bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing organic cathodes of aqueous zinc-ion batteries via nitro group modification
Authors: Wang Donghong , Qin Mengxuan , Zhang Changyou , Li Mengxue , Peng Chao , Zhi Chunyi , Li Qing , Zhu Lei
Published: January 2025

Nitro groups' high redox activity and electron-withdrawing capabilities increased the specific capacity and voltage plateaus. Additionally, the in situ produced azo bridges increased the conjugation of PTO and hence improved the cycle stability.
Impact of the hole transport layer on the space charge distribution and hysteresis in perovskite solar cells analysed by capacitance–voltage profiling
Authors: Regalado-Pérez E. , Díaz-Cruz Evelyn B. , Villanueva-Cab J.
Published: January 2025

The interplay of interface-accumulated mobile ions and electronic carriers governs the apparent doping profiles (Nappvs. W). The hole transport layer influences the shape of the apparent doping profiles by modulating interfacial charge accumulation.
A study of alpha-synuclein and poly(N-isopropylacrylamide) complex formation through detailed atomistic simulations
Authors: Ektirici Sisem , Harmandaris Vagelis
Published: January 2025

Atomistic simulations over 1.5 μs reveal that PNIPAM stabilizes α-syn through hydrophobic interactions in the non-amyloid component NAC region, leading to more compact conformations.
Influence of matrix stiffness on microstructure evolution and magnetization of magneto-active elastomers
Authors: Roghani Mehran , Romeis Dirk , Borin Dmitry , Saphiannikova Marina
Published: January 2025

The presented unified mean-field model predicts the magnetization behavior of Magneto-Active Elastomer (MAE) disks with different matrix stiffness undergoing microstructure evolution in agreement with experiment.
Construction of a graphene/cellulose aerogel embedded with UiO-66-CN for highly efficient uranium capture via electro-adsorption
Authors: Tian Jinhao , Li Nan , Luo Yu , Xing Hao , Su Ruidian , Wang Lei
Published: January 2025

UiO-66-CN/GCA was demonstrated to be a promising material for highly efficient electro-adsorption of uranium in seawater, achieving an impressive 110.1 mg g−1 of adsorption capacity in natural seawater in only 24 h.
Pb2B10O16(OH)2·B(OH)3·H2O: significantly enhanced second harmonic generation via substituting metal cations in isostructural compounds with Pb2+
Authors: Cai Xintong , Liu Kaitong , Zhang Yanhui
Published: January 2025

Second harmonic generation can be significantly enhanced via substituting metal cations in isostructural compounds with Pb2+ for Pb2B10O16(OH)2·B(OH)3·H2O.
Boosting photoelectricity based on self-supported flexible metal–organic framework arrays for photo-Fenton-like degradation of organic pollutants
Authors: Wang Shenghao , Wang Yajuan , Cao Linbo , Zhang Jiasheng , Liu Yuqing , Wang Bo , Li Mingmin
Published: January 2025

Boosted adsorption and degradation of organic pollutants based on self-supported flexible metal–organic framework arrays.
Retraction: String ball-like SnS2/ZnTe heterostructures with improved bifunctional photo/electrocatalytic activity towards overall water splitting
Authors: Awais Muhammad , Aslam Sidra , Ashiq Muhammad Naeem , Mirza Misbah , Safdar Muhammad
Published: January 2025

Retraction of ‘String ball-like SnS2/ZnTe heterostructures with improved bifunctional photo/electrocatalytic activity towards overall water splitting’ by Muhammad Awais et al., New J. Chem., 2024, 48, 3247–3257, https://doi.org/10.1039/D3NJ04353C.
Quantifying Tinnitus Perception Improvement: Deriving the Minimal Clinically Important Difference of the Minimum Masking Level
Authors: Jin Tae-Jun , Lee Sumin , Lee Donghyeok , Jin In-Ki
Published: January 2025

Purpose:

Tools that can reliably measure changes in the perception of tinnitus following interventions are lacking. The minimum masking level, defined as the lowest level at which tinnitus is completely masked, is a candidate for quantifying changes in tinnitus perception. In this study, we aimed to determine minimal clinically important differences for minimum masking level.

Method:

A 3-month tinnitus intervention combining counseling and sound therapy was conducted in 74 participants with chronic tinnitus. Minimum masking levels were measured at baseline and 3 months. The clinical global impression was evaluated at 3 months to measure changes in participants' self-perception of tinnitus. The minimal clinically important difference of the minimum masking level was calculated using anchored-based, effect size, standard error measurement, and receiver operating characteristic curve analysis.

Results:

The minimal clinically important difference analysis of the minimum masking level yielded a −5.5 dB SL from the receiver operating characteristic curve, a −8.1 dB SL from the standard error measurement, a −9.2 dB SL from the effect size, and a −10.3 dB SL from the anchor-based analysis. Of these, the minimal clinically important difference value with optimized sensitivity (.704) and specificity (.957) was a −5.5 dB SL, determined using receiver operating characteristic analysis.

