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Carbon neutrality:Toward a sustainable future

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The Innovation 2021年第3期2卷 1-2页

作者： jing m.chen University of Toronto TorontoONCanada Fujian Normal University FuzhouFujianChina

Carbon neutrality refers to net-zero carbon dioxide(CO2)emissions attained by balancing the emission of CO2 with its removal so as to stop its increase in the atmosphere that causes global *** of February 2021,124 countries had pledged to achieve carbon neutrality by 2050 or *** is a remarkable development reached after the annual United Nations Conference of the Parties of 1995,in particular those of Kyoto(1997),Bonn(2001),Bali(2007),and Paris(2015),with progressively more concrete binding commitments to emission reduction by the parties(countries).

关键词： concrete neutral dioxide

Sensitivity of Estimated Total Canopy SIF Emission to Remotely Sensed LAI and BRDF Products

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Journal of Remote Sensing 2021年第1期2021卷 145-162页

作者： Zhaoying Zhang Yongguang Zhang jing m.chen Weimin Ju mirco migliavacca Tarek S.El-madany International Institute for Earth System Sciences Nanjing UniversityNanjingJiangsuChina Yuxiu Postdoctoral Institute Nanjing UniversityNanjingJiangsuChina Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural ResourcesSchool of Geography and Ocean ScienceNanjing UniversityNanjingJiangsuChina Huangshan Park Ecosystem Observation and Research Station Ministry of EducationChina Department of Geography and Planning University of TorontoTorontoOntarioCanada max Planck Institute for Biogeochemistry Department Biogeochemical Integration Germany

Remote sensing of solar-induced chlorophyll fluorescence(SIF)provides new possibilities to estimate terrestrial gross primary production(GPP).To mitigate the angular and canopy structural effects on original SIF observed by sensors(SIF_(obs)),it is recommended to derive total canopy SIF _(emission)(SIF_(total))of leaves within a canopy using canopy interception(i0)and reflectance of vegetation(R_(V)).However,the effects of the uncertainties in i_(0) and R_(V) on the estimation of SIFtotal have not been well ***,we evaluated such effects on the estimation of GPP using the Soil-Canopy-Observation of Photosynthesis and the Energy balance(SCOPE)*** SCOPE simulations showed that the R^(2) between GPP and SIF_(total) was clearly higher than that between GPP and SIFobs and the differences in R^(2)(ΔR^(2))tend to decrease with the increasing levels of uncertainties in i_(0) and *** resultantΔR^(2) decreased to zero when the uncertainty level in i0 and RV was~30%for red band SIF(RSIF,683 nm)and~20%for far-red band SIF(FRSIF,740 nm).In addition,as compared to the TROPOspheric monitoring Instrument(TROPOmI)SIFobs at both red and far-red bands,SIF_(total) derived using any combination of i_(0)(from mCD15,VNP15,and CGLS LAI products)and RV(from mCD34,mCD19,and VNP43 BRDF products)showed comparable improvements in estimating *** this study,we suggest a way to advance our understanding in the estimation of a more physiological relevant SIF datasets(SIF_(total))using current satellite products.

关键词： BRDF estimation SCOPE

modeling Long-term Forest Carbon Spatiotemporal Dynamics With Historical Climate and Recent Remote Sensing Data

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Science Foundation in China 2010年第1期18卷 30-56页

作者： jing m.chen International Institute of Earth System Science Nanjing University NanjingChina Department of Geography and Program in Planning University of Toronto Toronto M5S 3G3Canada

Forests have long life cycles of up to several hundred years and *** also have very different growth rates at different stages of their life *** the carbon cycle in forest ecosystems has long time scales,making it necessary to consider forest age in estimating the spatiotemporal dynamics of carbon sinks in *** focus of this article is to review methods for combining recent remote sensing data with historical climate data for estimating the forest carbon source and sink *** remote sensing provides useful data for the land surface in recent decades. The information derived from remote sensing data can be used for short-term forest growth estimation and for mapping forest stand age for longterm *** short-term forest growth estimation, remote sensing can provide forest structural parameters as inputs to process-based models,including big-leaf,two-leaf,and multi-layered models. These models use different strategies to upscale from leaf to canopy,and their reliability and suitability for remote sensing applications will be examined *** long-term forest carbon cycle estimation, the spatial distribution of the forest growth rate（net primary productivity,NPP） modeled using remote sensing data in recent years is a critical *** input can be combined with a forest age map to simulate the historical variation of NPP under the influence of climate and atmospheric changes. Another important component of the forest carbon cycle is heterotrophic respiration in the soil,which depends on the sizes of soil carbon pools as well as climate *** for estimating the soil carbon spatial distribution and its separation into pools are *** emphasis is placed on how to derive the soil carbon pools from NPP estimation in current years with consideration of forest carbon dynamics associated with stand age variation and climate and atmospheric *** role of disturbance in the forest carbon cycle an

