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GNN-based temporal knowledge reasoning for UAV mission planning systems

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 12-25页

作者： chai Rong Duan Xiaofang Wang Lixuan School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Unmanned aerial vehicles(UAVs)are increasingly applied in various mission scenarios for their versatility,scalability and cost-effectiveness.In UAV mission planning systems(UMPSs),an efficient mission planning strategy is essential to meet the requirements of UAV missions.However,rapidly changing environments and unforeseen threats pose challenges to UMPSs,making efficient mission planning difficult.To address these challenges,knowledge graph technology can be utilized to manage the complex relations and constraints among UAVs,missions,and environments.This paper investigates knowledge graph application in UMPSs,exploring its modeling,representation,and storage concepts and methodologies.Subsequently,the construction of a specialized knowledge graph for UMPS is detailed.Furthermore,the paper delves into knowledge reasoning within UMPSs,emphasizing its significance in timely updates in the dynamic environment.A graph neural network(GNN)-based approach is proposed for knowledge reasoning,leveraging GNNs to capture structural information and accurately predict missing entities or relations in the knowledge graph.For relation reasoning,path information is also incorporated to improve the accuracy of inference.To account for the temporal dynamics of the environment in UMPS,the influence of timestamps is captured through the attention mechanism.The effectiveness and applicability of the proposed knowledge reasoning method are verified via simulations.

关键词： unmanned aerial vehicle mission planning knowledge graph knowledge reasoning graph neural network

From risk control to resilience: developments and trends of urban roads designed as surface flood passages to cope with extreme storms

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 103-120页

作者： Zhiyu Shao Yuexin Li Huafeng Gong Hongxiang chai College of Environment and Ecology Chongqing UniversityChongqing 400030China Key Laboratory of Ecological Environment of Ministry of Education of Three Gorges Reservoir Area Chongqing UniversityChongqing 400030China T.Y.Lin International Engineering Consulting(China)Co.Ltd. Chongqing 400045China

Urban roads can be designated as surface flood passages to transport excess runoff during extreme storms, thereby preventing local flooding, which is known as the major drainage system. However, this practice poses significant risks, including human loss and property damage, due to the high flow rate and velocity carried by roads. Moreover, urban roads with low flood-resilience may significantly hamper the transportation function during severe storms, leading to dysfunction of the city. Therefore, there is an urgent need to transform risk-oriented flood passages into resilient urban road-based flood passages. This paper presents a systematic review of existing methodologies in designing a road network-based flood passage system, along with the discussion of new technologies to enhance system resilience. The study also addresses current knowledge gaps and future directions. The results indicate that flood management measures based on the urban road network should integrate accessibility assessment, lifeline and emergency planning to ensure human well-being outcomes. Furthermore, the special needs and features of vulnerable groups must be taken into serious consideration during the planning stage. In addition, a data-driven approach is recommended to facilitate real-time management and evaluate future works.

关键词： Major drainage Flood mitigation Resilient city Stormwater model Urban flooding

Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers

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Nano-Micro Letters 2024年第2期16卷 438-449页

作者： Jingyi Xie Fuli Wang Yanan Zhou Yiwen Dong Yongming chai Bin Dong State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580People’s Republic of China

The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h.

关键词： Hydroxyl spillover effect Internal polarization field Heterostructure Oxygen reduction reaction Anion exchange membrane water electrolysis

Material flow analysis and global warming potential assessment of an industrial insect-based bioconversion plant using housefly larvae

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Journal of Environmental Sciences 2024年第5期139卷 483-495页

作者： Tao Lu Fan Lü Nanlin Liao Honghui chai Hua Zhang Pinjing He Institute of Waste Treatment and Reclamation Tongji UniversityShanghai 200092China State Key Laboratory of Pollution Control and Source Reuse Tongji UniversityShanghai 200092China Zhejiang Qihe Ecological Technology Co. Ltd.Hangzhou 310052China

The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).

