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A survey on heavy metal concentrations in residential neighborhoods: The influence of secondary water supply systems

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Journal of Environmental Sciences 2022年第7期34卷 37-45页

作者： dong hu Jie Zeng Yue hu Xiali Fei Xinyan Xiao Mingbao Feng Xin Yu Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Freshwater Fishery Research Institute of Jiangsu Province Nanjing 210017China Xiamen Municipal Water Group.Ltd. Xiamen 361000China College of the Environment and Ecology Xiamen UniversityXiamen 361005China

Water quality deterioration often occurs in secondary water supply systems(SWSSs), and increased heavy metal concentrations can be a serious problem. In this survey, twelve residential neighborhoods were selected to investigate the influence of SWSSs on the seasonal changes in heavy metal concentrations from input water to tank and tap water. The concentrations of nine evaluated heavy metals in all groups of water samples were found to be far below the specified standard levels in China. The concentrations of Fe, Mn, and Zn increased significantly from the input water samples to the tank and tap water samples in spring and summer( p < 0.05), especially for the water samples that had been stagnant for a long time. Negative correlations were found between most of the heavy metals and residual chlorine(Fe, Cu, Zn, and As, r =-0.186 to-0.519, p < 0.05). In particular, a high negative correlation was observed between Fe and residual chlorine( r =-0.489 to-0.519, p < 0.01) in spring and summer. Fe and Mn displayed positive correlations with turbidity( r = 0.672 and 0.328, respectively;p < 0.05). In addition, Cr and As were found to be positively associated with some nutrients(NO, TN, and SO;r = 0.420-0.786, p < 0.01). The material of the storage tanks had little influence on the difference in heavy metal concentrations. Overall, this survey illustrated that SWSSs may pose a chronic threat to water quality and could provide useful information for practitioners.

关键词： Residential neighborhoods Secondary water supply systems Tank materials Water stagnation Residual chlorine Heavy metals

Fast-armored target detection based on multi-scale representation and guided anchor

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Defence Technology（防务技术） 2020年第4期16卷 922-932页

作者： Fan-jie Meng Xin-qing Wang Fa-ming Shao dong Wang Xiao-dong hu Department of Mechanical Engineering College of Field EngineeringArmy Engineering University of PLANanjing210007China

Focused on the task of fast and accurate armored target detection in ground battlefield,a detection method based on multi-scale representation network(MS-RN) and shape-fixed Guided Anchor(SF-GA)scheme is ***,considering the large-scale variation and camouflage of armored target,a new MS-RN integrating contextual information in battlefield environment is *** MS-RN extracts deep features from templates with different scales and strengthens the detection ability of small *** targets of different sizes are detected on different representation ***,aiming at the accuracy and real-time detection requirements,improved shape-fixed Guided Anchor is used on feature maps of different scales to recommend regions of interests(ROIs).Different from sliding or random anchor,the SF-GA can filter out 80% of the regions while still improving the recall.A special detection dataset for armored target,named Armored Target Dataset(ARTD),is constructed,based on which the comparable experiments with state-of-art detection methods are *** results show that the proposed method achieves outstanding performance in detection accuracy and efficiency,especially when small armored targets are involved.

关键词： red image RPN Fast-armored target detection based on multi-scale representation and guided anchor

基于改进YOLOv8卷积神经网络的蟹味菇检测方法

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农业工程 2024年第3期14卷 27-31页

作者：林宗缪马超胡冬上海市质量监督检验技术研究院上海201114 上海市农业科学院农业科技信息研究所上海201403

针对蟹味菇生产过程中更好地预估产量,对生长状态做到实时检测的问题,提出了一种基于改进YOLOv8卷积神经网络的蟹味菇识别检测方法。该方法参照PASCAL VOC数据集格式,构建了蟹味菇目标检测数据集,采用添加CBAM注意力机制对原算法进行改... 详细信息

针对蟹味菇生产过程中更好地预估产量,对生长状态做到实时检测的问题,提出了一种基于改进YOLOv8卷积神经网络的蟹味菇识别检测方法。该方法参照PASCAL VOC数据集格式,构建了蟹味菇目标检测数据集,采用添加CBAM注意力机制对原算法进行改进,并且与Faster R-CNN、SSD(single shot multibox detector)、原始YOLOv8等算法进行模型性能的试验对比。试验结果表明,改进的算法明显优于其他算法,其在测试集上的平均精度均值(mean average precision,mAP)和检测速度分别达到95%和91帧/s。此检测精度与检测时间满足蟹味菇的实时识别检测任务,为预估蟹味菇产量,提高生产管理水平提供了理论技术支持。

