检索结果-南通市图书馆

Automatic segmentation of stem and leaf components and individual maize plants in field terrestrial LiDAR data using convolutional neural networks

引用

The Crop Journal 2022年第5期10卷 1239-1250页

作者： Zurui Ao Fangfang Wu Saihan Hu Ying Sun Yanjun Su Qinghua Guo qinchuan xin Guangdong Key Laboratory for Urbanization and Geo-simulation Sun Yat-sen UniversityGuangzhou 510275GuangdongChina State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Department of Ecology College of Urban and Environmental Scienceand Key Laboratory of Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

High-throughput maize phenotyping at both organ and plant levels plays a key role in molecular breeding for increasing crop yields. Although the rapid development of light detection and ranging(Li DAR) provides a new way to characterize three-dimensional(3 D) plant structure, there is a need to develop robust algorithms for extracting 3 D phenotypic traits from Li DAR data to assist in gene identification and selection. Accurate 3 D phenotyping in field environments remains challenging, owing to difficulties in segmentation of organs and individual plants in field terrestrial Li DAR data. We describe a two-stage method that combines both convolutional neural networks(CNNs) and morphological characteristics to segment stems and leaves of individual maize plants in field environments. It initially extracts stem points using the Point CNN model and obtains stem instances by fitting 3 D cylinders to the points. It then segments the field Li DAR point cloud into individual plants using local point densities and 3 D morphological structures of maize plants. The method was tested using 40 samples from field observations and showed high accuracy in the segmentation of both organs(F-score =0.8207) and plants(Fscore =0.9909). The effectiveness of terrestrial Li DAR for phenotyping at organ(including leaf area and stem position) and individual plant(including individual height and crown width) levels in field environments was evaluated. The accuracies of derived stem position(position error =0.0141 m), plant height(R^(2)>0.99), crown width(R^(2)>0.90), and leaf area(R^(2)>0.85) allow investigating plant structural and functional phenotypes in a high-throughput way. This CNN-based solution overcomes the major challenges in organ-level phenotypic trait extraction associated with the organ segmentation, and potentially contributes to studies of plant phenomics and precision agriculture.

关键词： Terrestrial LiDAR Phenotype Organ segmentation Convolutional neural networks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

FROM-GC: 30 m global cropland extent derived through multisource data integration

引用

International Journal of Digital Earth 2013年第6期6卷 521-533页

作者： Le Yu Jie Wang Nicholas Clinton qinchuan xin Liheng Zhong Yanlei Chen Peng Gong Ministry of Education Key Laboratory for Earth System Modeling Center for Earth System ScienceTsinghua UniversityBeijingChina State Key Laboratory of Remote Sensing Science Jointly Sponsored by Institute of Remote Sensing and Digital EarthChinese Academy of Sciencesand Beijing Normal UniversityBeijingChina Department of Environmental Science Policy and ManagementUniversity of CaliforniaBerkeleyCAUSA

We report on a global cropland extent product at 30-m spatial resolution developed with two 30-m global land cover maps(***-GLC,Finer Resolution Observation and Monitoring,Global Land Cover;FROM-GLC=agg)and a 250-m cropland probability map.A common land cover validation sample database was used to determine optimal thresholds of cropland probability in different parts of the world to generate a cropland/noncropland mask according to the classification accuracies for cropland samples.A decision tree was then applied to combine two 250-m cropland masks:one existing mask from the literature and the other produced in this study,with the 30-m global land cover map *** the smallest difference with country-level cropland area in Food and Agriculture Organization Corporate Statistical(FAOSTAT)database,a final global cropland extent map was composited from the FROM-GLC,FROM-GLC-agg,and two masked crop=land *** this map FROM-GC(Global Cropland),we estimated the global cropland areas to be 1533.83 million hectares(Mha)in 2010,which is 6.95 Mha(0.45%)less than the area reported by the Food and Agriculture Organization(FAO)of the United Nations for the year 2010.A country-by=country comparison between the map and the FAOSTAT data showed a linear relationship(FROM-GC=1.05*FAOSTAT-1.2(Mha)with R^(2)=0.97).Africa,South America,Southeastern Asia,and Oceania are the regions with large discrepancies with the FAO survey.

