bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cosmological gravity on all scales. Part IV. 3× 2 pt Fisher forecasts for pixelised phenomenological modified gravity
Authors: Srinivasan Sankarshana , Thomas Daniel B. , Taylor Peter L. 
Published: February 2025

Abstract
Stage-IV large scale structure surveys are promising probes of gravity on cosmological scales. Due to the vast model-space in the modified gravity literature, model-independent parameterisations represent useful and scalable ways to test extensions of ΛCDM. In this work we use a recently validated approach of computing the non-linear 3 × 2 pt observables in modified gravity models with a time-varying effective gravitational constant μ and a gravitational slip η that is binned in redshift to produce Fisher forecasts for an LSST Y10-like survey. We also include in our modelling an effective nulling scheme for weak-lensing by applying the Bernardeau-Nishimichi-Taruya (BNT) transformation that localises the weak-lensing kernel enabling well-informed scale cuts. We show that the combination of improved non-linear modelling and better control of the scales that are modelled/cut yields high precision constraints on the cosmological and modified gravity parameters. We find that 4 redshift bins for μ of width corresponding to equal incremental ΛCDM growth is optimal given the state-of-the-art modelling and show how the BNT transformation can be used to mitigate the impact of small-scale systematic effects, such as baryonic feedback.
Light from darkness: history of a hot dark sector
Authors: Coy Rupert , Kimus Jean , Tytgat Michel H.G. 
Published: February 2025

Abstract
We study a scenario in which the expansion of the Early Universe is driven by a hot hidden sector (HS) with an initial temperature T' that is significantly higher than that of the visible sector (VS), T' ≫ T. The latter is assumed to be made of Standard Model (SM) particles and our main focus is on the possibility that dark matter (DM) is part of the dominant HS and that its abundance is set by secluded freeze-out. In particular, we study the subsequent evolution and fate of the DM companion particle after freeze-out all the way toward reheating of the VS. To make this scenario more concrete, we work within dark QED, a framework in which the DM is a Dirac fermion and its companion, a massive dark photon; coupling between the SM and HS is through kinetic mixing. We provide a detailed and comprehensive numerical and analytical analysis of the different regimes of reheating of the VS. Extending and complementing the work of Coy et al. on the“domain of thermal dark matter candidates” [1], we use our results to explore the viable parameter space of both the DM matter particle and its companion, here the dark photon. We show that current and future fixed target experiments can probe scenarios along which the expansion was driven by relativistic DM photons, a scenario dubbed relativistic reheating. We also set new bounds on the maximal temperature ratio T'/T and argue for an extension of the domain toward very large DM masses, m
dm ∼ 1011 GeV. These are possible assuming that DM annihilation is bounded by unitarity and that reheating of the VS occurs just before big bang nucleosynthesis. We also discuss some possible implications for (and constraints on) baryogenesis, including simple leptogenesis mechanisms, and how they may set additional constraints on the domain of DM candidates.
Laboratory test and analysis of mechanical parameters that affect the speed of polycrystalline diamond compact drill bit
Authors: Dong Zhiyu 
Published: February 2025

Abstract
Mechanical parameters which include weight on bit (WOB) and rotation speed have great influences on the drilling speed during the drilling process. During drilling operations, a different combination of mechanical parameters will lead to vary wide actual results when drilling to a different formation. For different formations, the rational combination of mechanical parameters can improve the speed of drilling footage, while unreasonable mechanical drilling process parameters can lead to slow or even cause PDC drill bit severe wear. In this paper, a reasonable mechanical parameter combination is given in the indoor experimental simulation of the impact on the speed of the drill bit when drilling core samples of different combinations. Laboratory experiments and field tests show that: the PDC drill bit for drilling speed is very sensitive to pressure, under the premise of a full purification at the bottom, the relationship between WOB and drilling speed is almost linear, but different rock strengths of WOB while drilling speed changes the rate is different. In fact, the pressure is gradually increased as the drilling, which will cause the debris to be not promptly cleared, making the drilling speed decrease. By a large number of laboratory and field tests, curves of PDC drilling speed and rotation speed can be obtained. When WOB is low, the drilling speed is increased with the increasing rotation speed, but when high drilling speed gradually slows down with increasing rotation speed, this is mainly caused by not timely removing cuttings.
Numerical simulation of different microstructures on fiber filtration efficiency
Authors: Chen Xueyan , Wang Jingyue , Wang Meiqing 
Published: February 2025