Conclusions:

The proposed minimal clinically important difference value of the minimum masking level (−5.5 dB SL) provides a good level of sensitivity and specificity. Therefore, the minimum masking level may be an alternative for measuring changes in tinnitus perception.

Supplemental Material:

https://doi.org/10.23641/asha.28156229
Location of grid forming converters when dealing with multi‐class stability problems
Authors: Fernandes Francisco , Lopes João Peças , Moreira Carlos
Published: January 2025

This work proposes an innovative methodology for the optimal placement of grid‐forming converters (GFM) in converter‐dominated grids while accounting for multiple stability classes. A heuristic‐based methodology is proposed to solve an optimisation problem whose objective function encompasses up to 4 stability indices obtained through the simulation of a shortlist of disturbances. The proposed methodology was employed in a modified version of the 39‐bus test system, using DigSILENT Power Factory as the simulation engine. First, the GFM placement problem is solved individually for the different stability classes to highlight the underlying physical phenomena that explain the optimality of the solutions and evidence the need for a multi‐class approach. Second, a multi‐class approach that combines the different stability indices through linear scalarisation (weights), using the normalised distance of each index to its limit as a way to define its importance, is adopted. For all the proposed fitness function formulations, the method successfully converged to a balanced solution among the various stability classes, thereby enhancing overall system stability.
Electrohydraulic effect of microsecond pulsed discharge in transformer oils
Authors: Wang Hang , Zhang Cheng , Wang Zhuofei , Zhang Shuai , Guo Kaihang , Shao Tao
Published: January 2025

The physical process of microsecond pulsed discharge in transformer oil is the foundation for studying the initial mechanics of faults in ultra‐high voltage transformers. However, the microsecond‐scale electrohydraulic effect in transformer oil has not been investigated yet. In this paper, the shock wave and bubble generated by microsecond pulsed discharge in transformer oil between needle‐needle electrodes are studied using a Schlieren system with a high‐speed camera. The results show that the discharge channel in the 0.1 mm oil gap forms in 9.50 µs when the streamer and the first shock wave are observed. The bubble between electrodes expands in the subsequent 218.50 µs. Then, the bubble collapses when the second shock wave is observed. The velocities of the first and the second shock wave are 1388.16 and 1465.46 m/s, respectively. With the gap distance increase, all the breakdown voltage, the discharge energy, and the ratio of the mechanical energy to total energy increase, the breakdown current, the acceleration of the container wall, and the velocity of the shock wave decrease. It can be concluded that the first shock wave is generated by the streamer of microsecond pulsed discharge and the second shock wave is induced by the rapid density change due to the bubble collapsing.
The effect of thermal misbalance on magnetohydrodynamic modes in coronal magnetic cylinders
Authors: Hejazi S. M. , Van Doorsselaere T. , Sadeghi M. , Kolotkov D. Y. , Hermans J.
Published: January 2025

Aims. It is well demonstrated that thermal misbalance, arising from the discrepancy between optically thin radiative energy loss and heating energy gain, disrupts the adiabatic nature of solar corona plasmas, directly affecting the propagation of slow magnetoacoustic waves. However, the extent to which this thermal misbalance, acting as a dispersion factor of an arbitrary intensity, influences the use of slow modes as seismological tools and affects sausage and kink harmonic modes within a magnetic plasma flux tube, remains unresolved.

Methods. This study investigates the dispersion of magnetohydrodynamic waves influenced by thermal misbalance in a cylindrical configuration with a finite axial magnetic field within solar coronal plasmas. Specifically, it examines how thermal misbalance, characterized by two distinct timescales directly linked to the cooling and heating functions, influences the dispersion relation. This investigation is a key approach for understanding non-adiabatic effects on the behaviour of these waves.

Results. The analysis explores the impact of non-adiabatic effects due to classical thermal misbalance, where the heating and cooling timescales vary across a range of values corresponding to each magnetohydrodynamic mode. The dispersion relation for magnetohydrodynamic waves propagating through a magnetic plasma tube, aligned with a finite magnetic field, is calculated under coronal conditions in the linear regime.

Conclusions. Our findings reveal that the effect of thermal misbalance on fast sausage and kink modes, consistent with previous studies on slabs, is small but slightly more pronounced than previously thought. The impact is smaller at long-wavelength limits but increases at shorter wavelengths, leading to higher damping rates. This minor effect on fast modes occurs despite the complex interaction of thermal misbalance terms within the dispersion relation, even at low-frequency limits defined by the characteristic timescales. Additionally, a very small amplification is observed, indicating a suppressed damping state for the long-wavelength fundamental fast kink mode. In contrast, slow magnetoacoustic modes are significantly affected by thermal misbalance, with the cusp frequency shifting slightly to lower values, which is significant for smaller longitudinal wavenumbers. This thermal misbalance likely accounts for the substantial attenuation observed in the propagation of slow magnetoacoustic waves within the solar atmosphere. The long-wavelength limit leads to an analytical expression that accurately describes the frequency shifts in slow modes due to misbalance, closely aligning with both numerical and observational results.
Toward the fabric of the Milky Way. I. The density of disk streams from a local 250^3 pc^3 volume
Authors: Ratzenbock Sebastian , Alves Joao , Emily Hunt L. , Miret-Roig Nuria , Meingast Stefan , Moller Torsten
Published: January 2025

