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面向异步电机模型预测直接转矩控制的自适应谐波消除方法

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电工技术学报 2025年第4期40卷 1078-1089页

作者：韩硕张勇军肖雄刘辰伟郭强北京科技大学高效轧制与智能制造国家工程研究中心北京102206 北京科技大学工程技术研究院北京102206

异步电机变频驱动系统在运行过程中会产生大量谐波,引发电机转矩脉动、损耗加重等问题,给电机性能及效率带来直接影响,因此有针对性地控制或消除驱动系统的谐波具有重要的研究意义。该文创新性地提出一种带有自适应谐波消除策略的模型... 详细信息

异步电机变频驱动系统在运行过程中会产生大量谐波,引发电机转矩脉动、损耗加重等问题,给电机性能及效率带来直接影响,因此有针对性地控制或消除驱动系统的谐波具有重要的研究意义。该文创新性地提出一种带有自适应谐波消除策略的模型预测直接转矩控制(AHE-MPDTC)方法,首次将自适应谐波消除策略引入到模型预测直接转矩控制中,通过调整自适应滤波器的权重,从目标函数得到的主输入信号中消除不期望出现的频率分量,从而获得较为理想的变换器输入参考电压。测试结果表明,所提出的方法在保证系统响应速度的基础上,可以有效消除由于变换器引起的5~25次谐波,从而提升异步电机调速系统的稳定性。

关键词：异步电机变频驱动模型预测控制自适应谐波消除

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低秩矩阵辅助的无人机影像建筑物立面纹理自动修复

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武汉大学学报(信息科学版) 2025年第1期50卷 144-152页

作者：景慧莹刘欣怡张永军任维成王雷姚永祥郭延庆武汉大学遥感信息工程学院湖北武汉430079 山东正元航空遥感技术有限公司山东济南250098 聊城市城乡规划设计研究院山东聊城252000

无人机数据采集过程中,受飞行高度、扫描视场角的限制,数据中的建筑物立面纹理存在遮挡问题,进而导致数据缺失。当前大量待修复数据都是采用人工勾选方式进行修复,人力成本高,时间消耗大。因此,从建筑物立面纹理低秩性和遮挡区域稀疏性... 详细信息

无人机数据采集过程中,受飞行高度、扫描视场角的限制,数据中的建筑物立面纹理存在遮挡问题,进而导致数据缺失。当前大量待修复数据都是采用人工勾选方式进行修复,人力成本高,时间消耗大。因此,从建筑物立面纹理低秩性和遮挡区域稀疏性切入,将建筑物立面纹理修复问题化为低秩矩阵补全问题,提出了一种低秩矩阵重建辅助的建筑物立面纹理自动修复算法。首先,利用鲁棒主成分分析自动完成立面纹理稀疏遮挡区域粗提取;然后,结合遮挡区域的先验条件填充精化得到稀疏区域,作为矩阵补全的约束条件;最后,在矩阵补全模型的基础上,采用非凸秩近似函数截断Schatten-p范数替代核范数,同时又引入总变分算子来解决建筑物立面纹理遮挡区域修复问题。仿真实验和真实数据结果表明:在建筑物低秩纹理修复中,所提算法的分割效果不亚于人工标记,修复效果优于现有算法,能自动提取出待修复区域,实现了人力解放和修复效果的双提升。

关键词：建筑物立面纹理自动修复遮挡物提取低秩矩阵矩阵补全非凸秩近似

Physical and Numerical Simulation for Inner Crack Healing in Metals

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上海交通大学学报 2004年第z2期38卷 130-135页

作者： Jingtao HAN Dongbin WEI yongjun zhang School of Material Science and Engineering UST Beijing 100083 P.R.China University of Wollongong NSW 2522 Australia SHOUGANG Research Institute of Technology Beijing 100041 P.R.China

The research purpose on the healing of inner crack in metallic materials is to provide an effective approach for improving their properties and prolonging their lifetime. The crack healing process of 20MnMo steel with inner pre-crack was analyzed. It was found that all inner cracks could be healed in different degree. There were very fine ferrite grains in healing region. The micro-crack healing process in single crystal of BBC-Fe was simulated by the molecule dynamics method, which showed that the critical temperature of crack healing in BBC-Fe is 673K. There were micro-voids, dislocations and twins left after crack healing.

