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The co-effect of image resolution and crown size on deep learning for individual tree detection and delineation

International Journal of Digital Earth 2023年第1期16卷 3753-3771页

作者： Zhenbang Hao Lili Lin Christopher J.Post Elena A.Mikhailova Kunyong Yu Huirong Fang Jian Liu Zhangzhou Institute of technology ZhangzhouPeople’s Republic of China College of Biological Science and Biotechnology Minnan Normal UniversityZhangzhouPeople’s Republic of China Department of Forestry and Environmental Conservation Clemson UniversityClemsonSCUSA university key Lab for geomatics technology and optimized resources utilization in fujian province FuzhouPeople’s Republic of China

Individual tree detection and delineation(ITDD)is an important subject in forestry and urban forestry.This study represents the first research to propose the concept of crown resolution to comprehensively evaluate the co-effect of image resolution and crown size on deep learning.Six images with different resolutions were derived from a DJI Unmanned Aerial Vehicle(UAV),and 1344 manually delineated Chinese fir(Cunninghamia lanceolata(Lamb)Hook)tree crowns were used for six training and validation mask region-based convolutional neural network(Mask R-CNN)models,while additional 476 delineated tree crowns were reserved for testing.The overall detection accuracy,the influence of different crown sizes,and crown resolutions were calculated to evaluate model performance accuracy with different image resolutions for ITDD.Results show that the highest accuracy was achieved when the crown resolution was between 800 and 12800 pixels/tree.The accuracy of ITDD was impacted by crown resolution,and it was unable to effectively identify Chinese fir when the crown resolution was less than 25 pixels/tree or higher than 12800 pixels/tree.The study highlights crown resolution as a critical factor affecting ITDD and suggests selecting the appropriate resolution based on the target detected crown size.

关键词： Mask R-CNN instance segmentation UAV image resolution crown-like characteristics

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Z型电荷分离介导的0D/2D AgVO_(3)/TiO_(2)异质结用于增强光催化CO_(2)还原

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Science China Materials 2024年第6期67卷 1820-1829页

作者：王鋙葶蒋娟姚楠左淦丞朱文磊郭秀云鲜啟鸣 State key laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Jiangsu Engineering Lab of Water and Soil Eco-Remediation School of EnvironmentNanjing Normal UniversityNanjing 210023China key laboratory of Chinese Cuisine Intangible Cultural Heritage technology Inheritance School of Tourism and CuisineYangzhou UniversityYangzhou 225127China

合理利用Z型电荷调节机制是提高光催化CO_(2)还原效率的有效策略.在本工作中,通过将AgVO_(3)量子点(QDs)原位锚定在TiO_(2)纳米片(NSs)上,从而构建了0D/2D AgVO_(3)/TiO_(2)直接Z型异质结光催化剂.TiO_(2)NSs抑制了AgVO_(3)量子点自身... 详细信息

合理利用Z型电荷调节机制是提高光催化CO_(2)还原效率的有效策略.在本工作中,通过将AgVO_(3)量子点(QDs)原位锚定在TiO_(2)纳米片(NSs)上,从而构建了0D/2D AgVO_(3)/TiO_(2)直接Z型异质结光催化剂.TiO_(2)NSs抑制了AgVO_(3)量子点自身的团聚,从而优化了体系的形貌结构.AgVO_(3)QDs增强了复合材料的光吸收能力,从而提高了对太阳光的利用效率.同时,两种单体之间匹配的能带结构和合适的内部界面电场(即(-)AgVO_(3)/(+)TiO_(2))促进了直接Z型异质结的构建,从而显著促进了光生电子-空穴对的分离,并保持了体系中最高的氧化还原电位.优化后的AgVO_(3)/TiO_(2)复合材料在没有任何助催化剂的情况下,表现出具有竞争力的光催化CO_(2)还原效率(CO,47.61μmol h-1g-1),是原始TiO_(2)NSs的20.97倍.本工作提出了一种直接Z型异质结的合理设计方法,为高效光催化CO_(2)还原催化剂的开发提供了指导.

