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Sampling-efficient path planning and improved actor-critic-based obstacle avoidance for autonomous robots

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Science China(Information Sciences) 2024年第5期67卷 197-214页

作者： Yefeng YANG Tao HUANG Tianqi WANG Wenyu YANG Han CHEN Boyang LI Chih-yung WEN Department of Aeronautical and Aviation engineering The Hong Kong Polytechnic University center for Control Theory and Guidance technology Harbin Institute of Technology School of engineering The University of Newcastle research center for Unmanned Autonomous Systems The Hong Kong Polytechnic University

Autonomous robots have garnered extensive utilization in diverse fields. Among the critical concerns for autonomous systems, path planning holds paramount importance. Notwithstanding considerable efforts in its development over the years, path planning for autonomous systems continues to grapple with challenges related to low planning efficiency and inadequate obstacle avoidance response in a timely *** study proposes a novel and systematic solution to the path planning problem within intricate office buildings. The solution consists of a global planner and a local planner. To handle the global planning aspect, an adaptive clustering-based dynamic programming rapidly exploring random tree(ACDP-RRT) algorithm is proposed. ACDP-RRT effectively identifies obstacles on the map by leveraging geometric *** obstacles are then represented as a collection of sequentially arranged convex polygons, optimizing the sampling region and significantly enhancing sampling efficiency. For local planning, a network decoupling actor-critic(ND-AC) algorithm is employed. The proposed ND-AC simplifies the local planner design process by integrating planning and control loops into a neural network(NN) trained via an end-to-end model-free deep reinforcement learning(DRL) framework. Moreover, the adoption of network decoupling(ND) techniques leads to an improved obstacle avoidance success rate when compared to conventional actor-critic(AC)-based methods. Extensive simulations and experiments are conducted to demonstrate the effectiveness and robustness of the proposed approach.

关键词： rapidly exploring random tree (RRT) adaptive clustering network decoupling actor critic (AC) path planning

research progress on simulation of multiscale mass transfer processes in gas-solid system by computational mass transfer

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Particuology 2024年第7期90卷 478-492页

作者： Xu Li Yaohui Wang Leifu Li Runye Zhang Hailun Ren Wenbin Li Zhongli Tang Donghui Zhang The research center of Chemical engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China The Department of Chemical engineering Tianjin Renai CollegeTianjin 301636China Collaborative Innovation center of Chemical Science and engineering(Tianjin) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Particle-fluid system is one of the most popular systems in chemical *** to complex interface structure and high-velocity turbulence,the momentum and mass transfer exhibit nonlinear characteristics,which pose a great challenge for further study and *** solve this problem,computational mass transfer(CMT)emerged and has been proved to be effective in deeply exploring the mass transfer behavior of particle-fluid ***,this paper reviews recent gas-solid numerical studies of turbulence issues from empirical to theoretical,then discusses interphase mass transfer rate models and the interfacial interaction ***,the present study particularly reviews researches on mass transfer process of fixed and fluidized regime by CMT,providing reliable analysis of turbulent anisotropy diffusivity as well as multiscale structure and presenting theoretical instruction for the industrial optimization of mass transfer processes in chemical engineering.

关键词： Fixed bed Fluidized bed Computational mass transfer Turbulent mass diffusion Multiscale Anisotropy

Graphene Nanoribbons Enhancing the Electronic Conductivity and Ionic Diffusion of Graphene Electrodes for High-Performance Microsupercapacitors

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Energy & Environmental Materials 2024年第4期7卷 285-294页

作者： Yan Zhang Huandi Zhang Xiaoxiao Wang Xiaowei Shi Zehua Zhao Yaling Wang Jiamei Liu Cheng Tang Guolong Wang Lei Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University center for Materials Chemistry Frontier Institute of Science and TechnologyXi'an Jiaotong University instrument Analysis center of Xi'an Jiaotong University Xi'an Jiaotong University

The electrochemical performance of microsupercapacitors with graphene electrodes is reduced by the issue of graphene sheets aggregation,which limits electrolyte ions penetration into *** the space between graphene sheets in electrodes facilitates the electrolyte ions penetration,but sacrifices its electronic conductivity which also influences the charge storage ability.

