昆明1943年5级地震的发震地段考证     

阚荣举  赵晋明 《地震研究》1993,16(1):96-99

结合资料记载与调查,认为该地震发生在昆明市区西南边缘的西山断裂地段。  相似文献   

印尼8.7级巨震后云南地震活动的频度变化   总被引：1，自引：0，他引：1  

郭铁栓  刘杰  郑大林  彭克银 《中国地震》2006,22(2):204-208

0引言 2004年12月26日在印尼苏门答腊西北近海发生了8．7级巨震，3月29日在距8．7级地震破裂区东南160km又发生了一次8．5级地震。8．7级地震发生后，余震向震中以北扩展达千米以上。如此剧烈的能量释放，对我国的地震活动有何影响是令人关注的，但清晰解答这个问题并非易事，主要原因是，一个地区的大地震发生后如何影响另一个地区地震活动的机制目前我们并不清楚。这个机制可能很复杂，涉及到应力在地壳和地幔内的传播、积累，以及与地质构造等的关系。因此，仅从时间尺度上判定一个地区的大地震对另一个地区地震活动是否有影响在认识上就存在分歧。例如，是一个地区的大地震发生后的波动在传播到另一个地区时直接触发的地震活动才被看作是影响？还是由于一个地区的大地震发生后的应力释放和调整影响到另一个地区的地震活动才被看作是影响？显然，这两方面的影响在时间尺度上存在差异。8．7级地震发生后不到20分钟，在我国云南的宾川发生了4．6级地震，其发震时间也是8．7级地震的面波到达该地区的时间（李刚等，2005）；  相似文献   

基于多分辨率分析的灰度调制影像融合方法研究     

林卉  张连蓬  张庆利  肖剑平 《遥感学报》2007,11(1):62-68

在遥感图像处理中,由于应用的需要,已经有很多算法可以用来融合高分辨率的全色影像和低分辨率的多光谱影像。本文阐述了小波变换的Mallat算法和a′Trous（多孔）算法,在此基础上,作者提出了一种基于多分辨率分析的灰度调制影像融合方法（MRAGM算法）,以SPOT全色影像与TM多光谱影像融合为例,详细给出了算法和解算步骤,最后分别用三种方法对SPOT高分辨率全色影像和TM低分辨率多光谱影像进行了融合,并且对融合后的影像从定性和定量方面都进行了评价,可以得出MRAGM方法比Mallat算法和a′Trous（多孔）算法的融合效果要好。  相似文献   

TRIFFID Photometry of Globular Cluster Cores — I. Photometric Techniques and Variable Stars in M15     

Butler  Shearer  Redfern  Colhoun  O'Kane  Penny  Morris  Griffiths  & Cullum 《Monthly notices of the Royal Astronomical Society》1998,296(2):379-391

The Galway/DIAS Image Sharpening Camera, TRIFFID, has been used to make observations in two colours of the centre of the post-core-collapse globular cluster M15. We present here our analysis of the photometry in B over two seasons. We have combined the complementary qualities of the HST 's high astrometric precision and TRIFFID's extended coverage and photometric precision, to perform crowded-field photometry in the innermost region of M15. Our technique virtually eliminates the problem of extreme crowding which has hitherto hampered studies of the variable star populations in globular cluster cores, and thereby provides an extension of the HST 's capability. Candidate variables detected with the HST have been confirmed and monitored over longer periods. We show that most of these are RR Lyrae stars, and that one is a short-period Type II Cepheid (the third to be discovered in M15). Our photometric study also produced evidence of a similar number of new variables. These also appear to be RR Lyrae stars, except for a possible eclipsing system. Further data from an upgraded version of TRIFFID have recently been obtained to help to refine the light curves of all these objects.  相似文献   

