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Distribution and mapping of temperate savanna in the sandy lands of eastern China

Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG Xin TIAN qi lu Institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry Institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry Institute of Great Green Wall Satellite Application Centre for Ecology and Environment MEE Institute of Microelectronics Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

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CO2-mediated bicarbonate conversion to concentrated formate in a CEM-based electrolyzer

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Journal of Energy Chemistry 2025年第1期100卷 605-611页

作者： Haocheng Xiong Donghuan Wu Haonan Li Andrew Li qikun Hu Siyao Song Bingjun Xu qi lu State Key Laboratory of Chemical Engineering Department of Chemical Engineering Tsinghua University College of Chemistry and Molecular Engineering Peking University Ordos Laboratory

Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO2emissions,as bicarbonate can be efficiently generated from the capture of atmospheric CO2using alkaline solutions with reactive *** this work,we present a CO2-mediated bicarbonate conversion to pure formate using a cation exchange membrane-based electrolyzer with a 25 cm2electrode *** electrolysis achieved selectivities exceeding 75%for formate at a total current of 2.5 A,achieving formate concentrations up to 1.2 M and yields as high as 95%over extended *** techno-economic assessment confirmed the economic viability of the process,highlighting the potential for bicarbonate electrolysis as a sustainable method for producing valuable chemicals.

关键词： Electrocatalysis Techno-economic assessments Electrochemistry Flow electrolyzer

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Spatiotemporal characteristics and influencing factors of vegetation water use efficiency on the Tibetan Plateau in 2001–2020

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Journal of Geographical Sciences 2025年第1期35卷 39-64页

作者： HE Chenyang WANG Yanjiao YAN Feng lu qi School of Ecological and Environmental Science East China Normal University Institute of Ecological Conservation and Restoration Chinese Academy of Forestry National Climate Center China Meteorological Administration

Water use efficiency （WUE）,as a pivotal indicator of the coupling degree within the carbon–water cycle of ecosystems,holds considerable importance in assessment of the carbon–water balance within terrestrial ***,in the context of global warming,WUE evolution and its primary drivers on the Tibetan Plateau remain *** study employed the ensemble empirical mode decomposition method and the random forest algorithm to decipher the nonlinear trends and drivers of WUE on the Tibetan Plateau in 2001–*** indicated an annual mean WUE of 0.8088 gC/mm·m2across the plateau,with a spatial gradient reflecting decrease from the southeast toward the *** manifesting monotonous trends of increase or decrease in WUE accounted for 23.64%and 9.69%of the total,***,66.67%of the region exhibited trend reversals,i.e.,39.94%of the area of the Tibetan Plateau showed transition from a trend of increase to a trend of decrease,and 26.73%of the area demonstrated a shift from a trend of decrease to a trend of *** factors accounted for 70.79%of the variability in *** leaf area index and temperature served as the major driving forces of WUE variation.

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Bang-Bang Principle of Time Optimal Controls and Null Controllability of Fractional Order Parabolic Equations

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Acta Mathematica Sinica,English Series 2010年第12期26卷 2377-2386页

作者： qi lu School of Mathematics Sichuan University Chengdu 610064 P. R. China

In this paper, we establish a bang-bang principle of time optimal controls for a controlled parabolic equation of fractional order evolved in a bounded domain Ω of R^n, with a controller w to be any given nonempty open subset of Ω. The problem is reduced to a new controllability property for this equation, i.e. the null controllability of the system at any given time T 〉 0 when the control is restricted to be active in ω× E, where E is any given subset of [0, T] with positive （Legesgue） measure. The desired controllability result is established by means of a sharp observability estimate on the eigenfunctions of the Dirichlet Laplacian due to Lebeau and Robbiano, and a delicate result in the measure theory due to Lions.

关键词： Bang-bang principle time optimal control null controllability fractional order parabolicequation

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Nonreciprocal Head-on Collision Between Two Nonlinear Solitary Waves in Granular Metamaterials with an Interface

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Acta Mechanica Solida Sinica 2022年第1期35卷 139-151页

作者： qi lu Yi-Ze Wang Department of Mechanics Tianjin UniversityTianjin 300350China

In this work,the head-on collision and transmission with nonreciprocal properties of opposite propagating solitary waves are studied,in which the interface between different granular chains is *** to the discontinuity of two periodic granular systems,the transmitted and reflected solitary waves are *** head-on collision appears at the interface and the reductive perturbation method is applied to derive the generated solitary *** to the derivation and numerical simulation,we can find that the transmitted and reflected solitary waves can propagate with the same speed when they locate at the same ***,the influences of both the arrangement and prestress are *** is found that the amplitude and velocity of solitary waves become larger because of a bigger prestress,which result in the nonreciprocal collision and transmission in the granular mechanical *** study is expected to be helpful for the design and application of elastic wave metamaterials and mechanical diodes with nonlinear solitary waves.

