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银河系结构的再认识——3.星流和潮汐尾
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作者 赵君亮 《自然杂志》 北大核心 2014年第4期235-240,共6页
银晕外区存在众多的星流,它们或源自银河系的矮伴星系,或源自球状星团。星流可以利用各类示踪星,并通过不同的途径来加以研究,对于探索银河系演化史和银河系暗晕的形状具有重要意义。
关键词 银河系 星流 人马星流 球状星团 潮汐尾
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GD-1星流金属丰度与运动特性分析
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作者 吴兴华 石维彬 +2 位作者 陈天翔 张哲 宋汉峰 《天文学报》 CAS CSCD 北大核心 2021年第2期63-73,共11页
星流在星系形成与演化过程中扮演了重要的角色,对银河系中星流的研究将有助于进一步探究银河系的合并历史.将LAMOST(Large Sky Area Multi-Object Fiber Spectroscopic Telescope)DR6光谱数据以及SDSS(Sloan Digital Sky Survey)DR12光... 星流在星系形成与演化过程中扮演了重要的角色,对银河系中星流的研究将有助于进一步探究银河系的合并历史.将LAMOST(Large Sky Area Multi-Object Fiber Spectroscopic Telescope)DR6光谱数据以及SDSS(Sloan Digital Sky Survey)DR12光谱数据分别与Gaia(Global Astrometric Interferometer for Astrophysics)DR2天体测量数据交叉匹配,获得恒星自行等数据.对GD-1星流在速度空间、几何空间和金属丰度上进行限制,从LAMOST DR6和SDSS DR12数据中共获得了157颗星流成员星.GD-1星流的平均金属丰度为[Fe/H]=-2.16±0.10 dex,延伸长度超过80°.收集前人给出的GD-1星流高概率成员星,组成较大的成员星样本进行对比分析,发现GD-1星流的金属丰度分布呈现内低外高的特点,沿着星流方向径向速度分布特点是两端大、中间小,ϕ_(1)=-20°(ϕ_(1)为GD-1星流坐标系横坐标)和ϕ_(1)=-60°附近的间隙是因为成员星运动差异形成的.根据成员星分布及其速度分布特性,推测GD-1星流起源位置是在ϕ_(1)=-40°附近. 展开更多
关键词 星流:运动 星流:恒星金属丰度 球状星团:瓦解 观测数据:郭守敬望远镜
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星流的搜寻 被引量:5
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作者 田浩 姜碧沩 《天文学进展》 CSCD 北大核心 2012年第1期64-76,共13页
在冷暗物质的宇宙学模型框架里,银河系(尤其是银晕)至少部分起源于对周围卫星星系的吸积。随着新技术和新设备的不断应用,大规模巡天项目的成功实施使天文学家获得了越来越多、越来越全面的关于银河系的数据。通过对这些数据进行分析,... 在冷暗物质的宇宙学模型框架里,银河系(尤其是银晕)至少部分起源于对周围卫星星系的吸积。随着新技术和新设备的不断应用,大规模巡天项目的成功实施使天文学家获得了越来越多、越来越全面的关于银河系的数据。通过对这些数据进行分析,天文学家发现了很多星流的候选体,为银河系的等级并合理论提供了观测上的证据。随着对星流研究的扩大和深入,人们对银河系及其结构和起源的了解也越来越详细。介绍了搜寻星流的方法,以及基于这些方法获得的星流研究结果。 展开更多
关键词 银河系 星流 银晕 演化
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《星流发愿文》与归义军初期时势研究 被引量:1
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作者 赵玉平 李沁 《中州学刊》 CSSCI 北大核心 2016年第9期142-148,共7页
敦煌文献P.2854《星流发愿文》为唐代敦煌归义军政权初期写本,用于观测到"星流变异"天象后举办佛教禳灾斋会时僧人祈愿宣诵。"星流变异"在中国传统星占中多预示凶兆,且在史籍中大都附会于国家政治军事时势。敦煌归... 敦煌文献P.2854《星流发愿文》为唐代敦煌归义军政权初期写本,用于观测到"星流变异"天象后举办佛教禳灾斋会时僧人祈愿宣诵。"星流变异"在中国传统星占中多预示凶兆,且在史籍中大都附会于国家政治军事时势。敦煌归义军政权初期受到来自唐王朝、周边吐蕃势力及西州回鹘等多方面的外部军事压力,张氏统治阶层内部也因权力斗争而暗流涌动。借助禳灾斋会这一形式,不仅可强化归义军辖下民众对张氏家族统治的认同感,亦可平抑政权内部斗争而潜藏的危机。 展开更多
关键词 敦煌 归义军 星流 禳灾 斋会
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“二星流”的发现及其在星系动力学形成和发展中的作用 被引量:1
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作者 丁蔚 《自然科学史研究》 1986年第2期179-192,共14页
1904年,荷兰天文学家J.C.Kapteyn(1851-1922)研究恒星运动的规律,发现了恒星在银道面内有两个优先运动的方向。基于这一现象,他提出"二星流"的假设,认为恒星除了太阳运动引起的视差动外,在银道面内还存在着彼此相背而行的两... 1904年,荷兰天文学家J.C.Kapteyn(1851-1922)研究恒星运动的规律,发现了恒星在银道面内有两个优先运动的方向。基于这一现象,他提出"二星流"的假设,认为恒星除了太阳运动引起的视差动外,在银道面内还存在着彼此相背而行的两大星流。" 展开更多
关键词 星系动力学 恒星自行 银河系自转 星流 速度椭球 较差自转 银道面 天文学家 奔赴点 椭球分布
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三星流
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作者 任雪松 《商务周刊》 2002年第17期42-46,共5页
不再是染黄的头发、颜色鲜艳的奇装异服、让人陷入狂热的韩剧韩星,三星公司——一个索尼、东芝惊惧的对手,他带来的“新韩流”是处于时尚前沿的手机、MP3播放器、等离子电视……
关键词 星流 三星电子公司 激光打印机 三星公司 代理商 终端销售商 总代理 消费者 出货量 数码时代
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6月深空指南——沿着银河的星流
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作者 马劲 《天文爱好者》 2024年第5期16-17,共2页
沿着银河南下,在天鹰座与盾牌座交界处,有一片亮星、暗星云集的区域,甚是精彩,无数暗星聚集成一片恒星云,是银河中较为明亮的一块,也是本月深空天体的背景舞台。
