group authentication
Authors: Mawlia Priyanka , Siwach Vikash
Published: January 2025

Quantum secret sharing plays a key role as a foundational method for distributing a secret to all participants in quantum cryptography. Group authentication plays a significant role in safeguarding information as it confirms the identity of communication parties. This paper presents a

d
−

level

t
,
m

threshold quantum secret-sharing scheme combined with group authentication. Group members can simultaneously authenticate their identities through group authentication. Using the Lagrange interpolation polynomial, the group authentication method disperses multiple secret shares to group members and later allows joint verification of some or all members. The complexities of the developed group authentication scheme are much lower than those found in widely recognized existing group authentication methods. This algorithm allows each participant to keep their secret shares secure and undisclosed. By avoiding transmission of these shares, external eavesdroppers are unable to obtain any secret information. This protocol offers security, efficiency, and practicality. Security analysis reveals its ability to resist intercept-resend attacks, entangle-measure attacks, collusion attacks, and forgery attacks. The proposed scheme ensures both confidentiality and integrity.
Collective attack free controlled quantum key agreement without quantum memory
Authors: Dutta Arindam , Pathak Anirban
Published: January 2025

Here we present a new protocol for controlled quantum key agreement and another protocol for key agreement with a specific focus on the security analysis. Specifically, detailed security proof is provided against impersonated fraudulent attack and collective attacks and it is established that the proposed protocols are not only secure, but they also satisfy other desired properties of such schemes (i.e., fairness and correctness). Further, the proposed schemes are critically compared with a set of schemes for quantum key agreement and an existing scheme for controlled quantum key agreement (Tang et al.’s protocol) in terms of efficiency and the required quantum resources. Especially, it is observed that in contrast to the existing schemes, the present scheme does not require quantum memory. In addition, the protocol for controlled quantum key agreement proposed here is found to require quantum resources (Bell state and single photon state) that are easier to produce and maintain compared to the quantum resources (GHZ states) needed for the only known existing protocol for the same purpose, i.e., Tang et al.’s protocol.
Photonic scheme to generate frequency 24-tupling mm-wave signal using three cascaded polarization modulators without filters
Authors: Yan Xueyao , Wang Dongfei , Li Zhenzhen
Published: January 2025

The paper proposes a new scheme for generating a frequency 24-tupling millimeter-wave (mm-wave) signal using three cascaded polarization modulators (PolMs). In the scheme, three polarization modulators with the cooperation of polarization controller (PC) and polarizer (Pol) in each subsystem are first employed to produce even order optical sidebands. Adjusting the phase shift of electrical phase shifters (EPS) to eliminate the unwanted even order optical sidebands except (6n)th order optical sidebands. Next, setting the modulation index to 4.968 to eliminate ±6th order sidebands. At last, adjusting the rotation angle of the polarizer placed behind the polarization beam combiner (PBC) to suppress 0th order optical carrier from the upper and lower branches. The obtained pure ±12th order sidebands are fed into the photodiode (PD) beat frequency. After detailed mathematical derivation and simulation verification, the accuracy of the scheme has been verified. The simulation results show that the optical sideband suppression ratio (OSSR) and the radio frequency spurious suppression ratio (RFSSR) can reach 54.49 dB and 43.86 dB, respectively. Moreover, the impacts of these non-ideal elements on OSSR and RFSSR are analyzed, and an admissible error extent is listed.
Resonant or asymmetric: the status of sub-GeV dark matter
Authors: Balan Sowmiya , Balázs Csaba , Bringmann Torsten , Cappiello Christopher , Catena Riccardo , Emken Timon , Gonzalo Tomás E. , Gray Taylor R. , Handley Will , Huynh Quan , Kahlhoefer Felix , Vincent Aaron C.
Published: January 2025

