bluuebunny/crossref_metadata_2025_split huggingface dataset:
The electrocaloric effect of lead-free Ba1−yCayTi1−xHfxO3 from direct and indirect measurements
Authors: Gracia David , Lafuerza Sara , Blasco Javier , Evangelisti Marco 
Published: December 2023

We report on the dielectric and electrocaloric properties of Ba1−yCayTi1−xHfxO3 for compositions 0.12 &lt; x &lt; 0.18 and y = 0.06, as well as x = 0.15 and 0 &lt; y &lt; 0.15, synthesized by the conventional solid-state reaction method. The addition of Hf/Ca broadens the ferroelectric-paraelectric phase transition while moving it toward room temperature. Two interferroelectric transitions are seen to converge, together with the ferroelectric–paraelectric phase transition, at ∼335 K for 0.12 &lt; xc &lt; 0.135 and y = 0.06. Consistent with the dielectric properties, the electrocaloric effect maximizes closer to room temperature with increasing Hf/Ca substitutions, which promote larger temperature spans. The electrocaloric responsivity gradually decreases from 0.2 to 0.1 K mm kV−1 with the addition of Hf/Ca. A homemade quasi-adiabatic calorimeter is employed to measure “directly” the electrocaloric data, which are also calculated from polarization-versus-electric-field cycles using “indirect” standard procedures. The comparison between measured and calculated values highlights the importance of having access to direct methods for a reliable determination of the electrocaloric effect.
Selective chemical etching for termination layer control of BaSnO3 and 2DEG formation at the LaInO3/BaSnO3 interface
Authors: Kim Seonghyeon , Kim Bongju , Char Kookrin 
Published: December 2023

An ex situ chemical etching method was developed to achieve a SnO2-terminated surface in BaSnO3 films. An SnO2-terminated surface is crucial for the formation of a (LaO)+/(SnO2)0 interface structure to form the two-dimensional electron gas (2DEG) state at the LaInO3 (LIO)/BaSnO3 (BSO) interface. By employing a 9:1 mixture of acetone and water, the etching rate of the surface barium oxide (BaO) layer could be effectively controlled, taking advantage of the solubility of BaO in water. To determine the optimal etching conditions, we investigated the relationship between the etching time and the resulting 2DEG conductance. The optimum times for maximizing the conductance of the 2DEG state were found to be 90 s on SrTiO3 substrates and 40 s on MgO substrates, generating a higher conductance than the in situ SnO2 dusting method reported earlier. The surface properties before and after the chemical etching were analyzed by angle reserved x-ray photoelectron spectroscopy.
Cavity online measurements with a coaxial electrical probe in an X band integrally sealed relativistic klystron amplifier
Authors: Zhang Wei , Ju Jinchuan , Ge Xingjun , Zhang Qiang , Dang Fangchao , Wang Tengfang , Zhou Yunxiao 
Published: December 2023

The electromagnetic characteristics of the input cavity with electron beams loaded are measured successfully in an X-band triaxial relativistic klystron amplifier (TKA) with a high frequency electrical probe. To solve the frequency response issue in the X band, a coaxial electrical probe is optimized and inserted obliquely into the input cavity at the designed angle so that the microwaves in the cavity can be sampled and extracted with the required coupling coefficient while the probe does not interfere with the solenoid coil, which is tightly integrated outside the TKA. Besides, the TKA is redesigned as a structure integrally sealed by the solenoid coil, and the secondary sealing induced by probe insertion is implemented on the flange of the solenoid coils rather than on the wall of the TKA, which is conducive to simplifying the coupling structure while maintaining the high vacuum level. The design is examined in a GW level TKA experiment, indicating that microwaves with a power of about 670 MW are generated in the input cavity at a frequency of 8.40 GHz, which is completely consistent with the injected and output microwave frequencies.
Room temperature ferromagnetism in the nanolaminated MAX phase (Mn1−xCrx)2GaC
Authors: Thorsteinsson E. B. , Dahlqvist M. , Elsukova A. , Petruhins A. , Persson P. O. Å. , Rosen J. , Ingason A. S. , Magnus F. 
Published: December 2023

