LNAPL Retention in Sandy Soil     

David W. Ostendorf  Robin J. Richards  Frank P. Beck 《Ground water》1993,31(2):285-292

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Field-induced anisotropy of magnetic susceptibility in rocks     

Ragbir S. Bhathal  Frank D. Stacey 《Pure and Applied Geophysics》1969,76(1):123-129

Summary An induced anisotropy of magnetic susceptibility results from the domain alignment which is produced by treating stationary specimens in a strong alternating field. Appreciable domain re-orientation occurs in fields as low as 50 oersteds and the effect must therefore normally be an important part of the process of alternating field demagnetization. Induced anisotropy has been measured in a number of igneous rocks with a range of palaeomagnetic stabilities and in magnetite powders of controlled grain sizes, dispersed in plaster or kaolin specimens which were mechanically deformed to produce instrinsic magnetic anisotropy by grain alignment. The saturation magnitude of the induced anisotropy is not a function of grain size but the saturating field required increases with decreasing grain size. In the larger grains, induced anisotropy is a function of grain orientation.  相似文献   

Relations between metamorphism and orogeny in a typical section of the Indian Himalayas   总被引：3，自引：0，他引：3  

W. Frank  G. Hoinkes  Christine Miller  F. Purtscheller  W. Richter  M. Thöni 《Mineralogy and Petrology》1973,20(4):303-332

Summary A comprehensive geological and petrological investigation has been undertaken in an area of about 10 000 km² in the Indian Himalaya (S-Lahul, Himachal Pradesh). The development of mineral assemblages in metamorphic rocks of medium grade is considered to be a dominant Alpine event, although almost exclusively Paleozoic and Precambrian rocks have been involved. The Barrowian type of this metamorphism, ranging from the anchi- to the sillimanite zone, took place under the elavated T-gradient of about 4°C/100 m. It is suggested that normal geothermal conditions prevailed only in the outermost zone of this orogenic belt. In the Late Tertiary this metamorphic series has been moved as a huge nappe upon the Lower Himalaya. During this process a unique feature of reverse metamorphism has been formed. It can be shown that this feature was caused by a combination of metamorphism and very rapid tectonic movements.

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Beziehungen zwischen Metamorphose und Orogenese in einem typischen Querschnitt des Indischen Himalaya

Zusammenfassung Ein etwa 10 000 km² großes Gebiet des Indischen Himalaya (S-Lahul, Himachal Pradesh) wurde einer umfassenden geologischen und petrographischen Bearbeitung unterzogen. Die Ausbildung der in den mittelgradig metamorphen Gesteinen vorliegenden Mineralparagenesen wird als ein dominant alpines Ereignis betrachtet, obwohl fast nur paläozoische und präkambrische Gesteine einbezogen wurden. Die Metamorphose selbst ist von Barrow-Typus und reicht von der Anchi- bis zur Sillimanitzone. Sie fand unter einem erhöhten Temperaturgradienten von etwa 4°C/100 m statt. Nur in der äußersten Zone des Orogens entsprach der Gradient etwa normalen geothermischen Verhältnissen. Im Spättertiär wurde diese alpin-metamorphe Serie in Form einer mächtigen Kristallindecke dem Niedrigen Himalaya aufgeschoben. Dabei wurde eine einzigartige Zone inverser Metamorphose ausgebildet. Es konnte gezeigt werden, daß diese inverse Metamorphose durch das Zusammenwirken von Metamorphose und sehr rasch ablaufender Tektonik entstand.

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With 13 Figures

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Dedicated to Prof. Dr. Dr. h. c.B. Sander on the occasion of his 90th birthday.  相似文献   

The Meteoritical Bulletin,No. 74, 1993 March.*     

Frank Wlotzka 《Meteoritics & planetary science》1993,28(1):146-153

Abstract— The Meteoritical Bulletin, Number 74, contains listings for 190 meteorites, including 112 from North Africa, 63 from Antarctica and eight from Australia and six from the U.S. Among the meteorites described are 15 type 3 ordinary chondrites, most notably Roosevelt County 075 which is the lowest petrologic type H chondrite known to date, two very similar ureilites (Nova 1 and Nullarbor 010), a howardite (Old Homestead 001), a CK3 chondrite (Camel Donga 003), a CV3 chondrite (Denman 002) and a major new CR chondrite (Acfer 311 and 10 meteorites with which it is paired).  相似文献   

Astrophysics in the laboratory     

Frank A. Podosek 《Meteoritics & planetary science》1992,27(4):326-326

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Lunar structure and dynamics - results from the apollo passive seismic experiment     

Gary Latham  Maurice Ewing  James Dorman  Yosio Nakamura  Frank Press  Nafi Toksőz  George Sutton  Fred Duennebier  David Lammlein 《Earth, Moon, and Planets》1973,7(3-4):396-421

