bluuebunny/crossref_metadata_2025 huggingface dataset:
What can the eye see with melanopsin?
Authors: Nugent Thomas W. , Zele Andrew J.
Published: November 2024

A subpopulation of human retinal ganglion cells contains the melanopsin photopigment, allowing them to act as a fifth photoreceptor class. These ganglion cells project to the visual cortex, but to reveal its intrinsic contribution to conscious vision is technically challenging as it requires melanopsin to be separated from the responses originating in the rods and three cone classes. Using a display engineered to isolate the melanopic visual response, we show that it detects lowpass spatial (≤0.35 cycles per degree) and temporal image content (≤1 Hz) but cannot reconstruct the stimulus form necessary for object recognition. We demonstrate that a model of the spatially diffuse intrinsically-photosensitive retinal ganglion cells’ sampling structure is predictive of the measured image reconstruction limits of melanopic spatial vision. Separately, we find that under five-photoreceptor silent substitution conditions, rod pathways alone can support form vision in bright lighting when typically thought to be in saturation. Form vision that is absent from melanopsin can be only perceived in mixtures of both melanopsin and rod signals because it is the rod pathway that sees the form. Our findings show that melanopsin’s unique tuning to the diffuse and slow-changing elements in the world provides a stabilized reference point for vision.
Lateral entorhinal cortex afferents reconfigure the activity in piriform cortex circuits
Authors: Pedroncini Olivia , Federman Noel , Marin-Burgin Antonia
Published: November 2024

Odors are key signals for guiding spatial behaviors such as foraging and navigation in rodents. Recent findings reveal that odor representations in the piriform cortex (PCx) also encode spatial context information. However, the brain origins of this information and its integration into PCx microcircuitry remain unclear. This study investigates the lateral entorhinal cortex (LEC) as a potential source of spatial contextual information affecting the PCx microcircuit and its olfactory responses. Using mice brain slices, we performed patch-clamp recordings on superficial (SP) and deep (DP) pyramidal neurons, as well as parvalbumin (PV) and somatostatin (SOM) inhibitory interneurons. Concurrently, we optogenetically stimulated excitatory LEC projections to observe their impact on PCx activity. Results show that LEC inputs are heterogeneously distributed in the PCx microcircuit, evoking larger excitatory currents in SP and PV neurons due to higher monosynaptic connectivity. LEC inputs also differentially affect inhibitory circuits, activating PV while suppressing SOM interneurons. Studying the interaction between LEC inputs and sensory signals from the lateral olfactory tract (LOT) revealed that simultaneous LEC and LOT activation increases spiking in SP and DP neurons, with DP neurons showing a sharpened response due to LEC-induced inhibition that suppresses delayed LOT-evoked spikes. This suggests a regulatory mechanism where LEC inputs inhibit recurrent activity by activating PV interneurons. Our findings demonstrate that LEC afferents reconfigure PCx activity, aiding the understanding of how odor objects form within the PCx by integrating olfactory and nonolfactory information.
Multimodal metaphors, political activism and Anglophone nationalism in Cameroon
Authors: Echitchi Raymond
Published: November 2024

This paper is part of a broader study of how separatist leaders from the English-speaking part of Cameroon resort
to discourse in order to push for their main political goal, which is the formation of a separate state. These last few years,
Cameroon politics has been characterized by an increase in secessionist sentiment amongst English-speaking citizens, thus yielding
the so-called Anglophone crisis which has now turned into a full-blown conflict between armed separatists and the country’s
military. The study presented here deals specifically with the use of multimodal metaphors to depict the plight of Anglophone
Cameroonians and also engage them in the struggle for self-determination. Therefore, cartoons published on separatist social media
pages were analyzed following approaches pertaining to cognitive linguistics and social semiotics (Lakoff & Johnson, 1980; Van Leeuwen, 2005). This research
has revealed that the cartoonist(s) resort(s) to various types of metaphor, including the journey metaphor, animal metaphors and
personification.
Real-time imaging reveals a role for macrophage protrusive motility in melanoma invasion
Authors: Ramakrishnan Gayathri , Miskolci Veronika , Hunter Miranda , Giese Morgan A. , Münch Daniela , Hou Yiran , Eliceiri Kevin W. , Lasarev Michael R. , White Richard M. , Huttenlocher Anna
Published: November 2024

Macrophages are primary cells of the innate immune system that mediate tumor progression. However, the motile behavior of macrophages and interactions with tumor cells are not well understood. Here, we exploit the optical transparency of larval zebrafish and perform real-time imaging of macrophage–melanoma interactions. We found that macrophages are highly motile in the tumor microenvironment. Macrophages extend dynamic projections between tumor cells that precede invasive melanoma migration. Modulating macrophage motility with a dominant inhibitory mutation in Rac2 inhibits recruitment to the tumor and impairs tumor invasion. However, a hyperactivating mutation in Rac2 does not affect macrophage recruitment but limits macrophage projections into the melanoma mass and reduces invasive melanoma cell migration. Taken together, these findings reveal a role for Rac2-mediated macrophage protrusive motility in melanoma invasion.
Two sides of the same coin: the

F

-statistic and the 5-vector method
Authors: D’Onofrio L , Astone P , Dal Pra S , D’Antonio S , Di Giovanni M , De Rosa R , Leaci P , Mastrogiovanni S , Mirasola L , Muciaccia F , Palomba C , Pierini L
Published: November 2024

