检索结果-南通市图书馆

Identification of banana fusarium wilt using supervised classification algorithms with UAV-based multi-spectral imagery

引用

International Journal of Agricultural and Biological Engineering 2020年第3期13卷 136-142,I0001页

作者： Huichun Ye Wenjiang huang shanyu huang Bei Cui Yingying Dong Anting Guo Yu Ren Yu Jin Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100094China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Earth Observation Hainan ProvinceSanya 572029China Chinese Academy of Agricultural Engineering Planning&Design Beijing 100125China University of Chinese Academy of Sciences Beijing 100049China School of Electronics and Information Engineering Anhui UniversityHefei 230601China

The disease of banana Fusarium wilt currently threatens banana production areas all over the *** and large-area monitoring of Fusarium wilt disease is very important for the disease treatment and crop planting *** objective of this study was to evaluate the performance of supervised classification algorithms such as support vector machine(SVM),random forest(RF),and artificial neural network(ANN)algorithms to identify locations that were infested or not infested with Fusarium *** unmanned aerial vehicle(UAV)equipped with a five-band multi-spectral sensor(blue,green,red,red-edge and near-infrared bands)was used to capture the multi-spectral imagery.A total of 139 ground sample-sites were surveyed to assess the occurrence of banana Fusarium *** results showed that the SVM,RF,and ANN algorithms exhibited good performance for identifying and mapping banana Fusarium wilt disease in UAV-based multi-spectral *** overall accuracies of the SVM,RF,and ANN were 91.4%,90.0%,and 91.1%,respectively for the pixel-based *** RF algorithm required significantly less training time than the SVM and ANN *** maps generated by the SVM,RF,and ANN algorithms showed the areas of occurrence of Fusarium wilt disease were in the range of 5.21-5.75 hm2,accounting for 36.3%-40.1%of the total planting area of bananas in the study *** results also showed that the inclusion of the red-edge band resulted in an increase in the overall accuracy of 2.9%-3.0%.A simulation of the resolutions of satellite-based imagery(i.e.,0.5 m,1 m,2 m,and 5 m resolutions)showed that imagery with a spatial resolution higher than 2 m resulted in good identification accuracy of Fusarium *** results of this study demonstrate that the RF classifier is well suited for the identification and mapping of banana Fusarium wilt disease from UAV-based remote sensing *** results provide guidance for disease treatment and crop planting adjustments.

关键词： banana fusarium wilt UAV-based multi-spectral remote sensing support vector machine artificial neural network random forest

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

A New Critical Nitrogen Dilution Curve for Rice Nitrogen Status Diagnosis in Northeast China

引用

Pedosphere 2018年第5期28卷 814-822页

作者： huang shanyu MIAO Yuxin CAO Qiang YAO Yinkun ZHAO Guangming YU Weifeng SHEN Jianning YU Kang Georg BARETH International Center for Agro-Informatics and Sustainable Development College of Resources and Environmental Sciences China Agricultural University Beijing 100193 (China) Institute of Geography University of Cologne K5ln 50923 (Germany) Precision Agriculture Center Department of Soil Water and Climate University of Minnesota St. Paul 55108 (USA) National Engineering and Technology Center for Information Agriculture Nanjing Agricultural University Nanjing 210095 (China) Qixing Farm Jiansanjiang Jiamusi 156399 (China)

In-season diagnosis of crop nitrogen(N) status is crucial for precision N management. Critical N(N_c) dilution curve and N nutrition index(NNI) have been proposed as effective methods to diagnose N status of different crops. The N_c dilution curves have been developed for indica rice in the tropical and temperate zones and japonica rice in the subtropical-temperate zone, but they have not been evaluated for short-season japonica rice in Northeast China. The objectives of this study were to evaluate the previously developed N_c dilution curves for rice in Northeast China and to develop a more suitable N_c dilution curve in this region. A total of17 N rate experiments were conducted in Sanjiang Plain, Heilongjiang Province in Northeast China from 2008 to 2013. The results indicated that none of the two previously developed N_c dilution curves was suitable to diagnose N status of the short-season japonica rice in Northeast China. A new N_c dilution curve was developed and can be described by the equation N_c = 27.7 W^(-0.34) if W ≥ 1 Mg dry matter(DM) ha^(-1) or N_c = 27.7 g kg^(-1) DM if W < 1 Mg DM ha^(-1), where W is the aboveground biomass. This new curve was lower than the previous curves. It was validated using a separate dataset, and it could discriminate non-N-limiting and N-limiting nutritional conditions. Additional studies are needed to further evaluate it for diagnosing N status of different rice cultivars in Northeast China and develop efficient non-destructive methods to estimate NNI for practical applications.

