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81.
Summary Changes occurring in the thermal structure of air masses in the Alps area and the West Mediterranean region, during cyclonic developments in the Gulf of Genoa, have been considered. The effect of the height and the form of the mountain ranges as well as that of the nonadiabatic processes, on the deformation of the thickness pattern, have been discussed. These factors have been further taken into consideration for a modification of the equations used inEstoque's method for the baroclinic model, and a new method has been developed for forecasting cyclogenesis in regions bounded by mountain ranges.
Zusasmmenfassung Es werden die Änderungen der thermischen Struktur der Luftmassen im Alpengebiet und im westlichen Mittelmeerraum bei der Entwicklung von Zyklonen im Golf von Genua aufgezeigt und die Einflüsse von Höhe und Form der Gebirgszüge sowie von nichtadiabatischen Vorgängen auf die Deformation der relativen Topographie besprochen. Diese Faktoren werden auch zur Modifikation der in der Methode vonEstoque für ein baroklines Modell verwendeten Gleichungen in Betracht gezogen und damit wird eine neue Methode zur Vorhersage der Zyklogenese unter dem Einfluß von Gebirgszügen entwickelt.

Résumé On expose dans ce mémoire à quelles modifications la structure thermique des masses d'air est soumise dans la région des Alpes et dans le bassin occidental de la Méditerranée lors du développement de dépressions sur le Golfe de Gênes. On y discute en outre l'influence de la hauteur et de la forme des chaînes de montagnes ainsi que celle des processus non-adiabatiques sur des déformations de la topographie relative. Tous ces éléments sont pris en considération pour leur adapter les équations utilisées dans le modèle baroclined'Estoque. Par là, on accède à une nouvelle méthode de prévision de la cyclogénèse, méthode qui tient compte de l'influence des chaînes de montagnes.


With 5 Figures  相似文献   
82.
Zusammenfassung Aus der Temperatur der Sonnenoberfläche und der Entfernung Sonne-Erde ergiebt sich die Solarkonstante 2.4 in Uebereinstimmung mit dem rohen Wert, der die Instrument-Temperatur berücksichtigt. Da an den meisten Observatorien die mittägliche Sonnenhöhe nicht ausreicht für eine genaue Bestimmung der Solarkonstante, wird 2.4 als rohe vorläufige Solarkonstante vorgeschlagen, bis im Laufe der nächsten 2 Jahre eine genauere Bestimmung vorliegt. Vermutlich ist auch die Strahlungskonstante von dem Temperaturfehler beeinflusst.  相似文献   
83.
84.
Summary The standard equations for the theory of atmospheric tides are solved here by an integral representation on the continuous spectrum of free oscillations. The model profile of back-ground temperature is that of the U.S. Standard Atmosphere in the lower and middle atmosphere, and in the lower thermosphere, above which an isothermal top extends to arbitrarily great heights. The top is warm enough to bring both the Lamb and the Pekeris modes into the continuous spectrum.Computations are made for semidiurnal lunar tidal pressure at sea level at the equator, and the contributions are partitioned according to vertical as well as horizontal structure. Almost all the response is taken up by the Lamb and Pekeris modes of the slowest westward-propagating gravity wave. At sea level, the Lamb-mode response is direct and is relatively insensitive to details of the temperature profile. The Pekeris mode at sea level has an indirect response-in competition with the Lamb mode-and, as has been known since the time of its discovery, it is quite sensitive to the temperature profile, in particular to stratopause temperature. In the standard atmosphere the Lamb mode contributes about +0.078 mb to tidal surface pressure at the equator and the Pekeris mode about –0.048 mb.The aim of this investigation is to illustrate some consequences of representing the tide in terms of the structures of free oscillations. To simplify that task as much as possible, all modifying influences were omitted, such as background wind and ocean or earth tide. Perhaps the main defect of this paper's implementation of the free-oscillation spectrum is that, in contrast to the conventional expansion in the structures of forced oscillations, it does not include dissipation, either implicity or explicity, and thus does not satisfy causality. Dissipation could be added implicity by means of an impedance condition, for example, which would cause up-going energy flux to exceed downgoing flux at the base of the isothermal top layer. To achieve complete causality, however, the dissipation must be modeled explicity. Nevertheless, since the Lamb and Pekeris modes are strongly trapped in the lower and middle atmosphere, where dissipation is rather weak (except possibly in the surface boundary layer), more realistic modeling is not likely to change the broad features of the present results.Symbols a earth's mean radius; expansion coefficient in (5.3) - b recursion variable in (7.4); proximity to resonance in (9.2) - c sound speed in (2.2); specific heatc p in (2.2) - f Coriolis parameter 2sin in (2.2) - g standard surface gravity - h equivalent depth - i ; discretization index