1986年2月4日太阳耀斑的演化研究   总被引：1，自引：0，他引：1  

肖速民  丁有济  M.J.Hagyard  J.B.Smith Jr 《中国天文和天体物理学报》1988,(4)

本文根据乌鲁木齐天文站的H_α耀斑及3.2cm射电流量观侧资料、云南天文台的黑子精细结构照相和Marshall Space Flight Center的向量磁场图,对1986年2月4日的六个耀斑的形态相关及演化联系,特别是0736UT 4B/3X大耀斑的发展过程进行了综合分析。主要结果是: 1.4日大耀斑的初始亮点和闪光相的主要形态演化,与活动区中沿中性线新浮现的强大电流/磁环系密切相关。后者的主要标志是沿中性线的长的剪切半影纤维及它两端的偶极旋涡黑子群(1_3F_3)。 2.上述大耀斑与1972年8月4日0624 UT大耀斑爆发的磁场背景及主要形态特征相似,表明两者的储能和触发机制可能相同。 3.大耀斑爆发的H_α初始亮点,双带出现,环系形成,亮物质抛射和吸收冕珥等现象同3.2cm射电流量的变化在时间上有较好的对应关系。 4.重复性的前期小耀斑爆发位置和发展趋势与大耀斑的主要形态及演化特征相似。它们相对于剪切的纵场中性线两侧的位置相近或相同。因而,可以看作上述强大电流/磁环系不稳性发展过程中的前置小爆发。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1986,38(3):295-316

Book Reviewed in this article: Marine Resources of Kuwait: Their Role in the Development of Non-oil Resources . Fatimah H. Y. al -Abdul -Razzak Recollections of a Revolution: Geography as Spatial Science . Mark Billinge , Derek Gregory and Ron Martin Entre l'Eden et l'Utopie . Luc Bureau Developments in Political Geography . M. A. Busteed The Elements of Graphing Data . William S. Cleveland Rural Resource Management . Paul J. Cloke and Chris C. Park Third World Atlas . Ben Crow and Alan Thomas Exploitation, Conservation, Preservation: A Geographic Perspective on Natural Resource Use . Susan L. Cutter , Hilary Lambert Renwick, and William H. Renwick . Wine Regions of the Southern Hemisphere . Harm Jan de Blij Regional Development: Problems and Policies in Eastern and Western Europe . George Demko The Geographer at Work . Peter R. Gould Change in the Amazon Basin . John Hemming Geography Since the Second World War . R. J. Johnston and P. Claval Urbanization in China: Town and Countryside in a Developing Economy 1949–2000 A.D. , R. J. R. Kirkby Transport and Communications for Pacific Microstates: Issues in Organisation and Management . Christopher C. Kissling Fluvial Forms and Processes . David Knighton The Urban Millennium . Josef W. Konvitz Technological Transition in Cartography . Mark Stephen Monmonier Field Guide to Soils and the Environment: Applications of Soil Surveys . Gerald W. Olson Northern Australia: The Arenas of Life and Ecosystems on Half a Continent . Don Parkes A Killing Rain: The Global Threat of Acid Rain . Thomas Pawlick From the Family Farm to Agribusiness: The Irrigation Crusade in California and the West, 1850–1931 . Donald J. Pisani Hybrid Maize Diffusion in Kenya . Franz -Michael Rundquist Warning and Response to the Mount St. Helens Eruption . Thomas F. Saarinen and James L. Sell Coastal Geomorphology in Australia . B. G. Thom Tropical Rain Forests of the Far East , 2nd ed . T. C. Whitmore The Dark Side of the Earth . Robert Muir Wood Categorical Data Analysis for Geographers and Environmental Scientists , Neil Wrigley  相似文献   

Assessing the Vibrational Frequencies of the Holweide Hospital in the City of Cologne (Germany) by Means of Ambient Seismic Noise Analysis and FE modelling     

Stefano?ParolaiEmail author  Andreas?F?cke  Sandra?M.?Richwalski  Lothar?Stempniwski 《Natural Hazards》2005,34(2):217-230

Ambient seismic noise measurements were conducted inside the Holweide Hospital (Cologne) for checking whether its frequencies of vibration fall into the range where soil amplification is expected. If this is the case, damage might increase in case of an earthquake due to an amplified structural response of the building. Two different techniques were used: the ratio between the horizontal and vertical components of the spectra recorded at stations located inside the building and the ratio between the corresponding components of the spectra recorded simultaneously inside the building and at a reference station placed outside. While the former method might be preferred because of less equipment involved, the latter has the advantage of producing more stable results and deleting automatically the influence of the sedimentary cover, which might obscure some eigenfrequencies of vibration of the building. An independently performed finite-element analysis of the hospital showed a good correlation between measured and calculated eigenmodes.  相似文献   

