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基于Modbus RTU协议实现1200 PLC对V20变频器的控制及监控
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作者 孙建中 洪明虎 +2 位作者 祁勤 夏明鹏 张宇豪 《工业控制计算机》 2026年第2期29-31,共3页
Modbus RTU协议简单且通用,易于实现和集成,易于将工业仪表、变频器等设备组成网络,实现参数设定、数据监控和启停控制等操作。以西门子S7-1200 PLC作为主站,西门子V20变频器作为从站,组态硬件系统;借助Modbus RTU协议实现主从站通信,分... Modbus RTU协议简单且通用,易于实现和集成,易于将工业仪表、变频器等设备组成网络,实现参数设定、数据监控和启停控制等操作。以西门子S7-1200 PLC作为主站,西门子V20变频器作为从站,组态硬件系统;借助Modbus RTU协议实现主从站通信,分析PLC实现变频器参数设定、参数读取数据监控及变频器控制等环节,给出主站PLC程序编写思路,实现对从站变频器的控制和监控。 展开更多
关键词 s7-1200 PLC v20变频器 Modbus RTU协议 Rs485
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基于CEW-YOLOv5s的高压输电线路绝缘子缺陷检测算法
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作者 方世康 洪炎 +2 位作者 宋宁 刘娱洁 李怀宝 《佳木斯大学学报(自然科学版)》 2026年第1期30-33,共4页
针对复杂环境下输电线路绝缘子小目标缺陷特征弱、边缘模糊及误检率高的问题,提出一种融合改进注意力机制、轻量级感受野增强与动态边框回归策略的CEW-YOLOv5s模型。首先,在主干网络引入改进的卷积块注意力机制CBAM-I,强化对小目标及边... 针对复杂环境下输电线路绝缘子小目标缺陷特征弱、边缘模糊及误检率高的问题,提出一种融合改进注意力机制、轻量级感受野增强与动态边框回归策略的CEW-YOLOv5s模型。首先,在主干网络引入改进的卷积块注意力机制CBAM-I,强化对小目标及边缘特征的关注;其次,将BottleneckCSP模块结构优化并替换C3模块,提升通道特征表达能力并降低模型复杂度;进而设计融合高效通道注意力的空间金字塔池化模块SPPF-E,扩大感受野并增强多尺度特征提取能力;最后,采用具备动态非单调聚焦机制的WIoU v3损失函数,优化边框回归过程并缓解正负样本不均衡问题。实验结果表明:所提模型的精确率、召回率与平均精确率均值分别达到94.6%、95.8%与96.4%,较原YOLOv5s模型分别提升1.9、3.2和3.3个百分点,检测速度达88.48 f/s。 展开更多
关键词 目标检测 YOLOv5s WIoU v3 绝缘子缺陷
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水热法制备Ti_(3)C_(2)@VS_(2)/S阴极材料及其在镁硫电池中的应用
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作者 葛佳音 寇准升 +3 位作者 闫晓燕 张晓华 赵新新 郭锦 《材料导报》 北大核心 2026年第4期1-7,共7页
为契合可持续发展能源需求,镁硫电池作为新型高能储能体系备受关注。本工作通过水热法成功构建了Ti_(3)C_(2)@VS_(2)/S复合材料作为镁硫电池的阴极,并通过电化学测试等方法系统评估了其性能。该材料在不同倍率条件下展现出优异的容量保... 为契合可持续发展能源需求,镁硫电池作为新型高能储能体系备受关注。本工作通过水热法成功构建了Ti_(3)C_(2)@VS_(2)/S复合材料作为镁硫电池的阴极,并通过电化学测试等方法系统评估了其性能。该材料在不同倍率条件下展现出优异的容量保持能力,在0.1C、0.2C、0.5C、1C、2C、5C下的初始放电比容量分别为1246.3 mAh·g^(-1)、1094.1 mAh·g^(-1)、978.1 mAh·g^(-1)、844.2 mAh·g^(-1)、568.3 mAh·g^(-1)、289.6 mAh·g^(-1);当倍率重新恢复至0.1C时,放电比容量仍稳定在1175.2 mAh·g^(-1),容量保持率达76.3%,且循环过程中容量衰减率也较低,为0.21%。本工作的结果为镁硫电池阴极材料的界面优化与动力学提升提供了重要实验依据。 展开更多
关键词 镁硫电池 Ti_(3)C_(2)Ti_(3)C_(2)@vs_(2)/s 水热法 电化学性能
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老树新花:2026 Moto Guzzi V100 Mandello S
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作者 方云飞 《摩托车》 2026年第1期54-59,共6页
作为拥有百年历史的经典品牌,摩托·古兹拥有与众不同的审美理念和技术特点,其中最具代表性、最有识别度的,就是90°夹角的横置V2发动机,左右缸如同张开双翅的烈火雄鹰,搭载骑手飞向自由空间。站在新百年的起点上,2024年摩托... 作为拥有百年历史的经典品牌,摩托·古兹拥有与众不同的审美理念和技术特点,其中最具代表性、最有识别度的,就是90°夹角的横置V2发动机,左右缸如同张开双翅的烈火雄鹰,搭载骑手飞向自由空间。站在新百年的起点上,2024年摩托·古兹迈出了革命步伐,推出了他们的首台搭载水冷发动机的V100Mandello。但是,这只雄鹰并没有止步于此,又推出了更加先进的V100Mandello S,加持更多的技术能量,让自由之旅澎湃着风火激情! 展开更多
关键词 v100 Mandello s Moto Guzzi
