bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical characteristics and trap signatures for Schottky barrier diodes on 4H-SiC, GaN-on-GaN, AlGaN/GaN epitaxial substrates
Authors: Kumari Shikha , Singh Rashmi , Kumar Shivam , Murty N V L Narasimha , Planson Dominique , Raynaud Christophe , Sonneville Camille , Morel Hervé , Phung Luong Viet , Ngo Thi Huong , De Mierry Philippe , Frayssinet Eric , Cordier Yvon , Maher Hassan , Sommet Raphael , Nallatamby Jean-Christophe , Raja P Vigneshwara 
Published: May 2024

Abstract
The forward and reverse current transport mechanisms, temperature dependence of Schottky barrier height (SBH) and ideality factor, barrier inhomogeneity analysis, and trap parameters for Schottky barrier diodes (SBDs) fabricated on 4H-SiC, GaN-on-GaN and AlGaN/GaN epitaxial substrates are reported. High SBH is identified for Ni/4H-SiC (1.31 eV) and Ti/4H-SiC (1.18 eV) SBDs with a low leakage current density of <10−8 A cm−2 at −200 V. Thermally stimulated capacitance detects the well-known Z1/2 electron trap at E
C—0.65 eV in both 4H-SiC SBDs, while an additional deep-level trap at E
C—1.13 eV is found only in Ni/4H-SiC SBDs. The vertical Ni/GaN SBD exhibits a promising SBH of 0.83 eV, and two electron traps at E
C—0.18 eV and E
C—0.56 eV are identified from deep-level transient Fourier spectroscopy. A peculiar two-diode model behavior is detected at metal/GaN/AlGaN/GaN interface of high-electron mobility transistor (HEMT); the first diode (SBH-1 of 1.15 eV) exists at the standard Metal/GaN Schottky junction, whereas the second diode (SBH-2 of 0.72 eV) forms due to the energy difference between the AlGaN conduction band and the heterojunction Fermi level. The compensational Fe-doping-related buffer traps at E
C—0.5 eV and E
C—0.6 eV are determined in the AlGaN/GaN HEMT, through the drain current transient spectroscopy experiments.
Understanding of multiway heat extraction using peripheral diamond in an AlGaN/GaN high electron mobility transistor by electrothermal simulations
Authors: Gohel Khush , Zhou Linhui , Mukhopadhyay Swarnav , Pasayat Shubhra S , Gupta Chirag 
Published: May 2024

Abstract
High-power operation of high electron mobility transistors (HEMTs) is limited due to a variety of thermal resistances in HEMT devices that cause self-heating effects (SHEs). To reduce SHEs, diamond heat spreaders integrated in the device have proven efficient in extracting heat from the device. In this report, we use electrothermal technology computer-aided design simulations to demonstrate a qualitative understanding of multiway heat extraction utilizing diamond heat spreaders to improve HEMT thermal performance at high DC output power densities (∼40 W mm−1). The impact of each heat extraction pathway is understood while considering the thermal boundary resistance between the diamond/GaN heterointerface and optimization of the GaN buffer layer thickness. Using these findings, we simulate an AlGaN/GaN HEMT device operating at 40 W mm−1 DC output power and demonstrate significant reduction in the temperature.
Multi-frequency composite wearable antenna for wireless communications
Authors: Shi Yangyi , Duan Junping , Zhang Bin , Ma Jian , Meng Qingya 
Published: May 2024

Abstract
This paper proposes a multi-band composite wearable antenna for wireless communication, which uses a monopole structure as the radiating body and achieves multi-band characteristics through slit-loading and multi-branching methods. A polymer composite substrate with high dielectric constant and low dielectric loss was prepared using in situ polymerization, and the optimal dielectric constant and loss angle tangent were obtained by controlling the coating ratio of melamine formaldehyde resin to carbon nanotubes (MWCNTs) and the filler doping rate to achieve miniaturization of the antenna. Comparative experimental results show that the obtained composites have high flexibility and good dielectric properties. The antenna operates in the frequency bands of 2.21–2.52 GHz, 3.07–3.87 GHz, and 4.36–6.03 GHz, which cover the frequency bands of WLAN and WiMAX and 5G applications. The antenna was fabricated and tested, and its performance roughly matched the simulation results. Meanwhile, the antenna has passed the SAR safety test and maintained a stable performance under different curvatures, so it has potential applications in the wireless communication system.
Electromagnetically-induced transparency assists the Raman gradient echo memory at moderate detuning, dependent on gradient order
Authors: Everett Jesse L , Papneja Ankit , Saha Arindam , Trainor Cameron , Tranter Aaron D , Buchler Ben C 
Published: May 2024