Sub-GeV dark matter (DM) particles produced via thermal freeze-out evade many of the strong constraints on heavier DM candidates but at the same time face a multitude of new constraints from laboratory experiments, astrophysical observations and cosmological data. In this work we combine all of these constraints in order to perform frequentist and Bayesian global analyses of fermionic and scalar sub-GeV DM coupled to a dark photon with kinetic mixing. For fermionic DM, we find viable parameter regions close to the dark photon resonance, which expand significantly when including a particle-antiparticle asymmetry. For scalar DM, the velocity-dependent annihilation cross section evades the strongest constraints even in the symmetric case. Using Bayesian model comparison, we show that both asymmetric fermionic DM and symmetric scalar DM are preferred over symmetric fermionic DM due to the reduced fine-tuning penalty. Finally, we explore the discovery prospects of near-future experiments both in the full parameter space and for specific benchmark points.
We find that the most commonly used benchmark scenarios are already in tension with existing constraints and propose a new benchmark point that can be targeted with future searches.
Merging and separation of polarization singularities in complex lattices
Authors: Wang Mengyao , Shi Tian , Ning Luhui , Liu Peng , Li Liangsheng , Zheng Ning
Published: January 2025

Bound states in the continuum (BICs) and circularly polarized states (CPSs), as far-field polarization singularities, by controlling geometric parameters of photonic crystals, exhibit their evolution in momentum space that can be observed. This offers significant potential in optics and photonics. Here, we reveal that in complex lattices, far-field polarization singularities can be flexibly manipulated while preserving structural symmetry. The change of the topological charge for the at-Γ BIC can generate new BICs or CPSs. At an off-Γ point, a BIC can spawn from the collision of two CPSs. As the structure thickness increases, this BIC will meet the at-Γ BIC. The merging of BICs can induce the topological charge transition and yield a large wavevector space around Γ point with ultrahigh quality (Q) factors. Our findings provide a novel degree of freedom for manipulating polarization singularities, which holds great promise in radiation modulation and singular optics.
Optimizing the proportion of stimulation area in a grid stimulus for user-friendly SSVEP-based BCIs
Authors: Gu Meng , Pei Weihua , Gao Xiaorong , Wang Yijun
Published: January 2025

Objective. Steady-state visual evoked potentials (SSVEPs) rely on the photic driving response to encode electroencephalogram (EEG) signals stably and efficiently. However, the user experience of the traditional stimulation with high-contrast flickers urgently needs to be improved. In this study, we introduce a novel paradigm of grid stimulation with weak flickering perception, distinguished by a markedly lower proportion of stimulation area in the overall pattern. Approach. In an offline single-target experiment, we investigated the unique characteristics of SSVEPs evoked by varying proportions in grid stimuli within low and medium frequency bands. Based on the analysis of simulation performance across a four-class brain–computer interface (BCI) task and the evaluation of user experience questionnaires, a subset of paradigms that balance performance and comfort were selected for implementation in four-target online BCI systems. Main results. Our results demonstrate that even ultra-low stimulation proportion paradigms can still evoke strong responses within specific frequency bands, effectively enhancing user experience with low and middle frequency stimuli. Notably, proportions of 0.94% and 2.10% within the 3–5 Hz range provide an optimal balance between performance and user experience. For frequencies extending up to 15 Hz, a 2.10% proportion remains ideal. At 20 Hz, slightly higher proportions of 3.75% and 8.43% maintain these benefits. Significance. These findings are crucial for advancing the development of effective and user-friendly SSVEP-based BCI systems.
Effects of helium irradiation damage on deuterium plasma-driven permeation through tungsten coated RAFM steel
Authors: Xu Yue , Tian Xiao-Ping , Tan Hong-Yan , Fu Hai-Ying , Ni Jun-Jie , Luo Lai-Ma , Wu Yu-Cheng
Published: January 2025

