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基于改进RRT^(*)FN算法的机械臂多场景运动规划

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中国机械工程 2021年第21期32卷 2590-2597页

作者：房立金吴政翰王怀震东北大学机器人科学与工程学院沈阳110000

针对固定节点数的渐进最优快速扩展随机树(RRT^(*)FN)算法精度低、对环境缺乏适应性等问题,提出了一种改进RRT^(*)FN的机械臂运动规划算法。在迭代过程中,结合目标偏向随机采样和椭球子集采样的优势,构造新的启发式方法对采样区域进行约... 详细信息

针对固定节点数的渐进最优快速扩展随机树(RRT^(*)FN)算法精度低、对环境缺乏适应性等问题,提出了一种改进RRT^(*)FN的机械臂运动规划算法。在迭代过程中,结合目标偏向随机采样和椭球子集采样的优势,构造新的启发式方法对采样区域进行约束,从而保证搜索路径更优。在扩展节点时,配置树中总节点数的预设值,并通过加权方法对树中叶子节点进行删减,避免了树规模的无限增长。在动态环境下,采用对节点剪枝与连接的启发式重规划方法,有效提高了对动态环境的适应能力。实验结果表明,该算法在规划过程中收敛速度更快,效率更高,具有较强的环境适应性。

关键词：渐进最优快速扩展随机树运动规划冗余机械臂启发式采样重规划

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用钾-氩法求地质事件真实年龄的方法探讨

现代地质 1989年第4期3卷 404-412页

作者：吴珍汉中国地质科学院研究生部

钾-氩法所测出的地质事件的表面年龄一般小于地质事件发生的真实年龄,其中很多没有地质意义。本文利用随机过程理论,在对地质体内^(40)Ar的逸散作用进行分析的基础上,推导出如下年龄计算公式: 在一定条件下,利用这些公式,可以据钾-氩法... 详细信息

钾-氩法所测出的地质事件的表面年龄一般小于地质事件发生的真实年龄,其中很多没有地质意义。本文利用随机过程理论,在对地质体内^(40)Ar的逸散作用进行分析的基础上,推导出如下年龄计算公式: 在一定条件下,利用这些公式,可以据钾-氩法测试资料求出地质体形成时代t+t^(0)、热扰动结束时代t^(0)及热事件所持续的时期t'。据所导出的公式,对冀东迁西群地层的年龄进行讨论,求得2500Ma左右结束的那期热事件所持续的时期t'为4.76亿年,迁西群形成时代为3000—3300Ma。检验表明,公式有效。

关键词：钾-氩法表面年龄真实年龄氩逸散马尔柯夫链平稳过程迁西群

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu Jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Resilience-incorporated seismic risk assessment of precast concrete frames with“dry”connections

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 403-425页

作者： wu Chenhao Tang Yuchuan Cao Xuyang wu Gang Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Nanjing 211102China Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095USA School of Civil Engineering Southeast UniversityNanjing 211102China College of Civil and Transportation Engineering Hohai UniversityNanjing 210024China

A resilience-incorporated risk assessment framework is proposed and demonstrated in this study to manifest the advantageous seismic resilience of precast concrete frame(PCF)structures with“dry”connections in terms of their low damage and rapid *** framework integrates various uncertainties in the seismic hazard,fragility,capacity,demand,loss functions,and post-earthquake *** this study,the PCF structures are distinguished from ordinary reinforced concrete frame(RCF)structures by characterizing multiple limit states for the PCF based on its unique damage ***,probabilistic story-wise pushover analyses are performed to yield story-wise capacities for the predefined limit *** the seismic resilience analysis,a step-wise recovery model is proposed to idealize the functionality recovery process,with separate considerations of the repair and non-repair *** recovery model leverages the economic loss and downtime to delineate the stochastic post-earthquake recovery curves for the resilience loss *** such,contingencies in the probabilistic post-earthquake repairs are incorporated and the empirical judgments on the recovery parameters are largely *** proposed framework is demonstrated through a comparative study between two“dry”connected PCFs and one RCF designed as alternative structural systems for a prototype *** results from the risk quantification indicate that the PCFs show reduced loss hazards and lower expected losses relative to the ***,the PCF equipped with energy dissipation devices at the“dry”connections largely reduces the expected economic loss,downtime,and resilience loss by 29%,56%,and 60%,respectively,compared to the RCF.

关键词： precast concrete frame non-emulative precast system seismic resilience seismic risk functional recovery

New findings on the influence of El Nino events on tropical cyclone formation

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Science China Earth Sciences 2024年第3期67卷 892-893页

作者： Liguang wu Department of Atmospheric and Oceanic Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China

Tropical cyclones typically form over warm tropical and subtropical ocean surfaces, as their formation and intensification rely primarily on the energy provided by the ocean. Pioneering research by Gray (1968) revealed that the formation of tropical cyclones requires the sea surface temperature (SST) to be no less than 26.5℃. Consequently, SST is commonly recognized as a crucial parameter among the environmental factors influencing tropical cyclone formation(Gray, 1979;Emanuel and Nolan, 2004).

