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Development of CONTHAC-3D and hydrogen distribution analysis of HPR1000

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Nuclear Science and Techniques 2024年第2期35卷 210-221页

作者： Hui Wang Jing-Jing Li Yuan Chang Gong-Lin Li ming ding China Nuclear Power Engineering Co.LTD. Beijing 100084China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin 100049China

An in-house code,CONTHAC-3D,was developed to calculate and analyze thermal-hydraulic phenomena in containments during severe accidents.CONTHAC-3D is a three-dimensional computational fluid dynamics code that can be applied to predict gas flow,diffusion,and steam condensation in a containment during a severe hypothetical accident,as well as to obtain an estimate of the local hydrogen concentration in various zones of the containment.CONTHAC-3D was developed using multiple models to simulate the features of the proprietary systems and equipment of HPR1000 and ACP100,such as the passive cooling system,passive autocatalytic recombiners and the passive air cooling system.To validate CONTHAC-3D,a GX6 test was performed at the Battelle Model Containment facility.The hydrogen concentration and temperature monitored by the GX6 test are accurately predicted by CONTHAC-3D.Subsequently,the hydrogen distribution in the HPR1000 containment during a severe accident was studied.The results show that the hydrogen removal rates calculated using CONTHAC-3D for different types of PARs agree well with the theoretical values,with an error of less than 1%.As the accident progresses,the hydrogen concentration in the lower compartment becomes higher than that in the large space,which implies that the lower compartment has a higher hydrogen risk than the dome and large space at a later stage of the accident.The amount of hydrogen removed by the PARs placed on the floor of the compartment is small;therefore,raising the installation height of these recombiners appropriately is recommended.However,we do not recommend installing all autocatalytic recombiners at high positions.The study findings in regard to the hydrogen distribution in the HPR1000 containment indicate that CONTHAC-3D can be applied to the study of hydrogen risk containment.

关键词： Hydrogen risk mitigation Pressurized water reactor HPR1000 Thermal hydraulic CONTHAC-3D

Gradient sparsification for efficient wireless federated learning with differential privacy

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Science China(Information Sciences) 2024年第4期67卷 272-288页

作者： Kang WEI Jun LI Chuan MA ming ding Feng SHU Haitao ZHAO Wen CHEN Hongbo ZHU School of Electronic and Optical Engineering Nanjing University of Science and Technology Zhejiang Lab Key Laboratory of Computer Network and Information Integration(Southeast University) Ministry of Education Data61 Commonwealth Scientific and Industrial Research Organisation School of Information and Communication Engineering Hainan University School of Communications and Information Engineering Nanjing University of Posts and Telecommunications School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Federated learning(FL) enables distributed clients to collaboratively train a machine learning model without sharing raw data with each other. However, it suffers from the leakage of private information from uploading models. In addition, as the model size grows, the training latency increases due to the limited transmission bandwidth and model performance degradation while using differential privacy(DP)protection. In this paper, we propose a gradient sparsification empowered FL framework with DP over wireless channels, to improve training efficiency without sacrificing convergence performance. Specifically, we first design a random sparsification algorithm to retain a fraction of the gradient elements in each client’s local model, thereby mitigating the performance degradation induced by DP and reducing the number of transmission parameters over wireless channels. Then, we analyze the convergence bound of the proposed algorithm, by modeling a non-convex FL problem. Next, we formulate a time-sequential stochastic optimization problem for minimizing the developed convergence bound, under the constraints of transmit power, the average transmitting delay, as well as the client’s DP requirement. Utilizing the Lyapunov drift-plus-penalty framework, we develop an analytical solution to the optimization problem. Extensive experiments have been implemented on three real-life datasets to demonstrate the effectiveness of our proposed algorithm. We show that our proposed algorithms can fully exploit the interworking between communication and computation to outperform the baselines, i.e., random scheduling, round robin, and delay-minimization algorithms.

关键词： federated learning differential privacy gradient sparsification Lyapunov drift convergence analysis

Communication Resource-Efficient Vehicle Platooning Control With Various Spacing Policies

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 362-376页

作者： Xiaohua Ge Qing-Long Han Xian-ming Zhang Derui ding IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.

