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Extremum seeking control for UAV close formation flight via improved pigeon-inspired optimization

Science China(Technological Sciences) 2024年第2期67卷 435-448页

作者： YUAN GuangSong duan HaiBin State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical EngineeringBeihang University(BUAA)Beijing 100083China

This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation *** proposed design scheme combines a Newton-Raphson method with an extended Kalman filter(EKF)to dynamically estimate the optimal position of the following UAV relative to the leading *** reflect the wake vortex effects reliably,the drag coefficient induced by the wake vortex is considered as a performance ***,the performance function is parameterized by the first-order and second-order terms of its Taylor series *** the excellent performance of nonlinear estimation,the EKF is used to estimate the gradient and the Hessian matrix of the parameterized performance *** output feedback of the proposed scheme is determined by iterative calculation of the Newton-Raphson *** with the traditional ESC and the classic ESC,the proposed design scheme avoids the slow continuous time integration of the *** allows a faster convergence of relative position ***,the proposed method can provide a smoother command during the seeking process as the second-order term of the performance function is taken into *** convergence analysis of the proposed design scheme is accomplished by showing that the output feedback is a supermartingale *** improve estimation performance of the EKF,a improved pigeon-inspired optimization(IPIO)is proposed to automatically tune the noise covariance *** Carlo simulations for a three-UAV close formation show that the proposed design scheme is robust to the initial position of the following UAV.

关键词： unmanned aerial vehicle close formation extremum seeking control Newton-Raphson method improved pigeon-inspired optimization

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Atomically dispersed Fe sites on hierarchically porous carbon nanoplates for oxygen reduction reaction

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Journal of Energy Chemistry 2024年第3期90卷 7-15,I0002页

作者： Ruixue Zheng Qinglei Meng Hao Zhang Teng Li Di Yang Li Zhang Xiaolong jia Changpeng Liu jianbing Zhu Xiaozheng duan Meiling Xiao Wei Xing State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina Laboratory of Advanced Power Sources Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesJiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhou 215123JiangsuChina State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina

Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air *** Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active *** by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) *** a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N *** from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(*** hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 *** dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR *** situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C *** work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.

关键词： Fe single atom catalysts Oxygen reduction reaction Mesoporous structure Active sites Zinc-air battery

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Landscape ecological risk assessment and its driving factors in the Weihe River basin,China

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Journal of Arid Land 2024年第5期16卷 603-614页

作者： CHANG Sen WEI Yaqi DAI Zhenzhong XU Wen WANG Xing duan jiajia ZOU liang ZHAO Guorong REN Xiaoying FENG Yongzhong College of Agronomy Northwest A&F UniversityYangling 712100China

Weihe River basin is of great significance to analyze the changes of land use pattern and landscape ecological risk and to improve the ecological basis of regional *** on land use data of the Weihe River basin in 2000,2010,and 2020,with the support of Aeronautical Reconnaissance Coverage Geographic Information System(ArcGIS),GeoDa,and other technologies,this study analyzed the spatial-temporal characteristics and driving factors of land use pattern and landscape ecological *** showed that land use structure of the Weihe River basin has changed significantly,with the decrease of cropland and the increase of forest land and construction *** the past 20 a,cropland has decreased by 7347.70 km2,and cropland was mainly converted into forest land,grassland,and construction *** fragmentation and dispersion of ecological landscape pattern in the Weihe River basin were improved,and land use pattern became more ***,landscape ecological risk of the Weihe River basin has been *** landscape ecological risk area decreased by 19,177.87 km2,high landscape ecological risk area decreased by 3904.35 km2,and moderate and low landscape ecological risk areas continued to *** is worth noting that landscape ecological risks in the upper reaches of the Weihe River basin are still relatively serious,especially in the contiguous areas of high ecological risk,such as Tianshui,Pingliang,Dingxi areas and some areas of Ningxia Hui Autonomous *** ecological risk showed obvious spatial dependence,and high ecological risk area was *** the driving factors,population density,precipitation,normalized difference vegetation index(NDVI),and their interactions are the most important factors affecting the landscape ecological risk of the Weihe River *** findings significantly contribute to our understanding of the ecological dynamics in the Weihe River basin,providing crucial insights for sustainable mana