MAX phases are a class of intrinsically nanolaminated materials, which combine features of metals and ceramics, owing to the alternating metallic and covalent bonding between atomic layers. Magnetic MAX phases have been known for a decade, but ferromagnetism at room temperature in this highly anisotropic system has been elusive, limiting their value as magnets in practice. Here, we show that a MAX phase with a strong ferromagnetic response is obtained by substituting Mn with Cr on the M-site in the well-known Mn2GaC. The ferromagnetic response is observed in (Mn1−xCrx)2GaC with 0.06 &lt; x &lt; 0.29 up to temperatures well exceeding room temperature (489 K). The strongest magnetization is achieved with x = 0.12, reaching a saturation moment of 1.25 μB and a remanence of 0.67 μB per M-atom at 3 K and maintaining 0.90 and 0.44 μB per M-atom, respectively, at 300 K. This is the first experimental report of a significant ferromagnetic response in a MAX phase at room temperature. The results open the door to the use of MAX phases in a broad range of applications, from bulk magnets in power electronics to spintronic devices.
Modeling cosmological perturbations of thermal inflation
Authors: Bae Jeong-Myeong , Hong Sungwook E , Zoe Heeseung 
Published: December 2023

Abstract
We consider a simple system consisting of matter, radiation and vacuum components to model the impact of thermal inflation on the evolution of primordial perturbations. The vacuum energy magnifies the primordial modes entering the horizon before its domination, making them potentially observable, and the resulting transfer function reflects the phase changes and energy contents. To determine the transfer function, we follow the curvature perturbation from well outside the horizon during radiation domination to well outside the horizon during vacuum domination and evaluate it on a constant radiation density hypersurface, as is appropriate for the case of thermal inflation. The shape of the transfer function is determined by the ratio of vacuum energy to radiation at matter-radiation equality, which we denote by

υ

, and has two characteristic scales,

k

a

and

k

b

, corresponding to the horizon sizes at matter radiation equality and the beginning of the inflation, respectively. If

υ
≪
1

, the Universe experiences radiation, matter and vacuum domination eras and the transfer function is flat for

k
≪

k

b

, oscillates with amplitude

1

/

5

for

k

b

≪
k
≪

k

a

and oscillates with amplitude 1 for

k
≫

k

a

. For

υ
≫
1

, the matter domination era disappears, and the transfer function reduces to being flat for

k
≪

k

b

and oscillating with amplitude 1 for

k
≫

k

b

.
Research progress and prospect of GaN Schottky diodes
Authors: Shao Yu , Zhang Fang , He Yunlong , Liu Peng , Sheng Baisong , Lu Xiaoli , Wang Zhan , Wang Xichen , Li Yuan , Zheng Xuefeng , Ma Xiaohua , Hao Yue 
Published: December 2023

Abstract
GaN (gallium nitride), as a third-generation semiconductor (wide-band semiconductor) material, is widely used in the fabrication of power devices with an excessive breakdown voltage and a low on-resistance due to the material’s excellent properties. Starting from the three basic structures, this paper analyses and summarizes the research progress of GaN SBD (schottky barrier diode) in recent years. The design and optimization methods of GaN-based SBD are introduced from various aspects, such as anode structure, termination type, epitaxial structure and substrate. The advantages and disadvantages of GaN-based SBD of different structures and the problems in the research process are summarized, and the future application fields of GaN-based SBD devices are prospected.
DBD-like and electrolytic regimes in pulsed and AC driven discharges in contact with water
Authors: van Rooij Olivier , Wubs Jente , Höft Hans , Sobota Ana 
Published: December 2023

