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Metal-organic frameworks and their composites for advanced lithium-ion batteries:Synthesis,progress and prospects

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Journal of Energy Chemistry 2024年第2期89卷 449-470,I0011页

作者： Chengcai Liu Borong Wu Tao Liu Yuanxing Zhang Jingwen Cui Lingjun Huang Guoqiang Tan Ling Zhang Yuefeng Su Feng Wu School of Material Science and Engineering Beijing Institute of TechnologyBeijing 100081China Chonging innovation Center Beijing Institute of TechnologyChongqing 401120China Collaborative innovation Center of Electric Vehicles in Beijing Beijing 100081China

Metal-organic frameworks(MOFs)are among the most promising materials for lithium-ion batteries(LIBs)owing to their high surface area,periodic porosity,adjustable pore size,and controllable chemical *** instance,their unique porous structures promote electrolyte penetration,ions transport,and make them ideal for battery *** the chemical composition of MOF can introduce more active sites for electrochemical ***,MOFs and their related composites have been extensively and thoroughly explored for ***,the reported reviews solely include the applications of MOFs in the electrode materials of LIBs and rarely involve other aspects.A systematic review of the application of MOFs in LIBs is essential for understanding the mechanism of MOFs and better designing related MOFs battery *** review systematically evaluates the latest developments in pristine MOFs and MOF composites for LIB applications,including MOFs as the main materials(anode,cathode,separators,and electrolytes)to auxiliary materials(coating layers and additives for electrodes).Furthermore,the synthesis,modification methods,challenges,and prospects for the application of MOFs in LIBs are discussed.

关键词： Metal-organic frameworks Electrodes Electrolytes Separators Lithium-ion batteries

Lithiophilic Li-Si alloy-solid electrolyte interface enabled by high-concentration dual salt-reinforced quasi-solid-state electrolyte

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Journal of Energy Chemistry 2024年第8期95卷 216-230,I0005页

作者： Yuanxing Zhang Ling Zhang Zhiguang Zhao Yuxiang Zhang Jingwen Cui Chengcai Liu Daobin Mu Yuefeng Su Borong Wu Feng Wu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing innovation Center Beijing Institute of TechnologyChongqing 401120China Collaborative innovation Center of Electric Vehicles in Beijing Beijing 100081China

Solid polymer electrolytes(SPEs)are urgently required to achieve practical solid-state lithium metal batteries(LMBs)and lithium-ion batteries(LIBs),Herein,we proposed a mechanism for modulating interfacial conduction and anode interfaces in high-concentration SPEs by *** electrolyte exhibits superior ionic conductivity and remarkable interface compatibility with salt-rich clusters:(1)polymer-plastic crystal electrolyte(P-PCE,TPU-SN matrix)dissociates ion pairs to facilitate Li+transport in the electrolyte and regulates Li^(+)diffusion in the *** crosslinking structure of the matrix compensates for the loss of mechanical strength at high-salt concentrations;(2)dual-anion TFSI^(-)_(n)-DFBOP^(-)_(m)in the Li^(+)solvation sheath facilitates facile Li^(+)desolvation and formation of salt-rich clusters and is conducive to the formation of Li conductive segments of TPU-SN matrix;(3)theoretical calculations indicate that the decomposition products of LiDFBOP form SEI with lower binding energy with LiF in the SN system,thereby enhancing the interfacial electrochemical redox kinetics of SPE and creating a solid interface SEI layer rich in *** a result,the optimized electrolyte exhibits an excellent ionic conductivity of9.31×10^(-4)S cm^(-1)at 30℃and a broadened electrochemical stability up to 4.73 *** designed electrolyte effectively prevents the formation of Li dendrites in Li symmetric cells for over 6500 h at0.1 mA cm^(-2).The specific Li-Si alloy-solid state half-cell capacity shows 711.6 mAh g^(-1)after 60 cycles at 0.3 A g^(-1).Excellent rate performance and cycling stability are achieved for these solid-state batteries with Li-Si alloy anodes and NCM 811 *** 811‖Prelithiated silicon-based anode solid-state cell delivers a discharge capacity of 195.55 mAh g^(-1)and a capacity retention of 97.8%after 120 *** 811‖Li solid-state cell also delivers capacity retention of 84.2%after 450 cycles.

