bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatio-temporal analysis of power deposition and vibrational excitation in pulsed N2 microwave discharges from 1D fluid modelling and experiments
Authors: Altin M , Viegas P , Vialetto L , van Rooij G J , Diomede P 
Published: March 2024

Abstract
Vibrational excitation of N2 beyond thermodynamic equilibrium enhances the reactivity of this molecule and the production of radicals. Experimentally measured temporal and spatial profiles of gas and vibrational temperature show that strong vibrational non-equilibrium is found in a pulsed microwave discharges at moderate pressure (25 mbar) in pure N2 outside the plasma core and as an effect of power pulsing. A one dimensional radial time-resolved self-consistent fluid model has been developed to study the mechanism of formation of vibrationally excited N2. In addition to the temperature maps, time-resolved measurements of spontaneous optical emission, electron density and electron temperature are used to validate the model and the choice of input power density. The model reveals two regions in the plasma: a core where chemistry is dominated by power deposition and where vibrational excitation starts within the first ∼10 µs and an outer region reliant on radial transport, where vibrational excitation is activated slowly during the whole length of the pulse (200 µs). The two regions are separated by a sharp gradient in the estimated deposited power density, which is revealed to be wider than the emission intensity profile used to estimate the plasma size. The low concentration of excited species outside the core prevents the gas from heating and the reduced quenching rates prevent the destruction of vibrationally excited N2, thereby maintaining the observed high non-equilibrium.
Electrical characteristics of the GEC reference cell at low pressure: a two-dimensional PIC/MCC modeling study
Authors: Chen Zili , Wang Hongyu , Yu Shimin , Wang Yu , Chen Zhipeng , Jiang Wei , Schulze Julian , Zhang Ya 
Published: March 2024

Abstract
The electrical characteristics of the Gaseous Electronics Conference reference cell at low pressures are investigated using a two-dimensional electrostatic implicit particle-in-cell/Monte Carlo collision model in cylindrical coordinates. The coupling between the complex reactor geometry and the external circuit is included via an equivalent capacitance calculated from the electric energy density and the charge conservation equation. The results of this model are compared with experimental measurements and other model calculations and show agreement. The plasma series resonance effect, closely related to electron heating, is observed in this numerical simulation of a strongly asymmetric reactor at low pressures. The plasma kinetics of the capacitively coupled discharge and details of the external circuit response, including electrical waveforms and higher-order harmonics, are discussed at different pressures, which provides important insights for understanding the power coupling mechanisms in capacitively coupled discharges.
A novel MOSFET with lateral–vertical charge coupling for extremely low C
gd
Authors: Wang Tongyang , Li Zehong , Li Luping , Yang Yang , Zhao Yishang , Xia Ziming , Zheng Yige , Ye Jun , Xiao Xuan 
Published: March 2024

Abstract
A novel MOSFET with lateral–vertical charge coupling (LVCC-MOSFET) is proposed in this paper. Lateral charge coupling is enabled by a metal field plate, lightly doped drain and P-Epi layer to reduce the C
gd. Vertical charge coupling is enabled by a shield gate, sinker and P-Epi layer to support a high breakdown voltage (BV) and further reduce the C
gd. By combining both lateral charge coupling and vertical charge coupling, which is first proposed in low-voltage power MOSFETs, the trade-off relationship between BV, R
on and C
gd can be significantly improved. It is verified by both small-signal analysis and transient capacitance simulation that the gate-to-drain capacitance of the proposed LVCC-MOSFET can be reduced by more than 99% without deterioration of BV and R
on. The LVCC-MOSFET achieves 93.7% reduction in Q
gd, and R
on × Q
gd is only 0.81 mΩ·nC, which is reduced by 93.9%. Furthermore, E
on and E
off can be reduced by 73.6% and 53.8%, respectively. The hot carrier injection reliability can be enhanced by reducing the electric field and the impact ionization generation rate near the drain-side gate oxide. Moreover, the LVCC-MOSFET can be feasibly manufactured with compatible fabrication process flow, and only three extra steps are needed.
Dual-band filtering and enhanced directional via tunable acoustic metamaterial antennas
Authors: Xiao Jiawei , Ding Xiaoxi , Pan Huafei , Zhang Ying , He Qingbo , Shao Yimin 
Published: March 2024

