bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and prototype test of a high-sensitivity reentrant-cavity based Schottky pickup
Authors: Wang Minwen , Zhuo Xin , Zhao Mingtong , Qiu Mengtong , Chen Wei , Wang Zhongming 
Published: March 2023

Schottky diagnostics is an important measure for the debunched beam during the injection phase of the Xi’an Proton Application Facility (XiPAF). The existing capacitive Schottky pickup has a relatively low sensitivity and a poor signal-to-noise ratio for the low-intensity beam. A resonant Schottky pickup based on the principle of a reentrant cavity is proposed. The effects of cavity geometric parameters on cavity properties are systematically studied. A prototype was built and tested to validate the simulation results. The prototype has a resonance frequency of 24.23 MHz, a Q value of 635, and a shunt impedance of 19.75 kΩ. The resonant Schottky pickup has the capability to detect as few as 2.3 × 106 protons with an energy of 7 MeV and a momentum spread of about 1% at the injection phase of XiPAF. The sensitivity is two orders of magnitude higher than the existing capacitive pickup.
Fabrication and performance of a nickel-chromium (NiCr) igniter integrated with TVS diode for ESD protection
Authors: Liu Wei , Ren Xiao-ming , Xie Rui-zhen , Liu Lan , Yu Ke-xin , Ji Xiang-fei , Ren Wei , Chu En-yi 
Published: March 2023

The NiCr igniter is a key element of MEMS-based electro-explosive device (mEED), while electrostatic discharge (ESD) may excite the igniter accidentally. To protect the NiCr igniter from damage by ESD, a novel NiCr igniter by integrating the igniter onto a TVS diode based substrate was designed and fabricated through semiconductor technology. The microscope photograph, resistivity, breakdown voltage, firing performance, and ESD protection ability were tested. The results show that the surface of the chip is smooth, the edges of key structures are clear, and there are no major scratches, cracks, and other phenomena on the whole device. The resistivity of all the TVS-mNiCr igniters is between 5 and 7 Ω, and the TVS diode resistance value is normal. The breakdown voltages of the eight types of TVS diodes with different structures are all between 3.5 and 5 V, and the TVS-mNiCr igniters can fire reliably at a constant current of 2 A. After the ESD test, the microscope of the igniter does not change significantly, meaning that the TVS-mNiCr igniter chip has a certain ability of ESD protection. It is of vital importance to guide the design of electrostatic tolerant ability for the MEMS-based electro-explosive device.
Legume persistence for grasslands in tableland environments of south-eastern Australia
Authors: Hayes Richard C. , Newell Matthew T. , Li Guangdi D. , Haling Rebecca E. , Harris Carol A. , Culvenor Richard A. , Badgery Warwick B. , Munday Neil , Price Andrew , Stutz Rebecca S. , Simpson Richard J. 
Published: March 2023

Context Improving the stability of legumes in grasslands in the face of variable seasonal conditions is key to mitigating risks posed by drought. Aims We assessed the persistence of a range of legume species and cultivars in order to inform legume choice for pasture improvement and identify priority species for further development. Methods Twenty field experiments in four series were conducted at sites with contrasting seasonal and soil characteristics in the ‘high-rainfall’ (560–920 mm long-term average) Tablelands and Monaro regions of New South Wales, Australia. Legumes were grown as pure swards and assessed periodically for seedling density, plant frequency and dry matter for up to 5 years. Key results Legume dry matter production was positively correlated with plant frequency. However, most legumes persisted poorly at most sites, particularly on soils of lower fertility. Subterranean clover (Trifolium subterraneum) cv. Goulburn was the best performing cultivar of that species across sites on the Southern Tablelands and Monaro. Yellow serradella (Ornithopus compressus) cvv. Avila and Yellotas showed promising persistence, particularly under drought conditions. White clover (T. repens) was the most broadly adapted of the perennial legumes across a range of soils, but persistence was still inadequate at many sites. Lucerne (Medicago sativa) was approximately twice as productive as the next-most productive species when soil conditions suited its growth, but it failed to persist on acidic, low-fertility soils. Conclusions Serradella species (yellow and French, O. sativus) and white clover, in conjunction with subterranean clover, offer the best near-term prospects for diversifying legume productivity and resilience under variable seasonal conditions in tableland environments. Implications An increased focus on phenology and seed characteristics is suggested to improve the persistence of annual and facultative perennial legume species in grasslands. Serradella and white clover are identified as the highest priorities for cultivar development for tableland environments of south-eastern Australia.
An attention-based long short-term memory prediction model for working conditions of copper electrolytic plates
Authors: Zhu Hongqiu , Peng Lei , Zhou Can , Dai Yusi , Peng Tianyu 
Published: March 2023