This work explores the relation between two data-analysis methods used in the search for continuous gravitational waves in LIGO-Virgo-KAGRA data: the

F

-statistic and the 5-vector method. We show that the 5-vector method can be derived from a maximum likelihood framework similar to the

F

-statistic. Our analysis demonstrates that the two methods are statistically equivalent, providing the same detection probability for a given false alarm rate. We extend this comparison to multiple detectors, highlighting differences from the standard approach that simply combines 5-vectors from each detector. In our maximum likelihood approach, each 5-vector is weighted by the observation time and sensitivity of its respective detector, resulting in efficient estimators and analytical distributions for the detection statistic. Additionally, we present the analytical computation of sensitivity for different searches, expressed in terms of the minimum detectable amplitude.
Ternary nodal-line semimetal InNbS2 for highly sensitive broadband terahertz photodetection
Authors: Yang Liu , Wang Dong , Li Jie , Wang Pengdong , Hou Xingang , Tang Keqin , Wang Lin , Dong Zhuo , Zhang Kai
Published: November 2024

Topological nodal-line semimetals (TNLSs) can be understood as a collection of two-dimensional Dirac Fermions along the line, which endows high mobility and extraordinary electrical transport in all directions near the Dirac points. Furthermore, the band geometry at the Fermi level can be easily modified by external field excitations. These features can bring intriguing properties, such as superconducting, Lifshitz transitions, strong light-matter interaction, and high photoconductivity, supporting low-energy carrier excitations and enhanced optical absorption at terahertz (THz) frequency ranges. Herein, a novel TNLS InNbS2-based THz photodetector was fabricated and the photoresponse within 0.02–0.3 THz was explored. A fast response speed of 15.4 μs, a maximum responsivity (R
I) of 1.4 A W–1, and a superb noise equivalent power (NEP) of 11.5 pW Hz−1/2 were achieved at 0.11 THz under a bias voltage of 100 mV due to the high photoconductive gain. Meanwhile, the high-resolution THz transmission imaging of a metallic rainbow was carried out to demonstrate the THz imaging functionality. These results explore new avenues for utilizing TNLSs in THz photodetection and establish a basis for the application in the THz field.
Interface mechanism of photon–magnon–phonon conversion in an epitaxial ferrite–dielectric structure
Authors: Tikhonov V V , Ptashenko A S , Sadovnikov A V
Published: November 2024

It is shown that in the transition layer of an epitaxial yttrium iron garnet (YIG) film, there are effects of intense power conversion and redistribution between electromagnetic waves (EMW), exchange spin waves (ESW) and acoustic waves (AW). These interconversion occurs during the casсade of double hybridization of EMW-ESW and secondary hybridization of ESW-AW. The necessary phase synchronism condition for this is ensured by the smooth distortion of the ESW dispersion within the thickness direction of the transition layer. The secondary hybridization of ESW-AW manifests itself in the intense excitation of AW, which are radiated into the depth of the gadolinium gallium garnet (GGG) substrate. In this case, magnetoacoustic resonances are excited in the YIG-GGG bilayer structure, for the observation of which strict parallelism and optical polishing of the reflecting surfaces of the YIG-GGG structures are required. An important advantage of magnetoacoustic resonances is the record high quality factor in the microwave range and high resistance to external atmospheric influences, which is of significant interest for the fabrication of highly stable magnetoacoustic microwave generators with discrete frequency tuning.
Direct measurements of the conventional and rotational magnetocaloric effects in Gd thick films
Authors: Pereira C S , Almeida R , Niehoff T , Kiefe R , Fontana E , Silva D J , Gottschall T , Wosnitza J , Devillers T , Dempsey N M , Amaral J S , Belo J H
Published: November 2024

Magnetic refrigeration (MR) offers a sustainable and emission-free solution to the prevalent heat-pumping systems used worldwide. Typically, it utilizes the magnetocaloric effect (MCE) to achieve cooling by changing the external magnetic field intensity. However, an alternative approach involves maintaining a fixed field intensity while manipulating its orientation to induce temperature changes, in an effect known as the rotating MCE (RMCE). While the RMCE has been extensively studied in materials with magnetocrystalline anisotropy, its investigation in polycrystalline magnetocaloric samples with asymmetric shapes has been lacking until recently. In this case, the RMCE is induced by the demagnetizing effect, which becomes more pronounced in high aspect-ratio sample geometries exhibiting different effective demagnetizing factors at different orientations, such as in films. In this work, we characterize the conventional and rotational MCE of 40 μm-thick gadolinium films through magnetization and direct temperature measurements. The maximum adiabatic temperature change achieved under a 1 T magnetic field was 2.05 K when the film was oriented in plane with the field and 1.25 K when the film was perpendicular to the magnetic field, corresponding to an adiabatic temperature difference of around 0.8 K which may be induced through magnetic field rotation. Additionally, the maximum adiabatic temperature change upon rotation is shown to exhibit a non-monotonous behavior with field intensity, displaying a peak value for field intensities of around 0.8 T. The high aspect ratio of the Gd film has been demonstrated to considerably enhance the intensity of demagnetizing field-based RMCE compared to bulk samples, paving the way for future research in this emerging field of MR cooling.
Doses from ionising radiation in paediatric cardiac catheterisations in Norway 1975–2021
Authors: Afroz S , Østerås B H , U S Thevethas , Meo M , Jahnen A , Dabin J , Thierry-Chef I , Robsahm T E , Døhlen G , Olerud H M
Published: November 2024