Abstract
The interaction of an ambient air plasma with a water surface in a pin–water electrode configuration is presented in a polydiagnostic study. A discharge was generated by applying different high-voltage (HV) waveforms to a metallic pin electrode, positioned 2 mm above the water surface of a Petri dish filled with demineralized water. For pulsed discharge operation, a clear distinction is observed between a dielectric barrier discharge regime featuring a transient discharge at the rising as well as at the falling slope of the HV pulse, while a steady discharge is present in the gap during the complete HV pulse for the electrolysis regime. The occurrence of those two regimes is coupled to the increasing conductivity of the water over time, which additionally results in a quick rise of the dissipated discharge power and an increase of the gas temperature. The AC driven discharges exhibit only the electrolysis regime and do not significantly evolve over the treatment time. The resulting water conductivity was found to be a function of the total dissipated energy, irrespective of the discharge driving mode. Additionally, the resulting water conductivity shows a strong correlation with the total transferred charge in the gas phase. The total dissipated energy can potentially be used as a global measure to compare different experiments involving plasma–water interaction across different setups in different research groups.
Probing beyond the standard model physics with double-beta decays
Authors: Bossio Elisabetta , Agostini Matteo 
Published: December 2023

Abstract
Nuclear double-beta decays are a unique probe to search for new physics beyond the standard model. Hypothesized particles, non-standard interactions, or the violation of fundamental symmetries would affect the decay kinematics, creating detectable and characteristic experimental signatures. In particular, the energy distribution of the electrons emitted in the decay gives an insight into the decay mechanism and has been studied in several isotopes and experiments. No deviations from the prediction of the standard model have been reported yet. However, several new experiments are underway or in preparation and will soon increase the sensitivity of these beyond-the-standard-model physics searches, exploring uncharted parts of the parameter space. This review brings together phenomenological and experimental aspects related to new-physics searches in double-beta decay experiments, focusing on the testable models, the most-sensitive detection techniques, and the discovery opportunities of this field.
A hierarchical transformer-based adaptive metric and joint-learning network for few-shot rolling bearing fault diagnosis
Authors: Meng Zong , Zhang Zhaohui , Guan Yang , Li Jimeng , Cao Lixiao , Zhu Meng , Fan Jingjing , Fan Fengjie 
Published: December 2023

Abstract
Recently, deep learning techniques have significantly bolstered the advancement of intelligent fault diagnosis. However, in engineering practice, the limited availability of fault samples poses considerable challenges to the existing methods. To address this problem, a hierarchical Transformer-based adaptive metric and joint-learning network (HTAMJN) is suggested in this paper. Firstly, a hierarchical progressive fusion encoder based on orthogonal self-attention is devised, which effectively enhances the model’s attention to local features and establishes comprehensive interdependencies. To reduce the demand for labeled data, a metric method with a coupling mechanism is proposed to adaptively enhance the metric benchmark, making the category representation more discriminative. Additionally, a joint optimization scheme based on the episodic paradigm is formulated to improve the recognition capability of the network for different categories under few-shot scenarios. The outcomes demonstrate that the HTAMJN outperforms several comparison models in both few-shot diagnosis and cross-domain recognition tasks in experiments conducted on three bearing datasets, exhibiting superior performance.
A novel continuous delay hidden layer deep belief network and its application in life prediction of rolling bearings
Authors: Wang Meiqi , Xu Jiayue , Niu Xiaowei , Chen Enli , Liu Pengfei 
Published: December 2023

Abstract
The traditional rolling bearing trend prediction method is difficult to predict the bearing degradation process comprehensively and scientifically, and the feature extraction is highly dependent on the manual experience method, and the prediction ability of the bearing measurement data with strong dynamic characteristics and nonlinear is very limited. Therefore, how to build a high-precision life prediction model has become an urgent problem and challenge. In this paper, a continuous delay hidden layer deep belief network (CDHLDBN), kernel principal component analysis (KPCA)-CDHLDBN, is proposed based on the KPCA preprocessing method. Firstly, a continuous deep belief network (CDHLDBN) with a delay layer is proposed, which makes the output of the hidden layer more fully consider the influence of the previous moment on the output of this moment, so as to avoid the defect of DBN model which is difficult to process the data with strong dynamic time series. Then, all visible layers of a continuous DBN with a delay layer are de-averaged, and then the simulated bearing sequence data is trained and predicted using the KPCA-CDHLDBN life prediction model. The results show that KPCA-CDHLDBN model can predict nonlinear dynamic time series data better than other deep learning models. Finally, it is applied to the performance degradation life prediction of rolling bearings. The performance of the proposed method was verified by the bearing accelerated life vibration data provided by PRONOSTIA experimental platform, and the performance of the proposed method was compared with that of the traditional DBN and its improved prediction model. The results show that KPCA-CDHLDBN has better prediction accuracy and faster prediction speed.
Thermal imaging based pre-diagnostics tool for Graves’ disease
Authors: Sharma Vaishali , Dhingra Vandana K , Shakya Snehlata , Kumar Ashok , Goswami Mayank 
Published: December 2023