关键词 暗星云 星流 恒星云 银河 深空 天体 聚集
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银河系恒星潮汐流的探测进展
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作者 赵君亮 《天文研究与技术》 CSCD 2014年第4期323-334,共12页
银晕外区存在众多星流,它们或源自银河系的矮伴星系,或源自晕族球状星团,常分别称为矮星系星流和球状星团潮汐尾。星流可以利用各类示踪星,并通过不同的途径加以探测,对若干代表性矮星系星流和球状星团潮汐尾的探测进展做了简要的介绍。
关键词 银河系 星流 人马星流 球状星团 潮汐尾 暗晕
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卡普坦在恒星天文学上的贡献 被引量:1
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作者 丁蔚 《自然辩证法通讯》 1988年第1期32-38,共7页
卡普坦(J.C.Kapteyn)是本世纪初极有影响的荷兰天文学家,恒星天文学的先驱者。1851年1月19日生于巴内韦尔德,1922年6月18日卒于阿姆斯特丹,享年71岁。1875年毕业于乌德勒支大学,获物理学博士学位。后到莱顿大学天文台任职,开始天文研究... 卡普坦(J.C.Kapteyn)是本世纪初极有影响的荷兰天文学家,恒星天文学的先驱者。1851年1月19日生于巴内韦尔德,1922年6月18日卒于阿姆斯特丹,享年71岁。1875年毕业于乌德勒支大学,获物理学博士学位。后到莱顿大学天文台任职,开始天文研究。自1878年起任格罗宁根大学天文学和理论力学教授。1884年在该校创建卡普坦天文实验室,任实验室主任,直至1921年退休。 展开更多
关键词 恒星天文学 银河系结构 天文学家 天文台 视星等 星流 天文研究 星系动力学 光度函数 观测资料
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银河系吸积和并合历史的研究
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作者 张子键 赵刚 《天文学进展》 CSCD 北大核心 2022年第4期506-534,共29页
冷暗物质模型预言银河系是由许多小的矮星系吸积和并合形成的,矮星系吸积和并合的过程会在银河系留下星流等子结构,通过对这些子结构进行探测和研究有助于更好地还原银河系形成历史。简要回顾关于银河系吸积和并合起源的研究历史,总结... 冷暗物质模型预言银河系是由许多小的矮星系吸积和并合形成的,矮星系吸积和并合的过程会在银河系留下星流等子结构,通过对这些子结构进行探测和研究有助于更好地还原银河系形成历史。简要回顾关于银河系吸积和并合起源的研究历史,总结了星流早期、中期、晚期在位置空间、运动学空间和化学空间的不同特点和分布;详细介绍了从这三个不同相空间探测和研究星流等子结构的方法。介绍了对两个典型子结构的研究结果,对这两个星流的详细研究有助于研究银河系的结构及其吸积和并合起源;此外给出了目前探测到的星流等子结构的列表。最后结合Gaia,对LAMOST Ⅱ期工程、CSST以及Subaru/PFS等光谱巡天项目开展银河系吸积和并合历史研究的前景进行了展望。 展开更多
关键词 银河系演化 吸积 并合 星流
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银河为何“荡漾”?新研究找到答案
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作者 《大学科普》 2021年第2期13-13,共1页
LAMOST最新科研进展。仰望星空,银河星波荡漾。这是由于银盘南北两侧存在一些交替出现的“恒星子结构”。长期以来,天文学家对于这些“恒星子结构”的来源争论不休。近日,西华师范大学物理与空间科学学院副研究员李静与国家天文台研究... LAMOST最新科研进展。仰望星空,银河星波荡漾。这是由于银盘南北两侧存在一些交替出现的“恒星子结构”。长期以来,天文学家对于这些“恒星子结构”的来源争论不休。近日,西华师范大学物理与空间科学学院副研究员李静与国家天文台研究员薛香香等研究者利用郭守敬望远镜(LAMOST)和欧空局(ESA)盖亚太空望远镜(Gaia)数据,对位于反银心的麒麟座星环、三角座-仙女座星流和A13等子结构的起源开展研究,证实它们起源于银盘,是银河系外盘的一部分。 展开更多
关键词 仙女座 银盘 太空望远镜 麒麟座 子结构 空间科学 星流 三角座
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古驿通信展新容
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作者 张虎林 《外向经济》 1995年第6期33-33,共1页
驻马店古为萱麻村,明代在此设立驿站,“一驿过一驿,驿骑如星流”,邮驿使这个自然村落由村变镇,逐步繁荣起来,这才有了驻马店,人又称宅驿城。 斗转星移,时光奔流。今日驻马店的通信已洗尽古驿旧容,以崭新的面貌跃入了现代通信的行列。 ... 驻马店古为萱麻村,明代在此设立驿站,“一驿过一驿,驿骑如星流”,邮驿使这个自然村落由村变镇,逐步繁荣起来,这才有了驻马店,人又称宅驿城。 斗转星移,时光奔流。今日驻马店的通信已洗尽古驿旧容,以崭新的面貌跃入了现代通信的行列。 驻马店现为全区邮电通信的中枢,辖九县一市邮电局所194个,全区邮电职工2870人。近些年来。 展开更多
关键词 驻马店 无线移动通信网 邮电通信 星流 邮电职工 星移 自然村落 路端 交换机容量 邮电局
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Mechanisms of Cyclovirobuxine D on APD Prolongation in Rat Ventricular Myocytes 被引量:1
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作者 陈庆文 单宏丽 +2 位作者 王赫 李哲 杨宝峰 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第3期142-147,共6页