Paediatric patients with congenital heart disease often undergo cardiac catheterisation procedures and are exposed to considerable ionising radiation early in life. This study aimed to develop a method for estimating the dose area product (P
KA) from paediatric cardiac catheterisation procedures (1975–1989) at a national centre for paediatric cardiology and to evaluate trends in P
KA and exposure parameters until 2021. Data from 2200 catheterisation procedures on 1685 patients (1975–1989) and 4184 procedures on 2139 patients (2000–2021) under 18 years of age were retrospectively collected. P
KA values were missing for 1975–1989 but available from 2000 onward. The missing P
KA was estimated from air kerma and beam area, based on exposure records and input from clinicians working at that time. P
KA trends were analysed over time and age. There was a 71% reduction in median P
KA from the period 1975–1989 (median 6.63 Gy cm2) to 2011–2021 (1.91 Gy cm2). The P
KA increases significantly (p = 0.0001) with patient age, which was associated with body weight. Approximately 80% of the total P
KA was from cine acquisition in 1975–1989, while 20% was from fluoroscopy. The P
KA estimate during 1975–1989 was considerably impacted by the assumptions of missing parameters such as tube filtration, focus-to-heart distance, beam area, and number of cine series. The decreasing trend in P
KA values was attributed to advancements in both technologies and clinical practices. The high contribution of cine acquisition to the total dose during 1975–1989 was due to factors such as a high frame rate, multiple acquisitions, and high tube current. The estimated P
KA values for the period 1975–1989 are of importance for the dose reconstruction and risk assessments in the EU epidemiology project Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy in Pediatrics(HARMONIC).
Design of a self-referenced laser scanning and ranging system
Authors: Yang Qingzhao , Shi Liheng , Zhou Siyu , Zhang Ruixue , Yuan Ding , Xiao Lin , Yang Hongzhi , Xie Yang , Li Lin , Wu Guanhao
Published: November 2024

The laser scanning and ranging system (LSRS) is a pivotal technology for conducting high-precision multi-dimensional measurements, with diverse applications in remote sensing, satellite formation flying, and surface profilometry. However, the capability to achieve accurate measurement of the current system is limited by the beam-pointing mechanism. Specifically, the rotation angle of the beam-pointing mechanism is too small to achieve zero-position self-calibration, and this mechanism can introduce errors that exceed the precision of distance measurement. Herein, we propose a self-referenced LSRS that can directly determine the measurement origin and avoid motion-induced optical path length errors into the interferometric arms. This system is achieved by placing the reference arm of the measurement system after the beam-pointing mechanism in the optical path. Using a dual-comb ranging system with a precision of ∼0.8 μm, we validated the performance of our design through scanning experiments with hollow retroreflectors and surface profile reconstruction of a gauge-block assembly. The experimental results demonstrate that our design achieves accurate measurements without pre-calibration or post-compensation, thereby enhancing its applicability to next-generation space missions.
A feature-preserving simplification method for dense point clouds based on voxel priority filtering
Authors: Zhou Zhihao , Zhu Huabo , Chen Yuzhao , Han Xu , Tao Yourui
Published: November 2024

The inherently high-dimensional and information-dense nature of point clouds requires substantial storage and computing resources, which severely limits their widespread applicability. It is crucial to simplify the point cloud data efficiently and accurately for various downstream tasks. To address the challenges of detail loss and time consumption, we propose a novel method that utilizes voxel filtering and partition sampling strategy for point cloud simplification. The voxel grid structure of original point cloud is established based on the spatial location of the points. The voxels are then classified as feature and non-feature voxels by calculating the Eigenentropy on the Gaussian sphere. Combined with an effective partition strategy for further sampling, the proposed method ensures global geometric consistency and preserves distinct features in the simplified point cloud. To evaluate the performance comprehensively, we conducted extensive experiments on the models of standard, industrial real-world scanning and natural scene datasets. Compared with several relevant approaches, the results demonstrate that the proposed method significantly enhances the flexibility and accuracy of point cloud simplification. It exhibits superior capabilities in engineering applications such as visualization, 3D reconstruction, and point cloud registration.
A method to get perfect balance point of differential eddy current displacement sensors
Authors: Zhu Shuyu , Chen Guangzheng , Xu Tao , Yin Jing , Feng Zhihua
Published: November 2024

This study introduces a novel method to increase the stability of the balance point in precision differential eddy current sensor (ECS) displacement sensors, which is crucial for achieving optimal performance and improving the interchangeability of sensor probes. The temperature drift coefficient at the electrical balance point (BTC), a common issue affecting the accuracy and reliability of measurements, is addressed through our approach. The BTC can be accurately adjusted by fine-tuning the length of the aluminum target, which aligns the zero-temperature drift position with the electrical balance position, thereby achieving a perfect balance point. The experimental results demonstrate that the proposed method significantly reduces the temperature drift near the balance point of the differential ECS. The BTC was effectively reduced from −7.21 nm/°C to 0.22 nm/°C. This substantial reduction in the BTC enhances the stability of the sensor, facilitating more reliable measurements in high-precision applications.
Removal of crossbar-switch interference from multi-rate beam position signals with wavelet packet transform
Authors: Tang Leilei , Sun Baogen , Wu Ruizhe , Lu Ping , Ma Xiaochao , Wang Anxin
Published: November 2024