关键词： YOLOv8 卷积神经网络蟹味菇目标检测 CBAM

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基于模糊PID的丘陵山地灌溉控制系统设计

中国农村水利水电 2024年第2期 109-114页

作者：廖洪铠刘志达龚立胡栋彭何欢浙江农林大学光机电工程学院浙江杭州311300 农业农村部东南丘陵山地农业装备重点实验室(部省共建) 浙江杭州311300

针对传统丘陵山地农业灌溉通常采用人工控制电磁阀进行灌溉所出现的水资源浪费、人工成本高等问题,设计了一套基于模糊控制和PID控制的丘陵山地农作物自动灌溉控制系统,将PID控制的稳定性和模糊控制的适应性相结合来控制灌溉时长。通过S... 详细信息

针对传统丘陵山地农业灌溉通常采用人工控制电磁阀进行灌溉所出现的水资源浪费、人工成本高等问题,设计了一套基于模糊控制和PID控制的丘陵山地农作物自动灌溉控制系统,将PID控制的稳定性和模糊控制的适应性相结合来控制灌溉时长。通过Simulink搭建的丘陵山地灌溉系统,分别用常规PID和模糊PID来控制该系统进行仿真实验。结果表明:模糊PID控制下的系统相比于常规PID控制,超调量和调节时间都明显降低,具有更高的稳定性、适应性和调节性能,可以用于丘陵山地农业自动灌溉系统中。

关键词：丘陵山地自动灌溉模糊PID控制 MATLAB仿真

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Recent Advances and Perspectives in the Synthesis and Applications of Tetrahydrocarbazol-4-ones

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Chinese Journal of Chemistry 2020年第7期38卷 737-752页

作者： Muhammad Usman Xu-dong hu Wen-Bo Liu Sauvage Center for Molecular Sciences Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei 430072China

Tetrahydrocarbazol-4-one represents a prevalent framework of numerous natural products and *** review summaries the recent synthetic progresses of this core structure,including Fischer indoliation,oxidative and reductive coupling,a-arylative cyclization by means of transition-metal catalysis or under metal-free conditions,and other *** recently emerged enantioselective catalytic methods of tetrahydrocarba20l-4-ones are also *** mechanistic insights and applications of these strategies as a key step in the total(formal)synthesis of complex alkaloids are highlighted as well.

关键词： methods. oxidative catalysis

含腐蚀缺陷输气管道高频声致振动响应规律数值模拟

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油气储运 2024年第4期43卷 404-411页

作者：陈严飞刘宇胡东尹意何明畅江楠中国石油大学(北京)机械与储运工程学院·油气管道输送安全国家工程研究中心

【目的】气体通过减压装置时产生的高频声学能量会激发输气管道管壁的高阶模态,导致管道结构出现声致振动,可能引起焊接支架、三通及管道腐蚀缺陷等不连续点处在短时间内发生疲劳失效。【方法】通过计算噪声谱,将声功率级转换为声压级,... 详细信息

【目的】气体通过减压装置时产生的高频声学能量会激发输气管道管壁的高阶模态,导致管道结构出现声致振动,可能引起焊接支架、三通及管道腐蚀缺陷等不连续点处在短时间内发生疲劳失效。【方法】通过计算噪声谱,将声功率级转换为声压级,量化了声源强度的影响;构建了含腐蚀缺陷的输气管道声致振动有限元模型,并将声压施加于模型管壁,研究了无量纲腐蚀缺陷长度、宽度及深度对输气管道声致振动的影响,并与英国能源研究所(Energy Institute,EI)导则评估结果进行对比。【结果】在不同的无量纲腐蚀缺陷长度下,输气管道的应力响应呈现出驼峰状变化,即应力水平随无量纲缺陷长度的增大先增后减,但应力集中现象随无量纲缺陷长度的增大而减弱;随着无量纲缺陷宽度的增加,输气管道的分布趋于均匀;管道应力随着无量纲缺陷深度增大呈马鞍形变化,即输气管道的应力水平先降后升。【结论】腐蚀缺陷的存在显著影响输气管道的应力响应,尤其是腐蚀缺陷长度对管道应力影响最为显著,但当无量纲腐蚀缺陷深度增至0.6后,其对输气管道应力、振动模态的影响显著增大,今后应重点关注腐蚀缺陷深度对声致振动的影响。通过对含腐蚀缺陷输气管道声致振动响应的定量分析,既为解决管道强烈振动问题提供了理论支撑,也为输气管道设计、建设及运维提供了参考依据。(图10,表5,参19)

