Mapping small-scale temperature and abundance structures in the core of the Perseus cluster     

J. S. Sanders  A. C. Fabian  S. W. Allen  R. W. Schmidt 《Monthly notices of the Royal Astronomical Society》2004,349(3):952-972

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INTEGRATING RACE AND ETHNICITY INTO GEOGRAPHIC GENDER STUDIES     

Rickie Sanders 《The Professional geographer》1990,42(2):228-231

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A balanced treatment of secondary currents,turbulence and dispersion in a depth-integrated hydrodynamic and bed deformation model for channel bends     

Lorenzo Begnudelli  Alessandro Valiani  Brett F. Sanders 《Advances in water resources》2010

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Heterotrophic bacterial and <Emphasis Type="Italic">Synechococcus</Emphasis> spp. Growth and mortality along the inshore-offshore in the East China Sea in summer     

An-Yi Tsai  Gwo-Ching Gong  Robert W. Sanders  Kuo-Ping Chiang  Chien-Fu Chao 《Journal of Oceanography》2012,68(1):151-162

This study used the dilution method to examine growth and grazing rates of heterotrophic bacteria and an autotrophic picoplankton, Synechococcus spp., from 1 to 11 July 2007 in the East China Sea. The main influence of oceanographic conditions in this aquatic system was the introduction of fresh, high-nutrient water from Changjiang River and the extremely nutrient-poor, high-salinity waters of Kuroshio Water. In these experiments, deviation from linearity in the relationship between dilution factor and net growth rate was significant in a large number of cases. Growth rates for heterotrophic bacteria ranged from 0.024 to 0.24, and for Synechococcus spp. from 0.03 to 0.21 h⁻¹. Grazing rates ranged from 0.02 to 0.19 and 0.01 to 0.13 h⁻¹, respectively. The spatial variations of Synechococcus spp. production to the primary production ratio (SP/PP) were low (<5%) in high Chl a environments and increased exponentially in low Chl a environments, indicating that Synechococcus spp. contributes to a large extent to the photosynthetic biomass in the open sea, especially in the more oligotrophic Kuroshio Water. Furthermore, the results of our dilution experiments suggest that nanoflagellates largely depend on heterotrophic bacteria as an important energy source. On average, heterotrophic bacteria contributes to 76 and 59% of carbon consumed by nanoflagellates within the plume (salinity <31) and outside of it (salinity >31).  相似文献   

Forming galaxies with MOND     

R. H. Sanders 《Monthly notices of the Royal Astronomical Society》2008,386(3):1588-1596

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Feedback through multiple outbursts in the cluster 2A 0335+096     

J. S. Sanders  A. C. Fabian  G. B. Taylor † 《Monthly notices of the Royal Astronomical Society》2009,396(3):1449-1459

We examine the core of the X-ray bright galaxy cluster 2A 0335+096 using deep Chandra X-ray imaging and spatially resolved spectroscopy, and include new radio observations. The set of around eight X-ray bright blobs in the core of the cluster, appearing like eggs in a bird's nest, contains multiphase gas from ∼0.5 to 2 keV. The morphology of the coolest X-ray emitting gas at 0.5 keV temperature is similar to the Hα emitting nebula known in this cluster, which surrounds the central galaxy. XMM–Newton grating spectra confirm the presence of material at these temperatures, showing reasonable agreement with Chandra emission measures. On scales of 80 to 250 kpc, there is a low temperature, high metallicity, swirl of intracluster medium as seen in other clusters. In the core, we find evidence for a further three X-ray cavities, in addition to the two previously discovered. Enhancements in 1.5 GHz radio emission are correlated with the X-ray cavities. The total  4 PV   enthalpy associated with the cavities is around  5 × 10⁵⁹ erg  . This energy would be enough to heat the cooling region for  ∼5 × 10⁷ yr  . We find a maximum pressure discontinuity of 26 per cent (2σ) across the surface brightness edge to the south-west of the cluster core. This corresponds to an upper limit on the Mach number of the cool core with respect to its surroundings of 0.55.  相似文献   

Giant cavities, cooling and metallicity substructure in Abell 2204     

J. S. Sanders  A. C. Fabian  G. B. Taylor 《Monthly notices of the Royal Astronomical Society》2009,393(1):71-82

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AzTEC Millimetre Survey of the COSMOS field – II. Source count overdensity and correlations with large-scale structure     

J. E. Austermann  I. Aretxaga  D. H. Hughes  Y. Kang  S. Kim  J. D. Lowenthal  T. A. Perera  D. B. Sanders  K. S. Scott  N. Scoville  G. W. Wilson  M. S. Yun 《Monthly notices of the Royal Astronomical Society》2009,393(4):1573-1583

We report an overdensity of bright submillimetre galaxies (SMGs) in the 0.15 deg² AzTEC/COSMOS survey and a spatial correlation between the SMGs and the optical-IR galaxy density at   z ≲ 1.1  . This portion of the COSMOS field shows a  ∼3σ  overdensity of robust SMG detections when compared to a background, or 'blank-field', population model that is consistent with SMG surveys of fields with no extragalactic bias. The SMG overdensity is most significant in the number of very bright detections (14 sources with measured fluxes   S _1.1 mm > 6  mJy), which is entirely incompatible with sample variance within our adopted blank-field number densities and infers an overdensity significance of  ≫ 4σ  . We find that the overdensity and spatial correlation to optical-IR galaxy density are most consistent with lensing of a background SMG population by foreground mass structures along the line of sight, rather than physical association of the SMGs with the   z ≲ 1.1  galaxies/clusters. The SMG positions are only weakly correlated with weak-lensing maps, suggesting that the dominant sources of correlation are individual galaxies and the more tenuous structures in the survey region, and not the massive and compact clusters. These results highlight the important roles cosmic variance and large-scale structure can play in the study of SMGs.  相似文献   

Plagioclase breakdown and regeneration reactions in Grenville kyanite eclogite at Glenelg,NW Scotland     

I. S. Sanders 《Contributions to Mineralogy and Petrology》1988,98(1):33-39

A rare type of eclogite at Glenelg contains finegrained, white streaks about 1 mm across consisting of kyanite-oligoclase ±quartz ±Kfeldspar. Garnet and omphacite bordering the streaks are relatively enriched in grossular and jadeite components respectively. The streaks are interpreted as former plagioclase which reacted with neighbouring garnet and omphacite during a period of shearing and compression. P-T conditions during the reaction are estimated as 740° C and 17 kbar. Subsequent reaction, manifest by narrow rims of oligoclase on kyanite, new growth of garnet and resorption of omphacite, is interpreted as an effect of near-isothermal decompression by about 2 kbar. The compressive phase is attributed to dextral transpression (oblique convergence) along the Grenville Front in Scotland.  相似文献   

The role of suspended sediments and phytoplankton in the partitioning and transport of silver in estuaries     

James G. Sanders  George R. Abbe 《Continental Shelf Research》1987,7(11-12)

Silver sorbs readily at low salinities to both phytoplankton and suspended sediments. As salinity increases, the degree of sorption decreases. Nearly 80% of silver sorbed to suspended sediments at low salinities will desorb at higher salinities, but desorption does not occur when silver is associated with phytoplankton. Thus, silver incorporation onto/into cellular material will increase the retention of silver within the estuary, reducing its rate of transport.  相似文献