Abstract
Infrared thermography Images of the facial region are taken from sixty persons. Scintigraphy and standard thyroid blood test are used to categorize these persons into thirty-three females and thirteen males suffering from Graves’ disease. This study is approved by the All-India Institute of Medical Science Rishikesh Ethics Committee with reference number AIIMS/IEC/19/997. Eleven Females and three males are found to be in healthy conditions and used as control. A convolutional neural networks (CNN) model is developed to automatically segment and extract the histogram-associated information within the thyroid and cheek region from the collected images. The sub-surface temperature of the thyroid gland and control is extracted using these set of images. We have acquired moderately correlated imaging biomarker with respect to age and gender from this sparse data. An Artificial Intelligence-based app is developed and deployed in a clinical environment to enrich the prognosis model in real time. An affordable Thermal plug-and-play addon device is developed to connect with any smartphone for faster diagnosis at the patient end to carry out this test now. This smartphone and AI-based app combination is successfully deployed as a point-of-care device. It is expected that this IR based preliminary test will automatically categorize healthy cases from patients. This step may save the clinicians to unnecessarily recommending the radioactive contamination-prone Scintigraphy and/or expensive and relatively slower thyroid blood tests. Such preliminary tests may (a) save costs to the patients and (b) relieve the burden on pathology labs. These two points are impactful for the healthcare industry, particularly in densely populated countries having low per capita income.
Ab
initio computation of low-temperature miscibility gap of V(Se,Te)2
Authors: Nayamadi Mahmoodabadi A , Modarresi M , R Roknabadi M 
Published: December 2023

Abstract
Monolayers of quasi-binary transition metal dichalcogenides are a focus of attention as they are expected to exhibit many exciting physical properties, but not much is known about their thermodynamic stability. In this study, we use a combination of global energy landscape exploration, local minimization using density functional theory, and thermodynamic analysis, to compute the composition-temperature phase diagram of the quasi-binary V(Se,Te)2 system, both for a 2H monolayer and for the analogous bulk material. We find that the phase diagram exhibits a miscibility gap, with a critical temperature T

c
= 500 K and T

c
= 650 K for monolayer and bulk, respectively, indicating that the system prefers to form solid solution phases. In particular, at room temperature, the thermodynamically stable phase of the monolayer would correspond to a decomposition into two solid solution monolayers, with ca. 90% Se and Te content, respectively.
Moment tracking and their coordinate transformations for macroparticles with an application to plasmas around black holes
Authors: Warwick Alexander , Gratus Jonathan 
Published: December 2023

Abstract
Particle-in-cell (PIC) codes usually represent large groups of particles as a single macroparticle. These codes are computationally efficient but lose information about the internal structure of the macroparticle. To improve the accuracy of these codes, this work presents a method in which, as well as tracking the macroparticle, the moments of the macroparticle are also tracked. Although the equations needed to track these moments are known, the coordinate transformations for moments where the space and time coordinates are mixed cannot be calculated using the standard method for representing moments. These coordinate transformations are important in astrophysical plasma, where there is no preferred coordinate system. This work uses the language of Schwartz distributions to calculate the coordinate transformations of moments. Both the moment tracking and coordinate transformation equations are tested by modelling the motion of uncharged particles in a circular orbit around a black hole in both Schwarzschild and Kruskal–Szekeres coordinates. Numerical testing shows that the error in tracking moments is small, and scales quadratically. This error can be improved by including higher order moments. By choosing an appropriate method for using these moments to deposit the charge back onto the grid, a full PIC code can be developed.
Rotation differential triboelectric nanogenerator for bird-repellent on transmission line towers
Authors: Zhang Pan , Lin Wanrong , Huang Wenbin , Wang Kuankuan 
Published: December 2023