Analysis of seismic signals from man-made impacts, moonquakes, and meteoroid impacts has established the presence of a lunar crust, approximately 60 km thick in the region of the Apollo seismic network; an underlying zone of nearly constant seismic velocity extending to a depth of about 1000 km, referred to as the mantle; and a lunar core, beginning at a depth of about 1000 km, in which shear waves are highly attenuated suggesting the presence of appreciable melting. Seismic velocitites in the crust reach 7 km s^–1 beneath the lower-velocity surface zone. This velocity corresponds to that expected for the gabbroic anorthosites found to predominate in the highlands, suggesting that rock of this composition is the major constituent of the lunar crust. The upper mantle velocity of about 8 km s^–1 for compressional waves corresponds to those of terrestrial olivines, pyroxenites and peridotites. The deep zone of melting may simply represent the depth at which solidus temperatures are exceeded in the lower mantle. If a silicate interior is assumed, as seems most plausible, minimum temperatures of between 1450°C and 1600°C at a depth of 1000 km are implied. The generation of deep moonquakes, which appear to be concentrated in a zone between 600 km and 1000 km deep, may now be explained as a consequence of the presence of fluids which facilitate dislocation. The preliminary estimate of meteoroid flux, based upon the statistics of seismic signals recorded from lunar impacts, is between one and three orders of magnitude lower than previous estimates from Earth-based measurements.Paper dedicated to Professor Harold C. Urey on the occasion of his 80th birthday on 29 April, 1973.  相似文献   

Dispersion and stability of waves in plasmas in the presence of a coriolis force     

Frank Verheest 《Astrophysics and Space Science》1974,28(1):91-99

The dispersion law for the propagation of waves in cold magnetized plasmas is derived for arbitrary directions of the rotation axis with respect to the static magnetic field. The waves are shown to be stable, not only in the case of a cold plasma, but in any plasma case which yields hermitian mobility tensors. An interesting special case is when the rotation and magnetization axes are parallel, because then for suitable values of rotation and external magnetic field the two effects can cancel each other, though only for one plasma species at the time. The rotation thus decisively affects and shifts the number and width of the existing pass- and stop-bands in a magnetized plasma. The inclusion of thermal effects through a scalar barotropic pressure is not nearly as significant.  相似文献   

A comparison between compton-synchrotron and Compton black-body emission in radio sources     

J. R. Albano  R. Terlevich  J. Frank 《Astrophysics and Space Science》1973,21(1):177-187

A simple relation between observational parameters of radiosources that allows to state the predominance in the X-ray emission of either the Compton-synchrotron or the Compton black-body effect is derived.The obtained results suggest that the Compton-synchrotron contribution is dominant in compact radiosources.Operated by the CNICT with the participation of the University of Buenos Aires and the Comisión Nacional de Estudios Geoheliofísicos.  相似文献   

Observations of the inner F and K coronas below λ2220     

Frank Q. Orrall  R. J. Speer 《Solar physics》1973,29(1):41-46

The inner coronal continuum has been observed and measured below 2220 on the slitless spectra obtained by Speer et al. (1970) at the 7 March 1970 eclipse. These observations set some constraints on the brightness of the inner F corona and hence on the scattering efficiency of the inner interplanetary dust cloud particles in the far ultraviolet. They neither confirm nor reject the possibility that the inner dust cloud has the same sharp upturn in scattering efficiency below 2000 observed in the zodiacal light and in the interstellar medium.On leave from Imperial College, London.This work was supported in part by NASA grant NGL 12-001-011. An I.A.U. travelgrant to one of us (R.J.S.) is gratefully acknowledged.  相似文献   

Modification Of The Standard ∈-Equation For The Stable Abl Through Enforced Consistency With Monin–Obukhov Similarity Theory     

Frank R. Freedman  Mark Z. Jacobson 《Boundary-Layer Meteorology》2003,106(3):383-410

A condition is derived for consistency of the standard-equation with Monin–Obukhov (MO) similarity theory of thestably-stratified surface layer. The condition is derivedby extending the procedure used to derive the analogous condition forneutral theory to stable stratification. It is shown that consistencywith MO theory requires a function of flux Richardson number, Ri_f, to be absorbed into either of two closure parameters, c ₁ or c ₂.Inconsistency, on the other hand, results if constant values of these are maintained for all Ri_f, as is done in standardapplication of the equation, and the large overpredictions ofturbulence found in such application to the one-dimensionalstable atmospheric boundary layer (1D-SBL) are traced to thisinconsistency. Guided by this, we formulate a MO-consistent-equation by absorbing the aforementioned function intoc ₁, and combine this with a Level-2.5 second-orderclosure model for vertical eddy viscosity and diffusivities.Numerical predictions of the 1D-SBL by the modified model converge to a quasi-steady state, rectifying the predictive failure of the standard -equation for the case.Quasi-steady predictions of non-dimensional variables agree stronglywith Nieuwstadt's theory. Qualitative accuracy of predictionsis inferred from comparisons to field data, large-eddy simulationresults and Rossby-number similarity relationships.  相似文献