关键词： metal inner crack healing simulation

A Model Predictive Control Algorithm Based on Biological Regulatory Mechanism and Operational Research

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IEEE/CAA Journal of Automatica Sinica 2023年第11期10卷 2174-2176页

作者： Jinying Yang yongjun zhang Tanju Yildirim Jiawei zhang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China National Institute for Materials Science Ibaraki 305-0047Japan School of Electrical and Information Engineering University of SydneySydney 2000Australia

Dear Editor,This letter presents an intelligent model predictive control algorithm inspired by biological regulatory mechanism and operational research. In terms of overall architecture, based on biological regulatory system and operational research theory, priority factor module and central coordination module are innovatively added on the basis structure of heuristic dynamic programming to carry out overall regulation of the system.

关键词： carry letter programming

Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

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Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： Liang CHENG Xiaolei CHEN Zhisen YE yongjun zhang State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional Machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. Simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

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极早产儿合并早产后呼吸疾病的危险因素分析

中华儿科杂志 2025年第1期63卷 50-54页

作者：尤优吕静雯周琳王丽平张菊风王利张拥军夏红萍上海交通大学医学院附属新华医院新生儿科上海200092

目的探讨极早产儿合并早产后呼吸疾病(PPRD)的危险因素。方法前瞻性队列研究。纳入2019年1月至2023年6月生后1周内于上海交通大学医学院附属新华医院新生儿重症监护病房住院的369例极早产儿,分析极早产儿校正年龄1岁内的呼吸系统疾病情... 详细信息

目的探讨极早产儿合并早产后呼吸疾病(PPRD)的危险因素。方法前瞻性队列研究。纳入2019年1月至2023年6月生后1周内于上海交通大学医学院附属新华医院新生儿重症监护病房住院的369例极早产儿,分析极早产儿校正年龄1岁内的呼吸系统疾病情况,并收集极早产儿和母亲的临床特征、早产儿并发症及相关治疗情况。根据是否合并PPRD将极早产儿分为PPRD组和无PPRD组。采用Mann Whitney U检验、χ^(2)检验或连续校正χ^(2)检验进行组间比较,应用多因素Logistic回归分析探讨PPRD的危险因素。结果369例极早产儿中男217例(58.8%),出生胎龄为30(28,31)周,出生体重为1320(1085,1590)g,116例(31.4%)合并PPRD,253例(68.6%)未合并PPRD。PPRD组极早产儿的出生胎龄和出生体重均低于无PPRD组(均P<0.001)。与无PPRD组相比,PPRD组男性更多,第1、5分钟Apgar评分均更低,剖宫产出生、支气管肺发育不良、应用肺表面活性物质治疗的极早产儿均更多,有创机械通气天数和总氧疗天数均更长,出院时年龄的体重Z评分更低,差异均有统计学意义(均P<0.05)。多因素Logistic回归分析显示,出生胎龄(OR=0.85,95%CI 0.73~0.99,P=0.037)、剖宫产出生(OR=2.23,95%CI 1.21~4.10,P=0.010)、有创机械通气天数≥7 d(OR=2.51,95%CI 1.43~4.39,P=0.001)和出院时年龄的体重Z评分(OR=0.82,95%CI 0.67~0.99,P=0.040)均是PPRD的独立危险因素。结论对于出生胎龄小、剖宫产出生、有创机械通气天数≥7 d及出院时年龄的体重Z评分低的极早产儿,出院后应密切观察是否合并PPRD,并给予规范的呼吸管理。

关键词：支气管肺发育不良危险因素婴儿,极早产早产后呼吸疾病

Plasma characteristics and material erosion mechanism in multi-channel wire electrical discharge machining