in (7.3) - j index for horizontal structure - k index for horizontal structure; upward unit vectork in (2.2) - m wave number in longitude - n spherical-harmonic degree; number of grid layers in a model layer - p tidal pressure perturbation; background pressurep 0 - q heating function (energy per mass per time) - r tidal state vector in (2.1) - s tidal entropy perturbation; background entropys 0 - t time - u tidal horizontal velocityu - w tidal vertical component of velocity - x excitation vector defined in (2.3); vertical coordinate lnp */p 0 [except in (3.8), where it is lnp /p 0] - y vertical-structure function in (7.1) - z geopotential height - A constant defined in (6.2) - C spherical-harmonic expansion coefficient in (3.6) - D vertical cross section defined in (5.6) and (5.9) - E eigenstate vector - F vertical-structure function for eigenstate pressure in (3.2) [re-defined with WKB scaling in (7.2)] - G vertical-structure function for eigenstate vertical velocity in (3.2) [re-defined with WKB scaling in (7.2)] - H pressure-scale height - I mode intensity defined in (8.1) - K quadratic form defined in (4.4) - L quadratic form defined in (4.4); horizontal-structure magnification factor defined in (5.11) - M vertical-structure magnification factor defined in (4.6) - P eigenstate pressure in (3.2); tidal pressure in (6.2) - R tidal state vector in (5.1) - S eigenstate entropy in (3.2); spherical surface area, in differential dS - T background molecular-scale (NOAA, 1976) absolute temperatureT 0 - U eigenstate horizontal velocityU in (3.2); coefficient in (7.3) - V horizontal-structure functionV for eigenstate horizontal velocity in (3.2); recursion variable in (7.3) - W eigenstate vertical velocity in (3.2) - X excitation vector in (5.1) - Y surface spherical harmonic in (3.7) - Z Hough function defined in (3.6) - +dH/dz - (1––)/2 - Kronecker delta; Dirac delta; correction operator in (7.6) - equilibrium tide elevation - (square-root of Hough-function eigenvalue) - ratio of specific gas constant to specific heat for air=2/7 - longitude - - - background density 0 - eigenstate frequency in (3.1) - proxy for heating functionq =c P/t - latitude - tide frequency - operator for the limitz - horizontal-structure function for eigenstate pressure in (3.2) - Hough function defined in (6.2) - earth's rotation speed - horizontal gradient operator - ()0 background variable - ()* surface value of background variable - () value at base of isothermal top layer - Õ state vector with zerow-component - , energy product defined in (2.4) - | | energy norm - ()* complex conjugate With 10 Figures  相似文献   
85.
A Modified Form of Mild-Slope Equation with Weakly Nonlinear Effect   总被引:6,自引:0,他引:6  
Nonlinear effect is of importance to waves propagating from deep water to shallow water.Thenon-linearity of waves is widely discussed due to its high precision in application.But there are still someproblems in dealing with the nonlinear waves in practice.In this paper,a modified form of mild-slope equa-tion with weakly nonlinear effect is derived by use of the nonlinear dispersion relation and the steady mild-slope equation containing energy dissipation.The modified form of mild-slope equation is convenient to solvenonlinear effect of waves.The model is tested against the laboratory measurement for the case of a submergedelliptical shoal on a slope beach given by Berkhoff et al,The present numerical results are also comparedwith those obtained through linear wave theory.Better agreement is obtained as the modified mild-slope e-quation is employed.And the modified mild-slope equation can reasonably simulate the weakly nonlinear ef-fect of wave propagation from deep water to coast.  相似文献   
86.
Summary Nickel-copper mineralization occurs near the base of a diorite intrusion close to its contact with hornfelsed Ordovician and Silurian shales and greywackes. The principal ore minerals are nickeline, gersdorffite, pyrrhotine, pentlandite and chalcopyrite with minor amounts of molybdenite, tellurobismutite, gold, sphalerite and argentopentlandite. Pyrite, marcasite, violarite and goethite also occur but are interpreted as later alteration products. Much of the pyrrhotine-rich mineralization at the base of the intrusion is in the form of blebs and interstitial aggregates with amphiboles, plagioclase feldspar, biotite, chlorite and quartz. Chalcopyrite-rich and nickeline-gersdorffite-rich mineralization occurs above this and immediately below unmineralized diorite in the form of patches, lenticular masses and stringers along joints and fractures.Whole rock and ore analyses and electron microprobe data on the silicates, sulphides and sulpharsenides are presented.The unmineralized diorite has low SiO2 and high MgO contents compared to typical diorites and relatively high Cr, Ni and Ti trace element values. In the mineralized diorite, platinum-group elements occur in very low concentrations in the pyrrhotineand chalcopyrite-rich assemblages but Pt, Pd and Au show significant enrichment in the nickeline-gersdorffite-rich mineralization.A magmatic origin for the mineralization is proposed rather than formation by hydrothermal solutions or metasomatism.