Abstract
The detection of acoustic signals in strong background noise plays a crucial role in industrial non-destructive, mechanical equipment health monitoring and acoustic communication. The major bottleneck of this technology lies in the limited high-sensitivity and high-directivity of acoustic sensors. Here, this study proposes a tunable acoustic metamaterial antenna (TAMAA) with a double bandgap and near-zero refractive index. Different from the traditional geometric scatterer, a gear-shaped structure is introduced to enhance the controllability of the acoustic system. We theoretically demonstrate the physical properties of the structure with a double bandgap and near-zero refractive index. Remarkably, the gear-shaped honeycomb lattice structure exhibits an adjustable bandgap region, which enables the multiplexing of both acoustic shielding and acoustic enhancement functions by controlling the rotation angle of the scatterer. Furthermore, through numerical computational and experimental studies, we demonstrate that the proposed TAMAA exhibits dual-band filtering capabilities and provides excellent acoustic directional enhancement. Moreover, it allows for the recovery of weak acoustic signals even in the presence of extremely low signal-to-noise ratio and strong spatial noise interference. This work breaks through the detection limits of conventional acoustic sensing systems and provides new ideas for the development of acoustic sensing detection.
A novel adjustable magnetorheological fluid gradient material of low frequency vibration isolation: a theoretical and experimental study
Authors: Sun Zebang , Zhao Dan , Dong Liqiang , Qi Jinming , Guo Chang , Liu Shaogang 
Published: March 2024

Abstract
In this paper, a novel adjustable magnetorheological fluid (MRF) gradient material for low-frequency control is proposed, and the vibration isolation performance of this gradient material is investigated theoretically and experimentally. The gradient material has an excellent ability to control the sound waves and vibrations. However, the currently prepared gradient material does not have the parameter adjustability. At the same time, the MRF can change its material parameters according to the external magnetic field. After applying the traveling magnetic field (TMF) to the MRF with continuously varying and adjustable magnetic induction strength, its material parameters will also be continuously varying and adjustable to constitute an adjustable gradient material. In order to investigate the vibration transfer characteristics of this adjustable gradient material, this paper establishes a micro-mechanical model of MRF and theoretically investigates and numerically calculates the mechanical impedance and vibration transfer characteristics of the adjustable gradient material through the machine-electric analogy theory. At the same time, experimental research was conducted by building an experimental platform to conduct experiments. The results show that the novel adjustable gradient material composed of a TMF and MRF has a good vibration suppression effect in the low-frequency range (10 ∼ 60 Hz) with the vibration level difference of up to 30 dB or more, which has a broad application prospect in the field of vibration control.
Design and analysis of an extended buckled beam piezoelectric energy harvester subjected to different axial preload
Authors: Sun Wen-Po , Su Wei-Jiun 
Published: March 2024

Abstract
In this paper, a piezoelectric energy harvester composed of a buckled beam and an extended beam with a tip mass is proposed. This study develops a mathematical model and a prototype of the energy harvester. The performance of the energy harvester is influenced by the axial load applied at the end of the buckled beam. Under an axial force below the critical load, the energy harvester exhibits a pre-buckling state with a hardening nonlinear characteristic. Conversely, when the axial force exceeds the critical load, a post-buckling state with a softening nonlinear characteristic is observed. Simulation results are validated through experiments, and the relationship between axial displacement and axial force is obtained through experimental data. Moreover, increasing the tip mass enhances the output voltage under the same acceleration. The energy harvester demonstrates superior performance in terms of output power and strain distribution compared to a cantilever counterpart.
An invertible hysteresis model for magnetorheological damper with improved adaption capability in frequency and amplitude
Authors: Xing Xudong , Chen Zhaobo , Yu Dong , Feng Zhongqiang , Liu Yuechen 
Published: March 2024