Aim To study the effects of cyclovirobuxine D on inward rectifier K^- current(I_(k1) ) > transient outward K^+ current (I_(to)), L-type Ca^(2+) current (I_(Ca-L)), and actionpotential duration (APD) in isolated rat... Aim To study the effects of cyclovirobuxine D on inward rectifier K^- current(I_(k1) ) > transient outward K^+ current (I_(to)), L-type Ca^(2+) current (I_(Ca-L)), and actionpotential duration (APD) in isolated rat ventricular myocytes. Methods The whole cell patch-clamptechniques were used to study the changes of I_(k1), I_(to), I_(Ca-L) and APD in rat ventricularmyocytes. Results Cyclovirobuxine D (1-10 μmol·L^(-1)) significantly prolonged APD_(50) andAPD_(90) in isolated rat ventricular myocytes. Resting potential (RP) was decreased by 10μmol·L^(-1) of cyclovirobuxine D. Cyclovirobuxine D significantly decreased both inward andoutward components of I_(k1) . At - 100 mV, 1 and 10 μmol·L^(-1) of cyclovirobuxine D decreasedI_(k1), density from (-8.0+- 1.1) pA/pF to ( - 4.1 +- 0.7) pA/pF and ( - 3.4 +- 0.8) pA/pF,respectively, whereas at - 30 mV, I-(k1) density was decreased from (1.10 +-0.24) pA/pF to (0.61+-0.18) pA/pF and (0.36+- 0.11) pA/pF, respectively. 1_(to) was markedly inhibited bycyclovirobuxine D from the test potential of 0 mV to + 60 mV. At + 40 mV, 1 and 10μmol·L^(-1) ofcyclovirobuxine D decreased I_(to) density from (8.9+- 2.0) pA/pF to (5.5 +- 1.2) pA/pF and (4.9+-0.9) pA/pF, respectively. Cyclovirobuxine D inhibited I_(Ca-L) in a concentration-dependentmanner. At 10 mV, 1 and 10μmol·L^(-1) of cyclovirobuxine D decreased I_(Ca-L) density from ( - 9.9+- 1.8) pA/pF to ( - 6.4 +- 1.4) pA/pF and (-4.2+-0.6) pA/pF, respectively. ConclusionCyclovirobuxine D significantly prolonged APD and inhibited I_(k1), I_(to), and I_(Ca-L) in ratventricular myocytes. The inhibitory effects of cyclovirobuxine D on _(k1) and I_(to) are majormolecular mechanisms of APD prolongation in rat. 展开更多
关键词 cyclovirobuxine D CARDIOMYOCYTES ion channels APD potassium channels L-type ca^(2+) current
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Shear-Flow Induced Secondary Circulation in Parallel Underwater Topographic Corrugation and Its Application to Satellite Image Interpretation 被引量:2
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作者 ZHENG Quanan ZHAO Qing +5 位作者 YUAN Yeli LIU Xian HU Jianyu LIU Xuehai YIN Liping YE Xiaomin 《Journal of Ocean University of China》 SCIE CAS 2012年第4期427-435,共9页
This study aims to figure out satellite imaging mechanisms for submerged sand ridges in the shallow water region in the case of the flow parallel to the topography corrugation.Solving the disturbance governing equatio... This study aims to figure out satellite imaging mechanisms for submerged sand ridges in the shallow water region in the case of the flow parallel to the topography corrugation.Solving the disturbance governing equations of the shear-flow yields the analytical solutions of the secondary circulation.The solutions indicate that a flow with a parabolic horizontal velocity shear and a sinusoidal vertical velocity shear will induce a pair of vortexes with opposite signs distributed symmetrically on the two sides of central line of a rectangular canal.In the case of the presence of surface Ekman layer with the direction of Ekman current opposite to(coincident with) the mean flow,the two vortexes converge(diverge) at the central line of canal in the upper layer and form a surface current convergent(divergent) zone along the central line of the canal.In the case of the absence of surface Ekman layer,there is no convergent(divergent) zone formed over the sea surface.The theoretical results are applied to interpretations of three convergent cases,one divergent case and statistics of 27 cases of satellite observations in the submerged sand ridge region of the Liaodong Shoal in the Bohai Sea.We found that the long,finger-like,bright patterns on SAR images are corresponding to the locations of the canals(or tidal channels) formed by two adjacent sand ridges rather than the sand ridges themselves. 展开更多