Die nickel-kupfer vererzung von Talnotry, Newton Stewart, Schottland
Zusammenfassung Die Nickel-Kupfer Vererzung befindet sich im Kontaktbereich einer Dioritintrusion mit hornfelsdurchdrungenen silurischen und ordovizischen Grauwacken. Die am häufigsten auftretenden Erzmineralien sind Nickelin, Gersdorffit, Pyrrhotin, Pentlandit, und Chalcopyrit mit kleineren Mengen von Molybdenit, Tellurwismuth, Gold, Sphalerit und Argentopentlandit. Weiters treten als spätere Umwandlungsprodukte Pyrit, Markasit, Violarit und Goethit auf. Ein großer Teil der Pyrrhotin-reichen Vererzung am Fuße des eingedrungenen Diorits bildet fleckige, lückenfüllende Aggregate zwischen den Silikatphasen (Amphibol, Plagioklas, Biotit, Chlorit, Quarz). Die Chalcopyrit- und Nickelin-Gersdorffit-reiche Vererzung tritt zwischen dem unvererzten Diorit im Hangenden und der Pyrrhotin-reichen Vererzung im Liegenden als linsige, lappenartige Konzentration und entlang von Fugen und Brücken auf.Vollgesteins-Analysen sowie ausgewählte Erzanalysen und Mikrosondenergebnisse der Silikate, Sulfide und Sulfarsenide liegen vor.Im Unterschied zu den typischen Dioriten zeigt der unvererzte Diorit einen niedrigen SiO2 und hohen MgO Gehalt und relativ hohe Cr, Ni und Ti Spurenelementwerte. Die Platingruppenelemente sind in den Pyrrhotin- und Chalcopyrit-reichen Vererzungen nur schwach vertreten, jedoch sind Pt, Pd und An in der Gersdorffit-reichen Vererzung stark angereichert.Ein magmatischer Ursprung dieser Vererzung, im Gegensatz zu einer metasomatischen Entstehung oder Bildung aus hydrothermalen Lösungen wird vermutet.


With 3 Figures  相似文献   
87.
Summary Two-time-level multiply-upstream semi-Lagrangian schemes were examined in the case of the self-advecting, one-dimensional nonlinear momentum conservation equation. The shock formation process was analyzed. It is pointed out that the shocks cannot be created in the truncated systems satisfying the Pudykiewicz, Benoit and Staniforth criterion.The numerical integrations were restricted to 12 h. It was shown that, at least in the sub-CFL range, increased complexity of the scheme can compensate reduced horizontal resolution. A considerable sensitivity of the schemes with respect to the time step was detected. In the super-CFL mode, several windows on various time scales were found within which the Pudykiewicz, Benoit and Staniforth criterion was satisfied. The time step of 1.44 times the maximum time step allowed by the CFL criterion was used in the semi-Lagrangian runs.The super-CFL, semi-Lagrangian solutions were diverging progressively from the sub-CFL ones as the forecasts advanced. This was also reflected in the energy spectra.Unacceptably large energy losses were encountered in the super-CFL, semi-Lagrangian runs. Most of these losses could be explained by the reduced mean wind speed, i.e., the amplitude of the zero wavenumber wave. At the same time, the energy content in the shorter waves increased. In a more complex model, such a situation would resemble a loss of zonal, and an increase of transient eddy kinetic energy.A trajectory error measure was defined as the maximum absolute value of the distance between the actual arriving point of the particle originating at the estimated departure point, and the grid point assumed to be the arrival point in the semi-Lagrangian procedure. In contrast to the sub-CFL regime, this measure could reach a considerable fraction of the grid distance in the computations with the super-CFL time steps.In the physical system considered, the trajectories are determined only by the velocities at the departure points. With the semi-Lagrangian schemes the distances traveled by the particles are estimated on the basis of the velocities at the points downstream with respect to the departure points. Thus, unless the solution is smooth (in space and time) on the scales of the extrapolation distances/times, the upstream extrapolation does not promise the convergence of the solution.With 16 Figures  相似文献   
88.
