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Microphysical Insights into a Tornadic Supercell from Dual-Polarization Radar Observations in Jiangsu, China on 14 May 2021

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Journal of Meteorological Research 2024年第2期38卷 303-320页

作者： chao yuan Yang BAI Pengfei SUN Hua BAI Lu XIA China Meteorological Administration Tornado Key Laboratory Foshan 528315 Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Panjin National Climate Observatory Panjin 124010 Yangzhou Meteorological Bureau of Jiangsu Province Yangzhou 225100 Yichun Meteorological Bureau of Heilongjiang Province Yichun 153000

Tornadoes are incredibly powerful and destructive natural events,yet the microphysical characteristics of the parent storm and its effects on tornadogenesis remain unclear.This study analyzed polarization radar data of a tornadic supercell that occurred in Jiangsu Province of China on 14 May 2021,in comparison with another tornadic supercell and two non-tornadic supercells that occurred in the same region in 2023.The two tornadic supercells exhibited lower differential reflectivity(ZDR)in the hook echo region compared with the non-tornadic supercells,indicating smaller median drop sizes.A distinct increase in ZDR from the melting of frozen hydrometeors,observed between2.5-and 4.0-km altitude in the non-tornadic storms,was absent in the tornadic cases.The non-tornadic supercells also displayed substantially higher specific differential phase(KDP)below the melting level,likely aroused from enhanced melting and cooling.These findings suggest fundamental microphysical contrasts between tornadic and nontornadic supercells.Specifically,tornadic supercells have smaller droplets and may reduce melting in hook echoes.Moreover,greater separation between the ZDR arc and the KDP foot was observed during tornadogenesis.The vertical gradient of KDP related to the cooling pool strength of the hook echo,regulating rear-flank downdraft thermodynamics.Despite the limited number of cases investigated,the findings of this study indicate that monitoring ZDR,KDP,and drop size distribution trends could assist with tornado prediction and warnings.

关键词： tornado polarimetric radar supercell hook echo drop size distribution

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Enhanced Electrical Properties of Styrene-grafted Polypropylene Insulation for Bulk Power Transmission HVDC Cables

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 361-370页

作者： Hao yuan Shixun Hu Yao Zhou chao yuan Wenbo Song Qing Shao Hongwei Shi Juan Li Jun Hu Qi Li Jinliang He SINOPEC Beijing Research Institute of Chemical Industry Beijing 100013China State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

Polypropylene(PP)is considered to be a rather promising material for HVDC cable insulation.Grafting modification has proved to be an effective method on the electrical property improvements of PP.This paper reports on the highlyenhanced electrical properties of styrene-grafted polypropylene(PP-g-St)and their related mechanism.The influence of grafting styrene on crystallization structures,thermal properties and electrical properties of PP-g-St are characterized and analyzed.These results show that PP-g-St exhibits remarkably enhanced DC volume resistivity,suppressed space charge accumulation and improved DC breakdown strengths as compared to PP.Crystallization observation shows PP-g-St has small,imperfect spherulites with indistinct boundaries,which is strongly correlated to enhanced electrical properties.This study provides an effective grafting strategy to design high-performance HVDC cable insulation materials for bulk power transmission systems.

关键词： Electrical properties grafting modification polypropylene styrene

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Analysis on the causes of massive stranding of Yellow Sea green tide on Lianyungang and Rizhao coasts in 2022

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Journal of Oceanology and Limnology 2024年第3期42卷 816-830页

作者： Lingjuan WU Juan HUANG Yi DING Guiyan LIU Shuai HUANG Song GAO chao yuan Jiangling XU Ping WU Rui HUANG Ruobing WEN Jie MEI North China Sea Marine Forecasting and Hazard Mitigation Center Ministry of Natural ResourcesQingdao 266061China Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266061China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an 710129China East China Sea Marine Forecasting and Hazard Mitigation Center Ministry of Natural ResourcesShanghai 200136China North China Sea Ecological Center Ministry of Natural ResourcesQingdao 266033China

