Morphological characters of the two-ribbon flare of 1981 May 13 and their explanation

We give a summary of the morphology of the two-ribbon flare of 1981 May 13. One striking feature is that the Ha flare began at about 0338' UT and the double-ribbon structure was formed about 0346, $\text{before}$ the impulsive phase of the radio 3 cm burst at 04 11 UT. The 3 cm radio burst flux beginning at 03 33 UT showed only slow, stepwise increases lasting half an hour until the impulsive phase and this type of increase is usually regarded to be a typical thermal process. Each step in the radio flux corresponded to a variation in the Ha flare, showing that the radio and Hα emissions during this period came from the same thermal source. In this paper, we explain this behaviour in terms of Hyder's model: we think that the magnetic trough supporting the solar prominence rose for some reason, causing the prominence matter (the dark filaments) to fall along the magnetic lines and to hit the chromosphere and trigger off the flare. We give rough estimates of the energy density, the height of prominence and the infall matter at the different radio increments. We also give a qualitative explanation for the appearances of the single-peak structure in the radio burst at 0411 and the covering of the sunspot shortly after at 04 13 and propose several possible mechanisms.     

新滩滑坡后两岸边坡的位移监测及形变趋势

本文介绍新滩滑坡后两岸边坡监测的工作,对边坡变形提出了趋势意见。认为新滩斜坡目前正处于整体稳定下的局部调整阶段,变形缓慢平稳,但要注视广家崖的危岩动态;链子崖仍有趋势性的倾江形变。5—6号缝围成的7万方危岩及江段的5万方危岩体尚有一触即崩之势,须加强监视。     

Spatial pattern and regional types of rural settlements in Xuzhou City, Jiangsu Province, China

This paper principally focuses on the morphological differences,spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China.Using satellite images of Xuzhou City taken in 2007 and 2008 and models of exploratory spatial data analysis(ESDA) and spatial metrics,the paper conducts a quantitative analysis of the morphological pattern of rural settlements,and finds significant characteristics.First,rural settlements in Xuzhou City are significantly agglomerated in terms of their spatial distribution;meanwhile,there is significant variation in the geographical density distribution.Second,the scale of rural settlements in Xuzhou City is larger than the average in Jiangsu Province,and the histogram of the scale data is more even and more like a gamma distribution.There are a significant high-value cluster in the scale distribution,and local negative correlation between the scale and density distribution of rural settlements in Xuzhou City.Third,the morphology of rural settlements in Xuzhou City shows relative regularity with good connection and integrity,but the spatial variation of the morphology is anisotropic.Finally,according to the characteristics of density,scale,and form of rural settlements,the rural settlements of Xuzhou City are divided into three types:A high-density and point-scattered type,a low-density and cluster-like type and a mass-like and sparse type.The research findings could be used as the scientific foundation for rural planning and community rebuilding,particularly in less-developed areas.     

A Catalog of Luminous Infrared Galaxies in the IRAS Survey and Second Data Release of SDSS

We selected a sample of luminous infrared galaxies by cross-identification of the Faint Source Catalogue (FSC) and Point Source Catalogue (PSC) of the IRAS Survey with the Second Data Release of the SDSS. The size of our sample is 1267 for FSC and 427 for PSC by using the 2σ significance level cross-section. The "likelihood ratio" method is used to estimate the individual's reliability and for defining two more reliable subsamples (908 for FSC and 356 for PSC). A catalog of infrared, optical and radio data is compiled and will be used in further work. Some statistical results show that luminous infrared galaxies are quite different from ultra-luminous infrared galaxies. The AGN fractions of galaxies at different infrared luminosities and the radio-infrared correlations are consistent with the previous studies.     

