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Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： ruoyu Han Yuchen Cao Yakun liu Xi Chen Ting li Chen li Pengfei li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina Department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

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FPGA-based Digital Implementation of Flexible Power Control for Three-phase to Single-phase MMC-based Advanced Co-phase Traction Power Supply System

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 2015-2027页

作者： Jiangpeng Yang Hongjian lin Haotian Zhu Zeliang Shu Lan Ma Changsong Cai Pengcheng Zhang li He ruoyu li Shasha Song Josep M.Guerrero National Rail Transportation Electrification and Automation Engineering Technology Research Center Chengdu 611756China School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China IEEE Department of Electrical Engineering City University of Hong KongHong KongChina School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Department of Energy Technology Aalborg UniversityAalborg 9220Denmark

A three-phase to single-phase modular multilevel converter based advanced co-phase traction power supply(MMC-ACTPS) system is an effective structure to address the concerns of phase splitting and poor power quality of the conventional electrified railway. Due to the large number of MMCACTPS system modules, I/O resources and computing speed have high requirements on processors. Moreover, the module capacitor balance is challenging because the sorting time is too long when the traditional sorting algorithm for voltage balance is used. To solve the above issues, a digital implementation scheme of flexible power control strategy for three-phase to single-phase MMC-ACTPS system based on field programmable gate array(FPGA), which has sufficient I/O resources, has been proposed. Due to the parallel execution characteristics of the FPGA, the execution time of the controller and the modulator can be greatly reduced compared with a digital signal processor(DSP) + FPGA or DSpace. In addition, an improved sorting algorithm is proposed to reduce the sorting time and the implementation steps are analyzed. Finally, simulation and experimental results are presented to demonstrate the effectiveness and correctness of the proposed control strategy.

关键词： Advanced co-phase power traction supply(ACTPS)system modular multilevel converter(MMC) digital implementation flexible power transmission circulating current mitigation

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模糊数学感官评价结合响应面法优化速溶老鹰茶配方

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现代食品科技 2024年第8期40卷 211-219页

作者：王藤赵明刘琨毅李珏洁李若愚梁正维伯年国雷鑫沙艮陈思琴马燕云南农业大学茶学院&食品科学技术学院云南昆明650201 云南农业大学西南中药材种质创新与利用国家地方联合工程研究中心&云南省药用植物生物学重点实验室云南特色植物提取实验室云南昆明650106 宜宾职业技术学院五粮液技术与食品工程学院四川宜宾644003

通过浸提、浓缩、喷雾干燥等工艺制作速溶老鹰茶,采用模糊数学感官评价法单因素、响应面试验结合,优化速溶老鹰茶配方,并测定其功能性成分。速溶老鹰茶优化配方为:速溶老鹰茶粉、甘草提取物、薄荷提取物的添加量分别为0.3、0.03、0.05 ... 详细信息

通过浸提、浓缩、喷雾干燥等工艺制作速溶老鹰茶,采用模糊数学感官评价法单因素、响应面试验结合,优化速溶老鹰茶配方,并测定其功能性成分。速溶老鹰茶优化配方为:速溶老鹰茶粉、甘草提取物、薄荷提取物的添加量分别为0.3、0.03、0.05 g。速溶茶滋味清凉甘甜,多酚、游离氨基酸、可溶性糖、总黄酮质量分数分别为4.11%、3.95%、5.86%和6.83%;高效液相色谱法检测到丝氨酸(5.88 mg/g)、天冬氨酸(1.70 mg/g)和谷氨酸(1.64 mg/g)、γ-氨基丁酸(0.21 mg/g)、等16种游离氨基酸,检测到儿茶素(9.26 mg/g)、杨梅素(1.53 mg/g)、芦丁(1.22 mg/g)、表儿茶素(1.09 mg/g)、槲皮素(0.48 mg/g)和山奈酚(0.44 mg/g)等11种多酚类物质。该研究开发了一种风味良好且富含黄酮、氨基酸等成分的速溶老鹰茶,具有一定的市场发展潜力。

关键词：速溶老鹰茶模糊数学感官评价响应面分析配方优化功能性成分

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Analysis of environmental selection pressure of superoxide dismutase in deep-sea sea cucumber

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Journal of Oceanology and limnology 2024年第3期42卷 893-904页

