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Biome reconstruction on the Tibetan Plateau since the Last Glacial Maximum using a machine learning method

Science China Earth Sciences 2022年第3期65卷 518-535页

作者： Feng qin Yan zhao Xianyong CAO Key Laboratory ofland Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Alpine Paleoecology and Human Adaptation(ALPHA)Group State Key Laboratory of Tibetan Plateau Earth System Science(LATPES)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Historical biome changes on the Tibetan Plateau provide important information that improves our understanding of the alpine vegetation responses to climate ***,a comprehensively quantitative reconstruction of the historical Tibetan Plateau biomes is not possible due to the lack of quantitative methods that enable appropriate classification of alpine biomes based on proxy data such as fossil pollen *** this study,a pollen-based biome classification model was developed by applying a random forest algorithm(a supervised machine learning method)based on modern pollen assemblages on and around the Tibetan Plateau,and its robustness was assessed by comparing its results with the predictions of the biomisation *** results indicated that modern biome distributions reconstructed using the random forest model based on modern pollen data generally concurred with the observed zonal *** random forest model had a significantly higher accuracy than the biomisation method,indicating the former is a more suitable tool for reconstructing alpine biome changes on the Tibetan *** random forest model was then applied to reconstruct the Tibetan Plateau biome changes from 22 ka BP to the present based on 51 fossil pollen *** reconstructed biome distribution changes on the Tibetan Plateau generally corresponded to global climate changes and Asian monsoon *** the Last Glacial Maximum,the Tibetan Plateau was mainly desert with subtropical forests distributed in the *** the last deglaciation,the alpine steppe began expanding and gradually became zonal vegetation in the central and eastern *** meadow occupied the eastern and southeastern areas of the Tibetan Plateau since the early Holocene,and the forest-meadow-steppe-desert pattern running southeast to northwest on the Tibetan Plateau was established *** the mid-Holocene,subtropical forests extended north,which reflected the“optimum”***

关键词： Biome reconstruction Random forest algorithm Biomisation method Pollen data Last Glacial Maximum Tibetan Plateau

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Variational-Iterative Solution of Ground State for Central Potential

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Communications in Theoretical Physics 2002年第7期38卷 15-18页

作者： zhao Wei-qin China Center of Advanced Science and Technology CCAST World Lab. P.O. Box 8730 Beijing 100080 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 9184-1 Beijing 100039 China

The newly developed iterative method based on Green function defined by quadratures along a single trajectory is combined with the variational method to solve the ground state quantum wave function for central *** an example, the method is applied to discuss the ground state solution of Yukawa potential, using Hulthen solution as the trial function.

关键词： iterative solution, variantional method, ground state

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Groundstate with Zero Eigenvalue for Generalized Sombrero-Shaped Potential in N-Dimensional Space

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Communications in Theoretical Physics 2008年第7期50卷 139-141页

作者： zhao Wei-qin China Center of Advanced Science and Technology （CCAST）（World Lab.） P.O. Box 8730 Beijing 100080 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918 （4-1） Beijing 100049 China

Based on an iterative method for solving the groundstate of Schrodinger equation, it is found that a kind of generalized Sombrero-shaped potentials in N-dimensional space has groundstates with zero eigenvalue. The res... 详细信息

关键词： iterative solution zero eigenvalue generalized Sombrero-shaped potential

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Editable semiconductor photo-electrodes for sustainable ammonia synthesis

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Nano Research 2024年第4期17卷 3107-3112页

作者： Ning lan Kun Du Erling zhao Wei zhao Tao Ling Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education Institute of New-EnergySchool of Materials Science and EngineeringTianjin UniversityTianjin 300072China School of Materials Science and Engineering Tianjin Chengjian UniversityTianjin 300384China

Powered by an inexhaustible supply of solar energy,photoelectrochemical(PEC)nitrogen reduction reaction(NRR)provides an ideal solution for the synthesis of green ammonia(NH_(3)).Although great efforts have been made in the past decades,there are still significant challenges in increasing the NH_(3) yields of the PEC-NRR *** addition to the issues of low activity and selectivity similar to electrochemical NRR,the progress of PEC-NRR is also impeded by the limited increase in NH_(3) yields as the electrode is ***,we propose an editable electrode design strategy that parallels unit photo-electrodes to achieve a linear increase in NH_(3) yields with electrode active *** demonstrate that the editable electrode design strategy minimizes the electrode charge transfer resistance,allowing more photo-generated carriers to reach the electrode surface and promote the catalytic *** believe that this editable electrode design strategy provides an avenue to achieve sustainable PEC NH_(3) production.