Abstract
It is found during the tests that the damping characteristics of the magnetorheological (MR) damper vary with the excitation amplitude and frequency. However, the existing MR damper models are not able to accommodate the change of excitation amplitude and frequency, which will lead to significant modeling errors. To deal with this problem, this paper analyzes the experimental data and obtains the regularity of the damping characteristics varying with the excitation. Subsequently, an excitation-adaptive MR damper model is constructed based on the hyperbolic tangent function. The proposed model is not only able to adapt to the change of excitation amplitude and frequency but also able to inverse, which is essential for MR damper controller construction. The fitting results show that compared with the existing models, the three normalized errors of the proposed model are improved from 22.61%, 13.96%, and 19.42%–6.30%, 3.81%, and 6.97%, respectively, indicating that the model excitation adaptivity is significantly improved. Furthermore, this study also proposed a damper controller based on the new model, and the simulation results verify the effectiveness of the controller. The proposed model brings the acceleration signal into the model to improve the model adaptivity, which introduces a novel approach to enhance the adaptivity of MR damper models.
Experimental bounds on linear-friction dissipative collapse models from levitated optomechanics
Authors: Di Bartolomeo Giovanni , Carlesso Matteo 
Published: March 2024

Abstract
Collapse models constitute an alternative to quantum mechanics that solve the well-know quantum measurement problem. In this framework, a novel approach to include dissipation in collapse models has been recently proposed, and awaits experimental scrutiny. Our work establishes experimental bounds on the so-constructed linear-friction dissipative Diósi-Penrose (dDP) and Continuous Spontaneous localisation (dCSL) models by exploiting experiments in the field of levitated optomechanics. Our results in the dDP case exclude collapse temperatures below 10−13 K and

6
×

10

−
12

K respectively for values of the localisation length smaller than 10−6 m and 10−8 m. In the dCSL case the entire parameter space is excluded for values of the temperature lower than

6
×

10

−
9

K.
Exploring the synergistic potential of mixed metal sulfides in hybrid supercapacitors
Authors: Iqbal Muhammad Zahir , Abbasi Usman , Khizar Asma , Wabaidur Saikh Mohammad , Alam Shahid , Iqbal Muhammad Javaid , Faisal Mian Muhammad 
Published: March 2024

Abstract
In energy reservoirs, hybrid supercapacitors (HSCs) have gained incredible recognition owing to their exceptional specific energy (Es), Specific power (Ps), and high cyclic stability. However, electroactive electrode materials with flashing electrochemical features and high storage ability are still required. In this regard, nickel-cobalt binary sulfide composites need further exploration as an electrode material owing to their high electrochemical properties, better conductivity, excellent redox reversibility, and high-rate capability. Here, we account the electrochemical activities and synthesis of composites including (nickel and cobalt sulfides). The composites were analyzed for structural and morphological analysis using XRD and SEM techniques, respectively. Amidst all other compositions, Ni0.75Co0.25S exhibited the optimum electrochemical performance measured in half-cell assembly with specific capacity (Qs) of 1147.6 Cg−1 and 900 Cg−1 at lowest scan rate and current density respectively. This electroactive electrode material together with activated carbon (AC) was further utilized in two cell assembly. This Hybrid device revealed ES of 50.21 Whkg−1 and Ps of 9350 Wkg−1 with capacity retention of 80.30% after consecutive charge discharge. The performance analysis of the actual device was further examined using a simulation approach, focusing on both capacitive and diffusive contributions by comparing the results of both linear and quadratic models. These attractive results revealed by Ni0.75Co0.25S signify it as favorable electrode material for hybrid supercapacitor applications.
Ion implantation induced p-type conductivity in FeS2 thin film
Authors: Chakraborty Rudra Narayan , Mahanta Dipta Suryya , Mazumder Santu , Senthilkumar Kasilingam 
Published: March 2024

