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Journal of Thermal Science 2024年第2期33卷 578-590页

作者： LI Xiaolin WANG Jun cao wenxiang ZHANG Xuesong School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China

This study is to utilize the heat-absorbing and releasing capabilities of phase change materials(PCM)to regulate the surface temperature fluctuations of batteries during charging and *** goal is to keep the battery within the optimal operating temperature *** impact of PCM thickness and phase change temperature on battery temperature is investigated by encircling a cylindrical battery with a PCM *** improve the thermal conductivity of PCM,expanded graphite(EG) is added to make a composite phase change material(CPCM),and the effects of various EG mass ratios on battery surface temperature and CPCM utilization level are *** findings indicate that increasing PCM thickness effectively extends temperature control time,but its impact is *** difference in phase change temperature of PCM controls the battery temperature in different temperature *** phase change temperatures are unsuitable for controlling battery temperature in high temperature *** addition of EG enhances the thermal conductivity of PCM,leading to further control of battery *** results show that the addition of 6%(mass ratio) EG to CPCM extends the effective temperature control time by 11 min and improves by 28% compared to a single *** CPCM utilization is also more satisfactory and achieved a balance between heat storage and thermal conductivity in a battery thermal management system(BTMS) based on PCM.

关键词： phase change material expanded graphite thermal management system effective control time

用于吊弦故障检测的CycleGAN样本生成方法研究

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传感器与微系统 2024年第8期43卷 49-52页

作者：肖昊宇顾桂梅曹文翔兰州交通大学自动化与电气工程学院甘肃兰州730070

针对深度学习算法在接触网吊弦缺陷识别时,存在数据样本不平衡、缺陷样本少、难以准确体现识别算法有效性的问题,提出了一种基于改进循环生成对抗网络(CycleGAN)模型的吊弦缺陷样本生成方法。首先,在生成器中用密集卷积块替换残差块,使... 详细信息

针对深度学习算法在接触网吊弦缺陷识别时,存在数据样本不平衡、缺陷样本少、难以准确体现识别算法有效性的问题,提出了一种基于改进循环生成对抗网络(CycleGAN)模型的吊弦缺陷样本生成方法。首先,在生成器中用密集卷积块替换残差块,使得生成模型表现更稳定,收敛速度更快;然后,在生成器卷积层和密集卷积块后添加坐标注意力机制,使得生成的吊弦缺陷样本更清晰;最后,将常见的缺陷吊弦数据迁移到正常吊弦数据上,生成吊弦缺陷样本。仿真实验结果表明:所提出的方法比深度卷积生成对抗网络(DCGAN)算法和CycleGAN算法生成的图像更清晰,最终所生成的样本可以替代真实样本。

关键词：吊弦循环生成对抗网络密集卷积网络坐标注意力机制样本扩充

基于改进YOLOv7算法的接触网吊弦线夹螺母状态识别方法

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兰州交通大学学报 2024年第2期43卷 68-75页

作者：曹文翔顾桂梅兰州交通大学自动化与电气工程学院兰州730070

针对传统的深度学习算法在处理铁路接触网吊弦线夹螺母时效果不佳,而人工巡检吊弦线夹螺母速度慢、难度大问题,提出一种改进的YOLOv7算法对接触网吊弦线夹螺母状态进行识别。首先,该算法在YOLOv7原有模型特征提取网络的末端融合卷积和... 详细信息

针对传统的深度学习算法在处理铁路接触网吊弦线夹螺母时效果不佳,而人工巡检吊弦线夹螺母速度慢、难度大问题,提出一种改进的YOLOv7算法对接触网吊弦线夹螺母状态进行识别。首先,该算法在YOLOv7原有模型特征提取网络的末端融合卷积和自我注意力机制,使算法既拥有注意力和卷积的优势,又与单一的卷积或注意力相比具有较小的计算量,以提升缺陷检测的速度;然后,在特征提取网络的输出端引入空间到深度卷积模块,以空间层到深度层取代池化层,以非跨行卷积层取代跨行卷积层,强化算法对螺母缺陷状态的识别能力;最后,在输出层加入新的移动网络轻量级坐标注意力机制,以得到方向感知和位置敏感的注意图,互补地应用于输出特征图,以更有利于接触网吊弦线夹螺母的识别。仿真实验结果表明:在未经裁剪的接触网吊弦数据集上,该算法对吊弦线夹螺母状态识别的正确率达到90%以上,平均检测准确率为98.5%,证明改进后YOLOv7算法在兼具检测速度的同时能更加准确地识别接触网吊弦线夹螺母状态。

关键词：接触网吊弦吊弦线夹螺母状态识别 YOLOv7 自注意力与卷积融合空间到深度卷积模块

基于MATLAB的双闭环直流调速系统的设计与仿真

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现代工业经济和信息化 2024年第3期14卷 272-274页

