CLASSIFICATION:OLDTIMERS AND NEWCOMERS     

ILDIKOE.FRANK  JEROMEH.FRIEDMAN 《地理学报(英文版)》1989,(2)

Classification and regression techniques are among the most used tools by chemometricians.Withclassification,the two classic methods are discriminant analysis and SIMCA.In this paper we discuss theconnection between these two methods and introduce two new ones of the same family:DASCO(discriminantanalysis with shrunken covariances)and RDA(regularized discriminant analysis).We demonstrate on bothsimulated and real data sets that their performance is superior to the old favorites.This is especially truein small-sample/high-dimension settings typical in chemistry.  相似文献   

Ion Probe Study of Silicate Inclusions from Colomera (ⅡE) Iron Meteorite: the Rare Earth Element Perspective     

HSU Weibiao 《《地质学报》英文版》2004,78(5)

Coupled with a petrographical study, I carried out an ion probe study of rare earth element microdistributions in mineral phases of silicate inclusions from the Colomera ⅡE iron meteorite. Most mineral grains have homogeneous REEs, but show considerable inter-grain variations by a factor of 2 to 100. The whole rock REE abundances for Colomera, estimated by combining REE data with modal abundances, are relatively LREE-enriched with REEs of -10'CI, which suggest that Colomera silicates were highly differentiated and might represent a low degree partial melt (-10%) of a chondritic source. REE geochemistry of Colomera silicate inclusions points to an origin that involves differentiation, dynamic mixing, remelting, reduction, recrystallization, and subsequent rapid cooling near the surface of a planetary body.  相似文献   

Evaluation of an Inexpensive Small-Diameter Temperature Logger for Documenting Ground Water–River Interactions     

Adam N. Johnson  Brian R. Boer  William W. Woessner  Jack A. Stanford  Geoffrey C. Poole  Steven A. Thomas  Scott J. O'Daniel 《Ground Water Monitoring & Remediation》2005,25(4):68-74

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On the possible utilization of Camelops by early man in North America     

Gary Haynes  Dennis Stanford 《Quaternary Research》1984,22(2):216-230

Camelops was a major faunal element in late Wisconsin biotic communities over much of North America. Interpretations of possible human association with Camelops are often based on poorly evaluated evidence. Ideal standards for acceptable evidence are compared here to the actual evidence that has been advanced. Of 25 fossil assemblages examined, 2 might be examples only of geological contemporaneity of humans and Camelops; 2 might indicate behavioral association of humans and Camelops bones; and 2 might indicate actual human utilization of Camelops (killing and/or butchering). Camelops bones interpreted as artifacts are similar to modern specimens affected by noncultural processes.  相似文献   

应用烃类流体包裹体GOI和成分研究凝析气藏成藏过程：以准噶尔盆地莫索湾地区为例   总被引：1，自引：1，他引：1  

曹剑金之钧  胡文瑄谢小敏王绪龙  姚素平 《岩石学报》2007,23(1):137-144

The Grains containing Oil Inclusions(GOI)data in currently gas/condensate-beating Jurassic and Cretaceous reservoir sandstones of Well Pen 5(the Mosuowan area of central Junggar Basin,NW China)are generally greater than the empirical threshold line of 5%.This is consistent with the gas-condensate section originally containing a palaeo-oil column.In order to assess the origin of the oil trapped in the oil inclusion and its relationship to the free oil/gas-condensate,a detailed molecular geochemical study was carried out for correlation between the free and inclusion oils.The paleo oil is most likely sourced from the Lower Permian Fengeheng Formation,which generated hydrocarbons primarily during Late Triassic and the oils were later secondarily altered and dysmigrated along faults likely during Late Jurassic-Early Cretaceous.In contrast,the current reservoired oil/gas-condensate mainly derived from the Middle Permian Lower Wuerhe Formation,whose peak generation time last from Late Cretaceous even to the present.This paper showed that integrated oil-bearing fluid inclusion analyses have likely allowed a complex multi-phase charge history to be recognized and resolved with a high degree of confidence.  相似文献   

Bulge Migration and Pinnacle Reef Development, Devonian Appalachian Foreland Basin     

Ver Straeten CA  Brett CE 《The Journal of geology》2000,108(3):339-352

Detailed stratigraphic analyses of Late Emsian and Early Eifelian (Lower to Middle Devonian) carbonate-dominated strata in the northern Appalachian Basin indicate anomalous, locally varying relative sea level changes and inversions of topography. The distribution of a major basal-bounding unconformity, basinal pinnacle reefs, local absence of parasequences, and eastward migration of shallow marine carbonate lithofacies and related biofacies in the Onondaga Limestone and underlying strata mark the retrograde migration of an elongate, northeast-southwest-trending area of positive relief, bordered on its cratonward side by a similarly migrating basin of intermediate depth. These features are thought to represent the forebulge and back-bulge basin of the Appalachian foreland basin system as it developed during a time of relative quiescence within the Acadian Orogeny. However, the relatively small size of the bulgelike feature (ca. 80-100-km-wide, 20-50-m positive relief), its great distance from the probable deformation front (>400 km), and the lack of a well-developed foredeep immediately adjacent to the bulgelike feature may indicate that it represents a smaller-scale flexural high ("flexural welt") superposed over the cratonward edge of the larger-scale classical forebulge of the basin. Development of shallow-water reefs on the crest of the bulge during sea level lowstand, followed by migration of the bulge and widespread transgression, permitted growth of economically significant pinnacle reefs in the deep basin center. Further subsurface reef exploration should concentrate along the projected position of the bulge during the basal Onondaga lowstand.  相似文献   