关键词：输气管道腐蚀缺陷声致振动疲劳失效高频激励能源研究所导则

华北平原地区HCFC-142b排放清单建立及环境影响分析

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中国环境科学 2024年第5期44卷 2847-2852页

作者：张大宇吴婧王彤刘泽华胡冬梅彭林华北电力大学环境科学与工程学院资源环境系统优化教育部重点实验室北京102206 北京交通大学环境学院智能交通绿色低碳技术教育部工程研究中心北京100044 北京交通大学交通能源与环境研究院北京100044

选择华北平原地区作为研究对象,采用排放因子法建立该区域2000~2060年HCFC-142b排放清单,探讨了其空间分布特征,并对不同行业开展了排放结果的敏感性分析.结果显示,该地区2000~2019年HCFC-142b累计排放量为34.0kt.其中,江苏、山东和河... 详细信息

选择华北平原地区作为研究对象,采用排放因子法建立该区域2000~2060年HCFC-142b排放清单,探讨了其空间分布特征,并对不同行业开展了排放结果的敏感性分析.结果显示,该地区2000~2019年HCFC-142b累计排放量为34.0kt.其中,江苏、山东和河南是排放量最大省份,累计排放量分别为595.1t、267.6t和***泡沫排放最大,其次是ICR行业,两个行业对排放结果最敏感的因子分别是初始排放因子和设备废弃率.排放预测显示,在《蒙特利尔议定书》管控下,该地区2020~2060年的累计减排潜力为151.9kt(9.9kt CFC-11-eq;350.9mt CO_(2)-eq).

关键词：臭氧类消耗全球变暖华北平原地区排放清单减排潜力

Determination of berberine in Phellodendron amurense from different sites of Changbai Mountain

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Journal of Forestry Research 2015年第1期26卷 201-207页

作者： Lin Ma Jun-qing Li Yuan-dong hu Key Laboratory for Silviculture and Conservation of Ministry of Education Forest CollegeBeijing Forestry University Landscape Architecture School Northeast Forestry University

Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in *** from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction（UPE）. And the quantity was measured by high performance liquid chromatography（HPLC）. First, the optimal HPLC conditions for berberine were identified with satisfactory precision（relative standard deviation, R SD／5.6 %）, good accuracy（relative error, R E／ 3.6 %） and good linear relation（R2= 0.9998） in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability（R SD= 3.28 %）, reproducibility（R SD= 4.72 %）,stability（R SD／ 1.27 %） and good recovery（99.54 %） for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of ***, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in *** varied significantly by site on Changbai Mountain.

关键词： Phellodendron amurense Berberine Changbai Mountain Altitudes Ultrahigh pressure extraction High performance liquid chromatography

Thermodynamic analysis and simulation for gas baffle entrance collimator of EAST-NBI system based on thermo-fluid coupled method

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Nuclear Science and Techniques 2018年第1期29卷 90-95页

作者： Ling Tao Chun-dong hu Yuan-Lai Xie Institute of Plasma Physics Chinese Academy of Sciences

The world's first full Experimental Advanced Superconducting Tokamak(EAST) is designed with the auxiliary heating method of neutral beam injection(NBI)system. Beam collimators are arranged on both sides of the beam channel for absorbing the divergence beam during the beam transmission process in the EAST-NBI *** gas baffle entrance collimator(GBEC) is a typical high-heat-flux component located at the entrance of gas baffle. An efficient and accurate analysis of its thermodynamic performance is of great significance to explore the working limit and to ensure safe operation of the system under a high-parameter steady-state condition. Based on the thermo-fluid coupled method, thermodynamic analysis and simulation of GBEC is performed to get the working states and corresponding operating limits at different beam extraction conditions. This study provides a theoretical guidance for the next step to achieve long pulse with highpower experimental operation and has an important reference to ensure the safe operation of the system.

关键词： Neutral beam injection High-heat-flux component Beam collimator Thermo-fluid coupled method Thermodynamic analysis