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The influences of canopy temperature measuring on the derived crop water stress index
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作者 WANG Hongxi LI Fei +4 位作者 SHEN Hongtao LI Mengyu YIN Gongchao FANG Qin SHAO Liwei 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2024年第9期1503-1519,共17页
Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the... Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management. 展开更多
关键词 Canopy temperature Measuring time Measuring height and direction Crop water stress index
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Real-Time Monitoring Method for Cow Rumination Behavior Based on Edge Computing and Improved MobileNet v3
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作者 ZHANG Yu LI Xiangting +4 位作者 SUN Yalin XUE Aidi ZHANG Yi JIANG Hailong SHEN Weizheng 《智慧农业(中英文)》 CSCD 2024年第4期29-41,共13页
[Objective]Real-time monitoring of cow ruminant behavior is of paramount importance for promptly obtaining relevant information about cow health and predicting cow diseases.Currently,various strategies have been propo... [Objective]Real-time monitoring of cow ruminant behavior is of paramount importance for promptly obtaining relevant information about cow health and predicting cow diseases.Currently,various strategies have been proposed for monitoring cow ruminant behavior,including video surveillance,sound recognition,and sensor monitoring methods.How‐ever,the application of edge device gives rise to the issue of inadequate real-time performance.To reduce the volume of data transmission and cloud computing workload while achieving real-time monitoring of dairy cow rumination behavior,a real-time monitoring method was proposed for cow ruminant behavior based on edge computing.[Methods]Autono‐mously designed edge devices were utilized to collect and process six-axis acceleration signals from cows in real-time.Based on these six-axis data,two distinct strategies,federated edge intelligence and split edge intelligence,were investigat‐ed for the real-time recognition of cow ruminant behavior.Focused on the real-time recognition method for cow ruminant behavior leveraging federated edge intelligence,the CA-MobileNet v3 network was proposed by enhancing the MobileNet v3 network with a collaborative attention mechanism.Additionally,a federated edge intelligence model was designed uti‐lizing the CA-MobileNet v3 network and the FedAvg federated aggregation algorithm.In the study on split edge intelli‐gence,a split edge intelligence model named MobileNet-LSTM was designed by integrating the MobileNet v3 network with a fusion collaborative attention mechanism and the Bi-LSTM network.[Results and Discussions]Through compara‐tive experiments with MobileNet v3 and MobileNet-LSTM,the federated edge intelligence model based on CA-Mo‐bileNet v3 achieved an average Precision rate,Recall rate,F1-Score,Specificity,and Accuracy of 97.1%,97.9%,97.5%,98.3%,and 98.2%,respectively,yielding the best recognition performance.[Conclusions]It is provided a real-time and effective method for monitoring cow ruminant behavior,and the proposed federated edge intelligence model can be ap‐plied in practical settings. 展开更多
