Pleistocene vertebrate faunas of Hungary. D. JÁNOSSY Publisher Elsevier 1986, US $90.00 or DFI 225.00 (208 pp) ISBN 0 444 99526 9     

A. J. Stuart 《第四纪科学杂志》1989,4(3):275-276

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ARCHAEOPTERYX (Letter)     

Stuart Baldwin 《地学学报》1989,1(5):501-501

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Magnetic Anomalies, Bathymetry and the Tectonic Evolution of the South Pacific since the Late Cretaceous   总被引：3，自引：0，他引：3  

Peter Molnar  Tanya Atwater  Jacqueline Mammerickx  Stuart M. Smith 《Geophysical Journal International》1975,40(3):383-420

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The Berkeley parasitic SETI Program     

Stuart Bowyer  Gerry Zeitlin  Jill Tarter  Michael Lampton  William J. Welch 《Icarus》1983,53(1):147-155

Parasitic programs for the Search for Extraterrestrial Intelligence (SETI), carried out concurrently with conventional radio astronomical observing programs, can be an attractive and cost-effective means of exploring the large multidimensional search space intrinsic to this effort. We describe a microprocessor-based automated SETI acquisition system which searches for and records spectra of narrowband signals in the IF band of an observatory receiver. Data taken with this system over 35 days at the Hat Creek Radio Observatory at 1612 MHz are discussed. Out of approximately 10⁵ spectra processed during this period, 4000 were identified by the system as containing narrowband signals and were recorded. Subsequent analysis indicates that over 3900 of these are due to local RF contamination. The remainder are undergoing further investigation.  相似文献   

Venus: Mesospheric hazes of ice,dust, and acid aerosols     

R.P. Turco  O.B. Toon  R.C. Whitten  R.G. Keesee 《Icarus》1983,53(1):18-25

We speculate on the origin and physical properties of haze in the upper atmosphere of Venus. It is argued that at least four distinct types of particles may be present. The densest and lowest haze, normally seen by spacecraft, probably consists of a submicron sulfuric acid aerosol which extends above the cloud tops (at ～70 km) up to ～80 km; this haze represents an extension of the upper cloud deck. Measurements of the temperature structure between 70 and 120 km indicate that two independent water ice layers may occasionally appear. The lower one can form between 80 and 100 km and is probably the detached haze layer seen in high-contrast limb photography. This ice layer is likely to be nucleated on sulfuric acid aerosols, and is analogous to the nacreous (stratospheric) clouds on Earth. At the Venus “mesopause” near 120 km, temperatures are frequently cold enough to allow ice nucleation on meteoric dust or ambient ions. The resulting haze (which is analogous to noctilucent clouds on Earth) is expected to be extremely tenous, and optically invisible. On both Earth and Venus, meteoric dust is present throughout the upper atmosphere and probably has similar properties.  相似文献   

The effects of near-vertical parallel cracks on shear-wave polarizations     

David C. Booth  Stuart Crampin  Evgenie M. Chesnokov  Maria A. Krasnova 《Geophysical Journal International》1986,87(2):583-594

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Possible production by lightning of aerosols and trace gases in Titan's atmosphere     

William J. Borucki  Christopher P. McKay  Robert C. Whitten 《Icarus》1984,60(2):260-273

Although lightning has not yet been observed in Titan's atmosphere, the presence of condensable vapors and the deposition of a significant amount of solar energy at the surface suggest the possibility of lightning activity. Based on an understanding of the relationship of lightning activity to the amount of convective energy available on Titan, a lightning energy dissipation rate of 4 × 10^?6, W/m² can be expected. This value is much lower than that for Earth or Jupiter, and is a result of both the reduced solar flux at Titan and the absorption of sunlight by the aerosols that lie above the convective layer. For this dissipation rate, the amount of HCN and C₂N₂ produced by lightning should be greater than that by solar UV, but could be less than that produced by electron precipitation and galactic cosmic rays. Equilibrium calculations indicate that large mole fractions of elemental solid phase carbon will also be produced. Using a simplified model of aerosol formation, coagulation, and settling, it is estimated that a lightning-produced aerosol could have a typical optical depth of 10^?2, with values as high as 0.1. The accumulation of soot over geological time might reach a meter or more in depth.  相似文献   

Association announcements     

E. H. T. Whitten  E. H. Timothy Whitten 《Mathematical Geology》1981,13(3):243-260

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Third William Christian Krumbein Medallist: Frederik Pieter Agterberg     

E. H. Timothy Whitten 《Mathematical Geology》1978,10(6):699-700

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Inversion of P-wave velocity anisotropy     

Stuart Crampin  David Bmford 《Geophysical Journal International》1977,49(1):123-132

Summary. We examine the way in which measurements of velocity anisotropy can add to our understanding of upper mantle structure. Measurements of P -wave velocity anisotropy in a single plane contain very little direct information about the anisotropic structure. A promising technique is to fit the observed velocity variation with a mixture of an assumed anisotropic constituent and a proportion of isotropic material. Using this technique, mixtures of orthorhombic and transversely isotropic olivine are obtained, which are in excellent agreement with observed velocity variations in the Pacific.  相似文献