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美国大气光化学监测点位布设的经验和启示
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作者 崔虎雄 柴文轩 +1 位作者 赵月 张国涵 《中国环境监测》 CAS CSCD 北大核心 2024年第5期1-8,共8页
我国大气光化学污染问题仍然形势严峻,逐渐成为影响我国环境空气质量的重要因素之一。光化学监测点位的科学布设,有助于准确反映我国光化学污染状况,为研究光化学污染的形成机制、污染成因及控制策略提供技术支持。在总结美国光化学监... 我国大气光化学污染问题仍然形势严峻,逐渐成为影响我国环境空气质量的重要因素之一。光化学监测点位的科学布设,有助于准确反映我国光化学污染状况,为研究光化学污染的形成机制、污染成因及控制策略提供技术支持。在总结美国光化学监测点位布设技术方法步骤和要求、点位布设发展历程基础上,结合我国光化学监测点位布设现状,探讨了我国光化学监测点位布设存在的问题,并提出了若干关于我国光化学监测点位布设的建议。 展开更多
关键词 大气 光化学监测 点位布设
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美国光化学污染监测的经验与启示 被引量:12
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作者 师耀龙 柴文轩 +4 位作者 李成 滕曼 杨楠 楚宝临 付强 《中国环境监测》 CAS CSCD 北大核心 2017年第5期49-56,共8页
针对光化学污染的严峻形势,中国应尽快建立国家层面的光化学监测网络,完善光化学监测的技术体系与质量管理体系,为重点地区光化学污染防治工作提供监测数据支持。研究在总结美国光化学评估监测网络发展历程、运行及其监测目标、技术体... 针对光化学污染的严峻形势,中国应尽快建立国家层面的光化学监测网络,完善光化学监测的技术体系与质量管理体系,为重点地区光化学污染防治工作提供监测数据支持。研究在总结美国光化学评估监测网络发展历程、运行及其监测目标、技术体系和质量管理体系的基础上,提出了明确光化学监测目标、制定优先监测VOCs名单、完善光化学监测技术体系和质量管理体系、建立光化学监测数据共享平台以及开展VOCs源解析等建设中国光化学监测网络的具体建议。 展开更多
关键词 光化学监测 挥发性有机物 光化学评估监测网络
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Tomato detection method using domain adaptive learning for dense planting environments 被引量:1
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作者 LI Yang HOU Wenhui +4 位作者 YANG Huihuang RAO Yuan WANG Tan JIN Xiu ZHU Jun 《农业工程学报》 EI CAS CSCD 北大核心 2024年第13期134-145,共12页
This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy ... This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production environments.To overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target domain.To construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain discrepancy.Furthermore,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target domain.Additionally,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster module.The experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,respectively.The model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 G.After acceleration processing,the detection accuracy of the TDA-YOLO model on the Jetson Xavier NX development board is 90.95%,the mAP value is 91.35%,and the detection time of each image is 21 ms,which can still meet the requirements of real-time detection of tomatoes in dense planting environment.The experimental results show that the proposed TDA-YOLO model can accurately and quickly detect tomatoes in dense planting environment,and at the same time avoid the use of a large number of annotated data,which provides technical support for the development of automatic harvesting systems for tomatoes and other fruits. 展开更多
关键词 PLANTS MODELS domain adaptive tomato detection illumination variation semi-supervised learning dense planting environments
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