作者：曹文祥李自成缪俊峰胡鹏飞彭才兴肖荣宇成都理工大学工程技术学院四川乐山614000

基于Matlab对双闭环直流调速系统进行了设计与实现,介绍了双闭环直流调速系统的原理及结构,通过实例对双闭环直流调速系统进行设计合适的控制策略,并使用Matlab进行仿真、建模和分析,其中转速调节器和电流调节器均采用带有限幅作用的PI... 详细信息

基于Matlab对双闭环直流调速系统进行了设计与实现,介绍了双闭环直流调速系统的原理及结构,通过实例对双闭环直流调速系统进行设计合适的控制策略,并使用Matlab进行仿真、建模和分析,其中转速调节器和电流调节器均采用带有限幅作用的PI调节器,然后通过实验的方法来验证所设计的双闭环直流调速系统的合理性和准确性.实验结果表明,基于Matlab的双闭环直流调速系统具有一定的抗负载扰动的能力,通过仿真实验的方法验证,所设计的双闭环直流调速系统能实现无静差调速.

关键词： MATLAB 双闭环直流调速电流调节器转速调节器无静差

不同侧链密度PCE制备的C-S-H/PCE结构及其对水泥早期水化的影响

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华南理工大学学报（自然科学版） 2023年第1期51卷 76-83,94页

作者：殷素红杨幸霖冯献曹文湘华南理工大学材料科学与工程学院广东广州510640

装配式建筑的发展使得在预制件生产中使用早强剂的需求越发强烈,人工合成水化硅酸钙(C-S-H)作为一种新型晶种早强剂,能够显著提高水泥基材料的早期强度,但其较差的分散性限制了其应用。文中以不同侧链密度聚羧酸减水剂(PCE)作为分散剂,... 详细信息

装配式建筑的发展使得在预制件生产中使用早强剂的需求越发强烈,人工合成水化硅酸钙(C-S-H)作为一种新型晶种早强剂,能够显著提高水泥基材料的早期强度,但其较差的分散性限制了其应用。文中以不同侧链密度聚羧酸减水剂(PCE)作为分散剂,通过共沉淀法合成了一系列C-S-H/PCE晶种早强剂,利用X射线衍射分析仪(XRD)、傅里叶红外光谱(FT-IR)、纳米粒度仪(DLS)等探究其对C-S-H晶种结构的影响,并深入研究了C-S-H/PCE晶种早强剂对水泥水化行为、硬化体强度和组成结构的影响。结果表明:PCE的侧链密度越小,C-S-H晶种分散得越好,粒径越小,中位粒径可达339.5 nm,晶种颗粒数量增多,可提供更多的成核位点;掺入C-S-H/PCE能显著加速水泥水化,使水化加速期放热峰提前1.3 h,8 h放热量增加10.8%;掺入C-S-H/PCE后,水泥净浆8 h和1 d龄期硬化体的孔隙率降低,抗压强度分别提高13%和15%。

关键词：人工合成水化硅酸钙聚羧酸减水剂侧链密度水泥早期水化

2015-2020年湖北省PM_(2.5)和臭氧复合污染特征演变分析

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环境科学研究 2022年第3期35卷 659-672页

作者：陈楠陈立王莉莉祝波操文祥许可丁青青兰博张周祥魏莱施艾琳王珂湖北省生态环境监测中心站湖北武汉430072 湖北省大气复合污染研究中心湖北武汉430078 湖北省行政许可技术评审中心湖北武汉430071 中国科学院大气物理研究所北京100029

为揭示湖北省PM_(2.5)和臭氧(O_(3))复合污染演变特征,基于湖北省17个地市的空气质量国控点和武汉市大气超级站组分监测数据,全面分析湖北省17个地市2015—2020年PM_(2.5)和O_(3)的时空变化特征及相关关系,探讨PM_(2.5)和O_(3)协同效应... 详细信息

