bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optically active and optically inactive radio galaxies as sub-populations of the main galaxy sample of the SDSS
Authors: Stasińska G. , Vale Asari N. , Wójtowicz A. , Kozieł-Wierzbowska D. 
Published: November 2024

Aims. We use the ROGUE I and II catalogues of radio sources associated with optical galaxies to revisit the characterization of radio active galactic nuclei (AGNs) in terms of radio luminosities and properties derived from the analyses of the optical spectra of their associated galaxies.
Methods. We propose a physically based classification of radio galaxies into ‘optically inactive’ and ‘optically active’ (OPARGs and OPIRGs). In our sample, there are 14 082 OPIRGs and 2721 OPARGs. After correcting for the Malmquist bias, we compared the global properties of our two classes of radio galaxies and put them in the context of the global population of galaxies. To compare the Eddington ratios of OPARGs with those of Seyferts, we devised a method to obtain the bolometric luminosities of these objects, taking into account the contribution of young stars to the observed line emission. We provide formulae to derive bolometric luminosities from the [O III] luminosity.
Results. We find that the distributions of radio luminosities of OPARGs and OPIRGs are undistinguishable. On average, the black hole masses and stellar masses in OPIRGs are larger than in OPARGs. OPARGs show signs of some recent star formation. Plotting the OPARGs in the BPT diagram and comparing their distribution with that of the remaining galaxies, we find that there is a sub-family of very high excitation OPARGs at the top of the AGN wing. This group is slightly displaced towards the left of the rest of the AGN galaxies, suggesting a stronger ionizing radiation field with respect to the gas pressure.
Conclusions. Only very-high excitation radio galaxies (VHERGs) have Eddington ratios higher than 10−2, which are canonically considered as the lower limit for the occurrence of radiative efficient accretion. If our estimates of the bolometric luminosities are correct, this means than only a small proportion of mainstream HERGs are indeed radiatively efficient.
Josephson effect in superconductive bridges: microscopic theory
Authors: Kulik I. O. , Omel’yanchuk A. N. 
Published: November 2024

A theory is developed for the stationary Josephson effect in superconductive constrictions (microbridges).The theory is based on the microscopic Eilenberger equations and is valid for arbitrary temperatures 0&lt;T&lt;Tc. The current-phase relationships I(Q) and critical current Ic(T) obtained differ from the corresponding expressions for a tunnel junction. The difference is greatest at low temperatures and for limitingly pure bridges. In the pure limit l≫a (where l is the free path length; a is the orifice radius) the current is expressed by the formula I(φ)=πΔ0(T)eRNsin(φ/2) th Δn(T)cos(φ/2)2T. The critical current of a pure microbridge at t = 0 is twice the critical current of a tunnel junction with the same normal resistance RN, and the phase-current relationship at the points Q = ±π is discontinuous. The properties of microbridges in the pure (l≫a) and dirty (l≪a) limits are compared.
A high-frequency, low-power resonant radio-frequency neutron spin flipper for high-resolution spectroscopy
Authors: McKay Sam , Kuhn Stephen J. , Shen Jiazhou , Li Fankang , Doskow Jak , Visser Gerard , Parnell Steven R. , Burrage Kaleb , Funama Fumiaki , Pynn Roger 
Published: November 2024

We present a resonant-mode, transverse-field, radio-frequency (rf) neutron spin flipper design that uses high-temperature superconducting films to ensure sharp transitions between uniform magnetic field regions. Resonant mode allows for low-power, high-frequency operation but requires strict homogeneity of the magnetic fields inside the device. This design was found to efficiently flip neutrons at 96.6 ± 0.6% at an effective frequency of 4 MHz in bootstrap configuration with a beam size of 2.4 × 2.5 cm2 and a wavelength of 0.4 nm. The high frequency and efficiency enable this device to perform high-resolution neutron spectroscopy with comparable performance with currently implemented rf flipper designs. The limitation of the maximum frequency was found due to the field homogeneity of the device. We numerically analyze the maximum possible efficiency of this design using a Bloch solver simulation with magnetic fields generated from finite-element simulations. We also discuss future improvements of the efficiency and frequency to the design based on the experimental and simulation results.
Borophene nanoclusters: Energetics and structures from analytical potentials
Authors: Zergani Farideh , Marques Jorge M. C. , Bartolomei Massimiliano , Pirani Fernando 
Published: November 2024

