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1.
RALPH W.CHANEY 《地质学报》1933,(1)
A small collection of fossil plants was made in 1930 by Dr.GeorgeB. Barbour,of Yenching University,in the course of his study of the sedimen-tary deposits near Taiku,Shansi Province (See text figure 1).My acknow-ledgement is due to Dr. Barbour,and to Dr. 相似文献
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By HEATHER D. GRAVEN † BRITTON B. STEPHENS THOMAS P. GUILDERSON TERESA L. CAMPOS DAVID S. SCHIMEL J. ELLIOTT CAMPBELL RALPH F. KEELING 《Tellus. Series B, Chemical and physical meteorology》2009,61(3):536-546
Measurements of Δ14 C in atmospheric CO2 are an effective method of separating CO2 additions from fossil fuel and biospheric sources or sinks of CO2 . We illustrate this technique with vertical profiles of CO2 and Δ14 C analysed in whole air flask samples collected above Colorado, USA in May and July 2004. Comparison of lower tropospheric composition to cleaner air at higher altitudes (>5 km) revealed considerable additions from respiration in the morning in both urban and rural locations. Afternoon concentrations were mainly governed by fossil fuel emissions and boundary layer depth, also showing net biospheric CO2 uptake in some cases. We estimate local industrial CO2 :CO emission ratios using in situ measurements of CO concentration. Ratios are found to vary by 100% and average 57 mole CO2 :1 mole CO, higher than expected from emissions inventories. Uncertainty in CO2 from different sources was ±1.1 to ±4.1 ppm for addition or uptake of −4.6 to 55.8 ppm, limited by Δ14 C measurement precision and uncertainty in background Δ14 C and CO2 levels. 相似文献
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In a short paper entitled "Evidences of the Use of Fire by Sinanthropus",Dr.Davidson Black has discussed the occurrence of burned bone fragments andcharcoal debris in association with the remains of Sinanthropus at Chou KouTien,and has concluded that Sina 相似文献
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RALPH A. WIGGINS 《Geophysical Prospecting》1966,14(4):427-440
Two-dimensional band-pass filters can be constructed by a simple extension of the theory of one-dimensional band-pass filters. Similarly to the one-dimensional analogue the shape of the two-dimensional filter is important in determining its effectiveness. The band-pass filter formulation can be further refined so that the filter will concentrate its rejection energies in certain areas of the ω, k plane. Such band-pass, band-reject filters are found by solving a set of simultaneous equations. 相似文献
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Dunes that are morphologically of linear type, many of which are probably of longitudinal type in a morphodynamic sense, are common in modern deserts, but their deposits are rarely identified in aeolian sandstones. One reason for non-recognition of such dunes is that they can migrate laterally when they are not exactly parallel to the long-term sand-transport direction, thereby depositing cross-strata that have unimodal cross-bed dip directions and consequently resemble deposits of transverse dunes. Dune-parallel components of sand transport can be recognized in ancient aeolian sands by examining compound cross-bedding formed by small dunes that migrated across the lee slopes of large dunes and documenting that the small dunes migrated with a component in a preferred along-crest direction over the large dunes. 相似文献
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MORRISON M. Shaunn PRABHU Anirudh ELEISH Ahme PAN Feifei ZHONG Hao HUANG Fang FOX Peter MA Xiaogang RALPH Jolyon GOLDEN J. Joshu DOWNS T. Robert LIU Chao RUNYON E. Simone HAZEN M. Robert 《《地质学报》英文版》2019,93(Z1):55-55
正The key to answering many compelling and complex questions in Earth,planetary,and life science lies in breaking down the barriers between scientific fields and harnessing the integrated,multi-disciplinary power of Earth,planetary,and bioscience data resources.We have a unique opportunity to integrate large and rapidly expanding"big data"resources,to enlist powerful analytical and visualization methods,and to answer multi-disciplinary questions that cannot be addressed by one field alone. 相似文献
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By RALPH KAHN REAS PETZOLD MANFRED WENDISCH EIKE BIERWIRTH TILMAN DINTER MICHAEL ESSELBORN MARCUS FIEBIG BIRGIT HEESE PETER KNIPPERTZ DETLEF MÜLLER ALEXANDER SCHLADITZ WOLFGANG VON HOYNINGEN-HUENE 《Tellus. Series B, Chemical and physical meteorology》2009,61(1):239-251
Coincident observations made over the Moroccan desert during the Sahara mineral dust experiment (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from multi-angle imaging spectroradiometer (MISR) observations, and to place the suborbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05–0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape and single-scattering albedo. For the three study days, the satellite observations (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away. 相似文献
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RALPH KRETZ 《Journal of Metamorphic Geology》1990,8(5):493-506
Garnet-biotite gneisses, some of which contain sillimanite or hornblende, are widespread within the Otter Lake terrain, a portion of the Grenville Province of the Canadian Shield. The metamorphic grade is upper amphibolite to, locally, lower granulite facies. The atomic ratio Fe2+/(Fe2++ Fe3+) in biotite ranges from 0.79 to 0.89 (ferrous iron determinations in 10 highly pure separates), with a mean of 0.86. Mg and Fe2+ atoms occupy 67–78% of the octahedral sites, the remainder are occupied by Fe3+, Ti, and Al, and some are vacant. Mg/(Mg + Fe2+), denoted X, in the analysed samples ranges from 0.32 to 0.65. Garnet contains 1–24% grossular, 1–12% spessartine and X ranges from 0.07 to 0.34. Compositional variation in biotite and garnet is examined in relation to three mineral equilibria: (I) biotite + sillimanite + quartz = garnet + K-feldspar + H2O; (II) pyrope + annite = almandine + phlogopite; (III) anorthite = grossular + sillimanite + quartz. Measurements of X (biotite) and X (garnet) are used to construct an illustrative model for equilibrium (I) which relates the observed variation in X to a temperature range of 70°C or a range in H2O activity of 0.6; the latter interpretation is preferred. In sillimanite-free gneisses, the distribution of Mg and Fe2+ between garnet (low in Ca and Mn) and biotite is adequately described by a distribution coefficient (KD) of 4.1 (equilibrium II). The observed increase in the distribution coefficient with increasing Ca in garnet is ln KD= 1.3 + 2.5 × 10?2 [Ca] where [Ca] = 100 Ca/(Mg + Fe2++ Mn + Ca). The distribution coefficient is apparently unaffected by the presence of up to 12% spessartine in garnet. In several specimens of garnet-sillimanite-plagioclase gneiss, the Ca contents of garnet and of plagioclase increase in unison, as required by equilibrium (III). The mean pressure calculated from these data (n= 17) is 5.9 kbar, and the 95% confidence limits are ±0.5 kbar. 相似文献