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Assessments of Data-Driven Deep Learning Models on One-Month Predictions of Pan-Arctic Sea Ice Thickness

Advances in Atmospheric Sciences 2024年第7期41卷 1379-1390页

作者： Chentao SONG Jiang ZHU xichen li Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

In recent years,deep learning methods have gradually been applied to prediction tasks related to Arctic sea ice concentration,but relatively little research has been conducted for larger spatial and temporal scales,mainly due to the limited time coverage of observations and reanalysis ***,deep learning predictions of sea ice thickness(SIT)have yet to receive ample *** this study,two data-driven deep learning(DL)models are built based on the ConvLSTM and fully convolutional U-net(FC-Unet)algorithms and trained using CMIP6 historical simulations for transfer learning and fine-tuned using reanalysis/*** models enable monthly predictions of Arctic SIT without considering the complex physical processes *** comprehensive assessments of prediction skills by season and region,the results suggest that using a broader set of CMIP6 data for transfer learning,as well as incorporating multiple climate variables as predictors,contribute to better prediction results,although both DL models can effectively predict the spatiotemporal features of SIT *** the predicted SIT anomalies of the FC-Unet model,the spatial correlations with reanalysis reach an average level of 89%over all months,while the temporal anomaly correlation coefficients are close to unity in most *** models also demonstrate robust performances in predicting SIT and SIE during extreme *** effectiveness and reliability of the proposed deep transfer learning models in predicting Arctic SIT can facilitate more accurate pan-Arctic predictions,aiding climate change research and real-time business applications.

关键词： Arctic sea ice thickness deep learning spatiotemporal sequence prediction transfer learning

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Uncertainties of ENSO-related Regional Hadley Circulation Anomalies within Eight Reanalysis Datasets

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Advances in Atmospheric Sciences 2024年第1期41卷 115-140页

作者： Yadi li xichen li Juan FENG Yi ZHOU Wenzhu WANG Yurong HOU International Center for Climate and Environment Sciences(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 101408China College of Global Change and Earth System Science(GCESS) Beijing Normal UniversityBeijing 100875China

El Nino-Southern Oscillation(ENSO),the leading mode of global interannual variability,usually intensifies the Hadley Circulation(HC),and meanwhile constrains its meridional extension,leading to an equatorward movement of the jet *** studies have investigated the response of HC to ENSO events using different reanalysis datasets and evaluated their capability in capturing the main features of ENSO-associated HC ***,these studies mainly focused on the global HC,represented by a zonal-mean mass stream function(MSF).Comparatively fewer studies have evaluated HC responses from a regional perspective,partly due to the prerequisite of the Stokes MSF,which prevents us from integrating a regional *** this study,we adopt a recently developed technique to construct the three-dimensional structure of HC and evaluate the capability of eight state-of-the-art reanalyses in reproducing the regional HC response to ENSO *** show that all eight reanalyses reproduce the spatial structure of HC responses well,with an intensified HC around the central-eastern Pacific but weakened circulations around the Indo-Pacific warm pool and tropical *** spatial correlation coefficient of the three-dimensional HC anomalies among the different datasets is always larger than ***,these datasets may not capture the amplitudes of the HC responses *** uncertainty is especially large for ENSO-associated equatorially asymmetric HC anomalies,with the maximum amplitude in Climate Forecast System Reanalysis(CFSR)being about 2.7 times the minimum value in the Twentieth Century Reanalysis(20CR).One should be careful when using reanalysis data to evaluate the intensity of ENSO-associated HC anomalies.