Boron shows a variety of properties, determining a chemistry rich and complementary to that of carbon, the neighbor atom in the Periodic Table. In this work, we investigated the strength and nature of the interaction involving B12 or B36 monomer, which represent molecular prototypes of borophene, the two-dimensional allotrope of elemental boron. For the representation of the intermolecular interaction, we developed new potential energy surfaces (PESs) that are based on accurate ab initio or density functional theory data. It is shown that borophene molecules are bound by weak intermolecular interactions of van der Waals nature, perturbed by antiaromatic effects. Moreover, the proposed PESs are given in an analytical form proper to investigate the structures and energetics of (B12)n and (B36)n clusters (with n = 2–10) by applying a global geometry optimization procedure. It is found that the most stable structures of (B12)n favor close contacts between the edges of the monomers, leading to cage-like clusters as n increases, and conversely, (B36)n clusters are mainly composed of stacked or herringbone structures. These results suggest the possibility to produce a novel class of two-dimensional borophene materials, exhibiting different features compared to graphene like structures, which could be of interest for the nanotechnology.
Statistical modelling and Bayesian inversion for a Compton imaging system: application to radioactive source localization
Authors: Tarpau Cécilia , Fang Ming , Zygalakis Konstantinos C , Pereyra Marcelo , Di Fulvio Angela , Altmann Yoann 
Published: November 2024

Abstract
This paper presents a statistical forward model for a Compton imaging system, called Compton imager. This system, under development at the University of Illinois Urbana Champaign, is a variant of Compton cameras with a single type of sensors which can simultaneously act as scatterers and absorbers. This imager is convenient for imaging situations requiring a wide field of view. The proposed statistical forward model is then used to solve the inverse problem of estimating the location and energy of point-like sources from observed data. This inverse problem is formulated and solved in a Bayesian framework by using a Metropolis within Gibbs algorithm for the estimation of the location, and an expectation-maximization algorithm for the estimation of the energy. This approach leads to more accurate estimation when compared with the deterministic standard back-projection approach, with the additional benefit of uncertainty quantification in the low photon imaging setting.
Interlayer excitons in MoS2/CSiH2/WS2 heterostructures: the role of the Janus intermediate layer
Authors: Yan Zhihui , Wang Shudong 
Published: November 2024

Abstract
The introduction of intermediate hexagonal boron nitride (hBN) between the bilayer transition metal dichalcogenide (TMD) heterostructures has been considered an efficient approach to manipulate the interlayer excitations. However, the hBN intercalation primarily serves as a spacer to increase the interlayer distance and alter the screening, without producing a significant band offset shift. Here, we use Janus monolayer CSiH2, possessing a prominent out-of-plane intrinsic dipole moment and large enough band gap, as an intercalation to build trilayer MoS2/CSiH2/WS2 heterostructures. Our calculated results by means of many-body perturbation theory reveal that the band alignment characteristics and the band gaps are dramatically altered in the presence of the CSiH2 monolayer, due to the large potential drop across the interface of bilayer TMDs. By solving the Bethe–Salpeter equation, we observe the static dipole moment of the interlayer excitons (IXs) can be reversed through tuning the stacking sequence of CSiH2. More importantly, the radiative lifetime of IX has been substantially prolonged in MoS2/CSiH2/WS2, several orders of magnitude longer than that of bilayer MoS2/WS2, and varies between 10–9–10–5 s at 0 K with different stacking sequence of CSiH2. Our explorations open the feasibility of simultaneously engineering the band alignment and the dipole moment of the dipolar IXs in TMD van der Waals heterostructures, through the introduction of Janus intercalation.
Analysis of the impact of high temporal resolution tropospheric parameters on GNSS station coordinate and troposphere estimation
Authors: Ding Wenwu , Qu Xiaochuan , Tan Xuanzhao , Zhang Xinyu , Yuan Yunbin 
Published: November 2024

