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七十年代以来的空间和地面观测表明,太阳耀斑是太阳大气中最剧烈的动力学过程。耀斑动力学的研究已成为当今太阳物理研究中重要的前沿课题之一.本文概要地介绍近年来在耀斑动力学过程的观测和理论方面的重要进展以及耀斑大气动力学的光谱诊断方法,并讨论了今后在观测和理论两方面的努力方向,为我国在即将到来的太阳22周峰年中的耀斑动力学研究提供参考. 相似文献
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太阳耀斑研究进展和展望 总被引：3，自引：0，他引：3
简要回顾了近年来对太阳耀斑研究在某些方面所取得的进展，这些领域空间和地面观测，耀斑光谱研究，耀斑的动力学模型和MHD数值模拟等，并对耀斑研究的前景作一简短的展望。 相似文献
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云南天文台是参加日地系统整体行为研究计划的单位之一,有四套太阳光学观测设备参加日地大事件的联合观测。它们是:13cm折射望远镜、18cm耀斑巡视望远镜、26cm高分辨太阳光球色球望远镜和多波段太阳光谱仪。13cm折射望远望和18cm耀斑巡视镜分别进行黑子描绘、照相和耀斑巡视的常规观测。它们所得的资料供云南天文台《太阳活动月报》、《中国太阳物理资料》发表。耀斑资料还供SGD发表。黑子和耀斑的常规观测为太阳活动预报提供及时的信息和基础。 26cm高分辨真空太阳光球色球望远镜用于太阳活动区现象特别是耀斑现象的精细结构研究。在耀斑观测中常使用H_a的±0.5A,±1.0A对人观测,所得的耀斑偏带照片清楚显示耀斑的亮点和亮块相对于黑子的位置,在耀斑研究中十分有用。 多波段太阳光谱仪的供光定天镜口径40cm,成像镜30cm,太阳象有152.2mm和418.5mm两个交替使用,色散1A/mm,10个波段分别为H_a、D_(1,2,3),H_δ、HeⅡ、H_β、H_γ、H,K、H_(9-13)和H_(13-∞)。利用计算机控制45°转象镜精确地快速扫描太阳象并控制10个波段的同时照相,这样可以快速地记录活动区中每一点的多波段光谱轮廓,进而测定各种物理量、为研究活动区物理场的时空演化提供重要手段。 相似文献
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我们用紫台多波段太阳光谱仪进行耀斑光谱观测。这架仪器能在Hα、D、M_g、H_β、H_γ、H、H_δ——K、H_θ——H_(12)和H_(13)——H∞等九个波段基本上同时拍摄耀斑光谱。太阳像直径为11.2厘米,二级光谱的实测分辨率约10万,线色散度约为1毫米/埃。在这次峰年期间,从1980年2月至1981年5月,我们一共拍到16套耀斑光谱底片。我们已开始用这些资料来研究,(1)耀斑的能量传输机制,(2)耀斑的热动平衡偏离,(3)地面与空间观测资料的配合,(4)形态研究,并已开始归算处理这些资料。 相似文献
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多云模型’’是处理太阳活动体光谱不对称轮廓的有效方法,本文给出了该方法的一个具体应用实例,利用云南天文台二维多波段太阳光谱仪观测的１９８９年８月１７日耀斑环Ｈβ波段光谱资料,得到了该耀斑环的视向速度场． 相似文献
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太阳空间观测揭示出太阳的高能电子、高能质子发射以及γ射线爆发。证实了有关的太阳射电辐射理论、揭示出太阳耀斑中的核反应。日冕物质抛射和耀斑等离子体云的空间观测揭示出它们之间的区别和联系, 认识到耀斑的热区和冷区。太阳和日球磁场观测发展了磁流体动力学理论 相似文献
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本文综述了近年来太阳和恒星白光耀斑研究的最新进展。文中着重讨论了两类白光耀斑的光谱特征，白光耀斑的大气模型，以及白光耀斑大气的加热机制等问题，并对恒星白光耀斑同太阳白光耀斑作了某些比较。 相似文献
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南京大学太阳塔CCD成像光谱观测系统和初步观测结果 总被引：1，自引：0，他引：1
本文介绍南京大学太阳塔的ＣＣＤ成像光谱观测系统的结构，工作方式，给出了该系统的一些性能测试结果，作为应用该系统的实例，文中给出了根据该系统观测的二维光谱资料，经处理得到的一个Ｈａ耀斑在线心和不同偏带处单色像的变化过程，该耀斑的亮度场轮廓图和速度场轮廓图。 相似文献
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Laura Schaefer 《Icarus》2004,169(1):216-241
We modified the MAGMA chemical equilibrium code developed by Fegley and Cameron (1987, Earth Planet. Sci. Lett. 82, 207-222) and used it to model vaporization of high temperature silicate lavas on Io. The MAGMA code computes chemical equilibria in a melt, between melt and its equilibrium vapor, and in the gas phase. The good agreement of MAGMA code results with experimental data and with other computer codes is demonstrated. The temperature-dependent pressure and composition of vapor in equilibrium with lava is calculated from 1700 to 2400 K for 109 different silicate lavas in the ONaKFeSiMgCaAlTi system. Results for five lavas (tholeiitic basalt, alkali basalt, Barberton komatiite, dunite, and a molten type B1 Ca, Al-rich inclusion) are discussed in detail. The effects of continuous fractional vaporization on chemistry of these lavas and their equilibrium vapor are presented. The predicted abundances (relative to Na) of K, Fe, Si, Al, Ca, and Ti in the vapor equilibrated with lavas at 1900 K are lower than published upper limits for Io's atmosphere (which do not include Mg). We predict evaporative