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An analytical approach to reconstruction of axisymmetric defects in pipelines using T(0,1)guided waves

Applied Mathematics and Mechanics(English Edition) 2020年第10期41卷 1479-1492页

作者： Yihui DA Bin WANG D.Z.LIU Zhenghua QIAN State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China School of Engineering University of East AngliaNorwich NR47TJU.K

Torsional guided waves have been widely utilized to inspect the surface corrosion in pipelines due to their simple displacement behaviors and the ability of longrange ***,the torsional mode T(0,1),which is the first order of torsional guided waves,plays the irreplaceable position and role,mainly because of its non-dispersion characteristic ***,one of the most pressing challenges faced in modern quality inspection is to detect the surface defects in pipelines with a high level of *** into account this situation,a quantitative reconstruction method using the torsional guided wave T(0,1)is proposed in this *** methodology for defect reconstruction consists of three ***,the reflection coefficients of the guided wave T(0,1)scattered by different sizes of axisymmetric defects are calculated using the developed hybrid finite element method(HFEM).Then,applying the boundary integral equation(BIE)and Born approximation,the Fourier transform of the surface defect profile can be analytically derived as the correlative product of reflection coefficients of the torsional guided wave T(0,1)and the fundamental solution of the intact pipeline in the frequency ***,reconstruction of defects is precisely performed by the inverse Fourier transform of the product in the frequency *** experiments show that the proposed approach is suitable for the detection of surface defects with arbitrary ***,the effects of the depth and width of surface defects on the accuracy of defect reconstruction are *** is noted that the reconstructive error is less than 10%,providing that the defect depth is no more than one half of the pipe thickness.

关键词： torsional guided wave hybrid finite element method(HFEM) boundary integral equation(BIE) quantitative reconstruction

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Nanoflower Microreactor Based Versatile Enhancer for Recognition Cofactor-Dependent Enzyme Biocatalysis Toward Saxitoxin Detection

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SSRN 2024年

作者： Wei, Liu-Na Luo, Lin Lei, Hong-Tao Guan, Tian Jiang, Cheng Yin, Qing-Chun Xu, Zhen-Lin Li, Chenzhong Guangdong Provincial Key Laboratory of Food Quality and Safety South China Agricultural University Guangzhou510642 China School of Medicine The Chinese University of Hong Kong Shenzhen518172 China Hainan Institute for Food Control Key Laboratory of Tropical Fruits and Vegetables Quality and Safety for State Market Regulation Haikou570314 China School of Biomedical Engineering China

Traditionally, investigations on the utilization efficiency and bioactivity of the organic carriers within organic-inorganic hybrid nanoflowers are critical for realizing sensitive immunosensors. Nevertheless, immunosensor sensitivity detection is regulated in a highly interactive way by different classes of biomolecules like antibodies and enzymes. In this work, we introduced a new alkaline phosphatase-antibody-CaHPO4 hybrid nanoflowers microreactor (AAHNFs)-based colorimetric immunoprobe design composed of biometric unit (antibody) integrating signal amplification element (enzyme) form via the biomineralization process. Specifically, it’s focuses on the influencing factors of antibody recognition activity in the formation mechanism of AAHNFs. The designed AAHNFs retain the ability of antibody recognition with enhanced protection effect on the encapsulated proteins against high temperature, organic solvents, and long-term storage, facilitated the selective construction of lock structures by antibodies against antigens. In addition, after hydrolyzing of ascorbic acid 2-phosphate by ALP, the generated ascorbic acid decomposes I2 to I-, which can induce the localized surface plasmon resonance properties of silver nanoplate effectively tuned through shape conversion. Further, a 3D-printed portable device integrated with a smartphone sensing platform was fabricated and applied to collection and analysis the data. Notably, the immunosensor has significantly improved the analytical performance with a detection range of 0.1-6.25 ng/mL and a low detection limit of 0.06 ng/mL for quantitative analysis of saxitoxin (STX). The average recoveries of STX in the real samples ranged from 85.86% to 105.91%. This work could be extended to other monitor targeted analytes events of interest for on-site rapid monitoring. © 2024, The Authors. All rights reserved.