关键词： forest carbon cycle forest age disturbance remote sensing NBP NPP NEP

A recent project shows that the microbial carbon pump is a primary mechanism driving ocean carbon uptake

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National Science Review 2018年第4期5卷 458-458页

作者： jing m.chen Louis Legendre Ronald Benner University of Toronto Laboratoire d'Oceéanographie de Villefranche Sorbonne UniversitéCNRS Department of Biological Sciences and marine Science Program University of South Carolina

The microbial carbon pump(mCP)contributes to ocean carbon sequestration by converting reactive organic matter into recalcitrant dissolved organic carbon(RDOC)that can remain in seawater for thousands of *** mCP is a potentially important ecosystem pathway operating in parallel with the well-known biological pump(BP),which turns atmospheric CO2 into particulate organic matter that sinks to deep waters and the

关键词： mCP A recent project shows that the microbial carbon pump is a primary mechanism driving ocean carbon uptake

A hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang Gao Xinyi Wang Xi chen Ben m.chen Department of mechanical and Automation Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unmanned aerial vehicles(UAVs)are emerging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long time to cover the entire *** using UAVs for inspections and repair works puts forward a requirement of improving time efficiency in large-scale and cluster *** paper presents a hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction to balance the workload and reduce the overall task completion *** proposed framework consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density map is developed to update global and local information for dynamic load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global map,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning method is used to minimize the total traveling cost of these viewpoints for obtaining a high-quality *** experiments are conducted in both a simulated and real environment to show the time efficiency,robustness,and effectiveness of the proposed ***,the whole system is implemented in real applications.

关键词： multi-UAV Coverage path planning Infrastructure inspection and reconstruction

China's current forest age structure will lead to weakened carbon sinks in the near future

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The Innovation 2023年第6期4卷 38-47页

作者： Rong Shang jing m.chen mingzhu Xu Xudong Lin Peng Li Guirui Yu Nianpeng He Li Xu Peng Gong Liangyun Liu Han Liu Wenzhe Jiao Key Laboratory for Humid Subtropical Eco-Geogr aphical Processes of the ministy of Education School of Geographical SciencesFujian Normal UniversityFuzhou 350117China Department of Geography and Planning University of TorontoTorontoOntario M5S 3G3Canada Key Laboratory of Ecosystem Network Observation and modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBejing 100101China Institute for Climate and Carbon Neutrality Department of Geography and Department of Earth SciencesUniversity of Hong KongHong Kong 999077China International Research Center of Big Data for Sustainable Development Goals Beijing 100094China Land Consolidation and Rehabilitation Center Ministry of Natural ResourcesBeijing 100035China Department of Civil and Environmental Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA

Forests are chiefly responsible for the terrestrial carbon sink that greatly re duces the buildup of CO_(2)concentrations in the atmosphere and alleviates climate *** predictions of terrestrial carbon sinks in the future have so far ignored the variation of forest carbon uptake with forest ***,we predict the role of China's current forest age in future carbon sink capacity by generating a high-resolution(30 m)forest age map in 2019 over China's landmass using satellite and forest inventory data and deriving forest growth curves using measurements of forest biomass and age in 3,121 *** China's forests currently have large proportions of young and middle-age stands,we project that China's forests will maintain high growth rates for about 15 ***,as the forests grow older,their net primary productivity will decline by 5.0%±1.4%in 2050,8.4%±1.6%in 2060,and 16.6%±2.8%in 2100,indicating weakened carbon sinks in the near *** weakening of forest carbon sinks can be potentially mitigated by optimizing forest age structure through selective logging and implementing new or improved *** finding is important not only for the global carbon cycle and climate projections but also for developing forest management strategies to enhance land sinks by alleviating the age effect.