Abstract
Optical quantum memories are essential for quantum communications and photonic quantum technologies. Ensemble optical memories based on 3-level interactions are a popular basis for implementing these memories. All such memories, however, suffer from loss due to scattering. In off-resonant 3-level interactions, such as the Raman gradient echo memory (GEM), scattering loss can be reduced by a large detuning from the intermediate state. In this work, we show how electromagnetically induced transparency adjacent to the Raman absorption line plays a crucial role in reducing scattering loss, so that maximum efficiency is in fact achieved at a moderate detuning. Furthermore, the effectiveness of the transparency, and therefore the efficiency of GEM, depends on the order in which gradients are applied to store and recall the light. We provide a theoretical analysis and show experimentally how the efficiency depends on gradient order and detuning.
Backstepping synchronization control for four-dimensional chaotic system based on DNA strand displacement
Authors: Sun Junwei , Wang Jinjiang , Shan Zhanjiang , Wang Yanfeng 
Published: May 2024

Abstract
Backstepping control is an important nonlinear control design method, which realizes the control of complex systems by constructing control law step by step, and has significant advantages for dealing with complex nonlinear systems. This article proposes a synchronization technique for four-dimensional chaotic systems using a combination of backstepping control method and DNA strand displacement technology. By relying on theoretical knowledge of DNA molecules, five basic chemical reaction modules such as trigger reaction, reference reaction, catalytic reaction, annihilation reaction and degradation reaction are given to construct a four-dimensional DNA chaotic system. On the basis of the relevant theory of chaotic dynamics, the constructed system is analyzed by Lyapunov exponent diagram and spectral entropy complexity algorithm, and the results come to the conclusion that the system reveals extremely complex and varied dynamic behaviors. Combining DNA strand displacement technology with backstepping control method, four controllers are developed to ensure that the trajectories of two homogeneous chaotic systems are synchronized. The numerical simulation results validate the feasibility and applicability of the proposed method. The method proposed in this paper may provide some references in the field of DNA molecular chaos synchronization control.
‘Exploration of photovoltaic behavior of bithiophene-functionalized dispiro-oxepine based hole-transporting materials for efficient perovskite solar cells’
Authors: Basharat Arslan , Sharafat Raheela , Zahid Waqar Ali , Shahzad Nabeel , Alomar Muneerah , Iqbal Javed 
Published: May 2024

Abstract
Perovskite solar cells (PSCs) have received great attention from researchers due to their superior photovoltaic properties, high efficiency, and low cost. In this study, bithiophene dispiro-oxepine based five hole-transporting materials (DDOF1, DDOF2, DDOF3, DDOF4, and DDOF5) are designed by the substitution of end-capped acceptors via thiophene-based bridge to enhance the photovoltaic properties of PSCs. The results showed that designed HTMs have deeper HOMO levels (−4.88 eV to −5.04 eV), high solubility, and compatible stability with lower energy gaps (2.04 eV to 2.59 eV) than the reference (EHOMO = −4.55 eV, Eg = −3.49 eV) and Spiro-OMeTAD (EHOMO = −4.47 eV, Eg = −3.86 eV), which improved hole extraction and the open-circuit voltage in the PSCs. Moreover, the binding energy (0.41 eV to 0.46 eV) and TDM analysis indicated that DDOF1-DDOF5 HTMs have high charge mobility compared to the reference molecule DDOF (0.61 eV). The DDOF1-DDOF5 HTMs indicated anticipated higher power conversion efficiency and open-circuit voltage than the reference molecule. Overall, our findings proved that designed molecules are efficient HTMs for the manufacture of high-efficiency PSCs in the solar industry.
Stable and improved voltage plate of Li/SOCl2 battery using carbon electrodes with active carbon
Authors: Xu Zhanwei , Zhao Yaze , Li Mengfan , Li Zhi , Li Jiaxing , Song Yingxuan , Lu Changyu , Li Jiayin , Zhang Ke 
Published: May 2024