Abstract
Copper is an important source of non-ferrous metals, with electrolytic refining being one of the main methods to produce fine copper. In the electrolytic process, plate states seriously affect the output and quality of the copper. Therefore, timely and accurate prediction of the working states of the plates is of great significance to the copper electrolytic refining process. Aiming at the issues associated with traditional plate state detection algorithms of large lag, poor anti-interference ability and low accuracy, a plate state prediction model based on a long short-term memory (LSTM) neural network with an attention mechanism is here proposed in this paper. The average gray values of the plates in infrared imagery are used to characterize the plates’ working states. To address the problems of large fluctuation and the large amount of time series data required in such a study, a double-layer LSTM neural network structure is used to improve the efficiency and accuracy of model training. Meanwhile, in view of the periodicity of the time series data and the possible correlation between adjacent data, a unique attention mechanism is proposed to enable the model to learn this correlation between the adjacent data so as to improve the accuracy of the model prediction. The experimental results show that the accuracy of the proposed model for plate state prediction reaches 95.11%. Compared with commonly used prediction algorithms, the plate state prediction model proposed in this paper demonstrates stronger prediction ability.
T
2 orientation anisotropy mapping of articular cartilage using qMRI
Authors: Leskinen Henri P P , Hänninen Nina E , Nissi Mikko J 
Published: March 2023

Abstract

Objective. To provide orientation-independent MR parameters potentially sensitive to articular cartilage degeneration by measuring isotropic and anisotropic components of T
2 relaxation, as well as 3D fiber orientation angle and anisotropy via multi-orientation MR scans. Approach. Seven bovine osteochondral plugs were scanned with a high angular resolution of thirty-seven orientations spanning 180° at 9.4 T. The obtained data was fitted to the magic angle model of anisotropic T
2 relaxation to produce pixel-wise maps of the parameters of interest. Quantitative Polarized Light Microscopy (qPLM) was used as a reference method for the anisotropy and fiber orientation. Main results. The number of scanned orientations was found to be sufficient for estimating both fiber orientation and anisotropy maps. The relaxation anisotropy maps demonstrated a high correspondence with qPLM reference measurements of the collagen anisotropy of the samples. The scans also enabled calculating orientation-independent T
2 maps. Little spatial variation was observed in the isotropic component of T
2 while the anisotropic component was much faster in the deep radial zone of cartilage. The estimated fiber orientation spanned the expected 0°–90° in samples that had a sufficiently thick superficial layer. The orientation-independent magnetic resonance imaging (MRI) measures can potentially reflect the true properties of articular cartilage more precisely and robustly. Significance. The methods presented in this study will likely improve the specificity of cartilage qMRI by allowing the assessment of the physical properties such as orientation and anisotropy of collagen fibers in articular cartilage.
Asymmetrical ignition of radio frequency discharge in atmospheric pressure cascade glow discharges
Authors: Zhang Yarong , Fang Junlin , Xu Shaofeng , Guo Ying , Shi Jianjun 
Published: March 2023

