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Bat Head Contains Soft Magnetic Particles:Evidence From Magnetism

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Bat Head Contains Soft Magnetic Particles:Evidence From Magn...

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Lanxiang Tian,~1 Wei Lin,~1Shuyi Zhang,~2and yongxin pan~(1*) 1 Biogeomagnetism Group,Paleomagnetism and Geochronology Laboratory, Key Laboratory of the Earth’s Deep Interior,Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing,China 2 School of Life Sciences,East China Normal University,Shanghai,China

Recent behavioral observations have indicated that bats can sense the Earth’s magnetic field. To unravel the magnetoreception mechanism,the present study has utilized magnetic measurements on three migratory species(Miniopterus fuliginosus,Chaerephon plicata,and Nyctalus plancyi)and three non-migratory species(Hipposideros armiger,Myotis ricketti,and Rhinolophus ferrumequinum). Room temperature isothermal remanent magnetization acquisition and alternating-field demagnetization showed that the bats’ heads contain soft magnetic *** analyses indicated that the saturation isothermal remanent magnetization of brains(SIRM)of migratory species is higher than those of non-migratory ***,the SIRMof migratory bats is greater than their ***-temperature magnetic measurements suggested that the magnetic particles are likely magnetite(FeO).This new evidence supports the assumption that some bats use magnetite particles for sensing and orientation in the Earth’s magnetic field.

关键词： bat magnetoreceptor magnetic measurements migratory non-migratory

基于多元离群点检测的动态目标去除SLAM方法

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探测与控制学报 2024年第5期46卷 64-70页

作者：王磊张茗宇潘明然张永鑫郝涌汀沈阳理工大学机械工程学院辽宁沈阳110159 辽沈工业集团研发中心辽宁沈阳110045

考虑动态环境下的目标移动对同步定位与建图(SLAM)位姿估计精度的影响,提出一种通过稠密光流计算像素运动并经过离群点检测的动态目标SLAM算法。采用稠密光流法计算图像序列的每个像素的运动信息进行动态目标判断,利用离群点检测对动态... 详细信息

考虑动态环境下的目标移动对同步定位与建图(SLAM)位姿估计精度的影响,提出一种通过稠密光流计算像素运动并经过离群点检测的动态目标SLAM算法。采用稠密光流法计算图像序列的每个像素的运动信息进行动态目标判断,利用离群点检测对动态目标进行提取,通过均值滤波对动态目标进行模糊剔除,消除动态目标对SLAM精度的影响。在TUM数据集与定制数据集上进行实验,在TUM数据集测试中,与基于特征点法的Orb-slam3标杆算法进行对比分析,在动态目标影响条件下,该算法得到的轨迹误差降低43.25%;搭建开放式四旋翼无人机测试系统,在定制数据集中,进行飞行试验,得到的估计轨迹位置误差控制在1 m内,满足使用场景要求,进一步验证了算法的有效性。

关键词：同步定位与建图稠密光流位姿估计动态目标离群点检测

Magnetic polarity ages of the fossil-bearing strata at the Sihetun section,West Liaoning:A preliminary result

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Magnetic polarity ages of the fossil-bearing strata at the S...

中国科学院地质与地球物理研究所2001学术年会

作者： pan yongxin~1,ZHU Rixiang~1,John Shaw~2 & ZHOU Yaoxiu~3 1.Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing 100101,China 2.Geomagnetism Laboratory,University of Liverpool,Liverpool L69 7ZE,UK 3.The Aviatic Remote Sensing Center,Ministry of Land and Resources, Beijing 100083,China

Rock-magnetic and palaeomagnetic studies have been carried out on the interval of famous fossil -bearing sedimentary rocks and its overlying basalts and underlying basalts at the Sihetun section,West Liaoning *** polarity was obtained for the sedimentary interval and the underlying basalts,while reversed polarity was found in the overlying *** account of the new Ar/(39)Ar ages(Swisher et al.,1999),we classified the fossil-bearing sedimentary interval into the Barremian M3n zone(Early Cretaceous age).Several abnormal horizons on magnetic properties,probably corresponding to the tuffs, were observed in the fossil-bearing sedimentary interval. This implies that the massive bio-extinction may link to dramatic environmental changes that were caused by volcanic eruptions.

