Language reproduction: reflections on the Welsh example     

John Aitchison  Harold Carter 《Area》1997,29(4):357-366

Summary Recent changes in the distribution of the Welsh language are related to a process of empowerment of a Welsh-speaking elite that has come into being as a consequence of economic change, especially deindustrialization. This situation is examined against theories of language shift, and the specific new routes along which language reproduction is directed are considered.  相似文献   

WAVE ENERGY ESTIMATES AND BLUFF RECESSION ALONG LAKE MICHIGAN'S SOUTHEAST SHORE*     

Jeffrey P. LaMoe  Harold A. Winters 《The Professional geographer》1989,41(3):349-358

Recession rates for unconsolidated bluffs at 23 sites along Lake Michigan's southeast shore are compared with deep water wave energy probabilities to estimate the relative degradational importance of recurrent 5, 10, 20, 50, and 100-year storms. Recession rates are based on measured bluff crest retreat while wave energies are calculated using standard water wave theory and data interpolated from a meteorologically based hindcast model. Correlation and regression tests suggest the following: (1) although wave energy is certainly a destructive factor, it explains less than half of the variation in bluff crest recession, supporting the interpretation that shorezone erosion here results from the interaction of numerous factors; and (2) over long time periods the total effect of more frequent moderate intensity storms is greater than that from rare, especially high energy events.  相似文献   

On the Interpretation of Pd     

Harold Jeffreys 《Geophysical Journal International》1958,1(3):191-197

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Tidal friction; the core; mountain and continent formation     

Harold Jeffreys 《Geophysical Journal International》1982,71(3):555-566

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THE CLAXTON,GEORGIA, METEORITE     

Harold Povenmire 《Meteoritics & planetary science》1985,20(3):541-544

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The smallest observable elements of magnetic flux     

Jingxiu Wang  Harold Zirin  Zhongxian Shi 《Solar physics》1985,98(2):241-253

We have followed disappearing elements of magnetic flux to determine the smallest elements detectable with the Big Bear videomagnetograph. All the elements followed were disappearing through interaction with elements of opposite polarity. The last remaining visible segment of magnectic field of such features can be used to infer the total magnetic flux of these and other small flux elements visible on the magnetograms.We used both photographic and digital videomagnetograms combining 4096 Zeeman frames made at Big Bear. Fifteen elements were measured near the vanishing point, in a 2–8 hr period. The minimum observable fluxes fall in the range of 1.0 × 10¹⁶ to 1.4 × 10¹⁷ Mx, and the apparent size of these elements is in the range of 1 to 9 square arc sec. The process of disappearance appears to be a smooth one. The smallest detectable elements of network field and ephemeral regions (ER) appear to be the same as the small intra-network (IN) field elements. The present limit is still instrumental; elements smaller than 1 × 10¹⁶ would not have been detected.Visiting Associates from Beijing Observatory, Academia Sinica, Beijing, China.  相似文献   

Two prominence eruptions and the problem of emission     

Harold Zirin 《Solar physics》1969,7(2):243-252

Two flare unconnected eruptions on January 15 and 29, 1968, are discussed. The first is a filament which turns bright and erupts upward, reappearing an hour later. The second is a large eruptive arch seen against the disk. The arch is bright at the top of its trajectory, turns dark, but produces chromospheric emission at the point of impact. The emission at the top of the arch is ascribed to the velocity shift of the illuminating chromospheric Ha line. It is shown that such emission will occur only if the motion is transverse to the line of sight and the prominence is optically thin.This research was supported by the National Science Foundation under Grant 1472, the Advanced Research Projects Agency under the Office of Naval Research Grant N00014-67-C-0140, and the National Aeronautics and Space Administration under Grant NGR 05 002 034.  相似文献   

P and S beyond 95°     

Harold Jeffreys 《Geophysical Journal International》1977,51(2):387-392

Summary. Data for P and S beyond 85° are used for earthquakes in the four epicentral regions that travel times have been found for (Japan, Europe, Central and South Pacific). They seem to disagree seriously with suggestions of a considerable change in the times and dt/dΔ for S from the Jeffreys—Bullen tables of 1939–40. There are signs of a sharp drop in dt/dΔ for both Pand S in the range 93–95° except for the Southern Pacific.  相似文献   

A charge-coupled device observation of Charon     

Harold J. Reitsema  Faith Vilas  Bradford A. Smith 《Icarus》1983,56(1):75-79

Images of Pluto which were obtained with a charge-coupled device (CCD) detector show an elongation caused by its satellite, Charon. Analysis of these images separates the planet and satellite components, and yields a Pluto/Charon brightness ratio of 5.5.  相似文献   

On imperfection of elasticity in the Earth's interior     

Harold Jeffreys 《Geophysical Journal International》1978,55(2):273-281

Summary. Attempts are made to estimate the distribution of damping with depth, based on the observed damping of P waves, of free vibrations, and of surface waves and partly on a discussion by D. L. Anderson and R. S. Hart. Results are consistent in order of magnitude, but could easily be wrong by a factor of 2. Comments are added on the need for further work. Stress is laid on the damping of the free nutation, which indicates that α in the modified Lomnitz law is about 0.2 on an average.  相似文献