We studied 12 disk streams found in a 250^3 pc^3 volume in the solar neighborhood, which we define as coeval and comoving stellar structures with aspect ratios greater than 3:1. Using Gaia Data Release 3 data and the advanced clustering algorithms SigMA and Uncover we identified and characterized these streams beyond the search volume, doubling, on average, their known populations. We estimate the number density of disk streams to be ≈ 820 objects,/,kpc^3 (for $|Z| < 100$,pc), or surface densities of ≈ 160 objects,/,kpc^2. These estimates surpass N-body estimates by one to two orders of magnitude and challenge the prevailing understanding of their destruction mechanisms. Our analysis reveals that these 12 disk streams are dynamically cold with 3D velocity dispersions between 2 and 5,km,s^-1, exhibit narrow sequences in the Hertzsprung-Russell diagram, and are highly elongated with average aspect ratios of 7:1, extending up to several hundred parsecs. We find evidence suggesting that one of the disk streams, currently embedded in the Scorpius-Centaurus association, is experiencing disruption, likely due to the primordial gas mass of the association.
Machine learning the gap between real and simulated nebulae
Authors: Belfiore Francesco , Ginolfi Michele , Blanc Guillermo , Boquien Mederic , Chevance Melanie , Congiu Enrico , Glover Simon C. O. , Groves Brent , Klessen Ralf S. , Eduardo Méndez-Delgado J. , Williams Thomas G.
Published: January 2025

Classifying ionised nebulae in nearby galaxies is crucial to studying stellar feedback mechanisms and understanding the physical conditions of the interstellar medium. This classification task is generally performed by comparing observed line ratios with photoionisation simulations of different types of nebulae (H II regions, planetary nebulae, and supernova remnants). However, due to simplifying assumptions, such simulations are generally unable to fully reproduce the line ratios in observed nebulae. This discrepancy limits the performance of the classical machine-learning approach, where a model is trained on the simulated data and then used to classify real nebulae. For this study, we used a domain-adversarial neural network (DANN) to bridge the gap between photoionisation models (source domain) and observed ionised nebulae from the PHANGS-MUSE survey (target domain). The DANN is an example of a domain-adaptation algorithm, whose goal is to maximise the performance of a model trained on labelled data in the source domain on an unlabelled target domain by extracting domain-invariant features. Our results indicate a significant improvement in classification performance in the target domain when employing the DANN framework compared to a classical neural network (NN) classifier. Additionally, we investigated the impact of adding noise to the source dataset, finding that noise injection acts as a form of regularisation, further enhancing the performances of both the NN and DANN models on the observational data. The combined use of domain adaptation and noise injection improved the classification accuracy in the target domain by 23%. This study highlights the potential of domain adaptation methods in tackling the domain-shift challenge when using theoretical models to train machine-learning pipelines in astronomy.
Effects of secular growth and mergers on the evolution of metallicity gradients and azimuthal variations in a Milky Way-like galaxy
Authors: Renaud Florent , Ratcliffe Bridget , Minchev Ivan , Haywood Misha , Di Matteo Paola , Agertz Oscar , Romeo Alessandro B.
Published: January 2025

We analyzed the evolution of the radial profiles and the azimuthal variations of the stellar metallicities from the VINTERGATAN simulation of a Milky Way-like galaxy. We find that negative gradients exist as soon as the disk settles at high redshift, and are maintained throughout the long-term evolution of the galaxy, including during major merger events. The inside-out growth of the disk and an overall outward radial migration tend to flatten these gradients in time. Major merger events only have a moderate and shortlived imprint on the [Fe/H] distributions with almost no radial dependence. The reason lies in the timescale for enrichment in Fe being significantly longer than the duration of the starbursts episodes, themselves slower than dynamical mixing during typical interactions. It results in signatures of major mergers becoming undetectable in [Fe/H] only a few megayears after pericenter passages. We note that considering other tracers like the warm interstellar medium, or monitoring the evolution of the metallicity gradient as a single value instead of a radial full profile could lead to different interpretations; we warn against oversimplifying this complex problem.
The polarisation behaviour of OJ 287 viewed through radio, millimetre, and optical observations between 2015 and 2017
Authors: Jormanainen J. , Hovatta T. , Lindfors E. , Berdyugin A. , Chamani W. , Fallah Ramazani V. , Jermak H. , Jorstad S. G. , Lähteenmäki A. , McCall C. , Nilsson K. , Smith P. , Steele I. A. , Tammi J. , Tornikoski M. , Wierda F.
Published: January 2025

