The ROSAT International X-ray/Optical Survey (RIXOS): source catalogue     

K. O. Mason  F. J. Carrera  G. Hasinger  H. Andernach  A. Aragon-Salamanca  X. Barcons  R. Bower  W. N. Brandt  G. Branduardi-Raymont  J. Burgos-Martín  F. Cabrera-Guerra  R. Carballo  F. Castander  R. S. Ellis  J. I. González-Serrano  E. Martínez-González  J. M. Martín-Mirones  R. G. McMahon  J. P. D. Mittaz  K. L. Nicholson  M. J. Page  I. Pérez-Fournon  E. M. Puchnarewicz  E. Romero-Colmenero  A. D. Schwope  B. Vila  M. G. Watson  D. Wonnacott 《Monthly notices of the Royal Astronomical Society》2000,311(3):456-484

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The ROSAT–ESO Flux-Limited X-ray (REFLEX) galaxy cluster survey – II. The spatial correlation function     

C. A. Collins  L. Guzzo  H. Böhringer  P. Schuecker  G. Chincarini  R. Cruddace  S. De Grandi  H. T. MacGillivray  D. M. Neumann  S. Schindler  P. Shaver  W. Voges 《Monthly notices of the Royal Astronomical Society》2000,319(3):939-948

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A critique of the UK’s JNCC seismic survey guidelines for minimising acoustic disturbance to marine mammals: Best practise?     

E.C.M. Parsons  Sarah J. Dolman  Michael Jasny  Mark P. Simmonds 《Marine pollution bulletin》2009,58(5):643-651

The United Kingdom’s statutory conservation agency, the Joint Nature Conservation Committee (JNCC), developed guidelines in 1995 to minimise acoustic disturbance of marine mammals by oil and gas industry seismic surveys. These were the first national guidelines to be developed and have subsequently become the standard, or basis, of international mitigation measures for noise pollution during seismic surveys. However, relatively few aspects of these measures have a firm scientific basis or proven efficacy. Existing guidelines do not offer adequate protection to marine mammals, given the complex propagation of airgun pulses; the difficulty of monitoring in particular the smaller, cryptic, and/or deep-diving species, such as beaked whales and porpoises; limitations in monitoring requirements; lack of baseline data; and other biological and acoustical complications or unknowns. Current guidelines offer a ‘common sense’ approach to noise mitigation, but in light of recent research and ongoing concerns, they should be updated, with broader measures needed to ensure adequate species protection and to address data gaps.  相似文献   

Re-evaluating the use of beached bird oiling rates to assess long-term trends in chronic oil pollution     

Wilhelm SI  Robertson GJ  Ryan PC  Tobin SF  Elliot RD 《Marine pollution bulletin》2009,58(2):249-255

The oiling rate (oiled birds/total birds) has become the international standard to analyze beached bird survey data. However, this index may not reliably track long-term changes in marine oil pollution in regions where other activities that kill seabirds vulnerable to oil, such as hunting and gill-netting, are also changing. We compare the oiling rate from beached bird surveys conducted in southeastern Newfoundland between 1984 and 2006 to an alternative approach, namely trends derived from a model examining the linear density of oiled birds (birds/km). In winter, there was no change in the oiling rate since 1984, while in summer oiling rates significantly increased. In contrast, the number of oiled birds/km showed a significant decline in both winter and summer. The discrepancy in these trends was attributed to steep declines in the number of unoiled birds found in both seasons. In winter, the decline in unoiled birds/km was related to a reduction in the legal murre hunt and less onshore winds, while in summer a reduced cod fishery resulting in fewer murres drowning in nets and warming summers may have lead to the decline. The significant declines in oiled birds/km over the past three decades are hopefully an indication of less oil being present in the marine environment. Although oiled bird densities since 2000 have remained relatively low for the region (winter: 0.58 birds/km, summer: 0.27 birds/km), they still exceed densities reported elsewhere in the world.  相似文献   

Processing Italian damage data to derive typological fragility curves   总被引：4，自引：0，他引：4  

M. Rota  A. Penna  C.L. Strobbia   《Soil Dynamics and Earthquake Engineering》2008,28(10-11):933

Typological fragility curves have been derived from post-earthquake survey data on building damage, collected in the areas affected by the most relevant Italian earthquakes of the last three decades. A complex and time consuming codification and reinterpretation work has been done on a set of about 150,000 survey building records, in order to define empirical damage probability matrices for several building typologies, characteristic of the Italian building stock. The obtained data have then been processed by advanced nonlinear regression methods in order to derive typological fragility curves. These curves, organised in five damage levels, provide useful information both for relative comparisons among typologies and for seismic risk analyses at different scales. By combining hazard definitions, fragility curves and inventory data, complete earthquake risk scenario studies can be performed, but even the single convolution of hazard and fragility allows to obtain typological risk maps, both for single damage state definitions and for concise average loss parameters. The very high potential of these results is shown by some applications reported in the paper.  相似文献   