关键词： photocatalytic CO_(2)reduction direct Z-scheme het-erojunction internal interfacial electric field TiO2 nanosheets AgVO_(3)quantum dots

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Developing a USLE cover and management factor(C)for forested regions of southern China

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Frontiers of Earth Science 2020年第3期14卷 660-672页

作者： Conghui Li Lili Lin Zhenbang Hao Christopher J.Post Zhanghao Chen Jian Liu Kunyong Yu fujian Agriculture and Forestry university Fuzhou350002China university key laboratory for geomatics technology and optimized resources utilization in fujian province Fuzhou350002China Department of Forestry and Environmental Conservation Clemson UniversityClemsonSC29634USA

The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion.This study tested a novel method to determine the cover and management factor(C)of this model by coupling the leaf area index(LAI)and soil basal respiration(SBR)to more accurately estimate a soil erosion map for a typical region with red soil in Hetian,fujian province,China.The spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field(R^2=0.66).The spatial distribution of the SBR was obtained using the Carnegie-Ames-Stanford Approach model and verified by soil respiration field observations(R^2=0.51).Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation,respectively.Finally,the C-factor was reconstructed using the proposed forest vegetation structure factor(Cs),which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall erosion.The feasibility of this new method was thoroughly verified using runoff plots(R2=0.55).The results demonstrated that Cs may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.

关键词： leaf area index remote sensing soil basal respiration forest vegetation structure factor vegetation layer structure

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A new framework for GEOBIA: accurate individual plant extraction and detection using high-resolution RGB data from UAVs

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International Journal of Digital Earth 2023年第1期16卷 2599-2622页

作者： Kaile Yang Zhangxi Ye Huan Liu Xiaoyu Su Chenhui Yu Houxi Zhang Riwen Lai College of Forestry Fujian Agriculture and Forestry UniversityFuzhou350028People’s Republic of China university key Lab for geomatics technology and optimized resources utilization in fujian province No.15 Shangxiadian RoadFuzhou350002FujianPeople’s Republic of China key laboratory of State Forestry and Grassland Administration on Soil and Water Conservation of Red Soil Region in Southern China Fuzhou350002People’s Republic of China Cross-Strait Collaborative Innovation Center of Soil and Water Conservation Fuzhou350002People’s Republic of China National Positioning Observation and Research Station of Red Soil Hill Ecosystem in Changting Fuzhou350002People’s Republic of China

Citrus(Citrus reticulata),which is an important economic crop worldwide,is often managed in a labor-intensive and inefficient manner in developing countries,thereby necessitating more rapid and accurate alternatives tofield surveys for improved crop management.In this study,we propose a novel method for individual tree segmentation from unmanned aerial vehicle remote sensing(RS)using a combination of geographic object-based image analysis(GEOBIA)and layer-adaptive Euclidean distance transformation-based watershed segmentation(LAEDT-WS).First,we use a GEOBIA support vector machine classifier that is optimized for features and parameters to identify the boundaries of citrus tree canopies accurately by generating mask images.Thereafter,our LAEDT workflow separates connected canopies and facilitates the accurate segmentation of individual canopies using WS.Our method exhibited an F1-score improvement of 10.75%compared to the traditional WS method based on the canopy height model.Furthermore,it achieved 0.01%and 1.38%higher F1-scores than the state-of-the-art deep learning detection networks YOLOX and YOLACT,respectively,on the test plot.Our method can be extended to detect larger-scale or more complex structured crops or economic plants by introducing morefinely detailed and transferable RS images,such as high-resolution or LiDAR-derived images,to improve the mask base map.

关键词： Crop management unmanned aerial vehicle remote sensing watershed segmentation geographic object-based image analysis

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Spatial variability of soil organic carbon and total nitrogen in the hilly red soil region of Southern China

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Journal of Forestry Research 2020年第6期31卷 2385-2394页

作者： Xiong Yao Kunyong Yu Yangbo Deng Jian Liu Zhuangjie Lai College of Forestry Fujian Agriculture and Forestry UniversityFuzhou 350002China university key Lab for geomatics technology and Optimize resources utilization in fujian province Fuzhou 350002China

