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Benchmarking of two three-dimensional numerical models in time/space domain to predict railway-induced ground vibrations 被引量:2
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作者 Jesus Fernandez-Ruiz Luis E.Medina Rodriguez +1 位作者 Pedro Alves Costa Margarita Martinez-Diaz 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第1期245-256,共12页
In the last 30 years,the scientific community has developed and proposed different models and numerical approaches for the study of vibrations induced by railway traffic.Most of them are formulated in the frequency/wa... In the last 30 years,the scientific community has developed and proposed different models and numerical approaches for the study of vibrations induced by railway traffic.Most of them are formulated in the frequency/wave number domain and with a 2.5D approach.Three-dimensional numerical models formulated in the time/space domain are less frequently used,mainly due to their high computational cost.Notwithstanding,these models present very attractive characteristics,such as the possibility of considering nonlinear behaviors or the modelling of excess pore pressure and non-homogeneous and non-periodic geometries in the longitudinal direction of the track.In this study,two 3D numerical approaches formulated in the time/space domain are compared and experimentally validated.The first one consists of a finite element approach and the second one of a finite difference approach.The experimental validation in an actual case situated in Carregado(Portugal)shows an acceptable fitting between the numerical results and the actual measurements for both models.However,there are some differences among them.This study therefore includes some recommendations for their use in practical soil dynamics and geotechnical engineering. 展开更多
关键词 railway vibrations time/space domain 3D numerical model finite difference method implicit finite element method
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Finite-time non-fragile filtering for nonlinear networked control systems via a mixed time/event-triggered transmission mechanism 被引量:2
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作者 Zhongda LU Junxiao LU +1 位作者 Jiaqi ZHANG Fengxia XU 《Control Theory and Technology》 EI CSCD 2020年第2期168-181,共14页
This paper is aimed at investigating the problem of mixed time/event-triggered finite-time non-fragile filtering for nonlinear networked control systems with delay.First,a fuzzy nonlinear networked control system mode... This paper is aimed at investigating the problem of mixed time/event-triggered finite-time non-fragile filtering for nonlinear networked control systems with delay.First,a fuzzy nonlinear networked control system model is established by interval type-2(IT2)Takagi-Sugeno(T-S)fuzzy model,the designed non-fragile filter resolves the filter parameter uncertainties and uses different membership functions from the IT2 T-S fuzzy model.Second,a novel mixed time/event-triggered transmission mechanism is proposed,which decreases the waste of network resources.Next,Bernoulli random variables are used to describe the cases of random switching mixed time/event-triggered transmission mechanism.Then,the error filtering system is designed by considering a Lyapunov function and a sufficient condition of finite-time boundedness.In addition,the existence conditions for the finite-time non-fragile filter are given by the linear matrix inequalities(LMIs).Finally,two simulation results are presented to prove the effectiveness of the obtained method. 展开更多