Science, policy and the management of sewage materials. The New York City experience     

Swanson RL  Bortman ML  O'Connor TP  Stanford HM 《Marine pollution bulletin》2004,49(9-10):679-687

Development of national policy on sewage sludge management is a classic example of incremental policy formulation [Fiorino, D.J. 1995. Making Environmental Policy. University of California Press. Berkeley, CA. p. 269]. Consequently, policy has developed piecemeal, and results are, in some ways, different than intended. Land application of sewage sludge has not been a panacea. Many of the same types of policy are now being raised about it. We demonstrate this by examining the management of sewage materials by New York City from near the turn of the 20th century, when ocean dumping was viewed as a means to alleviate some of the gross pollution in New York Harbor, to when ocean dumping was banned, and thence to the present when sludge is applied to land as "biosolids." Lessons learned during this long, sometimes contentious history can be applied to present situations--specifically not understanding the long-term consequences of land-based reuse and disposal technologies.  相似文献   

Mangrove (Avicennia marina subsp. australasica) litter production and decomposition in a temperate estuary     

RV Gladstone-Gallagher  CJ Lundquist  CA Pilditch 《新西兰海洋与淡水研究杂志》2013,47(1):24-37

Mangrove forests can provide important cross-boundary subsidies of organic matter to adjacent habitats through the production, export, decomposition and assimilation of litter. We quantified two of these components in a temperate mangrove forest in Whangamata Harbour, New Zealand: 1) litter production; and 2) decomposition rates as a function of tidal elevation, sediment type and burial depth. Litter traps sampled monthly for a year measured an annual detrital input of 3.24–5.38 t DW ha^?1, of which 77% occurred in summer. Decomposition rates depended on litter type, with leaves decomposing faster (63 d to decay by 50%) than pneumatophore and wood material (316 and 460 d, respectively). Buried leaf and wood litter decomposed 1.3–1.4 times slower than litter on the sediment surface; however, tidal elevation and sediment type (mud vs. sand) had no effect. The slow decay of litter (an order of magnitude slower than tropical mangrove litter) suggests that its incorporation into temperate marine food webs may be relatively slow.  相似文献   

Water transport through Hecate Strait,British Columbia     

William R. Crawford  W. Stanford Huggett  Michael J. Woodward 《大气与海洋》2013,51(3):301-320

Abstract

The transport of water through Hecate Strait, British Columbia, is investigated to determine seasonal cycles and to find optimal surrogate series from which a long time series of along‐strait transport can be inferred and applied to fisheries and pollution problems. It is believed that the strength of a year‐class of cod in this Strait varies inversely with the transport in winter. Therefore, a good surrogate series is required, one that extends back in time to compare with fisheries records and will continue into the future to determine fluctuations in the population of these species.

Current meters deployed for an 11‐month period in 1983–84 provide transport measurements. Subsurface pressure gauges were deployed at 10‐m depth at five sites around Hecate Strait for a two‐year period in 1982–84. The cross‐strait difference of pressures determined by two of these gauges (Beauchemin Channel and Atli Inlet) serves as the best transport indicator, with an average correlation coefficient r of 0.88. Longer, continuous series are provided by the records from float‐type sea‐level gauges at Prince Rupert (PR), Queen Charlotte City (QCC) and Bella Bella (BB). Local air pressure is added to these series to convert them to subsurface pressure. Time series of geostrophic and measured winds are also considered. Among these longer series, transport is predicted best by the combination (PR + BB)/2 ‐ QCC (r = 0.82), which represents a cross‐strait difference in subsurface pressure.  相似文献   

Isotope source table for a 25 M⊙ supernova     

Bradley S. Meyer  Thomas A. Weaver  Stanford E. Woosley 《Meteoritics & planetary science》1995,30(3):325-334

Abstract— We present a table giving the yields of 103 isotopes in eight distinct zones in the ejecta from the explosion of a 25 M star. Each zone in the ejecta is distinct isotopically due to the evolution and explosion of the star. Thus the table not only gives the yields of isotopes in the different zones of the ejecta but also provides information about the chemical environments in which each isotope is injected into the interstellar medium. The table is a summary of the nuclear yields from a single numerical model of the explosion of a massive star. The yields from a real supernova will vary from those in this table because of uncertainties in the input physics to the numerical model and because the real star may differ in mass, mass-loss rate, or metallicity from the modeled star. We argue that these uncertainties and variations, for the most part, will not change the direction of the largest isotopic effects in the different zones of the ejecta. This means that the table is quite generally applicable as a guide to understanding the ejecta of supernovae and as a characterization of possible chemical environments in which isotopes are injected into the interstellar medium.  相似文献