关键词： regional Hadley circulation ENSO atmosphere-ocean interaction reanalysis data

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A Study on Reconstruction of Surface Wind Speed in China Due to Various Climate Variabilities

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Journal of Northeast Agricultural University(English Edition) 2024年第2期31卷 53-65页

作者： li Yancong li xichen Sun Yankun Xu Jinhua College of Resources and Environment Northeast Agricultural UniversityHarbin 150030China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Gaoan Meteorological Bureau of Jiangxi Province Gaoan 330800JiangxiChina

Using European Centre for Medium-Range Weather Forecasts Reanalysis V5(ERA5)reanalysis data,this study investigated the reconstruction effects of various climate variabilities on surface wind speed in China from 1979 to *** results indicated that the reconstructed annual mean wind speed and the standard deviation of the annual mean wind speed,utilizing various climate variability indices,exhibited similar spatial modes to the reanalysis data,with spatial correlation coefficients of 0.99 and 0.94,*** the reconstruction of six major wind power installed capacity provinces/autonomous regions in China,the effects were notably good for Hebei and Shanxi provinces,with the correlation coefficients for the interannual regional average wind speed time series being 0.65 and 0.64,*** reconstruction effects of surface wind speed differed across seasons,with spring and summer reconstructions showing the highest correlation with reanalysis *** correlation coefficients for all seasons across most regions in China ranged between 0.4 and *** the reconstructed seasonal wind speeds for the six provinces/autonomous regions,Shanxi Province in spring exhibited the highest correlation with the reanalysis,with a coefficient of *** large-scale climate variability indices showed good reconstruction effects on the annual mean wind speed in China,and could explain the interannual variability trends of surface wind speed in most regions of China,particularly in the main wind energy provinces/autonomous regions.

关键词： wind speed wind energy correlation method climate variability European Centre for Medium-Range Weather Forecasts Reanalysis V5(ERA5)

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MOFs在催化有机分子转化中的应用

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化学进展 2024年第3期36卷 367-375页

作者：李希臣李政彭灿钱陈韩雨霏张涛南京医科大学药学院核药学系南京211166 南京医科大学核医药临床转化中心南京210029

金属有机框架化合物(MOF),又称多孔性配位聚合物,是有机配体与金属离子自组装而成的一类新型有机-无机杂化多孔材料,是纳米材料的重要组成部分。与其他多孔材料相比,MOFs具有较大的比表面积、高的孔隙率以及结构和性质可调等特性,使其... 详细信息

金属有机框架化合物(MOF),又称多孔性配位聚合物,是有机配体与金属离子自组装而成的一类新型有机-无机杂化多孔材料,是纳米材料的重要组成部分。与其他多孔材料相比,MOFs具有较大的比表面积、高的孔隙率以及结构和性质可调等特性,使其在非均相催化领域具有良好的应用前景。本文首先对MOFs催化的背景进行简述,然后对近年来报道的MOFs用于有机分子催化转化反应的进展进行了综述及展望,以期为MOFs催化有机反应的设计和开发提供参考。

关键词：金属有机框架材料非均相催化界面金属有机化学有机分子高附加值化学品

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青藏高原地表变暗与北极气候变化间的共振

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Science Bulletin 2024年第3期69卷 367-374页

作者：汤舒畅朴世龙 David M.Holland 阚飞汪涛姚檀栋李熙晨 Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China State Key Laboratory of Tibetan Plateau Earth System Resources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100085China Courant Institute of Mathematical Sciences New York UniversityNew YorkNY 0711USA Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China

The Tibetan Plateau(TP)exerts a profound influence on global climate over million-year timescales due to its past ***,whether the ongoing climate changes over the TP,particularly the persistent reduction in its local albedo(referred to as“TP surface darkening”),can exert global impacts remains *** this study,a state-of-the-art coupled land–atmosphere global climate model has been employed to scrutinize the impact of TP darkening on polar climate *** indicate that the projected TP darkening has the potential to generate a stationary Rossby wave train,thereby modulating the atmospheric circulation in the high-latitudes of the Northern Hemisphere and instigating a dipole-like surface air temperature anomaly pattern around the Arctic *** additional experiment suggests that the projected Arctic warming may in return warm the TP,thus forming a bi-directional linkage between these two climate *** their association with vast ice reservoirs,the elucidation of this mechanism in our study is crucial in advancing our comprehension of Earth system climate projections.