Abstract
Active carbon (AC) is synthesized using pitch coke as a precursor with a KOH activation approach followed. AC with different specific surface areas can be obtained by controlling the activation time of KOH. The activation time of AC1, AC2 and AC3 is 1 h, 1.5 h and 2 h, with the surface areas of 1233, 1484 and 1639 m2 g−1, respectively. The phase, surface chemical structure, morphology as well as the microstructure of the AC are investigated by XRD, Raman, IR, XPS, BET, SEM and TEM. The obtained ACs displayed a size around 300 μm with lots of nanoholes and functional group involving –OH, –COOH. When employed as the catalytic active materials in the carbon cathodes for Li/SOCl2 batteries, the discharged voltage was improved to around 0.15 V with an enhanced stable platform. Whereas the energy of the batteries containing the ACs is similar as that the conventional batteries, as well as the morphology of the carbon cathode with ACs exhibited a dense LiCl on the surface, suggesting that the ACs can enhance the reduction reaction of SOCl2, but could not act as the nucleation sites for the synthesis of nanoscale LiCl to form a loose film for a long discharge life.
Understanding dynamical phase transitions in a spinor Bose–Einstein condensate via quantum and semiclassical analyses
Authors: Niu Zhen-Xia , Wang Qian 
Published: May 2024

Abstract
Phase transitions in nonequilibrium dynamics of quantum many-body system, known as dynamical phase transitions (DPTs), play an important role for understanding various dynamical phenomena observed in different branches of physics. In general, there are two types of DPTs, the first one is characterized by distinct evolutionary behaviors of a physical observable, while the second one is marked by the vanishing overlap between the time-evolved and initial states. Here, we focus on exploring such DPTs from both quantum and semiclassical perspectives in a spinor Bose–Einstein condensate (BEC), an ideal platform for investigating nonequilibrium dynamics. Utilizing the sudden quench process, we demonstrate that the system exhibits both types of DPTs as the control parameter is quenched through the critical value, referring to as the critical quenching. We show analytically how to determine the critical quenching via the semiclassical approach and carry out a detailed examination of both semiclassical and quantum signatures of DPTs. In particular, we reveal that the occurrence of DPTs is triggered by the separatrix in the underlying semiclassical system. Our findings offer deeper insights into the properties of DPTs and verify the usefulness of semiclassical analysis for studying DPTs in quantum systems with well-defined semiclassical limit.
Microscopic structure of electromagnetic whistler wave damping by kinetic mechanisms in hot magnetized Vlasov plasmas
Authors: Paul Anjan , Sharma Devendra 
Published: May 2024

Abstract
Electromagnetic transverse perturbations propagating parallel to the external magnetic field in a warm electron plasma, specifically the warm electron whistler-mode waves, are simulated in Maxwellian as well as κ distributed (with energetic tail) electrons. The Vlasov-Maxwell phase-space continuum simulations are applied to the stable and unstable (i.e. isotropic and anisotropic) VDFs. The variation of real frequency from both numerical solution of dispersion relation and simulations show limited sensitivity to electron temperature in low wave-number regime as compared to high wave number regime, however the opposite holds for the imaginary frequency or the decay rate. The analytically predicted reduction in the decay rate of the whistler-mode with increasing electron temperature is recovered by the Vlasov-Maxwell simulations. The phase-space portraits of the these cases show that after the linear damping phase of the evolution, the particles are trapped in the wave magnetic field leading to the wave amplitudes oscillating about a mean value which follow the theoretical analysis. Palmadesso and Schmidt (1971) Physics of Fluids 14, 1411.
The Preisach model of hysteresis: fundamentals and applications
Authors: Semenov M E , Borzunov S V , Meleshenko P A , Sel’vesyuk N I 
Published: May 2024