OJ 287 is a bright blazar with century-long observations, and one of the strongest candidates to host a supermassive black hole binary. Its polarisation behaviour between 2015 and 2017 (MJD 57300–58000) contains several interesting events that we re-contextualise in this study. We collected optical photometric and polarimetric data from several telescopes and obtained high-cadence light curves from this period. In the radio band, we collected millimetre-wavelength polarisation data from the AMAPOLA programme. We combined them with existing multi-frequency polarimetric radio results and the results of very long-baseline interferometry imaging with the Global mm-VLBI Array at 86 GHz. In December 2015, an optical flare was seen according to the general relativistic binary black hole model. We suggest that the overall activity near the accretion disk and the jet base during this time may be connected to the onset of a new moving component, K, seen in the jet in March 2017. With the additional optical data, we find a fast polarisation angle rotation of ∼210° coinciding with the December 2015 flare, hinting at a possible link between these events. Based on the 86 GHz images, we calculated a new speed of 0.12 mas/yr for K, which places it inside the core at the time of the 2015 flare. This speed also supports the scenario in which the passage of K through the quasi-stationary feature S1 could have been the trigger for the very high-energy gamma-ray flare of OJ 287 seen in February 2017. With the millimetre-polarisation data, we establish that these bands follow the centimetre-band data but show a difference during the time when K passes through S1. This indicates that the millimetre bands trace substructures of the jet that are still unresolved in the centimetre bands.
Advanced HCCI Engines: Challenges and Potential Applications
Authors: Xie Mingyang
Published: January 2025

Homogeneous Charge Compression Ignition (HCCI) engines are considered an emerging internal combustion technology with significant potential for enhancing fuel efficiency and lowering emissions compared to traditional Spark Ignition (SI) and Compression Ignition (CI) engines. By igniting a homogeneous air-fuel mixture through compression without the need for a spark plug, HCCI engines achieve a more uniform and complete combustion process, resulting in lower NOx and particulate matter (PM) emissions. Despite these advantages, challenges such as limited control over combustion timing, susceptibility to knocking, and the generation of unburned hydrocarbons have hindered widespread adoption. Recent advancements in engine control strategies and hybrid technologies offer promising solutions to these critical issues, potentially enabling broader application of HCCI engines in both the automotive industry and power generation sectors. As research continues to address these challenges, HCCI engines may play a pivotal role in the future of more ‘green’ internal combustion systems with higher efficiency.
Development and application of pumped storage power generation system
Authors: Liu Zhengye
Published: January 2025

As one of the most crucial energy storage facilities in modern times, pumped storage technology utilizes the principle of gravitational potential energy and mechanical energy conversion of water to pump energy facility when the eelectric load is low, and release water to generate power when it is high. The technology mainly includes pumping pump, turbine and generator and other equipment, through the two stages of pumping and power generation cycle, to realize the storage and release of electric energy. Pumped storage power generation technology has the advantages of large scale, high efficiency, clean and environmental protection, and is widely used in power systems with stability and reliability, but it is still limited by geographical factors. With the use of clean energy and the growth of electricity demand on the electricity side, pumped storage power generation technology will continue to innovate and develop, and become an important part of energy facility in the future electricity system.
Analysis of parameter sensitivity and rainfall protection of vegetated concrete slab wall design on ecological slope
Authors: Rao Kunrong , Liang Yiyan , Jiao Wencan , Hu Zhaojian , Liu Xiaofei , Huang Zhen
Published: January 2025

Realizing coordination and unity between the safety and stability of high and steep slopes and ecological protection is a hot topic in the field of engineering. In this study, the combination of vegetated concrete slab walls and anchor cables is proposed to increase the stability of slopes against a background of engineering activities and natural disasters. Through indoor tests and numerical simulations, the mechanical properties and water permeability characteristics of recycled aggregate concrete produced from waste gravel are evaluated, and the correlation between the sensitivity and deformation laws of the slab wall parameters and slope stability are analyzed, as well as the role of the slab wall in achieving rainfall protection. The results show that the recycled aggregate permeable concrete has excellent water permeability while meeting the strength requirements; the thickness, bulk weight, and modulus of elasticity of the slab wall are positively correlated with slope stability, in which the thickness has the greatest influence; in addition, the vegetated concrete slab wall can effectively inhibit rainwater erosion and the formation of sliding surfaces and improve the safety of slopes. This study provides new ideas for resource recycling and the environmentally friendly ecological protection of slopes.
Thermal investigation of micro-polar tangent hyperbolic flow using a hybrid nanofluid approach
Authors: Abrar Muhammad Nasir , Kosar Shahzana , Razzaq Raheela
Published: January 2025

