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Analysis and Modeling of Time Output Characteristics for Distributed Photovoltaic and Energy Storage

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Energy Engineering 2024年第4期121卷 933-949页

作者： Kaicheng Liu Chen Liang Xiaoyang Dong liping Liu China Electric Power Research Institute Beijing100192China Electric Power Research Institute State Grid Gansu Electric Power CompanyLanzhou730000China State Key Laboratory of Power Grid Safety Beijing100084China

Due to the unpredictable output characteristics of distributed photovoltaics,their integration into the grid can lead to voltage fluctuations within the regional power ***,the development of spatial-temporal coordination and optimization control methods for distributed photovoltaics and energy storage systems is of utmost importance in various *** paper approaches the issue from the perspective of spatiotemporal forecasting of distributed photovoltaic(PV)generation and proposes a Temporal Convolutional-Long Short-Term Memory prediction model that combines Temporal Convolutional Networks(TCN)and Long Short-Term Memory(LSTM).To begin with,an analysis of the spatiotemporal distribution patterns of PV generation is conducted,and outlier data is handled using the 3σ ***,a novel approach that combines temporal convolution and LSTM networks is introduced,with TCN extracting spatial features and LSTM capturing temporal ***,a real spatiotemporal dataset from Gansu,China,is established to compare the performance of the proposed network against other *** results demonstrate that the model presented in this paper exhibits the highest predictive accuracy,with a single-step Mean Absolute Error(MAE)of 1.782 and an average Root Mean Square Error(RMSE)of 3.72 for multi-step predictions.

关键词： Photovoltaic power generation spatio-temporal prediction temporal convolutional network long short-term memory network

Parameter sensitivity analysis of the axial stability for a marine flexible pipe

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Petroleum 2024年第3期10卷 548-556页

作者： liping Tang Jiaxin Zou Kenan Song Yongheng Shi Li Liu School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500China School of Engineering University of AberdeenAberdeenAB243UEUK Oil&Gas Control Center National Petroleum and Natural Gas Pipeline Network Group Co.Ltd.Beijing100020China

Marine unbonded flexible pipes serve as the most essential equipment in offshore oil and gas exploration and *** compressive loads during installation or in service in the complex marine environment usually lead to buckling failure.A flexible pipe is a composite structure with multiple functional layers,of which the tensile armor layer plays a key role with regard to the response of the pipe subjected to axial *** this paper,a simplified three-dimensional finite element model is developed,focusing on the tensile layer and replacing the carcass layer,pressure sheath layer,and pressure armor layer by a cylindrical rigid body to reduce computational *** using this model,the buckling failure modes of the tensile armor layer(in particular the birdcaging phenomenon)are *** key parameters that affect the stability of the flexible pipe under axial compression and torsion are emphasized,and their effects on its axial and torsional stiffness are compared and *** results show that both the lay angle of the steel wires and the interlayer friction coefficient have a significant influence on the axial and torsional stiffness of the pipe,whereas the damaged length of the outer sheath has virtually no effect.

关键词： Flexible pipe Tensile armor Buckling failure Key parameters Stiffness

Efficient Digital Twin Placement for Blockchain-Empowered Wireless Computing Power Network

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Computers, Materials & Continua 2024年第7期80卷 587-603页

作者： Wei Wu Liang Yu liping Yang Yadong Zhang Peng Wang School of Cybersecurity Northwestern Polytechnical UniversityXi’an710126China

As an open network architecture,Wireless Computing PowerNetworks(WCPN)pose newchallenges for achieving efficient and secure resource management in networks,because of issues such as insecure communication channels and untrusted device ***,as a shared,immutable distributed ledger,provides a secure resource management solution for ***,integrating blockchain into WCPN faces challenges like device heterogeneity,monitoring communication states,and dynamic network *** Digital Twins(DT)can accurately maintain digital models of physical entities through real-time data updates and self-learning,enabling continuous optimization of WCPN,improving synchronization performance,ensuring real-time accuracy,and supporting smooth operation of WCPN *** this paper,we propose a DT for blockchain-empowered WCPN architecture that guarantees real-time data transmission between physical entities and digital *** adopt an enumeration-based optimal placement algorithm(EOPA)and an improved simulated annealing-based near-optimal placement algorithm(ISAPA)to achieve minimum average DT synchronization latency under the constraint of DT *** results show that the proposed solution in this paper outperforms benchmarks in terms of average synchronization latency.

关键词： Wireless computing power network blockchain digital twin placement minimum synchronization latency

UAV swarm air combat maneuver decision-making method based on multi-agent reinforcement learning and transferring

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Science China(Information Sciences) 2024年第8期67卷 49-66页

作者： Zhiqiang ZHENG Chen WEI Haibin duan State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical Engineering Beihang University

During short-range air combat involving unmanned aircraft vehicle(UAV) swarms, UAVs must make accurate maneuver decisions based on information from both enemy and friendly UAVs. This dual requirement of competition and cooperation presents a significant challenge in the field of unmanned air combat. In this paper, a method based on multi-agent reinforcement learning(MARL) is proposed to address this issue. An actor network containing three subnetworks that can handle different types of situational information is designed. Hence, the results from simpler one-on-one scenarios are leveraged to enhance the complex swarm air combat training process. Separate state spaces for local and global information are designed for the actor and critic networks. A detailed reward function is proposed to encourage *** prevent lazy participants in air combat, a reward assignment operation is applied to distribute these dense rewards. Simulation testing and ablation experiments demonstrate that both the transfer operation and reward assignment operation can effectively deal with the swarm air combat scenario, and reflect the effectiveness of the proposed method.