作者： Yanan li Zongfu CHEN Haibin ZHANG ruoyu liU Shuichun CHEN li liN Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding College of Animal Sciences and TechnologyZhongkai University of Agriculture and EngineeringGuangzhou 510222China Institute of Deep-sea Science and Engineering Chinese Academy of SciencesSanya 572000China College of Marine Science Fujian Agriculture and Forestry UniversityFuzhou 350002China Zhanjiang Tianli Sea Cucumber New Technology Development Co. Ltd.Zhanjiang 524000China

Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in *** a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is essential for the survival of sea *** MnSODs were identified from the transcriptomes of deep and shallow-sea sea *** explore their environmental adaptation mechanism,we conducted environmental selection pressure analysis through the branching site model of PAML *** obtained night positive selection sites,and two of them were significant(97F→H,134K→V):97F→H located in a highly conservative characteristic sequence,and its polarity c hange might have a great impact on the function of MnSOD;134K→V had a change in piezophilic a bility,which might help MnSOD adapt to the environment of high hydrostatic pressure in the *** further study the effect of these two positive selection sites on MnSOD,we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and *** show that 97F→H,134K→V might improve MnSOD’s efficiency of scavenging superoxide a nion and its ability to resist high hydrostatic pressure by moderately reducing its *** above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity,piezophilic behavior,and local *** study revealed the correlation between MnSOD and extreme environment,and will help improve our understanding of the organism’s adaptation mechanisms in deep sea.

关键词： Holothuroidea environmental adaptation positive selection point mutation

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不同贮藏温度和时间对草鱼肌肉品质的影响

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食品安全导刊 2024年第21期 51-53页

作者：朱雨杜美智艾节晴李若雨卓梅琴武汉轻工大学动物科学与营养工程学院湖北武汉430023

目的:研究不同贮藏温度和时间对草鱼肌肉品质的影响。方法:将草鱼肌肉贮藏于25℃、4℃温度下0h、24h、48h、72h后,检测其肌肉持水力、质构特性、pH值以及肉色的变化。结果:与新鲜肌肉(贮藏0 h)相比,相同贮藏温度下,随着贮藏时间的延长,... 详细信息

目的:研究不同贮藏温度和时间对草鱼肌肉品质的影响。方法:将草鱼肌肉贮藏于25℃、4℃温度下0h、24h、48h、72h后,检测其肌肉持水力、质构特性、pH值以及肉色的变化。结果:与新鲜肌肉(贮藏0 h)相比,相同贮藏温度下,随着贮藏时间的延长,草鱼肌肉持水力、硬度、弹性、内聚性、pH值等呈下降趋势,而明度、黄度呈上升趋势。与25℃相比,4℃贮藏有利于减缓草鱼肌肉持水力、硬度、弹性和内聚性的下降,同时有利于减缓明度和黄度的上升。结论:同一贮藏温度下,随着贮藏时间的延长,草鱼肌肉品质呈现下降趋势,4℃比25℃更有利于减缓肌肉品质的下降。

关键词：草鱼贮藏温度时间肌肉品质

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基于知识蒸馏的步态识别方法

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云南师范大学学报（自然科学版） 2024年第2期44卷 49-53页

作者：李若愚云利军金雪松杨彦辰程飞燕云南师范大学信息学院云南昆明650500 云南省教育厅计算机视觉与智能控制技术工程研究中心云南昆明650500 玉溪市第二人民医院信息网络中心云南玉溪653100

针对步态识别中网络模型复杂度高、参数量大、训练测试速度慢等问题,提出一种基于知识蒸馏的步态识别方法.通过知识蒸馏方法对ConvNext-KD模型进行训练,在不增加新训练数据集、模型复杂度和模型参数量的前提下,提高ConvNext-KD模型的识... 详细信息

针对步态识别中网络模型复杂度高、参数量大、训练测试速度慢等问题,提出一种基于知识蒸馏的步态识别方法.通过知识蒸馏方法对ConvNext-KD模型进行训练,在不增加新训练数据集、模型复杂度和模型参数量的前提下,提高ConvNext-KD模型的识别准确率.该方法在中科院CASIA-B和CASIA-C数据库中进行多次仿真实验.结果表明,ConvNext-KD模型在保持较小参数量和较低复杂度的同时,可以显著缩短训练测试的时长并取得较高识别准确率.