关键词： Catalysis

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Reactive Antistatic Agent Doped Copper Azide as a Primary Explosive with Simultaneously Enhanced Stability and Energy

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SSRN 2023年

作者： Xu, Jing Sun, Jian Ma, Xiaoxia Zhang, Lei Tong, Wenchao Yang, Li School of Mechatronical Engineering Beijing Institute of Technology Beijing100081 China State Key Laboratory of Explosion and Technology Beijing Institute of Technology Beijing100081 China Science and Technology on Applied Physical Chemistry Laboratory Shaanxi Applied Physics-Chemistry Research Institute Shaanxi Xi’an710061 China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120 China

The emergence of micro-priming systems expedites the demand for balancing the inherent contradiction between energy and safety in primary explosives. This paper proposes a new strategy (metal organic framework/reactive antistatic agent strategy, MOF/RAA strategy) which introduces the reactive antistatic agent (WO3) into ternary copper azide /carbon activity system by carbonization and azide of polyoxometalate-based metal–organic frameworks. Subsequent characterization validates that the novel reactive multi-component system (ternary copper azide /carbon/tungsten trioxide) performs well with both high electrostatic safety and remarkable detonating ability (detonate CL-20 as low as 0.98 mg) due to the electrical conductivity and active participation in secondary reaction of reactive antistatic agent (WO3). In general, this discovery has obtained prominent achievements in the application of copper azide in micro-initiating systems, providing a safe yet energy simultaneously enhanced way for the design and synthesis of novel energetic compounds. © 2023, The Authors. All rights reserved.

关键词： Antistatic agents

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Receding and Freezing Dynamics of a Supercooled Water Droplet Impinging Onto a Cold Surface

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SSRN 2023年

作者： Wang, Jingxin Bian, Qingyong Tian, Linlin Guo, Rongying Zhu, Chunling College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Jiangsu Nanjing210016 China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and Astronautics Jiangsu Nanjing210016 China

The impingement–freezing process of supercooled water droplets is the root cause of aircraft icing. This work presented an experimental investigation of a millimeter-sized supercooled droplet (-10 [[EQUATION]]) impinging onto a cold aluminate surface. The spreading/receding dynamics and freezing behavior of the impinging droplets, including the maximum spreading factor, spreading time, receding velocity, frozen area ratio, initial freezing height, and solidification time, were comprehensively analyzed. Intriguingly, the surface temperature had no significant effect on the spreading stage;however, cold surfaces decreased the receding velocity of the droplets in the inertial-capillary receding regime. Regardless of the three freezing modes (quasi-static, instantaneous, and delayed), the frozen area ratio increased with decreasing Weber number. For a Stefan number[[EQUATION]]0.12, the frozen area ratio increased with decreasing surface temperature;otherwise, it was independent of the surface temperature. With increasing Stefan and Weber numbers, the morphologies of the frozen droplets transitioned from a hemisphere and pointy pancake to a basin. In addition, we modified the prediction models for receding velocity and frozen area ratio. The universal initial freezing height of the asymmetry droplet was established by applying the' Two-ellipse' method. We present an empirical formula to describe the solidification time for impinging droplets on cold surfaces. This fundamental study provides valuable information for understanding aircraft icing and optimizing anti-icing systems. © 2023, The Authors. All rights reserved.

关键词： Dynamics

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Reliability Analysis Based on Optimization Random Forest Model and MCMC

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Computer Modeling in engineering & Sciences 2020年第11期125卷 801-814页

作者： Fan Yang Jianwei Ren State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an710049China

Based on the rapid simulation of Markov Chain on samples in failure region,a novel method of reliability analysis combiningMonte Carlo Markov Chain(MCMC)with random forest algorithmwas ***,a series of samples distributing around limit state function are generated by ***,the samples were taken as training data to establish the random forest ***,Monte Carlo simulation was used to evaluate the failure ***,examples demonstrate the proposed method possesses higher computational efficiency and accuracy.