关键词： Landsat MODIS global mapping FROM-GLC FROM-GLC-agg

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Improving the quantification of waterfowl migration with remote sensing and bird tracking

引用

Science Bulletin 2015年第23期60卷 1984-1993页

作者： Yali Si qinchuan xin Herbert H.T.Prins Willem F.de Boer Peng Gong Ministry of Education Key Laboratory for Earth System Modeling Center for Earth System Science Tsinghua University Joint Center for Global Change Studies Resource Ecology Group Wageningen University

Accurately quantifying waterfowl migration patterns is pertinent to monitor ecosystem health and control bird-borne infectious diseases. In this review, we summarize the current understanding of the environmental mechanisms that drive waterfowl migration and then investigate the effect of intra- and inter-annual change in food supply and temperature(e.g., climate change) on their migration patterns. Recent advances in remote sensing and animal tracking techniques make it possible to monitor these environmental factors over a wide range of scales and record bird movements in detail. The synergy of these techniques will facilitate substantial progress in our understanding of the environmental drivers of bird migration. We identify prospects for future studies to test existing hypotheses and develop models integrating up-todate knowledge, high-resolution remote sensing data and high-accuracy bird tracking data. This will allow us to predict when waterfowl will be where, in response to shortand long-term global environmental change.

关键词： Waterfowl migration · Environmentaldrivers · Phenology · Stopover ·Remote sensing ·Bird tracking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and analyzing supply-demand relationships of water resources in xinjiang from a perspective of ecosystem services

引用

Journal of Arid Land 2022年第2期14卷 115-138页

作者： LI Feng LI Yaoming ZHOU Xuewen YIN Zun LIU Tie xin qinchuan State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510275China Geophysical Fluid Dynamics Laboratory Princeton UniversityPrincetonNew JerseyNJ 08542USA

Water shortage is one bottleneck that limits economic and social developments in arid and semi-arid *** the impacts of climate change and human disturbance intensify across time,uncertainties in both water resource supplies and demands increase in arid and semi-arid *** a typical arid region in China,xinjiang Uygur Autonomous Region,as an example,water yield depth(WYD)and water utilization depth(WUD)from 2002 to 2018 were simulated using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model and socioeconomic *** supply-demand relationships of water resources were analyzed using the ecosystem service indices including water supply-demand difference(WSDD)and water supply rate(WSR).The internal factors in changes of WYD and WUD were explored using the controlled variable *** results show that the supplydemand relationships of water resources in xinjiang were in a slight deficit,but the deficit was alleviated due to increased precipitation and decreased WUD of *** generally experienced an increasing trend,and significant increase mainly occurred in the oasis areas surrounding both the Junggar Basin and Tarim *** had a downward trend with a decline of 20.70%,especially in oasis *** resources in most areas of xinjiang were fully utilized and the utilization efficiency of water resources *** water yield module in the InVEST model was calibrated and validated using gauging station data in xinjiang,and the result shows that the use of satellite-based water storage data helped to decrease the bias error of the InVEST model by 0.69×10^(8)m^(3).This study analyzed water resource supplies and demands from a perspective of ecosystem services,which expanded the scope of the application of ecosystem services and increased the research perspective of water resource *** results could provide guidance for water resource management such as spatial allocation and structural optimization of water

关键词： ecosystem services water resources climate change human activities arid and semi-arid areas InVEST model xinjiang

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

结合像元级和目标级的高分辨率遥感影像建筑物变化检测

引用

测绘学报 2018年第1期47卷 102-112页

作者：张志强张新长辛秦川杨晓羚中山大学地理科学与规划学院广东广州510275 广东省城市化与地理环境空间模拟重点实验室广东广州510275 广州大学广东广州510006 广东省城乡规划设计研究院广东广州510290

快速、精准的建筑物变化检测对城市规划建设等业务管理具有重要意义。随着卫星遥感技术的快速发展,基于高分辨率遥感影像的建筑物变化检测得到了广泛关注。针对像元级建筑物变化检测方法往往精度不足而目标级建筑物变化检测方法过程烦... 详细信息

快速、精准的建筑物变化检测对城市规划建设等业务管理具有重要意义。随着卫星遥感技术的快速发展,基于高分辨率遥感影像的建筑物变化检测得到了广泛关注。针对像元级建筑物变化检测方法往往精度不足而目标级建筑物变化检测方法过程烦琐等问题,本文提出结合像元级和目标级的高分辨率遥感影像建筑物变化检测方法。首先综合高分辨率遥感影像的多维特征,利用随机森林分类器进行影像集分类,以获取像元级建筑物变化检测结果;然后对后时相遥感影像进行图像分割,获得影像对象;最后融合像元级建筑物变化检测结果和影像对象,识别变化的建筑物目标。利用双时相QuickBird高分辨率遥感影像进行建筑物变化检测试验,结果表明:本文提出的方法能够削弱光照、观测角度等环境差异对建筑物变化检测的影响,显著改善建筑物变化的检测精度。