关键词 cow rumination behavior real-time monitoring edge computing improved MobileNet v3 edge intelligence model Bi-LSTM
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Seedling Stage Corn Line Detection Method Based on Improved YOLOv8
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作者 LI Hongbo TIAN Xin +5 位作者 RUAN Zhiwen LIU Shaowen REN Weiqi SU Zhongbin GAO Rui KONG Qingming 《智慧农业(中英文)》 CSCD 2024年第6期72-84,共13页
[Objective]Crop line extraction is critical for improving the efficiency of autonomous agricultural machines in the field.However,traditional detection methods struggle to maintain high accuracy and efficiency under c... [Objective]Crop line extraction is critical for improving the efficiency of autonomous agricultural machines in the field.However,traditional detection methods struggle to maintain high accuracy and efficiency under challenging conditions,such as strong light exposure and weed interference.The aims are to develop an effective crop line extraction method by combining YOLOv8-G,Affinity Propagation,and the Least Squares method to enhance detection accuracy and performance in complex field environments.[Methods]The proposed method employs machine vision techniques to address common field challenges.YOLOv8-G,an improved object detection algorithm that combines YOLOv8 and Ghost‐NetV2 for lightweight,high-speed performance,was used to detect the central points of crops.These points were then clustered using the Affinity Propagation algorithm,followed by the application of the Least Squares method to extract the crop lines.Comparative tests were conducted to evaluate multiple backbone networks within the YOLOv8 framework,and ablation studies were performed to validate the enhancements made in YOLOv8-G.[Results and Discussions]The performance of the proposed method was compared with classical object detection and clustering algorithms.The YOLOv8-G algorithm achieved average precision(AP)values of 98.22%,98.15%,and 97.32%for corn detection at 7,14,and 21 days after emergence,respectively.Additionally,the crop line extraction accuracy across all stages was 96.52%.These results demonstrate the model's ability to maintain high detection accuracy despite challenging conditions in the field.[Conclusions]The proposed crop line extraction method effectively addresses field challenges such as lighting and weed interference,enabling rapid and accurate crop identification.This approach supports the automatic navigation of agricultural machinery,offering significant improvements in the precision and efficiency of field operations. 展开更多
关键词 crop row detection YOLOv8-G BACKBONE affinity propagation least square method
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不同水平张杂谷对育成期坝上长尾鸡生长性能和血液抗氧化指标的影响 被引量:9
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作者 柳迪 赵国先 +5 位作者 马可为 郝艳霜 李树鹏 王琳 唐洁 张旭 《饲料工业》 北大核心 2018年第9期27-32,共6页