关键词： Markov chain random forest Monte Carlo simulation nonlinear function random uncertainty

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Synergistic Optimization of Power & Capacity Configuration Considering control Strategy for Flywheel Energy Storage Participating in Primary Frequency Regulation

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SSRN 2024年

作者： Liang, Lu Hong, Feng Ji, Weiming Jiang, Hui Hao, Junhong Fang, Fang Liu, Jizhen The State Key Laboratory of Alternate Electric Power System with Renewable Energy Sources North China Electric Power University Beijing102206 China School of Control and Computer Engineering North China Electric Power University Beijing102206 China Key Laboratory of Power Station Energy Transfer Conversion and System Ministry of Education School of Energy Power China

The intermittent and stochastic nature of renewable energy sources poses stern challenges to the frequency stability of new power system. The flywheel energy storage system (FESS), with its rapid response and high power density, plays a pivotal role in mitigating frequency fluctuations. To improve the performance of the FESS assisting thermal power unit (TPU), a collaborative optimization methodology of the capacity configuration and control strategy for FESS is presented in this paper. Aiming to enhance the primary frequency control (PFC) performance and reduce the life-cycle cost of the FESS, this paper established a capacity configuration model based on a dynamic adaptive control strategy, in which FESS compensates for the lack of TPU frequency regulation capability and recovery SOC actively. A case study demonstrated that the optimization model proposed is suitable for different frequency scenarios. It has been verified that the control strategy which is based on the SOC of FESS and frequency regulation capability of the TPU is economically more attractive compared to traditional strategies. In addition, this study revealed that a FESS with a charge/discharge rate of 7.5 C and rated power of 7.6 MW was appropriate for assisting a 600MW TPU in PFC by the optimal capacity configuration and control strategy. © 2024, The Authors. All rights reserved.

关键词： Wheels

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Potential Effects of Cu2+ Stress on Nitrogen Removal Performance, Microbial Characteristics, and Metabolism Pathways of Biofilm Reactor

SSRN

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SSRN 2024年

作者： Zhang, Shuai Huang, Xiao Dong, Wenyi Wang, Hongjie Hu, Liangshan Zhou, Guorun Zheng, Zhihao Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control School of Environmental Science and Engineering Nanjing University of Information Science & Technology Nanjing210044 China Shenzhen518055 China State Key Laboratory of Urban Water Resource and Environment School of Environment Harbin Institute of Technology Harbin150090 China

Sequencing batch biofilm reactors (SBBR) were utilized to investigate the impact of Cu2+ on nitrogen (N) removal and microbial characteristics. The result indicated that the low concentration of Cu2+ facilitated the removal of ammonia nitrogen (NH4+-N), total nitrogen (TN). Compared with the control group of the average effluent concentration, the average effluent concentrations of NH4+-N, TN were found to decrease by 40.53%, 15.86%, respectively. Conversely, the high concentration of Cu2+ resulted in a increase of 94.27%, 14.23% in the aforementioned parameters, compared with the control group. The addition of low concentrations of Cu2+ significantly (P © 2024, The Authors. All rights reserved.

关键词： Nitrogen removal

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Safe Path Following control of Autonomous Underwater Vehicles Based on Double Dipole Vector Field

Safe Path Following Control of Autonomous Underwater Vehicle...

引用

Asian control Conference

作者： Haoliang Wang Tan Li Lootha Loserian Muriatoy Dezhi Yu Pingxin Liu Ai Jichong Daoyi Lu Marine Engineering College Dalian Maritime University Dalian China Department of Automation Shanghai Jiaotong University Shanghai China State Key Laboratory of Maritime Technology and Safety Dalian China Dalian Key Laboratory of Swarm Control and Electrical Technology for Intelligent Ships Dalian China Marine Electrical Engineering College Dalian Maritime University Dalian China Hainan Railway Co. LTD Haikou China

ISBN: (数字)9789887581598

ISBN: (纸本)9798331540845

This paper studies a path following problem of autonomous underwater vehicle (AUV) in complex and harsh working environment. Firstly, a kinematic model of an AUV in the vertical plane is built by constructing an earth coordinate system and a body coordinate system. Secondly, a guidance pitch angle is proposed by using a double dipole vector field, and guidance speeds are designed based on the back-stepping method. Finally, the stability of the proposed control system is proved by Lyapunov stability theory. Simulation results verify the effectiveness of the real-time safe path following control of autonomous underwater vehicles based on double dipole vector field.