loss of alkalis, Fe, and Si during volcanic eruptions. Sodium is more volatile than K, and the Na/K ratio in the gas is decreased by fractional vaporization. This process can match Io's atmospheric Na/K ratio of 10±3 reported by Brown (2001, Icarus 151, 190-195). Silicon monoxide is an abundant species in the vapor above lavas. Spectroscopic searches are recommended for SiO at IR and mm wavelengths. Reactions of metallic vapors with S- and Cl-bearing volcanic gases may form other unusual gases including MgCl2, MgS, MgCl, FeCl2, FeS, FeCl, and SiS. 相似文献
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《中国天文和天体物理学报》2014,(10)
正Research in Astronomy and Astrophysics publishes original research papers and reviews on all branches of astronomy and astrophysics.Reviews are by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length to 6 printed pages).Authors who submit a paper are expected to be able to certify that the paper is original work, 相似文献
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Laura Schaefer 《Icarus》2005,173(2):454-468
We use chemical equilibrium calculations to model the speciation of alkalis and halogens in volcanic gases emitted on Io. The calculations cover wide temperature (500-2000 K) and pressure (10−6 to 10+1 bars) ranges, which overlap the nominal conditions at Pele (T=1760 K, P=0.01 bars). About 230 compounds of 11 elements (O, S, Li, Na, K, Rb, Cs, F, Cl, Br, I) are considered. The elemental abundances for O, S, Na, K, and Cl are based upon observations. CI chondritic elemental abundances relative to sulfur are used for the other alkalis and halogens (as yet unobserved on Io). We predict the major alkali species in Pele-like volcanic gases and the percentage distribution of each alkali are LiCl (73%), LiF (27%); NaCl (81%), Na (16%), NaF (3%); KCl (91%), K (5%), KF (4%); RbCl (93%), Rb (4%), RbF (3%); CsCl (92%), CsF (6%), Cs (2%). Likewise the major halogen species and the percentage distribution of each halogen are NaF (88%), KF (10%), LiF (2%); NaCl (89%), KCl (11%); NaBr (89%), KBr (10%), Br (1%); NaI (61%), I (30%), KI (9%). We predict the major halogen condensates and their condensation temperatures at P=0.01 bar are NaF (1115 K), LiF (970 K); NaCl (1050 K), KCl (950 K); KBr (750 K), RbBr (730 K), CsBr (645 K); and solid I2 (200 K). We also model disequilibrium chemistry of the alkalis and halogens in the volcanic plume. Based on this work and our prior modeling for Na, K, and Cl in a volcanic plume, we predict the major loss processes for the alkali halide gases are photolysis and/or condensation onto grains. Their estimated photochemical lifetimes range from a few minutes for alkali iodides to a few hours for alkali fluorides. Condensation is apparently the only loss process for elemental iodine. On the basis of elemental abundances and photochemical lifetimes, we recommend searching for gaseous KCl, NaF, LiF, LiCl, RbF, RbCl, CsF, and CsCl around volcanic vents during eruptions. Based on abundance considerations and observations of brown dwarfs we also recommend a search of Io's extended atmosphere and the Io plasma torus for neutral and ionized Li, Cs, Rb, and F. 相似文献