Abstract
A two-dimensional self-consistent fluid model was developed to investigate the ignition of radio frequency (RF) discharge in an atmospheric helium cascade glow discharge. In particular, the model considers the case where a pulsed discharge is excited ahead of the RF discharge by applying pulsed DC voltage and RF voltage to two parallel plate electrodes separately. The spatio-temporal distribution of electron, ion, electric field, and mean electron energy demonstrate that the electron and ion localize in the vicinity of RF electrode with the extinguishment of pulsed discharge, whereas a sheath region formed above the pulsed electrode due to the space charge. It explains the experimental findings of asymmetric ignition of RF discharge in the interelectrode gap. With the migration of ion towards the pulsed electrode, the RF discharge achieves the stable operation. Furthermore, the migration time of ion from the RF electrode to pulsed electrode is estimated to be 3.0 μs, which is consistent with the calculated migration time of ions across the discharge gap.
Design and proof-of-concept of an advanced protective system for the dissipation of tangential impact energy in helmets, based on non-Newtonian fluids
Authors: La Fauci Giuseppe , Parisi Mariafederica , Nanni Alessandro , Crosetta Lorenzo , Pugno Nicola M , Colonna Martino 
Published: March 2023

AbstractWe have designed and tested a device based on non-Newtonian fluids for the attenuation of tangential impacts energy in helmets. A shear thickening fluid based on borurated silicones has given the best results in terms of impact energy attenuation in a system that selectively mimics tangential impacts and for this reason it has been used to fill the chamber of a pad, prepared by additive manufacturing, for impact energy dissipation. The pad is composed of a case containing the fluid in which is immersed a rigid pin that is free to move in all direction and therefore is able to absorb energy during its movement inside the fluid. A motorcycle helmet, already composed of two concentrical expanded polystyrene (EPS) liners, has been implemented with seven pads between the two EPS layers. The two layers have only been connected by means of the dissipating pad and are free to rotate and to dissipate energy during the rotation. The results of oblique impacts according to ECE 22.06 with three impact positions, shows a reduction of the brain injury criterion of 14% for the helmet with the pads, compared to the standard helmet, with values well below the threshold imposed by the norm. On the contrary, the maximum of the peak rotational acceleration show a 3% increase. Nevertheless, the rotational acceleration versus time curves indicates that in all three orientations the time of the maximum is shifted towards longer times for the helmets with the pads, indicating that the pads retard the acceleration of the head due to the efficient rotation of the two EPS parts connected by the pads. The described system could be implemented with minimal modifications in existing protective sport and motorcycle helmets.
Emerging (2+1) D massive graviton in graphene-like systems
Authors: Salgado-Rebolledo Patricio , Pachos Jiannis K 
Published: March 2023

AbstractUnlike the fundamental forces of the Standard Model the quantum effects of gravity are still experimentally inaccessible. Rather surprisingly quantum aspects of gravity, such as massive gravitons, can emerge in experiments with fractional quantum Hall liquids. These liquids are analytically intractable and thus offer limited insight into the mechanism that gives rise to quantum gravity effects. To thoroughly understand this mechanism we employ a graphene-like system and we modify it appropriately in order to realise simple(2+1)-dimensional massive gravity model. More concretely, we employ(2+1)-dimensional Dirac fermions, emerging in the continuous limit of a fermionic honeycomb lattice, coupled to massive gravitons, simulated by bosonic modes positioned at the links of the lattice. The quantum character of gravity can be determined directly by measuring the correlations on the bosonic atoms or by the interactions they effectively induce on the fermions. The similarity of our approach to current optical lattice configurations suggests that quantum signatures of gravity can be simulated in the laboratory in the near future, thus providing a platform to address question on the unification theories, cosmology or the physics of black holes.
Validation of the New Small Wheel Micromegas sectors for the phase 1 upgrade of the muon forward spectrometer of the ATLAS experiment at CERN
Authors: Mancini G 
Published: March 2023

Abstract
The ATLAS experiment is currently upgrading the first muon station in the high-rapidity region with the New Small Wheels (NSW), based on large-size resistive Micromegas (MM) technology and small-strip Thin Gap Chambers (sTGC). The NSW system is going to be installed in the ATLAS underground cavern during the LHC long shutdown 2 (2021) to enter in operation for Run3 (starting in the first months of 2022). 128 Micromegas quadruplets, each composed by four measurement layers two to three square meters in size, are needed to build the two New Small Wheels, covering a total active area of about 1280 m2. The construction of all MM modules, carried out in France, Germany, Italy, Russia and Greece, is completed. Their mechanical integration into sectors, the installation of on-detector services and electronics, for the first NSW is also completed, along with all validation and acceptance tests. The preparation of the second NSW is very well advanced. The advanced status of the project, in view of the imminent installation of the two NSW in ATLAS by the fall of 2021 will be reported. Micromegas detector construction and integration into sectors is presented, together with results obtained with cosmic rays data during the validation tests and the impressive steps of the wheel assembly completion.
A-optimal active learning
Authors: Boesen Tue , Haber Eldad 
Published: March 2023

