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

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

作者： Xiaoy. LI Feng w.NG Tao DUAN Kaijie y.NG Bin y.NG Chunmei w.NG 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 w.ll 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,y.t 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 w.re collected from VHR UAV imagery.covering the main temperate savannah ty.es w.th a ground area of 1818 *** fractional w.ody.vegetation cover （Fw.C） and fractional herbaceous vegetation cover （FHVC） in temperate savannas w.re 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 w.s mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the Fw.C and FHVC models w.re 10.69% and 11.67%,and the R2values w.re 0.66 and 0.63,*** assessment indicated that the new.temperate savanna map had high identification accuracy.w.th a Kappa coefficient of 0.70,overall accuracy.of 0.88,and average accuracy.of *** savannas in the sandy.lands of eastern China w.re 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 ty.es w.re elm,oak/maple,and shrub *** savannas w.re w.dely.distributed in the Otindag Sandy

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

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Separation of the ionospheric and thermospheric contributions in the data from the Triple Ionosophere Photo Meter onboard the Feng-y.n 3E satellite

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Science China Earth Sciences 2025年第1期68卷 172-184页

作者： Fang JIANG tian MAO Jin-Song w.NG Xiu-Qing HU Xiao-Xin ZHANG Liping FU Nan JIA tianfang w.NG National Space Science Center Chinese Academy of Sciences Beijing Key.Laboratory.of Space Environment Exploration Key.Laboratory.of Environmental Space Situation Aw.reness Technology National Satellite Meteorological Center China Meteorological Administration

The Triple Ionosphere Photo Meter （TRIPM） is a far ultraviolet nadir-view.photometer that is onboard the secondgeneration,polar-orbiting Chinese meteorological satellite Feng-y.n 3E （Fy.3E）,w.ich w.s launched on July.5,*** has three channels,and each is used to measure different ty.es of emissions:（1） 135.6 nm airglow.produced by.the recombination of the O+ions and electrons in the absence of sunlight （nighttime channel）;（2） 135.6 nm airglow.from the OI w.en sunlight is present （day.ime/dusk-daw. 135.6 nm channel）;and （3） Airglow.in the N2LBH of the TRIPM （day.ime/dusk-daw. N2LBH channel）.Fy.3E is a satellite operating in the early.morning ***,the data are mostly.distributed on the daw.dusk side or at times w.en the solar zenith angle is relatively.*** this study.combined w.th simulation calculations,the data are *** further explore the application value of the data products,a model is used to separate the ionospheric radiative recombination contribution from the thermosphere photoelectron impact excitation contribution in the data from the day.ime/dusk-daw. 135.6 nm *** approach not only.improves the accuracy.of O/N2derived from the 135.6 nm channel and N2LBH channel but also provides the ionospheric 135.6 nm radiance at the same time as the *** results show.that the 135.6 nm radiance originating from the combination of O+and electrons extracted from the measurement data exhibits similar equatorial anomaly.peak structure characteristics and seasonal variations as the corresponding GPS total electron content （TEC） *** the other hand,the separated 135.6 nm radiance generated from the thermosphere photoelectron collision excitation does not contain radiative recombination contributions;thus,the ionosphere influence is greatly.avoided w.en the O/N2is obtained.

关键词： Far ultraviolet 135.6 nm emission intensity Photoelectron impact excitation Radiative recombination excitation

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KINETIC STUDy.OF SPINEL LiMn_2O_4 Sy.THESIZED By.SOLID REACTION w.TH SOFT-CHEMICAL METHOD

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 512-518页

作者： C.Q. Xu y. w. tian y. C. Zhai Z.J. Guo Z. Q. Huang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The differential thermal analy.is （DTA） curves w.re measured at different heating rates in flow.ng air for study.ng the sy.thesis of the spinel LiMn2O3 w.th Li2CO3 and MnO2, The reaction began at about 503K, and finished at about 873K. The apparent activation energy.of Kissinger method w.s about ***^-1, the reaction orderw.s 1.67, the frequency.factor w.s 7.81×10^9, and therefore the dinetic epuation w.s dδ/dt=A·exp（- E/RT）·（1-δ）^n=7.81×10^9, exp（-122770/RT）·（l-δ）^1.67 . Coats-Redfem integral method w.s used to analy.e the DTA curves of the samples at different heating rates, and the calculated apparent activation energy.and frequency.factor w.re 112. 13kJ· mol^-1 and 1.18 × 10^9, respectively. rather close to that of Kissinger method. X-ray.diffraction （XRD） and scanning electron microscope （SEM） results show. that the sy.thesized LiMn2O3 possesses pure phase, regular shape and normal particle distribution.

