High resolution absorption cross section measurements of SO₂ at 213 K in the wavelength region 172–240 nm     

D.E. Freeman  K. Yoshino  J.R. Esmond  W.H. Parkinson 《Planetary and Space Science》1984,32(9):1125-1134

Laboratory measurements at high resolution of the absorption cross section of SO₂ at the temperature 213 K have been performed in the wavelength region 172–240 nm with a 6.65 m scanning spectrometer/spectrograph operated at an instrumental width of 0.002 nm. The measured cross sections are presented graphically in representative wavelength regions and are available throughout the region 172–240 nm at wavenumber intervals of 0.4–0.1 cm^?1 as a numerical tabulation stored on magnetic tape from the National Space Science Data Center, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, U.S.A. The measured cross sections, which are relevant to the photochemistry of planetary atmospheres, possess significantly more spectroscopic structure, and are more accurate, than previous measurements made at lower resolution.  相似文献   

HIDEEP – an extragalactic blind survey for very low column-density neutral hydrogen     

R. F. Minchin  M. J. Disney  P. J. Boyce  W. J. G. de Blok  Q. A. Parker  G. D. Banks †  K. C. Freeman  D. A. Garcia  B. K. Gibson  M. Grossi  R. F. Haynes  P. M. Knezek  R. H. Lang  D. F. Malin  R. M. Price  I. M. Stewart  A. E. Wright 《Monthly notices of the Royal Astronomical Society》2003,346(3):787-802

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THE WATER-TABLE AQUIFER IN THE EASTERN COASTAL AREA OF BELGIUM     

W. DE BREUCK  G. DE MOOR 《水文科学杂志》2013,58(3):137-155

Abstract

A resistivity survey in Wenner arrangement has been conducted in the water-table aquifer in the eastern part of the Coastal Area of Belgium. Bore holes have been drilled to test the geoelectrical data and also to collect water samples. The chemical characteristics and the distribution of different water types explain the hydrochemistry of the water-table aquifer. The fresh-/brackish-water boundary as determined by the resistivity survey has been expressed in terms of total dissolved-solids content.  相似文献   

The Abbey Evaluation of Reference Sample IF-G. The Significance of Abbey's Method For Laboratory Quality     

B. T. DE HAAS  K. KOOPMANS 《Geostandards and Geoanalytical Research》1986,10(1):19-26

Abbey's select laboratories method has been applied to the reported data for major and minor elements in the proposed GIT-IWG reference sample IF-G. The final values obtained by this method have been compared with the recommended values published by Govindaraju in 1984. Slightly different percentages are suggested for MgO, K₂O and Fe₂O₃T. The importance of applying the Abbey method by participants in co-operative studies is emphasized. Such an application gives a better understanding of data treatment and of the degree of reliability of published final values; furthermore the objective score obtained for laboratory quality will stimulate participating laboratories to improve their analytical methods and procedures. As an illustration some improvements in the laboratory of the authors are mentioned.  相似文献   

Ag, Te and Pd in 17 Geochemical Reference Materials by Mass Spectrometric Isotope Dilution Analysis     

Robert D. LOSS  Kevin J.R. ROSMAN  John R. DE LAETER 《Geostandards and Geoanalytical Research》1983,7(2):321-324

Seventeen geochemical reference samples have been analysed for Ag, Te, Pd using mass spectrometric isotope dilution analysis. For most samples, analytical data on these elements were lacking. The concentration range encountered was generally in the nanogram levels.  相似文献   

Timing of diagenetic haematite growth in red pelagic limestones from Gubbio (Italy)     

J.E.T. Channell  R. Freeman  F. Heller  W. Lowrie 《Earth and Planetary Science Letters》1982,58(2):189-201

