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溢流面陡坡段上紊流边界层数值分析

水利学报 1989年第3期21卷 9-16页

作者：郑邦民陈飞勇武汉水利电力学院长江科学院

本文论述了溢流面上紊流边界层问题,采用k-ε二方程模型,并通过坐标变换将发展的边界层变为一个规则的矩形区域;最后用有限控制体积法和伽略金有限元法对变换后的方程进行数学离散并求解。通过两个计算实例,获得速度分布、边界层厚度、... 详细信息

本文论述了溢流面上紊流边界层问题,采用k-ε二方程模型,并通过坐标变换将发展的边界层变为一个规则的矩形区域;最后用有限控制体积法和伽略金有限元法对变换后的方程进行数学离散并求解。通过两个计算实例,获得速度分布、边界层厚度、紊动动能变化。水面线形状、平板及曲面边界层等资料,除紊动动能缺少实际资料验证外,其它计算均与试验结果符合良好。

关键词：溢流面陡坡段紊流边界层数值分析水力学

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流体力学中正交曲线座标张量的应用

武汉水利电力学院学报 1985年第1期 1-9页

作者：郑邦民武汉水利电力学院水力学教研室

文中利用了单向基向量(?)的局部正交性,得出以张量注标记号表示的(?)的统一公式,而有它在推求正交曲线坐标的场论向量公式及流体力学方程时,避免引入协变导数和克里斯多夫记号。较之现有一些场论和流体力学书中的作法,显得非常简便且几... 详细信息

文中利用了单向基向量(?)的局部正交性,得出以张量注标记号表示的(?)的统一公式,而有它在推求正交曲线坐标的场论向量公式及流体力学方程时,避免引入协变导数和克里斯多夫记号。较之现有一些场论和流体力学书中的作法,显得非常简便且几何概念明晰。向量与张量的各个分量或分解系数直接以基向量的显式表出。

关键词：基向量分解系数显式分量张量曲线坐标流体力学

Correlation between grain size,mechanical properties and deformed microstructure of Fe-20Mn-6Al-0.6C-0.15Si low-density steel

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Journal of Iron and Steel Research International 2025年第1期32卷 282-292页

作者： Qi Zhang Guang-hui Chen zheng-liang Xue zheng-kun Chen Guang Xu State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Red Eagle Novel Refractory Materials Research Institute Zhejiang Red Eagle Group Co.Ltd.Huzhou313000ZhejiangChina

The effects of austenite grain size on the deformed microstructure and mechanical properties of an Fe-20Mn-6Al-0.6C-0.15Si(wt.%)low-density steel were *** microstructure of the experimental steel after solution treatment was single austenitic *** austenite grain size increased with solution temperature and time.A model was established to show the relationship between temperature,time and austenite grain size for the experimental *** addition,as the solution temperature increased,the strength decreased,while the elongation first increased and then *** decrease in elongation after solution treatment at 1100℃ for 90 min is contributed to the over-coarse austenite ***,after solution treatment at 900℃ for 90 min,the strength-elongation product reached the highest value of 44.4 GPa%.As the austenite grain size increased,the intensity of//tensile direction fiber *** was accompanied by a decrease in dislocation density,resulting in a lower fraction of low-angle grain boundaries and a lower work hardening ***,the austenite grain size has a critical influence on the mechanical properties of the low-density *** grains lead to a lower yield strength due to the Hall-Petch effect and a lower tensile strength because of lower dislocation strengthening.

关键词： Austenitic low-density steel Solution treatment Grain size Mechanical property Deformed microstructure

An efficient conversion model between acceleration and pseudo-acceleration response spectra considering effects of magnitude,distance,and site class

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 15-30页

作者： Liu zheng Zhao Yan-Gang Zhang Haizhong Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China Faculty of Agriculture Yamagata University1-23Wakaba-machiTsuruoka-shiYamagata 997-8555Japan

Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic ***,only one of them is generally provided in most seismic ***,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site ***,we developed an SA/PSA model incorporating these ***,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large *** paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large *** this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of *** magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 *** ground motions were recorded at 338 stations covering four site *** comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.

