INSTRUMENT OBSERVATIONS     

H. F. Ross 《The Photogrammetric Record》1976,8(47):610-616

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Differential rotation and giant cell circulation of solar Ca+-network     

E. H. Schröter  H. Wöhl 《Solar physics》1976,49(1):19-32

We report new results obtained from high precision computer controlled tracings of ca. 400 bright Ca⁺-mottles made during summer 1975 in continuation of our 1974 program (Schröter and Wöhl, 1975). In particular, we looked in 1975 for the existence of a giant circulation pattern in the equatorial zone. We find for the differential rotation: = 13.93 – 2.90 sin² B (deg/day, sidereal) when combining the new measurements with those obtained in 1974. Observations from 26th April until June 19th give strong evidence that at that time four giant circulation cells, crossing the solar equator, (i.e. a nonaxisymmetric velocity field pattern with respect to the solar equator) did exist. This yields two more rapid and two slower rotating sectors with v = ±80 m s^–1. These giant cells transport angular momentum towards the equator.  相似文献   

Fraktionierung der spurenelemente bei der kristallisation: Hans-Eberhard Usdowski. Springer-Verlag,Berlin, 1975, 104 S., 42 Abb., DM 29,80     

Heinrich M. Köster 《Chemical Geology》1976,18(4):327

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Acoustic core logging in blast-damaged rock     

Richard E. Thill  Dennis V. D&#x;Andrea 《Engineering Geology》1976,10(1):13-36

Thill, R.E. and D' Andrea, D. V., 1975. Acoustic core logging in blast-damaged rock. Eng. Geol., 10: 13–36.The Bureau of Mines, in cooperation with the Duval Corp., conducted a blast-fragmentation experiment to determine the feasibility of preparing a porphyry copper-molybdenum deposit for in-situ leaching. The blast was designed with ten 9-inch-diameter blastholes to depths of 110 feet in an equilateral triangle configuration; spacings between blastholes were 15, 20, and 25 ft. One of the major problems in the experiment was in assessing blast damage. Acoustic core-logging equipment and methods were devised and used as one approach in solving this problem. Ultrasonic pulse travel-times were determined in four diametral directions at 2-ft intervals of depth to a final depth of 120 ft in three preblast and six postblast drill cores at the Duval test site. The acoustic logging program provided compressional wave travel-time at 0°, 45°, 90°, and 135° around the core circumference, maximum travel-time difference, mean compressional-wave velocity, and an anisotropy factor. Other acoustic parameters introduced in the analyses were stiffness modulus, seismic quality designation (SQD), and a compensated velocity to account for portions of the core that were nonrecoverable or too highly fractured to permit diametral travel-time measurements.The acoustic parameters all indicated the deterioration in structural quality from the preblast condition, in which the rock already was badly fractured and weathered, to the more highly fractured postblast condition. Because of the highly fragmented, poor structural condition of the rock after blasting, the rock was indicated to be suitable for in-situ leaching, at least at the 20- and 15-ft blasthole spacings, and even in some zones in the rock at the 25-ft blasthole spacing.  相似文献   

Search for neutral hydrogen with high negative velocities ejected from the galactic center     

I. F. Mirabel 《Astrophysics and Space Science》1976,39(2):415-417

A search for neutral hydrogen in the velocity range –300>V>–1000 km s^–1 has been made in the zone around the galactic nucleus. Observations of 100 points reveal no neutral hydrogen at such high velocities, with brightness temperatures exceeding 0.25 K in the latitude range |b|<1°, and 0.20 K for |b|1°.  相似文献   

A search for soft X-ray emission from stellar sources     

R. Mewe  J. Heise  E. H. B. M. Gronenschild  A. C. Brinkman  J. Schrijver  A. J. F. den Boggende 《Astrophysics and Space Science》1976,42(1):217-222

With the soft X-ray detector (0.2–0.284 keV) aboard the Astronomical Netherlands Satellite (ANS) we have searched for X-ray emission from hot star coronae and peculiar stars. On Sirius ( CMa) and Capella ( Aur) X-ray emission has been measured at 6 and 5 level, respectively, above background. In all other cases the search revealed no evidence for soft X-ray emission. Upper limits to the luminosities of about 25 star coronae (main-sequence stars, (sub)giants, and supergiants) and of 4 peculiar stars ( Sco, Lyr, P Cyg, and Car) have been obtained.Paper presented at the COSPAR/IAU Symposium on Fast Transients in X-and Gamma-Rays, held at Varna, Bulgaria, 29–31 May, 1975.  相似文献   

The T Tauri star RU Lupi and its circumstellar surrounding     

G.F. Gahm  H.L. Nordh  S.G. Olofsson 《Icarus》1975,24(3):372-378

From simultaneous spectroscopic and photometric observations of the T Tauri star RU Lup, which was followed for nine consecutive nights, it was found that most if not all of the light variations observed on this star were caused by variable circumstellar extinction. The character and the time-scale of the variations imply that the variations are due to dust concentrations of stellar dimension crossing the line of sight to the star. The implications of this interpretation and its possible bearing on problems of protoplanetary systems are discussed.  相似文献   

On the possibility of creating a radio-astronomical inertial coordinate system based on the measurement of arcs between QSOs with the aid of VLBI     

A. F. Dravskikh  A. M. Finkelstein  G. A. Krasinsky 《Astrophysics and Space Science》1975,38(2):255-266

The aim of this paper has been to discuss a possibility of the formation of an inertial system of coordinates, precise within 0″.001, with the aid of the measures of mutual angular distances of quasars by the VLBI technique used in radio-astronomy. Such a system depends on neither the rotation, nor revolution of the Earth around the Sun — a fact which permits a separation of the astronomical and geophysical aspects of the problem. The proposed system should permit us to resolve some general astrometric problems — such as of the precession and nutation of the Earth as well as of the motion of the terrestrial axis of rotation within the Earth, or fluctuations in the angular veoocity of terrestrial rotation.  相似文献   

The spectral reflectivity of select areas on Europa     

Thomas F. Greene  James R. Vermilon  Richard W. Shorthill  Roger N. Clark 《Icarus》1975,25(3):405-415

The July 12, 1973, occultation of Europa by Io was observed in 30 wavelength channels in the spectral region λλ3200-11, 000 Å with the 200-inch Hale telescope and a multichannel spectrometer. The data are presented in absolute units above the Earth's atmosphere. The data are analyzed to obtain the spectral reflectivity of seven localized areas on the disk of Europa centered on 324°W longitude. The equatorial material is confirmed to be darker than the eastward-skewed bright north polar cap and a hint is evident that the darker material as well may be somewhat redder than the cap material.  相似文献   

Buchbesprechungen     

F. Steinhauser 《Meteorology and Atmospheric Physics》1975,24(2):207-212

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