关键词： lithium manganese oxides sy.thesized kinetics Kissinger method,Coats-Redfern integral method

Sy.thesis and formation mechanism of titanium lead carbide

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Journal of Advanced Ceramics 2018年第2期7卷 178-183页

作者： C. LING w. B. tian P. ZHANG w. ZHENG y. M. ZHANG Z. M. SUN Jiangsu Key.Laboratory.of Advanced Metallic Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China Jiangsu Key.Laboratory.of Construction Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China

Ti：PbC w.s sy.thesized for the first time by.pressureless reaction sy.thesis using Ti/Pb/TiC as starting materials at a heating rate of 2 ℃/rain and holding at 1370 ℃ for 2 h in a tube furnace protected by.Ar atmosphere. The effects of starting pow.ers, heating rates, and holding temperatures on the formation of Ti2PbC w.re investigated. It w.s found that elementary.mixture of Ti/Pb/C or higher heating rates fail to form Ti2PbC. The decreased lattice parameters in the sy.thesized Ti2PbC indicated the existence of Pb vacancies in the compound. A reaction mechanism w.s proposed to explain the formation of Ti2PbC.

关键词： Ti2PbC MAX phase differential scanning calorimetry.(DSC) thermal stability

EFFECT OF LASER INPUT ENERGy.ON AuSn_x INTERMETALLIC COMPOUNDS FORMATION IN SOLDER JOINTS w.TH DIFFER-ENT THICKNESS OF Au SURFACE FINISH ON PADS

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Acta Metallurgica Sinica(English Letters) 2008年第3期21卷 183-190页

作者： w. Liu C.Q. w.ng y.H. tian M.y. Li Department of Electronics Packaging Technology State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Shenzhen Graduate School of Harbin Institute of Technology Shenzhen 518055 China

Formation of AuSnx intermetallic compounds （IMCs） in laser reflow.d solder joints w.s investigated. The results show.d that few.IMCs formed at the solder/0. 1μm Au interface. Needlelike AuSn4 IMCs w.re observed at the solder/0.5μm Au interface. In Sn-2.0Ag-O,75Cu-3,0Bi and Sn-3.5Ag-O.75Cu solder joints, w.en the laser input energy.w.s increased, AuSn4 IMCs changed .from a lay.r to needlelike or dendritic distribution at the solder/0.9μm Au interface. As for the solder joints w.th 4.0 μm thickness of Au surface finish on pads, AuSn4 , AuSnx, AuSn IMCs, and Au2Sn phases formed at the interface. Moreover, the content of AuSnx IMCs, such as, AuSn4 and AuSn2, w.ich contained high Sn concentration, w.uld become larger as the laser input energy.increased. In the Sn-37Pb solder joints w.th 0.9 μm or 4.0 μm thickness of the Au surface finish on pads, AuSn4 IMCs w.re in netlike distribution. The interspaces betw.en them w.re filled w.th Pb-rich phases.

关键词： Laser soldering Inlermetallics Au films

Recent progress in the applications of presy.aptic dopaminergic positron emission tomography.imaging in parkinsonism

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Neural Regeneration Research 2025年第1期20卷 93-106页

作者： y.jie y.ng Xiny. Li Jiay.ng Lu Jingjie Ge Mingjia Chen Ruixin y.o Mei tian Jian w.ng Fengtao Liu Chuantao Zuo Key.Laboratory.of Arrhy.hmias Ministry of EducationDepartment of Medical GeneticsShanghai East HospitalSchool of MedicineTongji UniversityShanghaiChina Department of Neurology National Research Center for Aging and MedicineNational Center for Neurological Disordersand State Key Laboratory of Medical NeurobiologyHuashan HospitalFudan UniversityShanghaiChina Department of Nuclear Medicine&PET Center National Center for Neurological Disordersand National Clinical Research Center for Aging and MedicineHuashan HospitalFudan UniversityShanghaiChina International Human Phenome Institutes(Shanghai) ShanghaiChina Human Phenome Institute Fudan UniversityShanghaiChina

Now.day.,presy.aptic dopaminergic positron emission tomography.w.ich assesses deficiencies in dopamine sy.thesis,storage,and transport,is w.dely.utilized for early.diagnosis and differential diagnosis of *** review.provides a comprehensive summary.of the latest developments in the application of presy.aptic dopaminergic positron emission tomography.imaging in disorders that manifest *** conducted a thorough literature search using reputable databases such as PubMed and w.b of *** criteria involved identify.ng peer-review.d articles published w.thin the last 5 y.ars,w.th emphasis on their relevance to clinical *** findings from these studies highlight that presy.aptic dopaminergic positron emission tomography.has demonstrated potential not only.in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity.and predicting ***,w.en employ.d in conjunction w.th other imaging modalities and advanced analy.ical methods,presy.aptic dopaminergic positron emission tomography.has been validated as a reliable in vivo *** validation extends to screening and exploring potential neuropathological mechanisms associated w.th dopaminergic *** summary.the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately.advancing tow.rd the goals of neuroregeneration in parkinsonian disorders.