Post-Tsunami Field Survey Procedures: An Outline     

Farreras  Salvador F. 《Natural Hazards》2000,21(2-3):207-214

Destructive tsunamis are infrequent comparedwith other natural disasters, andtheir evidences tend to disappear quickly.Conventional data acquisition havebeen limited in coverage and tend to beunreliable. Readily available andtransient data should be collectedby field survey teams as soon as possible.Since tsunamis are always triggered by the simultaneous or in-advanceoccurrence of another phenomena, they can be considered close to thesource as a syndrome, leaving a variety of almost simultaneous effectsat the nearby coasts. By observating the evidence left bythese local interaction effects, the surveyors should be able to identifyand evaluate at least the maximum horizontal extension and the verticalreach of the inundation. High water marks and lines of landward limitof sea grass, debris or sediment deposited, may help in this identification and measurement process.Guidelines to conduct post-tsunami field surveys and standards for theobservations have been established by the International Coordination Groupfor the Tsunami Warning System in the Pacific (ICG/ITSU) upon agreement with the scientific community. A Post-Tsunami Survey Field Guide was published by the Intergovernmental Oceanographic Commission (IOC) of UNESCO.  相似文献   

Superlarge-scale structure in the Durham/UKST Galaxy Redshift Survey     

Andrei G. Doroshkevich  Richard Fong  Henry J. McCracken  rew Ratcliffe  Tom Shanks  Victor I. Turchaninov 《Monthly notices of the Royal Astronomical Society》2000,315(4):767-777

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The European Large Area ISO Survey – II. Mid-infrared extragalactic source counts     

Stephen Serjeant  Seb Oliver  †  Michael Rowan-Robinson  Hans Crockett  Vasilis Missoulis  Tim Sumner  Carlotta Gruppioni  Robert G. Mann  Nick Eaton  David Elbaz  David L. Clements  Amanda Baker  reas Efstathiou  Catherine Cesarsky  Luigi Danese  Alberto Franceschini  Reinhardt Genzel  y Lawrence  Dietrich Lemke  Richard G. McMahon  George Miley  Jean-Loup Puget  Brigitte Rocca-Volmerange 《Monthly notices of the Royal Astronomical Society》2000,316(4):768-778

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Late-type stars found in the FBS. New carbon stars     

K. S. Gigoyan  D. Engels  N. Mauron  V. V. Hambaryan  C. Rossi  R. Gualandi 《Astrophysics》2008,51(2):209-217

We present new observations of seven late-type stars previously discovered in the First Byurakan Survey (FBS). These observations prove that they belong to the family of carbon (C) stars. Seventy-nine similar FBS C stars were previously known. The seven objects under analysis were presented in the FBS lists as M or C star candidates. Among the seven objects, six objects are confirmed by low-resolution spectra of the Hamburg Quasar Objective-Prism Survey. We also present for five of them moderate-resolution spectra obtained at optical wavelengths with a spectrograph equipped with a CCD detector. Three objects can be classified as N-type C stars. One object is an early CH-type C star. Most likely, the star FBS 1339+117 belongs to the group of carbon dwarfs. We estimate distances of these seven new C stars either by using their red-band magnitudes, or by using their near-infrared 2MASS J-K_S color and K_S-band magnitudes. Published in Astrofizika, Vol. 51, No. 2, pp. 255–265 (May 2008).  相似文献   

Statistical algorithms for identification of astronomical X‐ray sources     

H. Ziaeepour  S. Rosen 《Astronomische Nachrichten》2008,329(1):84-105

Observations of present and future X‐ray telescopes include a large number of ipitous sources of unknown types. They are a rich source of knowledge about X‐ray dominated astronomical objects, their distribution, and their evolution. The large number of these sources does not permit their individual spectroscopical follow‐up and classification. Here we use Chandra Multi‐Wavelength public data to investigate a number of statistical algorithms for classification of X‐ray sources with optical imaging follow‐up. We show that up to statistical uncertainties, each class of X‐ray sources has specific photometric characteristics that can be used for its classification. We assess the relative and absolute performance of classification methods and measured features by comparing the behaviour of physical quantities for statistically classified objects with what is obtained from spectroscopy. We find that among methods we have studied, multi‐dimensional probability distribution is the best for both classifying source type and redshift, but it needs a sufficiently large input (learning) data set. In absence of such data, a mixture of various methods can give a better final result.We discuss some of potential applications of the statistical classification and the enhancement of information obtained in this way. We also assess the effect of classification methods and input data set on the astronomical conclusions such as distribution and properties of X‐ray selected sources. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献