bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on gain-managed nonlinearity in Mamyshev oscillators
Authors: Lu Sihua , Guo Wei , Zhang Baofu , He Qiurun , Jiao Zhongxing , Lai Tianshu 
Published: August 2024

Abstract
Mamyshev oscillators and gain-managed nonlinear (GMN) amplifiers have the capability to generate high-power sub-50 fs pulses, but their close relationship has not been systematically investigated. In this paper, we numerically study the influence of gain-managed nonlinearity on the laser evolution and output characteristics of the Mamyshev oscillator. The impact of the gain fibre length, as well as the central wavelength and bandwidth of spectral filters on GMN evolution in the laser are investigated. The results indicate that optimizing these cavity parameters can lead to the GMN evolution, which can improve the output peak power by 1.5–4 times in Mamyshev oscillators.
Optical manipulations without light forces: deep superlattice for trapping and rotation of impurity particles in a buffer gas
Authors: Krasnov I V 
Published: August 2024

Abstract
We propose a scheme to obtain a deep optical superlattice (OSL) for resonant impurity particles in a buffer gas. In contrast to the well-known traditional methods of forming optical lattices (supelattices) that are based on the gradient force of radiation pressure, the presented scheme is based on the effect of a light induced drift (LID) in interfering light waves. The principle of its operation is based on the conception of so-called rectified forces induced by interfering bichromatic optical fields, which was developed earlier in the theory of resonant radiation-pressure forces. In the scheme under consideration, a deep OSL (with a period much larger than the optical wavelength) is formed due to the action of the effective rectified force on atomic particles which is proportional to the difference between the frequencies of transport collisions of excited and unexcited particles with buffer gas atoms.
Adaptive remaining useful life prediction method for aircraft engines under variable operational conditions based on multi-channel transformer
Authors: Cao Jinshan 
Published: August 2024

Abstract
Aiming at the problem of degradation trend being covered under time-varying operating conditions and insufficient generalization ability of prediction models, which leads to reduced predictive performance, a domain adaptive method (MC-TraMMDNet) combining improved multi-channel transformer and Maximum Mean Discrepancy (MMD) is proposed for end-to-end prediction of remaining useful life (RUL) of aircraft engines. Firstly, the monitoring data of variable operating conditions are clustered and normalized at the same lifespan scale based on the fault state data. Secondly, corresponding transformer encoders are established for each operating condition, and degradation information is comprehensively extracted for each operating condition through a multi-head self-attention mechanism and multi-channel convolutional network. In addition, to enhance the generalization of the model, the maximum mean difference heterogeneous domain adaptive layer is used to extract domain invariant features. Next, a multi-layer perceptron model is utilized for forecasting the remaining useful lifespan of aircraft engines in diverse operational environments. Finally, validation is carried out on the publicly available dataset C-MAPSS. In comparison to other methods, the results demonstrate that this method excels in both RMSE and Score. The evaluation indicators have decreased by about 9% and 35% respectively.
Design and implementation of 3D printed twin-propeller aeronautical model
Authors: Jiang Yangjiao , Duan Tianyu , Jiang Haofei , Chen Quan , Chen Yong 
Published: August 2024

Abstract
Based on the application requirements of 3D printing technology in aviation models, a twin-propeller aviation model manufactured by 3D printing technology was designed and realized. The twin-propeller model was designed using 3D modeling software, and 3D printing technology was used for physical fabrication. The detailed design and structural optimization of the model ensures that it achieves the best performance in terms of aerodynamics, stability, and propulsion efficiency. Through the production and assembly of 3D-printed parts, a scaled-down physical prototype was successfully made, and flight tests were simulated in the field. The experimental flight results show that the model has good flight stability and efficient propulsion ability. In addition, the application of 3D printing technology has also significantly shortened the manufacturing cycle of the model and improved the accuracy and consistency of manufacturing. The great potential of advanced manufacturing technology in the field of aerospace models has been demonstrated. This method not only improves the performance and manufacturing efficiency of the model but also provides a new idea and technical path for the design and manufacture of future aerospace vehicles.
Overall parameter design method and sensitivity analysis for solar aircraft
Authors: Wang Yuchen , Sun Kangwen , Liu Siyu , Tian Yongliang , Liang Haoquan 
Published: August 2024