关键词： Tibetan Plateau High-latitude Northern Hemisphere Arctic Climate change Albedo Surface darkening

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中阿科技论坛（中英文） 2024年第2期 98-102页

作者：吴文李溪辰汪璐胡威湖南工学院安全与管理工程学院湖南衡阳421002

情景意识是人因安全领域的关键要素,一直是工程领域密切关注的重要课题。为进一步了解国内外关于情景意识的研究现状、研究趋势,进而推测出今后的研究方向,文章以CNKI和Web of Science作为数据来源,运用文献计量分析法和共词分析法,借助... 详细信息

情景意识是人因安全领域的关键要素,一直是工程领域密切关注的重要课题。为进一步了解国内外关于情景意识的研究现状、研究趋势,进而推测出今后的研究方向,文章以CNKI和Web of Science作为数据来源,运用文献计量分析法和共词分析法,借助CiteSpace可视化文献分析工具,针对1995—2023年5月的国内外情景意识相关文献,从时间分布、核心期刊、重要作者、研究热点、研究趋势等方面进行对比分析。研究结果显示:国内外有关情景意识的研究热度一直呈现上升趋势,主要期刊集中于人因工程领域;研究热点方面,国内外虽都关注安全以及复杂系统中人的要素,但侧重点略有不同,未来的研究热点有可能是运用机器学习、模型建构等方法来研究复杂动力系统中操作者的情景意识。

关键词：情景意识研究热点研究前沿 CiteSpace 知识图谱

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Delayed Antarctic melt season reduces albedo feedback

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National Science Review 2023年第9期10卷 236-246页

作者： Lei liang Huadong Guo Shuang liang xichen li John C.Moore Xinwu li Xiao Cheng Wenjin Wu Yan liu Annette Rinke Gensuo Jia Feifei Pan Chen Gong Key Laboratory of Digital Earth Science Aerospace Information Research Institute Chinese Academy of Sciences 2. International Research Center of Big Data for Sustainable Development Goals Institute of Atmospheric Physics Chinese Academy of Sciences College of Global Change and Earth System Science Beijing Normal University Arctic Centre University of Lapland CAS Center for Excellence in Tibetan Plateau Earth Sciences School of Geospatial Engineering and Science Sun Yat-sen University Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Department of Geography University of North Texas

Antarctica’ s response to climate change varies greatly both spatially and *** melting impacts mass balance and also lowers surface *** use a 43-year record(from 1978 to 2020) of Antarctic snow melt seasons from space-borne microwave radiometers with a machine-learning algorithm to show that both the onset and the end of the melt season are being ***-causality analysis shows that melt end is delayed due to increased heat flux from the ocean to the atmosphere at minimum sea-ice extent from warming *** onset is Granger-caused primarily by the turbulent heat flux from ocean to atmosphere that is in turn driven by sea-ice *** snowmelt season leads to a net decrease in the absorption of solar irradiance,as a delayed summer means that higher albedo occurs after the period of maximum solar radiation,which changes Antarctica’s radiation balance more than sea-ice cover.

关键词： Antarctic ice sheet snowmelt season delay sea ice solar irradiance

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China’s Recent Progresses in Polar Climate Change and Its Interactions with the Global Climate System

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Advances in Atmospheric Sciences 2023年第8期40卷 1401-1428页