Hybrid nanofluids are recognized as advanced nanofluids due to their superior thermal properties and the potential advantages they offer in boosting the thermal efficiency of machines. Keeping the potential properties of hybrid nanofluids, this study aims to discuss the numerical solution for the the micro-rotating tangent hybrid nanofluid induced by a porous stretchable sheet. The physcial model is mathematically formulated. The mathematical formulation yields a set of non-linear partial differential equations. To derive a similarity solution, similarity variables are introduced. The numerical solution to the system of differential equations is achieved by engaging the Runge–Kutta–Fehlberg 45 (RKF-45) method, in conjunction with the shooting method. Graphical representations are employed to demonstrate the physical significance of relevant parameters. It is observed that a rise in both the permeability of the porous medium and the magnetic parameter lead to a significant decrease in the skin friction coefficient. Furthermore, as the Eckert number and heat source parameter reach substantial values, an increase in the heat transfer rate is foreseen. It is worth noting that by manipulating thermal relaxation and heat source parameters allows engineers to tailor systems for optimal performance, efficiency, and safety across various applications.
Femtosecond laser induced ultrafast interface dynamics between single layer graphene and quartz substrate: A theoretical study
Authors: Zhao Runping , Wang Xia , Wang Lei
Published: January 2025

SiO2 is the most widely used dielectric substrate for graphene devices. Theoretically investigating the interaction between graphene and SiO2 is vitally important for understanding graphene properties and improving device performance. In recent years, density functional theory (DFT) has been used to investigate the graphene–SiO2 interaction in ground states. However, the strong interface dynamics for an excited graphene–SiO2 system in ultrafast nonequilibrium processes was rarely researched. In this work, a real-time time-dependent density functional theory (rt-TDDFT) method was adopted to study the femtosecond laser induced ultrafast structure evolution and the underlying dynamics mechanism of the interface between a single layer graphene and a Si-terminated quartz substrate. This work indicates that rt-TDDFT is a promising method to study the strong electron dynamics and the coupled nuclear dynamics for graphene-SiO2 interfaces under ultrafast optical excitation, which benefits graphene device designs and mechanism analysis.
Helping physics departments thrive
Authors: Craig David , Hodapp Theodore , Jackson Michael
Published: January 2025

Capturing the wisdom of hundreds of individuals and departments, the Effective Practices for Physics Programs guide is a handbook for creating significant and sustainable change.
Rydberg blockade and quantum squeezing effects in a microwave mediated five-level inverted Y-type atomic system
Authors: Laskar Rejjak , Hossain Md Mabud , Saha Jayanta K
Published: January 2025

We propose a quantum mechanical model for observing Rydberg blockade and squeezing effects using a microwave field-assisted five-level inverted Y-type atom-laser interaction system. Using the mean field approximation, we calculate the mean and squeezed values of collective atomic operators and the probe field’s annihilation operator. Our model predicts that the presence of a signal field increases the number of probe photons transmitted under Rydberg blockade conditions as the control field strength increases. Additionally, it shows that higher number of probe photons are transmitted in the linear interaction regime compared to the non-linear regime. Under Rydberg blockade conditions, the probability of two or more photons in the same Rydberg superatom can be tuned by switching between linear and non-linear interaction regimes, and the positions of bunching or anti-bunching can be adjusted by toggling the signal field on or off. In the presence of the signal field, squeezing in probe transmittance can be maximized in both linear and non-linear regimes by increasing the strength of the control field.
Determination of QED correction to the 413 nm tune-out wavelength of 4He(

2
3

S
1

) using the radiative potential method
Authors: Lu Shan-Shan , Zhang Yong-Hui , Shi Ting-Yun , Tang Li-Yan
Published: January 2025

In contrast to previous perturbation calculations that employed the nonrelativistic quantum electrodynamics (QED) method, we have developed the relativistic configuration interaction combined with radiative potential (RCIRP) method to determine the QED correction of 413 nm tune-out wavelength of metastable helium, where the radiative potential operator is directly incorporated into the Dirac–Coulomb–Breit Hamiltonian to account for QED contributions. When the laser polarization vector is parallel or perpendicular to the quantization axis, present results for each magnetic sublevel of

2

3

S
1

state are in good accordance with existing theoretical and experimental values, indicating the correctness and effectiveness of the RCIRP method in the determination of QED corrections. Additionally, we find that the static dipole polarizability and tune-out wavelength exhibit high sensitivity to QED effect when the laser polarization vector is parallel to the quantization axis and the magnetic sublevel

M
J

=
±
1

, which provides theoretical support for future experimental measurement to test QED calculations.
Analytical solutions for optimal photon absorption into inhomogeneous spin memories
Authors: Bernád József Zsolt , Schilling Michael , Wen Yutian , Müller Matthias M , Calarco Tommaso , Bertet Patrice , Motzoi Felix
Published: January 2025

We investigate for optimal photon absorption a quantum electrodynamical model of an inhomogeneously-broadened spin ensemble coupled to a single-mode cavity. Solutions to this problem under experimental assumptions are developed in the Schrödinger picture without using perturbation theory concerning the cavity-spin interactions. Furthermore, we exploit the possibility of modulating the frequency and coupling rate of the resonator. We consider a one-photon input pulse and show some optimal scenarios, where exact formulas and numerical results are obtained for the absorption probabilities and the optimal pulse shapes. In particular, if the external loss dominates the internal loss of the cavity, we find the optimal cooperativity for different parameters and identify cases where absorption with a success probability larger than 99% is achieved.
Factors associated with radiation risk perception among Japanese university students
Authors: Yamaguchi Takumi , Yanagida Nobuhiko , Yamamoto Naoyuki , Matsunari Yuko
Published: January 2025

