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991.
Geologists unfamiliar with the application of probability theory to discrete data in other fields of research are usually acquainted with only three discrete theoretical frequency distributions: Poisson, binomial, and negative binomial distributions. In some situations these distributions may fail to adequately describe a set of experimental data. Other distributions such as the Poisson with zeros, Neyman type A, logarithmic with zeros, Poisson-binomial, and Thomas double Poisson together with the more common Poisson, binomial, and negative binomial form a generalized subset of discrete theoretical distributions, one of which should fit almost any experimental data set. A computer program is presented which allows testing of any combination of these distributions against observed discrete data. 相似文献
992.
The analysis of the introduction of charcoal cooking in Papua New Guinea illustrates the importance of a carefully planned implementation strategy in facilitating the acceptance of a new energy technology. Without the development of an effective demonstration and extension system, complete with educational and instructional materials presented in simple, understandable forms, even simple devices as charcoal cookers can fall victim to misunderstanding and misuse, which engender unnecessary dissatisfaction and disillusionment. The central government can greatly facilitate the adoption of new technologies by providing economic or other incentives to encourage their initial trial. Several principles for planners to observe in formulating implementation strategies are presented at the conclusion of the article. 相似文献
993.
994.
635 samples of suspended particulate matter (SPM), collected in the St. Lawrence river and estuary during periods of high and low river flow from a series of individual and anchor stations on a transect traversing the turbidity maximum zone, as well as two sediment box cores, were analyzed for Al, Si, Ca, Mg, Fe and Mn.An abrupt change in elemental composition occurs when traversing the front at the landward edge of the turbidity maximum. As the SPM concentration increases across the front from 20–200 mg l?1, the Ca/Al and Mg/Al ratios of the SPM increase and the Si/Al, Fe/Al and Mn/Al ratios decrease. The almost 50% decrease of the Mn/Al ratio is not related to changes in salinity. Within the turbidity maximum the tidal-averaged Si/Al, Ca/Al, Mg/Al and Fe/Al ratios of the SPM do not differ significantly from the landward to the seaward end of the turbidity zone, but on one tidal station the ratios of Si, Ca and Fe to Al are significantly lower at high river flow than at low flow. The Mn/Al ratio is insensitive to the extreme variations of either salinity (0.6–30‰) or SPM concentrations (10–480 mg l?1) within the turbidity zone. A tendency for higher Mn/Al ratios to be associated with near-bottom SPM, observed in the center of the turbidity zone during the low river flow period, is well developed in the lower reaches of the zone.Diagenetic mobilization within the rare fine-grained bottom sediments of the turbidity maximum is responsible for changes in Mn and Fe content of particulate matter, and early settling of coarse-grained components and size sorting within the zone are responsible for other compositional changes. Local sources, desorption and precipitation are apparently of secondary importance. The depletion of both Mn and Fe in the SPM and sediment of the upper estuary implies a net seaward escape of diagenetically mobilized metal. 相似文献
995.
James B. Pollack Edwin F. Erickson Fred C. Witteborn Charles Chackerian Audrey L. Summers Warren Van Camp Betty J. Baldwin Gordon C. Augason Lawrence J. Caroff 《Icarus》1974,23(1):8-26
We have obtained measurements of Venus' reflection spectrum in the 1.2 to 4.1-μm spectral region from a NASA-Ames operated Lear jet. This was accomplished by observing both Venus and the sun with a spectrometer that contained a circular, variable interference filter, whose effective spectral resolution was 2%. The aircraft results were compared with computer generated spectra of a number of cloud candidates. The only substance which gave an acceptable match to the profile of Venus' strong 3-μm absorption feature, was a water solution of sulfuric acid, that had a concentration of 75% or more H2SO4 by weight. However, our spectra also show a modest decline in reflectivity from 2.3 μm towards 1.2-μm wavekength, which is inconsistent with the flat spectrum of sulfuric acid in this spectral region. We hypothesize that this decline is due to impurities in the sulfuric acid droplets.We also compared our list of cloud candidates with several other observed properties of the Venus clouds. While this comparison does not provide as unique an answer as did our analysis of the 3-μm band, we find that, in agreement with the results of Young (1973) and Sill (1973), concentrated sulfuric acid solutions are compatible with these additional observed properties of the Venus clouds. We conclude that the visible cloud layer of Venus is composed of sulfuric acid solution droplets, whose concentration is 75% H2SO4, or greater, by weight. 相似文献
996.
997.
Charles L. Hyder 《Solar physics》1968,5(1):29-41
Analysis of the effects of polarization in lines used in longitudinal (Babcock) and transverse (Severny) magnetographs shows that previous straightforward analyses of observations may lead to spurious results. Measures of the longitudinal magnetic-field strengths in prominences and in the chromosphere have been underestimated by more than 10% whenever the measured field has been less than 10 gauss. Transverse magnetograph results are subject to resonance polarization effects that may dominate the magnetic signal. The panchromatic transverse magnetograph results discussed by Dollfus and Leroy are based solely on curve of growth polarization interpretations. Again, except within a few degrees of the center of the disk, resonance polarization effects can dominate, and radically change, the interpretations of the observations. 相似文献
998.
Charles J. Pellerin Jr. 《Solar physics》1975,41(2):449-458
A detailed study of the charge composition of heavy solar cosmic rays measured in the January 25, 1971 solar flare including differential fluxes for the even charged nuclei from carbon through argon is presented. The measurements are obtained for varying energy intervals for each nuclear species in the energy range from 10 to 35 MeV nucleon?1. In addition, abundances relative to oxygen are computed for all the above nuclei in the single energy interval from 15 to 25 MeV nucleon?1. This interval contains measurements for all of the species and as a result requires no spectral extrapolations. An upper limit for the abundance of calcium nuclei is also presented. These measurements, when combined with other experimental results, enable the energy dependence of abundance measurements as a function of nuclear charge to be discussed. It is seen that at energies above about 10 MeV nucleon?1, the variations of abundance ratios are limited to about a factor of 3 from flare to flare, in spite of large variations in other characteristics of these solar events. 相似文献
999.
Summary. Time series of unit vectors occur in geophysics as palaeomagnetic poles or poles of relative motion in plate tectonics, and it is often required to trace a smooth curve through the individual points. A simple method is given for interpolating such time series based on cubic splines. The curve obtained is smooth (e.g. possesses continuous curvature) and does not depend on the choice of coordinate axes. An extension with the same desirable properties is given for the case where the given data are inexact. 相似文献
1000.
More than 20 real periodicities ranging from 20 days to 2 years modulate the solar irradiance data accumulated since November 1978 by Nimbus 7. Many are quite strong during the first three years (solar maximum) and weak after that. There is a high correspondence between periods in irradiance and 28 periods predicted from the rotation and beating of global solar oscillations (r-modes and g-modes). Angular states = 1, 2, and 3 are detected as well as some unresolved r-mode power at higher . The prominence of beat periods implies a nonlinear system whose effective nonlinear power was measured to be about 2. This analysis constitutes a detection of r-modes in the Sun and determines from them a mean sidereal rotation rate for the convective envelope of 459 ± 4 nHz which converts to a period of 25.2 days (27.ld, synodic). 相似文献