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陆水水库防汛突发事件分析及应对措施

人民长江 2013年第18期44卷 63-65页

作者：杨亚峰杨振明张俊文长江水利委员会陆水试验枢纽管理局湖北赤壁437300

结合陆水水利枢纽的实际情况以及重点保护对象和防洪标准,对汛期可能出现的重大工程险情进行了分析,并在溃坝洪水计算的基础上,对其破坏程度进行了分析。针对可能发生的重大险情,制定了应对措施,提出要加强对工程险情的监测和巡视,发现... 详细信息

结合陆水水利枢纽的实际情况以及重点保护对象和防洪标准,对汛期可能出现的重大工程险情进行了分析,并在溃坝洪水计算的基础上,对其破坏程度进行了分析。针对可能发生的重大险情,制定了应对措施,提出要加强对工程险情的监测和巡视,发现险情及时上报,险情抢护要及时、措施要得力,应急保障措施要到位,平时加强防洪应急演练,在最大程度上降低防汛突发事件造成的不利影响。

关键词：突发事件应对措施应急保障陆水水库

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气候变化下水文模拟不确定性若干问题讨论

水资源保护 2023年第1期39卷 109-118,149页

作者：张力赵自阳王红瑞杨亚锋李晓军北京师范大学水科学研究院北京100875 华北理工大学理学院河北唐山063210 济南市水利工程服务中心山东济南250099

在阐释水文不确定性定义的基础上,根据气候变化下水文模拟不确定性的分类,总结了气候变化情景、水文模型和评估过程方面不确定性研究的基本范式,概述了每种不确定性的来源及影响,综述了气候变化下水文模拟不确定性研究进展。指出了未来... 详细信息

在阐释水文不确定性定义的基础上,根据气候变化下水文模拟不确定性的分类,总结了气候变化情景、水文模型和评估过程方面不确定性研究的基本范式,概述了每种不确定性的来源及影响,综述了气候变化下水文模拟不确定性研究进展。指出了未来水文系统模拟不确定性研究的重点和方向:结合复杂网络,增强对极端气候事件预估的可靠性;科学处理数据时间窗问题和冗余性,为无资料地区径流预测提供支撑;揭示变化环境下非平稳异方差性水文序列的发生规律。

关键词：气候变化水文系统水文模拟水文模型评估过程不确定性

Effect of Epoxy Resin on the Properties of Recycled Asphalt

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1149-1155页

作者： yang Ruochong CHEN Huimin yang Jun School of Transportation Southeast UniversityNanjing 211189China

To promote the recycling of reclaimed asphalt pavement(RAP),epoxy resin was used to prepare the epoxy-recycled asphalt *** effect of epoxy resin on the properties of aged asphalt binder was investigated based on the tensile test,flexural creep test,and laser scanning confocal *** curing characteristics and the mechanical performance of recycled asphalt with different epoxy contents were *** results show that the low-temperature performance,ductility,and strength of the aged asphalt binder were significantly improved when the epoxy content reached 40%.The curing time of epoxy-recycled asphalt should be at least 4 d to ensure the formation of good internal spatial network structure.

关键词： RAP epoxy resin aged asphalt mechanical performance

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水凝胶修复脊髓损伤作用机制的研究进展

中山大学学报（医学科学版） 2024年第5期45卷 785-796页

作者：杨溢珂任亚锋河南中医药大学康复医学院河南郑州450046 河南中医药大学第一附属医院河南郑州450000

脊髓损伤(SCI)是一种病情重、预后差的中枢神经系统疾病,其所导致的严重的感觉、运动或自主神经功能障碍极大地降低了患者的生活质量。尽管SCI的治疗和护理方面已经取得了相当大的进展,但由于药物不能通过血脊髓屏障直接输送到SCI部位,... 详细信息