关键词： Automated vehicles constant time headway spacing constant spacing cooperative adaptive cruise control event-triggered communication vehicle platooning

Planning of DC Electric Spring with Particle Swarm Optimization and Elitist Non-dominated Sorting Genetic Algorithm

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 574-583页

作者： Qingsong Wang Siwei Li Hao ding ming Cheng Giuseppe Buja School of Electrical Engineering and Jiangsu Provincial Key Laboratory of Smart Grid Technology and Equipment Southeast UniversityNanjing 210096China School of Software Engineering Southeast universitySuzhou 215123China

This paper addresses the planning problem of parallel DC electric springs (DCESs). DCES, a demand-side management method, realizes automatic matching of power consumption and power generation by adjusting non-critical load (NCL) and internal storage. It can offer higher power quality to critical load (CL), reduce power imbalance and relieve pressure on energy storage systems (RESs). In this paper, a planning method for parallel DCESs is proposed to maximize stability gain, economic benefits, and penetration of RESs. The planning model is a master optimization with sub-optimization to highlight the priority of objectives. Master optimization is used to improve stability of the network, and sub-optimization aims to improve economic benefit and allowable penetration of RESs. This issue is a multivariable nonlinear mixed integer problem, requiring huge calculations by using common solvers. Therefore, particle Swarm optimization (PSO) and Elitist non-dominated sorting genetic algorithm (NSGA-II) were used to solve this model. Considering uncertainty of RESs, this paper verifies effectiveness of the proposed planning method on IEEE 33-bus system based on deterministic scenarios obtained by scenario analysis.

关键词： DC distribution network DC electric spring non-dominated sorting genetic algorithm particle swarm optimization renewable energy source

Dissociation cross sections ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons with nucleons

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Communications in Theoretical Physics 2024年第4期76卷 93-112页

作者： Ruo-Qing ding Xiao-ming Xu H J Weber Department of Physics Shanghai UniversityBaoshanShanghai 200444China Department of Physics University of VirginiaCharlottesvilleVA 22904United States of America

We study the dissociation ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons in collision with nucleons,which takes place in high-energy proton-nucleus collisions.The quark interchange between a nucleon and a meson leads to the dissociation of the meson.We consider the reactions:■,■,■,■,■,■,■,■,■,and■,where R stands forψ(3770),ψ(4040),ψ(4160),orψ(4415).A reaction of a neutron and a meson corresponds to a reaction of a proton and the meson by replacing the up quark with the down quark and vice versa.Transition-amplitude formulas are derived from the S-matrix element.Unpolarized cross sections are calculated with the transition amplitudes for scattering in the prior form and in the post form.The cross sections relate to nodes in the radial wave functions ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons.

关键词： inelastic nucleon-charmonium scattering quark interchange relativistic constituent quark potential model

Buckling Properties of Water-Drop-Shaped Pressure Hulls with Various Shape Indices Under Hydrostatic External Pressure

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China Ocean Engineering 2024年第1期38卷 1-17页

作者： ding Xiao-de ZHANG Jian WANG Fang JIAO Hui-feng WANG ming-lu School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Shanghai Engineering Research Center of Marine Renewable Energy College of Engineering Science and Technol-ogyShanghai Ocean UniversityShanghai 201306China China Ship Scientific Research Center Wuxi 214082China

The water-drop-shaped pressure hull has a good streamline,which has good application prospect in the underwater observatory.Therefore,this study conducted analytical,experimental and numerical investigation of the buckling properties of water-drop-shaped pressure hulls under hydrostatic pressure.A water-drop experiment was conducted to design water-drop-shaped pressure hulls with various shape indices.The critical loads for the water-drop-shaped pressure hulls were resolved by using Mushtari’s formula.Several numerical simulations including linear buckling analysis and nonlinear buckling analysis including eigenmode imperfections were performed.The results indicated that the critical loads resolved by Mushtari's formula were in good agreement with the linear buckling loads from the numerical simulations.This formula can be extended to estimate the buckling capacity of water-drop-shaped pressure hulls.In addition,three groups of pressure hulls were fabricated by using stereolithography,a rapid prototyping technique.Subsequently,three groups of the pressure hulls were subjected to ultrasonic measurements,optical scanning,hydrostatic testing and numerical analysis.The experimental results were consistent with the numerical results.The results indicate that the sharp end of the water-drop-shaped pressure hulls exhibited instability compared with the blunt end.This paper provides a new solution to the limitations of experimental studies on the water-drop-shaped pressure hulls as well as a new configuration and evaluation method for underwater observatories.