关键词： magnetic polarity age Jehol fauna Sihetun section

Snapping magnetosome chains by asymmetric cell division in magnetotactic bacteria

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Snapping magnetosome chains by asymmetric cell division in m...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Wei Lin~(1,2) and yongxin pan~(1,2*) 1 Biogeomagnetism Group,Paleomagnetism and Geochronology Laboratory,Key Laboratory of the Earth’s Deep Interior,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China. 2 France-China Bio-Mineralization and Nano-Structures Laboratory,Chinese Academy of Sciences,Beijing 100029,China.

Summary The mechanism by which prokaryotic cells organize and segregate their intracellular organelles during cell division has recently been the subject of substantial *** other microorganisms,magnetotactic bacteria(MTB) form internal magnets(known as mag-netosome chain) for magnetic orientation,and thus face an additional challenge of dividing and equiparti-tioning this magnetic receptor to their daughter cells. Although MTB have been investigated more than four decades,it is only recently that the basic mechanism of how MTB divide and segregate their magnetic organelles has been *** this issue of Molecular Microbiology,the cell cycle of the model magnetotactic bacterium,Magnetospirillum gryph-iswaldense is characterized by Katzmann and *** authors have found that ***-iswaldense undergoes an asymmetric cell division along two planes.A novel wedge-like type of cellular constriction is observed before separation of daughter cells and magnetosome chains,which is assumed to help cell cope with the magnetic force within the mag-netosome *** data shows that the magneto- some chain becomes actively recruited to the cellular division site,in agreement with the previous suggestions described by Staniland et al.(2010),and the actin-like protein MamK is likely involved in this fast polar-to-midcell *** the use of cryo-electron tomography,an arc-shaped Z ring is observed near the division site,which is assumed to trigger the asymmetric septation of cell and magneto-some chain.

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基于电碳联合机制的电动汽车共享充电两阶段博弈协同调度策略

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电网技术 2024年第9期48卷 3584-3594,I0017,I0018,I0019页

作者：陈颉张晓东李隆意张鸿伟潘瑞苏永新湘潭大学自动化与电子信息学院湖南省湘潭市411105 国网湖南省电力公司岳阳供电分公司湖南省岳阳市414000

针对电力需求响应机制下电动汽车(electric vehicle,EV)共享充电调度场景中多元主体决策间的复杂博弈关系,该文提出了一种基于电-碳联合机制的EV共享充电两阶段博弈协同调度策略。首先,依据电-碳联合市场交易利润导向,构建第一阶段完全... 详细信息

针对电力需求响应机制下电动汽车(electric vehicle,EV)共享充电调度场景中多元主体决策间的复杂博弈关系,该文提出了一种基于电-碳联合机制的EV共享充电两阶段博弈协同调度策略。首先,依据电-碳联合市场交易利润导向,构建第一阶段完全信息动态博弈的电-碳联合竞价策略;其次,依据电-碳联合市场分配导向,构建第二阶段序贯博弈的电-碳联合分配策略。该两阶段策略分别采用交替方向乘子(alternating direction method of multipliers,ADMM)和最优响应算法进行优化,确保多主体共享充电最优均衡。算例分析表明,该策略可促进各主体参与电-碳联合市场交易,在确保自身利益最大化的前提下,实现EV充电负荷和共享充电设施合理匹配,降低充电成本,优化EV共享充电期间的碳排放量,其对“碳达峰、碳中和”政策实施意义重大。

关键词：博弈优化电动汽车共享充电电-碳联合机制

The tribological behavior of a surface-nanocrystallized magnesium alloy AZ31 sheet after ultrasonic shot peening treatment

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Journal of Magnesium and Alloys 2021年第4期9卷 1190-1203页

作者： Jianyue Zhang yongxin Jian Xuzhe Zhao Dean Meng Fusheng pan Qingyou Han School of Engineering Technology Purdue UniversityWest LafayetteIN 47906USA State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049PR China Böllhoff Inc TroyMI 48084USA School of Automobile Chang’an UniversityXi’an 710064PR China College of Materials Science and Engineering Chongqing UniversityChongqing 400045PR China