Electron beam position measurement of storage rings is a typical multi-channel signal acquisition system that suffers from crossbar-switch (CS) interference consisting of massive harmonics and artifacts when CS-based channel disequilibrium compensation is used. However, it is not an effective method for removing the interference from the turn-by-turn (TBT) beam position signal in CS working. In this paper, a method that combines wavelet packet transform and coefficient baseline shift techniques is proposed to remove the CS interference without distorting the actual TBT signal. This method starts with wavelet packet decomposition of the contaminated TBT signal, then wavelet coefficients are further processed by the baseline shift and finally the processed coefficients of whole subbands are reconstructed through filter banks to obtain a clean TBT signal. As a result, a clean and undistorted fast acquisition signal is obtained at a relatively slow rate through partial reconstruction without using a decimation filter and a notch filter. Results with synthetic and real TBT signals demonstrate the effectiveness of the proposed method. Moreover, the relative root mean square error and normalized correlation coefficient criteria are measured, which also show that the proposed method does not distort the actual TBT signal while removing the CS interference.
Variational robust filter with a heavy-tailed mixture model for GNSS/INS tightly coupled integration
Authors: Guo Baoyu , Tao Zhenqiang , Gao Jingxiang
Published: November 2024

In the tightly coupled integration of global navigation satellite systems (GNSS) and inertial navigation systems (INS) within complex environments, harsh observation conditions, signal multipath effects, and unknown pulse interference can easily lead to non-stationary heavy-tailed measurement noise. To address this challenge, in this paper, we first construct a heavy-tailed mixture (HM) model that is insensitive to prior noise statistics for modeling the likelihood probability density function. Subsequently, an improved variational Bayesian (VB) method is introduced to decouple the variational posterior updates for the state vector and the unknown parameters. Finally, an HM model-based variational robust filter (HMRKF) for GNSS/INS tightly coupled integration is proposed. The experimental results demonstrate that the HMRKF can adaptively infer the accurate measurement noise covariance matrix using the pre-selected measurement set and observation information, achieving an optimal estimation performance among the six schemes evaluated. Compared to the extended Kalman filter, the position, velocity, and yaw accuracy of the HMRKF are 56.66%, 76.35%, and 80.62% better, respectively. Additionally, the computational complexity of the improved VB method is more than 30% lower compared to the conventional VB method, significantly alleviating the algorithm’s computational burden. Therefore, the proposed HMRKF can ensure the integrated system’s navigation accuracy and robustness within non-stationary heavy-tailed noise environments.
A 3D calibration method for binocular vision system
Authors: He Qing , Ji Zhiwen , Li Qingying , Liu Xu
Published: November 2024

Binocular vision system calibration is extremely important in three-dimensional (3D) measurement. During the calibration process, the establishment of an appropriate objective function has a direct impact on the calibration accuracy. For common two-dimensional (2D) calibration methods, differences in 2D calibration and 3D measurement coordinate systems result in loss of accuracy. Furthermore, for the newly proposed 3D calibration methods, the epipolar constraints in the 2D pixel coordinate system and the reconstruction errors in the 3D physical space need to be balanced by weights, resulting in uncertainties in the calibration results. To address these issues, we propose a novel calibration method that minimizes the distances between the control point and the left and right camera rays. The distances between the control points and the camera rays describe the 3D reconstruction errors, and the distances between the left camera and the right camera rays describe the geometry information between the two cameras to ensure that the epipolar constraints are satisfied. As a result, these two types of constraints/errors are measured under the same 3D coordinate system. Therefore, the epipolar constraints and the reconstruction errors are naturally balanced. We have conducted computer simulations and real experiments, and the results show that the proposed calibration method is effective in improving the accuracy compared with the state-of-the-art methods.
A novel proposition of radiation energy conservation in radiation dose deformation using deformable image registration
Authors: Kim Jihun , Yoon Kyungho , Kim Jun Won , Kim Jin Sung
Published: November 2024

Objective. The purpose of this study is to analytically derive and validate a novel radiation energy conservation principle for dose mapping via deformable image registration (DIR). Approach. A radiation energy conservation principle for the DIR-based dose-deforming process was theoretically derived with a consideration of the volumetric Jacobian and proven using synthetic examples and a patient case. Furthermore, an energy difference error was proposed that can be used to evaluate the DIR-based dose accumulation uncertainty. For the analytical validation of the proposed energy conservation principle, a synthetic isotropic deformation was considered, and artificial deformation uncertainties were introduced. For the validation with a patient case, a ground truth set of computed tomography images and the corresponding deformation was generated. Radiation energy calculation was performed using both the ground truth deformation and another deformation with uncertainty. Main results. The suggested energy conservation principle was preserved with uncertainty-free deformation, but not with error-containing deformations using both the synthetic examples and the patient case. For a synthetic example with a tumor volume reduction of 27.1% (10% reduction in length in all directions), the energy difference error was calculated to be −29.8% and 37.2% for an over-deforming and under-deforming DIR uncertainty of 0.3 cm. The energy difference error for the patient case (tumor volume reduction of 37.6%) was 2.9% for a displacement vector field with a registration error of 2.0 ± 3.2 mm. Significance. A novel energy conservation principle for DIR-based dose deformation and the corresponding energy difference error were mathematically formulated and successfully validated using simple synthetic examples and a patient example. With a consideration of the volumetric Jacobian, this investigation proposed a radiation energy conservation principle which can be met only with uncertainty-free deformations.
Impact of deep and tail trap states on the electrical performance of double-gate ZnO thin film transistors
Authors: Jaiswal Saurabh , Singh Jitendra , Goswami Manish , Kandpal Kavindra
Published: November 2024

