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Recent progress in constructing fluorinated solid-electrolyte interphases for stable lithium metal anodes

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 270-291页

作者： Di Zhang Pengfei Lv Wei Qin Xin He Yuanhua He Civil Aircraft Fire Science and Safety Engineering Key Laboratory of Sichuan Province College of Civil Aviation Safety EngineeringCivil Aviation Flight University of ChinaGuanghan 618307China School of Chemical Engineering Sichuan UniversityChengdu 610065China

Lithium metal batteries(LMBs)are emerging as a promising energy storage solution owing to their high energy density and specific ***,the non-uniform plating of lithium and the potential rupture of the solid-electrolyte interphase(SEI)during extended cycling use may result in dendrite growth,which can penetrate the separator and pose significant short-circuit *** a stable SEI is essential for the long-term operation of the ***-rich SEI has garnered significant attention for its ability to effectively passivate electrodes,regulate lithium deposition,and inhibit electrolyte *** the structural components and preparation methods of existing fluorinated SEI is crucial for optimizing lithium metal anode *** paper reviews the research on optimizing LiF passivation interfaces to protect lithium metal *** focuses on four types of compositions in fluorinated SEI that work synergistically to enhance SEI *** instance,combining compounds with LiF can further enhance the mechanical strength and ionic conductivity of the *** metals with LiF significantly improves electrochemical performance at the SEI/anode interface,with a necessary focus on reducing electron tunneling ***,incorporating polymers with LiF offers balanced improvements in interfacial toughness and ionic conductivity,though maintaining structural stability over long cycles remains a critical area for future *** alloys combined with LiF increase surface energy and lithium affinity,challenges such as dendrite growth and volume expansion *** summary,this paper emphasizes the crucial role of interfacial structures in LMBs and offers comprehensive guidance for future design and development efforts in battery technology.

关键词： LiF lithium metal anodes solid-electrolyte interphase interface cycling stability

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Docking navigation method for UAV autonomous aerial refueling

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Science China(Information Sciences) 2019年第1期62卷 29-44页

作者： Delin LUO Jiang SHAO Yang XU Jinpeng ZHANG School of Aerospace Engineering Xiamen University China Airborne missile Academy aviation Key Laboratory of Science Technology on Airborne Guided Weapon

In this paper, a docking navigation method for autonomous aerial refueling(AAR) of unmanned aerial vehicles(UAVs) based on a binocular vision system(BVS) is proposed. A BVS simulation platform is built for simulation research purposes. First, unnecessary scene information in the image is filtered through green light-emitting diodes(LEDs) and filters. Then the image is processed via graying, binarization, and median filtering to highlight the connected area of the LED in the image. Subsequently, the center of mass of the connected area is selected as the feature point(FP), and the FPs are described using an improved Haar wavelet transform. The multidimensional description vector of FP is obtained and matched. Finally,the position and pose of the refueling cone sleeve are estimated. Simulation results show the effectiveness of the presented AAR navigation method.

关键词： autonomous aerial refueling AAR position and pose estimation improved Haar wavelet transform IHWT binocular vision system BVS BVS simulation platform

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Control of Corner Separation for a Linear Compressor Cascade via Bionic Slanting Riblets at the Endwall

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Journal of Thermal Science 2025年第1期 129-144页

作者： ZHANG Peng LI Yonghong CHENG Rixin Key Laboratory of Civil Aircraft Airworthiness Technology Civil Aviation University of China College of Aeronautical Engineering Civil Aviation University of China

A new passive control approach,utilizing bionic slanting riblets,is employed to mitigate the flow close to the blade endwall in a linear cascade,and its effectiveness and mechanism in controlling corner separation are investigated through numerical *** slanting riblets are positioned at the endwall upstream of the cascade channel,and the influence of riblet height,yaw angle and relative position on the control of corner separation is *** findings indicate that the application of slanting riblets can efficiently counteract corner separation across the stable operational ***,the introduction of riblets with a height of merely 0.1 times the boundary layer thickness results in a significant reduction in total pressure loss by up to 14.53%,while simultaneously enhancing the static pressure coefficient by 21.74%.Flow analysis reveals that minute vortices produced within the riblet channels tend to coalesce,forming a potent large-scale vortex near the boundary layer's base *** phenomenon results in reduced additional losses compared to conventional vortex ***,the induced vortex promotes enhanced mixing between the mainstream flow and boundary layer,inhibiting the lateral displacement of low-energy fluids within the endwall boundary ***,this delays the onset of separation vortex formation and eliminates vortex rings in the corner region,ultimately enhancing the aerodynamic efficiency of the cascade.