关键词： areal energy density graphene graphene nanoribbons microsupercapacitors structure engineering

Continuous gradient fusion class activation mapping: segmentation of laser-induced damage on large-aperture optics in dark-field images

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High Power Laser Science and engineering 2024年第1期12卷 30-41页

作者： Yueyue Han Yingyan Huang Hangcheng Dong Fengdong Chen Fa Zeng Zhitao Peng Qihua Zhu Guodong Liu School of instrumentation Science and engineering Harbin Institute of TechnologyHarbinChina research center of Laser Fusion China Academy of Engineering PhysicsMianyangChina

Segmenting dark-field images of laser-induced damage on large-aperture optics in high-power laser facilities is challenged by complicated damage morphology, uneven illumination and stray light interference. Fully supervised semantic segmentation algorithms have achieved state-of-the-art performance but rely on a large number of pixel-level labels, which are time-consuming and labor-consuming to produce. LayerCAM, an advanced weakly supervised semantic segmentation algorithm, can generate pixel-accurate results using only image-level labels, but its scattered and partially underactivated class activation regions degrade segmentation performance. In this paper, we propose a weakly supervised semantic segmentation method, continuous gradient class activation mapping(CAM) and its nonlinear multiscale fusion(continuous gradient fusion CAM). The method redesigns backpropagating gradients and nonlinearly activates multiscale fused heatmaps to generate more fine-grained class activation maps with an appropriate activation degree for different damage site sizes. Experiments on our dataset show that the proposed method can achieve segmentation performance comparable to that of fully supervised algorithms.

关键词： class activation maps laser-induced damage semantic segmentation weakly supervised learning

Adaptive observer-based integral event-triggered antivibration control of a full aircraft active landing gear system with irregular runway excitations

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Science China(Information Sciences) 2024年第6期67卷 248-261页

作者： Wenxiao HU Chenglong DU Fanbiao LI Xinmin CHEN Chunhua YANG Weihua GUI School of Automation Central South University research center in System engineering for Special Aircrafts Ningbo Institute of Materials Technology and EngineeringChinese Academy of Sciences

This study addresses the antivibration issue of a full aircraft active landing gear system(LGS)under landing impact and runway excitations via a novel adaptive observer-based integral event-triggered control method. First, a full aircraft active LGS comprising a front gear and two synchronized main left and right gears with active suspensions is established, where the information exchange among them is not implemented directly. Second, two adaptive observers are designed separately for the front and main LGSs to identify the varying damping parameters and estimate the system states simultaneously. Third, estimated states are transmitted to a shared network through a novel integral event-triggered mechanism(I-ETM);thus, the front and main LGSs are interconnected, and a networked control scheme for the aircraft LGS is constructed. Additionally, the integrated active control law is designed with the aid of the transmitted states of the front and main LGSs, enhancing the robustness against the pitch vibration of the ***, the L2-stability of the hybrid system is guaranteed to depress the vertical vibration effect of the landing impact and irregular runway excitations, thus improving passenger safety and comfort. Moreover,a codesign method is provided to obtain feasible solutions to the gain matrices of the observers and controllers simultaneously. Simulation and comparison results are presented to illustrate the effectiveness and superiority of the proposed control scheme in antivibration and saving communication resources.

关键词： aircraft active landing gear antivibration control integral event-triggered mechanism adaptive observer ${\mathcal{L}}_2$-stability

Improvement in hydrogen storage performance of MgH_(2) by vanadium doped with ZIF-8 derived a single-atom catalyst V-N-C

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Rare Metals 2024年第6期43卷 2623-2635页

作者： Fei-Fan Hong Wei-Tao Shi Ruo-Lin Zhao Yi Fan Zi-Qi Liu Si-Zhi Ding Hai-Zhen Liu Wen-Zheng Zhou Jin Guo Zhi-Qiang Lan Guangxi Novel Battery Materials research center of engineering technology and center on Nanoenergy research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationCarbon Peak and Neutrality Science and Technology Development InstituteSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Nanning engineering technology research center for Power Transmission System of New Energy Vehicle Transportation CollegeNanning UniversityNanning 530200China

Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is *** experimental results showed that the V-N-C had a good promoting effect on the hydrogen storage performance of MgH_(2),and the optimal addition amount of V-N-C was 10wt%.The hydrogenation and dehydrogenation apparent activation energies of 10 wt%V-N-C-catalyzed MgH_(2)were reduced by 44.9 and 53.5 kJ·mol^(-1),respectively,compared to those of additive-free MgH_(2).The 10 wt%V-N-C-catalyzed MgH_(2)could reabsorb 5.92 wt%of hydrogen in 50 min at 150℃,with a capacity retention rate of 99.1%after 30 cycles of hydrogen absorption and *** analysis showed that V-N-C was partially transformed into VN and metallic V when it was milled with MgH_(2);the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH_(2).This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V,N and C.

