冕洞面积与绿日冕亮度间的一些统计关系

研究了冕洞面积与绿日冕高度在太阳活动２０，２１，２２周中的一些关系：１）冕洞总面积的最大值，最小值出现在绿日冕亮度差率为一些定值处；２）当冕洞总面积是最大或最小值时，绿日冕亮度减小为０．３１～０．６１相对强度单位或０．１０～０．１１相对强度单位。     

冕洞边界区磁结构的探讨

摘要用Hell083nm单色像上的极区、低纬冕洞的边界,确定Fe]532.4nm纵向场全日面磁图上对应的极,低纬冕洞的边界.对光球上极、低纬冕洞边界足根连线范围内外的磁场强度,磁极性、磁场几何位形进行了分析讨论.观测结果表明t就极无涧大尺度范围来看,是单极开放场I就48h时标的加强磁结构来说,以开放场为主的情况下,有开放场与闭合场栩混杂的情况.就同时的极冕洞与低纬度冕洞边界足根连线附近磁场位形相比较,差别是明显的.     

日珥物理条件的研究

本文引进宏观物质团的运动以后,进一步证明了文[17]关于湍流速度V_t与μ有关的结论,因此用氢和氦线决定日珥温度最合理。利用文[3]的资料进行计算的结果,第一次把氢日珥和金属日珥的物理性质区别开来,前者T_t=7340,V,=4.3.N_2=2×10~(13);后者T_t=5520,V_t=6.7,N_2=1×10~(14),结果发现象色球一样,日珥也是温度高对应于密度小,温度低对应密度大。     

用完全线性化方法分析日珥和暗条的线光谱

本文提出用完全线性化方法,从一般的角度分析日珥、暗条等的线光谱,通过对多条谱线观测轮廓的拟合直接确定多普勒宽度△λ_D、线心光学厚度τ_(λ_0)。和阻尼宽度α等物理参数。本方法具有精度高、收敛快的特点。作为应用实例,给出了对文献[1]三个日珥H_α、H_β和H_γ线的分析结果。结果表明,以前一些人采用单条谱线确定△λ_D、τ_λ。和α,常常是不够准确的;为了可靠地研究加宽机制,照相测光的精度一般是不够的,需要采用精度更高的观测手段;对日珥来说,过去常用的公式(16)一般是不成立的,入射辐射的散射在日珥辐射的激发中起着重要的作用。     

太阳活动及其对天气和气候的影响

太阳是太阳系的中心天体，太阳活动对地球有很大影响．末文论述了太阳活动，特别是太阳黑子，耀斑，日珥及对地球的旱、涝、风灾与气候急剧变化的影响．     

太阳活动区漂移电场引起的日冕瞬变

在太阳活动区，当离子声波湍动充分发展后库仑碰撞阻尼和朗道无碰撞阻尼全部可以被忽略，在电场力大于阻尼力的瞬间，电子和离子将突然逃逸，在一定条件下，将产生爆发日珥和日冕物质抛射。     

日冕物理的辐射磁流体数值模拟研究

太阳的最外层大气日冕中发生着多种活动现象,如耀斑、日冕物质抛射、日珥、冕雨等.为了深入研究这些活动现象的非线性物理过程,通过辐射磁流体数值模拟,构建多维数值模型是主流的研究手段之一.数值模拟日冕等离子体的宏观行为需要求解磁流体力学、辐射、热传导和加热等物理过程.首先简要介绍了求解这些物理过程的主流数值算法.求解磁流体力学方程组的数值格式由网格界面值的重构方法、黎曼问题近似解法、磁场散度控制方法和时间积分方法等部分组成.之后,综述了辐射磁流体数值模拟对太阳活动区磁环、耀斑、日珥和冕雨等日冕中的活动现象的研究进展.     

1997年3月9日日食时的日冕结构和光度测量

在１９９７ 年３ 月９ 日日全食时, 我们于黑龙江省漠河市（ 西林吉） 作了一系列日冕的照相观测不同感光的日冕像上显示出赤道东西的宽冕流、两极区冕洞、极羽和２０ 多条极射线等结构特征本文综合一些日冕像的形态结构和亮度测量结果,给出日冕的形态结构图、等亮度图、两极区和赤道区东西的亮度分布图     

F数空间的度量特征及收敛性

本文引进了Ｆ数的扩张点和δ－距离概念；证明了Ｆ数空间中δ－踯与Ｈａｕｓｄｏｒｆｆ距离的等价性；探讨了Ｆ数空间的度量特征几种收敛性的关系。     

冷箭竹竹笋种群消长规律

研究了冷箭竹（Ｂａｓｈａｎｉａｆａｎｇｉａｎａ）无性系繁殖竹笋的种群消长规律；建立了冷箭竹活笋数、死笋数、总发笋数的消长预测模型；找出影响冷箭竹种群消长的主要因素；得出当年生活笋数与一年生成竹数对第２年的成活竹笋数有显著影响，二年生与多年生成竹数对第２年的死笋数有显著影响的结论．了解冷箭竹的种群发展和竹种资源数量是预测对大熊猫承载能力的科学依据．     

