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基于Sentinel-2时序数据的广东省英德市茶园分类研究

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光谱学与光谱分析 2024年第4期44卷 1136-1143页

作者：陈盼盼任艳敏赵春江李存军刘玉北京市农林科学院信息技术研究中心北京100097

茶叶是一种高附加值的经济作物,是我国南方山区乡村振兴的主要抓手。由于毁林种茶等破坏行为,导致森林资源破坏并引发水土流失等生态环境问题。快速准确获取茶园的空间分布对于政府监管和茶叶产业的规划发展至关重要。由于研究区天气多... 详细信息

茶叶是一种高附加值的经济作物,是我国南方山区乡村振兴的主要抓手。由于毁林种茶等破坏行为,导致森林资源破坏并引发水土流失等生态环境问题。快速准确获取茶园的空间分布对于政府监管和茶叶产业的规划发展至关重要。由于研究区天气多阴雨,茶园分布较为分散,与森林等植被光谱较为接近等原因,导致基于卫星影像提取茶园挑战性较大。为了摸清英德市的茶园空间分布,系统分析了中高分辨率的多光谱Sentinel-2影像数据,结合多时序多特征信息在茶园提取中的应用潜力。以英德市全境为研究区,选用2019年—2021年的9期Sentinel-2影像数据,详细分析了茶树生长的物候特征,进一步探究了茶园和其他地类在多时序中的特征变化,采用Relief算法对所有特征进行重要性排序。根据特征排序结果,选取特征权重值加权90%的特征因子,即7个植被指数特征和2个纹理特征,通过不同的组合排序构建了9种茶园分类场景,采用RF算法对所有分类场景进行精度评价,选取最佳分类场景,进一步探讨了RF分类算法和SVM分类算法对茶园提取的可行性。结果表明:(1)在进行英德市茶园提取时,2月和10月是采用多时相构造茶园多特征的最佳组合,可能因2月茶树处于萌芽期长出部分嫩绿的新叶易于和森林植被区分且在10月前后由于茶园进行了修剪其特征也较明显,因此两时相特征融合易于区分茶园。(2)RF分类方法与SVM分类方法相比,后者的精度较高,其总体精度达到91.56%,Kappa系数为0.89,生产者精度和用户精度分别为80.22%和84.56%。该研究为快速高效获取英德市茶园空间分布信息提供了一种高效的方法,同时为政府在进行茶叶产业规划、管理提供了数据支持。

关键词：茶园 Sentinel-2 时序特征机器学习分类

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压缩剪切平面应变试样的应力状态响应

塑性工程学报 2024年第7期31卷 188-194页

作者：赵宁许镱巍赵小松白峭峰王琛赵春江太原科技大学机械工程学院山西太原030024 山西电子科技学院智能制造产业学院山西临汾041000

为模拟金属塑性变形过程中的压缩剪切应力状态的平面应变特征,构建了平面压缩剪切试样。通过数字图像相关(DIC)技术和有限元模拟表征变形区Y方向的应力状态分布特征及压缩断裂过程。DIC结果显示,在压缩实验过程中,变形区的应变场分布与... 详细信息

为模拟金属塑性变形过程中的压缩剪切应力状态的平面应变特征,构建了平面压缩剪切试样。通过数字图像相关(DIC)技术和有限元模拟表征变形区Y方向的应力状态分布特征及压缩断裂过程。DIC结果显示,在压缩实验过程中,变形区的应变场分布与有限元结果吻合良好,有限元结果可靠。有限元结果表明,通过改变试样的缺口倾角,可以定量控制应力三轴度的大小,并且主应变方向与缺口倾角方向一致。在变形区Y方向发生压缩剪切的平面应变,同时试样边缘位置相对于中心位置具有更低的Lode角参数,具有双向压缩加载特征,使得静水压力增大,应力三轴度进一步降低至-0.823。

关键词：应力状态平面应变压缩剪切数字图像相关

Relationship of 2 100-2 300 nm Spectral Characteristics of Wheat Canopy to Leaf Area Index and Leaf N as Affected by Leaf Water Content

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Pedosphere 2006年第3期16卷 333-338页

作者： zhao chun-jiang WANG Ji-Hua LIU Liang-Yun HUANG Wen-jiang ZHOU Qi-Fa National Engineering Research Center for Information Technology in Agriculture Beijing 100089 （China） The State Key Laboratory of Plant Physiology and Biochemistry College of Life Sciences Zhejiang University Hangzhou 310012 （China）

The effects of leaf water status in a wheat canopy on the accuracy of estimating leaf area index (LAI) and N were determined in this study using extracted spectral characteristics in the 2 000-2 300 nm region of the short wave infrared (SWI) band. A newly defined spectral index, relative adsorptive index in the 2000-2300 nm region (RAI2000-2300), which can be calculated by RAI2000-2300 = (R2224 - R2054) (R2224 + R2054)-1 with R being the reflectance at 2224 or 2054 nm, was utilized. This spectral index, RAI2000-2300, was significantly correlated (P < 0.01) with green LAI and leaf N concentration and proved to be potentially valuable for monitoring plant green LAI and leaf N at the field canopy scale. Moreover, plant LAI could be monitored more easily and more successfully than plant leaf N. The study also showed that leaf water had a strong masking effect on the 2 000-2 300 nm spectral characteristics and both the coefficient between RAI2000-2300 and green LAI and that between RAI2000-2300 and leaf N content decreased as leaf water content increased.