Abstract
This paper establishes the overall parameter model for solar aircraft based on energy balance constraints and mass balance constraints. On this basis, a method for the overall parameter design considering the feasible design domain is proposed, with the aircraft’s total mass and wing area as optimization objectives. Sensitivity analysis and scenario study of the optimal configuration of solar-powered aircraft under various general parameters during the design process is conducted. Finally, a design scheme is introduced and compared with prototype data. The results verify the practical applicability of the scheme. The method proposed in this article can provide a reference for the conceptual design stage of solar aircraft.
Enhancing spool valve sealing performance with an annular groove
Authors: Xia Haijie , Zhang Guoqing 
Published: August 2024

Abstract
Spool valves in aviation engine fuel control devices have a vital effect on fuel supply to ensure the engine runs properly. Therefore, the sealing performance of valve components is particularly important for the overall performance and safety of the system. A more accurate fit between the valve body and the moving parts is needed to enhance the sealing performance of the spool valve. However, leaks still exist even with more precise manufacturing due to various factors. This paper proposes a novel design, an annular groove, which differs from previous methods and is described by the dimensionless design parameters of the spool valve. This paper concludes that dimensionless parameters depth h/d and relative position l/L of the annular groove have little influence on the leakage amount. Still, the width w/d has an obvious influence on that. The lower the w/d is, the smaller the leakage is, and the greater the vice versa. According to the simulation calculation, this is mainly because w is easier to induce the reverse pressure gradient of the flow field, leading to the formation of vortices within the annular groove and a consequent reduction in induced velocity, thereby minimizing leakage.
Impact of leading edge slat on stall performance of multi-element airfoils
Authors: Zhang Daqian , Shi Xionglin , Chen Zhongming 
Published: August 2024

Abstract
To ensure the safe takeoff and landing of large commercial aircraft, complex lift augmentation devices have been widely applied. Despite this, even at steep attack angles, leading edge slats on certain multi-element wings can still undergo airflow detachment. This leads to an enlarged wake area behind the slat, diminished airflow circulation around the wing segment, and a decrease in the lift generated by the airfoil. Consequently, this induces intricate air currents between the slat and the main section of the wing, as well as between the main wing and the trailing edge flap, potentially culminating in wing stalls and mishaps. To enhance the takeoff and landing capabilities of multi-element airfoils, the standard multi-element airfoil, 30P30N, was chosen for investigation. By applying the finite volume Reynolds-averaged Navier-Stokes (RANS) approach and utilizing the Fluent module within ANSYS Workbench, the impact of slat position and dimension at the leading edge on the stall behavior of the airfoil was examined. The findings indicate that choosing suitable positions and dimensions for leading-edge slats can efficiently postpone the start of airflow detachment over the wing sections, curb the spread of the airfoil’s wake, and diminish the detachment and blending of slat airflow with the downstream wing section’s boundary layer flow. This substantially improves the aircraft’s aerodynamic efficiency during low-speed takeoffs and landings.
Study on the hypersonic separation of the parallel configuration of the combined cycle two-stage orbit vehicle
Authors: Duan Yuxuan , Xu Zhendong , Liu Zhao , Li Suhang , Lv Zhixin 
Published: August 2024

