Radio Detection of a Rapid Disturbance Launched by a Solar Flare     

White SM  Janardhan P  Kundu MR 《The Astrophysical journal》2000,533(2):L167-L170

We report the direct observation of motion associated with a solar flare at a speed of 26,000 km s-1. The motion is seen from a radio source at 0.33 GHz, which suddenly starts moving during the flare. At its peak, the radio source covers a quiet region of dimension 500&arcsec;. Emission from any given location is sporadic. The disturbance itself does not seem to radiate, but it excites coronal features that continue to radiate after it passes. The inferred velocity is larger than any previously inferred velocity of a disturbance in the solar atmosphere apart from freely streaming beams of accelerated electrons. The observed motion of the source at a fixed frequency, low polarization, and moderate bandwidth are more consistent with the typical properties of moving type IV radio bursts than with classical coronal shock-associated type II bursts, but any disturbance at such a high velocity must be highly supersonic and should drive a shock. We speculate that the disturbance is associated with the realignment of magnetic fields connecting different portions of an active region.  相似文献   

Characteristics of the Intracontinental Porphyry Deposits in the Middle-Lower Yangtze River Valley Metallogenic Belt, Eastern China     

ZHOU Taof  WANG Shiwei  FAN Yu  YUAN Feng  ZHANG Dayu  Noel White 《《地质学报》英文版》2014,88(Z2):667-669

Please refer to the attachment(s) for more details  相似文献   

Sediments, nutrients and pesticide residues in event flow conditions in streams of the Mackay Whitsunday Region, Australia     

Mitchell C  Brodie J  White I 《Marine pollution bulletin》2005,51(1-4):23-36

The Mackay Whitsunday region covers 9000 km(2) in northeastern Australia. A study of diffuse pollutants during high flow events was conducted in coastal streams in this region. Sampling was conducted in the Pioneer River catchment during a high flow event in February 2002 and in Gooseponds Creek, Sandy Creek and Carmila Creek in March 2003. Concentrations of five herbicides; atrazine (1.3 microg l(-1)), diuron (8.5 microg l(-1)), 2,4-D (0.4 microg l(-1)), hexazinone (0.3 microg l(-1)) and ametryn (0.3 microg l(-1)) and high concentrations of nutrients (total nitrogen 1.14 mg l(-1), total phosphorus 0.20 mg l(-1)) and suspended sediments (620 mg l(-1)) were measured at Dumbleton Weir on the lower reaches of the Pioneer River. Drinking water guidelines for atrazine and 2,4-D were exceeded at Dumbleton Weir, low reliability trigger values for ecosystem protection for diuron were exceeded at three sites and primary industry guidelines for irrigation levels of diuron were also exceeded at Dumbleton Weir. Similar concentrations were found in the three smaller streams measured in 2003. Herbicides and fertilisers used in sugarcane cultivation were identified as the most likely major source of the herbicide residues and nutrients found.  相似文献   

Conceptual models for carbonate aquifers. 1969     

White WB 《Ground water》2012,50(2):180-186

The very diverse types of ground‐water behavior in carbonate terrains can be classified by relating the flow type to a particular hydrogeologic environment each exhibiting a characteristic cave morphology. The ground water may move by diffuse flow, by retarded flow, or by free flow. Diffuse flow occurs in less soluble rocks such as extremely shaley limestones or crystalline dolomites. Integrated conduits are rare. Caves tend to be small, irregular, and often little more than solutionally widened joints. Retarded flows occur in artesian environments and in situations where unfavorable stratigraphy forces ground water to be confined to relatively thin beds. Network cave patterns are characteristic since hydrodynamic forces are damped by the external controls. Solution occurs along many available joints. Free flowing aquifers are those in which solution has developed a subsurface drainage system logically regarded as an underground extension of surface streams. These streams may have fully developed surface tributaries as well as recharge from sinkholes and general infiltration. Characteristic cave patterns are those of integrated conduit systems which are often truncated into linear, angulate, and branchwork caves. Free Flow aquifers may be further subdivided into Open aquifers lying beneath karst plains and Capped aquifers in which significant parts of the drainage net lie beneath an insoluble cap rock. Other geologic factors such as structure, detailed lithology, relief, and locations of major streams, control the details of cave morphology and orientation of the drainage network.  相似文献   

华南后汛期降雨量的振动和分布   总被引：8，自引：0，他引：8  

何有海  关翠华  林锡贵  金祖辉 《热带气象学报》1998,14(4):359-363

对１９５９至１９８８年华南后汛期（７－９月）降雨量距平百分率的大尺度变化特征进行了分析,并与前汛期（４－６月）降雨量的情况进行了比较,同时探讨了后汛期降雨量异常的成因。结果表明,华南后汛期雨量存在明显的年际变化,且地区差异显著;后汛期降雨量的异常与热带西太平洋的海水温度、南海地区大气的对流活动及登陆我国东南沿海地区的热带气旋的频数有关。  相似文献   