陕西段家坡黄土剖面中布容／松山古地磁界线附近铱异常的发现及其启示   总被引：3，自引：0，他引：3  

马配学  侯泉林 《地质学报》1998,72(2):173-177

利用高灵敏度放射化学中子活化分析方法,对我国陕西段家坡黄土剖面早－中更新统（约０．７３Ｍａ）沉积界线附近铱和其它元素的丰度进行了测定。结果表明,在布容／松山（Ｂ／Ｍ）古地磁界线附近铱的含量明显增大,最大值为４６．３ｐｇ／ｇ。相对于整个剖面的平均背景值（约１５ｐｇ／ｇ）大约富集了３倍。用地壳元素钪进行标准化之后,铱异常十分明显,而其它元素在界线附近则没有变化。黄土剖面上铱异常的赋存层位与西南太平洋钻  相似文献   

Numerical simulation of NAPL flow in the subsurface     

L.K. Kuiper  T.K. Illangasekare 《Computational Geosciences》1998,2(3):171-189

A three-dimensional, three-phase numerical model is presented for simulating the movement of immiscible fluids, including nonaqueous-phase liquids (NAPLs), through porous media. The model is designed to simulate soil flume experiments and for practical application to a wide variety of contamination scenarios involving light or dense NAPLs in heterogeneous subsurface systems. The model is derived for the three-phase flow of water, NAPL, and air in porous media. The basic governing equations are based upon the mass conservation of the constitutents within the phases. The descretization chosen to transform the governing equations into the approximating equations, although logically regular, is very general. The approximating equations are a set of simultaneous coupled nonlinear equations which are solved by the Newton-Raphson method. The linear system solutions needed for the Newton-Raphson method are obtained using a matrix of preconditioner/accelerator iterative methods. Because of the special way the governing equations are implemented, the model is capable of simulating many of the phenomena considered necessary for the sucessful simulation of field problems including entry pressure phenomena, entrapment, and preferential flow paths. The model is verified by comparing it with several exact analytic test solutions and three soil flume experiments involving the introduction and movement of light nonaqueous-phase liquid (LNAPL) or dense nonaqueous-phase liquid (DNAPL) in heterogeneous sand containing a watertable. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Statistical properties of H II regions in the disc of M100     

Knapen 《Monthly notices of the Royal Astronomical Society》1998,297(1):255-264

From a new mosaic image in the Hα line of the complete disc of the spiral galaxy M100, a catalogue is composed listing 1948 individual H II regions. I give details of the data collection and reduction procedure, and of the production of the H II region catalogue. For each H II region, the catalogue gives its position relative to the centre of the galaxy, its deprojected distance to the centre, its radius and its calibrated luminosity. An indication is included as to whether the H II region is located in the arms, between them, or in the circumnuclear star-forming region. I present the results of a statistical study of properties of the H II regions. The luminosity function of the complete ensemble of H II regions shows a characteristic shape well fitted by a power-law slope in the higher luminosity range, and complying with literature values for galaxies like M100. Luminosity function slopes for arm and interarm H II region populations separately are found to be equal within the errors of the fits, indicating that whereas the density wave accumulates material into the arm regions, and may trigger star formation there, it does not in fact change the mass distribution of the star-forming clouds, nor the statistical properties of the H II region population. Diameter distributions and the radial number density distribution are discussed. The latter indicates those areas where most star formation occurs: the circumnuclear region and the spiral arms. The huge number of H II regions allowed the construction of a number of independent luminosity functions at different distances to the nucleus. The slope of the luminosity function shows a marginal decrease with increasing distance from the centre, which could indicate a gradual change towards shallower IMF slopes with increasing galactocentric distance, or an evolutionary effect.  相似文献   

Chlorinated hydrocarbons in gulls from the Baltic south coast     

Jerzy Falandysz 《Marine pollution bulletin》1980,11(3):75-80

Polychlorinated terphenyls among organochlorine pesticides and polychlorinated biphenyls were detected in some gulls from the Gdańsk Bay, Baltic Sea.  相似文献   

Testing modified Newtonian dynamic with Local Group spiral galaxies     

Edvige Corbelli  Paolo Salucci 《Monthly notices of the Royal Astronomical Society》2007,374(3):1051-1055

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The quasi-persistent neutron star soft X-ray transient 1M 1716−315 in quiescence     

P. G. Jonker  C. G. Bassa  S. Wachter 《Monthly notices of the Royal Astronomical Society》2007,377(3):1295-1300

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