In future fusion reactors, the first wall will be irradiated with hydrogen fuel (deuterium (D), tritium (T)) and helium (He) with low energies. In this work, the effects of He plasma irradiation on D permeation through tungsten (W) coated reduced activation ferritic/martensitic (RAFM) steel were systematically investigated by performing plasma-driven permeation (PDP) measurements in the temperature range of 523–833 K. The W coatings were prepared by magnetron sputtering. He plasma irradiation with different fluences was carried out in a linear plasma device. The results showed that as He irradiation fluence increased, the surface damage of W coatings intensified, resulting in a high steady-state D-PDP flux and effective diffusion coefficient. The effect of incident ion energy on D-PDP was also influenced by He pre-irradiation. After He irradiation with a fluence of 6.0 × 1024 He m−2, the D-PDP flux was found to decrease with increasing incident ion energy despite the fact that the sample temperature was gradually increasing. The He pre-damage affected the overall D transport by re-balancing the bulk diffusion and surface recombination processes, therefore determining the PDP flux. D-PDP through W + RAFM under simultaneous D + He mixture plasma exposure was studied as well. The results indicated that the presence of He reduced the ionization rate of the D plasma and decreased D-PDP flux. D-PDP regime under the mixture plasma exposure was verified by calculating the transport parameter. It was found that the D-PDP regime was not changed by He introduction, which remained in the RD regime (recombination-limited D release from upstream surface and diffusion-limited D release from downstream surface).
Hybrid hydrogen-electricity production using spherical tokamaks: a cost-driver sensitivity study and techno-economic analysis
Authors: Hidalgo-Salaverri J. , Griffiths T. , Xuereb Conti Z. , Cano-Megias P. , Chacartegui R. , Bluck M. , Ayllon-Guerola J. , Mancini A. , Garcia-Munoz M. , Viezzer E.
Published: January 2025

Hybrid fusion power plants, which produce both hydrogen and electricity, are proposed as a way to decarbonise the fossil-fuel-dominated primary energy market and improve plant economics. The main cost drivers of a fusion power plant based on a spherical tokamak have been identified using statistical analysis (Morris and Sobol methods) from a wide range of cases obtained with the systems code PROCESS. The analysis reveals the importance of plasma physics and reactor geometry on power plant economics. Three scenarios of advancing technophysical assumptions (conservative, moderate and optimistic) have been chosen to study the integration of the fusion reactor with the power block (Rankine, He-Brayton or super-critical-CO2-Feher) and with the PEM electrolyser. The super-critical-CO2 cycle returns the best results for the studied temperature range (500 ∘C–800 ∘C), with an efficiency between 40%–56%. The modelled PEM is in line with current commercial models with a consumption of 51.97 kWh kg−1 H2. The economic feasibility of these scenarios has been explored for a set of learning factors that consider the cheapening of the capital costs tied to experience. The LCOE of these scenarios have been compared against current price ranges of solar, wind and fission power and the LCOH against PEM prices, showing that the moderate and optimistic scenarios could be competitive for learning factors lower than 0.5 and capacity factors larger than 0.7. An extrapolation of the optimistic scenario shows that the hybrid fusion power plant in the French and German market can improve the plant profits by 15% and 66% respectively.
A continental approach to estimate the area required for proposed wind-power parks and their overlap with protected areas in Africa
Authors: Mayer Jana , Peters Rebecca , Bange Jens , Mauz Moritz , Platis Andreas , Zarfl Christiane
Published: January 2025

Wind energy (WE) is one of the key renewable energy technologies required to transform the energy sector to reduce climate change. In the global expansion of WE, one main concern is that wind-power parks (WPPs) take up large areas of land, causing conflicts with other uses such as nature conservation. Existing impact analyses for WPPs are mostly restricted to case studies, and it lacks studies that investigate potential impacts at a larger scale because no scientific consensus on the area associated to a WPP exists. This study proposes a continental, GIS-based approach to estimate the area required for proposed onshore WPPs and to estimate their potential overlap with protected areas (PAs) on the African continent. The results of the spatial analysis show that, in total, the currently proposed 149 WPPs would require 852 km2 of land on the African continent, thereof 11 would overlap with PAs. The overlaps sum up to an area of 42 km2, which corresponds to an affected nominal power of 834 MW (5% of the total projected wind power capacity). These findings reveal the need for further purposefully local in-depth analyses to investigate if the WPP can be operated in accordance with the conservation of the PA. This work provides new data and a transferable methodological approach on the expansion of WE and its potential space requirement and contributes to the investigation of potential land-use conflicts of proposed onshore WPPs on a broader scale.
Land conversions not climate effects are the dominant indirect consequence of sun-driven CO2 capture, conversion, and sequestration
Authors: Adam Moritz , Kleinen Thomas , May Matthias M , Rehfeld Kira
Published: January 2025