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H/V Spectral Ratio Reveals Seismic Response of Base-Isolated Large-Span High-Rise in Beijing
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作者 Zhangdi Xie Cantao Zhuang +2 位作者 Yong Wu Linghui Niu Jianming Zhao 《Structural Durability & Health Monitoring》 2026年第1期341-354,共14页
This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-fiel... This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping. 展开更多
关键词 H/v spectral ratio method seismic isolation system seismic response characteristics three-stage frequency gradient energy dissipation mechanism
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Evaluation of NLLoc positioning method and seismogenic structure analysis of Luanzhou M_(S)4.3 earthquake
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作者 Zhang Yang Wang Xiao-Shan +3 位作者 Chen Ting Lv Guo-Jun Yu Hai-lin Chen Jun-lin 《Applied Geophysics》 2025年第3期729-738,894,895,共12页
NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and vel... NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and velocity model.The results show that the NLLoc method exhibits high positioning accuracy and stability in terms of arrival time picking accuracy and station distribution;however,it is sensitive to the velocity model.The positioning accuracy is higher when the velocity model is smaller than the true velocity.We combined absolute and relative positioning methods.First,we use the NLLoc method for absolute positioning of seismic data and then the double difference positioning method for relative positioning to obtain a more accurate relocation result.Furthermore,we used the combined method to locate the earthquake sequence after collecting dense seismic array data on the Luanzhou M_(S)4.3 earthquake that occurred on April 16,2021,in Hebei Province.By fitting the fault plane with the relocated earthquake sequences,the results show that the strike and dip angles of the seismogenic fault of the Luanzhou M_(S)4.3 earthquake are 208.5°and 85.6°,respectively.This indicates a high-dip angle fault with North-North-East strike and North-West dip directions.Furthermore,we infer that the seismogenic fault of the Luanzhou M_(S)4.3 earthquake is the Lulong fault. 展开更多
关键词 NLLoc method Combined multiple positioning methods Luanzhou M_(s)4.3 earthquake seismogenic structure Lulong fault
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An Automatic Damage Detection Method Based on Adaptive Theory-Assisted Reinforcement Learning
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作者 Chengwen Zhang Qing Chun Yijie Lin 《Engineering》 2025年第7期188-202,共15页
Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real... Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real-time automated damage detection method by developing a theory-assisted adaptive mutiagent twin delayed deep deterministic(TA2-MATD3)policy gradient algorithm.First,the theoretical framework of reinforcement-learning-driven damage detection is established.To address the disadvantages of traditional mutiagent twin delayed deep deterministic(MATD3)method,the theory-assisted mechanism and the adaptive experience playback mechanism are introduced.Moreover,a historical residential house built in 1889 was taken as an example,using its 12-month structural health monitoring data.TA2-MATD3 was compared with existing damage detection methods in terms of the convergence ratio,online computing efficiency,and damage detection accuracy.The results show that the computational efficiency of TA2-MATD3 is approximately 117–160 times that of the traditional methods.The convergence ratio of damage detection on the training set is approximately 97%,and that on the test set is in the range of 86.2%–91.9%.In addition,the main apparent damages found in the field survey were identified by TA2-MATD3.The results indicate that the proposed method can significantly improve the online computing efficiency and damage detection accuracy.This research can provide novel perspectives for the use of reinforcement learning methods to conduct damage detection in online structural health monitoring. 展开更多
关键词 Reinforcement learning Theory-assisted Damage detection Newton’s method Model updating Architectural heritage
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Study on the Effects of Umbilical Acupuncture’s“Wind-Thunder Interaction Method”on Neuro-Vascular Regulatory Peptide Groups in SCH Patients with Liver Stagnation and Spleen Deficiency
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作者 Yongfeng Li Jialin Cheng +2 位作者 Hairong Wang Bihai Zhou Jianguo Mao 《Journal of Clinical and Nursing Research》 2025年第11期249-255,共7页
Objective:To evaluate the therapeutic efficacy of the umbilical acupuncture’s“Wind-Thunder Interaction Method”in treating schizophrenia(SCH)patients with liver stagnation and spleen deficiency.Methods:A total of 12... Objective:To evaluate the therapeutic efficacy of the umbilical acupuncture’s“Wind-Thunder Interaction Method”in treating schizophrenia(SCH)patients with liver stagnation and spleen deficiency.Methods:A total of 120 SCH patients with liver stagnation and spleen deficiency were selected and evenly divided by ball drawing.The umbilical acupuncture group received the“Wind-Thunder Interaction Method”,while the Western medicine group received pure Western medicine treatment.The outcomes