bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling between the Alfvén eigenmode and edge-coherent mode on the experimental advanced superconducting tokamak
Authors: Wang M Y , Liu A D , Zhou C , Zhuang G , Feng X , Zhang J , Zhong X M , Zhang R B , Wang Y H , Yang J X , Li H , Lan T , Xie J L , Liu H Q , Liu Z X , Mao W Z , Ding W X , Liu W D 
Published: March 2024

Abstract
High-frequency electromagnetic fluctuations and edge-coherent modes (ECMs) have been detected by Doppler reflectometry (DR) in the pedestal region of the Experimental Advanced Superconducting Tokamak. The frequency of the electromagnetic fluctuations was proportional to the Alfvén velocity and localized in the ellipticity-induced Alfvén eigenmodes (EAEs) gap in the Alfvén continuum. Therefore, the fluctuations are presumed to be EAE. The DR measurements of poloidal flow fluctuations show that EAEs and ECMs have amplitude envelopes that are localized near the bottom of the radial electric field well. Simultaneous EAE and ECM activity generates sidebands at

f

E
A
E

±

f

E
C
M

, the strengths of the upper and lower sidebands are unequal, with the upper sideband being stronger. This is consistent with the theoretical prediction of Chen et al. Compared with ECM-only discharges, the inclusion of EAEs leads to an increase in

D
α

intensity, thus indicating enhanced outward particle transport.
Weyl points and anomalous transport effects tuned by the Fe doping in Mn3Ge Weyl semimetal
Authors: Rai V , Jana S , Perßon J , Nandi S 
Published: March 2024

Abstract
The discovery of a significantly large anomalous Hall effect in the chiral antiferromagnetic system—Mn3Ge—indicates that the Weyl points are widely separated in phase space and positioned near the Fermi surface. In order to examine the effects of Fe substitution in Mn3Ge on the presence and location of the Weyl points, we synthesized (Mn

1
−
α

Fe

α

)
3

Ge (

α
=
0
−
0.30

) compounds. The AHE was observed in compounds up to α = 0.22, but only within the temperature range where the magnetic structure remains the same as the Mn3Ge. Additionally, positive longitudinal magnetoconductance and planar Hall effect (PHE) were detected within the same temperature and doping range. These findings strongly suggest the existence of Weyl points in (Mn

1
−
α

Fe

α

)
3

Ge (

α
=
0
−
0.22

) compounds. Further, we observed that with an increase in Fe doping fraction, there is a significant reduction in the magnitude of anomalous Hall conductivity, PHE, and positive longitudinal magnetoconductance, indicating that the Weyl points move further away from the Fermi surface. Consequently, it can be concluded that suitable dopants in the parent Weyl semimetals have the potential to tune the properties of Weyl points and the resulting anomalous electrical transport effects.
First-principles study on the electronic structure of n-type magnetic semiconductor Ba(Zn 1−x
Co x
)2As2
Authors: Zhi Guo-Xiang , Xu Chenchao , Zhao Xueqin , Dong Jinou , Guo Shengli , Man Huiyuan , Ding Cui , Fu Licheng , Gu Yilun , Xie Lingfeng , Pan Xun , Cao Chao , Ning Fanlong 
Published: March 2024

Abstract
We perform systematic first-principles calculations on the electronic structure of n-type magnetic semiconductor Ba(Zn

1
−
x

Co
x
)2As2 with the facilitation of HSE06 hybrid functional. Supercells are used to consider the doping of Co atoms, and the first-principles band structures are unfolded for clarity. Based on the calculation results, magnetic states are preferred by individual Co atoms doped in Ba(Zn

1
−
x

Co
x
)2As2 at diluted limit, and carriers are originated mainly from situations where only one Co atom exists in the nearest neighbor Zn sites out of certain doped Co atoms. The origination of carriers can be explained by the density of states and the unfolded band structure, where it is found that the scattering effects from single Co atom is small but quite large when more Co atoms are located at adjacent Zn sites. The large scattering effects of two adjacent Co atoms will alter the band structures near the Fermi-level. Carriers in Ba(Zn

