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At present, configuration management in operational and support stage of our military aircraft mainly depends on user own, which is short of informatization and has low efficiency, also is separated from configuration management in development and delivery stage. The connotation of configuration management in operational and support stage is researched, then a configuration management approach in operational and support stage based on analysis of configuration identification, configuration control, configuration status accounting, configuration audit is proposed. The proposed approach is applied to aircraft engineering, which shows high efficiency.

The aerial refueling is a kind of complex system engineering, and the influencing factors are closely related to the tanker and the receiver. Due to the special layout of single wing, large wingspan, high vertical tail and large landing gear fairing on the large tanker(soft refueling), the aerodynamic interference among the tanker, hose cone sleeve and receiver becomes very complicated during the process of refueling docking in air formation flight. By analyzing the main characteristics of domestic and foreign large-scale tanker and advanced reciever aircraft, the aerodynamic interference between tanker and receiver aircraft in the process of air refueling docking is summarized, the typical system of air refueling and refueling formation flight and the procedures of air refueling are studied, and the verification elements possibly influencing the safety docking control for air refueling are put forward and analyzed. The analysis of safety control verification elements can provide the theoretical guidance for the determination of the procedure of the soft air refueling and receiving docking, and basis for the selection of the air refueling and receiving docking speed.

The SiP(System in Package) is introduced. Based on the SiP technology,a microsystem composed of bare dies such as FPGA，ARM，SRAM is designed. The working principle of microsystem is introduced，and the implementation process of the product is described. The system has the characteristics of light weight,small volume and complete function.

In order to investigate the change in proline metabolism of two varieties of Hami melon fruits during low-temperature storage, ‘Xizhoumi 25’ and ‘Gashi’ melons were pre-cooled for 24 h and then placed for up to 42 days in a mechanical cold storage at (3.0 ± 0.5) ℃. Chilling injury symptoms were recorded, and chilling injury index, free proline content and proline metabolism-related indexes were measured every seven days . The results showed that the symptoms of chilling injury in ‘Gashi’ melon were significantly milder than those in ‘Xizhoumi 25’ melon, and as the storage time increased, free proline content, Δ1-pyrrolidine-5-carboxylic acid synthase (P5CS) activity, ornithine transaminase (OAT) activity and their relative gene expression increased significantly for both varieties; all these indicators were significantly higher in ‘Gashi’ melon than ‘Xizhoumi 25’ melon. The activity and relative gene expression of proline dehydrogenase (ProDH) decreased, indicating that both varieties of Hami melon fruits could resist chilling injury by increasing the free proline content and the activities of P5CS and OAT, the key enzymes for proline synthesis, and decreasing the activity of ProDH, the key enzyme for proline degradation. The metabolomics study revealed that the amino acid content of ‘Xizhoumi 25’melon decreased when the chilling injury became more serious, while the amino acid content of ‘Gashi’ melon showed an opposite trend. Whole gene synthesis of CmP5CS, a key enzyme gene involved in the proline metabolic pathway of Hami melon fruits, revealed that the Hami melon CmP5CS gene had the closest relatedness to melon (LOC103485529) P5CS, indicating functional similarity between them.

Aqueous Zn-ion hybrid supercapacitors (AZHSCs) combining the advantages of high‐energy batteries and high‐power supercapacitors see a bright future, but they still suffer from the poor capacity of carbonic cathodes. Herein, a functionalized porous carbon cloth (denoted as FPCC) electrode is demonstrated based on commercial carbon cloth (denoted as CC) tuning by structural and surface engineering. The constructed exfoliated porous carbon layer and the negatively charged functionalized interface not only increase the electrical double layer capacitance but also favor the chemical adsorption of Zn2+ to obtain additional pseudocapacitance. Consequently, the FPCC electrode delivers a high capacity of 0.16 mAh cm−2 at 4 mA cm−2, which is 923.8 times higher than CC, and a long cycle life (85.0% capacity retention after 30 000 cycles). More importantly, the Zn//FPCC AZHSC possesses an impressive energy density (3.3 mWh cm−3) and power density (240 mW cm−3), superior to many advanced batteries and supercapacitors. The quasi-solid-state device is also assembled as a demo. This modification strategy may provide new opportunities for high-performance AZHSCs. [ABSTRACT FROM AUTHOR]