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Persymmetric adaptive detection of range-spread targets in subspace interference plus Gaussian clutter

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Science China(Information Sciences) 2023年第5期66卷 271-282页

作者： Tao JIAN Jia HE Yu LIU You HE Congan XU Zikeng XIE research Institute of Information Fusion Naval Aviation University

In this paper, we consider the adaptive detection problem of range-spread targets embedded in subspace interference plus structured Gaussian clutter. The target signal and interference are assumed to lie in two linearly independent subspaces with unknown coordinates. The clutter component is modeled as a complex Gaussian vector with an unknown persymmetric covariance matrix. We leverage the persymmetric structure to design a two-step detector according to the Rao test criterion. The theoretical results show that the proposed detector possesses the constant false alarm rate property with respect to the clutter covariance matrix. Furthermore, the numerical results show that the proposed detector exhibits better detection performance than the existing unstructured subspace detectors, particularly under a limited training data size. In addition, the proposed detector outperforms the existing persymmetric subspace detectors.

关键词： adaptive detection persymmetry structured interference constant false alarm rate Rao test

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Robust fixed-time flight controller for a dual-system convertible UAV in the cruise mode

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Defence Technology（防务技术） 2024年第9期39卷 53-66页

作者： Lulu Chen Zhenbao Liu Qingqing Dang Wen Zhao Wenyu Chen School of Civil aviation Northwestern Polytechnical UniversityXi'an 710072China Shenzhen research Institute of Northwestern Polytechnical University Shenzhen 518057China Air and missile Defense College Air Force Engineering UniversityXi'an 710051China

This paper investigates the attitude tracking control problem for the cruise mode of a dual-system convertible unmanned aerial vehicle(UAV)in the presence of parameter uncertainties,unmodeled uncertainties and wind ***,a fixed-time disturbance observer(FXDO)based on the bi-limit homogeneity theory is designed to estimate the lumped disturbance of the convertible UAV ***,a fixed-time integral sliding mode control(FXISMC)is combined with the FXDO to achieve strong robustness and chattering ***-limit homogeneity theory and Lyapunov theory are applied to provide detailed proof of the fixed-time ***,numerical simulation experimental results verify the robustness of the proposed algorithm to model parameter uncertainties and wind *** addition,the proposed algorithm is deployed in a open-source UAV autopilot and its effectiveness is further demonstrated by hardware-in-the-loop experimental results.

关键词： Convertible UAV Flight control Disturbance observer Fixed-time control

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Feature analysis on US military aircraft engine advanced technology programs

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航空动力学报 2014年第7期29卷 1701-1709页

作者： LIANG Chun-hua SUN Ming-xia LIU Hong-xia Shenyang Engine Design and research Institute Aviation Industry Corporation of China

US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTET)program started in 1980 s,then to versatile affordable advanced turbine engine(VAATE)*** features and trends were summarized and concluded by literature statistics method,such as teams based on closely corporation among government,industries and academics,goals oriented with national defence strategies and weapon system development requirements,engineering manufacture and development including all relative disciplines and areas,verification measured by technology readiness level,the application extending to military aircraft engine,civilian engine,gas turbine and space vehicle,*** experience and lessons obtained can provide reference and guide for technology research and engineering manufacture and development of military aircraft engines in the world.

关键词： aircraft engine military aircraft engine advanced technology program technology corporation multi-discipline development technology verification

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Vulnerability analysis for airport networks based on fuzzy soft sets: From the structural and functional perspective

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Chinese Journal of Aeronautics 2015年第3期28卷 780-788页

作者： Li Shanmei Xu Xiaohao Air Traffic Management research Base Civil Aviation University of China

Abstract Recently, much attention has been paid to the reliability and vulnerability of critical infrastructure. In air traffic systems, the vulnerability analysis for airport networks can be used to guide air traffic administrations in their prioritization of the maintenance and repair of airports, as well as to avoid unnecessary disturbances in the planning of flight schedules. In this paper, the evaluation methods of airport importance and network efficiency arc established. Firstly, the evaluation indices of airport importance are proposed from both the topological and functional perspectives. The topological characteristics come from the structure of airport network and the functional features stem from the traffic flow distribution taking place inside the network. Secondly, an integrated evaluation method based on fuzzy soft set theory is proposed to identify the key airports, which can fuse together importance indices over different time intervals. Thirdly, an airport network efficiency method is established for the purpose of assessing the accuracy of the evaluation method. Finally, empirical studies using real traffic data of US and China＇s airport networks show that the evaluation method proposed in this papcr is the most accuratc. Thc vulucrability of US and China＇s airport networks is compared. The similarities and differences between airport geography distribution and airport importance distribution are discussed here and the dynamics of airport importance is studied as well.