were compared in terms of efficacy and other indicators.Results:The umbilical acupuncture group showed a higher total effective rate,a decrease in disease symptom scores,lower scores on the side effect rating scale,improved cognitive function scores,and excellent laboratory indicators,with p<0.05 between the groups.Conclusion:The“Wind-Thunder Interaction Method”of umbilical acupuncture demonstrated a relatively high effectiveness in treating SCH patients with liver stagnation and spleen deficiency,alleviating symptoms,reducing side effects,improving cognitive function,and facilitating the recovery of neuro-vascular regulatory peptide groups. 展开更多
关键词 Umbilical acupuncture’s“Wind-Thunder interaction method sCH Liver stagnation and spleen deficiency Neuro-vascular regulatory peptide groups
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A Self-Sacrifice Template Method to Produce FeS Encapsulated into N,S Co-Doped Carbon for Improved Lithium Storage Performance
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作者 Xu Liu Lan-Yun Yang +7 位作者 Li-Ting Zeng Yun Peng Chen-Xi Xu Lei Li Jia-Le Sun Yang-Yang Chen Liang Chen Zhao-Hui Hou 《Acta Metallurgica Sinica(English Letters)》 2025年第9期1637-1644,共8页
The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile ... The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile self-sacrifice template method is developed to prepare FeS encapsulated into N,S co-doped carbon(FeS/NSC)composite using melamine-cyanuric acid(MCA)supermolecule as a multifunctional template precursor.The function of MCA supermolecule for material synthesis is explored,revealing its special function as a dispersant,dopant and pore-forming agent.Furthermore,the effect of Fe source dosage on the morphology,structure and composition of the final products is explored.The resultant FeS/NSC-0.1(where 0.1 represents the mass of added Fe source)exhibits the most optimal proportion,characterized by a good dispersion status of FeS within the NSC matrix,effective N,S co-doping and ample porosity.Benefiting from these merits,the FeS/NSC-0.1 anode demonstrates significantly improved cycling stability and rate capability when compared to the counterparts.Undoubtedly,this work offers a universal method to produce advanced transition metal sulfide/carbon composite electrodes for energy storage and conversion systems. 展开更多
关键词 Lithium-ion batteries Lithium storage performance self-sacrifice template method Melamine-cyanuric acid(MCA)supermolecule Fes encapsulated into N s co-doped carbon(Fes/NsC)composite
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基于轻量化YOLO v5s-MCA的番茄成熟度检测方法 被引量:6