Abstract
The Preisach model is a well-known model of hysteresis in the modern nonlinear science. This paper provides an overview of works that are focusing on the study of dynamical systems from various areas (physics, economics, biology), where the Preisach model plays a key role in the formalization of hysteresis dependencies. Here we describe the input-output relations of the classical Preisach operator, its basic properties, methods of constructing the output using the demagnetization function formalism, a generalization of the classical Preisach operator for the case of vector input-output relations. Various generalizations of the model are described here in relation to systems containing ferromagnetic and ferroelectric materials. The main attention we pay to experimental works, where the Preisach model has been used for analytic description of the experimentally observed results. Also, we describe a wide range of the technical applications of the Preisach model in such fields as energy storage devices, systems under piezoelectric effect, models of systems with long-term memory. The properties of the Preisach operator in terms of reaction to stochastic external impacts are described and a generalization of the model for the case of the stochastic threshold numbers of its elementary components is given.
Performance analysis of an underwater wireless optical communication link with Lommel beam
Authors: Ma Yangbin , Wang Xinguang , Qin Changjian , Yuan Qiujie , Wang Le , Zhao Shengmei 
Published: May 2024

Abstract
In order to mitigate the stochastic interference of underwater channels and improve the quality of underwater communication systems, it is essential to study the performance of the underwater wireless optical communication (UWOC) links utilizing vortex beams with unique attributes. In this paper, the analytical formulae for the bit error rate (BER) and the average capacity of the UWOC link with diffraction-free Lommel beam are derived under the Rytov theory. Simulation results demonstrate that the system with a long wavelength, a high system signal-to-noise ratio(SNR), a small asymmetric parameter and receiving aperture diameter achieves a high average capacity and a low BER. Furthermore, in the underwater channel with a larger kinetic energy dissipation rate per unit mass of fluid and inner scale, a smaller mean-squared temperature dissipation rate, temperature salinity contribution ratio and transmission distance, the performance of the communication link can be improved. Meanwhile, it is found that the performance of the link with carrier Lommel beam are less sensitive to the topological charge, the scaling factor of the beam and the turbulent outer scale. These findings provide theoretical support for the design and implementation of an UWOC link utilizing the Lommel beam.
Modeling the unsteady wake of an impulsively started circular cylinder using refined potential flow theory
Authors: Amoloye Taofiq O 
Published: May 2024

Abstract
Cylindrical structures find usage in many engineering applications including tethered oil drums and engine canisters slung beneath helicopters in flight. The motion of air around such circular cylindrical structures and the helicopter presents interesting phenomena including flow separation, wakes and turbulence. The physics of these are enshrined in the continuity equation and the Navier–Stokes equations. Therefore, their studies are not only important in mathematics and physics, but they are also required for efficient helicopter operations. In practice, reduced-order models of these operations that take in aerodynamics models of the tethered loads are utilized for stability analysis, flight certification and pilot training because of the prohibitive cost of experimentation and computational analyses of these configurations. However, there is a dearth of realistic analytical models of finite cylinder flows because of the Navier–Stokes problem. Classical potential flow theory provides an avenue to develop such models, but the extant gaps in its predictions significantly preclude its usage for engineering applications. Attempting to bridge these gaps, this article introduces refined potential flow theory in which the governing equations and boundary conditions are satisfied. Viscous effects, fluctuations of the mean flow and three-dimensional effects are also incorporated. For characterization, refined potential flow theory is employed on an incompressible flow over an impulsively started circular cylinder for Reynolds numbers and non-dimensional times in the range

30
<
Re

<

10

4

and 0.2 ≤ T ≤ 77, 047 respectively. There is an excellent prediction of 0.209 for the Strouhal number at

Re

=

3
,
900

. At this transitional Reynolds number, the harmonics of the Strouhal frequency are also captured, and the characteristic irregular fluctuations at sub-Strouhal frequencies are discernible in the velocity spectra. As the flow becomes more turbulent, these become more pronounced at