The patent serves as a vital component of scientific text, and over time, escalating competition has generated a substantial demand for patent analysis encompassing areas such as company strategy and legal services, necessitating fast, accurate, and easily applicable similarity estimators. At present, conducting natural language processing(NLP) on patent content, including titles, abstracts, etc., can serve as an effective method for estimating similarity. However, the traditional NLP approach has some disadvantages, such as the requirement for a huge amount of labeled data and poor explanation of deep-learning-based model internals, exacerbated by the high compression of patent content. On the other hand, most knowledge-based deep learning models require a vast amount of additional analysis results as training variables in similarity estimation, which are limited due to human participation in the analysis part. Thus, in this research, addressing these challenges, we introduce a novel estimator to enhance the transparency of similarity estimation. This approach integrates a patent's content with international patent classification (IPC), leveraging bidirectional encoder representations from transformers (BERT), and non-negative matrix factorization (NMF). By integrating these techniques, we aim to improve knowledge discovery transparency in NLP across various IPC dimensions and incorporate more background knowledge into context similarity estimation. The experimental results demonstrate that our model is reliable, explainable, highly accurate, and practically usable. [ABSTRACT FROM AUTHOR]

Fan blade icing can affect efficiency and aerodynamic stability, and the shed ice may be sucked into the core of the engine, causing adverse effects or even damage to the compressor components. Ice accretion and shedding are among the key issues in engine design and tests. But they have not been clearly understood. In this work, ice shedding from rotating aero-engine fan blades during continuous icing is experimentally investigated under the relevant airworthiness requirements. The phenomena of icing and ice shedding under different ambient temperatures and engine speeds are recorded to obtain the ice-shedding time and the characteristic length of the residual ice. Force analysis is used to understand the corresponding behavior. The degree of ice-shedding balance D b is defined to explore the symmetry of ice shedding. The results show that the shedding time is significantly affected by the rotational speed, and the characteristic length will first shorten and then grow as the ambient temperature decreases. When the ice shedding is completed instantaneously, D b will show a violent shock. There is a critical ambient temperature, below which the ice accretion will worsen significantly as temperature decreases. For aero-engine fan blade icing tests during ground idle, the critical ambient temperature ranges from − 5   ∘ C to − 9   ∘ C. In order for the ice to shed faster, the engine speed has to reach a threshold. This study can shed light on the preliminary characteristics of ice shedding from rotating components and provide guidance and a data basis for the numerical simulation of fan blade icing and the design of an aero-engine. [ABSTRACT FROM AUTHOR]

Acceleration of objects in fluids widely exists in biological propulsions and contains rich unsteady fluid mechanisms. In this paper, the instantaneous drag force on accelerating normal flat plates (circular, elliptical, square, and rectangular plates) in a wide range of dimensionless acceleration ( a * = 1 6 ∼ 2) is measured, and the underlying mechanism for force generation is investigated. At first, we find that the drag force coefficient generally scales with the square root of a * when a * < 1.0 , coinciding with the scaling law given by Reijtenbagh et al. (PRL. 2023,130,174001). However, the drag force coefficient more linearly scales with a * rather than a * when a * > 1.0 , thereby indicating acceleration plays two distinct roles on the force generation depending on a * . Moreover, two scaling laws are built to quantitatively describe the two distinct roles of a * on the drag force generation. Based on fluid impulse, the drag force is largely contributed by the added mass of the accelerating plates (added mass force) and vorticity generation fed by the shear layer on the edge of the plates (vortex creation force). When a * < 1.0 , the vortex creation force scales with a * and almost contributes to the total drag force. When a * > 1.0 , the added mass force scaling with a * contributes to most of the drag force. Furthermore, the two force generation mechanisms associated with acceleration ( a * ) are independent, and a criterion based on the energy ratio is proposed to identify the transition of the two force generation mechanisms. The present results uncover the role of acceleration in force generation and explain the inconsistencies of using one quasi-steady model in describing the force on accelerating plates. [ABSTRACT FROM AUTHOR]