关键词：步态识别知识蒸馏 ConvNext

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芜湖市城区父母教养方式对学龄前儿童视屏时间的影响

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实用预防医学 2024年第1期31卷 21-24页

作者：余敏朱敏何海燕万宇辉李若瑜芜湖市妇幼保健计划生育服务中心安徽芜湖241000 安徽医科大学安徽合肥230032

目的了解芜湖市城区学龄前儿童父母教养方式与儿童视屏时间的关系。方法整群随机抽样法抽取芜湖市3个区即镜湖区、鸠江区以及经开区共12所幼儿园学龄前儿童,采用电子问卷调查形式收集儿童视屏时间、户外活动情况、家庭基本情况、父母教... 详细信息

目的了解芜湖市城区学龄前儿童父母教养方式与儿童视屏时间的关系。方法整群随机抽样法抽取芜湖市3个区即镜湖区、鸠江区以及经开区共12所幼儿园学龄前儿童,采用电子问卷调查形式收集儿童视屏时间、户外活动情况、家庭基本情况、父母教养方式问卷等资料,采用logistic回归方法分析影响儿童视屏时间的因素。结果芜湖市城区学龄前儿童每天视屏时间超过1 h的比例为41.49%,父母教养方式溺爱性得分为(8.84±2.33)分,民主性得分为(39.31±6.19)分,放任性得分为(14.18±3.98)分,专制性得分为(17.71±4.42)分,不一致性得分为(10.44±3.58)分。父母文化程度、主要照料人、户外活动时间、父母教养方式对儿童视屏时间超标率比较均具有统计学意义(P<0.05)。多因素分析结果显示,父亲文化程度高中及以下(OR=1.409,95%CI:1.174~1.691)、母亲文化程度高中及以下(OR=1.337,95%CI:1.116~1.602)、父母教养方式民主性低分组(OR=1.193,95%CI:1.039~1.369)是儿童视屏时间超标的危险因素,而儿童主要照料人是父母(OR=0.631,95%CI:0.536~0.742)、父母教养方式溺爱性低分组(OR=0.816,95%CI:0.704~0.946)、不一致性低分组(OR=0.827,95%CI:0.710~0.963)是儿童视屏时间超标的保护因素。结论芜湖市城区学龄前儿童视屏时间超标情况较普遍,父母的教养方式与儿童视屏时间相关,需加大宣传视屏时间过长危害的力度,提倡民主的教养方式,促进儿童健康成长。

关键词：父母教养方式视屏时间儿童学龄前

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A phase-field model for simulating the propagation behavior of mixed-mode cracks during the hydraulic fracturing process in fractured reservoirs

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 911-930页

作者： Dan ZHANG liangping YI Zhaozhong YANG Jingqiang ZHANG Gang CHEN ruoyu YANG Xiaogang li State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China Tarim Oilfield Company PetroChinaBayingolin Mongolian Autonomous Prefecture 841000Xinjiang Uygur Autonomous RegionChina Wuqi Oil Production Plant Shaanxi Yanchang PetroleumXi'an 716000China Exploration Division of PetroChina Southwest Oil and Gasfield Company Chengdu 610041China

A novel phase-field model for the propagation of mixed-mode hydraulic fractures,characterized by the formation of mixed-mode fractures due to the interactions between fluids and solids,is *** this model,the driving force for the phase field consists of both tensile and shear components,with the fluid contribution primarily manifesting in the tension driving *** displacement and pressure are solved simultaneously by an implicit *** numerical solution's iterative format is established by the finite element discretization and Newton-Raphson(NR)iterative *** correctness of the model is verified through the uniaxial compression physical experiments on fluid-pressurized rocks,and the limitations of the hydraulic fracture expansion phase-field model,which only considers mode I fractures,are *** addition,the influence of matrix mode II fracture toughness value,natural fracture mode II toughness value,and fracturing fluid injection rate on the hydraulic fracture propagation in porous media with natural fractures is studied.

