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181.
For about ten years, economic geography has enjoyed a renewal. Many researchers have found anchorage in different theoretical
currents in order to analyse current economic changes. Regulation theory has been particularly inspirational in these considerations.
This article represents a balance between different axes of research in regional economics, and their encounters with regulationist
ideas. The main schools of thought are presented in chronological order with the prominent actors and the research results
underlining the principal elements from each school. Finally, some prospects for the future are outlined.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
182.
183.
Georges Blaha 《Journal of Geodesy》1982,56(4):281-299
The present paper deals with the least-squares adjustment where the design matrix (A) is rank-deficient. The adjusted parameters \(\hat x\) as well as their variance-covariance matrix ( \(\sum _{\hat x} \) ) can be obtained as in the “standard” adjustment whereA has the full column rank, supplemented with constraints, \(C\hat x = w\) , whereC is the constraint matrix andw is sometimes called the “constant vector”. In this analysis only the inner adjustment constraints are considered, whereC has the full row rank equal to the rank deficiency ofA, andAC T =0. Perhaps the most important outcome points to the three kinds of results
- A general least-squares solution where both \(\hat x\) and \(\sum _{\hat x} \) are indeterminate corresponds tow=arbitrary random vector.
- The minimum trace (least-squares) solution where \(\hat x\) is indeterminate but \(\sum _{\hat x} \) is detemined (and trace \(\sum _{\hat x} \) corresponds tow=arbitrary constant vector.
- The minimum norm (least-squares) solution where both \(\hat x\) and \(\sum _{\hat x} \) are determined (and norm \(\hat x\) , trace \(\sum _{\hat x} \) corresponds tow?0
184.
Georges Boudon Michel P. Semet Pierre M. Vincent 《Journal of Volcanology and Geothermal Research》1987,33(4)
We recently reported (Boudon et al., 1984) on an eruption similar to that of May 18, 1980 at Mount St. Helens, that took place about 3100 years ago at la Soufrière, Guadeloupe. During the course of detailed geological mapping of the deposits of this event, older debris flow and blast deposits were recognized in the northern sector of the mapped area. Uncarbonized wood fragments in the debris flow have yielded ages ca. 11,500 y. B.P. The deposits extend from an amphitheater crater westward to the caribbean shore about 10 km downslope from the volcano. The deposits and crater structure suggest that they are the result of catastrophic flank failure like the event 3100 years ago. Unlike the latter activity, however, no magmatic component is found in the deposits. 相似文献
185.
Jean Besse Jean-Pierre Pozzi Georges Mascle Hugues Feinberg 《Earth and Planetary Science Letters》1984,67(3):377-390
Paleomagnetic analysis of Cenozoic sediments from the Iblean platform (12 sites, 100 samples) has provided four new poles. These data are combined with those available from volcanic series to yield a new apparent polar wander path for “stable” Sicily since the Upper Cretaceous. This curve, when compared to a revised curve for Africa (using a selection of available data points), demonstrates a 15° rotation of Sicily with respect to Africa during the Plio-Pleistocene. This rotation accounts for the extensional tectonic regime that prevails in the Pelagian Sea and which is evidenced by “en relais” rifts (Malta, Pantelleria, Linosa), associated with alkaline volcanism of Pliocene and Quaternary age. Paleomagnetic directions from various areas of the Italian Peninsula also indicate anticlockwise rotations with diverse amplitudes. The chronology of these rotations is consistent with a deformation of the western Italian margin during progressive suturation from north to south of the Corsican-Sardinian block since the end of the Oligocene. 相似文献
186.
An acoustic Doppler sounder has been used to document the behaviour of the stable atmospheric boundary layer during the “Coast” experiment, in April-May, 1983, on a homogeneous terrain near the Dutch coast. It has been shown that kaimal's model of the spectrum of velocity in the stable surface layer can be applied and that surface-layer parameterization can be used in the whole stable surface layer. Velocity spectra have been computed between .0005 c.p.s. and .1 c.p.s. and for the stability range for z/L between 0 and 10. It is to be noted that the information has been obtained using only sodar data. 相似文献
187.
Les teneurs de huit éléments des terres rares (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu) sont déterminées par l'analyse par l'activation neutronique instrumentale sur l'Echantillon Géochimique de Référence NBS 88a. Ces teneurs proviennent de la moyenne arithmétique de dix analyses de NBS 88a. Elles se comparent bien avec d'autres déterminations de ces éléments publiées dans la littérature. Dans la limite de la précision analytique, NBS 88a paraît homogène en ce qui concerne les terres rares. 相似文献
188.
Georges R. Darbre 《地震工程与结构动力学》1984,12(5):703-707
The modal base forces in structures having a straight-line mode of vibration are investigated. Making use of the orthogonality relationship between the different modes, a relation between the modal base shears and base moments is found in all but the straight-line mode. This relation states that the contribution of the inertia forces to the modal overturning moments referred to the centre of rotation of the straight-line mode is identically null. The contributions of the vertical forces and lateral constraints must, however, be accounted for. For the special case of the straight-line mode being proportional to the height of each storey, the centre of rotation coincides with the base of the structure. For the case of the straight-line mode being a uniform displacement, the centre of rotation is at infinity and the contribution of the inertia forces to the modal base shears identically disappears in all but the straight-line mode. 相似文献
189.
The 1977–1978 French New-Zealand summer campaign at Mount Erebus took place during a period of rather low activity. In such conditions, we could measure an output of 3 Ci of 210Pb, 100 Ci of 210Po and 1010 tons of sulfate per year.The 210Po seems to be the only element emitted by Mount Erebus whose contribution to the Antarctic atmosphere is significant: sulfur compounds as well as radon emitted by Mount Erebus during a period of quiescent activity, have a negligible contribution to the overall Antarctic budgets.The presence of long-lived radon daughters in volcanic gases, highly enriched in volatile elements, seems to be a characteristic of gases emitted directly from the magma at high temperature. 相似文献
190.