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The mass distribution of behind-armor debris generated during the normal penetration of an explosively formed projectile on rolled homogeneous armor steel 4

The mass distribution of behind-armor debris generated durin...

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4th International Conference on Defence technology, ICDT 2024

作者： Wei, Guoxu Guo, Rui Li, Xiangdong Zhang, Dongjiang Xu, Hongwei School of Mechanical Engineering Nanjing University of Science and Technology Nanjing210094 China National Key Laboratory of Land and Air Based Information Perception and Control Xi'an Modern Control Technology Research Institute Xi'an710065 China

To obtain the mass distribution law of behind-armor debris(BAD) produced by EFP vertically penetrating armored steel, the numerical simulation calculation of EFP vertically penetrating targets with different thicknesses (30mm~70mm) at different impact velocities (1600m/s~2000m/s) was carried out by using the numerical simulation method verified by experiments. Several classical natural fragment mass distribution models are used to study the mass distribution of the BAD generated by EFP and the target plate. The results show that the classical Mott formula is not suitable for describing the mass-quantity distribution of the BAD generated by warhead penetration, while the two-parameter Weibull distribution is a good fit for the mass distribution of the BAD, but both of them depend on the total number of fragments, and it is impossible to ensure that small debris is completely collected in the test. Therefore, it is often impossible to determine the total number of debris. In contrast, the Held distribution does not depend on the total number of debris, and the correlation coefficient of fitting results for the mass distribution of BAD is closest to 1, indicating that the Held distribution is the most suitable for describing the mass distribution of BAD. According to the variation of the characteristic parameter of Held distribution with the thickness of the target plate and EFP impact velocity, the mathematical expression between the characteristic parameter of Held formula and the dimensionless initial condition is established. Based on the Held distribution, a prediction model of the mass distribution of the BAD is established, which takes into account the impact velocity of EFP and the thickness of the target plate. The model estimation is in good agreement with the simulation results, which proves the accuracy of the established model. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Armor

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Deciphering decadal urban ozone trends from historical records since 1980

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national science Review 2024年第11期11卷 117-129页

作者： Haolin Wang Xiao Lu Paul I.Palmer Lin Zhang Keding Lu Ke Li Tatsuya Nagashima Ja-Ho Koo Hiroshi Tanimoto Haichao Wang Meng Gao Cheng He Kai Wu Shaojia Fan Yuanhang Zhang School of Atmospheric Sciences Sun Yat-sen University and Key Laboratory of Tropical Atmosphere-Ocean System Ministry of Education Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) School of Geo Sciences University of Edinburgh National Centre for Earth Observation University of Edinburgh Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking University State Key Joint Laboratory of Environmental Simulation and Pollution Control The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution ControlCollege of Environmental Sciences and Engineering Peking University Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science &Technology National Institute for Environmental Studies Department of Atmospheric Sciences Yonsei University Department of Geography Hong Kong Baptist University Department of Civil and Environmental Engineering University of California

Ozone pollution is a major environmental threat to human health. Timely assessment of ozone trends is crucial for informing environmental policy. Here we show that for the most recent decade（2013–2022） in the northern hemisphere, warm-season（April–September） mean daily 8-h average maximum ozone increases much faster in urban regions with top ozone levels(mainly in the North China Plain, 1.2 ± 1.3 ppbv year-1) than in other, low-ozone regions(0.2 ± 0.9 ppbv year-1). These trends widen the ozone differences across urban regions, and increase extreme pollution levels and health threats from a global perspective. Comparison of historical trends in different urban regions reveals that ozone increases in China during 2013–2022 differ in magnitude and mechanisms to historical periods in other regions since *** reflects a unique chemical environment characterized by exceptionally high nitrogen oxides and aerosol concentrations, where reducing ozone precursor emissions leads to substantial ozone *** increase in China has slowed down in 2018–2022 compared to 2013–2017, driven by ongoing emission reductions, but with ozone-favorable weather conditions. Historical ozone evolution in Japan and South Korea indicates that ozone increases should be suppressed with continuous emission *** temperature and associated wildfires have also reversed ozone decreases in the USA and Europe,with anthropogenic ozone control slowing down in recent decades.