Traps in ZnO thin film transistors (TFTs) affect the electrical characteristics of the device. Traps originate primarily due to the disordered nature of the deposited semiconductor channel or are present at the ZnO and gate-dielectric interface. This work studies the effect of traps in double-gate ZnO TFTs using technology computer-aided design. The grain boundary and interface traps are assumed to be localized at the ZnO/SiO2 interface and are defined within the energy bandgap of ZnO using a double-exponential function. The traps are assumed to be of the acceptor type. The concentration of tail states is assumed to be 103 times more than in the deep state, while the characteristic temperature of deep state traps is assumed to be higher than the tail states. In common mode operation (i.e. both top and bottom gates are shorted), the tail states dominate the device characteristic compared with the deep state, while in independent mode (i.e. both gates are biased independently) the deep state traps affect the device characteristics more than the tail states.
Generation of non-Gaussian states of light using deterministic photon subtraction
Authors: Pasharavesh Abdolreza , Bajcsy Michal
Published: November 2024

We explore a recently demonstrated deterministic photon subtraction scheme, based on single-photon Raman interaction with a Λ-type three-level atom, as a tool for manipulating quantum state of few-photon light pulses. We establish a comprehensive theoretical framework using input–output formalism and quantum regression theorem, enabling calculation of the first order autocorrelation matrices of the output light and identification of the temporal modes present in the generated light via their eigendecomposition. By modeling the entire system as a quantum network consisting multiple virtual cavities and a lambda-type emitter cascaded in two parallel guided modes of opposite propagation directions, we extract the quantum state occupying the modes of interest. For both squeezed vacuum and coherent light input pulses, the Wigner function of the output light after photon subtraction clearly reveals its non-Gaussian character. Furthermore, we propose a measurement-based scheme on the subtracted photon which can lead to conditional generation of quantum states resembling Schrodinger’s kitten state directly from coherent input light with fidelities above 99%. This result is particularly nothworthy, as coherent pulses, unlike the squeezed vacuum inputs commonly used in previous studies, are readily available in most experimental setups.
Abundant families of Jacobi elliptic function solutions and peculiar dynamical behavior for a generalized derivative nonlinear Schrödinger equation employing extended F-expansion method
Authors: Chen Wenxia , Ni Weixu , Tian Lixin , Yang Xiyan
Published: November 2024

This study investigates a generalized derivative nonlinear Schrödinger (GDNLS) equation , demonstrating how ultrashort pulses propagate in a single-mode optical fiber. The extended F-expansion method, which is a modification of Kudryashov’s auxiliary equation approach, is applied in this investigation to generate Jacobi elliptic solutions for the GDNLS. Three distinct solution instances are examined, and a variety of explicit solutions, including breathers, solitary waves, bright/dark solitons, bright-dark interaction solitons, a soliton-like solution, and a rogue-like solution, are obtained. To demonstrate the complex dynamical behavior of GDNLS equation, several representative solutions are chosen and their moduli are shown in three-dimensional, two-dimensional, and contour plots using Maple software.
White light emitting potential of samarium and dysprosium co-doped tellurite glass: effect of various gold nanoparticles contents
Authors: Gafar Shairah , Ghoshal Sib Krishna , Abd Aziz Muhammad Safwan , Hamzah Khaidzir
Published: November 2024

This paper reports the influence of gold nanoparticle (Au NPs) concentration variation on the physical properties of some Sm3+/Dy3+ co-doped zinc-sodium tellurite glasses. These glasses with composition of (58.8–z) TeO2–25ZnO–15Na2O–0.8Sm2O3–0.4Dy2O3–zAu (where z = 0.02, 0.04, 0.06, 0.08, and 0.10 mol%) were prepared via the melt-quenching approach and characterized. The obtained samples were transparent and amorphous. An increase in the glass density and refractive index was observed with the increase of Au NPs concentrations. FTIR and Raman spectra of the glasses identified vibration modes related to various chemical functional groups. The temperatures for the glass transition, crystallization, and melting were changed with the variation of Au NPs contents. The optical absorption spectra of the glasses showed 16 characteristic peaks (in the range of 350–1700 nm) of Sm3+ and Dy3+ transitions together with the localized surface plasmon absorption peak of Au NPs. The luminescence spectra under 380 nm excitation showed five significant peaks around 400–750 nm. The fluorescence lifetime decay profiles and Commission Internationale de l'éclairage (CIE) 1391 color chromaticity diagram exhibited the corresponding moderate white-light emission and color purity, indicating the white-light-emitting potency of the proposed glass system. It was surmised that by controlling Au NPs contents, the optical characteristics of the glass system can be customized.
A novel SRAM with SET and RESET functions using a novel 5-input majority gate in quantum-dot cellular automata (QCA) technology
Authors: Rathore Nitesh Kumar , Singh Pooran
Published: November 2024