关键词： editable electrode photoelectrochemical nitrogen reduction reaction parallel electrode ZnSe

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Optimization of MAC algorithm based on IEEE 802.15.4 in indoor positioning system

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High Technology Letters 2021年第1期27卷 86-94页

作者： Sun Guanyu qin Danyang lan Tingting Key Laboratory of Electronic and Communication Engineering Heilongjiang UniversityHarbin 150080P.R.China

The mobility of the targets asks for high requirements of the locating speed in indoor positioning *** standard medium access control(MAC)algorithm will often cause lots of packet conflicts and high transmission delay if multiple users communicate with one beacon at the same time,which will severely limit the speed of the ***,an optimized MAC algorithm is proposed based on channel reservation to enable users to reserve beacons.A frame threshold is set to ensure the users with shorter data frames do not depend on the reservation mechanism,and multiple users can achieve packets switching with relative beacon in a fixed sequence by using frequency division multiplexing *** simulation results show that the optimized MAC algorithm proposed in this paper can improve the positioning speed significantly while maintaining the positioning ***,the positioning accuracy can be increased to a certain extent if more channel resources can be obtained,so as to provide effective technical support for the location and tracking applications of indoor moving targets.

关键词： medium access control(MAC)algorithm indoor positioning multi-channel fingerprint identification IEEE 802.15.4

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Concordance of Kinematics and Lensing of Elliptical Galaxies with WMAP Cosmology

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Chinese Journal of Astronomy and Astrophysics 2006年第2期6卷 141-154页

作者： HongSheng zhao Bo qin National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 SUPA University of St. Andrews KY16 9SS UK

We explore degeneracies in strong lensing model so to make time delay data consistent with the WMAP （Wilkinson Microwave Anisotropy Probe） cosmology. Previous models using a singular isothermal lens often yield a time delay between the observed multiple images too small than the observed value if we ＂hardwire＂ the now widely quoted post-WMAP ＂high＂ value of the Hubble constant （Ho ～71 ± 4km s^-1 Mpc^-1）. Alternatively, the lens density profile （star plus dark matter） is required to be locally steeper than r-2 （isothermal） profile near the Einstein radius （of the order 3 kpc） to fit the time delays; a naive extrapolation of a very steep profile to large radius would imply a lens halo with a scale length of the order only 3 kpc, too compact to be consistent with CDM. We explore more sophisticated, mathematically smooth, positive lens mass density profiles which are consistent with a large halo and the post-WMAP H0. Thanks to the spherical monopole degeneracy, the ＂reshuffling＂ of the mass in a lens model does not affect the quality of the fit to the image positions, amplifications, and image time delays. Even better, unlike the better-known mass sheet degeneracy, the stellar mass-to-light and the H0 value are not affected either. We apply this monopole degeneracy to the quadruple imaged time-delay system PG 1115＋080. Finally we discuss the implications of the time delay data on the newly proposed relativistic MOND theory.

关键词： cosmological parameters - dark matter - distance scale - gravitational lensing

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Gradient solid electrolyte interphase induced by bisfuoroacetamide for stable lithium metal batteries

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Journal of Energy Chemistry 2022年第3期31卷 676-679,I0018页

作者： qin zhao Tianyi Ma Institute of Clean Energy Chemistry Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning ProvinceCollege of ChemistryLiaoning UniversityShenyang 110036LiaoningChina Centre for Translational Atomaterials Swinburne University of TechnologyHawthornVIC 3122Australia

With continuous development of portable electronics and electric vehicles,the conventional lithium-ion batteries(LIBs)could not meet the demand for higher energy density[1,2].Instead,the lithium metal batteries(LMBs)are regarded as the most promising candidate for next generation energy storage systems due to the highest specific capacity(3860 mAh g^(-1))and lowest redox potential(-3.04 V *** hydrogen electrode)of Li metal[3,4].

