bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionization Potential Depression Model for Warm/Hot and Dense Plasmas
Authors: Wu 武 Chensheng 晨晟 , Zhou 周 Fuyang 福阳 , Yan 颜 Jun 君 , Gao 高 Xiang 翔 , Wu 吴 Yong 勇 , Zeng 曾 Chunhua 春华 , Wang 王 Jianguo 建国 
Published: July 2024

Abstract
For warm/hot and dense plasmas (WDPs), ionization potential depression (IPD) plays a crucial role in determining its ionization balance and understanding the resultant microscopic plasma properties. A sophisticated and unified IPD model is necessary to resolve those existing discrepancies between theoretical and experimental results. However, the applicability of those widely used IPD models nowadays is limited, especially for the nonlocal thermodynamic equilibrium (non-LTE) dense plasma produced by short-pulse laser. In this work, we propose an IPD model that considers inelastic atomic processes, in which three-body recombination and collision ionization processes are found to play a crucial role in determining the electron distribution and IPD for a WDP. This IPD model is validated by reproducing latest experimental results of Al plasmas with a wide-range condition of 70 eV–700 eV temperature and 0.2–3 times solid density, as well as a typical non-LTE system of hollow Al ions. It is demonstrated that the present IPD model has a significant temperature dependence due to the consideration of the inelastic collision processes. With a lower computational cost and wider application range of plasma conditions, the proposed model is expected to provide a promising tool to study the ionization balance and the atomic processes, as well as the related radiation and particle transports properties of the WDP.
Impact of Co2+ substitution on structure and magnetic properties of M-type strontium ferrite with different Fe/Sr ratios
Authors: Sun 孙 Yang 洋 , Liu 刘 Ruoshui 若水 , Gong 宫 Huayang 华扬 , Shen 沈 Baogen 保根 
Published: July 2024

Abstract
Ion substitution has significantly improved the performance of ferrite magnets, and cobalt remains a key area of research. Studies on the mechanism of Co2+ in strontium ferrite, especially SrFe2n–x
Co
x
O19–δ
(n = 6.1–5.4; x = 0.05–0.20) synthesized using the ceramic method, showed that Co2+ preferentially enters the lattice as the Fe/Sr ratio decreases. This results in a decrease in the lattice constants a and c due to oxygen vacancies and iron ion deficiency. The impact of Co substitution on morphology is minor compared to the effect of the Fe/Sr ratio. As the Fe/Sr ratio decreases and the Co content increases, the saturation magnetization decreases. The magnetic anisotropy field exhibits a nonlinear change, generally increasing with higher Fe/Sr ratios and Co content. These changes in the performance of permanent magnets are attributed to the absence of Fe3+ ions at the 12k + 2a and 2b sites and the substitution of Co2+ at the 2b site. This suggests that by adjusting the Fe/Sr ratio and appropriate Co substitution, the magnetic anisotropy field of M-type strontium ferrite can be effectively optimized.
SQI-DOANet: electroencephalogram-based deep neural network for estimating signal quality index and depth of anaesthesia
Authors: Yu Rui , Zhou Zhuhuang , Xu Meng , Gao Meng , Zhu Meitong , Wu Shuicai , Gao Xiaorong , Bin Guangyu 
Published: July 2024