After the Fukushima Daiichi Nuclear Power Station accident, various information about radiation circulated throughout Japan, leading to diverse perceptions regarding the situation in Fukushima. These perceptions contributed to the social challenges faced by the residents of Fukushima at the time, including prejudice and discrimination. This heightened concern about radiation exposure, particularly among younger generations who were considering marriage or starting families. In the present study, we aimed to investigate the present status of radiation risk perception among university students in Japan and the factors associated with radiation risk perception among these students. A questionnaire survey was administered to university students throughout Japan. We collected demographic information as well as queried their perception of radiation risk (delayed health effects and genetic effects). The results showed that approximately 60% and 40% of respondents believed that delayed effects and genetic effects would occur among residents of Fukushima, respectively. Additionally, having a university major other than studying radiation techniques and living in western Japan were associated with these perceptions of risk. In the future, enhancing risk communication, especially among young populations in western Japan, is necessary to dispel anxiety about the risks from radiation exposure.
Study of the TOFPET2c ASIC in time-of-flight detection of x-rays for scatter rejection in medical imaging applications
Authors: Gaulin L-D , Nadig V , Herweg K , Lemaire G , Gagnon F , Bouchard J , Rossignol J , Schulz V , Fontaine R , Gundacker S
Published: January 2025

Objective. Integrating time-of-flight (ToF) measurements in radiography and computed tomography (CT) enables an approach for scatter rejection in imaging systems that eliminates the need for anti-scatter grids, potentially increasing system sensitivity and image quality. However, present hardware dedicated to the time-correlated measurement of x-rays is limited to a single pixel physically too large for the desired spatial resolution. A switch to highly integrated electronics and detectors is needed to progress towards detector arrays capable of acquiring images, while offering a timing resolution below 300 ps FWHM to achieve scatter rejection comparable to current anti-scatter grids. Approach. Using off-the-shelf scintillators, photodetectors and readouts designed for ToF positron emission tomography (PET) provides a preliminary evaluation of available highly integrated readout systems supporting detector arrays for ToF scatter rejection. The TOFPET2c ASIC from PETSys offers an established development platform necessary for fast and reliable results, with no known limitation regarding time-correlated detection of medical imaging x-rays (20–140 keV). Main results. Reliable photon detection down to 31 keV was achieved, reaching energy resolutions from 23% to 92% FWHM throughout the desired energy range. Optimal detector timing resolution (DTR) from 250 ps FWHM at 130 keV to 678 ps FWHM at 30 keV was reached. Strong time walk effects were observed, showing a time shift of 642 ps up to 1740 ps between events spanning the energies used in x-ray medical imaging. Significance. The TOFPET2c ASIC has shown its potential for ToF scatter rejection, but meets the time resolution requirement of 300 ps FWHM only for limited energies (110–140 keV). This significant timing degradation observed at lower energies limits the use of the TOFPET2c ASIC for ToF scatter rejection, but offers significant advancements regarding the understanding of the phenomenon arising from the time-correlated detection of medical imaging x-rays.
Resilience–runtime tradeoff relations for quantum algorithms
Authors: Pedro García-Pintos Luis , O’Leary Tom , Biswas Tanmoy , Bringewatt Jacob , Cincio Lukasz , Brady Lucas T , Liu Yi-Kai
Published: January 2025

A leading approach to algorithm design aims to minimize the number of operations in an algorithm’s compilation. One intuitively expects that reducing the number of operations may decrease the chance of errors. This paradigm is particularly prevalent in quantum computing, where gates are hard to implement and noise rapidly decreases a quantum computer’s potential to outperform classical computers. Here, we find that minimizing the number of operations in a quantum algorithm can be counterproductive, leading to a noise sensitivity that induces errors when running the algorithm in non-ideal conditions. To show this, we develop a framework to characterize the resilience of an algorithm to perturbative noises (including coherent errors, dephasing, and depolarizing noise). Some compilations of an algorithm can be resilient against certain noise sources while being unstable against other noises. We condense these results into a tradeoff relation between an algorithm’s number of operations and its noise resilience. We also show how this framework can be leveraged to identify compilations of an algorithm that are better suited to withstand certain noises.
Floquet topological phase transitions in 2D Su–Schrieffer–Heeger model: interplay between time reversal symmetry breaking and dimerization
Authors: Pena Adrian , Ostahie Bogdan , Radu Cristian
Published: January 2025