To obtain accurate spatial distribution maps of soil organic carbon(SOC)and total nitrogen(TN)in the Hetian Town in fujian province,China,soil samples from three depths(0–20,20–40,and 40–60 cm)at 59 sampling sites were sampled by using traditional analysis and geostatistical approach.The SOC and TN ranged from 2.26 to 47.54 g kg-1,and from 0.28 to 2.71 g kg-1,respectively.The coefficient of variation for SOC and TN was moderate at 49.02–55.87%for all depths.According to the nuggetto-sill ratio values,a moderate spatial dependence of SOC content and a strong spatial dependence of TN content were found in different soil depths,demonstrating that SOC content was affected by both extrinsic and intrinsic factors while TN content was mainly influenced by intrinsic factors.Indices of cross-validation,such as mean error,mean standardized error,were close to zero,indicating that ordinary kriging interpolation is a reliable method to predict the spatial distribution of SOC and TN in different soil depths.Interpolation using ordinary kriging indicated the spatial pattern of SOC and TN were characterized by higher in the periphery and lower in the middle.To improve the accuracy of spatial interpolation for soil properties,it is necessary and important to incorporate a probabilistic and machine learning methods in the future study.

关键词： SOC TN Spatial variability Geostatistics Red soil

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Decreasing the error in the measurement of the ecosystem effective leaf area index of a Pinus massoniana forest

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Journal of Forestry Research 2019年第4期30卷 1459-1470页

作者： Zhanghao Chen Kunyong Yu Jian Liu Fan Wang Yi Zhong Forestry College Fujian Agriculture and Forestry UniversityFuzhou 350000People's Republic of China university key Lab for geomatics technology and Optimize resources utilization in fujian province Fuzhou 350000People's Republic of China

Decreasing the forest ecosystem leaf-area index error(LAIe)helps accurately estimate the growth and light energy utilization of aboveground foliage.Analyzing light transmission in forest ecosystems can effectively determine LAIe.The LAI-2200 plant canopy analyzer(PCA)is used extensively for rapid field-effective LAI(LAIe)measurements and primarily to measure forest canopy LAIe values.However,sometimes this parameter must also be measured in forests with small clearings.In this study,we used the LAI-2200 PCA to obtain one A-value and four B-values each for the canopy,herbaceous layer,and forest ecosystem LAIe.Field measurements showed that the three LAIe types were obviously different.In certain quadrats,the average herbaceous layer(Dicranopteris dichotoma Bernh.)LAIe apparently exceeded that of the Pinus massoniana forest ecosystem.The sources of this error were measuring and recording A-value readings for small canopies and underestimating the ecosystem LAIe.We obtained similar coefficients of determination for both the pre-recomputation and post-recomputation of the canopy and forest ecosystem LAIe(R^2C 0.96 and R^2C 0.99,respectively);thus,the error was decreased.Measuring field LAIe with the LAI-2200 PCA and recomputation should compensate for LAIe underestimation in complex forest ecosystems.

关键词： LAI-2200 PCA Field LAIe measurement error Error reduction Pinus massoniana forest

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A high-tortuosity holey graphene in-situ derived from cytomembrane/cytoderm boosts ultrastable potassium storage

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Journal of Materials Science & technology 2023年第8期139卷 69-78页

作者： Jun Xiao Xin Min Yue Lin Qiyao Yu Wei Wang Xiaowen Wu Yangai Liu Zhaohui Huang Minghao Fang Beijing key laboratory of Materials utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences(Beijing)Beijing100083China CAS key laboratory of Design and Assembly of Functional Nanostructures and State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China university of Chinese Academy of Sciences Beijing100049China State key laboratory of Explosion Science and technology School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing100081China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