In 2022,Yellow Sea green tide caused by Ulva prolifera reached a historic minimum and the coastal areas of Shandong Peninsula were less affected.However,the largest amount of seaweed biomass has been washed ashore on Lianyungang and Rizhao coasts since 2015.We studied the development pattern of Yellow Sea green tide in 2022,and analyzed the key environmental factors on the growth and drifting,then discussed the possible reasons that resulted in the massive stranding of green tide biomass in Lianyungang and Rizhao.Results show under the combined influence of the east to southeast winds and currents with shoreward anomalies,green tide drifted to the coastal waters between Shandong and Jiangsu provinces and the distribution areas located westward compared with previous years(2008–2021).Floating U.prolifera rafts from the coastal waters of Binhai and Sheyang drifted continuously into the coastal waters of Lianyungang and Rizhao,providing important supplements for Yellow Sea green tide.Because green tide in 2022 distributed close to the coastal waters,the abundant nutrients might support their continuous high growth rate.In addition,the amount of rainfall around Shandong Peninsula from late June to early July were significantly higher than in previous years,which might promote the development of green tide to some extent.

关键词： Yellow Sea green tide stranding biomass development pattern environmental factor

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中国式现代化进程中活力与秩序的伦理调适

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道德与文明 2024年第3期 41-49页

作者：袁超中南大学哲学系湖南长沙410083

中国式现代化要努力实现社会活力迸发与社会有序运行的动态平衡,社会的有序运行为社会焕发活力提供了基本的场域,社会活力的迸发为社会秩序的有序发展带来更多的可能。努力营造一个既充满活力又和谐稳定的社会环境是正确处理活力与秩序... 详细信息

中国式现代化要努力实现社会活力迸发与社会有序运行的动态平衡,社会的有序运行为社会焕发活力提供了基本的场域,社会活力的迸发为社会秩序的有序发展带来更多的可能。努力营造一个既充满活力又和谐稳定的社会环境是正确处理活力与秩序之间关系的基本诉求。中国式现代化将活力与秩序充分融合,诠释了活力与秩序的辩证统一关系,展现出活力与秩序动态平衡的现代化架构。中国式现代化要坚持个体活力与集体秩序的伦理协同,坚持共同体活力与社会秩序的伦理协调,坚持国家活力与世界秩序的伦理适应。

关键词：中国式现代化活力秩序伦理调适

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政绩竞争与条块合作:指数驱动地方政府治理的运作逻辑——基于S市公安局“平安指数”项目的分析

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公共管理学报 2024年第2期21卷 29-39,171页

作者：原超山西大学政治与公共管理学院太原030006

指数何以驱动地方政府有效开展治理工作的?本文以S市公安局“平安指数”建设过程为案例,引入权力规训的理论视角,剖析指数在政府组织中的应用过程和运作机制。研究发现,指数治理是一个“条”与“块”在地方治理创新的政绩压力下,实现地... 详细信息

指数何以驱动地方政府有效开展治理工作的?本文以S市公安局“平安指数”建设过程为案例,引入权力规训的理论视角,剖析指数在政府组织中的应用过程和运作机制。研究发现,指数治理是一个“条”与“块”在地方治理创新的政绩压力下,实现地方权力与资源再分配的政治过程。一方面,作为一种稳定的向上级政府呈现政绩的表达渠道,指数体系将上级政府的注意力引导至有限的指标上,使得职能部门实现治理创新和部门边界的扩张。同时,“条”通过监控机制和考核机制,对下级块形成强激励,推动了地方条块的有效合作。另一方面,指数基于可视化和显示度特征,将“块”模糊的、难以测量的政绩以“指数”简易化、数字化和排名化的形式呈现给上级“块”和社会舆论,“条”调动“块”的积极性,形成了稳定的“印象政绩”,助推地方治理创新中的条块合作。研究结论可以为技术与组织关系以及基层治理中的条块关系研究提供可能的分析思路。

关键词：指数治理权力规训条块关系不确定性技术治理

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Spatial Distribution and Seasonal Variation of Hypoxic Zone in the Eastern Equatorial Indian Ocean

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Journal of Ocean University of China 2023年第4期22卷 918-929页

作者： XIE Linping WANG Baodong XIN Ming WANG Ying SUN Xia WEI Qinsheng LIU Lin yuan chao Key Laboratory of Marine Eco-Environmental Science and Technology First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

