Ellerman Bombs,Type Ⅱ White—light Flares and Magnetic Reconnection in the Solar Lower Atmosphere     

Peng－FeiChen  ChengFang 《中国天文和天体物理学报》2001,1(2):176-184

Ellerman bombs and type Ⅱ white-light flares share many common features despite the large energy gap between them.Both are considered to result from local heation in the solar lower atmosphere.This paper presents numerical simulations of magnetic reconnection occurring in such a deep atmosphere,with the aim to account for the common features of the two phenomena.Our numerical results manifest the following two typical characteristics of the assumed reconnection process:(1)magnetic reconnection saturates in-600-900s,which is just the lifetime of the two phenomens;(2)ionization in the upper chromosphere consumes quite a large part of the energy released through reconnection,making the heation effect most significant in the lower chromosphere.The applicationof the reconnection model to the two phenomena is discussed in detail.  相似文献   

广州白云山常绿阔叶林的结构特征   总被引：2，自引：0，他引：2  

何冰  尹爱国等 《广东海洋大学学报》2001,21(3):48-53

在线路调查和样方调查的基础上分析了广州白云山常绿阔叶林的结构特征，群落主要由亚热带科属组成，优势科为芸香科，五加科，茜草科，山茶科，壳斗科，鼠刺科，樟科等。优势树种也以相应的优势科属树种为主，群落中胸径≥3cm的个体密度较小，只有1964株/hm^2；群落较为低矮，平均高度只有6m；乔木垂直分化不明显，树种水平分布不均，白云山的植被是次生植被和人工造林改造的结果，只在山谷少数植被没受人类干扰，其现状植被是天然次生植被和人工植被的混合体，在一些由马尾松发展起来的群落，天然侵入的阔叶树种已在主要层中居优势；群落中可见马尾松衰退的痕迹。  相似文献   

致密碎屑岩储层裂缝和产能预测的单井建模——以新场气田沙溪庙组为例     

匡建超  邓少云等 《致密岩石气藏勘探开发》2001,(4):49-55

近年来，利用三维地震资料进行致密碎屑岩储层裂缝和产能的识别预测取得了一些进展，而这之中最重要也最基础的是单井裂缝和产能的建模工作。本以新场气田沙溪庙组致密储层为例，详细介绍了综合运用岩芯资料、测井资料和录井资料进行裂缝和产能单井建模的方法，为利用三维地震资料建立裂缝和产能的灰色遗传过程识别模式打下了良好的基础。  相似文献   

大宝山多金属矿区和外围磁异常特征及其找矿意义     

刘红松 《广东地质》1993,8(1):85-93

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MERLIN Images of Five Compact Symmetric Object Candidates at 1.6 GHz     

Hai－YanZhang  XiangLiu 《中国天文和天体物理学报》2001,1(2):129-132

1 INTRODUCTIONCompact Symmetric Objects (CSOs) are powerful and compact sources (overall size <1 bpc) with lobe emission on both sides of the central engine. The small size of these sourcesis almost certainly to be attributed to the youth of the sources themselves (ages < 104 yr) andnot due to a dense coallning medium (Readhead 1996). The unification scenario assumes thatCSOs evolve into compact steep spectrum (CSS) sotirces and then into Fanaroff-Riley type 11objects (Fanti 1995). …  相似文献   

鞍山地区中、上鞍山群变质沉积岩中黑云母化学成分及其意义     

刘道荣 《国土资源》1990,(3)

通过对中、上鞍山群变质沉积岩中黑云母化学成分的对比,确认区内两层位黑云母化学组分存在一定差异,这种差异主要反映了其形成时变质条件的不同。随变质程度增加,区内黑云母的Si、AI~Ⅵ,Fe~(3 )、Mg和K含量增加,而Fe~(2 )、Al~Ⅳ和CH降低,Mg/Fe~(2 )比值从1.00增至2.18。中鞍山群黑云母变质温度为550—620℃,变质压力在5×10~8Pa左右;上鞍山群黑云母变质温度为450-500℃,变质压力低于5×10~8Pa。黑云母含铁系数(f)可作为鞍山地区寻找富铁矿的一种标志。  相似文献   

矿产资源合理开发与矿山环境的综合治理--方法与政策   总被引：9，自引：0，他引：9  

张德明  刘树臣 《国土资源情报》2004,(5):27-31

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Magnetic Field Strengths and Structures from Radio Observations of Solar Active Regions     

Chang－XiZhang  G.B.Gelfreikh 《中国天文和天体物理学报》2002,2(3):266-276

Radio observations of some active regions (ARs) obtained with the Nobeyama radioheliograph at λ=1.76cm are used for estimating the magnetic field strength in the upper chromosphere, based on thermal bremsstrahlung. The results are compared with the magnetic field strength in the photosphere from observations with the Solar Magnetic Field Telescope (SMFT) at Huairou Solar Observing Station of Beijing Astronomical Observatory. The difference in the magnetic field strength between the two layers seems reasonable. The solar radio maps of active regions obtained with the Nobeyama radioheliograph, both in total intensity (I-map) and in circular polarizations (V-map), are compared with the optical magnetograms obtained with the SMFT. The comparison between the radio map in circular polarization and the longitudinal photospheric magnetogram of a plage region suggest that the radio map in circular polarization is a kind of magnetogram of the upper chromosphere. The comparison of the radio map in total intensity with the photospheric vector magnetogram of an AR shows that the radio map in total intensity gives indications of magnetic loops in the corona, thus we have a method of defining the coronal magnetic structure from the radio I-maps at λ=1.76 cm. Analysing the I-maps, we identified three components: (a) a compact bright source; (b) a narrow elongated structure connecting two main magnetic islands of opposite polarities (observed in both the optical and radio magnetograms); (c) a wide, diffuse, weak component that corresponds to a wide structure in the solar active region which shows in most cases an S or a reversed S contour, which is probably due to the differential rotation of the Sun. The last two components suggest coronal loops on different spatial scales above the neutral line of the longitudinal photospheric magnetic field.  相似文献   

宁陵县“废旧厂址”开新花     

冯业茂刘广林  郭妍妍 《河南国土资源》2004,(9):11-11

去年以来，宁陵县委、县政府加大招商引资力度，今年上半年该县通过招商引资签订合同金额9．7亿元，其中到位资金5．6亿元。经济发展必须以土地为载体，但国务院实行“三个暂停”，对占用农地实行了“急刹车”。该县国土资源局在认真贯彻落实国家土地政策，严格控制建设用地规模的同时，把目光投向了国有破产企业的闲置用地上，采取“提前介入、主动参与、密切配合、积极引导”的方式，深入挖潜，盘活存量，鼓励投资者在倒闭企业的土地上建厂兴业，走出一条集约用地的发展道路。一年来，先后有五家企业在闲置多年的土地上建起了新厂，共节约土地240多亩，安置下岗职工1000多人。  相似文献   

高频VLBI观测射电源的结构     

田文武  张海燕等 《云南天文台台刊》2001,(2):1-9

高频VLBI观测揭示出河外射电源在pc或者亚pc尺度上大都有核-喷流的内部结构，尤其是对平谱致密射电源中毫角秒尺度的子源，能以相当高的概率观测到它的视超光速现象。多频观测可监测到一些新喷流子源的出现，特别在射电激变源中这些新喷流子源的出现与宽带内（从光学到γ射线）的爆发相关。且得到的一些源的核区谱指数分布，为确认源的VLBI核提供了支持。  相似文献