Abstract

Objective. Monitoring the depth of anaesthesia (DOA) during surgery is of critical importance. However, during surgery electroencephalography (EEG) is usually subject to various disturbances that affect the accuracy of DOA. Therefore, accurately estimating noise in EEG and reliably assessing DOA remains an important challenge. In this paper, we proposed a signal quality index (SQI) network (SQINet) for assessing the EEG signal quality and a DOA network (DOANet) for analyzing EEG signals to precisely estimate DOA. The two networks are termed SQI-DOANet. Approach. The SQINet contained a shallow convolutional neural network to quickly determine the quality of the EEG signal. The DOANet comprised a feature extraction module for extracting features, a dual attention module for fusing multi-channel and multi-scale information, and a gated multilayer perceptron module for extracting temporal information. The performance of the SQI-DOANet model was validated by training and testing the model on the large VitalDB database, with the bispectral index (BIS) as the reference standard. Main results. The proposed DOANet yielded a Pearson correlation coefficient with the BIS score of 0.88 in the five-fold cross-validation, with a mean absolute error (MAE) of 4.81. The mean Pearson correlation coefficient of SQI-DOANet with the BIS score in the five-fold cross-validation was 0.82, with an MAE of 5.66. Significance. The SQI-DOANet model outperformed three compared methods. The proposed SQI-DOANet may be used as a new deep learning method for DOA estimation. The code of the SQI-DOANet will be made available publicly at https://github.com/YuRui8879/SQI-DOANet.
A model-based brain switch via periodic motor imagery modulation for asynchronous brain-computer interfaces
Authors: Meng Jianjun , Li Songwei , Li Guangye , Luo Ruijie , Sheng Xinjun , Zhu Xiangyang 
Published: July 2024

Abstract

Objective. Brain switches provide a tangible solution to asynchronized brain-computer interface, which decodes user intention without a pre-programmed structure. However, most brain switches based on electroencephalography signals have high false positive rates (FPRs), resulting in less practicality. This research aims to improve the operating mode and usability of the brain switch. Approach. Here, we propose a novel virtual physical model-based brain switch that leverages periodic active modulation. An optimization problem of minimizing the triggering time subject to a required FPR is formulated, numerical and analytical approximate solutions are obtained based on the model. Main results. Our motor imagery (MI)-based brain switch can reach 0.8FP/h FPR with a median triggering time of 58 s. We evaluated the proposed brain switch during online device control, and their average FPRs substantially outperformed the conventional brain switches in the literature. We further improved the proposed brain switch with the Common Spatial Pattern (CSP) and optimization method. An average FPR of 0.3 FPs/h was obtained for the MI-CSP-based brain switch, and the average triggering time improved to 21.6 s. Significance. This study provides a new approach that could significantly reduce the brain switch’s FPR to less than 1 Fps/h, which was less than 10% of the FPR (decreasing by more than a magnitude of order) by other endogenous methods, and the reaction time was comparable to the state-of-the-art approaches. This represents a significant advancement over the current non-invasive asynchronous BCI and will open widespread avenues for translating BCI towards clinical applications.
Wasserstein distance in speed limit inequalities for Markov jump processes
Authors: Shiraishi Naoto 
Published: July 2024

Abstract
The role of the Wasserstein distance in the thermodynamic speed limit inequalities for Markov jump processes is investigated. We elucidate the nature of the Wasserstein distance in the thermodynamic speed limit inequality from three different perspectives by resolving three remaining problems. First, we derive a unified speed limit inequality for a general weighted graph, which reproduces both the conventional speed limit inequality and the trade-off relation between current and entropy production as its special case. Second, we treat the setting where the tightest bound with the Wasserstein distance has not yet been obtained and investigate why such a bound is out of reach. Third, we compare the speed limit inequalities for Markov jump processes with the L1-Wasserstein distance and for overdamped Langevin systems with the L2-Wasserstein distance, and argue that these two have different origins, despite their apparent similarity.
Unexpected Electrical Breakdown Characteristics and Protection of PPU in Space Electric Propulsion System
Authors: Sheng Beifei , Ge Siqiao , Jiang Shuo , Zhang Xuan , He Fengping , Li Kang 
Published: July 2024

Abstract
The application of fully electric propulsion satellites will increase the risk of low-pressure discharge in electric propulsion devices, especially ion thrusters, whose unexpected breakdown will directly affect the reliability of satellite applications. Existing on-orbit cases show that the unexpected breakdown occurred in the power processing unit (PPU) of the ion thruster during orbit change, which led to the failure of thruster. Therefore, this paper analyses the high-voltage components inside the PPU, and systematically discusses the PPU and its working environment, the control and protection technology of unexpected electrical breakdown of the electric propulsion system and its aerospace engineering. In this paper, we discuss the electric field intensity and discharge margin of components in the PPU under different conditions, and further propose a method for insulation evaluation based on partial discharge (PD) detection. The research results show that the discharge margin in the PPU is close to the lowest discharge voltage level of uniform electric field, so reasonable insulation protection measures should be taken against discharge under high voltage condition. Furthermore, we propose a feasibility analysis method based on PD insulation defect detection, which provides a basis for quantitative analysis and evaluation of component insulation design in PPU systems.
End-to-end design of multistage high-pressure axial compressor for a promising aviation gas turbine engine
Authors: Goryachkin E S , Kudryashov I A 
Published: July 2024