关键词： Air traffic Airport network Complex networkFuzzy soft sets Key node

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A new dynamic pushback control method for reducing fuel-burn costs: Using predicted taxi-out time

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Chinese Journal of Aeronautics 2019年第3期32卷 660-673页

作者： Guan LIAN Yaping ZHANG Zhiwei XING Qian LUO Shaowu CHENG School of Transportation Science and Engineering Harbin Institute of Technology Ground Support Equipment research Base Civil Aviation University of China The Second research Institute of Civil aviation Administration of China

Long departure-taxi-out time leads to significant airport surface congestion, fuel-burn costs, and excessive emissions of greenhouse gases. To reduce these undesirable effects, a Predicted taxi-out time-based Dynamic Pushback Control(PDPC) method is proposed. The implementation of this method requires two steps: first, the taxi-out times for aircraft are predicted by the leastsquares support-vector regression approach of which the parameters are optimized by an introduced improved Firefly algorithm. Then, a dynamic pushback control model equipped with a linear gate-hold penalty function is built, along with a proposed iterative taxiway queue-threshold optimization algorithm for solving the model. A case study with data obtained from Beijing International airport(PEK) is presented. The taxi-out time prediction model achieves predictive accuracy within 3 min and 5 min by 84.71% and 95.66%, respectively. The results of the proposed pushback method show that total operation cost and fuel-burn cost achieve a 14.0% and 21.1%reduction, respectively, as compared to the traditional K-control policy.(3) From the perspective of implementation, using PDPC policy can significantly reduce the queue length in taxiway and taxi-out time. The total operation cost and fuel-burn cost can be curtailed by 37.2% and 52.1%,respectively, as compared to the non-enforcement of any pushback control mechanism. These results show that the proposed pushback control model can reduce fuel-burn costs and airport surface congestion effectively.

关键词： Airport surface operation Fuel-burn cost Gate-hold time Pushback control Taxi-out time prediction Taxiway queue threshold

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Influence of Non-Axisymmetric Terms on Circumferentially Averaged Method in Fan/Compressor

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Journal of Thermal Science 2013年第1期22卷 13-22页

作者： Ke Wan Hailiang Jin Donghai Jin Xingmin Gui Aeroengine Numerical Simulation research Center Beijing University of Aeronautics and Astronautics China aviation Powerplant research Institute

The governing equations are derived by circumferentially averaging the three-dimensional （3D） Navier-Stokes equations, which are solved using a time marching finite volume approach. Both Euler throughflow model and Navier-Stokes （N-S） throughflow model are employed to investigate the performance and flow fields of a highly loaded transonic single-stage fan ATS-2 and a four-stage fan. The results are compared with the experimental and three-dimensional computational results. It shows that the throughflow models can provide reasonable perform- ance characteristics and N-S throughflow model gives better predictions in endwall regions. A throughflow com- putation in which all the non-axisymmetric terms are included has been performed at off-design condition and the radial distributions of the flow field can be well described.

关键词： throughflow model circumferentiaily averaged non-axisymmetric terms fan

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A 2-step GPS carrier tracking loop for urban vehicle applications

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Journal of Systems Engineering and Electronics 2017年第5期28卷 817-826页

作者： Hongyang Zhang Luping Xu Yue Jian Xiaochen Ma School of Aerospace Science and Technology Xidian University Xi'an Flight Automatic Control research Institute Aviation Industry Corporation of China Xi'an Aeronautics Computing Technique research Institute Aviation Industry Corporation of China

Global positioning system (GPS) for vehicle applications in the urban area is challenged by low signal intensity. The carrier loop based on fast Fourier transform (FFT) can obtain a high signal to noise ratio (SNR) gain by increasing the observation time. However, this leads to a major problem that the acceleration cannot be ignored. The performance of the FFT-based loop will decline with the acceleration increasing. This paper discusses the effect of the dynamic on FFT first. Then a high performance carrier tracking loop for weak GPS L5 signals is proposed. It combines discrete chirp-Fourier transform (DCFT) and the phase fitting method to estimate Doppler frequency and Doppler rate simultaneously. First, a sequence of integration results is used to perform DCFT to estimate coarse Doppler frequency and Doppler rate. Second, the phase of the sequence is calculated and used to perform linear fitting. By the phase fitting method, the fine Doppler frequency and Doppler rate can be estimated. The computation cost is small because the integration results are used and the phase fitting method needs only coarse estimates of Doppler frequency and Doppler rate. Compared with FFT and DCFT, the precision of the phase fitting method is not limited by the resolution. Thus the proposed loop can get high precision and low carrier to noise ratio (C/N-0) tracking threshold. Simulation results show this loop has a great improvement than conventional loops for urban weak-signal applications.

关键词： satellite navigation receiver signal processing frequency lock loop

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