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Journal of Systems Science & Complexity 2024年第1期37卷 136-151页

作者： pan zi.i.chen ben m Department of mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

in this paper,the authors study the cooperative target-fencing problem for n-dimensional systems and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull formed by the ***,the dynamics of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the communication network and collision avoidance among the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a numerical example.

关键词： multi-agent systems networked systems target fencing

A hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang Gao Xinyi Wang Xi chen ben m.chen Department of mechanical and Automation Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unmanned aerial vehicles(UAVs)are emerging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long time to cover the entire *** using UAVs for inspections and repair works puts forward a requirement of improving time efficiency in large-scale and cluster *** paper presents a hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction to balance the workload and reduce the overall task completion *** proposed framework consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density map is developed to update global and local information for dynamic load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global map,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning method is used to minimize the total traveling cost of these viewpoints for obtaining a high-quality *** experiments are conducted in both a simulated and real environment to show the time efficiency,robustness,and effectiveness of the proposed ***,the whole system is implemented in real applications.

关键词： multi-UAV Coverage path planning infrastructure inspection and reconstruction

Effect of carbon material and surfactant on ink property and resulting surface cracks of fuel-cell microporous layers

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Chinese Journal of Chemical Engineering 2024年第5期69卷 1-12页

作者： Zhekun chen Weitong pan Longfei Tang Xueli chen Fuchen Wang Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Ensuring the consistency of electrode structure in proton-exchange-membrane fuel cells is highly desired yet challenging because of wide-existing and unguided cracks in the microporous layer(mPL). The first thing is to evaluate the homogeneity of mPL with cracks quantitatively. This paper proposes the homogeneity index of a full-scale mPL with an area of 50 cm~2, which is yet to be reported in the literature to our knowledge. Besides, the effects of the carbon material and surfactant on the ink and resulting mPL structure have been studied. The ink with a high network development degree produces an mPL with low crack density, but the ink with high PDi produces an mPL with low crack homogeneity. The polarity of the surfactant and the non-polarity of polytetrafluoroethylene(PTFE) are not mutually soluble,resulting in the heterogeneous PTFE distribution. The findings of this study provide guidelines for mPL fabrication.

关键词： Proton-exchange-membrane fuel cell microporous layer Crack density Crack homogeneity Polytetrafluoroethylene distribution Surfactant

A review on current development of thermophotovoltaic technology in heat recovery

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international Journal of Extreme manufacturing 2024年第2期6卷 297-323页

作者： Shuni chen Yanming Guo Qinghui pan Yong Shuai ministry of industry and information Technology Key Laboratory of Aerospace Thermophysics School of Energy Science and EngineeringHarbin Institute of TechnologyHarbin 150001People’s Republic of China

The burning of fossil fuels in industry results in significant carbon emissions,and the heat generated is often not fully *** high-temperature industries,thermophotovoltaics(TPVs)is an effective method for waste heat *** review covers two aspects of high-efficiency TPV systems and industrial waste heat *** the system level,representative results of TPV complete the systems,while selective emitters and photovoltaic cells in the last decade are *** key points of components to improve the energy conversion efficiency are further analyzed,and the related micro/nano-fabrication methods are *** the application level,the feasibility of TPV applications in high-temperature industries is shown from the world waste heat utilization *** potential of TPV in waste heat recovery and carbon neutrality is illustrated with the steel industry as an example.

关键词： thermophotovoltaic waste heat recovery micro/nano-fabrication carbon neutrality

mXene@c-mWCNT Adhesive Silica Nanofiber membranes Enhancing Electromagnetic interference Shielding and Thermal insulation Performance in Extreme Environments

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Nano-micro Letters 2024年第10期16卷 82-98页

作者： ziyuan Han Yutao Niu Xuetao Shi Duo pan Hu Liu Hua Qiu Weihua chen ben Bin Xu Zeinhom mEl-Bahy Hua Hou Eman Ramadan Elsharkawy mohammed AAmin Chuntai Liu Zhanhu Guo Key Laboratory of materials Processing and mold(Zhengzhou University) Ministry of EducationNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou 450002People's Republic of China School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026People's Republic of China Key Laboratory of multifunctional Nanomaterials and Smart Systems Advanced Materials DivisionSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123People's Republic of China Shaanxi Key Laboratory of macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China College of Chemistry&Green Catalysis Center Zhengzhou UniversityZhengzhou 450001People's Republic of China mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon Tyne NE18UK Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt Department of Chemistry Faculty of ScienceNorthern Border UniversityArarSaudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 1109921944 TaifSaudi Arabia