Abstract
The paper describes the results of an end-to-end design of a multistage high-pressure axial compressor for a promising aircraft engine. The design included the steps of initial design and detailed fine-tuning of the working process using three-dimensional numerical modelling. The initial design included the steps of flow path shape determination, design thermodynamic calculation, and one-dimensional gas dynamic calculation at the mid-diameter and height of the flow path. Statistical processing of parameters of known compressors was used to select parameters during the initial compressor design. The initial design was performed for several compressor configurations differing in the main design parameters: type of flow path, number of stages, speed and others. Three-dimensional modelling and comprehensive comparison of working process parameters were performed for the most promising of the obtained variants. On its basis, the most promising variant was selected, for which the subsequent refinement using three-dimensional numerical modelling was carried out. As a result of compressor design, all required parameters were achieved.
Temperature Field Analysis and Temperature Control of Vacuum Ultra High Speed Angular Contact Ball Bearings
Authors: Cui Baoli , Cheng Yongjun , Jia Pengyang , Liu Zhihui , Wang Bi , Ye Jun , Li Yangsen , Chen Weiyu , Wang Zixi 
Published: July 2024

Abstract
In order to investigate the temperature field distribution of bearings under vacuum and ultra-high-speed conditions and put forward a good temperature control method, this paper adopts the local method to analyse and calculate the temperature of various parts of the bearing, and establishes a simulation model of the bearing by using the finite element analysis method of ANSYS, and carries out a test on the experimental platform of the vacuum and ultra-high-speed motors, which proves that the temperature of the rollers is the highest, followed by the inner-ring raceway and the outer-ring raceway, and provides effective theoretical methods for the analysis of the temperature field of the angular contact ball bearing under the conditions of high vacuum and high speed; the temperature of the bearing as a whole is controlled by the structure of the installed water jacket.
LULAD (LUnar LAva tube Discoverer) Instrument for NASA’s Commercial Lunar Payload Services (CLPS) Program
Authors: Karmakar Riya , Shastri Bhardwaj , Choomjinda Ubol , Mukundan Arvind , Wang Hsiang-Chen 
Published: July 2024

Abstract
NASA’s latest lunar exploration program is Artemis. In-situ Resource Utilization (ISRU) will become more important as human space travel moves toward a lunar presence. CLPS helps the Artemis Program develop and use compact autonomous landers and rovers. A series of lunar micro-rovers will be launched in the coming years to collect data and conduct scientific research on the moon. Subterranean lava tubes on celestial bodies are promising habitats for human expansion beyond Earth. Due to its lack of atmosphere, the moon is vulnerable to meteoroid impacts and cosmic and solar particle radiation. These factors make surface lunar base construction difficult. Subterranean lava tubes can provide safety due to the many strata of lava basalt that form a thick roof several meters thick. This paper will discuss the design of the LUnar LAva tube Discoverer (LULAD) instrument, which aims to explore regions of interest and possibly find candidate lava tubes on the moon.
Experimental Investigation on Aerodynamic Performance of a Contra-rotor System
Authors: Xiao Jun , Shi Yongjie 
Published: July 2024

Abstract
The unique environment of Mars (low pressure, low density, and low temperature) causes rotorcraft to face a common situation: the low Reynolds number - high Mach number aerodynamics. The current study focuses on the aerodynamic performance of a series rotor blades under low-pressure and -density testing condition.
Firstly, the optimization of two-dimensional airfoils is carried out and its use as a basic configuration to design four sets of three-dimensional rotors. Secondly, the components of the experimental force measuring system are introduced. An experimental study of the APC 9*6E propeller in its hovering mode was undertaken as part of an effort to understand the acquisition accuracy of the force balance system. The experimental error is within 5 %, which proves that the accuracy of the force measuring platform meets the experimental requirements. Finally, rotors in single- and contra-rotating configurations are all tested. and the results are analyzed. The numerical simulations are also taken at the design conditions for the purposes of results comparison.
Design of improving volumetric efficiency of waverider based on area rule
Authors: Ma Haoyuan , Zhu Dehua , Lou Hao 
Published: July 2024