We theoretically study the 2D Su-Schrieffer-Heeger model in the context of Floquet topological insulators (FTIs). FTIs are systems which undergo topological phase transitions, governed by Chern numbers, as a result of time reversal symmetry (TRS) breaking by a time periodic process. In our proposed model, the condition of TRS breaking is achieved by circularly polarized light irradiation. We analytically show that TRS breaking is forbidden in the absence of second order neighbors hopping. In the absence of light irradiation, we identify a symmetry-protected degeneracy and prove the appearance of a flat band along a specific direction in the momentum space. Furthermore, we employ a novel method to show that the four unit cell atoms, in the absence of irradiation, can be interpreted as conserved spin states. With the breaking of TRS via light irradiation, these spin states are no longer conserved, leading to the emergence of chiral edge states. We also show how the interplay between the TRS breaking and dimerization leads to some complex topological phase transitions. The validity of our findings is substantiated through Chern numbers, spectral properties, localization of chiral edge states and simulations of quantum Hall transport. Our model is suitable not only for condensed matter (materials), but also for cold gases trapped in optical lattices or topolectrical circuits.
Recent progress on stability and applications of flexible perovskite photodetectors
Authors: Hu Ying , Zhang Qianpeng , Han Junchao , Lian Xinxin , Lv Hualiang , Pei Yu , Shen Siqing , Liang Yongli , Hu Hao , Chen Meng , Mo Xiaoliang , Chu Junhao
Published: January 2025

Flexible photodetectors have garnered significant attention by virtue of their potential applications in environmental monitoring, wearable healthcare, imaging sensing, and portable optical communications. Perovskites stand out as particularly promising materials for photodetectors, offering exceptional optoelectronic properties, tunable band gaps, low-temperature solution processing, and notable mechanical flexibility. In this review, we explore the latest progress in flexible perovskite photodetectors, emphasizing the strategies developed for photoactive materials and device structures to enhance optoelectronic performance and stability. Additionally, we discuss typical applications of these devices and offer insights into future directions and potential applications.
Calibrating laser Doppler anemometers utilizing an optical chopper
Authors: Crowley Christopher J , Shinder Iosif I , Moldover Michael R , Boyd Joey T , Filla B James , Johnson Aaron N
Published: January 2025

Laser Doppler anemometers (LDAs) use scattered light to determine velocity components of a flowing fluid. The operating principal of LDAs is simple conceptually; however, it is impractical to trace the LDA-determined velocities to the SI by characterizing the LDA’s subsystems that generate, detect, and process optical signals because these subsystems are complex and include proprietary features. To circumvent this, we calibrated the complete LDA systems utilizing an optical chopper blade as an accurate, SI-traceable velocity standard. The calibrations achieved the expanded velocity uncertainty 0.094% at a 95% confidence level. We calibrated two LDAs that differed in manufacturer, focal length (in the ratio 3.3:1), sensing volume (in the ratio 100:1), and orientation (vertical and horizontal bisectors of the LDA’s crossing beams). To compare the calibrations, we measured airspeeds in NIST’s wind tunnel using both LDAs. The results differed from each other by, at most, 0.2% throughout the airspeed range (0.5–30) m s−1.
A bilateral comparison of 227Th activity standards between National Physical Laboratory and National Institute of Standards and Technology
Authors: Fenwick Andrew J , Bergeron Denis E , Bendall Emma , Broder Brittany A , Cessna Jeffrey T , Collins Seán M , Pibida Leticia , Ramirez Natasha , Napoli Elisa
Published: January 2025

The National Physical Laboratory (United Kingdom) and the National Institute of Standards and Technology (United States) each determined the massic activity of a common solution of 227Th. Measurements at both laboratories were performed before radioactive equilibrium. The direct comparison showed good accord between the laboratories’ activity standards with a t-test score of 0.15 based on ionization chamber measurements. Challenges associated with pre-equilibrium comparisons are addressed and multiple comparison approaches are presented. The use of a hybrid comparison methodology using a model to correct asynchronously acquired data to an intermediate timepoint mitigates major sources of uncertainty and potential bias in extreme cases.
Transport and profile broadening in the private flux region of ASDEX upgrade and role for power exhaust
Authors: Brida D. , Grenfell G. , Grover O. , Silvagni D. , Faitsch M. , Stroth U. ,   the ASDEX Upgrade Team,   the EUROfusion Tokamak Exploitation Team
Published: January 2025

Understanding the transport processes that determine the plasma profile widths in the scrape-off layer (SOL) and divertor region of tokamaks is crucial for successful power and particle exhaust management in future devices. Plasma transport from the SOL into the private flux region (PFR) broadens the profiles and could mitigate the power exhaust challenge. Analysis of ion current profiles, measured by Langmuir probes in the ASDEX upgrade (AUG) tokamak, shows that the ion current width in the PFR, normalized by the flux expansion between outer target and midplane, is about 1.2 mm in L-mode and 0.9 mm in inter-ELM H-mode plasmas. The measured widths agree within a factor of two with predictions from an analytical model, based on Pfirsch-Schlüter flows. According to the model, the ion PFR width increases with the distance ΔR between the outer target and X-point major radii, and scales inversely with the poloidal magnetic field

B

p

. For the tokamaks ITER and SPARC the model predicts PFR widths below 0.3 mm.
Infernal instabilities in negative-triangularity plasmas with negative central shear
Authors: Zhang X.M. , Li L. , Liu Y.Q. , Dong Z.Y. , Li J.W. , Liang Y. , Zhong F.C.
Published: January 2025