关键词： Biomass waste Musca domestica Housefly larvae Life cycle assessment Global warming potential

Optoelectronic Synapses Based on MXene/Violet Phosphorus van der Waals Heterojunctions for Visual‑Olfactory Crossmodal Perception

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Nano-Micro Letters 2024年第6期16卷 38-52页

作者： Hailong Ma Huajing Fang Xinxing Xie Yanming Liu He Tian Yang chai Center for Advancing Materials Performance From the Nanoscale(CAMP‑Nano) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049People’s Republic of China Institute of Microelectronics and Beijing National Research Center for Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100084People’s Republic of China Department of Applied Physics The Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China

The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.

关键词： Violet phosphorus MXene Van der Waals heterojunctions Optoelectronic synapses Crossmodal perception

Provenance of the Lower Jurassic pyroclastic sediments in the Zigui Basin:Implication for crustal thickening in the eastern Qinling orogenic belt

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Science China Earth Sciences 2024年第1期67卷 196-207页

作者： Rong chai Jianghai YANG Yuansheng DU Chengshan WANG School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100023China School of Earth Sciences China University of Geosciences(Wuhan)Wuhan 430074China Chinese Academy of Geological Sciences Beijing 100037China

The Late Triassic witnessed significant collisional orogenic events in the Qinling orogenic belt,accompanied by magma underplating and tectonic deformation.These processes potentially resulted in substantial crustal thickening and uplift of the Qinling orogen.However,due to the absence of igneous rock records from this period in the eastern section of the Qinling orogen,the changes in crustal thickness during this orogenic process have not been thoroughly investigated.A series of foreland basins emerged during the Early Mesozoic to the south of the East Qinling orogenic belt.These basins have preserved clastic sedimentary rocks derived from the uplift and erosion of the orogenic belt.These sedimentary records serve as crucial records to reconstruct the evolutionary history of the Qinling orogen.To further clarify the collisional orogenic process of the Qinling orogenic belt,this study conducted in situ volcanic lithic fragment geochemistry,detrital zircon U-Pb chronology and trace element composition analysis on the sandstones of the Lower Jurassic Tongzhuyuan Formation in the Zigui Basin.The results suggest that the sandstones,which exhibit a significant abundance of volcanic lithic fragments,has a characteristic detrital zircon age group of 250–200 Ma,indicating a major provenance from the Triassic volcanic rocks.Combined with regional correlation and paleocurrent analysis,the detrital zircon U-Pb age data show that the source area of volcanic rocks should be in the Qinling orogenic belt to the north of the basin.This interpretation is further supported by the Triassic granitic rocks exposed in the western part of the orogenic belt,representing the magmatism during the Triassic collisional orogenesis in the Qinling orogen.Based on the co-varying relationships between present-day crust thickness with the chemical compositions of granite rocks and zircons,the La/Yb ratio of volcanic lithic fragments in the Tongzhuyuan Formation and the Eu/Eu*ratio of detrital zircons with Triassic ages indicate that the Qinling o

关键词： Qinling orogenic belt Zigui Basin Late Triassic Detrital zircons Crustal thickening

Research on the Asymmetric Effect of Fixed-Asset Investment on China's Primary Energy Production in the Context of Energy Transformation

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Journal of Systems Science & Complexity 2024年第3期37卷 1163-1183页

作者： chai Jian HE Peng ZHANG Xiaokong HOU Yamin School of Economics and Management Xidian UniversityXi'an 710126China

Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy transformation.However,energy projects have a long construction period,complex technology categories,and investment risks that greatly affect the development of energy transformation.Correctly judging the effect of investment changes on primary energy production is of great practical significance to the realization of the DCT.Based on this,NARDL and TVP-SV-VAR models are innovatively used to reveal the nonlinear effect of fixed-asset investment on China’s primary energy production.The results show that the marginal effect of investment growth on coal production is about 1.44 times that of investment reduction.Similarly,the marginal effect of oil and gas investment growth is about 1.21times that of investment reduction.Due to the influence of resource constraints,China’s traditional fossil energy still has varying degrees of path dependence on the investment-driven development model.For non-fossil energy,investment in hydropower and nuclear power has an inverse correlation with the change in production.Negative marginal efficiency and diseconomies of scale have hindered the development of the hydropower and nuclear power industries.In addition,the asymmetric effect is not yet significant for the short development time and technical constraints of wind and solar power.From the impulse response results,the impact curves of investment in wind and solar power are generally positive,and investment has different degrees of time-delay and time-varying effects on various energy production,which verifies the heterogeneity of investment adjustment mechanisms in different energy industries.

