Kirsch problem and the lower natural frequencies of a clamped square-plate     

P. A. A. Laura  V. Sonzogni 《Ocean Engineering》1997,24(10)

A clamped square-plate is subjected to a uniform state of stress in the x-direction. The present study deals with the basic question of determining the variation of the lower natural frequencies of transverse vibration of a plate as a small diameter, central hole is made in it, introducing a stress concentration field.  相似文献   

Geomorphology and sedimentology of the continental shelf adjacent to Mac. Robertson Land,East Antarctica: A scalped shelf     

P. T. Harris  P. E. O'Brien 《Geo-Marine Letters》1996,16(4):287-296

During the Quaternary, the Mac. Robertson shelf of East Antarctica was deeply eroded by glaciers and currents exposing the underlying basement, resulting in a scalped shelf. Major geomorphic zones are: (1) high-relief, ridge and valley topography (200–1400 m); (2) smooth sea floors associated with low-energy, depositional shelf valleys and basins (400–800 m); (3) low-relief, planated banktops (100–200 m); and (4) iceberg gouged and current reworked seaward-bank margins and upper slope (200 to < 630 m). About 90% of the shelf's surface has net erosional conditions and about 10% is net depositional. The sedimentary processes and deposits may be common to large areas of the East Antarctic margin.  相似文献   

Transverse vibrations of a rectangular cantilever plate with thickness varying in a discontinuous fashion     

R.E. Rossi  P.M. Belles  P.A.A. Laura  S. La Malfa  L. Ercoli  D. Pasqua 《Ocean Engineering》1996,23(3):271-276

A numerical solution is obtained for the title problem by means of the popular finite element method. An experimental investigation of the problem is also presented for plates of square planform. The agreement between theoretical and experimental values is very good in the case of the fundamental frequency, and reasonably good when the second and third normal modes of transverse vibration are considered. It is concluded that beneficial effects are obtained in the sense that one generates a lighter structural element with higher fundamental frequency of transverse vibration. Hence, dynamic stiffening is achieved.  相似文献   

The thermohaline fields and currents measured in the sub-arctic frontal zone of the Pacific Ocean     

V. I. Byshev  A. D. Shcherbinin 《Physical Oceanography》1995,6(4):263-271

Based on the MEGAPOLYGON data, it is shown that the large-scale elements of the thermohaline structure and the fields of currents in the baroclinic layer (down to 1200 m) are well coordinated. The circulation has a two-layer structure with a transitory layer at a depth of 1200 m. The topography of the isopycnic surface of the layer's core is formed under the influence of small-scale and mesoscale processes which realize the trans-frontal exchange.Translated by Mikhail M. Trufanov.  相似文献   

Fine vertical structure of currents and hydrological elements in the Black Sea     

V. M. Kushnir 《Physical Oceanography》1995,6(3):229-236

Data on the fine vertical structure of currents and hydrological elements in the Black Sea, obtained through the use of a hydrophysical OLT profiler, are examined. Vertical exchange coefficients are evaluated, whose distribution is characterized by the occurrence of minima in the seasonal pycnocline and main halocline, a maximum in the core of the cold intermediate layer (CIL), and relatively steady values within the 300–500 m layer. The vertical exchange coefficient values, are consistent with the data acquired through other techniques, and the profiles of this parameter vertically are more detailed.Translated by Vladimir A. Puchkin.  相似文献   

The near field of internal waves after the moving area of atmospheric pressures     

V. E. Veden'kov  V. F. Sannikov 《Physical Oceanography》1992,3(3):175-181

The near wave field generated by the travelling atmospheric pressure zone over a stratified fluid is studied within the framework of the linear theory of long waves allowing for the Coriolis force. The exact solution of the problem as a set of single integrals is deduced for the model distribution of pressures. The characteristics of the near wave field have been computed for the Väisälä-Brunt frequency profile takeu from observations. Their dependences on the geographical latitude and the wave generator travelling rate are analysed.Translated by Mikhail M. Trufanov.  相似文献   

Submersible observations of an iceberg pit and scour on the Grand Banks of Newfoundland     

J. V. Barrie  C. F. M. Lewis  D. R. Parrott  W. T. Collins 《Geo-Marine Letters》1992,12(1):1-6

An elongated sea bed depression (pit), 80 by 125 m and 10 m deep located on the Grand Banks of Newfoundland was identified on high resolution surficial geophysical survey lines and investigated using a manned submersible. The pit occurs at the termination of a long (greater than 3 km) iceberg scour, 1.5 m deep, and 80 m wide in 91 m of water. It is similar to other depressions in the region that indent the sea bed up to seven times deeper than the surrounding deepest iceberg furrows. The pit is interpreted to be the sea bed response to impact and loading by a rolling and grounding iceberg. The iceberg scour and pit appear to be of recent origin.  相似文献   

Joint Soviet-Turkish expedition in the Black Sea     

A. A. Bezborodov  S. L. Gokchen  V. N. Eremeev  I. T. Konuk  A. K. Saidam  E. M. Tirasin 《Physical Oceanography》1991,2(3):227-231

The hydrological and hydrochemical structures of the upper 300 m water column of the Black Sea in autumn 1988 have been studied. Regularities in the distribution of the physico-chemical characteristics in the zone of interaction between aerobic and anaerobic waters as well as the topography of the H₂S zone boundary and its connection with a certain density gradient have been found.Translated by Mikhail M. Trufanov.  相似文献   

Remote observations of the water circulation in the western Black Sea     

G. A. Grishin  I. G. Makeev  S. V. Motyzhev 《Physical Oceanography》1991,2(2):145-155

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Regional tectonic trends on the inner continental shelf off Konkan and Central West Coast of India     

M. V. Ramana 《Geo-Marine Letters》1986,6(1):1-5

Satellite imagery and offshore magnetic data were analysed to correlate regional tectonic elements on the inner continental shelf off Konkan and the adjacent Deccan plateau. Three statistically important lineament trends—N-S, WNW-ESE and ENE-WSW—that prevail on land are correlatable well with the offshore trends. This positive correlation suggests simultaneous deformation. The major magnetic lineament observed off Jaigad Bay, west coast of India, may be the extension of onshore lineaments. The correlation of both the offshore and onshore trends indicates that the fracture pattern of the crystalline basement has also controlled the offshore structural pattern.  相似文献