A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNm)with mXene@c-mWCNT hybrid *** flexible SNm with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the mXene@c-mWCNT_(x:y)films are prepared by vacuum filtration *** particular,the SNm and mXene@c-mWCNT_(6:4)as one unit layer(SmC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(Emi)shielding performance(average Emi SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SmC_(x))remains stable,and Emi shielding performance is greatly improved,especially for SmC_(3)with three unit layers,the average Emi SET is as high as 55.4 *** addition,the organic combination of rigid SNm and tough mXene@c-mWCNT_(6:4)makes SmC_(x)exhibit good mechanical tensile ***,SmC_(x)exhibit stable Emi shielding and excellent thermal insulation even in extreme heat and cold ***,this work provides a novel design idea and important reference value for Emi shielding and thermal insulation components used in extreme environmental protection equipment in the future.

关键词： SiO_(2)nanofiber membranes mXene@c-mWCNT Composite film Thermal insulation Electromagnetic interference shielding

Lithospheric strength of the Anatolian plateau and implications for strong earthquake activity in Turkey

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Geodesy and Geodynamics 2024年第3期15卷 209-218页

作者： Yuhang pan Shi chen Wen Shi institute of Geophysics China Earthquake AdministrationBeijing 100081China Beijing Baijiatuan Earth Science National Observation and Research Station Beijing 100095China

On February 6, 2023, the doublet earthquake including two main shocks with magnitudes m_(W)7.8 and m_(W)7.5, occurred near the western side of the East Anatolian Fault at the southeast boundary of the Anatolian Plateau in Turkey. Based on the WGm2012 Bouguer gravity anomaly data and the Etopo1topography data, this study first introduced a joint inversion of admittance and coherence functions and used the Bayesian optimal parameter estimation method to obtain the effective elastic thickness Teand loading ratio F of the lithosphere for various tectonic units in the Anatolian Plateau. Secondly, we discussed the characteristics and influencing factors of the lithospheric mechanical strength and analyzed its relationship with seismic activity. The lithospheric mechanical strength of the Anatolian Plateau showed clear lateral heterogeneity and a "weak-strong-weak" spatial pattern from east to west,reflecting various tectonic processes. At last, the strong seismic activity was found where the lithospheric strength was low in the Anatolian Plate. We also incorporated GPS strain rate and other results to investigate the tectonic background and primary causes of the m_(W)7.8 and m_(W)7.5 doublet earthquakes in Turkey. The results have a good insight into urban safety design in the Turkish region, including postdisaster rehabilitation, earthquake hazard assessment, and loss reduction.

关键词： Effective elastic thickness Anatolian plateau Turkey doublet earthquakes Bayesian optimization

Fabrication of AZ31/mg3Y Composites with Excellent Strength and Plasticity via Accumulated Rolling Bonding and Diffusion Annealing

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Acta metallurgica Sinica(English Letters) 2024年第2期37卷 339-352页

作者： Yang Feng Wenhuan chen Zheng Xu Weijun He Bin Jiang Fusheng pan College of materials Science and Engineering Chongqing UniversityChongqing400044China international Joint Laboratory for Light Alloys(ministry of Education) Chongqing UniversityChongqing400044China

AZ31/mg3Y composites with a layer thickness of 100-200μm were fabricated by accumulated rolling bonding(ARB),which was followed by diffusion annealing at 300℃ for 0-32 *** interface layer,containing numerous Al-Y precipitates,is formed in the mg3Y layer that is adjacent to the interface as a result of Al diffusing from the AZ31 layers into the mg3Y *** thickness of the interface layer gets increased and more precipitates are formed in the interface layer with the extension of the annealing *** microhardness of the AZ31 and mg3Y layer decreases firstly and then reaches a stable value,while the microhardness of the interface layer increases gradually with the extension of the annealing *** AZ31/mg3Y composites exhibit equivalent strength but increased ductility after diffusion annealing,in comparison to the as-rolled AZ31/mg3Y *** addition,the AZ31/mg3Y composites after annealing always present higher strength and ductility than AZ31/AZ31 composite,which was fabricated by the same process as that for the AZ31/mg3Y ***-deformation induced strengthening also plays an important role in the excellent strength and ductility of the annealed AZ31/mg3Y *** study can provide a direction for improving the plasticity and strength of magnesium alloys synergistically.