Abstract
This paper utilizes a coupled model of the lattice Boltzmann method and discrete element method (LBM-DEM) to simulate the flow field and particle motion in a three-dimensional porous medium. It investigates the impact of different microstructural characteristics of filter media on filtration performance under the same porosity conditions. The model not only considers the mechanisms of inertial deposition and electrostatic forces but also incorporates the effects of Brownian diffusion and dielectrophoresis, providing a preliminary comparison of various filtration mechanisms. The research results indicate that: (1) under identical porosity conditions, the filtration efficiency of unidirectional interlaced fibers significantly surpasses that of other fiber models with different microstructures; (2) the model integrating four filtration mechanisms demonstrates higher filtration efficiency.
A comparison design of truss-type leg between rack-type chord and pin-type chord
Authors: Zhang Yong , Qian Lijun , Gao Baokun , Sun Xuerong 
Published: February 2025

Abstract
The rack plate is the core structural part for conventional truss-type legs, meanwhile the rack plate limits the economical efficiency of legs due to its characteristics. Aiming at the limit of rack plate, this paper raises a type of pin-type chord for a truss-type leg according to engineering experience. Based on the same weight, taking a self-elevated platform for example, this study uses FEA software to analyze and compare the loads and leg results of rack-type chords and pin-type chords. The result shows the pin-type chord has better mechanical properties, which provides a reference for the optimization of the subsequent self-elevated truss-type leg.
Kronecker product and a related useful conjecture
Authors: Wang Xiling 
Published: February 2025

Abstract
This paper not only explores in detail the basic properties of the Kronecker product, such as the application of the union law, the distributive law, the transpose and the conjugate transpose, as well as the trace and the rank of the Kronecker product, but also rigorously proves these properties by means of mathematical induction or direct proofs. In addition, this paper extends these properties to Kronecker n-matrices and explores the applicability of inverse matrices and determinants to Kronecker products. More importantly, we introduce a conjecture related to the long-standing problem of distillability, which is partially solved when the number of nonzero elements is restricted. By showing the framework of the proof of the conjecture and a special case, we provide new perspectives for further research in this area.
δ calculus and generalized exponential function on time scales
Authors: Tang Yurong , Li Xin 
Published: February 2025

Abstract
This paper aims to develop δ calculus on time scales. First of all, the central difference derivative (δ derivative) and δ integral on a time scale are defined, and some fundamental properties are expounded. Secondly, the generalized exponential function and its theorems on a time scale are studied.
On 3-parameter generalized quaternions with k-pell-lucas numbers as components
Authors: Yong Deng , Tang Jian-Gang 
Published: February 2025

Abstract
At present, numerous research studies have been conducted on Fibonacci quaternions and their generalizations. Recently, Şentürk and Ünal introduced 3-parameter generalized quaternions. This paper introduces the k-Pell-Lucas 3-parameter generalized quaternions and explores their basic properties and Binet formula. Moreover, by using the Binet formula, some generalized forms of famous sequence identities are given.
Positive integer solutions of an equation involving Euler, generalized Euler, and Smarandache functions
Authors: Jiang Lianxia , Wang Li , Zhang Sibao , Tang Jiangang 
Published: February 2025

Abstract
This study investigates the positive integer solutions of an equation involving the Smarandache function. The equation is given by tφ(n) = φ
2 (n) + S(n
16), where φ(n) represents the Euler function, φ
e (n) represents the generalized Euler function with e as a positive integer, and S(n) represents the Smarandache function. The solutions of this equation are discussed, and it is proven that the equation only has positive integer solutions when t = 1, 2, 3, 6, 7, 9, 12, 17, 18, 19. Furthermore, all positive integer solutions of the equation are provided.
Analytical expression of convection-diffusion equation with diffusion related to space and momentum in supernova remnants
Authors: Fang Lili 
Published: February 2025

Abstract
Since the convection-diffusion equation was first used to discuss the transport properties of highenergy particles, the theory of shock particle acceleration has experienced rapid development. Scientists have proposed various acceleration mechanisms to explain the existence of these high-energy particles in supernova remnants, but the commonly accepted primary process is diffusion shock acceleration. The interaction between shock waves and particles can be approximated by the convection-diffusion equation. Previous research on the convection-diffusion equation focused on the correlation between diffusion coefficient and momentum, treating the diffusion coefficient as a spatial constant. However, in reality, the diffusion coefficient is related to both position and particle energy. So, in this article, we consider the position and energy dependence of the diffusion coefficient. By analyzing the actual physical environment in supernova remnants, we provide specific expressions of position and energy dependence, and use the (inverse) Laplace transform analysis method to obtain the specific analytical expression of the particle distribution function. Finally, our result is to present the particle distribution function at the positions before and after the shock wave in the form of the Whittaker M function, thus solving the more general particle propagation equation for diffusion shock wave acceleration – the convection-diffusion equation, which lays the foundation for further exploration of the radiation origin of supernova remnants.
Curvature estimation of the level set of solutions of the elliptic Hessian equation
Authors: Yu Xuemei , Kong Xiangming , Tian Xiaoqiang 
Published: February 2025