关键词： Prelithiation Li-Si alloy anode Solid-state electrolyte SEI layer

Absolute pose estimation of UAV based on large-scale satellite image

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Chinese Journal of Aeronautics 2024年第6期37卷 219-231页

作者： Hanyu WANG Qiang SHEN Zilong DENG Xinyi CAO Xiaokang Wang School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing institute of Technology Chongqing innovation Center Chongqing 401120China

Obtaining absolute pose based on pre-loaded satellite images is one of the important means of autonomous navigation for small Unmanned Aerial Vehicles(UAVs)in Global Navigation Satellite System(GNSS)denied *** of the previous works have tended to build Convolutional Neural Networks(CNNs)to extract features and then directly regress the pose,which will fail when solving the challenges caused by the huge viewpoint and size differences between“UAV-satellite”image pairs in real-world ***,this paper proposes a probability distribution/regression integrated deep model with the attention-guided triple fusion mechanism,which estimates discrete distributions in pose space and three-dimensional vectors in translation *** order to overcome the shortage of the relevant dataset,this paper simulates image datasets captured by UAVs with forward-facing cameras during target searching and autonomous *** effectiveness,superiority,and robustness of the proposed method are verified by simulated datasets and flight tests.

关键词： Satellite imagery Unmanned Aerial Vehicle(UAV) Deep neural networks Vision navigation von Mises-Fisher distribution

Early chatter identification based on optimized VMD with multi-band information fusion and compression method in robotic milling process

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Chinese Journal of Aeronautics 2024年第6期37卷 464-484页

作者： Sichen CHEN Zhiqiang LIANG Yuchao DU Zirui GAO Haoran ZHENG Zhibing LIU Tianyang QIU Xibin WANG School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing institute of Technology Chongqing innovation Center Chongqing 401120China

Undesirable self-excited chatter has always been a typical issue restricting the improvement of robotic milling quality and *** chatter identification based on processing signals can prompt operators to adjust the machining process and prevent chatter *** with the traditional machine tool,the uncertain multiple chatter frequency bands and the band-moving of the chatter frequency in robotic milling process make it more challenging to extract chatter *** paper proposes a novel method of chatter identification using optimized variational mode decomposition(OVMD)with multi-band information fusion and compression technology(MT).During the robotic milling process,the number of decomposed modes k and the penalty coefficient a are optimized based on the dominant component of frequency scope partition and fitness of the mode center ***,the mayfly optimization algorithm(MA)is employed to obtain the global optimal parameter *** order to conquer information collection about the uncertain multiple chatter frequency bands and the band-moving of the chatter frequency in robotic milling process,MT is presented to reduce computation and extract signal ***,the cross entropy of the image(CEI)is proposed as the final chatter indicator to identify the chatter *** robotic milling experiments are carried out to verify the proposed method,and the results show that it can distinguish the robotic milling condition by extracting the uncertain multiple chatter frequency bands and overcome the band-moving of the chatter frequency in robotic milling process.

关键词： Robotic milling Chatter detection Variational mode decomposition Information fusion and compression Chatter featur

A global model for evaluating discharge characteristics and performance of hollow cathodes

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Chinese Journal of Aeronautics 2024年第9期37卷 72-84页

作者： Feng TIAN Long MIAO Qimeng XIA Zhiwen WU Ningfei WANG Xiao HOU School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing innovation Center Beijing Institute of TechnologyChongqing 404100China

Hollow cathode,with the highest plasma density,current density,and temperature,becomes one of the most important components in the electro-thruster *** the electric-propulsion thruster performance is directly related to the ionization rate,reliability,and lifetime of the hollow cathode,this paper develops a global model to study the effects of discharge current,gas flow rate,and gas species on the discharge characteristics in the insert and orifice regions of the hollow *** emitter wall temperatures of hollow cathodes predicted by the global model are compared with experimental results from NSTAR thruster neutralization cathodes,confirming the model's *** influence of hollow cathode emitter material and structure sizes on the plasma parameters in the internal regions was also *** simulation results show that there is an optimal matching relationship between the discharge current and gas flow rate to guarantee the maximum ionization *** optimal working region for the hollow cathode has been deter-mined under different energetic,regime and structural *** global model established in this paper can quickly determine the key structure and operating parameters of hollow cathode at the design stage,and provide the theoretical basis for hollow cathode design and development.