Abstract
In terms of waverider’s aerodynamic performance degradation due to the design of increasing volume in engineering, it’s a solution to improve the design operations referring to area rule. With theory analysis and numerical simulation, the application of supersonic area rule at hypersonic speed was studied; an improved shape modification method based on area rule was developed and validated. The research results could support the design of improving volumetric efficiency of waverider and showed as follows: Object is supposed to be slender enough to ensure supersonic area rule’s application accuracy at hypersonic speed, which indicates the challenge to apply supersonic area rule to practical hypersonic vehicle due to unsatisfactory geometrical character; referring to some scholars’ development of area rule at hypersonic speed, improved shape modification method based on transonic area rule was developed and the influence of object’s geometrical character on drag reduction at hypersonic speed was studied; Applying the improved shape modification method, the modified combination of volume body and waverider had the drag reduced by 4% and volume increased by 31%, volumetric efficiency increased by 5%.
Design and Application of Micro-vibration Test Platform for Control Moment Gyroscope of Space Station
Authors: Yicun Xie , Qiang Jiang , Yao Wu , Zhiqiang Shen , Chuang Liu , Dong Li , Kexin Liu , Xinying Li 
Published: July 2024

Abstract
In order to obtain the disturbance force and torque of large control moment gyroscopes used in China space station, a calculation method of the resultant force and moment at the product center of mass was studied. A disturbance force testing system for large control moment gyroscopes was designed, and structural modal testing and disturbance force and torque testing were carried out on the rigid installation and isolator installation states of the control moment gyroscopes. By analyzing the root mean square values of disturbance force and torque, as well as the isolation efficiency at the operating frequency of the control torque gyroscope, it can be concluded that the isolator has a good isolation effect.
Tanker remote vision system:review and key technologies
Authors: Zhang Chao , Fan Zhenkai , Liu Yuxuan , Shi Aobo 
Published: July 2024

Abstract
The Remote Vision System (RVS) employed in tanker aircraft, crucial for furnishing operators with requisite visual acuity and informational support during air-to-air refueling maneuvers, has emerged as an indispensable component in modern tanker configurations, forming the bedrock of autonomous aerial refueling capabilities. This paper offers a comprehensive overview of the deployment, constituent elements, and evolutionary trajectory of visual augmentation systems implemented in KC-46A and A-330MRTT aircraft. Furthermore, it delineates key technological imperatives essential for the advancement of tanker visual systems, encompassing high-definition imaging sensors, multi-sensor data fusion methodologies, 3D virtual precise imaging techniques, and all-weather high-precision target data perception technologies. The elucidation of these critical facets serves as a foundational resource for guiding future research and development endeavors aimed at enhancing the efficacy and reliability of tanker remote vision systems
Geometry modeling of solar UAV: considerations and guidelines for design and analysis
Authors: Layachi Hemza , Bennaceur Mohamed amine 
Published: July 2024

Abstract
This paper describes a methodology of the geometry analysis of a solar UAV in order to satisfy energy flight requirements by the integration of PV panels. It is shown that the surface of an UAV’s wing has a direct relation to the structural weight. Since aerospace industry relay on weight saving concepts in order to enhance the overall performance, this paper shows the importance of an optimized selection of such geometry parameters in order to satisfy both concepts.
A Frequency Swept Interferometer (FIS) Based Sensing System for Mega Satellite Constellation
Authors: Jiang Yifei , Chao Zhong , He Wanxie , Bei Wan , Wu Shufan , Mo Qiankun 
Published: July 2024

