Detection of optical circular polarization in the Herbig Ae star WW Vul     

D. N. Shakhovskoi  O. S. Shulov  E. N. Kopatskaya 《Astronomy Letters》2001,27(6):376-378

UBVRI observations of circular polarization in WW Vul are presented. A positive polarization of ～0.1% was detected with a signal-to-noise ratio from 3 to 5 in each of the bands and more than 5 when averaged over all five bands. This observed polarization roughly corresponds to a 1% circular polarization of the radiation scattered in a circumstellar disk, which is most likely attributable to the significant alignment of scattering nonspherical dust grains. Since grain alignment is possible only in a magnetic field, this result provides circumstantial evidence for the existence of a magnetic field in the circumstellar disk of WW Vul.  相似文献   

Observations of circular polarization of Sco X-1     

O. S. Shulov  E. N. Kopatskaya 《Astrophysics》1972,8(4):366-367

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Mineral resource appraisal and mineral deposits computer files in the Geological Survey of Canada     

O. R. Eckstrand 《Mathematical Geology》1977,9(3):235-243

The Geological Survey of Canada (G.S.C.) has been involved in national appraisal of resources of certain commodities for nearly two decades beginning with a national study of iron deposits in 1955. In 1972, the first national appraisal to rapidly estimate total resources of Cu, Pb, Zn, Ni, Fe, Mo, and U in Canada was carried out largely by economic geologists. This exercise produced, among other things, a better definition of G.S. C. needs for building computer files in support of mineral deposits studies and mineral resource appraisal. Objectives of this paper are threefold: (1) to outline general methodology for the kind of mineral resource appraisal carried out by the G.S.C. in 1972; (2) to identify types of information required in that appraisal; and (3) to indicate types of information on mineral deposits for which it seems advantageous for the G.S.C. to construct computer files, and how these files relate to mineral resource appraisal. Methodology is fairly straightforward for appraisal of reserves (known, measured resources), but is much more problematic for appraisal of undiscovered resources. For the latter, G.S.C. economic geologists make use of two basic concepts: the deposit model, which is a generalized deposit type, distinguished by its geological attributes and host rock environment, and containing characteristic amounts of specified commodities; and the metallogenic region, which is a geographic area of more or less homogeneous geology deemed favorable for the presence of a particular deposit model. Background information required for appraisal of undiscovered resources includes the following: (a) data on distribution and geology of Canadian deposits and occurrences; (6) data on geology of important, foreign deposits; (c) knowledge of Canadian geology, commensurate with metallogenic requirements; (d) knowledge of current theories of ore-forming processes; and (e) appreciation of the amount, location, and effectiveness of past exploration in Canada. At present, only identity, location, and certain simple geological features of Canadian deposits are considered practical for a general computer file of mineral deposits. The fundamental activity of the G.S.C. in the sphere of mineral deposits is a number of broad studies on the geology of certain commodities in Canada carried out by economic geologists. Appraisal of mineral resources is based directly on the results of those studies, and is done by the same economic geologists. Construction of G.S.C. computer files is in response to needs defined by economic geologists, mainly in the context of their broad studies.This paper was presented at the International Geological Correlation Program (IGCP) Project 98 entitled Standards for Computer Applications in Resource Studies held at Loen, Norway, September 27–October 1, 1976.  相似文献   

Flare stars in the Pleiades. II     

V. A. Ambartsumyan  A. V. Mirzoyan  É. S. Parsamyan  O. S. Chavushyan  L. K. Erastova 《Astrophysics》1971,7(3):189-196

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Pulsars in supernova remnants     

P. R. Amnuél'  O. Kh. Guseinov  F. K. Kasumov 《Astrophysics》1972,8(4):329-331

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The Structural geology of the Troms Area (Barents-Sea)     

O. Øvrebø  E. Talleraas 《GeoJournal》1980,1(1):47-54

This paper reviews the exploration history of the Barents Sea part of the Norwegian continental shelf. The main structural elements which so far have been identified in the Troms/Finnmark/Barents Sea region are outlined and discussed. Special attention is given to the selected Area I outside Troms, where according to latest government plans, drilling will start in 1978.At least two different fault systems are discribed in Area I. The salt diapirs in the Tromsø Basin and their location relative to the fault pattern are discussed. A schematic structural model for Area I is suggested.  相似文献   

Oxygen exchange between a ‘model’ pond and the atmosphere     

O.R. Lehman 《Advances in water resources》1980,3(2):87-89

Oxygen exchange between a sheltered ‘model’ farm pond (6 m diameter and 2.5 m deep) and the atmosphere averaged 0.33 m/day for measurements made from April to December. This value was similar to those reported for isolated surfaces in sheltered waters and in laboratory tanks but below those of large, inland waters. Low average wind velocity (0.7 m/sec) probably caused the low O₂ exchange rate. Interactions between air and water temperatures and precipitation may be important factors governing short-term O₂ exchange in highly sheltered waters.  相似文献   

Study of intensity fluctuations in cosmic rays during Forbush-decreases on the basis of the data obtained with the inzmiran scintillation supertelescope     

L. I. Dorman  I. Ya. Libin  O. V. Gulinsky 《Astrophysics and Space Science》1980,73(2):337-347

The one-minute, five-minute, and hourly values of cosmic-ray intensity obtained with a scintillation telescope at Izmiran have been used to carry out the correlational and spectral analysis of large Forbush-decreases of cosmic rays in 1978. The spectra of power obtained for the periods of interplanetary disturbances are characterized by individual spectral lines whose amplitude exceeds at least a 95% interval of reliability.  相似文献   

A rate-type constitutive model for soil with a critical state     

R. O. Davis  G. Mullenger 《国际地质力学数值与分析法杂志》1978,2(3):255-282

A continuum representation for soil which incorporates the concepts of hypoelasticity and critical state theory is proposed. General, three-dimensional constitutive equations are formulated to relate specific volume, stress, rate of deformation and rate of change of stress, resulting in a mathematical material model which exhibits phenomenological features typical of soil response. The general constitutive equations are specialized to represent the particular cases of isotropic compression, constant, volume deformation, uniaxial compression and biaxial deformation. Methods are suggested for determining the model parameters to represent a specific soil using conventional triaxial test data. Comparisons of stress-strain response with published experimental data are shown.  相似文献   

Friedmann model universes in a centrally symmetric reference system     

K. P. Stanyukovich  O. Sh. Sharshekeev 《Astrophysics》1970,6(4):313-319

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