脊髓损伤(SCI)是一种病情重、预后差的中枢神经系统疾病,其所导致的严重的感觉、运动或自主神经功能障碍极大地降低了患者的生活质量。尽管SCI的治疗和护理方面已经取得了相当大的进展,但由于药物不能通过血脊髓屏障直接输送到SCI部位,且SCI后的局部微环境不利于植入干细胞的存活、分化和增殖,使SCI的临床疗效及预后并不令人满意。水凝胶因其优异的机械性能、可塑性以及良好的生物相容性和生物降解性,可以作为装载干细胞或药物的递送系统,提供良好的环境并控制其释放,也可以作为生物支架,支持和引导轴突再生,有效提高脊髓损伤的治疗效果。本文综述了水凝胶的分类及功能特性,并进一步讨论了水凝胶在SCI修复中的改善脊髓损伤的抑制性微环境、促进神经再生、促进血管生成、促进血脊髓屏障修复等机制的研究进展,以期为水凝胶治疗SCI的临床应用及未来脊髓再生策略的探索和发展提供理论依据。

关键词：脊髓损伤水凝胶作用机制微环境神经再生

Alignment efficient image-sentence retrieval considering transferable cross-modal representation learning

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Frontiers of Computer Science 2024年第1期18卷 77-91页

作者： yang yang Jinyi GUO Guangyu LI Lanyu LI Wenjie LI Jian yang School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Computing Hong Kong Polytechnic UniversityHong Kong 100872China State Key Lab.for Novel Software Technology Nanjing UniversityNanjing 210094China 14th Research Institute of China Electronics Technology Group Corporation Nanjing 210094China guangyu.li2017@***

Traditional image-sentence cross-modal retrieval methods usually aim to learn consistent representations of heterogeneous modalities,thereby to search similar instances in one modality according to the query from another modality in *** basic assumption behind these methods is that parallel multi-modal data(i.e.,different modalities of the same example are aligned)can be obtained in *** other words,the image-sentence cross-modal retrieval task is a supervised task with the alignments as ***,in many real-world applications,it is difficult to realign a large amount of parallel data for new scenarios due to the substantial labor costs,leading the non-parallel multi-modal data and existing methods cannot be used *** the other hand,there actually exists auxiliary parallel multi-modal data with similar semantics,which can assist the non-parallel data to learn the consistent ***,in this paper,we aim at“Alignment Efficient Image-Sentence Retrieval”(AEIR),which recurs to the auxiliary parallel image-sentence data as the source domain data,and takes the non-parallel data as the target domain *** single-modal transfer learning,AEIR learns consistent image-sentence cross-modal representations of target domain by transferring the alignments of existing parallel ***,AEIR learns the image-sentence consistent representations in source domain with parallel data,while transferring the alignment knowledge across domains by jointly optimizing a novel designed cross-domain cross-modal metric learning based constraint with intra-modal domain adversarial ***,we can effectively learn the consistent representations for target domain considering both the structure and semantic ***,extensive experiments on different transfer scenarios validate that AEIR can achieve better retrieval results comparing with the baselines.

关键词： image-sentence retrieval transfer learning semantic transfer structure transfer

Multi-UAV cooperative maneuver decision-making for pursuitevasion using improved MADRL

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Defence Technology（防务技术） 2024年第5期35卷 187-197页

作者： Delin Luo Zihao Fan Ziyi yang yang Xu School of Aerospace Engineering Xiamen UniversityXiamen 361102China School of Civil Aviation Northwestern Polytechnical UniversityXi'an 710072China

Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net network based on a communication mechanism is introduced into a deep reinforcement learning algorithm to solve the multi-agent problem. A layer of gated recurrent unit(GRU) is added to the actor-network structure to remember historical environmental states. Subsequently,another GRU is designed as a communication channel in the Comm Net core network layer to refine communication information between UAVs. Finally, the simulation results of the algorithm in two sets of scenarios are given, and the results show that the method has good effectiveness and applicability.