关键词 Interval type-2 Takagi-Sugeno fuzzy model networked control systems mixed time/event-triggered transmission mechanism finite-time non-fragile filter
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Efficient Time/Frequency Permutation of MIMO-OFDM Systems through Independent and Correlated Nakagami Fading Channels
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作者 Khodr A. SAAIFAN Emad K. AL-HUSSAINI 《International Journal of Communications, Network and System Sciences》 2009年第9期903-911,共9页
Space-Time Frequency (STF) codes for MIMO-OFDM over block-fading channel can achieve rate?? Mt and full-diversity Mt Mr Mb L which is the product of the number of transmit antennas Mt, receive antennas Mr, fading bloc... Space-Time Frequency (STF) codes for MIMO-OFDM over block-fading channel can achieve rate?? Mt and full-diversity Mt Mr Mb L which is the product of the number of transmit antennas Mt, receive antennas Mr, fading blocks Mb and channel taps L. In this article, time permutation is proposed to provide independent block-fading over Jake’s Doppler power spectrum channel. Moreover, we show the performance variations of STF code as channel delay spread changes. Therefore, we introduce a frequency/time permutation technique in order to remove the frequency correlation among sub-carriers, which subsequently increases the coding gain and achieves maximum diversity. Finally, the symbol error rate (SER) performance of the proposed time/frequency permuted STF codes over independent and correlated MIMO antenna branches under Nakagami fading channel is simulated. We show that the proposed systems provide better performance and more robust to large values of antennas correlation coefficients in comparison with the un-interleaved one. 展开更多
关键词 MIMO OFDM Space-time FREQUENCY Coding NAKAGAMI Fading Channel time/Frequency INTERLEAVING
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Factor Affecting Gel Time/Process-Ability of Urea Formaldehyde Resin Based Wood Adhesives 被引量:1
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作者 Ravindra V. Gadhave Prakash A. Mahanwar Pradeep T. Gadekar 《Open Journal of Polymer Chemistry》 2017年第2期33-42,共10页
Urea-formaldehyde (UF) resin presents the most utilized adhesive system in the manufacture of plywood, particleboard and fiberboard. At the temperatures above 100°C in the presence of hardener, this resin undergo... Urea-formaldehyde (UF) resin presents the most utilized adhesive system in the manufacture of plywood, particleboard and fiberboard. At the temperatures above 100°C in the presence of hardener, this resin undergoes cross-linking reaction and the formation of three dimensional cross linked structures takes place and bonding of wood particles in a hot press [1]. UF powder resins show high reactivity and good performance in the production and by their low price;however they lack in water resistance of the hardened resin [2]. Urea-formaldehyde (UF) resins are the most important type of adhesive resins for the production of wood based panels but process-ability and curing behavior of urea formaldehyde resin depended on various factors related to resin properties, types of wood and their properties, amount & type of catalyst, types and amount of polymers addition and environmental conditions [3]. This factor decides the process-ability of UF resin based composite during manufacturing of plywood, particle board and fiberboard. In this review paper, various factors affecting gel time and process-ability of UF resin based wood composite are reviewed. 展开更多
