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基于模型预测控制与改进人工势场法的多无人机路径规划

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控制与决策 2024年第7期39卷 2133-2141页

作者：鲜斌宋宁天津大学电气自动化与信息工程学院天津300072

模型预测控制(model predictive control,MPC)已成功地应用于无人机集群的路径规划.但其存在计算量大及单步运算时间长等不足,在实时运行中往往难以获得较高的控制频率.而离线的MPC需要准确的地图信息,难以处理地图中无法预测的动态障碍... 详细信息

模型预测控制(model predictive control,MPC)已成功地应用于无人机集群的路径规划.但其存在计算量大及单步运算时间长等不足,在实时运行中往往难以获得较高的控制频率.而离线的MPC需要准确的地图信息,难以处理地图中无法预测的动态障碍物.对此,提出一种结合离线MPC全局规划与在线改进人工势场法局部规划的方法.在利用MPC方法生成安全、平滑轨迹的同时,提高无人机在动态障碍物影响下的避障能力.通过引入调节力来处理传统人工势场法的局部极小值问题,并将目标与无人机的相对距离引入斥力函数,同时改进引力函数,以改善无人机在目标点处低速徘徊的问题.此外,设计一种事件触发的无人机轨迹变更与轨迹恢复策略,使无人机仅在必要时实施动态避障行为.在此基础上,最大化利用原来的规划轨迹.仿真验证结果表明,所提出的路径规划方法能够使无人机集群安全飞行至目标点,并且具有良好的动态避障能力.

关键词：多无人机模型预测控制人工势场路径规划动态障碍物事件触发

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： xian-Lin Yang Chang-Lin Lan Yu-Ting Wei Yi Zhang Gong jiang Bo Xie Yu Liu Hong-Tao Shen Xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

Analysis and comparison of retinal vascular parameters under different glucose metabolic status based on deep learning

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International Journal of Ophthalmology(English edition) 2024年第9期17卷 1581-1591页

作者： Yan jiang Di Gong Xiao-Hong Chen Lin Yang Jing-Jing Xu Qi-Jie Wei bin-bin Chen Yong-jiang Cai Wen-Qun Xi Zhe Zhang Departments of Laboratory Medicine the Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina Shenzhen Eye Hospital Jinan UniversityShenzhen 518040Guangdong ProvinceChina Center of Health Management Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Visionary Intelligence Ltd. Beijing 100080China Ophthalmology Center the Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina

AIM:To develop a deep learning-based model for automatic retinal vascular segmentation,analyzing and comparing parameters under diverse glucose metabolic status(normal,prediabetes,diabetes)and to assess the potential of artificial intelligence(AI)in image segmentation and retinal vascular parameters for predicting prediabetes and ***:Retinal fundus photos from 200 normal individuals,200 prediabetic patients,and 200 diabetic patients(600 eyes in total)were *** U-Net network served as the foundational architecture for retinal arteryvein *** automatic segmentation and evaluation system for retinal vascular parameters was trained,encompassing 26 ***:Significant differences were found in retinal vascular parameters across normal,prediabetes,and diabetes groups,including artery diameter(P=0.008),fractal dimension(P=0.000),vein curvature(P=0.003),C-zone artery branching vessel count(P=0.049),C-zone vein branching vessel count(P=0.041),artery branching angle(P=0.005),vein branching angle(P=0.001),artery angle asymmetry degree(P=0.003),vessel length density(P=0.000),and vessel area density(P=0.000),totaling 10 ***:The deep learning-based model facilitates retinal vascular parameter identification and quantification,revealing significant *** parameters exhibit potential as biomarkers for prediabetes and diabetes.

关键词： deep learning retinal vascular parameters segmentation model diabetes prediabetes

A novel method for producing benzene polycarboxylic acids by electrochemical oxidation of Zhaotong lignite in aqueous NaCl solution

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Carbon Resources Conversion 2024年第2期7卷 88-94页

作者： Ze-Zheng Li Wei-Jia jiang Yu-Gao Wang Zhi-Lei Wang Jun Shen xian-Yong Wei College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024ShanxiChina School of Basic Medicine Shanxi University of Chinese MedicineJinzhong 030619China Institute of Environmental Science Shanxi UniversityTaiyuan 030031China Shanxi Huayang New Material Technology Group Co. Ltd.YangquanShanxi 045000China Key Laboratory of Coal Processing and Efficient Utilization Ministry of EducationChina University of Mining&TechnologyXuzhou 221116JiangsuChina

