bluuebunny/crossref_metadata_2025_split huggingface dataset:
A photovoltaic power estimation model based on the improved local cloud occlusion index algorithm considering Sun block luminance
Authors: Yin Deyang , Zhai Kai , Zheng Jianfeng , Hou Qiankang , Mei Keqi 
Published: November 2024

Abstract
Accurate estimation of photovoltaic (PV) power generation is of great significance to the operation and optimization of the power grid. However, due to the rapid movement of clouds in a short period of time, the changes in PV power are intermittent and fluctuating. Nowadays, sky images have been widely used for PV power estimation, which can effectively extract overall or local cloud information. However, Sun halos are often mistaken for being part of clouds and lead to incorrect cloud coverage calculations. To solve this problem, this paper proposes a method to calculate the local cloud occlusion index based on an improved two-dimensional Gaussian function. In addition, a new parameter, Sun block luminance, is introduced to quantify the lighting conditions in the solar area. On the other hand, this paper constructs a novel hybrid model, which introduces asymmetric convolution and SE attention module to enhance the extraction ability of sky image features. The test results show that, under sunny and cloudy conditions, the RMSE, MAE and

R
2

values of the proposed model are 0.562, 0.462 and 0.989 on sunny days, 3.119, 2.248 and 0.774 on cloudy days, respectively, proving that the proposed model is superior to benchmark models.
Vlasov simulations of electric propulsion beam
Authors: Cui Chen , Wang Joseph 
Published: November 2024

Abstract
A grid-based Vlasov simulation model is developed to simulate the two-dimensional unmagnetized electric propulsion (EP) plasma beam emission process. Comparing to the standard fully kinetic Particle-in-Cell simulation, the grid-based Vlasov simulation method eliminates the interference of particle noise and is capable of resolving higher-order velocity moment, such as electron heat flux, accurately. Vlasov simulations are carried out to investigate the effects of microscopic electron kinetics on macroscopic electron thermodynamics in EP beam. We find that the electron velocity distribution function (eVDF) exhibits a near-Maxwellian shape but with a depleted negative velocity tail in the beam direction and a ‘top-hat’ shape in the transverse direction. Macroscopically, the electrons confined within the quasi-neutral beam core region has a near constant temperature along the beam direction but follow a near-adiabatic cooling process as they expand outward in the transverse direction. The electron heat flux is dominated by the x-direction tensor component. The connection between the eVDF skewness and the electron heat flux suggests a pathway to develop a microscopic physics based electron closure relation for macroscopic electron thermodynamic process in unmagnetized plasma beam expansion.
Nanoindentation mechanical studies of bulk AlN single crystals with different orientations
Authors: Zhou Hao , Chen Kebei , Gao Xiaodong , Zheng Shunan , Zeng Xionghui , Wang Chuang , Wang Yue , Pan Yangye , Xu Ke 
Published: November 2024

Abstract
This study utilized nanoindentation to perform nano-mechanical tests on freestanding aluminum nitride (AlN) single crystal substrates with (0002), (10–10), and (11–20) orientations prepared by the physical vapor transport (PVT) method with varying indentation depths. The results indicate that the c-plane exhibits greater hardness and smaller Young’s modulus compared to other orientations. Moreover, the mechanical properties of AlN with different orientations demonstrate consistency with the indentation size effect, showing a decrease in both hardness and Young’s modulus with increasing indentation depth. Surface morphology of the indentations was observed using SEM, revealing that at high loads, no obvious cracks were found in the c-plane indentation except for slight deformation, while the m-plane and a-plane indentations produced cracks extending along the a- and m-directions, respectively. Cathodoluminescence (CL) results demonstrated that dislocations and structural defects generated by the indentation produced the luminescence quenching. Notably, the inverted triangular dislocation slip region was clearly observed in the panchromatic CL images of c-plane indentation. The anisotropy of the phonon peaks at different crystal planes and the nature of the local stress at the indentation were further analyzed using Raman spectroscopy.
Joint impact of self-heating effect and lattice stress on the design performance of Si1−
xGex FinFET with advanced process integration
Authors: Zhao Pan , Zhou TaoYu , Liu NaiQi , He YanDong , Du Gang 
Published: December 2024