关键词 UREA FORMALDEHYDE RESINS Catalysts GEL time Wood pH Polyvinyl ACETATE Composite
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Feedback control for stochastic finite-time/fixed-time synchronization of stochastic coupled nonlinear systems
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作者 Hongxiao Hu Wenjing Yang Zhengtao Ding 《Control Theory and Technology》 EI CSCD 2023年第3期352-362,共11页
A novel feedback control is proposed to investigate the stochastic finite-time/fixed-time synchronization between two stochas-tic coupled nonlinear systems(SCNSs).Based on graph theory and Lyapunov function methods,so... A novel feedback control is proposed to investigate the stochastic finite-time/fixed-time synchronization between two stochas-tic coupled nonlinear systems(SCNSs).Based on graph theory and Lyapunov function methods,some effective stochastic finite-time/fixed-time synchronization criteria for SCNSs are established.Finally,the examples are included to demonstrate our analytical results. 展开更多
关键词 Stochastic finite-time synchronization Stochastic fixed-time synchronization Stochastic settling time
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TIME伤口床准备联合封闭式负压引流用于食管肿瘤术后颈部吻合瘘护理
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作者 李艳 周林荣 +4 位作者 龚兰娟 叶春燕 关雪红 李桃 李翠 《医学理论与实践》 2025年第16期2841-2843,共3页
目的:在食管肿瘤术后并发颈部吻合瘘患者护理中给予TIME伤口床准备联合封闭式负压引流的干预方式,就其护理效果进行分析。方法:选取2020年7月—2023年6月我科26例食管癌术后并发吻合口瘘患者为研究对象,采用随机数字表法将患者分为观察... 目的:在食管肿瘤术后并发颈部吻合瘘患者护理中给予TIME伤口床准备联合封闭式负压引流的干预方式,就其护理效果进行分析。方法:选取2020年7月—2023年6月我科26例食管癌术后并发吻合口瘘患者为研究对象,采用随机数字表法将患者分为观察组和对照组。观察组应用TIME伤口床准备联合封闭式负压引流治疗,对照组采用常规伤口换药处理,对比两组护理成效。结果:观察组术后15d内换药次数少于对照组,颈部切口愈合时间、经口进食流质时间以及术后住院时间明显短于对照组,同时观察组的6个月内吻合口狭窄发生率、6个月并发症发生率明显低于对照组(P<0.05);干预后,两组患者的QLQ-OES18各维度评分均较干预前降低,且观察组的各维度评分均低于对照组(P<0.05);观察组的护理总有效率显著高于对照组(P<0.05)。结论:TIME伤口床准备联合封闭式负压引流应用于食管肿瘤术后并发颈部吻合瘘护理中效果显著,可以有效缩短治疗时间,提高生活质量,改善预后,建议在临床上推广应用。 展开更多
关键词 食管肿瘤术后 颈部吻合瘘 time伤口床准备 封闭式负压引流 护理效果
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基于Thermal Time模型预测高加索三叶草花序生长和花期发展
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作者 张慧敏 王明玖 +3 位作者 提忠慧 刘嘉伟 曹克璠 马一鸣 《草地学报》 北大核心 2025年第3期850-858,共9页
Thermal time模型认为植物需要高于基准温度(Base temperature,Tb)累积固定量的热效应(Thermal time,Tt)来完成特定的发育阶段,低于Tb或未达到固定量的Tt,不发生发育阶段的转化。本文在中国青藏高原、内蒙古高原、东北平原和新西兰坎特... Thermal time模型认为植物需要高于基准温度(Base temperature,Tb)累积固定量的热效应(Thermal time,Tt)来完成特定的发育阶段,低于Tb或未达到固定量的Tt,不发生发育阶段的转化。本文在中国青藏高原、内蒙古高原、东北平原和新西兰坎特伯雷平原设置5个试验区,以高加索三叶草(Trifolium ambiguum Bieb.)为研究对象,观测单个花序发育速率和种群开花进展速率。基于试验区温度,运用Thermal time模型预测花序生长和花期进展,旨在量化花序开放和花期推进所需的热量条件,以此指导高加索三叶草饲草利用和种子生产。结果表明,高加索三叶草从现蕾发育到最大花序尺寸约需在2℃以上累积25℃·d;从始花期到盛花期需在7.5℃以上累积635℃·d;从盛花期到结实期存在地形差异,高原地区需在8.7℃以上累积1813℃·d,平原地区需在3℃以上累积1290℃·d。在高原地区高加索三叶草更适合饲草利用,在平原地区有种子生产利用的潜质。 展开更多
关键词 高加索三叶草 温度 基温 花期 热效应
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基于TimeGAN和LightGBM的多维时间序列故障样本扩充与诊断研究 被引量:1
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作者 马良玉 翟亮亮 韩立凯 《电力科学与工程》 2025年第9期13-21,共9页