In the nanoscale VLSI industry, Quantum-dot Cellular Automata (QCA) presents a novel substitute for conventional Complementary Metal-Oxide-Semiconductor (CMOS) technology. This paper introduces a new design that uses QCA technology. The design includes a 5-input Majority Gate (5-MG), a fundamental component in QCA, and a Static Random Access Memory (SRAM) cell with set and reset features. The recommended design offers a minimum clock cycle, a small QCA layout area, less cost function, and a sustainable arrangement to get the ideal size and latency while consuming less power. The proposed 5-input majority gate (MG) has a total area of 0.009 μm2 and a QCA cell count of 14. Further, a novel SRAM cell is implemented using the 5-input MG logic. The SRAM cell designed using 44 QCA cells has a clock latency of 1 and a layout area of 0.03 μm2. Compared to the conventional 5-MG SRAM cell the proposed 5-MG SRAM cell shows a 50% reduction in cell counts and a 62.5% reduction in total layout area.
Efficient numerical techniques for fractional integro-differential equations with weakly singular kernel
Authors: Panda Abhilipsa , Ghosh Bappa , Mohapatra Jugal
Published: November 2024

This paper addresses two finite difference approaches for computing the numerical solution to a Volterra-type fractional integro differential equation with a weakly singular kernel. The problem is discretized on a uniform mesh using the L1 technique for the Caputo fractional order derivative, and the integral component is solved using the product left rectangular rule. The approach proves to be first-order convergent. To improve the order of accuracy, a post-processing approach namely the Richardson extrapolation scheme is used, and the convergence rate is greatly increased to second order. Another difference scheme is developed to address the model problem by using the product trapezoidal rule for the weakly singular integral and the L1 technique for the fractional derivative. The product trapezoidal rule has a greater convergence rate than the product rectangular rule, hence the latter method provides more accurate results even without extrapolation. The comoutational cost is also reduced in the second scheme which can be seen from the tabular results. The error analysis is performed for both the suggested numerical algorithms, and some numerical experiments are performed to confirm the theoretical results.
A favorable catalytic root for the reduction reaction of SOCl2 from the constructed CoPc/CuPc composite
Authors: Xu Zhanwei , Li Jiaxing , Zhang Ziwei , Yao Kai , Zhang Ke , Li Jiayin , Zhao Yaze , Li Zhi
Published: November 2024

CoPc, as a catalyst for lithium thionyl chloride (Li/SOCl2) battery, is generally recognized as having catalytic activity, and its catalytic activity can be further improved by compounding it on some substrates. In this paper, CoPc/CuPc with smaller particle size was synthesized by two-step method. It was found that when the product was constructed, not only a loose film could be formed on the surface of carbon cathode, but also a large number of holes could be formed inside it. In addition, the adsorption of SOCl2 by CoPc and CuPc and the surface electrostatic charge distribution was studied by the first-principles density functional theory calculations (DFT). Compared with the bare, the voltage of the battery using the CoPc/CuPc composites as catalyst increased by 0.25 V, and the discharge time was prolonged by 12 min. Observing the morphology after discharge, it can be found that there are many particles around 200 nm on the surface and a large number of particles around 50 nm inside.
The BlackGEM Telescope Array. I. Overview
Authors: Groot P. J. , Bloemen S. , Vreeswijk P. M. , van Roestel J. C. J. , Jonker P. G. , Nelemans G. , Klein-Wolt M. , Lepoole R. , Pieterse D. L. A. , Rodenhuis M. , Boland W. , Haverkorn M. , Aerts C. , Bakker R. , Balster H. , Bekema M. , Dijkstra E. , Dolron P. , Elswijk E. , van Elteren A. , Engels A. , Fokker M. , de Haan M. , Hahn F. , ter Horst R. , Lesman D. , Kragt J. , Morren J. , Nillissen H. , Pessemier W. , Raskin G. , de Rijke A. , Scheers L. H. A. , Schuil M. , Timmer S. T. , Antunes Amaral L. , Arancibia-Rojas E. , Arcavi I. , Blagorodnova N. , Biswas S. , Breton R. P. , Dawson H. , Dayal P. , De Wet S. , Duffy C. , Faris S. , Fausnaugh M. , Gal-Yam A. , Geier S. , Horesh A. , Johnston C. , Katusiime G. , Kelley C. , Kosakowski A. , Kupfer T. , Leloudas G. , Levan A. , Modiano D. , Mogawana O. , Munday J. , Paice J. , Patat F. , Pelisoli I. , Ramsay G. , Ranaivomanana P. T. , Ruiz-Carmona R. , Schaffenroth V. , Scaringi S. , Stoppa F. , Street R. , Tranin H. , Uzundag M. , Valenti S. , Veresvarska M. , Vuc̆ković M. , Wichern H. C. I. , Wijers R. A. M. J. , Wijnands R. A. D. , Zimmerman E.
Published: November 2024