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Chinese Journal of Aeronautics 2024年第10期37卷 508-525页

作者： Guokang SU Chuanyun zhang Junfei LI Xiaolei CHEN Guixian LIU yongjun zhang State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional Machining Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China School of Mechanical Engineering Xi’an Technological UniversityXi’an 710021China

Multi-channel wire electrical discharge machining(MC-WEDM)is an advanced and high-efficiency machining technology,but its material erosion mechanism remains *** this study,dual-channel wire electrical discharge machining was utilized as a case study to investigate the impact of the plunging current on both the plasma characteristics and material erosion under complex discharge *** analysis was conducted on the charged particles in the plasma,revealing that the plunging current can influence the trajectory of the plasma by modifying the selfmagnetic *** particle tracking method was employed to simulate the motion of electrons,revealing that in MC-WEDM,electrons exhibited a larger and more uniform *** evolution of the plasma within a single-pulse discharge was observed using high-speed photography technology,and the discharge signals collected from different channels were *** was observed that the plasma in MC-WEDM experienced more intense back-and-forth sweeping on the workpiece surface,facilitating the ejection of molten metal from the molten *** oscillating plasma exhibits a larger processing area and a more uniform distribution of energy,resulting in the formation of larger and shallower discharge ***,the influence of the amplitude and time point of the plunging current on the volume and area of the discharge craters was ***,MC-WEDM significantly reduced the occurrence of holes and micro-cracks and exhibited a thinner recast layer in the continuous discharge experiment.

关键词： Multi-channel WEDM Discharge observation Plunging current Plasma characteristics Material erosion Discharge crater

Modified Sadowski formula-based model for the slope shape amplification effect under multistage slope blasting vibration

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International Journal of Mining Science and Technology 2024年第5期34卷 631-641页

作者： Xiaogang Wu Mingyang Wang Hao Lu yongjun zhang Wen Nie State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing 210007China State Key Laboratory of Metal Mine Safety and Health Ma’anshan 243000China School of Civil Engineering Qingdao University of TechnologyQingdao 266520China

Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity *** conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the *** address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration *** the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred *** findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging *** amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to ***,platforms without distinct crosssectional changes exhibit no pronounced amplification during *** addition,the vibration intensity decreases with distance as the rock height difference change *** results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world *** to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%).

关键词： Multistage slope Slope shape influence factor Continuous blasting Sadowski formula Amplification effect

A global evaluation of the associations between long-term dynamics of seed falls and rodents

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Integrative Zoology 2023年第5期18卷 831-842页

作者： Rui LIU yongjun zhang Hongmao zhang Lin CAO Chuan YAN State Key Laboratory of Grassland Agro-ecosystems College of Ecology&School of Life SciencesLanzhou UniversityLanzhouChina Institute of Evolution and Ecology College of Life SciencesCentral China Normal UniversityWuhanChina College of Ecology and Environmental Science Yunnan UniversityKunmingChina Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity Yunnan UniversityKunmingChina

One classic system of pulsed resource and animal population is mast seeding and population dynamics of seedeating rodents in ***,we still lack an understanding of the global patterns regarding the contributions of seed falls to rodent outbreaks or population *** analyzed a global dataset of coupled long-term time series of seed abundances and rodent populations from published literature,including 66 and 89 time series(156 rodent-seed pairs from 37 studies)for rodent and seed abundances,*** found only half of the examined rodent populations showed statistically significant coincidence between rodent outbreak and mastseeding *** all the coupled time series,seed abundance was found to positively correlate with rodent abundance with a one-year lag,and the relative importance of seed abundance was much lower than that of density dependence in affecting rodent population growth *** also found the relative importance of seed abundance decreased,but that of rodent density dependence increased with the latitude of *** the first time,our work provides a global pattern on the associations between seed falls and rodent population dynamics mostly in midand high-latitude forests,and highlights the necessity of more long-term studies on this subject in more forest ecosystems.

关键词： density dependence mast resource pulse rodent seed