Abstract
In pursuing sustainable energy solutions, thin-film solar cells based on the Copper zinc tin sulfide (CZTS) absorber material have garnered significant attention due to their earth-abundant and non-toxic composition. However, the modest efficiency demonstrated by CZTS solar cells has prompted researchers to investigate novel approaches to improve their performance. An area of potential advancement entails the integration of appropriate hole transport layers (HTLs). In this simulation-based study, we focused on FeS2 as a highly promising candidate for use as an HTL in CZTS-based solar cells. FeS2, traditionally considered n-type, was tailored to achieve p-type conductivity through the negative ion implantation (O, P, and As) process. 40 keV ion beam was utilized, with three doses (105, 1010, 1015 cm−2) applied for each ion beam. We demonstrate successful p-type doping of FeS2 with a hole concentration of ∼1020 cm−3 in case of 1015 cm−2 dose, paving the way for its integration as an effective HTL within the CZTS solar cell structure.
Edge-dependent electronic transport and diode effect in C3N nanoribbons
Authors: Berdiyorov G R 
Published: March 2024

Abstract
Quantum transport calculations are conducted for C3N nanoribbons with different edge terminations within the nonequilibrium Green’s function formalism in combination with density functional theory. The electronic transport in the system strongly depends on the properties of the edge states. For example, the current in metallic carbon-terminated nanoribbons is several orders of magnitude higher than the current in nitrogen-terminated nanoribbons with a semiconducting nature. In addition, C-terminated nanoribbons show very pronounced negative differential resistance. A diode structure with a rectification ratio of 10 is proposed, consisting of a heterojunction of C- and N-terminated nanoribbons. These findings can be of practical importance in creating functional device structures from this 2D material.
Synthesis of PANI@Ce-doped ZnO (PCZ) heterojunction: A UV-Driven photocatalyst for reduction of methylene blue and study of their structural, optical and electrical properties
Authors: Dhanda Ekta , Nain Aditi , Dahiya Sanjay 
Published: March 2024

Abstract
To address the significant issue of wastewater treatment, this research focused on synthesizing PANI@Ce-doped ZnO (PCZ) nanocomposites, a heterojunction with varying dopant concentrations. This heterojunction was prepared using an ultrasonic-assisted wet impregnation technique and underwent comprehensive analysis through several techniques, including XRD, UV-DRS, Photoluminescence, FE-SEM, EDAX, and Impedance Analyzer. The XRD study was done to analyse the crystalline nature of as synthesized nanocomposites, while FESEM with EDX confirm the nanoflower morphology and presence of each element respectively. The optical band gap energy (Eg) of the samples has been estimated using UV-DRS and is found in the visible region. The synergy between the organic and inorganic frameworks resulted in an additive effect on the photocatalyst’s degradation efficiency. In the photocatalytic degradation process, reactive oxygen species (ROSs), including O2, OH, and h+, played a crucial role in breaking down MB (Methylene Blue) using the PANI@Ce-doped ZnO nanocomposites. PCZ1 exhibited significantly elevated dye degradation efficiency (86.80%) in comparison to bare PANI (40.80%). This enhancement can be attributed to the improved transfer and separation of photogenerated charge carriers in prepared heterojunction.
Quasi-three-level laser pumped Yb:GdCOB tunable laser from 1030 to 1036 nm
Authors: Wang Jiarui , Zhang Yaoyu , Li Yongliang 
Published: March 2024

Abstract
We report a quasi-three-level laser pumped Ca4GdO(BO3)3 (Yb:GdCOB) tunable laser based on the transition from the 2
F
5/2 level to the 2
F
7/2 level. By adjusting the 902 nm pump power, a continuous waves Yb:GdCOB laser was obtained with the near-infrared wavelengths shifting from 1030 nm to 1036 nm. The highest tuning power of 2.5 W was achieved with a slope efficiency of 19.9%. To our knowledge, it is the first tunable Yb:GdCOB laser to be realized by adjusting the pump power. This work provides a novel method to generate tunable solid-state lasers with a compact and simple structure.
Quasi-classical theory of cyclotron resonance with accounting for dissipation
Authors: Sazonov S V 
Published: March 2024