Abstract
In this work we discuss the problem of active learning. We present an approach that is based on A-optimal experimental design of ill-posed problems and show how one can optimally label a data set by partially probing it, and use it to train a deep network. We present two approaches that make different assumptions on the data set. The first is based on a Bayesian interpretation of the semi-supervised learning problem with the graph Laplacian that is used for the prior distribution and the second is based on a frequentist approach, that updates the estimation of the bias term based on the recovery of the labels. We demonstrate that this approach can be highly efficient for estimating labels and training a deep network.
An accurate operational matrix method based on Lagrange polynomials for solving fractional-order pantograph delay and Riccati differential equations
Authors: Kumar Saurabh , Gupta Vikas , Kumar Ajay , Gómez-Aguilar J F 
Published: March 2023

Abstract
This paper introduces the fractional-order Lagrange polynomials approach to solve initial value problems for pantograph delay and Riccati differential equations involving fractional-order derivatives. The fractional derivative is determined as per the idea of Caputo. First, operational matrices of fractional integration with fractional-order Lagrange polynomials have been constructed using the Laplace transform. Then, we use these operational matrices and the collocation method to convert the given initial value problem to a system of algebraic equations. Subsequently, we use Newton’s iterative approach to solve the resultant system of algebraic equations. Error estimates for the function approximation also have been discussed. Finally, some numerical examples supported the theoretical findings by demonstrating the applicability and accuracy of the proposed strategy.
Ion acoustic solitons collision in spin-polarized relativistic quantum plasma
Authors: Gul Nabi , Zain Kanwal , Ahmad Rashid 
Published: March 2023

Abstract
The dynamics of electrostatic ion acoustic solitons collision in relativistic magnetized spin-polarized plasma is studied using a Magnetized Relativistic Quantum Hydrodynamics model. The plasmas components are relativistic degenerate electron with spin-up (n

e↑) and spin-down (n

e↓) concentrations, and relativistic inertial classical ions. In two-dimensional plasma geometry, a homogeneous external magnetic field is provided along the z-direction, i.e.

B
=

B

0

z

ˆ

. The extended Poincare Lighthill Kuo (PLK) approach is used to calculate the Kortewegde Vries equations for oppositely moving ion-acoustic solitons. Before and after collision, their trajectories and associated phase shifts are computed. Only negative polarity pulses of ion acoustic solitons are observed in our stated relativistic magnetized plasma. The spin density popularization ratio κ is shown to have a significant impact on the phase shifts of colliding solitons. It is found that when κ increases, one soliton's phase shift increases while the other soliton's phase shift decreases. The relativistic effects are also analyzed numerically and found that the phase shift of colliding ions acoustic solitons grows as the relativistic component rises from weakly to ultra-relativistic. It is observed that the phase shift of both solitons is to be dependent on their phase velocity with each other. Our research is noteworthy in that it focuses on, the astrophysical systems such as white dwarf, neutron star and pulsar.
P-bifurcation phenomena of the non-smooth modified rayleigh-duffing oscillator under the combined action of harmonic excitation and noise perturbation
Authors: Ma Shichao , Wang Liang , Zhang Jinxiu , Jia Wantao 
Published: March 2023