Removing carbon dioxide (CO2) from the atmosphere is required for mitigating climate change. Large-scale direct air capture combined with injecting CO2 into geological formations could retain carbon long-term, but demands a substantial amount of energy, pipeline infrastructure, and suitable sites for gaseous storage. Here, we study Earth system impacts of modular, sun-powered process chains, which combine direct air capture with (electro)chemical conversion of the captured CO2 into liquid or solid sink products and subsequent product storage (sDACCCS). Drawing on a novel explicit representation of CO2 removal in a state-of-the-art Earth system model, we find that these process chains can be renewably powered and have minimal implications for the climate and carbon cycle. However, to stabilize the planetary temperature two degrees above pre-industrial levels, CO2 capturing, conversion, and associated energy harvest demand up to 0.46% of the global land area in a high-efficiency scenario. This global land footprint increases to 2.82% when assuming present-day technology and pushing to the bounds of removal. Mitigating historical emission burdens within individual countries in this high-removal scenario requires converting an area equivalent to 40% of the European Union’s agricultural land. Scenarios assuming successful technological development could halve this environmental burden, but it is uncertain to what degree they could materialize. Therefore, ambitious decarbonization is vital to reduce the risk of land use conflicts if efficiencies remain lower than expected.
Generalized Siklos space-times
Authors: Araneda Bernardo , Murcia Ángel J
Published: January 2025

Motivated by supersymmetry methods in general relativity, we study four-dimensional Lorentzian space-times with a complex Dirac spinor field satisfying a Killing-spinor-like equation where the Killing constant is promoted to a complex function. We call the resulting geometry a generalized Siklos space-time. After deriving a number of identities for complex spaces, we specialize to Lorentz signature, where we show that the Killing function must be real and that the corresponding Dirac spinor is Majorana (as long as the space-time is not conformally flat), and we obtain the local form of the metric. We show that the purely gravitational degrees of freedom correspond to waves, whereas the matter sources generically correspond, via Einstein’s field equations, to a sum of pure radiation and a space-like perfect fluid. Consequently, we conclude that the physically relevant case is obtained when the Killing function is homogeneous on the wave surfaces.
Localization in quantum field theory for inertial and accelerated observers
Authors: Falcone R , Conti C
Published: January 2025

We study the problem of localization in quantum field theory (QFT) from the point of view of inertial and accelerated experimenters. We consider the Newton–Wigner, the algebraic QFT (AQFT) and the modal localization schemes, which are, respectively, based on the orthogonality condition for states localized in disjoint regions of space, on the algebraic approach to QFT and on the representation of single particles as positive frequency solution of the field equation. We show that only the AQFT scheme obeys causality and physical invariance under diffeomorphisms. Then, we consider the nonrelativistic limit of quantum fields in the Rindler frame. We demonstrate the convergence between the AQFT and the modal scheme and we show the emergence of the Born notion of localization of states and observables. Also, we study the scenario in which an experimenter prepares states over a background vacuum by means of nonrelativistic local operators and another experimenter carries out nonrelativistic local measurements in a different region. We find that the independence between preparation of states and measurements is not guaranteed when both experimenters are accelerated and the background state is different from Rindler vacuum, or when one of the two experimenters is inertial.
Polarization-dependent vibrational strong coupling in a metamaterial
Authors: Dayal Govind
Published: January 2025