Volcanic and Scientific Activity at Kick ’em Jenny Submarine Volcano 2001–2002: Implications for Volcanic Hazard in the Southern Grenadines,Lesser Antilles     

Jan?M.?LindsayEmail author  John?B.?Shepherd  Doug?Wilson 《Natural Hazards》2005,34(1):1-24

Kick em Jenny submarine volcano, ~8 km north of Grenada, has erupted at least 12 times since it was first discovered in 1939, making it the most frequently active volcano in the Lesser Antilles arc. The volcano lies in shallow water close to significant population centres and directly beneath a major shipping route, and as a consequence an understanding of the eruptive behaviour and potential hazards at the volcano is critical. The most recent eruption at Kick em Jenny occurred on December 4 2001, and differed significantly from past eruptions in that it was preceded by an intensive volcanic earthquake swarm. In March 2002 a multi-beam bathymetric survey of the volcano and its surroundings was carried out by the NOAA ship Ronald H Brown. This survey provided detailed three-dimensional images of the volcano, revealing the detailed morphology of the summit area. The volcano is capped by a summit crater which is breached to the northeast and which varies in diameter from 300 to 370 m. The depth to the summit (highest point on the crater rim) is 185 m and the depth to the lowest point inside the crater is 264 m. No dome is present within the crater. The crater and summit region of Kick em Jenny are located at the top of an asymmetrical cone which is about 1300 m from top to bottom on its western side. It lies within what appear to be the remnants of a much larger arcuate collapse structure. An evaluation of the morphology, bathymetry and eruptive history of the volcano indicates that the threat of eruption-generated tsunamis is considerably lower than previously thought, mainly because the volcano is no longer thought to be growing towards the surface. Of more major and immediate concern are the direct hazards associated with the volcano, such as ballistic ejecta, water disturbances and lowered water density due to degassing.  相似文献   

δ34S isotope values of dissolved sulfate (SO4 2−) as a tracer for battery acid (H2SO4) contamination in groundwater     

Thomas Pichler 《Environmental Geology》2005,47(2):215-224

The application of sulfur isotope (³⁴S) values of sulfate in groundwater provided the information necessary to evaluate the source, transport and fate of battery acid and associated contaminants at the Gulf Coast Recycling (GCR) facility. The chemical and isotopic composition of groundwater beneath the (GCR) property, a battery recycling facility in east Tampa, Florida, varies more than expected for an area of comparable size. Sulfate (SO₄^2–) values, for example, range from 1.2 to 11,500 mg/L and oxygen and hydrogen isotopes do not attenuate towards the weighted annual mean. Those samples that are high in sulfate generally have a low pH, which immediately indicates battery acid (H₂SO₄) contamination as a potential source for the sulfate. The low pH and high reactivity of the sulfuric acid groundwater cause the formation of hydrogeological microenvironments due to preferential dissolution of carbonate minerals, which in turn causes enhanced recharge and groundwater flow in certain areas; thus, the extreme scatter in the data set. Because of the difficult hydrogeology it is not straightforward to delineate the point-sources of contamination and up to five potential scenarios have to be evaluated: (1) seawater intrusion, (2) upwelling of high-sulfate groundwater, (3) local dissolution of gypsum, (4) an up-gradient contaminant source to the northeast of the GCR property and (5) battery acid contamination.  相似文献   

An integrated linear/non-linear flow model for the conduit-fissure-pore media in the karst triple void aquifer system   总被引：2，自引：0，他引：2  

J. M. Cheng  C. X. Chen 《Environmental Geology》2005,47(2):163-174

Most karstic aquifer media may be characterized as the triple-void media with highly-varied hydraulic properties, including matrix pore, fissure and conduit, in which liner flow may co-exist with non-linear flow. In this paper, an attempt is made to couple linear flow with non-linear flow in a single unified flow governing equations by introducing the concept of equivalent hydraulic conductivity (EHC) and deriving a general Darcys law for various flow. The expression of EHC in the karst conduit and fissure are also derived. The procedures of numerical implementation are demonstrated via an ideal model and a case study of karst aquifer system in the Beishan Ore Formation area, Guangxi Autonomous Region, China.  相似文献   