The spatial distribution and seasonal variations of the hypoxic zone in the eastern equatorial Indian Ocean were investigated using survey data collected from four cruises from 2013 to 2018.Results showed that hypoxic zone occurred all year round in the eastern equatorial Indian Ocean,and it spread southward in the shape of a double tongue at two depths with one at subsurface centered at a depth of 150 m and the other in intermediate water centered at a depth of 800 m.The southward expansion and maximum thickness of the hypoxic zone were greatest in the spring inter-monsoon and least in the summer monsoon.The hypoxic zone originated from the southward expansion of the hypoxic water in the Bay of Bengal and its spatial distribution was driven by southward output flux of mid-deep(100–1000 m)hypoxic water from the Bay of Bengal.The hypoxia southward expansion was blocked near the equator in the subsurface layer,because of mixing with multiple zonal circulations(e.g.,Wyrtki Jets and the equatorial undercurrent),which meant that the hypoxic zone extended over a smaller area than in the intermediate water.These new findings will contribute to an improved understanding of the hypoxic zone and will contribute to circulation research,particularly about intermediate circulation in the eastern equatorial Indian Ocean.

关键词： hypoxic zone spatial distribution vertical structure seasonal variation eastern equatorial Indian Ocean

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Seasonal Distribution of Observed Colored Dissolved Organic Matter(CDOM)in the Eastern Indian Ocean

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Journal of Ocean University of China 2023年第4期22卷 886-896页

作者： CAI Xiaoqing MENG Jie yuan chao LIU Rongjie HOU Erhu BI Dayong LI Yaoru QIAN Chengcheng ZHONG Shan Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266061China North China Sea Marine Forecasting Center Ministry of Natural ResourcesQingdao 266061China National Ocean Technology Center Ministry of Natural ResourcesTianjin 300112China The First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China North China Sea Environmental Monitoring Center Ministry of Natural ResourcesQingdao 266033China

Colored dissolved organic matter(CDOM)is a crucial constituent that affects the optical absorption properties of seawater.Owing to the relatively limited measured data on the spatial distribution characteristics of CDOM in the tropical eastern Indian Ocean,this study analyzes the optical absorption characteristics of CDOM in the southeast Indian Ocean using the data collected during four seasons from 2013 to 2017.This work also systematically describes the seasonal horizontal and vertical distribution characteristics of CDOM in this area and conducts a preliminary analysis of the relevant factors affecting CDOM absorption characteristics in this region.Results indicate that the CDOM ag(440)during summer was remarkably lower than that in the coastal waters of Europe and coastal waters of China but slightly higher than that in the western and southeast Pacific.The spatial distribution of surface CDOM shows remarkable seasonal differences,and the spatial distribution characteristics of CDOM in the 5°S,92°E region differ between spring/summer and autumn/winter.The values of ag(400)and ag(440)are weak/strong at a surface/subsurface level of 100 m,with differences found between summer and winter.The correlation of CDOM with temperature,salinity,and chlorophyll-a concentration is relatively low,indicating that CDOM is an independent driving mechanism influenced by phytoplankton degradation,photobleaching,and water mixing.

关键词： colored dissolved organic matter tropical eastern Indian Ocean distribution characteristics influencing factors

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基于注意力机制的高容量通用图像隐写模型

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软件学报 2024年第3期35卷 1502-1514页

作者：袁超王宏霞何沛松四川大学网络空间安全学院四川成都610065

随着深度学习与隐写技术的发展,深度神经网络在图像隐写领域的应用越发广泛,尤其是图像嵌入图像这一新兴的研究方向.主流的基于深度神经网络的图像嵌入图像隐写方法需要将载体图像和秘密图像一起输入隐写模型生成含密图像,而最近的研究... 详细信息

随着深度学习与隐写技术的发展,深度神经网络在图像隐写领域的应用越发广泛,尤其是图像嵌入图像这一新兴的研究方向.主流的基于深度神经网络的图像嵌入图像隐写方法需要将载体图像和秘密图像一起输入隐写模型生成含密图像,而最近的研究表明,隐写模型仅需要秘密图像作为输入,然后将模型输出的含密扰动添加到载体图像上,即可完成秘密图像的嵌入过程.这种不依赖载体图像的嵌入方式极大地扩展了隐写的应用场景,实现了隐写的通用性.但这种嵌入方式目前仅验证了秘密图像嵌入和恢复的可行性,而对隐写更重要的评价标准,即隐蔽性,未进行考虑和验证.提出一种基于注意力机制的高容量通用图像隐写模型USGAN,利用注意力模块,USGAN的编码器可以在通道维度上对秘密图像中像素位置的扰动强度分布进行调整,从而减小含密扰动对载体图像的影响.此外,利用基于CNN的隐写分析模型作为USGAN的目标模型,通过与目标模型进行对抗训练促使编码器学习生成含密对抗扰动,从而使含密图像同时成为攻击隐写分析模型的对抗样本.实验结果表明,所提模型不仅可以实现不依赖载体图像的通用嵌入方式,还进一步提高了隐写的隐蔽性.