A systematic numerical investigation is carried out to understand magnetohydrodynamic stability of the ideal infernal-kink instability in tokamak plasmas with both negative triangularity (neg-D) shaping and negative central shear for the equilibrium safety factor profile. The latter is motivated by the desire to form the internal transport barrier in the neg-D configuration, which is known to have difficulty in forming the edge transport barrier. The infernal-kink mode is generally found to be more unstable in neg-D plasmas as compared to their positive D-shaped (pos-D) counterpart. This is mainly due to less favorable (or even unfavorable) average magnetic curvature near the radial location of the minimum safety factor (

q

min

) as compared to the pos-D configuration. The larger Shafranov shift associated with the neg-D shape helps the mode stabilization but is not sufficient to overcome the destabilizing effect due to bad curvature. Strong poloidal mode coupling due to plasma shaping (toroidicity, elongation, triangularity, etc.) helps explain the slight shift with respect to that predicted by the analytic theory of the peak location of the computed mode growth versus

q

min

.
Reduced aerosols and intensified summertime rainfall in India during the pandemic suggest potentially more amplified precipitation in the future
Authors: Wang Fan , Gao Meng
Published: January 2025

Aerosol pollution is anticipated to decrease in the future, yet the associated effects of reduced aerosol loading on precipitation remain insufficiently explored. Widespread reductions in anthropogenic emission during COVID-19 lockdowns offer a unique opportunity to understand precipitation responses to changes in anthropogenic aerosols. Based on observations and regional and global climate-chemistry coupled model simulations, we attribute unprecedented precipitation in India during the 2021 lockdown to decreased aerosol levels due to emission reductions. Reduced aerosol loading leads to a northward shift of the subtropical westerly jet, which induces a westward movement of the subtropical southern branch trough and negative sea-level pressure anomalies over the eastern Arabian Sea. This shift facilitates water vapor transport from surrounding oceans to land, increasing precipitation in India by approximately 24.2% in May according to the Weather Research and Forecasting model coupled with chemistry simulations and by 28.5% over the entire lockdown period according to the Community Earth System Model version 2.1.3 simulations. Future projections under the lower aerosol emission scenario indicate an additional enhancement in monsoon precipitation in India. Our findings highlight the complex interplay between aerosol emissions and hydrometeorological dynamics, with implications for understanding future precipitation changes and providing theoretical reference for water resource management.
Arctic sea ice melting has produced distinct sea ice-atmosphere coupled patterns
Authors: Wu Bingyi
Published: January 2025

The possible influence of Arctic sea ice on weather events and climate variations has received considerable attention, while the evolution of its relationship with interannual variations of winter temperature across much of Eurasia remains poorly understood. This study quantitatively describes two distinct coupled patterns between autumn Arctic sea ice concentration in the Barents–Kara seas and the subsequent winter regional temperature over Eurasia. The leading coupled pattern dominantly depicts interannual variations of the cold Arctic―warm Eurasia or warm Arctic—cold Eurasia configuration, differing from the background warming pattern. While the second coupled pattern describes in-phase interannual variations of winter temperature over the Arctic and across much of Eurasia. This second pattern displayed an interdecadal transition in the early 2010s, from frequent occurrences of the cold Arctic―cold Eurasia pattern to the dominant warm Arctic―warm Eurasia configuration. Through this interdecadal transition, the warm Arctic―warm Eurasia configuration replaced the leading coupled pattern. The previously proposed the tropospheric and stratospheric processes cannot fully explain this Arctic―Eurasia temperature configuration. These findings underscore the pivotal role of Arctic sea ice melting in influencing the interannual and interdecadal variations of winter atmospheric circulation patterns and have significant implications for predicting short-term winter temperature trends over Eurasia.
Dualities for characteristic polynomial averages of complex symmetric and self dual non-Hermitian random matrices
Authors: Forrester Peter J
Published: January 2025

Ensembles of complex symmetric, and complex self dual random matrices are known to exhibit local statistical properties distinct from those of the non-Hermitian Ginibre ensembles. On the other hand, in distinction to the latter, the joint eigenvalue probability density function of these two ensembles are not known. Nonetheless, as carried out in the recent works of Liu and Zhang, Akemann et al and Kulkarni et al by considering averages of products of characteristic polynomials, analytic progress can be made. Here we show that an approach based on the theory of zonal polynomials provides an alternative to the diffusion operator or supersymmetric Grassmann integrations methods of these works. It has the advantage of not being restricted to a Gaussian unitary invariant measure on the matrix spaces. To illustrate this, as an extension, we consider averages of products and powers of characteristic polynomials for complex symmetric, and complex self dual random matrices subject to a spherical measure. In the case of powers, when comparing against the corresponding real Ginibre, respectively quaternion Ginibre averages with a spherical measure, one finds the qualitative feature of a decreasing (increasing) profile as the magnitude of the argument of the characteristic polynomial increases. This is analogous to the findings of the second two of the cited works in the Gaussian case.