The effect of fractional cloudiness on the oxidation of SO₂     

JAN MATTHIJSEN  KARSTEN SUHRE  PETER BECHTOLD  ROBERT ROSSET 《Tellus. Series B, Chemical and physical meteorology》1997,49(4):343-356

  相似文献   

What determines the distribution of seabirds at sea?   总被引：1，自引：0，他引：1  

KJELL EINAR ERIKSTAD  ROBERT T. BARRETT  FRIDTJOF MEHLUM 《Polar research》1990,8(1):1-1

  相似文献   

Modern and Holocene hydrographic characteristics of the shallow Kara Sea shelf (Siberia) as reflected by stable isotopes of bivalves and benthic foraminifera     

JOHANNES SIMSTICH  HELMUT ERLENKEUSER  INGO HARMS  ROBERT F. SPIELHAGEN  VLADIMIR STANOVOY 《Boreas: An International Journal of Quaternary Research》2005,34(3):252-263

River discharge of Ob and Yenisei to the Kara Sea is highly variable on seasonal and interannual time scales. River water dominates the shallow bottom water near the river mouths, making it warmer and less saline but seasonally and interannually more changeable than bottom water on the deeper shelf. This hydrographic pattern shows up in measurements and modelling, and in stable isotope records (δ¹⁸O, δ¹³C) along the growth axis of bivalve shells and in multiple analyses of single benthic foraminiferal shells. Average isotope ratios increase, but sample-internal variability decreases with water depth and distance from river mouths. However, isotope records of bivalves and foraminifera of a sediment core from a former submarine channel of Yenisei River reveal a different pattern. The retreat of the river mouth from this site due to early Holocene sea level rise led to increasing average isotope values up core, but not to the expected decrease of the in-sample isotope variability. Southward advection of cold saline water along the palaeo-river channel probably obscured the hydrographic variability during the early Holocene. Later, when sediment filled the channel, the hydrographic variability at the core location remained low, because the shallowing proceeded synchronously with the retreat of the river mouth.  相似文献   

PRINCIPAL COMPONENTS REGRESSION FOR ROUTINE MULTICOMPONENT UV DETERMINATIONS: A VALIDATION PROTOCOL     

PAULJ.GEMPERLINE  ALGER SALT 《地理学报(英文版)》1989,(1)

A validation protocol for multicomponent spectroscopic assays based on principal componentsregression is described. Factorial design and hypothesis tests are used to establish the linearity andabsence of interaction between components in the regression model. Testing considers multiple responsevariables simultaneously so that correlation between residuals is properly treated. Assay reproducibilityand sensitivity to related substances are evaluated.  相似文献   

MIXTURE ANGLYSIS USING FACTOR ANGLYSIS I: CALIBRATION AND QUANTITATION     

PAULJ.GEMPERLINE 《地理学报(英文版)》1989,(3)

One of the major application areas of factor analysis, multivariate calibration and quantitation, is coveredin this review. The algorithms, methodologies and applications covered include principal componentregression, target transformation factor analysis, singular value decomposition and rank annihilationfactor analysis. Many important areas of research having relevance to multivariate calibration andquantitation problems are also covered in this review, including background correction, measurementerror, rank determination, cross-validation, figures of merit, detection of invalid samples, experimentaldesign, sample selection, statistical inference and wavelength selection.  相似文献   

Gould Pond, Maine: late-glacial transitions from marine to upland environments     

R. SCOTT ANDERSON  GEORGE L. JACOBSON JR.    RONALD B. DAVIS  ROBERT STUCKENRATH 《Boreas: An International Journal of Quaternary Research》1992,21(4):359-371

Gould Pond sediments are unusual in North America in that they include a continuous record of change from marine to freshwater conditions during the late-glacial period, with a wide array of micro- and macrofossils deposited during a period of high sedimentation rate. Marine waters, much colder than those in the present Gulf of Maine, covered the site at the time of deglaciation (c. 13,200 BP). Plants characteristic of modem tundra grew on nearby uplands. Marine recession, due to isostatic rebound of the land, occurred from c . 12,800–12,200 BP. The lake water was completely freshened by 12,000 BP. A sparse shrub-herb tundra became established around Gould Pond as marine waters receded. Subsequent to 11,300 BP, sedges and other herbs became more abundant, and willow and Dryas less abundant, signifying increased warmth and decreased frost action. At least six tree species, all now common in the area, arrived around Gould Pond between c . 10,800 and 10,500 BP. This rapid transition was coincident with the most rapid major non-anthropogenic change of vegetation at sites across eastern North America during the postglacial period.  相似文献   

A change of editors for Boreas is on the way     

MAlTI ERONEN  PAUL FOGELBERG 《Boreas: An International Journal of Quaternary Research》1988,17(2):228-228

  相似文献   

The latest vertebrates are the earliest     

RICHARD J. ALDRIDGE  DEREK E. G. BRIGGS  IVAN J. SANSOM  M. PAUL SMITH 《Geology Today》1994,10(4):141-145

The teeth, or elements, ofconodonts are among the most important Palaeozoic microfossils. Despite this, the biological relationships of conodonts have long remained enigmatic. Recent evidence of their soft anatomy, and of the ultrastructure of the elements, has finally revealed that they are vertebrates. These discoveries push vertebrate origins firmly back into the Cambrian and add a large cohort of specialists to the ranks of the vertebrate palaeontologists.  相似文献   

Distribution of Late Silurian (?) and Early Devonian grey-green sandstones in the Liefdefjorden-Bockfjorden area, Spitsbergen     

TORE GJELSVIK  ROBERT ILYES 《Polar research》1991,9(1):77-87

Lithologic, petrographic and paleontologic data for the various areas of late Silurian (?) and early Devonian grey-green sandstones (greywackes) in the Liefdefjord area of northern Spitsbergen are evaluated. A number of new localities with fossil fauna have been detected in these sandstones, both to the north and south of Liefdcfjordcn. It is shown that vertebrate and invertebrate fossils occur at lower levels than hitherto believed. Differences in the amounts of plagioclase and potash feldspar in the sandstones north and south of the fjord, as well as the finds of fossils, suggest that the Siktefjellet Sandstone is restricted to the type area north of Liefdefjorden. The grey-green sandstones south of Liefdefjorden are correlated with the Andreebrecn Sandstone Formation of the Red Bay Group.  相似文献   

EXAMINING LARGE DATABASES:A CHEMOMETRIC APPROACH USING PRINCIPAL COMPONENT ANALYSIS     

ROBERT R.MEGLEN Department of Chemistry  Laboratory for Chemometrics  University of Colorado at Denver  PO Box  Denver  CO -  U.S.A. 《地理学报(英文版)》1991,(3)

Principal component analysis is used to examine large multivariate databases.The graphical approachto exploratory data analysis is described and illustrated with a single example of chemical compositiondata obtained on environmental dust particles.While the graphical approach to exploratory data analysishas certain advantages over the numerical procedures,the empirical approach described here should beviewed as complementary to the more robust treatments that statistical methodologies afford.  相似文献