Chronology and evolution of the Middle Proterozoic Albany‐Fraser Orogen,Western Australia     

D. R. Nelson  J. S. Myers  A. P. Nutman 《Australian Journal of Earth Sciences》2013,60(5):481-495

Geochemical and Sm‐Nd isotopic data, and 19 ion‐microprobe U‐Pb zircon dates are reported for gneiss and granite from the eastern part of the Albany‐Fraser Orogen. The orogen is dominated by granitic rocks derived from sources containing both Late Archaean and mantle‐derived components. Four major plutonic episodes have been identified at ca 2630 Ma, 1700–1600 Ma, ca 1300 Ma and ca 1160 Ma. Orthogneiss, largely derived from ca 2630 Ma and 1700–1600 Ma granitic precursors, forms a belt along the southeastern margin of the Yilgarn Craton. These rocks, together with gabbro of the Fraser Complex, were intruded by granitic magmas and metamorphosed in the granulite facies at ca 1300 Ma. They were then rapidly uplifted and transported westward along low‐angle thrust faults over the southeastern margin of the Yilgarn Craton. Between ca 1190 and 1130 Ma, granitic magmas were intruded throughout the eastern part of the orogen. These new data are integrated into a review of the geological evolution of the Albany‐Fraser Orogen and adjacent margin of eastern Antarctica, and possibly related rocks in the Musgrave Complex and Gawler Craton.  相似文献   

Effects of antifouling biocides to the germination and growth of the marine macroalga, Hormosira banksii (Turner) Desicaine     

Myers JH  Gunthorpe L  Allinson G  Duda S 《Marine pollution bulletin》2006,52(9):1048-1055

The International Maritime Organisation's (IMO) ban on the use of tributyltin in antifouling paints has inevitability increased the use of old fashioned antifoulants and/or the development of new paints containing 'booster biocides'. These newer paints are intended to be environmentally less harmful, however the broader environmental effects of these 'booster biocides' are poorly known. Germination and growth inhibition tests using the marine macroalga, Hormosira banksii (Turner) Desicaine were conducted to evaluate the toxicity of four new antifouling biocides in relation to tributyltin-oxide (TBTO). Each of the biocides significantly inhibited germination and growth of Hormosira banksii spores. Toxicity was in increasing order: diuron < zineb < seanine 211< zinc pyrithione < TBTO. However, the lack of knowledge on partitioning in the environment makes it difficult to make a full assessment on whether the four biocides tested offer an advantage over organotin paints in terms of environmental impact.  相似文献   

CLASS B0631+519: last of the Cosmic Lens All-Sky Survey lenses     

T. York  N. Jackson  I. W. A. Browne  L. V. E. Koopmans  J. P. McKean  M. A. Norbury  A. D. Biggs  R. D. Blandford  A. G. de Bruyn  C. D. Fassnacht  S. T. Myers  T. J. Pearson  P. M. Phillips  A. C. S. Readhead  D. Rusin  P. N. Wilkinson 《Monthly notices of the Royal Astronomical Society》2005,361(1):259-271

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Windows into the work of a geographical educator: Evelyn Stokes from the University of Waikato     

Garth Cant 《New Zealand geographer》2005,61(2):89-91

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The Cosmic Lens All-Sky Survey – II. Gravitational lens candidate selection and follow-up     

I. W. A. Browne  P. N. Wilkinson  N. J. F. Jackson  S. T. Myers  C. D. Fassnacht  L. V. E. Koopmans  D. R. Marlow  M. Norbury  D. Rusin  C. M. Sykes  A. D. Biggs  R. D. Blandford  A. G. de Bruyn  K.-H. Chae  P. Helbig  L. J. King  J. P. McKean  T. J. Pearson  P. M. Phillips  A. C. S. Readhead  E. Xanthopoulos  T. York 《Monthly notices of the Royal Astronomical Society》2003,341(1):13-32

We report the final results of the search for gravitationally lensed flat-spectrum radio sources found in the combination of CLASS (Cosmic Lens All-Sky Survey) and JVAS (Jodrell Bank VLA Astrometric Survey). VLA (Very Large Array) observations of 16 503 sources have been made, resulting in the largest sample of arcsec-scale lens systems available. Contained within the 16 503 sources is a complete sample of 11 685 sources which have two-point spectral indices between 1.4 and 5 GHz flatter than −0.5, and 5-GHz flux densities  ≥30 mJy  . A subset of 8958 sources form a well-defined statistical sample suitable for analysis of the lens statistics. We describe the systematic process by which 149 candidate lensed sources were picked from the statistical sample on the basis of possessing multiple compact components in the 0.2-arcsec resolution VLA maps. Candidates were followed up with 0.05-arcsec resolution MERLIN and 0.003-arcsec VLBA observations at 5 GHz and rejected as lens systems if they failed well-defined surface brightness and/or morphological tests. To illustrate the candidate elimination process, we show examples of sources representative of particular morphologies that have been ruled out by the follow-up observations. 194 additional candidates, not in the well-defined sample, were also followed up. Maps for all the candidates can be found on the World Wide Web at http://www.jb.man.ac.uk/research/gravlens/index.html . We summarize the properties of each of the 22 gravitational lens systems in JVAS/CLASS. 12 are double-image systems, nine are four-image systems and one is a six-image system. 13 constitute a statistically well-defined sample giving a point-source lensing rate of  1:690 ± 190  . The interpretation of the results in terms of the properties of the lensing galaxy population and cosmological parameters will be published elsewhere.  相似文献   

