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Retrieving crop leaf area index by assimilation of MODIS data into a crop growth model

science china Earth sciences 2010年第5期53卷 721-730页

作者： wang dongwei1,2.3. wang jindi1,{2. {3. shunlin4.1 state key laboratory of Remote sensing science, jointly sponsored by {12. Normal {13. and institute of Remote sensing applications, cas, beijing 100875, china 2.School of Geography, {12. key laboratory of Environmental Remote sensing and Digital City, {12. Normal {13., beijing 100875, china 3.Haihe River Water Conservancy Commission, Tianjin 3.0170, china 4 Department of Geography, {13. of Maryland, College Park, MD 2.742. USA state key {2. of Remote {3. science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications CAS Beijing China School of Geography Beijing Key Laboratory of Environmental Remote Sensing and Digital City Beijing Normal University Beijing China Haihe River Water Conservancy Commission Tianjin China Department of Geography University of Maryland College Park USA

Leaf area index (LAI) is an important parameter in monitoring crop growth. One of the methods for retrieving LAI from remotely sensed observations is through inversion of canopy reflectance models. Many model inversion methods fail to account for variable LAI values at different crop growth stages. In this research, we use the crop growth model to describe the LAI changes with crop growth, and consider a priori LAI values at different crop growth stages as constraint information. The key approach of this research is to assimilate multiple canopy reflectance values observed at different growth stages and a priori LAI values into a coupled crop growth and radiative transfer model sequentially using a variational data assimilation algorithm. Adjoint method is used to minimize the cost function. Any other information source can be easily incorporated into the inversion cost function. The validation results show that the time series of MODIS canopy reflectance can greatly reduce the uncertainty of the inverted LAI values. Compared with MODIS LAI product at Changping and Shunyi Counties of beijing, this method has significantly improved the estimated LAI temporal profile.

关键词： inversion leaf area index crop growth model time series MODIS

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Application of ensemble kalman filter to geophysical parameters retrieval in remote sensing:A case study of kernel-driven BRDF model inversion

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science china Earth sciences 2006年第6期49卷 632-640页

作者： QIN Jun1, YAN Guangjian1, LIU Shaomin1, liang shunlin2. ZHANG Hao1, {2. {3. & LI Xiaowen1 1. state key laboratory of Remote sensing science, School of Geography and Remote sensing, Research Center for RS&GIS, beijing Normal university,{12.,{13. 2. Department of Geography, 2.81 Lefrak Hall, university of Maryland, College Park, MD2.742. USA state key {2. of Remote {3. science School of Geography and Remote Sensing Research Center for RS&GIS Beijing Normal University Beijing China Department of Geography 2181 Lefrak Hall University of Maryland College Park USA

The use of a priori knowledge in remote sensing inversion has great implications for ensuring the stability of inversion process and reducing uncertainties in retrieved results, especially under the condition of insufficient observations. Common optimization algorithms have difficulties in providing posterior distribution and thus cannot directly acquire uncertainties in inversion results, which is of no benefit to remote sensing application. In this article, ensemble Kalman filter (EnKF) has been introduced to retrieve surface geophysical parameters from remote sensing observations, which has the capability of not merely obtaining inversion results but also giving its posterior distribution. To show the advantage of EnKF, it is compared to standard MODIS AMBRALS algorithm and highly effi-cient global optimization method SCE-UA. The inversion abilities of kernel-driven BRDF models with different kernel combinations at several main cover types are emphatically discussed when observa-tions are deficient and a priori knowledge is introduced into inversion.

关键词： remote sensing inversion, a priori knowledge, posterior distribution, ensemble kalman filter, BRDF, kernel-driven model, albedo.

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High-resolution remote thermometry based on Bi^(3.)-doped 0D zinc halide hybrids

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science china Chemistry 2024年第8期67卷 2599-2605页

作者： Cui-Mi Shi Shu-Hua Xue Jin-Yun wang liang-Jin Xu Zhong-Ning Chen state key {2. of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian science Technology Innovation Laboratory for Optoelectronic Information of ChinaFuzhou 350108China university of Chinese Academy of sciences Beijing 100049China

Developing highly sensitive optical thermometers is of great significance due to their capability to enable remote and non-contact temperature measurements, rendering them highly applicable in diverse and harsh environments. Herein we report a temperature-dependent phosphor of 0D metal halide hybrid by incorporating Bi^(3.)into the(MePPh_(3.)_(2.ZnCl_(4) matrix. Through Bi^(3.)doping,the initially non-luminescent(MePPh_(3.)_(2. ZnCl_(4) matrix exhibits a deep-blue emission centered at 453.nm, with a photoluminescence quantum yield(PLQY) of 5.71% and a Stokes shift of 75 nm at room temperature. Experimental characterization demonstrates that exciton-like luminescence of Bi^(3.)is mainly responsible for the blue emission. Single crystals of Bi^(3.)-doped(MePPh_(3.)_(2.ZnCl_(4) show an unusual correlation between photoluminescence(PL) lifetime and temperature. Particularly, the dependence of luminescence lifetime on temperature is most remarkable in the temperature range of 80 to 100 K with an exceptional sensitivity up to 0.09 K^(-1), representing one of the best levels for thermometry based on PL decay lifetime. Our work not only provides a viable strategy for designing a novel, environmentally friendly, and stable blue emitter, but also paves the way for precise thermometric application at low temperature.