Abstract
Based on the quasi-classical version of the canonical Caldirola–Kanai quantization, non-relativistic cyclotron resonance in a dissipative medium is studied. The corresponding particle propagator in the coordinate representation is found. It is shown that the combined effect of dissipation and a constant magnetic field reduces to the suppression of the quantum properties of a charged particle. In turn, a time-varying electric field that causes cyclotron resonance does not exhibit similar properties and does not affect the uncertainties of the particle coordinates.
Activation and depression of neural and hemodynamic responses induced by the intracortical microstimulation and visual stimulation in the mouse visual cortex
Authors: Suematsu Naofumi , Vazquez Alberto L , Kozai Takashi D Y 
Published: March 2024

Abstract

Objective. Intracortical microstimulation (ICMS) can be an effective method for restoring sensory perception in contemporary brain–machine interfaces. However, the mechanisms underlying better control of neuronal responses remain poorly understood, as well as the relationship between neuronal activity and other concomitant phenomena occurring around the stimulation site. Approach. Different microstimulation frequencies were investigated in vivo on Thy1-GCaMP6s mice using widefield and two-photon imaging to evaluate the evoked excitatory neural responses across multiple spatial scales as well as the induced hemodynamic responses. Specifically, we quantified stimulation-induced neuronal activation and depression in the mouse visual cortex and measured hemodynamic oxyhemoglobin and deoxyhemoglobin signals using mesoscopic-scale widefield imaging. Main results. Our calcium imaging findings revealed a preference for lower-frequency stimulation in driving stronger neuronal activation. A depressive response following the neural activation preferred a slightly higher frequency stimulation compared to the activation. Hemodynamic signals exhibited a comparable spatial spread to neural calcium signals. Oxyhemoglobin concentration around the stimulation site remained elevated during the post-activation (depression) period. Somatic and neuropil calcium responses measured by two-photon microscopy showed similar dependence on stimulation parameters, although the magnitudes measured in soma was greater than in neuropil. Furthermore, higher-frequency stimulation induced a more pronounced activation in soma compared to neuropil, while depression was predominantly induced in soma irrespective of stimulation frequencies. Significance. These results suggest that the mechanism underlying depression differs from activation, requiring ample oxygen supply, and affecting neurons. Our findings provide a novel understanding of evoked excitatory neuronal activity induced by ICMS and offer insights into neuro-devices that utilize both activation and depression phenomena to achieve desired neural responses.
Correlation of source parameters and beam properties in the early operation of the full size ITER negative ion beam source
Authors: Ugoletti M. , Agostini M. , Poggi C. , Sartori E. , Serianni G. , Zaniol B. 
Published: March 2024

Abstract
One of the requirements of Heating and current drive Neutral Beam injectors for ITER is a beam homogeneity greater than 90%, to achieve an optimal beam transmission while keeping the heat load consistently low on the acceleration electrodes. The large size and complexity of ITER negative ion source play a key role in determining the homogeneity of the negative ion current of each of the 1280 beamlets and their divergence, and it is studied in the full-scale prototype source SPIDER. In this work the plasma properties are studied by spectroscopic and electrostatic measurements in the drivers, where the plasma is generated, and in the expansion region, where the plasma drifts and negative ions are produced, and they are correlated with the properties of the beam. The non-homogeneous plasma density profile is related to the non-homogeneous availability of negative ions along the beam vertical profile, with and without cesium evaporation. Visible tomography, a technique capable of characterizing isolated beamlet properties, is used to study the beam’s dependence on plasma uniformity along the entire beam profile. Using these tools, it has been demonstrated how an increase in plasma density is linked to an improvement in beam homogeneity. The latter has been directly correlated with plasma homogeneity. The magnetic filter field and biases of the plasma grid and bias plate are responsible for the variation in plasma density and its homogeneity. Non-uniformities in the plasma’s top/bottom and left/right distributions have been studied and partially addressed experimentally. The first issue was resolved by adjusting the radio-frequency power supplied to the plasma in different vertical regions, while the second issue was addressed by reversing the direction of the magnetic filter field and increasing the plasma density.