关键词： japonica rice nitrogen nutrition index nitrogen use efficiency plant nitrogen concentration precision nitrogen mana-gement

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

Generation and application of replication-competent Venus-expressing H5N1,H7N9,and H9N2 influenza A viruses

引用

Science Bulletin 2018年第3期63卷 176-186页

作者： guangwen wang jie zhang fandi kong qibing li jinliang wang shujie ma yuhui zhao libin liang junping li nan sun lizheng guan yuan zhou chenchen zhou shanyu huang zhigao bu li jiang hualan chen chengjun li State Key Laboratory of Veterinary Biotechnology Harbin Veterinary Research Institute Chinese Academy of Agricultural Sciences Harbin 150069 China

The generation and application of replication-competent influenza A virus （IAV） expressing a reporter gene represent a valuable tool to elucidate the mechanism of viral pathogenesis and establish new coun- termeasures to combat the threat of influenza. Here, replication-competent 1AVs with a neuraminidase （NA） segment harboring a fluorescent reporter protein, Venus, were generated in the background of H5N1, H7N9, and H9N2 influenza viruses, the three subtypes of viruses with imminent pandemic poten- tial. All three reporter viruses maintained virion morphology, replicated with similar or slightly reduced titers relative to their parental viruses, and stably expressed the fluorescent signal for at least two pas- sages in embryonated chicken eggs. As a proof of concept, we demonstrated that these reporter viruses, used in combination with a high-content imaging system, can serve as a convenient and rapid tool for the screening of antivirals and host factors involved in the virus life cycle. Moreover. the reporter viruses demonstrated similar growth properties and tissue tropism as their parental viruses in mice, among which the HTN9 NA-Venus virus could potentially be used in ex vivo studies to better understand H7N9 pathogenesis or to develop novel therapeutics.

关键词： Replication-competent Influenza A virus H5N1 H7N9 H9N2 Venus

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

HIF-1α promotes SARS-CoV-2 infection and aggravates inflammatory responses to COVID-19

引用

Signal Transduction and Targeted Therapy 2021年第9期6卷 2857-2869页

作者： Mingfu Tian Weiyong Liu Xiang Li Peiyi Zhao Muhammad Adnan Shereen Chengliang Zhu shanyu huang Siyu Liu Xiao Yu Miaomiao Yue Pan Pan Wenbiao Wang Yongkui Li Xulin Chen Kailang Wu Zhen Luo Qiwei Zhang Jianguo Wu The First Affiliated Hospital Jinan UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Virology Institute of Medical MicrobiologyJinan UniversityGuangzhouChina Department of Clinical Laboratory Tongji HospitalHuazhong University of Science and TechnologyWuhanChina Hubei Provincial Center for Disease Control and Prevention WuhanChina State Key Laboratory of Virology College of Life SciencesWuhan UniversityWuhanChina Department of Clinical Laboratory Renmin HospitalWuhan UniversityWuhanChina Foshan Institute of Medical Microbiology FoshanChina

Cytokine storm induced by Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2)is a major pathological feature of Coronavirus Disease 2019(COVID-19)and a crucial determinant in COVID-19 *** the mechanism underlying the SARS-CoV-2-induced cytokine storm is critical for COVID-19 ***,we identify that SARS-CoV-2 ORF3a and host hypoxia-inducible factor-1α(HIF-1α)play key roles in the virus infection and pro-inflammatory responses.

关键词： infection Acute inflammatory

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

土壤有机碳空间变异性对采样密度的响应研究

引用

农业机械学报 2014年第12期45卷 215-223页

作者：叶回春黄珊瑜张世文张立平黄元仿黄亚捷中国农业大学资源与环境学院北京100193 科隆大学地理学院科隆50923 安徽理工大学地球与环境学院淮南232001

以北京地区土壤有机碳(SOC)为目标变量,对比4种不同采样密度下SOC质量比空间变异的结构变化以及在不同采样密度下不同空间预测方法对SOC质量比空间预测不确定性方面的表现。结果表明,SOC质量比关于地形因子的趋势属于宏观趋势,以低采样... 详细信息