Abstract
The security of transmission line towers is crucial to industrial development. Bird damage is a significant threat to transmission line towers in the field. However, the power supply to the bird-repellent devices is limited. In this work, we propose a rotation differential triboelectric nanogenerator (RD-TENG) to harvest wind energy for supplying electrical power to bird-repellent on transmission line towers. On the transmission line towers, the RD-TENG converts wind energy into electrical energy by rotation differential structure and stores power in a 1000 μF capacitor, then supplies power to the buzzer for bird-repellent. The device mainly consists of a wind cup, an input gear, output gears, and rotors. The RD-TENG can achieve double rotation speed by rotating the differential structure compared to the single gear counterpart, hence doubling the current and power output through triboelectric nanogenerator. The RD-TENG has a starting wind speed of 4 m s−1 and can operate normally at lower wind speeds. At a wind speed of 8 m s−1, the output performance of the RD-TENG is 830 V, 13.5 μA, 330 nC, and the peak power is 19.6 mW. This work realizes a new solution for bird-repellent on transmission lines through the TENG energy harvesting technique and also contributes to the subsequent smart grid construction.
Optical-pumping enantio-conversion of chiral mixtures in presence of tunneling between chiral states
Authors: Zou Fen , Ye Chong , Li Yong 
Published: December 2023

Abstract
Enantio-conversion of chiral mixtures, converting the mixtures composed of left- and right-handed chiral molecules into the homochiral ensembles, has become an important research topic in chemical and biological fields. In previous studies on enantio-conversion, the tunneling interaction between the left- and right-handed chiral states was often neglected. However, for certain chiral molecules, this tunneling interaction is significant and cannot be ignored. Here we propose a scheme for enantio-conversion of chiral mixtures through optical pumping based on a four-level model of chiral molecules, comprising two chiral ground states and two achiral excited states, with a tunneling interaction between the chiral states. Under one-photon large detuning and two-photon resonance conditions, one of the achiral excited states is eliminated adiabatically. By well designing the detuning and coupling strengths of the electromagnetic fields, the tunneling interaction between two chiral states and the interaction between one of the chiral states and the remaining achiral excited state can be eliminated. Consequently, one chiral state remains unchanged, while the other can be excited to an achiral excited state, establishing chiral-state-selective excitations. By numerically calculating the populations of two chiral ground states and the enantiomeric excess, we observe that high-efficiency enantio-conversion is achieved under the combined effects of system dissipation and chiral-state-selective excitations.
On two-parameter bifurcation and analog circuit implementation of a Chameleon chaotic system
Authors: Fan Weiwei , Xu Dan , Chen Zhiyin , Wang Ning , Xu Quan 
Published: December 2023

Abstract
In this paper, the two-parameter space bifurcation of a three-dimensional Chameleon system is investigated. It is called Chameleon since the type and the number of the system equilibrium are adjustable for different parameter configurations. Aided by the computation analysis, the graphic structures of two-parameter bifurcation of the Chameleon system are characterized for the first time. With different two-parameter configurations, the bifurcation evolution shows that various self-excited and hidden attractors exist. In addition, numerical demonstration of the two-dimensional slice through the attraction basin space is presented. The results show that the basin of attraction of the typical hidden chaotic attractor does not associated with the origin, which makes the attractor difficult to be numerically localized and experimentally observed. To solve the problem, offset boost scheme is adopted to control the basin of attraction and make it touch the origin, which allows to coin the hidden attractor via configuring zero initial value and making it feasible in experimental observation. Finally, the analog circuit-assisted experiment validated the feasibility of the scheme.