关键词 secondary circulation Bohai Sea submerged sand ridges satellite images
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On the asteroid-comet hazard mitigation problem for the earth
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作者 V V Ivashkin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第4期358-362,共5页
In frame of the asteroid-comet hazard problem study, a qualitative analysis of some methods for the effect on a celestial near-Earth object (NEO)-an asteroid, a comet — is carried out. The goal of the effect is a cor... In frame of the asteroid-comet hazard problem study, a qualitative analysis of some methods for the effect on a celestial near-Earth object (NEO)-an asteroid, a comet — is carried out. The goal of the effect is a correction of this object’s orbit, its deflection from the Earth to prevent their collision. There are studied a mechanical impact-kinetic effect of the spacecraft (SC), a thermonuclear effect, an effect on a cometary nucleus for a controlled change of its dusty mantle and, therefore, its sublimation activity. Qualitative models of these effects are developed. Numerical analysis results are given for a group of NEOs such as some asteroids from the Apollo family (Apollo, Castalia, Nereus, Orpheus, Phaethon, Toutatis, etc.) and from the Aten family (Aten, Hathor, Khufu, etc.) as well as some short-periodic comets like the comet P/Biela. There are studied some characteristics of the effects on the NEOs such as the velocity impulse (or acceleration) applied to the celestial body, its deflection from the Earth. The study is supported by the Russian Foundation of Basic Studies (Grant N 01-01-00133). 展开更多
关键词 hazard mitigation asteroid-comet hazard impact-kinetic effect
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Using Satellite Data to Analyze the Initiation and Evolution of Deep Convective Clouds 被引量:1
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作者 CAO Zhi-Qiang HUANG Qing-Ni ZHAO Su-Rong 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第6期445-450,共6页
In this study, two deep convective cloud cases were analyzed in detail to study their initiation and evolution. In both cases, all deep convective clouds were positioned at the rear of the cold front cloud bands and p... In this study, two deep convective cloud cases were analyzed in detail to study their initiation and evolution. In both cases, all deep convective clouds were positioned at the rear of the cold front cloud bands and propagated backward. Satellite data showed that prior to initiation of the deep convective clouds, thermodynamic and moist conditions were favorable for their formation. In the morning, a deep convective cloud at the rear of cold front cloud band propagated backward, the outflow boundary of which created favorable conditions for initiation. An additional deep convective cloud cluster moved in from the west and interacted with the outflow boundary to develop a mesoscale convective system(MCS) with large, ellipse-shaped deep convective clouds that brought strong rainfall. The initiation and evolution of these clouds are shown clearly in satellite data and provide significant information for nowcasting and short-term forecasting. 展开更多