1
−
x

Co
x
)2As2 mainly originate from the As-4p orbitals, with partial contributions from the Co-3d orbitals. Our work provides new insights into the origin of the n-type carriers in magnetic semiconductors and will inspire the development of new magnetic semiconducting systems.
Study on current-carrying tribological characteristics of C-Cu sliding electric contacts under water accumulation from rainfall condition
Authors: Gao Guoqiang , Wang Qingsong , Wang Hong , Qian Pengyu , Peng Wei , Ma Yaguang , Dong Deliang , Wang Xiangfei , He Shuhang , Yang Zefeng , Wu Guangning 
Published: March 2024

Abstract
Pantograph-OCS system sliding electrical contact is the only way for train energy transmission, which determines the safety and stability of energy transfer. And the current-carrying wear is the core factor that affecting the service performance of C-Cu contact pairs. C-Cu mate pairs often work for a long time in rainy/humid environments due to its exposed nature of work, and the contact interface often accumulates a large amount of water. Existing operating experience has shown that the carbon sliding plate of the pantograph experiences abnormal wear and frequent failure during rainfall, resulting in a significant decrease in service performance and lifespan. This article found that the thickness of the water film at the contact interface has a significant impact on the current carrying friction and wear performance of C-Cu contact pairs. When the thickness of the water film exceeds a certain range, the carbon skateboard will cause abnormal wear under high current, with the wear amount being more than three times the minimum value. The contact resistance also increases by 53.9%, which is related to the obstruction of current transmission. It also proves that the water film lubrication effect can be restored during the process of rainfall decreasing from large to small. The research can help to provide a suitable maintenance policy for pantograph and catenary system during the rainy season.
Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method
Authors: Oad Nisha , Pandya Divya , Rawat Sheetal , Chandra Prakash , Tyagi Mohit , Tripathi Brijesh , Gurrala Pavan 
Published: March 2024

Abstract
The powder material Gd3Ga3Al2O12:Ce (GGAG doped with Cerium) has garnered significant attention in radiation detection due to its high light yield and rapid decay time. Despite its potential, the synthesis of high-quality and reproducible GGAG:Ce scintillating powder remains a considerable challenge. In this study, we present a solvothermal approach with an annealing temperature of 1300 °C for producing cerium-doped GGAG powder with varying concentrations (4, 2, and 0.5 mol%). The structural and luminescent characteristics were meticulously examined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL), radioluminescence (RL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). XRD analysis confirmed the single-cubic phase garnet structure of the synthesized powder. By comparing the intermediate solvothermal products synthesized at different sintering temperatures (900 °C for 3 h and 1300 °C for 1 and 3 h), a direct correlation between solvothermal conditions and the structure/property relationships of the product was established. FESEM images revealed an ellipsoidal to irregular morphology of the as-synthesized GGAG:Ce microparticles, ranging from 0.1 to 0.3 μm, regardless of the Ce concentration. PL spectra demonstrated a strong emission peak at approximately 550 nm, characteristic of Ce3+ ions. RL data confirmed the peak luminescence at around 550 nm, with an almost twofold increase in intensity as the concentration of Ce3+ increased from 0.5 mol% to 4 mol%. XPS data disclosed the Ce3+/Ce4+ ratio in solvothermally synthesized GGAG:Ce, wherein Ce loading of 4 mol% demonstrated the increase in Ce3+ concentration to 95%, whereas the concentration of Ce4+ decreased to 5%. Notably, the highest luminescence efficiency was achieved with GGAG:Ce at a 4 mol% concentration. Thus, the solvothermal method employed in GGAG:Ce synthesis presents a straightforward approach, yielding rapid results with precise control over particle morphology and size.
Investigation of optical and electrical properties of TiO2, SiO2, and Ag single and multilayer thin films using spectroscopic ellipsometry and spectrophotometry methods: prepared by spin coating and DC magnetron sputtering
Authors: Entezarmahdi Hamid , Sedghi Hassan 
Published: March 2024

