直接表达区域的四叉树链式编码

提出一种用于直接表达区域的数据结构——四叉树链式编码。与常规四叉树结构比较,该方法具有压缩率高、表达直接等优点。本文还用C语言给出具体表达式和基本算法、效率分析。     

直接表达区域的四叉树链式编码

提出一种用于直接表达区域的数据结构－四叉树链式编码。与常规四叉树结构比较，该方法具有压缩率高、表达直接等优点。本还用Ｃ语言给出具体表达式和基本算法、效率分析。     

New Early Cretaceous Pterosaur-Bird Track Assemblage from Xinjiang, China: Palaeoethology and Palaeoenvironment

A pterosaur-bird track assemblage from a sandstone-siltstone-mudstone sequence of the Lower Cretaceous Tugulu Group of Xinjiang comprises the first pterosaur track record from this province and the largest specimen thus far known from China.The pterosaur tracks are assigned to the ichnogenus Pteraichnus based on the triangular overall-shape,the four elongate digit traces and the robust manual digit trace Ⅲ.Supposed trackmakers were dsungaripterid pterodactyloids whose skeletal remains are well known from the Tugulu Group.The bird tracks that occur on the same surface,are those of typical shorebirds,known from different other localities in southeast Asia.The congruence with Koreanaornis dodsoni described from the same stratigraphic level justifies an assignment to this ichnospecies.This is a further evidence of the co-occurrence of pterosaurs and birds in a typical iakeshore environment with possible seasonal alteration of water supply and aerial exposure indicated by wave ripples,mudcracks and repeated cycles of coarse to fine sediment.Pterosaurs and birds frequented the shoreline and may have fed also on the numerous invertebrates such as the Scoyenia tracemaker that left abundant burrows.     

昆明台前兆仪器故障分析

通过对昆明地震台多年前兆仪器故障的检修实例,总结工作中应熟悉掌握的故障排解方法。帮助台站人员快速排除类似故障,为台站资料的连续、可靠提供保障。     

Development trends among Moscow Oblast cities and some issues in the regulation of the growth of Moscow

Reasons for the continuing growth of central Moscow in comparison with little growth in subsidiary cities in the surrounding Moscow Oblast are examined. The author attributes this uneven growth to the concentration of shopping facilities in central Moscow. It is noted that past attempts to slow the growth of central Moscow have failed and that the only strategy likely to succeed in the future would involve developing the infrastructure of the surrounding subcenters.     

Plankton of the Baltic estuarine ecosystems with emphasis on Neva Estuary: a review of present knowledge and research perspectives

Different levels of eutrophication and pollution in the Baltic coastal waters in general, and in estuaries particularly define variations in the buffering capacity of ecosystems of these important filter zones between rivers and the adjacent Baltic Proper. Phyto- and zooplankton in the estuaries form important components of the pelagic food webs that participate in producing and structuring the matter, energy, and information fluxes in the ecosystems. Due to salinity gradients, estuaries provide a large variety of aquatic habitats for native populations of marine, brackish and fresh water plankton species. Non-indigenous planktonic species that expand their bio-geographical range and invade the Baltic coastal ecosystems also find favourable environments, establish permanent populations there, and impact aboriginal ecosystems. The dynamics of abundance, species diversity, population structure, productivity of planktonic communities, and peculiarities of trophic interactions in different Baltic estuaries are influenced by a number of common environmental factors. Being measured on the unified basis and monitored, changes (or stability) of structural and functional parameters of plankton communities can serve as indicators of alterations to the ecosystems. Comparative analyses and quantitative estimates of long-term changes in phyto- and zooplankton can contribute to evaluation of functional response of Baltic coastal ecosystems to anthropogenic stress. Both theoretical (modeling) and empirical studies of interactions within plankton communities aimed at the assessment of the role of planktonic organisms in water quality regulation, and applicability of these data for the evaluation of the status of ecosystems and their management can be considered as major goals for the future investigations in Baltic estuaries.     

运城地区黄河滩涂资源的开发和利用

黄河滩涂地形平坦,面积广阔,水热资源丰富,土地资源潜力较大。充分开发利用黄河滩涂资源,不仅可以缓解沿河地区人多地少的矛盾,而且也是振兴农村经济,兴农致富的战略措施。本文对运城地区黄河滩涂资源进行了科学评价,分析了目前的开发利用现状。并对前景进行了预测,最后提出要因地制宜开发利用滩涂资源,建立不同类型的商品性生产基地。     

利用雷达立体像对建立数字地形模型

讨论了运用阿尔玛日宇宙飞船在不同轨道所拍摄的重叠雷达影象来建立地球表面数字地形模型的方法，以及运用立体像对制作一张地表地形的三维影象数字图象的方法及处理过程的算法，运用与美国航天飞机成像雷达－Ｂ系统相像的北美大盆地沙漠影象，介绍了从两张重叠影象的处理中获取正射地形图影象的方法。     

矢量数据的一种分层动态组织方法

提出矢量数据分层组织的一种动态结构，在该结构中、单点、单字符或符号作为基元，以属性串组织基元，并分层叠置，采用区别于链式结构的动态通用串结构及Ｃ语言予以实现。