Offshore geotechnical surveys form part of an integrated investigation to rejuvenate a decrepit minor port at Badagara, Kerala on the southwestern coast of India. The sediments typify a fluvio-marine milieu ranging from silty clay, sand, silty sand, sandy silt and clayey silt. Geotechnical and sedimentological studies of shallow cores reveal the geotechnical aspects besides the depositional history of the sediments. Downcore geotechnical variations and regressive coefficients based on their inter-relationships highlight diverse factorial inferences. X-Ray Diffraction data indicate the prominent clay type.

A comparative evaluation of the geotechnical characteristics of clayey sediments off Badagara, with similar studies along various sectors of the Kerala coast, both on land as well as in the near shore, is broadly attempted. Geotechnical studies carried out earlier on the uplifted Cochin marine clays provide comparative data for evaluating the possible variations between present day marine clayey sediments occurring along the Kerala coast and uplifted marine clays which, besides their gross variations in levels with respect to the present sea-level, also obviously relate to a much older depositional environment and provenance during probable Holocene times.  相似文献   
89.
Zusammenfassung Ausgedehnte Granodiorit- und Granitmagmen intrudierten am Südrand des Rhodope-Massivs (Symvolongebirge und Kavala-Gebiet, Nordgriechenland) syntektonisch in bezug auf eine Formung, die durch überwiegend flach nach NE bis ENE tauchende Faltungs- und Scherungsachsen gekennzeichnet ist (B2-Tektonik). Die metamorphen Hüllgesteine wurden von der B2-Tektonik ebenfalls kräftig erfaßt. Ihr älteres Gefüge, das durch mittelsteil nach NNW tauchende B1-Achsen bestimmt war, kommt daher nur noch reliktisch vor. Der Mineralbestand sowohl der Magmatite als auch ihres metamorphen Rahmens wurde im Zuge der B2-Tektonik retrograd metamorph umgewandelt.Radiometrische Altersbestimmungen lassen erkennen, daß die magmatischen Gesteine spätestens im Oberkarbon kristallisierten, anschließend jedoch wiederholt aufgewärmt wurden. Das Alter der prämagmatischen Metamorphose der Hüllgesteine und der mit dieser in Zusammenhang stehenden B1-Tektonik kann demnach nicht jünger als kaledonisch sein.
Extensive granodioritic and granitic magmas were intruded in the southern margin of the Rhodope-Massif (Symvolon mountains and Kavala region, northern Greece). The intrusions took place syntectonically to a deformation which is characterized by predominantly gently NE to ENE plunging fold- and shear-axes (B2-folding). The mantling rocks, which have been metamorphosed long before this B2-folding have an older structure which is characterized by mediumly NNW plunging B1-axes, visible only in relicts. During the B2-folding the mineral contents of the igneous rocks and their metamorphic mantling rocks have been metamorphosed retrogressively.Radiometric dating indicates that the crystallization of the magmatic rocks have a minimum age of Upper-Carboniferous, but subsequently these rocks were reheated repeatedly. The age of the premagmatic metamorphism of the mantling rocks and that of the related B1-foldnig, therefore, cannot be younger than Caledonic.

Résumé Dans la partie sud du massif du Rhodope (montagnes du Symvolon et région de Kavala, Grèce du Nord) existent de grandes intrusions de magmas granodioritiques et granitiques. Les intrusions eurent lieu syntectoniquement au cours d'une phase de déformation caractérisée par des axes de plis et de cisaillement, généralement à plongement faible vers le NE à ENE (tectonique B2). Les roches encaissantes, qui furent métamorphisées longtemps avant cette phase de tectonique B2, ont une structure plus ancienne, caractérisée par des axes B1 plongeant moyennement vers le NNW. Cette structure est reconnaissable seulement dans des parties réiduelles. Durant la tectonique B2 les roches éruptives et les roches encaissantes métamorphisées subirent un métamorphisme rétrograde.Des datations radiométriques indiquent, pour la cristallisation des roches magmatiques, au minimum un âge Carbonifère supérieur. Dans la suite ces roches furent réchauffées â plusieures reprises. Le métamorphisme plus ancien des roches encaissantes et la tectonique B1 associée à ce métamorphisme ne peuvent donc pas Être plus récents que l'époque calédonienne.

Rhodope ( Symrolon Kavala, ) - . , , , , NE ENE (B2- ). 2. , B1 NNW, . , , . , , , , . , - B1 .
  相似文献   
90.
-The shear strength and deformation properties of soft clay are discussed first. Then some methods for predicting the performance of soft clay foundation are proposed. Finally, case histories are presented to illustrate some discussed aspects of soft clay.  相似文献   
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