关键词： "Dual Carbon"target fixed-asset investment primary energy NARDL nonlinearity

ZnSb/Ti_(3)C_(2)T_(x)MXene van der Waals heterojunction for flexible near-infrared photodetector arrays

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Journal of Semiconductors 2024年第5期45卷 99-105页

作者： Chuqiao Hu Ruiqing chai Zhongming Wei La Li Guozhen Shen State Key Laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronic Engineering University of Chinese Academy of SciencesBeijing 100049China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China

Two-dimension(2D)van der Waals heterojunction holds essential promise in achieving high-performance flexible near-infrared(NIR)photodetector.Here,we report the successful fabrication of ZnSb/Ti_(3)C_(2)T_(x)MXene based flexible NIR photodetector array via a facile photolithography technology.The single ZnSb/Ti_(3)C_(2)T_(x)photodetector exhibited a high light-to-dark current ratio of 4.98,fast response/recovery time(2.5/1.3 s)and excellent stability due to the tight connection between 2D ZnSb nanoplates and 2D Ti_(3)C_(2)T_(x)MXene nanoflakes,and the formed 2D van der Waals heterojunction.Thin polyethylene terephthalate(PET)substrate enables the ZnSb/Ti_(3)C_(2)T_(x)photodetector withstand bending such that stable photoelectrical properties with non-obvious change were maintained over 5000 bending cycles.Moreover,the ZnSb/Ti_(3)C_(2)T_(x)photodetectors were integrated into a 26×5 device array,realizing a NIR image sensing application.

关键词： ZnSb nanoplates Ti_(3)C_(2)T_(x)MXene van der Waals heterojunction flexible photodetector image sensing

Spatiotemporal mismatch of land use functions and land use efficiencies and their influencing factors:A case study in the Middle Reaches of the Yangtze River,China

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Journal of Geographical Sciences 2024年第1期34卷 62-88页

作者： GAO Yunxiao WANG Zhanqi chai Ji ZHANG Hongwei School of Public Administration China University of GeosciencesWuhan 430074China

Identification of the spatial mismatch between land use functions(LUFs)and land use efficiencies(LUEs)is essential to regional land use policies.However,previous studies about LUF-LUE mismatch and its driving factors have been insufficient.In this study,we explored the spatiotemporal mismatch of LUFs and LUEs and their influencing factors from 2000 to 2018 in the Middle Reaches of the Yangtze River(MRYR).Specifically,we used Spearman correlation analysis to reveal the trade-off relationship between LUFs and LUEs and determine the direction of the influencing factors on the LUF-LUE mismatch,adopted spatial mismatch analysis to measure the imbalance between LUFs and LUEs,and used the geographical detector model to analyze the factors influencing this spatial mismatch.The results showed that production function(PDF),living function(LVF),ecological function(ELF),agricultural production efficiency(APE),urban construction efficiency(UCE),and ecological services efficiency(ESE)all displayed significant spatial heterogeneity.The high trade-off areas were widely distributed and long-lasting in agricultural space and urban space,while gradually decreasing in ecological space.Wuhan and Changsha showed high spatial mismatch coefficients in urban space,but low spatial mismatch coefficients in agricultural space.Hunan generally presented high spatial mismatch coefficients in ecological space.Furthermore,the interaction of the proportion of cultivated area and transportation accessibility exacerbated the mismatch in agricultural space.The interaction effects of capital investment and technology innovation with other factors have the most intense impact on the mismatch in urban space.The internal factor for cultivated area interacts with other external factors to drastically affect ecological spatial mismatch.

关键词： land use function land use efficiency spatial mismatch analysis influencing factors Middle Reaches of the Yangtze River