地球物理测井数据格式及面向对象的数据读取   总被引：1，自引：0，他引：1  

李河  王祝文  李舟波  丁永浩 《物探与化探》2005,29(2):174-178

在进行地球物理测井数据处理或解释软件开发时,只有知道所处理的测井数据的格式,才能正确地进行读取、格式转换、数据处理以及绘图等工作。在对ECLIPS 5700数控测井系统XTF文件格式分析的基础上,基于内存映射文件技术,采用面向对象的方法创建了XTF文件数据读取类,实现了大数据量XTF文件数据的快速读取,也可为其它格式测井数据的格式转换和数据处理提供技术参考。  相似文献   

C/S模式WebGIS架构技术     

王占昌  刘春娥  包存义  张雪亭 《西北地质》2005,38(1):100-107

针对客户端／服务器(C／S)模式下三层体系构建原理以及地学空间数据库网络发布(WebGIS)特点,以MapGuide空间数据库引擎为核心,分析了嵌入式WebGIS功能接口和事件响应机理。提出了空间数据库与关系型数据库两大引擎之间实现互动链接的有效技术措施,从而弥补了MapGuide Viewer。插件赖以支持的MWF格式在专业属性数据操作方面的先天性不足。以青海地调院局域网建设实例为基础,详细阐述了C／S模式下青海省基础地学数据库网络框架建设的实现途径。该技术的成功运用,无疑拓宽了青海省地学数字化成果的共享应用渠道,提高了成果的再利用价值。  相似文献   

The general solution of the HENON–HEILES problem     

K.?E.?PapadakisEmail author  C.?L.?Goudas  G.?A.?Katsiaris 《Astrophysics and Space Science》2005,295(3):375-396

The general solution of the Henon–Heiles system is approximated inside a domain of the (x, C) of initial conditions (C is the energy constant). The method applied is that described by Poincaré as ‘the only “crack” permitting penetration into the non-integrable problems’ and involves calculation of a dense set of families of periodic solutions that covers the solution space of the problem. In the case of the Henon–Heiles potential we calculated the families of periodic solutions that re-enter after 1–108 oscillations. The density of the set of such families is defined by a pre-assigned parameter ε (Poincaré parameter), which ascertains that at least one periodic solution is computed and available within a distance ε from any point of the domain (x, C) for which the approximate general solution computed. The approximate general solution presented here corresponds to ε = 0.07. The same solution is further improved by “zooming” into four square sub-domain of (x, C), i.e. by computing sufficient number of families that reduce the density parameter to ε = 0.003. Further zooming to reduce the density parameter, say to ε = 10⁻⁶, or even smaller, although easily performable in both areas occupied by stable as well as unstable solutions, was found unnecessary. The stability of all members of each and all families computed was calculated and presented in this paper for both the large solution domain and for the sub-domains. The correspondence between areas of the approximate general solution occupied by stable periodic solutions and Poincaré sections with well-aligned section points and also correspondence between areas occupied by unstable solutions and Poincaré sections with randomly scattered section points is shown by calculating such sections. All calculations were performed using the Runge-Kutta (R-K) 8th order direct integration method and the large output received, consisting of many thousands of families is saved as “Atlas of the General Solution of the Henon–Heiles Problem,” including their stability and is available at request. It is concluded that approximation of the general solution of this system is straightforward and that the chaotic character of its Poincaré sections imposes no limitations or difficulties.  相似文献   

Climatological distribution of lightning density observed by satellites in China and its circumjacent regions   总被引：14，自引：1，他引：13  

MA Ming  TAO Shanchang  ZHU Baoyou & LU Weitao School of Earth  Space Sciences  University of Science  Technology of China  Hefei  China 《中国科学D辑(英文版)》2005,48(2):219-229

The 0.5°×0.5°grid resolution distribution of lightning density in China and its circumjacent regions have been analyzed by using the satellite-borne OTD (Apr 1995-Mar 2000) and LIS (Dec 1997-Mar 2003) databases. It is shown that: (i) Firstly, the variability of the lightning density (LD) is particularly pronounced over the different subareas, 9 times greater over the south than the north side of Himalayas Mountains, 2.5 times greater over the eastern than the western area of China. While the maximum and minimum LD are respectively 31.4fl/km2/a (in Guangzhou region) and less than 0.2fl/km2/a (in the desert of western China). Secondly, the LD of China's continent regularly varies with latitude and distance off coast, which is consistent with annual mean precipitation in varying trend. In conclusion, the Qinghai-Tibet Plateau, the China's three-step staircase topography and the latitude are three important factors affecting macro-scale characteristics of the LD distribution, (ii) The regional differences  相似文献