Abstract
The hypersonic vehicle is an important development direction of the future aerospace technology. An important role of this type of aircraft is as a carrier-level aircraft to send the orbit-level aircraft to a specified altitude and a specified speed and then return separately. Due to the high speed during separation, the serious aerodynamic load, and the severe wave system interference between the two aircraft, the safe separation of the aircraft is more challenging. In this paper, based on the Rocket based Combined Cycle (RBCC) two-stage orbiting carrier system, the research is conducted on the separation of the carrier based on the lift body configuration and upper stage rocket in the atmosphere at hypersonic conditions.
A real-time energy management method for APTMS based on FCM-BP neural network
Authors: Fu Jiecheng , Zhang Jingyang , Zheng Fengying 
Published: August 2024

Abstract
In order to improve the real-time performance of APTMS energy management and ensure fuel economy, a real-time energy management method based on a fuzzy C-means clustering algorithm combined with a BP neural network is proposed. Firstly, the coupling simulation model of APTMS and engine energy efficiency is established. The multi-source energy configuration parameters are obtained by using a particle swarm optimization algorithm combined with an off-line simulation of various flight conditions, and the energy management rule sample library is formed. The fuzzy C-means clustering algorithm is used to classify the energy management rule sample library, and some samples are extracted based on the ranking of membership degrees for the training of the neural network. Finally, the trained neural network predictor is used to predict multi-source energy parameters according to real-time flight conditions. The simulation results show that the FCM-BP neural network method can approach the effect of off-line optimization of PSO and achieve good multi-source energy parameter prediction. The maximum prediction error is 1.91 %, and the FCM-BP neural network method shortens the simulation time by 97.31 %, which has the ability of an online application.
A method of satellite constellation observation based on J2 perturbation application
Authors: Wang Biao , Song Xumin , Li Yiyong , Wang Weilin 
Published: August 2024

Abstract
In view of the problem of a large number of satellite observations, a method of satellite constellation observation by retrograde orbital spacecraft is proposed by applying the drift of J2
perturbation on the RAAN of the spacecraft. Firstly, the basic configuration and spatial position relationship of the satellite constellation are analyzed. Secondly, the influence of the J2
perturbation on the RAAN of the spacecraft is analyzed. Finally, by using the effect of J2
perturbation, the observation methods of single and multiple retrograde orbit spacecraft for satellite constellation are analyzed, respectively. The simulation results demonstrate the feasibility of this method of satellite constellation based on J2
perturbation application.
A Fast solution method for end-effector force extremum in redundant cable-driven parallel robots
Authors: Luo Yanhao 
Published: August 2024

Abstract
For the problem of quickly obtaining the range of load forces in a specific direction at the end-effector of an eight-cable, six-degree-of-freedom redundantly driven cable-parallel robot, a method based on geometric approaches in six-dimensional space for judging the extremum of the end-effector platform force is proposed, which involves shifting the convex hull formed by six-dimensional hyperplanes and intersecting it with a line or a two-dimensional section to determine the extremum of the feasible force of the end-effector, enabling rapid judgment of the force range that the platform can generate in any given orientation. Using an eight-cable, six-degree-of-freedom mechanism as an example, the proposed method establishes an end-effector position-acceleration image and utilizes position-acceleration curves to plan motion trajectories. The computed trajectory of cable forces satisfies the imposed constraints.
Research on architecture design method of civil aircraft pneumatic systems based on model
Authors: Yang Hao , Chen Dongsheng , John Benzie Thomas 
Published: August 2024

Abstract
The civil aircraft pneumatic system provides bleed air supply for multiple users of the aircraft, involving information exchange among multiple systems, and its system architecture is relatively complex. This paper adopts the SysML modeling language and proposes a model-based modeling method for the complex architecture of civil aircraft pneumatic systems. It transforms traditional document and experience-based pneumatic system design work into architecture design work based on pneumatic models and utilizes the correlation and traceability relationships of models to achieve state-machine modeling of pneumatic system architecture. Through simulation verification, the modeling method of pneumatic system architecture based on SysML modeling language can be efficiently applied to the design of pneumatic system architecture and can be extended to the design work of other system architectures.
Analysis of radial stiffness characteristics of deep groove ball bearing considering centrifugal effect under elastohydrodynamic lubrication
Authors: Wu Chao , Guo Xinyang , Yin Xuemei , He Zhoubiao , Cao Ning , Feng Haoyuan , Tang Biliang , Zhao Weifeng 
Published: August 2024