We report on polarization-dependent strong coupling between vibrational transitions and the electromagnetic mode of a molecule-embedded metamaterial cavity. The metamaterial cavity comprises a modified tri-layer structure of metal-insulator-metal, where the insulating layer is replaced by an infrared-active polymer. This polymer layer is sandwiched between an array of linear antennae on top and a continuous metal film at the bottom where the maximum field enhancement occurs. Using polarization-selective reflectivity simulation of the cavity, we analyze their response to different light polarization and find two orthogonally polarized optical systems with different coupling strengths, one strongly coupled and one weakly coupled. The strong coupling gives rise to the formation of lower and upper polaritons, while dark states emerge because of weak coupling. This ultrathin metamaterial with tunable properties can pave the way for developing active, dynamic, tunable infrared polaritonic devices, molecular sensors, site-selective chemical reaction control, and quantum information processing.
Feature Characterization for Profile Surface Texture
Authors: Müller Alexander , Eifler Matthias , Jawaid Arsalan , Seewig Joerg
Published: January 2025

Conventional field parameters for surface measurement use all data points, while feature characterization focuses on subsets extracted by watershed segmentation. This approach enables the extraction of specific features that are potentially responsible for the function of the surface or are a direct reflection of the manufacturing process, allowing for a more accurate assessment of both aspects. Feature characterization with the underlying watershed segmentation for areal surface topographies has been standardized for over a decade and is well established in industry and research. In contrast, feature characterization for surface profiles has been standardized recently, and the corresponding standard for watershed segmentation is planned to be published in the near future. Since the standards do not provide guidelines for implementation, this paper presents an unambiguous algorithm of the watershed segmentation and the feature characterization for surface profiles. This framework provides the basis for future work, mainly investigating the relationship between feature parameters based on feature characterization and the function of the surface or manufacturing process. For this purpose, recommendations for the configuration and extensions of the toolbox can also be developed, which could find their way into the ISO standards.
Study on improving tribological properties of brush/ring current carrying based on anodic oxidation
Authors: Li Chenshi , Zhao Xinze , Lv Yaru , Ying Rushu , Zhao Meiyun
Published: January 2025

Surface corrosion of the collector ring is an important factor that affects the current-carrying characteristics of the brush/ring system. A suitable surface film can effectively enhance the corrosion resistance of the surface and improve the tribological characteristics of the current-carrying ring. This paper focuses on the collector ring in the brush/ring current-carrying system of a hydrogenerator as the research object. Under the conditions of an anodic oxidation test with a current density of 0.004 A cm−2, optimized as the anodic oxidation technology, a surface film was formed by selecting oxidation times of 3, 5, 10, and 15 min (short duration, low current). The characteristics of the film were measured and analyzed using XPS, AFM, and SEM. Current-carrying tribological tests were conducted on a brush/ring current-carrying wear tester, and the relationship between surface film characteristics, polarization curves, and impedance spectra under different oxidation conditions was analyzed using an electrochemical device. The results show that, as oxidation time increases, the oxide film transitions from a dense barrier layer to a porous oxide film, with both the thickness of the oxide layer and the oxygen content in the film increasing. The wear mechanism evolves from ‘three-body’ wear to ‘two-body’ wear, and eventually to arc wear. An oxidation time of 10 min provides the best current-carrying performance, with a contact resistance of 1.118Ω and a friction coefficient of 0.2643. An oxidation time of 3 min offers the best corrosion resistance, with a maximum self-corrosion potential of −0.8784 V and a minimum corrosion current density of 3.872 × 10−6 A cm−2. The anodic oxide film effectively protects the collector ring from external corrosive factors, extending its service life. Additionally, it reduces friction and contact resistance to some extent, ensuring the long-term stable operation of the equipment in harsh environments.
A novel method of MPPT of photovoltaic power generation system based on MSINGO
Authors: Li Jie , Shan Yingge , Li Jinjun , Qi Shancheng , Wang Qi , Wang Dantong , Hu Yongtao
Published: January 2025