关键词： leaf area index nitrogen plant water status reflectance Triticum aestivum L.

Delineation and Scale Effect of Precision Agriculture Management Zones Using Yield Monitor Data Over Four Years

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Agricultural Sciences in China 2007年第2期6卷 180-188页

作者： LI Xiang PAN Yu-chun GE Zhong-qiang zhao chun-jiang National Engineering Research Center for Information Technology in Agriculture Beijing 100089 P.R. China Henan Information Industry Department Zhengzhou 450008 P.R.China Resource and Environment College Beijing Forestry University Beijing 100083 P.R.China

In this study, precision agriculture management zones were delineated using yield data over four years from the combine harvester equipped with yield monitor and DGPS receiver. Relative yields measured during each year were interpolated to 4 m2 grid size using ordinary kriging. The resultant interpolated yield maps were averaged across years to create a map of the mean relative yield, which was then used for cluster analysis. The mean yield map of post-classification was processed by applying majority filtering with window sizes that were equivalent to the grid sizes of 12, 20, 28, 36, 44, 52 and 60 m. The scale effect of management zones was evaluated using relative variance reduction, test of significant differences of the means of yield zones, spatial fragmentation, and spatial agreement. The results showed that the post-classification majority filtering （PCMF） eliminated lots of isolated cells or patches caused by random variation while preserving yield means, high variance reduction, general yield patterns, and high spatial agreement. The zoned result can be used as yield goal map for preplant or in-season fertilizer recommendation in precision agriculture.

关键词： precision agriculture management zone PCMF scale effect

Fatigue Damage Mechanism of Oil Film Bearing Sleeve

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Journal of Iron and Steel Research International 2007年第1期14卷 60-63,68页

作者： HUANG Qing-xue WANG Jian-mei MA Li-feng zhao chun-jiang School of Mechanical and Electrical Engineering Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China School of Mechanical Design and Automation Taiyuan University of Technology Taiyuan 030024 Shanxi China

With the rapid development of the steel industry, to keep pace with the current trend of high speed, continuous, and large-scale production that focuses on automation and high levels of efficiency, many state-owned steel companies are being equipped with oil film bearings. Through long-term on-spot inspection and research on the fatigue failure of oil film bearing, three segments of annulated fatigue breakage were found axially along the inner surface of the bearing sleeve. In order to elucidate the reason for the three-segment annulated damage under rolling load, numerical boundary element method was adopted to analyze the contact behaviors between the sleeve and rollneck. Failure mechanism was discussed in detail, the distributions of contact stress were analyzed, and the service lives of the sleeve for different positions on the inner surface were quantitatively described, which provided an effective means to decrease wear and adhesive damage of the sleeve and to increase the load capacity of oil film bearing and its service life as well.

关键词： oil film bearing fatigue failure analysis contact problem bearing life

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融合农村居民意图的健康知识推荐方法

计算机工程与设计 2024年第7期45卷 2142-2149页

作者：王馨悦吴华瑞陈雯柏韩笑朱华吉赵春江北京信息科技大学自动化学院北京市农林科学院信息技术研究中心国家农业信息化工程技术研究中心农业农村部数字乡村技术重点实验室

为提高农村居民健康认知水平，提出一种融合农村地区居民意图的健康知识推荐方法。考虑到村民对不同健康知识的偏好，建模用户层中村民与健康知识间的关系路径，捕获村民获取健康知识的潜在意图，利用图卷积与注意力机制传播聚合村民意... 详细信息

为提高农村居民健康认知水平，提出一种融合农村地区居民意图的健康知识推荐方法。考虑到村民对不同健康知识的偏好，建模用户层中村民与健康知识间的关系路径，捕获村民获取健康知识的潜在意图，利用图卷积与注意力机制传播聚合村民意图邻居节点信息，获得村民与健康知识的高阶邻域表示，通过双交叉聚合器将初始节点与邻域表示进行聚合，增强村民与健康知识的表示能力，实现村民健康知识精确推荐。基于农村健康知识数据集验证研究模型有效性，结果表明该模型在准确率、NDCG指标上均得到了一定程度的提高。

关键词：农村知识推荐注意力机制知识图谱嵌入传播健康知识神经网络

Heterogeneity Analysis of Cucumber Canopy in the Solar Greenhouse

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Journal of Integrative Agriculture 2014年第12期13卷 2645-2655页

作者： QIAN Ting-ting LU Sheng-lian zhao chun-jiang GUO Xin-yu WEN Wei-liang DU jian-jun Shanghai Jiao Tong University Beijing Research Center for Information Technology in Agriculture