关键词： air quality surface ozone trends

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A Revisit of Landsat-Observed Macroalgal Blooms in the Yellow Sea and East China Sea Before 2008

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Journal of Ocean University of China 2025年第2期24卷 525-531页

作者： YUAN Chao HUANG Juan WU Lingjuan XIAO Jie ZHANG Xuelei GAO Song LI Yifei XU Jiangling WANG Zongling Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation North China Sea Marine Forecasting and Hazard Mitigation CenterMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Ecology and Environmental Science Qingdao Marine Science and Technology CenterQingdao 266061China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an 710129China

Harmful macroalgal blooms caused by Ulva prolifera and Sargassum horneri are increasing in the Yellow Sea and East China ***,our understanding of macroalgal blooms before 2008 is fragmented and *** time-series Landsat imagery from 1984 to 2008,we examined macroalgal bloom events and their evolutionary *** results suggest that no macroalgal blooms were observed before *** blooms could be traced back to 1999 and occurred on a small scale in 2000,2004 and 2005,before escalating into large green tides in 2007 and ***,these Ulva blooms were confined to the southern Yellow Sea from May to *** comparison,Sargassum blooms were first detected in the East China Sea in March 2000 and occurred almost every year thereafter,although the size of the blooms showed significant interannual *** distribution areas generally moved northwards from March until the bloom dissipated in May or June,suggesting the influence of the monsoon and *** investigation provided some insight into the bloom history of these two harmful macroalgal blooms in the Yellow Sea and East China Sea.

关键词： macroalgal bloom green tide golden tide remote sensing Landsat Yellow Sea East China Sea

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Electroreduction of hexavalent chromium using a porous titanium flow-through electrode and intelligent prediction based on a back propagation neural network

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Frontiers of Environmental science & Engineering 2023年第8期17卷 69-79页

作者： Xinwan Zhang Guangyuan Meng Jinwen Hu Wanzi Xiao Tong Li Lehua Zhang Peng Chen National Engineering Laboratory for Industrial Wastewater Treatment School of Resources and Environmental EngineeringEast China University of Science and TechnologyShanghai 200237China Continuing Education Center Bozhou UniversityBozhou 236800China State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and TechnologyShanghai 200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Flow-through electrodes have been demonstrated to be effective for electroreduction of Cr(VI),but shortcomings are tedious preparation and short ***,porous titanium available in the market was studied as a flow-through electrode for Cr(VI)*** addition,the intelligent prediction of electrolytic performance based on a back propagation neural network(BPNN)was *** studies revealed that Cr(VI)electroreduction was a diffusion-controlled *** of the flow-through mode achieved a high limiting diffusion current as a result of enhanced mass transfer and favorable *** of Cr(VI)in the flow-through system was 1.95 times higher than in a parallel-plate electrode *** the influent(initial pH 2.0 and 106 mg/L Cr(VI))was treated at 5.0 V and a flux of 51 L/(h·m2),a reduction efficiency of~99.9%was obtained without cyclic electrolysis *** served as the supporting electrolyte and pH regulator,as reactive CrSO72−species were formed as a result of feeding HSO4−.Cr(III)was confirmed as the final product due to the sequential three-electron transport or disproportionation of the *** developed BPNN model achieved good prediction accuracy with respect to Cr(VI)electroreduction with a high correlation coefficient(R2=0.943).Additionally,the electroreduction efficiencies for various operating inputs were predicted based on the BPNN model,which demonstrates the evolutionary role of intelligent systems in future electrochemical technologies.

关键词： Flow-through electrode Hexavalent chromium Heavy metals Neural network Artificial intelligence

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A time-coded multi-concentration microfluidic chemical waveform generator for high-throughput probing suspension single-cell signaling

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Chinese Chemical Letters 2022年第6期33卷 3091-3096页

作者： Yiran Guo Peng Chen Zhaolong Gao Yiwei Li Shunji Li Xiaojun Feng Bi-Feng Liu The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory Systems Biology ThemeDepartment of Biomedical EngineeringCollege of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China The Key Laboratory of Ministry of Education for Image Processing and Intelligent Control School of Artificial Intelligence and AutomationHuazhong University of Science and TechnologyWuhan 430074China