关键词： lead-free hybrids Bi^(3.)doping blue emission temperature sensing

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Bimetallic NiCoP catalysts anchored on phosphorus-doped lignin-based carbon for robust oxygen evolution performance

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Rare Metals 2024年第7期43卷 3084-3095页

作者： Ling-Ying-Zi Xiong Bo-Wen Liu Lei Du Yue-Kuan Zhou Xu-liang Lin Huan wang Guangdong Engineering Technology Research Center for sensing Materials&Devices Guangzhou Key Laboratory of Sensing Materials&DevicesSchool of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Guangdong Provincial laboratory of Chemistry and Fine Chemical Engineering Jieyang Center Jieyang 515200China Sustainable Energy and Environment Thrust Function HubThe Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Division of Emerging Interdisciplinary Areas Department of Mechanical and Aerospace EngineeringThe Hong Kong University of Science and TechnologyHong Kong 999077China state key Lab of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China

Oxygen evolution reaction(OER)catalysts are the key core materials that determine the performance of fuel cells,metal-air batteries,electrolytic water decomposition,and other *** this work,a green lignin-based non-precious metal OER catalyst was prepared by a simple ***,c arboxylated lignin was used to complex Ni and Co in situ,and then they were placed with sodium hypophosphite in the same tube furnace for upstream and downstream high-temperature calcination to construct a lignin carbon-based Ni-Co bimetallic OER catalyst(NiCoP@C).The synthesized catalyst is a porous bimetallic phosphide with a three-dimensional network structure and high-density electrochemical active ***@C exhibited favorable catalytic activity for the oxygen evolution reaction(OER)with overpotential of 2.0 mV at 10 mA·cm~(-2.and a Tafel slope of 77 mV·dec~(-1).Additionally,it exhibited remarkable durability during *** functional theory(DFT)calculations revealed that by leveraging the distinctive structure of transition metal phosphide nanoparticles incorporated into a reticulated substrate,the NiCoP@C catalyst offered an increased number of active sites for OER catalysis,significantly enhancing its stability during practical *** present study broadens the utilization pathways of biomass to"turn waste into treasure,"aligning the development concept of green sustainable development.

关键词： Oxygen evolution reaction Lignin Carbon-based catalyst Nickel-cobalt bimetal Metal phosphide

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Bioinspired Tactile Sensation Based on Synergistic Microcrack-Bristle Structure Design toward High Mechanical Sensitivity and Direction-Resolving Capability

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Research 2024年第1期2023卷 611-624页

作者： Yiqun Zhang Qi Liu Wenjuan Ren Yangyang Song Hua Luo Yangyang Han liang He Xiaodong Wu Zhuqing wang School of Mechanical Engineering Sichuan UniversityChengdu 610065China Med+X Center for Manufacturing West China HospitalSichuan UniversityChengdu 610041China state key {2. of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu 610065China

Natural tactile sensation is complex,which involves not only contact force intensity detection but also the perception of the force direction,the surface texture,and other mechanical ***,the vast majority of the developed tactile sensors can only detect the normal force,but usually cannot resolve shear force or even distinguish the directions of the ***,we present a new paradigm of bioinspired tactile sensors for resolving both the intensity and the directions of mechanical stimulations via synergistic microcrack-bristle structure design and cross-shaped configuration *** microcrack sensing structure gives high mechanical sensitivity to the tactile sensors,and the synergistic bristle structure further amplifies the sensitivity of the *** cross-shaped configuration engineering of the synergistic microcrack-bristle structure further endows the tactile sensors with good capability to detect and distinguish the directions of the applied mechanical *** as-fabricated tactile sensors exhibit a high sensitivity(2..76 N^(−1)),low detection limit(5.4 mN),desirable stability(over 2.500 cycles),and good capability to resolve both mechanical intensity and directional *** promising application scenarios,surface texture recognition and biomimetic path explorations are successfully demonstrated with these tactile *** newly proposed tactile sensation strategy and technology have great potential applications in ingenious tactile sensation and construction of various robotic and bionic prostheses with high operational dexterity.