The sluggish K^(+)kinetics and structural instability of the generally-used graphite and other carbon-based materials hinder the development of potassium-ion batteries(PIBs)for high-rate capability and long-term cycling.Herein,inspired by the unique flake structure and chemical composition of cytomembrane and cytoderm,we design high-tortuosity holey graphene as a highly efficient anode for PIBs.The flake cytomembrane and cytoderm shrink into wrinkled morphology during drying and sintering and then convert into high-tortuosity graphene after oxidative exfoliating and thermal reducing process.Mean-while,the proteins,sugars,and glycolipids embedded in cytomembrane and cytoderm can in-situ form nanoholes with highly abundant oxygenic groups and heteroatoms around,which can be easily removed and finally the high-tortuosity holey graphene is obtained after a thermal reducing process.The stress distribution after K^(+)intercalation confirms the optimized release of strain caused by the volume change through the finite element method.Benefiting from the unique nanoholes shortening the ion-diffusion length,the synergy of wrinkled and holey structure stabilizing volume fluctuation,and the enhanced electronic conductivity and specific surface area,the high-tortuosity holey graphene demonstrates high reversible capacities of 410 mAh g^(-1)at 25 mA g^(-1)after 150 cycles and retains 91.5%at 2 A g^(-1)after 2500 cycles.

关键词： Potassium-ion batteries Graphene High tortuosity Cytomembrane and cytoderm Anode

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Retrieving chlorophyll content and equivalent water thickness of Moso bamboo(Phyllostachys pubescens) forests under Pantana phyllostachysae Chao-induced stress from Sentinel-2A/B images in a multiple LUTs-based PROSAIL framework

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Forest Ecosystems 2023年第2期10卷 252-267页

作者： Zhanghua Xu Anqi He Yiwei Zhang Zhenbang Hao Yifan Li Songyang Xiang Bin Li Lingyan Chen Hui Yu Wanling Shen Xuying Huang Xiaoyu Guo Zenglu Li College of Environment and Safety Engineering Academy of Geography and Ecological EnvironmentFuzhou UniversityFuzhou350108China fujian Provincial key laboratory of resources and Environment Monitoring&Sustainable Management and utilization Sanming365004China key laboratory of Spatial Data Mining&Information Sharing Ministry of EducationThe Academy of Digital ChinaFuzhou UniversityFuzhou350108China College of Forestry Fujian Agriculture and Forestry UniversityFuzhou350002China International Institute for Earth System Science Nanjing UniversityNanjing210023China

Biochemical components of Moso bamboo(Phyllostachys pubescens)are critical to physiological and ecological processes and play an important role in the material and energy cycles of the ecosystem.The coupled PROSPECT with SAIL(PROSAIL)radiative transfer model is widely used for vegetation biochemical component content inversion.However,the presence of leaf-eating pests,such as Pantana phyllostachysae Chao(PPC),weakens the performance of the model for estimating biochemical components of Moso bamboo and thus must be considered.Therefore,this study considered pest-induced stress signals associated with Sentinel-2A/B images and field data and established multiple sets of biochemical canopy reflectance look-up tables(LUTs)based on the PROSAIL framework by setting different parameter ranges according to infestation levels.Quantitative inversions of leaf area index(LAI),leaf chlorophyll content(LCC),and leaf equivalent water thickness(LEWT)were derived.The scale conversions from LCC to canopy chlorophyll content(CCC)and LEWT to canopy equivalent water thickness(CEWT)were calculated.The results showed that LAI,CCC,and CEWT were inversely related with PPC-induced stress.When applying multiple LUTs,the p-values were<0.01;the R2 values for LAI,CCC,and CEWT were 0.71,0.68,and 0.65 with root mean square error(RMSE)(normalized RMSE,NRMSE)values of 0.38(0.16),17.56μg cm-2(0.20),and 0.02 cm(0.51),respectively.Compared to the values obtained for the traditional PROSAIL model,for October,R2 values increased by 0.05 and 0.10 and NRMSE decreased by 0.09 and 0.02 for CCC and CEWT,respectively and RMSE decreased by 0.35μg cm-2 for CCC.The feasibility of the inverse strategy for integrating pest-induced stress factors into the PROSAIL model,while establishing multiple LUTs under different pest-induced damage levels,was successfully demonstrated and can potentially enhance future vegetation parameter inversion and monitoring of bamboo forest health and ecosystems.