The cellular response to the complex extracellular microenvironment is highly dynamic in time and type of extracellular *** reconstructing this process and analyzing the changes in receptor conformation on the cell membrane surface and intracellular or intercellular signaling has been a major challenge in analytical chemistry and biophysical *** this paper,a time-coded multiconcentration microfluidic chemical waveform generator was developed for the dynamic signaling probing with single-cell array of high temporal resolution,high throughput,and multi-concentration combination *** on innovative microchannel structure,sophisticated external control methods and multiplexing technology,the system not only allowed for temporally sequential permutations of the four concentrations of stimuli(time code),but also generated pulsed and continuous waveforms at different frequencies in a highly controllable ***,the single-cell trap array was set up to efficiently capture cells in suspension,dramatically increasing throughput and reducing experiment preparation *** maximum frequency of the platform was 1 Hz,and one cell could be stimulated at multiple *** show the ability of the system to investigate rapid biochemical events in high throughput,pulse stimulation and continuous stimulation of different frequencies and different time codes,combined with four concentrations of histamine(HA),were generated for probing G protein-coupled receptor(GPCR)signaling in He La ***,statistical analysis was performed for the mean peak height and mean peak area of the cellular *** believe that the time-coded multi-concentration microfluidic chemical waveform generator will provide a novel strategy for analytical chemistry,biophysics,cell signaling,and individualized medicine applications.

关键词： Microfluidics Dynamic stimulation Time code High-throughput Single-cell array

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Efficient photocatalytic NADH regeneration with Rh-loaded Z-scheme mediator-free system

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Chinese Chemical Letters 2024年第2期35卷 496-500页

作者： Yi Zhou Yiling He Ming Gao Ningkai Ding Juying Lei Yanbo Zhou State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and TechnologyShanghai 200237China National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery East China University of Science and TechnologyShanghai 200237China Shanghai Engineering Research Center for Multi-media Environmental Catalysis and Resource Utilization East China University of Science and TechnologyShanghai 200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Nicotinamide adenine dinucleotide(NADH)regeneration is necessary for the sustainable application of enzymatic *** Rh-based complex[Cp^(*)Rh(bpy)(H)]+has been widely used as an important mediator in NADH regeneration systems,but it is limited by complexity and high ***,a Z-scheme was constructed by loading Rh onto carbon nitride nanosheets/carbon nitride quantum dots(CN-CNQD).The resultant catalyst achieved a high yield of NADH in a mediator-free(M-free)system of 0.283 mmol L^(−1) g^(−1) min^(−1),which is 5.29 times that of pure *** enzyme introduction experiments confirmed that the enzyme active product 1,4-NADH could reach 34.21%selectivity in the M-free *** research revealed that the heterojunction between CNs and CNQDs improved the NADH regeneration activity in the traditional M-involved system,while Rh loading was proved to optimize the yield and selectivity of 1,4-NADH in M-free *** immobilized Rh shows more competitiveness than[Cp^(*)Rh(bpy)(H)]^(+).This study contributes to the construction of an M-free system for further application in greener,lower-cost enzymatic processes.

关键词： Photocatalysis NADH regeneration Mediator-free Carbon nitride Z-scheme

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Self-Contrastive Learning Fault Diagnosis Network for Signal Imaging: A Case Study

Self-Contrastive Learning Fault Diagnosis Network for Signal...

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2024 China Automation Congress, CAC 2024

作者： He, Wenbin Mao, Jianxu Wang, Yaonan Li, Zhe Yan, Feng Liu, Kexin College of Electrical & Information Engineering National Engineering Research Center of Robot Visual Perception & Control Technology Hunan University Hunan China College of Control Science & Engineering State Key Laboratory of Industrial Control Technology Zhejiang University Zhejiang China

ISBN: (纸本)9798350368604

The deep convolution method based on MSDP signal imaging has been proven to be an effective means of monitoring the robot grinding process. This method has very high requirements on the quality of imaging and requires a lot of computing resources. This paper proposes an image self-contrastive learning network that can effectively extract fault information from low-pixel fuzzy images and achieve efficient and accurate condition monitoring. The network first calculates the correlation distance matrix between two identical modified symmetrized dot pattern (MSDP) images and uses the generated similarity labels to calculate the contrast loss to extract the embedded features of the image. Finally, the classification network is trained using the cross entropy loss to achieve the classification of fault images. The method was verified on a robotic grinding platform to significantly reduce the calculation time while maintaining the recognition accuracy, which provides reliable technical support for the real-time monitoring of the robotic grinding process. © 2024 IEEE.