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作者 奚小波 丁杰源 +5 位作者 翁小祥 王昱 韩连杰 邹赟涵 唐子昊 张瑞宏 《农业机械学报》 北大核心 2025年第3期383-391,436,共10页
针对自然环境下番茄识别易受复杂背景干扰、相邻果实成熟度相似难以检测等问题,本文提出了一种轻量化YOLO v5s-MCA番茄成熟度识别模型,划分成熟期、转熟期、转色期和未熟期4个成熟度等级。该模型在YOLO v5s基础上使用MobileNetV3网络,... 针对自然环境下番茄识别易受复杂背景干扰、相邻果实成熟度相似难以检测等问题,本文提出了一种轻量化YOLO v5s-MCA番茄成熟度识别模型,划分成熟期、转熟期、转色期和未熟期4个成熟度等级。该模型在YOLO v5s基础上使用MobileNetV3网络,减少了模型参数量;在主干网络和颈部网络引入坐标注意力机制(Coordinate attention,CA),提高了模型对番茄特征表达能力;将颈部网络替换为加权双向特征金字塔网络BiFPN,强化了模型特征融合性能并提高了模型识别准确率;将颈部网络中的标准卷积模块改进为GSConv卷积,减轻了模型复杂度并提高了对目标信息的获取能力。试验结果表明,YOLO v5s-MCA模型参数量仅为2.33×10^(6),计算量仅为4.1×10^(9),模型内存占用量仅为4.83 MB,其精准度和平均精度均值分别达到92.8%和95.1%,相对YOLO v5s基础模型分别提升3.4、4.4个百分点。对比YOLO v3s、YOLO v5s、YOLO v5n、YOLO v7、YOLO v8n及YOLO v10n等6种模型,YOLO v5s-MCA模型轻量化效果与检测性能最优。 展开更多
关键词 番茄 成熟度检测 图像识别 YOLO v5s 轻量化
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Clinical application and research of Shao's “three-acupoint and five-needling method” 被引量:1
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作者 张奥 严兴科 刘安国 《World Journal of Acupuncture-Moxibustion》 CSCD 2017年第1期74-80,共7页
Professor SHAO Jing-ming has obtained more significant effect during the clinical practice in treatment of wheezing diseases by adopting "three-acupoint and five-needling method" created by himself, and the effect h... Professor SHAO Jing-ming has obtained more significant effect during the clinical practice in treatment of wheezing diseases by adopting "three-acupoint and five-needling method" created by himself, and the effect has been widely recognized by doctors and patients. After decades of development, Shao's "three-acupoint and five-needling method" has become a therapy with complete theoretical system and a large number of clinical research achievements, and its application scope has been expanded. In this paper, the achievements of Shao's "three-acupoint and five-needling method" during clinical studies in the early, middle and current development stages and related problems were reviewed comprehensively. 展开更多
关键词 three-acupoint andmethod wheezing diseases clinicain the same wayfive-needling method shao's needlingobservation different diseases be treated
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融合改进YOLO v5s与毫米波雷达的避障目标检测方法
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作者 胡炼 梁楚奇 +6 位作者 罗雅玲 柳诏迪 阮庆强 汪沛 黄培奎 王培 孙宜田 《农业机械学报》 北大核心 2025年第12期634-644,共11页