关键词 deep convective clouds satellite data INITIATION EVOLUTION
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Knotted Solitons in an Interacting Mixture of a Charged and a Neutral Superfluid for Neutron Stars
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作者 REN Ji-Rong GUO Heng ZHANG Xin-Hui LI Ran 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第9期555-560,共6页
By making use of the decomposition of U(1) gauge potential theory and the C-mapping method we discuss a mixture of interacting neutral and charged Bose condensates, which is supposed being realized in the interior o... By making use of the decomposition of U(1) gauge potential theory and the C-mapping method we discuss a mixture of interacting neutral and charged Bose condensates, which is supposed being realized in the interior of neutron stars in the form of a coexistent neutron superfluid and protonic superconductor. We propose that this system possesses vortex lines and two classes of knotted solitons. The topological charge of the vortex lines are characterized by the Hopf indices and the Brower degrees of φ-mapping, and the knotted solitons are described by nontrivial Hopf invariant and the BF action respectively. 展开更多
关键词 neutron stars topological excitations spontaneous breaking of gauge symmetries
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Onshore warm tongue and offshore cold tongue in the western Yellow Sea in winter:the evidence 被引量:2
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作者 SUN Junchuan YANG Dezhou +2 位作者 YIN Baoshu CHEN Haiying FENG Xingru 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第5期1475-1483,共9页
A winter onshore warm tongue extending from the Yellow Sea Warm Current to the southern Jiangsu coast, and an of fshore cold tongue extending from the southern Jiangsu coast to the southwest of Jeju Island(South Korea... A winter onshore warm tongue extending from the Yellow Sea Warm Current to the southern Jiangsu coast, and an of fshore cold tongue extending from the southern Jiangsu coast to the southwest of Jeju Island(South Korea), are newly identified based on the sea-surface temperature from satellite remote sensing, and further confirmed by the distribution of suspended sediments. In addition, there are two obvious thermal fronts associated with the onshore warm tongue and off shore cold tongue. The narrow gap between the two thermal fronts is supposed to be the pathway for the off shore transport of cold coastal water and suspended sediments. The concurrence of onshore warm and of fshore cold tongues suggests the concurrence of onshore and off shore currents in the western Yellow Sea in winter, which seems to be inconsistent with the previously accepted view that, in winter, the Yellow Sea Coastal Current flows from the Old Huanghe Delta to the southwest of Jeju Island. This distinctive phenomenon helps establish an updated view of the circulation in the western Yellow Sea in winter. 展开更多