关键词： Earth Autonomous underwater vehicles Simulation Kinematics Reliability engineering Vectors Real-time systems

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Research on Thermal Runaway Characteristics and Mechanism of Ncm811 Lithium-Ion Batteries Under Cross-Seasonal and Wide-Temperature Condition at -10℃~33℃: A Case Study in Qingdao, China

SSRN

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SSRN 2024年

作者： Zhou, Gang Yang, Siqi Liu, Yang Zhang, Qi Niu, Chenxi Zhang, Shengzhu Lu, Huaheng Wei, Zhikai Huang, Qi College of Safety and Environmental Engineering Shandong University of Science and Technology Qingdao266590 China Engineering Laboratory of Battery Safety and Accident Control of Petroleum and Chemical Industry Changzhou University Changzhou213164 China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing100081 China State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province the Ministry of Science and Technology Shandong University of Science and Technology Qingdao266590 China China Academy of Safety Science and Technology Beijing100012 China Department of Safety Engineering College of Safety and Environmental Engineering Shandong University of Science and Technology 579 Qianwangang Road Shandong Province Huangdao District Qingdao China

Multiple heat sources and extreme ambient temperatures pose more severe challenges to the safety performance of lithium-ion batteries ( LIBs), and the kinetic characterization of thermal runaway (TR) of LIBs at extreme temperatures has yet to be improved. In this paper, a coupled thermal abuse stimulation experimental platform was built to investigate the TR mechanism and flame eruption kinetics of LIBs induced by dual heat sources under a wide temperature range of -10~ 30 ℃ in the four seasons. The results showed that the TR onset time (Tonset) was gradually shortened with the increase of ambient temperature, in the order of Tonset-Winter＞Tonset-Spring＞Tonset-Autumn＞Tonset-Summer;for example, with 100% SOC (state of Charge), Tonset-Winter=2528 s, Tonset-Summer=2211 s, which was accelerated by 14.3%. However, TR maximum temperature (Tmax) showed the opposite trend, Tmax-summer=687.2 ℃, Tmax-winter=796.5 ℃, which decreased by 15.9%. When SOC ≥ 75%, the average warning time for TR disaster of LIB (from venting to the beginning of TR) is 254 s less than that of winter in the summer with higher temperature, which makes the adoption of emergency measures and escape more urgent. When SOC ≥ 50%, the TR process was accompanied by flame generation, and the flame eruption process was the most intense at 100% SOC, with a maximum flame area of about 4400 cm2, and its flame temperature was likewise the highest at 986.4 ℃. Carbon and metal oxides were detected in the TR ejecta, and the lower the ambient temperature, the finer the ejecta particles were. The results of the study provide an important scientific reference for improving the theory of TR of LIBs, guiding the investigation of TR and fire in new energy vehicles, and formulating relevant standards. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

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Identification of Abnormal Operating Conditions in Fused Magnesium Furnaces Using a Deep Multiview TSK Fuzzy System

Identification of Abnormal Operating Conditions in Fused Mag...

引用

Chinese Automation Congress (CAC)

作者： Chao Xi Gaochang Wu Zizhu Fan Feng Xu Hui Wang Xiaokun Tang School of Electrical and Automation Engineering East China Jiaotong University Nanchang China State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang China College of Computer Science and Technology Shanghai University of Electric Power Shanghai China Key Laboratory of Advanced Control and Optimization of Jiangxi Province East China Jiaotong University Nanchang China

ISBN: (数字)9798350368604

ISBN: (纸本)9798350368611

The smelting process of the fused magnesium furnace(FMF) is prone to semi-molten abnormal conditions, which may lead to low product quality and production efficiency, and is also prone to safety accidents. At present, the operating conditions of FMF mainly rely on manual observation of the furnace shell features for diagnosis, and it is hard to timely and effectively identify abnormalities in the smelting process. Given the difficulty in identifying abnormal operating conditions of FMF, this paper proposes a deep multiview fuzzy classification method(DMFC) that can automatically identify abnormal operating conditions. First, based on the three-phase current data, CNN and Transformer are used to extract features as multiple views. Secondly, the Takagi-Sugeno-Kang(TSK) fuzzy model is used as a single-view model, and the evidence theory is used for dynamic fusion of multiple views. This method can effectively fuse multiple deep features, and has strong scalability and a certain degree of interpretability. Through verification of the real historical data of multiple FMFs, our model has relatively high accuracy, false detection rate(FDR), and missed detection rate(MDR).

关键词： Fuses Heuristic algorithms Furnaces Smelting Production Feature extraction Transformers Magnesium Classification algorithms Unsupervised learning

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