The main science aim of the BlackGEM array is to detect optical counterparts to gravitational wave mergers. Additionally, the array will perform a set of synoptic surveys to detect Local Universe transients and short timescale variability in stars and binaries, as well as a six-filter all-sky survey down to ∼22nd mag. The BlackGEM Phase-I array consists of three optical wide-field unit telescopes. Each unit uses an f/5.5 modified Dall-Kirkham (Harmer-Wynne) design with a triplet corrector lens, and a 65 cm primary mirror, coupled with a 110Mpix CCD detector, that provides an instantaneous field-of-view of 2.7 square degrees, sampled at 0.″564 pixel−1. The total field-of-view for the array is 8.2 square degrees. Each telescope is equipped with a six-slot filter wheel containing an optimised Sloan set (BG-u, BG-g, BG-r, BG-i, BG-z) and a wider-band 440–720 nm (BG-q) filter. Each unit telescope is independent from the others. Cloud-based data processing is done in real time, and includes a transient-detection routine as well as a full-source optimal-photometry module. BlackGEM has been installed at the ESO La Silla observatory as of 2019 October. After a prolonged COVID-19 hiatus, science operations started on 2023 April 1 and will run for five years. Aside from its core scientific program, BlackGEM will give rise to a multitude of additional science cases in multi-colour time-domain astronomy, to the benefit of a variety of topics in astrophysics, such as infant supernovae, luminous red novae, asteroseismology of post-main-sequence objects, (ultracompact) binary stars, and the relation between gravitational wave counterparts and other classes of transients.
An audiovisual cognitive optimization strategy guided by salient object ranking for intelligent visual prothesis systems
Authors: Liang Junling , Li Heng , Chai Xinyu , Gao Qi , Zhou Meixuan , Guo Tianruo , Chen Yao , Di Liqing
Published: November 2024

Objective. Visual prostheses are effective tools for restoring vision, yet real-world complexities pose ongoing challenges. The progress in AI has led to the emergence of the concept of intelligent visual prosthetics with auditory support, leveraging deep learning to create practical artificial vision perception beyond merely restoring natural sight for the blind. Approach. This study introduces an object-based attention mechanism that simulates human gaze points when observing the external world to descriptions of physical regions. By transforming this mechanism into a ranking problem of salient entity regions, we introduce prior visual attention cues to build a new salient object ranking (SaOR) dataset, and propose a SaOR network aimed at providing depth perception for prosthetic vision. Furthermore, we propose a SaOR-guided image description method to align with human observation patterns, toward providing additional visual information by auditory feedback. Finally, the integration of the two aforementioned algorithms constitutes an audiovisual cognitive optimization strategy for prosthetic vision. Main results. Through conducting psychophysical experiments based on scene description tasks under simulated prosthetic vision, we verify that the SaOR method improves the subjects’ performance in terms of object identification and understanding the correlation among objects. Additionally, the cognitive optimization strategy incorporating image description further enhances their prosthetic visual cognition. Significance. This offers valuable technical insights for designing next-generation intelligent visual prostheses and establishes a theoretical groundwork for developing their visual information processing strategies. Code will be made publicly available.
Frequency-dependent phase entrainment of cortical cell types during tACS: computational modeling evidence
Authors: Gaugain Gabriel , Al Harrach Mariam , Yochum Maxime , Wendling Fabrice , Bikson Marom , Modolo Julien , Nikolayev Denys
Published: November 2024

Objective. Transcranial alternating current stimulation (tACS) enables non-invasive modulation of brain activity, holding promise for clinical and research applications. Yet, it remains unclear how the stimulation frequency differentially impacts various neuron types. Here, we aimed to quantify the frequency-dependent behavior of key neocortical cell types. Approach. We used both detailed (anatomical multicompartments) and simplified (three compartments) single-cell modeling approaches based on the Hodgkin–Huxley formalism to study neocortical excitatory and inhibitory cells under various tACS intensities and frequencies within the 5–50 Hz range at rest and during basal 10 Hz activity. Main results. L5 pyramidal cells (PCs) exhibited the highest polarizability at direct current, ranging from 0.21 to 0.25 mm and decaying exponentially with frequency. Inhibitory neurons displayed membrane resonance in the 5–15 Hz range with lower polarizability, although bipolar cells had higher polarizability. Layer 5 PC demonstrated the highest entrainment close to 10 Hz, which decayed with frequency. In contrast, inhibitory neurons entrainment increased with frequency, reaching levels akin to PC. Results from simplified models could replicate phase preferences, while amplitudes tended to follow opposite trends in PC. Significance. tACS-induced membrane polarization is frequency-dependent, revealing observable resonance behavior. Whilst optimal phase entrainment of sustained activity is achieved in PC when tACS frequency matches endogenous activity, inhibitory neurons tend to be entrained at higher frequencies. Consequently, our results highlight the potential for precise, cell-specific targeting for tACS.
Simulation study on the frequency modulation of sawtooth oscillation by plasma shape in tokamak
Authors: Zhang 张 Peijie 培杰 , Yang 杨 Jinhong 锦宏 , Ren 任 Zhenzhen 珍珍 , Xiao 肖 Zheng 政 , Chu 楚 Jiaxuan 家璇 , Kuang 邝 Jun 俊 , Wang 汪 Weihua 卫华
Published: November 2024

