Distribution and relative abundance of harbour porpoises (Phocoena phocoena L.), white-beaked dolphins (Lagenorhynchus albirostris Gray), and minke whales (Balaenoptera acutorostrata Lacepede) around the British Isles     

Northridge  Simon P.; Tasker  Mark L.; Webb  Andrew; Williams  James M. 《ICES Journal of Marine Science》1995,52(1):55-66

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Erratum     

Northridge  S. P.; Tasker  M. L.; Webb  A.; Williams  J. M. 《ICES Journal of Marine Science》1995,52(6):1005-1012

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Stochastic parallel gradient descent based adaptive optics used for a high contrast imaging coronagraph     

Bing Dong  De-Qing Ren  Xi Zhang Physics & Astronomy Department  California State University Northridge  CA  -  USA National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology  Chinese Academy of Sciences  Nanjing    China 《中国天文和天体物理学报》2011,(8)

An adaptive optics(AO) system based on a stochastic parallel gradient descent(SPGD) algorithm is proposed to reduce the speckle noises in the optical system of a stellar coronagraph in order to further improve the contrast. The principle of the SPGD algorithm is described briey and a metric suitable for point source imaging optimization is given. The feasibility and good performance of the SPGD algorithm is demonstrated by an experimental system featured with a 140-actuator deformable mirror and a Hartmann-...  相似文献