Abstract
Troposphere modelling accuracy can seriously influence the performance of precise global navigation satellite system (GNSS) positioning. The temporal interpolation accuracies of troposphere parameters become important with the improvement in troposphere modelling, especially during the periods of severe weather changes. In this study, a one-month experiment was conducted for 10 EUREF Permanent GNSS Network stations to analyse the temporal interpolation errors of numerical weather model derived troposphere parameters and their influences on GNSS station coordinate and troposphere estimation. The root mean square of the differences between the 1- and 6-hourly European Centre for Medium-Range Weather Forecasts reanalysis v5-derived troposphere parameters are 0.72/11.52 mm for the zenith hydrostatic/zenith wet delay (ZWD), while they are 7.09/91.84 mm for the slant hydrostatic/wet delay at a

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elevation angle. The corresponding influences on the estimated upper component and ZWD are 1.28 and 0.79 mm, respectively, in the daily static Precise Point Positioning ambiguity resolution solutions. However, the accuracy improvements are insignificant in the daily static solutions, mainly due to the drop of temporal interpolation errors with increasing elevation angles and the influence of other unmodeled systematic errors. In the 4-hourly static solutions, the accuracies of the up component improve 0.51 mm (5.9% in relative) and 0.29 mm (3.5% in relative) during the severe and stable periods, respectively. These impacts cannot be ignored in some GNSS subdaily applications, for example, monitoring non-tidal ocean loading effects, bedrock and monument thermal elastic effects, etc.
Miniaturized laser interferometer using dynamic current-wavelength modulation for high precision displacement measurement
Authors: Liao Chen-Yu , Lin Hsi-Hui , Chein Wei-Hsin , Chen Liang-Chia 
Published: November 2024

Abstract
This study proposes a compact displacement measurement interferometer facilitated by a novel dynamic current-wavelength modulation method for high-precision displacement measurement. This technique compensates for the modulation depth by precisely predicting the optical path difference with frequency-scanning interferometry to achieve consistent modulation depth over an extensive measurement range. Additionally, a wavelength-locking method was developed for the 1550 nm band, using the P7 absorption peak of hydrogen cyanide gas to lock the central wavelength of the laser. The experimental results showed that the wavelength stability can be kept within 128 fm for 8 h with the proposed method. Furthermore, the deviations are less than 40 nm compared to a calibrated laser interferometer within the 300 mm measurement range. This research offers precise positioning feedback for precision engineering, paving the way for advanced semiconductor manufacturing processes.
Temperature characteristics and nonlinear calibration model of self-enabled piezoelectric geocable for infrastructure monitoring
Authors: Liu Zhiming , Cai Guojun , Wang Jun , Kuang Kevin Sze Chiang , Liu Lulu , Zhao Zening 
Published: November 2024

Abstract
Sensor-enabled piezoelectric geocables (SPGCs) are used for strain and vibration monitoring of various infrastructures structures. However, as a distributed sensor, the influence of temperature on the monitoring signal of SPGCs is inevitable. This study tested the impedance change of SPGCs in static temperature-varying tests and carried out dynamic tensile tests at different temperatures. The static temperature-varying tests showed that, at temperatures ranging from −10 °C to 50 °C, the SPGC normalized impedance change value increased with increasing temperature. At temperatures ranging from −10 °C to 20 °C and 20 °C–50 °C, the normalized impedance change value and temperature were exponentially and linearly related, respectively. Dynamic tensile tests showed that the SPGC tensile strength and yield strain decreased with increasing temperature. With increasing temperature, the SPGC voltage waveform and value changed less, while the impedance response became more sensitive. Therefore, a nonlinear calibration model of the SPGC impedance-strain effect considering the temperature effect was proposed, which can be used for strain calculation under different field ambient temperatures. The test results revealed the influence of temperature on the mechanical and monitoring performance of SPGC, providing support for further engineering applications of this technology.
Group sparse low-rank algorithm for ultrasonic guided wave defect feature extraction
Authors: Li Xinxin , Wei Yuming , Tang Weili , Zhang Qian , Wang Zhijiao , Ye Zhenting , Mo Fujun 
Published: November 2024