为提高农场环境下无人驾驶农机对农田障碍物感知的准确性,针对视觉检测容易受光照和毫米波雷达检测易受车辆颠簸等,以及视觉检测目标算法在复杂田间下参数量大、计算量大、模型体积大的问题,本文提出一种融合视觉与毫米波雷达信息的无... 为提高农场环境下无人驾驶农机对农田障碍物感知的准确性,针对视觉检测容易受光照和毫米波雷达检测易受车辆颠簸等,以及视觉检测目标算法在复杂田间下参数量大、计算量大、模型体积大的问题,本文提出一种融合视觉与毫米波雷达信息的无人驾驶农机避障目标检测方法。首先过滤毫米波雷达的部分目标数据,并提出基于自适应扩展卡尔曼滤波的目标追踪算法。然后制作农场环境障碍物数据集,构建基于改进YOLO v5s的目标检测模型。随后,通过时间戳对齐和直接线性标定法的坐标变换,实现雷达点向图像像素坐标系的映射。最后,通过决策级融合方法和目标匹配策略构建毫米波雷达与视觉传感器的障碍物检测信息融合模型。试验结果表明,改进YOLO v5s模型平均精度均值为97.0%,与原始模型相近,但参数量、计算量、模型内存占用量仅分别为原YOLO v5s模型的40.2%、39.2%和38.2%,与YOLO v4-Tiny、YOLO v7-Tiny、YOLO v4和YOLO v7模型相比能够更好地平衡精确率与检测速度。多场景试验结果表明,本文提出的融合方法在白天试验时相较于雷达与视觉识别准确率分别提高2.67、15.07个百分点,夜间试验时融合检测方法能有效弥补视觉失效的情况,比单传感器算法具有更好的鲁棒性与准确性,同时基于融合检测方法有效实现了无人驾驶农机停车避障。 展开更多
关键词 YOLO v5s 农田障碍物检测 毫米波雷达 视觉目标检测 信息融合
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基于改进YOLO v5s算法的红枣缺陷检测与分拣方法
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作者 史鹏涛 田政伟 +1 位作者 李晓泽 危康乐 《江苏农业科学》 北大核心 2025年第5期83-88,共6页
针对当前生产活动中缺陷红枣的人工识别与分拣劳动强度大、效率低、分拣效果不理想的问题,设计一款基于机器视觉的红枣缺陷检测与分拣设备。首先建立多品种、多照明环境下的红枣缺陷检测样本图库,通过高斯滤波等数据增强技术增强了图像... 针对当前生产活动中缺陷红枣的人工识别与分拣劳动强度大、效率低、分拣效果不理想的问题,设计一款基于机器视觉的红枣缺陷检测与分拣设备。首先建立多品种、多照明环境下的红枣缺陷检测样本图库,通过高斯滤波等数据增强技术增强了图像表面特征,并利用图库分析了红枣缺陷形貌和图像特征。然后针对训练后的YOLO v5s模型检测效果不理想的问题,分别通过引入锚框尺寸优化和添加预测头、引入注意力分配机制和学习率自适应等方法对网络进行了改进与优化,优化后模型训练效果准确率提高7百分点,对红枣缺陷检测的效果有明显增强,与当前热门的检测网络YOLO v3、YOLO v4和YOLO v4-tiny模型对比,YOLO v5s模型平均精度均值分别高7.4、2.3、5.7百分点。试验结果表明,改进后的红枣缺陷检测网络能够有效实现红枣缺陷识别,平均检测准确率达到85.3%,其中黄河滩枣检测准确率可达到87.5%,与分拣设备配合使用能够较好地完成红枣缺陷识别与分拣任务。本研究设计的缺陷检测与分拣平台能够为相关农产品的智能化检测与自动分拣装备的设计与研发提供借鉴和参考。 展开更多
关键词 缺陷检测 机器视觉 自动分拣 YOLO v5s 红枣
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基于改进YOLO v5s的叶菜病虫害检测算法研究
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作者 贺洪江 刘毅祥 王双友 《江苏农业科学》 北大核心 2025年第5期244-250,共7页
叶菜病虫害的早期识别是提高叶菜产量和质量的重要保障,为提高常见叶菜病虫的检测精度,针对实际生产中的复杂环境,以YOLO v5s为基准模型,提出一种改进的FV-YOLO v5s模型。首先,在主干网络中融合CA注意力机制模块与C3特征提取模块,形成了... 叶菜病虫害的早期识别是提高叶菜产量和质量的重要保障,为提高常见叶菜病虫的检测精度,针对实际生产中的复杂环境,以YOLO v5s为基准模型,提出一种改进的FV-YOLO v5s模型。首先,在主干网络中融合CA注意力机制模块与C3特征提取模块,形成了C3CA模块以增强叶菜病虫害的特征提取能力。接着在颈部网络中使用Slim-neck范式设计,高效提取图像中小尺寸目标的特征,增强特征融合的效率。最后用WIoU损失对原损失函数CIoU进行替换,更快地达到收敛状态并提升模型检测性能。结果表明,新模型的精度、召回率和平均精度均值分别达到了92.2%、91.5%、94.8%。改进后的模型FV-YOLO v5s对比原YOLO v5s模型算法,精度、召回率、平均精度均值分别提高2.7、1.4、1.8百分点,优于现有的识别网络,包括YOLO v7、YOLO v8、Faster R-CNN等模型。FV-YOLO v5s模型适用于现代农业生产环境,有助于快速识别和检测叶菜病虫害,且该研究为智慧农业中的叶菜高品质和高产量提供了依据,从而最大限度地减少经济损失。 展开更多
关键词 叶菜病虫害 YOLO v5s CA注意力机制 slim-neck WIoU损失函数
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Comparative Analysis of Improving Effects of 12 Maize Populations with Improved S_1 Selection Method
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作者 孙峰成 冯勇 +6 位作者 付增娟 苏二虎 张来厚 赵瑞霞 刘志雄 石海波 李美娜 《Agricultural Science & Technology》 CAS 2014年第10期1687-1692,1713,共7页
ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of... ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment. 展开更多
关键词 lmproved s1 selection method Maize population Genetic gain Comparative analysis
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跨媒介叙事视域下V.S.奈保尔《抵达之谜》中的“如画”书写