关键词： Hollow cathode Global model Electric propulsion Discharge characteristics Optimal matching relationship

Unveiling of Terahertz Emission from Ultrafast Demagnetization and the Anomalous Hall Effect in a Single Ferromagnetic Film

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Chinese Physics Letters 2024年第4期41卷 45-50页

作者：蓝志强李章顺徐浩然刘凡金钻明彭滟朱亦鸣 Terahertz Technology innovation Research institute Terahertz Spectrum and Imaging Technology Cooperative Innovation CenterShanghai Key Lab of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China

Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond *** demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic *** addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric *** on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall *** experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.

关键词： magnetic magnetization polarity

Continuous advantage learning for minimum-time trajectory planning of autonomous vehicles

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Science China(Information Sciences) 2024年第7期67卷 285-294页

作者： Zhuo LI Weiran WU Jialin WANG Gang WANG Jian SUN School of Automation Beijing Institute of Technology Beijing institute of Technology Chongqing innovation Center China Academy of Launch Vehicle Technology Intelligent Game and Decision Laboratory

This paper investigates the minimum-time trajectory planning problem of an autonomous vehicle. To deal with unknown and uncertain dynamics of the vehicle, the trajectory planning problem is modeled as a Markov decision process with a continuous action space. To solve it, we propose a continuous advantage learning(CAL) algorithm based on the advantage-value equation, and adopt a stochastic policy in the form of multivariate Gaussian distribution to encourage exploration. A shared actor-critic architecture is designed to simultaneously approximate the stochastic policy and the value function, which greatly reduces the computation burden compared to general actor-critic methods. Moreover, the shared actor-critic is updated with a loss function built as mean square consistency error of the advantage-value equation, and the update step is performed several times at each time step to improve data efficiency. Simulations validate the effectiveness of the proposed CAL algorithm and its better performance than the soft actor-critic algorithm.

关键词： trajectory planning continuous advantage learning stochastic policy shared actor-critic

Alkylene-functionality in bridged and fused nitrogen-rich poly-cyclic energetic materials:Synthesis,structural diversity and energetic properties

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Defence Technology（防务技术） 2024年第5期35卷 18-46页

作者： Man Xu Nanxi Xiang Ping Yin Qi Lai Siping Pang School of Materials Science&Engineering Beijing Institute of TechnologyBeijing 100081China Beijing institute of Technology Chongqing innovation Center Chongqing 401120China

From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open *** the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark *** methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich ***,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic *** this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.

关键词： Energetic materials Alkyl bridge strategy Nitrogen-rich azoles Fused heterocycles Azoles

Large deflection deformation behavior of a Zr-based bulk metallic glass for compliant spinal fixation application

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Journal of Materials Science & Technology 2024年第6期173卷 86-99页

作者： Diao-Feng Li Chun-Guang Bai Zhi-Qiang Zhang Hui-Bo Zhang Nan Li Jian Zhao Shi-Changxu innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

A novel compliant spinal fixation designed based on the concept of compliant mechanisms can reduce the stress-shielding effect and adjacent segment degeneration(ASD)effectively,but propose higher requirements for the properties of the used *** metallic glasses(BMGs),as a kind of young biomaterials,exhibiting excellent comprehensive properties,which are attractive for compliant spinal ***,according to the practical service condition of the basic elements in compliant spinal fixation,large deflection deformation behaviors of Zr_(61)Ti_(2)Cu_(25)Al_(12)(at.%,ZT1)BMG beam,including elastic,yielding and plastic were investigated *** was shown that the theoretical nonlinear analytical solution curve as the benchmark not only with the capacity to predict the nonlinear load-deflection relation within the elastic deformation regime,but also assists to capture the yielding event roughly,which can be used as a powerful design tool for *** capture the beginning of the yielding event exactly,bending proof strength(σ_(p),0.05%)accompanied with tiny permanent strain of 0.05% was proposed and determined for BMGs in biomedical implant applications,which is of significance for setting the allowable operating limits of the basic flexible *** approach of interrupted loading-unloading cycles,plastic deformation driven by the bending moment can be classified into two typical stages:the initial stage which mainly characterized by the nucleation and intense interaction of abundant shear bands when the plastic strain below the critical value,and the second stage which dominated by the progressive propagation of shear bands and coupled with the emergence of shear offsets on tensile *** plasticity of BMG beam structures depends on the BMG's inherent plastic zone size(rp).When the half beam thickness less than that of the rp,the plastic deformation of BMGs will behave in a stable manner,which can be acted as the margin of safety effectiv

关键词： Metallic glasses Biomaterials Compliant spinal fixation Large deflection deformation Plastic deformation