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The extremely cold 2009-2010 winter and its relationship with the Arctic oscillation

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Frontiers of physics 2013年第5期8卷 590-603页

作者： Xin-Yu Wen Yong-Yun Hu ji-ping liu Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beijing 100871 China 2Department of Atmospheric and Environmental Sciences University at Albany State University of New York NY 12222 USA

The Northern-Hemisphere high-latitude continents experienced extremely cold weathers in winter 2009 2010. In the present paper, we show that the cold winter was associated with the activity of tile Arctic oscillation （AO）, which demonstrated the strongest negative polarity over the past six decades and persisted from December, 2009 to March, 2010. It is found that variations of the surface AO was closely linked to stratospheric polar vortex anomalies, and that the surface AO phases followed downward propagation of stratospheric Northern-Hemisphere Annular mode （NAM） anomalies during the winter. The case of 2009-2010 winter provides us with a typical example that anomalous stratospheric signals can be used to improve skills of long-range weather forecast and intra-seasonal climate prediction in winter time. We also show that the E1 Nifio event, which started developing from May 2009, might contribute the formation of exceptionally negative and persistent AO and stratospheric NAM, particularly over North Pacific and North America.

关键词： Arctic oscillation Northern-Hemisphere Annular mode (NAM) stratosphere planetarywaves weather forecast

Improved positioning algorithm based on two step least square in NLOS environments

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 58-63页

作者： WU Shi-xun LI ji-ping-yin liu Shou Department of Electronics and Communication Engineering Central China Normal University Wuhan 430079 China

Non-line-of-sight （NLOS） propagation is a major source of error for accurate time-of-arrival （TOA） location estimation. The two-step least square （LS） method, which does not need any information about the distribution of the NLOS error, has been studied in related researches to provide efficient location estimation of the mobile terminal （MT）. By observing the estimation of the error covariance matrix in the two-step LS method, this paper finds that the measured distances are more suitable than the initial estimated distances by maximum likelihood （ML） algorithm in NLOS environments. Moreover, by making use of the geometry relations among fixed terminals （FTs）, some measured distances which are corrupted by big NLOS errors may be reduced. Further, an iteration method can be adopted to further improve the performance of the algorithm. Accordingly, an improved algorithm based on the two-step LS method is proposed. Simulation results demonstrate that the improved algorithm has better performance than the two-step LS method and converges more quickly. Meanwhile, it is robust in different NLOS environments.

关键词： NLOS propagation TOA least square position algorithm maximum likelihood

Anisotropic elastic properties and ideal uniaxial compressive strength of TiB_2 from first principles calculations

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Chinese Physics B 2018年第7期27卷 443-449页

作者： Min Sun Chong-Yu Wang ji-ping liu School of Material Science and Engineering Beijing Institute of TechnologyBeijing 100081China Department of Physics Tsinghua UniversityBeijing 100084China

The structural, anisotropic elastic properties and the ideal compressive and tensile strengths of titanium diboride （TiB2） were investigated using first-principles calculations based on density functional theory. The stress-strain relationships of TiB2 under 〈10i0〉, 〈12i0〉, and 〈0001〉 compressive loads were calculated. Our results showed that the ideal uniaxial compressive strengths are ｜σ〈02i0〉）｜ = 142.96 GPa, ｜σ〈0001〉 ] = 188.75 GPa, and ｜σ〈10i0〉｜ = 245.33 GPa, at strains -0.16, -0.32, and -0.24, respectively. The variational trend is just the opposite to that of the ideal tensile strength with σ〈10i0〉 = 44.13 GPa, σ〈0001〉 = 47.03 GPa, and σ〈i2i0〉 = 56.09 GPa, at strains 0.14, 0.28, and 0.22, respectively. Furthermore, it was found that TiB2 is much stronger under compression than in tension. The ratios of the ideal compressive to tensile strengths are 5.56, 2.55, and 4.01 for crystallographic directions （10i0）, 〈12i0〉, and 〈0001〉, respectively. The present results are in excellent agreement with the most recent experimental data and should be helpful to the understanding of the compressive property of TiB2.