This study numerically investigates the impact of the tokamak plasma shape (elongation, triangularity, and aspect ratio) on the amplitude and period of sawtooth oscillations using the three-dimensional toroidal nonlinear magnetic fluid code CLT and the simulation results are qualitatively compared with the experimental observation in Tokamak Configuration Variable. The study reveals a frequency modulation phenomenon for the sawtooth period with respect to the elongation and aspect ratio. (1) The simulation results of the sawtooth linear phase show that a large elongation and a positive triangularity are beneficial for the stability of the internal kink mode, while a negative triangularity has limited effect on the stability of the internal kink mode. (2) The simulation results of the sawtooth oscillation phase show that the sawtooth period generally increases with the increase of elongation. However, when the elongation is relatively small, there is a significant peak in the sawtooth period, and this peak position is modulated by elongation and aspect ratio. Analysis suggests that the peak of the sawtooth period is caused by the occurrence of m/n = 3/2 mode during the sawtooth crashes. (3) The sawtooth period exhibits a monotonic increasing relation with the triangularity, while the sawtooth amplitude increases with both the elongation and triangularity.
Laser-cooling Cadmium Bosons and Fermions with Near Ultraviolet Triplet Excitations
Authors: Gibble Kurt
Published: November 2024

Cadmium is laser-cooled and trapped with excitations to triplet states with UVA light, first using only the 67 kHz wide 326 nm intercombination line and subsequently, for large loading rates, the 25 MHz wide 361 nm 3
P
2 → 3
D
3 transition. Eschewing the hard UV 229 nm 1
S
0 → 1
P
1 transition, only small magnetic fields gradients, less than 6 G cm−1, are required enabling a 100% transfer of atoms from the 361 nm trap to the 326 nm narrow-line trap. All 8 stable cadmium isotopes are straightforwardly trapped, including two nuclear-spin-

1
2

fermions that require no additional repumping. We observe evidence of 3
P
2 collisions limiting the number of trapped metastable atoms, report isotope shifts for 111Cd and 113Cd of the 326 nm 1
S
0 → 3
P
1, 480nm 3
P
1 → 3
S
1, and 361 nm 3
P
2 → 3
D
3 transitions, and measure the 114Cd 5s5p 3
P
2 → 5s5d 3
D
3 transition frequency to be 830 096 573(15) MHz.
Techniques on Crystal Oscillator Vibration Compensation
Authors: Mossammaparast M , Mullin P , Ronchetti L , Koehler R , Tiches N
Published: November 2024

Oven Controlled Crystal Oscillators (OCXOs) have been employed for precision timing and frequency distribution and synchronization applications, such as telecommunication, instrumentation, and test equipment in today’s Commercial, Military, Scientific, Space and Low Earth Orbit markets. Since 1978, Wenzel Laboratory has been researching and developing outstanding performance oscillators to provide the lowest phase noise, as low as -190dBc/Hz, and highest short-term stability for these markets. In this paper, various compensation techniques developed at Quantic Wenzel are discussed and compared. Quantic Wenzel employs such techniques to greatly improve the stability of its OCXOs in various mild to harsh vibration environments. Consequently, this lends itself to provide quieter performance in multiple applications, whether OCXOs are exposed to micro-vibration environments caused by disturbance sources onboard spacecraft or noisy environments such as a jet aircraft landing or taking off on a carrier. An example of a compact microcontroller-based vibration compensated OCXO developed at Quantic Wenzel will be presented. Such digitally controlled OCXOs can also be employed to correct for thermal drift or errors in GPS location when GPS signals become unavailable in telecom and navigation systems.
Towards Compact, Robust and Highly Stable Optical Frequency References for Space Applications
Authors: Wegehaupt T , Gohlke M , Kuschewski F , Oswald M , Abich K , Alam T , Blomberg T , Bischof J , Bußmeier A , Röder N , Wüst J , Grosse J , Sanjuan J , Schuldt T , Braxmaier C
Published: November 2024

Future space missions from different fields of applications, like global navigation satellite systems (GNSS), next generations of gravity missions or tests of fundamental physics will rely on optical frequency references. While laboratory setups of various optical frequency reference technologies already demonstrate frequency stabilities orders of magnitude better than current microwave references for space applications, another step must be accomplished for high performance optical references in space. One promising technology for this is Doppler-free spectroscopy of molecular iodine, for which we have already developed several iterations of laboratory setups with frequency instabilities down to the 10−15 level for integration times > 100 s. Based on the experience gained from this laboratory setups, we are now working on an iodine reference that will become the first optical clock in space as part of the COMPASSO mission. It will be delivered to the international space station in 2026 for a mission time of 2 years. In addition to the iodine development, we are currently working on a next iteration of a high-finesse optical cavity designed with emphasis on space compatibility to meet the requirements of the next generation of gravity missions. Both technologies together, the iodine spectroscopy unit and the high-finesse optical cavity, should form a hybrid setup suitable for new GNSS architectures.
DSAC and next generation high stability, long life trapped mercury ion frequency standards
Authors: Burt E.A. , Ely T.A. , Tjoelker R.L.
Published: November 2024

The methods of trapping and cooling of atoms and ions have been transformative for atomic clocks due to the reduction, and in some cases elimination, of major systematic frequency shifts. Continuously operating atomic clocks based on trapped mercury ions have existed for decades but until recently have been restricted to terrestrial applications. The recently completed Deep Space Atomic Clock (DSAC) mission demonstrated the first trapped ion clock operation in space. Here we review DSAC as well as follow-on improvements towards the realization of high stability, long life Hg ion atomic clocks for foreseen ground and flight application.