The speed and accuracy of Maximum Power Point Tracking (MPPT) have a significant impact on photovoltaic power generation. In this paper, a novel method is proposed for fast and accurate MPPT of photovoltaic power generation systems. First, the Northern Goshawk Optimization algorithm (NGO) is introduced in the MPPT. Second, a multi strategy is applied to improve the NGO, and MSINGO is proposed. In the MSINGO algorithm, the optimal individual leadership strategy enhances the optimization accuracy and convergence speed, the enhanced Levy flight strategy leads it to escape from the local optimum, and the pinhole imaging learning strategy guides the population towards the global optimum. Finally, MSINGO was applied to MPPT, and a simulation analysis of a single photovoltaic module and photovoltaic array under different working conditions was conducted and compared with other intelligent optimization algorithms. The results show that the proposed method can achieve MPPT with minimal time consumption and better tracking efficiency.
AtOMICS: A deep learning-based Automated Optomechanical Intelligent Coupling System for testing and characterization of silicon photonics chiplets
Authors: Flor Flores Jaime , Solomon Jim , Nasseraddin Connor , Yerebakan Talha , Matsko Andrey B. , Wong Chee Wei
Published: January 2025

Recent advances in silicon photonics promise to revolutionize modern technology by improving performance of everyday devices in multiple fields [1]. However, as the industry moves into a mass fabrication phase, the problem of effective testing of integrated silicon photonics devices remains to be solved. A cost-efficient manner that reduces schedule risk needs to involve automated testing of multiple devices that share common characteristics such as input-output coupling mechanisms, but at the same time needs to be generalizable to multiple types of devices and scenarios. In this paper we present a neural network-based automated system designed for in-plane fiber-chip-fiber testing, characterization, and active alignment of silicon photonic devices that use process-design-kit library edge couplers. The presented approach combines state-of-the-art computer vision techniques with time-series analysis, in order to control a testing setup that can process multiple devices and can be easily tuned to incorporate additional hardware. The system can operate at vacuum or atmospheric pressures and maintains stability for fairly long time periods in excess of a month.
Influence of large-scale atmospheric circulation and Mediterranean sea surface temperature to extreme land precipitation: the case of storm Alex
Authors: Terray Laurent , Bador Margot
Published: January 2025

Extreme (greater than 500 mm) amount of rain fell in southeastern France and northern Italy on 2nd and 3rd October 2020 during a ‘Mediterranean episode’ triggered by the powerful extratropical cyclone Alex. Here we use a dynamical adjustment methodology based on constructed analogues to assess the contributions of different drivers to the magnitude of this extreme precipitation event. We first show that the mean effect of the observed atmospheric circulation pattern, an intense low-pressure system centered over the coasts of Western Europe associated with a cold pool and a secondary low-pressure system, can explain about 80% of the precipitation event magnitude. By contrasting the effect of Alex atmospheric circulation with an anomalously warm Mediterranean sea and eastern Atlantic ocean versus neutral sea surface temperature (SST) conditions, we show that the influence of September 2020 positive SST anomalies can explain a large fraction of the 20% residual precipitation over southeastern France and northern Italy. Finally, based on a storyline approach, we find that the dynamic component, the atmospheric circulation contribution to the extreme precipitation event, was more extreme than it would have been, had it occurred during the mid-20th century. The increase in the magnitude of the dynamic component since 1950 follows a Clausius–Clapeyron scaling, in agreement with previous studies about the intensity changes of Mediterranean extreme precipitation episodes. (limit = 300 words).
The Univalence Principle
Authors: Ahrens Benedikt , North Paige , Shulman Michael , Tsementzis Dimitris
Published: January 2025

The Univalence Principle is the statement that equivalent mathematical structures are indistinguishable. We prove a general version of this principle that applies to all set-based, categorical, and higher-categorical structures defined in a non-algebraic and space-based style, as well as models of higher-order theories such as topological spaces. In particular, we formulate a general definition of indiscernibility for objects of any such structure, and a corresponding univalence condition that generalizes Rezk’s completeness condition for Segal spaces and ensures that all equivalences of structures are levelwise equivalences.