Abstract
Hessian equations are an important class of nonlinear partial differential equations. The geometric convexity estimation of PDE solutions and the estimation of the level set of solutions are important research topics in elliptical partial differential equation theory. Curvature is widely used to describe the degree of curvature of curves, which is a very important basis in the study of differential geometry. We will study the completely nonlinear elliptical Hessian equation σn
(D
2
u) = eu
in n-dimensional Euclidean space. Then, the auxiliary functions, which are directly related to the level set of the solutions, are established. Under the condition of 0 boundary Dirichlet, with the help of the Maximum principle, we will make an upper bound estimate of the curvature for the level set of the solutions. The main contents of this paper are mean curvature and Gauss curvature.
Several upper bound analysis for the maximum determinant of a matrix formed by 1 to n
2
Authors: Li Haosen 
Published: February 2025

Abstract
This paper discusses the upper bound analysis for the determinant of a matrix constructed using the numbers 1 to n
2. We propose four different methods to approximate the upper bound, including using the AM-GM inequality, Hadamard’s inequality, maximizing diagonal elements, and the Perron-Frobenius theorem. Our results provide important insights into the structure and properties of matrices that maximize their determinants.
Computational method of conformal mapping from unbounded multi-connected regions onto annulus with spiral slit domains
Authors: Luo Dan , Lu Yibin , Zhao Xin 
Published: February 2025

Abstract
In this paper, based on the charge simulation method, a conformal mapping computational method is proposed to map the unbounded multiply connected regions onto the annulus with spiral slit domains. In addition, for the system of pathological equations generated during the conformal mapping process, it is proposed to solve them by using the GMRES(m) method, which in turn constructs an approximate conformal mapping function with high accuracy. Finally, numerical examples validate the effectiveness of the algorithms in this paper.
Effect of optical polarization error on the magnetic resonance signal of NMOR atomic magnetometer
Authors: Tian Mengnan , Chai Yanchao , Lu Zhenglong , Quan Wei , Jiang Liwei 
Published: February 2025

Abstract
In NMOR magnetometers, we choose the linear polarized light to pump atoms, and the polarization state is the key factor affecting the evolution of alkali metal atoms. However, polarization errors are introduced due to the refraction of the glass surfaces of the cell and the imperfection of optical devices, which causes the actual laser light to be elliptically polarized. In this paper, the optical ellipticity for this system is accurately measured by the π transition principle first. Then, the magnetic resonance signals under different ellipticity are investigated theoretically and experimentally, and the atomic polarization state is visualized. The results show that the optical ellipticity error introduced by the system will reduce the measurement accuracy and sensitivity of the system, and it is meaningful to use high extinction ratio optical devices and introduce the quarter-wave plate to offset the circularly polarized components.
Modified biochar for the adsorption of roxarsone and arsenic Ions in water
Authors: Jiang Shixiong , Zhang Siyu , Dong Yuyao , Zhang Yujie 
Published: February 2025

Abstract
The research findings show that the maximum adsorption capacity of arsenic ions and roxarsone significantly increases under optimized reaction conditions (temperature 30°C, pH value 6, adsorbent dosage 0.6 g/L). The degree and direction of influence of different reaction conditions on the removal rate also vary[4]. The combination model of multiple linear regression and random forest regression shows good fitting between the predicted results and actual data, indicating that the model can accurately reflect the influence of adsorption conditions on the removal rate and provide support for the reliability of the experimental results. Based on the experimental data obtained under the optimal reaction conditions, these findings not only verify the high efficiency of modified biological carbon in removing arsenic under specific conditions[5], but also provide theoretical basis and data support for designing more efficient removal schemes and optimizing process parameters in the future.
A version of Schwarz lemma for perturbed Dirac operator in octonionic analysis
Authors: Shi Yingying , Wang Haiyan 
Published: February 2025

Abstract
As octonionic analysis is a non-associative extension of quaternionic analysis and the perturbed Dirac operator serves as a decomposition of the Helmholtz operator, the perturbed Dirac operator in octonionic analysis has garnered significant attention. This article focuses on the integral formula and the estimation of perturbed Dirac calculations within the framework of octonionic analysis. Firstly, we present the Cauchy-Pompeiu formula for perturbed Dirac operators using Stokes’ theorem. Subsequently, by applying the aforementioned integral formula in conjunction with the Poisson integral formula, we derive the estimated value of the function that is nullified by the perturbed Dirac operator, which yields a form of the Schwarz lemma.
Bell nonlocality measure of density matrix based on trace distance
Authors: Fu Yuxuan , Li Liting 
Published: February 2025