关键词：图像隐写注意力机制生成对抗网络对抗样本

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High Temperature Creep and Fracture Behavior of a Directionally Solidified Ni-base Superalloy

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Journal of Materials Science & Technology 1998年第3期14卷 219-225页

作者： yuan, chao Guo, Jianting Wang, Shuhe Yang, Hongcai Acad Sinica Inst Met Res Shenyang 110015 Peoples R China Northeastern Univ Dept Mat Sci & Engn Shenyang 110006 Peoples R China

The tensile creep-fracture properties of DZ17G, a directionally solidified superalloy, were investigated at 830-900 degree C. The results show that all of the creep curves exhibit negligible primary creep, relatively little steady-state creep and dominant tertiary creep stage. The higher apparent activation energy for creep (540 kJ/mol) suggests that the creep is controlled by Orowan bowing process. A large ratio of the fracture time to the onset time of tertiary creep is the consequence of microstructure change, i.e., gamma ' particles oriented coarsening parallel to the applied stress axis. The creep fracture data follow the Monkman-Grant relationship. The transgranular fracture mechanism proposed on the basis of the metallographic examinations is the linkage of the creep cracks which initiate at the discontinuities with the microstructure (such as the cast porosity, and the carbide/matrix interface) and also at the specimen surface, that propagate along the gamma / gamma ' interface with perpendicular to the applied stress axis, and the process of crack propagation can be described by the Tien model. (Edited author abstract) 31 Refs.

关键词： Nickel alloys

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基于改进灰狼优化算法的QFN芯片图像多阈值分割方法

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光学精密工程 2024年第6期32卷 930-944页

作者：巢渊徐魏刘文汇曹震张敏江苏理工学院机械工程学院江苏常州213001 常州祥明智能动力股份有限公司江苏常州213011

在QFN芯片封装缺陷检测中,增加图像分割环节可有效提高缺陷检测准确性与检测效率。针对图像分割中传统算法效率低、智能优化算法分割精度低稳定性差的问题,本文提出一种基于改进灰狼优化算法(IGWO)的图像多阈值分割方法。首先,改进原始... 详细信息

在QFN芯片封装缺陷检测中,增加图像分割环节可有效提高缺陷检测准确性与检测效率。针对图像分割中传统算法效率低、智能优化算法分割精度低稳定性差的问题,本文提出一种基于改进灰狼优化算法(IGWO)的图像多阈值分割方法。首先,改进原始灰狼优化算法非线性因子,平衡算法搜索效率与挖掘能力;其次,引入反向学习策略提高种群整体质量,引入正弦函数、调整头狼权重以改进灰狼更新策略,增强算法多样性与挖掘能力;然后,提出头狼靠拢与种群变异交替进行的位置更新策略,平衡算法收敛性能与跳出局部最优能力;最后,以Kapur熵为适应度函数,求解最优分割阈值。将本文提出的改进灰狼优化算法的多阈值图像分割方法,与灰狼优化算法(GWO)、基于翻筋斗觅食策略的灰狼优化算法(DSF-GWO)、基于莱维飞行的樽海鞘群优化算法(LSSA)、改进北方苍鹰算法(INGO)的图像分割方法进行实验对比,结果表明:本文方法在分割用时方面,约为DSF-GWO的1/2,INGO的1/4;在分割精度与稳定性方面,在进行QFN芯片缺陷图像的连续30次分割时,本文方法具有最大Kapur熵平均值、最小标准差与最短分割时间。因此本文方法可实现高精度、高稳定性与高效率的QFN芯片图像多阈值分割。

关键词：灰狼优化算法多阈值分割 Kapur熵 QFN

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