关键词： UAV swarm short-range air combat multi-agent reinforcement learning reward assignment transfer

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天然气水合物关键技术相关专利

油气储运 2017年第11期36卷 1237-1242,1250页

作者：段黎萍张静袁芳中国科学技术信息研究所

天然气水合物也称可燃冰,广泛分布于大陆架、海洋陆坡区及陆地永冻层下,其储量巨大,有可能成为未来最重要的潜在能源之一。世界各国针对天然气水合物开展了大量研究与开发,但是目前其尚未实现商业化开采。针对天然气水合物开采至应用环... 详细信息

天然气水合物也称可燃冰,广泛分布于大陆架、海洋陆坡区及陆地永冻层下,其储量巨大,有可能成为未来最重要的潜在能源之一。世界各国针对天然气水合物开展了大量研究与开发,但是目前其尚未实现商业化开采。针对天然气水合物开采至应用环节涉及的主要技术问题,利用德温特专利库进行了专利统计与分析。结果表明:日本、中国、韩国拥有的天然气水合物专利相对较多,欧美主要的石油与化工界巨头也在天然气水合物的关键技术点上有大布局;基于天然气水合物的专利布局角度,中国和日本最有可能率先实现商业化生产,但两国的专利分布均存在技术短板,需要在短缺的技术领域进一步进行研发和专利布局。

关键词：天然气水合物可燃冰专利分析关键技术

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Design, modeling, and evaluation of parallel continuum robots: A survey

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Science China(Technological Sciences) 2024年第3期67卷 673-695页

作者： CHEN GenLiang TANG ShuJie duan XuYang WANG Hao Meta Robotics Institute Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Digital Manufacturing for Thin-Walled Structures Shanghai Jiao Tong UniversityShanghai 200240China

Parallel continuum robots(PCRs) have attracted increasing attention in the robotics community due to their simplicity in structure,inherence with compliance, and easiness of realization. Over the past decade, a variety of novel designs have been reported to enrich their diversity. However, there is a lack of systematic review of these emerging robots. To this end, this paper conducts a comprehensive survey on the mechanism design, kinetostatic modeling and analysis, and performance evaluation. For these robots, kinetostatic modeling plays a fundamental role throughout the design, analysis, and control stages. A systematic review of the existing approaches for kinetostatic modeling and analysis is provided, and a comparison is made to distinguish their differences. As well, a classification is made according to the characteristics of structure and actuation. In addition, performance evaluation on the workspace, stability, and singularity is also overviewed. Finally, the scenarios of potential applications are elaborated, and future research prospects are discussed. We believe that the information provided in this paper will be particularly useful for those who are interested in PCRs.

关键词： parallel continuum robots classification kinetostatic modeling performance evaluation

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Prescribed-time leader-following consensus of linear multi-agent systems by bounded linear time-varying protocols

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Science China(Information Sciences) 2024年第1期67卷 140-153页

作者： Kai ZHANG Bin ZHOU Xuefei YANG Guangren duan Center for Control Theory and Guidance Technology Harbin Institute of Technology

This paper considers the prescribed-time leader-following consensus problem of input-constrained linear multi-agent systems under generally directed communication topology in two cases:the Laplacian matrix related to the entire communication topology between agents is either known or *** particular,the consensus problem for the former case is solved by a novel bounded linear time-varying(LTV) protocol,where the feedback gain is formulated by the parametric Lyapunov equation and the knowledge of the Laplacian ***,by utilizing a distributed observer,a fully bounded LTV protocol is proposed for the latter *** should be noted that,compared with the existing results,the system under consideration is more general,the designed protocols are linear,and the consensus problem is accomplished even in a fully distributed ***,the effectiveness of the proposed approach is verified by a numerical example.

关键词： leader-following consensus time-vary feedback prescribed-time control fully distributed consensus

Two-Dimensional Graphitic Carbon-Nitride(g-C_(3)N_(4))-Coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)Cathodes for High-Energy-Density and Long-Life Lithium Batteries

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Energy & Environmental Materials 2024年第6期7卷 140-149页

作者： Zhenliang duan Pengbo Zhai Ning Zhao Xiangxin Guo College of Physics Qingdao UniversityQingdao 266071China College of Materials Science and Engineering Qingdao UniversityQingdao 266071China Tianmushan Laboratory Xixi Octagon CityHangzhou 310023China

High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium ***,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle ***,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis *** an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal ***,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 *** a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C.

关键词： cathode materials g-C_(3)N_(4)coating LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) lithium batteries PVDF:LLZTO electrolyte membranes

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DIN1.2344钢注塑模具的裂纹分析

兵器材料科学与工程 2014年第6期37卷 118-121页

作者：段莉萍唐家耘中国兵器科学研究院宁波分院浙江宁波315103

DIN1.2344钢汽车灯罩注塑模具在最终精加工的型腔工作面发现有微细裂纹。采用着色渗透无损检测、化学成分分析、宏观形貌和微观形貌分析以及能谱分析等方法对裂纹进行研究。结果表明:在模具原材料中存在带状偏析、碳化物网和非金属夹杂... 详细信息

DIN1.2344钢汽车灯罩注塑模具在最终精加工的型腔工作面发现有微细裂纹。采用着色渗透无损检测、化学成分分析、宏观形貌和微观形貌分析以及能谱分析等方法对裂纹进行研究。结果表明:在模具原材料中存在带状偏析、碳化物网和非金属夹杂物等严重的组织缺陷,模具在调质热处理淬火冷却时也形成二次碳化物网;裂纹的产生主要是由于模具材料中存在非金属夹杂物等严重组织缺陷,模具设计有尖锐角也是导致早期脆性开裂的重要原因。

关键词： DIN1.2344钢注塑模具组织缺陷尖锐角裂纹

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