关键词： AZ31/mg3Y composite Accumulated rolling bonding Diffusion annealing Precipitates Strengthening

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

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Journal of Rare Earths 2024年第7期42卷 1394-1402,I0007页

作者： Jiaxin pan Longsheng Zhao Zheng Li Xiaowei Huang Zongyu Feng Jun chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China School of metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China GRiREm Hi–Tech Co. Ltd.Langfang065201China GRiREm Advanced materials Co. Ltd.Beijing100088China GRimAT Engineering institute Co. Ltd.Beijing101407China

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most common mining *** high contents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A comprehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ *** paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and *** results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare *** samples have distinct areas of enrichment for ion-exchangeable rare earths or ***-exchangeable rare earths are primary concentrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micromorphology and particle size of the clay *** inorganic hydroxy aluminum concentration in Chongzuo samples decreases continuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the concentration in Longyan samples(110.55-171.27 mg/kg)is almost independence with sampling *** results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the consumption of leaching agent.

关键词： Weathered crust elution-deposited rare earth ore Sequential extraction Occurrence Aluminum Rare earth elements

Exciting broadband thermochromic transmission property opposite to vanadium dioxide in the atmospheric window

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Science China(Technological Sciences) 2024年第7期67卷 2244-2254页

作者： GONG YiQuan GUO Yanming chen ShuNi Li meng pan QingHui SHUAi Yong ministry of industry and information Technology Key Laboratory of Aerospace Thermophysics School of Energy Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

The traditional telecommunications band performs poorly in harsh weather conditions due to atmospheric absorption. in recent years, researchers have begun to study optical communication through atmospheric windows, and optical switches are an essential component of optical communication. A broadband atmospheric window optical switch was proposed based on Vanadium dioxide and magnetic polaritons(mP). it is formed by the stacking of two metal-dielectric-metal structures. The simulation results show that the modulation depth can reach 98.38%, and the extinction ratio is 17.93 dB. By calculating the magnetic field, we confirmed that the reason for the “off” mode is the coupling between the different mP modes, while the “on”mode is the excitation of mP. The optical switch we proposed may be applied to radiation cooling and optical satellite communication.

关键词： optical communication thermochromic property atmospheric window optical switch magnetic polariton

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Stretchable and self-healing conductive fibers from hierarchical silver nanowires-assembled network

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Nano Research 2024年第2期17卷 763-770页

作者： Ying-Ying Wu Hong chen Fan Zhang pan Guo Haili Qin Huai-Ping Cong Anhui Province Key Laboratory of Advanced Catalytic materials and Reaction Engineering School of Chemistry and Chemical EngineeringHefei University of TechnologyHefei 230009China

Conductive fibers(CFs)with features of high conductivity,stretchability,self-healability,and electromechanical stability are key components of the increasingly popular wearable ***,since the lack of structural design of conductive network and interfacial interaction between soft polymer and conductive additives,it is still hard to enable CFs to meet above ***,we describe a facial drawing method from a hydrogel reservoir which is remolded into ultrathin and stretchable CFs with excellent multi-responsive *** hydrogel reservoir was fabricated in synergy of an ice-templating method and in situ polymerization using the assembled framework as a *** on the effective fabrication mechanism,the diameter of CFs could be well-tuned from 90 to 400μm by adjusting the dipping depth of the glass rod,accompanied with conductivity increased from 0.75 to 2.5 S/*** the hierarchical network structure was well maintained in the CFs,professional performances have been proved on the stretchability and electromechanical *** presence of massive hydrogen bonding and Ag–S bond enabled the CFs with excellent self-healability under the conditions of contact,electric field,and near infrared light,***,the CFs with high sensing property could be integrated into an advanced textile sensor through an effective healing-induced integration strategy,demonstrating its great potentials as superior two-dimensional(2D)electronic skins.

关键词： conductive fibers self-assembled silver nanowires Ag–S coordination self-healing flexible sensors