Abstract
In this work, spectroscopic ellipsometry was used to study the optical and electrical properties of TiO2 and SiO2 thin films deposited by spin-coating at different coating rotation speeds and annealed at various temperatures. In addition, Ag thin films of different thicknesses were deposited by DC magnetron sputtering at ambient temperature. In this method, the optical band gap for TiO2 thin films is between 3.15–3.85 eV, and for SiO2 thin films, it is between 3.2–3.8 eV. The optical properties, including reflectance, transmittance, and absorbance, of TiO2, SiO2, and Ag thin films in the form of single and multilayer thin films in the wavelength range of 200–2500 nm, were investigated using an ultraviolet-visible-near infrared (UV–vis-NIR) dual-beam spectrophotometer. In the TiO2/Ag/SiO2 multilayer thin film, the rejection was 58.6% −73.6% in the NIR wavelength range (800–2500 nm), and a transmittance of 40%–45% was achieved in the visible light range (400–700 nm).
Tribological behavior of autocatalytic Ni-P based duplex coatings
Authors: Biswas Palash , Das Suman Kalyan , Sahoo Prasanta 
Published: March 2024

Abstract
The present research evaluates the tribological performance of different Ni-P based duplex autocatalytic coatings (electroless coatings). The study investigates coatings including Ni-P/Ni-W-P, Ni-P/Ni-Mo-P, and Ni-P/Ni-Cu-P, examining various factors such as heat treatment conditions, sample composition, and their influence on the coatings’ performance. The phase structure of the coatings is influenced by heat treatment parameters viz. temperature and duration as well as phosphorus content. Notably, at temperatures above 400 °C, all duplex coatings form a robust nickel phosphide phase, enhancing hardness and wear resistance which is almost double of that in as-deposited state in some cases. When subjected to a temperature of 400 °C for duration of 1 h, the Ni-P/Ni-W-P coating displays the highest microhardness (1440 HV0.1) and the lowest wear rate (10.62 × 10−5. mm3. N−1. m−1) among all the duplex coatings. In all three duplex systems, the wear typically involves a combination of abrasive and adhesive mechanisms. Among the as-deposited coatings, the Ni-P/Ni-Cu-P demonstrates higher corrosion potential (E
corr −302 mV) and lower corrosion current (i
corr 1.83 × 10−5 mA cm−2) which imply superior corrosion resistance compared to the other duplex coatings. In the heat-treated state, the Ni-P/Ni-Mo-P duplex coating generally exhibits better corrosion resistance when compared to the other two types of duplex coatings.
Discover an accurate approximation of dynamical system without prior information and customized design
Authors: Wang Bochen , Wang Liang , Peng Jiahui , Dong Shuangqi , Xu Wei 
Published: March 2024

Abstract
Modeling dynamical systems is fraught with challenges when data can be collected but thorough analysis of the mechanism is absent. We design a method to discover unknown dynamical systems from data. The method discovers an accurate approximation of the model without the prior information and the customized design for each problem. The identification steps are straightforward as bringing in the data and then obtaining the model. The method begins with the simple idea that the equations of motion of many practical problems are Riemann integrable functions. For this reason, the Fourier series can decompose the equations of motion. In order to improve the accuracy, we design an extension that helps us to approximate unknown functions by the Fourier series with a high rate of convergence. The idea converts the difficulty of modeling the dynamical system into finding its Fourier series approximation. Convenient procedures enable the modeling of different problems. Numerical examples show that the new method discovers linear and nonlinear dynamical systems in the same steps and without the prior information.
Effective field theory of black hole perturbations in vector-tensor gravity
Authors: Aoki Katsuki , Gorji Mohammad Ali , Mukohyama Shinji , Takahashi Kazufumi , Yingcharoenrat Vicharit 
Published: March 2024

Abstract
We formulate the effective field theory (EFT) of vector-tensor gravity for perturbations around an arbitrary background with a timelike vector profile, which can be applied to study black hole perturbations. The vector profile spontaneously breaks both the time diffeomorphism and the U(1) symmetry, leaving their combination and the spatial diffeomorphism as the residual symmetries in the unitary gauge. We derive two sets of consistency relations which guarantee the residual symmetries of the EFT. Also, we provide the dictionary between our EFT coefficients and those of generalized Proca (GP) theories, which enables us to identify a simple subclass of the EFT that includes the GP theories as a special case. For this subclass, we consider the stealth Schwarzschild(-de Sitter) background solution with a constant temporal component of the vector field and study the decoupling limit of the longitudinal mode of the vector field, explicitly showing that the strong coupling problem arises due to vanishing sound speeds. This is in sharp contrast to the case of gauged ghost condensate, in which perturbations are weakly coupled thanks to certain higher-derivative terms, i.e., the scordatura terms. This implies that, in order to consistently describe this type of stealth solutions within the EFT, the scordatura terms must necessarily be taken into account in addition to those already included in the simple subclass.
Polarized images of charged particles in vortical motions around a magnetized Kerr black hole
Authors: Zhang Zhenyu , Hou Yehui , Hu Zezhou , Guo Minyong , Chen Bin 
Published: March 2024