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作者 刘须明 《外国语言文学》 2025年第4期74-83,135,共11页
“如画”书写具有明显的跨媒介叙事特征。“如画”书写在文本中创造出栩栩如生的画面来激发读者的想象力,以获得一种特别的审美体验。“如画”强调人的视觉行为,折射人对自然的认识和对如画景观中人的思考。奈保尔的《抵达之谜》以一种... “如画”书写具有明显的跨媒介叙事特征。“如画”书写在文本中创造出栩栩如生的画面来激发读者的想象力,以获得一种特别的审美体验。“如画”强调人的视觉行为,折射人对自然的认识和对如画景观中人的思考。奈保尔的《抵达之谜》以一种近距离的“凝视”方式,对英国南部乡村景观进行如画式书写,用冷静和客观的笔触,揭橥英帝国殖民主义的衰亡本质。如画景观与人物内心的情感互动、与殖民身份以及社会变迁紧密关联,形成了奈保尔式的如画书写特征。 展开更多
关键词 如画书写 跨媒介叙事:v.s.奈保尔 《抵达之谜》
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基于改进YOLOv8s的花色布疵点检测算法 被引量:1
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作者 王跃坤 徐洋 +2 位作者 余智祺 解国升 盛晓伟 《棉纺织技术》 2025年第2期41-48,共8页
针对花色布背景图案复杂、部分疵点目标小、与背景分离难度大,及其带来的自动化实时检测挑战等问题,提出一种基于改进YOLOv8s的花色布疵点检测算法。为增强网络检测疵点小目标的能力,引入BiFPN(Bi⁃directional Feature Pyramid)特征融... 针对花色布背景图案复杂、部分疵点目标小、与背景分离难度大,及其带来的自动化实时检测挑战等问题,提出一种基于改进YOLOv8s的花色布疵点检测算法。为增强网络检测疵点小目标的能力,引入BiFPN(Bi⁃directional Feature Pyramid)特征融合网络,充分融合语义信息和位置信息,增强算法区分疵点和背景的能力;同时,注意到疵点小目标中低质量样本对检测结果的影响,引入WIoU v3损失函数,抑制训练过程中低质量样本产生的有害梯度;最后,引入FasterBlock模型改进原始模型neck中的C2f模块,降低模型整体的参数量。结果表明:改进后的YOLOv8s模型在整个数据集的mAP@0.5∶0.95上可达59.6%,比原YOLOv8s模型提高了2.8个百分点;小目标的APs@0.5∶0.95可达45.1%,比原YOLOv8s模型提高了8.3个百分点;改进后模型参数量为10.557 M,检测速度可达131.6帧/s。认为:改进的YOLOv8s有效提升了沾污、花毛等小目标的检测效果。 展开更多
关键词 花色布 疵点检测 YOLOv8s BiFPN FasterBlock WIoU v3损失函数
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基于改进YOLO v5s的水下小目标检测算法 被引量:1
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作者 梁衡 刘儒一 +1 位作者 张典 宋廷强 《青岛科技大学学报(自然科学版)》 2025年第2期122-131,共10页
针对目前水下图像存在图像模糊以及小目标聚集导致水下小目标识别精度低的情况,提出一种基于改进YOLO v5s的水下小目标检测算法。在主干特征提取网络中嵌入卷积注意力模块,强化小目标信息,提高网络模型的特征提取能力。设计了一种改进... 针对目前水下图像存在图像模糊以及小目标聚集导致水下小目标识别精度低的情况,提出一种基于改进YOLO v5s的水下小目标检测算法。在主干特征提取网络中嵌入卷积注意力模块,强化小目标信息,提高网络模型的特征提取能力。设计了一种改进的C3模块C3Swin,在原始C3模块中加入Swin Transformer结构,在不同滑动窗口间进行信息交互,增强了全局信息的提取能力。对原始YOLO v5s的检测层进行重构,增加小目标检测层,提升小目标的检测精度。改进损失函数,使用α-iou对原损失函数进行优化,提升预测框的回归精度。实验结果表明,在URPC水下目标检测数据集中,本工作提出的算法平均精度均值(mAP)为86.9%,相较于原模型提升了2.9%,检测速度为62.7 Hz,优于主流算法,在保证检测速度的同时提升了检测精度。 展开更多
关键词 水下小目标检测 YOLO v5s 卷积注意力模块 swin Transformer α-iou
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肥胖非酒精性脂肪肝病儿童肠道菌群16S rRNA基因高变区V3~V4和V4测序结果比较
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作者 黄智航 韦佳 +7 位作者 罗家有 潘雄峰 韦彩连 周阳 肖淑娟 徐宁安 钟燕 罗米扬 《中南大学学报(医学版)》 北大核心 2025年第12期2312-2324,共13页
目的:16S rRNA基因测序是研究样本微生物结构的重要方法,然而,对同一样本选择不同高变区进行测序是否会对结果产生影响尚不清楚。本研究旨在比较肥胖非酒精性脂肪肝病(non-alcoholic fatty liver disease,NAFLD)儿童16S rRNA基因高变区V... 目的:16S rRNA基因测序是研究样本微生物结构的重要方法,然而,对同一样本选择不同高变区进行测序是否会对结果产生影响尚不清楚。本研究旨在比较肥胖非酒精性脂肪肝病(non-alcoholic fatty liver disease,NAFLD)儿童16S rRNA基因高变区V3~V4和V4测序结果的差异,为科学评估肥胖NAFLD儿童肠道菌群检测结果提供依据。方法:选择2020年1月至2021年9月在湖南省儿童医院就诊的肥胖NAFLD儿童和单纯肥胖儿童作为研究对象,采集粪便标本,提取样本总DNA,分别对肠道菌群V3~V4区和V4区进行PCR扩增后测序,比较2个高变区扩增后α和β多样性及菌群结构差异。