关键词： tropical cyclone ocean

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

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Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang wu Mingyu wu Yongfu Sun Yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

Two-layer autonomous intelligence dynamic trajectory planning method based on shield-tunnel ring-geology interactions

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Underground Space 2024年第6期19卷 227-250页

作者： Min Hu Bingjian wu Huiming wu Liefeng Pei SILC Business School Shanghai UniversityShanghai 201800China SHU-SUCG Research Centre for Building Industrialization Shanghai 201800China Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China

To solve the problem that current attitude planning methods do not fully consider the interaction and constraints among the shield,segmental tunnel ring,and geology,and cannot adapt to the changes in the actual engineering environment,or provide feasible long-term and short-term attitude planning,this paper proposes autonomous intelligent dynamic trajectory planning(AI-DTP)to provide tunnel ring and centimeter-layer planning targets for a self-driving shield to meet long-term accuracy and short-term ***-DTP introduces the Frenet coordinate system to solve the problem of inconsistent spatial representation of tunnel data,segmental tunnel ring location,and surrounding geological conditions,designs the long short-term memory attitude prediction model to accurately predict shield attitude change trend based on shield,tunnel,and geology,and uses a heuristic algorithm for trajectory ***-DTP provides ring-layer and centimeter-layer planning objectives that meet the needs of long-term accuracy and short-term correction of shield attitude *** the Hangzhou-Shaoxing Intercity Railroad Tunnel Project in China,the‘‘Zhiyu”shield equipped with the AI-DTP system was faster and more accurate than the manually controlled shield,with a smoother process and better quality of the completed tunnel.

关键词： Shield tunnel Trajectory planning Attitude control Self-driving Machine learning

On equivalence of state-based potential games

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Science China(Information Sciences) 2024年第6期67卷 313-327页

作者： Han wu Jinhuan WANG Institute of Mathematics School of ScienceHebei University of Technology

In this paper, we explore state-based potential games using the semi-tensor product of ***, applying the potential equation, we derive both a necessary and sufficient condition as well as a sufficient condition to verify whether a state-based game qualifies as a potential game. Next, we present two static equivalence conditions of state-based potential games. We then delve into dynamic equivalence. We propose a criterion that allows us to identify state-based games that are dynamically equivalent to state-based potential games and share similar dynamic properties. Ultimately, we introduce the concept of state-based networked evolutionary games. We provide a necessary and sufficient condition to ensure that a state-based networked evolutionary game can be classified as a state-based potential game.

关键词： semi-tensor product of matrices state-based potential game verification equivalence state-based networked evolutionary game

The Functional Redundancy of Neddylation E2s and E3s in Modulating the Fitness of Regulatory T Cells

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Research 2024年第2期2023卷 373-387页

作者： Di wu Yi Sun Cancer Institute(Key Laboratory of Cancer Prevention and Intervention China National Ministry of Education)of the Second Affiliated Hospital and Institute of Translational MedicineZhejiang University School of MedicineHangzhou 310029China Cancer Center of Zhejiang University Hangzhou 310029China Zhejang Provincial Clinical Research Center for Cancer Zhejang ProvinceChina Key Laboratory of Molecular Biology in Medical Sciences Zhejang ProvinceChina Research Center for Life Science and Human Health Binjiang Institute of Zhejiang UniversityHangzhou 310053China

Neddylation is necessary for activation of Cullin-RING ligases(CRLs),which degrade various immune regulatory *** recent study showed that while depletion of neddylation E2-E3 pair Ube2f-Sag in regulatory T(T_(reg))cells had no obvious phenotype,the same depletion of either Ube2m or Rbx1 caused inflammation disorders with different *** these E2s or E3s compensate each other in functional regulations of T_(reg)cells is,however,previously *** this report,we generated Foxp3^(Cre);Ube2m^(fl/fl);Ube2f^(fl/fl)or Foxp3^(Cre);Rbx1^(fl/fl);Sag^(fl/fl)double-null mice by simultaneous deletion of both neddylation E2s or E3s in T_(reg)cells,***,Ube2m&Ube2f double-null mice developed much severe autoimmune phenotypes than did Ube2m-null mice,indicating that Ube2m markedly compensates Ube2f in T_(reg)*** minor worsened autoimmune phenotypes seen at the very early stage in Rbx1&Sag double-null than Rbx1-null mice is likely due to already severe phenotypes of the later,indicating a minor compensation of Rbx1 for *** RNA profiling-based analyses revealed that up-and down-regulations of few signaling pathways in T_(reg)cells are associated with the severity of autoimmune ***,severer inflammation phenotypes seen in mice with double E3-null than with double E2-null T_(reg)cells indicate a neddylation-independent mechanism of 2 E3s,also known to serve as the RING component of CRLs in regulation of T_(reg)cell fitness.

关键词： Foxp3 inflammation markedly