关键词： MgH_(2) Hydrogen storage materials Catalyst Hydrogen storage perormance

Non-blind super-resolution reconstruction for laser-induced damage dark-field imaging of optical elements

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Chinese Optics Letters 2024年第4期22卷 36-41页

作者：王倩陈凤东韩越越曾发路程刘国栋 instrument Science and technology Harbin Institute of TechnologyHarbin 150001China research center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China

The laser-induced damage detection images used in high-power laser facilities have a dark background,few textures with sparse and small-sized damage sites,and slight degradation caused by slight defocus and optical diffraction,which make the image superresolution(SR)reconstruction *** propose a non-blind SR reconstruction method by using an exquisite mixing of high-,intermediate-,and low-frequency information at each stage of pixel reconstruction based on *** simplify the channel attention mechanism and activation function to focus on the useful channels and keep the global information in the *** pay more attention on the damage area in the loss function of our end-toend deep neural *** constructing a high-low resolution image pairs data set,we precisely measure the point spread function(PSF)of a low-resolution imaging system by using a Bernoulli calibration pattern;the influence of different distance and lateral position on PSFs is also considered.A high-resolution camera is used to acquire the ground-truth images,which is used to create a low-resolution image pairs data set by convolving with the measured *** on the data set,our network has achieved better results,which proves the effectiveness of our method.

关键词： laser-induced damage image superresolution image segmentation

Properties of Ultra-low Thermal Expansion LAS Transparent Glass-ceramics Prepared by Spodumene

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Journal of Wuhan University of technology(Materials Science) 2024年第3期39卷 541-550页

作者：何峰何子君 ZHOU Zhiqiang TIAN Yingliang ZHAO Zhiyong School of Materials Science and engineering Beijing University of TechnologyBeijing 100124China Department of Functional Material research Central Iron and Steel Research InstituteBeijing 100081China School of Materials Science and engineering Wuhan University of TechnologyWuhan 430070China National engineering research center of FPD Glass technology Xianyang 712000China

The glass-ceramics were prepared with the spodumene mineral as the main raw material,and the effects of ZrO_(2)replacing TiO_(2)on the samples were systematically *** results show that the substitution of ZrO_(2)for TiO_(2)is not conductive to precipitate𝛽β-quartz solid solution phase,but can improve the transparency and flexural strength of *** the glass-ceramic with the highest visible light transmittance(87%)and flexural strength(231.80 MPa)exhibits an ultra-low thermal expansion of-0.028×10^(-7)K^(-1)in the region of 30-700℃.

关键词： ultra-low thermal expansion LAS transparent glass-ceramics substitution of ZrO_(2)for TiO_(2) spodumene mineral

Peroxidase-like nanozyme based microenvironment-responsive injectable hydrogel for bacteria-infected wound healing

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Science China Technological Sciences 2024年第10期67卷 3247-3260页

作者： ZHOU Wei LI XiaNan TANG MengCheng PAN LingFeng WANG BeiBei ZHANG Hao ZHANG Han WANG ShiBo KONG XiangDong Institute of Smart Biomaterial Materials School of Materials Science and EngineeringZhejiang University of Science & Technology Zhejiang-Mauritius Joint research center for Biomaterials and Tissue engineering Zhejiang University of Science & Technology

Hydrogel stands out as one of the most attractive wound dressings due to its excellent moisturizing properties and capacity to absorb wound exudates. However, conventional hydrogel dressings often lack responsiveness to the microenvironment, merely acting as protective barriers for the wound. Consequently, they exhibit limited effectiveness in preventing infection and facilitating wound repair. To address these problems, we have developed a multifunctional injectable hydrogel, CF/MS@HG, based on peroxidase-like nanozymes, aiming at rapidly healing bacterial-infected wounds. The hydrogel is mainly composed of oxidized sodium alginate, aminated gelatin, and polylysine, encapsulating MIL-101(CuFe) NPs(CF) and manganese selenide nanoparticles(MnSe2NPs, or MS NPs). After injection, the complex rapidly gelatinizes at the infected wound site through a Schiff base reaction. In vitro experiments have demonstrated the hydrogel's strong adhesion and self-healing ***, CF exhibiting peroxidase(POD)-like activity, catalyzes in situ hydrogen peroxide(H2O2) to generate highly toxic hydroxyl radicals(·OH) within the wound microenvironment, inducing oxidative damage to bacteria. Meanwhile, MS decomposes into H2Se in the slightly acidic wound microenvironment, disrupting bacterial metabolism and inhibiting *** addition of polylysine further enhances the hydrogel's antibacterial properties. In vivo experiments have shown that the hydrogel exhibits excellent biological safety and significantly promotes wound healing. This multifunctional smart hydrogel holds great promise for the treatment of bacterial-infected wounds.

关键词： peroxidase-like nanozyme manganese selenide injectable hydrogel bacterial infection wound healing

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