Magneto-thermal convection in solar prominences

Coronal cavities are large low-density regions formed by hemispheric-scale magnetic flux ropes suspended in the Sun's outer atmosphere. They evolve over time, eventually erupting as the dark cores of coronal mass ejections. Although coronal mass ejections are common and can significantly affect planetary magnetospheres, the mechanisms by which cavities evolve to an eruptive state remain poorly understood. Recent optical observations of high-latitude 'polar crown' prominences within coronal cavities reveal dark, low-density 'bubbles' that undergo Rayleigh-Taylor instabilities to form dark plumes rising into overlying coronal cavities. These observations offered a possible mechanism for coronal cavity evolution, although the nature of the bubbles, particularly their buoyancy, was hitherto unclear. Here we report simultaneous optical and extreme-ultraviolet observations of polar crown prominences that show that these bubbles contain plasma at temperatures in the range (2.5-12)?×?10(5) kelvin, which is 25-120 times hotter than the overlying prominence. This identifies a source of the buoyancy, and suggests that the coronal cavity-prominence system supports a novel form of magneto-thermal convection in the solar atmosphere, challenging current hydromagnetic concepts of prominences and their relation to coronal cavities.     

冕流的白光偏振

研究了日冕白光冕流的偏振特性，包含：典型冕流的偏振度随日心距增大的变化；冕流白光高度在同一日心距处沿日面位置角的分布；不同日面纬度处冕流的偏振器；冕流中偏振亮度分布的不均匀性。     

An interpretation of density holes observed by Cluster and Double Star in solar wind

To interpret density holes in the solar wind,which are nonlinear structures observed by Cluster and Double Star,we propose an electrostatic ion fluid model.We derive the Sagdeev potential from the magnetohydrodynamic(MHD)equations and study the characteristics of nonlinear structures in our model.The results show that density depletions(or holes)can develop from linear ion acoustic waves or ion cyclotron waves in space plasmas when parameters such as Mach number,initial electric field and ratio of ion to electron temperature satisfy certain conditions.In our model,the relative density depletion(or density holes)is from 0 to 1, and the time duration of density holes is from 2 s to more than 98 s.These are in good agreement with the observations by Cluster and Double Star in the solar wind.Our model also shows that the density holes should be accompanied by bipolar electric field solitary structures,which have also been observed by Cluster in the solar wind.     

Coronal structure and brightness profile of the total solar eclipse on August 1, 2008

Solar corona is the outermost part of the solar atmosphere. Coronal activities influence space environment between the Sun and the Earth, space weather and the Earth itself. The total solar eclipse （TSE） is the best opportunity to observe the solar corona on ground. During the TSE 2008, a series of images of the corona and partial eclipse of solar disk were obtained using telescope and CCD camera. After image processing, preliminary results of coronal structure are given, and radial brightness profiles of the corona in directions of pole and equator of the Sun are measured. Though in solar activity minimum, the shape and structure of the corona are not symmetry. The equatorial regions are more extent than the polar one, and there are also larger differences between the east and west equatorial regions and between the south and north polar regions. Coronal streamers on east side of the equator, particularly the largest one in east-south direction, are very obvious. The coronal plume in south polar region consists of more polar rays than that in north polar region. These structures are also shown in other observations and data of SOHO. The radial brightness profiles in directions of pole and equator are similar to those of the Van de Hulst model in solar minimum, but there are a few differences due to coronal activity, which is shown in the isophote map of the corona.     

太阳风在日冕磁漏斗状结构中的起源——介绍一篇Science,Vol 308, 2005上的研究论文

Science杂志2005年4月22日一期发表了北京大学涂传诒教授的学术论文《太阳风在日冕漏斗状结构中的起源》。该文利用SOHO飞船的观测数据和无力场外推的假设,给出了太阳风在日冕中的起源高度和起源处的磁场结构。本文从太阳风的背景知识出发,阐述涂教授论文的科学思想和方法,最后介绍分析该论文的结论。     

Filamentary structure on the Sun from the magnetic Rayleigh-Taylor instability

Magnetic flux emerges from the solar surface as dark filaments connecting small sunspots with opposite polarities. The regions around the dark filaments are often bright in X-rays and are associated with jets. This implies plasma heating and acceleration, which are important for coronal heating. Previous two-dimensional simulations of such regions showed that magnetic reconnection between the coronal magnetic field and the emerging flux produced X-ray jets and flares, but left unresolved the origin of filamentary structure and the intermittent nature of the heating. Here we report three-dimensional simulations of emerging flux showing that the filamentary structure arises spontaneously from the magnetic Rayleigh-Taylor instability, contrary to the previous view that the dark filaments are isolated bundles of magnetic field that rise from the photosphere carrying the dense gas. As a result of the magnetic Rayleigh-Taylor instability, thin current sheets are formed in the emerging flux, and magnetic reconnection occurs between emerging flux and the pre-existing coronal field in a spatially intermittent way. This explains naturally the intermittent nature of coronal heating and the patchy brightenings in solar flares.     

人工光合成机理的时空分辨光谱研究进展

 综述了时空分辨光谱技术在人工光合成机理研究中的主要结果和最新进展，揭示了人工光合成中光生电子和空穴的分离、复合和反应等过程，利用成像光谱直接观测光生电荷的空间分布及其作用规律。时空分辨光谱的表征结果很好地解释了催化剂晶相、助催化剂的担载、相结结构的构筑、晶面调控等策略在光电催化过程中的作用机制。