关键词： ideal compressive strength electronic structure elastic property first principles calculation

The Predictability of Ocean Environments that Contributed to the 2020/21 Extreme Cold Events in China:2020/21 La Niña and 2020 Arctic Sea Ice Loss

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Advances in Atmospheric Sciences 2022年第4期39卷 658-675页

作者： Fei ZHENG ji-ping liu Xiang-Hui FANG Mi-Rong SONG Chao-Yuan YANG Yuan YUAN Ke-Xin LI ji WANG jiang ZHU International Center for Climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China Department of Atmospheric and Environmental Sciences University at Albany State University of New YorkAlbanyNY 12222USA Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China National Climate Center Beijing 100081China University of Chinese Academy of Sciences Beijing 100049China Beijing Municipal Climate Center Beijing 100089China

Several consecutive extreme cold events impacted China during the first half of winter 2020/21,breaking the low-temperature records in many *** to make accurate climate predictions of extreme cold events is still an urgent *** synergistic effect of the warm Arctic and cold tropical Pacific has been demonstrated to intensify the intrusions of cold air from polar regions into middle-high latitudes,further influencing the cold conditions in ***,climate models failed to predict these two ocean environments at expected lead *** seasonal climate forecasts only predicted the 2020/21 La Niña after the signal had already become apparent and significantly underestimated the observed Arctic sea ice loss in autumn 2020 with a 1-2 month *** this work,the corresponding physical factors that may help improve the accuracy of seasonal climate predictions are further *** the 2020/21 La Niña prediction,through sensitivity experiments involving different atmospheric-oceanic initial conditions,the predominant southeasterly wind anomalies over the equatorial Pacific in spring of 2020 are diagnosed to play an irreplaceable role in triggering this cold event.A reasonable inclusion of atmospheric surface winds into the initialization will help the model predict La Niña development from the early spring of *** predicting the Arctic sea ice loss in autumn 2020,an anomalously cyclonic circulation from the central Arctic Ocean predicted by the model,which swept abnormally hot air over Siberia into the Arctic Ocean,is recognized as an important contributor to successfully predicting the minimum Arctic sea ice extent.

关键词： extreme cold event predictability La Niña Arctic sea ice loss

Clathrin-dependent endocytosis predominantly mediates protein absorption by fat body from the hemolymph in Bombyx mori

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Insect Science 2020年第4期27卷 675-686页

作者： Yu-jie Wang Shu-Yan Li jia-Ye Zhao Kang Li jing Xu Xian-Ying Xu Wen-Mei Wu Rong Yang Yang Xiao Ming-Qiang Ye ji-ping liu Yang-jin Zhong Yang Cao Hui-Yu Yi Ling Tian Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center College of Animal ScienceSouth China Agricultural UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology Institute of Insect Science and TechnologySchool of Life SciencesSouth China Normal UniversityGuangzhouChina The Sericultural and Agri-Food Research Institute of the Guangdong Academy of Agricultural Sciences GuangzhouChina

During insect larval-pupal metamorphosis,proteins in the hemolymph are absorbed by the fat body for the maintenance of intracellular homeostasis;however,the type of proteins and how these proteins are internalized into the fat body are *** Bombyx mori,the developmental profiles o f total proteins in the hemolymph and fat body showed that hemolymph-decreased protein bands(55-100 kDa)were in accordance with those protein bands that increased in the fat *** o f clathrin-dependent endocytosis predominantly blocked the transportation o f 55-100 kDa proteins from the hemolymph into the fat body,which was further verified by RNA interference treatment o f *** hexamerins were shown to comprise〜90%of the total identified proteins in both the hemolymph and fat body by mass spectrum(MS)*** addition,hemolymphspecific proteins were mainly involved in material transportation,while fat body-specific proteins particularly participated in *** this paper,four hexamerins were found for the first time,and potential proteins absorbed by the fat body from the hemolymph through clathrin-dependent endocytosis were *** study sheds light on the protein absorption mechanism during insect metamorphosis.

关键词： Bombyx mori clathrin-mediated endocytosis fat body hemolymph uptake of proteins

大麦与纤毛鹅观草属间杂种F_5和BC_1F_4的同工酶研究

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Acta Botanica Sinica 1998年第3期40卷 263-269页

作者：李万几李逸平刘芳四川农业大学小麦研究所

对栽培大麦（ＨｏｒｄｅｕｍｖｕｌｇａｒｅＬ．品种“Ａｒｕｐｏ”）与纤毛鹅观草（Ｒｏｅｇｎｅｒｉａｃｉｌｉａｒｉｓ（Ｔｒｉｎ．）Ｎｅｖｓｋｉ）属间杂种后代Ｆ５和回交后代ＢＣ１Ｆ４（以“Ａｒｕｐｏ”作回交亲本）的不同类型... 详细信息

对栽培大麦（ＨｏｒｄｅｕｍｖｕｌｇａｒｅＬ．品种“Ａｒｕｐｏ”）与纤毛鹅观草（Ｒｏｅｇｎｅｒｉａｃｉｌｉａｒｉｓ（Ｔｒｉｎ．）Ｎｅｖｓｋｉ）属间杂种后代Ｆ５和回交后代ＢＣ１Ｆ４（以“Ａｒｕｐｏ”作回交亲本）的不同类型株系与其双亲的幼根、幼芽、幼穗、幼嫩籽粒分别进行了酯酶、过氧化物酶同工酶分析。结果Ｆ５和ＢＣ１Ｆ４各株系的酯酶同工酶、过氧化物酶同工酶酶谱具有母本“Ａｒｕｐｏ”全部或绝大多数酶带，父本Ｒ．ｃｉｌｉａｒｉｓ的１～３条酶带和数量不等的双亲所没有的新酶带，也出现酶带的减少。结果表明，纤毛鹅观草的遗传物质已稳定地遗传给了其自交和回交后代。酶谱变异与植株习性出现一定程度的关联。由于在不同时期内结构基因的表达起不同作用，因此，在用同工酶分析法鉴定易位系时，最好不同的器官采用不同的酶类或一种同工酶多时期连续分析。