关键词： land use ecological risk spatiotemporal distribution geographic detector driving factors

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Graphitic carbons: preparation, characterization,and application on K-ion batteries

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Rare Metals 2024年第9期43卷 4056-4075页

作者： Kang-Zhe Cao jia-Hui Ma Yu-Lian Dong Yu duan Run-Tian Zheng Dharani Bundhooa Hui-Qiao Liu Yong Lei College of Chemistry and Chemical Engineering Xinyang Normal University Xinyang Key Laboratory of Low-Carbon Energy Materials Fachgebiet Angewandte Nanophysik Institut für Physik & IMN MacroNano Technische Universit?t Ilmenau Laboratory of Inorganic Materials Chemistry (CMI) University of NamurB-5000 Namur

K-ion batteries(KIBs) have drawn much attention due to the abundant potassium reserves and wide accessibility as well as high energy density, which can be designed for large-scale energy storage systems. As the most promising anode materials for KIBs, graphitic carbons, especially those with an intermediate structure between the crystalline graphite and amorphous carbons become a hot research focus because of the improved rate capability and enhanced diffusion-controlled capacity at low voltage regions. Herein, we first review the structures of graphitic carbons in the view of graphitic domains and the structure changes in their K-ion intercalation compounds. Then, we summarize the preparation mechanisms and characterizations of graphitic carbons and the influence factors in their degree of graphitization. Furtherly, we illustrate the strategies to optimize their K-ion storage properties from four aspects, namely graphitic domain design, microstructure engineering, electrochemical active component regulation, and defect engineering. Finally, we propose the issues that urgently need to be solved in graphitic carbons and the possible solutions. We hope that this view could offer some inspiration for the further designing and optimizing of graphitic carbons for practical KIBs.

关键词： Anodes

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An engineered Cas12i nuclease that is an efficient genome editing tool in animals and plants

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The Innovation 2024年第2期5卷 61-69页

作者： Zhiqiang duan Yafeng liang jialei Sun Hongjin Zheng Tong Lin Pengyu Luo Mengge Wang Ruiheng Liu Ying Chen Shuhua Guo Nannan jia Hongtao Xie Meili Zhou Minghui Xia Kaijun Zhao Shuhui Wang Na Liu Yongling jia Wei Si Qitong Chen Yechun Hong Ruilin Tian jian-Kang Zhu Institute of Advanced Biotechnology and School of Medicine Southern University of Science and TechnologyShenzhen 518055China Bellagen Biotechnology Jinan 250000China Department of Medical Neuroscience School of MedicineKey University Laboratory of Metabolism and Health of GuangdongSouthern University of Science and TechnologyShenzhenGuangdong Province 518055China

The type V-I CRISPR-Cas system is becoming increasingly more attractive for genome ***,natural nucleases of this system often exhibit low efficiency,limiting their ***,we used structure-guided rational design and protein engineering to optimize an uncharacterized Cas12i nuclease,*** a result,we developed Cas-SF01,a Cas12i3 variant that exhibits significantly improved gene editing activity in mammalian ***-SF01 shows comparable or superior editing performance compared to SpCas9 and other Cas12 *** to natural Cas12i3,Cas-SF01 has an expanded PAM range and effectively recognizes NTTN and noncanonical NATN and TTVN *** addition,we identified an amino acid substitution,D876R,that markedly reduced the off-target effect while maintaining high on-target activity,leading to the development of CasSF01^(HiFi)(high-fidelity Cas-SF01).Finally,we show that Cas-SF01 has high gene editing activities in mice and *** results suggest that CasSF01 can serve as a robust gene editing platform with high efficiency and specificity for genome editing applications in various organisms.

