Microwave Type III Burst Group in the 1993 October 2 Flare     

Qijun Fu  Zhihai Qin  Yuying Liu  Guangli Huang 《Astrophysics and Space Science》1997,250(2):189-204

Microwave Type III bursts with positive frequency drifting rate were found by Stahli and Benz (1987) for first time. Type III events are especially interesting because they are well-known to be signatures of electron beams in coronal plasma, and they are effective means for diagnosting of source plasma. A microwave burst consisting of some microwave type III burst groups was registered at Beijing Astronomical Observatory with the 2545–2645–2840 MHz synchronous observing system. The distributions of frequency drifting rate, half power duration, and intensity for each impulse in the groups have been statistically analysed. From this analysis, some important parameters for the dynamic process in the flare are deduced and discussed.  相似文献   

A New Solar Radio Spectrometer at 1.10-2.06 GHz and First Observational Results   总被引：1，自引：0，他引：1  

Hui-Rong Ji  Qi-Jun Pu  Yi-Hua Yan  Yu-Ying Liu  Zhi-Jun Chen  Cheng-Ming Tan  Cong-Ling Cheng  De-Bang Lao  Shu-Ke Li  Zhi-Qiang Wang  Min-Hong Yu  Jian-Nong Liu  Li-Kang Zhang  Ji-Yong Gao National Astronomical Observatories  Chinese Academy of Sciences  Beijing  Hebei Semiconductor Research Institute  Shijiazhuang 《中国天文和天体物理学报》2005,5(4):433-441

An improved Solar Radio Spectrometer working at 1.10-2.06 GHz with much improved spectral and temporal resolution, has been accomplished by the National Astronomical Observatories and Hebei Semiconductor Research Institute, based on an old spectrometer at 1-2 GHz. The new spectrometer has a spectral resolution of 4 MHz and a temporal resolution of 5ms, with an instantaneous detectable range from 0.02 to 10 times of the quiet Sun flux. It can measure both left and right circular polarization with an accuracy of 10% in degree of polarization. Some results of preliminary observations that could not be recorded by the old spectrometer at 1-2 GHz are presented.  相似文献   

Generalized strain probing of constitutive models     

Youssef M. A. Hashash  Qingwei Fu  Jeremy Butkovich 《国际地质力学数值与分析法杂志》2004,28(15):1503-1519

Advanced material constitutive models are used to describe complex soil behaviour. These models are often used in the solution of boundary value problems under general loading conditions. Users and developers of constitutive models need to methodically investigate the represented soil response under a wide range of loading conditions. This paper presents a systematic procedure for probing constitutive models. A general incremental strain probe, 6D hyperspherical strain probe (HSP), is introduced to examine rate‐independent model response under all possible strain loading conditions. Two special cases of HSP, the true triaxial strain probe (TTSP) and the plane‐strain strain probe (PSSP), are used to generate 3‐D objects that represent model stress response to probing. The TTSP, PSSP and general HSP procedures are demonstrated using elasto‐plastic models. The objects resulting from the probing procedure readily highlight important model characteristics including anisotropy, yielding, hardening, softening and failure. The PSSP procedure is applied to a Neural Network (NN) based constitutive model. It shows that this probing is especially useful in understanding NN constitutive models, which do not contain explicit functions for yield surface, hardening, or anisotropy. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Evaluation of Fluorobenzoate Tracers in Surface Soils   总被引：2，自引：0，他引：2  

Dan B. Jaynes 《Ground water》1994,32(4):532-538

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The international politics of whaling: Peter J Stoett UBC Press, 1997, 228 pp. $65.00. ISBN 0-7748-0605-2     

Dan Goodman 《Marine Policy》1997,21(6):547-549

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海量多波段星表数据的交叉证认的实现   总被引：2，自引：1，他引：1  

高丹  张彦霞  赵永恒 《天文研究与技术》2005,2(3):186-193

许多天文学家需要星表来选源、证认和研究。目前国外有一些大的数据中心提供了星表查询、多源查询(即小样本交叉证认)、可视化等功能。但是随着大数据量及全波段天文时代的到来,这些服务已经越来越不能满足天文学家的需求。在详细分析了国外数据中心的服务后,提出了新的问题,并给出一套解决方案。着重讨论了任意两个星表的交叉证认和大数据量星表的交叉证认的实现,以及交叉证认结果的分类和参数的自由选择等方面的课题。  相似文献   

A concordance model of the Lyman α forest at z= 1.95     

Tridivesh Jena  Michael L. Norman  David Tytler  David Kirkman  Nao Suzuki  Angela Chapman  Carl Melis  Pascal Paschos  Brian O'Shea  Geoffrey So  Dan Lubin  Wen-Ching Lin  Dieter Reimers  Eckardt Janknecht  Cora Fechner 《Monthly notices of the Royal Astronomical Society》2005,361(1):70-96

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On the microwave millisecond spike emission and its associated phenomena during the impulsive phase of large solar flare     

Chun-sheng Li  Qi-jun Fu  Yu-hua Yan  Shu-ying Jiang  Hong-wei Li 《Chinese Astronomy and Astrophysics》1985,9(2):128-133

We propose a model of two acceleration regions, which can explain, on the basis of microwave maser caused by a “hollow-beam” distribution of electrons, the presence of millisecond spikes in the event of 1981 May 16 and their absence in the event of 1981 October 12, and the enhanced continuous emission in the latter. We have also uncovered relations among the features, e.g. the Type III_G, Type IV_DCIM and hard x-ray bursts, that accompany the microwave millisecond spikes during the impulsive phase of a large flare.  相似文献   

VO_IMPAT:中国虚拟天文台图像处理分析工具     

王丹  赵永恒 《天文研究与技术》2006,3(3):295-303

中国虚拟天文台图像处理分析工具（VO_IMPAT），是由国家天文台虚拟天文台项目组开发的一项服务，它提供了对数字巡天图像数据（Digital Sky Survey，DSS）、天文星表以及其他数据库的交互访问。VO_IMPAT的设计目的是实现多波段天文数据的融合。可以将不同波段的星表叠加到DSS底图上，如光学波段的USNO星表、近红外波段的2MASS星表、射电波段的NVSS星表和X射线波段的RASS星表。同时VO_IMPAT还可以对图像进行放大、缩小、伪彩色、等高线、直方图、尖锐化、平滑化、旋转等处理，不同的星表数据可以采用不同的颜色和图标显示。  相似文献   

试论质量体系有效性的保持     

付殿东  陈之中  滕磊 《地理信息世界》2001,(1)

提出了保持质量体系有效运行的前提和基础 ,关键和保证措施 ,并指出了组织企业保持质量体系持续有效的方法和途径。  相似文献