选择7例样本进行宏基因组测序,以此作为金标准评价V3~V4区和V4区测序的优劣。结果:共纳入145例研究对象,其中92例为病例组,53例为对照组。V3~V4区测序获得的操作分类单元(operational taxonomic units,OTUs)数目(16977)高于V4区测序(3362)。α多样性分析结果显示,总人群V3~V4区Shannon指数(5.49±1.11)与Chao 1指数(1843.04±580.78)均高于V4区Shannon指数(4.98±0.65)与Chao 1指数(379.59±47.27)(均P<0.001)。β多样性分析结果显示,V3~V4区和V4区获得的菌群结构整体存在差异,且组间差异大于组内差异(P<0.05)。Welch’s t检验结果显示,总人群V3~V4区和V4区测序在门、纲、目、科、属各水平检出的差异性菌群数目分别为2、9、35、33、72;病例组V3~V4区和V4区测序在各水平的差异性菌群数目分别为1、9、32、35、66;对照组V3~V4区和V4区测序在各水平的差异性菌群数目分别为0、7、27、21、0。线性判别分析效应大小(linear discriminant analysis effect size,LEfSe)分析结果显示,V3~V4区测序共发现29种菌群在病例组与对照组之间存在差异,V4区测序共发现7种菌群在病例组与对照组之间存在差异(均P<0.01)。敏感性分析显示,V3~V4区测序(5.41±1.62)与宏基因组测序(6.39±0.42)的Shannon指数的差异无统计学意义(P=0.169)、V3~V4区测序(1889.92±781.73)的Chao 1指数小于宏基因组测序(3092.71±505.89),差异有统计学意义(P<0.01)。V4区测序的Shannon指数和Chao 1指数均小于宏基因组测序,差异有统计学意义(分别4.89±0.94 vs 6.39±0.42,362.41±35.22 vs 3092.71±505.89,均P<0.01)。结论:16S rRNA基因的V3~V4区和V4区测序对研究肥胖儿童肠道菌群结构的结果有影响,V3~V4区更可能发现病例组与对照组之间的差异菌群,且对α多样性有更为准确的估计,可作为NAFLD儿童肠道菌群测序优先考虑的区域,但目前对16S rRNA基因测序V区的选择并无统一标准,要根据研究目的和样本特征综合选择检测区域和方法。 展开更多
关键词 肥胖儿童非酒精性脂肪肝病 肠道菌群 16s rRNA基因测序 v3~v4区 v4区 宏基因组测序
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Effect of synthesis methods on activity of V2O5/CeO2/WO3-TiO2 catalyst for selective catalytic reduction of NOx with NH3 被引量:17
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作者 沈美庆 徐丽丽 +4 位作者 王建强 李晨旭 王务林 王军 翟燕萍 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第3期259-267,共9页
The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction(SCR) of NO_x by NH_3. V/Ce/WTi-DP(deposition precipitation) catalyst showed excellent NH... The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction(SCR) of NO_x by NH_3. V/Ce/WTi-DP(deposition precipitation) catalyst showed excellent NH_3-SCR performance, especially the better medium-temperature activity and the less N_2O formation than V/Ce/WTi-IMP(impregnation). These catalysts were characterized by X-ray diffraction(XRD), Brumauer-Emmett-Teller(BET), X-ray photoelectron spectroscopy(XPS), temperature-programmed reduction(H_2-TPR), and in situ DRIFTS techniques. The XPS and H_2-TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of Oα and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method(DP) contributed to a greater amount of weakly adsorbed NO_2, monodentate nitrate and NH_3 species with better reactive activity. Meanwhile, the cis-N_2O_2^(2-) species, an intermediate for N_2O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N_2 selectivity for V/Ce/WTi-DP. 展开更多
关键词 v/WTi Ce-modified synthesis method Ce species NH3-sCR rare earths
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