The development of a coal-based synthetic route to produce benzene polycarboxylic acids(BPCAs)is of great importance for the highly efficient utilization of *** this paper,aqueous NaCl^(-)electrolytic system was used to oxidize Zhaotong lignite to prepare *** electrochemical oxidation of lignite in aqueous NaCl solution could produce more BPCAs than that in aqueous NaOH *** aqueous NaCl electrolytic system could in-suit produce a stable OCl^(-),which was synthesized by the combination reaction between Cl_(2)and OH􀀀generated in the anode or cathode,*** in-suit produced OCl^(-)would degrade the organic structures of the lignite dispersing in the electrolyte to generate *** formation of BPCAs could be greatly affected by current density,electrolysis time and the addition amount of NaCl in the electrolytic system,which resulted from that the factors played an important role in the generation of OCl^(-).The coal related model compounds including anthracene and phenanthrene were used to investigate the electrochemical oxidation mechanism of the *** results indicated that the aromatic ring structures in the lignite were attacked by O_(2)•^(-)from the OCl^(-)to afford BPCAs.

关键词： Lignite Benzene polycarboxylic acids Electrochemical oxidation Aqueous NaCl electrolytic system Coal related model compounds

Phase field modeling of grain stability of nanocrystalline alloys by explicitly incorporating mismatch strain

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Rare Metals 2024年第7期43卷 3370-3382页

作者： Min Zhou Hong-Hui Wu Yuan Wu Hui Wang Xiong-Jun Liu Sui-He jiang Xiao-bin Zhang Zhao-Ping Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083Cnina Institute for Carbon Neutrality University of Science and TechnologyBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Ab st ra ct Nanocrystalline materials exhibit unique properties due to their extremely high grain boundary(GB) ***,this high-density characteristic induces grain coarsening at elevated temperatures,thereby limiting the widespread application of nanocrystalline *** experimental observations revealed that GB segregation and second-phase pinning effectively hinder GB migration,thereby improving the stability of nanocry stalline *** this study,a mouified phase-field model that integrates mismatch strain,solute segregation and precipitation was developed to evaluate the influence of lattice misfit on the thermal stability of nanocrystalline *** simulation results indicated that introducing a suitable mismatch strain can effectively enhance the microstructural stability of nanocrystalline *** synergizing precipitation with an appropriate lattice misfit,the formation of second-phase particles in the bulk grains can be suppressed,thereby facilitating solute segregation/precipitation at the *** concentrated solute segregation and precipitation at the GBs effectively hinders grain migration,thereby preventing grain *** findings provide a new perspective on the design and regulation of nanocrystalline alloys with enhanced thermal stability.

关键词： Phase field model Mismatch strain Second-phase precipitation Grain boundary segregation Nanocrystalline alloys

Upcycling of Poly(butylene adipate-co-terephthalate)into Dual Covalent Adaptable Networks through Chain Breaking-Crosslinking Strategy

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Chinese Journal of Polymer Science 2024年第10期42卷 1505-1513,I0011页

作者： bin-Bo Wang Rong Huang Xin Wang Tao jiang Yi Wang Shuai Du Fa-Lin Li Jin Zhu Song-Qi Ma Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi214122China Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province Divisions of Polymers and CompositesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China

Poly(butylene adipate-co-terephthalate)(PBAT),a widely studied biodegradable material,has not effectively addressed the problem of plastic *** into consideration the cost-effectiveness,upcycling PBAT should take precedence over direct composting *** present work adopts a chain breaking-crosslinking strategy,upcycling PBAT into dual covalent adaptable networks(CANs).During the chainbreaking stage,the ammonolysis between PBAT and polyethyleneimine(PEI)established the primary crosslinked ***,styrene maleic anhydride copolymer(SMA)reacted with the hydroxyl group,culminating in the formation of dual covalent adaptable *** contrast to PBAT,the PBAT-dual-CANs exhibited a notable Young's modulus of 239 MPa,alongside an inherent resistance to creep and *** to catalysis from neighboring carboxyl group and excess hydroxyl groups,the PBAT-dual-CANs exhibited fast stress ***,they could be recycled through extrusion and hot-press reprocessing,while retaining their *** straightforward strategy offers a solution for dealing with plastic waste.