关键词： Contrastive Learning fault diagnosis robotic grinding signal imaging

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Investigation and Comparison of 5G Channel Models: From Qua DRi Ga, NYUSIM,and MG5G Perspectives

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Chinese Journal of Electronics 2022年第1期31卷 1-17页

作者： PANG Lihua ZHANG Jin ZHANG Yang HUANG Xinyi CHEN Yijian LI Jiandong School of Communication and Information Engineering Xi'an University of Science and Technology State Key Laboratory of Integrated Service Networks Xidian University National Mobile Communications Research Laboratory Southeast University Algorithm Department ZTE Corporation

This paper investigates and compares three channel models for the fifth generation(5 G) wireless communications: the quasi deterministic radio channel generator(Qua DRi Ga), the NYUSIM channel simulator model developed by New York University, and the more general 5 G(MG5 G) channel model. First, the characteristics of the modeling processes of the three models are introduced from the perspective of model ***, the small-scale parameter modeling strategies of the three models are compared from space/time/frequency domains as well as polarization aspect. In particular, the drifting of small-scale parameters is introduced in ***, through the simulation results of angular power spectrum, Doppler power spectrum density, temporal autocorrelation function, power delay profile, frequency correlation function, channel capacity, and eigenvalue distribution, the three models are comprehensively investigated. According to the simulation results, we clearly analyze the impact of the modeling strategy on the three channel models and give certain evaluations and suggestion which lay a solid foundation for link and system-level simulations for 5 G transmission algorithms.

关键词： model framework MG5G Perspectives quasideterministic radio channel generator channel capacity QuaDRiGa fifth generation wireless communications general 5G channel model 5G transmission algorithms wireless channels NYUSIM channel simulator model frequency correlation function 5G mobile communication power delay profile eigenvalue distribution eigenvalues and eigenfunctions channel models temporal autocorrelation function small-scale parameter angular power spectrum Doppler power spectrum density

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High spectral purity millimeter-wave generated from millihertz-linewidth lasers

High spectral purity millimeter-wave generated from milliher...

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2024 Asia Communications and Photonics Conference, ACP 2024 and International Conference on Information Photonics and Optical Communications, IPOC 2024

作者： Yang, Zhengyuxiao Ke, Haocheng Xiao, Yanlan Li, Houchen Li, Mo Zhang, Jian Xu, Jing Yang, Fan Wen, Huashun Zhou, Heng Key Laboratory of Optical Fiber Sensing and Communication Networks University of Electronic Science and Technology of China Chengdu611731 China Institute of Advanced Millimeter-Wave Technology University of Electronic Science and Technology of China Chengdu611731 China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan430074 China State Key Laboratory on Integrated Optoelectronics Chinese Academy of Sciences Beijing100083 China

ISBN: (纸本)9798350379266

关键词： Linewidth

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REDUNDANT DIGITAL BRAKE VALVE controlLER BIT DESIGN

REDUNDANT DIGITAL BRAKE VALVE CONTROLLER BIT DESIGN

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2024 CSAA/IET International Conference on Aircraft Utility Systems, AUS 2024

作者： Jin, Hongtao Gao, Xiaolong Wu, Shuai Li, Chuandong School of Automation Science and Electrical Engineering Beihang University Beijing100191 China National Key Laboratory of Aircraft Integrated Flight Control Beijing100191 China Ningbo Institute of Technology Beihang University Ningbo315800 China

High-speed switching valves are widely used in aerospace and other fields due to their simple structure and high resistance to contamination. The digital brake valve controller is the driving device of the digital brake valve, which requires high reliability. In this paper, a redundant digital brake valve controller scheme is proposed, and the corresponding BIT circuit is designed based on the structural characteristics of the brake valve driving circuit. The reliability model of the controller is established based on Markov process theory and analysed by simulation, and the results show that the reliability of this redundant digital brake valve controller is mentioned to be greatly improved. © The Institution of Engineering & technology 2024.

关键词： Markov processes

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