Re

=

9
,
500

when the predicted Strouhal number is within 10% of experimental result. In the fully developed stage, spectra analyses of the wake velocity components at some downstream locations also display Kolmogorov's Five-Thirds law of homogeneous isotropic turbulence. The present model can thus aid the development of reduced-order models of helicopter operations that feature tethered cylindrical loads.
Effect of particle size on optical and electrical properties of thin films – a simulation approach
Authors: Das Sudeep Kumar , Banerjee Diptonil , Roy Jitendra Nath 
Published: May 2024

Abstract
This paper presents a simulated investigation of the relationship between surface roughness and particle size as well as the resulting impact of the both on the thin film’s physical and optical properties. Non-porous thin films are created through computer simulation for a range of particle sizes following the random deposition with a surface relaxation approach. For the deposited thin films different fundamental parameters like transmittance, reflectance, absorption coefficients, frequency dependent dielectric constants, loss angle, refractive indices, optical band gap have all been calculated and in this process of calculation the fundamental values of two different materials; zinc oxide (ZnO and cadmium selenide (CdSe) are taken. It has been seen that when the particle sizes are comparable the calculated values of optical band gap of both ZnO and CdSe matches well with the experimental values of the same reported by others. This is probably the first effort to develop a direct relation between the particle size with different fundamental optical properties of different materials through simple simulation which agrees well with the experimental result. This would definitely help the experimental researchers in the field of material science to design their experiments as per the desired requirements.
Uncovering the potential of industrial waste: turning discarded resources into sustainable advanced materials
Authors: Rauf Ichsan , Heryanto Heryanto , Tahir Dahlang , Gaus Abd , Rinovian Asnan , Veeravelan K , Akouibaa Ahmed , Masrour Rachid , Akouibaa Abdelilah 
Published: May 2024

Abstract
To identify solutions for utilizing industrial wastes (slag, sludge, fly ash, and bottom ash) in the development of pro-environmental systems, this paper reviews existing literature and explores material characterization methods. A review analysis was conducted to uncover their potential, and it was found that many utilizations can be made to recycle them into sustainable materials. Structure characterization, optical-dielectric function, and morphology analysis were analyzed to confirm the recent review. Structural properties are represented by crystallite size and crystallinity, where nickel slag shows the smallest distribution (55 ± 10) nm with the highest crystallinity (25.42%), indicating its association with uniformity of response to external disturbances and micro-structural stability. From the analysis of optical and dielectric functions via Kramers Kronig relation, the widening of

∆
(
LO
−
TO
)

was shown by fly ash and slag indicating stable bonding suitable as x-ray shielding and sensor, while high electron loss functions were shown by sludge and bottom ash indicating high potential electronic transition performance. Based on their chemical and physical properties, these industrial wastes are not limited as construction materials and can even be upgraded to more advanced development materials.
Circularly polarized dielectric resonator based MIMO antenna for sub-6 GHz 5G cognitive radio applications
Authors: Rai Yajush , Sharma Anand , Agarwal Smriti , Gupta Rajeev 
Published: May 2024

Abstract
A 2-port wideband circular polarized (CP) multiple input multiple output (MIMO) dielectric resonator antenna (DRA) integrated with cognitive radio (CR) application is designed and investigated. This is a novel concept of integrating wideband CP-MIMO antenna based on dielectric resonator (DR), with CR concept. The multi-functional reconfigurable filter is designed within the feedline of the antenna making it applicable for both the operations of CR, namely, underlay and interweave. Rogers RT Duroid 5880 is used as the substrate for the designed CP-MIMO antenna. The antenna shows wide Axial Ratio (AR) bandwidth of 48.14% (2.2–3.50 GHz) and an overlapping bandwidth of 41.85% (2.37–3.50 GHz). The DR based MIMO antenna shows sensing range of 2.37–3.66 GHz. For the interweave operation, the designed CP-MIMO antenna shows narrowband frequency reconfigurability from 2.45–2.83 GHz. For the underlay case, the designed antenna shows band notch tunability between 3.23–3.62 GHz. The proposed antenna can be used effectively in sub-6 GHz band of the 5G communication systems.