Abstract
In advanced FinFET process simulations, a strong correlation exists between the stress induction mechanism and the severe self-heating effect (SHE). These two factors are interrelated, and their interaction further diminishes the thermal conductivity of the device. This article employs computer-aided design for three-dimensional simulations and introduces a process-oriented simulation method. We investigate the influence of various stress sources including lattice stress, channel stress, stress relaxation buffer (SRB), and source/drain (S/D) extrapolation stress on FinFET performance in different directions under self-heating conditions, specifically analyzing silicon germanium (SiGe) and germanium-based FinFET. The results indicate that, under the influence of SHE, the y–y direction stress in the device channel increases by nearly 600 MPa. Self-heating significantly affects stress distribution within the device; in simulations of germanium-based devices, the inferior intrinsic material properties and thermal conductivity of pure germanium result in a maximum lattice temperature that is substantially higher than that of pure silicon devices. The impact of SHE and lattice stress on the performance of advanced FinFET is explored, revealing that the coupling effect of self-heating and lattice stress has a profound influence on device design performance.
Magnetostrictive shunt for vibration control and isolation: model, characteristics and similarities with piezoelectric shunt
Authors: Berardengo M , Mercato M , Manzoni S 
Published: December 2024

Abstract
This paper addresses the use of magnetostrictive (MS) shunt for vibration control and isolation. The mathematical treatment and the analytical formulas obtained are compared to those related to piezoelectric shunt, showing that they present the same form, implying the possibility of using the shunt optimisation formulas and control techniques developed for piezoelectric shunt in the context of MS shunt. Furthermore, the paper evidences the aspects which make the two types of shunt different when considering practical applications, also highlighting their effect on the controlled system and the main implications on the feasibility of the MS shunt. The theoretical results were validated by means of an experimental campaign in which MS shunt was employed to the aim of vibration isolation.
Multi-direction vibration isolation via transverse isotropy control of metal rubber
Authors: Ma Yanhong , Tang Xiangxin , Wang Yongfeng , Hong Jie 
Published: December 2024

Abstract
Metal rubber (MR) is widely used for vibration isolation due to its high damping and designable stiffness, but the isolation efficiency is relatively low in the non-molding direction due to its transverse isotropy. In this paper, the transverse isotropy of MR is controlled by design of manufacturing parameters (wire diameter, spiral diameter and compression ratio), material parameter (relative density) and geometric structure, to improve the isolation efficiency in the non-molding direction. Firstly, the helix unit was adopted to establish the relation between the transverse isotropy of MR material and manufacturing parameters, and manufacturing parameters were designed to control the transverse isotropy of MR material. Next, based on parametric modeling and genetic algorithm, material parameters and geometric structure were optimized to control the transverse isotropy of MR isolator. Finally, the transverse isotropy of the designed MR isolator was tested by quasi-static experiments, and multi-direction vibration isolation performance was verified by random vibration experiments. It is demonstrated that the transverse isotropy is controlled efficiently, and the vibration isolation efficiencies of the proposed MR isolator are all up to 85% under 15–2000 Hz broadband random vibration in X, Y and Z directions.
Z

n

symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates
Authors: Guo Ze-Hong , Zhu Qizhong 
Published: November 2024

Abstract
Supersolid is an exotic state of matter characterized by both superfluid properties and periodic particle density modulation, due to spontaneous breaking of U(1) gauge symmetry and spatial translation symmetry, respectively. For conventional supersolids, continuous translation symmetry breaking is accompanied by one gapless Goldstone mode in the excitation spectra. An interesting question naturally arises: what is the consequence of breaking discrete translation symmetry for supersolids? In this work, we study the consequence of discrete symmetry breaking in a

Z

n

supersolid resulting from spontaneous breaking of a discrete

Z

n

symmetry, or equivalently, a discrete translation symmetry. This

Z

n

supersolid is realized in the stripe phase of spin–orbit-coupled Bose–Einstein condensate under an external periodic potential with period

1

/

n

of intrinsic stripe period. For

n
⩾
2

, there are n degenerate ground states with spontaneously broken lattice translation symmetry. The low-energy excitations of

