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Data-driven Robust State Estimation Through Off-line Learning and On-line Matching

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Journal of Modern Power Systems and Clean Energy 2021年第4期9卷 897-909页

作者： Yanbo chen hao chen Yang Jiao Jin Ma Yuzhang Lin State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Electrical&Electronic EngineeringNorth China Electric Power UniversityBeijing 102206China School of Electrical and Information Engineering University of SydneySydney 2006Australia Department of Electrical and Computer Engineering University of MassachusettsLowellMA 01852USA

To overcome the shortcomings of model-driven state estimation methods, this paper proposes a data-driven robust state estimation (DDSE) method through off-line learning and on-line matching. At the off-line learning stage, a linear regression equation is presented by clustering historical data from supervisory control and data acquisition (SCADA), which provides a guarantee for solving the over-learning problem of the existing DDSE methods;then a novel robust state estimation method that can be transformed into quadratic programming (QP) models is proposed to obtain the mapping relationship between the measurements and the state variables (MRBMS). The proposed QP models can well solve the problem of collinearity in historical data. Furthermore, the off-line learning stage is greatly accelerated from three aspects including reducing historical categories, constructing tree retrieval structure for known topologies, and using sensitivity analysis when solving QP models. At the on-line matching stage, by quickly matching the current snapshot with the historical ones, the corresponding MRBMS can be obtained, and then the estimation values of the state variables can be obtained. Simulations demonstrate that the proposed DDSE method has obvious advantages in terms of suppressing over-learning problems, dealing with collinearity problems, robustness, and computation efficiency.

关键词： Robust state estimation historical snapshot off-line learning on-line matching collinearity

Damage propagation and strength prediction of a single-lap interference-fit laminate structure

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Frontiers of Mechanical Engineering 2020年第4期15卷 558-570页

作者： Peng ZOU Xiangming chen hao chen Guanhua XU Full Scale Aircraft Structural Static/Fatigue Laboratory AVIC Aircraft Strength Research Institute of ChinaXi’an 710065China School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China

Experimental and finite element research was conducted on the bolted interference fit of a single-lap laminated structure to reveal the damage propagation mechanism and strength change law. A typical single-lap statically loading experiment was performed, and a finite element damage prediction model was built based on intralaminar progress damage theory. The model was programmed with a user subroutine and an interlaminar cohesive zone method. The deformation and damage propagation of the specimen were analyzed, and the failure mechanism of intralaminar and interlaminar damage during loading was discussed. The effect of secondary bending moment on load translation and damage distribution was revealed. The experimental and simulated load–displacement curves were compared to validate the developed model’s reliability, and the ultimate bearing strengths under different fit percentages were predicted. An optimal percentage was also recommended.

关键词： single-lap interference fit secondary bending moment damage mechanism bearing strength

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近70年黄河潼关站以下河段冲淤特征分析

水土保持研究 2025年第1期32卷 48-56页

作者：韩超王飞戈文艳陈昊史尚渝刘元昊西北农林科技大学水土保持科学与工程学院中国科学院水利部水土保持研究所

[目的]揭示黄河潼关以下河段冲淤变化过程及分布特征，为未来黄河下游水土保持和调水调沙工作提供参考。[方法]对1952—2022年来潼关—花园口段、下游游荡型河段、过渡型河段、弯曲型河段输沙特征和冲淤过程进行分析，采用趋势分析、突... 详细信息

[目的]揭示黄河潼关以下河段冲淤变化过程及分布特征，为未来黄河下游水土保持和调水调沙工作提供参考。[方法]对1952—2022年来潼关—花园口段、下游游荡型河段、过渡型河段、弯曲型河段输沙特征和冲淤过程进行分析，采用趋势分析、突变检验与回归分析等方法，确定了不同河段的输沙、冲淤变化特征及其相互影响。[结果]潼关以下河段年输沙量在显著减少(p<0.01),1996年后各站输沙量大幅降低，近20年来沙系数均低于0.01,表现冲刷特征。各河段年淤积量呈下降趋势，潼关—花园口段和弯曲型河段仍在持续淤积，花园口—艾山段近20年淤积量则为负值。研究时段内，潼关以下河段累计淤积泥沙186.84亿t,潼关—花园口段、游荡型河段、过渡型河段和弯曲型河段分别淤积了86.75亿t, 49.45亿t, 17.14亿t, 33.49亿t。另外，输沙量和来沙系数变化分别对潼关—花园口、游荡型河段和花园口以下河段淤积影响明显(p<0.01)。[结论]小浪底水利枢纽运行及调水调沙实施后，潼关以下河段年淤积量大幅减少，潼关—花园口和弯曲型河段承载了更多泥沙，花园口—艾山段则已由淤转冲。