关键词： acceleration response spectrum pseudo-acceleration response spectrum magnitude distance site class

Luminescence: a new perspective for investigating perovskite precursors

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Science China Materials 2025年第1期68卷 312-313页

作者： Haofeng zheng Shaocong Hou School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Wuhan University Shenzhen Research Institute Shenzhen 518057China

In the past two decades, perovskite materials have made significant progress in optoelectronic semiconductors, emerging as formidable candidates for the next generation of commercial solar cells, light-emitting diodes (LEDs), and *** the fundamental solution chemistry and photophysics in solution-processed perovskite devices is crucial for comprehending to achieve highly efficient optoelectronic devices.

关键词： optoelectronic diodes perovskite

A Comprehensive Survey of Few-shot Information Networks

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Machine Intelligence Research 2025年第1期22卷 60-78页

作者： Xinxin zheng Feihu Che Jianhua Tao School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China Institute of Automation Chinese Academy of SciencesBeijing100190China Department of Automation Tsinghua UniversityBeijing100084China

Information networks store rich information in the nodes and edges,which benefit many downstream tasks,such as recommender systems and knowledge graph *** networks contain homogeneous information,heterogeneous information and knowledge graphs.A significant number of surveys focus on one of the three parts and summarize the research works,but few surveys conclude and compare the three kinds of information *** addition,in real scenarios,lots of information networks lack sufficient labeled data,so the combination of meta-learning and information networks can bring in extended *** paper concentrates on few-shot information networks and systematically presents recent works to help analyze and follow related works.

关键词： Few-shot learning meta-learning homogeneous information networks heterogeneous information networks knowledge graphs

Knowledge As Not Only Justified True Beliefs in Vision

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IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 297-299页

作者： Wenbo zheng Fei-Yue Wang IEEE School of Computer Science and Artificial Intelligence Wuhan University of Technology Sanya Science and Education Innovation Park of Wuhan University of Technology the State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences

COMPUTATIONAL knowledge vision [1] is emphasized as a novel perspective or field in this paper. It first proposes the visual hierarchy and its connection to knowledge, stating that knowledge is a justified true belief. To further the previous research, we concisely summarize our recent works and suggest a new direction that knowledge is also a thought framework in vision.

关键词： Computational modeling Visualization Artificial intelligence Data models Visual perception Visual databases Training data

Multi-Objective optimization for stable and efficient cargo transportation of partial space elevator

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Defence Technology(防务技术) 2025年第2期44卷 17-29页

作者： Gefei Shi zheng H.Zhu School of Aeronautics and Astronautics Sun Yat-sen UniversityGuangzhou 510275China Shenzhen Key Laboratory of Intelligent Microsatellite Constellation Shenzhen 518107China Department of Mechanical Engineering York University4700 Keele StreetTorontoCanada

This paper proposed a new libration decoupling analytical speed function(LD-ASF)in lieu of the classic analytical speed function to control the climber's speed along a partial space elevator to improve libration stability in cargo *** LD-ASF is further optimized for payload transportation efficiency by a novel coordinate game theory to balance competing control objectives among payload transport speed,stable end body's libration,and overall control input via model predictive *** transfer period is divided into several sections to reduce computational *** validity and efficacy of the proposed LD-ASF and coordinate game-based model predictive control are demonstrated by computer *** results reveal that the optimized LD-ASF results in higher transportation speed,stable end body's libration,lower thrust fuel consumption,and more flexible optimization space than the classic analytical speed function.

关键词： Partial space elevator Stable transportation Libration decoupling analytical speed function Coordinate game Model predictive control Pareto optimization

Joint Probabilistic Scheduling and Resource Allocation for Wireless Networked Control Systems

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 258-260页

作者： Meng zheng Lei Zhang Wei Liang IEEE the State Key Laboratory of Robotics and the Key Laboratory of Networked Control Systems Shenyang Institute of Automation Chinese Academy of Sciences the University of Chinese Academy of Sciences

Dear Editor,This letter presents a joint probabilistic scheduling and resource allocation method(PSRA) for 5G-based wireless networked control systems(WNCSs). As a control-aware optimization method, PSRA minimizes the linear quadratic Gaussian(LQG) control cost of WNCSs by optimizing the activation probability of subsystems, the number of uplink repetitions, and the durations of uplink and downlink phases. Simulation results show that PSRA achieves smaller LQG control costs than existing works.

关键词： Networked control systems