Z

n

supersolid include a pseudo-Goldstone mode, whose excitation gap at long wavelength limit is found to decrease rapidly with n. We further numerically show that, when confined in a harmonic trap, a spin-dependent perturbation can result in the transition between degenerate ground states of

Z

n

supersolid. With the integer n tunable using the experimental technique of generating subwavelength optical lattice, the

Z

n

supersolid proposed here offers a cold atom platform to simulate physics related with generic

Z

n

symmetry breaking in a highly controllable setting.
Experimental Liouvillian exceptional points in a quantum system without Hamiltonian singularities
Authors: Abo Shilan , Tulewicz Patrycja , Bartkiewicz Karol , Özdemir Şahin K , Miranowicz Adam 
Published: November 2024

Abstract
Hamiltonian exceptional points (HEPs) are spectral degeneracies of non-Hermitian Hamiltonians describing classical and semiclassical open systems with losses and/or gain. However, this definition overlooks the occurrence of quantum jumps in the evolution of open quantum systems. These quantum effects are properly accounted for by considering quantum Liouvillians and their exceptional points (LEPs). Specifically, an LEP corresponds to the coalescence of two or more eigenvalues and the corresponding eigenmatrices of a given Liouvillian at critical values of external parameters (Minganti et al 2019 Phys. Rev. A 100 062131). Here, we explicitly describe how standard quantum process tomography, which reveals the dynamics of a quantum system, can be readily applied to detect and characterize quantum LEPs of quantum non-Hermitian systems. We conducted experiments on an IBM quantum processor to implement a prototype model with one-, two-, and three qubits simulating the decay of a single qubit through competing channels, resulting in LEPs but not HEPs. Subsequently, we performed tomographic reconstruction of the corresponding experimental Liouvillian and its LEPs using both single- and two-qubit operations. This example underscores the efficacy of process tomography in tuning and observing LEPs even in the absence of HEPs.
Alena Tensor in unification applications
Authors: Ogonowski Piotr , Skindzier Piotr 
Published: November 2024

Abstract
Alena Tensor is a recently discovered class of energy-momentum tensors that provides mathematical framework in which, as demonstrated in previous publications, the description of a physical system in curved spacetime and its description in flat spacetime with fields are equivalent. The description of a system with electromagnetic field based on Alena Tensor can be used to reconcile physical descriptions. (1) In curvilinear description, Einstein Field equations were obtained with Cosmological Constant related to the invariant of the electromagnetic field tensor, which can be interpreted as negative pressure of vacuum, filled with electromagnetic field. (2) In classical description for flat spacetime, three densities of four-forces were obtained: electromagnetic, against gravity (counteraction to gravitational free-fall), and the force responsible for the Abraham-Lorentz effect (radiation reaction force). Obtained connection of Einstein tensor with gravity and radiation reaction force, after transition to curvilinear description, excludes black hole singularities. There was obtained Lagrangian density and generalized canonical four-momentum, containing electromagnetic four-potential and a term responsible for the other two forces. In this description charged particles cannot remain at complete rest and should have spin, their energy results from the existence of energy of magnetic moment and the density of this energy is part of the Poynting four-vector. The distribution of charged matter was expressed as polarization-magnetization stress-energy tensor, what may explain why gravity is invisible in QED. 3) In quantum picture, QED Lagrangian density simplification was obtained, and the Dirac, Schrödinger and Klein–Gordon equations may be considered as approximations of the obtained quantum solution. Farther use of Alena Tensor in unification applications was also discussed.
Studies on α and cluster radioactivity using the improved universal (UNIV) curve
Authors: Santhosh K P 
Published: November 2024

Abstract
In this article, we modified the universal (UNIV) formula of Poenaru et al [Phys. Rev. C 83, 014601 (2011)] by including the disintegration energy-dependent formula as a preformation factor. The improved universal formula (Imp UNIV) is applied to α decay of 309 heavy nuclei in the region Z = 74–93 and found that the standard deviation,

σ

of decimal logarithmic half-life decreased from 0.64312 (UNIV) to 0.56467 (Imp UNIV). It is also observed that the

σ

value decreased from 0.70502 (UNIV) to 0.68189 (Imp UNIV) in the case of cluster radioactivity showing improvement of present formalism Imp UNIV over UNIV in reproducing experimental half-lives of α and cluster radioactivity of heavy nuclei. The α decay half-lives of 80 superheavy nuclei (SHN) with