为揭示湖北省PM_(2.5)和臭氧(O_(3))复合污染演变特征,基于湖北省17个地市的空气质量国控点和武汉市大气超级站组分监测数据,全面分析湖北省17个地市2015—2020年PM_(2.5)和O_(3)的时空变化特征及相关关系,探讨PM_(2.5)和O_(3)协同效应的成因机理.结果表明:①2015—2020年,湖北省PM_(2.5)显著改善,平均降幅为4.7μg/(m^(3)·a),但冬季负荷仍较高,主要集中于中部地区;O_(3)污染凸显,平均增幅为3.8μg/(m^(3)·a),污染集中在4—10月的暖季,东部地区最严重,近两年超标天数已与PM_(2.5)相当.②湖北省PM_(2.5)和O_(3)关联日趋密切,协同效应显著,日评价指标显示夏季二者呈显著正相关(相关系数为0.57),近两年当PM_(2.5)浓度≤50μg/m^(3)时,相关系数高达0.63;冬季PM_(2.5)浓度与Ox(O_(3)+NO_(2))浓度呈正相关,尤其2020年东部城市二者相关性高达0.46,显示大气氧化性对PM_(2.5)二次污染的重要性.③以武汉市为例,归纳PM_(2.5)和O_(3)复合污染的成因,暖季低PM_(2.5)背景下,高温、中等湿度和弱风速的气象条件以及VOCs和NO_(x)等前体物的高浓度排放,使得受VOCs主控的光化学反应加剧,易造成O_(3)污染,从而加强PM_(2.5)二次生成;冬季高的大气氧化性,叠加不利气象条件,促进颗粒物的二次生成,导致重污染时PM_(2.5)组分以硝酸盐等二次无机组分为主.研究显示,湖北省PM_(2.5)和O_(3)协同控制重点为,在保持现有NO_(x)控制力度基础上强化VOCs控制,遏制暖季和东部区域O_(3)浓度上升,加强冬季和中部PM_(2.5)治理.

关键词： PM_(2.5) 臭氧(O_(3)) 协同控制复合污染湖北省

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Quantitative phase imaging based on holography:trends and new perspectives

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Light(Science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

Dynamic Setting Method of Assessment Indicators for Power Curves of Renewable Energy Sources Considering Scarcity of Reserve Resources

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 101-114页

作者： Minghao cao Jilai Yu the Department of Electrical Engineering Harbin Institute of TechnologyHarbinChina

With the increasing proportion of renewable energy sources(RESs)in power grid,the reserve resource(RR)scarcity for correcting power deviation of RESs has become a potential ***,the power curve of RES needs to be more rigorously *** RR scarcity varies during different time periods,so the values of assessment indicators should be dynamically *** assessment indicators in this paper include two aspects,i.e.,deviation exemption ratio and penalty ***,this paper proposes a method for dynamically calculating the supply capacity and RR cost,primarily taking into account the operating status of thermal units,forecast information of RES,and load ***,after clarifying the logical relationship between the degree of RR scarcity and the values of assessment indicators,this paper establishes a mapping function between *** on this mapping function,a dynamic setting method for assessment indicators is *** the future,RES will generally be equipped with battery energy storage systems(BESSs).Reasonably utilizing BESSs to reduce the power deviation of RESs can increase the expected income of ***,this paper proposes a power curve optimization strategy for RESs considering self-owned *** case study demonstrates that the dynamic setting method of assessment indicators can increase the revenue of RESs while ensuring that the penalty fees paid by RESs to the grid are sufficient to cover the RR ***,the power curve optimization strategy can help RESs further increase income and fully utilize BESSs to reduce power deviation.

关键词： Renewable energy battery energy storage system(BESS) power curve assessment reserve service parameter setting

Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields,and proposed a problem whether their bound can be *** this paper,the author improves Wan-Zhang's bound from three *** proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric *** the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang's bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

Bioinspired Closed-loop CPG-based Control of a Robotic Manta for Autonomous Swimming

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Journal of Bionic Engineering 2024年第1期21卷 177-191页

作者： Yiwei Hao Yonghui cao Yingzhuo cao Xiong Mo Qiaogao Huang Lei Gong Guang Pan Yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo 315103China Key Laboratory of Unmanned Underwater Vehicle Technology of Ministry of Industry and Information Technology Xi'an 710072China

Fish in nature exhibit a variety of swimming modes such as forward swimming,backward swimming,turning,pitching,etc.,enabling them to swim in complex scenes such as coral *** is still difficult for a robotic fish to swim autonomously in a confined area as a real ***,we develop an untethered robotic manta as an experimental platform,which consists of two flexible pectoral fins and a tail fin,with three infrared sensors installed on the front,left,and right sides of the head to sense the surrounding *** generate multiple swimming modes of the robotic manta and online switching of different modes,we design a closed-loop Central Pattern Generator(CPG)controller based on distance information and use a combination of phase difference and amplitude of the CPG model to achieve stable and rapid adjustment of yaw *** verify the autonomous swimming ability of the robotic manta in complex scenes,we design an experimental scenario with a concave *** experimental results show that the robotic manta can achieve forward swimming,backward swimming,in situ turning within the concave obstacle,and finally exit from the area safely while relying on the perception of external obstacles,which can provide insight into the autonomous exploration of complex scenes by the biomimetic robotic ***,the swimming ability of the robotic manta is verified by field tests.

关键词： Biomimetic robotic manta Central Pattern Generator Closed-loop control Backward swimming