Radio galaxies in the 2SLAQ Luminous Red Galaxy Survey – I. The evolution of low-power radio galaxies to  z∼ 0.7      

Elaine M. Sadler  Russell D. Cannon  Tom Mauch  Paul J. Hancock  David A. Wake  Nic Ross  Scott M. Croom  Michael J. Drinkwater  Alastair C. Edge  Daniel Eisenstein  rew M. Hopkins  Helen M. Johnston  Robert Nichol  Kevin A. Pimbblet  Roberto De Propris  Isaac G. Roseboom  Donald P. Schneider  Tom Shanks 《Monthly notices of the Royal Astronomical Society》2007,381(1):211-227

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A review of the assessments of the major fisheries resources in South Africa     

CL de Moor  SJ Johnston  A Brandão  RA Rademeyer  JP Glazer  LB Furman 《African Journal of Marine Science》2015,37(3):285-311

The waters off South Africa's coastline boast a rich mix of commercially fished species. Quantitative assessments of these marine resources have developed from simple methods first applied in the 1970s, to models that encompass a wide range of methodologies. The more valuable resources have undergone regular assessments in recent decades, with frequencies closely related to the management approach employed for each fishery. Many of these assessments form the operating models used to simulation-test candidate management procedures. This paper provides a comprehensive review of the assessments of 11 of the most important fisheries resources in South Africa. Some assessments use simple biomass dynamics models, whereas others are a hybrid of age- and length-based models, each designed to model the specific characteristics of the resource and fishery concerned. Many of the assessments have been disaggregated by species/stock and/or area as related multispecies/stock/ distribution hypotheses have arisen. This paper explores the similarities and differences in the data available and the methods applied. The review indicates that, whereas the status of three of these resources cannot be estimated reliably at present, the status of six resources is considered to be reasonable to good, whereas that of abalone Haliotis midae and West Coast rock lobster Jasus lalandii remains poor.  相似文献   

State of the art of modelling two-phase flow in fractured rock     

Z. Wanfang  H. S. Wheater  P. M. Johnston 《Environmental Geology》1997,31(3-4):157-166

 Two-phase flow in fractured rock is an important phenomenon for a range of practical problems, not the least of which is non-aqueous phase liquid (NAPL) contamination of groundwater. Although multiphase systems have long been studied in the petroleum field, in the hydrogeological field progress has only just reaches the point where models are being developed. Scale effect is one of the main issues of concern. Although models presented in this paper have the potential to provide useful predictions, they can only be used to investigate a variety of possible scenarios with parameters being specified in the form of distribution of values. The calibration and validation of all but the simplest of these models poses a formidable task, with great demands on hydrogeologists and geophysicists to provide adequate data. Received: 20 May 1996 · Accepted: 19 August 1996  相似文献   

The magnetic field structure of SNR G328.4+0.2 from polarimetric observations at 19 GHz     

Simon Johnston  N. M. McClure-Griffiths  Bärbel Koribalski 《Monthly notices of the Royal Astronomical Society》2004,348(2):L19-L22

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Single pulses from PSR B1641–45     

Simon Johnston 《Monthly notices of the Royal Astronomical Society》2004,348(4):1229-1235

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A search for giant pulses in Vela-like pulsars     

Simon Johnston  Roger W. Romani 《Monthly notices of the Royal Astronomical Society》2002,332(1):109-115

We have carried out a survey for 'giant pulses' in six young, Vela-like pulsars. In no cases did we find single pulses with flux densities more than 10 times the mean flux density. However, in PSR  B1706–44  we have detected giant micro-pulses very similar to those seen in the Vela pulsar. In PSR  B1706–44  these giant micro-pulses appear on the trailing edge of the profile and have an intrinsic width of ∼1 ms. The cumulative probability distribution of their intensities is best described by a power law. If the power law continues to higher intensities, then  3.7×10⁶  rotations are required to obtain a pulse with 20× the mean pulse flux. This number is similar to the giant pulse rate in PSR B1937+21 and PSR  B1821–24  but significantly higher than that for the Crab.  相似文献   

High-resolution single-pulse studies of the Vela pulsar     

M. Kramer  S. Johnston  W. van Straten 《Monthly notices of the Royal Astronomical Society》2002,334(3):523-532

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METASTABLE GROWTH PATTERNS IN SOME TERRESTRIAL AND LUNAR ROCKS     

Harald I. Drever  Robert Johnston 《Meteoritics & planetary science》1972,7(3):327-340

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Analysis of compressible axially loaded piles in rock     

J. K. Kodikara  I. W. Johnston 《国际地质力学数值与分析法杂志》1994,18(6):427-437

Analytical solutions are developed for the prediction of the load–settlement response of a compressible axially loaded cast in situ pile in rock. The principal input parameters are derived from the τ–z curve which applies to the contact zone between the pile shaft and the embedment material. For larger diameter piles in rock, these τ–z curves can differ markedly from curves that apply to piles in clay and may include a significant strain hardening region prior to reaching peak strength. In addition to the complete analyses which would normally require the use of a computer, simplified solutions suitable for hand calculations have been derived for the peak load and the pile head displacement to peak. An example of the application of these simplified design calculations is presented.  相似文献   

|V|: new insight into the circular polarization of radio pulsars     

A. Karastergiou  S. Johnston  D. Mitra  A. G. J. van Leeuwen  R. T. Edwards 《Monthly notices of the Royal Astronomical Society》2003,344(4):L69-L73

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