火电机组热力系统故障往往会经历从轻微到严重的发展过程,而轻度和早期故障因特征不明显很容易被漏诊,这将导致故障进一步发展带来更严重的后果。鉴于机组实际运行中故障样本较为稀缺且记录的多为特征明显的中、重度故障样本,为提高轻... 火电机组热力系统故障往往会经历从轻微到严重的发展过程,而轻度和早期故障因特征不明显很容易被漏诊,这将导致故障进一步发展带来更严重的后果。鉴于机组实际运行中故障样本较为稀缺且记录的多为特征明显的中、重度故障样本,为提高轻度故障诊断的及时性和准确率,提出一种基于时间对抗生成网络(Time-series generative adversarial networks, Time GAN)和轻量级梯度提升机(Light gradient boosting machine, LightGBM)的多维时间序列故障样本扩充及故障诊断方法。数据方面,利用Time GAN对已有的中、重度故障数据进行扩充,生成反映真实故障样本分布且更具多样性的故障样本;模型方面,基于扩充后的故障样本集,采用贝叶斯寻优的LightGBM算法建立故障分类模型,以提高轻度和早期故障的识别能力。以600 MW火电机组高压加热器系统故障诊断为例开展实验研究,结果表明所提方法对轻微故障的诊断效果明显改善,验证了故障样本扩充和诊断方法的有效性。 展开更多
关键词 火电机组 故障诊断 多维时间序列 样本扩充 时间对抗生成网络 轻量级梯度提升机
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IoT Empowered Early Warning of Transmission Line Galloping Based on Integrated Optical Fiber Sensing and Weather Forecast Time Series Data 被引量:1
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作者 Zhe Li Yun Liang +1 位作者 Jinyu Wang Yang Gao 《Computers, Materials & Continua》 SCIE EI 2025年第1期1171-1192,共22页
Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced tran... Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false alarms.To address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather forecast.Initially,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused data.Furthermore,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network model.Subsequently,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this coefficient.Finally,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios. 展开更多
关键词 Optical fiber sensing multi-source data fusion early warning of galloping time series data IOT adaptive weighted learning irregular time series perception closed-loop attention mechanism
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基于TimesNet模型的CORS大地高时间序列预测研究
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作者 时文斌 蒋涛 +2 位作者 罗力 章传银 王伟 《测绘科学》 北大核心 2025年第6期45-54,共10页
针对基于物理参数的GNSS时间序列预测需要输入预测时刻的物理特征,这些未来时刻的特征取值通常很难获取的问题,该文引入深度学习模型TimesNet,以消除对未来时刻的物理特征输入的依赖,并选取10个连续运行基准站(CORS)站点的周解大地高时... 针对基于物理参数的GNSS时间序列预测需要输入预测时刻的物理特征,这些未来时刻的特征取值通常很难获取的问题,该文引入深度学习模型TimesNet,以消除对未来时刻的物理特征输入的依赖,并选取10个连续运行基准站(CORS)站点的周解大地高时序开展预测实验。实验结果表明,TimesNet在不同站点的均方根误差(RMSE)保持在2~9 mm,在同一站点3—12个月内预测精度波动幅度小于3 mm,说明该模型在长时序预测时具有更强的鲁棒性;此外,数据的离散特性会对预测精度和模型参数的敏感性产生显著影响。总体而言,TimesNet模型在周解大地高时序数据的预测中表现出较为理想的效果。 展开更多
关键词 timesNet 深度学习 连续运行参考站 时序分析 时序预测
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基于TimeGAN-Stacking的风电机组变桨系统故障诊断方法 被引量:2
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作者 潘美琪 贺兴 《太阳能学报》 北大核心 2025年第1期192-200,共9页
风电机组变桨系统的少量不均衡故障样本难以训练基于数据驱动的故障诊断模型,导致监测系统常常漏报或误报故障。针对上述问题,提出一种基于TimeGAN-Stacking的风电机组变桨系统故障诊断方法。在数据层面,由于原始样本类别不平衡,基于时... 风电机组变桨系统的少量不均衡故障样本难以训练基于数据驱动的故障诊断模型,导致监测系统常常漏报或误报故障。针对上述问题,提出一种基于TimeGAN-Stacking的风电机组变桨系统故障诊断方法。在数据层面,由于原始样本类别不平衡,基于时序生成对抗网络(TimeGAN)跟踪风电机组运行数据逐步概率分布的动态变化特征,同时优化生成样本的全局分布与局部分布,有效平衡且扩容风电机组多种故障综合样本集;在模型层面,建立Stacking集成模型,融合多个故障诊断器的优势,进一步提高故障诊断能力。最后,基于实际风场数据对所提方法进行测试,结果表明,所提出的TimeGAN-Stacking故障识别方法可有效诊断4种变桨故障。 展开更多
关键词 风电机组 数据挖掘 故障分析 深度学习 时序生成对抗网络 样本增强
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肠道病毒D68型流行基因型高灵敏通用型Real-time RT-PCR检测方法建立及应用
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作者 肖梦怡 韩振志 +11 位作者 路环环 丛如意 冀天娇 祝双利 孙强 刘莹 周蕾 栗凡 梁钰材 范华 肖金波 张勇 《病毒学报》 北大核心 2025年第3期625-633,共9页
自2014年肠道病毒D组68型(Enterovirus D68,EV-D68)引起急性弛缓性脊髓炎暴发以来,一直被广泛关注。建立一种快速、高效且便捷的EV-D68特异性Real-time RT-PCR检测方法,对于及时发现潜在的传染源并迅速阻断传播至关重要。本研究参考EV-... 自2014年肠道病毒D组68型(Enterovirus D68,EV-D68)引起急性弛缓性脊髓炎暴发以来,一直被广泛关注。建立一种快速、高效且便捷的EV-D68特异性Real-time RT-PCR检测方法,对于及时发现潜在的传染源并迅速阻断传播至关重要。本研究参考EV-D68各个基因型VP1区代表序列设计探针和引物,通过制作标准品,对其特异性、灵敏度以及重复性进行全面评价,并用临床样本检测其可靠性。结果显示,本研究所设计的探针和引物仅能检出EV-D68,其他73种血清型肠道病毒均无检出情况,最低检测下限为2×10^(1)拷贝/μL,拷贝数与循环阈值之间具有良好的线性关系(R^(2)=0.9933),重复性检测的变异系数小于1.70%,稳定性良好。采用本研究设计的探针和引物对41份临床样本进行检测时,实现了零漏检,与测序的金标准结果完全吻合,对于目前流行的B3和D3基因亚型可以实现全覆盖。综上所述,本研究设计的特异性探针引物在EV-D68检测中展现出高效且准确的特性,同时对目前流行的基因型具有较强的通用性,能够为EV-D68感染的临床诊断、疫情监测以及流行病学调查工作提供有力支持,为EV-D68的快速鉴定和相关疾病防控提供关键技术支撑。 展开更多