关键词： crack sensation directions

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Multistimuli-Responsive Luminescent Porous Organic Polymers with Chiroptical Properties and Acid-Induced Degradation

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Chinese Journal of Chemistry 2024年第16期42卷 1886-1894页

作者： Youling He Dongyang Fan liang Zhang Dong wang Ting Han Rongrong Hu Ben Zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhenGuangdong 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhenGuangdong 518060China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong999077China state key {2. of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China Universityof TechnologyGuangzhouGuangdong 510640China School of science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhen(CUHK-Shenzhen)Guangdong 518172China

Porous organic polymers(POPs)have attracted great attention in past *** diverse functional POPs have been developed,multistimuli-responsive POPs with excellent aggregate-state luminescence together with good chiroptical properties have rarely been ***,two pairs of Salen-type enantiomeric PoPs with multistimuli-responsive luminescence and chiral features were designed and synthesized by facile polycondensation reactions between polyfunctional aggregation-induced emission luminogen(AlEgen)-containing salicylaldehyde derivatives and chiral *** Salen units in polymer backbones as tetradentate ligands,a series of POP-metal complexes were further *** obtained POPs and metal complexes show good porosity,high thermal stability,and obvious circular dichroism ***,benefiting from the coexistence of AlEgen and Salen units in polymer structures,these POPs exhibit excellent luminescence performance in aggregate states and tunable fluorescence behaviors in response to external stimuli of Zn^(2.)ion,mechanical forces,organic solvent,and *** to the dynamic feature of Schiff base C=N bonds,the present POPs can efficiently undergo hydrolysis reactions under strong acidic conditions to reproduce the AlEgencontaining monomers,and such an acid-induced degradation process can be directly visualized and dynamically monitored via fluorescence *** properties collectively make the POPs candidate materials for {2. in heterogeneous asymmetric catalysis,fluorescence {3.,biomedicine,etc.

关键词： Polymers Stimuli-responsive luminescence Porous polymers Chirality Aggregation-induced emission Fluorescence Schiff bases Degradation

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Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

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Phyton-International Journal of Experimental Botany 2024年第3期93卷 467-486页

作者： Xiaojie liang Wei An Yuekun Li Yajun wang Xiaoya Qin Yanhong Cui Shuchai Su state key {2. of Efficient Production of Forest Resources The College of ForestryBeijing Forestry UniversityBeijing100083China National Wolfberry Engineering Research Center Wolfberry Science Research InstituteNingxia Academy of Agriculture and Forestry SciencesYinchuan750002China

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signiﬁ-cantly enhance fruit yield and Goji berry industrial development in Ningxia,*** study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2.,and high(N3.levels in soil microbial community structure(bacterial and fungal)at 2.diverse soil depths(0-2.,2.-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2.*** the observed physicochemical parameters exhibited signiﬁcant improvement(p0.05)differences among three group treatments(N1,N2.and N3..Furthermore,the functional enrichment analysis demonstrated signiﬁcant(p2.,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal ***,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

关键词： Goji berry production Ningxia,china differential nitrogen supplementation rates 16S RNA gene and IT1&IT2.region sequencing soil physicochemical properties

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Optimizing magnetoelastic properties by machine learning and high-throughput micromagnetic simulation

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Rare Metals 2024年第5期43卷 2251-2262页

作者： Jian-Hu Gong Zheng-Ming Zhang Cheng-liang Zhang Peng-Qiang Hu Chao Zhou Dun-Hui wang Sen Yang Division of Microelectronic Materials and Devices Hangzhou Dianzi UniversityHangzhou 310018China School of Physics MOEKey Laboratory forNonequilibrium Synthesis and Modulation of Condensed Matter and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an 710049China National laboratory of Solid state Microstructures Nanjing UniversityNanjing210093China

Magnetoelastic couplings in giant magnetostrictive materials(GMMs)attract significant interests due to their extensive applications in the fields of spintronics and energy harvesting *** the role of the selection of materials and the response to external fields is essential for attaining desired functionality of a ***,machine learning(ML)models are conducted to predict saturation magnetostrictions(λ_(s))in RFe_(2.-type(R=rare earth)GMMs with different *** to ML-predicted composition–λsrelations,it is discovered that the values ofλshigher than1100×10^(-6)are almost situated in the composition space surrounded by 0.2.≤x≤0.60 and 1.90≤y≤2.00 for the ternary compounds of Tb_(x)Dy_(1-x)Fe_(y).Assisted by ML predictions,the compositions are further narrowed down to the space surrounded by 0.2.≤x≤0.3. and 1.92.y≤1.97 for the excellent piezomagnetic(PM)performance in the Tb_(x)Dy_(1-x)Fe_(y)based PM device through our developed high-throughput(HTP)micromagnetic simulation(MMS)***,high sensitivities up to10.2.-13.61 m T·MPa^(-1)are observed in the optimized range within which the available experimental data fall *** work not only provides valuable insights toward understanding the mechanism of magnetoelastic couplings,but also paves the way for designing and optimizing highperformance magnetostrictive materials and PM sensing devices.