关键词：栽培大麦纤毛鹅观草属间杂种酯酶过氧化物酶

Adaptive Inverse Optimal Control for a Class of Nonlinear System

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Adaptive Inverse Optimal Control for a Class of Nonlinear Sy...

第三十届中国控制会议

作者： WANG Jun,ji ping,CHU Zhong,liu Wei Key Lab of Machine Vision and Intelligence Control Technology,Hefei University,Hefei 230601,P.R.China

＜正＞This paper introduces the basic idea of adaptive inverse optimal control,gives the solvable theorem of inverse optimal gain assignment problem,design inverse optimal controller using Backstepping algorithm and an adaptive update law for strict-feedback nonlinear continuous system with unknown time-varing bounded disturbance and constant unknown parameters,which is nonlinear,continuous and easier to *** adaptive control law and the parameter update laws can be obtained at the same time by this design *** results designed show simultaneously that inverse optimal systems yield stability margins,namely,achieving locally robustness,which is a nonlinear analog of Kalman’s margins for the linear quadratic regulator.

关键词： Strict-Feedback System Unknown Time-Varing Bounded Disturbance Inverse Optimal Backstepping Algorithm Adaptive

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利用相位共轭技术补偿光纤中色散效应的条件

光学学报 1989年第1期9卷 81-87页

作者：宁继平刘进军姚建铨吴元生天津大学精仪系激光教研室

利用相位共轭器的频率反转特性的,补偿光纤中的色散效应,在理论上和实验上得到了证明.由色散脉冲的傅里叶交换确定了光纤中二次色散效应可以被忽略的条件,得到了共轭器的反射率和带宽与非线性介质的长度L,参数|K|L之间的关系曲线,找到... 详细信息

利用相位共轭器的频率反转特性的,补偿光纤中的色散效应,在理论上和实验上得到了证明.由色散脉冲的傅里叶交换确定了光纤中二次色散效应可以被忽略的条件,得到了共轭器的反射率和带宽与非线性介质的长度L,参数|K|L之间的关系曲线,找到了影响补偿效果的主要因素.

关键词：相位共轭光纤色散效应

Gut microbiota-astrocyte axis: new insights into age-related cognitive decline

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Neural Regeneration Research 2025年第4期20卷 990-1008页

作者： Lan Zhang jingge Wei Xilei liu Dai Li Xiaoqi Pang Fanglian Chen Hailong Cao ping Lei Haihe Laboratory of Cell Ecosystem Department of GeriatricsTianjin Medical University General HospitalTianjinChina Tianjin Geriatrics Institute Tianjin Medical University General HospitalTianjinChina Department of Gastroenterology and Hepatology Tianjin Medical University General HospitalNational Key Clinical SpecialtyTianjin Institute of Digestive DiseasesTianjin Key Laboratory of Digestive DiseasesTianjinChina Department of Urology Tianjin Medical University General HospitalTianjinChina Tianjin Neurological Institution Tianjin Medical University General HospitalTianjinChina

With the rapidly aging human population,age-related cognitive decline and dementia are becoming increasingly prevalent *** is considered the main risk factor for cognitive decline and acts through alterations in the composition of the gut microbiota,microbial metabolites,and the functions of *** microbiota–gut–brain axis has been the focus of multiple studies and is closely associated with cognitive *** article provides a comprehensive review of the specific changes that occur in the composition of the gut microbiota and microbial metabolites in older individuals and discusses how the aging of astrocytes and reactive astrocytosis are closely related to age-related cognitive decline and neurodegenerative *** article also summarizes the gut microbiota components that affect astrocyte function,mainly through the vagus nerve,immune responses,circadian rhythms,and microbial ***,this article summarizes the mechanism by which the gut microbiota–astrocyte axis plays a role in Alzheimer’s and Parkinson’s *** findings have revealed the critical role of the microbiota–astrocyte axis in age-related cognitive decline,aiding in a deeper understanding of potential gut microbiome-based adjuvant therapy strategies for this condition.

关键词： age aging Alzheimer’s disease astrocytes cognitive decline dementia gut microbiota gut–brain axis microbial metabolites neuroinflammation Parkinson’s disease