关键词： Reinforcement learning UAV Maneuver decision GRU Cooperative control

Smoothed particle hydrodynamics based numerical study of hydroplaning considering permeability characteristics of runway surface

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 319-333页

作者： yang yang Xingyi ZHU Denis JELAGIN Alvaro GUARIN Key Laboratory of Road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 200092China Auto Engineering Research Institute BYD Auto Industry Company LimitedShenzhen 518118China Department of Civil and Architectural Engineering KTH Royal Institute of TechnologyStockholm 10044Sweden

The presence of water films on a runway surface presents a risk to the landing of *** tire of the aircraft is separated from the runway due to a hydrodynamic force exerted through the water film,a phenomenon called *** a lot of numerical investigations into hydroplaning have been conducted,only a few have considered the impact of the runway ***,computational problems,such as excessive distortion and computing efficiency decay,may arise with such numerical models when dealing with the thin water *** paper presents a numerical model comprising of the tire,water film,and the interaction with the runway,applying a mathematical model using the smoothed particle hydrodynamics and finite element(SPH-FE)*** material properties and geometric features of the tire model were included in the model framework and water film thicknesses from 0.75 mm to 7.5 mm were used in the numerical ***,this work investigated the impacts of both surface texture and the runway *** interaction between tire rubber and the rough runway was analyzed in terms of frictional force between the two *** SPH-FE model was validated with an empirical equation proposed by the National Aeronautics and Space Administration(NASA).Then the computational efficiency of the model was compared with the traditional coupled Eulerian-Lagrangian(CEL)*** on the SPH-FE model,four types of the runway(Flat,SMA-13,AC-13,and OGFC-13)were *** simulation of the asphalt runway shows that the SMA-13,AC-13,and OGFC-13 do not present a hydroplaning risk when the runway permeability coefficient exceeds 6%.

关键词： SPH-FE approach hydroplaning numerical simulation surface texture runway surface reconstruction

Fixed-Time Sliding Mode Control With Varying Exponent Coefficient for Modular Reconfigurable Flight Arrays

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 514-528页

作者： Jianquan yang Chunxi yang Xiufeng Zhang Jing Na Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500 Yunnan International Joint Laboratory of Intelligent Control and Aoolication of Advanced Equipment Kunming 650500China IEEE

The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular systems, we introduce a modular reconfigurable flight array(MRFA) to pursue a multifunction aircraft fitting for diverse tasks and requirements,and investigate the attitude control and the control allocation problem by using the modular reconfigurable flight array as a platform. First, considering the variable and irregular topological configuration of the modular array, a center-of-mass-independent flight array dynamics model is proposed to allow control allocation under over-actuated situations. Secondly, in order to meet the stable, fast and accurate attitude tracking performance of the MRFA, a fixed-time convergent sliding mode controller with state-dependent variable exponent coefficients is proposed to ensure fast convergence rate both away from and near the system equilibrium point without encountering the singularity. It is shown that the controller also has fixed-time convergent characteristics even in the presence of external disturbances. Finally,simulation results are provided to demonstrate the effectiveness of the proposed modeling and control strategies.

关键词： Control allocation dynamic model fixed-time stabilization modular reconfigurable flight array(MRFA) sliding mode

The action mechanism of the work done by the electric field force on moving charges to stimulate the emergence of carrier generation/recombination in a PN junction

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1001-1014页

作者： Lingyun GUO Yizhan yang Wanli yang Yuantai HU Department of Mechanics School of Aerospace EngineeringHubei Key Laboratory of Engineering Structural Analysis and Safety AssessmentHuazhong University of Science and TechnologyWuhan 430074China

It is discovered that the product of the current and the electric field in a PN junction should be regarded as the rate of work(power)done by the electric field force on moving charges(hole current and electron current),which was previously misinterpreted as solely a Joule heating *** clarify that it is exactly the work done by the electric field force on the moving charges to stimulate the emergence of non-equilibrium carriers,which triggers the novel physical *** regards to Joule heat,we point out that it should be calculated from Ohm’s law,rather than simply from the product of the current and the electric *** on this understanding,we conduct thorough discussion on the role of the electric field force in the process of carrier recombination and carrier *** thermal effects of carrier recombination and carrier generation followed are incorporated into the thermal equation of *** present study shows that the exothermic effect of carrier recombination leads to a temperature rise at the PN interface,while the endothermic effect of carrier generation causes a temperature reduction at the *** two opposite effects cause opposite heat flow directions in the PN junction under forward and backward bias voltages,highlighting the significance of managing device heating phenomena in design ***,this study possesses referential significance for the design and tuning on the performance of piezotronic devices.

关键词： piezoelectric semiconductor(PS) work done by electric field force thermal effect piezotronic device resistivity conductivity