关键词： Moso bamboo Chlorophyll content Equivalent water thickness PROSAIL model Multiple LUTs Pantana phyllostachysae Chao Sentinel-2A/B images

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Efficient homogenous catalysis of CO_(2) to generate cyclic carbonates by heterogenous and recyclable polypyrazoles

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Chinese Journal of Chemical Engineering 2022年第3期35卷 110-115页

作者： Zhen Lu Jie He Bogeng Guo Yulai Zhao Jingyu Cai Longqiang Xiao Linxi Hou Department of Materials-Oriented Chemical Engineering School of Chemical EngineeringFuzhou UniversityFuzhou 350116China Qingyuan Innovation laboratory Quanzhou 362801China fujian key laboratory of Advanced Manufacturing technology of Specialty Chemicals Fuzhou UniversityFuzhou 350116China

The cycloaddition between CO_(2)and epoxides to produce cyclic carbonate is an attractive and efficiency pathway for the utilization of CO_(2)as C1 source.The development of catalyst to mediate cycloaddition between CO_(2)and epoxides at low temperature and pressure is still a challenge.Herein,a series of polypyrazoles with glass transition temperature(T_(g))in the range of 42.3-52.5℃ were synthesized and served as catalyst to mediate the cycloaddition of CO_(2)and epoxides by the assistant of tetrabutylammonium bromide.The catalytic behaviors of polypyrazole on the model cycloaddition of CO_(2)to epichlorohydrin,including the reaction parameters optimization and versatility were investigated in detail,and excellent yield(99.9%)and selectivity(99%)were obtained under the optimized reaction conditions of70℃ and 1.0 MPa for 6.0 h.Noteworthily,the polypyrazole acts as homogeneous catalyst during reaction(higher than T_(g)).And under room temperature,polypyrazoles can be easily separated and recovered,which is a promising feature of a heterogeneous catalyst.Furthermore,the reaction mechanism was proposed.The DFT calculation suggested that the formation of hydrogen bond between pyrazole and epoxide greatly reduced the energy barrier,which play an important role in promoting CO_(2)cycloaddition.

关键词： Carbon dioxide CO_(2)conversion Cyclic carbonate Heterogeneous catalysis Polypyrazole

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Study on the Effect of Two-Step Saturated Steam Heat Treatment Process on the Properties of Reconstituted Bamboo

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Journal of Renewable Materials 2022年第12期10卷 3313-3334页

作者： Xin Han Zhichao Lou Chenglong Yuan Xinwu Wu Jie Liu Fujin Weng Yanjun Li Jiangsu Co-Innovaton Center of Eficient Processing and utilization of Forest resources Nanjing Forestry UniversityNanjingChina Zhejiang Academy of Forestry Sciences HangzhouChina key laboratory of National Forestry and Grassland Admini stration/Beijng for Bamboo&Rattan Science and technology BeiingChina College of Materials Science and Engineering Nanjing Forestry UniversityNanjingChina

With the aim of utilizing reconstituted bamboo as a carbon cycle oriented material,the improvement of physical and mechanical properties has been actively studied to solve using problems The saturated steam heat treatment process has been widely used in worldwide.With the development and exploration of this technology,two step satu-rated steam heat treatment process appears in some practical production,that is,affer a period of saturated steam heat treatment at a lower temperature,the bamboo bundles are taken out and seasoned for a period of time,and then put back into the heat tank again,and heated at a higher temperature for another period of time.During the two-step saturated steam heat treatment,the physical and mechanical properties of bamboo changed.However,the mechanism of two step saturated steam heat treatment has not been thoroughly discussed.For purpose that this paper all discuss and find out the mechanism of two step saturated steam heat treatment on the change of physical and mechanical properties of reconstituted bamboo.In this work,the one and two step saturated steam heat treat-ments were carried out according to the actual production parameters,and the physical and mechanical properties of the reconstituted bamboo board made of treated bamboo bundles were analyzed,including the color change,the thickness swelling(TS),modulus of elasticity(MOE),modulus of rupture(MOR)and shear strength.The results indicate that two-step saturated steam heat treatment is better than one step.Based on the detailed study of the chemical composition,crytalinity and micro morphologial characteristics of the heated bamboo bundles,it is further revealed that during two-step saturated steam heat treatment,oxygen air is added to the reaction system between the two heat treatment processes to further catalyze the oxidation of hemicellulose and enhance the crystal-linity of cellulose,so as to improve the properties of the final products.Our work has optimized the saturated steam heat treatment process which is widely used i

关键词： Modulus of elasticity modulus of rupture thickness swelling oxidation

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