Abstract
As the novel research of space technologies, non-terrestrial-network (NTN) is one of the most important technologies. Mega satellite constellation is the baseline of the NTN technologies. Unfortunately, as the density of satellite deployment, the risk of collisions between satellites also increases significantly. Therefore, sensing technology is an important solution to avoid collisions within constellation. In this article, a sensing system for satellite constellation is proposed. It contains multiple subsystems working together to ensure measurement accuracy. An accurate laser measurement based on frequency swept interferometer (FIS) is the core of the sensing technologies. With a sensing distance of a few hundred meters, the specific FSI system can realize microns meterss accuracy in many experiments. Those results guarantee the well performance of the sensing system.
Numerical analysis clarifying non-equilibrated periodic flows generated by dual-scaling Taylor’s analytical solution
Authors: Gong Xuanyou , Suzuki Hiroki , Kouchi Toshinori 
Published: July 2024

Abstract
This study investigates the properties of a flow field derived from the multiplexed Taylor solution, focusing on its impact on established equilibrium relationships. We numerically analyse a multiplexed flow field by introducing a secondary flow with twice the period of the original Taylor solution, hypothesising that this dualisation affects the balance between transient and viscous terms. The visualisation of the flow field and the time evolution of the kinetic energy are investigated. Using second and sixth order central differences and the fractional step method with BiCGStab, we analyse three flow fields with different coefficients in a two-dimensional periodic domain. The study shows that the dualisation of the flow field disturbs the equilibrium between the unsteady and viscous terms. The time-averaged kinetic energy shows that the evolution of the dualised field approaches the kinetic energy distribution of the analytical solution, with variations depending on the coefficient of the quadratic term. The spatial distribution of the kinetic energy in fully developed fields is also compared with the analytical solution.
Can Newtonian kinetic energy and Einsteinian rest-mass energy be expressed by the binomial expansion of the Lorentz factor? And how valid is using Einstein’s E = mc2 to calculate the nuclear fission energy?
Authors: Al-Ameen Talal , Mahmud Maythem , Muhi Imad 
Published: July 2024

Abstract
The binomial (Taylor) expansion of the Lorentz factor has been reconsidered here in an attempt to find out whether the Newtonian kinetic energy and the Einsteinian rest-mass energy are implicitly embedded in the mathematical structure of the binomial expansion of the Lorentz factor (as Einstein postulated in his Special Theory of Relativity). Advocates of Standard Special Relativity show that it is possible to obtain these two kinds of energy by multiplying both sides of the expansion of the Lorentz factor by the moving object’s rest mass m
0 and the square of the speed of light c
2. This study shows that the apparent reconciliation between classical and relativistic physics made possible by employing the binomial expansion of the Lorentz factor

γ
=

[
1
−
(

v
2

c
2

)
]

−

1
2

, where v is the moving object’s velocity, is challengeable. Also it is unclear how Einstein’s famous rest-mass energy equation E = m
0
c
2 from Ekinetic net
= mrelativistic c
2 − m
0
c
2 can be used to calculate the amount of nuclear fission energy released?
Attempt to compensate for effects of energy conservation error on static pressure fluctuation using sub-grid scale components with the Reynolds number dependence of isotropic/anisotropic steady turbulence
Authors: Chitose Makoto , Suzuki Hiroki , Kouchi Toshinori 
Published: July 2024

Abstract
This study focuses on the kinetic energy conservation error and the compensation effect by adjusting a model constant. The kinetic energy conservation error is caused by the implicit time integration of the second-order Crank-Nicholson method, and we investigate how much this error affects the RMS of the static pressure fluctuation. Anisotropic and isotropic external force terms are used to generate a steady turbulent flow field, and the numerical analysis employs Large Eddy Simulation (LES) and the Smagorinsky model. Studies have shown that the influence of kinetic energy conservation errors on turbulent kinetic energy is limited, but large-scale turbulent structures are affected by errors in anisotropic turbulent fields with large Re numbers. Ta. Regarding the compensation of the RMS of the static pressure fluctuation, it was shown that the error could be reduced in both isotropic and anisotropic fields by adjusting the model constant, but there was a clear difference for the turbulent kinetic energy. This result shows that the compensation of kinetic energy conservation errors by a model constant is not perfect and that the errors can have different effects on the turbulence statistics.