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《The Professional geographer》2013,65(3):257-258
Financial services are undergoing a major period of internationalization. National markets are interlinked by telecommunications, a process induced through deregulation and new communications technologies. This paper reviews the recent, intertwined trends in the finance and telecommunications industries in light of urban and regional restructuring theory, cites several company-specific examples, explores the impacts on the international urban hierarchy and the labor process (e.g., back offices), and assesses the role of teleports. Finally, it offers an agenda for further research. 相似文献
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V. R. S. Hutton D. I. Gough† G. J. K. Dawes J. Travassos 《Geophysical Journal International》1987,90(1):245-263
Summary. Magnetotelluric soundings have been made at 25 stations in the Rocky Mountain Trench (RMT) and Main Ranges near 53° N, close to the centre of a major conductivity anomaly which had been mapped in a magnetovariation array study. Most stations covered the frequency range 0.01–500 Hz and three stations 0.0002–500 Hz. the resistivity tensor shows low to moderate anisotropy in the RMT, but is strongly 2-D or 3-D in the Rocky Mountains. Apparent resistivities as a function of frequency are displayed in pseudosections along the Trench and along a transverse profile across the RMT and into the Main Ranges. In preparation for 2-D modelling, 1-D inversions have been used to construct resistivity-depth sections satisfying both magnitudes and phases of the MT responses. These show very low resistivities, in the range 1—10Ωm, in the upper crust under the RMT and even lower values under the Main Ranges. the latter values give strong confirmation of the Northern Rockies conductor reported by Bingham, Cough & Ingham and are in agreement with models of the conductors fitted to long-period magnetovariation fields by Ingham, Gough & Parkinson. the MT results here reported add some essential depth and resistivity information. It is suggested that the conductors beneath the Rocky Mountains Main Ranges and Trench constitute a thickening at the edge of the Canadian Cordilleran Regional (CCR) conductor. Gough has argued that a wide variety of geophysical and geological parameters indicate high temperatures and partial melting in the mantle under the CCR conductor. At the upper crustal depths penetrated in this magnetotelluric study, it is considered more probable that the high conductivity is caused by hot, saline water of mantle origin rather than silicate melt. the CCR in general may have two layers of fluid producing its high conductivity, silicate melt below and saline hot water above. 相似文献
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Anelastic Rayleigh Wave Attenuation In the Iberian Peninsula 总被引：1，自引：0，他引：1
Jose A. Canas Fernando De Miguel† Francisco Vidal† Gerardo Alguacil† 《Geophysical Journal International》1988,95(2):391-396
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Warwick D. Smith 《Geophysical Journal International》1986,86(3):815-838
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陈逢珍 《亚热带资源与环境学报》2002,17(2):5-6
本文针对《地图学》课程的特点，总结多年教学实践经验，提出了改革的方向：面向现代化，改革教学内容；面向社会经济发展方向，将科研成果有机地融入课程教学中；以创新思维为目标，有效采用启发式、讨论式、研究式教学方法。 相似文献
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