关键词： forest carbon structure

Optimizing photosynthetic and respiratory parameters based on the seasonal variation pattern in regional net ecosystem productivity obtained from atmospheric inversion

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Science Bulletin 2015年第34期60卷 1954-1961页

作者： Zhuoqi chen jing m.chen Xiaogu Zheng Fei Jiang Jun Qin Shupeng Zhang Wenping Yuan Weiming Ju Gang mo College of Global Change and Earth System Science Beijing Normal University International Institute for Earth System Science Nanjing University Department of Geography and Program in Planning University of Toronto Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of Sciences

In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation of the net carbon flux. An optimization scheme is proposed to estimate two key parameters （V2max and Q10） by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate V25max and Q10 of the boreal ecosystem productivity simulator （BEPS） to improve its NEP simulation in the boreal North American region. Then, in situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations from BEPS with initial and optimized parameters. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results implicate that it is possible to optimize ecosystem model parameters by different sensitivities of V25max and Q10 during growing and non-growing seasons through atmospheric inversion or data assimilation techniques.

关键词： Parameter optimization Land surfacemodel CO2 concentration measurements - NEP

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帽儿山地区森林冠层叶面积指数的地面观测与遥感反演

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应用生态学报 2010年第8期21卷 2117-2124页

作者：朱高龙居为民 jing m.chen 范文义周艳莲李显风李明泽南京大学国际地球系统科学研究所南京210093 闽江学院地理科学系福州350108 Department of Geography University of Toronto Ontario M5S 3G3 Canada 东北林业大学林学院哈尔滨150040 南京大学地理与海洋科学学院南京210093

叶面积指数(leaf area index,LAI)是陆地生态系统最重要的结构参数之一,遥感和基于冠层孔隙率模型的光学仪器观测是快速获取LAI的有效方法,但由于植被叶片的聚集效应,这些方法通常只能获取有效叶面积指数(effectiveLAI,LAIe).本文以东... 详细信息

叶面积指数(leaf area index,LAI)是陆地生态系统最重要的结构参数之一,遥感和基于冠层孔隙率模型的光学仪器观测是快速获取LAI的有效方法,但由于植被叶片的聚集效应,这些方法通常只能获取有效叶面积指数(effectiveLAI,LAIe).本文以东北林业大学帽儿山实验林场为研究区,利用LAI2000观测森林冠层LAIe,并结合TRAC观测的叶片聚集度系数估算了森林冠层LAI,并通过分析基于Landsat5-Tm数据计算的不同植被指数与LAIe之间的关系,建立了该区森林LAI遥感估算模型.结果表明:研究区阔叶林的LAI和LAIe基本相当,而针叶林的LAI比LAIe大27%;减化比值植被指数(reduced simple ratio,RSR)与该区LAIe的相关性最好(R2=0.763,n=23),最适合该区LAI的遥感提取.当海拔m时,LAI随海拔高度的上升而快速增大;当海拔在400～750 m时,LAI随海拔高度的上升缓慢增大;当海拔>750 m时,LAI呈下降趋势.研究区森林冠层LAI与森林地上生物量存在显著的正相关关系.

关键词：叶面积指数叶片聚集度系数 LAI2000 TRAC

Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma

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High Power Laser Science and Engineering 2024年第3期12卷 62-68页

作者： L.R.Yin X.F.Li Y.J.Gu N.Cao Q.Kong m.Büscher S.m.Weng m.chen Z.m.Sheng Key Laboratory of Nuclear Physics and Ion-beam Application(moE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghaiChina State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina SANKEN(Institute of Scientific and Industrial Research) Osaka UniversityOsakaJapan Sichuan Research Institute Shanghai Jiao Tong UniversityChengduChina Peter Grünberg Institut(PGI-6) Forschungszentrum JülichJülichGermany Institut für Laser-und Plasmaphysik Heinrich-Heine-Universität DüsseldorfDüsseldorfGermany Key Laboratory for Laser Plasmas(moE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina

Polarized electron beam production via laser wakefield acceleration in pre-polarized plasma is investigated by particlein-cell *** evolution of the electron beam polarization is studied based on the Thomas±Bargmann±michel±Telegdi equation for the transverse and longitudinal self-injection,and the depolarization process is found to be influenced by the injection *** the case of transverse self-injection,as found typically in the bubble regime,the spin precession of the accelerated electrons is mainly influenced by the ***,in the case of longitudinal injection in the quasi-1D regime(for example,*** et al.,***.110,135002(2013)),the direction of electron spin oscillates in the laser *** the electrons move around the laser axis,the net influence of the laser field is nearly zero and the contribution of the wakefield can be ***,an ultra-short electron beam with polarization of 99%can be obtained using longitudinal self-injection.

关键词： laser wakefield acceleration longitudinal self-injection particle-in-cell simulation polarized electron beam