Abstract
Ultrasonic guided wave (UGW) is highly valued in the field of nondestructive testing due to their slow energy decay and extensive detection range, displaying unique advantages particularly in the inspection of long weld defects. However, the signal of defective echo is easily masked by strong noise interference, which makes feature extraction difficult. To address this issue, this paper proposes a time–frequency analysis overlapping group sparse low-rank (TFAOGSL) model. Firstly, the group sparsity and low-rankness of UGW signals are revealed, and the TFAOGSL feature extraction is modeled on this basis. Secondly, the convexity condition of the TFAOGSL model is derived, and its optimal solution is deduced using the alternating direction method of multipliers algorithm in conjunction with the majorization–minimization algorithm. Additionally, optimal parameters for TFAOGSL were adaptively chosen using simulated signals. Finally, comparisons were made with some state-of-the-art methods, and the effectiveness of TFAOGSL was confirmed through UGW detection experiments for welding defects. The results demonstrated that this method can accurately extract defect features and has significant advantages compared to other methods.
A novel atmospheric microwave plasma source based on circular waveguide with double ridges for nitrogen fixation
Authors: Feng Kai , Wu Shaokun , Zheng Fang , Xiao Wei 
Published: November 2024

Abstract
The rectangular tapered waveguide is the most widely used atmospheric microwave plasma source because of its simple structure, reliable performance, and low cost. However, due to the small generated plasma volume and short residence time, this plasma source has low energy efficiency in gas conversion applications such as nitrogen fixation and methane reforming. This paper proposes a novel atmospheric-pressure microwave plasma source based on a circular waveguide to enlarge the plasma volume. Firstly, the microwave working mode in the circular waveguide is analyzed based on the electromagnetic theory. By optimizing the waveguide dimension and loading double metal ridges into the waveguide, the electric field will work in a superposition mode of TE111 and TM010 modes, focus on the discharge area, and reach its maximum intensity there. Secondly, this device is manufactured and used to generate plasma in different conditions. Compared with the rectangular tapered waveguide, this device can generate larger plasmas under the same conditions. Finally, an atmospheric microwave plasma experimental system is built for nitrogen fixation. Measured results show that the proposed device has higher nitrogen fixation production and lower energy cost compared to the rectangular tapered waveguide. Moreover, the proposed device is easy to cascade, thereby it has great potential for promotion in industrial applications.
Mechanical and tribological properties of AA2024 reinforced Al2O3 and ZrO2 hybrid composite
Authors: T Mohanraj , K Bharath Reddy , Pramanik A 
Published: November 2024

Abstract
Hybrid Metal Matrix Composite (HMMC) alloys are a very attractive material for excellent mechanical and tribological performance, and their properties can be easily customized by varying reinforcement types and amounts. This research investigated the mechanical and tribological properties of an Aluminium Alloy (AA) 2024 reinforced with 2 wt% Al2O3 and (2, 4, 6) wt% ZrO2 hybrid composites. The presence and distribution of reinforcements in the stir-casted samples were confirmed by SEM, EDS, and elemental mapping. The tribological tests were conducted on a pin-on-disc under dry and wet conditions using Taguchi’s L9 orthogonal array. The SAE 20w40 oil and SAE 20w40 oil mixed with TiO2 nano additive are lubricants. The hardness and tensile strength increase linearly with the addition of a single and continue to increase with multiple reinforcements. The HMMC exhibits a maximum hardness and tensile strength of 107 BHN and 209.281 MPa, respectively. The experimental results show that the dry condition’s wear rate is much higher than that of the composites lubricated with SAE 20w40, especially SAE 20w40 with TiO2 nano additive. Compared to the base material, AA2024 reinforced with 2 wt% of Al2O3 and 6 wt% of ZrO2 exhibited an enhanced wear resistance of 0.0002353 mm3/min and COF of 0.118 with nano lubricant which is 40% and 21% higher than base lubricant.
A low-power single ended half-select free 7 T SRAM cell with improved write margin at 32 nm technology node
Authors: Tripathi Arunima , Dahiya Ayush , Mittal Poornima 
Published: November 2024