以北京地区土壤有机碳(SOC)为目标变量,对比4种不同采样密度下SOC质量比空间变异的结构变化以及在不同采样密度下不同空间预测方法对SOC质量比空间预测不确定性方面的表现。结果表明,SOC质量比关于地形因子的趋势属于宏观趋势,以低采样密度的趋势拟合效果最优;随着采样密度的增加,SOC质量比及其去趋势后残差的系统内部随机变异逐渐增强,结构变异逐渐减弱,变异函数的分布也越平稳,空间预测的不确定性也逐渐减小。另外,变异函数的变程可能也影响空间预测的不确定性;增加采样密度和引入地形因子辅助的回归克里格法均可以提高北京地区SOC质量比的预测精度;在预测精度不降低的情况下,引入地形因子辅助可以在一定程度上减少采样的数量。

关键词：土壤有机碳空间变异尺度效应采样密度北京

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

Knock-in of exogenous sequences based on CRISPR/Cas9 targeting autosomal genes and sex chromosomes in the diamondback moth,Plutella xylostella

引用

Journal of Integrative Agriculture 2024年第9期23卷 3089-3103页

作者： shanyu Li Guifang Lin Haoqi Wen Haiyan Lu Anyuan Yin Chanqin Zheng Feifei Li Qingxuan Qiao Lu Jiao Ling Lin Yi Yan Xiujuan Xiang huang Liao Huiting Feng Yussuf Mohamed Salum Minsheng You Wei Chen Weiyi He State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops/Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops/International Joint Research Laboratory of Ecological Pest Control Ministry of EducationInstitute of Applied EcologyFujian Agriculture and Forestry UniversityFuzhou 350002China Ganzhou Key Laboratory of Greenhouse Vegetable Gannan Normal UniversityGanzhou 341000China

Genetic pest control strategies based on precise sex separation and only releasing sterile males can be accomplished by site-specific genome *** the current study,we showed that the mutation of single-allele Pxfl(2)d can significantly impair the normal mating behavior and testis development in male adults of the notorious cruciferous insect pest Plutella xylostella,in addition to its known functions in the ovarian development in female adults and egg *** CRISPR/Cas9-based knock-in experiments revealed that site-specific integration of an exogenous green fluorescent protein(GFP)gene into autosomal Pxfl(2)d for labelling mutants could be ***,this gene is not a suitable target for GFP insertion to establish a genetically stable knock-in strain because of the severe decline in reproductive *** further screened for the W-chromosome-linked and Z-chromosome-linked regions to test the knock-in efficiency mediated by CRISPR/*** results verified that both types of chromosomes can be targeted for the site-specific insertion of exogenous *** ultimately obtained a homozygous knock-in strain with the integration of both Cas9 and cyan fluorescent protein(CFP)expression cassettes on a Z-linked region in ***,which can also be used for early sex *** injecting the sgRNA targeting Pxfl(2)d alone into the eggs laid by female adults of the Z-Cas9-CFP strain,the gene editing efficiency reached 29.73%,confirming the success of expressing a functional Cas9 *** together,we demonstrated the feasibility of the knock-in of an exogenous gene to different genomic regions in ***,while the establishment of a heritable strain required the positioning of appropriate *** study provides an important working basis and technical support for further developing genetic strategies for insect pest control.

关键词： cruciferous specialist fl(2)d CRISPR/Cas9 knock-in sex chromosome

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

我国英语教材中批判性思维培养的研究综述

引用

英语教师 2022年第3期22卷 8-16页

作者：吴煌黄善愉许懿华南师范大学广东广州510631

为掌握我国英语教材中批判性思维培养研究的现状、不足和发展趋势,以中国知网数据库中主题为“英语教材中批判性思维培养”的期刊论文为语料来源,对其理论视角、研究主题、方法及对象进行分析。得出以下结论,现状:明确理论视角的文献不... 详细信息

为掌握我国英语教材中批判性思维培养研究的现状、不足和发展趋势,以中国知网数据库中主题为“英语教材中批判性思维培养”的期刊论文为语料来源,对其理论视角、研究主题、方法及对象进行分析。得出以下结论,现状:明确理论视角的文献不足一半;批判性思维分析研究、编写研究较少;实证研究较少。不足:未深挖批判性思维的内涵;忽略以批判性思维培养为导向的语料选择与呈现,教材使用研究忽略对批判性思维技能、倾向的分析;忽略非高中、非阅读板块。发展趋势:在前沿理论指导下,更全面地强化对教材中批判性思维的实证研究。

关键词：英语教材批判性思维理论视角中国知网数据库主题词检索

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

武夷山茶馆建筑演变探析

引用

福建建筑 2019年第2期 29-33页

作者：黄姗雨李婷婷武夷学院土木建筑学院福建南平345300

武夷山茶文化氛围浓厚,品茶会友是人们的日常行为。因此,武夷山几乎所有的建筑都为饮茶考虑了空间,与茶相关的建筑遍布市区、景区和山村,茶馆成为武夷山常见的建筑物。武夷山茶馆自唐至今经历了建筑形式、装饰、材料、功能等诸多变化。... 详细信息

