The elastic properties of single-crystal fayalite as determined by dynamical measurement techniques     

Donald G. Isaak  Earl K. Graham  Jay D. Bass  Hong Wang 《Pure and Applied Geophysics》1993,141(2-4):393-414

We present new elasticity measurements on single-crystal fayalite and combine our results with other data from resonance, pulse superposition interferometry, and Brillouin scattering to provide a set of recommended values for the adiabatic elastic moduliC _ij and their temperature variations. We use a resonance method (RPR) with specimens that were previously investigated by pulse superposition experiments. The nineC _ij of fayalite are determined from three new sets of measurements. One set of our newC _ij data is over the range 300–500 K. We believe that the relatively large discrep ncies found in someC _ij are due in large part to specimen inhomogeneities (chemical and microstructural) coupled with differences in the way various techniques sample, rather than only systematic errors associated with experimental procedures or in the preparations of the specimens.Our recommendeaC _ij's (GPa) and (C _ij/T) _p (GPa/K) are: The resulting values for the isotropic bulk and shear moduli,K _s and , and their temperature derivatives are:K _s=134(4) GPa; =50.7(0.3) GPa; (K _s/T) _p =–0.024(0.005) GPa/K; and (/T) _p =–0.013(0.001) GPa/K. An important conclusion is thatK _s increases as the Fe/(Fe+Mg) ratio in olivine is increased.  相似文献   

Editorial     

Earl W. Baker 《Organic Geochemistry》1985,8(1):vii

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Editorial     

Earl W. Baker 《Organic Geochemistry》1983,4(3-4)

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The contribution of humic substances to the acidity of colored natural waters   总被引：1，自引：0，他引：1  

Barry G. Oliver  Earl M. Thurman  Ronald L. Malcolm 《Geochimica et cosmochimica acta》1983,47(11):2031-2035

An operationally defined carboxyl content of humic substances extracted from rivers, streams, lakes, wetlands, and groundwaters throughout the United States and Canada is reported. Despite the diversity of the samples, only small variations were observed in this humic carboxyl content. The dissociation behavior of two combined fulvic/humic acid extracts was studied and it was found that the dissociation of the humics varied in a predictable manner with pH. Using a carboxyl content of 10 μeq/ mg humic organic carbon, and mass action quotient calculated from sample pH, the ionic balances of three highly colored Nova Scotia rivers were estimated.  相似文献   

Kinematic models of a dry convective boundary layer compared with dual-Doppler radar observations of wind fields     

Gossard  Earl E.  Frisch  A. S. 《Boundary-Layer Meteorology》1976,10(3):311-330

The kinematic structure of the convective boundary layer, observed by a dual-Doppler radar system, is compared with the structure predicted by simple shear models. We first consider the models to be inviscid, then add viscous effects. Model 1 assumes a linear ambient wind profile from the surface through the boundary layer, and a constant wind above. The shear layer is assumed to be statically neutral, but static stability is permitted in the region above the shear. Model 2 has a hyperbolic tangent ambient wind profile.After considering the inviscid models, some of the effects of viscosity are incorporated into the models in a crude way, and the results are compared.We conclude that although the presence of shear is important, the kinematic structure is relatively independent of the details of the wind and temperature profiles. Viscosity has important effects, especially near the critical level where the disturbance velocity is equal to the wind speed. The patterns predicted by both models agree very well with the dual-Doppler radar observations when viscosity is included.  相似文献   

Measuring channel and gully cross-sections with an airborne laser altimeter     

Jerry C. Ritchie  Earl H. Grissinger  Joseph B. Murphey  Jurgen D. Garbrecht 《水文研究》1994,8(3):237-243

A laser altimeter, making 4000 measurements per second, was used to measure channel and gully morphology. The laser measurements provide quick, accurate and readily obtained data on the cross-section and morphology of channels and gullies in relation to the adjacent landscape. Although ground based techniques can be used to make these measurements, using a laser altimeter mounted in an aircraft allows data to be collected faster, with greater density and detail, and in areas with limited access for ground surveys. The laser altimeter data are valuable for measuring channel and gully cross-sections and roughness in relation to the surrounding landscape, for assessing soil loss from gullies and channels, and for providing input to the understanding of gully and channel dynamics in the landscape.  相似文献   

High velocities and seismic anisotropy in Pleistocene turbidites off Western Canada     

Earl E. Davis  Ron M. Clowes 《Geophysical Journal International》1986,84(2):381-399

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Studies of unconsolidated sediments     

Earl Ingerson  Joseph L. Ramisch 《Mineralogy and Petrology》1954,4(1-4):117-124

Zusammenfassung Die Technik der Imprägnierung locker gefügter Sedimente mit Kunststoffen zur Herstellung orientierter Dünnschliffe für Gefügestudien wird beschrieben. Die Orientierung des Quarzgefüges von durch Wind- und Wasserwirkung gebildeten Rippelmarken wurde in dieser Weise untersucht und verglichen. Die durch Wasserströmungen gebildeten Rippel zeigen einen höheren Grad und einen etwas anderen Gesamtcharakter der Regelung. Die Unterschiede in der Größenverteilung der Quarzkörner in den beiden Arten von Rippelmarken gehen klar aus Mikrophotographien hervor.

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With 6 figures  相似文献   

Clarification in the identification of certain lines in the infrared solar spectrum     

Earl F. Montgomery 《Solar physics》1969,10(1):60-62

Forty-two unidentified spectral lines in Mohler's (1955) table of infrared solar spectrum wavelengths are shown to be solar, and three of these tentatively have been identified. One line, listed by Mohler as solar or telluric, is shown to be telluric.  相似文献   

Wetland Loss Patterns and Inundation-Productivity Relationships Prognosticate Widespread Salt Marsh Loss for Southern New England     

Elizabeth Burke Watson  Cathleen Wigand  Earl W. Davey  Holly M. Andrews  Joseph Bishop  Kenneth B. Raposa 《Estuaries and Coasts》2017,40(3):662-681

Tidal salt marsh is a key defense against, yet is especially vulnerable to, the effects of accelerated sea level rise. To determine whether salt marshes in southern New England will be stable given increasing inundation over the coming decades, we examined current loss patterns, inundation-productivity feedbacks, and sustaining processes. A multi-decadal analysis of salt marsh aerial extent using historic imagery and maps revealed that salt marsh vegetation loss is both widespread and accelerating, with vegetation loss rates over the past four decades summing to 17.3 %. Landward retreat of the marsh edge, widening and headward expansion of tidal channel networks, loss of marsh islands, and the development and enlargement of interior depressions found on the marsh platform contributed to vegetation loss. Inundation due to sea level rise is strongly suggested as a primary driver: vegetation loss rates were significantly negatively correlated with marsh elevation (r ²?=?0.96; p?=?0.0038), with marshes situated below mean high water (MHW) experiencing greater declines than marshes sitting well above MHW. Growth experiments with Spartina alterniflora, the Atlantic salt marsh ecosystem dominant, across a range of elevations and inundation regimes further established that greater inundation decreases belowground biomass production of S. alterniflora and, thus, negatively impacts organic matter accumulation. These results suggest that southern New England salt marshes are already experiencing deterioration and fragmentation in response to sea level rise and may not be stable as tidal flooding increases in the future.  相似文献