关键词： Poly(butylene adipate-co-terephthalate) Dynamic crosslinked networks Chain breaking-crosslinking strategy Upcycle Recycle

Experimental study on failure mechanism of soft rock-coal bodies in abandoned mines under cyclic dynamic loading

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第4期3卷 41-57页

作者： Dong Wang Yujing jiang bin Liang Zhijie Wen Jianlong Wang State Key Laboratory of Mining Disaster Prevention and Control Co–Founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and TechnologyQingdao266590China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing100083China Guizhou University Guiyang550525China

During the construction and operation of a pumped storage power station in an abandoned mine,the soft rockcoal body structure,comprising the roof and the residual coal pillars,encounters a complex stress environment characterized by cyclic *** study of its failure mechanism under cyclic dynamic loading holds significant theoretical and practical importance to stay the safety and stability of the abandoned mine pumped storage power *** this paper,we take“roof-residual coal pillar”soft rock-coal combinations with different percentages of rock as the research object,and study their mechanical properties,failure mechanism,energy evolution characteristics and acoustic emission distribution characteristics through cyclic dynamic loading *** results of the experiment indicate that:(1)Both weak cyclic dynamic loading and high rock percentage enhance the deformation resistance of soft rock-coal *** low-disturbance horizontal cyclic loading,its peak strength and modulus of elasticity increase with increasing rock percentage.(2)Under low-disturbance horizontal cyclic loading,an increasing trend is observed in the average total strain energy density,dissipation energy density,and elastic energy density of the combinations as the percentage of rock increases.(3)Under lowdisturbance horizontal cyclic loading,as the percentage of rock increases in the soft rock-coal combinations,the degree of failure in the rock body part progressively intensifies,while the destruction of the coal portion progressively decreases.(4)The large number of acoustic emission signals are generated at the instant of destabilization and destruction of the coal-rock combinations,mainly dominated by the signals generated by the destruction of the coal *** emission counts and absolute energy at key point N2 decrease as the percentage of rock *** b value is primarily distributed in the cyclic dynamic loading stage and the failure stage,both displaying

关键词： Soft rock-coal combinations Energy evolution Failure mechanism Cyclic dynamic loading Acoustic emission

Synthesis-temperature-dependent phase composition manipulation toward high thermoelectric performance in tetrahedrites

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Journal of Materials Science & Technology 2024年第1期168卷 124-130页

作者： Yiqing Wei Jiaqi Liu Zien Cheng Pengfei jiang Zizhen Zhou bin Zhang Guoyu Wang Guang Han Xu Lu Xiaoyuan Zhou Center of Quantum Materials and Devices College of PhysicsChongqing UniversityChongqing 401331China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 401331China Analytical and Testing Center Chongqing UniversityChongqing 401331China

Tetrahedrite,an Earth-abundant natural mineral,has attracted extensive research interest because of its excellent thermoelectric ***,tetrahedrite samples comprising Cu-poor Cu_(12)Sb_(4)S_(13)and Cu-rich Cu_(14)Sb_(4)S_(13)phases have been synthesized using a colloidal method,in which the ratio of two phases is manipulated by controlling the synthesis temperature to improve the thermoelectric *** is found that an ultralow total thermal conductivity of∼0.3 W m^(−1)K^(−1)at 723 K is realized in the sample with a Cu-rich phase fraction of∼50%,which can be attributed to maximized phonon scattering by phase *** a result,combined with a decent power factor,this sample obtains an optimal zT of 1.15,which is about 85%higher than that of the sample with a Cu-rich phase fraction of∼64%and comparable to zT values of other eco-friendly,abundant Cu-based thermoelectric *** work demonstrates an effective synthesis-temperature-dependent phase composition manipulation strategy toward enhanced thermoelectric performance in tetrahedrites.

关键词： Tetrahedrite Thermoelectric Colloidal method Phase manipulation Thermal conductivity

Wideband spectrum sensing using step-sampling based on the multipath nyquist folding receiver

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Defence Technology（防务技术） 2024年第1期31卷 523-536页

作者： Kai-lun Tian Kai-li jiang Sen Cao Jian Gao Ying Xiong bin Tang Xu-ying Zhang Yan-fei Li University of Electronic Science and Technology of China Chengdu611731China China Electronics Technology Group Corporation 29th Research Institute Chengdu610036China

Wideband spectrum sensing with a high-speed analog-digital converter(ADC) presents a challenge for practical *** Nyquist folding receiver(NYFR) is a promising scheme for achieving cost-effective real-time spectrum sensing,which is subject to the complexity of processing the modulated *** this case,a multipath NYFR architecture with a step-sampling rate for the different paths is *** different numbers of digital channels for each path are designed based on the Chinese remainder theorem(CRT).Then,the detectable frequency range is divided into multiple frequency grids,and the Nyquist zone(NZ) of the input can be obtained by sensing these ***,high-precision parameter estimation is performed by utilizing the NYFR *** with the existing methods,the scheme proposed in this paper overcomes the challenge of NZ estimation,information damage,many computations,low accuracy,and high false alarm *** simulation experiments verify the effectiveness of the proposed architecture in this paper.

关键词： Wideband spectrum sensing Sub-Nyquist sampling Step-sampling Nyquist folding receiver(NYFR) Multisignal processing