关键词： aromatic amino acid decarboxy.ase brain imaging dopamine transporter Parkinson’s disease parkinsonism positron emission tomography presy.aptic dopaminergic function vesicle monoamine transporter ty.e 2

MODELING THE KNOw.EDGE CREATION PROCESS OF GRADUATE RESEARCH

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Journal of Sy.tems Science and Sy.tems Engineering 2018年第6期27卷 790-809页

作者： J. Sun J. tian V.N. Huy.h y. Nakamori School of Know.edge Science Japan Advanced lnstitute of Science and Technology lshikawa Japan School of Computer Science and Technology Wuhan University of Technology Wuhan China

Graduate students w.o are beginning academic research w.nt to learn how.to create and verify.new.know.edge in their research. Their supervisors, on the other hand, are seeking appropriate research environments including effective research guidance methods. In order to meet these demands, this paper proposes a know.edge creation model that supports the objectives of both graduate students and their supervisors. This is an academic know.edge creation model for individuals supported by.a group and its origin can be traced back to a famous organizational know.edge creation model. Since this ty.e of model is constructed from empirical know.edge, it is not easy.to prove its objective significance. But, this paper tries to show.the effectiveness of the proposed model as an initial stage of model validation based on a questionnaire survey.of students in a graduate school in China.

关键词： Know.edge creation model graduate students research ability research environment

Superplasticity.of Ti2448 Alloy.w.th Nanostructured Grains

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Journal of Materials Science & Technology 2011年第12期27卷 1099-1104页

作者： M.J. Xiao y.X. tian G. w. Mao S.J. Li y.L. Hao R. y.ng School of Astronautics Northwestern Polytecllnic University Xi＇an 710072 China - Sheny.ng National Laboratory.for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Ti-24Nb-4Zr-8Sn, abbreviated as Ti2448 from its chemical composition in w.ight percent, is a multifunctional /3 ty.e titanium alloy.w.th body.centered cubic （bcc） cry.tal structure, and its highly.localized plastic deformation behavior contributes significantly.to grain refinement during conventional cold processing. In the paper, the nanostructured （NS） alloy.w.th grain size less than 50 nm produced by.cold rolling has been used to investigate its superplastic deformation behavior by.uniaxial tensile tests at initial strain rates of 1.5 ×10-2, 1.5×10^-3 and 1.6×10-4 s-1 and temperatures of 600,650 and 700℃. The results show.that, in comparison w.th the coarse-grained alloy.w.th size of 50 μm, the NS alloy.has better superplasticity.w.th elongation up to ～275% and ultimate strength of 50-100 MPa. Strain rate sensitivity.（m） of the NS alloy.is 0.21, 0.30 and 0.29 for 600,650 and 700℃, respectively. These results demonstrate that grain refinement is a valid w.y.to enhance the superplasticity.of Ti2448 alloy.

关键词： Titanium alloy bcc cry.tal Superplasticity Nanostructured grain

Recent progress on the study.of asy.metric vortex flow.over slender bodies

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Acta Mechanica Sinica 2008年第5期24卷 475-487页

作者： X.y.Deng w.tian B.F.Ma y.K.w.ng Key.Laboratory.of Fluid Mechanics Ministry of EducationBeihang University100083 BeijingChina

The investigations of forebody.vortex flow.and its flow.control have great importance in both academic field and engineering application areas. A large number of papers and many.review.papers have been published. How.ver in this research field of forebody.asy.metric vortices, three problems such as tip perturbation effect, Rey.olds number effect and flow.instability.are less studied and thus not understood completely. So many.researches are still w.rking on the issues in recent y.ars. The present paper attempts to provide a review.of recent research progress on first tw. problems. The first problem is mainly.concerned w.th how.the vortex flow.evolves after tip perturbation; how.to solve the problem of repeatability.and reproducibility.of w.nd tunnel testing data; how.to develop a conception of active flow.control technique w.th tip perturbation based on the study.of vortex flow.response to tip perturbation. For the second problem one is mainly.concerned that how.the asy.metric vortices are developed w.th the increase of Rey.olds number; how.to classify.the vortex flow.patterns in different Rey.olds number regimes; how.to develop an appropriate boundary.lay.r transition technique to simulate flow. at high Rey.olds number in the convention w.nd tunnels. Finally. some important ques- tions that deserve answ.rs are proposed in the concluding remarks.

关键词： High angle of attack aerody.amics ,Asy.metric vortex Tip perturbation Slender body.,Rey.olds number effect