Abstract
A single-ended single port 7T SRAM bit-cell with a process-variation tolerant architecture and half-select resilience at 32 nm CMOS technology node is presented. The proposed 7 T (7TP) SRAM bit-cell integrates a low threshold voltage (LVTH) feedback cutting transistor along with nominal VTH devices. The reliability of the 7TP cell is presented for process, voltage and temperature (PVT) variations to account for local/global variations incurred during CMOS fabrication. 7TP SRAM bit-cell consistently exhibits 6-σ deviation for static noise margin (SNM), Write Margin (WM) and delay using 1000-point Monte Carlo simulations. The 7TP bit-cell shows improved WM, SNM, power consumption and delay compared to other SRAM cell architectures. The 7TP has the lowest normalized WM-1(WM- 0) of 8.5025%(8.5025%) compared to 17.0150%(46.0875%), 36.5800%(36.5800%), 17.0150%(53.5725%), 53.5450%(14.3650%), 11.8925%(11.8925%) for 7Tn, 7Ti, 7Tj, 8T and 11T SRAM cells respectively. The read-1(read-0) and write-1(write-0) power of the 7TP cell is 887.2 nW(10.09 μW) and 1087 nW(26.6 μW) respectively. The write-1 power of 8 T, 9 T and 10 T cells is 112.2%, 113.70%, and 136.11% of 7TP cell respectively. The proposed cell has the second-best HSNM/RSNM value of 0.269 V at VDD = 0.8 V. The area of the proposed cell is 0.104 sq. μm, the least among other SRAM bit-cells.
Observation of microsphere clusters separated by pulsed laser in water environment
Authors: Ge Yang , Zhou Gaoqian , Yang Xulong , Chen Ying , Tang Xianqi , Sun Jiapeng , Li Hanyang 
Published: November 2024

Abstract
A separation experiment of polystyrene microspheres in water based on tapered fiber pulsed laser system was carried out. We analyzed the motion images during the separation of polystyrene microsphere clusters and investigated the influence of laser energy and initial cluster positions on the separation results. Through the study of bubbles generated by pulsed laser separation of microsphere clusters, we summarized the process of micron-sized bubble formation and the factors contributing to their prolonged existence. Additionally, we clarified the separation mechanism of microsphere clusters. The results indicate that as the laser energy increases, the separation effect of microsphere clusters improves from 151 μm to 170 μm. When the laser energy is 50.1 μJ, a more significant initial distance leads to weaker separation effects. Furthermore, the diameter of micron-sized bubbles is positively correlated with separation effects.
Geometric theory of (extended) time-reversal symmetries in stochastic processes: I. Finite dimension
Authors: O’Byrne J , Cates M E 
Published: November 2024

Abstract
In this article, we analyze three classes of time-reversal of a Markov process with Gaussian noise on a manifold. We first unveil a commutativity constraint for the most general of these time-reversals to be well defined. Then we give a triad of necessary and sufficient conditions for the stochastic process to be time-reversible. While most reversibility conditions in the literature require knowledge of the stationary probability, our conditions do not, and therefore can be analytically checked in a systematic way. We then show that the mathematical objects whose cancellation is required by our reversibility conditions play the role of independent sources of entropy production. Furthermore, we give a geometric interpretation of the so-called irreversible cycle-affinity as the vorticity of a certain vector field for a Riemannian geometry given by the diffusion tensor. We also discuss the relation between the time-reversability of the stochastic process and that of an associated deterministic dynamics: its Stratonovitch average. Finally, we show that a suitable choice of a reference measure—that can be considered as a prior or a gauge, depending on the context—allows to study a stochastic process in a way that is both coordinate-free and independent of the prescription used to define stochastic integrals. When this reference measure plays the role of a gauge choice, we interpret our previous results through the lens of gauge theory and prove them to be gauge-invariant.