PSDF: Particle Stream Data Format for N-body simulations     

Will M. Farr  Jeff AmesPiet Hut  Junichiro MakinoSteve McMillan  Takayuki MuranushiKoichi Nakamura  Keigo NitadoriSimon Portegies Zwart 《New Astronomy》2012,17(5):520-523

We present a data format for the output of general N-body simulations, allowing the presence of individual time steps. By specifying a standard, different N-body integrators and different visualization and analysis programs can all share the simulation data, independent of the type of programs used to produce the data. Our Particle Stream Data Format, PSDF, is specified in YAML, based on the same approach as XML but with a simpler syntax. Together with a specification of PSDF, we provide background and motivation, as well as specific examples in a variety of computer languages. We also offer a web site from which these examples can be retrieved, in order to make it easy to augment existing codes in order to give them the option to produce PSDF output.  相似文献   

Climate Change on Newfoundland and Labrador Shelves: Results From a Regional Downscaled Ocean and Sea-Ice Model Under an A1B Forcing Scenario 2011–2069     

Guoqi Han  Zhimin Ma  Zhenxia Long  Will Perrie  Joël Chassé 《大气与海洋》2019,57(1):3-17

Climate change may affect ocean and ice conditions in coastal oceans and thus have significant impacts on coastal infrastructure, marine navigation, and marine ecosystems. In this study a three-dimensional ice–ocean model is developed to examine likely changes of ocean and ice conditions over the Newfoundland and Labrador Shelves in response to climate change. The model is configured with a horizontal grid of approximately 7?km and a vertical grid of 46 levels and is run from 1979 to 2069. The projection period is 2011 to 2069 under a median emission scenario A1B used by the Intergovernmental Panel on Climate Change. For the projection period, the surface atmospheric forcing fields used are from the Canadian Regional Climate Model over the North Atlantic. The open boundary conditions come from the Canadian Global Climate Model, Version 3 (CGCM3), adjusted for the 1981–2010 mean of the Simple Ocean Data Assimilation model output. The simulated fields over the 1981–2010 period have patterns consistent with observations. Over the Newfoundland and Labrador Shelves during the projection period, the model shows general trends of warming, freshening, and decreasing ice. From 2011 to 2069, the model projects that under A1B sea surface temperature will increase by 1.4°C; bottom temperature will increase by 1.6°C; sea surface salinity will decrease by 0.7; bottom salinity will decrease by 0.3; and sea-ice extent will decrease by 70%. The sea level will rise by 0.11?m at the St. John's tide-gauge station because of oceanographic change, and the freshwater transport of the Labrador Current will double as a result of freshening. The regional ice–ocean model reproduces more realistic present climate conditions and projects considerably different future climate conditions than CGCM3.  相似文献   

Effect of particle size distribution on the bio-cementation of coarse aggregates   总被引：1，自引：0，他引：1  

Aamir Mahawish  Abdelmalek Bouazza  Will P. Gates 《Acta Geotechnica》2018,13(4):1019-1025

The effect of grain size distribution on the unconfined compressive strength (UCS) of bio-cemented granular columns is examined. Fine and coarse aggregates were mixed in various percentages to obtain five different grain size distributions. A four-phase percolation strategy was adopted where a bacterial suspension and a cementation solution (urea and calcium chloride) were percolated sequentially. The results show that a gap-graded particle size distribution can improve the UCS of bio-cemented coarser granular materials. A maximum UCS of approximately 575 kPa was achieved with a particle size distribution containing 75% coarse aggregate and 25% fine aggregate. Furthermore, the minimum UCS obtained has applications where mitigation of excessive bulging of stone/sand columns, and possible slumping that might occur during their installation, is needed. The finding also implies that the amount of biochemical treatments can be reduced by adding fine aggregate to coarse aggregate resulting in effective bio-cementation within the pore matrix of the coarse aggregate column as it could substantially reduce the cost associated with bio-cementation process. Scanning electron microscopy results confirm that adding fine aggregate to coarse aggregate provides more bridging contacts (connected by calcium carbonate precipitation) between coarse aggregate particles, and hence, the maximum UCS achieved was not necessarily associated with the maximum calcium carbonate precipitation.  相似文献   

The Confrontation between General Relativity and Experiment     

Clifford M. Will 《Astrophysics and Space Science》2003,283(4):543-552

We review the experimental evidence for Einstein's general relativity. Tests of the Einstein Equivalence Principle support the postulates of curved spacetime and bound variations of fundamental constants in space and time, while solar-system experiments strongly confirm weak-field general relativity. The Binary Pulsar provides tests of gravitational-wave damping and of strong-field general relativity. Future experiments, such as the Gravity Probe B Gyroscope Experiment, a satellite test of the Equivalence principle, and tests of gravity at short distance to look for extra spatial dimensions could further constrain alternatives to general relativity. Laser interferometric gravitational-wave observatories on Earth and in space may provide new tests of scalar-tensor gravity and graviton-mass theories via the properties of gravitational waves. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications     

Shaun Cole  Will J. Percival  John A. Peacock  Peder Norberg  Carlton M. Baugh  Carlos S. Frenk  Ivan Baldry  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Matthew Colless  Chris Collins  Warrick Couch  Nicholas J. G. Cross  Gavin Dalton  Vincent R. Eke  Roberto De Propris  Simon P. Driver  George Efstathiou  Richard S. Ellis  Karl Glazebrook  Carole Jackson  Adrian Jenkins  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve Maddox  Darren Madgwick  Bruce A. Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,362(2):505-534

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Engineering geology for tomorrow's cities,edited by M.G. Culshaw, H.J. Reeves, I. Jefferson and T.W. Spink. Geological Society Engineering Geology Special Publication, 22, London, 2009. No. of pages: 303. Price: £95.00. ISBN 978‐1‐86239‐290‐8 (hardback).     

Will Hughes 《Geological Journal》2013,48(1):108-109

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