Z
≥
104

have also been investigated by UNIV and Imp UNIV formula and the

σ

value is found as 1.10681 and 0.69399 respectively, which shows that experimental α half-lives of SHN can be reproduced well by using Imp UNIV formula. The plot connecting the sum of the decimal logarithm of half-life and preformation factor,

log

10

T

1
/
2

(
s
)

+

log

10

S

versus the decimal logarithm of external penetrability,

−

log

10

P

s

for Imp UNIV is found linear for both α and cluster radioactivity with the same slope and intercept showing the universal nature of the curve. The good agreement between our predictions on α decay of Og (Z = 118) isotopes with the generalized liquid drop model (GLDM) and Royer formula reveals our formalism's reliability. The neutron shell closure at N = 184 and N ≈ 200 are evident in our study. The prediction of the unobserved α and cluster radioactivity performed in this study will be helpful for future experiments.
Revisiting spins of primordial black holes in a matter-dominated era based on peak theory
Authors: Saito Daiki , Harada Tomohiro , Koga Yasutaka , Yoo Chul-Moon 
Published: November 2024

Abstract
We estimate the probability distribution for the spins of the primordial black holes (PBHs) that formed during an early matter-dominated era in the Universe.
We employ the Zel'dovich approximation and focus on the linear-order effect of cosmological perturbations which causes the tidal torque.
Assuming that the fluctuations obey Gaussian statistics, we apply the peak theory of random Gaussian variables to compute the root mean square (RMS) and the probability distribution of the non-dimensional Kerr parameter a
* at their formation.
The value of a
* is evaluated through the angular momentum at the turn-around time.
We find that the RMS a̅
* with a given amplitude of the fluctuation δ
pk decreases as the amplitude increases.
This behavior allows us to set the threshold value of the amplitude of the fluctuation through the under-extremal condition a̅
* < 1.
Then we discuss the impact of spin and anisotropic collapse on the production rate of PBHs.
We find that, for σ
H ≤ 10-3 with σ
H being the square root of the variance of the fluctuation at the horizon reentry, the suppression from the spin effect is dominant, while the effect of anisotropy becomes more important for σ
H > 10-3.
Since a̅
* can be written as a function of ν := δ
pk/σ
H, we can obtain the probability distribution of a̅
*, P(a̅
*), through the probability distribution of ν characterized by a given power spectrum of the fluctuation.
P(a̅
*) depends on σ
H and the parameter γ that characterizes the width of the power spectrum.
It is shown that, in the parameter regions of our interests, substantial values of PBH spins are expected in contrast to the PBH formation in a radiation-dominated universe.
For instance, with γ = 0.6 and σ
H = 0.1, P(a̅
*) takes a maximum at aa̅
* ≃ 0.25.
Effects of Kinetic Ballooning Modes on the electron distribution function in the core of high-performance tokamak plasmas
Authors: Mazzi S. , Giruzzi G. , Camenen Y. , Dumont R. , Fontana M. , de la Luna E. , Orsitto F.P. , Senni L. , Aleynikova K. , Brunner S. , Frei B.J. , Garcia J. , Zocco A. , Frigione D. , Garzotti L. , Rimini F. , van Eester D. , Contributors JET , EUROfusion Tokamak Exploitation Team the 
Published: November 2024