Abstract
Quantum information technology exhibits advantages in terms of algorithm efficiency, communication security, and other aspects compared to classical information technology, partially due to quantum nonlocality, which is a characteristic that distinguishes quantum mechanics from classical mechanics. Compared to quantum entanglement and quantum steering, Bell nonlocality exhibits stronger quantum properties in a certain sense. However, research on efficient estimation of Bell nonlocality of general quantum states remains rare. This work proposes a generalized Bell nonlocality measure of density matrices. Our method generalizes the fundamental matrix for classical correlation and applies it to experimental scenarios of various dimensions. We prove that this measure of Bell nonlocality is well-defined. We also propose a relaxation algorithm for numerically estimating this measure. Applying the see-saw method, the algorithm obtains an upper bound on this measure. Numerical experiments show the effectiveness of our method in low dimensions and suggest that it could be used in high dimensions.
Research on resonance frequency of low-frequency bender disk transducer under high pressure
Authors: Wang Jian , Yu Yongpo 
Published: February 2025

Abstract
Due to the low resonance frequency, the existing low-frequency bender disk transducer is difficult to resist due to high hydrostatic pressure due to its rigidity. With the introduction of the air pressure compensation technology, the transducer has the ability to dynamically balance with the increase of the external water pressure in its inner cavity, while the problem caused by large depth use is that the resonance frequency of the transducer increases with the increase of the inner cavity gas stiffness. Firstly, the equivalent circuit model of the transducer with and without air pressure compensation is analyzed, and the resonant frequency variation of the transducer is qualitatively analyzed. Then, the finite element model of air pressure compensation is established to calculate the resonant frequency of a bender disk transducer with a fixed size of acoustic radiation surface, and the variation trend of cavity height and resonant frequency of the transducer is found. Then, the physical production of the transducer is completed. Through the comparison between the test results and the simulation values, it is verified that the finite element simulation method can predict the frequency deviation phenomenon of the air pressure compensation bender disk transducer.
Injective coloring of edge corona product of graphs
Authors: Zhao Wenying , Tian Shuangliang 
Published: February 2025

Abstract
The injective chromatic number χi(G) of a graph G is the minimum number of colors needed to color the vertices of G such that different vertices with the same neighbor are colored differently. In this here, we get some exact values of the injective chromatic number of the edge corona product of some graphs.
Analyses on combustion characteristics and the region of corrosion failure risk of high-temperature heating-surface in peak-loading power plant boiler
Authors: Xu Nan , Ding Shaoming , Hu Yuan , Li Yanhui , Wu Hongying , Wang Lei , Ju Guangyu , Han Fengshuang 
Published: February 2025

Abstract
Deep peaking will be the operating norm for thermal power units to address the intermittent supply of clean energy. However, the heat exchanger serves the temperature fluctuation conditions in the boiler during deep peaking. It will result in a risk of corrosion failure of high-temperature heating surfaces such as superheater and reheater. The paper investigated the combustion characteristics of coal-fired boilers at 100% and 50% loads. The temperature and velocity field distributions under different loads are clarified. The corrosion failure risk area of the furnace heating surface in the boiler was also analyzed based on the flue gas temperature distribution in the boiler furnace at 100% and 50% loads. The results show that the 10th platen of the rear platen superheater is at the highest service temperature and in the region with more significant temperature fluctuations, which is susceptible to corrosion failure. The paper provides a theoretical reference for the safe operation and periodic maintenance of deep-peaking units.
Techno-economic and environmental evaluation of integrated microgrid systems for electrification and hydrogen production
Authors: Hussam Wisam K. , Jaman Asif , Mibarki Raouf , Mahmud Rafid Al , Sheard Gregory J. 
Published: February 2025

Abstract
The present work investigates the feasibility of electrolyzer-based hydrogen generation through a hybrid renewable energy system. Evaluations focusing on technical, economic and environmental evaluations are conducted to determine the optimized system architectures that maximize energy efficiency and environmental benefits. Three hybrid renewable energy systems were assessed, including grid-connected and grid isolated configurations of solar PV array, wind turbines (WT), hydrogen fuel cells, and backup battery bank. The lowest levelized energy cost, at 0.539 $/kWh, and the lowest cost of producing hydrogen, at 6.85 $/kg were achieved by integrating solar PV and wind turbine with the grid connectivity. Integrating Solar PV and wind turbine connected to the power supply grid resulted in the lowest levelized energy cost, at However, in the case of a grid-isolated system utilizing fuel cells or battery storage banks, the hydrogen cost rises above 8.0 $/kg due to the higher capital expenses associated with the system. With yearly carbon dioxide emissions of 240841.66 kg, the optimized system produces 111 877 kg of green hydrogen annually. Additionally, the optimized system (System 1) has the lowest Human Health Damage (HHD) and Ecosystem Damage (ESD), with its Human Development Index (HDI) slightly surpassing those of Systems 2 and 3. However, System 3 creates more jobs.