作者： xichen li Xianyao CHEN Bingyi WU Xiao CHENG Minghu DING Ruibo LEI Di QI Qizhen SUN Xiaoyu WANG Wenli ZHONG Lei ZHENG Meijiao XIN Xiaocen SHEN Chentao SONG Yurong HOU Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Frontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory Ocean University of ChinaQingdao 266100China Qingdao National Laboratory for Marine Science and Technology Qingdao 266061China Department of Atmospheric and Oceanic Sciences/Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China CMA-FDU Joint Laboratory of Marine Meteorology Shanghai 200438China School of Geospatial Engineering and Science Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-sen UniversityZhuhai 519082China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Key Laboratory for Polar Science of the MNR Polar Research Institute of ChinaShanghai 200136China Polar and Marine Research Institute Jimei UniversityXiamen 361021China Polar Research and Forecasting Division National Marine Environmental Forecasting CenterBeijing 100081China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to *** has been actively engaging in polar *** observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate ***,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past *** Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic *** Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic *** Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar *** climate changes may also feedback to the entire Earth climate *** adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower *** change has also driven rapid Arctic and Southern ocean *** researchers have made a series of advances in understanding these processes,as reviewed in this paper.

关键词： polar climate change recent progress in China Arctic amplification tropical-polar interactions global sea level rise stratospheric circulation

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Extended State Observer-based Position Sensorless Control for Automotive Ultra-high-speed PMSM

Extended State Observer-based Position Sensorless Control fo...

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2022中国汽车工程学会年会暨展览会

作者： Xu Yao lin Cheng Xing Jilei li xichen National Engineering Research Center of Electric Vehicles Beijing Institute of Technology State Key Laboratory of Automotive Safety and Energy Tsinghua University

Ultra-high-speed permanent magnet synchronous motor(PMSM) is widely used to drive fuel cell air compressors and electric turbochargers,and its high efficiency and stable control is an effective way to improve the power density of automotive power *** the installation space and detection reliability,the automotive ultra-high-speed PMSM is generally not equipped with a rotor position sensor,and the required high-precision rotor position information is obtained by a position sensorless control *** traditional position sensorless control method based on the extended back electromotive force(EEMF) uses the PI observation error compensator to estimate the EEMF for position *** PI parameter tuning is complicated,and the position estimation error becomes larger with the motor parameters change,which is easy to cause control ***,a novel EEMF-based position sensorless control method based on the extended state observer(ESO) is proposed in this *** the ultra-local model of the EEMF,the disturbance term isobserved by designing the *** estimated EEMF used for position estimation is calculated by a tracking *** method is simple to be tuned and can not only obtain more accurate rotor position information but also suppress the disturbance of motor parameters to a certain ***,the effectiveness of the proposed position sensorless scheme is verified on a 15 kW ultrahigh-speed PMSM by simulation tests.

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Energy basis of recognition of base pair for platinum-based antitumour drug ZD0473 and cisplatin

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Science China Chemistry 2008年第4期51卷 359-366页

作者： HAO Lan li xichen TAN HongWei CHEN GuangJu JIA MuXin College of Chemistry Beijing Normal UniversityBeijing 100875China Beijing General Research Institute of Mining and Metallurgy Beijing 100044China

Platinum-based antitumour drug ZD0473 was designed to reduce the cisplatin resistance to the tumor cells. In this paper, the mixed method of molecular mechanics and quantum chemistry, HF/lanl2dz// MM/uff and B3LYP/lanl2dz//6-31G*, are used to investigate the differences between four types of GG, 3′AG5′, 3′GA5′, and AA complexes, which are formed from four discrete DNA fragments recognized by ZD0473 and cisplatin. The results show that the binding interaction of both ZD0473 and cisplatin drugs with the GG base pair is much stronger than with other base pairs, namely the recognition capability of such drugs to the GG base pair is more considerable. Moreover, the interaction of four complexes of ZD0473 with DNA fragments is stronger than that of cisplatin with corresponding DNA fragments, which indicates the stronger binding capability of ZD0473 with DNA fragments and high antitumour activity of ZD0473. The main reason for easier forming of 3′GA5′ complex than the 3′AG5′ one is that the drug molecule prefers to bind with a single G base to form a monoligand compound firstly; then the con- figuration transformation from such monoligand compound to the bi-ligand one is limited.

关键词： ZD0473 MM/uff//HF/lanl2dz DNA fragment GG 3′AG5′ 3′GA5′

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