A magnesium alloy AZ31 sheet was processed by ultrasonic shot peening treatment to fabricate a surface nanocrystalline,and a ball-on-disk dry sliding wear test was performed to evaluate the tribological behavior after *** microstructure observation indicated a gradient nanocrystalline structure was formed after USSP *** microhardness at the top surface was improved from 60 HV to 145 HV after *** formed nanocrystalline resulted in an easy formation of MgO patches on the surface and reduced the coefficient of ***,the formed nanocrystalline leaded to a retard of delamination with increasing the sliding speed and applied load,which was due to its stronger *** high sliding speed(0.5 m/s)and high applied load(50 N),it was firstly found that the formed nanocrystalline prevented the happening of thermal softening and *** possible reasons accounting for the prevention of thennal softening and melting were discussed accordingly.

关键词： AZ31Mg alloy Ultrasonic shot peening Surface-nanocrystallization Wear mechanism

Testing for the presence of magnetite in theupper-beak skin of homing pigeons

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Testing for the presence of magnetite in theupper-beak skin ...

中国科学院地质与地球物理研究所2006学术年会

作者： Lanxiang Tian~1,Bo Xiao~1,Wei Linl,Shuyi Zhang~2,Rixiang Zhu~1 & yongxin pan~(1,*) (1 Paleomagnetism and Geochronology Laboratory(SKL-LE),Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing,100029,China 2 Institute of Zoology,Chinese Academy of Sciences,Beijing, 100080,China

We carried out magnetic and nonmagnetic experiments on fresh,upper-beak skin tissue samples isolated from six pairs of homing pigeons to test whether the tissue contains magnetite *** of(1) room-temperature isothermal remanent magnetization(IRM) acquisition and alternating field(AF) demagnetization,(2) low-temperature demagnetization of saturation IRM acquired at 5 K in a field of 5 tesla(T)(SIRM5 K) after zero-field cooled(ZFC) and field cooled(FC) treatments,and(3) cycling of the saturation IRM acquired at 300 K in a field of 5 T(SIRM300 K) between 5 and 300 K,indicate the presence of magnetite in the measured samples.A significant loss of SIRM5 K below 20 K suggests the dominance of superparamagnetic(SPM) *** SIRM acquisition capacity of the female pigeon is stronger than that of the male pigeon in all four measured pairs,suggesting for the first time that the magnetite concentration is probably sex *** microscopic observation on the histological sections stained with Prussian Blue detected the presence of some tiny,dotted, dark-blue staining Fe3+ aggregates(size 1-4 /m) located directly beneath the subcutis within strands of connective tissue,nearby the rim of the regions full of red *** results of this study support the idea that homing pigeons may have a magnetite-based receptor,which potentially could be used for sensing the Earth magnetic field during navigation.

关键词： homing pigeon Columbia livia magnetite SQUID magnetometer Low-temperature magnetic property Prussian Blue reaction

Magnetostratigraphic age of the Xiantai Paleolithic site in the Nihewan Basin and implications for early human colonization of Northeast Asia

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Magnetostratigraphic age of the Xiantai Paleolithic site in ...

中国科学院地质与地球物理研究所2006学术年会

作者： Chenglong Deng~a,Qi Wei~b,Rixiang Zhu~a,Hongqiang Wang~a,Rui Zhang~a,Hong Ao~a,Liao Chang~c, yongxin pan~a a Paleomagnetism and Geochronology Laboratory(SKL-LE),Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China b Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044, China c School of Ocean and Earth Science,University of Southampton,Southampton SO14 3ZH,UK