关键词： mixed-mode crack hydraulic fracturing poro-elasticity phase-field method(PFM)

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逍遥丸对代谢相关脂肪性肝炎大鼠粪便内源性代谢产物的影响

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山西医科大学学报 2024年第1期55卷 36-43页

作者：张馨月张玉伟李梦琪孟雅楠李若瑜苗宇船山西中医药大学病理教研室晋中030619 山西中医药大学附属医院脑病科

目的运用代谢组学技术研究逍遥丸对代谢相关脂肪性肝炎大鼠的疗效及其机制。方法24只SD雄性大鼠随机分为3组:对照组、模型组和逍遥丸组(XYW组)。模型组和XYW组给予高脂饮食、背部皮下注射四氯化碳、饥饱失常和夹尾联合刺激4周建立代谢... 详细信息

目的运用代谢组学技术研究逍遥丸对代谢相关脂肪性肝炎大鼠的疗效及其机制。方法24只SD雄性大鼠随机分为3组:对照组、模型组和逍遥丸组(XYW组)。模型组和XYW组给予高脂饮食、背部皮下注射四氯化碳、饥饱失常和夹尾联合刺激4周建立代谢相关脂肪性肝炎模型,造模成功后,XYW组给予逍遥丸水溶液0.3348 g/(kg·d),给药4周。造模和给药期间,观察大鼠一般情况。给药结束后检测不同组别大鼠的血清生化指标总胆固醇(T-CHO)、甘油三酯(TG)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转氨酶(AST)、低密度脂蛋白胆固醇(LDL-C)、单核细胞趋化蛋白-1(MCP-1)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-10(IL-10)和氧化应激指标丙二醛(MDA)、超氧化物歧化酶(SOD)。运用苏木素-伊红(HE)染色法对大鼠肝组织进行病理切片观察。运用核磁共振氢谱技术测定大鼠粪便代谢产物。结果模型组大鼠毛发晦暗、易惹怒,情绪低落、无精打采、动作迟缓、胃口不佳、排便稀溏;与模型组相比,XYW组大鼠的一般情况有显著改善。与对照组相比,模型组大鼠血清中T-CHO、TG、ALT、AST、LDL-C、MCP-1、TNF-α、IL-6水平显著升高(均P<0.05),IL-10水平显著降低(P<0.05);与模型组相比,XYW组大鼠T-CHO、TG、ALT、AST、LDL-C、MCP-1、TNF-α、IL-6水平显著降低(均P<0.05),IL-10水平显著上升(P<0.05)。与对照组相比,模型组大鼠MDA水平显著升高(P<0.01),SOD水平显著降低(P<0.01);与模型组相比,XYW组大鼠MDA水平显著降低(P<0.01),SOD水平显著上升(P<0.01)。HE染色结果显示,与对照组相比,模型组肝脏脂肪空泡及炎性细胞浸润增多;与模型组相比,XYW组肝脏脂肪空泡及炎性细胞浸润减少。代谢组学结果显示,与对照组相比,模型组粪便中次黄嘌呤、D-葡萄糖、N-乙酰糖蛋白、丙酸、亮氨酸、酪氨酸、胆碱、甲酸、D-木糖、苏氨酸代谢物水平发生显著变化(均P<0.05),包括苯丙氨酸、酪氨酸和色氨酸的生物合成,酪氨酸代谢等多种代谢途径;与模型组相比,XYW组粪便中次黄嘌呤、D-葡萄糖、N-乙酰糖蛋白、丙酸、亮氨酸、酪氨酸、胆碱、甲酸、D-木糖、苏氨酸代谢物水平出现显著回调(均P<0.05)。结论逍遥丸能够通过改善氨基酸代谢、脂质代谢、糖代谢紊乱,减轻氧化应激和炎症损伤保护肝细胞,改善代谢相关脂肪性肝炎。

关键词：逍遥丸代谢相关脂肪性肝炎核磁共振氢谱(1H-NMR) 粪便代谢组学

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Analyses on an electronic voltage transformer's failure by its resonance with very fast transient overvoltage and suppression

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High Voltage 2024年第1期9卷 150-162页

作者： ruoyu Han Houda Zhu Qing Chen Hongbin li Yue Tong linshan Han Yang Jiao School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhanChina China Electric Power Research Institute WuhanChina School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhanChina

As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary *** a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'*** address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an *** this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary *** addition,simulations and laboratory tests are conducted to prove this method's validity.

关键词： transient resonance mentioned

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