Magnetite, haematite, and to a minor extent maghaemite are recognised in the Cretaceous and Paleocene red pelagic limestones at Gubbio. The magnetite is detrital (or biological), whereas the haematite grew during diagenesis from a goethitic precursor. Thermal and AF demagnetization of samples collected from close to reversal boundaries indicate that the various magnetization components do not record the polarity reversal at exactly the same stratigraphic level. In the few tens of centimetersbelow a recorded geomagnetic reversal, defined by the magnetite magnetization, some of the haematite grains are magnetized in the post-reversal field. The blocking temperature spectra of this haematite fraction (with post-reversal magnetization) are found to shift toward higher temperatures as the reversal boundary is approached. The blocking temperature spectra reflect the grain size spectra of the haematite, which we interpret as arising by the continual nucleation of grains down to a certain burial depth where the conditions are no longer conducive to further haematite growth. The depth below reversal boundaries to which haematite with post-reversal magnetization can occur, is estimated to be about 60 cm (after compaction), and is equivalent to a time of about 10⁵ years for these particular sediments. A detailed study of the magnetization components at reversal boundaries indicates that the first diagenetic growth of haematite through the single-domain critical volume occurs prior to the mechanical fixation of the detrital (or biological) magnetite. Subsequently the diagenetic haematite grains do not rotate in response to the ambient geomagnetic field polarity as easily as the magnetite, because of their occurrence as pigmentary coatings on larger non-magnetic grains.  相似文献   

高原东部春季降水云层的微物理特征分析   总被引：17，自引：20，他引：17  

李仑格  德力格尔 《高原气象》2001,20(2):191-196

利用人工增雨飞机和机载PMS粒子探测系统，对高原东部地区春季人工增雨主要降水云层的微物理结构进行大量探测研究。根据1995年和1997年共15架次的飞行探测资料，分析研究了高原东部低层大气气溶胶微粒的分布特征及其与大气层结的关系，着重分析了高原东部春季降水云层的云粒子、降水粒子以及冰晶、过冷水的一些初步分布特征。  相似文献   

Vandermonde matrix analysis of long‐period seismograms     

Freeman Gilbert 《Geophysical Journal International》2001,146(3):843-849

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Consistent fractionation of 13C in nature and in the laboratory: growth-rate effects in some haptophyte algae     

Bidigare RR  Fluegge A  Freeman KH  Hanson KL  Hayes JM  Hollander D  Jasper JP  King LL  Laws EA  Milder J  Millero FJ  Pancost R  Popp BN  Steinberg PA  Wakeham SG 《Global biogeochemical cycles》1997,11(2):279-292

The carbon isotopic fractionation accompanying formation of biomass by alkenone-producing algae in natural marine environments varies systematically with the concentration of dissolved phosphate. Specifically, if the fractionation is expressed by epsilon p approximately delta e - delta p, where delta e and delta p are the delta 13C values for dissolved CO2 and for algal biomass (determined by isotopic analysis of C37 alkadienones), respectively, and if Ce is the concentration of dissolved CO2, micromole kg-1, then b = 38 + 160*[PO4], where [PO4] is the concentration of dissolved phosphate, microM, and b = (25 - epsilon p)Ce. The correlation found between b and [PO4] is due to effects linking nutrient levels to growth rates and cellular carbon budgets for alkenone-containing algae, most likely by trace-metal limitations on algal growth. The relationship reported here is characteristic of 39 samples (r2 = 0.95) from the Santa Monica Basin (six different times during the annual cycle), the equatorial Pacific (boreal spring and fall cruises as well as during an iron-enrichment experiment), and the Peru upwelling zone. Points representative of samples from the Sargasso Sea ([PO4] < or = 0.1 microM) fall above the b = f[PO4] line. Analysis of correlations expected between mu (growth rate), epsilon p, and Ce shows that, for our entire data set, most variations in epsilon p result from variations in mu rather than Ce. Accordingly, before concentrations of dissolved CO2 can be estimated from isotopic fractionations, some means of accounting for variations in growth rate must be found, perhaps by drawing on relationships between [PO4] and Cd/Ca ratios in shells of planktonic foraminifera.  相似文献   

INTRICATED CROSS-STRATIFICATION DUE TO INTERACTION OF A MEGA RIPPLE WITH ITS LEE-SIDE SYSTEM OF BACKFLOW RIPPLES (UPPER-POINTBAR DEPOSITS, LOWER RHINE)     

J. R. BOERSMA  E. A. VAN DE  MEENE R. C. TJALSMA 《Sedimentology》1968,11(3-4):147-162

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