Timing of the early habitation and stone technologies in the Nihewan Basin,North China has provided insights into our understanding of early human adaptability to high northern latitudes in East *** we contribute to this topic with detailed magnetostratigraphic investigation,coupled with mineral magnetic measurements and palynological analyses on a lacustrine sequence in this basin,which contains the Xiantai Paleolithic *** and hematite were identified as the main carriers for the characteristic remanent magnetizations. Magnetostratigraphic results show that the Xiantai lacustrine sequence recorded the Brunhes chron,the Jaramillo and the Olduvai subchrons,and successive reverse polarity portions of the intervening Matuyama *** correlation in terms of lithology,magnetic susceptibility and magnetic polarity sequences between the Xiantai and Xiaochangliang sections indicates that the Xiantai artefact layer is readily contemporary with the Xiaochangiiang artefact layer,which has been previously estimated to be about 1.36 Ma[***,***,***, ***,***,***,***,***,***,***,***,Earliest presence of humans in northeast Asia,Nature 413(2001) 413-417.[1]].Early humans of the Xiantai Paleolithic site lived in a steppe paleoenvironment indicated from fossil pollens. Furthermore,the combined evidence of our magnetostratigraphy and previously published magnetochronology and paleoclimate data documents that early humans of North China were able to adjust to an increasing variability of paleoclimates and paleoenvironments over the Early Pleistocene.

关键词： magnetostratigraphy Xiantai Paleolithic site Nihewan Basin Early Pleistocene human evolution

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江西官山濒危植物穗花杉种群结构与动态

江西农业大学学报 2023年第6期45卷 1418-1430页

作者：胡千惠陈琳赖媛彭巧华方平福张盼盼廖婷高建新潘永鑫杨清培江西农业大学林学院/江西省竹子种质资源与利用重点实验室江西南昌330045 江西官山国家级自然保护区管理局江西宜春336000

【目的】穗花杉是我国特有的珍稀濒危植物,具有较高的观赏价值和经济价值,是生物多样性的重要组成部分,分布较广但是数量稀少。旨在研究其种群年龄结构和数量动态变化并分析其产生原因,从而为其保育策略提供理论基础。【方法】在江西官... 详细信息

【目的】穗花杉是我国特有的珍稀濒危植物,具有较高的观赏价值和经济价值,是生物多样性的重要组成部分,分布较广但是数量稀少。旨在研究其种群年龄结构和数量动态变化并分析其产生原因,从而为其保育策略提供理论基础。【方法】在江西官山国家级自然保护区采用样地调查法,设立7个20 m×20 m的穗花杉样地(GS-01、GS-02、GS-03、GS-04、GS-05、GS-06、GS-07),对其物种组成、数量、胸径等数据进行调查分析。采用径级结构代替年龄结构的方法,探讨江西官山穗花杉种群的年龄结构,并绘制出静态生命表,得出种群存活曲线、死亡曲线、生存函数曲线和时间序列预测表。【结果】(1)7个样地共有物种33科56属67种,构成群落的优势科是樟科Lauraceae、山茶科Theaceae、壳斗科Fagaceae,穗花杉在不同样地的不同冠层中的优势地位不同,如在乔木层中,GS-24样地穗花杉重要值最大(64.95),GS-28样地穗花杉重要值最小(4.24)。(2)不同样地内的穗花杉种群年龄结构不同,GS-01、GS-02、GS-07样地的穗花杉种群年龄结构为增长型,GS-03、GS-04、GS-05、GS-06样地穗花杉年龄结构为稳定型。(3)随着龄级的增加,穗花杉的标准化存活率(lx)、龄级间存活数(Lx)、期望寿命(Ex)逐渐降低,龄级间死亡率(qx)、致死力(Kx)逐渐增加,标准化死亡数(dx)在第Ⅲ龄级最高,随后逐渐降低。(4)穗花杉种群存活曲线趋于Deevey-Ⅱ型。(5)根据4种生存函数的分析可以发现,穗花杉在幼苗时期发育状况比较平稳,到达中小径级后发育速率明显增加,而老年个体的发育速率则比较迟缓。(6)在经历了2、3、4个龄级时间后,随着时间推移,各个龄级时间之后的穗花杉种群个体数量均出现小幅度增加。【结论】研究穗花杉的存活现状以及原因,并对未来进行预测,这对于制定穗花杉相关的保护措施具有重要的意义。研究中江西官山穗花杉种群的年龄结构属于增长型,穗花杉的种群动态和时间序列预测总的来看表现为增长的趋势。总体来看江西官山穗花杉种群的生长状况较为良好,形成了较为稳定的群落结构,建议减少人类活动对这片区域的干扰,让穗花杉幼苗能保持增长的趋势,以不断补充穗花杉种群内衰老的个体。

关键词：穗花杉年龄结构静态生命表生存函数时间序列预测数量动态