关键词： Magnetostriction Piezomagnetic effect Machine learning Micromagnetic simulation

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Organic-inorganic hybrid piezotronic bipolar junction transistor for pressure sensing

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Microsystems & Nanoengineering 2024年第3期10卷 229-244页

作者： Emad Iranmanesh Zihao liang Weiwei Li Congwei Liao Shunyu Jin Chuan Liu Kai wang Shengdong Zhang Charalampos Doumanidis Gehan A.J.Amaratunga Hang Zhou Guangdong Provincial key laboratory of In-Memory Computing Chips School of Electronic and Computer EngineeringPeking University Shenzhen Graduate SchoolShenzhen 518055P.R.China School of Mechanical Engineering Guangdong Technion-Israel Institute of TechnologyShantou 515063P.R.China state key {2. of Microelectronics Device and Integrated Technology Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029P.R.China Hefei National Research Center for Physical sciences at the Microscale University of Science and Technology of ChinaHefei 23000PR China School of Electronics and Information Technology Sun Yat-sen UniversityNo.132 East Waihuan RoadGuangzhou 510006P.R.China Department of Mechanical Aerospaceand Biomedical EngineeringUniversity of South AlabamaShelby Hall3128MobileAL 36688USA Electrical Engineering Division Department of EngineeringUniversity of Cambridge9 JJ Thomson AvenueCambridge CB30FAUnited Kingdom Zhejiang university International CampusHainingChina

With the rapid development of the Internet of Things(IoTs),wearable sensors are playing an increasingly important role in daily monitoring of personal health and *** signal-to-noise-ratio has become the most critical performance factor to *** enhance it,on the one hand,good sensing materials/devices have been employed;on the other hand,signal amplification and noise reduction circuits have been ***,most of these devices and circuits work in an active sampling mode,requiring frequent data acquisition and hence,entailing high-power *** this scenario,a flexible and wearable event-triggered sensor with embedded signal amplification without an external power supply is of great ***,we report a flexible two-terminal piezotronic n-p-n bipolar junction transistor(PBJT)that acts as an autonomous and highly sensitive,current-and/or voltage-mediated pressure *** PBJT is formed by two back-to-back piezotronic diodes which are defined as emitter-base and collectorbase *** force exertion on the emitter side,as a result of the piezoelectric effect,the emitter-base diode is forward biased while the collector-base diode is reverse *** to the inherent BJT amplification effect,the PBJT achieves record-high sensitivities of 13..7 kPa^(-1)(current-based)and 88.66 kPa^(-1)(voltage-based)in sensing *** PBJT also has a fast response time ofstate of the art not only in terms of sensitivity but also in regard to being self-driven and autonomous,making it promising for pressure sensing and other IoT applications.

关键词： bipolar transistor IoT

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Estimating global land surface broadband thermal-infrared emissivityusing advanced very high resolution radiometer optical data

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International Journal of Digital Earth 2013年第S01期6卷 34-49页

作者： Jie Cheng shunlin liang state key {2. of Remote {3. science College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina Department of Geographical science University of MarylandCollege ParkMDUSA

An algorithm for retrieving global eight-day 5 km broadband emissivity (BBE)from advanced very high resolution radiometer (AVHRR) visible and nearinfrared data from 1981 through 1999 was presented. Land surface was dividedinto three types according to its normalized difference vegetation index (NDVI)values: bare soil, vegetated area, and transition zone. For each type, BBE at813.5 mm was formulated as a nonlinear function of AVHRR reflectance forChannels 1 and 2. Given difficulties in validating coarse emissivity products withground measurements, the algorithm was cross-validated by comparing retrievedBBE with BBE derived through different methods. Retrieved BBE was initiallycompared with BBE derived from moderate-resolution imaging spectroradiometer (MODIS) albedos. Respective absolute bias and root-mean-square errorwere less than 0.003.and 0.014 for bare soil, less than 0.002.and 0.011 fortransition zones, and 0.002.and 0.005 for vegetated areas. Retrieved BBE wasalso compared with BBE obtained through the NDVI threshold method. Theproposed algorithm was better than the NDVI threshold method, particularly forbare soil. Finally, retrieved BBE and BBE derived from MODIS data wereconsistent, as were the two BBE values.

关键词： earth observation broadband emissivity global land surface satellite soil taxonomy advanced very high resolution radiometer moderate-resolution imaging spectroradiometer

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