关键词： system attractive rational

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Improving hydrogen evolution reaction efficiency through lattice tuning

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Nano Research 2024年第7期17卷 5907-5913页

作者： Zipeng Zhao Haotian Liu Wenpei Gao Praveen Kolla Wang Xue Zeyan Liu Jinghua Guo Sanjeev Mukerjee Xiaoqing Pan Qingying jia Xiangfeng duan Yu Huang Department of Materials Science and Engineering University of CaliforniaLos AngelesCalifornia 90095USA Department of Chemical Engineering and Materials Science University of CaliforniaIrvineCalifornia 92697USA Materials Science and Engineering North Carolina State UniversityRaleighNorth Carolina 27695USA Department of Chemistry and Chemical Biology Northeastern UniversityBostonMassachusetts 02115USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCalifornia 90095USA Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCalifornia 94720USA Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCalifornia 95064USA Department of Physics and Astronomy University of CaliforniaIrvineCalifornia 92697USA California Nanosystems Institute University of CaliforniaLos AngelesCalifornia 90095USA

The intermittent nature of renewable energy sources sets a requirement for efficient energy storage to mitigate the conflict between energy supply and *** is a promising choice for energy storage due to its high energy ***,the conversion of electrical energy to chemical energy stored in hydrogen through water electrolysis suffers from low efficiency,and the electricity cost dominates the total cost of hydrogen ***,we report the study of improving the hydrogen evolution reaction activity of Pt-based catalysts by building a nanoscale surface NiO and Pt interface,further optimizing the performance via tuning the lattice parameter of the core of nanoparticles,which can be achieved by varying the dealloying annealing *** optimized PtCuNi-O/C and PtNi-O/C catalysts are demonstrated to be one of the best catalysts,with a mass activity(MA)of 9.1 and 8.7 mA/μgPt,which is 9.9-fold and 9.5-fold of that of Pt/C,respectively.

关键词： lattice tuning Pt-based catalyst hydrogen evolution reaction electrocatalysis

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Drogue detection for autonomous aerial refueling via hybrid pigeon-inspired optimized color opponent and saliency aggregation

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Chinese Journal of Aeronautics 2024年第5期37卷 27-38页

作者： Tongyan WU Haibin duan Yanming FAN State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100083China Virtual Reality Fundamental Research Laboratory Department of Mathematics and TheoriesPeng Cheng LaboratoryShenzhen 518000China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

Drogue detection is one of the challenging tasks in autonomous aerial refueling due to the requirement for accuracy and *** detection based on image intrinsic cues can achieve fast detection,but with poor *** studies reveal that optimization-based methods provide accurate and quick solutions for saliency *** paper presents a hybrid pigeon-inspired optimization method,the optimized color opponent,that aims to adjust the weight of color opponent channels to detect the drogue *** can optimize the weights in the selected aerial refueling scene offline,and the results are applied for drogue detection in the scene.A novel algorithm aggregated by the optimized color opponent and robust background detection is presented to provide better precision and *** results on benchmark datasets and aerial refueling images show that the proposed method successfully extracts the saliency region or drogue and exhibits superior performance against the other saliency detection methods with intrinsic *** algorithm designed in this paper is competent for the drogue detection task of autonomous aerial refueling.

关键词： Autonomous aerial refueling Drones Hybrid pigeon-inspired optimization Color opponent Saliency detection Saliency aggregation

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Simultaneous enhancement of strength and ductility via microband formation and nanotwinning in an L1_(2)-strengthened alloy

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Fundamental Research 2024年第1期4卷 147-157页

作者： Lu Yang Dingshan liang Zhuo Cheng Ranxi duan Chuanxin Zhong Junhua Luan Zengbao jiao Fuzeng Ren Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

Metallic alloys with high strength and large ductility are required for extreme structural ***,the achievement of ultrahigh strength often results in a substantially decreased ***,we report a strategy to achieve the strength-ductility synergy by tailoring the alloy composition to control the local stacking fault energy(SFE)of the face-centered-cubic(fcc)matrix in an L1_(2)-strengthened superlattice *** a proof of concept,based on the thermodynamic calculations,we developed a non-equiatomic CoCrNi_(2)(Al_(0.2)Nb_(0.2))alloy using phase separation to create a near-equiatomic low SFE disordered CoCrNi medium-entropy alloy matrix with in situ formed high-content coherent Ni_(3)(Al,Nb)-type ordered nanoprecipitates(∼12 nm).The alloy achieves a high tensile strength up to 1.6 GPa and a uniform ductility of 33%.The low SFE of the fcc matrix promotes the formation of nanotwins and parallel microbands during plastic deformation which could remarkably enhance the strain hardening *** work provides a strategy for developing ultrahigh-strength alloys with large uniform ductility.