关键词： Granular metamaterial Nonlinear solitary waves Head-on collision Interface Nonreciprocal properties

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On the lower bounds of the curvatures in a bounded domain

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Science China Mathematics 2015年第1期58卷 1-10页

作者： lu qi Keng Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences

Let KD（z, z） be the Bergman kernel of a bounded domain 7P in Cn and Sect （z, ） and Ricci （z, ） be the holomorphic sectional curvature and Ricci curvature of the Bergman metric ds2 = T T：）（z,N）dzCdz respectively at the point z E T with tangent vector . It is proved by constructing suitable minimal functions that where z ∈D1 D D2, D1 is a ball contained in D and D2 is a ball containing D.

关键词： minimal function minimal integral lower bound

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Heisenberg Group and Energy-Momentum Conservative Law in de-Sitter Spaces—— In Memory of the 100th Anniversary of Einstein＇s Special Relativity and the 70th Anniversary of Dirac＇s de-Sitter Spaces

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Communications in Theoretical Physics 2005年第3X期44卷 389-392页

作者： lu qi-Keng Institute of Mathematics Academy of Mathematics and System Sciences the Chinese Academy of Sciences Beijing 100080 China

In 1935 Dirac established the physical wave equations in the de-Sitter spaces but neither energy-momentum operators nor their conservative laws were given. In this article it is proved that in the de-Sitter group there is a subgroup group isomorphic to the Heisenberg group and the generators of this groups are the energy-momentum operators which obey a conservative law.

关键词： energy-momentum conservation Heisenberg grup de-Sitter space

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Exponential Attractor of the 3D Derivative Ginzburg-Landau Equation

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Acta Mathematica Sinica,English Series 2008年第5期24卷 809-828页

作者： Shu Juan lu qi Shao lu Department of Mathematics & LMIB Beijing University of Aeronautics and Astronautics Beijing 100083 P. R. China

In this paper, we consider a derivative Ginzburg-Landau-type equation with periodic initial-value condition in three-dimensional spaces. Sufficient conditions for existence and uniqueness of a global solution are obtained by uniform a priori estimates of the solution. Furthermore, the existence of a global attractor and an exponential attractor with finite dimensions are proved.

关键词： derivative Ginzburg-Landau equation global attractor exponential attractor Hausdorff dimension fractal dimension

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Influence of gut bacteria on type 2 diabetes:Mechanisms and therapeutic strategy

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World Journal of Diabetes 2025年第1期16卷 27-33页

作者： Xue Wen lu-Ming qi Kui Zhao College of Health and Rehabilitation Chengdu University of Traditional Chinese MedicineChengdu 610000Sichuan ProvinceChina College of Materials and Chemical Engineering Southwest Forestry UniversityKunming 650224Yunnan ProvinceChina

The onset and progression of type 2 diabetes mellitus(T2DM)are strongly associated with imbalances in gut bacteria,making the gut microbiome a new potential therapeutic *** commentary examines the recent publication in World Journal of *** article explores the association between T2DM and gut microbiota,with a focus on the pathophysiological changes related to *** proposes innovative microbiome-targeted therapeutic strategies and evaluates the challenges and future directions of such *** editorial summarizes the key points of their discussion of the role of the gut microbiome in T2DM and elaborates on the influence of specific gut microbial species on the disease through the host–microbiota metabolic *** provides new insights for future research on gut-microbiota-based interventions for T2DM.

关键词： Type 2 diabetes Intestinal microbiome Intestinal axis Biological pathways Treatment Short-chain fatty acids

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A novel compilation method of comprehensive mission spectrum of aero-engine maneuvering load based on use-related mission segment

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Chinese Journal of Aeronautics 2023年第3期36卷 161-170页

作者： Xuming NIU qi lu Zhigang SUN Yingdong SONG Jiangsu Province Key Laboratory of Aerospace Power System and College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Laboratory of Aero-Engine Thermal Environment and Structure Ministry of Industry and Information Technology College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China College of Energy and Power Engineering and State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Comprehensive Mission Spectrum(CMS)of an aero-engine can reflect the usage characteristics of the *** can provide load input for engine life prediction and accelerated mission *** this paper,a novel compilation method of CMS of aero-engine maneuvering load based on mission segment is ***,the use-related Typical Mission Segment(TMS)of maneuvering load is divided and identified according to spectral ***,the mathematical model of different kinds of TMS are established based on stochastic process ***,the CMS of maneuvering load is compiled based on *** proposed method can accurately quantify the compilation of *** compiled CMS shows good agreement with the original load *** to damage consistency inspection,the compiled CMS is consistent with the damage caused by the original load spectrum in terms of low cycle fatigue.

关键词： Aero-engine Comprehensive mission spectrum Maneuvering load Spectrum compilation Typical mission segment

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