关键词 肠道病毒D组68型 实时荧光定量RT-PCR 特异性 灵敏度 重复性
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基于Time2Vec-BiGRU-SA深度学习模型的碳价格预测
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作者 杨楠 毕贵红 +3 位作者 李玉洪 孔凡文 骆钊 王瑞 《电力科学与工程》 2025年第9期1-12,共12页
碳交易价格预测对政策制定与市场稳态的维护至关重要,但碳价时间序列的非线性、非平稳性等特征给其精准预测带来困难。为此,提出基于时序特征向量映射模块、双向门控循环单元和自注意力机制融合的深度学习模型。模型集成3个分支:直接处... 碳交易价格预测对政策制定与市场稳态的维护至关重要,但碳价时间序列的非线性、非平稳性等特征给其精准预测带来困难。为此,提出基于时序特征向量映射模块、双向门控循环单元和自注意力机制融合的深度学习模型。模型集成3个分支:直接处理原始碳价时间序列;构建碳价序列多尺度分量矩阵;基于灰色关联度分析与极端随机树方法筛选出与碳价相关的关键变量。各分支均利用时序特征向量映射模块编码时间信息。双向门控循环单元捕捉双向长时依赖。自注意力机制模型加权特征进行综合集成。实证研究显示,该模型单步及多步预测精度高,均优于基准模型,模型具有优越性与稳健性。 展开更多
关键词 深度学习 碳市场价格 多变量时间序列预测 多分支输入 time2Vec
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基于拓展Volume-Time理论的串联空气间隙非同期击穿过程分析
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作者 姚晓飞 常晓雪 +5 位作者 丁健刚 陈佳莉 刘学 王建华 刘志远 耿英三 《高压电器》 北大核心 2025年第3期119-127,159,共10页
为了认识串联空气间隙的击穿过程,以球—球间隙为研究对象,设计了“非对称组合间隙”,即总间隙距离不变的条件下分别单独调整两个间隙的距离使上下间隙距离不一致。采用拓展Volume-Time理论计算了串联双间隙的U50%,并解释了雷电冲击电... 为了认识串联空气间隙的击穿过程,以球—球间隙为研究对象,设计了“非对称组合间隙”,即总间隙距离不变的条件下分别单独调整两个间隙的距离使上下间隙距离不一致。采用拓展Volume-Time理论计算了串联双间隙的U50%,并解释了雷电冲击电压下非对称组合空气间隙的非同期击穿物理过程。实验结果表明,上下间隙距离分布不均匀程度对串联空气间隙击穿电压和击穿延时的影响;不均匀程度较大时,较低电压下存在单个间隙放电、总体不击穿的现象,较高电压下两间隙将出现非同期击穿;不均匀程度较小时,两间隙同期击穿。为了解释这种现象,文中采用拓展Volume-Time理论,通过确定临界体积、临界面积等关键参数来计算串联双间隙的击穿电压。并把串联双空气间隙击穿的原因解释为,空气间隙电场的有效体积与有效面积超过临界值。因此,双间隙非同期击穿的产生是由于当一个间隙达到了击穿起始条件,而另一个间隙还未达到击穿起始条件。 展开更多
关键词 双断口开关 串联空气间隙 雷电冲击电压 非同期击穿特性 Volume-time理论
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Accurate determination of reaction rate constants for lithium-ion batteries by characteristic time-decomposed overpotential 被引量:1
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作者 Yifu Chen Haitao Zhu +7 位作者 Mengyuan Zhou Maoyuan Li Ruoyu Xiong Shuaiyi Yang Shiyu Zhang Yun Zhang Jingying Xie Huamin Zhou 《Journal of Energy Chemistry》 2025年第7期608-618,共11页
The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi... The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization. 展开更多
关键词 Kinetic parameter determination Decomposed overpotentials Charge transfer overpotential Characteristic time Single-layer particle
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The RhSPL4-RhPRR5L module positively regulates flowering time in rose(Rosa hybrida) 被引量:1
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作者 Ziwei Huang Guoqin Liu +10 位作者 Rui Chen Hao Zhang Dan Wang Daliang Li Yixin Zhang Huijun Yan Kaixue Tang Junping Gao Nan Ma Weikun Jing Xiaofeng Zhou 《Horticultural Plant Journal》 2025年第5期1930-1942,共13页
The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA P... The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA PROMOTER BINDING PROTEIN-LIKE4(RhSPL4)positively regulates flowering time in rose.Transient silencing or overexpression transgenic rose plants of RhSPL4 exhibited delayed or early flowering,respectively.Analysis of transcriptome data from transgenic lines overexpressing RhSPL4 compared to the wild type indicated that differentially expressed genes were significantly enriched in the circadian rhythm pathway.Among the proteins encoded by these genes,RhSPL4 binds to the promoter of PSEUDO-RESPONSE REGULATOR 5-LIKE(RhPRR5L),as