关键词：水沙变化黄河下游冲淤过程淤积现状

Enzymatic nitrous oxide emissions from wastewater treatment

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Frontiers of Environmental Science & Engineering 2018年第1期12卷 113-124页

作者： Gang Guo Yayi Wang Tianwei hao Di Wu Guang-hao chen Department of Civil ＆ Environmental Engineering The Hong Kong University of Science and Technology Hong Kong 999077 China State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China Institute for Advanced Study The Hong Kong University of Science and Technology Hong Kong 999077 China Hong Kong Branch of the Chinese National Engineering Research Center for Control ＆ Treatment of Heavy Metal Pollution The Hong Kong University of Science and Technology Hong Kong 999077 China Wastewater Treatment Laboratory FYT Graduate School The Hong Kong University of Science and Technology Guangzhou 511458 China

Nitrous oxide （N20）, a potent greenhouse gas, is emitted during nitrogen rernoval in wastewater treatment, significantly contributing to greenhouse effect. Nitrogen removal generally involves nitrification and denitrification catalyzed by specific enzymes. N20 production and consumption vary considerably in response to specific enzyme-catalyzed nitrogen imbalances, but the mechanisms are not yet completely understood. Studying the regulation of related enzymes＂ activity is essential to minimize N20 emissions during wastewater treatment. This paper aims to review the poorly understood related enzymes that most commonly involved in producing and consuming N20 in terms of their nature, structure and catalytic mechanisms. The pathways of N20 emission during wastewater treatment are briefly introduced. The key environmental factors influencing N20 emission through regulatory enzymes are summarized and the enzyme-based mechanisms are revealed. Several enzyme- based techniques for mitigating N20 emissions directly or indirectly are proposed. Finally, areas for further research on N20 release during wastewater treatment are discussed.

关键词： Nitrous oxideMitigationEnzyme catalysisNitrogen removalWastewater treatment

Ultrathin Zn-free anode based on Ti_(3)C_(2)T_(x) and nanocellulose enabling high-durability aqueous hybrid Zn-Na battery with Zn2+/Na+co-intercalation mechanism

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Nano Research 2023年第1期16卷 536-544页

作者： hao chen Weijun Zhou Minfeng chen Qinghua Tian Xiang Han Jizhang chen College of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037China Key Laboratory of Surface&Interface Science of Polymer Materials of Zhejiang Province Department of ChemistryZhejiang Sci-Tech UniversityHangzhou 310018China Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China

With low cost and high safety,aqueous zinc-based batteries have received considerable ***,the excess utilization of zinc metal in the anodes of these batteries reduces energy density and increases ***,an ultrathin electrode of approximately 6.2μm thick is constructed by coating Ti_(3)C_(2)T_(x)/nanocellulose hybrid onto a stainless steel *** electrode is used as the Zn-free anode for aqueous hybrid Zn-Na battery,in which,a concentrated electrolyte is used to improve electrochemical *** Ti_(3)C_(2)T_(x)/nanocellulose coating is found to improve the electrolyte wettability,facilitate desolvation process of hydrated Zn^(2+) ions,lower nucleation overpotential,improve zinc plating kinetics,guide horizontal zinc plating along the Zn(002)facet,and inhibit parasitic side *** is also found that the Na_(3)V_(2)(PO_(4))_(3) cathode material adopts a highly reversible Zn^(2+)/Na^(+)co-intercalation charge storage mechanism in this *** to these benefits,the assembled hybrid Zn-Na battery exhibits excellent rate capability,superior cyclability,and good anti-freezing *** work provides a new concept of electrode design for electrochemical energy storage.

关键词： MXene-based composites ultrathin electrodes electrode surface coatings aqueous hybrid batteries co-intercalation charge storage mechanisms

Superhydrophilic–superhydrophobic patterned surfaces:From simplified fabrication to emerging applications

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Nanotechnology and Precision Engineering 2022年第3期5卷 55-79页

作者： hao chen Xiaoping Li Dachao Li State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise *** surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental *** review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned ***,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are ***,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are ***,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.