关键词： L1_(2)-strengthened superlattice alloy Stacking fault energy Nanotwins Microbands Strain hardening

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Improvement for creep strength of a second-generation single crystal superalloy by design of heat treatments

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Rare Metals 2024年第1期43卷 342-350页

作者： Wan-Shun Xia Xin-Bao Zhao jia-Chen Xu Quan-Zhao Yue Qing-Qing Ding Huan-Chang duan Yue-Feng Gu Hong-Bin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Silicon and Advanced Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Design of heat treatments is related to the key technology for development of nickel-based single crystal superalloys(Ni-SXs). Based on the full understanding of the solidification characteristics, this work applies optimization design of heat treatments for a second-generation Ni-SX. Microstructure evolution and creep properties are compared in the material under conventional/standard(Std.) and optimized(Opt.) treatments. For the Std. sample,strong dendritic segregations determine inconsistent microstructure evolution in the dendritic(D) and interdendritic region(ID), while the latter serves as weak area to have the prior microcrack initiation, damaging overall performance of the alloy. The Opt. treatment applies higher homogenization temperature, leading to overall reduced segregations, while not inducing incipient melting. A lower temperature of first-step ageing is used to lower the size ofγ'particles. These help to form the more uniform microstructure in dendritic and interdendritic region and relieve the inconsistent microstructure evolution. The balanced local strength makes ID no longer as the weak area,thus restricting microcrack initiation. Great improvement of high temperature and low stress property is obtained by this progress, leading to the pronounced increase of creep rupture life under 1100 °C/140 MPa.

关键词： Single crystal superalloy Heat treatment Segregation Solidification Creep property

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Defect-induced synthesis of nanoscale hierarchically porous metal-organic frameworks with tunable porosity for enhanced volatile organic compound adsorption

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Nano Materials Science 2024年第4期6卷 467-474页

作者： Kuan liang Weibiao Guo Linmei Li Huidong Cai Haiqi Zhang Jingjing Li Feng Xu jian Yan Daofei Lv Hongxia Xi Chongxiong duan Guangdong Provincial Key Laboratory of Intelligent Food Manufacturing Foshan University School of Materials Science and Hydrogen Engineering Foshan University School of Chemistry and Chemical Engineering South China University of Technology School of Environmental and Chemical Engineering Foshan University

Nanoscale hierarchically porous metal-organic frameworks （NH-MOFs） synergistically combine the advantages of nanoscale MOFs and hierarchically porous MOFs,resulting in remarkable characteristics such as increased specific surface area,greater porosity,and enhanced exposure of active ***,nanoscale hierarchically porous UIO-66 （UIO-66＿X） was synthesized using a defect-induced strategy that employed ethylene diamine tetraacetic acid （EDTA） as a *** introduced EDTA occupies the coordination sites of organic ligands,promoting the formation and growth of UIO-66 crystal nuclei and inducing defects during *** as-synthesized UIO-66＿X crystals exhibit a uniform distribution with an average size of approximately 100 *** addition,the total pore volume attains a remarkable value of 0.95 cm3g-1,with mesopores constituting 36.8%of the ***,the porosities of UIO-66＿X can be easily tuned by controlling the molar ratio of EDTA/Zr4+.In addition,the as-synthesized UIO-66＿X exhibits excellent adsorption capacities for n-hexane (344 mg g-1) and pxylene (218 mg g-1),which are 44.5%and 27.5%higher than those of conventional UIO-66,***,the adsorption behavior of n-hexane and p-xylene molecules in UIO-66＿X was investigated using density functional theory simulations.

关键词： Nanoscale hierarchically porous MOFs Tunable porosities Enhanced VOC adsorption

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