Abstract
In this work, we study the images of a Kerr black hole (BH) immersed in uniform magnetic
fields, illuminated by the synchrotron radiation of charged particles in the jet. We particularly
focus on the spontaneously vortical motions (SVMs) of charged particles in the jet region and
investigate the polarized images of electromagnetic radiations from the trajectories along
SVMs. We notice that there is a critical value ω_c for charged particle released at a given
initial position and subjected an outward force, and once |qB_0/m|=|ω_B|>|ω_c| charged
particles can move along SVMs in the jet region. We obtain the polarized images of the
electromagnetic radiations from the trajectories along SVMs. Our simplified model suggests that
the SVM radiations can act as the light source to illuminate the BH and form a photon
ring structure.
A study of U-isotope ground state properties with covariant energy density functional*
Authors: Wang 王 Junchen 俊辰 , Tian 田 Yuan 源 , Xu 续 Ruirui 瑞瑞 , Cui 崔 Ying 莹 , Tao 陶 Xi 曦 , Sun 孙 Xiaodong 小东 , Zhang 张 Zhi 智 , Zhang 张 Yue 玥 , Han 韩 Yinlu 银录 , Ge 葛 Zhigang 智刚 , Shu 舒 Nengchuan 能川 
Published: March 2024

Abstract
In this study, we systematically analyzed the ground state of uranium isotopes from 225 to 240. In our calculations, we used the covariant energy density functional of density-dependent meson exchange interaction (DD-ME2) with separable pairing interaction (TMR). Using the multiple deformation constraint, we calculated the potential energy surface (PES) of the uranium isotopes for both even-even and even-odd nuclei with quadrupole and octupole deformation. Based on our calculation and upon comparing the experimental data and Hartree-Fock-Bogoliubov calculations with Gogny D1S calculation data, the ground state of uranium isotopes with reflection-asymmetric deformation was found to be preferred.
Numerical study on the effect of radial inlet chamber on the performance of oblique flow compressor
Authors: Chen Jixiang , Zuo Zhitao , Zhou Xin , Guo Wenbin , Sun Jianting , Chen Haisheng 
Published: March 2024

Abstract
The oblique flow compressor is one of the key components in compressed air energy storage (CAES) system, which has the advantages of high single-stage pressure ratio, wide operating range, high efficiency and large mass flow. In this paper, a numerical method is used to study the first-stage oblique flow compressor in a compressor group with radial inlet chamber (RIC), and the oblique flow compressor performance with axial inlet is compared. The results show that the RIC makes the overall performance curve of compressor shift downward, the stable working range is reduced by 15.75%, and the isentropic efficiency and pressure ratio are reduced by 1.54% and 1.57% respectively under the design conditions. The RIC makes the impeller inlet aerodynamic parameters circumferential distribution non-uniformity, which declines the compressor performance. And the rotation of the impeller also destroys the original symmetrical flow distribution of the RIC.
Pressurization process and performance analysis of gear-claw hydrogen circulating pump used in PEMFC system
Authors: Pan Shiyang , Wang Jun , Zhao Xin , Ren Chunji , Xin Yuanjie , Wang Zengli , Cui Dong 
Published: March 2024

Abstract
Owing to the structure of the gear-claw rotor, working chambers of claw pumps are divided into small multi-chambers by a pair of intermeshing claw rotors in the mixing process, and the transient flow in multi-chambers is complicated, which results in the increase of the pump consumption. Hence, it is necessary to study the transient flow and working process of gear-claw hydrogen circulating pumps to optimize the pump performance. In this study, the meshing model of a high-order curve and its conjugate curve was proposed, and the profile composition of the gear-claw rotor was introduced. The influence of the radius ratio of claw addendum arc on the performance including relative carryover, built-in volume ratio and volume utilization was analyzed. The flow field of gear-claw hydrogen circulating pump including pressure and velocity field was analyzed by using numerical simulations. Furthermore, the p-V diagram of pumps was obtained. It is found that the gas in the compression chamber is mixed with the gas in the carryover, and the initial pressure in the compression chamber is 130.78kPa, which increases by 29.07% compared to the original initial pressure in the compression chamber. Therefore, an overcompression phenomenon at the end of the compression process (at the beginning of the discharge process) occurs.
Effect of the number of guide vanes on cavitation characteristics and pressure pulsation of centrifugal pumps
Authors: Dong Wei , He Fan , Ai Gaigai , Liang Wuke , Li Peixuan , Fan Xugang 
Published: March 2024