关键词： Superhydrophobicity Superhydrophilicity Wettability patterns Droplet array Biosensor

k_(eff)uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

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Nuclear Science and Techniques 2021年第11期32卷 105-118页

作者： Rong-Rui Yang Yuan Yuan chen hao Ji Ma Guang-hao Liu Fundamental Science on Nuclear Safety and Simulation Technology Laboratory College of Nuclear Science and TechnologyHarbin Engineering UniversityHarbin 150001China Department of Reactor Technology Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBeijing 100089China

To benefit from recent advances in modeling and computational algorithms,as well as the availability of new covariance data,sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors(HTGRs).In particular,the contribution of nuclear data to the k_(eff)uncertainty is an important part of the uncertainty analysis of small-sized HTGR physical *** this study,a small-sized HTGR designed by China Nuclear Power Engineering Co.,*** selected for k_(eff)uncertainty analysis during full lifetime burnup *** of the cold zero power(CZP)condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation,depletion calculation,and sensitivity and uncertainty *** the sensitivity analysis,the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Track length importance Characterization(CLUTCH)method was applied to obtain sensitive information,and the "sandwich" method was used to quantify the k_(eff)*** also compared the k_(eff)uncertainties to other typical *** results show that ^(235)U is the largest contributor to k_(eff)uncertainty for both the CZP and depletion conditions,while the contribution of ^(239)Pu is not very significant because of the design of low discharge *** is worth noting that the radioactive capture reaction of ^(28)Si significantly contributes to the k_(eff)uncertainty owing to its specific fuel ***,the k_(eff)uncertainty during the full lifetime depletion process was relatively stable,only increasing by 1.12%owing to the low discharge burnup design of small-sized *** numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HTGR.

关键词： Small-sized HTGR SU analysis Nuclear data Burnup

Field investigation on severely damaged aseismic buildings in 2014 Ludian earthquake

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Earthquake Engineering and Engineering Vibration 2015年第1期14卷 169-176页

作者： Lin Xuchuan Zhang haoyu chen Hongfu chen hao Lin Junqi Institute of Engineering Mechanics China Earthquake Administration Key Laboratory of Earthquake Engineering and Engineering Vibration China Earthquake Administration

The 2014 magnitude 6.5 Ludian earthquake caused a death toll of 617, many landslides and tens of thousands of collapsed buildings. A field investigation to evaluate the damage to buildings was carried out immediately after the occurrence of the earthquake. Severely damaged aseismic buildings, which were basically observed in the downtown of Longtoushan Town, were carefully examined one by one with the aim to improve design codes. This paper summarizes the damage observed to the investigated aseismic buildings in both the structural and local levels. A common failure mode was observed that most of the aseismic buildings, such as RC frame structures and confined masonry structures, were similarly destroyed by severe damage or complete collapse of the first story. The related strong ground motion, which was recorded at the nearby station, had a short duration of less than 20 s but a very large PGA up to 1.0 g. The RC frames based on the new design codes still failed to achieve the design target for ＂strong column, weak beam＂. Typical local failure details, which were related to the interaction between RC columns and infill walls and between constructional columns and masonry walls, are summarized with preliminary analyses.

关键词： Ludian earthquake field investigation aseismic buildings structural collapse local failure

Seismic damage to structures in the Ms6.5 Ludian earthquake

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Earthquake Engineering and Engineering Vibration 2016年第1期15卷 173-186页

作者： chen hao Xie Quancai Dai Boyang Zhang haoyu chen Hongfu Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering Mechanics CEA Harbin 150080 China Earthquake Administration of Yunnan Province Kunming 650224 China

On 3 August 2014, the Ludian earthquake struck northwest Yunnan Province with a surface wave magnitude of 6.5. This moderate earthquake unexpectedly caused high fatalities and great economic loss. Four strong motion stations were located in the areas with intensity V, VI, VII and IX, near the epicentre. The characteristics of the ground motion are discussed herein, including 1） ground motion was strong at a period of less than 1.4 s, which covered the natural vibration period of a large number of structures; and 2） the release energy was concentrated geographically. Based on materials collected during emergency building inspections, the damage patterns of adobe, masonry, timber frame and reinforced concrete （RC） frame structures in areas with different intensities are summarised. Earthquake damage matrices of local buildings are also given for fragility evaluation and earthquake damage prediction. It is found that the collapse ratios of RC frame and confined masonry structures based on the new design code are significantly lower than non-seismic buildings. However, the RC frame structures still failed to achieve the ＇strong column, weak beam＇ design target. Traditional timber frame structures with a light infill wall showed good aseismic performance.

关键词： Ludian earthquake investigations of seismic damage masonry structure RC frame timber flame adobehouse