Abstract
The rotor system’s vibration is influenced by the stiffness of high-speed deep groove ball bearings, with their radial stiffness affected by the oil film and centrifugal effect in elastohydrodynamic lubrication. To explore the influence of their combined action, the comprehensive radial stiffness calculation model of deep groove ball bearing is constructed and calculated by MATLAB software. An analysis is conducted on the individual and combined impact of radial stiffness under various viscosity, speed, and load conditions, considering the effects of the oil film, centrifugal force of the rolling body, and centrifugal expansion of the inner ring. The influence of bearing ball size on radial stiffness is obtained. The findings indicate that with the enlargement of the ball size, the comprehensive stiffness also increases. The viscosity reduces the synthetical stiffness, and the synthetical radial stiffness declines as viscosity rises. An increase in rotating speed results induce a decrease in stiffness due to the coupling effect, however, the centrifugal expansion causes the stiffness to rise as the rotating speed increases. In addition, under single factor and coupling conditions, the increase in the applied load results in a rise in radial stiffness.
Numerical simulation research for scramjet inlet separation control
Authors: Pan Sha , Wang Yaping , Fu Yuqing , Sheng An , Xi Wenxiong 
Published: August 2024

Abstract
According to the characteristics of the scramjet, numerical analysis and simulation of its inlet and separation control are carried out. CFD method is used to simulate the scramjet under shock/boundary layer interaction and separation. By setting the overflow slot, the separation zone is sucked out. The results show that the size of the separation zone can be greatly reduced, the inlet flow rate and Mach number can be increased, and the drag force can be effectively reduced. Optimization results and modifications are put forward to improve engine performance, which can also be applied to further engineering research.
Study on mechanical-electronic-hydraulic co-simulation of automatic antenna array splicing device
Authors: Chen Dongdong , Liu Tong 
Published: August 2024

Abstract
The automatic antenna array splicing device of a ground radar contains two sets of six DOF parallel mechanisms. It is a complex splicing system that integrates mechanical, electronic, and hydraulic. It’s difficult to describe the system exactly by only one simulation software. The mechanical, hydraulic, and control simulation models could be established using LMS Motion, AMESim, and MATLAB/Simulink software, and then integrated into MATLAB/Simulink through data interaction technology. Finally, the mechanical, electronic, and hydraulic co-simulation of the automatic antenna array splicing device could be realized. The splicing trajectory planning method and the coordinated control method of the servo valve-controlled parallel cylinders are simulated, and the results are consistent with reality. It can provide an effective means for the design, analysis, and optimization of the automatic antenna array splicing device.
Study on the influence of Salt spray environment on impact fatigue of Gun parts
Authors: Ye W H , Qiao Z P , Li J A , Xue J , Xu L N 
Published: August 2024

Abstract
In this study, live firing experiments were carried out on a certain type of automatic rifle in salt spray corrosion environment and non-corrosion daily environment. The purpose of this study is to explore the influence of salt spray environment on the impact fatigue of gun parts. In the salt fog environment, the fatigue life decreased significantly. Test the mechanical properties of the material, establish the finite element analysis model of the parts to analyze the stress distribution during impact, and observe the fracture morphology of the live ammunition experimental parts. The experimental results show that the impact toughness of the material decreases in salt fog environment, and the cumulative damage degree is greater after cyclic impact. Due to the coupling effect of plastic deformation accumulated in the corrosion medium and the stress concentration area, a large number of corrosion defects are more likely to occur. The existence of corrosion defects greatly promotes the crack initiation and propagation, forms a penetrating fatigue groove, and significantly reduces the corrosion fatigue life.
Facile synthesis of mesoporous zinc oxide nanoparticle as a drug delivery system evaluated by IVIVE in PBPK modeling
Authors: Kumar Koushi , Raju Nirmala Nithya , Nazeer Abdul Azeez 
Published: August 2024