Abstract
Centrifugal pumps play an important role in the national economy, they usually have complex flow fields and abundant flow structures. Based on the K-ε turbulence model and Zwart cavitation model, ANSYS was used to analyze the large guide vane centrifugal pump. Four schemes are proposed, each with 11, 13, 15, and 17 guide vanes respectively. When operating under different flow conditions, the external characteristics of the pump were analyzed and compared. The cavitation characteristics of the pump at the design flowrate and the pressure pulsation in the vaneless zone were analyzed. The influence of guide vane number on cavitation performance and pressure fluctuation in the vaneless region of the pump was studied. The final results show that the cavitation variation patterns of different schemes are similar. Z
0=13 has the best cavitation performance, and Z
0=17 has the worst cavitation performance. The change in guide vane numbers will affect the number of peaks and valleys at each monitoring point in the cycle, which correspond to guide vane numbers. Appropriately increasing guide vane numbers can reduce the amplitude of pressure fluctuation to a certain extent and reduce the pressure difference, which is beneficial for maintaining a stable state during unit operation.
Investigation on the operation and gas-liquid two phase flow characteristics of vane type deep-sea pump
Authors: Luo Xingqi , Yan Sina , Feng Jianjun , Li Chenhao , Sun Shuaihui , Zhu Guojun , Zhang Lefu , Xie Hang 
Published: March 2024

Abstract
The development of oil and gas resources towards the deep sea is an inevitable trend in international energy development. Due to its advantages of high production and transportation efficiency, good flow safety and low investment cost, oil and gas mixed transportation technology has become the preferred technology for deep-sea oil and gas production and transportation system. The core device of the oil-gas mixed transportation system is the gas-liquid two-phase flow pump. Under the gas-liquid two-phase condition, the pressure surging will occur with the increase of the inlet gas volume fraction (IGVF) in the pump. At this time, the pressurization capacity of the pump decreases significantly, accompanied by violent vibration, resulting in extremely unstable operation. To solve this problem, the numerical simulation and experiment of the two-phase operation characteristics of a centrifugal pump and a semi-open mixed-flow pump were carried out in this study. The influence of operating parameters on its pressurization capacity was clarified, and the internal gas-liquid distribution was visually tested, revealing the distribution and its spatiotemporal evolution of gas-phase in the impeller. Finally, the unsteady characteristics of pressure surging were analyzed in detail.
Investigation of the influence of the gap between impeller and diffuser in the pressure pulsation characteristics of a centrifugal pump
Authors: Sun J , Yan W Z , Wang W J 
Published: March 2024

Abstract
The volute centrifugal pump is the core equipment in large-scale water transfer project. The instability of the unit during operation is mainly due to the hydraulic vibration inside the mechanical parts, and pressure pulsation in the “bladeless area” of impeller and diffuser is the main reason for the hydraulic vibration. This paper investigated the change of pump efficiency and head on different values impeller-diffuser gap, and comparatively analyzed the pressure pulsation characteristics of centrifugal pump. The findings demonstrated that the large gap between the impeller and diffuser, the higher pump efficiency and the lower head. The high pressure regions at the impeller outlet and diffuser inlet were significantly narrowed at gap values of 10 mm and 12 mm. With the increase of the gap, the distribution of the flow field in the impeller and diffuser region became more uniform and the intensity of pressure pulsation was decreased. While the gap value was 12 mm, for the impeller monitoring point on the pressure coefficient ranged within ±0.05. This study illustrated the impact of impeller-diffuser gap value on the internal pressure pulsation of centrifugal pumps, it offered as a certain reference for improving the operational stability of the pumps.