Abstract
This article is dedicated to study the physical causes of a long-standing issue experienced in different tokamak devices throughout the last decades: the observed discrepancies between electron cyclotron emission (ECE) and Thomson Scattering (TS) diagnostic measurements at high temperature in the core tokamak plasmas. A recently developed heuristic model (Fontana et al 2023 Phys. Plasmas
30 122503), tested on an extensive data set from multiple pulses in the frame of recent JET campaigns, showed that such ECE-TS discrepancy could be reconciled by introducing a bipolar perturbation in the electron distribution function. Such a perturbation indeed modifies the EC emission and absorption spectra. Nonetheless, the heuristic model does not provide the physical mechanisms causing such a bipolar perturbation. In this work, detailed gyrokinetic analyses unveil the unexplored wave-particle interaction between electrons and the Kinetic Ballooning Modes (KBMs) in tokamak plasmas. The numerical studies of the core of a selected high-temperature pulse of the JET device revealed that the electron-β was large enough to destabilize KBMs. Such KBMs affect the electron distribution function in momentum space with a characteristic bipolar structure. The position of the bipolar structure in the velocity space is intimately linked to the electron diamagnetic frequency. The amplitude of the perturbation, assessed through nonlinear computations, is shown to be dependent on the amplitude of the KBM-induced turbulent fluxes. Thus, this study demonstrates that KBMs, destabilized by the high-β plasma conditions achieved in the core of high-temperature scenarios, perturb the electron distribution function forming bipolar structures in momentum space and, thereby, modifying the EC spectrum. Therefore, the reported mechanism may represent an intriguing explanation of the ECE-TS measurement discrepancy in the deep core of high-temperature plasmas.
Numerical studies of sawtooth crashes with non-monotonic safety factor profiles
Authors: Wang X. , Zhang W. , Ma Z.W. 
Published: December 2024

Abstract
The sawtooth crashes with non-monotonic q profiles are numerically investigated by the three-dimensional, toroidal-geometry MHD code (CLT). We find that, when the initial q profiles are non-monotonic, the precursors of the sawtooth crashes are with high n rather than the m/n= 1/1 kink mode (where m and n are the poloidal and toroidal mode numbers); and multiple flux tubes form just before sawtooth crashes. The dominant mode transits from higher n to n = 1 through mode-mode coupling at the nonlinear stage, and the final pressure crash is still dominated by the 1/1 mode.
Quantitative assessment system for placental gross examination with precise localization of umbilical cord insertion point
Authors: Liu Yiming , Liang Yuehua , Yu Ting , Tao Xiang , Wu Xin , Wang Yan , Li Qingli 
Published: November 2024

Abstract
A quantitative assessment for measuring the placenta during gross examination is a crucial step in evaluating the health status of both the mother and the fetus. However, in the current clinical practice, time-consuming and observer-variant drawbacks are caused due to manual measurement and subjective determination of placental characteristics. Therefore, we propose a quantitative assessment system for placenta gross examination to efficiently and accurately measuring placental characteristics according to Amsterdam Consensus, including weight and thickness of placenta, length and width of placental disc, length and diameter of umbilical cord, distance from umbilical cord insertion point to placental edges, etc. The proposed system consists of (1) an instrument designed for standard acquisition of image, weight and thickness of placenta and (2) an algorithm for quantitative morphological assessment based on precise segmentation of placental disc and umbilical cord and localization of umbilical cord insertion point. Considering the complexity of spatial distribution and ambiguous texture of umbilical cord insertion point, we design Umbilical Cord Insertion Point Candidate Generator to provide reliable umbilical cord insertion point location by employing prior structural knowledge of umbilical cord. Therefore, we integrate the Umbilical Cord Insertion Point Candidate Generator with a Base Detector to ensure umbilical cord insertion point is provided when the Base Detector fails to generate high-scoring candidate points. Experimental results on our self-collected placenta dataset demonstrate the effectiveness of our proposed algorithm. The measurements of placental morphological assessment are calculated based on segmentation and localization results. Our proposed quantitative assessment system, along with its associated instrument and algorithm, can automatically extract numerical measurements to boost the standardization and efficiency of placental gross examination.
The physics of quantum 2.0: challenges in understanding quantum matter
Authors: Lal Siddhartha , Shreshtha Mayank 
Published: December 2024

Abstract
Almost a century on from the culmination of the first revolution in quantum physics, we are poised for another. Even as we engage in the creation of impactful quantum technologies, it is imperative for us to face the challenges in understanding the phenomenology of various emergent forms of quantum matter. This will involve building on decades of progress in quantum condensed matter physics, and going beyond the well-established Ginzburg–Landau–Wilson paradigm for quantum matter. We outline and discuss several outstanding challenges, including the need to explore and identify the organisational principles that can guide the development of theories, key experimental phenomenologies that continue to confound, and the formulation of methods that enable progress. These efforts will enable the prediction of new quantum materials whose properties facilitate the creation of next generation technologies.