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Li Xin-nan Zhang Hai-ying Cui Xiang-qun Jiang Zi-bo Zheng Yi Liu Xing-tao Ni Hou-kun 《Chinese Astronomy and Astrophysics》2012
A special stressed annular polishing technique is proposed to mill the off-axis aspheric sub-mirrors of a large segmented mirror with an annular polishing machine. Based on the basic principle of stressed annular polishing technique, a set of special stressing mechanisms are designed to convert milling the aspheric surfaces of sub-mirrors with different off-axis distances into milling the spherical surfaces with identical radii of curvature, so that they can be pol- ished simultaneously on a continuous polishing machine. It took about contin- uous 40 hours to polish a scaled-down mirror of the planning Chinese Future Giant Telescope (CFGT) using this technique. This mirror has the 330 mm di- ameter, 3.6 m off-axis distance, and the 21.6 m radius of curvature, and its max- imum asphericity is 16 micron. The experiment shows that this method has a high effciency, suits batch manufacturing, especially the batch manufacturing of aspheric sub-mirrors of the segmented primary mirror of an extremely large aperture telescope. 相似文献
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In this paper, we investigate the dynamics of Born–Infeld (B–I) phantom model in the ω–ω′ plane, which is defined by the equation of state parameter for the dark energy and its derivative with respect to N (the logarithm of the scale factor a). We find the scalar field equation of motion in ω–ω′ plane, and show mathematically the property of attractor solutions which correspond to ω
φ
∼−1, Ω
φ
=1, which avoid the “Big rip” problem and meets the current observations well.
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In astronomical observations at optical wavelengths, a fast image tracking system can be adopted to reduce the effects of the atmospheric seeing and telescopic tracking error, and therefore improve the observing efficiency. Aiming at the need of astronomical observations, totally 5 kinds of algorithms in two categories were selected to make a comparative study on their accuracies and stabilities under different noise conditions by both numerical experiment and laboratory test. The results indicate that the normalized cross-correlation method and barycenter method have not only a higher accuracy but also a better reliability against interferences, they will be applied to the high-resolution spectrograph of the Xinglong 2.16 m telescope and the scienti?c instruments of the SONG (Stellar Observations Network Group) project, respectively. 相似文献
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Marcelo Samuel Berman 《Astrophysics and Space Science》2008,314(1-3):79-82
A combined BCDE (Brans-Dicke and Einstein-Cartan) theory with lambda-term is developed through Raychaudhuri’s equation, for
inflationary scenario. It involves a variable cosmological constant, which decreases with time, jointly with energy density,
cosmic pressure, shear, vorticity, and Hubble’s parameter, while the scale factor, total spin and scalar field increase exponentially.
The post-inflationary fluid resembles a perfect one, though total spin grows, but the angular speed does not (Astrophys. Space
Sci. 312: 275, 2007d).
相似文献