Our work builds on Makkai’s First-Order Logic with Dependent Sorts, but is expressed in Voevodsky’s Univalent Foundations (UF), extending previous work on the Structure Identity Principle and univalent categories in UF. This enables indistinguishability to be expressed simply as identification, and yields a formal theory that is interpretable in classical homotopy theory, but also in other higher topos models. It follows that Univalent Foundations is a fully equivalence-invariant foundation for higher-categorical mathematics, as intended by Voevodsky.
Generation of antagonistic biparatopic anti-CD30 antibody from an agonistic antibody by precise epitope determination and utilization of structural characteristics of CD30 molecule
Authors: Akiba Hiroki , Ise Tomoko , Satoh Reiko , Abe Yasuhiro , Tsumoto Kouhei , Ohno Hiroaki , Kamada Haruhiko , Nagata Satoshi
Published: January 2025

Background

CD30 is a member of the tumor necrosis factor receptor superfamily. Recently, blocking CD30-dependent intracellular signaling has emerged as potential strategy for immunological regulation. Development of antibody-based CD30 antagonists is therefore of significant interest. However, a key challenge is that the bivalent form of natural antibody can crosslink CD30 molecules, leading to signal transduction even in the absence of specific ligand, CD153. Biparatopic antibodies (BpAbs) offer a solution, using two different variable fragments (Fvs) to bind distinct epitopes on a single antigen molecule. BpAbs format is an attractive alternative of natural antibody by potentially avoiding unwanted crosslinking and signaling induction.

Methods

We systematically characterized 36 BpAbs, each designed with pairs of Fvs binding to nine distinct epitopes across the CD30 extracellular domain. We first identified the precise epitope sites of the nine antibodies by assessing the binding to multiple orthologous CD30 proteins and mutants. We then produced the 36 BpAbs and analyzed their biological activities and binding modes.

Results

Among 36 BpAbs, we identified both potent ligand-independent agonists and ligand-blocking antagonists, with many displayed reduced signal activation, including 1:1-binding antagonists derived from AC10, a strong agonist developed for lymphoma therapy. Epitope dependency in reduced signaling activity was observed and associated with the flexible nature of CD30 protein.

Conclusions

We successfully developed antagonistic BpAbs against CD30 by controlling the stoichiometry of antibody–antigen binding mode. This study elucidated the mechanism of signaling induction, informing the design strategies of the development of biparatopic antibodies.
Conservation genomics within government led conservation planning: an Australian case study exploring cost and benefit for threatened flora
Authors: Doyle Chantelle A T , Cascini Manuela , Yap Jia-Yee Samantha , Matthews Hannah , Hogbin Patricia M , Wilson Trevor C , Mahon Erica , Brown Dianne , Mulcahy Aaron , Brown Rachel , Rossetto Maurizio
Published: January 2025

The importance of conserving plant genetic diversity has been recognised since the 1980’s, but genetic research tools for improving conservation remain largely absent from standard planning. Using an Australian case study framework of the New South Wales Government’s Saving our Species program, we outline the costs and benefits associated with conducting genomic analysis within a conservation strategy to inform for example, taxonomic resolution, targeted monitoring, translocations and ex situ collections. Despite a reported sentiment that costs are prohibitive, our study identified that where genetics reports have been provided (32 to date), the cost of genetic sampling, analysis and advice is less than 10% of the total Government investment (SoS program) and will continue decreasing proportionally throughout the years as other management occurs. We identified the largest Government investment was for maintenance and monitoring actions. On-ground practitioner feedback from the reports identified that the main reason for requesting genetics was to inform translocation or ex situ collection. However, from the total of two hundred and sixty-nine plant species with translocation or ex situ conservation actions planned, 75.4% still do not have provisions for genomics, suggesting that knowledge of the utility of this practice is low among practitioners. Responsive feedback also demonstrated that 90% of respondents seek additional learning, thus there is merit in providing future genomics focused workshops.
Exploring common and distinct neural basis of procrastination and impulsivity through elastic net regression
Authors: Yin Yao , Su Ti , Wang Xueke , Hu Bowen , Zhang Rong , Zhou Feng , Feng Tingyong
Published: January 2025