关键词：建筑物变化检测信息融合随机森林影像分割高空间分辨率

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Automatic segmentation of stem and leaf components and individual maize plants in field terrestrial LiDAR data using convolutional neural networks

引用

The Crop Journal 2022年第5期

作者： Zurui Ao Fangfang Wu Saihan Hu Ying Sun Yanjun Su Qinghua Guo qinchuan xin

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

Efficient microwave absorption achieved through in situ construction of core-shell Co Fe_(2)O_(4)@mesoporous carbon hollow spheres

引用

International Journal of Minerals,Metallurgy and Materials 2023年第3期30卷 504-514页

作者： Lianggui Ren Yiqun Wang xin Zhang qinchuan He Guanglei Wu College of Materials and Chemistry&Chemical Engineering Chengdu University of TechnologyChengdu 610059China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

Cobalt ferrite(CoFe_(2)O_(4)),with good chemical stability and magnetic loss,can be used to prepare composites with a unique structure and high *** this study,CoFe_(2)O_(4)@mesoporous carbon hollow spheres(MCHS)with a core-shell structure were prepared by introducing CoFe_(2)O_(4)magnetic particles into hollow mesoporous carbon through a simple in situ ***,the microwave absorption performance of the CoFe_(2)O_(4)@MCHS composites was *** and dielectric losses can be effectively coordinated by constructing the porous structure and adjusting the ratio of MCHS and CoFe_(2)O_(4).Results show that the impedance matching and absorption properties of the Co Fe_(2)O_(4)@MCHS composites can be altered by tweaking the mass ratio of MCHS and CoFe_(2)O_(4).The minimum reflection loss of the Co Fe_(2)O_(4)@MCHS composites reaches-29.7 dB at 5.8 *** addition,the effective absorption bandwidth is 3.7 GHz,with the thickness being 2.5 *** boosted microwave absorption can be ascribed to the porous core-shell structure and introduction of magnetic *** coordination between the microporous morphology and the core-shell structure is conducive to improving the attenuation coefficient and achieving good impedance *** porous core-shell structure provides large solid-void and CoFe_(2)O_(4)-C interfaces to induce interfacial polarization and extend the electromagnetic waves’multiple scattering and ***,natural resonance,exchange resonance,and eddy current loss work together for the magnetic *** method provides a practical solution to prepare core-shell structure microwave absorbents.

关键词： porous core-shell structure microwave absorption interface polarization ferrite structure-controllable

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SiewertⅡ型食管胃结合部腺癌根治性切除全腹腔镜Overlap吻合与腹腔镜辅助端侧吻合的短期安全性比较:多中心回顾性队列研究

引用

中华胃肠外科杂志 2024年第1期27卷 47-53页

作者：周海鲲高晓鹏时飞宇王靖宇杨秦川李世森柳金强纪盼盼王伟东余鹏飞高瑞祺郭欣季刚卫江鹏空军军医大学第一附属医院胃肠外科西安710032 山西省运城市中心医院胃肠外科运城044000 西安交通大学第一附属医院普通外科西安710061

目的比较Siewert Ⅱ型食管胃结合部腺癌根治性切除后全腹腔镜Overlap吻合与腹腔镜辅助端侧吻合两种消化道重建方式的短期安全性。方法本研究采用回顾性队列研究的方法。其中空军军医大学第一附属医院2021年11月至2023年7月收治89例、西... 详细信息