武夷山茶文化氛围浓厚,品茶会友是人们的日常行为。因此,武夷山几乎所有的建筑都为饮茶考虑了空间,与茶相关的建筑遍布市区、景区和山村,茶馆成为武夷山常见的建筑物。武夷山茶馆自唐至今经历了建筑形式、装饰、材料、功能等诸多变化。目前,武夷山茶馆建筑形态多样,分布广泛,建筑风格从追求高雅极致到寻常朴素家居,服务模式依赖于建筑功能。基此,为进一步助推武夷山茶建筑文化发展,文章探析了武夷山各类茶居的建筑、历史及其风格和服务功能等,并考量其发展趋势。

关键词：武夷山茶馆演变茶文化

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

基于Sentinel-1/2影像的水稻种植面积提取方法研究——以三江平原为例

引用

遥感技术与应用 2023年第1期38卷 78-89页

作者：乔树亭叶回春黄文江黄珊瑜刘荣豪郭安廷钱彬祥太原理工大学水利科学与工程学院山西太原030024 中国科学院空天信息创新研究院数字地球重点实验室北京100094 中国科学院空天信息研究院海南研究院海南省地球观测重点实验室海南三亚572029 中国科学院大学北京100094 农业农村部规划设计研究院北京100125

水稻是中国主要粮食作物之一,稻米产量关系到民生福祉。及时、准确地获取水稻种植面积信息及其空间分布状况对于区域农业发展规划和产量评估具有重要意义。针对水稻与其他农作物易混以及光学数据易受云雨天气影响等问题,以东北三江平原... 详细信息

水稻是中国主要粮食作物之一,稻米产量关系到民生福祉。及时、准确地获取水稻种植面积信息及其空间分布状况对于区域农业发展规划和产量评估具有重要意义。针对水稻与其他农作物易混以及光学数据易受云雨天气影响等问题,以东北三江平原为例,利用中高分辨率Sentinel-1微波数据、Sentinel-2光学数据,分别构建时序水体指数SDWI和植被指数NDVI组成水稻完整的物候生长曲线,分析水稻移栽期、分蘖期、抽穗期、成熟期4个重要生长时期不同的光谱差异,通过阈值分割和组合不同时期的数据,来实现水稻不同物候时期种植面积的提取,并与传统的基于单一光学数据的方法进行对比。研究结果表明:经过地表样本点的验证,所构建方法可以精确提取三江平原水稻几个关键生育期的种植面积并且优于单一使用光学数据的方法。同时利用单生育期影像例如移栽期影像提取水稻面积也可使总体精度达到87.08%,随着生育期数据的完整,总体精度也不断提高,其中基于全生育期的面积提取总体精度也高达91.88%,Kappa系数为0.834,可以满足实际应用需求。因此这种的多源数据结合的水稻种植面积提取方法能够准确、高效地提取三江平原水稻不同物候时期种植面积,为短期内的农情调查管理和区域农业可持续发展提供依据。

关键词：水稻面积提取物候特征 Sentinel-2 Sentinel-1 三江平原

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

Covert voice over internet protocol communications based on spatial model

引用

Science China(Technological Sciences) 2016年第1期59卷 117-127页

作者： huang YongFeng TANG shanyu Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Tsinghua National Laboratory for Information Science and Technology Tsinghua UniversityBeijing 100084China School of Computer Science China University of GeosciencesWuhan 430074China Department of Computing London Metropolitan UniversityLondon N7 8DBUnited Kingdom

This paper presents a new spatial steganography model for covert communications over voice over internet protocol(Vo IP), providing a solution to the issue of increasing the capacity of covert Vo IP channels without compromising the imperceptibility of the channels. Drawing from Orthogonal Modulation Theory in communications, the model introduced two concepts, orthogonal data hiding features and data hiding vectors, to covert Vo IP communications. By taking into account the variation characteristics of Vo IP audio streams in the time domain, a hiding vector negotiation mechanism was suggested to achieve dynamic self-adaptive steganography in media streams. Experimental results on Vo IP steganography show that the proposed steganographic method effectively depicted the spatial and temporal characteristics of Vo IP audio streams, and enhanced robustness against detection of steganalysis tools, thereby improving the security of covert Vo IP communications.

关键词： covert communication multimedia networking Vo IP data security

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：