Detailed analysis of canopy structural heterogeneity is an essential step in conducting parameters for a canopy structural model. This paper aims to analyze the structural heterogeneity of a cucumber （Cucumis sativus L.） canopy by means of analyzing leaf distribution in a greenhouse environment with natural sunlight and also to assess the effect of structural canopy heterogeneity on light interception and photosynthesis. Two experiments and four measurements were carried out in autumn 2011 and spring 2012. A static virtual three-dimensional （3D） canopy structure was reconstructed using a 3D digitizing method. The diurnal variation of photosynthesis rate was measured using CIRAS-2 photosynthesis system. The results showed that, leaf azimuth as tested with the Rayleigh-test was homogeneous at vine tip over stage but turned heterogeneous at fruit harvest stage. After eliminating the inlfuence of the environment on the azimuth using the von Mises-Fisher method, the angle between two successive leaves was 144°;at the same time, a rule for the azimuth distribution in the canopy was established, stating that the azimuth distribution in cucumber followed a law which was positive spin and anti-spin. Leaf elevation angle of south-oriented leaves was on average 13.8° higher than that of north-oriented leaves. The horizontal distribution of light interception and photosynthesis differed signiifcantly between differently oriented leaves. East-and west-oriented leaves exhibited the highest photosynthetic rate. In conclusion, detailed analysis of canopy structural heterogeneity in this study indicated that leaf azimuth and elevation angle were heterogeneous in cucumber canopy and they should be explicitly described as they have a great impact both on light distribution and photosynthesis.

关键词： heterogeneity inclination leaf azimuth light interception photosynthesis

Insight into the Role of Isolated Gold Atoms-Ceria Conjunction in Catalyzing the Water-Gas Shift Reaction

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Chinese Journal of Chemistry 2024年第6期42卷 636-644页

作者： Xin-Pu Fu Hui-zhao Wei-Wei Wang chun-jiang Jia Key Laboratory for Colloid and Interface Chemistry Key Laboratory of Special Aggregated MaterialsSchool of Chemistry and Chemical EngineeringShandong UniversityJinanShandong250100 China

As the promising catalysts for the water-gas shift(WGS)reaction,the activity of Au-CeO_(2) composites is susceptible to the aggregation size and electronic state of Au *** reports were extensively focused on the discrepancy between nonmetallic Au and metallic Au nanoparticles,whereas the understanding of the authentic role of the isolated Au atoms was ***,we investigated the catalytic behavior and structural information over two types of Au/CeO_(2) catalysts,in which the predominant conjunctions were isolated Au1-CeO_(2) and Aun-CeO_(2),*** on comprehensive characterizations,particularly by in-situ Raman and in-situ DRIFTS,we found that the isolated Au atoms were responsible for enhancing the reducibility of the CeO_(2) *** CO adsorption ability on the isolated Au sites was significantly inferior to clustered Au atoms,especially at relatively high temperatures(>200°C).As a result,the boosted O vacancy on the isolated Au1-CeO_(2) conjunctions could improve the H2O activation ability for the Au-CeO_(2) catalysts and demonstrate a comparable activity to the clustered Aun-CeO_(2) *** work might deepen understanding of the catalytic function for the isolated Au1 site within Au/CeO_(2) systems while catalyzing the WGS reaction.

关键词： Isolated Au atoms Ceria-based catalysts Water-gas shift reaction Defect Adsorption

Problem identification and revitalization strategies for the recovery and reconstruction of traditional villages in the Ms 6.8 Luding Earthquake

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Journal of Mountain Science 2024年第2期21卷 361-379页

作者： HUANG Chao QIU Jian LIU chun jiang Rui zhao Chuanrong ZHANG Yi School of Architecture and Research Center of Space Planning and Engineering Design Southwest Jiaotong UniversityChengdu 611756China Sichuan Provincial Rural Construction and Development Center Chengdu 610041China Sichuan Institute of Urban and Rural Construction Chengdu 610043China China Association for Promoting Democracy(CAPD)Sichuan Provincial Committee Chengdu 610016China Sichuan Provincial Architectural Design and Research Institute(SADI) Chengdu 610095China

Post-disaster reconstruction is a topic of global concern,and traditional villages have special heritage attributes and need to face more requirements and obstacles in post-disaster *** paper summarizes four concepts based on the research on post-disaster reconstruction both domestically and internationally,as well as the recovery and reconstruction of cultural *** a field survey of traditional villages in the Ms 6.8 Luding earthquake-stricken area,it is found that there are problems such as insufficient awareness of heritage value,misalignment of scientific reconstruction technology,and insufficient protection of reconstruction elements during the reconstruction *** villages face the risk of declining or even loss of heritage *** order to effectively protect traditional villages and inherit the carrier of regional culture,four targeted reconstruction response strategies are proposed,i.e.,to"establish special planning for traditional village preservation","emphasize recovery of the authenticity of village heritage","ensure elements for village heritage recovery"and"promote the activation and utilization of village heritage",based on the problems discovered during the survey and the four concepts summarized in the research on post-disaster reconstruction of traditional *** research results hope to provide useful reference for ancient cultural areas affected by earthquakes on how to protect cultural heritage during the post-disaster reconstruction process.

关键词： Seismic hazard Decision making Traditional village Cultural heritage protection Post-earthquake recovery and reconstruction Revitalization strategy