Connection Between Chromospheric Events and Photospheric Dynamics

We analyzed chromospheric events and their connection to oscillation phenomena and photospheric dynamics. The observations were done with the New Solar Telescope of Big Bear Solar Observatory using a broad-band imager at the wavelength of a TiO band and FISS spectrograph scanning Ca?ii and Hα spectral lines. The event in Ca?ii showed strong plasma flows and propagating waves in the chromosphere. The movement of the footpoints of flux tubes in the photosphere indicated flux tube entanglement and magnetic reconnection as a possible cause of the observed brightening and waves propagating in the chromosphere. An upward propagating train of waves was observed at the site of the downflow event in Hα. There was no clear relationship between photospheric waves and the Ca?ii and Hα events. Our observations indicate that chromospheric waves that were previously thought to originate from the photosphere may be generated by some events in the chromosphere as well.     

The theory of relativity and super-luminal speeds

According to the different properties between the ds ² and the ds ⁴, it is discussed that the space-time will have the catastrophe nature on the Finsler metric ds ⁴ (see Cao, 1990, Paper II). The space-time transformations and the physical quantities will suddenly change at the catastrophe theory of the space-time. It will be supposed that only the dual velocity of the super-luminal-speed could be observed (see Cao, 1988). If so, a particle with the super-luminal-speedv>c, could be regarded as its anti-particle with the dual velocityv ₁=c ²/v<c.The project was supported by National Natural Science Foundation of China.     

Uraninite—An economic uranium mineral in metamorphic uranium deposit No. 3075

Uraninite from the metamorphic deposit investigated is divided into two groups on the basis of its occurrence and physical and chemical properties. Uraninite of the first group occurs as distorted crystals in the form of elongated cubesa {100}; the second group occurs mainly in the form of rhombo-dodecahedrad {100}, all belonging to the GaF₂ type in the isometric system. The chemical formulae are 8UO₂·UO₃·PbO for the first group and 5UO₂·UO₃·PbO for the second. Isotopic dating yields 1,900 and 300 m. y. for the formation time of uraninite in this deposit. The former value corresponds to the main mineralization period and the latter represents the reformation event.     

Spatial-temporal pattern and differences of land use changes in the Three Gorges Reservoir Area of China during 1975�C2005

Regional land use changes are an important part of global changes. The research on land use changes in the Three Gorges Reservoir Area of China attracts a lot of attention owing to the Three Gorges Dam building. The Three Gorges Reservoir Area becomes one of the important research areas. This study analyzed the transforming processes and traits of each land use type and the regional differences of land use changes during the past 30 years, summarized the distribution of different land use types in different buffer zones and regresses the equation areas and different buffer distances based on buffer analyses and regression analyses, and then analyzed the transforming rules in different buffer distances, got the optimal influence distances. The research results indicate that, (1) cultivated land lies at the northwest of the reservoir and was decreasing, however, the construction land was increasing, especially the urban construction land, a large number of land was flooded because of the reservoir water level rise; (2) urban area was sprawling quickly in developed and neighboring areas, and a great deal of cultivated land and a considerable amount of grassland were occupied; in the earlier time, rural settlements occupied lots of cultivated land and a sum of forestry land in the later time; (3) the optimum influenced distances for cultivated land and forestry land were 10–35 km, and for urban and rural settlements were in 5–20 km. Overall, this research can reflect the spatial-temporal characteristics of land use changes during the 30 years, and it is helpful for urban planning and land use planning in the reservoir area.     

广东雷州地区3种滨珊瑚系统发生关系的研究

对雷州常见的3种滨珊瑚科珊瑚：澄黄滨珊瑚（Porites lutea）、灰黑滨珊瑚（Porites nigrescens）、普哥滨珊瑚（Porites pukoensis）,共32个样本的12S rRNA基因序列进行了PCR扩增和测序,研究其系统发生关系。结果显示,所得的3种珊瑚的12S rRNA基因长度在728～908 bp之间,G+C含量在34.3%～39.2%之间,遗传距离在0.004~0.019之间。利用邻接（NJ）法、最大似然（ML）法和不加权对群分析(UPGMA)法构建的系统进化树显示：3种珊瑚被分成了2个支系,澄黄滨珊瑚和灰黑滨珊瑚聚合在一个分支上,而普格滨珊瑚在另一支,这一研究结果与传统形态学分类研究的结果存在一定差异。