目的比较Siewert Ⅱ型食管胃结合部腺癌根治性切除后全腹腔镜Overlap吻合与腹腔镜辅助端侧吻合两种消化道重建方式的短期安全性。方法本研究采用回顾性队列研究的方法。其中空军军医大学第一附属医院2021年11月至2023年7月收治89例、西安交通大学第一附属医院2020年12月至2021年6月期间收治36例和山西省运城市中心医院2021年9月至2022年11月期间收治14例, 共计139例行根治性手术切除的SiewertⅡ型食管胃结合部腺癌患者临床资料纳入分析。全组男性107例(77.0%), 女性32例(23.0%);年龄(62.5±9.3)岁。48例行全腹腔镜Overlap吻合(Overlap吻合组), 91例行腹腔镜辅助端侧吻合(端侧吻合组)。比较两组患者的临床资料、手术信息、病理结果、术后恢复情况及相关并发症发生情况。结果 Overlap吻合组与端侧吻合组患者的一般临床资料比较差异无统计学意义(均P>0.05), 两组具有可比性。Overlap吻合组与端侧吻合组的手术时间比较, 差异无统计学意义[(267.2±60.1)min比(262.8±70.6)min, t=0.370, P=0.712], 但Overlap吻合组的术中出血量更少[100(50, 100)ml比100(50, 175)ml, Z=2.776, P=0.005]。与端侧吻合组比较, Overlap吻合组可获得更长的肿瘤距离上切缘[(1.7±1.0)cm比(1.3±0.9)cm, t=2.487, P=0.014], 更长的肿瘤距离下切缘[(9.5±2.9)cm比(7.9±3.5)cm, t=2.667, P=0.009]。与端侧吻合组比较, Overlap吻合组患者术后首次下床活动时间更早[1.0(1.0, 2.0)d比2.0(1.0, 3.0)d, Z=3.117, P=0.002], 首次饮水时间更早[(4.7±2.6)d比(6.2±3.0)d, t=2.851, P=0.005], 首次进食时间更早[(6.0±2.7)d和(7.1±3.0)d, t=2.170, P=0.032], 差异均有统计学意义(均P0.05)。Overlap吻合组与端侧吻合组手术相关并发症的发生率分别为22.9%(11/48)和19.8%(18/91), 两组比较差异无统计学意义(χ^(2)=0.187, P=0.831);进一步比较并发症Clavien-Dindo分级, 差异也无统计学意义(Z=0.406, P=0.685)。结论全腹腔镜Overlap吻合和腹腔镜辅助端侧吻合均可用于SiewertⅡ型食管胃结合部腺癌的根治手术, 全腹腔镜Overlap吻合可获得更好的上切缘和下切缘, 更有利于术后恢复;但端侧吻合费用更低。

关键词：食管胃结合部肿瘤胃癌根治术腹腔镜食管空肠吻合术

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

歌曲《锦绣秦川》创作特点与演唱技巧分析

引用

交响（西安音乐学院学报） 2024年第1期43卷 125-129页

作者：王欣西安音乐学院陕西西安710061

歌曲《锦绣秦川》由徐思萱作词,赵季平作曲,是赵季平声乐作品中运用秦腔音乐元素进行创作的代表作品之一,具有较高的艺术价值。这首歌曲描绘了八百里秦川的壮丽宏伟,也表达了西北人民对自然、家乡和美好生活的热爱与赞美,从而被广为传... 详细信息

歌曲《锦绣秦川》由徐思萱作词,赵季平作曲,是赵季平声乐作品中运用秦腔音乐元素进行创作的代表作品之一,具有较高的艺术价值。这首歌曲描绘了八百里秦川的壮丽宏伟,也表达了西北人民对自然、家乡和美好生活的热爱与赞美,从而被广为传唱。在创作中,作曲家运用了大量的秦腔音乐元素,包括秦腔音乐的调式、板式及伴奏织体等。为了更好地突出陕西地域风格和表现演唱技巧,歌唱者在演唱时须融入陕西方言、秦腔演唱中的润腔,更要注重演唱过程中的情感表达等,如此才能更准确地演绎这首歌曲。

关键词：《锦绣秦川》创作特点演唱技巧秦腔元素

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

新型城镇化建设地理空间信息智能处理关键技术及应用

引用

建设科技 2021年第13期 92-95页

作者：张新长刘小平李朝奎邓敏吴志峰曹凯滨辛秦川孙颖黄健锋李乐林杨文涛石岩刘慧敏黄悦广州大学广州510006 中山大学广州510275 湖南科技大学湘潭411201 中南大学长沙410083 广州市增城区城乡规划与测绘地理信息研究院广州511300

本项目基于新型城镇化智能管理对地理空间信息智能处理技术的迫切需求,以信息感知→信息融合→知识发现→应用服务为主线,构建了现代城镇地理空间信息“感—融—知—用”完整的技术体系,为新型城镇化建设与精细管理提供了原创性的技术支... 详细信息

本项目基于新型城镇化智能管理对地理空间信息智能处理技术的迫切需求,以信息感知→信息融合→知识发现→应用服务为主线,构建了现代城镇地理空间信息“感—融—知—用”完整的技术体系,为新型城镇化建设与精细管理提供了原创性的技术支撑,推进了国土空间优化和城镇统一监管,从而创新了新型城镇智能化的管理模式。项目开发了空间数据库管理与更新系统、地理空间信息整合与快速更新软件平台等技术与平台,有效地提高了应用单位的数据质量和项目实施效率。开发了集成地理模拟和空间优化模块的FLUS模型提供给近200所国内外的高校使用,并应用于全国三十多座城市,为空间规划提供了技术支撑。

关键词：新型城镇化建设空间信息动态感知与数据高效获取空间信息融合与级联更新时空数据智能处理与知识发现空间信息可视化与辅助决策应用

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：