试验旨在研究饲粮中不同水平张家口杂交谷子(简称"张杂谷")对11~18周龄坝上长尾鸡生长性能和血液抗氧化指标的影响,为张杂谷的应用提供依据。试验选取11周龄坝上长尾鸡576只,随机分为6组,每组设4个重复,每重复24只鸡,Ⅰ~Ⅴ组... 试验旨在研究饲粮中不同水平张家口杂交谷子(简称"张杂谷")对11~18周龄坝上长尾鸡生长性能和血液抗氧化指标的影响,为张杂谷的应用提供依据。试验选取11周龄坝上长尾鸡576只,随机分为6组,每组设4个重复,每重复24只鸡,Ⅰ~Ⅴ组为试验组,分别饲喂5%、10%、15%、20%和25%的张杂谷饲粮,张杂谷替代部分玉米和麸皮(换算比例为1谷子=0.66玉米+0.34麸皮)配制的试验日粮。预试期7 d,正试期49 d。结果表明:(1)蛋鸡日粮中应用一定比例张杂谷对试验鸡日增重和料重比未产生显著影响,其中试验Ⅱ组(应用量10%)日增重数值最大,料重比数值最低,但与对照组差异均不显著(P>0.05);(2)饲粮中应用张杂谷对血清SOD、MDA、GSH-Px和CAT均有显著影响(P<0.05),随着张杂谷应用水平的增加,血液中SOD活力、GSH-Px活力和CAT活力呈现先增加后降低的趋势,MDA含量呈现先降低后增加的趋势,试验Ⅱ组和Ⅲ组显著优于其他组。综合以上测定指标,张杂谷能量饲料替代一定比例玉米和麸皮饲喂坝上长尾鸡可行,并有改善抗氧化功能的作用。在坝上长尾鸡饲粮中适宜水平为10%~15%。 展开更多
关键词 坝上长尾鸡 张杂谷 生长性能 血液抗氧化指标
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利用计算机分析电压互感器在实负载下的误差
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作者 胡晓光 欧阳斌 +2 位作者 林果 莉东 李明 《电测与仪表》 北大核心 1999年第5期14-17,20,共5页
电压互感器的计量误差(精度)是其在额定负载下所产生的误差,当负载变化时其误差随之变化。针对电压互感器在实负载下所产生的实际误差建立了数学模型,这样根据已知负载下的误差值,利用计算机对数学模型进行分析、计算,可准确地得... 电压互感器的计量误差(精度)是其在额定负载下所产生的误差,当负载变化时其误差随之变化。针对电压互感器在实负载下所产生的实际误差建立了数学模型,这样根据已知负载下的误差值,利用计算机对数学模型进行分析、计算,可准确地得到电压互感器在各实负载下的实际误差。 展开更多
关键词 计算机 电压互感器 误差分析 实负载
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基于改进遗传算法的农村配电网无功优化算法 被引量:4
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作者 王岩河 肖志刚 +1 位作者 陈丽 张曙光 《农业机械学报》 EI CAS CSCD 北大核心 2006年第6期148-150,147,共4页
为了保证农村配电网中的电压质量和电力系统的稳定性,解决以往无功优化算法中遗传算法计算时间过长的问题,提出了改进遗传算法与灵敏度相结合的无功优化算法及模型,在灵敏度分析的基础上确定初始种群,提高了初始种群的质量并避免了搜索... 为了保证农村配电网中的电压质量和电力系统的稳定性,解决以往无功优化算法中遗传算法计算时间过长的问题,提出了改进遗传算法与灵敏度相结合的无功优化算法及模型,在灵敏度分析的基础上确定初始种群,提高了初始种群的质量并避免了搜索的盲目性,运用改进的交叉和变异算子使得遗传操作得到改善。通过对算例的优化结果可以看出,改进后的无功优化算法优越,计算速度快,实用性强。 展开更多
关键词 电力系统 无功优化 灵敏度分析 遗传算法
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以人为本──物业管理永恒的主题 被引量:5
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作者 张旭 刁玉斌 梁学庆 《商业研究》 北大核心 2002年第3期149-151,共3页
物业管理行业近年来在我国取得了迅速发展,但同时也暴露出很多问题,"以人为本"对解决这些问题有非常重要的意义。物业管理公司在实践中应严格贯彻"以人为本"原则,实现物业管理行业持续健康发展。
关键词 以人为本 物业管理 中国
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阳极氧化与化学放氮气结合的一步法N掺杂TiO2纳米管的制备、表征及光催化活性 被引量:1
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作者 徐英操 尤宏 《功能材料》 EI CAS CSCD 北大核心 2015年第10期10110-10113,共4页
亚硝酸钠在酸性条件下可以与尿素发生反应生成氮气,在阳极氧化制备Ti O2纳米管的电解液中加入放出氮气反应需要的试剂,控制酸度连续放氮,实现了一步法N掺杂的Ti O2纳米管的新制备方法。并且通过SEM、EDS、XRD、XPS等表征手段对N掺杂和... 亚硝酸钠在酸性条件下可以与尿素发生反应生成氮气,在阳极氧化制备Ti O2纳米管的电解液中加入放出氮气反应需要的试剂,控制酸度连续放氮,实现了一步法N掺杂的Ti O2纳米管的新制备方法。并且通过SEM、EDS、XRD、XPS等表征手段对N掺杂和未掺杂的Ti O2纳米管的表面形貌和晶型结构及元素组成进行了对比分析,最后通过甲基橙的光催化降解来表征了N-Ti O2制备过程中盐酸浓度和亚硝酸钠浓度对光催化活性的影响。 展开更多
关键词 TiO2 N掺杂 光催化 纳米管 尿素
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不同措施对高寒旱地莜麦土壤水分和籽粒产量的影响 被引量:3
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作者 肖凯 王殿武 褚达华 《河北农业大学学报》 CAS CSCD 北大核心 1995年第S1期92-97,共6页
试验表明.在坡梁地生态类型区,不同耕作措施的产量以深耕最高.其次为免耕,浅耕最低,不同栽培措施如覆膜、秸秆覆盖和保水剂拌种+抗旱剂喷施均比对照具有明显的贮水、保墒和增产效果,其表现规律为覆膜优于秸秆,覆盖优于保水剂拌... 试验表明.在坡梁地生态类型区,不同耕作措施的产量以深耕最高.其次为免耕,浅耕最低,不同栽培措施如覆膜、秸秆覆盖和保水剂拌种+抗旱剂喷施均比对照具有明显的贮水、保墒和增产效果,其表现规律为覆膜优于秸秆,覆盖优于保水剂拌种+抗旱剂喷施;在滩地生态类型区,不同栽培措施以铺沙的贮水、保墒和增产效果最好,其次为秸秆覆盖处理和保水剂拌种+抗旱剂喷施处理,各措施亦均比对照显著增产.各处理可改善植物地上和地下的生育状况土壤水分状况. 展开更多
关键词 耕作栽培措施 土壤水分 植株生长发育 产量
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