revealed in yeast one-hybrid,dual-Luciferase/Renilla luciferase reporter,chromatin immunoprecipitation-quantitative PCR and electrophoretic mobility shift assay.Furthermore,RhSPL4 specifically binds to the478 to441 bp region of the RhPRR5L promoter and activates its transcription.The silencing of RhPRR5L delayed flowering time in rose,resembling the phenotype of RhSPL4-silenced plants.Together,these results indicate that the RhSPL4-RhPRR5L module positively regulates flowering time in rose,laying the foundation for the genetic improvement of flowering time in this important horticultural crop. 展开更多
关键词 SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 4 Flowering time Circadian clock PSEUDO-RESPONSE REGULATORS Rosa hybrida
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Integrated Optical True Time Delay Phased Array Antenna Systems 被引量:1
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作者 Qi Zihang Yang Linhui +1 位作者 Zhao Wenyu Li Xiuping 《China Communications》 2025年第5期152-172,共21页
The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled p... The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled phased array antenna system is a necessary trend for the future development of the phased array,and it is also a major focus and difficulty in the current research of integrated microwave photonics.This paper firstly introduces the basic principle and development history of optical true time delay phased array antenna system based on microwave photonics,and briefly introduces the main implementation methods and integration platform of optical true time delay.Then,the application and development prospect of optical true time delay technology in beam control of phased array antenna system are mainly presented.Finally,according to the current research progress,the possible research directions of integrated optically controlled phased array antenna systems in the future are proposed. 展开更多
关键词 microwave photonics optical switch optical true time delay phased array antenna siliconbased integration
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Three-dimensional line-of-sight-angle-constrained leader-following cooperative interception guidance law with prespecified impact time 被引量:1
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作者 Hao YOU Xinlong CHANG Jiufen ZHAO 《Chinese Journal of Aeronautics》 2025年第1期491-506,共16页
To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D lea... To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law. 展开更多
关键词 Three-dimensional cooperative interception Leader-following missiles Prespecified impact time LOS-angle-constrained Fixed-time stability Global integral sliding mode
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Mechanism Study on the Effect of Retarder on Polyurethane Setting Time Based on Molecular Simulation
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作者 WU Yuxuan XU Wenyuan +1 位作者 YU Tianlai JI Yongcheng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2025年第1期224-231,共8页