冰岛裂谷北部阿斯基亚火山之下岩浆运动引起的下地壳地震     

H.  Soosalu  J.  Key  R.  S.  White  C.  Knox  P.  Einarsson  S.  S.  Jakobsdottir  胡亚轩 《世界地震译丛》2009,(6):19-26

裂谷中的下地壳层通常由于高温而呈韧性,火山岩浆活动会引发地震。冰鸟中大西洋裂谷的特点是热流高,大量岩浆聚集成高达25～30km厚的地壳,在上部8km内常发生地震。2006年7～8月在冰岛北部裂谷带阿斯基亚火山周围布设了20台地震仪进行观测,记录到位于脆韧性边界1700次震源深度为7～8km的上地壳地震;还记录到多数以震群形式发生在其他非震层的下地壳内和完全非震层的中地壳之下14～26km的100个M1〈1．5级小地震。在2007年7～8月的重复测量中,更是观测到2倍以上的下地壳地震事件。大地测量和重力数据显示,在阿斯基亚火山下存在熔岩流,当熔岩从岩浆房通过地壳流向阿斯基亚火山的过程中引发地震,也表明在活动裂谷带中岩浆在张开的岩脉中运移几米距离可引发爆裂。  相似文献   

THE PROVENANCE OF THE DHARAMSALA FORMATION     

Nikki White  Eduardo Garzanti  Malcolm Pringle  Randy Parrish    Geoff Nowell  Yani Najman  Mike Bickle  Peter Friend  Hazel Chapman  Doug Burbank  Ashok Maithani WT  ”BX 《地学前缘》2000,(Z1)

THE PROVENANCE OF THE DHARAMSALA FORMATION1　NajmanY ,GarzantiE .ReconstructingearlyHimalayantectonicevolutionandpaleogeographyfromTertiaryforelandbasinsediments,NorthernIndia[J].GSABulletin ,2 0 0 0 .inpress 2　OliverGJH ,JohnsonMRW ,FallickAE .AgeofmetamorphismintheLesserHimalayaandthemainCentralThrustzone ,GarhwalIndia :resultsofillitecrystallinity ,4 0 Ar 3 9ArfusionandK Arstudies[J].GeolMag 1995 ,132 (2 ) :139～149. 3　PognanteU ,CastelliD ,BennaP ,eta…  相似文献   

杨绳武(1940—1984)事略          下载免费PDF全文

D.E.White  王鸿祯 《地质论评》1985,31(6):576,578

[杨绳武同志因参加中美地质科技协作项目在美不幸因雪崩殉职,已近一年。事件发生后,其在英从学和协作的怀特(D.E.White)博士曾寄我悼唁长函,述及其在英研究完成、但尚未最后定稿的奥陶纪珊瑚专著,并表示将迅速促其出版,其后又为是文悼念,托周志毅同志带来。杨绳武同志在国内工作,广泛涉及区域地层及古生物,并非限于床板珊瑚,留英期间潜心珊瑚研究,以严密系统见长,而不以多建属种为务。归国以后,参加中美协作项目,涉及地质多个方面,实已为一成熟的地质古生物学者。盛年硕学,方期为祖国地质科学争光,猝然离去,痛何如之。观  相似文献   

南海南部海洋上层的热振荡   总被引：17，自引：2，他引：17  

何有海  关翠华  甘子钧 《海洋学报》1992,14(3):19-28

对1961-1973年南海南部(14°N以南,106°-120°E)海区0-400m的温度-深度资料、以2个月为时间步长、在2(经度)×2(纬度)的网格上进行统计,并计算了表层至100m垂直平均温度(TAV)。结果表明,TAV的年平均和季节分布是东南高、西北低,等温线大致呈东北-西南走向。TAV的经验正交函数(EOF)分析结果表明,本海区的TAV有显著的年际变化,存在着约2-4年的振荡周期,且与ENSO事件密切相关。在埃尔尼诺年,本海区的TAV增加,且有沿海盆向赤道增大的趋势。这种异常状况也存在于100m以深水层。在ENSO事件期间等温线普遍下沉,下沉的深度随深度而减少,随纬度由西向东减少,下沉的幅度随ENSO事件、季节及海域而异。究其原因主要与埃尔尼诺年季风减弱和海洋中的涡旋活动变化有关。此外,强副高的影响也使海洋上层得热增多。  相似文献   

太平洋热状况与我国旱涝关系研究综述   总被引：3，自引：0，他引：3  

翁学传  赵永平  何有海 《海洋科学》1994,18(1):22-26

全球气候变化是目前人们关心的一个重要问题。已有的研究表明，海洋在全球气候变化中起着非常重要的作用。早在本世纪５０年代初，我国的气象学家就着手研究海洋对气候的影响［１］。自７０年代起，我国学者相继研究了中纬度海洋的海表水温（ＳＳＴ）对大气环流和我国降水的影响。并开始较系统地分析热带海洋对西太平洋副热带高压（以下简称副高）和我国降水的影响。近年来随着国际合作的不断增多，我国的海气相互作用研究进展较迅速，特别是海洋对我国气候变化的研究取得了不少成果。本文仅就太平洋热状况与我国旱涝关系研究所取得的主要结…  相似文献