Abstract
In this paper, the stochastic dynamics of a modified Rayleigh-Duffing oscillator with Coulomb frictional damping and elastic impact is investigated under combined harmonic and noise excitations. On the premise of retaining the non-smooth properties, a non-smooth steady-state probability density response numerical calculation method is introduced by taking advantage of Markov process. Utilizing this method, the stochastic P-bifurcation phenomena of oscillators without and with externally excitation are discussed in detail by inscribing changes in the topology of the steady-state probability density function. It is displayed that certain nonlinear damping coefficient and external excitation amplitude change the structure of the response, and that both the friction coefficient and the elastic coefficient of the contact surface induce stochastic P-bifurcation phenomena in systems without and with harmonic excitation, respectively. This study reveals the effect of non-smooth factors on the stability of the Rayleigh-Duffing oscillator.
Supercool subtleties of cosmological phase transitions
Authors: Athron Peter , Balázs Csaba , Morris Lachlan 
Published: March 2023

Abstract
We investigate rarely explored details of supercooled cosmological first-order phase transitions at the electroweak scale, which may lead to strong gravitational wave signals or explain the cosmic baryon asymmetry. The nucleation temperature is often used in phase transition analyses, and is defined through the nucleation condition: on average one bubble has nucleated per Hubble volume. We argue that the nucleation temperature is neither a fundamental nor essential quantity in phase transition analysis. We illustrate scenarios where a transition can complete without satisfying the nucleation condition, and conversely where the nucleation condition is satisfied but the transition does not complete. We also find that simple nucleation heuristics, which are defined to approximate the nucleation temperature, break down for strong supercooling. Thus, studies that rely on the nucleation temperature — approximated or otherwise — may misclassify the completion of a transition. Further, we find that the nucleation temperature decouples from the progress of the transition for strong supercooling. We advocate use of the percolation temperature as a reference temperature for gravitational wave production, because the percolation temperature is directly connected to transition progress and the collision of bubbles. Finally, we provide model-independent bounds on the bubble wall velocity that allow one to predict whether a transition completes based only on knowledge of the bounce action curve. We apply our methods to find empirical bounds on the bubble wall velocity for which the physical volume of the false vacuum decreases during the transition. We verify the accuracy of our predictions using benchmarks from a high temperature expansion of the Standard Model and from the real scalar singlet model.
A C-shaped miniaturized coil for transcranial magnetic stimulation in rodents
Authors: Jiang Wenxuan , Isenhart Robert , Liu Charles Y , Song Dong 
Published: March 2023

Abstract

Objective. Transcranial magnetic stimulation (TMS) is a non-invasive technique widely used for neuromodulation. Animal models are essential for investigating the underlying mechanisms of TMS. However, the lack of miniaturized coils hinders the TMS studies in small animals, since most commercial coils are designed for humans and thus incapable of focal stimulation in small animals. Furthermore, it is difficult to perform electrophysiological recordings at the TMS focal point using conventional coils. Approach. We designed, fabricated, and tested a novel miniaturized TMS coil (4-by-7 mm) that consisted of a C-shaped iron powder core and insulated copper wires (30 turns). The resulting magnetic and electric fields were characterized with experimental measurements and finite element modeling. The efficacy of this coil in neuromodulation was validated with electrophysiological recordings of single-unit activities (SUAs), somatosensory evoked potentials (SSEPs), and motor evoked potentials (MEPs) in rats (n = 32) following repetitive TMS (rTMS; 3 min, 10 Hz). Main results. This coil could generate a maximum magnetic field of 460 mT and an electric field of 7.2 V m−1 in the rat brain according to our simulations. With subthreshold rTMS focally delivered over the sensorimotor cortex, mean firing rates of primary somatosensory and motor cortical neurons significantly increased (154

±

5% and 160

±

9% from the baseline level, respectively); MEP and SSEP amplitude significantly increased (136

±

9%) and decreased (74

±

4%), respectively. Significance. This miniaturized C-shaped coil enabled focal TMS and concurrent electrophysiological recording/stimulation at the TMS focal point. It provided a useful tool to investigate the neural responses and underlying mechanisms of TMS in small animal models. Using this paradigm, we for the first time observed distinct modulatory effects on SUAs, SSEPs, and MEPs with the same rTMS protocol in anesthetized rats. These results suggested that multiple neurobiological mechanisms in the sensorimotor pathways were differentially modulated by rTMS.