This study identified castor oil and phosphate ester as effective retarders through setting time,tensile,and flexural tests,and determined their optimal dosages.The mechanism by which phosphate ester affects the setti... This study identified castor oil and phosphate ester as effective retarders through setting time,tensile,and flexural tests,and determined their optimal dosages.The mechanism by which phosphate ester affects the setting time of polyurethane was further investigated using molecular dynamics simulations.Fourier transform infrared spectroscopy was also employed to systematically study the physical and chemical interactions between phosphate esters and polyurethane materials.The results demonstrate that a 1%concentration of phosphate ester provides the most effective retarding effect with minimal impact on the strength of polyurethane.When phosphate ester is added to the B component of the two-component polyurethane system,its interaction energy with component A decreases,as do the diffusion coefficient and aggregation degree of component B on the surface of component A.This reduction in interaction slows the setting time.Additionally,the addition of phosphate ester to polyurethane leads to the disappearance or weakening of functional groups,indicating competitive interactions within the phosphate ester components that inhibit the reaction rate. 展开更多
关键词 POLYURETHANE RETARDER setting time molecular dynamics diffusion coefficient
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DecMamba:Mamba Utilizing Series Decomposition for Multivariate Time Series Forecasting
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作者 Jianxin Feng Jianhao Zhang +2 位作者 Ge Cao Zhiguo Liu Yuanming Ding 《Computers, Materials & Continua》 SCIE EI 2025年第1期1049-1068,共20页
Multivariate time series forecasting iswidely used in traffic planning,weather forecasting,and energy consumption.Series decomposition algorithms can help models better understand the underlying patterns of the origin... Multivariate time series forecasting iswidely used in traffic planning,weather forecasting,and energy consumption.Series decomposition algorithms can help models better understand the underlying patterns of the original series to improve the forecasting accuracy of multivariate time series.However,the decomposition kernel of previous decomposition-based models is fixed,and these models have not considered the differences in frequency fluctuations between components.These problems make it difficult to analyze the intricate temporal variations of real-world time series.In this paper,we propose a series decomposition-based Mamba model,DecMamba,to obtain the intricate temporal dependencies and the dependencies among different variables of multivariate time series.A variable-level adaptive kernel combination search module is designed to interact with information on different trends and periods between variables.Two backbone structures are proposed to emphasize the differences in frequency fluctuations of seasonal and trend components.Mamba with superior performance is used instead of a Transformer in backbone structures to capture the dependencies among different variables.A new embedding block is designed to capture the temporal features better,especially for the high-frequency seasonal component whose semantic information is difficult to acquire.A gating mechanism is introduced to the decoder in the seasonal backbone to improve the prediction accuracy.A comparison with ten state-of-the-art models on seven real-world datasets demonstrates that DecMamba can better model the temporal dependencies and the dependencies among different variables,guaranteeing better prediction performance for multivariate time series. 展开更多
关键词 Data prediction time series Mamba series decomposition
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