河北平原水系密度与隐伏活动构造的关系

以1926年出版的比例尺为1：5万的顺直地形图作为基础图件，用地理信息系统技术对河北平原作水系密度计量分析，揭示隐伏在第四纪巨厚的沉积物之下活动构造的信息，研究结果证实水系线密度统计图与使用其它地球科学方法获得的成果，例如基底活动断块图，地貌类型图和第四纪厚度图都有很好的对应，特别与布格重力图对应更好，研究结果发现水系密度图与布格重力异常图在总体一致性较好的前提下，多处反向异常区均为近代强震发生的区域，提出这种地表水系密度统计研究的成果不仅可以揭示深部隐伏的活动构造，而且具有较明确的时间含义。     

Research on the geography of agricultural change: redundant or revitalized?

Summary Future research directions for agricultural geography were the subject of debate in Area in the late 1980s, and the subsequent application of political economy ideas undoubtedly revived interest in agricultural research. This paper argues that agricultural geography contains greater diversity than the dominant political economy discourse would suggest. It reviews 'other' areas of agricultural research such as policy, post- productivism, people, culture and animals, presenting future suggestions which should ensure that agricultural research continues revitalized rather than redundant into the next millennium.     

Observations of OH maser lines at an 18-cm wavelength in 9P/Temper1 and Lulin C/2007 N3 comets with RT-22 at the Crimean Astrophysical Observatory

Investigations on OH maser lines in comets have been performed with the RT-22 at CrAO. The results of observations of 9P/Temper1 and Lulin C/2007 N3 comets in the OH molecule line at a wavelength of 18 cm are presented. An original technique for observation data analysis has been developed. The gas production rate of OH molecules in these comets is estimated.     

Structural elements in southeastern Quebec,northwestern Appalachians,Canada

An attempt is made to correlate and separate in terms of style and time two contrasting sets of structural elements in the northwestern part of the Appalachian Uplands in the Province of Quebec, Canada. There is sufficient evidence to indicate that a fold system with north-south trending axes is superimposed on a fold system with east-west axes. It is suggested that the two sets of structures represent pulses of one long-continued deformation accompanied by corresponding early and late phases of metamorphism.

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Zusammenfassung Es wurde versucht, in den Appalachen des südöstlichen Teiles der Provinz Quebec, Kanada, zwei ungleichzeitige tektonische Systeme verschiedenen Baustils zu trennen. Die komplexen Kleinstrukturen zeigen, da\ Ost-West streichende Faltenachsen von einer jüngeren Nord-Süd-Faltung überprägt worden sind. Der Autor ist der Meinung, da\ die zwei tektonischen Systeme, die von einer frühen und späten Phase der Metamorphose begleitet werden, den zeitlich getrennten Verformungsstadien einer Orogenese entsprechen.

     

Numerical simulation of the interaction between two high-energy plasma bunches in the ionosphere

The 3D MHD algorithm developed by us has been adapted to modeling the interaction between two plasma bunches in the ionosphere, mainly in order to sufficiently correctly describe the physics of the interaction between two plasma regions with regard to the ionospheric inhomogeneity and the geomagnetic field action. Modeling has been performed for several versions of location of the plasma region centers.     

Patterns of pH change inferred from chrysophyte microfossils in Adirondack and northern New England lakes

The silica-scaled chrysophytes are being used increasingly in paleolimnological studies of lake acidification. This study compares the distribution of scaled chrysophytes in the surface sediment of a calibration set of lakes from the Adirondack Park and from northern New England. With the exception of two taxa, species distributions with respect to pH are similar in the two regions. The stratigraphic distribution of chrysophytes is then compared in five Adirondack and three New England lakes. All the presently acid lakes indicate recent lake acidification, with more acid tolerant chrysophytes increasing in relative frequency in the recent sediments. Because the timing of these species changes is unrelated to any watershed disturbances that may have occurred in the lakes' catchments, atmospheric deposition of acids is believed responsible for these recent pH changes.This is the seventh of a series of papers to be published by this journal which is a contribution of the Paleoecological Investigation of Recent Lake Acidification (PIRLA) project. Drs. D. F. Charles and D. R. Whitehead are guest editors for this series.     

Archaeal Communities of Frozen Quaternary Sediments of Marine Origin on the Coast of Western Spitsbergen

Izvestiya, Atmospheric and Oceanic Physics - The archaeal composition of permafrost samples taken during the drilling of frozen marine sediments in the area of the Barentsburg coal mine on the east...