关键词 onshore warm tongue offshore cold tongue cross-shelf exchange western Yellow Sea
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Variability of surface velocity in the Kuroshio Current and adjacent waters derived from Argos drifter buoys and satellite altimeter data 被引量:11
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作者 马超 吴德星 林霄沛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第2期208-217,共10页
By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from ... By combining Argos drifter buoys and TOPEX/POSEIDON altimeter data, the time series of sea-surface velocity fields in the Kuroshio Current (KC) and adjacent regions are established. And the variability of the KC from the Luzon Strait to the Tokara Strait is studied based on the velocity fields. The results show that the dominant variability period varies in different segments of the KC: The primary period near the Luzon Strait and to the east of Taiwan Island is the intra-seasonal time scale; the KC on the continental shelf of the ECS is the steadiest segment without obvious periodicity, while the Tokara Strait shows the period of seasonal variability. The diverse periods are caused by the Rossby waves propagating from the interior ocean, with adjustments in topography of island chain and local wind stress. 展开更多
关键词 ARGOS ALTIMETER KUROSHIO VARIABILITY
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Preliminary Study on the Dynamic Variations of the Surface Thermal Flux before and after the M_S5.7 Earthquake of 2005 in Jiujiang City,Jiangxi Province 被引量:1
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作者 Chen Meihua Deng Zhihui +2 位作者 Wang Yu Liao Zhihui Zu Jinhua 《Earthquake Research in China》 2008年第2期175-184,共10页
The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiuj... The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiujiang City,Jiangxi Province are summarized in this paper.It is found that before the earthquake significant SLHF anomalies and air temperature anomalies occurred in the epicentral area and its vicinity.The air temperature anomalies appeared from the 2nd to the 13th of November,2005 and were concentrated at the epicentral area and in its southern part.Then two days later,that is,from the 4th to the 15th of November 2005,significant SLHF anomalies occurred in the epicentral area and to its northern area where many lakes are distributed along the active faults.During the anomalous period,the SLHF and air temperature at 2m exceeded the sum of average daily value over 26 years and 1.5 times of its mean square deviation.Both anomalies had maintained for 12 days with a peculiar distribution related to the tectonic active zone.It is considered that both of air temperature anomalies and SLHF anomalies are correlated to the movement of thermal flux from underground prior to earthquake.SLHF anomalies occurred over wide regions covered with abundant water,whereas air temperature anomalies occurred over land. 展开更多
关键词 Air temperature Surface latent heat flux Earthquake anomaly Jiujiang earthquake Satellite remote sensing
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