关键词： Bisfuoroacetamide Lithium metal batteries Electrolyte interphase

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Calcite U-Pb Geochronology Revealing Late Ediacaran-Early Paleozoic Hydrothermal Alteration in the Stenian-Tonian Carbonate of Northeastern North China Craton

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Journal of Earth Science 2023年第6期34卷 1724-1731页

作者： Rong Cao Hanqing zhao Zhongwu lan State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China

Two calcite LA-ICP-MS U-Pb ages of 534±26 Ma(MSWD=5.9)and 456±43 Ma(MSWD=3.8)were obtained from the Nanfen Formation,Xihe Group in the southern Liaoning Prov-ince,northeastern China,which significantly postdate the theoretical depositional age of sampling *** means they represent timing of post-depositional hydrothermal event possibly induced by syn-chronous far-field magmatism in the South *** of common Pb enriched muddy compo-nents coupled with input of"mantle"-like common Pb could account for the relatively low U contents and high common Pb contents in the dated muddy *** recommend that micro-domains of carbonates are prescreened by rapid in situ carbonate U-Pb geochronology to demonstrate whether they are of primary or secondary origin before utilizing them for chemostratigraphic study.

关键词： carbonates geochronology LA-ICP-MS Xihe Group hydrothermal origin

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Variation in reproductive life-history traits of Chinese Bulbuls(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,China

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Avian Research 2023年第2期14卷 174-181页

作者： Xingmin Chen qin Zhang Sisi lan qin Huang Shuihua Chen Yanping Wang Laboratory of Island Biogeography and Conservation Biology College of Life SciencesNanjing Normal UniversityNanjing210023China College of Chemistry and Life Sciences Zhejiang Normal UniversityJinhua321004China Zhejiang Museum of Natural History Hangzhou310012China Zhejiang Provincial Museum Hangzhou310007China

Urbanization brings new selection pressures to wildlife living in cities,and changes in the life-history traits of urban species can reflect their responses to such *** date,most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America,while such studies are often lacking in quickly developing countries in Asia(e.g.,China).In this study,we examined the variations in reproductive life-history traits of Chinese Bulbuls(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,*** detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to *** collected data on seven life-history traits(laying date,incubation period,nestling period,clutch size,egg volume,hatching success rate,and fledging success rate).We used infrared cameras to record the number of feedings per hour as the measure of food resources for the *** measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding *** then calculated the urbanization synthetic index(USI)as a measure of the level of urbanization and examined its relationship with the seven life-history *** found that Chinese Bulbuls laid eggs significantly earlier with increasing ***,the other six life-history traits did not vary significantly with the ***,the feeding frequency of chicks increased significantly with the USI,but the nest predation pressure of Chinese Bulbuls decreased significantly with the *** food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese *** study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.

关键词： Feeding frequency Laying date Life-history trait Nest predation Urbanization Urbanization synthetic index(USI)

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Functional analyses of an E3 ligase gene AIP2 from wheat in Arabidopsis revealed its roles in seed germination and pre‐harvest sprouting

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Journal of Integrative Plant Biology 2014年第5期56卷 480-491页

作者： Dong-Yao Gao zhao-Shi Xu Yi He Yong-Wei Sun You-Zhi Ma lan-qin Xia Institute of Crop Sciences/The National Key Facility for Crop Gene Resources and Genetic Improvement the Chinese Academy of Agricultural Sciences (CAAS) Agricultural and Sideline Base Unit 65426 of the People’s Liberation Army

Pre‐harvest sprouting（PHS） seriously affects wheat yield and quality of the grain. ABI3 is a key factor in the activation of seed development and repression of germination in Arabidopsis. An ABI3‐interacting protein（AIP2） could polyubiquitinate ABI3, impair seed dormancy and promote seed germination in Arabidopsis. In this study,two wheat AIP2 genes, TaAIP2A and TaAIP2B, were *** localization assay and yeast two‐hybrid analysis revealed that TaAIP2A and TaAIP2B may function through interaction with wheat Viviporous‐1（TaVp1）. The transcripts TaAIP2A and TaAIP2B were more abundant in wheat PHS susceptible cultivars than that of resistant ones, and decreased gradually following seed development. Expression of TaAIP2A and TaAIP2B in Arabidopsis aip2‐1 mutant lines resulted in earlier flowering, promotion of seed germination,and reduced ABA sensitivity, respectively, somehow mimicking the phenotype of the wild type, with TaAIP2B having a stronger role in these aspects. Furthermore, the expression ofupstream genes ABI1 and ABI2 were upregulated, whereas that of downstream genes ABI3 and ABI5 were downregulated in both TaAIP2A and TaAIP2B complemented lines upon ABA treatment. These results suggested that wheat AIP2s could negatively regulate the ABA signaling pathway and play important roles in seed germination, and thus wheat PHS resistance finally.

关键词： ABA responsiveness AIP2 Arabidopsis E3 ligase functional analysis pre‐harvest sprouting Triticum aestivum L

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