CLASS B0445+123: a new two-image gravitational lens system     

M. K. Argo  N. J. Jackson  I. W. A. Browne  T. York  J. P. McKean  A. D. Biggs  R. D. Blandford  A. G. de Bruyn  K. H. Chae  C. D. Fassnacht  L. V. E. Koopmans  S. T. Myers  M. Norbury  T. J. Pearson  P. M. Phillips  A. C. S. Readhead  D. Rusin  P. N. Wilkinson 《Monthly notices of the Royal Astronomical Society》2003,338(4):957-961

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Chemical Telemetry of OH Observed to Measure Interstellar Magnetic Fields     

Dr Serena Viti PhD  Thomas W. Hartquist  Philip C. Myers 《Astrophysics and Space Science》2006,302(1-4):109-115

We present models for the chemistry in gas moving towards the ionization front of an HII region. When it is far from the ionization front, the gas is highly depleted of elements more massive than helium. However, as it approaches the ionization front, ices are destroyed and species formed on the grain surfaces are injected into the gas phase. Photodissociation removes gas phase molecular species as the gas flows towards the ionization front. We identify models for which the OH column densities are comparable to those measured in observations undertaken to study the magnetic fields in star forming regions and give results for the column densities of other species that should be abundant if the observed OH arises through a combination of the liberation of H₂O from surfaces and photodissociation. They include CH₃OH, H₂CO, and H₂S. Observations of these other species may help establish the nature of the OH spatial distribution in the clouds, which is important for the interpretation of the magnetic field results.  相似文献   

Resolving the Degeneracy: Experimental Tests of the New Self Creation Cosmology and a Heterodox Prediction for Gravity Probe B     

Garth A. Barber 《Astrophysics and Space Science》2006,305(2):169-176

The new theory of Self Creation Cosmology has been shown to yield a concordant cosmological solution that does not require inflation, exotic non-baryonic Dark matter or unknown Dark Energy to fit observational constraints. In vacuo there is a conformal equivalence between this theory and canonical General Relativity and as a consequence an experimental degeneracy exists as the two theories predict identical results in the standard tests. However, there are three definitive experiments that are able to resolve this degeneracy and distinguish between the two theories. Here these standard tests and definitive experiments are described. One of the definitive predictions, that of the geodetic precession of a gyroscope, has just been measured on the Gravity Probe B satellite, which is at the present time of writing in the data processing stage. This is the first opportunity to falsify Self Creation Cosmology. The theory predicts a ‘frame-dragging’ result equal to GR but a geodetic precession of only 2/3 the GR value. When applied to the Gravity Probe B satellite, Self Creation Cosmology predicts an E–W gravitomagnetic/frame-dragging precession, equal to that of GR, of 40.9 milliarcsec/yr but a N–S gyroscope (geodetic + Thomas) precession of just 4.4096 arcsec/yr.  相似文献   

The 2dF–SDSS LRG and QSO (2SLAQ) Survey: the z < 2.1 quasar luminosity function from 5645 quasars to g= 21.85     

Gordon T. Richards  Scott M. Croom  Scott F. Anderson  Joss Bland-Hawthorn  Brian J. Boyle  Roberto De Propris  Michael J. Drinkwater  Xiaohui Fan  James E. Gunn  &#;eljko Ivezi&#;  Sebastian Jester  Jon Loveday  Avery Meiksin  Lance Miller  Adam Myers  Robert C. Nichol  Phil J. Outram  Kevin A. Pimbblet  Isaac G. Roseboom  Nic Ross  Donald P. Schneider  Tom Shanks  Robert G. Sharp  Chris Stoughton  Michael A. Strauss  Alexander S. Szalay  Daniel E. Vanden Berk  Donald G. York 《Monthly notices of the Royal Astronomical Society》2005,360(3):839-852

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Galaxy evolution: Inhomogeneous halo collapse     

Jeannette M. Myers  Dieter H. Hartmann  Lih-Sin The 《Astrophysics and Space Science》2003,284(2):787-790

In an effort to study the halo globular clusters we perform a simulation of inhomogeneous halo collapse using a SPH/N-body code. We include dark matter particles, (cooling) gas, and stars. Supernova feedback is included as a heat source for the gas in the local environment of star forming regions. We find this model cannot reproduce the age distribution and spatial distribution of halo globular clusters. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献