Prior work highlighted that procrastination and impulsivity shared a common neuroanatomical basis in the dorsolateral prefrontal cortex, implying a tight relationship between these traits. However, theorists hold that procrastination is motivated by avoiding aversiveness, while impulsivity is driven by approaching immediate pleasure. Hence, exploring the common and distinct neural basis underlying procrastination and impulsivity through functional neuroimaging becomes imperative. To address this, we employed elastic net regression to examine the links between whole-brain resting-state functional connectivity and these traits in 822 university students from China. Results showed that the functional connections between the default network and the visual network were positively associated with both traits, indicating that the dysfunction of higher-order cognition (eg self-control) may account for their tight relationship. A distinct neural basis was also identified: Procrastination was negatively associated with functional connections between the frontal-parietal network and the ventral-attention network and between the cingular-opercular network and the subcortical network. In contrast, connections between the default network and the somato-motor network were negatively associated with impulsivity. These findings suggest that procrastination may be rooted in emotion-regulation deficits, while impulsivity may be rooted in reward-processing deficits. This deeper understanding of their neural basis provides insights for developing targeted interventions.
Analysing technical change with heterodox price theories
Authors: Bloch Harry
Published: January 2025

Elements of price theory from Schumpeterian, Sraffian and post-Keynesian economics are combined to analyse the impact of labour-saving technical change on prices. The resulting synthesis incorporates the realism of post-Keynesian pricing rules and the emphasis on long-period analysis by Sraffa along with Schumpeter’s insight that capitalism develops ‘from within’ in a disruptive and uneven manner through innovations. Applying elements from heterodox theories to analyse the relationship between technical change and the movement of prices demonstrates the fruitfulness of heterodox price theory in understanding the development of modern capitalist economies.
The Relationships between Subjective Wellbeing and Frailty: Staying with a Positive Mind, Stepping away from Accelerated Aging
Authors: Liu Yuchen , Cai Wenjie , Wittenberg Eve , Kim Dae Hyun , Bloom David E , Kubzansky Laura D , Seligman Benjamin J
Published: January 2025

Background

Subjective wellbeing (SWB) is a crucial measure of life quality in older adults. Understanding its relationship with frailty may inform strategies to promote healthy aging.

Methods

We analyzed data for older adults aged ≥ 60 years old from Waves 3 and 4 of the China Health and Retirement Longitudinal Study. SWB was measured based on participants’ self-reported overall satisfaction with life. A frailty index was developed using the deficit accumulation approach. We conducted a cross-sectional Poisson regression to investigate the relationship between SWB and counts of frailty deficits. Additionally, we conducted a longitudinal analysis to determine the three-year relative risk of clinically significant frailty progression or mortality for different levels of SWB. The analyses were adjusted for individual weights, including adjustments for household nonresponse.

Results

The cross-sectional analysis included 9,702 individuals. After adjusting for covariates, lower baseline life satisfaction was associated with higher counts of frailty deficits (mean deficit counts ratio [95% confidence interval]: 1.66 [1.54, 1.78] for “not satisfied” and 1.06 [1.02, 1.10] for “somewhat satisfied” relative to the reference “very satisfied”). The longitudinal analysis included 8,599 individuals. Participants who were “not satisfied” with life at baseline were at a greater risk of frailty progression compared with those who were “very satisfied” (risk ratio: 1.16 [1.00, 1.35]).

Conclusion

Our study finds that a lower level of SWB is associated with more severe frailty. It is also associated with frailty progression or death. These results emphasize that both psychological wellbeing and physical health are essential components of healthy aging.
Should the Unified Patent Court Set FRAND Terms?
Authors: Meier-Beck Peter
Published: January 2025

Matthias Leistner recently addressed the question of how the Unified Patent Court should implement the decision of the Court of Justice of the European Union (CJEU) in Huawei v. ZTE in patent infringement proceedings involving a FRAND defence (GRUR Patent 2024, 327). In this context, he takes the view that the Unified Patent Court could and should – like the English courts – determine the terms of a FRAND licence agreement in the case of mutually ‘willing’ parties who are neither able to agree on the terms of such an agreement nor willing to accept a binding provision and its modalities by an arbitration tribunal or a third party. This article attempts to shed light on the prerequisites and limits of such a judicial FRAND determination.