Abstract
This study focuses on the development of mesoporous zinc oxide nanoparticles (mZNPs) via the sol–gel technique, utilizing polyethylene glycol-6000 (PEG-6000) as a capping agent. The research aims to investigate the suitability of these nanoparticles for drug delivery purposes. The analysis of the synthesized material validates the existence of a hexagonal system of zinc oxide with space group P6
3cm and HRTM confirmed the crystallinity and morphology of the nanoparticles ranging from 15–20 nm, revealing the formation of pores attributed to the presence of PEG-6000. The mZNPs exhibit a BET surface area of 28.3 m2. g−1, with Langmuir surface area measurements indicating 46 m2. g−1. Analysis employing the BJH method outlines pore diameters ranging from approximately 2–5 nm at a relative pressure of around 0.99. Furthermore, these mZNPs demonstrated drug delivery attributes, with 43.3% loading efficiency and 80.33% entrapment efficiency for aspirin. Notably, the release kinetics of aspirin from the mZNPs were investigated in simulated fluids of varying pH, with the highest release (98.1%) observed in simulated intestinal fluid (pH 6.8). The formulation exhibits typical time-dependent release kinetics under mild pH conditions (7.4 and 6.8), while transitioning to erosion-controlled diffusion mechanisms in acidic pH conditions (1.2). Furthermore, mathematical models, including Higuchi’s, Korsmeyer’s, and Weibull’s, were employed to assess release kinetics, offering parameters for in-vitro to in-vivo pharmacokinetic predictions. In the framework of PBPK modeling, renal clearance was computationally simulated at a rate of 45 min−1, whereas biliary clearance was modeled to occur at 0.05 min−1. Utilizing these model-derived parameters, the projected half-life of aspirin administered via mZNPs was determined to be 3.1 h. The potential applications of these findings extend to the development of effective drug delivery systems, warranting consideration for future animal model studies involving aspirin and mZNPs.
The Goals of EU and UK Competition Law
Authors: Lianos Ioannis , Korah Valentine , Siciliani Paolo 
Published: August 2024

Abstract
This chapter provides an overview of the goals of competition law in the EU and UK. It first considers the aims and objectives of competition law from a normative perspective, focusing on how competition fosters growth and economic development, the fundamental assumptions of the economic welfare/efficiency paradigm of competition law, the link between economic efficiency and consumer welfare, criticism of the narrow economic welfare perspective in competition law and the separability thesis, the role of the competitive process in the promotion of innovation, consumer protection, freedom to compete/freedom to trade, and fairness and equality of opportunity. The chapter then presents a positive law account of competition law aims and examines market integration as a primary objective of EU competition law before concluding with an analysis of the political and ideological content of competition law.
The Personal Scope of the EU and UK Competition Law
Authors: Lianos Ioannis , Korah Valentine , Siciliani Paolo 
Published: August 2024

Abstract
This chapter discusses the principle of personal responsibility in EU and UK competition law, first by explaining the concept of ‘undertaking’ and its functional definition, along with the meaning of the concept of ‘economic activity’. The meaning of the concept of ‘entity’ and its implications on the attribution of responsibility for competition law infringements are then examined. The chapter goes on to consider the scope and limits of the competitive order and offers some illustrations of the functional approach with regard to the concept of undertaking and the question of the scope of competition law in relation to collective agreements. It also analyses the single entity doctrine and its application in competition law, the single economic entity doctrine and intra-corporate group relations, corporate groups and imputation of the anticompetitive conduct, the meaning of ‘decisive influence’, and corporate reorganisation, corporate shapeshifting and succession (economic continuity) of an entity.