关键词： buckling pressure hull water drop underwater observatory

Mechanism of Qili Qiangxin Capsule for Heart Failure Based on miR133a-Endoplasmic Reticulum Stress

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Chinese Journal of Integrative Medicine 2024年第5期30卷 398-407页

作者： JI Xiao-di YANG ding CUI Xi-yuan LOU Li-xia NIE Bo ZHAO Jiu-li ZHAO ming-jing WU Ai-ming Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine Key Laboratory of Chinese Internal Medicine of Ministry of Education and BeijingBeijing 100700China Department of Traditional Chinese Medicine Fuwai HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100037China

Objective:To investigate the pharmacological mechanism of Qili Qiangxin Capsule(QLQX)improvement of heart failure(HF)based on miR133a-endoplasmic reticulum stress(ERS)pathway.Methods:A left coronary artery ligation-induced HF after myocardial infarction model was used in this study.Rats were randomly assigned to the sham group,the model group,the QLQX group[0.32 g/(kg·d)],and the captopril group[2.25 mg/(kg·d)],15 rats per group,followed by 4 weeks of medication.Cardiac function such as left ventricular ejection fraction(EF),fractional shortening(FS),left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),the maximal rate of increase of left ventricular pressure(+dp/dt max),and the maximal rate of decrease of left ventricular pressure(–dp/dt max)were monitored by echocardiography and hemodynamics.Hematoxylin and eosin(HE)and Masson stainings were used to visualize pathological changes in myocardial tissue.The m RNA expression of mi R133a,glucose-regulated protein78(GRP78),inositol-requiring enzyme 1(IRE1),activating transcription factor 6(ATF6),X-box binding protein1(XBP1),C/EBP homologous protein(CHOP)and Caspase 12 were detected by RT-PCR.The protein expression of GRP78,p-IRE1/IRE1ratio,cleaved-ATF6,XBP1-s(the spliced form of XBP1),CHOP and Caspase 12 were detected by Western blot.Td T-mediated d UTP nick-end labeling(TUNEL)staining was used to detect the rate of apoptosis.Results:QLQX significantly improved cardiac function as evidenced by increased EF,FS,LVSP,+dp/dt max,-dp/dt max,and decreased LVEDP(P<0.05,P<0.01).HE staining showed that QLQX ameliorated cardiac pathologic damage to some extent.Masson staining indicated that QLQX significantly reduced collagen volume fraction in myocardial tissue(P<0.01).Results from RT-PCR and Western blot showed that QLQX significantly increased the expression of mi R133a and inhibited the m RNA expressions of GRP78,IRE1,ATF6 and XBP1,as well as decreased the protein expressions of GRP78,cleaved-ATF6 and XBP1-s and decreased p-IRE1/IRE1 rati

关键词： heart failure Qili Qiangxin Capsule miR133a endoplasmic reticulum stress apoptosis

Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression

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China Ocean Engineering 2024年第2期38卷 313-325页

作者： DONG Wen-bo ZHOU Li ding Shi-feng WANG Ai-ming CAI Jin-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of navigation.In the Arctic,merchant ships with low ice class often navigate in channels opened up by icebreakers.Navigation in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large extent.The ship may get stuck if steered into ice fields off the channel.Under this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable method.In this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point regression.The first stage employs the image segmentation method to extract channel regions.In the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression network.The training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel dataset.The evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second.

关键词： ice channel ship navigation identification image segmentation corner point regression

On-demand engineerable visible spectrum by fine control of electrochemical reactions

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National Science Review 2024年第3期11卷 239-249页

作者： Qirong Liu Lei Liu Yongping Zheng Min Li Baofu ding Xungang Diao Hui-ming Cheng Yongbing Tang Advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Energy and Power Engineering North University of China School of Resource Environment and Safety EngineeringHunan University of Science and Technology School of Energy and Power Engineering Beihang University Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Tunability of optical performance is one of the key technologies for adaptive optoelectronic applications,such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve this goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of dings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.

关键词： electrochromics fine control spectral tunability high precision galvanostatic control